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