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1/*
2 * This file implements the perfmon-2 subsystem which is used
3 * to program the IA-64 Performance Monitoring Unit (PMU).
4 *
5 * The initial version of perfmon.c was written by
6 * Ganesh Venkitachalam, IBM Corp.
7 *
8 * Then it was modified for perfmon-1.x by Stephane Eranian and
9 * David Mosberger, Hewlett Packard Co.
10 *
11 * Version Perfmon-2.x is a rewrite of perfmon-1.x
12 * by Stephane Eranian, Hewlett Packard Co.
13 *
14 * Copyright (C) 1999-2005 Hewlett Packard Co
15 * Stephane Eranian <eranian@hpl.hp.com>
16 * David Mosberger-Tang <davidm@hpl.hp.com>
17 *
18 * More information about perfmon available at:
19 * http://www.hpl.hp.com/research/linux/perfmon
20 */
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/interrupt.h>
26#include <linux/proc_fs.h>
27#include <linux/seq_file.h>
28#include <linux/init.h>
29#include <linux/vmalloc.h>
30#include <linux/mm.h>
31#include <linux/sysctl.h>
32#include <linux/list.h>
33#include <linux/file.h>
34#include <linux/poll.h>
35#include <linux/vfs.h>
36#include <linux/smp.h>
37#include <linux/pagemap.h>
38#include <linux/mount.h>
39#include <linux/bitops.h>
40#include <linux/capability.h>
41#include <linux/rcupdate.h>
42#include <linux/completion.h>
43#include <linux/tracehook.h>
44#include <linux/slab.h>
45
46#include <asm/errno.h>
47#include <asm/intrinsics.h>
48#include <asm/page.h>
49#include <asm/perfmon.h>
50#include <asm/processor.h>
51#include <asm/signal.h>
52#include <asm/system.h>
53#include <asm/uaccess.h>
54#include <asm/delay.h>
55
56#ifdef CONFIG_PERFMON
57/*
58 * perfmon context state
59 */
60#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
61#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
62#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
63#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
64
65#define PFM_INVALID_ACTIVATION (~0UL)
66
67#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
68#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
69
70/*
71 * depth of message queue
72 */
73#define PFM_MAX_MSGS 32
74#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
75
76/*
77 * type of a PMU register (bitmask).
78 * bitmask structure:
79 * bit0 : register implemented
80 * bit1 : end marker
81 * bit2-3 : reserved
82 * bit4 : pmc has pmc.pm
83 * bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
84 * bit6-7 : register type
85 * bit8-31: reserved
86 */
87#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
88#define PFM_REG_IMPL 0x1 /* register implemented */
89#define PFM_REG_END 0x2 /* end marker */
90#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
91#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
92#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
93#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
94#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
95
96#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
97#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
98
99#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
100
101/* i assumed unsigned */
102#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
103#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
104
105/* XXX: these assume that register i is implemented */
106#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
107#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
108#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
109#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
110
111#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
112#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
113#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
114#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
115
116#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
117#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
118
119#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
120#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
121#define PFM_CTX_TASK(h) (h)->ctx_task
122
123#define PMU_PMC_OI 5 /* position of pmc.oi bit */
124
125/* XXX: does not support more than 64 PMDs */
126#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
127#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
128
129#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
130
131#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
132#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
133#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
134#define PFM_CODE_RR 0 /* requesting code range restriction */
135#define PFM_DATA_RR 1 /* requestion data range restriction */
136
137#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
138#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
139#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
140
141#define RDEP(x) (1UL<<(x))
142
143/*
144 * context protection macros
145 * in SMP:
146 * - we need to protect against CPU concurrency (spin_lock)
147 * - we need to protect against PMU overflow interrupts (local_irq_disable)
148 * in UP:
149 * - we need to protect against PMU overflow interrupts (local_irq_disable)
150 *
151 * spin_lock_irqsave()/spin_unlock_irqrestore():
152 * in SMP: local_irq_disable + spin_lock
153 * in UP : local_irq_disable
154 *
155 * spin_lock()/spin_lock():
156 * in UP : removed automatically
157 * in SMP: protect against context accesses from other CPU. interrupts
158 * are not masked. This is useful for the PMU interrupt handler
159 * because we know we will not get PMU concurrency in that code.
160 */
161#define PROTECT_CTX(c, f) \
162 do { \
163 DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
164 spin_lock_irqsave(&(c)->ctx_lock, f); \
165 DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
166 } while(0)
167
168#define UNPROTECT_CTX(c, f) \
169 do { \
170 DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
171 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
172 } while(0)
173
174#define PROTECT_CTX_NOPRINT(c, f) \
175 do { \
176 spin_lock_irqsave(&(c)->ctx_lock, f); \
177 } while(0)
178
179
180#define UNPROTECT_CTX_NOPRINT(c, f) \
181 do { \
182 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
183 } while(0)
184
185
186#define PROTECT_CTX_NOIRQ(c) \
187 do { \
188 spin_lock(&(c)->ctx_lock); \
189 } while(0)
190
191#define UNPROTECT_CTX_NOIRQ(c) \
192 do { \
193 spin_unlock(&(c)->ctx_lock); \
194 } while(0)
195
196
197#ifdef CONFIG_SMP
198
199#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
200#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
201#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
202
203#else /* !CONFIG_SMP */
204#define SET_ACTIVATION(t) do {} while(0)
205#define GET_ACTIVATION(t) do {} while(0)
206#define INC_ACTIVATION(t) do {} while(0)
207#endif /* CONFIG_SMP */
208
209#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
210#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
211#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
212
213#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
214#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
215
216#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
217
218/*
219 * cmp0 must be the value of pmc0
220 */
221#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
222
223#define PFMFS_MAGIC 0xa0b4d889
224
225/*
226 * debugging
227 */
228#define PFM_DEBUGGING 1
229#ifdef PFM_DEBUGGING
230#define DPRINT(a) \
231 do { \
232 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
233 } while (0)
234
235#define DPRINT_ovfl(a) \
236 do { \
237 if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
238 } while (0)
239#endif
240
241/*
242 * 64-bit software counter structure
243 *
244 * the next_reset_type is applied to the next call to pfm_reset_regs()
245 */
246typedef struct {
247 unsigned long val; /* virtual 64bit counter value */
248 unsigned long lval; /* last reset value */
249 unsigned long long_reset; /* reset value on sampling overflow */
250 unsigned long short_reset; /* reset value on overflow */
251 unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
252 unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
253 unsigned long seed; /* seed for random-number generator */
254 unsigned long mask; /* mask for random-number generator */
255 unsigned int flags; /* notify/do not notify */
256 unsigned long eventid; /* overflow event identifier */
257} pfm_counter_t;
258
259/*
260 * context flags
261 */
262typedef struct {
263 unsigned int block:1; /* when 1, task will blocked on user notifications */
264 unsigned int system:1; /* do system wide monitoring */
265 unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
266 unsigned int is_sampling:1; /* true if using a custom format */
267 unsigned int excl_idle:1; /* exclude idle task in system wide session */
268 unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
269 unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
270 unsigned int no_msg:1; /* no message sent on overflow */
271 unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
272 unsigned int reserved:22;
273} pfm_context_flags_t;
274
275#define PFM_TRAP_REASON_NONE 0x0 /* default value */
276#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
277#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
278
279
280/*
281 * perfmon context: encapsulates all the state of a monitoring session
282 */
283
284typedef struct pfm_context {
285 spinlock_t ctx_lock; /* context protection */
286
287 pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
288 unsigned int ctx_state; /* state: active/inactive (no bitfield) */
289
290 struct task_struct *ctx_task; /* task to which context is attached */
291
292 unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
293
294 struct completion ctx_restart_done; /* use for blocking notification mode */
295
296 unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
297 unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
298 unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
299
300 unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
301 unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
302 unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
303
304 unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
305
306 unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
307 unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
308 unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
309 unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
310
311 pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
312
313 unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
314 unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
315
316 unsigned long ctx_saved_psr_up; /* only contains psr.up value */
317
318 unsigned long ctx_last_activation; /* context last activation number for last_cpu */
319 unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
320 unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
321
322 int ctx_fd; /* file descriptor used my this context */
323 pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
324
325 pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
326 void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
327 unsigned long ctx_smpl_size; /* size of sampling buffer */
328 void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
329
330 wait_queue_head_t ctx_msgq_wait;
331 pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
332 int ctx_msgq_head;
333 int ctx_msgq_tail;
334 struct fasync_struct *ctx_async_queue;
335
336 wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
337} pfm_context_t;
338
339/*
340 * magic number used to verify that structure is really
341 * a perfmon context
342 */
343#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
344
345#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
346
347#ifdef CONFIG_SMP
348#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
349#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
350#else
351#define SET_LAST_CPU(ctx, v) do {} while(0)
352#define GET_LAST_CPU(ctx) do {} while(0)
353#endif
354
355
356#define ctx_fl_block ctx_flags.block
357#define ctx_fl_system ctx_flags.system
358#define ctx_fl_using_dbreg ctx_flags.using_dbreg
359#define ctx_fl_is_sampling ctx_flags.is_sampling
360#define ctx_fl_excl_idle ctx_flags.excl_idle
361#define ctx_fl_going_zombie ctx_flags.going_zombie
362#define ctx_fl_trap_reason ctx_flags.trap_reason
363#define ctx_fl_no_msg ctx_flags.no_msg
364#define ctx_fl_can_restart ctx_flags.can_restart
365
366#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
367#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
368
369/*
370 * global information about all sessions
371 * mostly used to synchronize between system wide and per-process
372 */
373typedef struct {
374 spinlock_t pfs_lock; /* lock the structure */
375
376 unsigned int pfs_task_sessions; /* number of per task sessions */
377 unsigned int pfs_sys_sessions; /* number of per system wide sessions */
378 unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
379 unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
380 struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
381} pfm_session_t;
382
383/*
384 * information about a PMC or PMD.
385 * dep_pmd[]: a bitmask of dependent PMD registers
386 * dep_pmc[]: a bitmask of dependent PMC registers
387 */
388typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
389typedef struct {
390 unsigned int type;
391 int pm_pos;
392 unsigned long default_value; /* power-on default value */
393 unsigned long reserved_mask; /* bitmask of reserved bits */
394 pfm_reg_check_t read_check;
395 pfm_reg_check_t write_check;
396 unsigned long dep_pmd[4];
397 unsigned long dep_pmc[4];
398} pfm_reg_desc_t;
399
400/* assume cnum is a valid monitor */
401#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
402
403/*
404 * This structure is initialized at boot time and contains
405 * a description of the PMU main characteristics.
406 *
407 * If the probe function is defined, detection is based
408 * on its return value:
409 * - 0 means recognized PMU
410 * - anything else means not supported
411 * When the probe function is not defined, then the pmu_family field
412 * is used and it must match the host CPU family such that:
413 * - cpu->family & config->pmu_family != 0
414 */
415typedef struct {
416 unsigned long ovfl_val; /* overflow value for counters */
417
418 pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
419 pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
420
421 unsigned int num_pmcs; /* number of PMCS: computed at init time */
422 unsigned int num_pmds; /* number of PMDS: computed at init time */
423 unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
424 unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
425
426 char *pmu_name; /* PMU family name */
427 unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
428 unsigned int flags; /* pmu specific flags */
429 unsigned int num_ibrs; /* number of IBRS: computed at init time */
430 unsigned int num_dbrs; /* number of DBRS: computed at init time */
431 unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
432 int (*probe)(void); /* customized probe routine */
433 unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
434} pmu_config_t;
435/*
436 * PMU specific flags
437 */
438#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
439
440/*
441 * debug register related type definitions
442 */
443typedef struct {
444 unsigned long ibr_mask:56;
445 unsigned long ibr_plm:4;
446 unsigned long ibr_ig:3;
447 unsigned long ibr_x:1;
448} ibr_mask_reg_t;
449
450typedef struct {
451 unsigned long dbr_mask:56;
452 unsigned long dbr_plm:4;
453 unsigned long dbr_ig:2;
454 unsigned long dbr_w:1;
455 unsigned long dbr_r:1;
456} dbr_mask_reg_t;
457
458typedef union {
459 unsigned long val;
460 ibr_mask_reg_t ibr;
461 dbr_mask_reg_t dbr;
462} dbreg_t;
463
464
465/*
466 * perfmon command descriptions
467 */
468typedef struct {
469 int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
470 char *cmd_name;
471 int cmd_flags;
472 unsigned int cmd_narg;
473 size_t cmd_argsize;
474 int (*cmd_getsize)(void *arg, size_t *sz);
475} pfm_cmd_desc_t;
476
477#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
478#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
479#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
480#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
481
482
483#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
484#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
485#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
486#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
487#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
488
489#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
490
491typedef struct {
492 unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
493 unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
494 unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
495 unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
496 unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
497 unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
498 unsigned long pfm_smpl_handler_calls;
499 unsigned long pfm_smpl_handler_cycles;
500 char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
501} pfm_stats_t;
502
503/*
504 * perfmon internal variables
505 */
506static pfm_stats_t pfm_stats[NR_CPUS];
507static pfm_session_t pfm_sessions; /* global sessions information */
508
509static DEFINE_SPINLOCK(pfm_alt_install_check);
510static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
511
512static struct proc_dir_entry *perfmon_dir;
513static pfm_uuid_t pfm_null_uuid = {0,};
514
515static spinlock_t pfm_buffer_fmt_lock;
516static LIST_HEAD(pfm_buffer_fmt_list);
517
518static pmu_config_t *pmu_conf;
519
520/* sysctl() controls */
521pfm_sysctl_t pfm_sysctl;
522EXPORT_SYMBOL(pfm_sysctl);
523
524static ctl_table pfm_ctl_table[]={
525 {
526 .procname = "debug",
527 .data = &pfm_sysctl.debug,
528 .maxlen = sizeof(int),
529 .mode = 0666,
530 .proc_handler = proc_dointvec,
531 },
532 {
533 .procname = "debug_ovfl",
534 .data = &pfm_sysctl.debug_ovfl,
535 .maxlen = sizeof(int),
536 .mode = 0666,
537 .proc_handler = proc_dointvec,
538 },
539 {
540 .procname = "fastctxsw",
541 .data = &pfm_sysctl.fastctxsw,
542 .maxlen = sizeof(int),
543 .mode = 0600,
544 .proc_handler = proc_dointvec,
545 },
546 {
547 .procname = "expert_mode",
548 .data = &pfm_sysctl.expert_mode,
549 .maxlen = sizeof(int),
550 .mode = 0600,
551 .proc_handler = proc_dointvec,
552 },
553 {}
554};
555static ctl_table pfm_sysctl_dir[] = {
556 {
557 .procname = "perfmon",
558 .mode = 0555,
559 .child = pfm_ctl_table,
560 },
561 {}
562};
563static ctl_table pfm_sysctl_root[] = {
564 {
565 .procname = "kernel",
566 .mode = 0555,
567 .child = pfm_sysctl_dir,
568 },
569 {}
570};
571static struct ctl_table_header *pfm_sysctl_header;
572
573static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
574
575#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
576#define pfm_get_cpu_data(a,b) per_cpu(a, b)
577
578static inline void
579pfm_put_task(struct task_struct *task)
580{
581 if (task != current) put_task_struct(task);
582}
583
584static inline void
585pfm_reserve_page(unsigned long a)
586{
587 SetPageReserved(vmalloc_to_page((void *)a));
588}
589static inline void
590pfm_unreserve_page(unsigned long a)
591{
592 ClearPageReserved(vmalloc_to_page((void*)a));
593}
594
595static inline unsigned long
596pfm_protect_ctx_ctxsw(pfm_context_t *x)
597{
598 spin_lock(&(x)->ctx_lock);
599 return 0UL;
600}
601
602static inline void
603pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
604{
605 spin_unlock(&(x)->ctx_lock);
606}
607
608static inline unsigned int
609pfm_do_munmap(struct mm_struct *mm, unsigned long addr, size_t len, int acct)
610{
611 return do_munmap(mm, addr, len);
612}
613
614static inline unsigned long
615pfm_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, unsigned long exec)
616{
617 return get_unmapped_area(file, addr, len, pgoff, flags);
618}
619
620/* forward declaration */
621static const struct dentry_operations pfmfs_dentry_operations;
622
623static struct dentry *
624pfmfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data)
625{
626 return mount_pseudo(fs_type, "pfm:", NULL, &pfmfs_dentry_operations,
627 PFMFS_MAGIC);
628}
629
630static struct file_system_type pfm_fs_type = {
631 .name = "pfmfs",
632 .mount = pfmfs_mount,
633 .kill_sb = kill_anon_super,
634};
635
636DEFINE_PER_CPU(unsigned long, pfm_syst_info);
637DEFINE_PER_CPU(struct task_struct *, pmu_owner);
638DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
639DEFINE_PER_CPU(unsigned long, pmu_activation_number);
640EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
641
642
643/* forward declaration */
644static const struct file_operations pfm_file_ops;
645
646/*
647 * forward declarations
648 */
649#ifndef CONFIG_SMP
650static void pfm_lazy_save_regs (struct task_struct *ta);
651#endif
652
653void dump_pmu_state(const char *);
654static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
655
656#include "perfmon_itanium.h"
657#include "perfmon_mckinley.h"
658#include "perfmon_montecito.h"
659#include "perfmon_generic.h"
660
661static pmu_config_t *pmu_confs[]={
662 &pmu_conf_mont,
663 &pmu_conf_mck,
664 &pmu_conf_ita,
665 &pmu_conf_gen, /* must be last */
666 NULL
667};
668
669
670static int pfm_end_notify_user(pfm_context_t *ctx);
671
672static inline void
673pfm_clear_psr_pp(void)
674{
675 ia64_rsm(IA64_PSR_PP);
676 ia64_srlz_i();
677}
678
679static inline void
680pfm_set_psr_pp(void)
681{
682 ia64_ssm(IA64_PSR_PP);
683 ia64_srlz_i();
684}
685
686static inline void
687pfm_clear_psr_up(void)
688{
689 ia64_rsm(IA64_PSR_UP);
690 ia64_srlz_i();
691}
692
693static inline void
694pfm_set_psr_up(void)
695{
696 ia64_ssm(IA64_PSR_UP);
697 ia64_srlz_i();
698}
699
700static inline unsigned long
701pfm_get_psr(void)
702{
703 unsigned long tmp;
704 tmp = ia64_getreg(_IA64_REG_PSR);
705 ia64_srlz_i();
706 return tmp;
707}
708
709static inline void
710pfm_set_psr_l(unsigned long val)
711{
712 ia64_setreg(_IA64_REG_PSR_L, val);
713 ia64_srlz_i();
714}
715
716static inline void
717pfm_freeze_pmu(void)
718{
719 ia64_set_pmc(0,1UL);
720 ia64_srlz_d();
721}
722
723static inline void
724pfm_unfreeze_pmu(void)
725{
726 ia64_set_pmc(0,0UL);
727 ia64_srlz_d();
728}
729
730static inline void
731pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
732{
733 int i;
734
735 for (i=0; i < nibrs; i++) {
736 ia64_set_ibr(i, ibrs[i]);
737 ia64_dv_serialize_instruction();
738 }
739 ia64_srlz_i();
740}
741
742static inline void
743pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
744{
745 int i;
746
747 for (i=0; i < ndbrs; i++) {
748 ia64_set_dbr(i, dbrs[i]);
749 ia64_dv_serialize_data();
750 }
751 ia64_srlz_d();
752}
753
754/*
755 * PMD[i] must be a counter. no check is made
756 */
757static inline unsigned long
758pfm_read_soft_counter(pfm_context_t *ctx, int i)
759{
760 return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
761}
762
763/*
764 * PMD[i] must be a counter. no check is made
765 */
766static inline void
767pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
768{
769 unsigned long ovfl_val = pmu_conf->ovfl_val;
770
771 ctx->ctx_pmds[i].val = val & ~ovfl_val;
772 /*
773 * writing to unimplemented part is ignore, so we do not need to
774 * mask off top part
775 */
776 ia64_set_pmd(i, val & ovfl_val);
777}
778
779static pfm_msg_t *
780pfm_get_new_msg(pfm_context_t *ctx)
781{
782 int idx, next;
783
784 next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
785
786 DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
787 if (next == ctx->ctx_msgq_head) return NULL;
788
789 idx = ctx->ctx_msgq_tail;
790 ctx->ctx_msgq_tail = next;
791
792 DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
793
794 return ctx->ctx_msgq+idx;
795}
796
797static pfm_msg_t *
798pfm_get_next_msg(pfm_context_t *ctx)
799{
800 pfm_msg_t *msg;
801
802 DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
803
804 if (PFM_CTXQ_EMPTY(ctx)) return NULL;
805
806 /*
807 * get oldest message
808 */
809 msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
810
811 /*
812 * and move forward
813 */
814 ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
815
816 DPRINT(("ctx=%p head=%d tail=%d type=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, msg->pfm_gen_msg.msg_type));
817
818 return msg;
819}
820
821static void
822pfm_reset_msgq(pfm_context_t *ctx)
823{
824 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
825 DPRINT(("ctx=%p msgq reset\n", ctx));
826}
827
828static void *
829pfm_rvmalloc(unsigned long size)
830{
831 void *mem;
832 unsigned long addr;
833
834 size = PAGE_ALIGN(size);
835 mem = vzalloc(size);
836 if (mem) {
837 //printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
838 addr = (unsigned long)mem;
839 while (size > 0) {
840 pfm_reserve_page(addr);
841 addr+=PAGE_SIZE;
842 size-=PAGE_SIZE;
843 }
844 }
845 return mem;
846}
847
848static void
849pfm_rvfree(void *mem, unsigned long size)
850{
851 unsigned long addr;
852
853 if (mem) {
854 DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
855 addr = (unsigned long) mem;
856 while ((long) size > 0) {
857 pfm_unreserve_page(addr);
858 addr+=PAGE_SIZE;
859 size-=PAGE_SIZE;
860 }
861 vfree(mem);
862 }
863 return;
864}
865
866static pfm_context_t *
867pfm_context_alloc(int ctx_flags)
868{
869 pfm_context_t *ctx;
870
871 /*
872 * allocate context descriptor
873 * must be able to free with interrupts disabled
874 */
875 ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
876 if (ctx) {
877 DPRINT(("alloc ctx @%p\n", ctx));
878
879 /*
880 * init context protection lock
881 */
882 spin_lock_init(&ctx->ctx_lock);
883
884 /*
885 * context is unloaded
886 */
887 ctx->ctx_state = PFM_CTX_UNLOADED;
888
889 /*
890 * initialization of context's flags
891 */
892 ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
893 ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
894 ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
895 /*
896 * will move to set properties
897 * ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
898 */
899
900 /*
901 * init restart semaphore to locked
902 */
903 init_completion(&ctx->ctx_restart_done);
904
905 /*
906 * activation is used in SMP only
907 */
908 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
909 SET_LAST_CPU(ctx, -1);
910
911 /*
912 * initialize notification message queue
913 */
914 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
915 init_waitqueue_head(&ctx->ctx_msgq_wait);
916 init_waitqueue_head(&ctx->ctx_zombieq);
917
918 }
919 return ctx;
920}
921
922static void
923pfm_context_free(pfm_context_t *ctx)
924{
925 if (ctx) {
926 DPRINT(("free ctx @%p\n", ctx));
927 kfree(ctx);
928 }
929}
930
931static void
932pfm_mask_monitoring(struct task_struct *task)
933{
934 pfm_context_t *ctx = PFM_GET_CTX(task);
935 unsigned long mask, val, ovfl_mask;
936 int i;
937
938 DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
939
940 ovfl_mask = pmu_conf->ovfl_val;
941 /*
942 * monitoring can only be masked as a result of a valid
943 * counter overflow. In UP, it means that the PMU still
944 * has an owner. Note that the owner can be different
945 * from the current task. However the PMU state belongs
946 * to the owner.
947 * In SMP, a valid overflow only happens when task is
948 * current. Therefore if we come here, we know that
949 * the PMU state belongs to the current task, therefore
950 * we can access the live registers.
951 *
952 * So in both cases, the live register contains the owner's
953 * state. We can ONLY touch the PMU registers and NOT the PSR.
954 *
955 * As a consequence to this call, the ctx->th_pmds[] array
956 * contains stale information which must be ignored
957 * when context is reloaded AND monitoring is active (see
958 * pfm_restart).
959 */
960 mask = ctx->ctx_used_pmds[0];
961 for (i = 0; mask; i++, mask>>=1) {
962 /* skip non used pmds */
963 if ((mask & 0x1) == 0) continue;
964 val = ia64_get_pmd(i);
965
966 if (PMD_IS_COUNTING(i)) {
967 /*
968 * we rebuild the full 64 bit value of the counter
969 */
970 ctx->ctx_pmds[i].val += (val & ovfl_mask);
971 } else {
972 ctx->ctx_pmds[i].val = val;
973 }
974 DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
975 i,
976 ctx->ctx_pmds[i].val,
977 val & ovfl_mask));
978 }
979 /*
980 * mask monitoring by setting the privilege level to 0
981 * we cannot use psr.pp/psr.up for this, it is controlled by
982 * the user
983 *
984 * if task is current, modify actual registers, otherwise modify
985 * thread save state, i.e., what will be restored in pfm_load_regs()
986 */
987 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
988 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
989 if ((mask & 0x1) == 0UL) continue;
990 ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
991 ctx->th_pmcs[i] &= ~0xfUL;
992 DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
993 }
994 /*
995 * make all of this visible
996 */
997 ia64_srlz_d();
998}
999
1000/*
1001 * must always be done with task == current
1002 *
1003 * context must be in MASKED state when calling
1004 */
1005static void
1006pfm_restore_monitoring(struct task_struct *task)
1007{
1008 pfm_context_t *ctx = PFM_GET_CTX(task);
1009 unsigned long mask, ovfl_mask;
1010 unsigned long psr, val;
1011 int i, is_system;
1012
1013 is_system = ctx->ctx_fl_system;
1014 ovfl_mask = pmu_conf->ovfl_val;
1015
1016 if (task != current) {
1017 printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
1018 return;
1019 }
1020 if (ctx->ctx_state != PFM_CTX_MASKED) {
1021 printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
1022 task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
1023 return;
1024 }
1025 psr = pfm_get_psr();
1026 /*
1027 * monitoring is masked via the PMC.
1028 * As we restore their value, we do not want each counter to
1029 * restart right away. We stop monitoring using the PSR,
1030 * restore the PMC (and PMD) and then re-establish the psr
1031 * as it was. Note that there can be no pending overflow at
1032 * this point, because monitoring was MASKED.
1033 *
1034 * system-wide session are pinned and self-monitoring
1035 */
1036 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1037 /* disable dcr pp */
1038 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
1039 pfm_clear_psr_pp();
1040 } else {
1041 pfm_clear_psr_up();
1042 }
1043 /*
1044 * first, we restore the PMD
1045 */
1046 mask = ctx->ctx_used_pmds[0];
1047 for (i = 0; mask; i++, mask>>=1) {
1048 /* skip non used pmds */
1049 if ((mask & 0x1) == 0) continue;
1050
1051 if (PMD_IS_COUNTING(i)) {
1052 /*
1053 * we split the 64bit value according to
1054 * counter width
1055 */
1056 val = ctx->ctx_pmds[i].val & ovfl_mask;
1057 ctx->ctx_pmds[i].val &= ~ovfl_mask;
1058 } else {
1059 val = ctx->ctx_pmds[i].val;
1060 }
1061 ia64_set_pmd(i, val);
1062
1063 DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
1064 i,
1065 ctx->ctx_pmds[i].val,
1066 val));
1067 }
1068 /*
1069 * restore the PMCs
1070 */
1071 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
1072 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
1073 if ((mask & 0x1) == 0UL) continue;
1074 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1075 ia64_set_pmc(i, ctx->th_pmcs[i]);
1076 DPRINT(("[%d] pmc[%d]=0x%lx\n",
1077 task_pid_nr(task), i, ctx->th_pmcs[i]));
1078 }
1079 ia64_srlz_d();
1080
1081 /*
1082 * must restore DBR/IBR because could be modified while masked
1083 * XXX: need to optimize
1084 */
1085 if (ctx->ctx_fl_using_dbreg) {
1086 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
1087 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
1088 }
1089
1090 /*
1091 * now restore PSR
1092 */
1093 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1094 /* enable dcr pp */
1095 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
1096 ia64_srlz_i();
1097 }
1098 pfm_set_psr_l(psr);
1099}
1100
1101static inline void
1102pfm_save_pmds(unsigned long *pmds, unsigned long mask)
1103{
1104 int i;
1105
1106 ia64_srlz_d();
1107
1108 for (i=0; mask; i++, mask>>=1) {
1109 if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
1110 }
1111}
1112
1113/*
1114 * reload from thread state (used for ctxw only)
1115 */
1116static inline void
1117pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
1118{
1119 int i;
1120 unsigned long val, ovfl_val = pmu_conf->ovfl_val;
1121
1122 for (i=0; mask; i++, mask>>=1) {
1123 if ((mask & 0x1) == 0) continue;
1124 val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
1125 ia64_set_pmd(i, val);
1126 }
1127 ia64_srlz_d();
1128}
1129
1130/*
1131 * propagate PMD from context to thread-state
1132 */
1133static inline void
1134pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
1135{
1136 unsigned long ovfl_val = pmu_conf->ovfl_val;
1137 unsigned long mask = ctx->ctx_all_pmds[0];
1138 unsigned long val;
1139 int i;
1140
1141 DPRINT(("mask=0x%lx\n", mask));
1142
1143 for (i=0; mask; i++, mask>>=1) {
1144
1145 val = ctx->ctx_pmds[i].val;
1146
1147 /*
1148 * We break up the 64 bit value into 2 pieces
1149 * the lower bits go to the machine state in the
1150 * thread (will be reloaded on ctxsw in).
1151 * The upper part stays in the soft-counter.
1152 */
1153 if (PMD_IS_COUNTING(i)) {
1154 ctx->ctx_pmds[i].val = val & ~ovfl_val;
1155 val &= ovfl_val;
1156 }
1157 ctx->th_pmds[i] = val;
1158
1159 DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
1160 i,
1161 ctx->th_pmds[i],
1162 ctx->ctx_pmds[i].val));
1163 }
1164}
1165
1166/*
1167 * propagate PMC from context to thread-state
1168 */
1169static inline void
1170pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
1171{
1172 unsigned long mask = ctx->ctx_all_pmcs[0];
1173 int i;
1174
1175 DPRINT(("mask=0x%lx\n", mask));
1176
1177 for (i=0; mask; i++, mask>>=1) {
1178 /* masking 0 with ovfl_val yields 0 */
1179 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1180 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
1181 }
1182}
1183
1184
1185
1186static inline void
1187pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
1188{
1189 int i;
1190
1191 for (i=0; mask; i++, mask>>=1) {
1192 if ((mask & 0x1) == 0) continue;
1193 ia64_set_pmc(i, pmcs[i]);
1194 }
1195 ia64_srlz_d();
1196}
1197
1198static inline int
1199pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
1200{
1201 return memcmp(a, b, sizeof(pfm_uuid_t));
1202}
1203
1204static inline int
1205pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
1206{
1207 int ret = 0;
1208 if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
1209 return ret;
1210}
1211
1212static inline int
1213pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
1214{
1215 int ret = 0;
1216 if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
1217 return ret;
1218}
1219
1220
1221static inline int
1222pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
1223 int cpu, void *arg)
1224{
1225 int ret = 0;
1226 if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
1227 return ret;
1228}
1229
1230static inline int
1231pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
1232 int cpu, void *arg)
1233{
1234 int ret = 0;
1235 if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
1236 return ret;
1237}
1238
1239static inline int
1240pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1241{
1242 int ret = 0;
1243 if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
1244 return ret;
1245}
1246
1247static inline int
1248pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1249{
1250 int ret = 0;
1251 if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
1252 return ret;
1253}
1254
1255static pfm_buffer_fmt_t *
1256__pfm_find_buffer_fmt(pfm_uuid_t uuid)
1257{
1258 struct list_head * pos;
1259 pfm_buffer_fmt_t * entry;
1260
1261 list_for_each(pos, &pfm_buffer_fmt_list) {
1262 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
1263 if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
1264 return entry;
1265 }
1266 return NULL;
1267}
1268
1269/*
1270 * find a buffer format based on its uuid
1271 */
1272static pfm_buffer_fmt_t *
1273pfm_find_buffer_fmt(pfm_uuid_t uuid)
1274{
1275 pfm_buffer_fmt_t * fmt;
1276 spin_lock(&pfm_buffer_fmt_lock);
1277 fmt = __pfm_find_buffer_fmt(uuid);
1278 spin_unlock(&pfm_buffer_fmt_lock);
1279 return fmt;
1280}
1281
1282int
1283pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
1284{
1285 int ret = 0;
1286
1287 /* some sanity checks */
1288 if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
1289
1290 /* we need at least a handler */
1291 if (fmt->fmt_handler == NULL) return -EINVAL;
1292
1293 /*
1294 * XXX: need check validity of fmt_arg_size
1295 */
1296
1297 spin_lock(&pfm_buffer_fmt_lock);
1298
1299 if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
1300 printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
1301 ret = -EBUSY;
1302 goto out;
1303 }
1304 list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
1305 printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
1306
1307out:
1308 spin_unlock(&pfm_buffer_fmt_lock);
1309 return ret;
1310}
1311EXPORT_SYMBOL(pfm_register_buffer_fmt);
1312
1313int
1314pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
1315{
1316 pfm_buffer_fmt_t *fmt;
1317 int ret = 0;
1318
1319 spin_lock(&pfm_buffer_fmt_lock);
1320
1321 fmt = __pfm_find_buffer_fmt(uuid);
1322 if (!fmt) {
1323 printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
1324 ret = -EINVAL;
1325 goto out;
1326 }
1327 list_del_init(&fmt->fmt_list);
1328 printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
1329
1330out:
1331 spin_unlock(&pfm_buffer_fmt_lock);
1332 return ret;
1333
1334}
1335EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
1336
1337extern void update_pal_halt_status(int);
1338
1339static int
1340pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
1341{
1342 unsigned long flags;
1343 /*
1344 * validity checks on cpu_mask have been done upstream
1345 */
1346 LOCK_PFS(flags);
1347
1348 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1349 pfm_sessions.pfs_sys_sessions,
1350 pfm_sessions.pfs_task_sessions,
1351 pfm_sessions.pfs_sys_use_dbregs,
1352 is_syswide,
1353 cpu));
1354
1355 if (is_syswide) {
1356 /*
1357 * cannot mix system wide and per-task sessions
1358 */
1359 if (pfm_sessions.pfs_task_sessions > 0UL) {
1360 DPRINT(("system wide not possible, %u conflicting task_sessions\n",
1361 pfm_sessions.pfs_task_sessions));
1362 goto abort;
1363 }
1364
1365 if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
1366
1367 DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
1368
1369 pfm_sessions.pfs_sys_session[cpu] = task;
1370
1371 pfm_sessions.pfs_sys_sessions++ ;
1372
1373 } else {
1374 if (pfm_sessions.pfs_sys_sessions) goto abort;
1375 pfm_sessions.pfs_task_sessions++;
1376 }
1377
1378 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1379 pfm_sessions.pfs_sys_sessions,
1380 pfm_sessions.pfs_task_sessions,
1381 pfm_sessions.pfs_sys_use_dbregs,
1382 is_syswide,
1383 cpu));
1384
1385 /*
1386 * disable default_idle() to go to PAL_HALT
1387 */
1388 update_pal_halt_status(0);
1389
1390 UNLOCK_PFS(flags);
1391
1392 return 0;
1393
1394error_conflict:
1395 DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
1396 task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
1397 cpu));
1398abort:
1399 UNLOCK_PFS(flags);
1400
1401 return -EBUSY;
1402
1403}
1404
1405static int
1406pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
1407{
1408 unsigned long flags;
1409 /*
1410 * validity checks on cpu_mask have been done upstream
1411 */
1412 LOCK_PFS(flags);
1413
1414 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1415 pfm_sessions.pfs_sys_sessions,
1416 pfm_sessions.pfs_task_sessions,
1417 pfm_sessions.pfs_sys_use_dbregs,
1418 is_syswide,
1419 cpu));
1420
1421
1422 if (is_syswide) {
1423 pfm_sessions.pfs_sys_session[cpu] = NULL;
1424 /*
1425 * would not work with perfmon+more than one bit in cpu_mask
1426 */
1427 if (ctx && ctx->ctx_fl_using_dbreg) {
1428 if (pfm_sessions.pfs_sys_use_dbregs == 0) {
1429 printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
1430 } else {
1431 pfm_sessions.pfs_sys_use_dbregs--;
1432 }
1433 }
1434 pfm_sessions.pfs_sys_sessions--;
1435 } else {
1436 pfm_sessions.pfs_task_sessions--;
1437 }
1438 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1439 pfm_sessions.pfs_sys_sessions,
1440 pfm_sessions.pfs_task_sessions,
1441 pfm_sessions.pfs_sys_use_dbregs,
1442 is_syswide,
1443 cpu));
1444
1445 /*
1446 * if possible, enable default_idle() to go into PAL_HALT
1447 */
1448 if (pfm_sessions.pfs_task_sessions == 0 && pfm_sessions.pfs_sys_sessions == 0)
1449 update_pal_halt_status(1);
1450
1451 UNLOCK_PFS(flags);
1452
1453 return 0;
1454}
1455
1456/*
1457 * removes virtual mapping of the sampling buffer.
1458 * IMPORTANT: cannot be called with interrupts disable, e.g. inside
1459 * a PROTECT_CTX() section.
1460 */
1461static int
1462pfm_remove_smpl_mapping(struct task_struct *task, void *vaddr, unsigned long size)
1463{
1464 int r;
1465
1466 /* sanity checks */
1467 if (task->mm == NULL || size == 0UL || vaddr == NULL) {
1468 printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
1469 return -EINVAL;
1470 }
1471
1472 DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
1473
1474 /*
1475 * does the actual unmapping
1476 */
1477 down_write(&task->mm->mmap_sem);
1478
1479 DPRINT(("down_write done smpl_vaddr=%p size=%lu\n", vaddr, size));
1480
1481 r = pfm_do_munmap(task->mm, (unsigned long)vaddr, size, 0);
1482
1483 up_write(&task->mm->mmap_sem);
1484 if (r !=0) {
1485 printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
1486 }
1487
1488 DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
1489
1490 return 0;
1491}
1492
1493/*
1494 * free actual physical storage used by sampling buffer
1495 */
1496#if 0
1497static int
1498pfm_free_smpl_buffer(pfm_context_t *ctx)
1499{
1500 pfm_buffer_fmt_t *fmt;
1501
1502 if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
1503
1504 /*
1505 * we won't use the buffer format anymore
1506 */
1507 fmt = ctx->ctx_buf_fmt;
1508
1509 DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
1510 ctx->ctx_smpl_hdr,
1511 ctx->ctx_smpl_size,
1512 ctx->ctx_smpl_vaddr));
1513
1514 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1515
1516 /*
1517 * free the buffer
1518 */
1519 pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
1520
1521 ctx->ctx_smpl_hdr = NULL;
1522 ctx->ctx_smpl_size = 0UL;
1523
1524 return 0;
1525
1526invalid_free:
1527 printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
1528 return -EINVAL;
1529}
1530#endif
1531
1532static inline void
1533pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
1534{
1535 if (fmt == NULL) return;
1536
1537 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1538
1539}
1540
1541/*
1542 * pfmfs should _never_ be mounted by userland - too much of security hassle,
1543 * no real gain from having the whole whorehouse mounted. So we don't need
1544 * any operations on the root directory. However, we need a non-trivial
1545 * d_name - pfm: will go nicely and kill the special-casing in procfs.
1546 */
1547static struct vfsmount *pfmfs_mnt __read_mostly;
1548
1549static int __init
1550init_pfm_fs(void)
1551{
1552 int err = register_filesystem(&pfm_fs_type);
1553 if (!err) {
1554 pfmfs_mnt = kern_mount(&pfm_fs_type);
1555 err = PTR_ERR(pfmfs_mnt);
1556 if (IS_ERR(pfmfs_mnt))
1557 unregister_filesystem(&pfm_fs_type);
1558 else
1559 err = 0;
1560 }
1561 return err;
1562}
1563
1564static ssize_t
1565pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
1566{
1567 pfm_context_t *ctx;
1568 pfm_msg_t *msg;
1569 ssize_t ret;
1570 unsigned long flags;
1571 DECLARE_WAITQUEUE(wait, current);
1572 if (PFM_IS_FILE(filp) == 0) {
1573 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1574 return -EINVAL;
1575 }
1576
1577 ctx = filp->private_data;
1578 if (ctx == NULL) {
1579 printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
1580 return -EINVAL;
1581 }
1582
1583 /*
1584 * check even when there is no message
1585 */
1586 if (size < sizeof(pfm_msg_t)) {
1587 DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
1588 return -EINVAL;
1589 }
1590
1591 PROTECT_CTX(ctx, flags);
1592
1593 /*
1594 * put ourselves on the wait queue
1595 */
1596 add_wait_queue(&ctx->ctx_msgq_wait, &wait);
1597
1598
1599 for(;;) {
1600 /*
1601 * check wait queue
1602 */
1603
1604 set_current_state(TASK_INTERRUPTIBLE);
1605
1606 DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
1607
1608 ret = 0;
1609 if(PFM_CTXQ_EMPTY(ctx) == 0) break;
1610
1611 UNPROTECT_CTX(ctx, flags);
1612
1613 /*
1614 * check non-blocking read
1615 */
1616 ret = -EAGAIN;
1617 if(filp->f_flags & O_NONBLOCK) break;
1618
1619 /*
1620 * check pending signals
1621 */
1622 if(signal_pending(current)) {
1623 ret = -EINTR;
1624 break;
1625 }
1626 /*
1627 * no message, so wait
1628 */
1629 schedule();
1630
1631 PROTECT_CTX(ctx, flags);
1632 }
1633 DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
1634 set_current_state(TASK_RUNNING);
1635 remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
1636
1637 if (ret < 0) goto abort;
1638
1639 ret = -EINVAL;
1640 msg = pfm_get_next_msg(ctx);
1641 if (msg == NULL) {
1642 printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
1643 goto abort_locked;
1644 }
1645
1646 DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
1647
1648 ret = -EFAULT;
1649 if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
1650
1651abort_locked:
1652 UNPROTECT_CTX(ctx, flags);
1653abort:
1654 return ret;
1655}
1656
1657static ssize_t
1658pfm_write(struct file *file, const char __user *ubuf,
1659 size_t size, loff_t *ppos)
1660{
1661 DPRINT(("pfm_write called\n"));
1662 return -EINVAL;
1663}
1664
1665static unsigned int
1666pfm_poll(struct file *filp, poll_table * wait)
1667{
1668 pfm_context_t *ctx;
1669 unsigned long flags;
1670 unsigned int mask = 0;
1671
1672 if (PFM_IS_FILE(filp) == 0) {
1673 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1674 return 0;
1675 }
1676
1677 ctx = filp->private_data;
1678 if (ctx == NULL) {
1679 printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
1680 return 0;
1681 }
1682
1683
1684 DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
1685
1686 poll_wait(filp, &ctx->ctx_msgq_wait, wait);
1687
1688 PROTECT_CTX(ctx, flags);
1689
1690 if (PFM_CTXQ_EMPTY(ctx) == 0)
1691 mask = POLLIN | POLLRDNORM;
1692
1693 UNPROTECT_CTX(ctx, flags);
1694
1695 DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
1696
1697 return mask;
1698}
1699
1700static long
1701pfm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1702{
1703 DPRINT(("pfm_ioctl called\n"));
1704 return -EINVAL;
1705}
1706
1707/*
1708 * interrupt cannot be masked when coming here
1709 */
1710static inline int
1711pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
1712{
1713 int ret;
1714
1715 ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
1716
1717 DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1718 task_pid_nr(current),
1719 fd,
1720 on,
1721 ctx->ctx_async_queue, ret));
1722
1723 return ret;
1724}
1725
1726static int
1727pfm_fasync(int fd, struct file *filp, int on)
1728{
1729 pfm_context_t *ctx;
1730 int ret;
1731
1732 if (PFM_IS_FILE(filp) == 0) {
1733 printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
1734 return -EBADF;
1735 }
1736
1737 ctx = filp->private_data;
1738 if (ctx == NULL) {
1739 printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
1740 return -EBADF;
1741 }
1742 /*
1743 * we cannot mask interrupts during this call because this may
1744 * may go to sleep if memory is not readily avalaible.
1745 *
1746 * We are protected from the conetxt disappearing by the get_fd()/put_fd()
1747 * done in caller. Serialization of this function is ensured by caller.
1748 */
1749 ret = pfm_do_fasync(fd, filp, ctx, on);
1750
1751
1752 DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1753 fd,
1754 on,
1755 ctx->ctx_async_queue, ret));
1756
1757 return ret;
1758}
1759
1760#ifdef CONFIG_SMP
1761/*
1762 * this function is exclusively called from pfm_close().
1763 * The context is not protected at that time, nor are interrupts
1764 * on the remote CPU. That's necessary to avoid deadlocks.
1765 */
1766static void
1767pfm_syswide_force_stop(void *info)
1768{
1769 pfm_context_t *ctx = (pfm_context_t *)info;
1770 struct pt_regs *regs = task_pt_regs(current);
1771 struct task_struct *owner;
1772 unsigned long flags;
1773 int ret;
1774
1775 if (ctx->ctx_cpu != smp_processor_id()) {
1776 printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
1777 ctx->ctx_cpu,
1778 smp_processor_id());
1779 return;
1780 }
1781 owner = GET_PMU_OWNER();
1782 if (owner != ctx->ctx_task) {
1783 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
1784 smp_processor_id(),
1785 task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
1786 return;
1787 }
1788 if (GET_PMU_CTX() != ctx) {
1789 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
1790 smp_processor_id(),
1791 GET_PMU_CTX(), ctx);
1792 return;
1793 }
1794
1795 DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
1796 /*
1797 * the context is already protected in pfm_close(), we simply
1798 * need to mask interrupts to avoid a PMU interrupt race on
1799 * this CPU
1800 */
1801 local_irq_save(flags);
1802
1803 ret = pfm_context_unload(ctx, NULL, 0, regs);
1804 if (ret) {
1805 DPRINT(("context_unload returned %d\n", ret));
1806 }
1807
1808 /*
1809 * unmask interrupts, PMU interrupts are now spurious here
1810 */
1811 local_irq_restore(flags);
1812}
1813
1814static void
1815pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
1816{
1817 int ret;
1818
1819 DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
1820 ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 1);
1821 DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
1822}
1823#endif /* CONFIG_SMP */
1824
1825/*
1826 * called for each close(). Partially free resources.
1827 * When caller is self-monitoring, the context is unloaded.
1828 */
1829static int
1830pfm_flush(struct file *filp, fl_owner_t id)
1831{
1832 pfm_context_t *ctx;
1833 struct task_struct *task;
1834 struct pt_regs *regs;
1835 unsigned long flags;
1836 unsigned long smpl_buf_size = 0UL;
1837 void *smpl_buf_vaddr = NULL;
1838 int state, is_system;
1839
1840 if (PFM_IS_FILE(filp) == 0) {
1841 DPRINT(("bad magic for\n"));
1842 return -EBADF;
1843 }
1844
1845 ctx = filp->private_data;
1846 if (ctx == NULL) {
1847 printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
1848 return -EBADF;
1849 }
1850
1851 /*
1852 * remove our file from the async queue, if we use this mode.
1853 * This can be done without the context being protected. We come
1854 * here when the context has become unreachable by other tasks.
1855 *
1856 * We may still have active monitoring at this point and we may
1857 * end up in pfm_overflow_handler(). However, fasync_helper()
1858 * operates with interrupts disabled and it cleans up the
1859 * queue. If the PMU handler is called prior to entering
1860 * fasync_helper() then it will send a signal. If it is
1861 * invoked after, it will find an empty queue and no
1862 * signal will be sent. In both case, we are safe
1863 */
1864 PROTECT_CTX(ctx, flags);
1865
1866 state = ctx->ctx_state;
1867 is_system = ctx->ctx_fl_system;
1868
1869 task = PFM_CTX_TASK(ctx);
1870 regs = task_pt_regs(task);
1871
1872 DPRINT(("ctx_state=%d is_current=%d\n",
1873 state,
1874 task == current ? 1 : 0));
1875
1876 /*
1877 * if state == UNLOADED, then task is NULL
1878 */
1879
1880 /*
1881 * we must stop and unload because we are losing access to the context.
1882 */
1883 if (task == current) {
1884#ifdef CONFIG_SMP
1885 /*
1886 * the task IS the owner but it migrated to another CPU: that's bad
1887 * but we must handle this cleanly. Unfortunately, the kernel does
1888 * not provide a mechanism to block migration (while the context is loaded).
1889 *
1890 * We need to release the resource on the ORIGINAL cpu.
1891 */
1892 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
1893
1894 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
1895 /*
1896 * keep context protected but unmask interrupt for IPI
1897 */
1898 local_irq_restore(flags);
1899
1900 pfm_syswide_cleanup_other_cpu(ctx);
1901
1902 /*
1903 * restore interrupt masking
1904 */
1905 local_irq_save(flags);
1906
1907 /*
1908 * context is unloaded at this point
1909 */
1910 } else
1911#endif /* CONFIG_SMP */
1912 {
1913
1914 DPRINT(("forcing unload\n"));
1915 /*
1916 * stop and unload, returning with state UNLOADED
1917 * and session unreserved.
1918 */
1919 pfm_context_unload(ctx, NULL, 0, regs);
1920
1921 DPRINT(("ctx_state=%d\n", ctx->ctx_state));
1922 }
1923 }
1924
1925 /*
1926 * remove virtual mapping, if any, for the calling task.
1927 * cannot reset ctx field until last user is calling close().
1928 *
1929 * ctx_smpl_vaddr must never be cleared because it is needed
1930 * by every task with access to the context
1931 *
1932 * When called from do_exit(), the mm context is gone already, therefore
1933 * mm is NULL, i.e., the VMA is already gone and we do not have to
1934 * do anything here
1935 */
1936 if (ctx->ctx_smpl_vaddr && current->mm) {
1937 smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
1938 smpl_buf_size = ctx->ctx_smpl_size;
1939 }
1940
1941 UNPROTECT_CTX(ctx, flags);
1942
1943 /*
1944 * if there was a mapping, then we systematically remove it
1945 * at this point. Cannot be done inside critical section
1946 * because some VM function reenables interrupts.
1947 *
1948 */
1949 if (smpl_buf_vaddr) pfm_remove_smpl_mapping(current, smpl_buf_vaddr, smpl_buf_size);
1950
1951 return 0;
1952}
1953/*
1954 * called either on explicit close() or from exit_files().
1955 * Only the LAST user of the file gets to this point, i.e., it is
1956 * called only ONCE.
1957 *
1958 * IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
1959 * (fput()),i.e, last task to access the file. Nobody else can access the
1960 * file at this point.
1961 *
1962 * When called from exit_files(), the VMA has been freed because exit_mm()
1963 * is executed before exit_files().
1964 *
1965 * When called from exit_files(), the current task is not yet ZOMBIE but we
1966 * flush the PMU state to the context.
1967 */
1968static int
1969pfm_close(struct inode *inode, struct file *filp)
1970{
1971 pfm_context_t *ctx;
1972 struct task_struct *task;
1973 struct pt_regs *regs;
1974 DECLARE_WAITQUEUE(wait, current);
1975 unsigned long flags;
1976 unsigned long smpl_buf_size = 0UL;
1977 void *smpl_buf_addr = NULL;
1978 int free_possible = 1;
1979 int state, is_system;
1980
1981 DPRINT(("pfm_close called private=%p\n", filp->private_data));
1982
1983 if (PFM_IS_FILE(filp) == 0) {
1984 DPRINT(("bad magic\n"));
1985 return -EBADF;
1986 }
1987
1988 ctx = filp->private_data;
1989 if (ctx == NULL) {
1990 printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
1991 return -EBADF;
1992 }
1993
1994 PROTECT_CTX(ctx, flags);
1995
1996 state = ctx->ctx_state;
1997 is_system = ctx->ctx_fl_system;
1998
1999 task = PFM_CTX_TASK(ctx);
2000 regs = task_pt_regs(task);
2001
2002 DPRINT(("ctx_state=%d is_current=%d\n",
2003 state,
2004 task == current ? 1 : 0));
2005
2006 /*
2007 * if task == current, then pfm_flush() unloaded the context
2008 */
2009 if (state == PFM_CTX_UNLOADED) goto doit;
2010
2011 /*
2012 * context is loaded/masked and task != current, we need to
2013 * either force an unload or go zombie
2014 */
2015
2016 /*
2017 * The task is currently blocked or will block after an overflow.
2018 * we must force it to wakeup to get out of the
2019 * MASKED state and transition to the unloaded state by itself.
2020 *
2021 * This situation is only possible for per-task mode
2022 */
2023 if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
2024
2025 /*
2026 * set a "partial" zombie state to be checked
2027 * upon return from down() in pfm_handle_work().
2028 *
2029 * We cannot use the ZOMBIE state, because it is checked
2030 * by pfm_load_regs() which is called upon wakeup from down().
2031 * In such case, it would free the context and then we would
2032 * return to pfm_handle_work() which would access the
2033 * stale context. Instead, we set a flag invisible to pfm_load_regs()
2034 * but visible to pfm_handle_work().
2035 *
2036 * For some window of time, we have a zombie context with
2037 * ctx_state = MASKED and not ZOMBIE
2038 */
2039 ctx->ctx_fl_going_zombie = 1;
2040
2041 /*
2042 * force task to wake up from MASKED state
2043 */
2044 complete(&ctx->ctx_restart_done);
2045
2046 DPRINT(("waking up ctx_state=%d\n", state));
2047
2048 /*
2049 * put ourself to sleep waiting for the other
2050 * task to report completion
2051 *
2052 * the context is protected by mutex, therefore there
2053 * is no risk of being notified of completion before
2054 * begin actually on the waitq.
2055 */
2056 set_current_state(TASK_INTERRUPTIBLE);
2057 add_wait_queue(&ctx->ctx_zombieq, &wait);
2058
2059 UNPROTECT_CTX(ctx, flags);
2060
2061 /*
2062 * XXX: check for signals :
2063 * - ok for explicit close
2064 * - not ok when coming from exit_files()
2065 */
2066 schedule();
2067
2068
2069 PROTECT_CTX(ctx, flags);
2070
2071
2072 remove_wait_queue(&ctx->ctx_zombieq, &wait);
2073 set_current_state(TASK_RUNNING);
2074
2075 /*
2076 * context is unloaded at this point
2077 */
2078 DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
2079 }
2080 else if (task != current) {
2081#ifdef CONFIG_SMP
2082 /*
2083 * switch context to zombie state
2084 */
2085 ctx->ctx_state = PFM_CTX_ZOMBIE;
2086
2087 DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
2088 /*
2089 * cannot free the context on the spot. deferred until
2090 * the task notices the ZOMBIE state
2091 */
2092 free_possible = 0;
2093#else
2094 pfm_context_unload(ctx, NULL, 0, regs);
2095#endif
2096 }
2097
2098doit:
2099 /* reload state, may have changed during opening of critical section */
2100 state = ctx->ctx_state;
2101
2102 /*
2103 * the context is still attached to a task (possibly current)
2104 * we cannot destroy it right now
2105 */
2106
2107 /*
2108 * we must free the sampling buffer right here because
2109 * we cannot rely on it being cleaned up later by the
2110 * monitored task. It is not possible to free vmalloc'ed
2111 * memory in pfm_load_regs(). Instead, we remove the buffer
2112 * now. should there be subsequent PMU overflow originally
2113 * meant for sampling, the will be converted to spurious
2114 * and that's fine because the monitoring tools is gone anyway.
2115 */
2116 if (ctx->ctx_smpl_hdr) {
2117 smpl_buf_addr = ctx->ctx_smpl_hdr;
2118 smpl_buf_size = ctx->ctx_smpl_size;
2119 /* no more sampling */
2120 ctx->ctx_smpl_hdr = NULL;
2121 ctx->ctx_fl_is_sampling = 0;
2122 }
2123
2124 DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
2125 state,
2126 free_possible,
2127 smpl_buf_addr,
2128 smpl_buf_size));
2129
2130 if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
2131
2132 /*
2133 * UNLOADED that the session has already been unreserved.
2134 */
2135 if (state == PFM_CTX_ZOMBIE) {
2136 pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
2137 }
2138
2139 /*
2140 * disconnect file descriptor from context must be done
2141 * before we unlock.
2142 */
2143 filp->private_data = NULL;
2144
2145 /*
2146 * if we free on the spot, the context is now completely unreachable
2147 * from the callers side. The monitored task side is also cut, so we
2148 * can freely cut.
2149 *
2150 * If we have a deferred free, only the caller side is disconnected.
2151 */
2152 UNPROTECT_CTX(ctx, flags);
2153
2154 /*
2155 * All memory free operations (especially for vmalloc'ed memory)
2156 * MUST be done with interrupts ENABLED.
2157 */
2158 if (smpl_buf_addr) pfm_rvfree(smpl_buf_addr, smpl_buf_size);
2159
2160 /*
2161 * return the memory used by the context
2162 */
2163 if (free_possible) pfm_context_free(ctx);
2164
2165 return 0;
2166}
2167
2168static int
2169pfm_no_open(struct inode *irrelevant, struct file *dontcare)
2170{
2171 DPRINT(("pfm_no_open called\n"));
2172 return -ENXIO;
2173}
2174
2175
2176
2177static const struct file_operations pfm_file_ops = {
2178 .llseek = no_llseek,
2179 .read = pfm_read,
2180 .write = pfm_write,
2181 .poll = pfm_poll,
2182 .unlocked_ioctl = pfm_ioctl,
2183 .open = pfm_no_open, /* special open code to disallow open via /proc */
2184 .fasync = pfm_fasync,
2185 .release = pfm_close,
2186 .flush = pfm_flush
2187};
2188
2189static int
2190pfmfs_delete_dentry(const struct dentry *dentry)
2191{
2192 return 1;
2193}
2194
2195static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
2196{
2197 return dynamic_dname(dentry, buffer, buflen, "pfm:[%lu]",
2198 dentry->d_inode->i_ino);
2199}
2200
2201static const struct dentry_operations pfmfs_dentry_operations = {
2202 .d_delete = pfmfs_delete_dentry,
2203 .d_dname = pfmfs_dname,
2204};
2205
2206
2207static struct file *
2208pfm_alloc_file(pfm_context_t *ctx)
2209{
2210 struct file *file;
2211 struct inode *inode;
2212 struct path path;
2213 struct qstr this = { .name = "" };
2214
2215 /*
2216 * allocate a new inode
2217 */
2218 inode = new_inode(pfmfs_mnt->mnt_sb);
2219 if (!inode)
2220 return ERR_PTR(-ENOMEM);
2221
2222 DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
2223
2224 inode->i_mode = S_IFCHR|S_IRUGO;
2225 inode->i_uid = current_fsuid();
2226 inode->i_gid = current_fsgid();
2227
2228 /*
2229 * allocate a new dcache entry
2230 */
2231 path.dentry = d_alloc(pfmfs_mnt->mnt_sb->s_root, &this);
2232 if (!path.dentry) {
2233 iput(inode);
2234 return ERR_PTR(-ENOMEM);
2235 }
2236 path.mnt = mntget(pfmfs_mnt);
2237
2238 d_add(path.dentry, inode);
2239
2240 file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
2241 if (!file) {
2242 path_put(&path);
2243 return ERR_PTR(-ENFILE);
2244 }
2245
2246 file->f_flags = O_RDONLY;
2247 file->private_data = ctx;
2248
2249 return file;
2250}
2251
2252static int
2253pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
2254{
2255 DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
2256
2257 while (size > 0) {
2258 unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
2259
2260
2261 if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
2262 return -ENOMEM;
2263
2264 addr += PAGE_SIZE;
2265 buf += PAGE_SIZE;
2266 size -= PAGE_SIZE;
2267 }
2268 return 0;
2269}
2270
2271/*
2272 * allocate a sampling buffer and remaps it into the user address space of the task
2273 */
2274static int
2275pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
2276{
2277 struct mm_struct *mm = task->mm;
2278 struct vm_area_struct *vma = NULL;
2279 unsigned long size;
2280 void *smpl_buf;
2281
2282
2283 /*
2284 * the fixed header + requested size and align to page boundary
2285 */
2286 size = PAGE_ALIGN(rsize);
2287
2288 DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
2289
2290 /*
2291 * check requested size to avoid Denial-of-service attacks
2292 * XXX: may have to refine this test
2293 * Check against address space limit.
2294 *
2295 * if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
2296 * return -ENOMEM;
2297 */
2298 if (size > task_rlimit(task, RLIMIT_MEMLOCK))
2299 return -ENOMEM;
2300
2301 /*
2302 * We do the easy to undo allocations first.
2303 *
2304 * pfm_rvmalloc(), clears the buffer, so there is no leak
2305 */
2306 smpl_buf = pfm_rvmalloc(size);
2307 if (smpl_buf == NULL) {
2308 DPRINT(("Can't allocate sampling buffer\n"));
2309 return -ENOMEM;
2310 }
2311
2312 DPRINT(("smpl_buf @%p\n", smpl_buf));
2313
2314 /* allocate vma */
2315 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
2316 if (!vma) {
2317 DPRINT(("Cannot allocate vma\n"));
2318 goto error_kmem;
2319 }
2320 INIT_LIST_HEAD(&vma->anon_vma_chain);
2321
2322 /*
2323 * partially initialize the vma for the sampling buffer
2324 */
2325 vma->vm_mm = mm;
2326 vma->vm_file = filp;
2327 vma->vm_flags = VM_READ| VM_MAYREAD |VM_RESERVED;
2328 vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
2329
2330 /*
2331 * Now we have everything we need and we can initialize
2332 * and connect all the data structures
2333 */
2334
2335 ctx->ctx_smpl_hdr = smpl_buf;
2336 ctx->ctx_smpl_size = size; /* aligned size */
2337
2338 /*
2339 * Let's do the difficult operations next.
2340 *
2341 * now we atomically find some area in the address space and
2342 * remap the buffer in it.
2343 */
2344 down_write(&task->mm->mmap_sem);
2345
2346 /* find some free area in address space, must have mmap sem held */
2347 vma->vm_start = pfm_get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS, 0);
2348 if (vma->vm_start == 0UL) {
2349 DPRINT(("Cannot find unmapped area for size %ld\n", size));
2350 up_write(&task->mm->mmap_sem);
2351 goto error;
2352 }
2353 vma->vm_end = vma->vm_start + size;
2354 vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
2355
2356 DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
2357
2358 /* can only be applied to current task, need to have the mm semaphore held when called */
2359 if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
2360 DPRINT(("Can't remap buffer\n"));
2361 up_write(&task->mm->mmap_sem);
2362 goto error;
2363 }
2364
2365 get_file(filp);
2366
2367 /*
2368 * now insert the vma in the vm list for the process, must be
2369 * done with mmap lock held
2370 */
2371 insert_vm_struct(mm, vma);
2372
2373 mm->total_vm += size >> PAGE_SHIFT;
2374 vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
2375 vma_pages(vma));
2376 up_write(&task->mm->mmap_sem);
2377
2378 /*
2379 * keep track of user level virtual address
2380 */
2381 ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
2382 *(unsigned long *)user_vaddr = vma->vm_start;
2383
2384 return 0;
2385
2386error:
2387 kmem_cache_free(vm_area_cachep, vma);
2388error_kmem:
2389 pfm_rvfree(smpl_buf, size);
2390
2391 return -ENOMEM;
2392}
2393
2394/*
2395 * XXX: do something better here
2396 */
2397static int
2398pfm_bad_permissions(struct task_struct *task)
2399{
2400 const struct cred *tcred;
2401 uid_t uid = current_uid();
2402 gid_t gid = current_gid();
2403 int ret;
2404
2405 rcu_read_lock();
2406 tcred = __task_cred(task);
2407
2408 /* inspired by ptrace_attach() */
2409 DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
2410 uid,
2411 gid,
2412 tcred->euid,
2413 tcred->suid,
2414 tcred->uid,
2415 tcred->egid,
2416 tcred->sgid));
2417
2418 ret = ((uid != tcred->euid)
2419 || (uid != tcred->suid)
2420 || (uid != tcred->uid)
2421 || (gid != tcred->egid)
2422 || (gid != tcred->sgid)
2423 || (gid != tcred->gid)) && !capable(CAP_SYS_PTRACE);
2424
2425 rcu_read_unlock();
2426 return ret;
2427}
2428
2429static int
2430pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
2431{
2432 int ctx_flags;
2433
2434 /* valid signal */
2435
2436 ctx_flags = pfx->ctx_flags;
2437
2438 if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
2439
2440 /*
2441 * cannot block in this mode
2442 */
2443 if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
2444 DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
2445 return -EINVAL;
2446 }
2447 } else {
2448 }
2449 /* probably more to add here */
2450
2451 return 0;
2452}
2453
2454static int
2455pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
2456 unsigned int cpu, pfarg_context_t *arg)
2457{
2458 pfm_buffer_fmt_t *fmt = NULL;
2459 unsigned long size = 0UL;
2460 void *uaddr = NULL;
2461 void *fmt_arg = NULL;
2462 int ret = 0;
2463#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
2464
2465 /* invoke and lock buffer format, if found */
2466 fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
2467 if (fmt == NULL) {
2468 DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
2469 return -EINVAL;
2470 }
2471
2472 /*
2473 * buffer argument MUST be contiguous to pfarg_context_t
2474 */
2475 if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
2476
2477 ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
2478
2479 DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
2480
2481 if (ret) goto error;
2482
2483 /* link buffer format and context */
2484 ctx->ctx_buf_fmt = fmt;
2485 ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
2486
2487 /*
2488 * check if buffer format wants to use perfmon buffer allocation/mapping service
2489 */
2490 ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
2491 if (ret) goto error;
2492
2493 if (size) {
2494 /*
2495 * buffer is always remapped into the caller's address space
2496 */
2497 ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
2498 if (ret) goto error;
2499
2500 /* keep track of user address of buffer */
2501 arg->ctx_smpl_vaddr = uaddr;
2502 }
2503 ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
2504
2505error:
2506 return ret;
2507}
2508
2509static void
2510pfm_reset_pmu_state(pfm_context_t *ctx)
2511{
2512 int i;
2513
2514 /*
2515 * install reset values for PMC.
2516 */
2517 for (i=1; PMC_IS_LAST(i) == 0; i++) {
2518 if (PMC_IS_IMPL(i) == 0) continue;
2519 ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
2520 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
2521 }
2522 /*
2523 * PMD registers are set to 0UL when the context in memset()
2524 */
2525
2526 /*
2527 * On context switched restore, we must restore ALL pmc and ALL pmd even
2528 * when they are not actively used by the task. In UP, the incoming process
2529 * may otherwise pick up left over PMC, PMD state from the previous process.
2530 * As opposed to PMD, stale PMC can cause harm to the incoming
2531 * process because they may change what is being measured.
2532 * Therefore, we must systematically reinstall the entire
2533 * PMC state. In SMP, the same thing is possible on the
2534 * same CPU but also on between 2 CPUs.
2535 *
2536 * The problem with PMD is information leaking especially
2537 * to user level when psr.sp=0
2538 *
2539 * There is unfortunately no easy way to avoid this problem
2540 * on either UP or SMP. This definitively slows down the
2541 * pfm_load_regs() function.
2542 */
2543
2544 /*
2545 * bitmask of all PMCs accessible to this context
2546 *
2547 * PMC0 is treated differently.
2548 */
2549 ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
2550
2551 /*
2552 * bitmask of all PMDs that are accessible to this context
2553 */
2554 ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
2555
2556 DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
2557
2558 /*
2559 * useful in case of re-enable after disable
2560 */
2561 ctx->ctx_used_ibrs[0] = 0UL;
2562 ctx->ctx_used_dbrs[0] = 0UL;
2563}
2564
2565static int
2566pfm_ctx_getsize(void *arg, size_t *sz)
2567{
2568 pfarg_context_t *req = (pfarg_context_t *)arg;
2569 pfm_buffer_fmt_t *fmt;
2570
2571 *sz = 0;
2572
2573 if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
2574
2575 fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
2576 if (fmt == NULL) {
2577 DPRINT(("cannot find buffer format\n"));
2578 return -EINVAL;
2579 }
2580 /* get just enough to copy in user parameters */
2581 *sz = fmt->fmt_arg_size;
2582 DPRINT(("arg_size=%lu\n", *sz));
2583
2584 return 0;
2585}
2586
2587
2588
2589/*
2590 * cannot attach if :
2591 * - kernel task
2592 * - task not owned by caller
2593 * - task incompatible with context mode
2594 */
2595static int
2596pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
2597{
2598 /*
2599 * no kernel task or task not owner by caller
2600 */
2601 if (task->mm == NULL) {
2602 DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
2603 return -EPERM;
2604 }
2605 if (pfm_bad_permissions(task)) {
2606 DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
2607 return -EPERM;
2608 }
2609 /*
2610 * cannot block in self-monitoring mode
2611 */
2612 if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
2613 DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
2614 return -EINVAL;
2615 }
2616
2617 if (task->exit_state == EXIT_ZOMBIE) {
2618 DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
2619 return -EBUSY;
2620 }
2621
2622 /*
2623 * always ok for self
2624 */
2625 if (task == current) return 0;
2626
2627 if (!task_is_stopped_or_traced(task)) {
2628 DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
2629 return -EBUSY;
2630 }
2631 /*
2632 * make sure the task is off any CPU
2633 */
2634 wait_task_inactive(task, 0);
2635
2636 /* more to come... */
2637
2638 return 0;
2639}
2640
2641static int
2642pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
2643{
2644 struct task_struct *p = current;
2645 int ret;
2646
2647 /* XXX: need to add more checks here */
2648 if (pid < 2) return -EPERM;
2649
2650 if (pid != task_pid_vnr(current)) {
2651
2652 read_lock(&tasklist_lock);
2653
2654 p = find_task_by_vpid(pid);
2655
2656 /* make sure task cannot go away while we operate on it */
2657 if (p) get_task_struct(p);
2658
2659 read_unlock(&tasklist_lock);
2660
2661 if (p == NULL) return -ESRCH;
2662 }
2663
2664 ret = pfm_task_incompatible(ctx, p);
2665 if (ret == 0) {
2666 *task = p;
2667 } else if (p != current) {
2668 pfm_put_task(p);
2669 }
2670 return ret;
2671}
2672
2673
2674
2675static int
2676pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2677{
2678 pfarg_context_t *req = (pfarg_context_t *)arg;
2679 struct file *filp;
2680 struct path path;
2681 int ctx_flags;
2682 int fd;
2683 int ret;
2684
2685 /* let's check the arguments first */
2686 ret = pfarg_is_sane(current, req);
2687 if (ret < 0)
2688 return ret;
2689
2690 ctx_flags = req->ctx_flags;
2691
2692 ret = -ENOMEM;
2693
2694 fd = get_unused_fd();
2695 if (fd < 0)
2696 return fd;
2697
2698 ctx = pfm_context_alloc(ctx_flags);
2699 if (!ctx)
2700 goto error;
2701
2702 filp = pfm_alloc_file(ctx);
2703 if (IS_ERR(filp)) {
2704 ret = PTR_ERR(filp);
2705 goto error_file;
2706 }
2707
2708 req->ctx_fd = ctx->ctx_fd = fd;
2709
2710 /*
2711 * does the user want to sample?
2712 */
2713 if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
2714 ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
2715 if (ret)
2716 goto buffer_error;
2717 }
2718
2719 DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d\n",
2720 ctx,
2721 ctx_flags,
2722 ctx->ctx_fl_system,
2723 ctx->ctx_fl_block,
2724 ctx->ctx_fl_excl_idle,
2725 ctx->ctx_fl_no_msg,
2726 ctx->ctx_fd));
2727
2728 /*
2729 * initialize soft PMU state
2730 */
2731 pfm_reset_pmu_state(ctx);
2732
2733 fd_install(fd, filp);
2734
2735 return 0;
2736
2737buffer_error:
2738 path = filp->f_path;
2739 put_filp(filp);
2740 path_put(&path);
2741
2742 if (ctx->ctx_buf_fmt) {
2743 pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
2744 }
2745error_file:
2746 pfm_context_free(ctx);
2747
2748error:
2749 put_unused_fd(fd);
2750 return ret;
2751}
2752
2753static inline unsigned long
2754pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
2755{
2756 unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
2757 unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
2758 extern unsigned long carta_random32 (unsigned long seed);
2759
2760 if (reg->flags & PFM_REGFL_RANDOM) {
2761 new_seed = carta_random32(old_seed);
2762 val -= (old_seed & mask); /* counter values are negative numbers! */
2763 if ((mask >> 32) != 0)
2764 /* construct a full 64-bit random value: */
2765 new_seed |= carta_random32(old_seed >> 32) << 32;
2766 reg->seed = new_seed;
2767 }
2768 reg->lval = val;
2769 return val;
2770}
2771
2772static void
2773pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2774{
2775 unsigned long mask = ovfl_regs[0];
2776 unsigned long reset_others = 0UL;
2777 unsigned long val;
2778 int i;
2779
2780 /*
2781 * now restore reset value on sampling overflowed counters
2782 */
2783 mask >>= PMU_FIRST_COUNTER;
2784 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2785
2786 if ((mask & 0x1UL) == 0UL) continue;
2787
2788 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2789 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2790
2791 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2792 }
2793
2794 /*
2795 * Now take care of resetting the other registers
2796 */
2797 for(i = 0; reset_others; i++, reset_others >>= 1) {
2798
2799 if ((reset_others & 0x1) == 0) continue;
2800
2801 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2802
2803 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2804 is_long_reset ? "long" : "short", i, val));
2805 }
2806}
2807
2808static void
2809pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2810{
2811 unsigned long mask = ovfl_regs[0];
2812 unsigned long reset_others = 0UL;
2813 unsigned long val;
2814 int i;
2815
2816 DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
2817
2818 if (ctx->ctx_state == PFM_CTX_MASKED) {
2819 pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
2820 return;
2821 }
2822
2823 /*
2824 * now restore reset value on sampling overflowed counters
2825 */
2826 mask >>= PMU_FIRST_COUNTER;
2827 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2828
2829 if ((mask & 0x1UL) == 0UL) continue;
2830
2831 val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2832 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2833
2834 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2835
2836 pfm_write_soft_counter(ctx, i, val);
2837 }
2838
2839 /*
2840 * Now take care of resetting the other registers
2841 */
2842 for(i = 0; reset_others; i++, reset_others >>= 1) {
2843
2844 if ((reset_others & 0x1) == 0) continue;
2845
2846 val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2847
2848 if (PMD_IS_COUNTING(i)) {
2849 pfm_write_soft_counter(ctx, i, val);
2850 } else {
2851 ia64_set_pmd(i, val);
2852 }
2853 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2854 is_long_reset ? "long" : "short", i, val));
2855 }
2856 ia64_srlz_d();
2857}
2858
2859static int
2860pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2861{
2862 struct task_struct *task;
2863 pfarg_reg_t *req = (pfarg_reg_t *)arg;
2864 unsigned long value, pmc_pm;
2865 unsigned long smpl_pmds, reset_pmds, impl_pmds;
2866 unsigned int cnum, reg_flags, flags, pmc_type;
2867 int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
2868 int is_monitor, is_counting, state;
2869 int ret = -EINVAL;
2870 pfm_reg_check_t wr_func;
2871#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
2872
2873 state = ctx->ctx_state;
2874 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
2875 is_system = ctx->ctx_fl_system;
2876 task = ctx->ctx_task;
2877 impl_pmds = pmu_conf->impl_pmds[0];
2878
2879 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
2880
2881 if (is_loaded) {
2882 /*
2883 * In system wide and when the context is loaded, access can only happen
2884 * when the caller is running on the CPU being monitored by the session.
2885 * It does not have to be the owner (ctx_task) of the context per se.
2886 */
2887 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
2888 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
2889 return -EBUSY;
2890 }
2891 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
2892 }
2893 expert_mode = pfm_sysctl.expert_mode;
2894
2895 for (i = 0; i < count; i++, req++) {
2896
2897 cnum = req->reg_num;
2898 reg_flags = req->reg_flags;
2899 value = req->reg_value;
2900 smpl_pmds = req->reg_smpl_pmds[0];
2901 reset_pmds = req->reg_reset_pmds[0];
2902 flags = 0;
2903
2904
2905 if (cnum >= PMU_MAX_PMCS) {
2906 DPRINT(("pmc%u is invalid\n", cnum));
2907 goto error;
2908 }
2909
2910 pmc_type = pmu_conf->pmc_desc[cnum].type;
2911 pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
2912 is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
2913 is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
2914
2915 /*
2916 * we reject all non implemented PMC as well
2917 * as attempts to modify PMC[0-3] which are used
2918 * as status registers by the PMU
2919 */
2920 if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
2921 DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
2922 goto error;
2923 }
2924 wr_func = pmu_conf->pmc_desc[cnum].write_check;
2925 /*
2926 * If the PMC is a monitor, then if the value is not the default:
2927 * - system-wide session: PMCx.pm=1 (privileged monitor)
2928 * - per-task : PMCx.pm=0 (user monitor)
2929 */
2930 if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
2931 DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
2932 cnum,
2933 pmc_pm,
2934 is_system));
2935 goto error;
2936 }
2937
2938 if (is_counting) {
2939 /*
2940 * enforce generation of overflow interrupt. Necessary on all
2941 * CPUs.
2942 */
2943 value |= 1 << PMU_PMC_OI;
2944
2945 if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
2946 flags |= PFM_REGFL_OVFL_NOTIFY;
2947 }
2948
2949 if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
2950
2951 /* verify validity of smpl_pmds */
2952 if ((smpl_pmds & impl_pmds) != smpl_pmds) {
2953 DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
2954 goto error;
2955 }
2956
2957 /* verify validity of reset_pmds */
2958 if ((reset_pmds & impl_pmds) != reset_pmds) {
2959 DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
2960 goto error;
2961 }
2962 } else {
2963 if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
2964 DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
2965 goto error;
2966 }
2967 /* eventid on non-counting monitors are ignored */
2968 }
2969
2970 /*
2971 * execute write checker, if any
2972 */
2973 if (likely(expert_mode == 0 && wr_func)) {
2974 ret = (*wr_func)(task, ctx, cnum, &value, regs);
2975 if (ret) goto error;
2976 ret = -EINVAL;
2977 }
2978
2979 /*
2980 * no error on this register
2981 */
2982 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
2983
2984 /*
2985 * Now we commit the changes to the software state
2986 */
2987
2988 /*
2989 * update overflow information
2990 */
2991 if (is_counting) {
2992 /*
2993 * full flag update each time a register is programmed
2994 */
2995 ctx->ctx_pmds[cnum].flags = flags;
2996
2997 ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
2998 ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
2999 ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
3000
3001 /*
3002 * Mark all PMDS to be accessed as used.
3003 *
3004 * We do not keep track of PMC because we have to
3005 * systematically restore ALL of them.
3006 *
3007 * We do not update the used_monitors mask, because
3008 * if we have not programmed them, then will be in
3009 * a quiescent state, therefore we will not need to
3010 * mask/restore then when context is MASKED.
3011 */
3012 CTX_USED_PMD(ctx, reset_pmds);
3013 CTX_USED_PMD(ctx, smpl_pmds);
3014 /*
3015 * make sure we do not try to reset on
3016 * restart because we have established new values
3017 */
3018 if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3019 }
3020 /*
3021 * Needed in case the user does not initialize the equivalent
3022 * PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
3023 * possible leak here.
3024 */
3025 CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
3026
3027 /*
3028 * keep track of the monitor PMC that we are using.
3029 * we save the value of the pmc in ctx_pmcs[] and if
3030 * the monitoring is not stopped for the context we also
3031 * place it in the saved state area so that it will be
3032 * picked up later by the context switch code.
3033 *
3034 * The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
3035 *
3036 * The value in th_pmcs[] may be modified on overflow, i.e., when
3037 * monitoring needs to be stopped.
3038 */
3039 if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
3040
3041 /*
3042 * update context state
3043 */
3044 ctx->ctx_pmcs[cnum] = value;
3045
3046 if (is_loaded) {
3047 /*
3048 * write thread state
3049 */
3050 if (is_system == 0) ctx->th_pmcs[cnum] = value;
3051
3052 /*
3053 * write hardware register if we can
3054 */
3055 if (can_access_pmu) {
3056 ia64_set_pmc(cnum, value);
3057 }
3058#ifdef CONFIG_SMP
3059 else {
3060 /*
3061 * per-task SMP only here
3062 *
3063 * we are guaranteed that the task is not running on the other CPU,
3064 * we indicate that this PMD will need to be reloaded if the task
3065 * is rescheduled on the CPU it ran last on.
3066 */
3067 ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
3068 }
3069#endif
3070 }
3071
3072 DPRINT(("pmc[%u]=0x%lx ld=%d apmu=%d flags=0x%x all_pmcs=0x%lx used_pmds=0x%lx eventid=%ld smpl_pmds=0x%lx reset_pmds=0x%lx reloads_pmcs=0x%lx used_monitors=0x%lx ovfl_regs=0x%lx\n",
3073 cnum,
3074 value,
3075 is_loaded,
3076 can_access_pmu,
3077 flags,
3078 ctx->ctx_all_pmcs[0],
3079 ctx->ctx_used_pmds[0],
3080 ctx->ctx_pmds[cnum].eventid,
3081 smpl_pmds,
3082 reset_pmds,
3083 ctx->ctx_reload_pmcs[0],
3084 ctx->ctx_used_monitors[0],
3085 ctx->ctx_ovfl_regs[0]));
3086 }
3087
3088 /*
3089 * make sure the changes are visible
3090 */
3091 if (can_access_pmu) ia64_srlz_d();
3092
3093 return 0;
3094error:
3095 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3096 return ret;
3097}
3098
3099static int
3100pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3101{
3102 struct task_struct *task;
3103 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3104 unsigned long value, hw_value, ovfl_mask;
3105 unsigned int cnum;
3106 int i, can_access_pmu = 0, state;
3107 int is_counting, is_loaded, is_system, expert_mode;
3108 int ret = -EINVAL;
3109 pfm_reg_check_t wr_func;
3110
3111
3112 state = ctx->ctx_state;
3113 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3114 is_system = ctx->ctx_fl_system;
3115 ovfl_mask = pmu_conf->ovfl_val;
3116 task = ctx->ctx_task;
3117
3118 if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
3119
3120 /*
3121 * on both UP and SMP, we can only write to the PMC when the task is
3122 * the owner of the local PMU.
3123 */
3124 if (likely(is_loaded)) {
3125 /*
3126 * In system wide and when the context is loaded, access can only happen
3127 * when the caller is running on the CPU being monitored by the session.
3128 * It does not have to be the owner (ctx_task) of the context per se.
3129 */
3130 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3131 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3132 return -EBUSY;
3133 }
3134 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3135 }
3136 expert_mode = pfm_sysctl.expert_mode;
3137
3138 for (i = 0; i < count; i++, req++) {
3139
3140 cnum = req->reg_num;
3141 value = req->reg_value;
3142
3143 if (!PMD_IS_IMPL(cnum)) {
3144 DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
3145 goto abort_mission;
3146 }
3147 is_counting = PMD_IS_COUNTING(cnum);
3148 wr_func = pmu_conf->pmd_desc[cnum].write_check;
3149
3150 /*
3151 * execute write checker, if any
3152 */
3153 if (unlikely(expert_mode == 0 && wr_func)) {
3154 unsigned long v = value;
3155
3156 ret = (*wr_func)(task, ctx, cnum, &v, regs);
3157 if (ret) goto abort_mission;
3158
3159 value = v;
3160 ret = -EINVAL;
3161 }
3162
3163 /*
3164 * no error on this register
3165 */
3166 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
3167
3168 /*
3169 * now commit changes to software state
3170 */
3171 hw_value = value;
3172
3173 /*
3174 * update virtualized (64bits) counter
3175 */
3176 if (is_counting) {
3177 /*
3178 * write context state
3179 */
3180 ctx->ctx_pmds[cnum].lval = value;
3181
3182 /*
3183 * when context is load we use the split value
3184 */
3185 if (is_loaded) {
3186 hw_value = value & ovfl_mask;
3187 value = value & ~ovfl_mask;
3188 }
3189 }
3190 /*
3191 * update reset values (not just for counters)
3192 */
3193 ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
3194 ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
3195
3196 /*
3197 * update randomization parameters (not just for counters)
3198 */
3199 ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
3200 ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
3201
3202 /*
3203 * update context value
3204 */
3205 ctx->ctx_pmds[cnum].val = value;
3206
3207 /*
3208 * Keep track of what we use
3209 *
3210 * We do not keep track of PMC because we have to
3211 * systematically restore ALL of them.
3212 */
3213 CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
3214
3215 /*
3216 * mark this PMD register used as well
3217 */
3218 CTX_USED_PMD(ctx, RDEP(cnum));
3219
3220 /*
3221 * make sure we do not try to reset on
3222 * restart because we have established new values
3223 */
3224 if (is_counting && state == PFM_CTX_MASKED) {
3225 ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3226 }
3227
3228 if (is_loaded) {
3229 /*
3230 * write thread state
3231 */
3232 if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
3233
3234 /*
3235 * write hardware register if we can
3236 */
3237 if (can_access_pmu) {
3238 ia64_set_pmd(cnum, hw_value);
3239 } else {
3240#ifdef CONFIG_SMP
3241 /*
3242 * we are guaranteed that the task is not running on the other CPU,
3243 * we indicate that this PMD will need to be reloaded if the task
3244 * is rescheduled on the CPU it ran last on.
3245 */
3246 ctx->ctx_reload_pmds[0] |= 1UL << cnum;
3247#endif
3248 }
3249 }
3250
3251 DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
3252 "long_reset=0x%lx notify=%c seed=0x%lx mask=0x%lx used_pmds=0x%lx reset_pmds=0x%lx reload_pmds=0x%lx all_pmds=0x%lx ovfl_regs=0x%lx\n",
3253 cnum,
3254 value,
3255 is_loaded,
3256 can_access_pmu,
3257 hw_value,
3258 ctx->ctx_pmds[cnum].val,
3259 ctx->ctx_pmds[cnum].short_reset,
3260 ctx->ctx_pmds[cnum].long_reset,
3261 PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
3262 ctx->ctx_pmds[cnum].seed,
3263 ctx->ctx_pmds[cnum].mask,
3264 ctx->ctx_used_pmds[0],
3265 ctx->ctx_pmds[cnum].reset_pmds[0],
3266 ctx->ctx_reload_pmds[0],
3267 ctx->ctx_all_pmds[0],
3268 ctx->ctx_ovfl_regs[0]));
3269 }
3270
3271 /*
3272 * make changes visible
3273 */
3274 if (can_access_pmu) ia64_srlz_d();
3275
3276 return 0;
3277
3278abort_mission:
3279 /*
3280 * for now, we have only one possibility for error
3281 */
3282 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3283 return ret;
3284}
3285
3286/*
3287 * By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
3288 * Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
3289 * interrupt is delivered during the call, it will be kept pending until we leave, making
3290 * it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
3291 * guaranteed to return consistent data to the user, it may simply be old. It is not
3292 * trivial to treat the overflow while inside the call because you may end up in
3293 * some module sampling buffer code causing deadlocks.
3294 */
3295static int
3296pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3297{
3298 struct task_struct *task;
3299 unsigned long val = 0UL, lval, ovfl_mask, sval;
3300 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3301 unsigned int cnum, reg_flags = 0;
3302 int i, can_access_pmu = 0, state;
3303 int is_loaded, is_system, is_counting, expert_mode;
3304 int ret = -EINVAL;
3305 pfm_reg_check_t rd_func;
3306
3307 /*
3308 * access is possible when loaded only for
3309 * self-monitoring tasks or in UP mode
3310 */
3311
3312 state = ctx->ctx_state;
3313 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3314 is_system = ctx->ctx_fl_system;
3315 ovfl_mask = pmu_conf->ovfl_val;
3316 task = ctx->ctx_task;
3317
3318 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3319
3320 if (likely(is_loaded)) {
3321 /*
3322 * In system wide and when the context is loaded, access can only happen
3323 * when the caller is running on the CPU being monitored by the session.
3324 * It does not have to be the owner (ctx_task) of the context per se.
3325 */
3326 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3327 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3328 return -EBUSY;
3329 }
3330 /*
3331 * this can be true when not self-monitoring only in UP
3332 */
3333 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3334
3335 if (can_access_pmu) ia64_srlz_d();
3336 }
3337 expert_mode = pfm_sysctl.expert_mode;
3338
3339 DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
3340 is_loaded,
3341 can_access_pmu,
3342 state));
3343
3344 /*
3345 * on both UP and SMP, we can only read the PMD from the hardware register when
3346 * the task is the owner of the local PMU.
3347 */
3348
3349 for (i = 0; i < count; i++, req++) {
3350
3351 cnum = req->reg_num;
3352 reg_flags = req->reg_flags;
3353
3354 if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
3355 /*
3356 * we can only read the register that we use. That includes
3357 * the one we explicitly initialize AND the one we want included
3358 * in the sampling buffer (smpl_regs).
3359 *
3360 * Having this restriction allows optimization in the ctxsw routine
3361 * without compromising security (leaks)
3362 */
3363 if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
3364
3365 sval = ctx->ctx_pmds[cnum].val;
3366 lval = ctx->ctx_pmds[cnum].lval;
3367 is_counting = PMD_IS_COUNTING(cnum);
3368
3369 /*
3370 * If the task is not the current one, then we check if the
3371 * PMU state is still in the local live register due to lazy ctxsw.
3372 * If true, then we read directly from the registers.
3373 */
3374 if (can_access_pmu){
3375 val = ia64_get_pmd(cnum);
3376 } else {
3377 /*
3378 * context has been saved
3379 * if context is zombie, then task does not exist anymore.
3380 * In this case, we use the full value saved in the context (pfm_flush_regs()).
3381 */
3382 val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
3383 }
3384 rd_func = pmu_conf->pmd_desc[cnum].read_check;
3385
3386 if (is_counting) {
3387 /*
3388 * XXX: need to check for overflow when loaded
3389 */
3390 val &= ovfl_mask;
3391 val += sval;
3392 }
3393
3394 /*
3395 * execute read checker, if any
3396 */
3397 if (unlikely(expert_mode == 0 && rd_func)) {
3398 unsigned long v = val;
3399 ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
3400 if (ret) goto error;
3401 val = v;
3402 ret = -EINVAL;
3403 }
3404
3405 PFM_REG_RETFLAG_SET(reg_flags, 0);
3406
3407 DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
3408
3409 /*
3410 * update register return value, abort all if problem during copy.
3411 * we only modify the reg_flags field. no check mode is fine because
3412 * access has been verified upfront in sys_perfmonctl().
3413 */
3414 req->reg_value = val;
3415 req->reg_flags = reg_flags;
3416 req->reg_last_reset_val = lval;
3417 }
3418
3419 return 0;
3420
3421error:
3422 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3423 return ret;
3424}
3425
3426int
3427pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3428{
3429 pfm_context_t *ctx;
3430
3431 if (req == NULL) return -EINVAL;
3432
3433 ctx = GET_PMU_CTX();
3434
3435 if (ctx == NULL) return -EINVAL;
3436
3437 /*
3438 * for now limit to current task, which is enough when calling
3439 * from overflow handler
3440 */
3441 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3442
3443 return pfm_write_pmcs(ctx, req, nreq, regs);
3444}
3445EXPORT_SYMBOL(pfm_mod_write_pmcs);
3446
3447int
3448pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3449{
3450 pfm_context_t *ctx;
3451
3452 if (req == NULL) return -EINVAL;
3453
3454 ctx = GET_PMU_CTX();
3455
3456 if (ctx == NULL) return -EINVAL;
3457
3458 /*
3459 * for now limit to current task, which is enough when calling
3460 * from overflow handler
3461 */
3462 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3463
3464 return pfm_read_pmds(ctx, req, nreq, regs);
3465}
3466EXPORT_SYMBOL(pfm_mod_read_pmds);
3467
3468/*
3469 * Only call this function when a process it trying to
3470 * write the debug registers (reading is always allowed)
3471 */
3472int
3473pfm_use_debug_registers(struct task_struct *task)
3474{
3475 pfm_context_t *ctx = task->thread.pfm_context;
3476 unsigned long flags;
3477 int ret = 0;
3478
3479 if (pmu_conf->use_rr_dbregs == 0) return 0;
3480
3481 DPRINT(("called for [%d]\n", task_pid_nr(task)));
3482
3483 /*
3484 * do it only once
3485 */
3486 if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
3487
3488 /*
3489 * Even on SMP, we do not need to use an atomic here because
3490 * the only way in is via ptrace() and this is possible only when the
3491 * process is stopped. Even in the case where the ctxsw out is not totally
3492 * completed by the time we come here, there is no way the 'stopped' process
3493 * could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
3494 * So this is always safe.
3495 */
3496 if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
3497
3498 LOCK_PFS(flags);
3499
3500 /*
3501 * We cannot allow setting breakpoints when system wide monitoring
3502 * sessions are using the debug registers.
3503 */
3504 if (pfm_sessions.pfs_sys_use_dbregs> 0)
3505 ret = -1;
3506 else
3507 pfm_sessions.pfs_ptrace_use_dbregs++;
3508
3509 DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
3510 pfm_sessions.pfs_ptrace_use_dbregs,
3511 pfm_sessions.pfs_sys_use_dbregs,
3512 task_pid_nr(task), ret));
3513
3514 UNLOCK_PFS(flags);
3515
3516 return ret;
3517}
3518
3519/*
3520 * This function is called for every task that exits with the
3521 * IA64_THREAD_DBG_VALID set. This indicates a task which was
3522 * able to use the debug registers for debugging purposes via
3523 * ptrace(). Therefore we know it was not using them for
3524 * performance monitoring, so we only decrement the number
3525 * of "ptraced" debug register users to keep the count up to date
3526 */
3527int
3528pfm_release_debug_registers(struct task_struct *task)
3529{
3530 unsigned long flags;
3531 int ret;
3532
3533 if (pmu_conf->use_rr_dbregs == 0) return 0;
3534
3535 LOCK_PFS(flags);
3536 if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
3537 printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
3538 ret = -1;
3539 } else {
3540 pfm_sessions.pfs_ptrace_use_dbregs--;
3541 ret = 0;
3542 }
3543 UNLOCK_PFS(flags);
3544
3545 return ret;
3546}
3547
3548static int
3549pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3550{
3551 struct task_struct *task;
3552 pfm_buffer_fmt_t *fmt;
3553 pfm_ovfl_ctrl_t rst_ctrl;
3554 int state, is_system;
3555 int ret = 0;
3556
3557 state = ctx->ctx_state;
3558 fmt = ctx->ctx_buf_fmt;
3559 is_system = ctx->ctx_fl_system;
3560 task = PFM_CTX_TASK(ctx);
3561
3562 switch(state) {
3563 case PFM_CTX_MASKED:
3564 break;
3565 case PFM_CTX_LOADED:
3566 if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
3567 /* fall through */
3568 case PFM_CTX_UNLOADED:
3569 case PFM_CTX_ZOMBIE:
3570 DPRINT(("invalid state=%d\n", state));
3571 return -EBUSY;
3572 default:
3573 DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
3574 return -EINVAL;
3575 }
3576
3577 /*
3578 * In system wide and when the context is loaded, access can only happen
3579 * when the caller is running on the CPU being monitored by the session.
3580 * It does not have to be the owner (ctx_task) of the context per se.
3581 */
3582 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3583 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3584 return -EBUSY;
3585 }
3586
3587 /* sanity check */
3588 if (unlikely(task == NULL)) {
3589 printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
3590 return -EINVAL;
3591 }
3592
3593 if (task == current || is_system) {
3594
3595 fmt = ctx->ctx_buf_fmt;
3596
3597 DPRINT(("restarting self %d ovfl=0x%lx\n",
3598 task_pid_nr(task),
3599 ctx->ctx_ovfl_regs[0]));
3600
3601 if (CTX_HAS_SMPL(ctx)) {
3602
3603 prefetch(ctx->ctx_smpl_hdr);
3604
3605 rst_ctrl.bits.mask_monitoring = 0;
3606 rst_ctrl.bits.reset_ovfl_pmds = 0;
3607
3608 if (state == PFM_CTX_LOADED)
3609 ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3610 else
3611 ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3612 } else {
3613 rst_ctrl.bits.mask_monitoring = 0;
3614 rst_ctrl.bits.reset_ovfl_pmds = 1;
3615 }
3616
3617 if (ret == 0) {
3618 if (rst_ctrl.bits.reset_ovfl_pmds)
3619 pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
3620
3621 if (rst_ctrl.bits.mask_monitoring == 0) {
3622 DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
3623
3624 if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
3625 } else {
3626 DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
3627
3628 // cannot use pfm_stop_monitoring(task, regs);
3629 }
3630 }
3631 /*
3632 * clear overflowed PMD mask to remove any stale information
3633 */
3634 ctx->ctx_ovfl_regs[0] = 0UL;
3635
3636 /*
3637 * back to LOADED state
3638 */
3639 ctx->ctx_state = PFM_CTX_LOADED;
3640
3641 /*
3642 * XXX: not really useful for self monitoring
3643 */
3644 ctx->ctx_fl_can_restart = 0;
3645
3646 return 0;
3647 }
3648
3649 /*
3650 * restart another task
3651 */
3652
3653 /*
3654 * When PFM_CTX_MASKED, we cannot issue a restart before the previous
3655 * one is seen by the task.
3656 */
3657 if (state == PFM_CTX_MASKED) {
3658 if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
3659 /*
3660 * will prevent subsequent restart before this one is
3661 * seen by other task
3662 */
3663 ctx->ctx_fl_can_restart = 0;
3664 }
3665
3666 /*
3667 * if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
3668 * the task is blocked or on its way to block. That's the normal
3669 * restart path. If the monitoring is not masked, then the task
3670 * can be actively monitoring and we cannot directly intervene.
3671 * Therefore we use the trap mechanism to catch the task and
3672 * force it to reset the buffer/reset PMDs.
3673 *
3674 * if non-blocking, then we ensure that the task will go into
3675 * pfm_handle_work() before returning to user mode.
3676 *
3677 * We cannot explicitly reset another task, it MUST always
3678 * be done by the task itself. This works for system wide because
3679 * the tool that is controlling the session is logically doing
3680 * "self-monitoring".
3681 */
3682 if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
3683 DPRINT(("unblocking [%d]\n", task_pid_nr(task)));
3684 complete(&ctx->ctx_restart_done);
3685 } else {
3686 DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
3687
3688 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
3689
3690 PFM_SET_WORK_PENDING(task, 1);
3691
3692 set_notify_resume(task);
3693
3694 /*
3695 * XXX: send reschedule if task runs on another CPU
3696 */
3697 }
3698 return 0;
3699}
3700
3701static int
3702pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3703{
3704 unsigned int m = *(unsigned int *)arg;
3705
3706 pfm_sysctl.debug = m == 0 ? 0 : 1;
3707
3708 printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
3709
3710 if (m == 0) {
3711 memset(pfm_stats, 0, sizeof(pfm_stats));
3712 for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
3713 }
3714 return 0;
3715}
3716
3717/*
3718 * arg can be NULL and count can be zero for this function
3719 */
3720static int
3721pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3722{
3723 struct thread_struct *thread = NULL;
3724 struct task_struct *task;
3725 pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
3726 unsigned long flags;
3727 dbreg_t dbreg;
3728 unsigned int rnum;
3729 int first_time;
3730 int ret = 0, state;
3731 int i, can_access_pmu = 0;
3732 int is_system, is_loaded;
3733
3734 if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
3735
3736 state = ctx->ctx_state;
3737 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3738 is_system = ctx->ctx_fl_system;
3739 task = ctx->ctx_task;
3740
3741 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3742
3743 /*
3744 * on both UP and SMP, we can only write to the PMC when the task is
3745 * the owner of the local PMU.
3746 */
3747 if (is_loaded) {
3748 thread = &task->thread;
3749 /*
3750 * In system wide and when the context is loaded, access can only happen
3751 * when the caller is running on the CPU being monitored by the session.
3752 * It does not have to be the owner (ctx_task) of the context per se.
3753 */
3754 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3755 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3756 return -EBUSY;
3757 }
3758 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3759 }
3760
3761 /*
3762 * we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
3763 * ensuring that no real breakpoint can be installed via this call.
3764 *
3765 * IMPORTANT: regs can be NULL in this function
3766 */
3767
3768 first_time = ctx->ctx_fl_using_dbreg == 0;
3769
3770 /*
3771 * don't bother if we are loaded and task is being debugged
3772 */
3773 if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
3774 DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
3775 return -EBUSY;
3776 }
3777
3778 /*
3779 * check for debug registers in system wide mode
3780 *
3781 * If though a check is done in pfm_context_load(),
3782 * we must repeat it here, in case the registers are
3783 * written after the context is loaded
3784 */
3785 if (is_loaded) {
3786 LOCK_PFS(flags);
3787
3788 if (first_time && is_system) {
3789 if (pfm_sessions.pfs_ptrace_use_dbregs)
3790 ret = -EBUSY;
3791 else
3792 pfm_sessions.pfs_sys_use_dbregs++;
3793 }
3794 UNLOCK_PFS(flags);
3795 }
3796
3797 if (ret != 0) return ret;
3798
3799 /*
3800 * mark ourself as user of the debug registers for
3801 * perfmon purposes.
3802 */
3803 ctx->ctx_fl_using_dbreg = 1;
3804
3805 /*
3806 * clear hardware registers to make sure we don't
3807 * pick up stale state.
3808 *
3809 * for a system wide session, we do not use
3810 * thread.dbr, thread.ibr because this process
3811 * never leaves the current CPU and the state
3812 * is shared by all processes running on it
3813 */
3814 if (first_time && can_access_pmu) {
3815 DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
3816 for (i=0; i < pmu_conf->num_ibrs; i++) {
3817 ia64_set_ibr(i, 0UL);
3818 ia64_dv_serialize_instruction();
3819 }
3820 ia64_srlz_i();
3821 for (i=0; i < pmu_conf->num_dbrs; i++) {
3822 ia64_set_dbr(i, 0UL);
3823 ia64_dv_serialize_data();
3824 }
3825 ia64_srlz_d();
3826 }
3827
3828 /*
3829 * Now install the values into the registers
3830 */
3831 for (i = 0; i < count; i++, req++) {
3832
3833 rnum = req->dbreg_num;
3834 dbreg.val = req->dbreg_value;
3835
3836 ret = -EINVAL;
3837
3838 if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
3839 DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
3840 rnum, dbreg.val, mode, i, count));
3841
3842 goto abort_mission;
3843 }
3844
3845 /*
3846 * make sure we do not install enabled breakpoint
3847 */
3848 if (rnum & 0x1) {
3849 if (mode == PFM_CODE_RR)
3850 dbreg.ibr.ibr_x = 0;
3851 else
3852 dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
3853 }
3854
3855 PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
3856
3857 /*
3858 * Debug registers, just like PMC, can only be modified
3859 * by a kernel call. Moreover, perfmon() access to those
3860 * registers are centralized in this routine. The hardware
3861 * does not modify the value of these registers, therefore,
3862 * if we save them as they are written, we can avoid having
3863 * to save them on context switch out. This is made possible
3864 * by the fact that when perfmon uses debug registers, ptrace()
3865 * won't be able to modify them concurrently.
3866 */
3867 if (mode == PFM_CODE_RR) {
3868 CTX_USED_IBR(ctx, rnum);
3869
3870 if (can_access_pmu) {
3871 ia64_set_ibr(rnum, dbreg.val);
3872 ia64_dv_serialize_instruction();
3873 }
3874
3875 ctx->ctx_ibrs[rnum] = dbreg.val;
3876
3877 DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
3878 rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
3879 } else {
3880 CTX_USED_DBR(ctx, rnum);
3881
3882 if (can_access_pmu) {
3883 ia64_set_dbr(rnum, dbreg.val);
3884 ia64_dv_serialize_data();
3885 }
3886 ctx->ctx_dbrs[rnum] = dbreg.val;
3887
3888 DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
3889 rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
3890 }
3891 }
3892
3893 return 0;
3894
3895abort_mission:
3896 /*
3897 * in case it was our first attempt, we undo the global modifications
3898 */
3899 if (first_time) {
3900 LOCK_PFS(flags);
3901 if (ctx->ctx_fl_system) {
3902 pfm_sessions.pfs_sys_use_dbregs--;
3903 }
3904 UNLOCK_PFS(flags);
3905 ctx->ctx_fl_using_dbreg = 0;
3906 }
3907 /*
3908 * install error return flag
3909 */
3910 PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
3911
3912 return ret;
3913}
3914
3915static int
3916pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3917{
3918 return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
3919}
3920
3921static int
3922pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3923{
3924 return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
3925}
3926
3927int
3928pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3929{
3930 pfm_context_t *ctx;
3931
3932 if (req == NULL) return -EINVAL;
3933
3934 ctx = GET_PMU_CTX();
3935
3936 if (ctx == NULL) return -EINVAL;
3937
3938 /*
3939 * for now limit to current task, which is enough when calling
3940 * from overflow handler
3941 */
3942 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3943
3944 return pfm_write_ibrs(ctx, req, nreq, regs);
3945}
3946EXPORT_SYMBOL(pfm_mod_write_ibrs);
3947
3948int
3949pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3950{
3951 pfm_context_t *ctx;
3952
3953 if (req == NULL) return -EINVAL;
3954
3955 ctx = GET_PMU_CTX();
3956
3957 if (ctx == NULL) return -EINVAL;
3958
3959 /*
3960 * for now limit to current task, which is enough when calling
3961 * from overflow handler
3962 */
3963 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3964
3965 return pfm_write_dbrs(ctx, req, nreq, regs);
3966}
3967EXPORT_SYMBOL(pfm_mod_write_dbrs);
3968
3969
3970static int
3971pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3972{
3973 pfarg_features_t *req = (pfarg_features_t *)arg;
3974
3975 req->ft_version = PFM_VERSION;
3976 return 0;
3977}
3978
3979static int
3980pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3981{
3982 struct pt_regs *tregs;
3983 struct task_struct *task = PFM_CTX_TASK(ctx);
3984 int state, is_system;
3985
3986 state = ctx->ctx_state;
3987 is_system = ctx->ctx_fl_system;
3988
3989 /*
3990 * context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
3991 */
3992 if (state == PFM_CTX_UNLOADED) return -EINVAL;
3993
3994 /*
3995 * In system wide and when the context is loaded, access can only happen
3996 * when the caller is running on the CPU being monitored by the session.
3997 * It does not have to be the owner (ctx_task) of the context per se.
3998 */
3999 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
4000 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
4001 return -EBUSY;
4002 }
4003 DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
4004 task_pid_nr(PFM_CTX_TASK(ctx)),
4005 state,
4006 is_system));
4007 /*
4008 * in system mode, we need to update the PMU directly
4009 * and the user level state of the caller, which may not
4010 * necessarily be the creator of the context.
4011 */
4012 if (is_system) {
4013 /*
4014 * Update local PMU first
4015 *
4016 * disable dcr pp
4017 */
4018 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
4019 ia64_srlz_i();
4020
4021 /*
4022 * update local cpuinfo
4023 */
4024 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4025
4026 /*
4027 * stop monitoring, does srlz.i
4028 */
4029 pfm_clear_psr_pp();
4030
4031 /*
4032 * stop monitoring in the caller
4033 */
4034 ia64_psr(regs)->pp = 0;
4035
4036 return 0;
4037 }
4038 /*
4039 * per-task mode
4040 */
4041
4042 if (task == current) {
4043 /* stop monitoring at kernel level */
4044 pfm_clear_psr_up();
4045
4046 /*
4047 * stop monitoring at the user level
4048 */
4049 ia64_psr(regs)->up = 0;
4050 } else {
4051 tregs = task_pt_regs(task);
4052
4053 /*
4054 * stop monitoring at the user level
4055 */
4056 ia64_psr(tregs)->up = 0;
4057
4058 /*
4059 * monitoring disabled in kernel at next reschedule
4060 */
4061 ctx->ctx_saved_psr_up = 0;
4062 DPRINT(("task=[%d]\n", task_pid_nr(task)));
4063 }
4064 return 0;
4065}
4066
4067
4068static int
4069pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4070{
4071 struct pt_regs *tregs;
4072 int state, is_system;
4073
4074 state = ctx->ctx_state;
4075 is_system = ctx->ctx_fl_system;
4076
4077 if (state != PFM_CTX_LOADED) return -EINVAL;
4078
4079 /*
4080 * In system wide and when the context is loaded, access can only happen
4081 * when the caller is running on the CPU being monitored by the session.
4082 * It does not have to be the owner (ctx_task) of the context per se.
4083 */
4084 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
4085 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
4086 return -EBUSY;
4087 }
4088
4089 /*
4090 * in system mode, we need to update the PMU directly
4091 * and the user level state of the caller, which may not
4092 * necessarily be the creator of the context.
4093 */
4094 if (is_system) {
4095
4096 /*
4097 * set user level psr.pp for the caller
4098 */
4099 ia64_psr(regs)->pp = 1;
4100
4101 /*
4102 * now update the local PMU and cpuinfo
4103 */
4104 PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
4105
4106 /*
4107 * start monitoring at kernel level
4108 */
4109 pfm_set_psr_pp();
4110
4111 /* enable dcr pp */
4112 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
4113 ia64_srlz_i();
4114
4115 return 0;
4116 }
4117
4118 /*
4119 * per-process mode
4120 */
4121
4122 if (ctx->ctx_task == current) {
4123
4124 /* start monitoring at kernel level */
4125 pfm_set_psr_up();
4126
4127 /*
4128 * activate monitoring at user level
4129 */
4130 ia64_psr(regs)->up = 1;
4131
4132 } else {
4133 tregs = task_pt_regs(ctx->ctx_task);
4134
4135 /*
4136 * start monitoring at the kernel level the next
4137 * time the task is scheduled
4138 */
4139 ctx->ctx_saved_psr_up = IA64_PSR_UP;
4140
4141 /*
4142 * activate monitoring at user level
4143 */
4144 ia64_psr(tregs)->up = 1;
4145 }
4146 return 0;
4147}
4148
4149static int
4150pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4151{
4152 pfarg_reg_t *req = (pfarg_reg_t *)arg;
4153 unsigned int cnum;
4154 int i;
4155 int ret = -EINVAL;
4156
4157 for (i = 0; i < count; i++, req++) {
4158
4159 cnum = req->reg_num;
4160
4161 if (!PMC_IS_IMPL(cnum)) goto abort_mission;
4162
4163 req->reg_value = PMC_DFL_VAL(cnum);
4164
4165 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
4166
4167 DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
4168 }
4169 return 0;
4170
4171abort_mission:
4172 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
4173 return ret;
4174}
4175
4176static int
4177pfm_check_task_exist(pfm_context_t *ctx)
4178{
4179 struct task_struct *g, *t;
4180 int ret = -ESRCH;
4181
4182 read_lock(&tasklist_lock);
4183
4184 do_each_thread (g, t) {
4185 if (t->thread.pfm_context == ctx) {
4186 ret = 0;
4187 goto out;
4188 }
4189 } while_each_thread (g, t);
4190out:
4191 read_unlock(&tasklist_lock);
4192
4193 DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
4194
4195 return ret;
4196}
4197
4198static int
4199pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4200{
4201 struct task_struct *task;
4202 struct thread_struct *thread;
4203 struct pfm_context_t *old;
4204 unsigned long flags;
4205#ifndef CONFIG_SMP
4206 struct task_struct *owner_task = NULL;
4207#endif
4208 pfarg_load_t *req = (pfarg_load_t *)arg;
4209 unsigned long *pmcs_source, *pmds_source;
4210 int the_cpu;
4211 int ret = 0;
4212 int state, is_system, set_dbregs = 0;
4213
4214 state = ctx->ctx_state;
4215 is_system = ctx->ctx_fl_system;
4216 /*
4217 * can only load from unloaded or terminated state
4218 */
4219 if (state != PFM_CTX_UNLOADED) {
4220 DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
4221 req->load_pid,
4222 ctx->ctx_state));
4223 return -EBUSY;
4224 }
4225
4226 DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
4227
4228 if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
4229 DPRINT(("cannot use blocking mode on self\n"));
4230 return -EINVAL;
4231 }
4232
4233 ret = pfm_get_task(ctx, req->load_pid, &task);
4234 if (ret) {
4235 DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
4236 return ret;
4237 }
4238
4239 ret = -EINVAL;
4240
4241 /*
4242 * system wide is self monitoring only
4243 */
4244 if (is_system && task != current) {
4245 DPRINT(("system wide is self monitoring only load_pid=%d\n",
4246 req->load_pid));
4247 goto error;
4248 }
4249
4250 thread = &task->thread;
4251
4252 ret = 0;
4253 /*
4254 * cannot load a context which is using range restrictions,
4255 * into a task that is being debugged.
4256 */
4257 if (ctx->ctx_fl_using_dbreg) {
4258 if (thread->flags & IA64_THREAD_DBG_VALID) {
4259 ret = -EBUSY;
4260 DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
4261 goto error;
4262 }
4263 LOCK_PFS(flags);
4264
4265 if (is_system) {
4266 if (pfm_sessions.pfs_ptrace_use_dbregs) {
4267 DPRINT(("cannot load [%d] dbregs in use\n",
4268 task_pid_nr(task)));
4269 ret = -EBUSY;
4270 } else {
4271 pfm_sessions.pfs_sys_use_dbregs++;
4272 DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
4273 set_dbregs = 1;
4274 }
4275 }
4276
4277 UNLOCK_PFS(flags);
4278
4279 if (ret) goto error;
4280 }
4281
4282 /*
4283 * SMP system-wide monitoring implies self-monitoring.
4284 *
4285 * The programming model expects the task to
4286 * be pinned on a CPU throughout the session.
4287 * Here we take note of the current CPU at the
4288 * time the context is loaded. No call from
4289 * another CPU will be allowed.
4290 *
4291 * The pinning via shed_setaffinity()
4292 * must be done by the calling task prior
4293 * to this call.
4294 *
4295 * systemwide: keep track of CPU this session is supposed to run on
4296 */
4297 the_cpu = ctx->ctx_cpu = smp_processor_id();
4298
4299 ret = -EBUSY;
4300 /*
4301 * now reserve the session
4302 */
4303 ret = pfm_reserve_session(current, is_system, the_cpu);
4304 if (ret) goto error;
4305
4306 /*
4307 * task is necessarily stopped at this point.
4308 *
4309 * If the previous context was zombie, then it got removed in
4310 * pfm_save_regs(). Therefore we should not see it here.
4311 * If we see a context, then this is an active context
4312 *
4313 * XXX: needs to be atomic
4314 */
4315 DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
4316 thread->pfm_context, ctx));
4317
4318 ret = -EBUSY;
4319 old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
4320 if (old != NULL) {
4321 DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
4322 goto error_unres;
4323 }
4324
4325 pfm_reset_msgq(ctx);
4326
4327 ctx->ctx_state = PFM_CTX_LOADED;
4328
4329 /*
4330 * link context to task
4331 */
4332 ctx->ctx_task = task;
4333
4334 if (is_system) {
4335 /*
4336 * we load as stopped
4337 */
4338 PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
4339 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4340
4341 if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
4342 } else {
4343 thread->flags |= IA64_THREAD_PM_VALID;
4344 }
4345
4346 /*
4347 * propagate into thread-state
4348 */
4349 pfm_copy_pmds(task, ctx);
4350 pfm_copy_pmcs(task, ctx);
4351
4352 pmcs_source = ctx->th_pmcs;
4353 pmds_source = ctx->th_pmds;
4354
4355 /*
4356 * always the case for system-wide
4357 */
4358 if (task == current) {
4359
4360 if (is_system == 0) {
4361
4362 /* allow user level control */
4363 ia64_psr(regs)->sp = 0;
4364 DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
4365
4366 SET_LAST_CPU(ctx, smp_processor_id());
4367 INC_ACTIVATION();
4368 SET_ACTIVATION(ctx);
4369#ifndef CONFIG_SMP
4370 /*
4371 * push the other task out, if any
4372 */
4373 owner_task = GET_PMU_OWNER();
4374 if (owner_task) pfm_lazy_save_regs(owner_task);
4375#endif
4376 }
4377 /*
4378 * load all PMD from ctx to PMU (as opposed to thread state)
4379 * restore all PMC from ctx to PMU
4380 */
4381 pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
4382 pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
4383
4384 ctx->ctx_reload_pmcs[0] = 0UL;
4385 ctx->ctx_reload_pmds[0] = 0UL;
4386
4387 /*
4388 * guaranteed safe by earlier check against DBG_VALID
4389 */
4390 if (ctx->ctx_fl_using_dbreg) {
4391 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
4392 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
4393 }
4394 /*
4395 * set new ownership
4396 */
4397 SET_PMU_OWNER(task, ctx);
4398
4399 DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
4400 } else {
4401 /*
4402 * when not current, task MUST be stopped, so this is safe
4403 */
4404 regs = task_pt_regs(task);
4405
4406 /* force a full reload */
4407 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4408 SET_LAST_CPU(ctx, -1);
4409
4410 /* initial saved psr (stopped) */
4411 ctx->ctx_saved_psr_up = 0UL;
4412 ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
4413 }
4414
4415 ret = 0;
4416
4417error_unres:
4418 if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
4419error:
4420 /*
4421 * we must undo the dbregs setting (for system-wide)
4422 */
4423 if (ret && set_dbregs) {
4424 LOCK_PFS(flags);
4425 pfm_sessions.pfs_sys_use_dbregs--;
4426 UNLOCK_PFS(flags);
4427 }
4428 /*
4429 * release task, there is now a link with the context
4430 */
4431 if (is_system == 0 && task != current) {
4432 pfm_put_task(task);
4433
4434 if (ret == 0) {
4435 ret = pfm_check_task_exist(ctx);
4436 if (ret) {
4437 ctx->ctx_state = PFM_CTX_UNLOADED;
4438 ctx->ctx_task = NULL;
4439 }
4440 }
4441 }
4442 return ret;
4443}
4444
4445/*
4446 * in this function, we do not need to increase the use count
4447 * for the task via get_task_struct(), because we hold the
4448 * context lock. If the task were to disappear while having
4449 * a context attached, it would go through pfm_exit_thread()
4450 * which also grabs the context lock and would therefore be blocked
4451 * until we are here.
4452 */
4453static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
4454
4455static int
4456pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4457{
4458 struct task_struct *task = PFM_CTX_TASK(ctx);
4459 struct pt_regs *tregs;
4460 int prev_state, is_system;
4461 int ret;
4462
4463 DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
4464
4465 prev_state = ctx->ctx_state;
4466 is_system = ctx->ctx_fl_system;
4467
4468 /*
4469 * unload only when necessary
4470 */
4471 if (prev_state == PFM_CTX_UNLOADED) {
4472 DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
4473 return 0;
4474 }
4475
4476 /*
4477 * clear psr and dcr bits
4478 */
4479 ret = pfm_stop(ctx, NULL, 0, regs);
4480 if (ret) return ret;
4481
4482 ctx->ctx_state = PFM_CTX_UNLOADED;
4483
4484 /*
4485 * in system mode, we need to update the PMU directly
4486 * and the user level state of the caller, which may not
4487 * necessarily be the creator of the context.
4488 */
4489 if (is_system) {
4490
4491 /*
4492 * Update cpuinfo
4493 *
4494 * local PMU is taken care of in pfm_stop()
4495 */
4496 PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
4497 PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
4498
4499 /*
4500 * save PMDs in context
4501 * release ownership
4502 */
4503 pfm_flush_pmds(current, ctx);
4504
4505 /*
4506 * at this point we are done with the PMU
4507 * so we can unreserve the resource.
4508 */
4509 if (prev_state != PFM_CTX_ZOMBIE)
4510 pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
4511
4512 /*
4513 * disconnect context from task
4514 */
4515 task->thread.pfm_context = NULL;
4516 /*
4517 * disconnect task from context
4518 */
4519 ctx->ctx_task = NULL;
4520
4521 /*
4522 * There is nothing more to cleanup here.
4523 */
4524 return 0;
4525 }
4526
4527 /*
4528 * per-task mode
4529 */
4530 tregs = task == current ? regs : task_pt_regs(task);
4531
4532 if (task == current) {
4533 /*
4534 * cancel user level control
4535 */
4536 ia64_psr(regs)->sp = 1;
4537
4538 DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
4539 }
4540 /*
4541 * save PMDs to context
4542 * release ownership
4543 */
4544 pfm_flush_pmds(task, ctx);
4545
4546 /*
4547 * at this point we are done with the PMU
4548 * so we can unreserve the resource.
4549 *
4550 * when state was ZOMBIE, we have already unreserved.
4551 */
4552 if (prev_state != PFM_CTX_ZOMBIE)
4553 pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
4554
4555 /*
4556 * reset activation counter and psr
4557 */
4558 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4559 SET_LAST_CPU(ctx, -1);
4560
4561 /*
4562 * PMU state will not be restored
4563 */
4564 task->thread.flags &= ~IA64_THREAD_PM_VALID;
4565
4566 /*
4567 * break links between context and task
4568 */
4569 task->thread.pfm_context = NULL;
4570 ctx->ctx_task = NULL;
4571
4572 PFM_SET_WORK_PENDING(task, 0);
4573
4574 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
4575 ctx->ctx_fl_can_restart = 0;
4576 ctx->ctx_fl_going_zombie = 0;
4577
4578 DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
4579
4580 return 0;
4581}
4582
4583
4584/*
4585 * called only from exit_thread(): task == current
4586 * we come here only if current has a context attached (loaded or masked)
4587 */
4588void
4589pfm_exit_thread(struct task_struct *task)
4590{
4591 pfm_context_t *ctx;
4592 unsigned long flags;
4593 struct pt_regs *regs = task_pt_regs(task);
4594 int ret, state;
4595 int free_ok = 0;
4596
4597 ctx = PFM_GET_CTX(task);
4598
4599 PROTECT_CTX(ctx, flags);
4600
4601 DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
4602
4603 state = ctx->ctx_state;
4604 switch(state) {
4605 case PFM_CTX_UNLOADED:
4606 /*
4607 * only comes to this function if pfm_context is not NULL, i.e., cannot
4608 * be in unloaded state
4609 */
4610 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
4611 break;
4612 case PFM_CTX_LOADED:
4613 case PFM_CTX_MASKED:
4614 ret = pfm_context_unload(ctx, NULL, 0, regs);
4615 if (ret) {
4616 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4617 }
4618 DPRINT(("ctx unloaded for current state was %d\n", state));
4619
4620 pfm_end_notify_user(ctx);
4621 break;
4622 case PFM_CTX_ZOMBIE:
4623 ret = pfm_context_unload(ctx, NULL, 0, regs);
4624 if (ret) {
4625 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4626 }
4627 free_ok = 1;
4628 break;
4629 default:
4630 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
4631 break;
4632 }
4633 UNPROTECT_CTX(ctx, flags);
4634
4635 { u64 psr = pfm_get_psr();
4636 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
4637 BUG_ON(GET_PMU_OWNER());
4638 BUG_ON(ia64_psr(regs)->up);
4639 BUG_ON(ia64_psr(regs)->pp);
4640 }
4641
4642 /*
4643 * All memory free operations (especially for vmalloc'ed memory)
4644 * MUST be done with interrupts ENABLED.
4645 */
4646 if (free_ok) pfm_context_free(ctx);
4647}
4648
4649/*
4650 * functions MUST be listed in the increasing order of their index (see permfon.h)
4651 */
4652#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
4653#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
4654#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
4655#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
4656#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
4657
4658static pfm_cmd_desc_t pfm_cmd_tab[]={
4659/* 0 */PFM_CMD_NONE,
4660/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4661/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4662/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4663/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
4664/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
4665/* 6 */PFM_CMD_NONE,
4666/* 7 */PFM_CMD_NONE,
4667/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
4668/* 9 */PFM_CMD_NONE,
4669/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
4670/* 11 */PFM_CMD_NONE,
4671/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
4672/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
4673/* 14 */PFM_CMD_NONE,
4674/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4675/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
4676/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
4677/* 18 */PFM_CMD_NONE,
4678/* 19 */PFM_CMD_NONE,
4679/* 20 */PFM_CMD_NONE,
4680/* 21 */PFM_CMD_NONE,
4681/* 22 */PFM_CMD_NONE,
4682/* 23 */PFM_CMD_NONE,
4683/* 24 */PFM_CMD_NONE,
4684/* 25 */PFM_CMD_NONE,
4685/* 26 */PFM_CMD_NONE,
4686/* 27 */PFM_CMD_NONE,
4687/* 28 */PFM_CMD_NONE,
4688/* 29 */PFM_CMD_NONE,
4689/* 30 */PFM_CMD_NONE,
4690/* 31 */PFM_CMD_NONE,
4691/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
4692/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
4693};
4694#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
4695
4696static int
4697pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
4698{
4699 struct task_struct *task;
4700 int state, old_state;
4701
4702recheck:
4703 state = ctx->ctx_state;
4704 task = ctx->ctx_task;
4705
4706 if (task == NULL) {
4707 DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
4708 return 0;
4709 }
4710
4711 DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
4712 ctx->ctx_fd,
4713 state,
4714 task_pid_nr(task),
4715 task->state, PFM_CMD_STOPPED(cmd)));
4716
4717 /*
4718 * self-monitoring always ok.
4719 *
4720 * for system-wide the caller can either be the creator of the
4721 * context (to one to which the context is attached to) OR
4722 * a task running on the same CPU as the session.
4723 */
4724 if (task == current || ctx->ctx_fl_system) return 0;
4725
4726 /*
4727 * we are monitoring another thread
4728 */
4729 switch(state) {
4730 case PFM_CTX_UNLOADED:
4731 /*
4732 * if context is UNLOADED we are safe to go
4733 */
4734 return 0;
4735 case PFM_CTX_ZOMBIE:
4736 /*
4737 * no command can operate on a zombie context
4738 */
4739 DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
4740 return -EINVAL;
4741 case PFM_CTX_MASKED:
4742 /*
4743 * PMU state has been saved to software even though
4744 * the thread may still be running.
4745 */
4746 if (cmd != PFM_UNLOAD_CONTEXT) return 0;
4747 }
4748
4749 /*
4750 * context is LOADED or MASKED. Some commands may need to have
4751 * the task stopped.
4752 *
4753 * We could lift this restriction for UP but it would mean that
4754 * the user has no guarantee the task would not run between
4755 * two successive calls to perfmonctl(). That's probably OK.
4756 * If this user wants to ensure the task does not run, then
4757 * the task must be stopped.
4758 */
4759 if (PFM_CMD_STOPPED(cmd)) {
4760 if (!task_is_stopped_or_traced(task)) {
4761 DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
4762 return -EBUSY;
4763 }
4764 /*
4765 * task is now stopped, wait for ctxsw out
4766 *
4767 * This is an interesting point in the code.
4768 * We need to unprotect the context because
4769 * the pfm_save_regs() routines needs to grab
4770 * the same lock. There are danger in doing
4771 * this because it leaves a window open for
4772 * another task to get access to the context
4773 * and possibly change its state. The one thing
4774 * that is not possible is for the context to disappear
4775 * because we are protected by the VFS layer, i.e.,
4776 * get_fd()/put_fd().
4777 */
4778 old_state = state;
4779
4780 UNPROTECT_CTX(ctx, flags);
4781
4782 wait_task_inactive(task, 0);
4783
4784 PROTECT_CTX(ctx, flags);
4785
4786 /*
4787 * we must recheck to verify if state has changed
4788 */
4789 if (ctx->ctx_state != old_state) {
4790 DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
4791 goto recheck;
4792 }
4793 }
4794 return 0;
4795}
4796
4797/*
4798 * system-call entry point (must return long)
4799 */
4800asmlinkage long
4801sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
4802{
4803 struct file *file = NULL;
4804 pfm_context_t *ctx = NULL;
4805 unsigned long flags = 0UL;
4806 void *args_k = NULL;
4807 long ret; /* will expand int return types */
4808 size_t base_sz, sz, xtra_sz = 0;
4809 int narg, completed_args = 0, call_made = 0, cmd_flags;
4810 int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
4811 int (*getsize)(void *arg, size_t *sz);
4812#define PFM_MAX_ARGSIZE 4096
4813
4814 /*
4815 * reject any call if perfmon was disabled at initialization
4816 */
4817 if (unlikely(pmu_conf == NULL)) return -ENOSYS;
4818
4819 if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
4820 DPRINT(("invalid cmd=%d\n", cmd));
4821 return -EINVAL;
4822 }
4823
4824 func = pfm_cmd_tab[cmd].cmd_func;
4825 narg = pfm_cmd_tab[cmd].cmd_narg;
4826 base_sz = pfm_cmd_tab[cmd].cmd_argsize;
4827 getsize = pfm_cmd_tab[cmd].cmd_getsize;
4828 cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
4829
4830 if (unlikely(func == NULL)) {
4831 DPRINT(("invalid cmd=%d\n", cmd));
4832 return -EINVAL;
4833 }
4834
4835 DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
4836 PFM_CMD_NAME(cmd),
4837 cmd,
4838 narg,
4839 base_sz,
4840 count));
4841
4842 /*
4843 * check if number of arguments matches what the command expects
4844 */
4845 if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
4846 return -EINVAL;
4847
4848restart_args:
4849 sz = xtra_sz + base_sz*count;
4850 /*
4851 * limit abuse to min page size
4852 */
4853 if (unlikely(sz > PFM_MAX_ARGSIZE)) {
4854 printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
4855 return -E2BIG;
4856 }
4857
4858 /*
4859 * allocate default-sized argument buffer
4860 */
4861 if (likely(count && args_k == NULL)) {
4862 args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
4863 if (args_k == NULL) return -ENOMEM;
4864 }
4865
4866 ret = -EFAULT;
4867
4868 /*
4869 * copy arguments
4870 *
4871 * assume sz = 0 for command without parameters
4872 */
4873 if (sz && copy_from_user(args_k, arg, sz)) {
4874 DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
4875 goto error_args;
4876 }
4877
4878 /*
4879 * check if command supports extra parameters
4880 */
4881 if (completed_args == 0 && getsize) {
4882 /*
4883 * get extra parameters size (based on main argument)
4884 */
4885 ret = (*getsize)(args_k, &xtra_sz);
4886 if (ret) goto error_args;
4887
4888 completed_args = 1;
4889
4890 DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
4891
4892 /* retry if necessary */
4893 if (likely(xtra_sz)) goto restart_args;
4894 }
4895
4896 if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
4897
4898 ret = -EBADF;
4899
4900 file = fget(fd);
4901 if (unlikely(file == NULL)) {
4902 DPRINT(("invalid fd %d\n", fd));
4903 goto error_args;
4904 }
4905 if (unlikely(PFM_IS_FILE(file) == 0)) {
4906 DPRINT(("fd %d not related to perfmon\n", fd));
4907 goto error_args;
4908 }
4909
4910 ctx = file->private_data;
4911 if (unlikely(ctx == NULL)) {
4912 DPRINT(("no context for fd %d\n", fd));
4913 goto error_args;
4914 }
4915 prefetch(&ctx->ctx_state);
4916
4917 PROTECT_CTX(ctx, flags);
4918
4919 /*
4920 * check task is stopped
4921 */
4922 ret = pfm_check_task_state(ctx, cmd, flags);
4923 if (unlikely(ret)) goto abort_locked;
4924
4925skip_fd:
4926 ret = (*func)(ctx, args_k, count, task_pt_regs(current));
4927
4928 call_made = 1;
4929
4930abort_locked:
4931 if (likely(ctx)) {
4932 DPRINT(("context unlocked\n"));
4933 UNPROTECT_CTX(ctx, flags);
4934 }
4935
4936 /* copy argument back to user, if needed */
4937 if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
4938
4939error_args:
4940 if (file)
4941 fput(file);
4942
4943 kfree(args_k);
4944
4945 DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
4946
4947 return ret;
4948}
4949
4950static void
4951pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
4952{
4953 pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
4954 pfm_ovfl_ctrl_t rst_ctrl;
4955 int state;
4956 int ret = 0;
4957
4958 state = ctx->ctx_state;
4959 /*
4960 * Unlock sampling buffer and reset index atomically
4961 * XXX: not really needed when blocking
4962 */
4963 if (CTX_HAS_SMPL(ctx)) {
4964
4965 rst_ctrl.bits.mask_monitoring = 0;
4966 rst_ctrl.bits.reset_ovfl_pmds = 0;
4967
4968 if (state == PFM_CTX_LOADED)
4969 ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4970 else
4971 ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4972 } else {
4973 rst_ctrl.bits.mask_monitoring = 0;
4974 rst_ctrl.bits.reset_ovfl_pmds = 1;
4975 }
4976
4977 if (ret == 0) {
4978 if (rst_ctrl.bits.reset_ovfl_pmds) {
4979 pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
4980 }
4981 if (rst_ctrl.bits.mask_monitoring == 0) {
4982 DPRINT(("resuming monitoring\n"));
4983 if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
4984 } else {
4985 DPRINT(("stopping monitoring\n"));
4986 //pfm_stop_monitoring(current, regs);
4987 }
4988 ctx->ctx_state = PFM_CTX_LOADED;
4989 }
4990}
4991
4992/*
4993 * context MUST BE LOCKED when calling
4994 * can only be called for current
4995 */
4996static void
4997pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
4998{
4999 int ret;
5000
5001 DPRINT(("entering for [%d]\n", task_pid_nr(current)));
5002
5003 ret = pfm_context_unload(ctx, NULL, 0, regs);
5004 if (ret) {
5005 printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
5006 }
5007
5008 /*
5009 * and wakeup controlling task, indicating we are now disconnected
5010 */
5011 wake_up_interruptible(&ctx->ctx_zombieq);
5012
5013 /*
5014 * given that context is still locked, the controlling
5015 * task will only get access when we return from
5016 * pfm_handle_work().
5017 */
5018}
5019
5020static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
5021
5022 /*
5023 * pfm_handle_work() can be called with interrupts enabled
5024 * (TIF_NEED_RESCHED) or disabled. The down_interruptible
5025 * call may sleep, therefore we must re-enable interrupts
5026 * to avoid deadlocks. It is safe to do so because this function
5027 * is called ONLY when returning to user level (pUStk=1), in which case
5028 * there is no risk of kernel stack overflow due to deep
5029 * interrupt nesting.
5030 */
5031void
5032pfm_handle_work(void)
5033{
5034 pfm_context_t *ctx;
5035 struct pt_regs *regs;
5036 unsigned long flags, dummy_flags;
5037 unsigned long ovfl_regs;
5038 unsigned int reason;
5039 int ret;
5040
5041 ctx = PFM_GET_CTX(current);
5042 if (ctx == NULL) {
5043 printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
5044 task_pid_nr(current));
5045 return;
5046 }
5047
5048 PROTECT_CTX(ctx, flags);
5049
5050 PFM_SET_WORK_PENDING(current, 0);
5051
5052 regs = task_pt_regs(current);
5053
5054 /*
5055 * extract reason for being here and clear
5056 */
5057 reason = ctx->ctx_fl_trap_reason;
5058 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
5059 ovfl_regs = ctx->ctx_ovfl_regs[0];
5060
5061 DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
5062
5063 /*
5064 * must be done before we check for simple-reset mode
5065 */
5066 if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
5067 goto do_zombie;
5068
5069 //if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
5070 if (reason == PFM_TRAP_REASON_RESET)
5071 goto skip_blocking;
5072
5073 /*
5074 * restore interrupt mask to what it was on entry.
5075 * Could be enabled/diasbled.
5076 */
5077 UNPROTECT_CTX(ctx, flags);
5078
5079 /*
5080 * force interrupt enable because of down_interruptible()
5081 */
5082 local_irq_enable();
5083
5084 DPRINT(("before block sleeping\n"));
5085
5086 /*
5087 * may go through without blocking on SMP systems
5088 * if restart has been received already by the time we call down()
5089 */
5090 ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
5091
5092 DPRINT(("after block sleeping ret=%d\n", ret));
5093
5094 /*
5095 * lock context and mask interrupts again
5096 * We save flags into a dummy because we may have
5097 * altered interrupts mask compared to entry in this
5098 * function.
5099 */
5100 PROTECT_CTX(ctx, dummy_flags);
5101
5102 /*
5103 * we need to read the ovfl_regs only after wake-up
5104 * because we may have had pfm_write_pmds() in between
5105 * and that can changed PMD values and therefore
5106 * ovfl_regs is reset for these new PMD values.
5107 */
5108 ovfl_regs = ctx->ctx_ovfl_regs[0];
5109
5110 if (ctx->ctx_fl_going_zombie) {
5111do_zombie:
5112 DPRINT(("context is zombie, bailing out\n"));
5113 pfm_context_force_terminate(ctx, regs);
5114 goto nothing_to_do;
5115 }
5116 /*
5117 * in case of interruption of down() we don't restart anything
5118 */
5119 if (ret < 0)
5120 goto nothing_to_do;
5121
5122skip_blocking:
5123 pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
5124 ctx->ctx_ovfl_regs[0] = 0UL;
5125
5126nothing_to_do:
5127 /*
5128 * restore flags as they were upon entry
5129 */
5130 UNPROTECT_CTX(ctx, flags);
5131}
5132
5133static int
5134pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
5135{
5136 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5137 DPRINT(("ignoring overflow notification, owner is zombie\n"));
5138 return 0;
5139 }
5140
5141 DPRINT(("waking up somebody\n"));
5142
5143 if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
5144
5145 /*
5146 * safe, we are not in intr handler, nor in ctxsw when
5147 * we come here
5148 */
5149 kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
5150
5151 return 0;
5152}
5153
5154static int
5155pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
5156{
5157 pfm_msg_t *msg = NULL;
5158
5159 if (ctx->ctx_fl_no_msg == 0) {
5160 msg = pfm_get_new_msg(ctx);
5161 if (msg == NULL) {
5162 printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
5163 return -1;
5164 }
5165
5166 msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
5167 msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
5168 msg->pfm_ovfl_msg.msg_active_set = 0;
5169 msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
5170 msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
5171 msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
5172 msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
5173 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5174 }
5175
5176 DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
5177 msg,
5178 ctx->ctx_fl_no_msg,
5179 ctx->ctx_fd,
5180 ovfl_pmds));
5181
5182 return pfm_notify_user(ctx, msg);
5183}
5184
5185static int
5186pfm_end_notify_user(pfm_context_t *ctx)
5187{
5188 pfm_msg_t *msg;
5189
5190 msg = pfm_get_new_msg(ctx);
5191 if (msg == NULL) {
5192 printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
5193 return -1;
5194 }
5195 /* no leak */
5196 memset(msg, 0, sizeof(*msg));
5197
5198 msg->pfm_end_msg.msg_type = PFM_MSG_END;
5199 msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
5200 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5201
5202 DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
5203 msg,
5204 ctx->ctx_fl_no_msg,
5205 ctx->ctx_fd));
5206
5207 return pfm_notify_user(ctx, msg);
5208}
5209
5210/*
5211 * main overflow processing routine.
5212 * it can be called from the interrupt path or explicitly during the context switch code
5213 */
5214static void pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx,
5215 unsigned long pmc0, struct pt_regs *regs)
5216{
5217 pfm_ovfl_arg_t *ovfl_arg;
5218 unsigned long mask;
5219 unsigned long old_val, ovfl_val, new_val;
5220 unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
5221 unsigned long tstamp;
5222 pfm_ovfl_ctrl_t ovfl_ctrl;
5223 unsigned int i, has_smpl;
5224 int must_notify = 0;
5225
5226 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
5227
5228 /*
5229 * sanity test. Should never happen
5230 */
5231 if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
5232
5233 tstamp = ia64_get_itc();
5234 mask = pmc0 >> PMU_FIRST_COUNTER;
5235 ovfl_val = pmu_conf->ovfl_val;
5236 has_smpl = CTX_HAS_SMPL(ctx);
5237
5238 DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
5239 "used_pmds=0x%lx\n",
5240 pmc0,
5241 task ? task_pid_nr(task): -1,
5242 (regs ? regs->cr_iip : 0),
5243 CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
5244 ctx->ctx_used_pmds[0]));
5245
5246
5247 /*
5248 * first we update the virtual counters
5249 * assume there was a prior ia64_srlz_d() issued
5250 */
5251 for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
5252
5253 /* skip pmd which did not overflow */
5254 if ((mask & 0x1) == 0) continue;
5255
5256 /*
5257 * Note that the pmd is not necessarily 0 at this point as qualified events
5258 * may have happened before the PMU was frozen. The residual count is not
5259 * taken into consideration here but will be with any read of the pmd via
5260 * pfm_read_pmds().
5261 */
5262 old_val = new_val = ctx->ctx_pmds[i].val;
5263 new_val += 1 + ovfl_val;
5264 ctx->ctx_pmds[i].val = new_val;
5265
5266 /*
5267 * check for overflow condition
5268 */
5269 if (likely(old_val > new_val)) {
5270 ovfl_pmds |= 1UL << i;
5271 if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
5272 }
5273
5274 DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
5275 i,
5276 new_val,
5277 old_val,
5278 ia64_get_pmd(i) & ovfl_val,
5279 ovfl_pmds,
5280 ovfl_notify));
5281 }
5282
5283 /*
5284 * there was no 64-bit overflow, nothing else to do
5285 */
5286 if (ovfl_pmds == 0UL) return;
5287
5288 /*
5289 * reset all control bits
5290 */
5291 ovfl_ctrl.val = 0;
5292 reset_pmds = 0UL;
5293
5294 /*
5295 * if a sampling format module exists, then we "cache" the overflow by
5296 * calling the module's handler() routine.
5297 */
5298 if (has_smpl) {
5299 unsigned long start_cycles, end_cycles;
5300 unsigned long pmd_mask;
5301 int j, k, ret = 0;
5302 int this_cpu = smp_processor_id();
5303
5304 pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
5305 ovfl_arg = &ctx->ctx_ovfl_arg;
5306
5307 prefetch(ctx->ctx_smpl_hdr);
5308
5309 for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
5310
5311 mask = 1UL << i;
5312
5313 if ((pmd_mask & 0x1) == 0) continue;
5314
5315 ovfl_arg->ovfl_pmd = (unsigned char )i;
5316 ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
5317 ovfl_arg->active_set = 0;
5318 ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
5319 ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
5320
5321 ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
5322 ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
5323 ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
5324
5325 /*
5326 * copy values of pmds of interest. Sampling format may copy them
5327 * into sampling buffer.
5328 */
5329 if (smpl_pmds) {
5330 for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
5331 if ((smpl_pmds & 0x1) == 0) continue;
5332 ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
5333 DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
5334 }
5335 }
5336
5337 pfm_stats[this_cpu].pfm_smpl_handler_calls++;
5338
5339 start_cycles = ia64_get_itc();
5340
5341 /*
5342 * call custom buffer format record (handler) routine
5343 */
5344 ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
5345
5346 end_cycles = ia64_get_itc();
5347
5348 /*
5349 * For those controls, we take the union because they have
5350 * an all or nothing behavior.
5351 */
5352 ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
5353 ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
5354 ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
5355 /*
5356 * build the bitmask of pmds to reset now
5357 */
5358 if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
5359
5360 pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
5361 }
5362 /*
5363 * when the module cannot handle the rest of the overflows, we abort right here
5364 */
5365 if (ret && pmd_mask) {
5366 DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
5367 pmd_mask<<PMU_FIRST_COUNTER));
5368 }
5369 /*
5370 * remove the pmds we reset now from the set of pmds to reset in pfm_restart()
5371 */
5372 ovfl_pmds &= ~reset_pmds;
5373 } else {
5374 /*
5375 * when no sampling module is used, then the default
5376 * is to notify on overflow if requested by user
5377 */
5378 ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
5379 ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
5380 ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
5381 ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
5382 /*
5383 * if needed, we reset all overflowed pmds
5384 */
5385 if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
5386 }
5387
5388 DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
5389
5390 /*
5391 * reset the requested PMD registers using the short reset values
5392 */
5393 if (reset_pmds) {
5394 unsigned long bm = reset_pmds;
5395 pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
5396 }
5397
5398 if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
5399 /*
5400 * keep track of what to reset when unblocking
5401 */
5402 ctx->ctx_ovfl_regs[0] = ovfl_pmds;
5403
5404 /*
5405 * check for blocking context
5406 */
5407 if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
5408
5409 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
5410
5411 /*
5412 * set the perfmon specific checking pending work for the task
5413 */
5414 PFM_SET_WORK_PENDING(task, 1);
5415
5416 /*
5417 * when coming from ctxsw, current still points to the
5418 * previous task, therefore we must work with task and not current.
5419 */
5420 set_notify_resume(task);
5421 }
5422 /*
5423 * defer until state is changed (shorten spin window). the context is locked
5424 * anyway, so the signal receiver would come spin for nothing.
5425 */
5426 must_notify = 1;
5427 }
5428
5429 DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
5430 GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
5431 PFM_GET_WORK_PENDING(task),
5432 ctx->ctx_fl_trap_reason,
5433 ovfl_pmds,
5434 ovfl_notify,
5435 ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
5436 /*
5437 * in case monitoring must be stopped, we toggle the psr bits
5438 */
5439 if (ovfl_ctrl.bits.mask_monitoring) {
5440 pfm_mask_monitoring(task);
5441 ctx->ctx_state = PFM_CTX_MASKED;
5442 ctx->ctx_fl_can_restart = 1;
5443 }
5444
5445 /*
5446 * send notification now
5447 */
5448 if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
5449
5450 return;
5451
5452sanity_check:
5453 printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
5454 smp_processor_id(),
5455 task ? task_pid_nr(task) : -1,
5456 pmc0);
5457 return;
5458
5459stop_monitoring:
5460 /*
5461 * in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
5462 * Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
5463 * come here as zombie only if the task is the current task. In which case, we
5464 * can access the PMU hardware directly.
5465 *
5466 * Note that zombies do have PM_VALID set. So here we do the minimal.
5467 *
5468 * In case the context was zombified it could not be reclaimed at the time
5469 * the monitoring program exited. At this point, the PMU reservation has been
5470 * returned, the sampiing buffer has been freed. We must convert this call
5471 * into a spurious interrupt. However, we must also avoid infinite overflows
5472 * by stopping monitoring for this task. We can only come here for a per-task
5473 * context. All we need to do is to stop monitoring using the psr bits which
5474 * are always task private. By re-enabling secure montioring, we ensure that
5475 * the monitored task will not be able to re-activate monitoring.
5476 * The task will eventually be context switched out, at which point the context
5477 * will be reclaimed (that includes releasing ownership of the PMU).
5478 *
5479 * So there might be a window of time where the number of per-task session is zero
5480 * yet one PMU might have a owner and get at most one overflow interrupt for a zombie
5481 * context. This is safe because if a per-task session comes in, it will push this one
5482 * out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
5483 * session is force on that CPU, given that we use task pinning, pfm_save_regs() will
5484 * also push our zombie context out.
5485 *
5486 * Overall pretty hairy stuff....
5487 */
5488 DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
5489 pfm_clear_psr_up();
5490 ia64_psr(regs)->up = 0;
5491 ia64_psr(regs)->sp = 1;
5492 return;
5493}
5494
5495static int
5496pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
5497{
5498 struct task_struct *task;
5499 pfm_context_t *ctx;
5500 unsigned long flags;
5501 u64 pmc0;
5502 int this_cpu = smp_processor_id();
5503 int retval = 0;
5504
5505 pfm_stats[this_cpu].pfm_ovfl_intr_count++;
5506
5507 /*
5508 * srlz.d done before arriving here
5509 */
5510 pmc0 = ia64_get_pmc(0);
5511
5512 task = GET_PMU_OWNER();
5513 ctx = GET_PMU_CTX();
5514
5515 /*
5516 * if we have some pending bits set
5517 * assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
5518 */
5519 if (PMC0_HAS_OVFL(pmc0) && task) {
5520 /*
5521 * we assume that pmc0.fr is always set here
5522 */
5523
5524 /* sanity check */
5525 if (!ctx) goto report_spurious1;
5526
5527 if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
5528 goto report_spurious2;
5529
5530 PROTECT_CTX_NOPRINT(ctx, flags);
5531
5532 pfm_overflow_handler(task, ctx, pmc0, regs);
5533
5534 UNPROTECT_CTX_NOPRINT(ctx, flags);
5535
5536 } else {
5537 pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
5538 retval = -1;
5539 }
5540 /*
5541 * keep it unfrozen at all times
5542 */
5543 pfm_unfreeze_pmu();
5544
5545 return retval;
5546
5547report_spurious1:
5548 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
5549 this_cpu, task_pid_nr(task));
5550 pfm_unfreeze_pmu();
5551 return -1;
5552report_spurious2:
5553 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
5554 this_cpu,
5555 task_pid_nr(task));
5556 pfm_unfreeze_pmu();
5557 return -1;
5558}
5559
5560static irqreturn_t
5561pfm_interrupt_handler(int irq, void *arg)
5562{
5563 unsigned long start_cycles, total_cycles;
5564 unsigned long min, max;
5565 int this_cpu;
5566 int ret;
5567 struct pt_regs *regs = get_irq_regs();
5568
5569 this_cpu = get_cpu();
5570 if (likely(!pfm_alt_intr_handler)) {
5571 min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
5572 max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
5573
5574 start_cycles = ia64_get_itc();
5575
5576 ret = pfm_do_interrupt_handler(arg, regs);
5577
5578 total_cycles = ia64_get_itc();
5579
5580 /*
5581 * don't measure spurious interrupts
5582 */
5583 if (likely(ret == 0)) {
5584 total_cycles -= start_cycles;
5585
5586 if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
5587 if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
5588
5589 pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
5590 }
5591 }
5592 else {
5593 (*pfm_alt_intr_handler->handler)(irq, arg, regs);
5594 }
5595
5596 put_cpu();
5597 return IRQ_HANDLED;
5598}
5599
5600/*
5601 * /proc/perfmon interface, for debug only
5602 */
5603
5604#define PFM_PROC_SHOW_HEADER ((void *)(long)nr_cpu_ids+1)
5605
5606static void *
5607pfm_proc_start(struct seq_file *m, loff_t *pos)
5608{
5609 if (*pos == 0) {
5610 return PFM_PROC_SHOW_HEADER;
5611 }
5612
5613 while (*pos <= nr_cpu_ids) {
5614 if (cpu_online(*pos - 1)) {
5615 return (void *)*pos;
5616 }
5617 ++*pos;
5618 }
5619 return NULL;
5620}
5621
5622static void *
5623pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
5624{
5625 ++*pos;
5626 return pfm_proc_start(m, pos);
5627}
5628
5629static void
5630pfm_proc_stop(struct seq_file *m, void *v)
5631{
5632}
5633
5634static void
5635pfm_proc_show_header(struct seq_file *m)
5636{
5637 struct list_head * pos;
5638 pfm_buffer_fmt_t * entry;
5639 unsigned long flags;
5640
5641 seq_printf(m,
5642 "perfmon version : %u.%u\n"
5643 "model : %s\n"
5644 "fastctxsw : %s\n"
5645 "expert mode : %s\n"
5646 "ovfl_mask : 0x%lx\n"
5647 "PMU flags : 0x%x\n",
5648 PFM_VERSION_MAJ, PFM_VERSION_MIN,
5649 pmu_conf->pmu_name,
5650 pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
5651 pfm_sysctl.expert_mode > 0 ? "Yes": "No",
5652 pmu_conf->ovfl_val,
5653 pmu_conf->flags);
5654
5655 LOCK_PFS(flags);
5656
5657 seq_printf(m,
5658 "proc_sessions : %u\n"
5659 "sys_sessions : %u\n"
5660 "sys_use_dbregs : %u\n"
5661 "ptrace_use_dbregs : %u\n",
5662 pfm_sessions.pfs_task_sessions,
5663 pfm_sessions.pfs_sys_sessions,
5664 pfm_sessions.pfs_sys_use_dbregs,
5665 pfm_sessions.pfs_ptrace_use_dbregs);
5666
5667 UNLOCK_PFS(flags);
5668
5669 spin_lock(&pfm_buffer_fmt_lock);
5670
5671 list_for_each(pos, &pfm_buffer_fmt_list) {
5672 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
5673 seq_printf(m, "format : %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x %s\n",
5674 entry->fmt_uuid[0],
5675 entry->fmt_uuid[1],
5676 entry->fmt_uuid[2],
5677 entry->fmt_uuid[3],
5678 entry->fmt_uuid[4],
5679 entry->fmt_uuid[5],
5680 entry->fmt_uuid[6],
5681 entry->fmt_uuid[7],
5682 entry->fmt_uuid[8],
5683 entry->fmt_uuid[9],
5684 entry->fmt_uuid[10],
5685 entry->fmt_uuid[11],
5686 entry->fmt_uuid[12],
5687 entry->fmt_uuid[13],
5688 entry->fmt_uuid[14],
5689 entry->fmt_uuid[15],
5690 entry->fmt_name);
5691 }
5692 spin_unlock(&pfm_buffer_fmt_lock);
5693
5694}
5695
5696static int
5697pfm_proc_show(struct seq_file *m, void *v)
5698{
5699 unsigned long psr;
5700 unsigned int i;
5701 int cpu;
5702
5703 if (v == PFM_PROC_SHOW_HEADER) {
5704 pfm_proc_show_header(m);
5705 return 0;
5706 }
5707
5708 /* show info for CPU (v - 1) */
5709
5710 cpu = (long)v - 1;
5711 seq_printf(m,
5712 "CPU%-2d overflow intrs : %lu\n"
5713 "CPU%-2d overflow cycles : %lu\n"
5714 "CPU%-2d overflow min : %lu\n"
5715 "CPU%-2d overflow max : %lu\n"
5716 "CPU%-2d smpl handler calls : %lu\n"
5717 "CPU%-2d smpl handler cycles : %lu\n"
5718 "CPU%-2d spurious intrs : %lu\n"
5719 "CPU%-2d replay intrs : %lu\n"
5720 "CPU%-2d syst_wide : %d\n"
5721 "CPU%-2d dcr_pp : %d\n"
5722 "CPU%-2d exclude idle : %d\n"
5723 "CPU%-2d owner : %d\n"
5724 "CPU%-2d context : %p\n"
5725 "CPU%-2d activations : %lu\n",
5726 cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
5727 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
5728 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
5729 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
5730 cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
5731 cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
5732 cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
5733 cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
5734 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
5735 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
5736 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
5737 cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
5738 cpu, pfm_get_cpu_data(pmu_ctx, cpu),
5739 cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
5740
5741 if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
5742
5743 psr = pfm_get_psr();
5744
5745 ia64_srlz_d();
5746
5747 seq_printf(m,
5748 "CPU%-2d psr : 0x%lx\n"
5749 "CPU%-2d pmc0 : 0x%lx\n",
5750 cpu, psr,
5751 cpu, ia64_get_pmc(0));
5752
5753 for (i=0; PMC_IS_LAST(i) == 0; i++) {
5754 if (PMC_IS_COUNTING(i) == 0) continue;
5755 seq_printf(m,
5756 "CPU%-2d pmc%u : 0x%lx\n"
5757 "CPU%-2d pmd%u : 0x%lx\n",
5758 cpu, i, ia64_get_pmc(i),
5759 cpu, i, ia64_get_pmd(i));
5760 }
5761 }
5762 return 0;
5763}
5764
5765const struct seq_operations pfm_seq_ops = {
5766 .start = pfm_proc_start,
5767 .next = pfm_proc_next,
5768 .stop = pfm_proc_stop,
5769 .show = pfm_proc_show
5770};
5771
5772static int
5773pfm_proc_open(struct inode *inode, struct file *file)
5774{
5775 return seq_open(file, &pfm_seq_ops);
5776}
5777
5778
5779/*
5780 * we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
5781 * during pfm_enable() hence before pfm_start(). We cannot assume monitoring
5782 * is active or inactive based on mode. We must rely on the value in
5783 * local_cpu_data->pfm_syst_info
5784 */
5785void
5786pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
5787{
5788 struct pt_regs *regs;
5789 unsigned long dcr;
5790 unsigned long dcr_pp;
5791
5792 dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
5793
5794 /*
5795 * pid 0 is guaranteed to be the idle task. There is one such task with pid 0
5796 * on every CPU, so we can rely on the pid to identify the idle task.
5797 */
5798 if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
5799 regs = task_pt_regs(task);
5800 ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
5801 return;
5802 }
5803 /*
5804 * if monitoring has started
5805 */
5806 if (dcr_pp) {
5807 dcr = ia64_getreg(_IA64_REG_CR_DCR);
5808 /*
5809 * context switching in?
5810 */
5811 if (is_ctxswin) {
5812 /* mask monitoring for the idle task */
5813 ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
5814 pfm_clear_psr_pp();
5815 ia64_srlz_i();
5816 return;
5817 }
5818 /*
5819 * context switching out
5820 * restore monitoring for next task
5821 *
5822 * Due to inlining this odd if-then-else construction generates
5823 * better code.
5824 */
5825 ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
5826 pfm_set_psr_pp();
5827 ia64_srlz_i();
5828 }
5829}
5830
5831#ifdef CONFIG_SMP
5832
5833static void
5834pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
5835{
5836 struct task_struct *task = ctx->ctx_task;
5837
5838 ia64_psr(regs)->up = 0;
5839 ia64_psr(regs)->sp = 1;
5840
5841 if (GET_PMU_OWNER() == task) {
5842 DPRINT(("cleared ownership for [%d]\n",
5843 task_pid_nr(ctx->ctx_task)));
5844 SET_PMU_OWNER(NULL, NULL);
5845 }
5846
5847 /*
5848 * disconnect the task from the context and vice-versa
5849 */
5850 PFM_SET_WORK_PENDING(task, 0);
5851
5852 task->thread.pfm_context = NULL;
5853 task->thread.flags &= ~IA64_THREAD_PM_VALID;
5854
5855 DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
5856}
5857
5858
5859/*
5860 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
5861 */
5862void
5863pfm_save_regs(struct task_struct *task)
5864{
5865 pfm_context_t *ctx;
5866 unsigned long flags;
5867 u64 psr;
5868
5869
5870 ctx = PFM_GET_CTX(task);
5871 if (ctx == NULL) return;
5872
5873 /*
5874 * we always come here with interrupts ALREADY disabled by
5875 * the scheduler. So we simply need to protect against concurrent
5876 * access, not CPU concurrency.
5877 */
5878 flags = pfm_protect_ctx_ctxsw(ctx);
5879
5880 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5881 struct pt_regs *regs = task_pt_regs(task);
5882
5883 pfm_clear_psr_up();
5884
5885 pfm_force_cleanup(ctx, regs);
5886
5887 BUG_ON(ctx->ctx_smpl_hdr);
5888
5889 pfm_unprotect_ctx_ctxsw(ctx, flags);
5890
5891 pfm_context_free(ctx);
5892 return;
5893 }
5894
5895 /*
5896 * save current PSR: needed because we modify it
5897 */
5898 ia64_srlz_d();
5899 psr = pfm_get_psr();
5900
5901 BUG_ON(psr & (IA64_PSR_I));
5902
5903 /*
5904 * stop monitoring:
5905 * This is the last instruction which may generate an overflow
5906 *
5907 * We do not need to set psr.sp because, it is irrelevant in kernel.
5908 * It will be restored from ipsr when going back to user level
5909 */
5910 pfm_clear_psr_up();
5911
5912 /*
5913 * keep a copy of psr.up (for reload)
5914 */
5915 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5916
5917 /*
5918 * release ownership of this PMU.
5919 * PM interrupts are masked, so nothing
5920 * can happen.
5921 */
5922 SET_PMU_OWNER(NULL, NULL);
5923
5924 /*
5925 * we systematically save the PMD as we have no
5926 * guarantee we will be schedule at that same
5927 * CPU again.
5928 */
5929 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
5930
5931 /*
5932 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
5933 * we will need it on the restore path to check
5934 * for pending overflow.
5935 */
5936 ctx->th_pmcs[0] = ia64_get_pmc(0);
5937
5938 /*
5939 * unfreeze PMU if had pending overflows
5940 */
5941 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
5942
5943 /*
5944 * finally, allow context access.
5945 * interrupts will still be masked after this call.
5946 */
5947 pfm_unprotect_ctx_ctxsw(ctx, flags);
5948}
5949
5950#else /* !CONFIG_SMP */
5951void
5952pfm_save_regs(struct task_struct *task)
5953{
5954 pfm_context_t *ctx;
5955 u64 psr;
5956
5957 ctx = PFM_GET_CTX(task);
5958 if (ctx == NULL) return;
5959
5960 /*
5961 * save current PSR: needed because we modify it
5962 */
5963 psr = pfm_get_psr();
5964
5965 BUG_ON(psr & (IA64_PSR_I));
5966
5967 /*
5968 * stop monitoring:
5969 * This is the last instruction which may generate an overflow
5970 *
5971 * We do not need to set psr.sp because, it is irrelevant in kernel.
5972 * It will be restored from ipsr when going back to user level
5973 */
5974 pfm_clear_psr_up();
5975
5976 /*
5977 * keep a copy of psr.up (for reload)
5978 */
5979 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5980}
5981
5982static void
5983pfm_lazy_save_regs (struct task_struct *task)
5984{
5985 pfm_context_t *ctx;
5986 unsigned long flags;
5987
5988 { u64 psr = pfm_get_psr();
5989 BUG_ON(psr & IA64_PSR_UP);
5990 }
5991
5992 ctx = PFM_GET_CTX(task);
5993
5994 /*
5995 * we need to mask PMU overflow here to
5996 * make sure that we maintain pmc0 until
5997 * we save it. overflow interrupts are
5998 * treated as spurious if there is no
5999 * owner.
6000 *
6001 * XXX: I don't think this is necessary
6002 */
6003 PROTECT_CTX(ctx,flags);
6004
6005 /*
6006 * release ownership of this PMU.
6007 * must be done before we save the registers.
6008 *
6009 * after this call any PMU interrupt is treated
6010 * as spurious.
6011 */
6012 SET_PMU_OWNER(NULL, NULL);
6013
6014 /*
6015 * save all the pmds we use
6016 */
6017 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
6018
6019 /*
6020 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
6021 * it is needed to check for pended overflow
6022 * on the restore path
6023 */
6024 ctx->th_pmcs[0] = ia64_get_pmc(0);
6025
6026 /*
6027 * unfreeze PMU if had pending overflows
6028 */
6029 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
6030
6031 /*
6032 * now get can unmask PMU interrupts, they will
6033 * be treated as purely spurious and we will not
6034 * lose any information
6035 */
6036 UNPROTECT_CTX(ctx,flags);
6037}
6038#endif /* CONFIG_SMP */
6039
6040#ifdef CONFIG_SMP
6041/*
6042 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
6043 */
6044void
6045pfm_load_regs (struct task_struct *task)
6046{
6047 pfm_context_t *ctx;
6048 unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
6049 unsigned long flags;
6050 u64 psr, psr_up;
6051 int need_irq_resend;
6052
6053 ctx = PFM_GET_CTX(task);
6054 if (unlikely(ctx == NULL)) return;
6055
6056 BUG_ON(GET_PMU_OWNER());
6057
6058 /*
6059 * possible on unload
6060 */
6061 if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
6062
6063 /*
6064 * we always come here with interrupts ALREADY disabled by
6065 * the scheduler. So we simply need to protect against concurrent
6066 * access, not CPU concurrency.
6067 */
6068 flags = pfm_protect_ctx_ctxsw(ctx);
6069 psr = pfm_get_psr();
6070
6071 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6072
6073 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6074 BUG_ON(psr & IA64_PSR_I);
6075
6076 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
6077 struct pt_regs *regs = task_pt_regs(task);
6078
6079 BUG_ON(ctx->ctx_smpl_hdr);
6080
6081 pfm_force_cleanup(ctx, regs);
6082
6083 pfm_unprotect_ctx_ctxsw(ctx, flags);
6084
6085 /*
6086 * this one (kmalloc'ed) is fine with interrupts disabled
6087 */
6088 pfm_context_free(ctx);
6089
6090 return;
6091 }
6092
6093 /*
6094 * we restore ALL the debug registers to avoid picking up
6095 * stale state.
6096 */
6097 if (ctx->ctx_fl_using_dbreg) {
6098 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6099 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6100 }
6101 /*
6102 * retrieve saved psr.up
6103 */
6104 psr_up = ctx->ctx_saved_psr_up;
6105
6106 /*
6107 * if we were the last user of the PMU on that CPU,
6108 * then nothing to do except restore psr
6109 */
6110 if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
6111
6112 /*
6113 * retrieve partial reload masks (due to user modifications)
6114 */
6115 pmc_mask = ctx->ctx_reload_pmcs[0];
6116 pmd_mask = ctx->ctx_reload_pmds[0];
6117
6118 } else {
6119 /*
6120 * To avoid leaking information to the user level when psr.sp=0,
6121 * we must reload ALL implemented pmds (even the ones we don't use).
6122 * In the kernel we only allow PFM_READ_PMDS on registers which
6123 * we initialized or requested (sampling) so there is no risk there.
6124 */
6125 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6126
6127 /*
6128 * ALL accessible PMCs are systematically reloaded, unused registers
6129 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6130 * up stale configuration.
6131 *
6132 * PMC0 is never in the mask. It is always restored separately.
6133 */
6134 pmc_mask = ctx->ctx_all_pmcs[0];
6135 }
6136 /*
6137 * when context is MASKED, we will restore PMC with plm=0
6138 * and PMD with stale information, but that's ok, nothing
6139 * will be captured.
6140 *
6141 * XXX: optimize here
6142 */
6143 if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6144 if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6145
6146 /*
6147 * check for pending overflow at the time the state
6148 * was saved.
6149 */
6150 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6151 /*
6152 * reload pmc0 with the overflow information
6153 * On McKinley PMU, this will trigger a PMU interrupt
6154 */
6155 ia64_set_pmc(0, ctx->th_pmcs[0]);
6156 ia64_srlz_d();
6157 ctx->th_pmcs[0] = 0UL;
6158
6159 /*
6160 * will replay the PMU interrupt
6161 */
6162 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6163
6164 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6165 }
6166
6167 /*
6168 * we just did a reload, so we reset the partial reload fields
6169 */
6170 ctx->ctx_reload_pmcs[0] = 0UL;
6171 ctx->ctx_reload_pmds[0] = 0UL;
6172
6173 SET_LAST_CPU(ctx, smp_processor_id());
6174
6175 /*
6176 * dump activation value for this PMU
6177 */
6178 INC_ACTIVATION();
6179 /*
6180 * record current activation for this context
6181 */
6182 SET_ACTIVATION(ctx);
6183
6184 /*
6185 * establish new ownership.
6186 */
6187 SET_PMU_OWNER(task, ctx);
6188
6189 /*
6190 * restore the psr.up bit. measurement
6191 * is active again.
6192 * no PMU interrupt can happen at this point
6193 * because we still have interrupts disabled.
6194 */
6195 if (likely(psr_up)) pfm_set_psr_up();
6196
6197 /*
6198 * allow concurrent access to context
6199 */
6200 pfm_unprotect_ctx_ctxsw(ctx, flags);
6201}
6202#else /* !CONFIG_SMP */
6203/*
6204 * reload PMU state for UP kernels
6205 * in 2.5 we come here with interrupts disabled
6206 */
6207void
6208pfm_load_regs (struct task_struct *task)
6209{
6210 pfm_context_t *ctx;
6211 struct task_struct *owner;
6212 unsigned long pmd_mask, pmc_mask;
6213 u64 psr, psr_up;
6214 int need_irq_resend;
6215
6216 owner = GET_PMU_OWNER();
6217 ctx = PFM_GET_CTX(task);
6218 psr = pfm_get_psr();
6219
6220 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6221 BUG_ON(psr & IA64_PSR_I);
6222
6223 /*
6224 * we restore ALL the debug registers to avoid picking up
6225 * stale state.
6226 *
6227 * This must be done even when the task is still the owner
6228 * as the registers may have been modified via ptrace()
6229 * (not perfmon) by the previous task.
6230 */
6231 if (ctx->ctx_fl_using_dbreg) {
6232 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6233 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6234 }
6235
6236 /*
6237 * retrieved saved psr.up
6238 */
6239 psr_up = ctx->ctx_saved_psr_up;
6240 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6241
6242 /*
6243 * short path, our state is still there, just
6244 * need to restore psr and we go
6245 *
6246 * we do not touch either PMC nor PMD. the psr is not touched
6247 * by the overflow_handler. So we are safe w.r.t. to interrupt
6248 * concurrency even without interrupt masking.
6249 */
6250 if (likely(owner == task)) {
6251 if (likely(psr_up)) pfm_set_psr_up();
6252 return;
6253 }
6254
6255 /*
6256 * someone else is still using the PMU, first push it out and
6257 * then we'll be able to install our stuff !
6258 *
6259 * Upon return, there will be no owner for the current PMU
6260 */
6261 if (owner) pfm_lazy_save_regs(owner);
6262
6263 /*
6264 * To avoid leaking information to the user level when psr.sp=0,
6265 * we must reload ALL implemented pmds (even the ones we don't use).
6266 * In the kernel we only allow PFM_READ_PMDS on registers which
6267 * we initialized or requested (sampling) so there is no risk there.
6268 */
6269 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6270
6271 /*
6272 * ALL accessible PMCs are systematically reloaded, unused registers
6273 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6274 * up stale configuration.
6275 *
6276 * PMC0 is never in the mask. It is always restored separately
6277 */
6278 pmc_mask = ctx->ctx_all_pmcs[0];
6279
6280 pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6281 pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6282
6283 /*
6284 * check for pending overflow at the time the state
6285 * was saved.
6286 */
6287 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6288 /*
6289 * reload pmc0 with the overflow information
6290 * On McKinley PMU, this will trigger a PMU interrupt
6291 */
6292 ia64_set_pmc(0, ctx->th_pmcs[0]);
6293 ia64_srlz_d();
6294
6295 ctx->th_pmcs[0] = 0UL;
6296
6297 /*
6298 * will replay the PMU interrupt
6299 */
6300 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6301
6302 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6303 }
6304
6305 /*
6306 * establish new ownership.
6307 */
6308 SET_PMU_OWNER(task, ctx);
6309
6310 /*
6311 * restore the psr.up bit. measurement
6312 * is active again.
6313 * no PMU interrupt can happen at this point
6314 * because we still have interrupts disabled.
6315 */
6316 if (likely(psr_up)) pfm_set_psr_up();
6317}
6318#endif /* CONFIG_SMP */
6319
6320/*
6321 * this function assumes monitoring is stopped
6322 */
6323static void
6324pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
6325{
6326 u64 pmc0;
6327 unsigned long mask2, val, pmd_val, ovfl_val;
6328 int i, can_access_pmu = 0;
6329 int is_self;
6330
6331 /*
6332 * is the caller the task being monitored (or which initiated the
6333 * session for system wide measurements)
6334 */
6335 is_self = ctx->ctx_task == task ? 1 : 0;
6336
6337 /*
6338 * can access PMU is task is the owner of the PMU state on the current CPU
6339 * or if we are running on the CPU bound to the context in system-wide mode
6340 * (that is not necessarily the task the context is attached to in this mode).
6341 * In system-wide we always have can_access_pmu true because a task running on an
6342 * invalid processor is flagged earlier in the call stack (see pfm_stop).
6343 */
6344 can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
6345 if (can_access_pmu) {
6346 /*
6347 * Mark the PMU as not owned
6348 * This will cause the interrupt handler to do nothing in case an overflow
6349 * interrupt was in-flight
6350 * This also guarantees that pmc0 will contain the final state
6351 * It virtually gives us full control on overflow processing from that point
6352 * on.
6353 */
6354 SET_PMU_OWNER(NULL, NULL);
6355 DPRINT(("releasing ownership\n"));
6356
6357 /*
6358 * read current overflow status:
6359 *
6360 * we are guaranteed to read the final stable state
6361 */
6362 ia64_srlz_d();
6363 pmc0 = ia64_get_pmc(0); /* slow */
6364
6365 /*
6366 * reset freeze bit, overflow status information destroyed
6367 */
6368 pfm_unfreeze_pmu();
6369 } else {
6370 pmc0 = ctx->th_pmcs[0];
6371 /*
6372 * clear whatever overflow status bits there were
6373 */
6374 ctx->th_pmcs[0] = 0;
6375 }
6376 ovfl_val = pmu_conf->ovfl_val;
6377 /*
6378 * we save all the used pmds
6379 * we take care of overflows for counting PMDs
6380 *
6381 * XXX: sampling situation is not taken into account here
6382 */
6383 mask2 = ctx->ctx_used_pmds[0];
6384
6385 DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
6386
6387 for (i = 0; mask2; i++, mask2>>=1) {
6388
6389 /* skip non used pmds */
6390 if ((mask2 & 0x1) == 0) continue;
6391
6392 /*
6393 * can access PMU always true in system wide mode
6394 */
6395 val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
6396
6397 if (PMD_IS_COUNTING(i)) {
6398 DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
6399 task_pid_nr(task),
6400 i,
6401 ctx->ctx_pmds[i].val,
6402 val & ovfl_val));
6403
6404 /*
6405 * we rebuild the full 64 bit value of the counter
6406 */
6407 val = ctx->ctx_pmds[i].val + (val & ovfl_val);
6408
6409 /*
6410 * now everything is in ctx_pmds[] and we need
6411 * to clear the saved context from save_regs() such that
6412 * pfm_read_pmds() gets the correct value
6413 */
6414 pmd_val = 0UL;
6415
6416 /*
6417 * take care of overflow inline
6418 */
6419 if (pmc0 & (1UL << i)) {
6420 val += 1 + ovfl_val;
6421 DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
6422 }
6423 }
6424
6425 DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
6426
6427 if (is_self) ctx->th_pmds[i] = pmd_val;
6428
6429 ctx->ctx_pmds[i].val = val;
6430 }
6431}
6432
6433static struct irqaction perfmon_irqaction = {
6434 .handler = pfm_interrupt_handler,
6435 .flags = IRQF_DISABLED,
6436 .name = "perfmon"
6437};
6438
6439static void
6440pfm_alt_save_pmu_state(void *data)
6441{
6442 struct pt_regs *regs;
6443
6444 regs = task_pt_regs(current);
6445
6446 DPRINT(("called\n"));
6447
6448 /*
6449 * should not be necessary but
6450 * let's take not risk
6451 */
6452 pfm_clear_psr_up();
6453 pfm_clear_psr_pp();
6454 ia64_psr(regs)->pp = 0;
6455
6456 /*
6457 * This call is required
6458 * May cause a spurious interrupt on some processors
6459 */
6460 pfm_freeze_pmu();
6461
6462 ia64_srlz_d();
6463}
6464
6465void
6466pfm_alt_restore_pmu_state(void *data)
6467{
6468 struct pt_regs *regs;
6469
6470 regs = task_pt_regs(current);
6471
6472 DPRINT(("called\n"));
6473
6474 /*
6475 * put PMU back in state expected
6476 * by perfmon
6477 */
6478 pfm_clear_psr_up();
6479 pfm_clear_psr_pp();
6480 ia64_psr(regs)->pp = 0;
6481
6482 /*
6483 * perfmon runs with PMU unfrozen at all times
6484 */
6485 pfm_unfreeze_pmu();
6486
6487 ia64_srlz_d();
6488}
6489
6490int
6491pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6492{
6493 int ret, i;
6494 int reserve_cpu;
6495
6496 /* some sanity checks */
6497 if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
6498
6499 /* do the easy test first */
6500 if (pfm_alt_intr_handler) return -EBUSY;
6501
6502 /* one at a time in the install or remove, just fail the others */
6503 if (!spin_trylock(&pfm_alt_install_check)) {
6504 return -EBUSY;
6505 }
6506
6507 /* reserve our session */
6508 for_each_online_cpu(reserve_cpu) {
6509 ret = pfm_reserve_session(NULL, 1, reserve_cpu);
6510 if (ret) goto cleanup_reserve;
6511 }
6512
6513 /* save the current system wide pmu states */
6514 ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
6515 if (ret) {
6516 DPRINT(("on_each_cpu() failed: %d\n", ret));
6517 goto cleanup_reserve;
6518 }
6519
6520 /* officially change to the alternate interrupt handler */
6521 pfm_alt_intr_handler = hdl;
6522
6523 spin_unlock(&pfm_alt_install_check);
6524
6525 return 0;
6526
6527cleanup_reserve:
6528 for_each_online_cpu(i) {
6529 /* don't unreserve more than we reserved */
6530 if (i >= reserve_cpu) break;
6531
6532 pfm_unreserve_session(NULL, 1, i);
6533 }
6534
6535 spin_unlock(&pfm_alt_install_check);
6536
6537 return ret;
6538}
6539EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
6540
6541int
6542pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6543{
6544 int i;
6545 int ret;
6546
6547 if (hdl == NULL) return -EINVAL;
6548
6549 /* cannot remove someone else's handler! */
6550 if (pfm_alt_intr_handler != hdl) return -EINVAL;
6551
6552 /* one at a time in the install or remove, just fail the others */
6553 if (!spin_trylock(&pfm_alt_install_check)) {
6554 return -EBUSY;
6555 }
6556
6557 pfm_alt_intr_handler = NULL;
6558
6559 ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
6560 if (ret) {
6561 DPRINT(("on_each_cpu() failed: %d\n", ret));
6562 }
6563
6564 for_each_online_cpu(i) {
6565 pfm_unreserve_session(NULL, 1, i);
6566 }
6567
6568 spin_unlock(&pfm_alt_install_check);
6569
6570 return 0;
6571}
6572EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
6573
6574/*
6575 * perfmon initialization routine, called from the initcall() table
6576 */
6577static int init_pfm_fs(void);
6578
6579static int __init
6580pfm_probe_pmu(void)
6581{
6582 pmu_config_t **p;
6583 int family;
6584
6585 family = local_cpu_data->family;
6586 p = pmu_confs;
6587
6588 while(*p) {
6589 if ((*p)->probe) {
6590 if ((*p)->probe() == 0) goto found;
6591 } else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
6592 goto found;
6593 }
6594 p++;
6595 }
6596 return -1;
6597found:
6598 pmu_conf = *p;
6599 return 0;
6600}
6601
6602static const struct file_operations pfm_proc_fops = {
6603 .open = pfm_proc_open,
6604 .read = seq_read,
6605 .llseek = seq_lseek,
6606 .release = seq_release,
6607};
6608
6609int __init
6610pfm_init(void)
6611{
6612 unsigned int n, n_counters, i;
6613
6614 printk("perfmon: version %u.%u IRQ %u\n",
6615 PFM_VERSION_MAJ,
6616 PFM_VERSION_MIN,
6617 IA64_PERFMON_VECTOR);
6618
6619 if (pfm_probe_pmu()) {
6620 printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
6621 local_cpu_data->family);
6622 return -ENODEV;
6623 }
6624
6625 /*
6626 * compute the number of implemented PMD/PMC from the
6627 * description tables
6628 */
6629 n = 0;
6630 for (i=0; PMC_IS_LAST(i) == 0; i++) {
6631 if (PMC_IS_IMPL(i) == 0) continue;
6632 pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
6633 n++;
6634 }
6635 pmu_conf->num_pmcs = n;
6636
6637 n = 0; n_counters = 0;
6638 for (i=0; PMD_IS_LAST(i) == 0; i++) {
6639 if (PMD_IS_IMPL(i) == 0) continue;
6640 pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
6641 n++;
6642 if (PMD_IS_COUNTING(i)) n_counters++;
6643 }
6644 pmu_conf->num_pmds = n;
6645 pmu_conf->num_counters = n_counters;
6646
6647 /*
6648 * sanity checks on the number of debug registers
6649 */
6650 if (pmu_conf->use_rr_dbregs) {
6651 if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
6652 printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
6653 pmu_conf = NULL;
6654 return -1;
6655 }
6656 if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
6657 printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
6658 pmu_conf = NULL;
6659 return -1;
6660 }
6661 }
6662
6663 printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
6664 pmu_conf->pmu_name,
6665 pmu_conf->num_pmcs,
6666 pmu_conf->num_pmds,
6667 pmu_conf->num_counters,
6668 ffz(pmu_conf->ovfl_val));
6669
6670 /* sanity check */
6671 if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
6672 printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
6673 pmu_conf = NULL;
6674 return -1;
6675 }
6676
6677 /*
6678 * create /proc/perfmon (mostly for debugging purposes)
6679 */
6680 perfmon_dir = proc_create("perfmon", S_IRUGO, NULL, &pfm_proc_fops);
6681 if (perfmon_dir == NULL) {
6682 printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
6683 pmu_conf = NULL;
6684 return -1;
6685 }
6686
6687 /*
6688 * create /proc/sys/kernel/perfmon (for debugging purposes)
6689 */
6690 pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
6691
6692 /*
6693 * initialize all our spinlocks
6694 */
6695 spin_lock_init(&pfm_sessions.pfs_lock);
6696 spin_lock_init(&pfm_buffer_fmt_lock);
6697
6698 init_pfm_fs();
6699
6700 for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
6701
6702 return 0;
6703}
6704
6705__initcall(pfm_init);
6706
6707/*
6708 * this function is called before pfm_init()
6709 */
6710void
6711pfm_init_percpu (void)
6712{
6713 static int first_time=1;
6714 /*
6715 * make sure no measurement is active
6716 * (may inherit programmed PMCs from EFI).
6717 */
6718 pfm_clear_psr_pp();
6719 pfm_clear_psr_up();
6720
6721 /*
6722 * we run with the PMU not frozen at all times
6723 */
6724 pfm_unfreeze_pmu();
6725
6726 if (first_time) {
6727 register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
6728 first_time=0;
6729 }
6730
6731 ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
6732 ia64_srlz_d();
6733}
6734
6735/*
6736 * used for debug purposes only
6737 */
6738void
6739dump_pmu_state(const char *from)
6740{
6741 struct task_struct *task;
6742 struct pt_regs *regs;
6743 pfm_context_t *ctx;
6744 unsigned long psr, dcr, info, flags;
6745 int i, this_cpu;
6746
6747 local_irq_save(flags);
6748
6749 this_cpu = smp_processor_id();
6750 regs = task_pt_regs(current);
6751 info = PFM_CPUINFO_GET();
6752 dcr = ia64_getreg(_IA64_REG_CR_DCR);
6753
6754 if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
6755 local_irq_restore(flags);
6756 return;
6757 }
6758
6759 printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
6760 this_cpu,
6761 from,
6762 task_pid_nr(current),
6763 regs->cr_iip,
6764 current->comm);
6765
6766 task = GET_PMU_OWNER();
6767 ctx = GET_PMU_CTX();
6768
6769 printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
6770
6771 psr = pfm_get_psr();
6772
6773 printk("->CPU%d pmc0=0x%lx psr.pp=%d psr.up=%d dcr.pp=%d syst_info=0x%lx user_psr.up=%d user_psr.pp=%d\n",
6774 this_cpu,
6775 ia64_get_pmc(0),
6776 psr & IA64_PSR_PP ? 1 : 0,
6777 psr & IA64_PSR_UP ? 1 : 0,
6778 dcr & IA64_DCR_PP ? 1 : 0,
6779 info,
6780 ia64_psr(regs)->up,
6781 ia64_psr(regs)->pp);
6782
6783 ia64_psr(regs)->up = 0;
6784 ia64_psr(regs)->pp = 0;
6785
6786 for (i=1; PMC_IS_LAST(i) == 0; i++) {
6787 if (PMC_IS_IMPL(i) == 0) continue;
6788 printk("->CPU%d pmc[%d]=0x%lx thread_pmc[%d]=0x%lx\n", this_cpu, i, ia64_get_pmc(i), i, ctx->th_pmcs[i]);
6789 }
6790
6791 for (i=1; PMD_IS_LAST(i) == 0; i++) {
6792 if (PMD_IS_IMPL(i) == 0) continue;
6793 printk("->CPU%d pmd[%d]=0x%lx thread_pmd[%d]=0x%lx\n", this_cpu, i, ia64_get_pmd(i), i, ctx->th_pmds[i]);
6794 }
6795
6796 if (ctx) {
6797 printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
6798 this_cpu,
6799 ctx->ctx_state,
6800 ctx->ctx_smpl_vaddr,
6801 ctx->ctx_smpl_hdr,
6802 ctx->ctx_msgq_head,
6803 ctx->ctx_msgq_tail,
6804 ctx->ctx_saved_psr_up);
6805 }
6806 local_irq_restore(flags);
6807}
6808
6809/*
6810 * called from process.c:copy_thread(). task is new child.
6811 */
6812void
6813pfm_inherit(struct task_struct *task, struct pt_regs *regs)
6814{
6815 struct thread_struct *thread;
6816
6817 DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
6818
6819 thread = &task->thread;
6820
6821 /*
6822 * cut links inherited from parent (current)
6823 */
6824 thread->pfm_context = NULL;
6825
6826 PFM_SET_WORK_PENDING(task, 0);
6827
6828 /*
6829 * the psr bits are already set properly in copy_threads()
6830 */
6831}
6832#else /* !CONFIG_PERFMON */
6833asmlinkage long
6834sys_perfmonctl (int fd, int cmd, void *arg, int count)
6835{
6836 return -ENOSYS;
6837}
6838#endif /* CONFIG_PERFMON */
1/*
2 * This file implements the perfmon-2 subsystem which is used
3 * to program the IA-64 Performance Monitoring Unit (PMU).
4 *
5 * The initial version of perfmon.c was written by
6 * Ganesh Venkitachalam, IBM Corp.
7 *
8 * Then it was modified for perfmon-1.x by Stephane Eranian and
9 * David Mosberger, Hewlett Packard Co.
10 *
11 * Version Perfmon-2.x is a rewrite of perfmon-1.x
12 * by Stephane Eranian, Hewlett Packard Co.
13 *
14 * Copyright (C) 1999-2005 Hewlett Packard Co
15 * Stephane Eranian <eranian@hpl.hp.com>
16 * David Mosberger-Tang <davidm@hpl.hp.com>
17 *
18 * More information about perfmon available at:
19 * http://www.hpl.hp.com/research/linux/perfmon
20 */
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/interrupt.h>
26#include <linux/proc_fs.h>
27#include <linux/seq_file.h>
28#include <linux/init.h>
29#include <linux/vmalloc.h>
30#include <linux/mm.h>
31#include <linux/sysctl.h>
32#include <linux/list.h>
33#include <linux/file.h>
34#include <linux/poll.h>
35#include <linux/vfs.h>
36#include <linux/smp.h>
37#include <linux/pagemap.h>
38#include <linux/mount.h>
39#include <linux/bitops.h>
40#include <linux/capability.h>
41#include <linux/rcupdate.h>
42#include <linux/completion.h>
43#include <linux/tracehook.h>
44#include <linux/slab.h>
45
46#include <asm/errno.h>
47#include <asm/intrinsics.h>
48#include <asm/page.h>
49#include <asm/perfmon.h>
50#include <asm/processor.h>
51#include <asm/signal.h>
52#include <asm/uaccess.h>
53#include <asm/delay.h>
54
55#ifdef CONFIG_PERFMON
56/*
57 * perfmon context state
58 */
59#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
60#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
61#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
62#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
63
64#define PFM_INVALID_ACTIVATION (~0UL)
65
66#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
67#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
68
69/*
70 * depth of message queue
71 */
72#define PFM_MAX_MSGS 32
73#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
74
75/*
76 * type of a PMU register (bitmask).
77 * bitmask structure:
78 * bit0 : register implemented
79 * bit1 : end marker
80 * bit2-3 : reserved
81 * bit4 : pmc has pmc.pm
82 * bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
83 * bit6-7 : register type
84 * bit8-31: reserved
85 */
86#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
87#define PFM_REG_IMPL 0x1 /* register implemented */
88#define PFM_REG_END 0x2 /* end marker */
89#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
90#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
91#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
92#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
93#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
94
95#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
96#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
97
98#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
99
100/* i assumed unsigned */
101#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
102#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
103
104/* XXX: these assume that register i is implemented */
105#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
106#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
107#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
108#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
109
110#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
111#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
112#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
113#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
114
115#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
116#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
117
118#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
119#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
120#define PFM_CTX_TASK(h) (h)->ctx_task
121
122#define PMU_PMC_OI 5 /* position of pmc.oi bit */
123
124/* XXX: does not support more than 64 PMDs */
125#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
126#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
127
128#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
129
130#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
131#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
132#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
133#define PFM_CODE_RR 0 /* requesting code range restriction */
134#define PFM_DATA_RR 1 /* requestion data range restriction */
135
136#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
137#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
138#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
139
140#define RDEP(x) (1UL<<(x))
141
142/*
143 * context protection macros
144 * in SMP:
145 * - we need to protect against CPU concurrency (spin_lock)
146 * - we need to protect against PMU overflow interrupts (local_irq_disable)
147 * in UP:
148 * - we need to protect against PMU overflow interrupts (local_irq_disable)
149 *
150 * spin_lock_irqsave()/spin_unlock_irqrestore():
151 * in SMP: local_irq_disable + spin_lock
152 * in UP : local_irq_disable
153 *
154 * spin_lock()/spin_lock():
155 * in UP : removed automatically
156 * in SMP: protect against context accesses from other CPU. interrupts
157 * are not masked. This is useful for the PMU interrupt handler
158 * because we know we will not get PMU concurrency in that code.
159 */
160#define PROTECT_CTX(c, f) \
161 do { \
162 DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
163 spin_lock_irqsave(&(c)->ctx_lock, f); \
164 DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
165 } while(0)
166
167#define UNPROTECT_CTX(c, f) \
168 do { \
169 DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
170 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
171 } while(0)
172
173#define PROTECT_CTX_NOPRINT(c, f) \
174 do { \
175 spin_lock_irqsave(&(c)->ctx_lock, f); \
176 } while(0)
177
178
179#define UNPROTECT_CTX_NOPRINT(c, f) \
180 do { \
181 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
182 } while(0)
183
184
185#define PROTECT_CTX_NOIRQ(c) \
186 do { \
187 spin_lock(&(c)->ctx_lock); \
188 } while(0)
189
190#define UNPROTECT_CTX_NOIRQ(c) \
191 do { \
192 spin_unlock(&(c)->ctx_lock); \
193 } while(0)
194
195
196#ifdef CONFIG_SMP
197
198#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
199#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
200#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
201
202#else /* !CONFIG_SMP */
203#define SET_ACTIVATION(t) do {} while(0)
204#define GET_ACTIVATION(t) do {} while(0)
205#define INC_ACTIVATION(t) do {} while(0)
206#endif /* CONFIG_SMP */
207
208#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
209#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
210#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
211
212#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
213#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
214
215#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
216
217/*
218 * cmp0 must be the value of pmc0
219 */
220#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
221
222#define PFMFS_MAGIC 0xa0b4d889
223
224/*
225 * debugging
226 */
227#define PFM_DEBUGGING 1
228#ifdef PFM_DEBUGGING
229#define DPRINT(a) \
230 do { \
231 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
232 } while (0)
233
234#define DPRINT_ovfl(a) \
235 do { \
236 if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
237 } while (0)
238#endif
239
240/*
241 * 64-bit software counter structure
242 *
243 * the next_reset_type is applied to the next call to pfm_reset_regs()
244 */
245typedef struct {
246 unsigned long val; /* virtual 64bit counter value */
247 unsigned long lval; /* last reset value */
248 unsigned long long_reset; /* reset value on sampling overflow */
249 unsigned long short_reset; /* reset value on overflow */
250 unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
251 unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
252 unsigned long seed; /* seed for random-number generator */
253 unsigned long mask; /* mask for random-number generator */
254 unsigned int flags; /* notify/do not notify */
255 unsigned long eventid; /* overflow event identifier */
256} pfm_counter_t;
257
258/*
259 * context flags
260 */
261typedef struct {
262 unsigned int block:1; /* when 1, task will blocked on user notifications */
263 unsigned int system:1; /* do system wide monitoring */
264 unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
265 unsigned int is_sampling:1; /* true if using a custom format */
266 unsigned int excl_idle:1; /* exclude idle task in system wide session */
267 unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
268 unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
269 unsigned int no_msg:1; /* no message sent on overflow */
270 unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
271 unsigned int reserved:22;
272} pfm_context_flags_t;
273
274#define PFM_TRAP_REASON_NONE 0x0 /* default value */
275#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
276#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
277
278
279/*
280 * perfmon context: encapsulates all the state of a monitoring session
281 */
282
283typedef struct pfm_context {
284 spinlock_t ctx_lock; /* context protection */
285
286 pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
287 unsigned int ctx_state; /* state: active/inactive (no bitfield) */
288
289 struct task_struct *ctx_task; /* task to which context is attached */
290
291 unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
292
293 struct completion ctx_restart_done; /* use for blocking notification mode */
294
295 unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
296 unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
297 unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
298
299 unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
300 unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
301 unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
302
303 unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
304
305 unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
306 unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
307 unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
308 unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
309
310 pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
311
312 unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
313 unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
314
315 unsigned long ctx_saved_psr_up; /* only contains psr.up value */
316
317 unsigned long ctx_last_activation; /* context last activation number for last_cpu */
318 unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
319 unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
320
321 int ctx_fd; /* file descriptor used my this context */
322 pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
323
324 pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
325 void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
326 unsigned long ctx_smpl_size; /* size of sampling buffer */
327 void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
328
329 wait_queue_head_t ctx_msgq_wait;
330 pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
331 int ctx_msgq_head;
332 int ctx_msgq_tail;
333 struct fasync_struct *ctx_async_queue;
334
335 wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
336} pfm_context_t;
337
338/*
339 * magic number used to verify that structure is really
340 * a perfmon context
341 */
342#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
343
344#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
345
346#ifdef CONFIG_SMP
347#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
348#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
349#else
350#define SET_LAST_CPU(ctx, v) do {} while(0)
351#define GET_LAST_CPU(ctx) do {} while(0)
352#endif
353
354
355#define ctx_fl_block ctx_flags.block
356#define ctx_fl_system ctx_flags.system
357#define ctx_fl_using_dbreg ctx_flags.using_dbreg
358#define ctx_fl_is_sampling ctx_flags.is_sampling
359#define ctx_fl_excl_idle ctx_flags.excl_idle
360#define ctx_fl_going_zombie ctx_flags.going_zombie
361#define ctx_fl_trap_reason ctx_flags.trap_reason
362#define ctx_fl_no_msg ctx_flags.no_msg
363#define ctx_fl_can_restart ctx_flags.can_restart
364
365#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
366#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
367
368/*
369 * global information about all sessions
370 * mostly used to synchronize between system wide and per-process
371 */
372typedef struct {
373 spinlock_t pfs_lock; /* lock the structure */
374
375 unsigned int pfs_task_sessions; /* number of per task sessions */
376 unsigned int pfs_sys_sessions; /* number of per system wide sessions */
377 unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
378 unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
379 struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
380} pfm_session_t;
381
382/*
383 * information about a PMC or PMD.
384 * dep_pmd[]: a bitmask of dependent PMD registers
385 * dep_pmc[]: a bitmask of dependent PMC registers
386 */
387typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
388typedef struct {
389 unsigned int type;
390 int pm_pos;
391 unsigned long default_value; /* power-on default value */
392 unsigned long reserved_mask; /* bitmask of reserved bits */
393 pfm_reg_check_t read_check;
394 pfm_reg_check_t write_check;
395 unsigned long dep_pmd[4];
396 unsigned long dep_pmc[4];
397} pfm_reg_desc_t;
398
399/* assume cnum is a valid monitor */
400#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
401
402/*
403 * This structure is initialized at boot time and contains
404 * a description of the PMU main characteristics.
405 *
406 * If the probe function is defined, detection is based
407 * on its return value:
408 * - 0 means recognized PMU
409 * - anything else means not supported
410 * When the probe function is not defined, then the pmu_family field
411 * is used and it must match the host CPU family such that:
412 * - cpu->family & config->pmu_family != 0
413 */
414typedef struct {
415 unsigned long ovfl_val; /* overflow value for counters */
416
417 pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
418 pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
419
420 unsigned int num_pmcs; /* number of PMCS: computed at init time */
421 unsigned int num_pmds; /* number of PMDS: computed at init time */
422 unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
423 unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
424
425 char *pmu_name; /* PMU family name */
426 unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
427 unsigned int flags; /* pmu specific flags */
428 unsigned int num_ibrs; /* number of IBRS: computed at init time */
429 unsigned int num_dbrs; /* number of DBRS: computed at init time */
430 unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
431 int (*probe)(void); /* customized probe routine */
432 unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
433} pmu_config_t;
434/*
435 * PMU specific flags
436 */
437#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
438
439/*
440 * debug register related type definitions
441 */
442typedef struct {
443 unsigned long ibr_mask:56;
444 unsigned long ibr_plm:4;
445 unsigned long ibr_ig:3;
446 unsigned long ibr_x:1;
447} ibr_mask_reg_t;
448
449typedef struct {
450 unsigned long dbr_mask:56;
451 unsigned long dbr_plm:4;
452 unsigned long dbr_ig:2;
453 unsigned long dbr_w:1;
454 unsigned long dbr_r:1;
455} dbr_mask_reg_t;
456
457typedef union {
458 unsigned long val;
459 ibr_mask_reg_t ibr;
460 dbr_mask_reg_t dbr;
461} dbreg_t;
462
463
464/*
465 * perfmon command descriptions
466 */
467typedef struct {
468 int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
469 char *cmd_name;
470 int cmd_flags;
471 unsigned int cmd_narg;
472 size_t cmd_argsize;
473 int (*cmd_getsize)(void *arg, size_t *sz);
474} pfm_cmd_desc_t;
475
476#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
477#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
478#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
479#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
480
481
482#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
483#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
484#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
485#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
486#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
487
488#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
489
490typedef struct {
491 unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
492 unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
493 unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
494 unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
495 unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
496 unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
497 unsigned long pfm_smpl_handler_calls;
498 unsigned long pfm_smpl_handler_cycles;
499 char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
500} pfm_stats_t;
501
502/*
503 * perfmon internal variables
504 */
505static pfm_stats_t pfm_stats[NR_CPUS];
506static pfm_session_t pfm_sessions; /* global sessions information */
507
508static DEFINE_SPINLOCK(pfm_alt_install_check);
509static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
510
511static struct proc_dir_entry *perfmon_dir;
512static pfm_uuid_t pfm_null_uuid = {0,};
513
514static spinlock_t pfm_buffer_fmt_lock;
515static LIST_HEAD(pfm_buffer_fmt_list);
516
517static pmu_config_t *pmu_conf;
518
519/* sysctl() controls */
520pfm_sysctl_t pfm_sysctl;
521EXPORT_SYMBOL(pfm_sysctl);
522
523static ctl_table pfm_ctl_table[]={
524 {
525 .procname = "debug",
526 .data = &pfm_sysctl.debug,
527 .maxlen = sizeof(int),
528 .mode = 0666,
529 .proc_handler = proc_dointvec,
530 },
531 {
532 .procname = "debug_ovfl",
533 .data = &pfm_sysctl.debug_ovfl,
534 .maxlen = sizeof(int),
535 .mode = 0666,
536 .proc_handler = proc_dointvec,
537 },
538 {
539 .procname = "fastctxsw",
540 .data = &pfm_sysctl.fastctxsw,
541 .maxlen = sizeof(int),
542 .mode = 0600,
543 .proc_handler = proc_dointvec,
544 },
545 {
546 .procname = "expert_mode",
547 .data = &pfm_sysctl.expert_mode,
548 .maxlen = sizeof(int),
549 .mode = 0600,
550 .proc_handler = proc_dointvec,
551 },
552 {}
553};
554static ctl_table pfm_sysctl_dir[] = {
555 {
556 .procname = "perfmon",
557 .mode = 0555,
558 .child = pfm_ctl_table,
559 },
560 {}
561};
562static ctl_table pfm_sysctl_root[] = {
563 {
564 .procname = "kernel",
565 .mode = 0555,
566 .child = pfm_sysctl_dir,
567 },
568 {}
569};
570static struct ctl_table_header *pfm_sysctl_header;
571
572static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
573
574#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
575#define pfm_get_cpu_data(a,b) per_cpu(a, b)
576
577static inline void
578pfm_put_task(struct task_struct *task)
579{
580 if (task != current) put_task_struct(task);
581}
582
583static inline void
584pfm_reserve_page(unsigned long a)
585{
586 SetPageReserved(vmalloc_to_page((void *)a));
587}
588static inline void
589pfm_unreserve_page(unsigned long a)
590{
591 ClearPageReserved(vmalloc_to_page((void*)a));
592}
593
594static inline unsigned long
595pfm_protect_ctx_ctxsw(pfm_context_t *x)
596{
597 spin_lock(&(x)->ctx_lock);
598 return 0UL;
599}
600
601static inline void
602pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
603{
604 spin_unlock(&(x)->ctx_lock);
605}
606
607/* forward declaration */
608static const struct dentry_operations pfmfs_dentry_operations;
609
610static struct dentry *
611pfmfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data)
612{
613 return mount_pseudo(fs_type, "pfm:", NULL, &pfmfs_dentry_operations,
614 PFMFS_MAGIC);
615}
616
617static struct file_system_type pfm_fs_type = {
618 .name = "pfmfs",
619 .mount = pfmfs_mount,
620 .kill_sb = kill_anon_super,
621};
622
623DEFINE_PER_CPU(unsigned long, pfm_syst_info);
624DEFINE_PER_CPU(struct task_struct *, pmu_owner);
625DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
626DEFINE_PER_CPU(unsigned long, pmu_activation_number);
627EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
628
629
630/* forward declaration */
631static const struct file_operations pfm_file_ops;
632
633/*
634 * forward declarations
635 */
636#ifndef CONFIG_SMP
637static void pfm_lazy_save_regs (struct task_struct *ta);
638#endif
639
640void dump_pmu_state(const char *);
641static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
642
643#include "perfmon_itanium.h"
644#include "perfmon_mckinley.h"
645#include "perfmon_montecito.h"
646#include "perfmon_generic.h"
647
648static pmu_config_t *pmu_confs[]={
649 &pmu_conf_mont,
650 &pmu_conf_mck,
651 &pmu_conf_ita,
652 &pmu_conf_gen, /* must be last */
653 NULL
654};
655
656
657static int pfm_end_notify_user(pfm_context_t *ctx);
658
659static inline void
660pfm_clear_psr_pp(void)
661{
662 ia64_rsm(IA64_PSR_PP);
663 ia64_srlz_i();
664}
665
666static inline void
667pfm_set_psr_pp(void)
668{
669 ia64_ssm(IA64_PSR_PP);
670 ia64_srlz_i();
671}
672
673static inline void
674pfm_clear_psr_up(void)
675{
676 ia64_rsm(IA64_PSR_UP);
677 ia64_srlz_i();
678}
679
680static inline void
681pfm_set_psr_up(void)
682{
683 ia64_ssm(IA64_PSR_UP);
684 ia64_srlz_i();
685}
686
687static inline unsigned long
688pfm_get_psr(void)
689{
690 unsigned long tmp;
691 tmp = ia64_getreg(_IA64_REG_PSR);
692 ia64_srlz_i();
693 return tmp;
694}
695
696static inline void
697pfm_set_psr_l(unsigned long val)
698{
699 ia64_setreg(_IA64_REG_PSR_L, val);
700 ia64_srlz_i();
701}
702
703static inline void
704pfm_freeze_pmu(void)
705{
706 ia64_set_pmc(0,1UL);
707 ia64_srlz_d();
708}
709
710static inline void
711pfm_unfreeze_pmu(void)
712{
713 ia64_set_pmc(0,0UL);
714 ia64_srlz_d();
715}
716
717static inline void
718pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
719{
720 int i;
721
722 for (i=0; i < nibrs; i++) {
723 ia64_set_ibr(i, ibrs[i]);
724 ia64_dv_serialize_instruction();
725 }
726 ia64_srlz_i();
727}
728
729static inline void
730pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
731{
732 int i;
733
734 for (i=0; i < ndbrs; i++) {
735 ia64_set_dbr(i, dbrs[i]);
736 ia64_dv_serialize_data();
737 }
738 ia64_srlz_d();
739}
740
741/*
742 * PMD[i] must be a counter. no check is made
743 */
744static inline unsigned long
745pfm_read_soft_counter(pfm_context_t *ctx, int i)
746{
747 return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
748}
749
750/*
751 * PMD[i] must be a counter. no check is made
752 */
753static inline void
754pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
755{
756 unsigned long ovfl_val = pmu_conf->ovfl_val;
757
758 ctx->ctx_pmds[i].val = val & ~ovfl_val;
759 /*
760 * writing to unimplemented part is ignore, so we do not need to
761 * mask off top part
762 */
763 ia64_set_pmd(i, val & ovfl_val);
764}
765
766static pfm_msg_t *
767pfm_get_new_msg(pfm_context_t *ctx)
768{
769 int idx, next;
770
771 next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
772
773 DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
774 if (next == ctx->ctx_msgq_head) return NULL;
775
776 idx = ctx->ctx_msgq_tail;
777 ctx->ctx_msgq_tail = next;
778
779 DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
780
781 return ctx->ctx_msgq+idx;
782}
783
784static pfm_msg_t *
785pfm_get_next_msg(pfm_context_t *ctx)
786{
787 pfm_msg_t *msg;
788
789 DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
790
791 if (PFM_CTXQ_EMPTY(ctx)) return NULL;
792
793 /*
794 * get oldest message
795 */
796 msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
797
798 /*
799 * and move forward
800 */
801 ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
802
803 DPRINT(("ctx=%p head=%d tail=%d type=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, msg->pfm_gen_msg.msg_type));
804
805 return msg;
806}
807
808static void
809pfm_reset_msgq(pfm_context_t *ctx)
810{
811 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
812 DPRINT(("ctx=%p msgq reset\n", ctx));
813}
814
815static void *
816pfm_rvmalloc(unsigned long size)
817{
818 void *mem;
819 unsigned long addr;
820
821 size = PAGE_ALIGN(size);
822 mem = vzalloc(size);
823 if (mem) {
824 //printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
825 addr = (unsigned long)mem;
826 while (size > 0) {
827 pfm_reserve_page(addr);
828 addr+=PAGE_SIZE;
829 size-=PAGE_SIZE;
830 }
831 }
832 return mem;
833}
834
835static void
836pfm_rvfree(void *mem, unsigned long size)
837{
838 unsigned long addr;
839
840 if (mem) {
841 DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
842 addr = (unsigned long) mem;
843 while ((long) size > 0) {
844 pfm_unreserve_page(addr);
845 addr+=PAGE_SIZE;
846 size-=PAGE_SIZE;
847 }
848 vfree(mem);
849 }
850 return;
851}
852
853static pfm_context_t *
854pfm_context_alloc(int ctx_flags)
855{
856 pfm_context_t *ctx;
857
858 /*
859 * allocate context descriptor
860 * must be able to free with interrupts disabled
861 */
862 ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
863 if (ctx) {
864 DPRINT(("alloc ctx @%p\n", ctx));
865
866 /*
867 * init context protection lock
868 */
869 spin_lock_init(&ctx->ctx_lock);
870
871 /*
872 * context is unloaded
873 */
874 ctx->ctx_state = PFM_CTX_UNLOADED;
875
876 /*
877 * initialization of context's flags
878 */
879 ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
880 ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
881 ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
882 /*
883 * will move to set properties
884 * ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
885 */
886
887 /*
888 * init restart semaphore to locked
889 */
890 init_completion(&ctx->ctx_restart_done);
891
892 /*
893 * activation is used in SMP only
894 */
895 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
896 SET_LAST_CPU(ctx, -1);
897
898 /*
899 * initialize notification message queue
900 */
901 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
902 init_waitqueue_head(&ctx->ctx_msgq_wait);
903 init_waitqueue_head(&ctx->ctx_zombieq);
904
905 }
906 return ctx;
907}
908
909static void
910pfm_context_free(pfm_context_t *ctx)
911{
912 if (ctx) {
913 DPRINT(("free ctx @%p\n", ctx));
914 kfree(ctx);
915 }
916}
917
918static void
919pfm_mask_monitoring(struct task_struct *task)
920{
921 pfm_context_t *ctx = PFM_GET_CTX(task);
922 unsigned long mask, val, ovfl_mask;
923 int i;
924
925 DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
926
927 ovfl_mask = pmu_conf->ovfl_val;
928 /*
929 * monitoring can only be masked as a result of a valid
930 * counter overflow. In UP, it means that the PMU still
931 * has an owner. Note that the owner can be different
932 * from the current task. However the PMU state belongs
933 * to the owner.
934 * In SMP, a valid overflow only happens when task is
935 * current. Therefore if we come here, we know that
936 * the PMU state belongs to the current task, therefore
937 * we can access the live registers.
938 *
939 * So in both cases, the live register contains the owner's
940 * state. We can ONLY touch the PMU registers and NOT the PSR.
941 *
942 * As a consequence to this call, the ctx->th_pmds[] array
943 * contains stale information which must be ignored
944 * when context is reloaded AND monitoring is active (see
945 * pfm_restart).
946 */
947 mask = ctx->ctx_used_pmds[0];
948 for (i = 0; mask; i++, mask>>=1) {
949 /* skip non used pmds */
950 if ((mask & 0x1) == 0) continue;
951 val = ia64_get_pmd(i);
952
953 if (PMD_IS_COUNTING(i)) {
954 /*
955 * we rebuild the full 64 bit value of the counter
956 */
957 ctx->ctx_pmds[i].val += (val & ovfl_mask);
958 } else {
959 ctx->ctx_pmds[i].val = val;
960 }
961 DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
962 i,
963 ctx->ctx_pmds[i].val,
964 val & ovfl_mask));
965 }
966 /*
967 * mask monitoring by setting the privilege level to 0
968 * we cannot use psr.pp/psr.up for this, it is controlled by
969 * the user
970 *
971 * if task is current, modify actual registers, otherwise modify
972 * thread save state, i.e., what will be restored in pfm_load_regs()
973 */
974 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
975 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
976 if ((mask & 0x1) == 0UL) continue;
977 ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
978 ctx->th_pmcs[i] &= ~0xfUL;
979 DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
980 }
981 /*
982 * make all of this visible
983 */
984 ia64_srlz_d();
985}
986
987/*
988 * must always be done with task == current
989 *
990 * context must be in MASKED state when calling
991 */
992static void
993pfm_restore_monitoring(struct task_struct *task)
994{
995 pfm_context_t *ctx = PFM_GET_CTX(task);
996 unsigned long mask, ovfl_mask;
997 unsigned long psr, val;
998 int i, is_system;
999
1000 is_system = ctx->ctx_fl_system;
1001 ovfl_mask = pmu_conf->ovfl_val;
1002
1003 if (task != current) {
1004 printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
1005 return;
1006 }
1007 if (ctx->ctx_state != PFM_CTX_MASKED) {
1008 printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
1009 task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
1010 return;
1011 }
1012 psr = pfm_get_psr();
1013 /*
1014 * monitoring is masked via the PMC.
1015 * As we restore their value, we do not want each counter to
1016 * restart right away. We stop monitoring using the PSR,
1017 * restore the PMC (and PMD) and then re-establish the psr
1018 * as it was. Note that there can be no pending overflow at
1019 * this point, because monitoring was MASKED.
1020 *
1021 * system-wide session are pinned and self-monitoring
1022 */
1023 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1024 /* disable dcr pp */
1025 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
1026 pfm_clear_psr_pp();
1027 } else {
1028 pfm_clear_psr_up();
1029 }
1030 /*
1031 * first, we restore the PMD
1032 */
1033 mask = ctx->ctx_used_pmds[0];
1034 for (i = 0; mask; i++, mask>>=1) {
1035 /* skip non used pmds */
1036 if ((mask & 0x1) == 0) continue;
1037
1038 if (PMD_IS_COUNTING(i)) {
1039 /*
1040 * we split the 64bit value according to
1041 * counter width
1042 */
1043 val = ctx->ctx_pmds[i].val & ovfl_mask;
1044 ctx->ctx_pmds[i].val &= ~ovfl_mask;
1045 } else {
1046 val = ctx->ctx_pmds[i].val;
1047 }
1048 ia64_set_pmd(i, val);
1049
1050 DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
1051 i,
1052 ctx->ctx_pmds[i].val,
1053 val));
1054 }
1055 /*
1056 * restore the PMCs
1057 */
1058 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
1059 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
1060 if ((mask & 0x1) == 0UL) continue;
1061 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1062 ia64_set_pmc(i, ctx->th_pmcs[i]);
1063 DPRINT(("[%d] pmc[%d]=0x%lx\n",
1064 task_pid_nr(task), i, ctx->th_pmcs[i]));
1065 }
1066 ia64_srlz_d();
1067
1068 /*
1069 * must restore DBR/IBR because could be modified while masked
1070 * XXX: need to optimize
1071 */
1072 if (ctx->ctx_fl_using_dbreg) {
1073 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
1074 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
1075 }
1076
1077 /*
1078 * now restore PSR
1079 */
1080 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1081 /* enable dcr pp */
1082 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
1083 ia64_srlz_i();
1084 }
1085 pfm_set_psr_l(psr);
1086}
1087
1088static inline void
1089pfm_save_pmds(unsigned long *pmds, unsigned long mask)
1090{
1091 int i;
1092
1093 ia64_srlz_d();
1094
1095 for (i=0; mask; i++, mask>>=1) {
1096 if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
1097 }
1098}
1099
1100/*
1101 * reload from thread state (used for ctxw only)
1102 */
1103static inline void
1104pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
1105{
1106 int i;
1107 unsigned long val, ovfl_val = pmu_conf->ovfl_val;
1108
1109 for (i=0; mask; i++, mask>>=1) {
1110 if ((mask & 0x1) == 0) continue;
1111 val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
1112 ia64_set_pmd(i, val);
1113 }
1114 ia64_srlz_d();
1115}
1116
1117/*
1118 * propagate PMD from context to thread-state
1119 */
1120static inline void
1121pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
1122{
1123 unsigned long ovfl_val = pmu_conf->ovfl_val;
1124 unsigned long mask = ctx->ctx_all_pmds[0];
1125 unsigned long val;
1126 int i;
1127
1128 DPRINT(("mask=0x%lx\n", mask));
1129
1130 for (i=0; mask; i++, mask>>=1) {
1131
1132 val = ctx->ctx_pmds[i].val;
1133
1134 /*
1135 * We break up the 64 bit value into 2 pieces
1136 * the lower bits go to the machine state in the
1137 * thread (will be reloaded on ctxsw in).
1138 * The upper part stays in the soft-counter.
1139 */
1140 if (PMD_IS_COUNTING(i)) {
1141 ctx->ctx_pmds[i].val = val & ~ovfl_val;
1142 val &= ovfl_val;
1143 }
1144 ctx->th_pmds[i] = val;
1145
1146 DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
1147 i,
1148 ctx->th_pmds[i],
1149 ctx->ctx_pmds[i].val));
1150 }
1151}
1152
1153/*
1154 * propagate PMC from context to thread-state
1155 */
1156static inline void
1157pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
1158{
1159 unsigned long mask = ctx->ctx_all_pmcs[0];
1160 int i;
1161
1162 DPRINT(("mask=0x%lx\n", mask));
1163
1164 for (i=0; mask; i++, mask>>=1) {
1165 /* masking 0 with ovfl_val yields 0 */
1166 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1167 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
1168 }
1169}
1170
1171
1172
1173static inline void
1174pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
1175{
1176 int i;
1177
1178 for (i=0; mask; i++, mask>>=1) {
1179 if ((mask & 0x1) == 0) continue;
1180 ia64_set_pmc(i, pmcs[i]);
1181 }
1182 ia64_srlz_d();
1183}
1184
1185static inline int
1186pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
1187{
1188 return memcmp(a, b, sizeof(pfm_uuid_t));
1189}
1190
1191static inline int
1192pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
1193{
1194 int ret = 0;
1195 if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
1196 return ret;
1197}
1198
1199static inline int
1200pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
1201{
1202 int ret = 0;
1203 if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
1204 return ret;
1205}
1206
1207
1208static inline int
1209pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
1210 int cpu, void *arg)
1211{
1212 int ret = 0;
1213 if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
1214 return ret;
1215}
1216
1217static inline int
1218pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
1219 int cpu, void *arg)
1220{
1221 int ret = 0;
1222 if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
1223 return ret;
1224}
1225
1226static inline int
1227pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1228{
1229 int ret = 0;
1230 if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
1231 return ret;
1232}
1233
1234static inline int
1235pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1236{
1237 int ret = 0;
1238 if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
1239 return ret;
1240}
1241
1242static pfm_buffer_fmt_t *
1243__pfm_find_buffer_fmt(pfm_uuid_t uuid)
1244{
1245 struct list_head * pos;
1246 pfm_buffer_fmt_t * entry;
1247
1248 list_for_each(pos, &pfm_buffer_fmt_list) {
1249 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
1250 if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
1251 return entry;
1252 }
1253 return NULL;
1254}
1255
1256/*
1257 * find a buffer format based on its uuid
1258 */
1259static pfm_buffer_fmt_t *
1260pfm_find_buffer_fmt(pfm_uuid_t uuid)
1261{
1262 pfm_buffer_fmt_t * fmt;
1263 spin_lock(&pfm_buffer_fmt_lock);
1264 fmt = __pfm_find_buffer_fmt(uuid);
1265 spin_unlock(&pfm_buffer_fmt_lock);
1266 return fmt;
1267}
1268
1269int
1270pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
1271{
1272 int ret = 0;
1273
1274 /* some sanity checks */
1275 if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
1276
1277 /* we need at least a handler */
1278 if (fmt->fmt_handler == NULL) return -EINVAL;
1279
1280 /*
1281 * XXX: need check validity of fmt_arg_size
1282 */
1283
1284 spin_lock(&pfm_buffer_fmt_lock);
1285
1286 if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
1287 printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
1288 ret = -EBUSY;
1289 goto out;
1290 }
1291 list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
1292 printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
1293
1294out:
1295 spin_unlock(&pfm_buffer_fmt_lock);
1296 return ret;
1297}
1298EXPORT_SYMBOL(pfm_register_buffer_fmt);
1299
1300int
1301pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
1302{
1303 pfm_buffer_fmt_t *fmt;
1304 int ret = 0;
1305
1306 spin_lock(&pfm_buffer_fmt_lock);
1307
1308 fmt = __pfm_find_buffer_fmt(uuid);
1309 if (!fmt) {
1310 printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
1311 ret = -EINVAL;
1312 goto out;
1313 }
1314 list_del_init(&fmt->fmt_list);
1315 printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
1316
1317out:
1318 spin_unlock(&pfm_buffer_fmt_lock);
1319 return ret;
1320
1321}
1322EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
1323
1324extern void update_pal_halt_status(int);
1325
1326static int
1327pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
1328{
1329 unsigned long flags;
1330 /*
1331 * validity checks on cpu_mask have been done upstream
1332 */
1333 LOCK_PFS(flags);
1334
1335 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1336 pfm_sessions.pfs_sys_sessions,
1337 pfm_sessions.pfs_task_sessions,
1338 pfm_sessions.pfs_sys_use_dbregs,
1339 is_syswide,
1340 cpu));
1341
1342 if (is_syswide) {
1343 /*
1344 * cannot mix system wide and per-task sessions
1345 */
1346 if (pfm_sessions.pfs_task_sessions > 0UL) {
1347 DPRINT(("system wide not possible, %u conflicting task_sessions\n",
1348 pfm_sessions.pfs_task_sessions));
1349 goto abort;
1350 }
1351
1352 if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
1353
1354 DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
1355
1356 pfm_sessions.pfs_sys_session[cpu] = task;
1357
1358 pfm_sessions.pfs_sys_sessions++ ;
1359
1360 } else {
1361 if (pfm_sessions.pfs_sys_sessions) goto abort;
1362 pfm_sessions.pfs_task_sessions++;
1363 }
1364
1365 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1366 pfm_sessions.pfs_sys_sessions,
1367 pfm_sessions.pfs_task_sessions,
1368 pfm_sessions.pfs_sys_use_dbregs,
1369 is_syswide,
1370 cpu));
1371
1372 /*
1373 * disable default_idle() to go to PAL_HALT
1374 */
1375 update_pal_halt_status(0);
1376
1377 UNLOCK_PFS(flags);
1378
1379 return 0;
1380
1381error_conflict:
1382 DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
1383 task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
1384 cpu));
1385abort:
1386 UNLOCK_PFS(flags);
1387
1388 return -EBUSY;
1389
1390}
1391
1392static int
1393pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
1394{
1395 unsigned long flags;
1396 /*
1397 * validity checks on cpu_mask have been done upstream
1398 */
1399 LOCK_PFS(flags);
1400
1401 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1402 pfm_sessions.pfs_sys_sessions,
1403 pfm_sessions.pfs_task_sessions,
1404 pfm_sessions.pfs_sys_use_dbregs,
1405 is_syswide,
1406 cpu));
1407
1408
1409 if (is_syswide) {
1410 pfm_sessions.pfs_sys_session[cpu] = NULL;
1411 /*
1412 * would not work with perfmon+more than one bit in cpu_mask
1413 */
1414 if (ctx && ctx->ctx_fl_using_dbreg) {
1415 if (pfm_sessions.pfs_sys_use_dbregs == 0) {
1416 printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
1417 } else {
1418 pfm_sessions.pfs_sys_use_dbregs--;
1419 }
1420 }
1421 pfm_sessions.pfs_sys_sessions--;
1422 } else {
1423 pfm_sessions.pfs_task_sessions--;
1424 }
1425 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1426 pfm_sessions.pfs_sys_sessions,
1427 pfm_sessions.pfs_task_sessions,
1428 pfm_sessions.pfs_sys_use_dbregs,
1429 is_syswide,
1430 cpu));
1431
1432 /*
1433 * if possible, enable default_idle() to go into PAL_HALT
1434 */
1435 if (pfm_sessions.pfs_task_sessions == 0 && pfm_sessions.pfs_sys_sessions == 0)
1436 update_pal_halt_status(1);
1437
1438 UNLOCK_PFS(flags);
1439
1440 return 0;
1441}
1442
1443/*
1444 * removes virtual mapping of the sampling buffer.
1445 * IMPORTANT: cannot be called with interrupts disable, e.g. inside
1446 * a PROTECT_CTX() section.
1447 */
1448static int
1449pfm_remove_smpl_mapping(void *vaddr, unsigned long size)
1450{
1451 struct task_struct *task = current;
1452 int r;
1453
1454 /* sanity checks */
1455 if (task->mm == NULL || size == 0UL || vaddr == NULL) {
1456 printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
1457 return -EINVAL;
1458 }
1459
1460 DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
1461
1462 /*
1463 * does the actual unmapping
1464 */
1465 r = vm_munmap((unsigned long)vaddr, size);
1466
1467 if (r !=0) {
1468 printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
1469 }
1470
1471 DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
1472
1473 return 0;
1474}
1475
1476/*
1477 * free actual physical storage used by sampling buffer
1478 */
1479#if 0
1480static int
1481pfm_free_smpl_buffer(pfm_context_t *ctx)
1482{
1483 pfm_buffer_fmt_t *fmt;
1484
1485 if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
1486
1487 /*
1488 * we won't use the buffer format anymore
1489 */
1490 fmt = ctx->ctx_buf_fmt;
1491
1492 DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
1493 ctx->ctx_smpl_hdr,
1494 ctx->ctx_smpl_size,
1495 ctx->ctx_smpl_vaddr));
1496
1497 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1498
1499 /*
1500 * free the buffer
1501 */
1502 pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
1503
1504 ctx->ctx_smpl_hdr = NULL;
1505 ctx->ctx_smpl_size = 0UL;
1506
1507 return 0;
1508
1509invalid_free:
1510 printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
1511 return -EINVAL;
1512}
1513#endif
1514
1515static inline void
1516pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
1517{
1518 if (fmt == NULL) return;
1519
1520 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1521
1522}
1523
1524/*
1525 * pfmfs should _never_ be mounted by userland - too much of security hassle,
1526 * no real gain from having the whole whorehouse mounted. So we don't need
1527 * any operations on the root directory. However, we need a non-trivial
1528 * d_name - pfm: will go nicely and kill the special-casing in procfs.
1529 */
1530static struct vfsmount *pfmfs_mnt __read_mostly;
1531
1532static int __init
1533init_pfm_fs(void)
1534{
1535 int err = register_filesystem(&pfm_fs_type);
1536 if (!err) {
1537 pfmfs_mnt = kern_mount(&pfm_fs_type);
1538 err = PTR_ERR(pfmfs_mnt);
1539 if (IS_ERR(pfmfs_mnt))
1540 unregister_filesystem(&pfm_fs_type);
1541 else
1542 err = 0;
1543 }
1544 return err;
1545}
1546
1547static ssize_t
1548pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
1549{
1550 pfm_context_t *ctx;
1551 pfm_msg_t *msg;
1552 ssize_t ret;
1553 unsigned long flags;
1554 DECLARE_WAITQUEUE(wait, current);
1555 if (PFM_IS_FILE(filp) == 0) {
1556 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1557 return -EINVAL;
1558 }
1559
1560 ctx = filp->private_data;
1561 if (ctx == NULL) {
1562 printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
1563 return -EINVAL;
1564 }
1565
1566 /*
1567 * check even when there is no message
1568 */
1569 if (size < sizeof(pfm_msg_t)) {
1570 DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
1571 return -EINVAL;
1572 }
1573
1574 PROTECT_CTX(ctx, flags);
1575
1576 /*
1577 * put ourselves on the wait queue
1578 */
1579 add_wait_queue(&ctx->ctx_msgq_wait, &wait);
1580
1581
1582 for(;;) {
1583 /*
1584 * check wait queue
1585 */
1586
1587 set_current_state(TASK_INTERRUPTIBLE);
1588
1589 DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
1590
1591 ret = 0;
1592 if(PFM_CTXQ_EMPTY(ctx) == 0) break;
1593
1594 UNPROTECT_CTX(ctx, flags);
1595
1596 /*
1597 * check non-blocking read
1598 */
1599 ret = -EAGAIN;
1600 if(filp->f_flags & O_NONBLOCK) break;
1601
1602 /*
1603 * check pending signals
1604 */
1605 if(signal_pending(current)) {
1606 ret = -EINTR;
1607 break;
1608 }
1609 /*
1610 * no message, so wait
1611 */
1612 schedule();
1613
1614 PROTECT_CTX(ctx, flags);
1615 }
1616 DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
1617 set_current_state(TASK_RUNNING);
1618 remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
1619
1620 if (ret < 0) goto abort;
1621
1622 ret = -EINVAL;
1623 msg = pfm_get_next_msg(ctx);
1624 if (msg == NULL) {
1625 printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
1626 goto abort_locked;
1627 }
1628
1629 DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
1630
1631 ret = -EFAULT;
1632 if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
1633
1634abort_locked:
1635 UNPROTECT_CTX(ctx, flags);
1636abort:
1637 return ret;
1638}
1639
1640static ssize_t
1641pfm_write(struct file *file, const char __user *ubuf,
1642 size_t size, loff_t *ppos)
1643{
1644 DPRINT(("pfm_write called\n"));
1645 return -EINVAL;
1646}
1647
1648static unsigned int
1649pfm_poll(struct file *filp, poll_table * wait)
1650{
1651 pfm_context_t *ctx;
1652 unsigned long flags;
1653 unsigned int mask = 0;
1654
1655 if (PFM_IS_FILE(filp) == 0) {
1656 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1657 return 0;
1658 }
1659
1660 ctx = filp->private_data;
1661 if (ctx == NULL) {
1662 printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
1663 return 0;
1664 }
1665
1666
1667 DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
1668
1669 poll_wait(filp, &ctx->ctx_msgq_wait, wait);
1670
1671 PROTECT_CTX(ctx, flags);
1672
1673 if (PFM_CTXQ_EMPTY(ctx) == 0)
1674 mask = POLLIN | POLLRDNORM;
1675
1676 UNPROTECT_CTX(ctx, flags);
1677
1678 DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
1679
1680 return mask;
1681}
1682
1683static long
1684pfm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1685{
1686 DPRINT(("pfm_ioctl called\n"));
1687 return -EINVAL;
1688}
1689
1690/*
1691 * interrupt cannot be masked when coming here
1692 */
1693static inline int
1694pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
1695{
1696 int ret;
1697
1698 ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
1699
1700 DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1701 task_pid_nr(current),
1702 fd,
1703 on,
1704 ctx->ctx_async_queue, ret));
1705
1706 return ret;
1707}
1708
1709static int
1710pfm_fasync(int fd, struct file *filp, int on)
1711{
1712 pfm_context_t *ctx;
1713 int ret;
1714
1715 if (PFM_IS_FILE(filp) == 0) {
1716 printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
1717 return -EBADF;
1718 }
1719
1720 ctx = filp->private_data;
1721 if (ctx == NULL) {
1722 printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
1723 return -EBADF;
1724 }
1725 /*
1726 * we cannot mask interrupts during this call because this may
1727 * may go to sleep if memory is not readily avalaible.
1728 *
1729 * We are protected from the conetxt disappearing by the get_fd()/put_fd()
1730 * done in caller. Serialization of this function is ensured by caller.
1731 */
1732 ret = pfm_do_fasync(fd, filp, ctx, on);
1733
1734
1735 DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1736 fd,
1737 on,
1738 ctx->ctx_async_queue, ret));
1739
1740 return ret;
1741}
1742
1743#ifdef CONFIG_SMP
1744/*
1745 * this function is exclusively called from pfm_close().
1746 * The context is not protected at that time, nor are interrupts
1747 * on the remote CPU. That's necessary to avoid deadlocks.
1748 */
1749static void
1750pfm_syswide_force_stop(void *info)
1751{
1752 pfm_context_t *ctx = (pfm_context_t *)info;
1753 struct pt_regs *regs = task_pt_regs(current);
1754 struct task_struct *owner;
1755 unsigned long flags;
1756 int ret;
1757
1758 if (ctx->ctx_cpu != smp_processor_id()) {
1759 printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
1760 ctx->ctx_cpu,
1761 smp_processor_id());
1762 return;
1763 }
1764 owner = GET_PMU_OWNER();
1765 if (owner != ctx->ctx_task) {
1766 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
1767 smp_processor_id(),
1768 task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
1769 return;
1770 }
1771 if (GET_PMU_CTX() != ctx) {
1772 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
1773 smp_processor_id(),
1774 GET_PMU_CTX(), ctx);
1775 return;
1776 }
1777
1778 DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
1779 /*
1780 * the context is already protected in pfm_close(), we simply
1781 * need to mask interrupts to avoid a PMU interrupt race on
1782 * this CPU
1783 */
1784 local_irq_save(flags);
1785
1786 ret = pfm_context_unload(ctx, NULL, 0, regs);
1787 if (ret) {
1788 DPRINT(("context_unload returned %d\n", ret));
1789 }
1790
1791 /*
1792 * unmask interrupts, PMU interrupts are now spurious here
1793 */
1794 local_irq_restore(flags);
1795}
1796
1797static void
1798pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
1799{
1800 int ret;
1801
1802 DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
1803 ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 1);
1804 DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
1805}
1806#endif /* CONFIG_SMP */
1807
1808/*
1809 * called for each close(). Partially free resources.
1810 * When caller is self-monitoring, the context is unloaded.
1811 */
1812static int
1813pfm_flush(struct file *filp, fl_owner_t id)
1814{
1815 pfm_context_t *ctx;
1816 struct task_struct *task;
1817 struct pt_regs *regs;
1818 unsigned long flags;
1819 unsigned long smpl_buf_size = 0UL;
1820 void *smpl_buf_vaddr = NULL;
1821 int state, is_system;
1822
1823 if (PFM_IS_FILE(filp) == 0) {
1824 DPRINT(("bad magic for\n"));
1825 return -EBADF;
1826 }
1827
1828 ctx = filp->private_data;
1829 if (ctx == NULL) {
1830 printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
1831 return -EBADF;
1832 }
1833
1834 /*
1835 * remove our file from the async queue, if we use this mode.
1836 * This can be done without the context being protected. We come
1837 * here when the context has become unreachable by other tasks.
1838 *
1839 * We may still have active monitoring at this point and we may
1840 * end up in pfm_overflow_handler(). However, fasync_helper()
1841 * operates with interrupts disabled and it cleans up the
1842 * queue. If the PMU handler is called prior to entering
1843 * fasync_helper() then it will send a signal. If it is
1844 * invoked after, it will find an empty queue and no
1845 * signal will be sent. In both case, we are safe
1846 */
1847 PROTECT_CTX(ctx, flags);
1848
1849 state = ctx->ctx_state;
1850 is_system = ctx->ctx_fl_system;
1851
1852 task = PFM_CTX_TASK(ctx);
1853 regs = task_pt_regs(task);
1854
1855 DPRINT(("ctx_state=%d is_current=%d\n",
1856 state,
1857 task == current ? 1 : 0));
1858
1859 /*
1860 * if state == UNLOADED, then task is NULL
1861 */
1862
1863 /*
1864 * we must stop and unload because we are losing access to the context.
1865 */
1866 if (task == current) {
1867#ifdef CONFIG_SMP
1868 /*
1869 * the task IS the owner but it migrated to another CPU: that's bad
1870 * but we must handle this cleanly. Unfortunately, the kernel does
1871 * not provide a mechanism to block migration (while the context is loaded).
1872 *
1873 * We need to release the resource on the ORIGINAL cpu.
1874 */
1875 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
1876
1877 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
1878 /*
1879 * keep context protected but unmask interrupt for IPI
1880 */
1881 local_irq_restore(flags);
1882
1883 pfm_syswide_cleanup_other_cpu(ctx);
1884
1885 /*
1886 * restore interrupt masking
1887 */
1888 local_irq_save(flags);
1889
1890 /*
1891 * context is unloaded at this point
1892 */
1893 } else
1894#endif /* CONFIG_SMP */
1895 {
1896
1897 DPRINT(("forcing unload\n"));
1898 /*
1899 * stop and unload, returning with state UNLOADED
1900 * and session unreserved.
1901 */
1902 pfm_context_unload(ctx, NULL, 0, regs);
1903
1904 DPRINT(("ctx_state=%d\n", ctx->ctx_state));
1905 }
1906 }
1907
1908 /*
1909 * remove virtual mapping, if any, for the calling task.
1910 * cannot reset ctx field until last user is calling close().
1911 *
1912 * ctx_smpl_vaddr must never be cleared because it is needed
1913 * by every task with access to the context
1914 *
1915 * When called from do_exit(), the mm context is gone already, therefore
1916 * mm is NULL, i.e., the VMA is already gone and we do not have to
1917 * do anything here
1918 */
1919 if (ctx->ctx_smpl_vaddr && current->mm) {
1920 smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
1921 smpl_buf_size = ctx->ctx_smpl_size;
1922 }
1923
1924 UNPROTECT_CTX(ctx, flags);
1925
1926 /*
1927 * if there was a mapping, then we systematically remove it
1928 * at this point. Cannot be done inside critical section
1929 * because some VM function reenables interrupts.
1930 *
1931 */
1932 if (smpl_buf_vaddr) pfm_remove_smpl_mapping(smpl_buf_vaddr, smpl_buf_size);
1933
1934 return 0;
1935}
1936/*
1937 * called either on explicit close() or from exit_files().
1938 * Only the LAST user of the file gets to this point, i.e., it is
1939 * called only ONCE.
1940 *
1941 * IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
1942 * (fput()),i.e, last task to access the file. Nobody else can access the
1943 * file at this point.
1944 *
1945 * When called from exit_files(), the VMA has been freed because exit_mm()
1946 * is executed before exit_files().
1947 *
1948 * When called from exit_files(), the current task is not yet ZOMBIE but we
1949 * flush the PMU state to the context.
1950 */
1951static int
1952pfm_close(struct inode *inode, struct file *filp)
1953{
1954 pfm_context_t *ctx;
1955 struct task_struct *task;
1956 struct pt_regs *regs;
1957 DECLARE_WAITQUEUE(wait, current);
1958 unsigned long flags;
1959 unsigned long smpl_buf_size = 0UL;
1960 void *smpl_buf_addr = NULL;
1961 int free_possible = 1;
1962 int state, is_system;
1963
1964 DPRINT(("pfm_close called private=%p\n", filp->private_data));
1965
1966 if (PFM_IS_FILE(filp) == 0) {
1967 DPRINT(("bad magic\n"));
1968 return -EBADF;
1969 }
1970
1971 ctx = filp->private_data;
1972 if (ctx == NULL) {
1973 printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
1974 return -EBADF;
1975 }
1976
1977 PROTECT_CTX(ctx, flags);
1978
1979 state = ctx->ctx_state;
1980 is_system = ctx->ctx_fl_system;
1981
1982 task = PFM_CTX_TASK(ctx);
1983 regs = task_pt_regs(task);
1984
1985 DPRINT(("ctx_state=%d is_current=%d\n",
1986 state,
1987 task == current ? 1 : 0));
1988
1989 /*
1990 * if task == current, then pfm_flush() unloaded the context
1991 */
1992 if (state == PFM_CTX_UNLOADED) goto doit;
1993
1994 /*
1995 * context is loaded/masked and task != current, we need to
1996 * either force an unload or go zombie
1997 */
1998
1999 /*
2000 * The task is currently blocked or will block after an overflow.
2001 * we must force it to wakeup to get out of the
2002 * MASKED state and transition to the unloaded state by itself.
2003 *
2004 * This situation is only possible for per-task mode
2005 */
2006 if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
2007
2008 /*
2009 * set a "partial" zombie state to be checked
2010 * upon return from down() in pfm_handle_work().
2011 *
2012 * We cannot use the ZOMBIE state, because it is checked
2013 * by pfm_load_regs() which is called upon wakeup from down().
2014 * In such case, it would free the context and then we would
2015 * return to pfm_handle_work() which would access the
2016 * stale context. Instead, we set a flag invisible to pfm_load_regs()
2017 * but visible to pfm_handle_work().
2018 *
2019 * For some window of time, we have a zombie context with
2020 * ctx_state = MASKED and not ZOMBIE
2021 */
2022 ctx->ctx_fl_going_zombie = 1;
2023
2024 /*
2025 * force task to wake up from MASKED state
2026 */
2027 complete(&ctx->ctx_restart_done);
2028
2029 DPRINT(("waking up ctx_state=%d\n", state));
2030
2031 /*
2032 * put ourself to sleep waiting for the other
2033 * task to report completion
2034 *
2035 * the context is protected by mutex, therefore there
2036 * is no risk of being notified of completion before
2037 * begin actually on the waitq.
2038 */
2039 set_current_state(TASK_INTERRUPTIBLE);
2040 add_wait_queue(&ctx->ctx_zombieq, &wait);
2041
2042 UNPROTECT_CTX(ctx, flags);
2043
2044 /*
2045 * XXX: check for signals :
2046 * - ok for explicit close
2047 * - not ok when coming from exit_files()
2048 */
2049 schedule();
2050
2051
2052 PROTECT_CTX(ctx, flags);
2053
2054
2055 remove_wait_queue(&ctx->ctx_zombieq, &wait);
2056 set_current_state(TASK_RUNNING);
2057
2058 /*
2059 * context is unloaded at this point
2060 */
2061 DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
2062 }
2063 else if (task != current) {
2064#ifdef CONFIG_SMP
2065 /*
2066 * switch context to zombie state
2067 */
2068 ctx->ctx_state = PFM_CTX_ZOMBIE;
2069
2070 DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
2071 /*
2072 * cannot free the context on the spot. deferred until
2073 * the task notices the ZOMBIE state
2074 */
2075 free_possible = 0;
2076#else
2077 pfm_context_unload(ctx, NULL, 0, regs);
2078#endif
2079 }
2080
2081doit:
2082 /* reload state, may have changed during opening of critical section */
2083 state = ctx->ctx_state;
2084
2085 /*
2086 * the context is still attached to a task (possibly current)
2087 * we cannot destroy it right now
2088 */
2089
2090 /*
2091 * we must free the sampling buffer right here because
2092 * we cannot rely on it being cleaned up later by the
2093 * monitored task. It is not possible to free vmalloc'ed
2094 * memory in pfm_load_regs(). Instead, we remove the buffer
2095 * now. should there be subsequent PMU overflow originally
2096 * meant for sampling, the will be converted to spurious
2097 * and that's fine because the monitoring tools is gone anyway.
2098 */
2099 if (ctx->ctx_smpl_hdr) {
2100 smpl_buf_addr = ctx->ctx_smpl_hdr;
2101 smpl_buf_size = ctx->ctx_smpl_size;
2102 /* no more sampling */
2103 ctx->ctx_smpl_hdr = NULL;
2104 ctx->ctx_fl_is_sampling = 0;
2105 }
2106
2107 DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
2108 state,
2109 free_possible,
2110 smpl_buf_addr,
2111 smpl_buf_size));
2112
2113 if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
2114
2115 /*
2116 * UNLOADED that the session has already been unreserved.
2117 */
2118 if (state == PFM_CTX_ZOMBIE) {
2119 pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
2120 }
2121
2122 /*
2123 * disconnect file descriptor from context must be done
2124 * before we unlock.
2125 */
2126 filp->private_data = NULL;
2127
2128 /*
2129 * if we free on the spot, the context is now completely unreachable
2130 * from the callers side. The monitored task side is also cut, so we
2131 * can freely cut.
2132 *
2133 * If we have a deferred free, only the caller side is disconnected.
2134 */
2135 UNPROTECT_CTX(ctx, flags);
2136
2137 /*
2138 * All memory free operations (especially for vmalloc'ed memory)
2139 * MUST be done with interrupts ENABLED.
2140 */
2141 if (smpl_buf_addr) pfm_rvfree(smpl_buf_addr, smpl_buf_size);
2142
2143 /*
2144 * return the memory used by the context
2145 */
2146 if (free_possible) pfm_context_free(ctx);
2147
2148 return 0;
2149}
2150
2151static int
2152pfm_no_open(struct inode *irrelevant, struct file *dontcare)
2153{
2154 DPRINT(("pfm_no_open called\n"));
2155 return -ENXIO;
2156}
2157
2158
2159
2160static const struct file_operations pfm_file_ops = {
2161 .llseek = no_llseek,
2162 .read = pfm_read,
2163 .write = pfm_write,
2164 .poll = pfm_poll,
2165 .unlocked_ioctl = pfm_ioctl,
2166 .open = pfm_no_open, /* special open code to disallow open via /proc */
2167 .fasync = pfm_fasync,
2168 .release = pfm_close,
2169 .flush = pfm_flush
2170};
2171
2172static int
2173pfmfs_delete_dentry(const struct dentry *dentry)
2174{
2175 return 1;
2176}
2177
2178static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
2179{
2180 return dynamic_dname(dentry, buffer, buflen, "pfm:[%lu]",
2181 dentry->d_inode->i_ino);
2182}
2183
2184static const struct dentry_operations pfmfs_dentry_operations = {
2185 .d_delete = pfmfs_delete_dentry,
2186 .d_dname = pfmfs_dname,
2187};
2188
2189
2190static struct file *
2191pfm_alloc_file(pfm_context_t *ctx)
2192{
2193 struct file *file;
2194 struct inode *inode;
2195 struct path path;
2196 struct qstr this = { .name = "" };
2197
2198 /*
2199 * allocate a new inode
2200 */
2201 inode = new_inode(pfmfs_mnt->mnt_sb);
2202 if (!inode)
2203 return ERR_PTR(-ENOMEM);
2204
2205 DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
2206
2207 inode->i_mode = S_IFCHR|S_IRUGO;
2208 inode->i_uid = current_fsuid();
2209 inode->i_gid = current_fsgid();
2210
2211 /*
2212 * allocate a new dcache entry
2213 */
2214 path.dentry = d_alloc(pfmfs_mnt->mnt_root, &this);
2215 if (!path.dentry) {
2216 iput(inode);
2217 return ERR_PTR(-ENOMEM);
2218 }
2219 path.mnt = mntget(pfmfs_mnt);
2220
2221 d_add(path.dentry, inode);
2222
2223 file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
2224 if (!file) {
2225 path_put(&path);
2226 return ERR_PTR(-ENFILE);
2227 }
2228
2229 file->f_flags = O_RDONLY;
2230 file->private_data = ctx;
2231
2232 return file;
2233}
2234
2235static int
2236pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
2237{
2238 DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
2239
2240 while (size > 0) {
2241 unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
2242
2243
2244 if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
2245 return -ENOMEM;
2246
2247 addr += PAGE_SIZE;
2248 buf += PAGE_SIZE;
2249 size -= PAGE_SIZE;
2250 }
2251 return 0;
2252}
2253
2254/*
2255 * allocate a sampling buffer and remaps it into the user address space of the task
2256 */
2257static int
2258pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
2259{
2260 struct mm_struct *mm = task->mm;
2261 struct vm_area_struct *vma = NULL;
2262 unsigned long size;
2263 void *smpl_buf;
2264
2265
2266 /*
2267 * the fixed header + requested size and align to page boundary
2268 */
2269 size = PAGE_ALIGN(rsize);
2270
2271 DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
2272
2273 /*
2274 * check requested size to avoid Denial-of-service attacks
2275 * XXX: may have to refine this test
2276 * Check against address space limit.
2277 *
2278 * if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
2279 * return -ENOMEM;
2280 */
2281 if (size > task_rlimit(task, RLIMIT_MEMLOCK))
2282 return -ENOMEM;
2283
2284 /*
2285 * We do the easy to undo allocations first.
2286 *
2287 * pfm_rvmalloc(), clears the buffer, so there is no leak
2288 */
2289 smpl_buf = pfm_rvmalloc(size);
2290 if (smpl_buf == NULL) {
2291 DPRINT(("Can't allocate sampling buffer\n"));
2292 return -ENOMEM;
2293 }
2294
2295 DPRINT(("smpl_buf @%p\n", smpl_buf));
2296
2297 /* allocate vma */
2298 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
2299 if (!vma) {
2300 DPRINT(("Cannot allocate vma\n"));
2301 goto error_kmem;
2302 }
2303 INIT_LIST_HEAD(&vma->anon_vma_chain);
2304
2305 /*
2306 * partially initialize the vma for the sampling buffer
2307 */
2308 vma->vm_mm = mm;
2309 vma->vm_file = filp;
2310 vma->vm_flags = VM_READ| VM_MAYREAD |VM_RESERVED;
2311 vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
2312
2313 /*
2314 * Now we have everything we need and we can initialize
2315 * and connect all the data structures
2316 */
2317
2318 ctx->ctx_smpl_hdr = smpl_buf;
2319 ctx->ctx_smpl_size = size; /* aligned size */
2320
2321 /*
2322 * Let's do the difficult operations next.
2323 *
2324 * now we atomically find some area in the address space and
2325 * remap the buffer in it.
2326 */
2327 down_write(&task->mm->mmap_sem);
2328
2329 /* find some free area in address space, must have mmap sem held */
2330 vma->vm_start = get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS);
2331 if (IS_ERR_VALUE(vma->vm_start)) {
2332 DPRINT(("Cannot find unmapped area for size %ld\n", size));
2333 up_write(&task->mm->mmap_sem);
2334 goto error;
2335 }
2336 vma->vm_end = vma->vm_start + size;
2337 vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
2338
2339 DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
2340
2341 /* can only be applied to current task, need to have the mm semaphore held when called */
2342 if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
2343 DPRINT(("Can't remap buffer\n"));
2344 up_write(&task->mm->mmap_sem);
2345 goto error;
2346 }
2347
2348 get_file(filp);
2349
2350 /*
2351 * now insert the vma in the vm list for the process, must be
2352 * done with mmap lock held
2353 */
2354 insert_vm_struct(mm, vma);
2355
2356 mm->total_vm += size >> PAGE_SHIFT;
2357 vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
2358 vma_pages(vma));
2359 up_write(&task->mm->mmap_sem);
2360
2361 /*
2362 * keep track of user level virtual address
2363 */
2364 ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
2365 *(unsigned long *)user_vaddr = vma->vm_start;
2366
2367 return 0;
2368
2369error:
2370 kmem_cache_free(vm_area_cachep, vma);
2371error_kmem:
2372 pfm_rvfree(smpl_buf, size);
2373
2374 return -ENOMEM;
2375}
2376
2377/*
2378 * XXX: do something better here
2379 */
2380static int
2381pfm_bad_permissions(struct task_struct *task)
2382{
2383 const struct cred *tcred;
2384 uid_t uid = current_uid();
2385 gid_t gid = current_gid();
2386 int ret;
2387
2388 rcu_read_lock();
2389 tcred = __task_cred(task);
2390
2391 /* inspired by ptrace_attach() */
2392 DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
2393 uid,
2394 gid,
2395 tcred->euid,
2396 tcred->suid,
2397 tcred->uid,
2398 tcred->egid,
2399 tcred->sgid));
2400
2401 ret = ((uid != tcred->euid)
2402 || (uid != tcred->suid)
2403 || (uid != tcred->uid)
2404 || (gid != tcred->egid)
2405 || (gid != tcred->sgid)
2406 || (gid != tcred->gid)) && !capable(CAP_SYS_PTRACE);
2407
2408 rcu_read_unlock();
2409 return ret;
2410}
2411
2412static int
2413pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
2414{
2415 int ctx_flags;
2416
2417 /* valid signal */
2418
2419 ctx_flags = pfx->ctx_flags;
2420
2421 if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
2422
2423 /*
2424 * cannot block in this mode
2425 */
2426 if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
2427 DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
2428 return -EINVAL;
2429 }
2430 } else {
2431 }
2432 /* probably more to add here */
2433
2434 return 0;
2435}
2436
2437static int
2438pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
2439 unsigned int cpu, pfarg_context_t *arg)
2440{
2441 pfm_buffer_fmt_t *fmt = NULL;
2442 unsigned long size = 0UL;
2443 void *uaddr = NULL;
2444 void *fmt_arg = NULL;
2445 int ret = 0;
2446#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
2447
2448 /* invoke and lock buffer format, if found */
2449 fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
2450 if (fmt == NULL) {
2451 DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
2452 return -EINVAL;
2453 }
2454
2455 /*
2456 * buffer argument MUST be contiguous to pfarg_context_t
2457 */
2458 if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
2459
2460 ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
2461
2462 DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
2463
2464 if (ret) goto error;
2465
2466 /* link buffer format and context */
2467 ctx->ctx_buf_fmt = fmt;
2468 ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
2469
2470 /*
2471 * check if buffer format wants to use perfmon buffer allocation/mapping service
2472 */
2473 ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
2474 if (ret) goto error;
2475
2476 if (size) {
2477 /*
2478 * buffer is always remapped into the caller's address space
2479 */
2480 ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
2481 if (ret) goto error;
2482
2483 /* keep track of user address of buffer */
2484 arg->ctx_smpl_vaddr = uaddr;
2485 }
2486 ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
2487
2488error:
2489 return ret;
2490}
2491
2492static void
2493pfm_reset_pmu_state(pfm_context_t *ctx)
2494{
2495 int i;
2496
2497 /*
2498 * install reset values for PMC.
2499 */
2500 for (i=1; PMC_IS_LAST(i) == 0; i++) {
2501 if (PMC_IS_IMPL(i) == 0) continue;
2502 ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
2503 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
2504 }
2505 /*
2506 * PMD registers are set to 0UL when the context in memset()
2507 */
2508
2509 /*
2510 * On context switched restore, we must restore ALL pmc and ALL pmd even
2511 * when they are not actively used by the task. In UP, the incoming process
2512 * may otherwise pick up left over PMC, PMD state from the previous process.
2513 * As opposed to PMD, stale PMC can cause harm to the incoming
2514 * process because they may change what is being measured.
2515 * Therefore, we must systematically reinstall the entire
2516 * PMC state. In SMP, the same thing is possible on the
2517 * same CPU but also on between 2 CPUs.
2518 *
2519 * The problem with PMD is information leaking especially
2520 * to user level when psr.sp=0
2521 *
2522 * There is unfortunately no easy way to avoid this problem
2523 * on either UP or SMP. This definitively slows down the
2524 * pfm_load_regs() function.
2525 */
2526
2527 /*
2528 * bitmask of all PMCs accessible to this context
2529 *
2530 * PMC0 is treated differently.
2531 */
2532 ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
2533
2534 /*
2535 * bitmask of all PMDs that are accessible to this context
2536 */
2537 ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
2538
2539 DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
2540
2541 /*
2542 * useful in case of re-enable after disable
2543 */
2544 ctx->ctx_used_ibrs[0] = 0UL;
2545 ctx->ctx_used_dbrs[0] = 0UL;
2546}
2547
2548static int
2549pfm_ctx_getsize(void *arg, size_t *sz)
2550{
2551 pfarg_context_t *req = (pfarg_context_t *)arg;
2552 pfm_buffer_fmt_t *fmt;
2553
2554 *sz = 0;
2555
2556 if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
2557
2558 fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
2559 if (fmt == NULL) {
2560 DPRINT(("cannot find buffer format\n"));
2561 return -EINVAL;
2562 }
2563 /* get just enough to copy in user parameters */
2564 *sz = fmt->fmt_arg_size;
2565 DPRINT(("arg_size=%lu\n", *sz));
2566
2567 return 0;
2568}
2569
2570
2571
2572/*
2573 * cannot attach if :
2574 * - kernel task
2575 * - task not owned by caller
2576 * - task incompatible with context mode
2577 */
2578static int
2579pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
2580{
2581 /*
2582 * no kernel task or task not owner by caller
2583 */
2584 if (task->mm == NULL) {
2585 DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
2586 return -EPERM;
2587 }
2588 if (pfm_bad_permissions(task)) {
2589 DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
2590 return -EPERM;
2591 }
2592 /*
2593 * cannot block in self-monitoring mode
2594 */
2595 if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
2596 DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
2597 return -EINVAL;
2598 }
2599
2600 if (task->exit_state == EXIT_ZOMBIE) {
2601 DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
2602 return -EBUSY;
2603 }
2604
2605 /*
2606 * always ok for self
2607 */
2608 if (task == current) return 0;
2609
2610 if (!task_is_stopped_or_traced(task)) {
2611 DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
2612 return -EBUSY;
2613 }
2614 /*
2615 * make sure the task is off any CPU
2616 */
2617 wait_task_inactive(task, 0);
2618
2619 /* more to come... */
2620
2621 return 0;
2622}
2623
2624static int
2625pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
2626{
2627 struct task_struct *p = current;
2628 int ret;
2629
2630 /* XXX: need to add more checks here */
2631 if (pid < 2) return -EPERM;
2632
2633 if (pid != task_pid_vnr(current)) {
2634
2635 read_lock(&tasklist_lock);
2636
2637 p = find_task_by_vpid(pid);
2638
2639 /* make sure task cannot go away while we operate on it */
2640 if (p) get_task_struct(p);
2641
2642 read_unlock(&tasklist_lock);
2643
2644 if (p == NULL) return -ESRCH;
2645 }
2646
2647 ret = pfm_task_incompatible(ctx, p);
2648 if (ret == 0) {
2649 *task = p;
2650 } else if (p != current) {
2651 pfm_put_task(p);
2652 }
2653 return ret;
2654}
2655
2656
2657
2658static int
2659pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2660{
2661 pfarg_context_t *req = (pfarg_context_t *)arg;
2662 struct file *filp;
2663 struct path path;
2664 int ctx_flags;
2665 int fd;
2666 int ret;
2667
2668 /* let's check the arguments first */
2669 ret = pfarg_is_sane(current, req);
2670 if (ret < 0)
2671 return ret;
2672
2673 ctx_flags = req->ctx_flags;
2674
2675 ret = -ENOMEM;
2676
2677 fd = get_unused_fd();
2678 if (fd < 0)
2679 return fd;
2680
2681 ctx = pfm_context_alloc(ctx_flags);
2682 if (!ctx)
2683 goto error;
2684
2685 filp = pfm_alloc_file(ctx);
2686 if (IS_ERR(filp)) {
2687 ret = PTR_ERR(filp);
2688 goto error_file;
2689 }
2690
2691 req->ctx_fd = ctx->ctx_fd = fd;
2692
2693 /*
2694 * does the user want to sample?
2695 */
2696 if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
2697 ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
2698 if (ret)
2699 goto buffer_error;
2700 }
2701
2702 DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d\n",
2703 ctx,
2704 ctx_flags,
2705 ctx->ctx_fl_system,
2706 ctx->ctx_fl_block,
2707 ctx->ctx_fl_excl_idle,
2708 ctx->ctx_fl_no_msg,
2709 ctx->ctx_fd));
2710
2711 /*
2712 * initialize soft PMU state
2713 */
2714 pfm_reset_pmu_state(ctx);
2715
2716 fd_install(fd, filp);
2717
2718 return 0;
2719
2720buffer_error:
2721 path = filp->f_path;
2722 put_filp(filp);
2723 path_put(&path);
2724
2725 if (ctx->ctx_buf_fmt) {
2726 pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
2727 }
2728error_file:
2729 pfm_context_free(ctx);
2730
2731error:
2732 put_unused_fd(fd);
2733 return ret;
2734}
2735
2736static inline unsigned long
2737pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
2738{
2739 unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
2740 unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
2741 extern unsigned long carta_random32 (unsigned long seed);
2742
2743 if (reg->flags & PFM_REGFL_RANDOM) {
2744 new_seed = carta_random32(old_seed);
2745 val -= (old_seed & mask); /* counter values are negative numbers! */
2746 if ((mask >> 32) != 0)
2747 /* construct a full 64-bit random value: */
2748 new_seed |= carta_random32(old_seed >> 32) << 32;
2749 reg->seed = new_seed;
2750 }
2751 reg->lval = val;
2752 return val;
2753}
2754
2755static void
2756pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2757{
2758 unsigned long mask = ovfl_regs[0];
2759 unsigned long reset_others = 0UL;
2760 unsigned long val;
2761 int i;
2762
2763 /*
2764 * now restore reset value on sampling overflowed counters
2765 */
2766 mask >>= PMU_FIRST_COUNTER;
2767 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2768
2769 if ((mask & 0x1UL) == 0UL) continue;
2770
2771 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2772 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2773
2774 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2775 }
2776
2777 /*
2778 * Now take care of resetting the other registers
2779 */
2780 for(i = 0; reset_others; i++, reset_others >>= 1) {
2781
2782 if ((reset_others & 0x1) == 0) continue;
2783
2784 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2785
2786 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2787 is_long_reset ? "long" : "short", i, val));
2788 }
2789}
2790
2791static void
2792pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2793{
2794 unsigned long mask = ovfl_regs[0];
2795 unsigned long reset_others = 0UL;
2796 unsigned long val;
2797 int i;
2798
2799 DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
2800
2801 if (ctx->ctx_state == PFM_CTX_MASKED) {
2802 pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
2803 return;
2804 }
2805
2806 /*
2807 * now restore reset value on sampling overflowed counters
2808 */
2809 mask >>= PMU_FIRST_COUNTER;
2810 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2811
2812 if ((mask & 0x1UL) == 0UL) continue;
2813
2814 val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2815 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2816
2817 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2818
2819 pfm_write_soft_counter(ctx, i, val);
2820 }
2821
2822 /*
2823 * Now take care of resetting the other registers
2824 */
2825 for(i = 0; reset_others; i++, reset_others >>= 1) {
2826
2827 if ((reset_others & 0x1) == 0) continue;
2828
2829 val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2830
2831 if (PMD_IS_COUNTING(i)) {
2832 pfm_write_soft_counter(ctx, i, val);
2833 } else {
2834 ia64_set_pmd(i, val);
2835 }
2836 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2837 is_long_reset ? "long" : "short", i, val));
2838 }
2839 ia64_srlz_d();
2840}
2841
2842static int
2843pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2844{
2845 struct task_struct *task;
2846 pfarg_reg_t *req = (pfarg_reg_t *)arg;
2847 unsigned long value, pmc_pm;
2848 unsigned long smpl_pmds, reset_pmds, impl_pmds;
2849 unsigned int cnum, reg_flags, flags, pmc_type;
2850 int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
2851 int is_monitor, is_counting, state;
2852 int ret = -EINVAL;
2853 pfm_reg_check_t wr_func;
2854#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
2855
2856 state = ctx->ctx_state;
2857 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
2858 is_system = ctx->ctx_fl_system;
2859 task = ctx->ctx_task;
2860 impl_pmds = pmu_conf->impl_pmds[0];
2861
2862 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
2863
2864 if (is_loaded) {
2865 /*
2866 * In system wide and when the context is loaded, access can only happen
2867 * when the caller is running on the CPU being monitored by the session.
2868 * It does not have to be the owner (ctx_task) of the context per se.
2869 */
2870 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
2871 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
2872 return -EBUSY;
2873 }
2874 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
2875 }
2876 expert_mode = pfm_sysctl.expert_mode;
2877
2878 for (i = 0; i < count; i++, req++) {
2879
2880 cnum = req->reg_num;
2881 reg_flags = req->reg_flags;
2882 value = req->reg_value;
2883 smpl_pmds = req->reg_smpl_pmds[0];
2884 reset_pmds = req->reg_reset_pmds[0];
2885 flags = 0;
2886
2887
2888 if (cnum >= PMU_MAX_PMCS) {
2889 DPRINT(("pmc%u is invalid\n", cnum));
2890 goto error;
2891 }
2892
2893 pmc_type = pmu_conf->pmc_desc[cnum].type;
2894 pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
2895 is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
2896 is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
2897
2898 /*
2899 * we reject all non implemented PMC as well
2900 * as attempts to modify PMC[0-3] which are used
2901 * as status registers by the PMU
2902 */
2903 if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
2904 DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
2905 goto error;
2906 }
2907 wr_func = pmu_conf->pmc_desc[cnum].write_check;
2908 /*
2909 * If the PMC is a monitor, then if the value is not the default:
2910 * - system-wide session: PMCx.pm=1 (privileged monitor)
2911 * - per-task : PMCx.pm=0 (user monitor)
2912 */
2913 if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
2914 DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
2915 cnum,
2916 pmc_pm,
2917 is_system));
2918 goto error;
2919 }
2920
2921 if (is_counting) {
2922 /*
2923 * enforce generation of overflow interrupt. Necessary on all
2924 * CPUs.
2925 */
2926 value |= 1 << PMU_PMC_OI;
2927
2928 if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
2929 flags |= PFM_REGFL_OVFL_NOTIFY;
2930 }
2931
2932 if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
2933
2934 /* verify validity of smpl_pmds */
2935 if ((smpl_pmds & impl_pmds) != smpl_pmds) {
2936 DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
2937 goto error;
2938 }
2939
2940 /* verify validity of reset_pmds */
2941 if ((reset_pmds & impl_pmds) != reset_pmds) {
2942 DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
2943 goto error;
2944 }
2945 } else {
2946 if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
2947 DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
2948 goto error;
2949 }
2950 /* eventid on non-counting monitors are ignored */
2951 }
2952
2953 /*
2954 * execute write checker, if any
2955 */
2956 if (likely(expert_mode == 0 && wr_func)) {
2957 ret = (*wr_func)(task, ctx, cnum, &value, regs);
2958 if (ret) goto error;
2959 ret = -EINVAL;
2960 }
2961
2962 /*
2963 * no error on this register
2964 */
2965 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
2966
2967 /*
2968 * Now we commit the changes to the software state
2969 */
2970
2971 /*
2972 * update overflow information
2973 */
2974 if (is_counting) {
2975 /*
2976 * full flag update each time a register is programmed
2977 */
2978 ctx->ctx_pmds[cnum].flags = flags;
2979
2980 ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
2981 ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
2982 ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
2983
2984 /*
2985 * Mark all PMDS to be accessed as used.
2986 *
2987 * We do not keep track of PMC because we have to
2988 * systematically restore ALL of them.
2989 *
2990 * We do not update the used_monitors mask, because
2991 * if we have not programmed them, then will be in
2992 * a quiescent state, therefore we will not need to
2993 * mask/restore then when context is MASKED.
2994 */
2995 CTX_USED_PMD(ctx, reset_pmds);
2996 CTX_USED_PMD(ctx, smpl_pmds);
2997 /*
2998 * make sure we do not try to reset on
2999 * restart because we have established new values
3000 */
3001 if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3002 }
3003 /*
3004 * Needed in case the user does not initialize the equivalent
3005 * PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
3006 * possible leak here.
3007 */
3008 CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
3009
3010 /*
3011 * keep track of the monitor PMC that we are using.
3012 * we save the value of the pmc in ctx_pmcs[] and if
3013 * the monitoring is not stopped for the context we also
3014 * place it in the saved state area so that it will be
3015 * picked up later by the context switch code.
3016 *
3017 * The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
3018 *
3019 * The value in th_pmcs[] may be modified on overflow, i.e., when
3020 * monitoring needs to be stopped.
3021 */
3022 if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
3023
3024 /*
3025 * update context state
3026 */
3027 ctx->ctx_pmcs[cnum] = value;
3028
3029 if (is_loaded) {
3030 /*
3031 * write thread state
3032 */
3033 if (is_system == 0) ctx->th_pmcs[cnum] = value;
3034
3035 /*
3036 * write hardware register if we can
3037 */
3038 if (can_access_pmu) {
3039 ia64_set_pmc(cnum, value);
3040 }
3041#ifdef CONFIG_SMP
3042 else {
3043 /*
3044 * per-task SMP only here
3045 *
3046 * we are guaranteed that the task is not running on the other CPU,
3047 * we indicate that this PMD will need to be reloaded if the task
3048 * is rescheduled on the CPU it ran last on.
3049 */
3050 ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
3051 }
3052#endif
3053 }
3054
3055 DPRINT(("pmc[%u]=0x%lx ld=%d apmu=%d flags=0x%x all_pmcs=0x%lx used_pmds=0x%lx eventid=%ld smpl_pmds=0x%lx reset_pmds=0x%lx reloads_pmcs=0x%lx used_monitors=0x%lx ovfl_regs=0x%lx\n",
3056 cnum,
3057 value,
3058 is_loaded,
3059 can_access_pmu,
3060 flags,
3061 ctx->ctx_all_pmcs[0],
3062 ctx->ctx_used_pmds[0],
3063 ctx->ctx_pmds[cnum].eventid,
3064 smpl_pmds,
3065 reset_pmds,
3066 ctx->ctx_reload_pmcs[0],
3067 ctx->ctx_used_monitors[0],
3068 ctx->ctx_ovfl_regs[0]));
3069 }
3070
3071 /*
3072 * make sure the changes are visible
3073 */
3074 if (can_access_pmu) ia64_srlz_d();
3075
3076 return 0;
3077error:
3078 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3079 return ret;
3080}
3081
3082static int
3083pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3084{
3085 struct task_struct *task;
3086 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3087 unsigned long value, hw_value, ovfl_mask;
3088 unsigned int cnum;
3089 int i, can_access_pmu = 0, state;
3090 int is_counting, is_loaded, is_system, expert_mode;
3091 int ret = -EINVAL;
3092 pfm_reg_check_t wr_func;
3093
3094
3095 state = ctx->ctx_state;
3096 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3097 is_system = ctx->ctx_fl_system;
3098 ovfl_mask = pmu_conf->ovfl_val;
3099 task = ctx->ctx_task;
3100
3101 if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
3102
3103 /*
3104 * on both UP and SMP, we can only write to the PMC when the task is
3105 * the owner of the local PMU.
3106 */
3107 if (likely(is_loaded)) {
3108 /*
3109 * In system wide and when the context is loaded, access can only happen
3110 * when the caller is running on the CPU being monitored by the session.
3111 * It does not have to be the owner (ctx_task) of the context per se.
3112 */
3113 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3114 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3115 return -EBUSY;
3116 }
3117 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3118 }
3119 expert_mode = pfm_sysctl.expert_mode;
3120
3121 for (i = 0; i < count; i++, req++) {
3122
3123 cnum = req->reg_num;
3124 value = req->reg_value;
3125
3126 if (!PMD_IS_IMPL(cnum)) {
3127 DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
3128 goto abort_mission;
3129 }
3130 is_counting = PMD_IS_COUNTING(cnum);
3131 wr_func = pmu_conf->pmd_desc[cnum].write_check;
3132
3133 /*
3134 * execute write checker, if any
3135 */
3136 if (unlikely(expert_mode == 0 && wr_func)) {
3137 unsigned long v = value;
3138
3139 ret = (*wr_func)(task, ctx, cnum, &v, regs);
3140 if (ret) goto abort_mission;
3141
3142 value = v;
3143 ret = -EINVAL;
3144 }
3145
3146 /*
3147 * no error on this register
3148 */
3149 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
3150
3151 /*
3152 * now commit changes to software state
3153 */
3154 hw_value = value;
3155
3156 /*
3157 * update virtualized (64bits) counter
3158 */
3159 if (is_counting) {
3160 /*
3161 * write context state
3162 */
3163 ctx->ctx_pmds[cnum].lval = value;
3164
3165 /*
3166 * when context is load we use the split value
3167 */
3168 if (is_loaded) {
3169 hw_value = value & ovfl_mask;
3170 value = value & ~ovfl_mask;
3171 }
3172 }
3173 /*
3174 * update reset values (not just for counters)
3175 */
3176 ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
3177 ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
3178
3179 /*
3180 * update randomization parameters (not just for counters)
3181 */
3182 ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
3183 ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
3184
3185 /*
3186 * update context value
3187 */
3188 ctx->ctx_pmds[cnum].val = value;
3189
3190 /*
3191 * Keep track of what we use
3192 *
3193 * We do not keep track of PMC because we have to
3194 * systematically restore ALL of them.
3195 */
3196 CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
3197
3198 /*
3199 * mark this PMD register used as well
3200 */
3201 CTX_USED_PMD(ctx, RDEP(cnum));
3202
3203 /*
3204 * make sure we do not try to reset on
3205 * restart because we have established new values
3206 */
3207 if (is_counting && state == PFM_CTX_MASKED) {
3208 ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3209 }
3210
3211 if (is_loaded) {
3212 /*
3213 * write thread state
3214 */
3215 if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
3216
3217 /*
3218 * write hardware register if we can
3219 */
3220 if (can_access_pmu) {
3221 ia64_set_pmd(cnum, hw_value);
3222 } else {
3223#ifdef CONFIG_SMP
3224 /*
3225 * we are guaranteed that the task is not running on the other CPU,
3226 * we indicate that this PMD will need to be reloaded if the task
3227 * is rescheduled on the CPU it ran last on.
3228 */
3229 ctx->ctx_reload_pmds[0] |= 1UL << cnum;
3230#endif
3231 }
3232 }
3233
3234 DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
3235 "long_reset=0x%lx notify=%c seed=0x%lx mask=0x%lx used_pmds=0x%lx reset_pmds=0x%lx reload_pmds=0x%lx all_pmds=0x%lx ovfl_regs=0x%lx\n",
3236 cnum,
3237 value,
3238 is_loaded,
3239 can_access_pmu,
3240 hw_value,
3241 ctx->ctx_pmds[cnum].val,
3242 ctx->ctx_pmds[cnum].short_reset,
3243 ctx->ctx_pmds[cnum].long_reset,
3244 PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
3245 ctx->ctx_pmds[cnum].seed,
3246 ctx->ctx_pmds[cnum].mask,
3247 ctx->ctx_used_pmds[0],
3248 ctx->ctx_pmds[cnum].reset_pmds[0],
3249 ctx->ctx_reload_pmds[0],
3250 ctx->ctx_all_pmds[0],
3251 ctx->ctx_ovfl_regs[0]));
3252 }
3253
3254 /*
3255 * make changes visible
3256 */
3257 if (can_access_pmu) ia64_srlz_d();
3258
3259 return 0;
3260
3261abort_mission:
3262 /*
3263 * for now, we have only one possibility for error
3264 */
3265 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3266 return ret;
3267}
3268
3269/*
3270 * By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
3271 * Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
3272 * interrupt is delivered during the call, it will be kept pending until we leave, making
3273 * it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
3274 * guaranteed to return consistent data to the user, it may simply be old. It is not
3275 * trivial to treat the overflow while inside the call because you may end up in
3276 * some module sampling buffer code causing deadlocks.
3277 */
3278static int
3279pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3280{
3281 struct task_struct *task;
3282 unsigned long val = 0UL, lval, ovfl_mask, sval;
3283 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3284 unsigned int cnum, reg_flags = 0;
3285 int i, can_access_pmu = 0, state;
3286 int is_loaded, is_system, is_counting, expert_mode;
3287 int ret = -EINVAL;
3288 pfm_reg_check_t rd_func;
3289
3290 /*
3291 * access is possible when loaded only for
3292 * self-monitoring tasks or in UP mode
3293 */
3294
3295 state = ctx->ctx_state;
3296 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3297 is_system = ctx->ctx_fl_system;
3298 ovfl_mask = pmu_conf->ovfl_val;
3299 task = ctx->ctx_task;
3300
3301 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3302
3303 if (likely(is_loaded)) {
3304 /*
3305 * In system wide and when the context is loaded, access can only happen
3306 * when the caller is running on the CPU being monitored by the session.
3307 * It does not have to be the owner (ctx_task) of the context per se.
3308 */
3309 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3310 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3311 return -EBUSY;
3312 }
3313 /*
3314 * this can be true when not self-monitoring only in UP
3315 */
3316 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3317
3318 if (can_access_pmu) ia64_srlz_d();
3319 }
3320 expert_mode = pfm_sysctl.expert_mode;
3321
3322 DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
3323 is_loaded,
3324 can_access_pmu,
3325 state));
3326
3327 /*
3328 * on both UP and SMP, we can only read the PMD from the hardware register when
3329 * the task is the owner of the local PMU.
3330 */
3331
3332 for (i = 0; i < count; i++, req++) {
3333
3334 cnum = req->reg_num;
3335 reg_flags = req->reg_flags;
3336
3337 if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
3338 /*
3339 * we can only read the register that we use. That includes
3340 * the one we explicitly initialize AND the one we want included
3341 * in the sampling buffer (smpl_regs).
3342 *
3343 * Having this restriction allows optimization in the ctxsw routine
3344 * without compromising security (leaks)
3345 */
3346 if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
3347
3348 sval = ctx->ctx_pmds[cnum].val;
3349 lval = ctx->ctx_pmds[cnum].lval;
3350 is_counting = PMD_IS_COUNTING(cnum);
3351
3352 /*
3353 * If the task is not the current one, then we check if the
3354 * PMU state is still in the local live register due to lazy ctxsw.
3355 * If true, then we read directly from the registers.
3356 */
3357 if (can_access_pmu){
3358 val = ia64_get_pmd(cnum);
3359 } else {
3360 /*
3361 * context has been saved
3362 * if context is zombie, then task does not exist anymore.
3363 * In this case, we use the full value saved in the context (pfm_flush_regs()).
3364 */
3365 val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
3366 }
3367 rd_func = pmu_conf->pmd_desc[cnum].read_check;
3368
3369 if (is_counting) {
3370 /*
3371 * XXX: need to check for overflow when loaded
3372 */
3373 val &= ovfl_mask;
3374 val += sval;
3375 }
3376
3377 /*
3378 * execute read checker, if any
3379 */
3380 if (unlikely(expert_mode == 0 && rd_func)) {
3381 unsigned long v = val;
3382 ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
3383 if (ret) goto error;
3384 val = v;
3385 ret = -EINVAL;
3386 }
3387
3388 PFM_REG_RETFLAG_SET(reg_flags, 0);
3389
3390 DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
3391
3392 /*
3393 * update register return value, abort all if problem during copy.
3394 * we only modify the reg_flags field. no check mode is fine because
3395 * access has been verified upfront in sys_perfmonctl().
3396 */
3397 req->reg_value = val;
3398 req->reg_flags = reg_flags;
3399 req->reg_last_reset_val = lval;
3400 }
3401
3402 return 0;
3403
3404error:
3405 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3406 return ret;
3407}
3408
3409int
3410pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3411{
3412 pfm_context_t *ctx;
3413
3414 if (req == NULL) return -EINVAL;
3415
3416 ctx = GET_PMU_CTX();
3417
3418 if (ctx == NULL) return -EINVAL;
3419
3420 /*
3421 * for now limit to current task, which is enough when calling
3422 * from overflow handler
3423 */
3424 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3425
3426 return pfm_write_pmcs(ctx, req, nreq, regs);
3427}
3428EXPORT_SYMBOL(pfm_mod_write_pmcs);
3429
3430int
3431pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3432{
3433 pfm_context_t *ctx;
3434
3435 if (req == NULL) return -EINVAL;
3436
3437 ctx = GET_PMU_CTX();
3438
3439 if (ctx == NULL) return -EINVAL;
3440
3441 /*
3442 * for now limit to current task, which is enough when calling
3443 * from overflow handler
3444 */
3445 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3446
3447 return pfm_read_pmds(ctx, req, nreq, regs);
3448}
3449EXPORT_SYMBOL(pfm_mod_read_pmds);
3450
3451/*
3452 * Only call this function when a process it trying to
3453 * write the debug registers (reading is always allowed)
3454 */
3455int
3456pfm_use_debug_registers(struct task_struct *task)
3457{
3458 pfm_context_t *ctx = task->thread.pfm_context;
3459 unsigned long flags;
3460 int ret = 0;
3461
3462 if (pmu_conf->use_rr_dbregs == 0) return 0;
3463
3464 DPRINT(("called for [%d]\n", task_pid_nr(task)));
3465
3466 /*
3467 * do it only once
3468 */
3469 if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
3470
3471 /*
3472 * Even on SMP, we do not need to use an atomic here because
3473 * the only way in is via ptrace() and this is possible only when the
3474 * process is stopped. Even in the case where the ctxsw out is not totally
3475 * completed by the time we come here, there is no way the 'stopped' process
3476 * could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
3477 * So this is always safe.
3478 */
3479 if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
3480
3481 LOCK_PFS(flags);
3482
3483 /*
3484 * We cannot allow setting breakpoints when system wide monitoring
3485 * sessions are using the debug registers.
3486 */
3487 if (pfm_sessions.pfs_sys_use_dbregs> 0)
3488 ret = -1;
3489 else
3490 pfm_sessions.pfs_ptrace_use_dbregs++;
3491
3492 DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
3493 pfm_sessions.pfs_ptrace_use_dbregs,
3494 pfm_sessions.pfs_sys_use_dbregs,
3495 task_pid_nr(task), ret));
3496
3497 UNLOCK_PFS(flags);
3498
3499 return ret;
3500}
3501
3502/*
3503 * This function is called for every task that exits with the
3504 * IA64_THREAD_DBG_VALID set. This indicates a task which was
3505 * able to use the debug registers for debugging purposes via
3506 * ptrace(). Therefore we know it was not using them for
3507 * performance monitoring, so we only decrement the number
3508 * of "ptraced" debug register users to keep the count up to date
3509 */
3510int
3511pfm_release_debug_registers(struct task_struct *task)
3512{
3513 unsigned long flags;
3514 int ret;
3515
3516 if (pmu_conf->use_rr_dbregs == 0) return 0;
3517
3518 LOCK_PFS(flags);
3519 if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
3520 printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
3521 ret = -1;
3522 } else {
3523 pfm_sessions.pfs_ptrace_use_dbregs--;
3524 ret = 0;
3525 }
3526 UNLOCK_PFS(flags);
3527
3528 return ret;
3529}
3530
3531static int
3532pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3533{
3534 struct task_struct *task;
3535 pfm_buffer_fmt_t *fmt;
3536 pfm_ovfl_ctrl_t rst_ctrl;
3537 int state, is_system;
3538 int ret = 0;
3539
3540 state = ctx->ctx_state;
3541 fmt = ctx->ctx_buf_fmt;
3542 is_system = ctx->ctx_fl_system;
3543 task = PFM_CTX_TASK(ctx);
3544
3545 switch(state) {
3546 case PFM_CTX_MASKED:
3547 break;
3548 case PFM_CTX_LOADED:
3549 if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
3550 /* fall through */
3551 case PFM_CTX_UNLOADED:
3552 case PFM_CTX_ZOMBIE:
3553 DPRINT(("invalid state=%d\n", state));
3554 return -EBUSY;
3555 default:
3556 DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
3557 return -EINVAL;
3558 }
3559
3560 /*
3561 * In system wide and when the context is loaded, access can only happen
3562 * when the caller is running on the CPU being monitored by the session.
3563 * It does not have to be the owner (ctx_task) of the context per se.
3564 */
3565 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3566 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3567 return -EBUSY;
3568 }
3569
3570 /* sanity check */
3571 if (unlikely(task == NULL)) {
3572 printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
3573 return -EINVAL;
3574 }
3575
3576 if (task == current || is_system) {
3577
3578 fmt = ctx->ctx_buf_fmt;
3579
3580 DPRINT(("restarting self %d ovfl=0x%lx\n",
3581 task_pid_nr(task),
3582 ctx->ctx_ovfl_regs[0]));
3583
3584 if (CTX_HAS_SMPL(ctx)) {
3585
3586 prefetch(ctx->ctx_smpl_hdr);
3587
3588 rst_ctrl.bits.mask_monitoring = 0;
3589 rst_ctrl.bits.reset_ovfl_pmds = 0;
3590
3591 if (state == PFM_CTX_LOADED)
3592 ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3593 else
3594 ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3595 } else {
3596 rst_ctrl.bits.mask_monitoring = 0;
3597 rst_ctrl.bits.reset_ovfl_pmds = 1;
3598 }
3599
3600 if (ret == 0) {
3601 if (rst_ctrl.bits.reset_ovfl_pmds)
3602 pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
3603
3604 if (rst_ctrl.bits.mask_monitoring == 0) {
3605 DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
3606
3607 if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
3608 } else {
3609 DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
3610
3611 // cannot use pfm_stop_monitoring(task, regs);
3612 }
3613 }
3614 /*
3615 * clear overflowed PMD mask to remove any stale information
3616 */
3617 ctx->ctx_ovfl_regs[0] = 0UL;
3618
3619 /*
3620 * back to LOADED state
3621 */
3622 ctx->ctx_state = PFM_CTX_LOADED;
3623
3624 /*
3625 * XXX: not really useful for self monitoring
3626 */
3627 ctx->ctx_fl_can_restart = 0;
3628
3629 return 0;
3630 }
3631
3632 /*
3633 * restart another task
3634 */
3635
3636 /*
3637 * When PFM_CTX_MASKED, we cannot issue a restart before the previous
3638 * one is seen by the task.
3639 */
3640 if (state == PFM_CTX_MASKED) {
3641 if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
3642 /*
3643 * will prevent subsequent restart before this one is
3644 * seen by other task
3645 */
3646 ctx->ctx_fl_can_restart = 0;
3647 }
3648
3649 /*
3650 * if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
3651 * the task is blocked or on its way to block. That's the normal
3652 * restart path. If the monitoring is not masked, then the task
3653 * can be actively monitoring and we cannot directly intervene.
3654 * Therefore we use the trap mechanism to catch the task and
3655 * force it to reset the buffer/reset PMDs.
3656 *
3657 * if non-blocking, then we ensure that the task will go into
3658 * pfm_handle_work() before returning to user mode.
3659 *
3660 * We cannot explicitly reset another task, it MUST always
3661 * be done by the task itself. This works for system wide because
3662 * the tool that is controlling the session is logically doing
3663 * "self-monitoring".
3664 */
3665 if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
3666 DPRINT(("unblocking [%d]\n", task_pid_nr(task)));
3667 complete(&ctx->ctx_restart_done);
3668 } else {
3669 DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
3670
3671 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
3672
3673 PFM_SET_WORK_PENDING(task, 1);
3674
3675 set_notify_resume(task);
3676
3677 /*
3678 * XXX: send reschedule if task runs on another CPU
3679 */
3680 }
3681 return 0;
3682}
3683
3684static int
3685pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3686{
3687 unsigned int m = *(unsigned int *)arg;
3688
3689 pfm_sysctl.debug = m == 0 ? 0 : 1;
3690
3691 printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
3692
3693 if (m == 0) {
3694 memset(pfm_stats, 0, sizeof(pfm_stats));
3695 for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
3696 }
3697 return 0;
3698}
3699
3700/*
3701 * arg can be NULL and count can be zero for this function
3702 */
3703static int
3704pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3705{
3706 struct thread_struct *thread = NULL;
3707 struct task_struct *task;
3708 pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
3709 unsigned long flags;
3710 dbreg_t dbreg;
3711 unsigned int rnum;
3712 int first_time;
3713 int ret = 0, state;
3714 int i, can_access_pmu = 0;
3715 int is_system, is_loaded;
3716
3717 if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
3718
3719 state = ctx->ctx_state;
3720 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3721 is_system = ctx->ctx_fl_system;
3722 task = ctx->ctx_task;
3723
3724 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3725
3726 /*
3727 * on both UP and SMP, we can only write to the PMC when the task is
3728 * the owner of the local PMU.
3729 */
3730 if (is_loaded) {
3731 thread = &task->thread;
3732 /*
3733 * In system wide and when the context is loaded, access can only happen
3734 * when the caller is running on the CPU being monitored by the session.
3735 * It does not have to be the owner (ctx_task) of the context per se.
3736 */
3737 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3738 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3739 return -EBUSY;
3740 }
3741 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3742 }
3743
3744 /*
3745 * we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
3746 * ensuring that no real breakpoint can be installed via this call.
3747 *
3748 * IMPORTANT: regs can be NULL in this function
3749 */
3750
3751 first_time = ctx->ctx_fl_using_dbreg == 0;
3752
3753 /*
3754 * don't bother if we are loaded and task is being debugged
3755 */
3756 if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
3757 DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
3758 return -EBUSY;
3759 }
3760
3761 /*
3762 * check for debug registers in system wide mode
3763 *
3764 * If though a check is done in pfm_context_load(),
3765 * we must repeat it here, in case the registers are
3766 * written after the context is loaded
3767 */
3768 if (is_loaded) {
3769 LOCK_PFS(flags);
3770
3771 if (first_time && is_system) {
3772 if (pfm_sessions.pfs_ptrace_use_dbregs)
3773 ret = -EBUSY;
3774 else
3775 pfm_sessions.pfs_sys_use_dbregs++;
3776 }
3777 UNLOCK_PFS(flags);
3778 }
3779
3780 if (ret != 0) return ret;
3781
3782 /*
3783 * mark ourself as user of the debug registers for
3784 * perfmon purposes.
3785 */
3786 ctx->ctx_fl_using_dbreg = 1;
3787
3788 /*
3789 * clear hardware registers to make sure we don't
3790 * pick up stale state.
3791 *
3792 * for a system wide session, we do not use
3793 * thread.dbr, thread.ibr because this process
3794 * never leaves the current CPU and the state
3795 * is shared by all processes running on it
3796 */
3797 if (first_time && can_access_pmu) {
3798 DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
3799 for (i=0; i < pmu_conf->num_ibrs; i++) {
3800 ia64_set_ibr(i, 0UL);
3801 ia64_dv_serialize_instruction();
3802 }
3803 ia64_srlz_i();
3804 for (i=0; i < pmu_conf->num_dbrs; i++) {
3805 ia64_set_dbr(i, 0UL);
3806 ia64_dv_serialize_data();
3807 }
3808 ia64_srlz_d();
3809 }
3810
3811 /*
3812 * Now install the values into the registers
3813 */
3814 for (i = 0; i < count; i++, req++) {
3815
3816 rnum = req->dbreg_num;
3817 dbreg.val = req->dbreg_value;
3818
3819 ret = -EINVAL;
3820
3821 if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
3822 DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
3823 rnum, dbreg.val, mode, i, count));
3824
3825 goto abort_mission;
3826 }
3827
3828 /*
3829 * make sure we do not install enabled breakpoint
3830 */
3831 if (rnum & 0x1) {
3832 if (mode == PFM_CODE_RR)
3833 dbreg.ibr.ibr_x = 0;
3834 else
3835 dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
3836 }
3837
3838 PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
3839
3840 /*
3841 * Debug registers, just like PMC, can only be modified
3842 * by a kernel call. Moreover, perfmon() access to those
3843 * registers are centralized in this routine. The hardware
3844 * does not modify the value of these registers, therefore,
3845 * if we save them as they are written, we can avoid having
3846 * to save them on context switch out. This is made possible
3847 * by the fact that when perfmon uses debug registers, ptrace()
3848 * won't be able to modify them concurrently.
3849 */
3850 if (mode == PFM_CODE_RR) {
3851 CTX_USED_IBR(ctx, rnum);
3852
3853 if (can_access_pmu) {
3854 ia64_set_ibr(rnum, dbreg.val);
3855 ia64_dv_serialize_instruction();
3856 }
3857
3858 ctx->ctx_ibrs[rnum] = dbreg.val;
3859
3860 DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
3861 rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
3862 } else {
3863 CTX_USED_DBR(ctx, rnum);
3864
3865 if (can_access_pmu) {
3866 ia64_set_dbr(rnum, dbreg.val);
3867 ia64_dv_serialize_data();
3868 }
3869 ctx->ctx_dbrs[rnum] = dbreg.val;
3870
3871 DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
3872 rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
3873 }
3874 }
3875
3876 return 0;
3877
3878abort_mission:
3879 /*
3880 * in case it was our first attempt, we undo the global modifications
3881 */
3882 if (first_time) {
3883 LOCK_PFS(flags);
3884 if (ctx->ctx_fl_system) {
3885 pfm_sessions.pfs_sys_use_dbregs--;
3886 }
3887 UNLOCK_PFS(flags);
3888 ctx->ctx_fl_using_dbreg = 0;
3889 }
3890 /*
3891 * install error return flag
3892 */
3893 PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
3894
3895 return ret;
3896}
3897
3898static int
3899pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3900{
3901 return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
3902}
3903
3904static int
3905pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3906{
3907 return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
3908}
3909
3910int
3911pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3912{
3913 pfm_context_t *ctx;
3914
3915 if (req == NULL) return -EINVAL;
3916
3917 ctx = GET_PMU_CTX();
3918
3919 if (ctx == NULL) return -EINVAL;
3920
3921 /*
3922 * for now limit to current task, which is enough when calling
3923 * from overflow handler
3924 */
3925 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3926
3927 return pfm_write_ibrs(ctx, req, nreq, regs);
3928}
3929EXPORT_SYMBOL(pfm_mod_write_ibrs);
3930
3931int
3932pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3933{
3934 pfm_context_t *ctx;
3935
3936 if (req == NULL) return -EINVAL;
3937
3938 ctx = GET_PMU_CTX();
3939
3940 if (ctx == NULL) return -EINVAL;
3941
3942 /*
3943 * for now limit to current task, which is enough when calling
3944 * from overflow handler
3945 */
3946 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3947
3948 return pfm_write_dbrs(ctx, req, nreq, regs);
3949}
3950EXPORT_SYMBOL(pfm_mod_write_dbrs);
3951
3952
3953static int
3954pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3955{
3956 pfarg_features_t *req = (pfarg_features_t *)arg;
3957
3958 req->ft_version = PFM_VERSION;
3959 return 0;
3960}
3961
3962static int
3963pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3964{
3965 struct pt_regs *tregs;
3966 struct task_struct *task = PFM_CTX_TASK(ctx);
3967 int state, is_system;
3968
3969 state = ctx->ctx_state;
3970 is_system = ctx->ctx_fl_system;
3971
3972 /*
3973 * context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
3974 */
3975 if (state == PFM_CTX_UNLOADED) return -EINVAL;
3976
3977 /*
3978 * In system wide and when the context is loaded, access can only happen
3979 * when the caller is running on the CPU being monitored by the session.
3980 * It does not have to be the owner (ctx_task) of the context per se.
3981 */
3982 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3983 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3984 return -EBUSY;
3985 }
3986 DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
3987 task_pid_nr(PFM_CTX_TASK(ctx)),
3988 state,
3989 is_system));
3990 /*
3991 * in system mode, we need to update the PMU directly
3992 * and the user level state of the caller, which may not
3993 * necessarily be the creator of the context.
3994 */
3995 if (is_system) {
3996 /*
3997 * Update local PMU first
3998 *
3999 * disable dcr pp
4000 */
4001 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
4002 ia64_srlz_i();
4003
4004 /*
4005 * update local cpuinfo
4006 */
4007 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4008
4009 /*
4010 * stop monitoring, does srlz.i
4011 */
4012 pfm_clear_psr_pp();
4013
4014 /*
4015 * stop monitoring in the caller
4016 */
4017 ia64_psr(regs)->pp = 0;
4018
4019 return 0;
4020 }
4021 /*
4022 * per-task mode
4023 */
4024
4025 if (task == current) {
4026 /* stop monitoring at kernel level */
4027 pfm_clear_psr_up();
4028
4029 /*
4030 * stop monitoring at the user level
4031 */
4032 ia64_psr(regs)->up = 0;
4033 } else {
4034 tregs = task_pt_regs(task);
4035
4036 /*
4037 * stop monitoring at the user level
4038 */
4039 ia64_psr(tregs)->up = 0;
4040
4041 /*
4042 * monitoring disabled in kernel at next reschedule
4043 */
4044 ctx->ctx_saved_psr_up = 0;
4045 DPRINT(("task=[%d]\n", task_pid_nr(task)));
4046 }
4047 return 0;
4048}
4049
4050
4051static int
4052pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4053{
4054 struct pt_regs *tregs;
4055 int state, is_system;
4056
4057 state = ctx->ctx_state;
4058 is_system = ctx->ctx_fl_system;
4059
4060 if (state != PFM_CTX_LOADED) return -EINVAL;
4061
4062 /*
4063 * In system wide and when the context is loaded, access can only happen
4064 * when the caller is running on the CPU being monitored by the session.
4065 * It does not have to be the owner (ctx_task) of the context per se.
4066 */
4067 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
4068 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
4069 return -EBUSY;
4070 }
4071
4072 /*
4073 * in system mode, we need to update the PMU directly
4074 * and the user level state of the caller, which may not
4075 * necessarily be the creator of the context.
4076 */
4077 if (is_system) {
4078
4079 /*
4080 * set user level psr.pp for the caller
4081 */
4082 ia64_psr(regs)->pp = 1;
4083
4084 /*
4085 * now update the local PMU and cpuinfo
4086 */
4087 PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
4088
4089 /*
4090 * start monitoring at kernel level
4091 */
4092 pfm_set_psr_pp();
4093
4094 /* enable dcr pp */
4095 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
4096 ia64_srlz_i();
4097
4098 return 0;
4099 }
4100
4101 /*
4102 * per-process mode
4103 */
4104
4105 if (ctx->ctx_task == current) {
4106
4107 /* start monitoring at kernel level */
4108 pfm_set_psr_up();
4109
4110 /*
4111 * activate monitoring at user level
4112 */
4113 ia64_psr(regs)->up = 1;
4114
4115 } else {
4116 tregs = task_pt_regs(ctx->ctx_task);
4117
4118 /*
4119 * start monitoring at the kernel level the next
4120 * time the task is scheduled
4121 */
4122 ctx->ctx_saved_psr_up = IA64_PSR_UP;
4123
4124 /*
4125 * activate monitoring at user level
4126 */
4127 ia64_psr(tregs)->up = 1;
4128 }
4129 return 0;
4130}
4131
4132static int
4133pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4134{
4135 pfarg_reg_t *req = (pfarg_reg_t *)arg;
4136 unsigned int cnum;
4137 int i;
4138 int ret = -EINVAL;
4139
4140 for (i = 0; i < count; i++, req++) {
4141
4142 cnum = req->reg_num;
4143
4144 if (!PMC_IS_IMPL(cnum)) goto abort_mission;
4145
4146 req->reg_value = PMC_DFL_VAL(cnum);
4147
4148 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
4149
4150 DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
4151 }
4152 return 0;
4153
4154abort_mission:
4155 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
4156 return ret;
4157}
4158
4159static int
4160pfm_check_task_exist(pfm_context_t *ctx)
4161{
4162 struct task_struct *g, *t;
4163 int ret = -ESRCH;
4164
4165 read_lock(&tasklist_lock);
4166
4167 do_each_thread (g, t) {
4168 if (t->thread.pfm_context == ctx) {
4169 ret = 0;
4170 goto out;
4171 }
4172 } while_each_thread (g, t);
4173out:
4174 read_unlock(&tasklist_lock);
4175
4176 DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
4177
4178 return ret;
4179}
4180
4181static int
4182pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4183{
4184 struct task_struct *task;
4185 struct thread_struct *thread;
4186 struct pfm_context_t *old;
4187 unsigned long flags;
4188#ifndef CONFIG_SMP
4189 struct task_struct *owner_task = NULL;
4190#endif
4191 pfarg_load_t *req = (pfarg_load_t *)arg;
4192 unsigned long *pmcs_source, *pmds_source;
4193 int the_cpu;
4194 int ret = 0;
4195 int state, is_system, set_dbregs = 0;
4196
4197 state = ctx->ctx_state;
4198 is_system = ctx->ctx_fl_system;
4199 /*
4200 * can only load from unloaded or terminated state
4201 */
4202 if (state != PFM_CTX_UNLOADED) {
4203 DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
4204 req->load_pid,
4205 ctx->ctx_state));
4206 return -EBUSY;
4207 }
4208
4209 DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
4210
4211 if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
4212 DPRINT(("cannot use blocking mode on self\n"));
4213 return -EINVAL;
4214 }
4215
4216 ret = pfm_get_task(ctx, req->load_pid, &task);
4217 if (ret) {
4218 DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
4219 return ret;
4220 }
4221
4222 ret = -EINVAL;
4223
4224 /*
4225 * system wide is self monitoring only
4226 */
4227 if (is_system && task != current) {
4228 DPRINT(("system wide is self monitoring only load_pid=%d\n",
4229 req->load_pid));
4230 goto error;
4231 }
4232
4233 thread = &task->thread;
4234
4235 ret = 0;
4236 /*
4237 * cannot load a context which is using range restrictions,
4238 * into a task that is being debugged.
4239 */
4240 if (ctx->ctx_fl_using_dbreg) {
4241 if (thread->flags & IA64_THREAD_DBG_VALID) {
4242 ret = -EBUSY;
4243 DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
4244 goto error;
4245 }
4246 LOCK_PFS(flags);
4247
4248 if (is_system) {
4249 if (pfm_sessions.pfs_ptrace_use_dbregs) {
4250 DPRINT(("cannot load [%d] dbregs in use\n",
4251 task_pid_nr(task)));
4252 ret = -EBUSY;
4253 } else {
4254 pfm_sessions.pfs_sys_use_dbregs++;
4255 DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
4256 set_dbregs = 1;
4257 }
4258 }
4259
4260 UNLOCK_PFS(flags);
4261
4262 if (ret) goto error;
4263 }
4264
4265 /*
4266 * SMP system-wide monitoring implies self-monitoring.
4267 *
4268 * The programming model expects the task to
4269 * be pinned on a CPU throughout the session.
4270 * Here we take note of the current CPU at the
4271 * time the context is loaded. No call from
4272 * another CPU will be allowed.
4273 *
4274 * The pinning via shed_setaffinity()
4275 * must be done by the calling task prior
4276 * to this call.
4277 *
4278 * systemwide: keep track of CPU this session is supposed to run on
4279 */
4280 the_cpu = ctx->ctx_cpu = smp_processor_id();
4281
4282 ret = -EBUSY;
4283 /*
4284 * now reserve the session
4285 */
4286 ret = pfm_reserve_session(current, is_system, the_cpu);
4287 if (ret) goto error;
4288
4289 /*
4290 * task is necessarily stopped at this point.
4291 *
4292 * If the previous context was zombie, then it got removed in
4293 * pfm_save_regs(). Therefore we should not see it here.
4294 * If we see a context, then this is an active context
4295 *
4296 * XXX: needs to be atomic
4297 */
4298 DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
4299 thread->pfm_context, ctx));
4300
4301 ret = -EBUSY;
4302 old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
4303 if (old != NULL) {
4304 DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
4305 goto error_unres;
4306 }
4307
4308 pfm_reset_msgq(ctx);
4309
4310 ctx->ctx_state = PFM_CTX_LOADED;
4311
4312 /*
4313 * link context to task
4314 */
4315 ctx->ctx_task = task;
4316
4317 if (is_system) {
4318 /*
4319 * we load as stopped
4320 */
4321 PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
4322 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4323
4324 if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
4325 } else {
4326 thread->flags |= IA64_THREAD_PM_VALID;
4327 }
4328
4329 /*
4330 * propagate into thread-state
4331 */
4332 pfm_copy_pmds(task, ctx);
4333 pfm_copy_pmcs(task, ctx);
4334
4335 pmcs_source = ctx->th_pmcs;
4336 pmds_source = ctx->th_pmds;
4337
4338 /*
4339 * always the case for system-wide
4340 */
4341 if (task == current) {
4342
4343 if (is_system == 0) {
4344
4345 /* allow user level control */
4346 ia64_psr(regs)->sp = 0;
4347 DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
4348
4349 SET_LAST_CPU(ctx, smp_processor_id());
4350 INC_ACTIVATION();
4351 SET_ACTIVATION(ctx);
4352#ifndef CONFIG_SMP
4353 /*
4354 * push the other task out, if any
4355 */
4356 owner_task = GET_PMU_OWNER();
4357 if (owner_task) pfm_lazy_save_regs(owner_task);
4358#endif
4359 }
4360 /*
4361 * load all PMD from ctx to PMU (as opposed to thread state)
4362 * restore all PMC from ctx to PMU
4363 */
4364 pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
4365 pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
4366
4367 ctx->ctx_reload_pmcs[0] = 0UL;
4368 ctx->ctx_reload_pmds[0] = 0UL;
4369
4370 /*
4371 * guaranteed safe by earlier check against DBG_VALID
4372 */
4373 if (ctx->ctx_fl_using_dbreg) {
4374 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
4375 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
4376 }
4377 /*
4378 * set new ownership
4379 */
4380 SET_PMU_OWNER(task, ctx);
4381
4382 DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
4383 } else {
4384 /*
4385 * when not current, task MUST be stopped, so this is safe
4386 */
4387 regs = task_pt_regs(task);
4388
4389 /* force a full reload */
4390 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4391 SET_LAST_CPU(ctx, -1);
4392
4393 /* initial saved psr (stopped) */
4394 ctx->ctx_saved_psr_up = 0UL;
4395 ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
4396 }
4397
4398 ret = 0;
4399
4400error_unres:
4401 if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
4402error:
4403 /*
4404 * we must undo the dbregs setting (for system-wide)
4405 */
4406 if (ret && set_dbregs) {
4407 LOCK_PFS(flags);
4408 pfm_sessions.pfs_sys_use_dbregs--;
4409 UNLOCK_PFS(flags);
4410 }
4411 /*
4412 * release task, there is now a link with the context
4413 */
4414 if (is_system == 0 && task != current) {
4415 pfm_put_task(task);
4416
4417 if (ret == 0) {
4418 ret = pfm_check_task_exist(ctx);
4419 if (ret) {
4420 ctx->ctx_state = PFM_CTX_UNLOADED;
4421 ctx->ctx_task = NULL;
4422 }
4423 }
4424 }
4425 return ret;
4426}
4427
4428/*
4429 * in this function, we do not need to increase the use count
4430 * for the task via get_task_struct(), because we hold the
4431 * context lock. If the task were to disappear while having
4432 * a context attached, it would go through pfm_exit_thread()
4433 * which also grabs the context lock and would therefore be blocked
4434 * until we are here.
4435 */
4436static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
4437
4438static int
4439pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4440{
4441 struct task_struct *task = PFM_CTX_TASK(ctx);
4442 struct pt_regs *tregs;
4443 int prev_state, is_system;
4444 int ret;
4445
4446 DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
4447
4448 prev_state = ctx->ctx_state;
4449 is_system = ctx->ctx_fl_system;
4450
4451 /*
4452 * unload only when necessary
4453 */
4454 if (prev_state == PFM_CTX_UNLOADED) {
4455 DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
4456 return 0;
4457 }
4458
4459 /*
4460 * clear psr and dcr bits
4461 */
4462 ret = pfm_stop(ctx, NULL, 0, regs);
4463 if (ret) return ret;
4464
4465 ctx->ctx_state = PFM_CTX_UNLOADED;
4466
4467 /*
4468 * in system mode, we need to update the PMU directly
4469 * and the user level state of the caller, which may not
4470 * necessarily be the creator of the context.
4471 */
4472 if (is_system) {
4473
4474 /*
4475 * Update cpuinfo
4476 *
4477 * local PMU is taken care of in pfm_stop()
4478 */
4479 PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
4480 PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
4481
4482 /*
4483 * save PMDs in context
4484 * release ownership
4485 */
4486 pfm_flush_pmds(current, ctx);
4487
4488 /*
4489 * at this point we are done with the PMU
4490 * so we can unreserve the resource.
4491 */
4492 if (prev_state != PFM_CTX_ZOMBIE)
4493 pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
4494
4495 /*
4496 * disconnect context from task
4497 */
4498 task->thread.pfm_context = NULL;
4499 /*
4500 * disconnect task from context
4501 */
4502 ctx->ctx_task = NULL;
4503
4504 /*
4505 * There is nothing more to cleanup here.
4506 */
4507 return 0;
4508 }
4509
4510 /*
4511 * per-task mode
4512 */
4513 tregs = task == current ? regs : task_pt_regs(task);
4514
4515 if (task == current) {
4516 /*
4517 * cancel user level control
4518 */
4519 ia64_psr(regs)->sp = 1;
4520
4521 DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
4522 }
4523 /*
4524 * save PMDs to context
4525 * release ownership
4526 */
4527 pfm_flush_pmds(task, ctx);
4528
4529 /*
4530 * at this point we are done with the PMU
4531 * so we can unreserve the resource.
4532 *
4533 * when state was ZOMBIE, we have already unreserved.
4534 */
4535 if (prev_state != PFM_CTX_ZOMBIE)
4536 pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
4537
4538 /*
4539 * reset activation counter and psr
4540 */
4541 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4542 SET_LAST_CPU(ctx, -1);
4543
4544 /*
4545 * PMU state will not be restored
4546 */
4547 task->thread.flags &= ~IA64_THREAD_PM_VALID;
4548
4549 /*
4550 * break links between context and task
4551 */
4552 task->thread.pfm_context = NULL;
4553 ctx->ctx_task = NULL;
4554
4555 PFM_SET_WORK_PENDING(task, 0);
4556
4557 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
4558 ctx->ctx_fl_can_restart = 0;
4559 ctx->ctx_fl_going_zombie = 0;
4560
4561 DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
4562
4563 return 0;
4564}
4565
4566
4567/*
4568 * called only from exit_thread(): task == current
4569 * we come here only if current has a context attached (loaded or masked)
4570 */
4571void
4572pfm_exit_thread(struct task_struct *task)
4573{
4574 pfm_context_t *ctx;
4575 unsigned long flags;
4576 struct pt_regs *regs = task_pt_regs(task);
4577 int ret, state;
4578 int free_ok = 0;
4579
4580 ctx = PFM_GET_CTX(task);
4581
4582 PROTECT_CTX(ctx, flags);
4583
4584 DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
4585
4586 state = ctx->ctx_state;
4587 switch(state) {
4588 case PFM_CTX_UNLOADED:
4589 /*
4590 * only comes to this function if pfm_context is not NULL, i.e., cannot
4591 * be in unloaded state
4592 */
4593 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
4594 break;
4595 case PFM_CTX_LOADED:
4596 case PFM_CTX_MASKED:
4597 ret = pfm_context_unload(ctx, NULL, 0, regs);
4598 if (ret) {
4599 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4600 }
4601 DPRINT(("ctx unloaded for current state was %d\n", state));
4602
4603 pfm_end_notify_user(ctx);
4604 break;
4605 case PFM_CTX_ZOMBIE:
4606 ret = pfm_context_unload(ctx, NULL, 0, regs);
4607 if (ret) {
4608 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4609 }
4610 free_ok = 1;
4611 break;
4612 default:
4613 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
4614 break;
4615 }
4616 UNPROTECT_CTX(ctx, flags);
4617
4618 { u64 psr = pfm_get_psr();
4619 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
4620 BUG_ON(GET_PMU_OWNER());
4621 BUG_ON(ia64_psr(regs)->up);
4622 BUG_ON(ia64_psr(regs)->pp);
4623 }
4624
4625 /*
4626 * All memory free operations (especially for vmalloc'ed memory)
4627 * MUST be done with interrupts ENABLED.
4628 */
4629 if (free_ok) pfm_context_free(ctx);
4630}
4631
4632/*
4633 * functions MUST be listed in the increasing order of their index (see permfon.h)
4634 */
4635#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
4636#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
4637#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
4638#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
4639#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
4640
4641static pfm_cmd_desc_t pfm_cmd_tab[]={
4642/* 0 */PFM_CMD_NONE,
4643/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4644/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4645/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4646/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
4647/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
4648/* 6 */PFM_CMD_NONE,
4649/* 7 */PFM_CMD_NONE,
4650/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
4651/* 9 */PFM_CMD_NONE,
4652/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
4653/* 11 */PFM_CMD_NONE,
4654/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
4655/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
4656/* 14 */PFM_CMD_NONE,
4657/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4658/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
4659/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
4660/* 18 */PFM_CMD_NONE,
4661/* 19 */PFM_CMD_NONE,
4662/* 20 */PFM_CMD_NONE,
4663/* 21 */PFM_CMD_NONE,
4664/* 22 */PFM_CMD_NONE,
4665/* 23 */PFM_CMD_NONE,
4666/* 24 */PFM_CMD_NONE,
4667/* 25 */PFM_CMD_NONE,
4668/* 26 */PFM_CMD_NONE,
4669/* 27 */PFM_CMD_NONE,
4670/* 28 */PFM_CMD_NONE,
4671/* 29 */PFM_CMD_NONE,
4672/* 30 */PFM_CMD_NONE,
4673/* 31 */PFM_CMD_NONE,
4674/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
4675/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
4676};
4677#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
4678
4679static int
4680pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
4681{
4682 struct task_struct *task;
4683 int state, old_state;
4684
4685recheck:
4686 state = ctx->ctx_state;
4687 task = ctx->ctx_task;
4688
4689 if (task == NULL) {
4690 DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
4691 return 0;
4692 }
4693
4694 DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
4695 ctx->ctx_fd,
4696 state,
4697 task_pid_nr(task),
4698 task->state, PFM_CMD_STOPPED(cmd)));
4699
4700 /*
4701 * self-monitoring always ok.
4702 *
4703 * for system-wide the caller can either be the creator of the
4704 * context (to one to which the context is attached to) OR
4705 * a task running on the same CPU as the session.
4706 */
4707 if (task == current || ctx->ctx_fl_system) return 0;
4708
4709 /*
4710 * we are monitoring another thread
4711 */
4712 switch(state) {
4713 case PFM_CTX_UNLOADED:
4714 /*
4715 * if context is UNLOADED we are safe to go
4716 */
4717 return 0;
4718 case PFM_CTX_ZOMBIE:
4719 /*
4720 * no command can operate on a zombie context
4721 */
4722 DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
4723 return -EINVAL;
4724 case PFM_CTX_MASKED:
4725 /*
4726 * PMU state has been saved to software even though
4727 * the thread may still be running.
4728 */
4729 if (cmd != PFM_UNLOAD_CONTEXT) return 0;
4730 }
4731
4732 /*
4733 * context is LOADED or MASKED. Some commands may need to have
4734 * the task stopped.
4735 *
4736 * We could lift this restriction for UP but it would mean that
4737 * the user has no guarantee the task would not run between
4738 * two successive calls to perfmonctl(). That's probably OK.
4739 * If this user wants to ensure the task does not run, then
4740 * the task must be stopped.
4741 */
4742 if (PFM_CMD_STOPPED(cmd)) {
4743 if (!task_is_stopped_or_traced(task)) {
4744 DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
4745 return -EBUSY;
4746 }
4747 /*
4748 * task is now stopped, wait for ctxsw out
4749 *
4750 * This is an interesting point in the code.
4751 * We need to unprotect the context because
4752 * the pfm_save_regs() routines needs to grab
4753 * the same lock. There are danger in doing
4754 * this because it leaves a window open for
4755 * another task to get access to the context
4756 * and possibly change its state. The one thing
4757 * that is not possible is for the context to disappear
4758 * because we are protected by the VFS layer, i.e.,
4759 * get_fd()/put_fd().
4760 */
4761 old_state = state;
4762
4763 UNPROTECT_CTX(ctx, flags);
4764
4765 wait_task_inactive(task, 0);
4766
4767 PROTECT_CTX(ctx, flags);
4768
4769 /*
4770 * we must recheck to verify if state has changed
4771 */
4772 if (ctx->ctx_state != old_state) {
4773 DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
4774 goto recheck;
4775 }
4776 }
4777 return 0;
4778}
4779
4780/*
4781 * system-call entry point (must return long)
4782 */
4783asmlinkage long
4784sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
4785{
4786 struct file *file = NULL;
4787 pfm_context_t *ctx = NULL;
4788 unsigned long flags = 0UL;
4789 void *args_k = NULL;
4790 long ret; /* will expand int return types */
4791 size_t base_sz, sz, xtra_sz = 0;
4792 int narg, completed_args = 0, call_made = 0, cmd_flags;
4793 int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
4794 int (*getsize)(void *arg, size_t *sz);
4795#define PFM_MAX_ARGSIZE 4096
4796
4797 /*
4798 * reject any call if perfmon was disabled at initialization
4799 */
4800 if (unlikely(pmu_conf == NULL)) return -ENOSYS;
4801
4802 if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
4803 DPRINT(("invalid cmd=%d\n", cmd));
4804 return -EINVAL;
4805 }
4806
4807 func = pfm_cmd_tab[cmd].cmd_func;
4808 narg = pfm_cmd_tab[cmd].cmd_narg;
4809 base_sz = pfm_cmd_tab[cmd].cmd_argsize;
4810 getsize = pfm_cmd_tab[cmd].cmd_getsize;
4811 cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
4812
4813 if (unlikely(func == NULL)) {
4814 DPRINT(("invalid cmd=%d\n", cmd));
4815 return -EINVAL;
4816 }
4817
4818 DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
4819 PFM_CMD_NAME(cmd),
4820 cmd,
4821 narg,
4822 base_sz,
4823 count));
4824
4825 /*
4826 * check if number of arguments matches what the command expects
4827 */
4828 if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
4829 return -EINVAL;
4830
4831restart_args:
4832 sz = xtra_sz + base_sz*count;
4833 /*
4834 * limit abuse to min page size
4835 */
4836 if (unlikely(sz > PFM_MAX_ARGSIZE)) {
4837 printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
4838 return -E2BIG;
4839 }
4840
4841 /*
4842 * allocate default-sized argument buffer
4843 */
4844 if (likely(count && args_k == NULL)) {
4845 args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
4846 if (args_k == NULL) return -ENOMEM;
4847 }
4848
4849 ret = -EFAULT;
4850
4851 /*
4852 * copy arguments
4853 *
4854 * assume sz = 0 for command without parameters
4855 */
4856 if (sz && copy_from_user(args_k, arg, sz)) {
4857 DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
4858 goto error_args;
4859 }
4860
4861 /*
4862 * check if command supports extra parameters
4863 */
4864 if (completed_args == 0 && getsize) {
4865 /*
4866 * get extra parameters size (based on main argument)
4867 */
4868 ret = (*getsize)(args_k, &xtra_sz);
4869 if (ret) goto error_args;
4870
4871 completed_args = 1;
4872
4873 DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
4874
4875 /* retry if necessary */
4876 if (likely(xtra_sz)) goto restart_args;
4877 }
4878
4879 if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
4880
4881 ret = -EBADF;
4882
4883 file = fget(fd);
4884 if (unlikely(file == NULL)) {
4885 DPRINT(("invalid fd %d\n", fd));
4886 goto error_args;
4887 }
4888 if (unlikely(PFM_IS_FILE(file) == 0)) {
4889 DPRINT(("fd %d not related to perfmon\n", fd));
4890 goto error_args;
4891 }
4892
4893 ctx = file->private_data;
4894 if (unlikely(ctx == NULL)) {
4895 DPRINT(("no context for fd %d\n", fd));
4896 goto error_args;
4897 }
4898 prefetch(&ctx->ctx_state);
4899
4900 PROTECT_CTX(ctx, flags);
4901
4902 /*
4903 * check task is stopped
4904 */
4905 ret = pfm_check_task_state(ctx, cmd, flags);
4906 if (unlikely(ret)) goto abort_locked;
4907
4908skip_fd:
4909 ret = (*func)(ctx, args_k, count, task_pt_regs(current));
4910
4911 call_made = 1;
4912
4913abort_locked:
4914 if (likely(ctx)) {
4915 DPRINT(("context unlocked\n"));
4916 UNPROTECT_CTX(ctx, flags);
4917 }
4918
4919 /* copy argument back to user, if needed */
4920 if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
4921
4922error_args:
4923 if (file)
4924 fput(file);
4925
4926 kfree(args_k);
4927
4928 DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
4929
4930 return ret;
4931}
4932
4933static void
4934pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
4935{
4936 pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
4937 pfm_ovfl_ctrl_t rst_ctrl;
4938 int state;
4939 int ret = 0;
4940
4941 state = ctx->ctx_state;
4942 /*
4943 * Unlock sampling buffer and reset index atomically
4944 * XXX: not really needed when blocking
4945 */
4946 if (CTX_HAS_SMPL(ctx)) {
4947
4948 rst_ctrl.bits.mask_monitoring = 0;
4949 rst_ctrl.bits.reset_ovfl_pmds = 0;
4950
4951 if (state == PFM_CTX_LOADED)
4952 ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4953 else
4954 ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4955 } else {
4956 rst_ctrl.bits.mask_monitoring = 0;
4957 rst_ctrl.bits.reset_ovfl_pmds = 1;
4958 }
4959
4960 if (ret == 0) {
4961 if (rst_ctrl.bits.reset_ovfl_pmds) {
4962 pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
4963 }
4964 if (rst_ctrl.bits.mask_monitoring == 0) {
4965 DPRINT(("resuming monitoring\n"));
4966 if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
4967 } else {
4968 DPRINT(("stopping monitoring\n"));
4969 //pfm_stop_monitoring(current, regs);
4970 }
4971 ctx->ctx_state = PFM_CTX_LOADED;
4972 }
4973}
4974
4975/*
4976 * context MUST BE LOCKED when calling
4977 * can only be called for current
4978 */
4979static void
4980pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
4981{
4982 int ret;
4983
4984 DPRINT(("entering for [%d]\n", task_pid_nr(current)));
4985
4986 ret = pfm_context_unload(ctx, NULL, 0, regs);
4987 if (ret) {
4988 printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
4989 }
4990
4991 /*
4992 * and wakeup controlling task, indicating we are now disconnected
4993 */
4994 wake_up_interruptible(&ctx->ctx_zombieq);
4995
4996 /*
4997 * given that context is still locked, the controlling
4998 * task will only get access when we return from
4999 * pfm_handle_work().
5000 */
5001}
5002
5003static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
5004
5005 /*
5006 * pfm_handle_work() can be called with interrupts enabled
5007 * (TIF_NEED_RESCHED) or disabled. The down_interruptible
5008 * call may sleep, therefore we must re-enable interrupts
5009 * to avoid deadlocks. It is safe to do so because this function
5010 * is called ONLY when returning to user level (pUStk=1), in which case
5011 * there is no risk of kernel stack overflow due to deep
5012 * interrupt nesting.
5013 */
5014void
5015pfm_handle_work(void)
5016{
5017 pfm_context_t *ctx;
5018 struct pt_regs *regs;
5019 unsigned long flags, dummy_flags;
5020 unsigned long ovfl_regs;
5021 unsigned int reason;
5022 int ret;
5023
5024 ctx = PFM_GET_CTX(current);
5025 if (ctx == NULL) {
5026 printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
5027 task_pid_nr(current));
5028 return;
5029 }
5030
5031 PROTECT_CTX(ctx, flags);
5032
5033 PFM_SET_WORK_PENDING(current, 0);
5034
5035 regs = task_pt_regs(current);
5036
5037 /*
5038 * extract reason for being here and clear
5039 */
5040 reason = ctx->ctx_fl_trap_reason;
5041 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
5042 ovfl_regs = ctx->ctx_ovfl_regs[0];
5043
5044 DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
5045
5046 /*
5047 * must be done before we check for simple-reset mode
5048 */
5049 if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
5050 goto do_zombie;
5051
5052 //if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
5053 if (reason == PFM_TRAP_REASON_RESET)
5054 goto skip_blocking;
5055
5056 /*
5057 * restore interrupt mask to what it was on entry.
5058 * Could be enabled/diasbled.
5059 */
5060 UNPROTECT_CTX(ctx, flags);
5061
5062 /*
5063 * force interrupt enable because of down_interruptible()
5064 */
5065 local_irq_enable();
5066
5067 DPRINT(("before block sleeping\n"));
5068
5069 /*
5070 * may go through without blocking on SMP systems
5071 * if restart has been received already by the time we call down()
5072 */
5073 ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
5074
5075 DPRINT(("after block sleeping ret=%d\n", ret));
5076
5077 /*
5078 * lock context and mask interrupts again
5079 * We save flags into a dummy because we may have
5080 * altered interrupts mask compared to entry in this
5081 * function.
5082 */
5083 PROTECT_CTX(ctx, dummy_flags);
5084
5085 /*
5086 * we need to read the ovfl_regs only after wake-up
5087 * because we may have had pfm_write_pmds() in between
5088 * and that can changed PMD values and therefore
5089 * ovfl_regs is reset for these new PMD values.
5090 */
5091 ovfl_regs = ctx->ctx_ovfl_regs[0];
5092
5093 if (ctx->ctx_fl_going_zombie) {
5094do_zombie:
5095 DPRINT(("context is zombie, bailing out\n"));
5096 pfm_context_force_terminate(ctx, regs);
5097 goto nothing_to_do;
5098 }
5099 /*
5100 * in case of interruption of down() we don't restart anything
5101 */
5102 if (ret < 0)
5103 goto nothing_to_do;
5104
5105skip_blocking:
5106 pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
5107 ctx->ctx_ovfl_regs[0] = 0UL;
5108
5109nothing_to_do:
5110 /*
5111 * restore flags as they were upon entry
5112 */
5113 UNPROTECT_CTX(ctx, flags);
5114}
5115
5116static int
5117pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
5118{
5119 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5120 DPRINT(("ignoring overflow notification, owner is zombie\n"));
5121 return 0;
5122 }
5123
5124 DPRINT(("waking up somebody\n"));
5125
5126 if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
5127
5128 /*
5129 * safe, we are not in intr handler, nor in ctxsw when
5130 * we come here
5131 */
5132 kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
5133
5134 return 0;
5135}
5136
5137static int
5138pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
5139{
5140 pfm_msg_t *msg = NULL;
5141
5142 if (ctx->ctx_fl_no_msg == 0) {
5143 msg = pfm_get_new_msg(ctx);
5144 if (msg == NULL) {
5145 printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
5146 return -1;
5147 }
5148
5149 msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
5150 msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
5151 msg->pfm_ovfl_msg.msg_active_set = 0;
5152 msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
5153 msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
5154 msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
5155 msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
5156 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5157 }
5158
5159 DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
5160 msg,
5161 ctx->ctx_fl_no_msg,
5162 ctx->ctx_fd,
5163 ovfl_pmds));
5164
5165 return pfm_notify_user(ctx, msg);
5166}
5167
5168static int
5169pfm_end_notify_user(pfm_context_t *ctx)
5170{
5171 pfm_msg_t *msg;
5172
5173 msg = pfm_get_new_msg(ctx);
5174 if (msg == NULL) {
5175 printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
5176 return -1;
5177 }
5178 /* no leak */
5179 memset(msg, 0, sizeof(*msg));
5180
5181 msg->pfm_end_msg.msg_type = PFM_MSG_END;
5182 msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
5183 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5184
5185 DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
5186 msg,
5187 ctx->ctx_fl_no_msg,
5188 ctx->ctx_fd));
5189
5190 return pfm_notify_user(ctx, msg);
5191}
5192
5193/*
5194 * main overflow processing routine.
5195 * it can be called from the interrupt path or explicitly during the context switch code
5196 */
5197static void pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx,
5198 unsigned long pmc0, struct pt_regs *regs)
5199{
5200 pfm_ovfl_arg_t *ovfl_arg;
5201 unsigned long mask;
5202 unsigned long old_val, ovfl_val, new_val;
5203 unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
5204 unsigned long tstamp;
5205 pfm_ovfl_ctrl_t ovfl_ctrl;
5206 unsigned int i, has_smpl;
5207 int must_notify = 0;
5208
5209 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
5210
5211 /*
5212 * sanity test. Should never happen
5213 */
5214 if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
5215
5216 tstamp = ia64_get_itc();
5217 mask = pmc0 >> PMU_FIRST_COUNTER;
5218 ovfl_val = pmu_conf->ovfl_val;
5219 has_smpl = CTX_HAS_SMPL(ctx);
5220
5221 DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
5222 "used_pmds=0x%lx\n",
5223 pmc0,
5224 task ? task_pid_nr(task): -1,
5225 (regs ? regs->cr_iip : 0),
5226 CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
5227 ctx->ctx_used_pmds[0]));
5228
5229
5230 /*
5231 * first we update the virtual counters
5232 * assume there was a prior ia64_srlz_d() issued
5233 */
5234 for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
5235
5236 /* skip pmd which did not overflow */
5237 if ((mask & 0x1) == 0) continue;
5238
5239 /*
5240 * Note that the pmd is not necessarily 0 at this point as qualified events
5241 * may have happened before the PMU was frozen. The residual count is not
5242 * taken into consideration here but will be with any read of the pmd via
5243 * pfm_read_pmds().
5244 */
5245 old_val = new_val = ctx->ctx_pmds[i].val;
5246 new_val += 1 + ovfl_val;
5247 ctx->ctx_pmds[i].val = new_val;
5248
5249 /*
5250 * check for overflow condition
5251 */
5252 if (likely(old_val > new_val)) {
5253 ovfl_pmds |= 1UL << i;
5254 if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
5255 }
5256
5257 DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
5258 i,
5259 new_val,
5260 old_val,
5261 ia64_get_pmd(i) & ovfl_val,
5262 ovfl_pmds,
5263 ovfl_notify));
5264 }
5265
5266 /*
5267 * there was no 64-bit overflow, nothing else to do
5268 */
5269 if (ovfl_pmds == 0UL) return;
5270
5271 /*
5272 * reset all control bits
5273 */
5274 ovfl_ctrl.val = 0;
5275 reset_pmds = 0UL;
5276
5277 /*
5278 * if a sampling format module exists, then we "cache" the overflow by
5279 * calling the module's handler() routine.
5280 */
5281 if (has_smpl) {
5282 unsigned long start_cycles, end_cycles;
5283 unsigned long pmd_mask;
5284 int j, k, ret = 0;
5285 int this_cpu = smp_processor_id();
5286
5287 pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
5288 ovfl_arg = &ctx->ctx_ovfl_arg;
5289
5290 prefetch(ctx->ctx_smpl_hdr);
5291
5292 for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
5293
5294 mask = 1UL << i;
5295
5296 if ((pmd_mask & 0x1) == 0) continue;
5297
5298 ovfl_arg->ovfl_pmd = (unsigned char )i;
5299 ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
5300 ovfl_arg->active_set = 0;
5301 ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
5302 ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
5303
5304 ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
5305 ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
5306 ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
5307
5308 /*
5309 * copy values of pmds of interest. Sampling format may copy them
5310 * into sampling buffer.
5311 */
5312 if (smpl_pmds) {
5313 for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
5314 if ((smpl_pmds & 0x1) == 0) continue;
5315 ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
5316 DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
5317 }
5318 }
5319
5320 pfm_stats[this_cpu].pfm_smpl_handler_calls++;
5321
5322 start_cycles = ia64_get_itc();
5323
5324 /*
5325 * call custom buffer format record (handler) routine
5326 */
5327 ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
5328
5329 end_cycles = ia64_get_itc();
5330
5331 /*
5332 * For those controls, we take the union because they have
5333 * an all or nothing behavior.
5334 */
5335 ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
5336 ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
5337 ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
5338 /*
5339 * build the bitmask of pmds to reset now
5340 */
5341 if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
5342
5343 pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
5344 }
5345 /*
5346 * when the module cannot handle the rest of the overflows, we abort right here
5347 */
5348 if (ret && pmd_mask) {
5349 DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
5350 pmd_mask<<PMU_FIRST_COUNTER));
5351 }
5352 /*
5353 * remove the pmds we reset now from the set of pmds to reset in pfm_restart()
5354 */
5355 ovfl_pmds &= ~reset_pmds;
5356 } else {
5357 /*
5358 * when no sampling module is used, then the default
5359 * is to notify on overflow if requested by user
5360 */
5361 ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
5362 ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
5363 ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
5364 ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
5365 /*
5366 * if needed, we reset all overflowed pmds
5367 */
5368 if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
5369 }
5370
5371 DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
5372
5373 /*
5374 * reset the requested PMD registers using the short reset values
5375 */
5376 if (reset_pmds) {
5377 unsigned long bm = reset_pmds;
5378 pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
5379 }
5380
5381 if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
5382 /*
5383 * keep track of what to reset when unblocking
5384 */
5385 ctx->ctx_ovfl_regs[0] = ovfl_pmds;
5386
5387 /*
5388 * check for blocking context
5389 */
5390 if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
5391
5392 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
5393
5394 /*
5395 * set the perfmon specific checking pending work for the task
5396 */
5397 PFM_SET_WORK_PENDING(task, 1);
5398
5399 /*
5400 * when coming from ctxsw, current still points to the
5401 * previous task, therefore we must work with task and not current.
5402 */
5403 set_notify_resume(task);
5404 }
5405 /*
5406 * defer until state is changed (shorten spin window). the context is locked
5407 * anyway, so the signal receiver would come spin for nothing.
5408 */
5409 must_notify = 1;
5410 }
5411
5412 DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
5413 GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
5414 PFM_GET_WORK_PENDING(task),
5415 ctx->ctx_fl_trap_reason,
5416 ovfl_pmds,
5417 ovfl_notify,
5418 ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
5419 /*
5420 * in case monitoring must be stopped, we toggle the psr bits
5421 */
5422 if (ovfl_ctrl.bits.mask_monitoring) {
5423 pfm_mask_monitoring(task);
5424 ctx->ctx_state = PFM_CTX_MASKED;
5425 ctx->ctx_fl_can_restart = 1;
5426 }
5427
5428 /*
5429 * send notification now
5430 */
5431 if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
5432
5433 return;
5434
5435sanity_check:
5436 printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
5437 smp_processor_id(),
5438 task ? task_pid_nr(task) : -1,
5439 pmc0);
5440 return;
5441
5442stop_monitoring:
5443 /*
5444 * in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
5445 * Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
5446 * come here as zombie only if the task is the current task. In which case, we
5447 * can access the PMU hardware directly.
5448 *
5449 * Note that zombies do have PM_VALID set. So here we do the minimal.
5450 *
5451 * In case the context was zombified it could not be reclaimed at the time
5452 * the monitoring program exited. At this point, the PMU reservation has been
5453 * returned, the sampiing buffer has been freed. We must convert this call
5454 * into a spurious interrupt. However, we must also avoid infinite overflows
5455 * by stopping monitoring for this task. We can only come here for a per-task
5456 * context. All we need to do is to stop monitoring using the psr bits which
5457 * are always task private. By re-enabling secure montioring, we ensure that
5458 * the monitored task will not be able to re-activate monitoring.
5459 * The task will eventually be context switched out, at which point the context
5460 * will be reclaimed (that includes releasing ownership of the PMU).
5461 *
5462 * So there might be a window of time where the number of per-task session is zero
5463 * yet one PMU might have a owner and get at most one overflow interrupt for a zombie
5464 * context. This is safe because if a per-task session comes in, it will push this one
5465 * out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
5466 * session is force on that CPU, given that we use task pinning, pfm_save_regs() will
5467 * also push our zombie context out.
5468 *
5469 * Overall pretty hairy stuff....
5470 */
5471 DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
5472 pfm_clear_psr_up();
5473 ia64_psr(regs)->up = 0;
5474 ia64_psr(regs)->sp = 1;
5475 return;
5476}
5477
5478static int
5479pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
5480{
5481 struct task_struct *task;
5482 pfm_context_t *ctx;
5483 unsigned long flags;
5484 u64 pmc0;
5485 int this_cpu = smp_processor_id();
5486 int retval = 0;
5487
5488 pfm_stats[this_cpu].pfm_ovfl_intr_count++;
5489
5490 /*
5491 * srlz.d done before arriving here
5492 */
5493 pmc0 = ia64_get_pmc(0);
5494
5495 task = GET_PMU_OWNER();
5496 ctx = GET_PMU_CTX();
5497
5498 /*
5499 * if we have some pending bits set
5500 * assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
5501 */
5502 if (PMC0_HAS_OVFL(pmc0) && task) {
5503 /*
5504 * we assume that pmc0.fr is always set here
5505 */
5506
5507 /* sanity check */
5508 if (!ctx) goto report_spurious1;
5509
5510 if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
5511 goto report_spurious2;
5512
5513 PROTECT_CTX_NOPRINT(ctx, flags);
5514
5515 pfm_overflow_handler(task, ctx, pmc0, regs);
5516
5517 UNPROTECT_CTX_NOPRINT(ctx, flags);
5518
5519 } else {
5520 pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
5521 retval = -1;
5522 }
5523 /*
5524 * keep it unfrozen at all times
5525 */
5526 pfm_unfreeze_pmu();
5527
5528 return retval;
5529
5530report_spurious1:
5531 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
5532 this_cpu, task_pid_nr(task));
5533 pfm_unfreeze_pmu();
5534 return -1;
5535report_spurious2:
5536 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
5537 this_cpu,
5538 task_pid_nr(task));
5539 pfm_unfreeze_pmu();
5540 return -1;
5541}
5542
5543static irqreturn_t
5544pfm_interrupt_handler(int irq, void *arg)
5545{
5546 unsigned long start_cycles, total_cycles;
5547 unsigned long min, max;
5548 int this_cpu;
5549 int ret;
5550 struct pt_regs *regs = get_irq_regs();
5551
5552 this_cpu = get_cpu();
5553 if (likely(!pfm_alt_intr_handler)) {
5554 min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
5555 max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
5556
5557 start_cycles = ia64_get_itc();
5558
5559 ret = pfm_do_interrupt_handler(arg, regs);
5560
5561 total_cycles = ia64_get_itc();
5562
5563 /*
5564 * don't measure spurious interrupts
5565 */
5566 if (likely(ret == 0)) {
5567 total_cycles -= start_cycles;
5568
5569 if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
5570 if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
5571
5572 pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
5573 }
5574 }
5575 else {
5576 (*pfm_alt_intr_handler->handler)(irq, arg, regs);
5577 }
5578
5579 put_cpu();
5580 return IRQ_HANDLED;
5581}
5582
5583/*
5584 * /proc/perfmon interface, for debug only
5585 */
5586
5587#define PFM_PROC_SHOW_HEADER ((void *)(long)nr_cpu_ids+1)
5588
5589static void *
5590pfm_proc_start(struct seq_file *m, loff_t *pos)
5591{
5592 if (*pos == 0) {
5593 return PFM_PROC_SHOW_HEADER;
5594 }
5595
5596 while (*pos <= nr_cpu_ids) {
5597 if (cpu_online(*pos - 1)) {
5598 return (void *)*pos;
5599 }
5600 ++*pos;
5601 }
5602 return NULL;
5603}
5604
5605static void *
5606pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
5607{
5608 ++*pos;
5609 return pfm_proc_start(m, pos);
5610}
5611
5612static void
5613pfm_proc_stop(struct seq_file *m, void *v)
5614{
5615}
5616
5617static void
5618pfm_proc_show_header(struct seq_file *m)
5619{
5620 struct list_head * pos;
5621 pfm_buffer_fmt_t * entry;
5622 unsigned long flags;
5623
5624 seq_printf(m,
5625 "perfmon version : %u.%u\n"
5626 "model : %s\n"
5627 "fastctxsw : %s\n"
5628 "expert mode : %s\n"
5629 "ovfl_mask : 0x%lx\n"
5630 "PMU flags : 0x%x\n",
5631 PFM_VERSION_MAJ, PFM_VERSION_MIN,
5632 pmu_conf->pmu_name,
5633 pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
5634 pfm_sysctl.expert_mode > 0 ? "Yes": "No",
5635 pmu_conf->ovfl_val,
5636 pmu_conf->flags);
5637
5638 LOCK_PFS(flags);
5639
5640 seq_printf(m,
5641 "proc_sessions : %u\n"
5642 "sys_sessions : %u\n"
5643 "sys_use_dbregs : %u\n"
5644 "ptrace_use_dbregs : %u\n",
5645 pfm_sessions.pfs_task_sessions,
5646 pfm_sessions.pfs_sys_sessions,
5647 pfm_sessions.pfs_sys_use_dbregs,
5648 pfm_sessions.pfs_ptrace_use_dbregs);
5649
5650 UNLOCK_PFS(flags);
5651
5652 spin_lock(&pfm_buffer_fmt_lock);
5653
5654 list_for_each(pos, &pfm_buffer_fmt_list) {
5655 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
5656 seq_printf(m, "format : %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x %s\n",
5657 entry->fmt_uuid[0],
5658 entry->fmt_uuid[1],
5659 entry->fmt_uuid[2],
5660 entry->fmt_uuid[3],
5661 entry->fmt_uuid[4],
5662 entry->fmt_uuid[5],
5663 entry->fmt_uuid[6],
5664 entry->fmt_uuid[7],
5665 entry->fmt_uuid[8],
5666 entry->fmt_uuid[9],
5667 entry->fmt_uuid[10],
5668 entry->fmt_uuid[11],
5669 entry->fmt_uuid[12],
5670 entry->fmt_uuid[13],
5671 entry->fmt_uuid[14],
5672 entry->fmt_uuid[15],
5673 entry->fmt_name);
5674 }
5675 spin_unlock(&pfm_buffer_fmt_lock);
5676
5677}
5678
5679static int
5680pfm_proc_show(struct seq_file *m, void *v)
5681{
5682 unsigned long psr;
5683 unsigned int i;
5684 int cpu;
5685
5686 if (v == PFM_PROC_SHOW_HEADER) {
5687 pfm_proc_show_header(m);
5688 return 0;
5689 }
5690
5691 /* show info for CPU (v - 1) */
5692
5693 cpu = (long)v - 1;
5694 seq_printf(m,
5695 "CPU%-2d overflow intrs : %lu\n"
5696 "CPU%-2d overflow cycles : %lu\n"
5697 "CPU%-2d overflow min : %lu\n"
5698 "CPU%-2d overflow max : %lu\n"
5699 "CPU%-2d smpl handler calls : %lu\n"
5700 "CPU%-2d smpl handler cycles : %lu\n"
5701 "CPU%-2d spurious intrs : %lu\n"
5702 "CPU%-2d replay intrs : %lu\n"
5703 "CPU%-2d syst_wide : %d\n"
5704 "CPU%-2d dcr_pp : %d\n"
5705 "CPU%-2d exclude idle : %d\n"
5706 "CPU%-2d owner : %d\n"
5707 "CPU%-2d context : %p\n"
5708 "CPU%-2d activations : %lu\n",
5709 cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
5710 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
5711 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
5712 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
5713 cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
5714 cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
5715 cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
5716 cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
5717 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
5718 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
5719 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
5720 cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
5721 cpu, pfm_get_cpu_data(pmu_ctx, cpu),
5722 cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
5723
5724 if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
5725
5726 psr = pfm_get_psr();
5727
5728 ia64_srlz_d();
5729
5730 seq_printf(m,
5731 "CPU%-2d psr : 0x%lx\n"
5732 "CPU%-2d pmc0 : 0x%lx\n",
5733 cpu, psr,
5734 cpu, ia64_get_pmc(0));
5735
5736 for (i=0; PMC_IS_LAST(i) == 0; i++) {
5737 if (PMC_IS_COUNTING(i) == 0) continue;
5738 seq_printf(m,
5739 "CPU%-2d pmc%u : 0x%lx\n"
5740 "CPU%-2d pmd%u : 0x%lx\n",
5741 cpu, i, ia64_get_pmc(i),
5742 cpu, i, ia64_get_pmd(i));
5743 }
5744 }
5745 return 0;
5746}
5747
5748const struct seq_operations pfm_seq_ops = {
5749 .start = pfm_proc_start,
5750 .next = pfm_proc_next,
5751 .stop = pfm_proc_stop,
5752 .show = pfm_proc_show
5753};
5754
5755static int
5756pfm_proc_open(struct inode *inode, struct file *file)
5757{
5758 return seq_open(file, &pfm_seq_ops);
5759}
5760
5761
5762/*
5763 * we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
5764 * during pfm_enable() hence before pfm_start(). We cannot assume monitoring
5765 * is active or inactive based on mode. We must rely on the value in
5766 * local_cpu_data->pfm_syst_info
5767 */
5768void
5769pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
5770{
5771 struct pt_regs *regs;
5772 unsigned long dcr;
5773 unsigned long dcr_pp;
5774
5775 dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
5776
5777 /*
5778 * pid 0 is guaranteed to be the idle task. There is one such task with pid 0
5779 * on every CPU, so we can rely on the pid to identify the idle task.
5780 */
5781 if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
5782 regs = task_pt_regs(task);
5783 ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
5784 return;
5785 }
5786 /*
5787 * if monitoring has started
5788 */
5789 if (dcr_pp) {
5790 dcr = ia64_getreg(_IA64_REG_CR_DCR);
5791 /*
5792 * context switching in?
5793 */
5794 if (is_ctxswin) {
5795 /* mask monitoring for the idle task */
5796 ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
5797 pfm_clear_psr_pp();
5798 ia64_srlz_i();
5799 return;
5800 }
5801 /*
5802 * context switching out
5803 * restore monitoring for next task
5804 *
5805 * Due to inlining this odd if-then-else construction generates
5806 * better code.
5807 */
5808 ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
5809 pfm_set_psr_pp();
5810 ia64_srlz_i();
5811 }
5812}
5813
5814#ifdef CONFIG_SMP
5815
5816static void
5817pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
5818{
5819 struct task_struct *task = ctx->ctx_task;
5820
5821 ia64_psr(regs)->up = 0;
5822 ia64_psr(regs)->sp = 1;
5823
5824 if (GET_PMU_OWNER() == task) {
5825 DPRINT(("cleared ownership for [%d]\n",
5826 task_pid_nr(ctx->ctx_task)));
5827 SET_PMU_OWNER(NULL, NULL);
5828 }
5829
5830 /*
5831 * disconnect the task from the context and vice-versa
5832 */
5833 PFM_SET_WORK_PENDING(task, 0);
5834
5835 task->thread.pfm_context = NULL;
5836 task->thread.flags &= ~IA64_THREAD_PM_VALID;
5837
5838 DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
5839}
5840
5841
5842/*
5843 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
5844 */
5845void
5846pfm_save_regs(struct task_struct *task)
5847{
5848 pfm_context_t *ctx;
5849 unsigned long flags;
5850 u64 psr;
5851
5852
5853 ctx = PFM_GET_CTX(task);
5854 if (ctx == NULL) return;
5855
5856 /*
5857 * we always come here with interrupts ALREADY disabled by
5858 * the scheduler. So we simply need to protect against concurrent
5859 * access, not CPU concurrency.
5860 */
5861 flags = pfm_protect_ctx_ctxsw(ctx);
5862
5863 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5864 struct pt_regs *regs = task_pt_regs(task);
5865
5866 pfm_clear_psr_up();
5867
5868 pfm_force_cleanup(ctx, regs);
5869
5870 BUG_ON(ctx->ctx_smpl_hdr);
5871
5872 pfm_unprotect_ctx_ctxsw(ctx, flags);
5873
5874 pfm_context_free(ctx);
5875 return;
5876 }
5877
5878 /*
5879 * save current PSR: needed because we modify it
5880 */
5881 ia64_srlz_d();
5882 psr = pfm_get_psr();
5883
5884 BUG_ON(psr & (IA64_PSR_I));
5885
5886 /*
5887 * stop monitoring:
5888 * This is the last instruction which may generate an overflow
5889 *
5890 * We do not need to set psr.sp because, it is irrelevant in kernel.
5891 * It will be restored from ipsr when going back to user level
5892 */
5893 pfm_clear_psr_up();
5894
5895 /*
5896 * keep a copy of psr.up (for reload)
5897 */
5898 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5899
5900 /*
5901 * release ownership of this PMU.
5902 * PM interrupts are masked, so nothing
5903 * can happen.
5904 */
5905 SET_PMU_OWNER(NULL, NULL);
5906
5907 /*
5908 * we systematically save the PMD as we have no
5909 * guarantee we will be schedule at that same
5910 * CPU again.
5911 */
5912 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
5913
5914 /*
5915 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
5916 * we will need it on the restore path to check
5917 * for pending overflow.
5918 */
5919 ctx->th_pmcs[0] = ia64_get_pmc(0);
5920
5921 /*
5922 * unfreeze PMU if had pending overflows
5923 */
5924 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
5925
5926 /*
5927 * finally, allow context access.
5928 * interrupts will still be masked after this call.
5929 */
5930 pfm_unprotect_ctx_ctxsw(ctx, flags);
5931}
5932
5933#else /* !CONFIG_SMP */
5934void
5935pfm_save_regs(struct task_struct *task)
5936{
5937 pfm_context_t *ctx;
5938 u64 psr;
5939
5940 ctx = PFM_GET_CTX(task);
5941 if (ctx == NULL) return;
5942
5943 /*
5944 * save current PSR: needed because we modify it
5945 */
5946 psr = pfm_get_psr();
5947
5948 BUG_ON(psr & (IA64_PSR_I));
5949
5950 /*
5951 * stop monitoring:
5952 * This is the last instruction which may generate an overflow
5953 *
5954 * We do not need to set psr.sp because, it is irrelevant in kernel.
5955 * It will be restored from ipsr when going back to user level
5956 */
5957 pfm_clear_psr_up();
5958
5959 /*
5960 * keep a copy of psr.up (for reload)
5961 */
5962 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5963}
5964
5965static void
5966pfm_lazy_save_regs (struct task_struct *task)
5967{
5968 pfm_context_t *ctx;
5969 unsigned long flags;
5970
5971 { u64 psr = pfm_get_psr();
5972 BUG_ON(psr & IA64_PSR_UP);
5973 }
5974
5975 ctx = PFM_GET_CTX(task);
5976
5977 /*
5978 * we need to mask PMU overflow here to
5979 * make sure that we maintain pmc0 until
5980 * we save it. overflow interrupts are
5981 * treated as spurious if there is no
5982 * owner.
5983 *
5984 * XXX: I don't think this is necessary
5985 */
5986 PROTECT_CTX(ctx,flags);
5987
5988 /*
5989 * release ownership of this PMU.
5990 * must be done before we save the registers.
5991 *
5992 * after this call any PMU interrupt is treated
5993 * as spurious.
5994 */
5995 SET_PMU_OWNER(NULL, NULL);
5996
5997 /*
5998 * save all the pmds we use
5999 */
6000 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
6001
6002 /*
6003 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
6004 * it is needed to check for pended overflow
6005 * on the restore path
6006 */
6007 ctx->th_pmcs[0] = ia64_get_pmc(0);
6008
6009 /*
6010 * unfreeze PMU if had pending overflows
6011 */
6012 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
6013
6014 /*
6015 * now get can unmask PMU interrupts, they will
6016 * be treated as purely spurious and we will not
6017 * lose any information
6018 */
6019 UNPROTECT_CTX(ctx,flags);
6020}
6021#endif /* CONFIG_SMP */
6022
6023#ifdef CONFIG_SMP
6024/*
6025 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
6026 */
6027void
6028pfm_load_regs (struct task_struct *task)
6029{
6030 pfm_context_t *ctx;
6031 unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
6032 unsigned long flags;
6033 u64 psr, psr_up;
6034 int need_irq_resend;
6035
6036 ctx = PFM_GET_CTX(task);
6037 if (unlikely(ctx == NULL)) return;
6038
6039 BUG_ON(GET_PMU_OWNER());
6040
6041 /*
6042 * possible on unload
6043 */
6044 if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
6045
6046 /*
6047 * we always come here with interrupts ALREADY disabled by
6048 * the scheduler. So we simply need to protect against concurrent
6049 * access, not CPU concurrency.
6050 */
6051 flags = pfm_protect_ctx_ctxsw(ctx);
6052 psr = pfm_get_psr();
6053
6054 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6055
6056 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6057 BUG_ON(psr & IA64_PSR_I);
6058
6059 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
6060 struct pt_regs *regs = task_pt_regs(task);
6061
6062 BUG_ON(ctx->ctx_smpl_hdr);
6063
6064 pfm_force_cleanup(ctx, regs);
6065
6066 pfm_unprotect_ctx_ctxsw(ctx, flags);
6067
6068 /*
6069 * this one (kmalloc'ed) is fine with interrupts disabled
6070 */
6071 pfm_context_free(ctx);
6072
6073 return;
6074 }
6075
6076 /*
6077 * we restore ALL the debug registers to avoid picking up
6078 * stale state.
6079 */
6080 if (ctx->ctx_fl_using_dbreg) {
6081 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6082 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6083 }
6084 /*
6085 * retrieve saved psr.up
6086 */
6087 psr_up = ctx->ctx_saved_psr_up;
6088
6089 /*
6090 * if we were the last user of the PMU on that CPU,
6091 * then nothing to do except restore psr
6092 */
6093 if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
6094
6095 /*
6096 * retrieve partial reload masks (due to user modifications)
6097 */
6098 pmc_mask = ctx->ctx_reload_pmcs[0];
6099 pmd_mask = ctx->ctx_reload_pmds[0];
6100
6101 } else {
6102 /*
6103 * To avoid leaking information to the user level when psr.sp=0,
6104 * we must reload ALL implemented pmds (even the ones we don't use).
6105 * In the kernel we only allow PFM_READ_PMDS on registers which
6106 * we initialized or requested (sampling) so there is no risk there.
6107 */
6108 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6109
6110 /*
6111 * ALL accessible PMCs are systematically reloaded, unused registers
6112 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6113 * up stale configuration.
6114 *
6115 * PMC0 is never in the mask. It is always restored separately.
6116 */
6117 pmc_mask = ctx->ctx_all_pmcs[0];
6118 }
6119 /*
6120 * when context is MASKED, we will restore PMC with plm=0
6121 * and PMD with stale information, but that's ok, nothing
6122 * will be captured.
6123 *
6124 * XXX: optimize here
6125 */
6126 if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6127 if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6128
6129 /*
6130 * check for pending overflow at the time the state
6131 * was saved.
6132 */
6133 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6134 /*
6135 * reload pmc0 with the overflow information
6136 * On McKinley PMU, this will trigger a PMU interrupt
6137 */
6138 ia64_set_pmc(0, ctx->th_pmcs[0]);
6139 ia64_srlz_d();
6140 ctx->th_pmcs[0] = 0UL;
6141
6142 /*
6143 * will replay the PMU interrupt
6144 */
6145 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6146
6147 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6148 }
6149
6150 /*
6151 * we just did a reload, so we reset the partial reload fields
6152 */
6153 ctx->ctx_reload_pmcs[0] = 0UL;
6154 ctx->ctx_reload_pmds[0] = 0UL;
6155
6156 SET_LAST_CPU(ctx, smp_processor_id());
6157
6158 /*
6159 * dump activation value for this PMU
6160 */
6161 INC_ACTIVATION();
6162 /*
6163 * record current activation for this context
6164 */
6165 SET_ACTIVATION(ctx);
6166
6167 /*
6168 * establish new ownership.
6169 */
6170 SET_PMU_OWNER(task, ctx);
6171
6172 /*
6173 * restore the psr.up bit. measurement
6174 * is active again.
6175 * no PMU interrupt can happen at this point
6176 * because we still have interrupts disabled.
6177 */
6178 if (likely(psr_up)) pfm_set_psr_up();
6179
6180 /*
6181 * allow concurrent access to context
6182 */
6183 pfm_unprotect_ctx_ctxsw(ctx, flags);
6184}
6185#else /* !CONFIG_SMP */
6186/*
6187 * reload PMU state for UP kernels
6188 * in 2.5 we come here with interrupts disabled
6189 */
6190void
6191pfm_load_regs (struct task_struct *task)
6192{
6193 pfm_context_t *ctx;
6194 struct task_struct *owner;
6195 unsigned long pmd_mask, pmc_mask;
6196 u64 psr, psr_up;
6197 int need_irq_resend;
6198
6199 owner = GET_PMU_OWNER();
6200 ctx = PFM_GET_CTX(task);
6201 psr = pfm_get_psr();
6202
6203 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6204 BUG_ON(psr & IA64_PSR_I);
6205
6206 /*
6207 * we restore ALL the debug registers to avoid picking up
6208 * stale state.
6209 *
6210 * This must be done even when the task is still the owner
6211 * as the registers may have been modified via ptrace()
6212 * (not perfmon) by the previous task.
6213 */
6214 if (ctx->ctx_fl_using_dbreg) {
6215 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6216 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6217 }
6218
6219 /*
6220 * retrieved saved psr.up
6221 */
6222 psr_up = ctx->ctx_saved_psr_up;
6223 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6224
6225 /*
6226 * short path, our state is still there, just
6227 * need to restore psr and we go
6228 *
6229 * we do not touch either PMC nor PMD. the psr is not touched
6230 * by the overflow_handler. So we are safe w.r.t. to interrupt
6231 * concurrency even without interrupt masking.
6232 */
6233 if (likely(owner == task)) {
6234 if (likely(psr_up)) pfm_set_psr_up();
6235 return;
6236 }
6237
6238 /*
6239 * someone else is still using the PMU, first push it out and
6240 * then we'll be able to install our stuff !
6241 *
6242 * Upon return, there will be no owner for the current PMU
6243 */
6244 if (owner) pfm_lazy_save_regs(owner);
6245
6246 /*
6247 * To avoid leaking information to the user level when psr.sp=0,
6248 * we must reload ALL implemented pmds (even the ones we don't use).
6249 * In the kernel we only allow PFM_READ_PMDS on registers which
6250 * we initialized or requested (sampling) so there is no risk there.
6251 */
6252 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6253
6254 /*
6255 * ALL accessible PMCs are systematically reloaded, unused registers
6256 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6257 * up stale configuration.
6258 *
6259 * PMC0 is never in the mask. It is always restored separately
6260 */
6261 pmc_mask = ctx->ctx_all_pmcs[0];
6262
6263 pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6264 pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6265
6266 /*
6267 * check for pending overflow at the time the state
6268 * was saved.
6269 */
6270 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6271 /*
6272 * reload pmc0 with the overflow information
6273 * On McKinley PMU, this will trigger a PMU interrupt
6274 */
6275 ia64_set_pmc(0, ctx->th_pmcs[0]);
6276 ia64_srlz_d();
6277
6278 ctx->th_pmcs[0] = 0UL;
6279
6280 /*
6281 * will replay the PMU interrupt
6282 */
6283 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6284
6285 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6286 }
6287
6288 /*
6289 * establish new ownership.
6290 */
6291 SET_PMU_OWNER(task, ctx);
6292
6293 /*
6294 * restore the psr.up bit. measurement
6295 * is active again.
6296 * no PMU interrupt can happen at this point
6297 * because we still have interrupts disabled.
6298 */
6299 if (likely(psr_up)) pfm_set_psr_up();
6300}
6301#endif /* CONFIG_SMP */
6302
6303/*
6304 * this function assumes monitoring is stopped
6305 */
6306static void
6307pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
6308{
6309 u64 pmc0;
6310 unsigned long mask2, val, pmd_val, ovfl_val;
6311 int i, can_access_pmu = 0;
6312 int is_self;
6313
6314 /*
6315 * is the caller the task being monitored (or which initiated the
6316 * session for system wide measurements)
6317 */
6318 is_self = ctx->ctx_task == task ? 1 : 0;
6319
6320 /*
6321 * can access PMU is task is the owner of the PMU state on the current CPU
6322 * or if we are running on the CPU bound to the context in system-wide mode
6323 * (that is not necessarily the task the context is attached to in this mode).
6324 * In system-wide we always have can_access_pmu true because a task running on an
6325 * invalid processor is flagged earlier in the call stack (see pfm_stop).
6326 */
6327 can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
6328 if (can_access_pmu) {
6329 /*
6330 * Mark the PMU as not owned
6331 * This will cause the interrupt handler to do nothing in case an overflow
6332 * interrupt was in-flight
6333 * This also guarantees that pmc0 will contain the final state
6334 * It virtually gives us full control on overflow processing from that point
6335 * on.
6336 */
6337 SET_PMU_OWNER(NULL, NULL);
6338 DPRINT(("releasing ownership\n"));
6339
6340 /*
6341 * read current overflow status:
6342 *
6343 * we are guaranteed to read the final stable state
6344 */
6345 ia64_srlz_d();
6346 pmc0 = ia64_get_pmc(0); /* slow */
6347
6348 /*
6349 * reset freeze bit, overflow status information destroyed
6350 */
6351 pfm_unfreeze_pmu();
6352 } else {
6353 pmc0 = ctx->th_pmcs[0];
6354 /*
6355 * clear whatever overflow status bits there were
6356 */
6357 ctx->th_pmcs[0] = 0;
6358 }
6359 ovfl_val = pmu_conf->ovfl_val;
6360 /*
6361 * we save all the used pmds
6362 * we take care of overflows for counting PMDs
6363 *
6364 * XXX: sampling situation is not taken into account here
6365 */
6366 mask2 = ctx->ctx_used_pmds[0];
6367
6368 DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
6369
6370 for (i = 0; mask2; i++, mask2>>=1) {
6371
6372 /* skip non used pmds */
6373 if ((mask2 & 0x1) == 0) continue;
6374
6375 /*
6376 * can access PMU always true in system wide mode
6377 */
6378 val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
6379
6380 if (PMD_IS_COUNTING(i)) {
6381 DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
6382 task_pid_nr(task),
6383 i,
6384 ctx->ctx_pmds[i].val,
6385 val & ovfl_val));
6386
6387 /*
6388 * we rebuild the full 64 bit value of the counter
6389 */
6390 val = ctx->ctx_pmds[i].val + (val & ovfl_val);
6391
6392 /*
6393 * now everything is in ctx_pmds[] and we need
6394 * to clear the saved context from save_regs() such that
6395 * pfm_read_pmds() gets the correct value
6396 */
6397 pmd_val = 0UL;
6398
6399 /*
6400 * take care of overflow inline
6401 */
6402 if (pmc0 & (1UL << i)) {
6403 val += 1 + ovfl_val;
6404 DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
6405 }
6406 }
6407
6408 DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
6409
6410 if (is_self) ctx->th_pmds[i] = pmd_val;
6411
6412 ctx->ctx_pmds[i].val = val;
6413 }
6414}
6415
6416static struct irqaction perfmon_irqaction = {
6417 .handler = pfm_interrupt_handler,
6418 .flags = IRQF_DISABLED,
6419 .name = "perfmon"
6420};
6421
6422static void
6423pfm_alt_save_pmu_state(void *data)
6424{
6425 struct pt_regs *regs;
6426
6427 regs = task_pt_regs(current);
6428
6429 DPRINT(("called\n"));
6430
6431 /*
6432 * should not be necessary but
6433 * let's take not risk
6434 */
6435 pfm_clear_psr_up();
6436 pfm_clear_psr_pp();
6437 ia64_psr(regs)->pp = 0;
6438
6439 /*
6440 * This call is required
6441 * May cause a spurious interrupt on some processors
6442 */
6443 pfm_freeze_pmu();
6444
6445 ia64_srlz_d();
6446}
6447
6448void
6449pfm_alt_restore_pmu_state(void *data)
6450{
6451 struct pt_regs *regs;
6452
6453 regs = task_pt_regs(current);
6454
6455 DPRINT(("called\n"));
6456
6457 /*
6458 * put PMU back in state expected
6459 * by perfmon
6460 */
6461 pfm_clear_psr_up();
6462 pfm_clear_psr_pp();
6463 ia64_psr(regs)->pp = 0;
6464
6465 /*
6466 * perfmon runs with PMU unfrozen at all times
6467 */
6468 pfm_unfreeze_pmu();
6469
6470 ia64_srlz_d();
6471}
6472
6473int
6474pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6475{
6476 int ret, i;
6477 int reserve_cpu;
6478
6479 /* some sanity checks */
6480 if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
6481
6482 /* do the easy test first */
6483 if (pfm_alt_intr_handler) return -EBUSY;
6484
6485 /* one at a time in the install or remove, just fail the others */
6486 if (!spin_trylock(&pfm_alt_install_check)) {
6487 return -EBUSY;
6488 }
6489
6490 /* reserve our session */
6491 for_each_online_cpu(reserve_cpu) {
6492 ret = pfm_reserve_session(NULL, 1, reserve_cpu);
6493 if (ret) goto cleanup_reserve;
6494 }
6495
6496 /* save the current system wide pmu states */
6497 ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
6498 if (ret) {
6499 DPRINT(("on_each_cpu() failed: %d\n", ret));
6500 goto cleanup_reserve;
6501 }
6502
6503 /* officially change to the alternate interrupt handler */
6504 pfm_alt_intr_handler = hdl;
6505
6506 spin_unlock(&pfm_alt_install_check);
6507
6508 return 0;
6509
6510cleanup_reserve:
6511 for_each_online_cpu(i) {
6512 /* don't unreserve more than we reserved */
6513 if (i >= reserve_cpu) break;
6514
6515 pfm_unreserve_session(NULL, 1, i);
6516 }
6517
6518 spin_unlock(&pfm_alt_install_check);
6519
6520 return ret;
6521}
6522EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
6523
6524int
6525pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6526{
6527 int i;
6528 int ret;
6529
6530 if (hdl == NULL) return -EINVAL;
6531
6532 /* cannot remove someone else's handler! */
6533 if (pfm_alt_intr_handler != hdl) return -EINVAL;
6534
6535 /* one at a time in the install or remove, just fail the others */
6536 if (!spin_trylock(&pfm_alt_install_check)) {
6537 return -EBUSY;
6538 }
6539
6540 pfm_alt_intr_handler = NULL;
6541
6542 ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
6543 if (ret) {
6544 DPRINT(("on_each_cpu() failed: %d\n", ret));
6545 }
6546
6547 for_each_online_cpu(i) {
6548 pfm_unreserve_session(NULL, 1, i);
6549 }
6550
6551 spin_unlock(&pfm_alt_install_check);
6552
6553 return 0;
6554}
6555EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
6556
6557/*
6558 * perfmon initialization routine, called from the initcall() table
6559 */
6560static int init_pfm_fs(void);
6561
6562static int __init
6563pfm_probe_pmu(void)
6564{
6565 pmu_config_t **p;
6566 int family;
6567
6568 family = local_cpu_data->family;
6569 p = pmu_confs;
6570
6571 while(*p) {
6572 if ((*p)->probe) {
6573 if ((*p)->probe() == 0) goto found;
6574 } else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
6575 goto found;
6576 }
6577 p++;
6578 }
6579 return -1;
6580found:
6581 pmu_conf = *p;
6582 return 0;
6583}
6584
6585static const struct file_operations pfm_proc_fops = {
6586 .open = pfm_proc_open,
6587 .read = seq_read,
6588 .llseek = seq_lseek,
6589 .release = seq_release,
6590};
6591
6592int __init
6593pfm_init(void)
6594{
6595 unsigned int n, n_counters, i;
6596
6597 printk("perfmon: version %u.%u IRQ %u\n",
6598 PFM_VERSION_MAJ,
6599 PFM_VERSION_MIN,
6600 IA64_PERFMON_VECTOR);
6601
6602 if (pfm_probe_pmu()) {
6603 printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
6604 local_cpu_data->family);
6605 return -ENODEV;
6606 }
6607
6608 /*
6609 * compute the number of implemented PMD/PMC from the
6610 * description tables
6611 */
6612 n = 0;
6613 for (i=0; PMC_IS_LAST(i) == 0; i++) {
6614 if (PMC_IS_IMPL(i) == 0) continue;
6615 pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
6616 n++;
6617 }
6618 pmu_conf->num_pmcs = n;
6619
6620 n = 0; n_counters = 0;
6621 for (i=0; PMD_IS_LAST(i) == 0; i++) {
6622 if (PMD_IS_IMPL(i) == 0) continue;
6623 pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
6624 n++;
6625 if (PMD_IS_COUNTING(i)) n_counters++;
6626 }
6627 pmu_conf->num_pmds = n;
6628 pmu_conf->num_counters = n_counters;
6629
6630 /*
6631 * sanity checks on the number of debug registers
6632 */
6633 if (pmu_conf->use_rr_dbregs) {
6634 if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
6635 printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
6636 pmu_conf = NULL;
6637 return -1;
6638 }
6639 if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
6640 printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
6641 pmu_conf = NULL;
6642 return -1;
6643 }
6644 }
6645
6646 printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
6647 pmu_conf->pmu_name,
6648 pmu_conf->num_pmcs,
6649 pmu_conf->num_pmds,
6650 pmu_conf->num_counters,
6651 ffz(pmu_conf->ovfl_val));
6652
6653 /* sanity check */
6654 if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
6655 printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
6656 pmu_conf = NULL;
6657 return -1;
6658 }
6659
6660 /*
6661 * create /proc/perfmon (mostly for debugging purposes)
6662 */
6663 perfmon_dir = proc_create("perfmon", S_IRUGO, NULL, &pfm_proc_fops);
6664 if (perfmon_dir == NULL) {
6665 printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
6666 pmu_conf = NULL;
6667 return -1;
6668 }
6669
6670 /*
6671 * create /proc/sys/kernel/perfmon (for debugging purposes)
6672 */
6673 pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
6674
6675 /*
6676 * initialize all our spinlocks
6677 */
6678 spin_lock_init(&pfm_sessions.pfs_lock);
6679 spin_lock_init(&pfm_buffer_fmt_lock);
6680
6681 init_pfm_fs();
6682
6683 for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
6684
6685 return 0;
6686}
6687
6688__initcall(pfm_init);
6689
6690/*
6691 * this function is called before pfm_init()
6692 */
6693void
6694pfm_init_percpu (void)
6695{
6696 static int first_time=1;
6697 /*
6698 * make sure no measurement is active
6699 * (may inherit programmed PMCs from EFI).
6700 */
6701 pfm_clear_psr_pp();
6702 pfm_clear_psr_up();
6703
6704 /*
6705 * we run with the PMU not frozen at all times
6706 */
6707 pfm_unfreeze_pmu();
6708
6709 if (first_time) {
6710 register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
6711 first_time=0;
6712 }
6713
6714 ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
6715 ia64_srlz_d();
6716}
6717
6718/*
6719 * used for debug purposes only
6720 */
6721void
6722dump_pmu_state(const char *from)
6723{
6724 struct task_struct *task;
6725 struct pt_regs *regs;
6726 pfm_context_t *ctx;
6727 unsigned long psr, dcr, info, flags;
6728 int i, this_cpu;
6729
6730 local_irq_save(flags);
6731
6732 this_cpu = smp_processor_id();
6733 regs = task_pt_regs(current);
6734 info = PFM_CPUINFO_GET();
6735 dcr = ia64_getreg(_IA64_REG_CR_DCR);
6736
6737 if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
6738 local_irq_restore(flags);
6739 return;
6740 }
6741
6742 printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
6743 this_cpu,
6744 from,
6745 task_pid_nr(current),
6746 regs->cr_iip,
6747 current->comm);
6748
6749 task = GET_PMU_OWNER();
6750 ctx = GET_PMU_CTX();
6751
6752 printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
6753
6754 psr = pfm_get_psr();
6755
6756 printk("->CPU%d pmc0=0x%lx psr.pp=%d psr.up=%d dcr.pp=%d syst_info=0x%lx user_psr.up=%d user_psr.pp=%d\n",
6757 this_cpu,
6758 ia64_get_pmc(0),
6759 psr & IA64_PSR_PP ? 1 : 0,
6760 psr & IA64_PSR_UP ? 1 : 0,
6761 dcr & IA64_DCR_PP ? 1 : 0,
6762 info,
6763 ia64_psr(regs)->up,
6764 ia64_psr(regs)->pp);
6765
6766 ia64_psr(regs)->up = 0;
6767 ia64_psr(regs)->pp = 0;
6768
6769 for (i=1; PMC_IS_LAST(i) == 0; i++) {
6770 if (PMC_IS_IMPL(i) == 0) continue;
6771 printk("->CPU%d pmc[%d]=0x%lx thread_pmc[%d]=0x%lx\n", this_cpu, i, ia64_get_pmc(i), i, ctx->th_pmcs[i]);
6772 }
6773
6774 for (i=1; PMD_IS_LAST(i) == 0; i++) {
6775 if (PMD_IS_IMPL(i) == 0) continue;
6776 printk("->CPU%d pmd[%d]=0x%lx thread_pmd[%d]=0x%lx\n", this_cpu, i, ia64_get_pmd(i), i, ctx->th_pmds[i]);
6777 }
6778
6779 if (ctx) {
6780 printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
6781 this_cpu,
6782 ctx->ctx_state,
6783 ctx->ctx_smpl_vaddr,
6784 ctx->ctx_smpl_hdr,
6785 ctx->ctx_msgq_head,
6786 ctx->ctx_msgq_tail,
6787 ctx->ctx_saved_psr_up);
6788 }
6789 local_irq_restore(flags);
6790}
6791
6792/*
6793 * called from process.c:copy_thread(). task is new child.
6794 */
6795void
6796pfm_inherit(struct task_struct *task, struct pt_regs *regs)
6797{
6798 struct thread_struct *thread;
6799
6800 DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
6801
6802 thread = &task->thread;
6803
6804 /*
6805 * cut links inherited from parent (current)
6806 */
6807 thread->pfm_context = NULL;
6808
6809 PFM_SET_WORK_PENDING(task, 0);
6810
6811 /*
6812 * the psr bits are already set properly in copy_threads()
6813 */
6814}
6815#else /* !CONFIG_PERFMON */
6816asmlinkage long
6817sys_perfmonctl (int fd, int cmd, void *arg, int count)
6818{
6819 return -ENOSYS;
6820}
6821#endif /* CONFIG_PERFMON */