Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file implements the perfmon-2 subsystem which is used
4 * to program the IA-64 Performance Monitoring Unit (PMU).
5 *
6 * The initial version of perfmon.c was written by
7 * Ganesh Venkitachalam, IBM Corp.
8 *
9 * Then it was modified for perfmon-1.x by Stephane Eranian and
10 * David Mosberger, Hewlett Packard Co.
11 *
12 * Version Perfmon-2.x is a rewrite of perfmon-1.x
13 * by Stephane Eranian, Hewlett Packard Co.
14 *
15 * Copyright (C) 1999-2005 Hewlett Packard Co
16 * Stephane Eranian <eranian@hpl.hp.com>
17 * David Mosberger-Tang <davidm@hpl.hp.com>
18 *
19 * More information about perfmon available at:
20 * http://www.hpl.hp.com/research/linux/perfmon
21 */
22
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/sched.h>
26#include <linux/sched/task.h>
27#include <linux/sched/task_stack.h>
28#include <linux/interrupt.h>
29#include <linux/proc_fs.h>
30#include <linux/seq_file.h>
31#include <linux/init.h>
32#include <linux/vmalloc.h>
33#include <linux/mm.h>
34#include <linux/sysctl.h>
35#include <linux/list.h>
36#include <linux/file.h>
37#include <linux/poll.h>
38#include <linux/vfs.h>
39#include <linux/smp.h>
40#include <linux/pagemap.h>
41#include <linux/mount.h>
42#include <linux/pseudo_fs.h>
43#include <linux/bitops.h>
44#include <linux/capability.h>
45#include <linux/rcupdate.h>
46#include <linux/completion.h>
47#include <linux/tracehook.h>
48#include <linux/slab.h>
49#include <linux/cpu.h>
50
51#include <asm/errno.h>
52#include <asm/intrinsics.h>
53#include <asm/page.h>
54#include <asm/perfmon.h>
55#include <asm/processor.h>
56#include <asm/signal.h>
57#include <linux/uaccess.h>
58#include <asm/delay.h>
59
60#ifdef CONFIG_PERFMON
61/*
62 * perfmon context state
63 */
64#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
65#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
66#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
67#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
68
69#define PFM_INVALID_ACTIVATION (~0UL)
70
71#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
72#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
73
74/*
75 * depth of message queue
76 */
77#define PFM_MAX_MSGS 32
78#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
79
80/*
81 * type of a PMU register (bitmask).
82 * bitmask structure:
83 * bit0 : register implemented
84 * bit1 : end marker
85 * bit2-3 : reserved
86 * bit4 : pmc has pmc.pm
87 * bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
88 * bit6-7 : register type
89 * bit8-31: reserved
90 */
91#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
92#define PFM_REG_IMPL 0x1 /* register implemented */
93#define PFM_REG_END 0x2 /* end marker */
94#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
95#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
96#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
97#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
98#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
99
100#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
101#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
102
103#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
104
105/* i assumed unsigned */
106#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
107#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
108
109/* XXX: these assume that register i is implemented */
110#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
111#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
112#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
113#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
114
115#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
116#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
117#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
118#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
119
120#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
121#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
122
123#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
124#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
125#define PFM_CTX_TASK(h) (h)->ctx_task
126
127#define PMU_PMC_OI 5 /* position of pmc.oi bit */
128
129/* XXX: does not support more than 64 PMDs */
130#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
131#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
132
133#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
134
135#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
136#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
137#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
138#define PFM_CODE_RR 0 /* requesting code range restriction */
139#define PFM_DATA_RR 1 /* requestion data range restriction */
140
141#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
142#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
143#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
144
145#define RDEP(x) (1UL<<(x))
146
147/*
148 * context protection macros
149 * in SMP:
150 * - we need to protect against CPU concurrency (spin_lock)
151 * - we need to protect against PMU overflow interrupts (local_irq_disable)
152 * in UP:
153 * - we need to protect against PMU overflow interrupts (local_irq_disable)
154 *
155 * spin_lock_irqsave()/spin_unlock_irqrestore():
156 * in SMP: local_irq_disable + spin_lock
157 * in UP : local_irq_disable
158 *
159 * spin_lock()/spin_lock():
160 * in UP : removed automatically
161 * in SMP: protect against context accesses from other CPU. interrupts
162 * are not masked. This is useful for the PMU interrupt handler
163 * because we know we will not get PMU concurrency in that code.
164 */
165#define PROTECT_CTX(c, f) \
166 do { \
167 DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
168 spin_lock_irqsave(&(c)->ctx_lock, f); \
169 DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
170 } while(0)
171
172#define UNPROTECT_CTX(c, f) \
173 do { \
174 DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
175 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
176 } while(0)
177
178#define PROTECT_CTX_NOPRINT(c, f) \
179 do { \
180 spin_lock_irqsave(&(c)->ctx_lock, f); \
181 } while(0)
182
183
184#define UNPROTECT_CTX_NOPRINT(c, f) \
185 do { \
186 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
187 } while(0)
188
189
190#define PROTECT_CTX_NOIRQ(c) \
191 do { \
192 spin_lock(&(c)->ctx_lock); \
193 } while(0)
194
195#define UNPROTECT_CTX_NOIRQ(c) \
196 do { \
197 spin_unlock(&(c)->ctx_lock); \
198 } while(0)
199
200
201#ifdef CONFIG_SMP
202
203#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
204#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
205#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
206
207#else /* !CONFIG_SMP */
208#define SET_ACTIVATION(t) do {} while(0)
209#define GET_ACTIVATION(t) do {} while(0)
210#define INC_ACTIVATION(t) do {} while(0)
211#endif /* CONFIG_SMP */
212
213#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
214#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
215#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
216
217#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
218#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
219
220#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
221
222/*
223 * cmp0 must be the value of pmc0
224 */
225#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
226
227#define PFMFS_MAGIC 0xa0b4d889
228
229/*
230 * debugging
231 */
232#define PFM_DEBUGGING 1
233#ifdef PFM_DEBUGGING
234#define DPRINT(a) \
235 do { \
236 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
237 } while (0)
238
239#define DPRINT_ovfl(a) \
240 do { \
241 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; } \
242 } while (0)
243#endif
244
245/*
246 * 64-bit software counter structure
247 *
248 * the next_reset_type is applied to the next call to pfm_reset_regs()
249 */
250typedef struct {
251 unsigned long val; /* virtual 64bit counter value */
252 unsigned long lval; /* last reset value */
253 unsigned long long_reset; /* reset value on sampling overflow */
254 unsigned long short_reset; /* reset value on overflow */
255 unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
256 unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
257 unsigned long seed; /* seed for random-number generator */
258 unsigned long mask; /* mask for random-number generator */
259 unsigned int flags; /* notify/do not notify */
260 unsigned long eventid; /* overflow event identifier */
261} pfm_counter_t;
262
263/*
264 * context flags
265 */
266typedef struct {
267 unsigned int block:1; /* when 1, task will blocked on user notifications */
268 unsigned int system:1; /* do system wide monitoring */
269 unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
270 unsigned int is_sampling:1; /* true if using a custom format */
271 unsigned int excl_idle:1; /* exclude idle task in system wide session */
272 unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
273 unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
274 unsigned int no_msg:1; /* no message sent on overflow */
275 unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
276 unsigned int reserved:22;
277} pfm_context_flags_t;
278
279#define PFM_TRAP_REASON_NONE 0x0 /* default value */
280#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
281#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
282
283
284/*
285 * perfmon context: encapsulates all the state of a monitoring session
286 */
287
288typedef struct pfm_context {
289 spinlock_t ctx_lock; /* context protection */
290
291 pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
292 unsigned int ctx_state; /* state: active/inactive (no bitfield) */
293
294 struct task_struct *ctx_task; /* task to which context is attached */
295
296 unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
297
298 struct completion ctx_restart_done; /* use for blocking notification mode */
299
300 unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
301 unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
302 unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
303
304 unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
305 unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
306 unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
307
308 unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
309
310 unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
311 unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
312 unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
313 unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
314
315 pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
316
317 unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
318 unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
319
320 unsigned long ctx_saved_psr_up; /* only contains psr.up value */
321
322 unsigned long ctx_last_activation; /* context last activation number for last_cpu */
323 unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
324 unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
325
326 int ctx_fd; /* file descriptor used my this context */
327 pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
328
329 pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
330 void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
331 unsigned long ctx_smpl_size; /* size of sampling buffer */
332 void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
333
334 wait_queue_head_t ctx_msgq_wait;
335 pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
336 int ctx_msgq_head;
337 int ctx_msgq_tail;
338 struct fasync_struct *ctx_async_queue;
339
340 wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
341} pfm_context_t;
342
343/*
344 * magic number used to verify that structure is really
345 * a perfmon context
346 */
347#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
348
349#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
350
351#ifdef CONFIG_SMP
352#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
353#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
354#else
355#define SET_LAST_CPU(ctx, v) do {} while(0)
356#define GET_LAST_CPU(ctx) do {} while(0)
357#endif
358
359
360#define ctx_fl_block ctx_flags.block
361#define ctx_fl_system ctx_flags.system
362#define ctx_fl_using_dbreg ctx_flags.using_dbreg
363#define ctx_fl_is_sampling ctx_flags.is_sampling
364#define ctx_fl_excl_idle ctx_flags.excl_idle
365#define ctx_fl_going_zombie ctx_flags.going_zombie
366#define ctx_fl_trap_reason ctx_flags.trap_reason
367#define ctx_fl_no_msg ctx_flags.no_msg
368#define ctx_fl_can_restart ctx_flags.can_restart
369
370#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
371#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
372
373/*
374 * global information about all sessions
375 * mostly used to synchronize between system wide and per-process
376 */
377typedef struct {
378 spinlock_t pfs_lock; /* lock the structure */
379
380 unsigned int pfs_task_sessions; /* number of per task sessions */
381 unsigned int pfs_sys_sessions; /* number of per system wide sessions */
382 unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
383 unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
384 struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
385} pfm_session_t;
386
387/*
388 * information about a PMC or PMD.
389 * dep_pmd[]: a bitmask of dependent PMD registers
390 * dep_pmc[]: a bitmask of dependent PMC registers
391 */
392typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
393typedef struct {
394 unsigned int type;
395 int pm_pos;
396 unsigned long default_value; /* power-on default value */
397 unsigned long reserved_mask; /* bitmask of reserved bits */
398 pfm_reg_check_t read_check;
399 pfm_reg_check_t write_check;
400 unsigned long dep_pmd[4];
401 unsigned long dep_pmc[4];
402} pfm_reg_desc_t;
403
404/* assume cnum is a valid monitor */
405#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
406
407/*
408 * This structure is initialized at boot time and contains
409 * a description of the PMU main characteristics.
410 *
411 * If the probe function is defined, detection is based
412 * on its return value:
413 * - 0 means recognized PMU
414 * - anything else means not supported
415 * When the probe function is not defined, then the pmu_family field
416 * is used and it must match the host CPU family such that:
417 * - cpu->family & config->pmu_family != 0
418 */
419typedef struct {
420 unsigned long ovfl_val; /* overflow value for counters */
421
422 pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
423 pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
424
425 unsigned int num_pmcs; /* number of PMCS: computed at init time */
426 unsigned int num_pmds; /* number of PMDS: computed at init time */
427 unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
428 unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
429
430 char *pmu_name; /* PMU family name */
431 unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
432 unsigned int flags; /* pmu specific flags */
433 unsigned int num_ibrs; /* number of IBRS: computed at init time */
434 unsigned int num_dbrs; /* number of DBRS: computed at init time */
435 unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
436 int (*probe)(void); /* customized probe routine */
437 unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
438} pmu_config_t;
439/*
440 * PMU specific flags
441 */
442#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
443
444/*
445 * debug register related type definitions
446 */
447typedef struct {
448 unsigned long ibr_mask:56;
449 unsigned long ibr_plm:4;
450 unsigned long ibr_ig:3;
451 unsigned long ibr_x:1;
452} ibr_mask_reg_t;
453
454typedef struct {
455 unsigned long dbr_mask:56;
456 unsigned long dbr_plm:4;
457 unsigned long dbr_ig:2;
458 unsigned long dbr_w:1;
459 unsigned long dbr_r:1;
460} dbr_mask_reg_t;
461
462typedef union {
463 unsigned long val;
464 ibr_mask_reg_t ibr;
465 dbr_mask_reg_t dbr;
466} dbreg_t;
467
468
469/*
470 * perfmon command descriptions
471 */
472typedef struct {
473 int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
474 char *cmd_name;
475 int cmd_flags;
476 unsigned int cmd_narg;
477 size_t cmd_argsize;
478 int (*cmd_getsize)(void *arg, size_t *sz);
479} pfm_cmd_desc_t;
480
481#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
482#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
483#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
484#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
485
486
487#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
488#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
489#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
490#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
491#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
492
493#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
494
495typedef struct {
496 unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
497 unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
498 unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
499 unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
500 unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
501 unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
502 unsigned long pfm_smpl_handler_calls;
503 unsigned long pfm_smpl_handler_cycles;
504 char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
505} pfm_stats_t;
506
507/*
508 * perfmon internal variables
509 */
510static pfm_stats_t pfm_stats[NR_CPUS];
511static pfm_session_t pfm_sessions; /* global sessions information */
512
513static DEFINE_SPINLOCK(pfm_alt_install_check);
514static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
515
516static struct proc_dir_entry *perfmon_dir;
517static pfm_uuid_t pfm_null_uuid = {0,};
518
519static spinlock_t pfm_buffer_fmt_lock;
520static LIST_HEAD(pfm_buffer_fmt_list);
521
522static pmu_config_t *pmu_conf;
523
524/* sysctl() controls */
525pfm_sysctl_t pfm_sysctl;
526EXPORT_SYMBOL(pfm_sysctl);
527
528static struct ctl_table pfm_ctl_table[] = {
529 {
530 .procname = "debug",
531 .data = &pfm_sysctl.debug,
532 .maxlen = sizeof(int),
533 .mode = 0666,
534 .proc_handler = proc_dointvec,
535 },
536 {
537 .procname = "debug_ovfl",
538 .data = &pfm_sysctl.debug_ovfl,
539 .maxlen = sizeof(int),
540 .mode = 0666,
541 .proc_handler = proc_dointvec,
542 },
543 {
544 .procname = "fastctxsw",
545 .data = &pfm_sysctl.fastctxsw,
546 .maxlen = sizeof(int),
547 .mode = 0600,
548 .proc_handler = proc_dointvec,
549 },
550 {
551 .procname = "expert_mode",
552 .data = &pfm_sysctl.expert_mode,
553 .maxlen = sizeof(int),
554 .mode = 0600,
555 .proc_handler = proc_dointvec,
556 },
557 {}
558};
559static struct ctl_table pfm_sysctl_dir[] = {
560 {
561 .procname = "perfmon",
562 .mode = 0555,
563 .child = pfm_ctl_table,
564 },
565 {}
566};
567static struct ctl_table pfm_sysctl_root[] = {
568 {
569 .procname = "kernel",
570 .mode = 0555,
571 .child = pfm_sysctl_dir,
572 },
573 {}
574};
575static struct ctl_table_header *pfm_sysctl_header;
576
577static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
578
579#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
580#define pfm_get_cpu_data(a,b) per_cpu(a, b)
581
582static inline void
583pfm_put_task(struct task_struct *task)
584{
585 if (task != current) put_task_struct(task);
586}
587
588static inline unsigned long
589pfm_protect_ctx_ctxsw(pfm_context_t *x)
590{
591 spin_lock(&(x)->ctx_lock);
592 return 0UL;
593}
594
595static inline void
596pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
597{
598 spin_unlock(&(x)->ctx_lock);
599}
600
601/* forward declaration */
602static const struct dentry_operations pfmfs_dentry_operations;
603
604static int pfmfs_init_fs_context(struct fs_context *fc)
605{
606 struct pseudo_fs_context *ctx = init_pseudo(fc, PFMFS_MAGIC);
607 if (!ctx)
608 return -ENOMEM;
609 ctx->dops = &pfmfs_dentry_operations;
610 return 0;
611}
612
613static struct file_system_type pfm_fs_type = {
614 .name = "pfmfs",
615 .init_fs_context = pfmfs_init_fs_context,
616 .kill_sb = kill_anon_super,
617};
618MODULE_ALIAS_FS("pfmfs");
619
620DEFINE_PER_CPU(unsigned long, pfm_syst_info);
621DEFINE_PER_CPU(struct task_struct *, pmu_owner);
622DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
623DEFINE_PER_CPU(unsigned long, pmu_activation_number);
624EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
625
626
627/* forward declaration */
628static const struct file_operations pfm_file_ops;
629
630/*
631 * forward declarations
632 */
633#ifndef CONFIG_SMP
634static void pfm_lazy_save_regs (struct task_struct *ta);
635#endif
636
637void dump_pmu_state(const char *);
638static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
639
640#include "perfmon_itanium.h"
641#include "perfmon_mckinley.h"
642#include "perfmon_montecito.h"
643#include "perfmon_generic.h"
644
645static pmu_config_t *pmu_confs[]={
646 &pmu_conf_mont,
647 &pmu_conf_mck,
648 &pmu_conf_ita,
649 &pmu_conf_gen, /* must be last */
650 NULL
651};
652
653
654static int pfm_end_notify_user(pfm_context_t *ctx);
655
656static inline void
657pfm_clear_psr_pp(void)
658{
659 ia64_rsm(IA64_PSR_PP);
660 ia64_srlz_i();
661}
662
663static inline void
664pfm_set_psr_pp(void)
665{
666 ia64_ssm(IA64_PSR_PP);
667 ia64_srlz_i();
668}
669
670static inline void
671pfm_clear_psr_up(void)
672{
673 ia64_rsm(IA64_PSR_UP);
674 ia64_srlz_i();
675}
676
677static inline void
678pfm_set_psr_up(void)
679{
680 ia64_ssm(IA64_PSR_UP);
681 ia64_srlz_i();
682}
683
684static inline unsigned long
685pfm_get_psr(void)
686{
687 unsigned long tmp;
688 tmp = ia64_getreg(_IA64_REG_PSR);
689 ia64_srlz_i();
690 return tmp;
691}
692
693static inline void
694pfm_set_psr_l(unsigned long val)
695{
696 ia64_setreg(_IA64_REG_PSR_L, val);
697 ia64_srlz_i();
698}
699
700static inline void
701pfm_freeze_pmu(void)
702{
703 ia64_set_pmc(0,1UL);
704 ia64_srlz_d();
705}
706
707static inline void
708pfm_unfreeze_pmu(void)
709{
710 ia64_set_pmc(0,0UL);
711 ia64_srlz_d();
712}
713
714static inline void
715pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
716{
717 int i;
718
719 for (i=0; i < nibrs; i++) {
720 ia64_set_ibr(i, ibrs[i]);
721 ia64_dv_serialize_instruction();
722 }
723 ia64_srlz_i();
724}
725
726static inline void
727pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
728{
729 int i;
730
731 for (i=0; i < ndbrs; i++) {
732 ia64_set_dbr(i, dbrs[i]);
733 ia64_dv_serialize_data();
734 }
735 ia64_srlz_d();
736}
737
738/*
739 * PMD[i] must be a counter. no check is made
740 */
741static inline unsigned long
742pfm_read_soft_counter(pfm_context_t *ctx, int i)
743{
744 return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
745}
746
747/*
748 * PMD[i] must be a counter. no check is made
749 */
750static inline void
751pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
752{
753 unsigned long ovfl_val = pmu_conf->ovfl_val;
754
755 ctx->ctx_pmds[i].val = val & ~ovfl_val;
756 /*
757 * writing to unimplemented part is ignore, so we do not need to
758 * mask off top part
759 */
760 ia64_set_pmd(i, val & ovfl_val);
761}
762
763static pfm_msg_t *
764pfm_get_new_msg(pfm_context_t *ctx)
765{
766 int idx, next;
767
768 next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
769
770 DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
771 if (next == ctx->ctx_msgq_head) return NULL;
772
773 idx = ctx->ctx_msgq_tail;
774 ctx->ctx_msgq_tail = next;
775
776 DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
777
778 return ctx->ctx_msgq+idx;
779}
780
781static pfm_msg_t *
782pfm_get_next_msg(pfm_context_t *ctx)
783{
784 pfm_msg_t *msg;
785
786 DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
787
788 if (PFM_CTXQ_EMPTY(ctx)) return NULL;
789
790 /*
791 * get oldest message
792 */
793 msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
794
795 /*
796 * and move forward
797 */
798 ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
799
800 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));
801
802 return msg;
803}
804
805static void
806pfm_reset_msgq(pfm_context_t *ctx)
807{
808 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
809 DPRINT(("ctx=%p msgq reset\n", ctx));
810}
811
812static pfm_context_t *
813pfm_context_alloc(int ctx_flags)
814{
815 pfm_context_t *ctx;
816
817 /*
818 * allocate context descriptor
819 * must be able to free with interrupts disabled
820 */
821 ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
822 if (ctx) {
823 DPRINT(("alloc ctx @%p\n", ctx));
824
825 /*
826 * init context protection lock
827 */
828 spin_lock_init(&ctx->ctx_lock);
829
830 /*
831 * context is unloaded
832 */
833 ctx->ctx_state = PFM_CTX_UNLOADED;
834
835 /*
836 * initialization of context's flags
837 */
838 ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
839 ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
840 ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
841 /*
842 * will move to set properties
843 * ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
844 */
845
846 /*
847 * init restart semaphore to locked
848 */
849 init_completion(&ctx->ctx_restart_done);
850
851 /*
852 * activation is used in SMP only
853 */
854 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
855 SET_LAST_CPU(ctx, -1);
856
857 /*
858 * initialize notification message queue
859 */
860 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
861 init_waitqueue_head(&ctx->ctx_msgq_wait);
862 init_waitqueue_head(&ctx->ctx_zombieq);
863
864 }
865 return ctx;
866}
867
868static void
869pfm_context_free(pfm_context_t *ctx)
870{
871 if (ctx) {
872 DPRINT(("free ctx @%p\n", ctx));
873 kfree(ctx);
874 }
875}
876
877static void
878pfm_mask_monitoring(struct task_struct *task)
879{
880 pfm_context_t *ctx = PFM_GET_CTX(task);
881 unsigned long mask, val, ovfl_mask;
882 int i;
883
884 DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
885
886 ovfl_mask = pmu_conf->ovfl_val;
887 /*
888 * monitoring can only be masked as a result of a valid
889 * counter overflow. In UP, it means that the PMU still
890 * has an owner. Note that the owner can be different
891 * from the current task. However the PMU state belongs
892 * to the owner.
893 * In SMP, a valid overflow only happens when task is
894 * current. Therefore if we come here, we know that
895 * the PMU state belongs to the current task, therefore
896 * we can access the live registers.
897 *
898 * So in both cases, the live register contains the owner's
899 * state. We can ONLY touch the PMU registers and NOT the PSR.
900 *
901 * As a consequence to this call, the ctx->th_pmds[] array
902 * contains stale information which must be ignored
903 * when context is reloaded AND monitoring is active (see
904 * pfm_restart).
905 */
906 mask = ctx->ctx_used_pmds[0];
907 for (i = 0; mask; i++, mask>>=1) {
908 /* skip non used pmds */
909 if ((mask & 0x1) == 0) continue;
910 val = ia64_get_pmd(i);
911
912 if (PMD_IS_COUNTING(i)) {
913 /*
914 * we rebuild the full 64 bit value of the counter
915 */
916 ctx->ctx_pmds[i].val += (val & ovfl_mask);
917 } else {
918 ctx->ctx_pmds[i].val = val;
919 }
920 DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
921 i,
922 ctx->ctx_pmds[i].val,
923 val & ovfl_mask));
924 }
925 /*
926 * mask monitoring by setting the privilege level to 0
927 * we cannot use psr.pp/psr.up for this, it is controlled by
928 * the user
929 *
930 * if task is current, modify actual registers, otherwise modify
931 * thread save state, i.e., what will be restored in pfm_load_regs()
932 */
933 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
934 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
935 if ((mask & 0x1) == 0UL) continue;
936 ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
937 ctx->th_pmcs[i] &= ~0xfUL;
938 DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
939 }
940 /*
941 * make all of this visible
942 */
943 ia64_srlz_d();
944}
945
946/*
947 * must always be done with task == current
948 *
949 * context must be in MASKED state when calling
950 */
951static void
952pfm_restore_monitoring(struct task_struct *task)
953{
954 pfm_context_t *ctx = PFM_GET_CTX(task);
955 unsigned long mask, ovfl_mask;
956 unsigned long psr, val;
957 int i, is_system;
958
959 is_system = ctx->ctx_fl_system;
960 ovfl_mask = pmu_conf->ovfl_val;
961
962 if (task != current) {
963 printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
964 return;
965 }
966 if (ctx->ctx_state != PFM_CTX_MASKED) {
967 printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
968 task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
969 return;
970 }
971 psr = pfm_get_psr();
972 /*
973 * monitoring is masked via the PMC.
974 * As we restore their value, we do not want each counter to
975 * restart right away. We stop monitoring using the PSR,
976 * restore the PMC (and PMD) and then re-establish the psr
977 * as it was. Note that there can be no pending overflow at
978 * this point, because monitoring was MASKED.
979 *
980 * system-wide session are pinned and self-monitoring
981 */
982 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
983 /* disable dcr pp */
984 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
985 pfm_clear_psr_pp();
986 } else {
987 pfm_clear_psr_up();
988 }
989 /*
990 * first, we restore the PMD
991 */
992 mask = ctx->ctx_used_pmds[0];
993 for (i = 0; mask; i++, mask>>=1) {
994 /* skip non used pmds */
995 if ((mask & 0x1) == 0) continue;
996
997 if (PMD_IS_COUNTING(i)) {
998 /*
999 * we split the 64bit value according to
1000 * counter width
1001 */
1002 val = ctx->ctx_pmds[i].val & ovfl_mask;
1003 ctx->ctx_pmds[i].val &= ~ovfl_mask;
1004 } else {
1005 val = ctx->ctx_pmds[i].val;
1006 }
1007 ia64_set_pmd(i, val);
1008
1009 DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
1010 i,
1011 ctx->ctx_pmds[i].val,
1012 val));
1013 }
1014 /*
1015 * restore the PMCs
1016 */
1017 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
1018 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
1019 if ((mask & 0x1) == 0UL) continue;
1020 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1021 ia64_set_pmc(i, ctx->th_pmcs[i]);
1022 DPRINT(("[%d] pmc[%d]=0x%lx\n",
1023 task_pid_nr(task), i, ctx->th_pmcs[i]));
1024 }
1025 ia64_srlz_d();
1026
1027 /*
1028 * must restore DBR/IBR because could be modified while masked
1029 * XXX: need to optimize
1030 */
1031 if (ctx->ctx_fl_using_dbreg) {
1032 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
1033 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
1034 }
1035
1036 /*
1037 * now restore PSR
1038 */
1039 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1040 /* enable dcr pp */
1041 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
1042 ia64_srlz_i();
1043 }
1044 pfm_set_psr_l(psr);
1045}
1046
1047static inline void
1048pfm_save_pmds(unsigned long *pmds, unsigned long mask)
1049{
1050 int i;
1051
1052 ia64_srlz_d();
1053
1054 for (i=0; mask; i++, mask>>=1) {
1055 if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
1056 }
1057}
1058
1059/*
1060 * reload from thread state (used for ctxw only)
1061 */
1062static inline void
1063pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
1064{
1065 int i;
1066 unsigned long val, ovfl_val = pmu_conf->ovfl_val;
1067
1068 for (i=0; mask; i++, mask>>=1) {
1069 if ((mask & 0x1) == 0) continue;
1070 val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
1071 ia64_set_pmd(i, val);
1072 }
1073 ia64_srlz_d();
1074}
1075
1076/*
1077 * propagate PMD from context to thread-state
1078 */
1079static inline void
1080pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
1081{
1082 unsigned long ovfl_val = pmu_conf->ovfl_val;
1083 unsigned long mask = ctx->ctx_all_pmds[0];
1084 unsigned long val;
1085 int i;
1086
1087 DPRINT(("mask=0x%lx\n", mask));
1088
1089 for (i=0; mask; i++, mask>>=1) {
1090
1091 val = ctx->ctx_pmds[i].val;
1092
1093 /*
1094 * We break up the 64 bit value into 2 pieces
1095 * the lower bits go to the machine state in the
1096 * thread (will be reloaded on ctxsw in).
1097 * The upper part stays in the soft-counter.
1098 */
1099 if (PMD_IS_COUNTING(i)) {
1100 ctx->ctx_pmds[i].val = val & ~ovfl_val;
1101 val &= ovfl_val;
1102 }
1103 ctx->th_pmds[i] = val;
1104
1105 DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
1106 i,
1107 ctx->th_pmds[i],
1108 ctx->ctx_pmds[i].val));
1109 }
1110}
1111
1112/*
1113 * propagate PMC from context to thread-state
1114 */
1115static inline void
1116pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
1117{
1118 unsigned long mask = ctx->ctx_all_pmcs[0];
1119 int i;
1120
1121 DPRINT(("mask=0x%lx\n", mask));
1122
1123 for (i=0; mask; i++, mask>>=1) {
1124 /* masking 0 with ovfl_val yields 0 */
1125 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1126 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
1127 }
1128}
1129
1130
1131
1132static inline void
1133pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
1134{
1135 int i;
1136
1137 for (i=0; mask; i++, mask>>=1) {
1138 if ((mask & 0x1) == 0) continue;
1139 ia64_set_pmc(i, pmcs[i]);
1140 }
1141 ia64_srlz_d();
1142}
1143
1144static inline int
1145pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
1146{
1147 return memcmp(a, b, sizeof(pfm_uuid_t));
1148}
1149
1150static inline int
1151pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
1152{
1153 int ret = 0;
1154 if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
1155 return ret;
1156}
1157
1158static inline int
1159pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
1160{
1161 int ret = 0;
1162 if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
1163 return ret;
1164}
1165
1166
1167static inline int
1168pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
1169 int cpu, void *arg)
1170{
1171 int ret = 0;
1172 if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
1173 return ret;
1174}
1175
1176static inline int
1177pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
1178 int cpu, void *arg)
1179{
1180 int ret = 0;
1181 if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
1182 return ret;
1183}
1184
1185static inline int
1186pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1187{
1188 int ret = 0;
1189 if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
1190 return ret;
1191}
1192
1193static inline int
1194pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1195{
1196 int ret = 0;
1197 if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
1198 return ret;
1199}
1200
1201static pfm_buffer_fmt_t *
1202__pfm_find_buffer_fmt(pfm_uuid_t uuid)
1203{
1204 struct list_head * pos;
1205 pfm_buffer_fmt_t * entry;
1206
1207 list_for_each(pos, &pfm_buffer_fmt_list) {
1208 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
1209 if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
1210 return entry;
1211 }
1212 return NULL;
1213}
1214
1215/*
1216 * find a buffer format based on its uuid
1217 */
1218static pfm_buffer_fmt_t *
1219pfm_find_buffer_fmt(pfm_uuid_t uuid)
1220{
1221 pfm_buffer_fmt_t * fmt;
1222 spin_lock(&pfm_buffer_fmt_lock);
1223 fmt = __pfm_find_buffer_fmt(uuid);
1224 spin_unlock(&pfm_buffer_fmt_lock);
1225 return fmt;
1226}
1227
1228int
1229pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
1230{
1231 int ret = 0;
1232
1233 /* some sanity checks */
1234 if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
1235
1236 /* we need at least a handler */
1237 if (fmt->fmt_handler == NULL) return -EINVAL;
1238
1239 /*
1240 * XXX: need check validity of fmt_arg_size
1241 */
1242
1243 spin_lock(&pfm_buffer_fmt_lock);
1244
1245 if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
1246 printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
1247 ret = -EBUSY;
1248 goto out;
1249 }
1250 list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
1251 printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
1252
1253out:
1254 spin_unlock(&pfm_buffer_fmt_lock);
1255 return ret;
1256}
1257EXPORT_SYMBOL(pfm_register_buffer_fmt);
1258
1259int
1260pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
1261{
1262 pfm_buffer_fmt_t *fmt;
1263 int ret = 0;
1264
1265 spin_lock(&pfm_buffer_fmt_lock);
1266
1267 fmt = __pfm_find_buffer_fmt(uuid);
1268 if (!fmt) {
1269 printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
1270 ret = -EINVAL;
1271 goto out;
1272 }
1273 list_del_init(&fmt->fmt_list);
1274 printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
1275
1276out:
1277 spin_unlock(&pfm_buffer_fmt_lock);
1278 return ret;
1279
1280}
1281EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
1282
1283static int
1284pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
1285{
1286 unsigned long flags;
1287 /*
1288 * validity checks on cpu_mask have been done upstream
1289 */
1290 LOCK_PFS(flags);
1291
1292 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1293 pfm_sessions.pfs_sys_sessions,
1294 pfm_sessions.pfs_task_sessions,
1295 pfm_sessions.pfs_sys_use_dbregs,
1296 is_syswide,
1297 cpu));
1298
1299 if (is_syswide) {
1300 /*
1301 * cannot mix system wide and per-task sessions
1302 */
1303 if (pfm_sessions.pfs_task_sessions > 0UL) {
1304 DPRINT(("system wide not possible, %u conflicting task_sessions\n",
1305 pfm_sessions.pfs_task_sessions));
1306 goto abort;
1307 }
1308
1309 if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
1310
1311 DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
1312
1313 pfm_sessions.pfs_sys_session[cpu] = task;
1314
1315 pfm_sessions.pfs_sys_sessions++ ;
1316
1317 } else {
1318 if (pfm_sessions.pfs_sys_sessions) goto abort;
1319 pfm_sessions.pfs_task_sessions++;
1320 }
1321
1322 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1323 pfm_sessions.pfs_sys_sessions,
1324 pfm_sessions.pfs_task_sessions,
1325 pfm_sessions.pfs_sys_use_dbregs,
1326 is_syswide,
1327 cpu));
1328
1329 /*
1330 * Force idle() into poll mode
1331 */
1332 cpu_idle_poll_ctrl(true);
1333
1334 UNLOCK_PFS(flags);
1335
1336 return 0;
1337
1338error_conflict:
1339 DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
1340 task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
1341 cpu));
1342abort:
1343 UNLOCK_PFS(flags);
1344
1345 return -EBUSY;
1346
1347}
1348
1349static int
1350pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
1351{
1352 unsigned long flags;
1353 /*
1354 * validity checks on cpu_mask have been done upstream
1355 */
1356 LOCK_PFS(flags);
1357
1358 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1359 pfm_sessions.pfs_sys_sessions,
1360 pfm_sessions.pfs_task_sessions,
1361 pfm_sessions.pfs_sys_use_dbregs,
1362 is_syswide,
1363 cpu));
1364
1365
1366 if (is_syswide) {
1367 pfm_sessions.pfs_sys_session[cpu] = NULL;
1368 /*
1369 * would not work with perfmon+more than one bit in cpu_mask
1370 */
1371 if (ctx && ctx->ctx_fl_using_dbreg) {
1372 if (pfm_sessions.pfs_sys_use_dbregs == 0) {
1373 printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
1374 } else {
1375 pfm_sessions.pfs_sys_use_dbregs--;
1376 }
1377 }
1378 pfm_sessions.pfs_sys_sessions--;
1379 } else {
1380 pfm_sessions.pfs_task_sessions--;
1381 }
1382 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1383 pfm_sessions.pfs_sys_sessions,
1384 pfm_sessions.pfs_task_sessions,
1385 pfm_sessions.pfs_sys_use_dbregs,
1386 is_syswide,
1387 cpu));
1388
1389 /* Undo forced polling. Last session reenables pal_halt */
1390 cpu_idle_poll_ctrl(false);
1391
1392 UNLOCK_PFS(flags);
1393
1394 return 0;
1395}
1396
1397/*
1398 * removes virtual mapping of the sampling buffer.
1399 * IMPORTANT: cannot be called with interrupts disable, e.g. inside
1400 * a PROTECT_CTX() section.
1401 */
1402static int
1403pfm_remove_smpl_mapping(void *vaddr, unsigned long size)
1404{
1405 struct task_struct *task = current;
1406 int r;
1407
1408 /* sanity checks */
1409 if (task->mm == NULL || size == 0UL || vaddr == NULL) {
1410 printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
1411 return -EINVAL;
1412 }
1413
1414 DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
1415
1416 /*
1417 * does the actual unmapping
1418 */
1419 r = vm_munmap((unsigned long)vaddr, size);
1420
1421 if (r !=0) {
1422 printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
1423 }
1424
1425 DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
1426
1427 return 0;
1428}
1429
1430/*
1431 * free actual physical storage used by sampling buffer
1432 */
1433#if 0
1434static int
1435pfm_free_smpl_buffer(pfm_context_t *ctx)
1436{
1437 pfm_buffer_fmt_t *fmt;
1438
1439 if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
1440
1441 /*
1442 * we won't use the buffer format anymore
1443 */
1444 fmt = ctx->ctx_buf_fmt;
1445
1446 DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
1447 ctx->ctx_smpl_hdr,
1448 ctx->ctx_smpl_size,
1449 ctx->ctx_smpl_vaddr));
1450
1451 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1452
1453 /*
1454 * free the buffer
1455 */
1456 vfree(ctx->ctx_smpl_hdr);
1457
1458 ctx->ctx_smpl_hdr = NULL;
1459 ctx->ctx_smpl_size = 0UL;
1460
1461 return 0;
1462
1463invalid_free:
1464 printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
1465 return -EINVAL;
1466}
1467#endif
1468
1469static inline void
1470pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
1471{
1472 if (fmt == NULL) return;
1473
1474 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1475
1476}
1477
1478/*
1479 * pfmfs should _never_ be mounted by userland - too much of security hassle,
1480 * no real gain from having the whole whorehouse mounted. So we don't need
1481 * any operations on the root directory. However, we need a non-trivial
1482 * d_name - pfm: will go nicely and kill the special-casing in procfs.
1483 */
1484static struct vfsmount *pfmfs_mnt __read_mostly;
1485
1486static int __init
1487init_pfm_fs(void)
1488{
1489 int err = register_filesystem(&pfm_fs_type);
1490 if (!err) {
1491 pfmfs_mnt = kern_mount(&pfm_fs_type);
1492 err = PTR_ERR(pfmfs_mnt);
1493 if (IS_ERR(pfmfs_mnt))
1494 unregister_filesystem(&pfm_fs_type);
1495 else
1496 err = 0;
1497 }
1498 return err;
1499}
1500
1501static ssize_t
1502pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
1503{
1504 pfm_context_t *ctx;
1505 pfm_msg_t *msg;
1506 ssize_t ret;
1507 unsigned long flags;
1508 DECLARE_WAITQUEUE(wait, current);
1509 if (PFM_IS_FILE(filp) == 0) {
1510 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1511 return -EINVAL;
1512 }
1513
1514 ctx = filp->private_data;
1515 if (ctx == NULL) {
1516 printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
1517 return -EINVAL;
1518 }
1519
1520 /*
1521 * check even when there is no message
1522 */
1523 if (size < sizeof(pfm_msg_t)) {
1524 DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
1525 return -EINVAL;
1526 }
1527
1528 PROTECT_CTX(ctx, flags);
1529
1530 /*
1531 * put ourselves on the wait queue
1532 */
1533 add_wait_queue(&ctx->ctx_msgq_wait, &wait);
1534
1535
1536 for(;;) {
1537 /*
1538 * check wait queue
1539 */
1540
1541 set_current_state(TASK_INTERRUPTIBLE);
1542
1543 DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
1544
1545 ret = 0;
1546 if(PFM_CTXQ_EMPTY(ctx) == 0) break;
1547
1548 UNPROTECT_CTX(ctx, flags);
1549
1550 /*
1551 * check non-blocking read
1552 */
1553 ret = -EAGAIN;
1554 if(filp->f_flags & O_NONBLOCK) break;
1555
1556 /*
1557 * check pending signals
1558 */
1559 if(signal_pending(current)) {
1560 ret = -EINTR;
1561 break;
1562 }
1563 /*
1564 * no message, so wait
1565 */
1566 schedule();
1567
1568 PROTECT_CTX(ctx, flags);
1569 }
1570 DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
1571 set_current_state(TASK_RUNNING);
1572 remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
1573
1574 if (ret < 0) goto abort;
1575
1576 ret = -EINVAL;
1577 msg = pfm_get_next_msg(ctx);
1578 if (msg == NULL) {
1579 printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
1580 goto abort_locked;
1581 }
1582
1583 DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
1584
1585 ret = -EFAULT;
1586 if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
1587
1588abort_locked:
1589 UNPROTECT_CTX(ctx, flags);
1590abort:
1591 return ret;
1592}
1593
1594static ssize_t
1595pfm_write(struct file *file, const char __user *ubuf,
1596 size_t size, loff_t *ppos)
1597{
1598 DPRINT(("pfm_write called\n"));
1599 return -EINVAL;
1600}
1601
1602static __poll_t
1603pfm_poll(struct file *filp, poll_table * wait)
1604{
1605 pfm_context_t *ctx;
1606 unsigned long flags;
1607 __poll_t mask = 0;
1608
1609 if (PFM_IS_FILE(filp) == 0) {
1610 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1611 return 0;
1612 }
1613
1614 ctx = filp->private_data;
1615 if (ctx == NULL) {
1616 printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
1617 return 0;
1618 }
1619
1620
1621 DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
1622
1623 poll_wait(filp, &ctx->ctx_msgq_wait, wait);
1624
1625 PROTECT_CTX(ctx, flags);
1626
1627 if (PFM_CTXQ_EMPTY(ctx) == 0)
1628 mask = EPOLLIN | EPOLLRDNORM;
1629
1630 UNPROTECT_CTX(ctx, flags);
1631
1632 DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
1633
1634 return mask;
1635}
1636
1637static long
1638pfm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1639{
1640 DPRINT(("pfm_ioctl called\n"));
1641 return -EINVAL;
1642}
1643
1644/*
1645 * interrupt cannot be masked when coming here
1646 */
1647static inline int
1648pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
1649{
1650 int ret;
1651
1652 ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
1653
1654 DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1655 task_pid_nr(current),
1656 fd,
1657 on,
1658 ctx->ctx_async_queue, ret));
1659
1660 return ret;
1661}
1662
1663static int
1664pfm_fasync(int fd, struct file *filp, int on)
1665{
1666 pfm_context_t *ctx;
1667 int ret;
1668
1669 if (PFM_IS_FILE(filp) == 0) {
1670 printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
1671 return -EBADF;
1672 }
1673
1674 ctx = filp->private_data;
1675 if (ctx == NULL) {
1676 printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
1677 return -EBADF;
1678 }
1679 /*
1680 * we cannot mask interrupts during this call because this may
1681 * may go to sleep if memory is not readily avalaible.
1682 *
1683 * We are protected from the conetxt disappearing by the get_fd()/put_fd()
1684 * done in caller. Serialization of this function is ensured by caller.
1685 */
1686 ret = pfm_do_fasync(fd, filp, ctx, on);
1687
1688
1689 DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1690 fd,
1691 on,
1692 ctx->ctx_async_queue, ret));
1693
1694 return ret;
1695}
1696
1697#ifdef CONFIG_SMP
1698/*
1699 * this function is exclusively called from pfm_close().
1700 * The context is not protected at that time, nor are interrupts
1701 * on the remote CPU. That's necessary to avoid deadlocks.
1702 */
1703static void
1704pfm_syswide_force_stop(void *info)
1705{
1706 pfm_context_t *ctx = (pfm_context_t *)info;
1707 struct pt_regs *regs = task_pt_regs(current);
1708 struct task_struct *owner;
1709 unsigned long flags;
1710 int ret;
1711
1712 if (ctx->ctx_cpu != smp_processor_id()) {
1713 printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
1714 ctx->ctx_cpu,
1715 smp_processor_id());
1716 return;
1717 }
1718 owner = GET_PMU_OWNER();
1719 if (owner != ctx->ctx_task) {
1720 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
1721 smp_processor_id(),
1722 task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
1723 return;
1724 }
1725 if (GET_PMU_CTX() != ctx) {
1726 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
1727 smp_processor_id(),
1728 GET_PMU_CTX(), ctx);
1729 return;
1730 }
1731
1732 DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
1733 /*
1734 * the context is already protected in pfm_close(), we simply
1735 * need to mask interrupts to avoid a PMU interrupt race on
1736 * this CPU
1737 */
1738 local_irq_save(flags);
1739
1740 ret = pfm_context_unload(ctx, NULL, 0, regs);
1741 if (ret) {
1742 DPRINT(("context_unload returned %d\n", ret));
1743 }
1744
1745 /*
1746 * unmask interrupts, PMU interrupts are now spurious here
1747 */
1748 local_irq_restore(flags);
1749}
1750
1751static void
1752pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
1753{
1754 int ret;
1755
1756 DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
1757 ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 1);
1758 DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
1759}
1760#endif /* CONFIG_SMP */
1761
1762/*
1763 * called for each close(). Partially free resources.
1764 * When caller is self-monitoring, the context is unloaded.
1765 */
1766static int
1767pfm_flush(struct file *filp, fl_owner_t id)
1768{
1769 pfm_context_t *ctx;
1770 struct task_struct *task;
1771 struct pt_regs *regs;
1772 unsigned long flags;
1773 unsigned long smpl_buf_size = 0UL;
1774 void *smpl_buf_vaddr = NULL;
1775 int state, is_system;
1776
1777 if (PFM_IS_FILE(filp) == 0) {
1778 DPRINT(("bad magic for\n"));
1779 return -EBADF;
1780 }
1781
1782 ctx = filp->private_data;
1783 if (ctx == NULL) {
1784 printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
1785 return -EBADF;
1786 }
1787
1788 /*
1789 * remove our file from the async queue, if we use this mode.
1790 * This can be done without the context being protected. We come
1791 * here when the context has become unreachable by other tasks.
1792 *
1793 * We may still have active monitoring at this point and we may
1794 * end up in pfm_overflow_handler(). However, fasync_helper()
1795 * operates with interrupts disabled and it cleans up the
1796 * queue. If the PMU handler is called prior to entering
1797 * fasync_helper() then it will send a signal. If it is
1798 * invoked after, it will find an empty queue and no
1799 * signal will be sent. In both case, we are safe
1800 */
1801 PROTECT_CTX(ctx, flags);
1802
1803 state = ctx->ctx_state;
1804 is_system = ctx->ctx_fl_system;
1805
1806 task = PFM_CTX_TASK(ctx);
1807 regs = task_pt_regs(task);
1808
1809 DPRINT(("ctx_state=%d is_current=%d\n",
1810 state,
1811 task == current ? 1 : 0));
1812
1813 /*
1814 * if state == UNLOADED, then task is NULL
1815 */
1816
1817 /*
1818 * we must stop and unload because we are losing access to the context.
1819 */
1820 if (task == current) {
1821#ifdef CONFIG_SMP
1822 /*
1823 * the task IS the owner but it migrated to another CPU: that's bad
1824 * but we must handle this cleanly. Unfortunately, the kernel does
1825 * not provide a mechanism to block migration (while the context is loaded).
1826 *
1827 * We need to release the resource on the ORIGINAL cpu.
1828 */
1829 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
1830
1831 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
1832 /*
1833 * keep context protected but unmask interrupt for IPI
1834 */
1835 local_irq_restore(flags);
1836
1837 pfm_syswide_cleanup_other_cpu(ctx);
1838
1839 /*
1840 * restore interrupt masking
1841 */
1842 local_irq_save(flags);
1843
1844 /*
1845 * context is unloaded at this point
1846 */
1847 } else
1848#endif /* CONFIG_SMP */
1849 {
1850
1851 DPRINT(("forcing unload\n"));
1852 /*
1853 * stop and unload, returning with state UNLOADED
1854 * and session unreserved.
1855 */
1856 pfm_context_unload(ctx, NULL, 0, regs);
1857
1858 DPRINT(("ctx_state=%d\n", ctx->ctx_state));
1859 }
1860 }
1861
1862 /*
1863 * remove virtual mapping, if any, for the calling task.
1864 * cannot reset ctx field until last user is calling close().
1865 *
1866 * ctx_smpl_vaddr must never be cleared because it is needed
1867 * by every task with access to the context
1868 *
1869 * When called from do_exit(), the mm context is gone already, therefore
1870 * mm is NULL, i.e., the VMA is already gone and we do not have to
1871 * do anything here
1872 */
1873 if (ctx->ctx_smpl_vaddr && current->mm) {
1874 smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
1875 smpl_buf_size = ctx->ctx_smpl_size;
1876 }
1877
1878 UNPROTECT_CTX(ctx, flags);
1879
1880 /*
1881 * if there was a mapping, then we systematically remove it
1882 * at this point. Cannot be done inside critical section
1883 * because some VM function reenables interrupts.
1884 *
1885 */
1886 if (smpl_buf_vaddr) pfm_remove_smpl_mapping(smpl_buf_vaddr, smpl_buf_size);
1887
1888 return 0;
1889}
1890/*
1891 * called either on explicit close() or from exit_files().
1892 * Only the LAST user of the file gets to this point, i.e., it is
1893 * called only ONCE.
1894 *
1895 * IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
1896 * (fput()),i.e, last task to access the file. Nobody else can access the
1897 * file at this point.
1898 *
1899 * When called from exit_files(), the VMA has been freed because exit_mm()
1900 * is executed before exit_files().
1901 *
1902 * When called from exit_files(), the current task is not yet ZOMBIE but we
1903 * flush the PMU state to the context.
1904 */
1905static int
1906pfm_close(struct inode *inode, struct file *filp)
1907{
1908 pfm_context_t *ctx;
1909 struct task_struct *task;
1910 struct pt_regs *regs;
1911 DECLARE_WAITQUEUE(wait, current);
1912 unsigned long flags;
1913 unsigned long smpl_buf_size = 0UL;
1914 void *smpl_buf_addr = NULL;
1915 int free_possible = 1;
1916 int state, is_system;
1917
1918 DPRINT(("pfm_close called private=%p\n", filp->private_data));
1919
1920 if (PFM_IS_FILE(filp) == 0) {
1921 DPRINT(("bad magic\n"));
1922 return -EBADF;
1923 }
1924
1925 ctx = filp->private_data;
1926 if (ctx == NULL) {
1927 printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
1928 return -EBADF;
1929 }
1930
1931 PROTECT_CTX(ctx, flags);
1932
1933 state = ctx->ctx_state;
1934 is_system = ctx->ctx_fl_system;
1935
1936 task = PFM_CTX_TASK(ctx);
1937 regs = task_pt_regs(task);
1938
1939 DPRINT(("ctx_state=%d is_current=%d\n",
1940 state,
1941 task == current ? 1 : 0));
1942
1943 /*
1944 * if task == current, then pfm_flush() unloaded the context
1945 */
1946 if (state == PFM_CTX_UNLOADED) goto doit;
1947
1948 /*
1949 * context is loaded/masked and task != current, we need to
1950 * either force an unload or go zombie
1951 */
1952
1953 /*
1954 * The task is currently blocked or will block after an overflow.
1955 * we must force it to wakeup to get out of the
1956 * MASKED state and transition to the unloaded state by itself.
1957 *
1958 * This situation is only possible for per-task mode
1959 */
1960 if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
1961
1962 /*
1963 * set a "partial" zombie state to be checked
1964 * upon return from down() in pfm_handle_work().
1965 *
1966 * We cannot use the ZOMBIE state, because it is checked
1967 * by pfm_load_regs() which is called upon wakeup from down().
1968 * In such case, it would free the context and then we would
1969 * return to pfm_handle_work() which would access the
1970 * stale context. Instead, we set a flag invisible to pfm_load_regs()
1971 * but visible to pfm_handle_work().
1972 *
1973 * For some window of time, we have a zombie context with
1974 * ctx_state = MASKED and not ZOMBIE
1975 */
1976 ctx->ctx_fl_going_zombie = 1;
1977
1978 /*
1979 * force task to wake up from MASKED state
1980 */
1981 complete(&ctx->ctx_restart_done);
1982
1983 DPRINT(("waking up ctx_state=%d\n", state));
1984
1985 /*
1986 * put ourself to sleep waiting for the other
1987 * task to report completion
1988 *
1989 * the context is protected by mutex, therefore there
1990 * is no risk of being notified of completion before
1991 * begin actually on the waitq.
1992 */
1993 set_current_state(TASK_INTERRUPTIBLE);
1994 add_wait_queue(&ctx->ctx_zombieq, &wait);
1995
1996 UNPROTECT_CTX(ctx, flags);
1997
1998 /*
1999 * XXX: check for signals :
2000 * - ok for explicit close
2001 * - not ok when coming from exit_files()
2002 */
2003 schedule();
2004
2005
2006 PROTECT_CTX(ctx, flags);
2007
2008
2009 remove_wait_queue(&ctx->ctx_zombieq, &wait);
2010 set_current_state(TASK_RUNNING);
2011
2012 /*
2013 * context is unloaded at this point
2014 */
2015 DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
2016 }
2017 else if (task != current) {
2018#ifdef CONFIG_SMP
2019 /*
2020 * switch context to zombie state
2021 */
2022 ctx->ctx_state = PFM_CTX_ZOMBIE;
2023
2024 DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
2025 /*
2026 * cannot free the context on the spot. deferred until
2027 * the task notices the ZOMBIE state
2028 */
2029 free_possible = 0;
2030#else
2031 pfm_context_unload(ctx, NULL, 0, regs);
2032#endif
2033 }
2034
2035doit:
2036 /* reload state, may have changed during opening of critical section */
2037 state = ctx->ctx_state;
2038
2039 /*
2040 * the context is still attached to a task (possibly current)
2041 * we cannot destroy it right now
2042 */
2043
2044 /*
2045 * we must free the sampling buffer right here because
2046 * we cannot rely on it being cleaned up later by the
2047 * monitored task. It is not possible to free vmalloc'ed
2048 * memory in pfm_load_regs(). Instead, we remove the buffer
2049 * now. should there be subsequent PMU overflow originally
2050 * meant for sampling, the will be converted to spurious
2051 * and that's fine because the monitoring tools is gone anyway.
2052 */
2053 if (ctx->ctx_smpl_hdr) {
2054 smpl_buf_addr = ctx->ctx_smpl_hdr;
2055 smpl_buf_size = ctx->ctx_smpl_size;
2056 /* no more sampling */
2057 ctx->ctx_smpl_hdr = NULL;
2058 ctx->ctx_fl_is_sampling = 0;
2059 }
2060
2061 DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
2062 state,
2063 free_possible,
2064 smpl_buf_addr,
2065 smpl_buf_size));
2066
2067 if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
2068
2069 /*
2070 * UNLOADED that the session has already been unreserved.
2071 */
2072 if (state == PFM_CTX_ZOMBIE) {
2073 pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
2074 }
2075
2076 /*
2077 * disconnect file descriptor from context must be done
2078 * before we unlock.
2079 */
2080 filp->private_data = NULL;
2081
2082 /*
2083 * if we free on the spot, the context is now completely unreachable
2084 * from the callers side. The monitored task side is also cut, so we
2085 * can freely cut.
2086 *
2087 * If we have a deferred free, only the caller side is disconnected.
2088 */
2089 UNPROTECT_CTX(ctx, flags);
2090
2091 /*
2092 * All memory free operations (especially for vmalloc'ed memory)
2093 * MUST be done with interrupts ENABLED.
2094 */
2095 vfree(smpl_buf_addr);
2096
2097 /*
2098 * return the memory used by the context
2099 */
2100 if (free_possible) pfm_context_free(ctx);
2101
2102 return 0;
2103}
2104
2105static const struct file_operations pfm_file_ops = {
2106 .llseek = no_llseek,
2107 .read = pfm_read,
2108 .write = pfm_write,
2109 .poll = pfm_poll,
2110 .unlocked_ioctl = pfm_ioctl,
2111 .fasync = pfm_fasync,
2112 .release = pfm_close,
2113 .flush = pfm_flush
2114};
2115
2116static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
2117{
2118 return dynamic_dname(dentry, buffer, buflen, "pfm:[%lu]",
2119 d_inode(dentry)->i_ino);
2120}
2121
2122static const struct dentry_operations pfmfs_dentry_operations = {
2123 .d_delete = always_delete_dentry,
2124 .d_dname = pfmfs_dname,
2125};
2126
2127
2128static struct file *
2129pfm_alloc_file(pfm_context_t *ctx)
2130{
2131 struct file *file;
2132 struct inode *inode;
2133 struct path path;
2134 struct qstr this = { .name = "" };
2135
2136 /*
2137 * allocate a new inode
2138 */
2139 inode = new_inode(pfmfs_mnt->mnt_sb);
2140 if (!inode)
2141 return ERR_PTR(-ENOMEM);
2142
2143 DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
2144
2145 inode->i_mode = S_IFCHR|S_IRUGO;
2146 inode->i_uid = current_fsuid();
2147 inode->i_gid = current_fsgid();
2148
2149 /*
2150 * allocate a new dcache entry
2151 */
2152 path.dentry = d_alloc(pfmfs_mnt->mnt_root, &this);
2153 if (!path.dentry) {
2154 iput(inode);
2155 return ERR_PTR(-ENOMEM);
2156 }
2157 path.mnt = mntget(pfmfs_mnt);
2158
2159 d_add(path.dentry, inode);
2160
2161 file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
2162 if (IS_ERR(file)) {
2163 path_put(&path);
2164 return file;
2165 }
2166
2167 file->f_flags = O_RDONLY;
2168 file->private_data = ctx;
2169
2170 return file;
2171}
2172
2173static int
2174pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
2175{
2176 DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
2177
2178 while (size > 0) {
2179 unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
2180
2181
2182 if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
2183 return -ENOMEM;
2184
2185 addr += PAGE_SIZE;
2186 buf += PAGE_SIZE;
2187 size -= PAGE_SIZE;
2188 }
2189 return 0;
2190}
2191
2192/*
2193 * allocate a sampling buffer and remaps it into the user address space of the task
2194 */
2195static int
2196pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
2197{
2198 struct mm_struct *mm = task->mm;
2199 struct vm_area_struct *vma = NULL;
2200 unsigned long size;
2201 void *smpl_buf;
2202
2203
2204 /*
2205 * the fixed header + requested size and align to page boundary
2206 */
2207 size = PAGE_ALIGN(rsize);
2208
2209 DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
2210
2211 /*
2212 * check requested size to avoid Denial-of-service attacks
2213 * XXX: may have to refine this test
2214 * Check against address space limit.
2215 *
2216 * if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
2217 * return -ENOMEM;
2218 */
2219 if (size > task_rlimit(task, RLIMIT_MEMLOCK))
2220 return -ENOMEM;
2221
2222 /*
2223 * We do the easy to undo allocations first.
2224 */
2225 smpl_buf = vzalloc(size);
2226 if (smpl_buf == NULL) {
2227 DPRINT(("Can't allocate sampling buffer\n"));
2228 return -ENOMEM;
2229 }
2230
2231 DPRINT(("smpl_buf @%p\n", smpl_buf));
2232
2233 /* allocate vma */
2234 vma = vm_area_alloc(mm);
2235 if (!vma) {
2236 DPRINT(("Cannot allocate vma\n"));
2237 goto error_kmem;
2238 }
2239
2240 /*
2241 * partially initialize the vma for the sampling buffer
2242 */
2243 vma->vm_file = get_file(filp);
2244 vma->vm_flags = VM_READ|VM_MAYREAD|VM_DONTEXPAND|VM_DONTDUMP;
2245 vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
2246
2247 /*
2248 * Now we have everything we need and we can initialize
2249 * and connect all the data structures
2250 */
2251
2252 ctx->ctx_smpl_hdr = smpl_buf;
2253 ctx->ctx_smpl_size = size; /* aligned size */
2254
2255 /*
2256 * Let's do the difficult operations next.
2257 *
2258 * now we atomically find some area in the address space and
2259 * remap the buffer in it.
2260 */
2261 down_write(&task->mm->mmap_sem);
2262
2263 /* find some free area in address space, must have mmap sem held */
2264 vma->vm_start = get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS);
2265 if (IS_ERR_VALUE(vma->vm_start)) {
2266 DPRINT(("Cannot find unmapped area for size %ld\n", size));
2267 up_write(&task->mm->mmap_sem);
2268 goto error;
2269 }
2270 vma->vm_end = vma->vm_start + size;
2271 vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
2272
2273 DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
2274
2275 /* can only be applied to current task, need to have the mm semaphore held when called */
2276 if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
2277 DPRINT(("Can't remap buffer\n"));
2278 up_write(&task->mm->mmap_sem);
2279 goto error;
2280 }
2281
2282 /*
2283 * now insert the vma in the vm list for the process, must be
2284 * done with mmap lock held
2285 */
2286 insert_vm_struct(mm, vma);
2287
2288 vm_stat_account(vma->vm_mm, vma->vm_flags, vma_pages(vma));
2289 up_write(&task->mm->mmap_sem);
2290
2291 /*
2292 * keep track of user level virtual address
2293 */
2294 ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
2295 *(unsigned long *)user_vaddr = vma->vm_start;
2296
2297 return 0;
2298
2299error:
2300 vm_area_free(vma);
2301error_kmem:
2302 vfree(smpl_buf);
2303
2304 return -ENOMEM;
2305}
2306
2307/*
2308 * XXX: do something better here
2309 */
2310static int
2311pfm_bad_permissions(struct task_struct *task)
2312{
2313 const struct cred *tcred;
2314 kuid_t uid = current_uid();
2315 kgid_t gid = current_gid();
2316 int ret;
2317
2318 rcu_read_lock();
2319 tcred = __task_cred(task);
2320
2321 /* inspired by ptrace_attach() */
2322 DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
2323 from_kuid(&init_user_ns, uid),
2324 from_kgid(&init_user_ns, gid),
2325 from_kuid(&init_user_ns, tcred->euid),
2326 from_kuid(&init_user_ns, tcred->suid),
2327 from_kuid(&init_user_ns, tcred->uid),
2328 from_kgid(&init_user_ns, tcred->egid),
2329 from_kgid(&init_user_ns, tcred->sgid)));
2330
2331 ret = ((!uid_eq(uid, tcred->euid))
2332 || (!uid_eq(uid, tcred->suid))
2333 || (!uid_eq(uid, tcred->uid))
2334 || (!gid_eq(gid, tcred->egid))
2335 || (!gid_eq(gid, tcred->sgid))
2336 || (!gid_eq(gid, tcred->gid))) && !capable(CAP_SYS_PTRACE);
2337
2338 rcu_read_unlock();
2339 return ret;
2340}
2341
2342static int
2343pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
2344{
2345 int ctx_flags;
2346
2347 /* valid signal */
2348
2349 ctx_flags = pfx->ctx_flags;
2350
2351 if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
2352
2353 /*
2354 * cannot block in this mode
2355 */
2356 if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
2357 DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
2358 return -EINVAL;
2359 }
2360 } else {
2361 }
2362 /* probably more to add here */
2363
2364 return 0;
2365}
2366
2367static int
2368pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
2369 unsigned int cpu, pfarg_context_t *arg)
2370{
2371 pfm_buffer_fmt_t *fmt = NULL;
2372 unsigned long size = 0UL;
2373 void *uaddr = NULL;
2374 void *fmt_arg = NULL;
2375 int ret = 0;
2376#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
2377
2378 /* invoke and lock buffer format, if found */
2379 fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
2380 if (fmt == NULL) {
2381 DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
2382 return -EINVAL;
2383 }
2384
2385 /*
2386 * buffer argument MUST be contiguous to pfarg_context_t
2387 */
2388 if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
2389
2390 ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
2391
2392 DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
2393
2394 if (ret) goto error;
2395
2396 /* link buffer format and context */
2397 ctx->ctx_buf_fmt = fmt;
2398 ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
2399
2400 /*
2401 * check if buffer format wants to use perfmon buffer allocation/mapping service
2402 */
2403 ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
2404 if (ret) goto error;
2405
2406 if (size) {
2407 /*
2408 * buffer is always remapped into the caller's address space
2409 */
2410 ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
2411 if (ret) goto error;
2412
2413 /* keep track of user address of buffer */
2414 arg->ctx_smpl_vaddr = uaddr;
2415 }
2416 ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
2417
2418error:
2419 return ret;
2420}
2421
2422static void
2423pfm_reset_pmu_state(pfm_context_t *ctx)
2424{
2425 int i;
2426
2427 /*
2428 * install reset values for PMC.
2429 */
2430 for (i=1; PMC_IS_LAST(i) == 0; i++) {
2431 if (PMC_IS_IMPL(i) == 0) continue;
2432 ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
2433 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
2434 }
2435 /*
2436 * PMD registers are set to 0UL when the context in memset()
2437 */
2438
2439 /*
2440 * On context switched restore, we must restore ALL pmc and ALL pmd even
2441 * when they are not actively used by the task. In UP, the incoming process
2442 * may otherwise pick up left over PMC, PMD state from the previous process.
2443 * As opposed to PMD, stale PMC can cause harm to the incoming
2444 * process because they may change what is being measured.
2445 * Therefore, we must systematically reinstall the entire
2446 * PMC state. In SMP, the same thing is possible on the
2447 * same CPU but also on between 2 CPUs.
2448 *
2449 * The problem with PMD is information leaking especially
2450 * to user level when psr.sp=0
2451 *
2452 * There is unfortunately no easy way to avoid this problem
2453 * on either UP or SMP. This definitively slows down the
2454 * pfm_load_regs() function.
2455 */
2456
2457 /*
2458 * bitmask of all PMCs accessible to this context
2459 *
2460 * PMC0 is treated differently.
2461 */
2462 ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
2463
2464 /*
2465 * bitmask of all PMDs that are accessible to this context
2466 */
2467 ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
2468
2469 DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
2470
2471 /*
2472 * useful in case of re-enable after disable
2473 */
2474 ctx->ctx_used_ibrs[0] = 0UL;
2475 ctx->ctx_used_dbrs[0] = 0UL;
2476}
2477
2478static int
2479pfm_ctx_getsize(void *arg, size_t *sz)
2480{
2481 pfarg_context_t *req = (pfarg_context_t *)arg;
2482 pfm_buffer_fmt_t *fmt;
2483
2484 *sz = 0;
2485
2486 if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
2487
2488 fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
2489 if (fmt == NULL) {
2490 DPRINT(("cannot find buffer format\n"));
2491 return -EINVAL;
2492 }
2493 /* get just enough to copy in user parameters */
2494 *sz = fmt->fmt_arg_size;
2495 DPRINT(("arg_size=%lu\n", *sz));
2496
2497 return 0;
2498}
2499
2500
2501
2502/*
2503 * cannot attach if :
2504 * - kernel task
2505 * - task not owned by caller
2506 * - task incompatible with context mode
2507 */
2508static int
2509pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
2510{
2511 /*
2512 * no kernel task or task not owner by caller
2513 */
2514 if (task->mm == NULL) {
2515 DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
2516 return -EPERM;
2517 }
2518 if (pfm_bad_permissions(task)) {
2519 DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
2520 return -EPERM;
2521 }
2522 /*
2523 * cannot block in self-monitoring mode
2524 */
2525 if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
2526 DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
2527 return -EINVAL;
2528 }
2529
2530 if (task->exit_state == EXIT_ZOMBIE) {
2531 DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
2532 return -EBUSY;
2533 }
2534
2535 /*
2536 * always ok for self
2537 */
2538 if (task == current) return 0;
2539
2540 if (!task_is_stopped_or_traced(task)) {
2541 DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
2542 return -EBUSY;
2543 }
2544 /*
2545 * make sure the task is off any CPU
2546 */
2547 wait_task_inactive(task, 0);
2548
2549 /* more to come... */
2550
2551 return 0;
2552}
2553
2554static int
2555pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
2556{
2557 struct task_struct *p = current;
2558 int ret;
2559
2560 /* XXX: need to add more checks here */
2561 if (pid < 2) return -EPERM;
2562
2563 if (pid != task_pid_vnr(current)) {
2564 /* make sure task cannot go away while we operate on it */
2565 p = find_get_task_by_vpid(pid);
2566 if (!p)
2567 return -ESRCH;
2568 }
2569
2570 ret = pfm_task_incompatible(ctx, p);
2571 if (ret == 0) {
2572 *task = p;
2573 } else if (p != current) {
2574 pfm_put_task(p);
2575 }
2576 return ret;
2577}
2578
2579
2580
2581static int
2582pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2583{
2584 pfarg_context_t *req = (pfarg_context_t *)arg;
2585 struct file *filp;
2586 struct path path;
2587 int ctx_flags;
2588 int fd;
2589 int ret;
2590
2591 /* let's check the arguments first */
2592 ret = pfarg_is_sane(current, req);
2593 if (ret < 0)
2594 return ret;
2595
2596 ctx_flags = req->ctx_flags;
2597
2598 ret = -ENOMEM;
2599
2600 fd = get_unused_fd_flags(0);
2601 if (fd < 0)
2602 return fd;
2603
2604 ctx = pfm_context_alloc(ctx_flags);
2605 if (!ctx)
2606 goto error;
2607
2608 filp = pfm_alloc_file(ctx);
2609 if (IS_ERR(filp)) {
2610 ret = PTR_ERR(filp);
2611 goto error_file;
2612 }
2613
2614 req->ctx_fd = ctx->ctx_fd = fd;
2615
2616 /*
2617 * does the user want to sample?
2618 */
2619 if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
2620 ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
2621 if (ret)
2622 goto buffer_error;
2623 }
2624
2625 DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d\n",
2626 ctx,
2627 ctx_flags,
2628 ctx->ctx_fl_system,
2629 ctx->ctx_fl_block,
2630 ctx->ctx_fl_excl_idle,
2631 ctx->ctx_fl_no_msg,
2632 ctx->ctx_fd));
2633
2634 /*
2635 * initialize soft PMU state
2636 */
2637 pfm_reset_pmu_state(ctx);
2638
2639 fd_install(fd, filp);
2640
2641 return 0;
2642
2643buffer_error:
2644 path = filp->f_path;
2645 put_filp(filp);
2646 path_put(&path);
2647
2648 if (ctx->ctx_buf_fmt) {
2649 pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
2650 }
2651error_file:
2652 pfm_context_free(ctx);
2653
2654error:
2655 put_unused_fd(fd);
2656 return ret;
2657}
2658
2659static inline unsigned long
2660pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
2661{
2662 unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
2663 unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
2664 extern unsigned long carta_random32 (unsigned long seed);
2665
2666 if (reg->flags & PFM_REGFL_RANDOM) {
2667 new_seed = carta_random32(old_seed);
2668 val -= (old_seed & mask); /* counter values are negative numbers! */
2669 if ((mask >> 32) != 0)
2670 /* construct a full 64-bit random value: */
2671 new_seed |= carta_random32(old_seed >> 32) << 32;
2672 reg->seed = new_seed;
2673 }
2674 reg->lval = val;
2675 return val;
2676}
2677
2678static void
2679pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2680{
2681 unsigned long mask = ovfl_regs[0];
2682 unsigned long reset_others = 0UL;
2683 unsigned long val;
2684 int i;
2685
2686 /*
2687 * now restore reset value on sampling overflowed counters
2688 */
2689 mask >>= PMU_FIRST_COUNTER;
2690 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2691
2692 if ((mask & 0x1UL) == 0UL) continue;
2693
2694 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2695 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2696
2697 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2698 }
2699
2700 /*
2701 * Now take care of resetting the other registers
2702 */
2703 for(i = 0; reset_others; i++, reset_others >>= 1) {
2704
2705 if ((reset_others & 0x1) == 0) continue;
2706
2707 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2708
2709 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2710 is_long_reset ? "long" : "short", i, val));
2711 }
2712}
2713
2714static void
2715pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2716{
2717 unsigned long mask = ovfl_regs[0];
2718 unsigned long reset_others = 0UL;
2719 unsigned long val;
2720 int i;
2721
2722 DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
2723
2724 if (ctx->ctx_state == PFM_CTX_MASKED) {
2725 pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
2726 return;
2727 }
2728
2729 /*
2730 * now restore reset value on sampling overflowed counters
2731 */
2732 mask >>= PMU_FIRST_COUNTER;
2733 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2734
2735 if ((mask & 0x1UL) == 0UL) continue;
2736
2737 val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2738 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2739
2740 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2741
2742 pfm_write_soft_counter(ctx, i, val);
2743 }
2744
2745 /*
2746 * Now take care of resetting the other registers
2747 */
2748 for(i = 0; reset_others; i++, reset_others >>= 1) {
2749
2750 if ((reset_others & 0x1) == 0) continue;
2751
2752 val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2753
2754 if (PMD_IS_COUNTING(i)) {
2755 pfm_write_soft_counter(ctx, i, val);
2756 } else {
2757 ia64_set_pmd(i, val);
2758 }
2759 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2760 is_long_reset ? "long" : "short", i, val));
2761 }
2762 ia64_srlz_d();
2763}
2764
2765static int
2766pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2767{
2768 struct task_struct *task;
2769 pfarg_reg_t *req = (pfarg_reg_t *)arg;
2770 unsigned long value, pmc_pm;
2771 unsigned long smpl_pmds, reset_pmds, impl_pmds;
2772 unsigned int cnum, reg_flags, flags, pmc_type;
2773 int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
2774 int is_monitor, is_counting, state;
2775 int ret = -EINVAL;
2776 pfm_reg_check_t wr_func;
2777#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
2778
2779 state = ctx->ctx_state;
2780 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
2781 is_system = ctx->ctx_fl_system;
2782 task = ctx->ctx_task;
2783 impl_pmds = pmu_conf->impl_pmds[0];
2784
2785 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
2786
2787 if (is_loaded) {
2788 /*
2789 * In system wide and when the context is loaded, access can only happen
2790 * when the caller is running on the CPU being monitored by the session.
2791 * It does not have to be the owner (ctx_task) of the context per se.
2792 */
2793 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
2794 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
2795 return -EBUSY;
2796 }
2797 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
2798 }
2799 expert_mode = pfm_sysctl.expert_mode;
2800
2801 for (i = 0; i < count; i++, req++) {
2802
2803 cnum = req->reg_num;
2804 reg_flags = req->reg_flags;
2805 value = req->reg_value;
2806 smpl_pmds = req->reg_smpl_pmds[0];
2807 reset_pmds = req->reg_reset_pmds[0];
2808 flags = 0;
2809
2810
2811 if (cnum >= PMU_MAX_PMCS) {
2812 DPRINT(("pmc%u is invalid\n", cnum));
2813 goto error;
2814 }
2815
2816 pmc_type = pmu_conf->pmc_desc[cnum].type;
2817 pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
2818 is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
2819 is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
2820
2821 /*
2822 * we reject all non implemented PMC as well
2823 * as attempts to modify PMC[0-3] which are used
2824 * as status registers by the PMU
2825 */
2826 if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
2827 DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
2828 goto error;
2829 }
2830 wr_func = pmu_conf->pmc_desc[cnum].write_check;
2831 /*
2832 * If the PMC is a monitor, then if the value is not the default:
2833 * - system-wide session: PMCx.pm=1 (privileged monitor)
2834 * - per-task : PMCx.pm=0 (user monitor)
2835 */
2836 if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
2837 DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
2838 cnum,
2839 pmc_pm,
2840 is_system));
2841 goto error;
2842 }
2843
2844 if (is_counting) {
2845 /*
2846 * enforce generation of overflow interrupt. Necessary on all
2847 * CPUs.
2848 */
2849 value |= 1 << PMU_PMC_OI;
2850
2851 if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
2852 flags |= PFM_REGFL_OVFL_NOTIFY;
2853 }
2854
2855 if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
2856
2857 /* verify validity of smpl_pmds */
2858 if ((smpl_pmds & impl_pmds) != smpl_pmds) {
2859 DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
2860 goto error;
2861 }
2862
2863 /* verify validity of reset_pmds */
2864 if ((reset_pmds & impl_pmds) != reset_pmds) {
2865 DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
2866 goto error;
2867 }
2868 } else {
2869 if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
2870 DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
2871 goto error;
2872 }
2873 /* eventid on non-counting monitors are ignored */
2874 }
2875
2876 /*
2877 * execute write checker, if any
2878 */
2879 if (likely(expert_mode == 0 && wr_func)) {
2880 ret = (*wr_func)(task, ctx, cnum, &value, regs);
2881 if (ret) goto error;
2882 ret = -EINVAL;
2883 }
2884
2885 /*
2886 * no error on this register
2887 */
2888 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
2889
2890 /*
2891 * Now we commit the changes to the software state
2892 */
2893
2894 /*
2895 * update overflow information
2896 */
2897 if (is_counting) {
2898 /*
2899 * full flag update each time a register is programmed
2900 */
2901 ctx->ctx_pmds[cnum].flags = flags;
2902
2903 ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
2904 ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
2905 ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
2906
2907 /*
2908 * Mark all PMDS to be accessed as used.
2909 *
2910 * We do not keep track of PMC because we have to
2911 * systematically restore ALL of them.
2912 *
2913 * We do not update the used_monitors mask, because
2914 * if we have not programmed them, then will be in
2915 * a quiescent state, therefore we will not need to
2916 * mask/restore then when context is MASKED.
2917 */
2918 CTX_USED_PMD(ctx, reset_pmds);
2919 CTX_USED_PMD(ctx, smpl_pmds);
2920 /*
2921 * make sure we do not try to reset on
2922 * restart because we have established new values
2923 */
2924 if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
2925 }
2926 /*
2927 * Needed in case the user does not initialize the equivalent
2928 * PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
2929 * possible leak here.
2930 */
2931 CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
2932
2933 /*
2934 * keep track of the monitor PMC that we are using.
2935 * we save the value of the pmc in ctx_pmcs[] and if
2936 * the monitoring is not stopped for the context we also
2937 * place it in the saved state area so that it will be
2938 * picked up later by the context switch code.
2939 *
2940 * The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
2941 *
2942 * The value in th_pmcs[] may be modified on overflow, i.e., when
2943 * monitoring needs to be stopped.
2944 */
2945 if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
2946
2947 /*
2948 * update context state
2949 */
2950 ctx->ctx_pmcs[cnum] = value;
2951
2952 if (is_loaded) {
2953 /*
2954 * write thread state
2955 */
2956 if (is_system == 0) ctx->th_pmcs[cnum] = value;
2957
2958 /*
2959 * write hardware register if we can
2960 */
2961 if (can_access_pmu) {
2962 ia64_set_pmc(cnum, value);
2963 }
2964#ifdef CONFIG_SMP
2965 else {
2966 /*
2967 * per-task SMP only here
2968 *
2969 * we are guaranteed that the task is not running on the other CPU,
2970 * we indicate that this PMD will need to be reloaded if the task
2971 * is rescheduled on the CPU it ran last on.
2972 */
2973 ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
2974 }
2975#endif
2976 }
2977
2978 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",
2979 cnum,
2980 value,
2981 is_loaded,
2982 can_access_pmu,
2983 flags,
2984 ctx->ctx_all_pmcs[0],
2985 ctx->ctx_used_pmds[0],
2986 ctx->ctx_pmds[cnum].eventid,
2987 smpl_pmds,
2988 reset_pmds,
2989 ctx->ctx_reload_pmcs[0],
2990 ctx->ctx_used_monitors[0],
2991 ctx->ctx_ovfl_regs[0]));
2992 }
2993
2994 /*
2995 * make sure the changes are visible
2996 */
2997 if (can_access_pmu) ia64_srlz_d();
2998
2999 return 0;
3000error:
3001 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3002 return ret;
3003}
3004
3005static int
3006pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3007{
3008 struct task_struct *task;
3009 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3010 unsigned long value, hw_value, ovfl_mask;
3011 unsigned int cnum;
3012 int i, can_access_pmu = 0, state;
3013 int is_counting, is_loaded, is_system, expert_mode;
3014 int ret = -EINVAL;
3015 pfm_reg_check_t wr_func;
3016
3017
3018 state = ctx->ctx_state;
3019 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3020 is_system = ctx->ctx_fl_system;
3021 ovfl_mask = pmu_conf->ovfl_val;
3022 task = ctx->ctx_task;
3023
3024 if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
3025
3026 /*
3027 * on both UP and SMP, we can only write to the PMC when the task is
3028 * the owner of the local PMU.
3029 */
3030 if (likely(is_loaded)) {
3031 /*
3032 * In system wide and when the context is loaded, access can only happen
3033 * when the caller is running on the CPU being monitored by the session.
3034 * It does not have to be the owner (ctx_task) of the context per se.
3035 */
3036 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3037 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3038 return -EBUSY;
3039 }
3040 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3041 }
3042 expert_mode = pfm_sysctl.expert_mode;
3043
3044 for (i = 0; i < count; i++, req++) {
3045
3046 cnum = req->reg_num;
3047 value = req->reg_value;
3048
3049 if (!PMD_IS_IMPL(cnum)) {
3050 DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
3051 goto abort_mission;
3052 }
3053 is_counting = PMD_IS_COUNTING(cnum);
3054 wr_func = pmu_conf->pmd_desc[cnum].write_check;
3055
3056 /*
3057 * execute write checker, if any
3058 */
3059 if (unlikely(expert_mode == 0 && wr_func)) {
3060 unsigned long v = value;
3061
3062 ret = (*wr_func)(task, ctx, cnum, &v, regs);
3063 if (ret) goto abort_mission;
3064
3065 value = v;
3066 ret = -EINVAL;
3067 }
3068
3069 /*
3070 * no error on this register
3071 */
3072 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
3073
3074 /*
3075 * now commit changes to software state
3076 */
3077 hw_value = value;
3078
3079 /*
3080 * update virtualized (64bits) counter
3081 */
3082 if (is_counting) {
3083 /*
3084 * write context state
3085 */
3086 ctx->ctx_pmds[cnum].lval = value;
3087
3088 /*
3089 * when context is load we use the split value
3090 */
3091 if (is_loaded) {
3092 hw_value = value & ovfl_mask;
3093 value = value & ~ovfl_mask;
3094 }
3095 }
3096 /*
3097 * update reset values (not just for counters)
3098 */
3099 ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
3100 ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
3101
3102 /*
3103 * update randomization parameters (not just for counters)
3104 */
3105 ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
3106 ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
3107
3108 /*
3109 * update context value
3110 */
3111 ctx->ctx_pmds[cnum].val = value;
3112
3113 /*
3114 * Keep track of what we use
3115 *
3116 * We do not keep track of PMC because we have to
3117 * systematically restore ALL of them.
3118 */
3119 CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
3120
3121 /*
3122 * mark this PMD register used as well
3123 */
3124 CTX_USED_PMD(ctx, RDEP(cnum));
3125
3126 /*
3127 * make sure we do not try to reset on
3128 * restart because we have established new values
3129 */
3130 if (is_counting && state == PFM_CTX_MASKED) {
3131 ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3132 }
3133
3134 if (is_loaded) {
3135 /*
3136 * write thread state
3137 */
3138 if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
3139
3140 /*
3141 * write hardware register if we can
3142 */
3143 if (can_access_pmu) {
3144 ia64_set_pmd(cnum, hw_value);
3145 } else {
3146#ifdef CONFIG_SMP
3147 /*
3148 * we are guaranteed that the task is not running on the other CPU,
3149 * we indicate that this PMD will need to be reloaded if the task
3150 * is rescheduled on the CPU it ran last on.
3151 */
3152 ctx->ctx_reload_pmds[0] |= 1UL << cnum;
3153#endif
3154 }
3155 }
3156
3157 DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
3158 "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",
3159 cnum,
3160 value,
3161 is_loaded,
3162 can_access_pmu,
3163 hw_value,
3164 ctx->ctx_pmds[cnum].val,
3165 ctx->ctx_pmds[cnum].short_reset,
3166 ctx->ctx_pmds[cnum].long_reset,
3167 PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
3168 ctx->ctx_pmds[cnum].seed,
3169 ctx->ctx_pmds[cnum].mask,
3170 ctx->ctx_used_pmds[0],
3171 ctx->ctx_pmds[cnum].reset_pmds[0],
3172 ctx->ctx_reload_pmds[0],
3173 ctx->ctx_all_pmds[0],
3174 ctx->ctx_ovfl_regs[0]));
3175 }
3176
3177 /*
3178 * make changes visible
3179 */
3180 if (can_access_pmu) ia64_srlz_d();
3181
3182 return 0;
3183
3184abort_mission:
3185 /*
3186 * for now, we have only one possibility for error
3187 */
3188 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3189 return ret;
3190}
3191
3192/*
3193 * By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
3194 * Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
3195 * interrupt is delivered during the call, it will be kept pending until we leave, making
3196 * it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
3197 * guaranteed to return consistent data to the user, it may simply be old. It is not
3198 * trivial to treat the overflow while inside the call because you may end up in
3199 * some module sampling buffer code causing deadlocks.
3200 */
3201static int
3202pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3203{
3204 struct task_struct *task;
3205 unsigned long val = 0UL, lval, ovfl_mask, sval;
3206 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3207 unsigned int cnum, reg_flags = 0;
3208 int i, can_access_pmu = 0, state;
3209 int is_loaded, is_system, is_counting, expert_mode;
3210 int ret = -EINVAL;
3211 pfm_reg_check_t rd_func;
3212
3213 /*
3214 * access is possible when loaded only for
3215 * self-monitoring tasks or in UP mode
3216 */
3217
3218 state = ctx->ctx_state;
3219 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3220 is_system = ctx->ctx_fl_system;
3221 ovfl_mask = pmu_conf->ovfl_val;
3222 task = ctx->ctx_task;
3223
3224 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3225
3226 if (likely(is_loaded)) {
3227 /*
3228 * In system wide and when the context is loaded, access can only happen
3229 * when the caller is running on the CPU being monitored by the session.
3230 * It does not have to be the owner (ctx_task) of the context per se.
3231 */
3232 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3233 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3234 return -EBUSY;
3235 }
3236 /*
3237 * this can be true when not self-monitoring only in UP
3238 */
3239 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3240
3241 if (can_access_pmu) ia64_srlz_d();
3242 }
3243 expert_mode = pfm_sysctl.expert_mode;
3244
3245 DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
3246 is_loaded,
3247 can_access_pmu,
3248 state));
3249
3250 /*
3251 * on both UP and SMP, we can only read the PMD from the hardware register when
3252 * the task is the owner of the local PMU.
3253 */
3254
3255 for (i = 0; i < count; i++, req++) {
3256
3257 cnum = req->reg_num;
3258 reg_flags = req->reg_flags;
3259
3260 if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
3261 /*
3262 * we can only read the register that we use. That includes
3263 * the one we explicitly initialize AND the one we want included
3264 * in the sampling buffer (smpl_regs).
3265 *
3266 * Having this restriction allows optimization in the ctxsw routine
3267 * without compromising security (leaks)
3268 */
3269 if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
3270
3271 sval = ctx->ctx_pmds[cnum].val;
3272 lval = ctx->ctx_pmds[cnum].lval;
3273 is_counting = PMD_IS_COUNTING(cnum);
3274
3275 /*
3276 * If the task is not the current one, then we check if the
3277 * PMU state is still in the local live register due to lazy ctxsw.
3278 * If true, then we read directly from the registers.
3279 */
3280 if (can_access_pmu){
3281 val = ia64_get_pmd(cnum);
3282 } else {
3283 /*
3284 * context has been saved
3285 * if context is zombie, then task does not exist anymore.
3286 * In this case, we use the full value saved in the context (pfm_flush_regs()).
3287 */
3288 val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
3289 }
3290 rd_func = pmu_conf->pmd_desc[cnum].read_check;
3291
3292 if (is_counting) {
3293 /*
3294 * XXX: need to check for overflow when loaded
3295 */
3296 val &= ovfl_mask;
3297 val += sval;
3298 }
3299
3300 /*
3301 * execute read checker, if any
3302 */
3303 if (unlikely(expert_mode == 0 && rd_func)) {
3304 unsigned long v = val;
3305 ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
3306 if (ret) goto error;
3307 val = v;
3308 ret = -EINVAL;
3309 }
3310
3311 PFM_REG_RETFLAG_SET(reg_flags, 0);
3312
3313 DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
3314
3315 /*
3316 * update register return value, abort all if problem during copy.
3317 * we only modify the reg_flags field. no check mode is fine because
3318 * access has been verified upfront in sys_perfmonctl().
3319 */
3320 req->reg_value = val;
3321 req->reg_flags = reg_flags;
3322 req->reg_last_reset_val = lval;
3323 }
3324
3325 return 0;
3326
3327error:
3328 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3329 return ret;
3330}
3331
3332int
3333pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3334{
3335 pfm_context_t *ctx;
3336
3337 if (req == NULL) return -EINVAL;
3338
3339 ctx = GET_PMU_CTX();
3340
3341 if (ctx == NULL) return -EINVAL;
3342
3343 /*
3344 * for now limit to current task, which is enough when calling
3345 * from overflow handler
3346 */
3347 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3348
3349 return pfm_write_pmcs(ctx, req, nreq, regs);
3350}
3351EXPORT_SYMBOL(pfm_mod_write_pmcs);
3352
3353int
3354pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3355{
3356 pfm_context_t *ctx;
3357
3358 if (req == NULL) return -EINVAL;
3359
3360 ctx = GET_PMU_CTX();
3361
3362 if (ctx == NULL) return -EINVAL;
3363
3364 /*
3365 * for now limit to current task, which is enough when calling
3366 * from overflow handler
3367 */
3368 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3369
3370 return pfm_read_pmds(ctx, req, nreq, regs);
3371}
3372EXPORT_SYMBOL(pfm_mod_read_pmds);
3373
3374/*
3375 * Only call this function when a process it trying to
3376 * write the debug registers (reading is always allowed)
3377 */
3378int
3379pfm_use_debug_registers(struct task_struct *task)
3380{
3381 pfm_context_t *ctx = task->thread.pfm_context;
3382 unsigned long flags;
3383 int ret = 0;
3384
3385 if (pmu_conf->use_rr_dbregs == 0) return 0;
3386
3387 DPRINT(("called for [%d]\n", task_pid_nr(task)));
3388
3389 /*
3390 * do it only once
3391 */
3392 if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
3393
3394 /*
3395 * Even on SMP, we do not need to use an atomic here because
3396 * the only way in is via ptrace() and this is possible only when the
3397 * process is stopped. Even in the case where the ctxsw out is not totally
3398 * completed by the time we come here, there is no way the 'stopped' process
3399 * could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
3400 * So this is always safe.
3401 */
3402 if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
3403
3404 LOCK_PFS(flags);
3405
3406 /*
3407 * We cannot allow setting breakpoints when system wide monitoring
3408 * sessions are using the debug registers.
3409 */
3410 if (pfm_sessions.pfs_sys_use_dbregs> 0)
3411 ret = -1;
3412 else
3413 pfm_sessions.pfs_ptrace_use_dbregs++;
3414
3415 DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
3416 pfm_sessions.pfs_ptrace_use_dbregs,
3417 pfm_sessions.pfs_sys_use_dbregs,
3418 task_pid_nr(task), ret));
3419
3420 UNLOCK_PFS(flags);
3421
3422 return ret;
3423}
3424
3425/*
3426 * This function is called for every task that exits with the
3427 * IA64_THREAD_DBG_VALID set. This indicates a task which was
3428 * able to use the debug registers for debugging purposes via
3429 * ptrace(). Therefore we know it was not using them for
3430 * performance monitoring, so we only decrement the number
3431 * of "ptraced" debug register users to keep the count up to date
3432 */
3433int
3434pfm_release_debug_registers(struct task_struct *task)
3435{
3436 unsigned long flags;
3437 int ret;
3438
3439 if (pmu_conf->use_rr_dbregs == 0) return 0;
3440
3441 LOCK_PFS(flags);
3442 if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
3443 printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
3444 ret = -1;
3445 } else {
3446 pfm_sessions.pfs_ptrace_use_dbregs--;
3447 ret = 0;
3448 }
3449 UNLOCK_PFS(flags);
3450
3451 return ret;
3452}
3453
3454static int
3455pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3456{
3457 struct task_struct *task;
3458 pfm_buffer_fmt_t *fmt;
3459 pfm_ovfl_ctrl_t rst_ctrl;
3460 int state, is_system;
3461 int ret = 0;
3462
3463 state = ctx->ctx_state;
3464 fmt = ctx->ctx_buf_fmt;
3465 is_system = ctx->ctx_fl_system;
3466 task = PFM_CTX_TASK(ctx);
3467
3468 switch(state) {
3469 case PFM_CTX_MASKED:
3470 break;
3471 case PFM_CTX_LOADED:
3472 if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
3473 /* fall through */
3474 case PFM_CTX_UNLOADED:
3475 case PFM_CTX_ZOMBIE:
3476 DPRINT(("invalid state=%d\n", state));
3477 return -EBUSY;
3478 default:
3479 DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
3480 return -EINVAL;
3481 }
3482
3483 /*
3484 * In system wide and when the context is loaded, access can only happen
3485 * when the caller is running on the CPU being monitored by the session.
3486 * It does not have to be the owner (ctx_task) of the context per se.
3487 */
3488 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3489 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3490 return -EBUSY;
3491 }
3492
3493 /* sanity check */
3494 if (unlikely(task == NULL)) {
3495 printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
3496 return -EINVAL;
3497 }
3498
3499 if (task == current || is_system) {
3500
3501 fmt = ctx->ctx_buf_fmt;
3502
3503 DPRINT(("restarting self %d ovfl=0x%lx\n",
3504 task_pid_nr(task),
3505 ctx->ctx_ovfl_regs[0]));
3506
3507 if (CTX_HAS_SMPL(ctx)) {
3508
3509 prefetch(ctx->ctx_smpl_hdr);
3510
3511 rst_ctrl.bits.mask_monitoring = 0;
3512 rst_ctrl.bits.reset_ovfl_pmds = 0;
3513
3514 if (state == PFM_CTX_LOADED)
3515 ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3516 else
3517 ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3518 } else {
3519 rst_ctrl.bits.mask_monitoring = 0;
3520 rst_ctrl.bits.reset_ovfl_pmds = 1;
3521 }
3522
3523 if (ret == 0) {
3524 if (rst_ctrl.bits.reset_ovfl_pmds)
3525 pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
3526
3527 if (rst_ctrl.bits.mask_monitoring == 0) {
3528 DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
3529
3530 if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
3531 } else {
3532 DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
3533
3534 // cannot use pfm_stop_monitoring(task, regs);
3535 }
3536 }
3537 /*
3538 * clear overflowed PMD mask to remove any stale information
3539 */
3540 ctx->ctx_ovfl_regs[0] = 0UL;
3541
3542 /*
3543 * back to LOADED state
3544 */
3545 ctx->ctx_state = PFM_CTX_LOADED;
3546
3547 /*
3548 * XXX: not really useful for self monitoring
3549 */
3550 ctx->ctx_fl_can_restart = 0;
3551
3552 return 0;
3553 }
3554
3555 /*
3556 * restart another task
3557 */
3558
3559 /*
3560 * When PFM_CTX_MASKED, we cannot issue a restart before the previous
3561 * one is seen by the task.
3562 */
3563 if (state == PFM_CTX_MASKED) {
3564 if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
3565 /*
3566 * will prevent subsequent restart before this one is
3567 * seen by other task
3568 */
3569 ctx->ctx_fl_can_restart = 0;
3570 }
3571
3572 /*
3573 * if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
3574 * the task is blocked or on its way to block. That's the normal
3575 * restart path. If the monitoring is not masked, then the task
3576 * can be actively monitoring and we cannot directly intervene.
3577 * Therefore we use the trap mechanism to catch the task and
3578 * force it to reset the buffer/reset PMDs.
3579 *
3580 * if non-blocking, then we ensure that the task will go into
3581 * pfm_handle_work() before returning to user mode.
3582 *
3583 * We cannot explicitly reset another task, it MUST always
3584 * be done by the task itself. This works for system wide because
3585 * the tool that is controlling the session is logically doing
3586 * "self-monitoring".
3587 */
3588 if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
3589 DPRINT(("unblocking [%d]\n", task_pid_nr(task)));
3590 complete(&ctx->ctx_restart_done);
3591 } else {
3592 DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
3593
3594 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
3595
3596 PFM_SET_WORK_PENDING(task, 1);
3597
3598 set_notify_resume(task);
3599
3600 /*
3601 * XXX: send reschedule if task runs on another CPU
3602 */
3603 }
3604 return 0;
3605}
3606
3607static int
3608pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3609{
3610 unsigned int m = *(unsigned int *)arg;
3611
3612 pfm_sysctl.debug = m == 0 ? 0 : 1;
3613
3614 printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
3615
3616 if (m == 0) {
3617 memset(pfm_stats, 0, sizeof(pfm_stats));
3618 for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
3619 }
3620 return 0;
3621}
3622
3623/*
3624 * arg can be NULL and count can be zero for this function
3625 */
3626static int
3627pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3628{
3629 struct thread_struct *thread = NULL;
3630 struct task_struct *task;
3631 pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
3632 unsigned long flags;
3633 dbreg_t dbreg;
3634 unsigned int rnum;
3635 int first_time;
3636 int ret = 0, state;
3637 int i, can_access_pmu = 0;
3638 int is_system, is_loaded;
3639
3640 if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
3641
3642 state = ctx->ctx_state;
3643 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3644 is_system = ctx->ctx_fl_system;
3645 task = ctx->ctx_task;
3646
3647 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3648
3649 /*
3650 * on both UP and SMP, we can only write to the PMC when the task is
3651 * the owner of the local PMU.
3652 */
3653 if (is_loaded) {
3654 thread = &task->thread;
3655 /*
3656 * In system wide and when the context is loaded, access can only happen
3657 * when the caller is running on the CPU being monitored by the session.
3658 * It does not have to be the owner (ctx_task) of the context per se.
3659 */
3660 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3661 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3662 return -EBUSY;
3663 }
3664 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3665 }
3666
3667 /*
3668 * we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
3669 * ensuring that no real breakpoint can be installed via this call.
3670 *
3671 * IMPORTANT: regs can be NULL in this function
3672 */
3673
3674 first_time = ctx->ctx_fl_using_dbreg == 0;
3675
3676 /*
3677 * don't bother if we are loaded and task is being debugged
3678 */
3679 if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
3680 DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
3681 return -EBUSY;
3682 }
3683
3684 /*
3685 * check for debug registers in system wide mode
3686 *
3687 * If though a check is done in pfm_context_load(),
3688 * we must repeat it here, in case the registers are
3689 * written after the context is loaded
3690 */
3691 if (is_loaded) {
3692 LOCK_PFS(flags);
3693
3694 if (first_time && is_system) {
3695 if (pfm_sessions.pfs_ptrace_use_dbregs)
3696 ret = -EBUSY;
3697 else
3698 pfm_sessions.pfs_sys_use_dbregs++;
3699 }
3700 UNLOCK_PFS(flags);
3701 }
3702
3703 if (ret != 0) return ret;
3704
3705 /*
3706 * mark ourself as user of the debug registers for
3707 * perfmon purposes.
3708 */
3709 ctx->ctx_fl_using_dbreg = 1;
3710
3711 /*
3712 * clear hardware registers to make sure we don't
3713 * pick up stale state.
3714 *
3715 * for a system wide session, we do not use
3716 * thread.dbr, thread.ibr because this process
3717 * never leaves the current CPU and the state
3718 * is shared by all processes running on it
3719 */
3720 if (first_time && can_access_pmu) {
3721 DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
3722 for (i=0; i < pmu_conf->num_ibrs; i++) {
3723 ia64_set_ibr(i, 0UL);
3724 ia64_dv_serialize_instruction();
3725 }
3726 ia64_srlz_i();
3727 for (i=0; i < pmu_conf->num_dbrs; i++) {
3728 ia64_set_dbr(i, 0UL);
3729 ia64_dv_serialize_data();
3730 }
3731 ia64_srlz_d();
3732 }
3733
3734 /*
3735 * Now install the values into the registers
3736 */
3737 for (i = 0; i < count; i++, req++) {
3738
3739 rnum = req->dbreg_num;
3740 dbreg.val = req->dbreg_value;
3741
3742 ret = -EINVAL;
3743
3744 if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
3745 DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
3746 rnum, dbreg.val, mode, i, count));
3747
3748 goto abort_mission;
3749 }
3750
3751 /*
3752 * make sure we do not install enabled breakpoint
3753 */
3754 if (rnum & 0x1) {
3755 if (mode == PFM_CODE_RR)
3756 dbreg.ibr.ibr_x = 0;
3757 else
3758 dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
3759 }
3760
3761 PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
3762
3763 /*
3764 * Debug registers, just like PMC, can only be modified
3765 * by a kernel call. Moreover, perfmon() access to those
3766 * registers are centralized in this routine. The hardware
3767 * does not modify the value of these registers, therefore,
3768 * if we save them as they are written, we can avoid having
3769 * to save them on context switch out. This is made possible
3770 * by the fact that when perfmon uses debug registers, ptrace()
3771 * won't be able to modify them concurrently.
3772 */
3773 if (mode == PFM_CODE_RR) {
3774 CTX_USED_IBR(ctx, rnum);
3775
3776 if (can_access_pmu) {
3777 ia64_set_ibr(rnum, dbreg.val);
3778 ia64_dv_serialize_instruction();
3779 }
3780
3781 ctx->ctx_ibrs[rnum] = dbreg.val;
3782
3783 DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
3784 rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
3785 } else {
3786 CTX_USED_DBR(ctx, rnum);
3787
3788 if (can_access_pmu) {
3789 ia64_set_dbr(rnum, dbreg.val);
3790 ia64_dv_serialize_data();
3791 }
3792 ctx->ctx_dbrs[rnum] = dbreg.val;
3793
3794 DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
3795 rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
3796 }
3797 }
3798
3799 return 0;
3800
3801abort_mission:
3802 /*
3803 * in case it was our first attempt, we undo the global modifications
3804 */
3805 if (first_time) {
3806 LOCK_PFS(flags);
3807 if (ctx->ctx_fl_system) {
3808 pfm_sessions.pfs_sys_use_dbregs--;
3809 }
3810 UNLOCK_PFS(flags);
3811 ctx->ctx_fl_using_dbreg = 0;
3812 }
3813 /*
3814 * install error return flag
3815 */
3816 PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
3817
3818 return ret;
3819}
3820
3821static int
3822pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3823{
3824 return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
3825}
3826
3827static int
3828pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3829{
3830 return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
3831}
3832
3833int
3834pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3835{
3836 pfm_context_t *ctx;
3837
3838 if (req == NULL) return -EINVAL;
3839
3840 ctx = GET_PMU_CTX();
3841
3842 if (ctx == NULL) return -EINVAL;
3843
3844 /*
3845 * for now limit to current task, which is enough when calling
3846 * from overflow handler
3847 */
3848 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3849
3850 return pfm_write_ibrs(ctx, req, nreq, regs);
3851}
3852EXPORT_SYMBOL(pfm_mod_write_ibrs);
3853
3854int
3855pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3856{
3857 pfm_context_t *ctx;
3858
3859 if (req == NULL) return -EINVAL;
3860
3861 ctx = GET_PMU_CTX();
3862
3863 if (ctx == NULL) return -EINVAL;
3864
3865 /*
3866 * for now limit to current task, which is enough when calling
3867 * from overflow handler
3868 */
3869 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3870
3871 return pfm_write_dbrs(ctx, req, nreq, regs);
3872}
3873EXPORT_SYMBOL(pfm_mod_write_dbrs);
3874
3875
3876static int
3877pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3878{
3879 pfarg_features_t *req = (pfarg_features_t *)arg;
3880
3881 req->ft_version = PFM_VERSION;
3882 return 0;
3883}
3884
3885static int
3886pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3887{
3888 struct pt_regs *tregs;
3889 struct task_struct *task = PFM_CTX_TASK(ctx);
3890 int state, is_system;
3891
3892 state = ctx->ctx_state;
3893 is_system = ctx->ctx_fl_system;
3894
3895 /*
3896 * context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
3897 */
3898 if (state == PFM_CTX_UNLOADED) return -EINVAL;
3899
3900 /*
3901 * In system wide and when the context is loaded, access can only happen
3902 * when the caller is running on the CPU being monitored by the session.
3903 * It does not have to be the owner (ctx_task) of the context per se.
3904 */
3905 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3906 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3907 return -EBUSY;
3908 }
3909 DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
3910 task_pid_nr(PFM_CTX_TASK(ctx)),
3911 state,
3912 is_system));
3913 /*
3914 * in system mode, we need to update the PMU directly
3915 * and the user level state of the caller, which may not
3916 * necessarily be the creator of the context.
3917 */
3918 if (is_system) {
3919 /*
3920 * Update local PMU first
3921 *
3922 * disable dcr pp
3923 */
3924 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
3925 ia64_srlz_i();
3926
3927 /*
3928 * update local cpuinfo
3929 */
3930 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
3931
3932 /*
3933 * stop monitoring, does srlz.i
3934 */
3935 pfm_clear_psr_pp();
3936
3937 /*
3938 * stop monitoring in the caller
3939 */
3940 ia64_psr(regs)->pp = 0;
3941
3942 return 0;
3943 }
3944 /*
3945 * per-task mode
3946 */
3947
3948 if (task == current) {
3949 /* stop monitoring at kernel level */
3950 pfm_clear_psr_up();
3951
3952 /*
3953 * stop monitoring at the user level
3954 */
3955 ia64_psr(regs)->up = 0;
3956 } else {
3957 tregs = task_pt_regs(task);
3958
3959 /*
3960 * stop monitoring at the user level
3961 */
3962 ia64_psr(tregs)->up = 0;
3963
3964 /*
3965 * monitoring disabled in kernel at next reschedule
3966 */
3967 ctx->ctx_saved_psr_up = 0;
3968 DPRINT(("task=[%d]\n", task_pid_nr(task)));
3969 }
3970 return 0;
3971}
3972
3973
3974static int
3975pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3976{
3977 struct pt_regs *tregs;
3978 int state, is_system;
3979
3980 state = ctx->ctx_state;
3981 is_system = ctx->ctx_fl_system;
3982
3983 if (state != PFM_CTX_LOADED) return -EINVAL;
3984
3985 /*
3986 * In system wide and when the context is loaded, access can only happen
3987 * when the caller is running on the CPU being monitored by the session.
3988 * It does not have to be the owner (ctx_task) of the context per se.
3989 */
3990 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3991 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3992 return -EBUSY;
3993 }
3994
3995 /*
3996 * in system mode, we need to update the PMU directly
3997 * and the user level state of the caller, which may not
3998 * necessarily be the creator of the context.
3999 */
4000 if (is_system) {
4001
4002 /*
4003 * set user level psr.pp for the caller
4004 */
4005 ia64_psr(regs)->pp = 1;
4006
4007 /*
4008 * now update the local PMU and cpuinfo
4009 */
4010 PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
4011
4012 /*
4013 * start monitoring at kernel level
4014 */
4015 pfm_set_psr_pp();
4016
4017 /* enable dcr pp */
4018 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
4019 ia64_srlz_i();
4020
4021 return 0;
4022 }
4023
4024 /*
4025 * per-process mode
4026 */
4027
4028 if (ctx->ctx_task == current) {
4029
4030 /* start monitoring at kernel level */
4031 pfm_set_psr_up();
4032
4033 /*
4034 * activate monitoring at user level
4035 */
4036 ia64_psr(regs)->up = 1;
4037
4038 } else {
4039 tregs = task_pt_regs(ctx->ctx_task);
4040
4041 /*
4042 * start monitoring at the kernel level the next
4043 * time the task is scheduled
4044 */
4045 ctx->ctx_saved_psr_up = IA64_PSR_UP;
4046
4047 /*
4048 * activate monitoring at user level
4049 */
4050 ia64_psr(tregs)->up = 1;
4051 }
4052 return 0;
4053}
4054
4055static int
4056pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4057{
4058 pfarg_reg_t *req = (pfarg_reg_t *)arg;
4059 unsigned int cnum;
4060 int i;
4061 int ret = -EINVAL;
4062
4063 for (i = 0; i < count; i++, req++) {
4064
4065 cnum = req->reg_num;
4066
4067 if (!PMC_IS_IMPL(cnum)) goto abort_mission;
4068
4069 req->reg_value = PMC_DFL_VAL(cnum);
4070
4071 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
4072
4073 DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
4074 }
4075 return 0;
4076
4077abort_mission:
4078 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
4079 return ret;
4080}
4081
4082static int
4083pfm_check_task_exist(pfm_context_t *ctx)
4084{
4085 struct task_struct *g, *t;
4086 int ret = -ESRCH;
4087
4088 read_lock(&tasklist_lock);
4089
4090 do_each_thread (g, t) {
4091 if (t->thread.pfm_context == ctx) {
4092 ret = 0;
4093 goto out;
4094 }
4095 } while_each_thread (g, t);
4096out:
4097 read_unlock(&tasklist_lock);
4098
4099 DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
4100
4101 return ret;
4102}
4103
4104static int
4105pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4106{
4107 struct task_struct *task;
4108 struct thread_struct *thread;
4109 struct pfm_context_t *old;
4110 unsigned long flags;
4111#ifndef CONFIG_SMP
4112 struct task_struct *owner_task = NULL;
4113#endif
4114 pfarg_load_t *req = (pfarg_load_t *)arg;
4115 unsigned long *pmcs_source, *pmds_source;
4116 int the_cpu;
4117 int ret = 0;
4118 int state, is_system, set_dbregs = 0;
4119
4120 state = ctx->ctx_state;
4121 is_system = ctx->ctx_fl_system;
4122 /*
4123 * can only load from unloaded or terminated state
4124 */
4125 if (state != PFM_CTX_UNLOADED) {
4126 DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
4127 req->load_pid,
4128 ctx->ctx_state));
4129 return -EBUSY;
4130 }
4131
4132 DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
4133
4134 if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
4135 DPRINT(("cannot use blocking mode on self\n"));
4136 return -EINVAL;
4137 }
4138
4139 ret = pfm_get_task(ctx, req->load_pid, &task);
4140 if (ret) {
4141 DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
4142 return ret;
4143 }
4144
4145 ret = -EINVAL;
4146
4147 /*
4148 * system wide is self monitoring only
4149 */
4150 if (is_system && task != current) {
4151 DPRINT(("system wide is self monitoring only load_pid=%d\n",
4152 req->load_pid));
4153 goto error;
4154 }
4155
4156 thread = &task->thread;
4157
4158 ret = 0;
4159 /*
4160 * cannot load a context which is using range restrictions,
4161 * into a task that is being debugged.
4162 */
4163 if (ctx->ctx_fl_using_dbreg) {
4164 if (thread->flags & IA64_THREAD_DBG_VALID) {
4165 ret = -EBUSY;
4166 DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
4167 goto error;
4168 }
4169 LOCK_PFS(flags);
4170
4171 if (is_system) {
4172 if (pfm_sessions.pfs_ptrace_use_dbregs) {
4173 DPRINT(("cannot load [%d] dbregs in use\n",
4174 task_pid_nr(task)));
4175 ret = -EBUSY;
4176 } else {
4177 pfm_sessions.pfs_sys_use_dbregs++;
4178 DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
4179 set_dbregs = 1;
4180 }
4181 }
4182
4183 UNLOCK_PFS(flags);
4184
4185 if (ret) goto error;
4186 }
4187
4188 /*
4189 * SMP system-wide monitoring implies self-monitoring.
4190 *
4191 * The programming model expects the task to
4192 * be pinned on a CPU throughout the session.
4193 * Here we take note of the current CPU at the
4194 * time the context is loaded. No call from
4195 * another CPU will be allowed.
4196 *
4197 * The pinning via shed_setaffinity()
4198 * must be done by the calling task prior
4199 * to this call.
4200 *
4201 * systemwide: keep track of CPU this session is supposed to run on
4202 */
4203 the_cpu = ctx->ctx_cpu = smp_processor_id();
4204
4205 ret = -EBUSY;
4206 /*
4207 * now reserve the session
4208 */
4209 ret = pfm_reserve_session(current, is_system, the_cpu);
4210 if (ret) goto error;
4211
4212 /*
4213 * task is necessarily stopped at this point.
4214 *
4215 * If the previous context was zombie, then it got removed in
4216 * pfm_save_regs(). Therefore we should not see it here.
4217 * If we see a context, then this is an active context
4218 *
4219 * XXX: needs to be atomic
4220 */
4221 DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
4222 thread->pfm_context, ctx));
4223
4224 ret = -EBUSY;
4225 old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
4226 if (old != NULL) {
4227 DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
4228 goto error_unres;
4229 }
4230
4231 pfm_reset_msgq(ctx);
4232
4233 ctx->ctx_state = PFM_CTX_LOADED;
4234
4235 /*
4236 * link context to task
4237 */
4238 ctx->ctx_task = task;
4239
4240 if (is_system) {
4241 /*
4242 * we load as stopped
4243 */
4244 PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
4245 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4246
4247 if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
4248 } else {
4249 thread->flags |= IA64_THREAD_PM_VALID;
4250 }
4251
4252 /*
4253 * propagate into thread-state
4254 */
4255 pfm_copy_pmds(task, ctx);
4256 pfm_copy_pmcs(task, ctx);
4257
4258 pmcs_source = ctx->th_pmcs;
4259 pmds_source = ctx->th_pmds;
4260
4261 /*
4262 * always the case for system-wide
4263 */
4264 if (task == current) {
4265
4266 if (is_system == 0) {
4267
4268 /* allow user level control */
4269 ia64_psr(regs)->sp = 0;
4270 DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
4271
4272 SET_LAST_CPU(ctx, smp_processor_id());
4273 INC_ACTIVATION();
4274 SET_ACTIVATION(ctx);
4275#ifndef CONFIG_SMP
4276 /*
4277 * push the other task out, if any
4278 */
4279 owner_task = GET_PMU_OWNER();
4280 if (owner_task) pfm_lazy_save_regs(owner_task);
4281#endif
4282 }
4283 /*
4284 * load all PMD from ctx to PMU (as opposed to thread state)
4285 * restore all PMC from ctx to PMU
4286 */
4287 pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
4288 pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
4289
4290 ctx->ctx_reload_pmcs[0] = 0UL;
4291 ctx->ctx_reload_pmds[0] = 0UL;
4292
4293 /*
4294 * guaranteed safe by earlier check against DBG_VALID
4295 */
4296 if (ctx->ctx_fl_using_dbreg) {
4297 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
4298 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
4299 }
4300 /*
4301 * set new ownership
4302 */
4303 SET_PMU_OWNER(task, ctx);
4304
4305 DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
4306 } else {
4307 /*
4308 * when not current, task MUST be stopped, so this is safe
4309 */
4310 regs = task_pt_regs(task);
4311
4312 /* force a full reload */
4313 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4314 SET_LAST_CPU(ctx, -1);
4315
4316 /* initial saved psr (stopped) */
4317 ctx->ctx_saved_psr_up = 0UL;
4318 ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
4319 }
4320
4321 ret = 0;
4322
4323error_unres:
4324 if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
4325error:
4326 /*
4327 * we must undo the dbregs setting (for system-wide)
4328 */
4329 if (ret && set_dbregs) {
4330 LOCK_PFS(flags);
4331 pfm_sessions.pfs_sys_use_dbregs--;
4332 UNLOCK_PFS(flags);
4333 }
4334 /*
4335 * release task, there is now a link with the context
4336 */
4337 if (is_system == 0 && task != current) {
4338 pfm_put_task(task);
4339
4340 if (ret == 0) {
4341 ret = pfm_check_task_exist(ctx);
4342 if (ret) {
4343 ctx->ctx_state = PFM_CTX_UNLOADED;
4344 ctx->ctx_task = NULL;
4345 }
4346 }
4347 }
4348 return ret;
4349}
4350
4351/*
4352 * in this function, we do not need to increase the use count
4353 * for the task via get_task_struct(), because we hold the
4354 * context lock. If the task were to disappear while having
4355 * a context attached, it would go through pfm_exit_thread()
4356 * which also grabs the context lock and would therefore be blocked
4357 * until we are here.
4358 */
4359static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
4360
4361static int
4362pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4363{
4364 struct task_struct *task = PFM_CTX_TASK(ctx);
4365 struct pt_regs *tregs;
4366 int prev_state, is_system;
4367 int ret;
4368
4369 DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
4370
4371 prev_state = ctx->ctx_state;
4372 is_system = ctx->ctx_fl_system;
4373
4374 /*
4375 * unload only when necessary
4376 */
4377 if (prev_state == PFM_CTX_UNLOADED) {
4378 DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
4379 return 0;
4380 }
4381
4382 /*
4383 * clear psr and dcr bits
4384 */
4385 ret = pfm_stop(ctx, NULL, 0, regs);
4386 if (ret) return ret;
4387
4388 ctx->ctx_state = PFM_CTX_UNLOADED;
4389
4390 /*
4391 * in system mode, we need to update the PMU directly
4392 * and the user level state of the caller, which may not
4393 * necessarily be the creator of the context.
4394 */
4395 if (is_system) {
4396
4397 /*
4398 * Update cpuinfo
4399 *
4400 * local PMU is taken care of in pfm_stop()
4401 */
4402 PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
4403 PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
4404
4405 /*
4406 * save PMDs in context
4407 * release ownership
4408 */
4409 pfm_flush_pmds(current, ctx);
4410
4411 /*
4412 * at this point we are done with the PMU
4413 * so we can unreserve the resource.
4414 */
4415 if (prev_state != PFM_CTX_ZOMBIE)
4416 pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
4417
4418 /*
4419 * disconnect context from task
4420 */
4421 task->thread.pfm_context = NULL;
4422 /*
4423 * disconnect task from context
4424 */
4425 ctx->ctx_task = NULL;
4426
4427 /*
4428 * There is nothing more to cleanup here.
4429 */
4430 return 0;
4431 }
4432
4433 /*
4434 * per-task mode
4435 */
4436 tregs = task == current ? regs : task_pt_regs(task);
4437
4438 if (task == current) {
4439 /*
4440 * cancel user level control
4441 */
4442 ia64_psr(regs)->sp = 1;
4443
4444 DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
4445 }
4446 /*
4447 * save PMDs to context
4448 * release ownership
4449 */
4450 pfm_flush_pmds(task, ctx);
4451
4452 /*
4453 * at this point we are done with the PMU
4454 * so we can unreserve the resource.
4455 *
4456 * when state was ZOMBIE, we have already unreserved.
4457 */
4458 if (prev_state != PFM_CTX_ZOMBIE)
4459 pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
4460
4461 /*
4462 * reset activation counter and psr
4463 */
4464 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4465 SET_LAST_CPU(ctx, -1);
4466
4467 /*
4468 * PMU state will not be restored
4469 */
4470 task->thread.flags &= ~IA64_THREAD_PM_VALID;
4471
4472 /*
4473 * break links between context and task
4474 */
4475 task->thread.pfm_context = NULL;
4476 ctx->ctx_task = NULL;
4477
4478 PFM_SET_WORK_PENDING(task, 0);
4479
4480 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
4481 ctx->ctx_fl_can_restart = 0;
4482 ctx->ctx_fl_going_zombie = 0;
4483
4484 DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
4485
4486 return 0;
4487}
4488
4489
4490/*
4491 * called only from exit_thread()
4492 * we come here only if the task has a context attached (loaded or masked)
4493 */
4494void
4495pfm_exit_thread(struct task_struct *task)
4496{
4497 pfm_context_t *ctx;
4498 unsigned long flags;
4499 struct pt_regs *regs = task_pt_regs(task);
4500 int ret, state;
4501 int free_ok = 0;
4502
4503 ctx = PFM_GET_CTX(task);
4504
4505 PROTECT_CTX(ctx, flags);
4506
4507 DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
4508
4509 state = ctx->ctx_state;
4510 switch(state) {
4511 case PFM_CTX_UNLOADED:
4512 /*
4513 * only comes to this function if pfm_context is not NULL, i.e., cannot
4514 * be in unloaded state
4515 */
4516 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
4517 break;
4518 case PFM_CTX_LOADED:
4519 case PFM_CTX_MASKED:
4520 ret = pfm_context_unload(ctx, NULL, 0, regs);
4521 if (ret) {
4522 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4523 }
4524 DPRINT(("ctx unloaded for current state was %d\n", state));
4525
4526 pfm_end_notify_user(ctx);
4527 break;
4528 case PFM_CTX_ZOMBIE:
4529 ret = pfm_context_unload(ctx, NULL, 0, regs);
4530 if (ret) {
4531 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4532 }
4533 free_ok = 1;
4534 break;
4535 default:
4536 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
4537 break;
4538 }
4539 UNPROTECT_CTX(ctx, flags);
4540
4541 { u64 psr = pfm_get_psr();
4542 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
4543 BUG_ON(GET_PMU_OWNER());
4544 BUG_ON(ia64_psr(regs)->up);
4545 BUG_ON(ia64_psr(regs)->pp);
4546 }
4547
4548 /*
4549 * All memory free operations (especially for vmalloc'ed memory)
4550 * MUST be done with interrupts ENABLED.
4551 */
4552 if (free_ok) pfm_context_free(ctx);
4553}
4554
4555/*
4556 * functions MUST be listed in the increasing order of their index (see permfon.h)
4557 */
4558#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
4559#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
4560#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
4561#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
4562#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
4563
4564static pfm_cmd_desc_t pfm_cmd_tab[]={
4565/* 0 */PFM_CMD_NONE,
4566/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4567/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4568/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4569/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
4570/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
4571/* 6 */PFM_CMD_NONE,
4572/* 7 */PFM_CMD_NONE,
4573/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
4574/* 9 */PFM_CMD_NONE,
4575/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
4576/* 11 */PFM_CMD_NONE,
4577/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
4578/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
4579/* 14 */PFM_CMD_NONE,
4580/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4581/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
4582/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
4583/* 18 */PFM_CMD_NONE,
4584/* 19 */PFM_CMD_NONE,
4585/* 20 */PFM_CMD_NONE,
4586/* 21 */PFM_CMD_NONE,
4587/* 22 */PFM_CMD_NONE,
4588/* 23 */PFM_CMD_NONE,
4589/* 24 */PFM_CMD_NONE,
4590/* 25 */PFM_CMD_NONE,
4591/* 26 */PFM_CMD_NONE,
4592/* 27 */PFM_CMD_NONE,
4593/* 28 */PFM_CMD_NONE,
4594/* 29 */PFM_CMD_NONE,
4595/* 30 */PFM_CMD_NONE,
4596/* 31 */PFM_CMD_NONE,
4597/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
4598/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
4599};
4600#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
4601
4602static int
4603pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
4604{
4605 struct task_struct *task;
4606 int state, old_state;
4607
4608recheck:
4609 state = ctx->ctx_state;
4610 task = ctx->ctx_task;
4611
4612 if (task == NULL) {
4613 DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
4614 return 0;
4615 }
4616
4617 DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
4618 ctx->ctx_fd,
4619 state,
4620 task_pid_nr(task),
4621 task->state, PFM_CMD_STOPPED(cmd)));
4622
4623 /*
4624 * self-monitoring always ok.
4625 *
4626 * for system-wide the caller can either be the creator of the
4627 * context (to one to which the context is attached to) OR
4628 * a task running on the same CPU as the session.
4629 */
4630 if (task == current || ctx->ctx_fl_system) return 0;
4631
4632 /*
4633 * we are monitoring another thread
4634 */
4635 switch(state) {
4636 case PFM_CTX_UNLOADED:
4637 /*
4638 * if context is UNLOADED we are safe to go
4639 */
4640 return 0;
4641 case PFM_CTX_ZOMBIE:
4642 /*
4643 * no command can operate on a zombie context
4644 */
4645 DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
4646 return -EINVAL;
4647 case PFM_CTX_MASKED:
4648 /*
4649 * PMU state has been saved to software even though
4650 * the thread may still be running.
4651 */
4652 if (cmd != PFM_UNLOAD_CONTEXT) return 0;
4653 }
4654
4655 /*
4656 * context is LOADED or MASKED. Some commands may need to have
4657 * the task stopped.
4658 *
4659 * We could lift this restriction for UP but it would mean that
4660 * the user has no guarantee the task would not run between
4661 * two successive calls to perfmonctl(). That's probably OK.
4662 * If this user wants to ensure the task does not run, then
4663 * the task must be stopped.
4664 */
4665 if (PFM_CMD_STOPPED(cmd)) {
4666 if (!task_is_stopped_or_traced(task)) {
4667 DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
4668 return -EBUSY;
4669 }
4670 /*
4671 * task is now stopped, wait for ctxsw out
4672 *
4673 * This is an interesting point in the code.
4674 * We need to unprotect the context because
4675 * the pfm_save_regs() routines needs to grab
4676 * the same lock. There are danger in doing
4677 * this because it leaves a window open for
4678 * another task to get access to the context
4679 * and possibly change its state. The one thing
4680 * that is not possible is for the context to disappear
4681 * because we are protected by the VFS layer, i.e.,
4682 * get_fd()/put_fd().
4683 */
4684 old_state = state;
4685
4686 UNPROTECT_CTX(ctx, flags);
4687
4688 wait_task_inactive(task, 0);
4689
4690 PROTECT_CTX(ctx, flags);
4691
4692 /*
4693 * we must recheck to verify if state has changed
4694 */
4695 if (ctx->ctx_state != old_state) {
4696 DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
4697 goto recheck;
4698 }
4699 }
4700 return 0;
4701}
4702
4703/*
4704 * system-call entry point (must return long)
4705 */
4706asmlinkage long
4707sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
4708{
4709 struct fd f = {NULL, 0};
4710 pfm_context_t *ctx = NULL;
4711 unsigned long flags = 0UL;
4712 void *args_k = NULL;
4713 long ret; /* will expand int return types */
4714 size_t base_sz, sz, xtra_sz = 0;
4715 int narg, completed_args = 0, call_made = 0, cmd_flags;
4716 int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
4717 int (*getsize)(void *arg, size_t *sz);
4718#define PFM_MAX_ARGSIZE 4096
4719
4720 /*
4721 * reject any call if perfmon was disabled at initialization
4722 */
4723 if (unlikely(pmu_conf == NULL)) return -ENOSYS;
4724
4725 if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
4726 DPRINT(("invalid cmd=%d\n", cmd));
4727 return -EINVAL;
4728 }
4729
4730 func = pfm_cmd_tab[cmd].cmd_func;
4731 narg = pfm_cmd_tab[cmd].cmd_narg;
4732 base_sz = pfm_cmd_tab[cmd].cmd_argsize;
4733 getsize = pfm_cmd_tab[cmd].cmd_getsize;
4734 cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
4735
4736 if (unlikely(func == NULL)) {
4737 DPRINT(("invalid cmd=%d\n", cmd));
4738 return -EINVAL;
4739 }
4740
4741 DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
4742 PFM_CMD_NAME(cmd),
4743 cmd,
4744 narg,
4745 base_sz,
4746 count));
4747
4748 /*
4749 * check if number of arguments matches what the command expects
4750 */
4751 if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
4752 return -EINVAL;
4753
4754restart_args:
4755 sz = xtra_sz + base_sz*count;
4756 /*
4757 * limit abuse to min page size
4758 */
4759 if (unlikely(sz > PFM_MAX_ARGSIZE)) {
4760 printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
4761 return -E2BIG;
4762 }
4763
4764 /*
4765 * allocate default-sized argument buffer
4766 */
4767 if (likely(count && args_k == NULL)) {
4768 args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
4769 if (args_k == NULL) return -ENOMEM;
4770 }
4771
4772 ret = -EFAULT;
4773
4774 /*
4775 * copy arguments
4776 *
4777 * assume sz = 0 for command without parameters
4778 */
4779 if (sz && copy_from_user(args_k, arg, sz)) {
4780 DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
4781 goto error_args;
4782 }
4783
4784 /*
4785 * check if command supports extra parameters
4786 */
4787 if (completed_args == 0 && getsize) {
4788 /*
4789 * get extra parameters size (based on main argument)
4790 */
4791 ret = (*getsize)(args_k, &xtra_sz);
4792 if (ret) goto error_args;
4793
4794 completed_args = 1;
4795
4796 DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
4797
4798 /* retry if necessary */
4799 if (likely(xtra_sz)) goto restart_args;
4800 }
4801
4802 if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
4803
4804 ret = -EBADF;
4805
4806 f = fdget(fd);
4807 if (unlikely(f.file == NULL)) {
4808 DPRINT(("invalid fd %d\n", fd));
4809 goto error_args;
4810 }
4811 if (unlikely(PFM_IS_FILE(f.file) == 0)) {
4812 DPRINT(("fd %d not related to perfmon\n", fd));
4813 goto error_args;
4814 }
4815
4816 ctx = f.file->private_data;
4817 if (unlikely(ctx == NULL)) {
4818 DPRINT(("no context for fd %d\n", fd));
4819 goto error_args;
4820 }
4821 prefetch(&ctx->ctx_state);
4822
4823 PROTECT_CTX(ctx, flags);
4824
4825 /*
4826 * check task is stopped
4827 */
4828 ret = pfm_check_task_state(ctx, cmd, flags);
4829 if (unlikely(ret)) goto abort_locked;
4830
4831skip_fd:
4832 ret = (*func)(ctx, args_k, count, task_pt_regs(current));
4833
4834 call_made = 1;
4835
4836abort_locked:
4837 if (likely(ctx)) {
4838 DPRINT(("context unlocked\n"));
4839 UNPROTECT_CTX(ctx, flags);
4840 }
4841
4842 /* copy argument back to user, if needed */
4843 if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
4844
4845error_args:
4846 if (f.file)
4847 fdput(f);
4848
4849 kfree(args_k);
4850
4851 DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
4852
4853 return ret;
4854}
4855
4856static void
4857pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
4858{
4859 pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
4860 pfm_ovfl_ctrl_t rst_ctrl;
4861 int state;
4862 int ret = 0;
4863
4864 state = ctx->ctx_state;
4865 /*
4866 * Unlock sampling buffer and reset index atomically
4867 * XXX: not really needed when blocking
4868 */
4869 if (CTX_HAS_SMPL(ctx)) {
4870
4871 rst_ctrl.bits.mask_monitoring = 0;
4872 rst_ctrl.bits.reset_ovfl_pmds = 0;
4873
4874 if (state == PFM_CTX_LOADED)
4875 ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4876 else
4877 ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4878 } else {
4879 rst_ctrl.bits.mask_monitoring = 0;
4880 rst_ctrl.bits.reset_ovfl_pmds = 1;
4881 }
4882
4883 if (ret == 0) {
4884 if (rst_ctrl.bits.reset_ovfl_pmds) {
4885 pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
4886 }
4887 if (rst_ctrl.bits.mask_monitoring == 0) {
4888 DPRINT(("resuming monitoring\n"));
4889 if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
4890 } else {
4891 DPRINT(("stopping monitoring\n"));
4892 //pfm_stop_monitoring(current, regs);
4893 }
4894 ctx->ctx_state = PFM_CTX_LOADED;
4895 }
4896}
4897
4898/*
4899 * context MUST BE LOCKED when calling
4900 * can only be called for current
4901 */
4902static void
4903pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
4904{
4905 int ret;
4906
4907 DPRINT(("entering for [%d]\n", task_pid_nr(current)));
4908
4909 ret = pfm_context_unload(ctx, NULL, 0, regs);
4910 if (ret) {
4911 printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
4912 }
4913
4914 /*
4915 * and wakeup controlling task, indicating we are now disconnected
4916 */
4917 wake_up_interruptible(&ctx->ctx_zombieq);
4918
4919 /*
4920 * given that context is still locked, the controlling
4921 * task will only get access when we return from
4922 * pfm_handle_work().
4923 */
4924}
4925
4926static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
4927
4928 /*
4929 * pfm_handle_work() can be called with interrupts enabled
4930 * (TIF_NEED_RESCHED) or disabled. The down_interruptible
4931 * call may sleep, therefore we must re-enable interrupts
4932 * to avoid deadlocks. It is safe to do so because this function
4933 * is called ONLY when returning to user level (pUStk=1), in which case
4934 * there is no risk of kernel stack overflow due to deep
4935 * interrupt nesting.
4936 */
4937void
4938pfm_handle_work(void)
4939{
4940 pfm_context_t *ctx;
4941 struct pt_regs *regs;
4942 unsigned long flags, dummy_flags;
4943 unsigned long ovfl_regs;
4944 unsigned int reason;
4945 int ret;
4946
4947 ctx = PFM_GET_CTX(current);
4948 if (ctx == NULL) {
4949 printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
4950 task_pid_nr(current));
4951 return;
4952 }
4953
4954 PROTECT_CTX(ctx, flags);
4955
4956 PFM_SET_WORK_PENDING(current, 0);
4957
4958 regs = task_pt_regs(current);
4959
4960 /*
4961 * extract reason for being here and clear
4962 */
4963 reason = ctx->ctx_fl_trap_reason;
4964 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
4965 ovfl_regs = ctx->ctx_ovfl_regs[0];
4966
4967 DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
4968
4969 /*
4970 * must be done before we check for simple-reset mode
4971 */
4972 if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
4973 goto do_zombie;
4974
4975 //if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
4976 if (reason == PFM_TRAP_REASON_RESET)
4977 goto skip_blocking;
4978
4979 /*
4980 * restore interrupt mask to what it was on entry.
4981 * Could be enabled/diasbled.
4982 */
4983 UNPROTECT_CTX(ctx, flags);
4984
4985 /*
4986 * force interrupt enable because of down_interruptible()
4987 */
4988 local_irq_enable();
4989
4990 DPRINT(("before block sleeping\n"));
4991
4992 /*
4993 * may go through without blocking on SMP systems
4994 * if restart has been received already by the time we call down()
4995 */
4996 ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
4997
4998 DPRINT(("after block sleeping ret=%d\n", ret));
4999
5000 /*
5001 * lock context and mask interrupts again
5002 * We save flags into a dummy because we may have
5003 * altered interrupts mask compared to entry in this
5004 * function.
5005 */
5006 PROTECT_CTX(ctx, dummy_flags);
5007
5008 /*
5009 * we need to read the ovfl_regs only after wake-up
5010 * because we may have had pfm_write_pmds() in between
5011 * and that can changed PMD values and therefore
5012 * ovfl_regs is reset for these new PMD values.
5013 */
5014 ovfl_regs = ctx->ctx_ovfl_regs[0];
5015
5016 if (ctx->ctx_fl_going_zombie) {
5017do_zombie:
5018 DPRINT(("context is zombie, bailing out\n"));
5019 pfm_context_force_terminate(ctx, regs);
5020 goto nothing_to_do;
5021 }
5022 /*
5023 * in case of interruption of down() we don't restart anything
5024 */
5025 if (ret < 0)
5026 goto nothing_to_do;
5027
5028skip_blocking:
5029 pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
5030 ctx->ctx_ovfl_regs[0] = 0UL;
5031
5032nothing_to_do:
5033 /*
5034 * restore flags as they were upon entry
5035 */
5036 UNPROTECT_CTX(ctx, flags);
5037}
5038
5039static int
5040pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
5041{
5042 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5043 DPRINT(("ignoring overflow notification, owner is zombie\n"));
5044 return 0;
5045 }
5046
5047 DPRINT(("waking up somebody\n"));
5048
5049 if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
5050
5051 /*
5052 * safe, we are not in intr handler, nor in ctxsw when
5053 * we come here
5054 */
5055 kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
5056
5057 return 0;
5058}
5059
5060static int
5061pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
5062{
5063 pfm_msg_t *msg = NULL;
5064
5065 if (ctx->ctx_fl_no_msg == 0) {
5066 msg = pfm_get_new_msg(ctx);
5067 if (msg == NULL) {
5068 printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
5069 return -1;
5070 }
5071
5072 msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
5073 msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
5074 msg->pfm_ovfl_msg.msg_active_set = 0;
5075 msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
5076 msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
5077 msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
5078 msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
5079 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5080 }
5081
5082 DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
5083 msg,
5084 ctx->ctx_fl_no_msg,
5085 ctx->ctx_fd,
5086 ovfl_pmds));
5087
5088 return pfm_notify_user(ctx, msg);
5089}
5090
5091static int
5092pfm_end_notify_user(pfm_context_t *ctx)
5093{
5094 pfm_msg_t *msg;
5095
5096 msg = pfm_get_new_msg(ctx);
5097 if (msg == NULL) {
5098 printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
5099 return -1;
5100 }
5101 /* no leak */
5102 memset(msg, 0, sizeof(*msg));
5103
5104 msg->pfm_end_msg.msg_type = PFM_MSG_END;
5105 msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
5106 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5107
5108 DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
5109 msg,
5110 ctx->ctx_fl_no_msg,
5111 ctx->ctx_fd));
5112
5113 return pfm_notify_user(ctx, msg);
5114}
5115
5116/*
5117 * main overflow processing routine.
5118 * it can be called from the interrupt path or explicitly during the context switch code
5119 */
5120static void pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx,
5121 unsigned long pmc0, struct pt_regs *regs)
5122{
5123 pfm_ovfl_arg_t *ovfl_arg;
5124 unsigned long mask;
5125 unsigned long old_val, ovfl_val, new_val;
5126 unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
5127 unsigned long tstamp;
5128 pfm_ovfl_ctrl_t ovfl_ctrl;
5129 unsigned int i, has_smpl;
5130 int must_notify = 0;
5131
5132 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
5133
5134 /*
5135 * sanity test. Should never happen
5136 */
5137 if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
5138
5139 tstamp = ia64_get_itc();
5140 mask = pmc0 >> PMU_FIRST_COUNTER;
5141 ovfl_val = pmu_conf->ovfl_val;
5142 has_smpl = CTX_HAS_SMPL(ctx);
5143
5144 DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
5145 "used_pmds=0x%lx\n",
5146 pmc0,
5147 task ? task_pid_nr(task): -1,
5148 (regs ? regs->cr_iip : 0),
5149 CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
5150 ctx->ctx_used_pmds[0]));
5151
5152
5153 /*
5154 * first we update the virtual counters
5155 * assume there was a prior ia64_srlz_d() issued
5156 */
5157 for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
5158
5159 /* skip pmd which did not overflow */
5160 if ((mask & 0x1) == 0) continue;
5161
5162 /*
5163 * Note that the pmd is not necessarily 0 at this point as qualified events
5164 * may have happened before the PMU was frozen. The residual count is not
5165 * taken into consideration here but will be with any read of the pmd via
5166 * pfm_read_pmds().
5167 */
5168 old_val = new_val = ctx->ctx_pmds[i].val;
5169 new_val += 1 + ovfl_val;
5170 ctx->ctx_pmds[i].val = new_val;
5171
5172 /*
5173 * check for overflow condition
5174 */
5175 if (likely(old_val > new_val)) {
5176 ovfl_pmds |= 1UL << i;
5177 if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
5178 }
5179
5180 DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
5181 i,
5182 new_val,
5183 old_val,
5184 ia64_get_pmd(i) & ovfl_val,
5185 ovfl_pmds,
5186 ovfl_notify));
5187 }
5188
5189 /*
5190 * there was no 64-bit overflow, nothing else to do
5191 */
5192 if (ovfl_pmds == 0UL) return;
5193
5194 /*
5195 * reset all control bits
5196 */
5197 ovfl_ctrl.val = 0;
5198 reset_pmds = 0UL;
5199
5200 /*
5201 * if a sampling format module exists, then we "cache" the overflow by
5202 * calling the module's handler() routine.
5203 */
5204 if (has_smpl) {
5205 unsigned long start_cycles, end_cycles;
5206 unsigned long pmd_mask;
5207 int j, k, ret = 0;
5208 int this_cpu = smp_processor_id();
5209
5210 pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
5211 ovfl_arg = &ctx->ctx_ovfl_arg;
5212
5213 prefetch(ctx->ctx_smpl_hdr);
5214
5215 for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
5216
5217 mask = 1UL << i;
5218
5219 if ((pmd_mask & 0x1) == 0) continue;
5220
5221 ovfl_arg->ovfl_pmd = (unsigned char )i;
5222 ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
5223 ovfl_arg->active_set = 0;
5224 ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
5225 ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
5226
5227 ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
5228 ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
5229 ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
5230
5231 /*
5232 * copy values of pmds of interest. Sampling format may copy them
5233 * into sampling buffer.
5234 */
5235 if (smpl_pmds) {
5236 for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
5237 if ((smpl_pmds & 0x1) == 0) continue;
5238 ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
5239 DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
5240 }
5241 }
5242
5243 pfm_stats[this_cpu].pfm_smpl_handler_calls++;
5244
5245 start_cycles = ia64_get_itc();
5246
5247 /*
5248 * call custom buffer format record (handler) routine
5249 */
5250 ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
5251
5252 end_cycles = ia64_get_itc();
5253
5254 /*
5255 * For those controls, we take the union because they have
5256 * an all or nothing behavior.
5257 */
5258 ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
5259 ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
5260 ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
5261 /*
5262 * build the bitmask of pmds to reset now
5263 */
5264 if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
5265
5266 pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
5267 }
5268 /*
5269 * when the module cannot handle the rest of the overflows, we abort right here
5270 */
5271 if (ret && pmd_mask) {
5272 DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
5273 pmd_mask<<PMU_FIRST_COUNTER));
5274 }
5275 /*
5276 * remove the pmds we reset now from the set of pmds to reset in pfm_restart()
5277 */
5278 ovfl_pmds &= ~reset_pmds;
5279 } else {
5280 /*
5281 * when no sampling module is used, then the default
5282 * is to notify on overflow if requested by user
5283 */
5284 ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
5285 ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
5286 ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
5287 ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
5288 /*
5289 * if needed, we reset all overflowed pmds
5290 */
5291 if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
5292 }
5293
5294 DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
5295
5296 /*
5297 * reset the requested PMD registers using the short reset values
5298 */
5299 if (reset_pmds) {
5300 unsigned long bm = reset_pmds;
5301 pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
5302 }
5303
5304 if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
5305 /*
5306 * keep track of what to reset when unblocking
5307 */
5308 ctx->ctx_ovfl_regs[0] = ovfl_pmds;
5309
5310 /*
5311 * check for blocking context
5312 */
5313 if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
5314
5315 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
5316
5317 /*
5318 * set the perfmon specific checking pending work for the task
5319 */
5320 PFM_SET_WORK_PENDING(task, 1);
5321
5322 /*
5323 * when coming from ctxsw, current still points to the
5324 * previous task, therefore we must work with task and not current.
5325 */
5326 set_notify_resume(task);
5327 }
5328 /*
5329 * defer until state is changed (shorten spin window). the context is locked
5330 * anyway, so the signal receiver would come spin for nothing.
5331 */
5332 must_notify = 1;
5333 }
5334
5335 DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
5336 GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
5337 PFM_GET_WORK_PENDING(task),
5338 ctx->ctx_fl_trap_reason,
5339 ovfl_pmds,
5340 ovfl_notify,
5341 ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
5342 /*
5343 * in case monitoring must be stopped, we toggle the psr bits
5344 */
5345 if (ovfl_ctrl.bits.mask_monitoring) {
5346 pfm_mask_monitoring(task);
5347 ctx->ctx_state = PFM_CTX_MASKED;
5348 ctx->ctx_fl_can_restart = 1;
5349 }
5350
5351 /*
5352 * send notification now
5353 */
5354 if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
5355
5356 return;
5357
5358sanity_check:
5359 printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
5360 smp_processor_id(),
5361 task ? task_pid_nr(task) : -1,
5362 pmc0);
5363 return;
5364
5365stop_monitoring:
5366 /*
5367 * in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
5368 * Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
5369 * come here as zombie only if the task is the current task. In which case, we
5370 * can access the PMU hardware directly.
5371 *
5372 * Note that zombies do have PM_VALID set. So here we do the minimal.
5373 *
5374 * In case the context was zombified it could not be reclaimed at the time
5375 * the monitoring program exited. At this point, the PMU reservation has been
5376 * returned, the sampiing buffer has been freed. We must convert this call
5377 * into a spurious interrupt. However, we must also avoid infinite overflows
5378 * by stopping monitoring for this task. We can only come here for a per-task
5379 * context. All we need to do is to stop monitoring using the psr bits which
5380 * are always task private. By re-enabling secure montioring, we ensure that
5381 * the monitored task will not be able to re-activate monitoring.
5382 * The task will eventually be context switched out, at which point the context
5383 * will be reclaimed (that includes releasing ownership of the PMU).
5384 *
5385 * So there might be a window of time where the number of per-task session is zero
5386 * yet one PMU might have a owner and get at most one overflow interrupt for a zombie
5387 * context. This is safe because if a per-task session comes in, it will push this one
5388 * out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
5389 * session is force on that CPU, given that we use task pinning, pfm_save_regs() will
5390 * also push our zombie context out.
5391 *
5392 * Overall pretty hairy stuff....
5393 */
5394 DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
5395 pfm_clear_psr_up();
5396 ia64_psr(regs)->up = 0;
5397 ia64_psr(regs)->sp = 1;
5398 return;
5399}
5400
5401static int
5402pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
5403{
5404 struct task_struct *task;
5405 pfm_context_t *ctx;
5406 unsigned long flags;
5407 u64 pmc0;
5408 int this_cpu = smp_processor_id();
5409 int retval = 0;
5410
5411 pfm_stats[this_cpu].pfm_ovfl_intr_count++;
5412
5413 /*
5414 * srlz.d done before arriving here
5415 */
5416 pmc0 = ia64_get_pmc(0);
5417
5418 task = GET_PMU_OWNER();
5419 ctx = GET_PMU_CTX();
5420
5421 /*
5422 * if we have some pending bits set
5423 * assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
5424 */
5425 if (PMC0_HAS_OVFL(pmc0) && task) {
5426 /*
5427 * we assume that pmc0.fr is always set here
5428 */
5429
5430 /* sanity check */
5431 if (!ctx) goto report_spurious1;
5432
5433 if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
5434 goto report_spurious2;
5435
5436 PROTECT_CTX_NOPRINT(ctx, flags);
5437
5438 pfm_overflow_handler(task, ctx, pmc0, regs);
5439
5440 UNPROTECT_CTX_NOPRINT(ctx, flags);
5441
5442 } else {
5443 pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
5444 retval = -1;
5445 }
5446 /*
5447 * keep it unfrozen at all times
5448 */
5449 pfm_unfreeze_pmu();
5450
5451 return retval;
5452
5453report_spurious1:
5454 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
5455 this_cpu, task_pid_nr(task));
5456 pfm_unfreeze_pmu();
5457 return -1;
5458report_spurious2:
5459 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
5460 this_cpu,
5461 task_pid_nr(task));
5462 pfm_unfreeze_pmu();
5463 return -1;
5464}
5465
5466static irqreturn_t
5467pfm_interrupt_handler(int irq, void *arg)
5468{
5469 unsigned long start_cycles, total_cycles;
5470 unsigned long min, max;
5471 int this_cpu;
5472 int ret;
5473 struct pt_regs *regs = get_irq_regs();
5474
5475 this_cpu = get_cpu();
5476 if (likely(!pfm_alt_intr_handler)) {
5477 min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
5478 max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
5479
5480 start_cycles = ia64_get_itc();
5481
5482 ret = pfm_do_interrupt_handler(arg, regs);
5483
5484 total_cycles = ia64_get_itc();
5485
5486 /*
5487 * don't measure spurious interrupts
5488 */
5489 if (likely(ret == 0)) {
5490 total_cycles -= start_cycles;
5491
5492 if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
5493 if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
5494
5495 pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
5496 }
5497 }
5498 else {
5499 (*pfm_alt_intr_handler->handler)(irq, arg, regs);
5500 }
5501
5502 put_cpu();
5503 return IRQ_HANDLED;
5504}
5505
5506/*
5507 * /proc/perfmon interface, for debug only
5508 */
5509
5510#define PFM_PROC_SHOW_HEADER ((void *)(long)nr_cpu_ids+1)
5511
5512static void *
5513pfm_proc_start(struct seq_file *m, loff_t *pos)
5514{
5515 if (*pos == 0) {
5516 return PFM_PROC_SHOW_HEADER;
5517 }
5518
5519 while (*pos <= nr_cpu_ids) {
5520 if (cpu_online(*pos - 1)) {
5521 return (void *)*pos;
5522 }
5523 ++*pos;
5524 }
5525 return NULL;
5526}
5527
5528static void *
5529pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
5530{
5531 ++*pos;
5532 return pfm_proc_start(m, pos);
5533}
5534
5535static void
5536pfm_proc_stop(struct seq_file *m, void *v)
5537{
5538}
5539
5540static void
5541pfm_proc_show_header(struct seq_file *m)
5542{
5543 struct list_head * pos;
5544 pfm_buffer_fmt_t * entry;
5545 unsigned long flags;
5546
5547 seq_printf(m,
5548 "perfmon version : %u.%u\n"
5549 "model : %s\n"
5550 "fastctxsw : %s\n"
5551 "expert mode : %s\n"
5552 "ovfl_mask : 0x%lx\n"
5553 "PMU flags : 0x%x\n",
5554 PFM_VERSION_MAJ, PFM_VERSION_MIN,
5555 pmu_conf->pmu_name,
5556 pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
5557 pfm_sysctl.expert_mode > 0 ? "Yes": "No",
5558 pmu_conf->ovfl_val,
5559 pmu_conf->flags);
5560
5561 LOCK_PFS(flags);
5562
5563 seq_printf(m,
5564 "proc_sessions : %u\n"
5565 "sys_sessions : %u\n"
5566 "sys_use_dbregs : %u\n"
5567 "ptrace_use_dbregs : %u\n",
5568 pfm_sessions.pfs_task_sessions,
5569 pfm_sessions.pfs_sys_sessions,
5570 pfm_sessions.pfs_sys_use_dbregs,
5571 pfm_sessions.pfs_ptrace_use_dbregs);
5572
5573 UNLOCK_PFS(flags);
5574
5575 spin_lock(&pfm_buffer_fmt_lock);
5576
5577 list_for_each(pos, &pfm_buffer_fmt_list) {
5578 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
5579 seq_printf(m, "format : %16phD %s\n",
5580 entry->fmt_uuid, entry->fmt_name);
5581 }
5582 spin_unlock(&pfm_buffer_fmt_lock);
5583
5584}
5585
5586static int
5587pfm_proc_show(struct seq_file *m, void *v)
5588{
5589 unsigned long psr;
5590 unsigned int i;
5591 int cpu;
5592
5593 if (v == PFM_PROC_SHOW_HEADER) {
5594 pfm_proc_show_header(m);
5595 return 0;
5596 }
5597
5598 /* show info for CPU (v - 1) */
5599
5600 cpu = (long)v - 1;
5601 seq_printf(m,
5602 "CPU%-2d overflow intrs : %lu\n"
5603 "CPU%-2d overflow cycles : %lu\n"
5604 "CPU%-2d overflow min : %lu\n"
5605 "CPU%-2d overflow max : %lu\n"
5606 "CPU%-2d smpl handler calls : %lu\n"
5607 "CPU%-2d smpl handler cycles : %lu\n"
5608 "CPU%-2d spurious intrs : %lu\n"
5609 "CPU%-2d replay intrs : %lu\n"
5610 "CPU%-2d syst_wide : %d\n"
5611 "CPU%-2d dcr_pp : %d\n"
5612 "CPU%-2d exclude idle : %d\n"
5613 "CPU%-2d owner : %d\n"
5614 "CPU%-2d context : %p\n"
5615 "CPU%-2d activations : %lu\n",
5616 cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
5617 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
5618 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
5619 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
5620 cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
5621 cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
5622 cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
5623 cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
5624 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
5625 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
5626 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
5627 cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
5628 cpu, pfm_get_cpu_data(pmu_ctx, cpu),
5629 cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
5630
5631 if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
5632
5633 psr = pfm_get_psr();
5634
5635 ia64_srlz_d();
5636
5637 seq_printf(m,
5638 "CPU%-2d psr : 0x%lx\n"
5639 "CPU%-2d pmc0 : 0x%lx\n",
5640 cpu, psr,
5641 cpu, ia64_get_pmc(0));
5642
5643 for (i=0; PMC_IS_LAST(i) == 0; i++) {
5644 if (PMC_IS_COUNTING(i) == 0) continue;
5645 seq_printf(m,
5646 "CPU%-2d pmc%u : 0x%lx\n"
5647 "CPU%-2d pmd%u : 0x%lx\n",
5648 cpu, i, ia64_get_pmc(i),
5649 cpu, i, ia64_get_pmd(i));
5650 }
5651 }
5652 return 0;
5653}
5654
5655const struct seq_operations pfm_seq_ops = {
5656 .start = pfm_proc_start,
5657 .next = pfm_proc_next,
5658 .stop = pfm_proc_stop,
5659 .show = pfm_proc_show
5660};
5661
5662/*
5663 * we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
5664 * during pfm_enable() hence before pfm_start(). We cannot assume monitoring
5665 * is active or inactive based on mode. We must rely on the value in
5666 * local_cpu_data->pfm_syst_info
5667 */
5668void
5669pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
5670{
5671 struct pt_regs *regs;
5672 unsigned long dcr;
5673 unsigned long dcr_pp;
5674
5675 dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
5676
5677 /*
5678 * pid 0 is guaranteed to be the idle task. There is one such task with pid 0
5679 * on every CPU, so we can rely on the pid to identify the idle task.
5680 */
5681 if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
5682 regs = task_pt_regs(task);
5683 ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
5684 return;
5685 }
5686 /*
5687 * if monitoring has started
5688 */
5689 if (dcr_pp) {
5690 dcr = ia64_getreg(_IA64_REG_CR_DCR);
5691 /*
5692 * context switching in?
5693 */
5694 if (is_ctxswin) {
5695 /* mask monitoring for the idle task */
5696 ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
5697 pfm_clear_psr_pp();
5698 ia64_srlz_i();
5699 return;
5700 }
5701 /*
5702 * context switching out
5703 * restore monitoring for next task
5704 *
5705 * Due to inlining this odd if-then-else construction generates
5706 * better code.
5707 */
5708 ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
5709 pfm_set_psr_pp();
5710 ia64_srlz_i();
5711 }
5712}
5713
5714#ifdef CONFIG_SMP
5715
5716static void
5717pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
5718{
5719 struct task_struct *task = ctx->ctx_task;
5720
5721 ia64_psr(regs)->up = 0;
5722 ia64_psr(regs)->sp = 1;
5723
5724 if (GET_PMU_OWNER() == task) {
5725 DPRINT(("cleared ownership for [%d]\n",
5726 task_pid_nr(ctx->ctx_task)));
5727 SET_PMU_OWNER(NULL, NULL);
5728 }
5729
5730 /*
5731 * disconnect the task from the context and vice-versa
5732 */
5733 PFM_SET_WORK_PENDING(task, 0);
5734
5735 task->thread.pfm_context = NULL;
5736 task->thread.flags &= ~IA64_THREAD_PM_VALID;
5737
5738 DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
5739}
5740
5741
5742/*
5743 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
5744 */
5745void
5746pfm_save_regs(struct task_struct *task)
5747{
5748 pfm_context_t *ctx;
5749 unsigned long flags;
5750 u64 psr;
5751
5752
5753 ctx = PFM_GET_CTX(task);
5754 if (ctx == NULL) return;
5755
5756 /*
5757 * we always come here with interrupts ALREADY disabled by
5758 * the scheduler. So we simply need to protect against concurrent
5759 * access, not CPU concurrency.
5760 */
5761 flags = pfm_protect_ctx_ctxsw(ctx);
5762
5763 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5764 struct pt_regs *regs = task_pt_regs(task);
5765
5766 pfm_clear_psr_up();
5767
5768 pfm_force_cleanup(ctx, regs);
5769
5770 BUG_ON(ctx->ctx_smpl_hdr);
5771
5772 pfm_unprotect_ctx_ctxsw(ctx, flags);
5773
5774 pfm_context_free(ctx);
5775 return;
5776 }
5777
5778 /*
5779 * save current PSR: needed because we modify it
5780 */
5781 ia64_srlz_d();
5782 psr = pfm_get_psr();
5783
5784 BUG_ON(psr & (IA64_PSR_I));
5785
5786 /*
5787 * stop monitoring:
5788 * This is the last instruction which may generate an overflow
5789 *
5790 * We do not need to set psr.sp because, it is irrelevant in kernel.
5791 * It will be restored from ipsr when going back to user level
5792 */
5793 pfm_clear_psr_up();
5794
5795 /*
5796 * keep a copy of psr.up (for reload)
5797 */
5798 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5799
5800 /*
5801 * release ownership of this PMU.
5802 * PM interrupts are masked, so nothing
5803 * can happen.
5804 */
5805 SET_PMU_OWNER(NULL, NULL);
5806
5807 /*
5808 * we systematically save the PMD as we have no
5809 * guarantee we will be schedule at that same
5810 * CPU again.
5811 */
5812 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
5813
5814 /*
5815 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
5816 * we will need it on the restore path to check
5817 * for pending overflow.
5818 */
5819 ctx->th_pmcs[0] = ia64_get_pmc(0);
5820
5821 /*
5822 * unfreeze PMU if had pending overflows
5823 */
5824 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
5825
5826 /*
5827 * finally, allow context access.
5828 * interrupts will still be masked after this call.
5829 */
5830 pfm_unprotect_ctx_ctxsw(ctx, flags);
5831}
5832
5833#else /* !CONFIG_SMP */
5834void
5835pfm_save_regs(struct task_struct *task)
5836{
5837 pfm_context_t *ctx;
5838 u64 psr;
5839
5840 ctx = PFM_GET_CTX(task);
5841 if (ctx == NULL) return;
5842
5843 /*
5844 * save current PSR: needed because we modify it
5845 */
5846 psr = pfm_get_psr();
5847
5848 BUG_ON(psr & (IA64_PSR_I));
5849
5850 /*
5851 * stop monitoring:
5852 * This is the last instruction which may generate an overflow
5853 *
5854 * We do not need to set psr.sp because, it is irrelevant in kernel.
5855 * It will be restored from ipsr when going back to user level
5856 */
5857 pfm_clear_psr_up();
5858
5859 /*
5860 * keep a copy of psr.up (for reload)
5861 */
5862 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5863}
5864
5865static void
5866pfm_lazy_save_regs (struct task_struct *task)
5867{
5868 pfm_context_t *ctx;
5869 unsigned long flags;
5870
5871 { u64 psr = pfm_get_psr();
5872 BUG_ON(psr & IA64_PSR_UP);
5873 }
5874
5875 ctx = PFM_GET_CTX(task);
5876
5877 /*
5878 * we need to mask PMU overflow here to
5879 * make sure that we maintain pmc0 until
5880 * we save it. overflow interrupts are
5881 * treated as spurious if there is no
5882 * owner.
5883 *
5884 * XXX: I don't think this is necessary
5885 */
5886 PROTECT_CTX(ctx,flags);
5887
5888 /*
5889 * release ownership of this PMU.
5890 * must be done before we save the registers.
5891 *
5892 * after this call any PMU interrupt is treated
5893 * as spurious.
5894 */
5895 SET_PMU_OWNER(NULL, NULL);
5896
5897 /*
5898 * save all the pmds we use
5899 */
5900 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
5901
5902 /*
5903 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
5904 * it is needed to check for pended overflow
5905 * on the restore path
5906 */
5907 ctx->th_pmcs[0] = ia64_get_pmc(0);
5908
5909 /*
5910 * unfreeze PMU if had pending overflows
5911 */
5912 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
5913
5914 /*
5915 * now get can unmask PMU interrupts, they will
5916 * be treated as purely spurious and we will not
5917 * lose any information
5918 */
5919 UNPROTECT_CTX(ctx,flags);
5920}
5921#endif /* CONFIG_SMP */
5922
5923#ifdef CONFIG_SMP
5924/*
5925 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
5926 */
5927void
5928pfm_load_regs (struct task_struct *task)
5929{
5930 pfm_context_t *ctx;
5931 unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
5932 unsigned long flags;
5933 u64 psr, psr_up;
5934 int need_irq_resend;
5935
5936 ctx = PFM_GET_CTX(task);
5937 if (unlikely(ctx == NULL)) return;
5938
5939 BUG_ON(GET_PMU_OWNER());
5940
5941 /*
5942 * possible on unload
5943 */
5944 if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
5945
5946 /*
5947 * we always come here with interrupts ALREADY disabled by
5948 * the scheduler. So we simply need to protect against concurrent
5949 * access, not CPU concurrency.
5950 */
5951 flags = pfm_protect_ctx_ctxsw(ctx);
5952 psr = pfm_get_psr();
5953
5954 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
5955
5956 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
5957 BUG_ON(psr & IA64_PSR_I);
5958
5959 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
5960 struct pt_regs *regs = task_pt_regs(task);
5961
5962 BUG_ON(ctx->ctx_smpl_hdr);
5963
5964 pfm_force_cleanup(ctx, regs);
5965
5966 pfm_unprotect_ctx_ctxsw(ctx, flags);
5967
5968 /*
5969 * this one (kmalloc'ed) is fine with interrupts disabled
5970 */
5971 pfm_context_free(ctx);
5972
5973 return;
5974 }
5975
5976 /*
5977 * we restore ALL the debug registers to avoid picking up
5978 * stale state.
5979 */
5980 if (ctx->ctx_fl_using_dbreg) {
5981 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
5982 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
5983 }
5984 /*
5985 * retrieve saved psr.up
5986 */
5987 psr_up = ctx->ctx_saved_psr_up;
5988
5989 /*
5990 * if we were the last user of the PMU on that CPU,
5991 * then nothing to do except restore psr
5992 */
5993 if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
5994
5995 /*
5996 * retrieve partial reload masks (due to user modifications)
5997 */
5998 pmc_mask = ctx->ctx_reload_pmcs[0];
5999 pmd_mask = ctx->ctx_reload_pmds[0];
6000
6001 } else {
6002 /*
6003 * To avoid leaking information to the user level when psr.sp=0,
6004 * we must reload ALL implemented pmds (even the ones we don't use).
6005 * In the kernel we only allow PFM_READ_PMDS on registers which
6006 * we initialized or requested (sampling) so there is no risk there.
6007 */
6008 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6009
6010 /*
6011 * ALL accessible PMCs are systematically reloaded, unused registers
6012 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6013 * up stale configuration.
6014 *
6015 * PMC0 is never in the mask. It is always restored separately.
6016 */
6017 pmc_mask = ctx->ctx_all_pmcs[0];
6018 }
6019 /*
6020 * when context is MASKED, we will restore PMC with plm=0
6021 * and PMD with stale information, but that's ok, nothing
6022 * will be captured.
6023 *
6024 * XXX: optimize here
6025 */
6026 if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6027 if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6028
6029 /*
6030 * check for pending overflow at the time the state
6031 * was saved.
6032 */
6033 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6034 /*
6035 * reload pmc0 with the overflow information
6036 * On McKinley PMU, this will trigger a PMU interrupt
6037 */
6038 ia64_set_pmc(0, ctx->th_pmcs[0]);
6039 ia64_srlz_d();
6040 ctx->th_pmcs[0] = 0UL;
6041
6042 /*
6043 * will replay the PMU interrupt
6044 */
6045 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6046
6047 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6048 }
6049
6050 /*
6051 * we just did a reload, so we reset the partial reload fields
6052 */
6053 ctx->ctx_reload_pmcs[0] = 0UL;
6054 ctx->ctx_reload_pmds[0] = 0UL;
6055
6056 SET_LAST_CPU(ctx, smp_processor_id());
6057
6058 /*
6059 * dump activation value for this PMU
6060 */
6061 INC_ACTIVATION();
6062 /*
6063 * record current activation for this context
6064 */
6065 SET_ACTIVATION(ctx);
6066
6067 /*
6068 * establish new ownership.
6069 */
6070 SET_PMU_OWNER(task, ctx);
6071
6072 /*
6073 * restore the psr.up bit. measurement
6074 * is active again.
6075 * no PMU interrupt can happen at this point
6076 * because we still have interrupts disabled.
6077 */
6078 if (likely(psr_up)) pfm_set_psr_up();
6079
6080 /*
6081 * allow concurrent access to context
6082 */
6083 pfm_unprotect_ctx_ctxsw(ctx, flags);
6084}
6085#else /* !CONFIG_SMP */
6086/*
6087 * reload PMU state for UP kernels
6088 * in 2.5 we come here with interrupts disabled
6089 */
6090void
6091pfm_load_regs (struct task_struct *task)
6092{
6093 pfm_context_t *ctx;
6094 struct task_struct *owner;
6095 unsigned long pmd_mask, pmc_mask;
6096 u64 psr, psr_up;
6097 int need_irq_resend;
6098
6099 owner = GET_PMU_OWNER();
6100 ctx = PFM_GET_CTX(task);
6101 psr = pfm_get_psr();
6102
6103 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6104 BUG_ON(psr & IA64_PSR_I);
6105
6106 /*
6107 * we restore ALL the debug registers to avoid picking up
6108 * stale state.
6109 *
6110 * This must be done even when the task is still the owner
6111 * as the registers may have been modified via ptrace()
6112 * (not perfmon) by the previous task.
6113 */
6114 if (ctx->ctx_fl_using_dbreg) {
6115 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6116 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6117 }
6118
6119 /*
6120 * retrieved saved psr.up
6121 */
6122 psr_up = ctx->ctx_saved_psr_up;
6123 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6124
6125 /*
6126 * short path, our state is still there, just
6127 * need to restore psr and we go
6128 *
6129 * we do not touch either PMC nor PMD. the psr is not touched
6130 * by the overflow_handler. So we are safe w.r.t. to interrupt
6131 * concurrency even without interrupt masking.
6132 */
6133 if (likely(owner == task)) {
6134 if (likely(psr_up)) pfm_set_psr_up();
6135 return;
6136 }
6137
6138 /*
6139 * someone else is still using the PMU, first push it out and
6140 * then we'll be able to install our stuff !
6141 *
6142 * Upon return, there will be no owner for the current PMU
6143 */
6144 if (owner) pfm_lazy_save_regs(owner);
6145
6146 /*
6147 * To avoid leaking information to the user level when psr.sp=0,
6148 * we must reload ALL implemented pmds (even the ones we don't use).
6149 * In the kernel we only allow PFM_READ_PMDS on registers which
6150 * we initialized or requested (sampling) so there is no risk there.
6151 */
6152 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6153
6154 /*
6155 * ALL accessible PMCs are systematically reloaded, unused registers
6156 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6157 * up stale configuration.
6158 *
6159 * PMC0 is never in the mask. It is always restored separately
6160 */
6161 pmc_mask = ctx->ctx_all_pmcs[0];
6162
6163 pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6164 pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6165
6166 /*
6167 * check for pending overflow at the time the state
6168 * was saved.
6169 */
6170 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6171 /*
6172 * reload pmc0 with the overflow information
6173 * On McKinley PMU, this will trigger a PMU interrupt
6174 */
6175 ia64_set_pmc(0, ctx->th_pmcs[0]);
6176 ia64_srlz_d();
6177
6178 ctx->th_pmcs[0] = 0UL;
6179
6180 /*
6181 * will replay the PMU interrupt
6182 */
6183 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6184
6185 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6186 }
6187
6188 /*
6189 * establish new ownership.
6190 */
6191 SET_PMU_OWNER(task, ctx);
6192
6193 /*
6194 * restore the psr.up bit. measurement
6195 * is active again.
6196 * no PMU interrupt can happen at this point
6197 * because we still have interrupts disabled.
6198 */
6199 if (likely(psr_up)) pfm_set_psr_up();
6200}
6201#endif /* CONFIG_SMP */
6202
6203/*
6204 * this function assumes monitoring is stopped
6205 */
6206static void
6207pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
6208{
6209 u64 pmc0;
6210 unsigned long mask2, val, pmd_val, ovfl_val;
6211 int i, can_access_pmu = 0;
6212 int is_self;
6213
6214 /*
6215 * is the caller the task being monitored (or which initiated the
6216 * session for system wide measurements)
6217 */
6218 is_self = ctx->ctx_task == task ? 1 : 0;
6219
6220 /*
6221 * can access PMU is task is the owner of the PMU state on the current CPU
6222 * or if we are running on the CPU bound to the context in system-wide mode
6223 * (that is not necessarily the task the context is attached to in this mode).
6224 * In system-wide we always have can_access_pmu true because a task running on an
6225 * invalid processor is flagged earlier in the call stack (see pfm_stop).
6226 */
6227 can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
6228 if (can_access_pmu) {
6229 /*
6230 * Mark the PMU as not owned
6231 * This will cause the interrupt handler to do nothing in case an overflow
6232 * interrupt was in-flight
6233 * This also guarantees that pmc0 will contain the final state
6234 * It virtually gives us full control on overflow processing from that point
6235 * on.
6236 */
6237 SET_PMU_OWNER(NULL, NULL);
6238 DPRINT(("releasing ownership\n"));
6239
6240 /*
6241 * read current overflow status:
6242 *
6243 * we are guaranteed to read the final stable state
6244 */
6245 ia64_srlz_d();
6246 pmc0 = ia64_get_pmc(0); /* slow */
6247
6248 /*
6249 * reset freeze bit, overflow status information destroyed
6250 */
6251 pfm_unfreeze_pmu();
6252 } else {
6253 pmc0 = ctx->th_pmcs[0];
6254 /*
6255 * clear whatever overflow status bits there were
6256 */
6257 ctx->th_pmcs[0] = 0;
6258 }
6259 ovfl_val = pmu_conf->ovfl_val;
6260 /*
6261 * we save all the used pmds
6262 * we take care of overflows for counting PMDs
6263 *
6264 * XXX: sampling situation is not taken into account here
6265 */
6266 mask2 = ctx->ctx_used_pmds[0];
6267
6268 DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
6269
6270 for (i = 0; mask2; i++, mask2>>=1) {
6271
6272 /* skip non used pmds */
6273 if ((mask2 & 0x1) == 0) continue;
6274
6275 /*
6276 * can access PMU always true in system wide mode
6277 */
6278 val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
6279
6280 if (PMD_IS_COUNTING(i)) {
6281 DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
6282 task_pid_nr(task),
6283 i,
6284 ctx->ctx_pmds[i].val,
6285 val & ovfl_val));
6286
6287 /*
6288 * we rebuild the full 64 bit value of the counter
6289 */
6290 val = ctx->ctx_pmds[i].val + (val & ovfl_val);
6291
6292 /*
6293 * now everything is in ctx_pmds[] and we need
6294 * to clear the saved context from save_regs() such that
6295 * pfm_read_pmds() gets the correct value
6296 */
6297 pmd_val = 0UL;
6298
6299 /*
6300 * take care of overflow inline
6301 */
6302 if (pmc0 & (1UL << i)) {
6303 val += 1 + ovfl_val;
6304 DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
6305 }
6306 }
6307
6308 DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
6309
6310 if (is_self) ctx->th_pmds[i] = pmd_val;
6311
6312 ctx->ctx_pmds[i].val = val;
6313 }
6314}
6315
6316static struct irqaction perfmon_irqaction = {
6317 .handler = pfm_interrupt_handler,
6318 .name = "perfmon"
6319};
6320
6321static void
6322pfm_alt_save_pmu_state(void *data)
6323{
6324 struct pt_regs *regs;
6325
6326 regs = task_pt_regs(current);
6327
6328 DPRINT(("called\n"));
6329
6330 /*
6331 * should not be necessary but
6332 * let's take not risk
6333 */
6334 pfm_clear_psr_up();
6335 pfm_clear_psr_pp();
6336 ia64_psr(regs)->pp = 0;
6337
6338 /*
6339 * This call is required
6340 * May cause a spurious interrupt on some processors
6341 */
6342 pfm_freeze_pmu();
6343
6344 ia64_srlz_d();
6345}
6346
6347void
6348pfm_alt_restore_pmu_state(void *data)
6349{
6350 struct pt_regs *regs;
6351
6352 regs = task_pt_regs(current);
6353
6354 DPRINT(("called\n"));
6355
6356 /*
6357 * put PMU back in state expected
6358 * by perfmon
6359 */
6360 pfm_clear_psr_up();
6361 pfm_clear_psr_pp();
6362 ia64_psr(regs)->pp = 0;
6363
6364 /*
6365 * perfmon runs with PMU unfrozen at all times
6366 */
6367 pfm_unfreeze_pmu();
6368
6369 ia64_srlz_d();
6370}
6371
6372int
6373pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6374{
6375 int ret, i;
6376 int reserve_cpu;
6377
6378 /* some sanity checks */
6379 if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
6380
6381 /* do the easy test first */
6382 if (pfm_alt_intr_handler) return -EBUSY;
6383
6384 /* one at a time in the install or remove, just fail the others */
6385 if (!spin_trylock(&pfm_alt_install_check)) {
6386 return -EBUSY;
6387 }
6388
6389 /* reserve our session */
6390 for_each_online_cpu(reserve_cpu) {
6391 ret = pfm_reserve_session(NULL, 1, reserve_cpu);
6392 if (ret) goto cleanup_reserve;
6393 }
6394
6395 /* save the current system wide pmu states */
6396 on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
6397
6398 /* officially change to the alternate interrupt handler */
6399 pfm_alt_intr_handler = hdl;
6400
6401 spin_unlock(&pfm_alt_install_check);
6402
6403 return 0;
6404
6405cleanup_reserve:
6406 for_each_online_cpu(i) {
6407 /* don't unreserve more than we reserved */
6408 if (i >= reserve_cpu) break;
6409
6410 pfm_unreserve_session(NULL, 1, i);
6411 }
6412
6413 spin_unlock(&pfm_alt_install_check);
6414
6415 return ret;
6416}
6417EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
6418
6419int
6420pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6421{
6422 int i;
6423
6424 if (hdl == NULL) return -EINVAL;
6425
6426 /* cannot remove someone else's handler! */
6427 if (pfm_alt_intr_handler != hdl) return -EINVAL;
6428
6429 /* one at a time in the install or remove, just fail the others */
6430 if (!spin_trylock(&pfm_alt_install_check)) {
6431 return -EBUSY;
6432 }
6433
6434 pfm_alt_intr_handler = NULL;
6435
6436 on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
6437
6438 for_each_online_cpu(i) {
6439 pfm_unreserve_session(NULL, 1, i);
6440 }
6441
6442 spin_unlock(&pfm_alt_install_check);
6443
6444 return 0;
6445}
6446EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
6447
6448/*
6449 * perfmon initialization routine, called from the initcall() table
6450 */
6451static int init_pfm_fs(void);
6452
6453static int __init
6454pfm_probe_pmu(void)
6455{
6456 pmu_config_t **p;
6457 int family;
6458
6459 family = local_cpu_data->family;
6460 p = pmu_confs;
6461
6462 while(*p) {
6463 if ((*p)->probe) {
6464 if ((*p)->probe() == 0) goto found;
6465 } else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
6466 goto found;
6467 }
6468 p++;
6469 }
6470 return -1;
6471found:
6472 pmu_conf = *p;
6473 return 0;
6474}
6475
6476int __init
6477pfm_init(void)
6478{
6479 unsigned int n, n_counters, i;
6480
6481 printk("perfmon: version %u.%u IRQ %u\n",
6482 PFM_VERSION_MAJ,
6483 PFM_VERSION_MIN,
6484 IA64_PERFMON_VECTOR);
6485
6486 if (pfm_probe_pmu()) {
6487 printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
6488 local_cpu_data->family);
6489 return -ENODEV;
6490 }
6491
6492 /*
6493 * compute the number of implemented PMD/PMC from the
6494 * description tables
6495 */
6496 n = 0;
6497 for (i=0; PMC_IS_LAST(i) == 0; i++) {
6498 if (PMC_IS_IMPL(i) == 0) continue;
6499 pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
6500 n++;
6501 }
6502 pmu_conf->num_pmcs = n;
6503
6504 n = 0; n_counters = 0;
6505 for (i=0; PMD_IS_LAST(i) == 0; i++) {
6506 if (PMD_IS_IMPL(i) == 0) continue;
6507 pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
6508 n++;
6509 if (PMD_IS_COUNTING(i)) n_counters++;
6510 }
6511 pmu_conf->num_pmds = n;
6512 pmu_conf->num_counters = n_counters;
6513
6514 /*
6515 * sanity checks on the number of debug registers
6516 */
6517 if (pmu_conf->use_rr_dbregs) {
6518 if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
6519 printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
6520 pmu_conf = NULL;
6521 return -1;
6522 }
6523 if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
6524 printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
6525 pmu_conf = NULL;
6526 return -1;
6527 }
6528 }
6529
6530 printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
6531 pmu_conf->pmu_name,
6532 pmu_conf->num_pmcs,
6533 pmu_conf->num_pmds,
6534 pmu_conf->num_counters,
6535 ffz(pmu_conf->ovfl_val));
6536
6537 /* sanity check */
6538 if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
6539 printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
6540 pmu_conf = NULL;
6541 return -1;
6542 }
6543
6544 /*
6545 * create /proc/perfmon (mostly for debugging purposes)
6546 */
6547 perfmon_dir = proc_create_seq("perfmon", S_IRUGO, NULL, &pfm_seq_ops);
6548 if (perfmon_dir == NULL) {
6549 printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
6550 pmu_conf = NULL;
6551 return -1;
6552 }
6553
6554 /*
6555 * create /proc/sys/kernel/perfmon (for debugging purposes)
6556 */
6557 pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
6558
6559 /*
6560 * initialize all our spinlocks
6561 */
6562 spin_lock_init(&pfm_sessions.pfs_lock);
6563 spin_lock_init(&pfm_buffer_fmt_lock);
6564
6565 init_pfm_fs();
6566
6567 for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
6568
6569 return 0;
6570}
6571
6572__initcall(pfm_init);
6573
6574/*
6575 * this function is called before pfm_init()
6576 */
6577void
6578pfm_init_percpu (void)
6579{
6580 static int first_time=1;
6581 /*
6582 * make sure no measurement is active
6583 * (may inherit programmed PMCs from EFI).
6584 */
6585 pfm_clear_psr_pp();
6586 pfm_clear_psr_up();
6587
6588 /*
6589 * we run with the PMU not frozen at all times
6590 */
6591 pfm_unfreeze_pmu();
6592
6593 if (first_time) {
6594 register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
6595 first_time=0;
6596 }
6597
6598 ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
6599 ia64_srlz_d();
6600}
6601
6602/*
6603 * used for debug purposes only
6604 */
6605void
6606dump_pmu_state(const char *from)
6607{
6608 struct task_struct *task;
6609 struct pt_regs *regs;
6610 pfm_context_t *ctx;
6611 unsigned long psr, dcr, info, flags;
6612 int i, this_cpu;
6613
6614 local_irq_save(flags);
6615
6616 this_cpu = smp_processor_id();
6617 regs = task_pt_regs(current);
6618 info = PFM_CPUINFO_GET();
6619 dcr = ia64_getreg(_IA64_REG_CR_DCR);
6620
6621 if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
6622 local_irq_restore(flags);
6623 return;
6624 }
6625
6626 printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
6627 this_cpu,
6628 from,
6629 task_pid_nr(current),
6630 regs->cr_iip,
6631 current->comm);
6632
6633 task = GET_PMU_OWNER();
6634 ctx = GET_PMU_CTX();
6635
6636 printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
6637
6638 psr = pfm_get_psr();
6639
6640 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",
6641 this_cpu,
6642 ia64_get_pmc(0),
6643 psr & IA64_PSR_PP ? 1 : 0,
6644 psr & IA64_PSR_UP ? 1 : 0,
6645 dcr & IA64_DCR_PP ? 1 : 0,
6646 info,
6647 ia64_psr(regs)->up,
6648 ia64_psr(regs)->pp);
6649
6650 ia64_psr(regs)->up = 0;
6651 ia64_psr(regs)->pp = 0;
6652
6653 for (i=1; PMC_IS_LAST(i) == 0; i++) {
6654 if (PMC_IS_IMPL(i) == 0) continue;
6655 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]);
6656 }
6657
6658 for (i=1; PMD_IS_LAST(i) == 0; i++) {
6659 if (PMD_IS_IMPL(i) == 0) continue;
6660 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]);
6661 }
6662
6663 if (ctx) {
6664 printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
6665 this_cpu,
6666 ctx->ctx_state,
6667 ctx->ctx_smpl_vaddr,
6668 ctx->ctx_smpl_hdr,
6669 ctx->ctx_msgq_head,
6670 ctx->ctx_msgq_tail,
6671 ctx->ctx_saved_psr_up);
6672 }
6673 local_irq_restore(flags);
6674}
6675
6676/*
6677 * called from process.c:copy_thread(). task is new child.
6678 */
6679void
6680pfm_inherit(struct task_struct *task, struct pt_regs *regs)
6681{
6682 struct thread_struct *thread;
6683
6684 DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
6685
6686 thread = &task->thread;
6687
6688 /*
6689 * cut links inherited from parent (current)
6690 */
6691 thread->pfm_context = NULL;
6692
6693 PFM_SET_WORK_PENDING(task, 0);
6694
6695 /*
6696 * the psr bits are already set properly in copy_threads()
6697 */
6698}
6699#else /* !CONFIG_PERFMON */
6700asmlinkage long
6701sys_perfmonctl (int fd, int cmd, void *arg, int count)
6702{
6703 return -ENOSYS;
6704}
6705#endif /* CONFIG_PERFMON */
1/*
2 * This file implements the perfmon-2 subsystem which is used
3 * to program the IA-64 Performance Monitoring Unit (PMU).
4 *
5 * The initial version of perfmon.c was written by
6 * Ganesh Venkitachalam, IBM Corp.
7 *
8 * Then it was modified for perfmon-1.x by Stephane Eranian and
9 * David Mosberger, Hewlett Packard Co.
10 *
11 * Version Perfmon-2.x is a rewrite of perfmon-1.x
12 * by Stephane Eranian, Hewlett Packard Co.
13 *
14 * Copyright (C) 1999-2005 Hewlett Packard Co
15 * Stephane Eranian <eranian@hpl.hp.com>
16 * David Mosberger-Tang <davidm@hpl.hp.com>
17 *
18 * More information about perfmon available at:
19 * http://www.hpl.hp.com/research/linux/perfmon
20 */
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/interrupt.h>
26#include <linux/proc_fs.h>
27#include <linux/seq_file.h>
28#include <linux/init.h>
29#include <linux/vmalloc.h>
30#include <linux/mm.h>
31#include <linux/sysctl.h>
32#include <linux/list.h>
33#include <linux/file.h>
34#include <linux/poll.h>
35#include <linux/vfs.h>
36#include <linux/smp.h>
37#include <linux/pagemap.h>
38#include <linux/mount.h>
39#include <linux/bitops.h>
40#include <linux/capability.h>
41#include <linux/rcupdate.h>
42#include <linux/completion.h>
43#include <linux/tracehook.h>
44#include <linux/slab.h>
45
46#include <asm/errno.h>
47#include <asm/intrinsics.h>
48#include <asm/page.h>
49#include <asm/perfmon.h>
50#include <asm/processor.h>
51#include <asm/signal.h>
52#include <asm/system.h>
53#include <asm/uaccess.h>
54#include <asm/delay.h>
55
56#ifdef CONFIG_PERFMON
57/*
58 * perfmon context state
59 */
60#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
61#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
62#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
63#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
64
65#define PFM_INVALID_ACTIVATION (~0UL)
66
67#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
68#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
69
70/*
71 * depth of message queue
72 */
73#define PFM_MAX_MSGS 32
74#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
75
76/*
77 * type of a PMU register (bitmask).
78 * bitmask structure:
79 * bit0 : register implemented
80 * bit1 : end marker
81 * bit2-3 : reserved
82 * bit4 : pmc has pmc.pm
83 * bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
84 * bit6-7 : register type
85 * bit8-31: reserved
86 */
87#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
88#define PFM_REG_IMPL 0x1 /* register implemented */
89#define PFM_REG_END 0x2 /* end marker */
90#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
91#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
92#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
93#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
94#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
95
96#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
97#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
98
99#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
100
101/* i assumed unsigned */
102#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
103#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
104
105/* XXX: these assume that register i is implemented */
106#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
107#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
108#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
109#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
110
111#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
112#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
113#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
114#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
115
116#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
117#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
118
119#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
120#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
121#define PFM_CTX_TASK(h) (h)->ctx_task
122
123#define PMU_PMC_OI 5 /* position of pmc.oi bit */
124
125/* XXX: does not support more than 64 PMDs */
126#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
127#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
128
129#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
130
131#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
132#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
133#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
134#define PFM_CODE_RR 0 /* requesting code range restriction */
135#define PFM_DATA_RR 1 /* requestion data range restriction */
136
137#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
138#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
139#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
140
141#define RDEP(x) (1UL<<(x))
142
143/*
144 * context protection macros
145 * in SMP:
146 * - we need to protect against CPU concurrency (spin_lock)
147 * - we need to protect against PMU overflow interrupts (local_irq_disable)
148 * in UP:
149 * - we need to protect against PMU overflow interrupts (local_irq_disable)
150 *
151 * spin_lock_irqsave()/spin_unlock_irqrestore():
152 * in SMP: local_irq_disable + spin_lock
153 * in UP : local_irq_disable
154 *
155 * spin_lock()/spin_lock():
156 * in UP : removed automatically
157 * in SMP: protect against context accesses from other CPU. interrupts
158 * are not masked. This is useful for the PMU interrupt handler
159 * because we know we will not get PMU concurrency in that code.
160 */
161#define PROTECT_CTX(c, f) \
162 do { \
163 DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
164 spin_lock_irqsave(&(c)->ctx_lock, f); \
165 DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
166 } while(0)
167
168#define UNPROTECT_CTX(c, f) \
169 do { \
170 DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
171 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
172 } while(0)
173
174#define PROTECT_CTX_NOPRINT(c, f) \
175 do { \
176 spin_lock_irqsave(&(c)->ctx_lock, f); \
177 } while(0)
178
179
180#define UNPROTECT_CTX_NOPRINT(c, f) \
181 do { \
182 spin_unlock_irqrestore(&(c)->ctx_lock, f); \
183 } while(0)
184
185
186#define PROTECT_CTX_NOIRQ(c) \
187 do { \
188 spin_lock(&(c)->ctx_lock); \
189 } while(0)
190
191#define UNPROTECT_CTX_NOIRQ(c) \
192 do { \
193 spin_unlock(&(c)->ctx_lock); \
194 } while(0)
195
196
197#ifdef CONFIG_SMP
198
199#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
200#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
201#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
202
203#else /* !CONFIG_SMP */
204#define SET_ACTIVATION(t) do {} while(0)
205#define GET_ACTIVATION(t) do {} while(0)
206#define INC_ACTIVATION(t) do {} while(0)
207#endif /* CONFIG_SMP */
208
209#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
210#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
211#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
212
213#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
214#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
215
216#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
217
218/*
219 * cmp0 must be the value of pmc0
220 */
221#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
222
223#define PFMFS_MAGIC 0xa0b4d889
224
225/*
226 * debugging
227 */
228#define PFM_DEBUGGING 1
229#ifdef PFM_DEBUGGING
230#define DPRINT(a) \
231 do { \
232 if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
233 } while (0)
234
235#define DPRINT_ovfl(a) \
236 do { \
237 if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
238 } while (0)
239#endif
240
241/*
242 * 64-bit software counter structure
243 *
244 * the next_reset_type is applied to the next call to pfm_reset_regs()
245 */
246typedef struct {
247 unsigned long val; /* virtual 64bit counter value */
248 unsigned long lval; /* last reset value */
249 unsigned long long_reset; /* reset value on sampling overflow */
250 unsigned long short_reset; /* reset value on overflow */
251 unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
252 unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
253 unsigned long seed; /* seed for random-number generator */
254 unsigned long mask; /* mask for random-number generator */
255 unsigned int flags; /* notify/do not notify */
256 unsigned long eventid; /* overflow event identifier */
257} pfm_counter_t;
258
259/*
260 * context flags
261 */
262typedef struct {
263 unsigned int block:1; /* when 1, task will blocked on user notifications */
264 unsigned int system:1; /* do system wide monitoring */
265 unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
266 unsigned int is_sampling:1; /* true if using a custom format */
267 unsigned int excl_idle:1; /* exclude idle task in system wide session */
268 unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
269 unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
270 unsigned int no_msg:1; /* no message sent on overflow */
271 unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
272 unsigned int reserved:22;
273} pfm_context_flags_t;
274
275#define PFM_TRAP_REASON_NONE 0x0 /* default value */
276#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
277#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
278
279
280/*
281 * perfmon context: encapsulates all the state of a monitoring session
282 */
283
284typedef struct pfm_context {
285 spinlock_t ctx_lock; /* context protection */
286
287 pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
288 unsigned int ctx_state; /* state: active/inactive (no bitfield) */
289
290 struct task_struct *ctx_task; /* task to which context is attached */
291
292 unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
293
294 struct completion ctx_restart_done; /* use for blocking notification mode */
295
296 unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
297 unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
298 unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
299
300 unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
301 unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
302 unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
303
304 unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
305
306 unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
307 unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
308 unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
309 unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
310
311 pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
312
313 unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
314 unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
315
316 unsigned long ctx_saved_psr_up; /* only contains psr.up value */
317
318 unsigned long ctx_last_activation; /* context last activation number for last_cpu */
319 unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
320 unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
321
322 int ctx_fd; /* file descriptor used my this context */
323 pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
324
325 pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
326 void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
327 unsigned long ctx_smpl_size; /* size of sampling buffer */
328 void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
329
330 wait_queue_head_t ctx_msgq_wait;
331 pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
332 int ctx_msgq_head;
333 int ctx_msgq_tail;
334 struct fasync_struct *ctx_async_queue;
335
336 wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
337} pfm_context_t;
338
339/*
340 * magic number used to verify that structure is really
341 * a perfmon context
342 */
343#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
344
345#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
346
347#ifdef CONFIG_SMP
348#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
349#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
350#else
351#define SET_LAST_CPU(ctx, v) do {} while(0)
352#define GET_LAST_CPU(ctx) do {} while(0)
353#endif
354
355
356#define ctx_fl_block ctx_flags.block
357#define ctx_fl_system ctx_flags.system
358#define ctx_fl_using_dbreg ctx_flags.using_dbreg
359#define ctx_fl_is_sampling ctx_flags.is_sampling
360#define ctx_fl_excl_idle ctx_flags.excl_idle
361#define ctx_fl_going_zombie ctx_flags.going_zombie
362#define ctx_fl_trap_reason ctx_flags.trap_reason
363#define ctx_fl_no_msg ctx_flags.no_msg
364#define ctx_fl_can_restart ctx_flags.can_restart
365
366#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
367#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
368
369/*
370 * global information about all sessions
371 * mostly used to synchronize between system wide and per-process
372 */
373typedef struct {
374 spinlock_t pfs_lock; /* lock the structure */
375
376 unsigned int pfs_task_sessions; /* number of per task sessions */
377 unsigned int pfs_sys_sessions; /* number of per system wide sessions */
378 unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
379 unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
380 struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
381} pfm_session_t;
382
383/*
384 * information about a PMC or PMD.
385 * dep_pmd[]: a bitmask of dependent PMD registers
386 * dep_pmc[]: a bitmask of dependent PMC registers
387 */
388typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
389typedef struct {
390 unsigned int type;
391 int pm_pos;
392 unsigned long default_value; /* power-on default value */
393 unsigned long reserved_mask; /* bitmask of reserved bits */
394 pfm_reg_check_t read_check;
395 pfm_reg_check_t write_check;
396 unsigned long dep_pmd[4];
397 unsigned long dep_pmc[4];
398} pfm_reg_desc_t;
399
400/* assume cnum is a valid monitor */
401#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
402
403/*
404 * This structure is initialized at boot time and contains
405 * a description of the PMU main characteristics.
406 *
407 * If the probe function is defined, detection is based
408 * on its return value:
409 * - 0 means recognized PMU
410 * - anything else means not supported
411 * When the probe function is not defined, then the pmu_family field
412 * is used and it must match the host CPU family such that:
413 * - cpu->family & config->pmu_family != 0
414 */
415typedef struct {
416 unsigned long ovfl_val; /* overflow value for counters */
417
418 pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
419 pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
420
421 unsigned int num_pmcs; /* number of PMCS: computed at init time */
422 unsigned int num_pmds; /* number of PMDS: computed at init time */
423 unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
424 unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
425
426 char *pmu_name; /* PMU family name */
427 unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
428 unsigned int flags; /* pmu specific flags */
429 unsigned int num_ibrs; /* number of IBRS: computed at init time */
430 unsigned int num_dbrs; /* number of DBRS: computed at init time */
431 unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
432 int (*probe)(void); /* customized probe routine */
433 unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
434} pmu_config_t;
435/*
436 * PMU specific flags
437 */
438#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
439
440/*
441 * debug register related type definitions
442 */
443typedef struct {
444 unsigned long ibr_mask:56;
445 unsigned long ibr_plm:4;
446 unsigned long ibr_ig:3;
447 unsigned long ibr_x:1;
448} ibr_mask_reg_t;
449
450typedef struct {
451 unsigned long dbr_mask:56;
452 unsigned long dbr_plm:4;
453 unsigned long dbr_ig:2;
454 unsigned long dbr_w:1;
455 unsigned long dbr_r:1;
456} dbr_mask_reg_t;
457
458typedef union {
459 unsigned long val;
460 ibr_mask_reg_t ibr;
461 dbr_mask_reg_t dbr;
462} dbreg_t;
463
464
465/*
466 * perfmon command descriptions
467 */
468typedef struct {
469 int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
470 char *cmd_name;
471 int cmd_flags;
472 unsigned int cmd_narg;
473 size_t cmd_argsize;
474 int (*cmd_getsize)(void *arg, size_t *sz);
475} pfm_cmd_desc_t;
476
477#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
478#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
479#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
480#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
481
482
483#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
484#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
485#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
486#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
487#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
488
489#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
490
491typedef struct {
492 unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
493 unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
494 unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
495 unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
496 unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
497 unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
498 unsigned long pfm_smpl_handler_calls;
499 unsigned long pfm_smpl_handler_cycles;
500 char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
501} pfm_stats_t;
502
503/*
504 * perfmon internal variables
505 */
506static pfm_stats_t pfm_stats[NR_CPUS];
507static pfm_session_t pfm_sessions; /* global sessions information */
508
509static DEFINE_SPINLOCK(pfm_alt_install_check);
510static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
511
512static struct proc_dir_entry *perfmon_dir;
513static pfm_uuid_t pfm_null_uuid = {0,};
514
515static spinlock_t pfm_buffer_fmt_lock;
516static LIST_HEAD(pfm_buffer_fmt_list);
517
518static pmu_config_t *pmu_conf;
519
520/* sysctl() controls */
521pfm_sysctl_t pfm_sysctl;
522EXPORT_SYMBOL(pfm_sysctl);
523
524static ctl_table pfm_ctl_table[]={
525 {
526 .procname = "debug",
527 .data = &pfm_sysctl.debug,
528 .maxlen = sizeof(int),
529 .mode = 0666,
530 .proc_handler = proc_dointvec,
531 },
532 {
533 .procname = "debug_ovfl",
534 .data = &pfm_sysctl.debug_ovfl,
535 .maxlen = sizeof(int),
536 .mode = 0666,
537 .proc_handler = proc_dointvec,
538 },
539 {
540 .procname = "fastctxsw",
541 .data = &pfm_sysctl.fastctxsw,
542 .maxlen = sizeof(int),
543 .mode = 0600,
544 .proc_handler = proc_dointvec,
545 },
546 {
547 .procname = "expert_mode",
548 .data = &pfm_sysctl.expert_mode,
549 .maxlen = sizeof(int),
550 .mode = 0600,
551 .proc_handler = proc_dointvec,
552 },
553 {}
554};
555static ctl_table pfm_sysctl_dir[] = {
556 {
557 .procname = "perfmon",
558 .mode = 0555,
559 .child = pfm_ctl_table,
560 },
561 {}
562};
563static ctl_table pfm_sysctl_root[] = {
564 {
565 .procname = "kernel",
566 .mode = 0555,
567 .child = pfm_sysctl_dir,
568 },
569 {}
570};
571static struct ctl_table_header *pfm_sysctl_header;
572
573static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
574
575#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
576#define pfm_get_cpu_data(a,b) per_cpu(a, b)
577
578static inline void
579pfm_put_task(struct task_struct *task)
580{
581 if (task != current) put_task_struct(task);
582}
583
584static inline void
585pfm_reserve_page(unsigned long a)
586{
587 SetPageReserved(vmalloc_to_page((void *)a));
588}
589static inline void
590pfm_unreserve_page(unsigned long a)
591{
592 ClearPageReserved(vmalloc_to_page((void*)a));
593}
594
595static inline unsigned long
596pfm_protect_ctx_ctxsw(pfm_context_t *x)
597{
598 spin_lock(&(x)->ctx_lock);
599 return 0UL;
600}
601
602static inline void
603pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
604{
605 spin_unlock(&(x)->ctx_lock);
606}
607
608static inline unsigned int
609pfm_do_munmap(struct mm_struct *mm, unsigned long addr, size_t len, int acct)
610{
611 return do_munmap(mm, addr, len);
612}
613
614static inline unsigned long
615pfm_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, unsigned long exec)
616{
617 return get_unmapped_area(file, addr, len, pgoff, flags);
618}
619
620/* forward declaration */
621static const struct dentry_operations pfmfs_dentry_operations;
622
623static struct dentry *
624pfmfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data)
625{
626 return mount_pseudo(fs_type, "pfm:", NULL, &pfmfs_dentry_operations,
627 PFMFS_MAGIC);
628}
629
630static struct file_system_type pfm_fs_type = {
631 .name = "pfmfs",
632 .mount = pfmfs_mount,
633 .kill_sb = kill_anon_super,
634};
635
636DEFINE_PER_CPU(unsigned long, pfm_syst_info);
637DEFINE_PER_CPU(struct task_struct *, pmu_owner);
638DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
639DEFINE_PER_CPU(unsigned long, pmu_activation_number);
640EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
641
642
643/* forward declaration */
644static const struct file_operations pfm_file_ops;
645
646/*
647 * forward declarations
648 */
649#ifndef CONFIG_SMP
650static void pfm_lazy_save_regs (struct task_struct *ta);
651#endif
652
653void dump_pmu_state(const char *);
654static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
655
656#include "perfmon_itanium.h"
657#include "perfmon_mckinley.h"
658#include "perfmon_montecito.h"
659#include "perfmon_generic.h"
660
661static pmu_config_t *pmu_confs[]={
662 &pmu_conf_mont,
663 &pmu_conf_mck,
664 &pmu_conf_ita,
665 &pmu_conf_gen, /* must be last */
666 NULL
667};
668
669
670static int pfm_end_notify_user(pfm_context_t *ctx);
671
672static inline void
673pfm_clear_psr_pp(void)
674{
675 ia64_rsm(IA64_PSR_PP);
676 ia64_srlz_i();
677}
678
679static inline void
680pfm_set_psr_pp(void)
681{
682 ia64_ssm(IA64_PSR_PP);
683 ia64_srlz_i();
684}
685
686static inline void
687pfm_clear_psr_up(void)
688{
689 ia64_rsm(IA64_PSR_UP);
690 ia64_srlz_i();
691}
692
693static inline void
694pfm_set_psr_up(void)
695{
696 ia64_ssm(IA64_PSR_UP);
697 ia64_srlz_i();
698}
699
700static inline unsigned long
701pfm_get_psr(void)
702{
703 unsigned long tmp;
704 tmp = ia64_getreg(_IA64_REG_PSR);
705 ia64_srlz_i();
706 return tmp;
707}
708
709static inline void
710pfm_set_psr_l(unsigned long val)
711{
712 ia64_setreg(_IA64_REG_PSR_L, val);
713 ia64_srlz_i();
714}
715
716static inline void
717pfm_freeze_pmu(void)
718{
719 ia64_set_pmc(0,1UL);
720 ia64_srlz_d();
721}
722
723static inline void
724pfm_unfreeze_pmu(void)
725{
726 ia64_set_pmc(0,0UL);
727 ia64_srlz_d();
728}
729
730static inline void
731pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
732{
733 int i;
734
735 for (i=0; i < nibrs; i++) {
736 ia64_set_ibr(i, ibrs[i]);
737 ia64_dv_serialize_instruction();
738 }
739 ia64_srlz_i();
740}
741
742static inline void
743pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
744{
745 int i;
746
747 for (i=0; i < ndbrs; i++) {
748 ia64_set_dbr(i, dbrs[i]);
749 ia64_dv_serialize_data();
750 }
751 ia64_srlz_d();
752}
753
754/*
755 * PMD[i] must be a counter. no check is made
756 */
757static inline unsigned long
758pfm_read_soft_counter(pfm_context_t *ctx, int i)
759{
760 return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
761}
762
763/*
764 * PMD[i] must be a counter. no check is made
765 */
766static inline void
767pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
768{
769 unsigned long ovfl_val = pmu_conf->ovfl_val;
770
771 ctx->ctx_pmds[i].val = val & ~ovfl_val;
772 /*
773 * writing to unimplemented part is ignore, so we do not need to
774 * mask off top part
775 */
776 ia64_set_pmd(i, val & ovfl_val);
777}
778
779static pfm_msg_t *
780pfm_get_new_msg(pfm_context_t *ctx)
781{
782 int idx, next;
783
784 next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
785
786 DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
787 if (next == ctx->ctx_msgq_head) return NULL;
788
789 idx = ctx->ctx_msgq_tail;
790 ctx->ctx_msgq_tail = next;
791
792 DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
793
794 return ctx->ctx_msgq+idx;
795}
796
797static pfm_msg_t *
798pfm_get_next_msg(pfm_context_t *ctx)
799{
800 pfm_msg_t *msg;
801
802 DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
803
804 if (PFM_CTXQ_EMPTY(ctx)) return NULL;
805
806 /*
807 * get oldest message
808 */
809 msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
810
811 /*
812 * and move forward
813 */
814 ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
815
816 DPRINT(("ctx=%p head=%d tail=%d type=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, msg->pfm_gen_msg.msg_type));
817
818 return msg;
819}
820
821static void
822pfm_reset_msgq(pfm_context_t *ctx)
823{
824 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
825 DPRINT(("ctx=%p msgq reset\n", ctx));
826}
827
828static void *
829pfm_rvmalloc(unsigned long size)
830{
831 void *mem;
832 unsigned long addr;
833
834 size = PAGE_ALIGN(size);
835 mem = vzalloc(size);
836 if (mem) {
837 //printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
838 addr = (unsigned long)mem;
839 while (size > 0) {
840 pfm_reserve_page(addr);
841 addr+=PAGE_SIZE;
842 size-=PAGE_SIZE;
843 }
844 }
845 return mem;
846}
847
848static void
849pfm_rvfree(void *mem, unsigned long size)
850{
851 unsigned long addr;
852
853 if (mem) {
854 DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
855 addr = (unsigned long) mem;
856 while ((long) size > 0) {
857 pfm_unreserve_page(addr);
858 addr+=PAGE_SIZE;
859 size-=PAGE_SIZE;
860 }
861 vfree(mem);
862 }
863 return;
864}
865
866static pfm_context_t *
867pfm_context_alloc(int ctx_flags)
868{
869 pfm_context_t *ctx;
870
871 /*
872 * allocate context descriptor
873 * must be able to free with interrupts disabled
874 */
875 ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
876 if (ctx) {
877 DPRINT(("alloc ctx @%p\n", ctx));
878
879 /*
880 * init context protection lock
881 */
882 spin_lock_init(&ctx->ctx_lock);
883
884 /*
885 * context is unloaded
886 */
887 ctx->ctx_state = PFM_CTX_UNLOADED;
888
889 /*
890 * initialization of context's flags
891 */
892 ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
893 ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
894 ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
895 /*
896 * will move to set properties
897 * ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
898 */
899
900 /*
901 * init restart semaphore to locked
902 */
903 init_completion(&ctx->ctx_restart_done);
904
905 /*
906 * activation is used in SMP only
907 */
908 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
909 SET_LAST_CPU(ctx, -1);
910
911 /*
912 * initialize notification message queue
913 */
914 ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
915 init_waitqueue_head(&ctx->ctx_msgq_wait);
916 init_waitqueue_head(&ctx->ctx_zombieq);
917
918 }
919 return ctx;
920}
921
922static void
923pfm_context_free(pfm_context_t *ctx)
924{
925 if (ctx) {
926 DPRINT(("free ctx @%p\n", ctx));
927 kfree(ctx);
928 }
929}
930
931static void
932pfm_mask_monitoring(struct task_struct *task)
933{
934 pfm_context_t *ctx = PFM_GET_CTX(task);
935 unsigned long mask, val, ovfl_mask;
936 int i;
937
938 DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
939
940 ovfl_mask = pmu_conf->ovfl_val;
941 /*
942 * monitoring can only be masked as a result of a valid
943 * counter overflow. In UP, it means that the PMU still
944 * has an owner. Note that the owner can be different
945 * from the current task. However the PMU state belongs
946 * to the owner.
947 * In SMP, a valid overflow only happens when task is
948 * current. Therefore if we come here, we know that
949 * the PMU state belongs to the current task, therefore
950 * we can access the live registers.
951 *
952 * So in both cases, the live register contains the owner's
953 * state. We can ONLY touch the PMU registers and NOT the PSR.
954 *
955 * As a consequence to this call, the ctx->th_pmds[] array
956 * contains stale information which must be ignored
957 * when context is reloaded AND monitoring is active (see
958 * pfm_restart).
959 */
960 mask = ctx->ctx_used_pmds[0];
961 for (i = 0; mask; i++, mask>>=1) {
962 /* skip non used pmds */
963 if ((mask & 0x1) == 0) continue;
964 val = ia64_get_pmd(i);
965
966 if (PMD_IS_COUNTING(i)) {
967 /*
968 * we rebuild the full 64 bit value of the counter
969 */
970 ctx->ctx_pmds[i].val += (val & ovfl_mask);
971 } else {
972 ctx->ctx_pmds[i].val = val;
973 }
974 DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
975 i,
976 ctx->ctx_pmds[i].val,
977 val & ovfl_mask));
978 }
979 /*
980 * mask monitoring by setting the privilege level to 0
981 * we cannot use psr.pp/psr.up for this, it is controlled by
982 * the user
983 *
984 * if task is current, modify actual registers, otherwise modify
985 * thread save state, i.e., what will be restored in pfm_load_regs()
986 */
987 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
988 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
989 if ((mask & 0x1) == 0UL) continue;
990 ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
991 ctx->th_pmcs[i] &= ~0xfUL;
992 DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
993 }
994 /*
995 * make all of this visible
996 */
997 ia64_srlz_d();
998}
999
1000/*
1001 * must always be done with task == current
1002 *
1003 * context must be in MASKED state when calling
1004 */
1005static void
1006pfm_restore_monitoring(struct task_struct *task)
1007{
1008 pfm_context_t *ctx = PFM_GET_CTX(task);
1009 unsigned long mask, ovfl_mask;
1010 unsigned long psr, val;
1011 int i, is_system;
1012
1013 is_system = ctx->ctx_fl_system;
1014 ovfl_mask = pmu_conf->ovfl_val;
1015
1016 if (task != current) {
1017 printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
1018 return;
1019 }
1020 if (ctx->ctx_state != PFM_CTX_MASKED) {
1021 printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
1022 task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
1023 return;
1024 }
1025 psr = pfm_get_psr();
1026 /*
1027 * monitoring is masked via the PMC.
1028 * As we restore their value, we do not want each counter to
1029 * restart right away. We stop monitoring using the PSR,
1030 * restore the PMC (and PMD) and then re-establish the psr
1031 * as it was. Note that there can be no pending overflow at
1032 * this point, because monitoring was MASKED.
1033 *
1034 * system-wide session are pinned and self-monitoring
1035 */
1036 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1037 /* disable dcr pp */
1038 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
1039 pfm_clear_psr_pp();
1040 } else {
1041 pfm_clear_psr_up();
1042 }
1043 /*
1044 * first, we restore the PMD
1045 */
1046 mask = ctx->ctx_used_pmds[0];
1047 for (i = 0; mask; i++, mask>>=1) {
1048 /* skip non used pmds */
1049 if ((mask & 0x1) == 0) continue;
1050
1051 if (PMD_IS_COUNTING(i)) {
1052 /*
1053 * we split the 64bit value according to
1054 * counter width
1055 */
1056 val = ctx->ctx_pmds[i].val & ovfl_mask;
1057 ctx->ctx_pmds[i].val &= ~ovfl_mask;
1058 } else {
1059 val = ctx->ctx_pmds[i].val;
1060 }
1061 ia64_set_pmd(i, val);
1062
1063 DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
1064 i,
1065 ctx->ctx_pmds[i].val,
1066 val));
1067 }
1068 /*
1069 * restore the PMCs
1070 */
1071 mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
1072 for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
1073 if ((mask & 0x1) == 0UL) continue;
1074 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1075 ia64_set_pmc(i, ctx->th_pmcs[i]);
1076 DPRINT(("[%d] pmc[%d]=0x%lx\n",
1077 task_pid_nr(task), i, ctx->th_pmcs[i]));
1078 }
1079 ia64_srlz_d();
1080
1081 /*
1082 * must restore DBR/IBR because could be modified while masked
1083 * XXX: need to optimize
1084 */
1085 if (ctx->ctx_fl_using_dbreg) {
1086 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
1087 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
1088 }
1089
1090 /*
1091 * now restore PSR
1092 */
1093 if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
1094 /* enable dcr pp */
1095 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
1096 ia64_srlz_i();
1097 }
1098 pfm_set_psr_l(psr);
1099}
1100
1101static inline void
1102pfm_save_pmds(unsigned long *pmds, unsigned long mask)
1103{
1104 int i;
1105
1106 ia64_srlz_d();
1107
1108 for (i=0; mask; i++, mask>>=1) {
1109 if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
1110 }
1111}
1112
1113/*
1114 * reload from thread state (used for ctxw only)
1115 */
1116static inline void
1117pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
1118{
1119 int i;
1120 unsigned long val, ovfl_val = pmu_conf->ovfl_val;
1121
1122 for (i=0; mask; i++, mask>>=1) {
1123 if ((mask & 0x1) == 0) continue;
1124 val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
1125 ia64_set_pmd(i, val);
1126 }
1127 ia64_srlz_d();
1128}
1129
1130/*
1131 * propagate PMD from context to thread-state
1132 */
1133static inline void
1134pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
1135{
1136 unsigned long ovfl_val = pmu_conf->ovfl_val;
1137 unsigned long mask = ctx->ctx_all_pmds[0];
1138 unsigned long val;
1139 int i;
1140
1141 DPRINT(("mask=0x%lx\n", mask));
1142
1143 for (i=0; mask; i++, mask>>=1) {
1144
1145 val = ctx->ctx_pmds[i].val;
1146
1147 /*
1148 * We break up the 64 bit value into 2 pieces
1149 * the lower bits go to the machine state in the
1150 * thread (will be reloaded on ctxsw in).
1151 * The upper part stays in the soft-counter.
1152 */
1153 if (PMD_IS_COUNTING(i)) {
1154 ctx->ctx_pmds[i].val = val & ~ovfl_val;
1155 val &= ovfl_val;
1156 }
1157 ctx->th_pmds[i] = val;
1158
1159 DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
1160 i,
1161 ctx->th_pmds[i],
1162 ctx->ctx_pmds[i].val));
1163 }
1164}
1165
1166/*
1167 * propagate PMC from context to thread-state
1168 */
1169static inline void
1170pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
1171{
1172 unsigned long mask = ctx->ctx_all_pmcs[0];
1173 int i;
1174
1175 DPRINT(("mask=0x%lx\n", mask));
1176
1177 for (i=0; mask; i++, mask>>=1) {
1178 /* masking 0 with ovfl_val yields 0 */
1179 ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
1180 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
1181 }
1182}
1183
1184
1185
1186static inline void
1187pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
1188{
1189 int i;
1190
1191 for (i=0; mask; i++, mask>>=1) {
1192 if ((mask & 0x1) == 0) continue;
1193 ia64_set_pmc(i, pmcs[i]);
1194 }
1195 ia64_srlz_d();
1196}
1197
1198static inline int
1199pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
1200{
1201 return memcmp(a, b, sizeof(pfm_uuid_t));
1202}
1203
1204static inline int
1205pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
1206{
1207 int ret = 0;
1208 if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
1209 return ret;
1210}
1211
1212static inline int
1213pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
1214{
1215 int ret = 0;
1216 if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
1217 return ret;
1218}
1219
1220
1221static inline int
1222pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
1223 int cpu, void *arg)
1224{
1225 int ret = 0;
1226 if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
1227 return ret;
1228}
1229
1230static inline int
1231pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
1232 int cpu, void *arg)
1233{
1234 int ret = 0;
1235 if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
1236 return ret;
1237}
1238
1239static inline int
1240pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1241{
1242 int ret = 0;
1243 if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
1244 return ret;
1245}
1246
1247static inline int
1248pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
1249{
1250 int ret = 0;
1251 if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
1252 return ret;
1253}
1254
1255static pfm_buffer_fmt_t *
1256__pfm_find_buffer_fmt(pfm_uuid_t uuid)
1257{
1258 struct list_head * pos;
1259 pfm_buffer_fmt_t * entry;
1260
1261 list_for_each(pos, &pfm_buffer_fmt_list) {
1262 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
1263 if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
1264 return entry;
1265 }
1266 return NULL;
1267}
1268
1269/*
1270 * find a buffer format based on its uuid
1271 */
1272static pfm_buffer_fmt_t *
1273pfm_find_buffer_fmt(pfm_uuid_t uuid)
1274{
1275 pfm_buffer_fmt_t * fmt;
1276 spin_lock(&pfm_buffer_fmt_lock);
1277 fmt = __pfm_find_buffer_fmt(uuid);
1278 spin_unlock(&pfm_buffer_fmt_lock);
1279 return fmt;
1280}
1281
1282int
1283pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
1284{
1285 int ret = 0;
1286
1287 /* some sanity checks */
1288 if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
1289
1290 /* we need at least a handler */
1291 if (fmt->fmt_handler == NULL) return -EINVAL;
1292
1293 /*
1294 * XXX: need check validity of fmt_arg_size
1295 */
1296
1297 spin_lock(&pfm_buffer_fmt_lock);
1298
1299 if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
1300 printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
1301 ret = -EBUSY;
1302 goto out;
1303 }
1304 list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
1305 printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
1306
1307out:
1308 spin_unlock(&pfm_buffer_fmt_lock);
1309 return ret;
1310}
1311EXPORT_SYMBOL(pfm_register_buffer_fmt);
1312
1313int
1314pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
1315{
1316 pfm_buffer_fmt_t *fmt;
1317 int ret = 0;
1318
1319 spin_lock(&pfm_buffer_fmt_lock);
1320
1321 fmt = __pfm_find_buffer_fmt(uuid);
1322 if (!fmt) {
1323 printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
1324 ret = -EINVAL;
1325 goto out;
1326 }
1327 list_del_init(&fmt->fmt_list);
1328 printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
1329
1330out:
1331 spin_unlock(&pfm_buffer_fmt_lock);
1332 return ret;
1333
1334}
1335EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
1336
1337extern void update_pal_halt_status(int);
1338
1339static int
1340pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
1341{
1342 unsigned long flags;
1343 /*
1344 * validity checks on cpu_mask have been done upstream
1345 */
1346 LOCK_PFS(flags);
1347
1348 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1349 pfm_sessions.pfs_sys_sessions,
1350 pfm_sessions.pfs_task_sessions,
1351 pfm_sessions.pfs_sys_use_dbregs,
1352 is_syswide,
1353 cpu));
1354
1355 if (is_syswide) {
1356 /*
1357 * cannot mix system wide and per-task sessions
1358 */
1359 if (pfm_sessions.pfs_task_sessions > 0UL) {
1360 DPRINT(("system wide not possible, %u conflicting task_sessions\n",
1361 pfm_sessions.pfs_task_sessions));
1362 goto abort;
1363 }
1364
1365 if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
1366
1367 DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
1368
1369 pfm_sessions.pfs_sys_session[cpu] = task;
1370
1371 pfm_sessions.pfs_sys_sessions++ ;
1372
1373 } else {
1374 if (pfm_sessions.pfs_sys_sessions) goto abort;
1375 pfm_sessions.pfs_task_sessions++;
1376 }
1377
1378 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1379 pfm_sessions.pfs_sys_sessions,
1380 pfm_sessions.pfs_task_sessions,
1381 pfm_sessions.pfs_sys_use_dbregs,
1382 is_syswide,
1383 cpu));
1384
1385 /*
1386 * disable default_idle() to go to PAL_HALT
1387 */
1388 update_pal_halt_status(0);
1389
1390 UNLOCK_PFS(flags);
1391
1392 return 0;
1393
1394error_conflict:
1395 DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
1396 task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
1397 cpu));
1398abort:
1399 UNLOCK_PFS(flags);
1400
1401 return -EBUSY;
1402
1403}
1404
1405static int
1406pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
1407{
1408 unsigned long flags;
1409 /*
1410 * validity checks on cpu_mask have been done upstream
1411 */
1412 LOCK_PFS(flags);
1413
1414 DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1415 pfm_sessions.pfs_sys_sessions,
1416 pfm_sessions.pfs_task_sessions,
1417 pfm_sessions.pfs_sys_use_dbregs,
1418 is_syswide,
1419 cpu));
1420
1421
1422 if (is_syswide) {
1423 pfm_sessions.pfs_sys_session[cpu] = NULL;
1424 /*
1425 * would not work with perfmon+more than one bit in cpu_mask
1426 */
1427 if (ctx && ctx->ctx_fl_using_dbreg) {
1428 if (pfm_sessions.pfs_sys_use_dbregs == 0) {
1429 printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
1430 } else {
1431 pfm_sessions.pfs_sys_use_dbregs--;
1432 }
1433 }
1434 pfm_sessions.pfs_sys_sessions--;
1435 } else {
1436 pfm_sessions.pfs_task_sessions--;
1437 }
1438 DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
1439 pfm_sessions.pfs_sys_sessions,
1440 pfm_sessions.pfs_task_sessions,
1441 pfm_sessions.pfs_sys_use_dbregs,
1442 is_syswide,
1443 cpu));
1444
1445 /*
1446 * if possible, enable default_idle() to go into PAL_HALT
1447 */
1448 if (pfm_sessions.pfs_task_sessions == 0 && pfm_sessions.pfs_sys_sessions == 0)
1449 update_pal_halt_status(1);
1450
1451 UNLOCK_PFS(flags);
1452
1453 return 0;
1454}
1455
1456/*
1457 * removes virtual mapping of the sampling buffer.
1458 * IMPORTANT: cannot be called with interrupts disable, e.g. inside
1459 * a PROTECT_CTX() section.
1460 */
1461static int
1462pfm_remove_smpl_mapping(struct task_struct *task, void *vaddr, unsigned long size)
1463{
1464 int r;
1465
1466 /* sanity checks */
1467 if (task->mm == NULL || size == 0UL || vaddr == NULL) {
1468 printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
1469 return -EINVAL;
1470 }
1471
1472 DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
1473
1474 /*
1475 * does the actual unmapping
1476 */
1477 down_write(&task->mm->mmap_sem);
1478
1479 DPRINT(("down_write done smpl_vaddr=%p size=%lu\n", vaddr, size));
1480
1481 r = pfm_do_munmap(task->mm, (unsigned long)vaddr, size, 0);
1482
1483 up_write(&task->mm->mmap_sem);
1484 if (r !=0) {
1485 printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
1486 }
1487
1488 DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
1489
1490 return 0;
1491}
1492
1493/*
1494 * free actual physical storage used by sampling buffer
1495 */
1496#if 0
1497static int
1498pfm_free_smpl_buffer(pfm_context_t *ctx)
1499{
1500 pfm_buffer_fmt_t *fmt;
1501
1502 if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
1503
1504 /*
1505 * we won't use the buffer format anymore
1506 */
1507 fmt = ctx->ctx_buf_fmt;
1508
1509 DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
1510 ctx->ctx_smpl_hdr,
1511 ctx->ctx_smpl_size,
1512 ctx->ctx_smpl_vaddr));
1513
1514 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1515
1516 /*
1517 * free the buffer
1518 */
1519 pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
1520
1521 ctx->ctx_smpl_hdr = NULL;
1522 ctx->ctx_smpl_size = 0UL;
1523
1524 return 0;
1525
1526invalid_free:
1527 printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
1528 return -EINVAL;
1529}
1530#endif
1531
1532static inline void
1533pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
1534{
1535 if (fmt == NULL) return;
1536
1537 pfm_buf_fmt_exit(fmt, current, NULL, NULL);
1538
1539}
1540
1541/*
1542 * pfmfs should _never_ be mounted by userland - too much of security hassle,
1543 * no real gain from having the whole whorehouse mounted. So we don't need
1544 * any operations on the root directory. However, we need a non-trivial
1545 * d_name - pfm: will go nicely and kill the special-casing in procfs.
1546 */
1547static struct vfsmount *pfmfs_mnt __read_mostly;
1548
1549static int __init
1550init_pfm_fs(void)
1551{
1552 int err = register_filesystem(&pfm_fs_type);
1553 if (!err) {
1554 pfmfs_mnt = kern_mount(&pfm_fs_type);
1555 err = PTR_ERR(pfmfs_mnt);
1556 if (IS_ERR(pfmfs_mnt))
1557 unregister_filesystem(&pfm_fs_type);
1558 else
1559 err = 0;
1560 }
1561 return err;
1562}
1563
1564static ssize_t
1565pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
1566{
1567 pfm_context_t *ctx;
1568 pfm_msg_t *msg;
1569 ssize_t ret;
1570 unsigned long flags;
1571 DECLARE_WAITQUEUE(wait, current);
1572 if (PFM_IS_FILE(filp) == 0) {
1573 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1574 return -EINVAL;
1575 }
1576
1577 ctx = filp->private_data;
1578 if (ctx == NULL) {
1579 printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
1580 return -EINVAL;
1581 }
1582
1583 /*
1584 * check even when there is no message
1585 */
1586 if (size < sizeof(pfm_msg_t)) {
1587 DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
1588 return -EINVAL;
1589 }
1590
1591 PROTECT_CTX(ctx, flags);
1592
1593 /*
1594 * put ourselves on the wait queue
1595 */
1596 add_wait_queue(&ctx->ctx_msgq_wait, &wait);
1597
1598
1599 for(;;) {
1600 /*
1601 * check wait queue
1602 */
1603
1604 set_current_state(TASK_INTERRUPTIBLE);
1605
1606 DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
1607
1608 ret = 0;
1609 if(PFM_CTXQ_EMPTY(ctx) == 0) break;
1610
1611 UNPROTECT_CTX(ctx, flags);
1612
1613 /*
1614 * check non-blocking read
1615 */
1616 ret = -EAGAIN;
1617 if(filp->f_flags & O_NONBLOCK) break;
1618
1619 /*
1620 * check pending signals
1621 */
1622 if(signal_pending(current)) {
1623 ret = -EINTR;
1624 break;
1625 }
1626 /*
1627 * no message, so wait
1628 */
1629 schedule();
1630
1631 PROTECT_CTX(ctx, flags);
1632 }
1633 DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
1634 set_current_state(TASK_RUNNING);
1635 remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
1636
1637 if (ret < 0) goto abort;
1638
1639 ret = -EINVAL;
1640 msg = pfm_get_next_msg(ctx);
1641 if (msg == NULL) {
1642 printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
1643 goto abort_locked;
1644 }
1645
1646 DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
1647
1648 ret = -EFAULT;
1649 if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
1650
1651abort_locked:
1652 UNPROTECT_CTX(ctx, flags);
1653abort:
1654 return ret;
1655}
1656
1657static ssize_t
1658pfm_write(struct file *file, const char __user *ubuf,
1659 size_t size, loff_t *ppos)
1660{
1661 DPRINT(("pfm_write called\n"));
1662 return -EINVAL;
1663}
1664
1665static unsigned int
1666pfm_poll(struct file *filp, poll_table * wait)
1667{
1668 pfm_context_t *ctx;
1669 unsigned long flags;
1670 unsigned int mask = 0;
1671
1672 if (PFM_IS_FILE(filp) == 0) {
1673 printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
1674 return 0;
1675 }
1676
1677 ctx = filp->private_data;
1678 if (ctx == NULL) {
1679 printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
1680 return 0;
1681 }
1682
1683
1684 DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
1685
1686 poll_wait(filp, &ctx->ctx_msgq_wait, wait);
1687
1688 PROTECT_CTX(ctx, flags);
1689
1690 if (PFM_CTXQ_EMPTY(ctx) == 0)
1691 mask = POLLIN | POLLRDNORM;
1692
1693 UNPROTECT_CTX(ctx, flags);
1694
1695 DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
1696
1697 return mask;
1698}
1699
1700static long
1701pfm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1702{
1703 DPRINT(("pfm_ioctl called\n"));
1704 return -EINVAL;
1705}
1706
1707/*
1708 * interrupt cannot be masked when coming here
1709 */
1710static inline int
1711pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
1712{
1713 int ret;
1714
1715 ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
1716
1717 DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1718 task_pid_nr(current),
1719 fd,
1720 on,
1721 ctx->ctx_async_queue, ret));
1722
1723 return ret;
1724}
1725
1726static int
1727pfm_fasync(int fd, struct file *filp, int on)
1728{
1729 pfm_context_t *ctx;
1730 int ret;
1731
1732 if (PFM_IS_FILE(filp) == 0) {
1733 printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
1734 return -EBADF;
1735 }
1736
1737 ctx = filp->private_data;
1738 if (ctx == NULL) {
1739 printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
1740 return -EBADF;
1741 }
1742 /*
1743 * we cannot mask interrupts during this call because this may
1744 * may go to sleep if memory is not readily avalaible.
1745 *
1746 * We are protected from the conetxt disappearing by the get_fd()/put_fd()
1747 * done in caller. Serialization of this function is ensured by caller.
1748 */
1749 ret = pfm_do_fasync(fd, filp, ctx, on);
1750
1751
1752 DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
1753 fd,
1754 on,
1755 ctx->ctx_async_queue, ret));
1756
1757 return ret;
1758}
1759
1760#ifdef CONFIG_SMP
1761/*
1762 * this function is exclusively called from pfm_close().
1763 * The context is not protected at that time, nor are interrupts
1764 * on the remote CPU. That's necessary to avoid deadlocks.
1765 */
1766static void
1767pfm_syswide_force_stop(void *info)
1768{
1769 pfm_context_t *ctx = (pfm_context_t *)info;
1770 struct pt_regs *regs = task_pt_regs(current);
1771 struct task_struct *owner;
1772 unsigned long flags;
1773 int ret;
1774
1775 if (ctx->ctx_cpu != smp_processor_id()) {
1776 printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
1777 ctx->ctx_cpu,
1778 smp_processor_id());
1779 return;
1780 }
1781 owner = GET_PMU_OWNER();
1782 if (owner != ctx->ctx_task) {
1783 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
1784 smp_processor_id(),
1785 task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
1786 return;
1787 }
1788 if (GET_PMU_CTX() != ctx) {
1789 printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
1790 smp_processor_id(),
1791 GET_PMU_CTX(), ctx);
1792 return;
1793 }
1794
1795 DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
1796 /*
1797 * the context is already protected in pfm_close(), we simply
1798 * need to mask interrupts to avoid a PMU interrupt race on
1799 * this CPU
1800 */
1801 local_irq_save(flags);
1802
1803 ret = pfm_context_unload(ctx, NULL, 0, regs);
1804 if (ret) {
1805 DPRINT(("context_unload returned %d\n", ret));
1806 }
1807
1808 /*
1809 * unmask interrupts, PMU interrupts are now spurious here
1810 */
1811 local_irq_restore(flags);
1812}
1813
1814static void
1815pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
1816{
1817 int ret;
1818
1819 DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
1820 ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 1);
1821 DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
1822}
1823#endif /* CONFIG_SMP */
1824
1825/*
1826 * called for each close(). Partially free resources.
1827 * When caller is self-monitoring, the context is unloaded.
1828 */
1829static int
1830pfm_flush(struct file *filp, fl_owner_t id)
1831{
1832 pfm_context_t *ctx;
1833 struct task_struct *task;
1834 struct pt_regs *regs;
1835 unsigned long flags;
1836 unsigned long smpl_buf_size = 0UL;
1837 void *smpl_buf_vaddr = NULL;
1838 int state, is_system;
1839
1840 if (PFM_IS_FILE(filp) == 0) {
1841 DPRINT(("bad magic for\n"));
1842 return -EBADF;
1843 }
1844
1845 ctx = filp->private_data;
1846 if (ctx == NULL) {
1847 printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
1848 return -EBADF;
1849 }
1850
1851 /*
1852 * remove our file from the async queue, if we use this mode.
1853 * This can be done without the context being protected. We come
1854 * here when the context has become unreachable by other tasks.
1855 *
1856 * We may still have active monitoring at this point and we may
1857 * end up in pfm_overflow_handler(). However, fasync_helper()
1858 * operates with interrupts disabled and it cleans up the
1859 * queue. If the PMU handler is called prior to entering
1860 * fasync_helper() then it will send a signal. If it is
1861 * invoked after, it will find an empty queue and no
1862 * signal will be sent. In both case, we are safe
1863 */
1864 PROTECT_CTX(ctx, flags);
1865
1866 state = ctx->ctx_state;
1867 is_system = ctx->ctx_fl_system;
1868
1869 task = PFM_CTX_TASK(ctx);
1870 regs = task_pt_regs(task);
1871
1872 DPRINT(("ctx_state=%d is_current=%d\n",
1873 state,
1874 task == current ? 1 : 0));
1875
1876 /*
1877 * if state == UNLOADED, then task is NULL
1878 */
1879
1880 /*
1881 * we must stop and unload because we are losing access to the context.
1882 */
1883 if (task == current) {
1884#ifdef CONFIG_SMP
1885 /*
1886 * the task IS the owner but it migrated to another CPU: that's bad
1887 * but we must handle this cleanly. Unfortunately, the kernel does
1888 * not provide a mechanism to block migration (while the context is loaded).
1889 *
1890 * We need to release the resource on the ORIGINAL cpu.
1891 */
1892 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
1893
1894 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
1895 /*
1896 * keep context protected but unmask interrupt for IPI
1897 */
1898 local_irq_restore(flags);
1899
1900 pfm_syswide_cleanup_other_cpu(ctx);
1901
1902 /*
1903 * restore interrupt masking
1904 */
1905 local_irq_save(flags);
1906
1907 /*
1908 * context is unloaded at this point
1909 */
1910 } else
1911#endif /* CONFIG_SMP */
1912 {
1913
1914 DPRINT(("forcing unload\n"));
1915 /*
1916 * stop and unload, returning with state UNLOADED
1917 * and session unreserved.
1918 */
1919 pfm_context_unload(ctx, NULL, 0, regs);
1920
1921 DPRINT(("ctx_state=%d\n", ctx->ctx_state));
1922 }
1923 }
1924
1925 /*
1926 * remove virtual mapping, if any, for the calling task.
1927 * cannot reset ctx field until last user is calling close().
1928 *
1929 * ctx_smpl_vaddr must never be cleared because it is needed
1930 * by every task with access to the context
1931 *
1932 * When called from do_exit(), the mm context is gone already, therefore
1933 * mm is NULL, i.e., the VMA is already gone and we do not have to
1934 * do anything here
1935 */
1936 if (ctx->ctx_smpl_vaddr && current->mm) {
1937 smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
1938 smpl_buf_size = ctx->ctx_smpl_size;
1939 }
1940
1941 UNPROTECT_CTX(ctx, flags);
1942
1943 /*
1944 * if there was a mapping, then we systematically remove it
1945 * at this point. Cannot be done inside critical section
1946 * because some VM function reenables interrupts.
1947 *
1948 */
1949 if (smpl_buf_vaddr) pfm_remove_smpl_mapping(current, smpl_buf_vaddr, smpl_buf_size);
1950
1951 return 0;
1952}
1953/*
1954 * called either on explicit close() or from exit_files().
1955 * Only the LAST user of the file gets to this point, i.e., it is
1956 * called only ONCE.
1957 *
1958 * IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
1959 * (fput()),i.e, last task to access the file. Nobody else can access the
1960 * file at this point.
1961 *
1962 * When called from exit_files(), the VMA has been freed because exit_mm()
1963 * is executed before exit_files().
1964 *
1965 * When called from exit_files(), the current task is not yet ZOMBIE but we
1966 * flush the PMU state to the context.
1967 */
1968static int
1969pfm_close(struct inode *inode, struct file *filp)
1970{
1971 pfm_context_t *ctx;
1972 struct task_struct *task;
1973 struct pt_regs *regs;
1974 DECLARE_WAITQUEUE(wait, current);
1975 unsigned long flags;
1976 unsigned long smpl_buf_size = 0UL;
1977 void *smpl_buf_addr = NULL;
1978 int free_possible = 1;
1979 int state, is_system;
1980
1981 DPRINT(("pfm_close called private=%p\n", filp->private_data));
1982
1983 if (PFM_IS_FILE(filp) == 0) {
1984 DPRINT(("bad magic\n"));
1985 return -EBADF;
1986 }
1987
1988 ctx = filp->private_data;
1989 if (ctx == NULL) {
1990 printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
1991 return -EBADF;
1992 }
1993
1994 PROTECT_CTX(ctx, flags);
1995
1996 state = ctx->ctx_state;
1997 is_system = ctx->ctx_fl_system;
1998
1999 task = PFM_CTX_TASK(ctx);
2000 regs = task_pt_regs(task);
2001
2002 DPRINT(("ctx_state=%d is_current=%d\n",
2003 state,
2004 task == current ? 1 : 0));
2005
2006 /*
2007 * if task == current, then pfm_flush() unloaded the context
2008 */
2009 if (state == PFM_CTX_UNLOADED) goto doit;
2010
2011 /*
2012 * context is loaded/masked and task != current, we need to
2013 * either force an unload or go zombie
2014 */
2015
2016 /*
2017 * The task is currently blocked or will block after an overflow.
2018 * we must force it to wakeup to get out of the
2019 * MASKED state and transition to the unloaded state by itself.
2020 *
2021 * This situation is only possible for per-task mode
2022 */
2023 if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
2024
2025 /*
2026 * set a "partial" zombie state to be checked
2027 * upon return from down() in pfm_handle_work().
2028 *
2029 * We cannot use the ZOMBIE state, because it is checked
2030 * by pfm_load_regs() which is called upon wakeup from down().
2031 * In such case, it would free the context and then we would
2032 * return to pfm_handle_work() which would access the
2033 * stale context. Instead, we set a flag invisible to pfm_load_regs()
2034 * but visible to pfm_handle_work().
2035 *
2036 * For some window of time, we have a zombie context with
2037 * ctx_state = MASKED and not ZOMBIE
2038 */
2039 ctx->ctx_fl_going_zombie = 1;
2040
2041 /*
2042 * force task to wake up from MASKED state
2043 */
2044 complete(&ctx->ctx_restart_done);
2045
2046 DPRINT(("waking up ctx_state=%d\n", state));
2047
2048 /*
2049 * put ourself to sleep waiting for the other
2050 * task to report completion
2051 *
2052 * the context is protected by mutex, therefore there
2053 * is no risk of being notified of completion before
2054 * begin actually on the waitq.
2055 */
2056 set_current_state(TASK_INTERRUPTIBLE);
2057 add_wait_queue(&ctx->ctx_zombieq, &wait);
2058
2059 UNPROTECT_CTX(ctx, flags);
2060
2061 /*
2062 * XXX: check for signals :
2063 * - ok for explicit close
2064 * - not ok when coming from exit_files()
2065 */
2066 schedule();
2067
2068
2069 PROTECT_CTX(ctx, flags);
2070
2071
2072 remove_wait_queue(&ctx->ctx_zombieq, &wait);
2073 set_current_state(TASK_RUNNING);
2074
2075 /*
2076 * context is unloaded at this point
2077 */
2078 DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
2079 }
2080 else if (task != current) {
2081#ifdef CONFIG_SMP
2082 /*
2083 * switch context to zombie state
2084 */
2085 ctx->ctx_state = PFM_CTX_ZOMBIE;
2086
2087 DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
2088 /*
2089 * cannot free the context on the spot. deferred until
2090 * the task notices the ZOMBIE state
2091 */
2092 free_possible = 0;
2093#else
2094 pfm_context_unload(ctx, NULL, 0, regs);
2095#endif
2096 }
2097
2098doit:
2099 /* reload state, may have changed during opening of critical section */
2100 state = ctx->ctx_state;
2101
2102 /*
2103 * the context is still attached to a task (possibly current)
2104 * we cannot destroy it right now
2105 */
2106
2107 /*
2108 * we must free the sampling buffer right here because
2109 * we cannot rely on it being cleaned up later by the
2110 * monitored task. It is not possible to free vmalloc'ed
2111 * memory in pfm_load_regs(). Instead, we remove the buffer
2112 * now. should there be subsequent PMU overflow originally
2113 * meant for sampling, the will be converted to spurious
2114 * and that's fine because the monitoring tools is gone anyway.
2115 */
2116 if (ctx->ctx_smpl_hdr) {
2117 smpl_buf_addr = ctx->ctx_smpl_hdr;
2118 smpl_buf_size = ctx->ctx_smpl_size;
2119 /* no more sampling */
2120 ctx->ctx_smpl_hdr = NULL;
2121 ctx->ctx_fl_is_sampling = 0;
2122 }
2123
2124 DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
2125 state,
2126 free_possible,
2127 smpl_buf_addr,
2128 smpl_buf_size));
2129
2130 if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
2131
2132 /*
2133 * UNLOADED that the session has already been unreserved.
2134 */
2135 if (state == PFM_CTX_ZOMBIE) {
2136 pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
2137 }
2138
2139 /*
2140 * disconnect file descriptor from context must be done
2141 * before we unlock.
2142 */
2143 filp->private_data = NULL;
2144
2145 /*
2146 * if we free on the spot, the context is now completely unreachable
2147 * from the callers side. The monitored task side is also cut, so we
2148 * can freely cut.
2149 *
2150 * If we have a deferred free, only the caller side is disconnected.
2151 */
2152 UNPROTECT_CTX(ctx, flags);
2153
2154 /*
2155 * All memory free operations (especially for vmalloc'ed memory)
2156 * MUST be done with interrupts ENABLED.
2157 */
2158 if (smpl_buf_addr) pfm_rvfree(smpl_buf_addr, smpl_buf_size);
2159
2160 /*
2161 * return the memory used by the context
2162 */
2163 if (free_possible) pfm_context_free(ctx);
2164
2165 return 0;
2166}
2167
2168static int
2169pfm_no_open(struct inode *irrelevant, struct file *dontcare)
2170{
2171 DPRINT(("pfm_no_open called\n"));
2172 return -ENXIO;
2173}
2174
2175
2176
2177static const struct file_operations pfm_file_ops = {
2178 .llseek = no_llseek,
2179 .read = pfm_read,
2180 .write = pfm_write,
2181 .poll = pfm_poll,
2182 .unlocked_ioctl = pfm_ioctl,
2183 .open = pfm_no_open, /* special open code to disallow open via /proc */
2184 .fasync = pfm_fasync,
2185 .release = pfm_close,
2186 .flush = pfm_flush
2187};
2188
2189static int
2190pfmfs_delete_dentry(const struct dentry *dentry)
2191{
2192 return 1;
2193}
2194
2195static char *pfmfs_dname(struct dentry *dentry, char *buffer, int buflen)
2196{
2197 return dynamic_dname(dentry, buffer, buflen, "pfm:[%lu]",
2198 dentry->d_inode->i_ino);
2199}
2200
2201static const struct dentry_operations pfmfs_dentry_operations = {
2202 .d_delete = pfmfs_delete_dentry,
2203 .d_dname = pfmfs_dname,
2204};
2205
2206
2207static struct file *
2208pfm_alloc_file(pfm_context_t *ctx)
2209{
2210 struct file *file;
2211 struct inode *inode;
2212 struct path path;
2213 struct qstr this = { .name = "" };
2214
2215 /*
2216 * allocate a new inode
2217 */
2218 inode = new_inode(pfmfs_mnt->mnt_sb);
2219 if (!inode)
2220 return ERR_PTR(-ENOMEM);
2221
2222 DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
2223
2224 inode->i_mode = S_IFCHR|S_IRUGO;
2225 inode->i_uid = current_fsuid();
2226 inode->i_gid = current_fsgid();
2227
2228 /*
2229 * allocate a new dcache entry
2230 */
2231 path.dentry = d_alloc(pfmfs_mnt->mnt_sb->s_root, &this);
2232 if (!path.dentry) {
2233 iput(inode);
2234 return ERR_PTR(-ENOMEM);
2235 }
2236 path.mnt = mntget(pfmfs_mnt);
2237
2238 d_add(path.dentry, inode);
2239
2240 file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
2241 if (!file) {
2242 path_put(&path);
2243 return ERR_PTR(-ENFILE);
2244 }
2245
2246 file->f_flags = O_RDONLY;
2247 file->private_data = ctx;
2248
2249 return file;
2250}
2251
2252static int
2253pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
2254{
2255 DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
2256
2257 while (size > 0) {
2258 unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
2259
2260
2261 if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
2262 return -ENOMEM;
2263
2264 addr += PAGE_SIZE;
2265 buf += PAGE_SIZE;
2266 size -= PAGE_SIZE;
2267 }
2268 return 0;
2269}
2270
2271/*
2272 * allocate a sampling buffer and remaps it into the user address space of the task
2273 */
2274static int
2275pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
2276{
2277 struct mm_struct *mm = task->mm;
2278 struct vm_area_struct *vma = NULL;
2279 unsigned long size;
2280 void *smpl_buf;
2281
2282
2283 /*
2284 * the fixed header + requested size and align to page boundary
2285 */
2286 size = PAGE_ALIGN(rsize);
2287
2288 DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
2289
2290 /*
2291 * check requested size to avoid Denial-of-service attacks
2292 * XXX: may have to refine this test
2293 * Check against address space limit.
2294 *
2295 * if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
2296 * return -ENOMEM;
2297 */
2298 if (size > task_rlimit(task, RLIMIT_MEMLOCK))
2299 return -ENOMEM;
2300
2301 /*
2302 * We do the easy to undo allocations first.
2303 *
2304 * pfm_rvmalloc(), clears the buffer, so there is no leak
2305 */
2306 smpl_buf = pfm_rvmalloc(size);
2307 if (smpl_buf == NULL) {
2308 DPRINT(("Can't allocate sampling buffer\n"));
2309 return -ENOMEM;
2310 }
2311
2312 DPRINT(("smpl_buf @%p\n", smpl_buf));
2313
2314 /* allocate vma */
2315 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
2316 if (!vma) {
2317 DPRINT(("Cannot allocate vma\n"));
2318 goto error_kmem;
2319 }
2320 INIT_LIST_HEAD(&vma->anon_vma_chain);
2321
2322 /*
2323 * partially initialize the vma for the sampling buffer
2324 */
2325 vma->vm_mm = mm;
2326 vma->vm_file = filp;
2327 vma->vm_flags = VM_READ| VM_MAYREAD |VM_RESERVED;
2328 vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
2329
2330 /*
2331 * Now we have everything we need and we can initialize
2332 * and connect all the data structures
2333 */
2334
2335 ctx->ctx_smpl_hdr = smpl_buf;
2336 ctx->ctx_smpl_size = size; /* aligned size */
2337
2338 /*
2339 * Let's do the difficult operations next.
2340 *
2341 * now we atomically find some area in the address space and
2342 * remap the buffer in it.
2343 */
2344 down_write(&task->mm->mmap_sem);
2345
2346 /* find some free area in address space, must have mmap sem held */
2347 vma->vm_start = pfm_get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS, 0);
2348 if (vma->vm_start == 0UL) {
2349 DPRINT(("Cannot find unmapped area for size %ld\n", size));
2350 up_write(&task->mm->mmap_sem);
2351 goto error;
2352 }
2353 vma->vm_end = vma->vm_start + size;
2354 vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
2355
2356 DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
2357
2358 /* can only be applied to current task, need to have the mm semaphore held when called */
2359 if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
2360 DPRINT(("Can't remap buffer\n"));
2361 up_write(&task->mm->mmap_sem);
2362 goto error;
2363 }
2364
2365 get_file(filp);
2366
2367 /*
2368 * now insert the vma in the vm list for the process, must be
2369 * done with mmap lock held
2370 */
2371 insert_vm_struct(mm, vma);
2372
2373 mm->total_vm += size >> PAGE_SHIFT;
2374 vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
2375 vma_pages(vma));
2376 up_write(&task->mm->mmap_sem);
2377
2378 /*
2379 * keep track of user level virtual address
2380 */
2381 ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
2382 *(unsigned long *)user_vaddr = vma->vm_start;
2383
2384 return 0;
2385
2386error:
2387 kmem_cache_free(vm_area_cachep, vma);
2388error_kmem:
2389 pfm_rvfree(smpl_buf, size);
2390
2391 return -ENOMEM;
2392}
2393
2394/*
2395 * XXX: do something better here
2396 */
2397static int
2398pfm_bad_permissions(struct task_struct *task)
2399{
2400 const struct cred *tcred;
2401 uid_t uid = current_uid();
2402 gid_t gid = current_gid();
2403 int ret;
2404
2405 rcu_read_lock();
2406 tcred = __task_cred(task);
2407
2408 /* inspired by ptrace_attach() */
2409 DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
2410 uid,
2411 gid,
2412 tcred->euid,
2413 tcred->suid,
2414 tcred->uid,
2415 tcred->egid,
2416 tcred->sgid));
2417
2418 ret = ((uid != tcred->euid)
2419 || (uid != tcred->suid)
2420 || (uid != tcred->uid)
2421 || (gid != tcred->egid)
2422 || (gid != tcred->sgid)
2423 || (gid != tcred->gid)) && !capable(CAP_SYS_PTRACE);
2424
2425 rcu_read_unlock();
2426 return ret;
2427}
2428
2429static int
2430pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
2431{
2432 int ctx_flags;
2433
2434 /* valid signal */
2435
2436 ctx_flags = pfx->ctx_flags;
2437
2438 if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
2439
2440 /*
2441 * cannot block in this mode
2442 */
2443 if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
2444 DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
2445 return -EINVAL;
2446 }
2447 } else {
2448 }
2449 /* probably more to add here */
2450
2451 return 0;
2452}
2453
2454static int
2455pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
2456 unsigned int cpu, pfarg_context_t *arg)
2457{
2458 pfm_buffer_fmt_t *fmt = NULL;
2459 unsigned long size = 0UL;
2460 void *uaddr = NULL;
2461 void *fmt_arg = NULL;
2462 int ret = 0;
2463#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
2464
2465 /* invoke and lock buffer format, if found */
2466 fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
2467 if (fmt == NULL) {
2468 DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
2469 return -EINVAL;
2470 }
2471
2472 /*
2473 * buffer argument MUST be contiguous to pfarg_context_t
2474 */
2475 if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
2476
2477 ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
2478
2479 DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
2480
2481 if (ret) goto error;
2482
2483 /* link buffer format and context */
2484 ctx->ctx_buf_fmt = fmt;
2485 ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
2486
2487 /*
2488 * check if buffer format wants to use perfmon buffer allocation/mapping service
2489 */
2490 ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
2491 if (ret) goto error;
2492
2493 if (size) {
2494 /*
2495 * buffer is always remapped into the caller's address space
2496 */
2497 ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
2498 if (ret) goto error;
2499
2500 /* keep track of user address of buffer */
2501 arg->ctx_smpl_vaddr = uaddr;
2502 }
2503 ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
2504
2505error:
2506 return ret;
2507}
2508
2509static void
2510pfm_reset_pmu_state(pfm_context_t *ctx)
2511{
2512 int i;
2513
2514 /*
2515 * install reset values for PMC.
2516 */
2517 for (i=1; PMC_IS_LAST(i) == 0; i++) {
2518 if (PMC_IS_IMPL(i) == 0) continue;
2519 ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
2520 DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
2521 }
2522 /*
2523 * PMD registers are set to 0UL when the context in memset()
2524 */
2525
2526 /*
2527 * On context switched restore, we must restore ALL pmc and ALL pmd even
2528 * when they are not actively used by the task. In UP, the incoming process
2529 * may otherwise pick up left over PMC, PMD state from the previous process.
2530 * As opposed to PMD, stale PMC can cause harm to the incoming
2531 * process because they may change what is being measured.
2532 * Therefore, we must systematically reinstall the entire
2533 * PMC state. In SMP, the same thing is possible on the
2534 * same CPU but also on between 2 CPUs.
2535 *
2536 * The problem with PMD is information leaking especially
2537 * to user level when psr.sp=0
2538 *
2539 * There is unfortunately no easy way to avoid this problem
2540 * on either UP or SMP. This definitively slows down the
2541 * pfm_load_regs() function.
2542 */
2543
2544 /*
2545 * bitmask of all PMCs accessible to this context
2546 *
2547 * PMC0 is treated differently.
2548 */
2549 ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
2550
2551 /*
2552 * bitmask of all PMDs that are accessible to this context
2553 */
2554 ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
2555
2556 DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
2557
2558 /*
2559 * useful in case of re-enable after disable
2560 */
2561 ctx->ctx_used_ibrs[0] = 0UL;
2562 ctx->ctx_used_dbrs[0] = 0UL;
2563}
2564
2565static int
2566pfm_ctx_getsize(void *arg, size_t *sz)
2567{
2568 pfarg_context_t *req = (pfarg_context_t *)arg;
2569 pfm_buffer_fmt_t *fmt;
2570
2571 *sz = 0;
2572
2573 if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
2574
2575 fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
2576 if (fmt == NULL) {
2577 DPRINT(("cannot find buffer format\n"));
2578 return -EINVAL;
2579 }
2580 /* get just enough to copy in user parameters */
2581 *sz = fmt->fmt_arg_size;
2582 DPRINT(("arg_size=%lu\n", *sz));
2583
2584 return 0;
2585}
2586
2587
2588
2589/*
2590 * cannot attach if :
2591 * - kernel task
2592 * - task not owned by caller
2593 * - task incompatible with context mode
2594 */
2595static int
2596pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
2597{
2598 /*
2599 * no kernel task or task not owner by caller
2600 */
2601 if (task->mm == NULL) {
2602 DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
2603 return -EPERM;
2604 }
2605 if (pfm_bad_permissions(task)) {
2606 DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
2607 return -EPERM;
2608 }
2609 /*
2610 * cannot block in self-monitoring mode
2611 */
2612 if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
2613 DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
2614 return -EINVAL;
2615 }
2616
2617 if (task->exit_state == EXIT_ZOMBIE) {
2618 DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
2619 return -EBUSY;
2620 }
2621
2622 /*
2623 * always ok for self
2624 */
2625 if (task == current) return 0;
2626
2627 if (!task_is_stopped_or_traced(task)) {
2628 DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
2629 return -EBUSY;
2630 }
2631 /*
2632 * make sure the task is off any CPU
2633 */
2634 wait_task_inactive(task, 0);
2635
2636 /* more to come... */
2637
2638 return 0;
2639}
2640
2641static int
2642pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
2643{
2644 struct task_struct *p = current;
2645 int ret;
2646
2647 /* XXX: need to add more checks here */
2648 if (pid < 2) return -EPERM;
2649
2650 if (pid != task_pid_vnr(current)) {
2651
2652 read_lock(&tasklist_lock);
2653
2654 p = find_task_by_vpid(pid);
2655
2656 /* make sure task cannot go away while we operate on it */
2657 if (p) get_task_struct(p);
2658
2659 read_unlock(&tasklist_lock);
2660
2661 if (p == NULL) return -ESRCH;
2662 }
2663
2664 ret = pfm_task_incompatible(ctx, p);
2665 if (ret == 0) {
2666 *task = p;
2667 } else if (p != current) {
2668 pfm_put_task(p);
2669 }
2670 return ret;
2671}
2672
2673
2674
2675static int
2676pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2677{
2678 pfarg_context_t *req = (pfarg_context_t *)arg;
2679 struct file *filp;
2680 struct path path;
2681 int ctx_flags;
2682 int fd;
2683 int ret;
2684
2685 /* let's check the arguments first */
2686 ret = pfarg_is_sane(current, req);
2687 if (ret < 0)
2688 return ret;
2689
2690 ctx_flags = req->ctx_flags;
2691
2692 ret = -ENOMEM;
2693
2694 fd = get_unused_fd();
2695 if (fd < 0)
2696 return fd;
2697
2698 ctx = pfm_context_alloc(ctx_flags);
2699 if (!ctx)
2700 goto error;
2701
2702 filp = pfm_alloc_file(ctx);
2703 if (IS_ERR(filp)) {
2704 ret = PTR_ERR(filp);
2705 goto error_file;
2706 }
2707
2708 req->ctx_fd = ctx->ctx_fd = fd;
2709
2710 /*
2711 * does the user want to sample?
2712 */
2713 if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
2714 ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
2715 if (ret)
2716 goto buffer_error;
2717 }
2718
2719 DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d\n",
2720 ctx,
2721 ctx_flags,
2722 ctx->ctx_fl_system,
2723 ctx->ctx_fl_block,
2724 ctx->ctx_fl_excl_idle,
2725 ctx->ctx_fl_no_msg,
2726 ctx->ctx_fd));
2727
2728 /*
2729 * initialize soft PMU state
2730 */
2731 pfm_reset_pmu_state(ctx);
2732
2733 fd_install(fd, filp);
2734
2735 return 0;
2736
2737buffer_error:
2738 path = filp->f_path;
2739 put_filp(filp);
2740 path_put(&path);
2741
2742 if (ctx->ctx_buf_fmt) {
2743 pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
2744 }
2745error_file:
2746 pfm_context_free(ctx);
2747
2748error:
2749 put_unused_fd(fd);
2750 return ret;
2751}
2752
2753static inline unsigned long
2754pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
2755{
2756 unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
2757 unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
2758 extern unsigned long carta_random32 (unsigned long seed);
2759
2760 if (reg->flags & PFM_REGFL_RANDOM) {
2761 new_seed = carta_random32(old_seed);
2762 val -= (old_seed & mask); /* counter values are negative numbers! */
2763 if ((mask >> 32) != 0)
2764 /* construct a full 64-bit random value: */
2765 new_seed |= carta_random32(old_seed >> 32) << 32;
2766 reg->seed = new_seed;
2767 }
2768 reg->lval = val;
2769 return val;
2770}
2771
2772static void
2773pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2774{
2775 unsigned long mask = ovfl_regs[0];
2776 unsigned long reset_others = 0UL;
2777 unsigned long val;
2778 int i;
2779
2780 /*
2781 * now restore reset value on sampling overflowed counters
2782 */
2783 mask >>= PMU_FIRST_COUNTER;
2784 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2785
2786 if ((mask & 0x1UL) == 0UL) continue;
2787
2788 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2789 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2790
2791 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2792 }
2793
2794 /*
2795 * Now take care of resetting the other registers
2796 */
2797 for(i = 0; reset_others; i++, reset_others >>= 1) {
2798
2799 if ((reset_others & 0x1) == 0) continue;
2800
2801 ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2802
2803 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2804 is_long_reset ? "long" : "short", i, val));
2805 }
2806}
2807
2808static void
2809pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
2810{
2811 unsigned long mask = ovfl_regs[0];
2812 unsigned long reset_others = 0UL;
2813 unsigned long val;
2814 int i;
2815
2816 DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
2817
2818 if (ctx->ctx_state == PFM_CTX_MASKED) {
2819 pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
2820 return;
2821 }
2822
2823 /*
2824 * now restore reset value on sampling overflowed counters
2825 */
2826 mask >>= PMU_FIRST_COUNTER;
2827 for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
2828
2829 if ((mask & 0x1UL) == 0UL) continue;
2830
2831 val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
2832 reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
2833
2834 DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
2835
2836 pfm_write_soft_counter(ctx, i, val);
2837 }
2838
2839 /*
2840 * Now take care of resetting the other registers
2841 */
2842 for(i = 0; reset_others; i++, reset_others >>= 1) {
2843
2844 if ((reset_others & 0x1) == 0) continue;
2845
2846 val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
2847
2848 if (PMD_IS_COUNTING(i)) {
2849 pfm_write_soft_counter(ctx, i, val);
2850 } else {
2851 ia64_set_pmd(i, val);
2852 }
2853 DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
2854 is_long_reset ? "long" : "short", i, val));
2855 }
2856 ia64_srlz_d();
2857}
2858
2859static int
2860pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
2861{
2862 struct task_struct *task;
2863 pfarg_reg_t *req = (pfarg_reg_t *)arg;
2864 unsigned long value, pmc_pm;
2865 unsigned long smpl_pmds, reset_pmds, impl_pmds;
2866 unsigned int cnum, reg_flags, flags, pmc_type;
2867 int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
2868 int is_monitor, is_counting, state;
2869 int ret = -EINVAL;
2870 pfm_reg_check_t wr_func;
2871#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
2872
2873 state = ctx->ctx_state;
2874 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
2875 is_system = ctx->ctx_fl_system;
2876 task = ctx->ctx_task;
2877 impl_pmds = pmu_conf->impl_pmds[0];
2878
2879 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
2880
2881 if (is_loaded) {
2882 /*
2883 * In system wide and when the context is loaded, access can only happen
2884 * when the caller is running on the CPU being monitored by the session.
2885 * It does not have to be the owner (ctx_task) of the context per se.
2886 */
2887 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
2888 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
2889 return -EBUSY;
2890 }
2891 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
2892 }
2893 expert_mode = pfm_sysctl.expert_mode;
2894
2895 for (i = 0; i < count; i++, req++) {
2896
2897 cnum = req->reg_num;
2898 reg_flags = req->reg_flags;
2899 value = req->reg_value;
2900 smpl_pmds = req->reg_smpl_pmds[0];
2901 reset_pmds = req->reg_reset_pmds[0];
2902 flags = 0;
2903
2904
2905 if (cnum >= PMU_MAX_PMCS) {
2906 DPRINT(("pmc%u is invalid\n", cnum));
2907 goto error;
2908 }
2909
2910 pmc_type = pmu_conf->pmc_desc[cnum].type;
2911 pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
2912 is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
2913 is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
2914
2915 /*
2916 * we reject all non implemented PMC as well
2917 * as attempts to modify PMC[0-3] which are used
2918 * as status registers by the PMU
2919 */
2920 if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
2921 DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
2922 goto error;
2923 }
2924 wr_func = pmu_conf->pmc_desc[cnum].write_check;
2925 /*
2926 * If the PMC is a monitor, then if the value is not the default:
2927 * - system-wide session: PMCx.pm=1 (privileged monitor)
2928 * - per-task : PMCx.pm=0 (user monitor)
2929 */
2930 if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
2931 DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
2932 cnum,
2933 pmc_pm,
2934 is_system));
2935 goto error;
2936 }
2937
2938 if (is_counting) {
2939 /*
2940 * enforce generation of overflow interrupt. Necessary on all
2941 * CPUs.
2942 */
2943 value |= 1 << PMU_PMC_OI;
2944
2945 if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
2946 flags |= PFM_REGFL_OVFL_NOTIFY;
2947 }
2948
2949 if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
2950
2951 /* verify validity of smpl_pmds */
2952 if ((smpl_pmds & impl_pmds) != smpl_pmds) {
2953 DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
2954 goto error;
2955 }
2956
2957 /* verify validity of reset_pmds */
2958 if ((reset_pmds & impl_pmds) != reset_pmds) {
2959 DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
2960 goto error;
2961 }
2962 } else {
2963 if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
2964 DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
2965 goto error;
2966 }
2967 /* eventid on non-counting monitors are ignored */
2968 }
2969
2970 /*
2971 * execute write checker, if any
2972 */
2973 if (likely(expert_mode == 0 && wr_func)) {
2974 ret = (*wr_func)(task, ctx, cnum, &value, regs);
2975 if (ret) goto error;
2976 ret = -EINVAL;
2977 }
2978
2979 /*
2980 * no error on this register
2981 */
2982 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
2983
2984 /*
2985 * Now we commit the changes to the software state
2986 */
2987
2988 /*
2989 * update overflow information
2990 */
2991 if (is_counting) {
2992 /*
2993 * full flag update each time a register is programmed
2994 */
2995 ctx->ctx_pmds[cnum].flags = flags;
2996
2997 ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
2998 ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
2999 ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
3000
3001 /*
3002 * Mark all PMDS to be accessed as used.
3003 *
3004 * We do not keep track of PMC because we have to
3005 * systematically restore ALL of them.
3006 *
3007 * We do not update the used_monitors mask, because
3008 * if we have not programmed them, then will be in
3009 * a quiescent state, therefore we will not need to
3010 * mask/restore then when context is MASKED.
3011 */
3012 CTX_USED_PMD(ctx, reset_pmds);
3013 CTX_USED_PMD(ctx, smpl_pmds);
3014 /*
3015 * make sure we do not try to reset on
3016 * restart because we have established new values
3017 */
3018 if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3019 }
3020 /*
3021 * Needed in case the user does not initialize the equivalent
3022 * PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
3023 * possible leak here.
3024 */
3025 CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
3026
3027 /*
3028 * keep track of the monitor PMC that we are using.
3029 * we save the value of the pmc in ctx_pmcs[] and if
3030 * the monitoring is not stopped for the context we also
3031 * place it in the saved state area so that it will be
3032 * picked up later by the context switch code.
3033 *
3034 * The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
3035 *
3036 * The value in th_pmcs[] may be modified on overflow, i.e., when
3037 * monitoring needs to be stopped.
3038 */
3039 if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
3040
3041 /*
3042 * update context state
3043 */
3044 ctx->ctx_pmcs[cnum] = value;
3045
3046 if (is_loaded) {
3047 /*
3048 * write thread state
3049 */
3050 if (is_system == 0) ctx->th_pmcs[cnum] = value;
3051
3052 /*
3053 * write hardware register if we can
3054 */
3055 if (can_access_pmu) {
3056 ia64_set_pmc(cnum, value);
3057 }
3058#ifdef CONFIG_SMP
3059 else {
3060 /*
3061 * per-task SMP only here
3062 *
3063 * we are guaranteed that the task is not running on the other CPU,
3064 * we indicate that this PMD will need to be reloaded if the task
3065 * is rescheduled on the CPU it ran last on.
3066 */
3067 ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
3068 }
3069#endif
3070 }
3071
3072 DPRINT(("pmc[%u]=0x%lx ld=%d apmu=%d flags=0x%x all_pmcs=0x%lx used_pmds=0x%lx eventid=%ld smpl_pmds=0x%lx reset_pmds=0x%lx reloads_pmcs=0x%lx used_monitors=0x%lx ovfl_regs=0x%lx\n",
3073 cnum,
3074 value,
3075 is_loaded,
3076 can_access_pmu,
3077 flags,
3078 ctx->ctx_all_pmcs[0],
3079 ctx->ctx_used_pmds[0],
3080 ctx->ctx_pmds[cnum].eventid,
3081 smpl_pmds,
3082 reset_pmds,
3083 ctx->ctx_reload_pmcs[0],
3084 ctx->ctx_used_monitors[0],
3085 ctx->ctx_ovfl_regs[0]));
3086 }
3087
3088 /*
3089 * make sure the changes are visible
3090 */
3091 if (can_access_pmu) ia64_srlz_d();
3092
3093 return 0;
3094error:
3095 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3096 return ret;
3097}
3098
3099static int
3100pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3101{
3102 struct task_struct *task;
3103 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3104 unsigned long value, hw_value, ovfl_mask;
3105 unsigned int cnum;
3106 int i, can_access_pmu = 0, state;
3107 int is_counting, is_loaded, is_system, expert_mode;
3108 int ret = -EINVAL;
3109 pfm_reg_check_t wr_func;
3110
3111
3112 state = ctx->ctx_state;
3113 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3114 is_system = ctx->ctx_fl_system;
3115 ovfl_mask = pmu_conf->ovfl_val;
3116 task = ctx->ctx_task;
3117
3118 if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
3119
3120 /*
3121 * on both UP and SMP, we can only write to the PMC when the task is
3122 * the owner of the local PMU.
3123 */
3124 if (likely(is_loaded)) {
3125 /*
3126 * In system wide and when the context is loaded, access can only happen
3127 * when the caller is running on the CPU being monitored by the session.
3128 * It does not have to be the owner (ctx_task) of the context per se.
3129 */
3130 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3131 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3132 return -EBUSY;
3133 }
3134 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3135 }
3136 expert_mode = pfm_sysctl.expert_mode;
3137
3138 for (i = 0; i < count; i++, req++) {
3139
3140 cnum = req->reg_num;
3141 value = req->reg_value;
3142
3143 if (!PMD_IS_IMPL(cnum)) {
3144 DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
3145 goto abort_mission;
3146 }
3147 is_counting = PMD_IS_COUNTING(cnum);
3148 wr_func = pmu_conf->pmd_desc[cnum].write_check;
3149
3150 /*
3151 * execute write checker, if any
3152 */
3153 if (unlikely(expert_mode == 0 && wr_func)) {
3154 unsigned long v = value;
3155
3156 ret = (*wr_func)(task, ctx, cnum, &v, regs);
3157 if (ret) goto abort_mission;
3158
3159 value = v;
3160 ret = -EINVAL;
3161 }
3162
3163 /*
3164 * no error on this register
3165 */
3166 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
3167
3168 /*
3169 * now commit changes to software state
3170 */
3171 hw_value = value;
3172
3173 /*
3174 * update virtualized (64bits) counter
3175 */
3176 if (is_counting) {
3177 /*
3178 * write context state
3179 */
3180 ctx->ctx_pmds[cnum].lval = value;
3181
3182 /*
3183 * when context is load we use the split value
3184 */
3185 if (is_loaded) {
3186 hw_value = value & ovfl_mask;
3187 value = value & ~ovfl_mask;
3188 }
3189 }
3190 /*
3191 * update reset values (not just for counters)
3192 */
3193 ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
3194 ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
3195
3196 /*
3197 * update randomization parameters (not just for counters)
3198 */
3199 ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
3200 ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
3201
3202 /*
3203 * update context value
3204 */
3205 ctx->ctx_pmds[cnum].val = value;
3206
3207 /*
3208 * Keep track of what we use
3209 *
3210 * We do not keep track of PMC because we have to
3211 * systematically restore ALL of them.
3212 */
3213 CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
3214
3215 /*
3216 * mark this PMD register used as well
3217 */
3218 CTX_USED_PMD(ctx, RDEP(cnum));
3219
3220 /*
3221 * make sure we do not try to reset on
3222 * restart because we have established new values
3223 */
3224 if (is_counting && state == PFM_CTX_MASKED) {
3225 ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
3226 }
3227
3228 if (is_loaded) {
3229 /*
3230 * write thread state
3231 */
3232 if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
3233
3234 /*
3235 * write hardware register if we can
3236 */
3237 if (can_access_pmu) {
3238 ia64_set_pmd(cnum, hw_value);
3239 } else {
3240#ifdef CONFIG_SMP
3241 /*
3242 * we are guaranteed that the task is not running on the other CPU,
3243 * we indicate that this PMD will need to be reloaded if the task
3244 * is rescheduled on the CPU it ran last on.
3245 */
3246 ctx->ctx_reload_pmds[0] |= 1UL << cnum;
3247#endif
3248 }
3249 }
3250
3251 DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
3252 "long_reset=0x%lx notify=%c seed=0x%lx mask=0x%lx used_pmds=0x%lx reset_pmds=0x%lx reload_pmds=0x%lx all_pmds=0x%lx ovfl_regs=0x%lx\n",
3253 cnum,
3254 value,
3255 is_loaded,
3256 can_access_pmu,
3257 hw_value,
3258 ctx->ctx_pmds[cnum].val,
3259 ctx->ctx_pmds[cnum].short_reset,
3260 ctx->ctx_pmds[cnum].long_reset,
3261 PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
3262 ctx->ctx_pmds[cnum].seed,
3263 ctx->ctx_pmds[cnum].mask,
3264 ctx->ctx_used_pmds[0],
3265 ctx->ctx_pmds[cnum].reset_pmds[0],
3266 ctx->ctx_reload_pmds[0],
3267 ctx->ctx_all_pmds[0],
3268 ctx->ctx_ovfl_regs[0]));
3269 }
3270
3271 /*
3272 * make changes visible
3273 */
3274 if (can_access_pmu) ia64_srlz_d();
3275
3276 return 0;
3277
3278abort_mission:
3279 /*
3280 * for now, we have only one possibility for error
3281 */
3282 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3283 return ret;
3284}
3285
3286/*
3287 * By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
3288 * Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
3289 * interrupt is delivered during the call, it will be kept pending until we leave, making
3290 * it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
3291 * guaranteed to return consistent data to the user, it may simply be old. It is not
3292 * trivial to treat the overflow while inside the call because you may end up in
3293 * some module sampling buffer code causing deadlocks.
3294 */
3295static int
3296pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3297{
3298 struct task_struct *task;
3299 unsigned long val = 0UL, lval, ovfl_mask, sval;
3300 pfarg_reg_t *req = (pfarg_reg_t *)arg;
3301 unsigned int cnum, reg_flags = 0;
3302 int i, can_access_pmu = 0, state;
3303 int is_loaded, is_system, is_counting, expert_mode;
3304 int ret = -EINVAL;
3305 pfm_reg_check_t rd_func;
3306
3307 /*
3308 * access is possible when loaded only for
3309 * self-monitoring tasks or in UP mode
3310 */
3311
3312 state = ctx->ctx_state;
3313 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3314 is_system = ctx->ctx_fl_system;
3315 ovfl_mask = pmu_conf->ovfl_val;
3316 task = ctx->ctx_task;
3317
3318 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3319
3320 if (likely(is_loaded)) {
3321 /*
3322 * In system wide and when the context is loaded, access can only happen
3323 * when the caller is running on the CPU being monitored by the session.
3324 * It does not have to be the owner (ctx_task) of the context per se.
3325 */
3326 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3327 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3328 return -EBUSY;
3329 }
3330 /*
3331 * this can be true when not self-monitoring only in UP
3332 */
3333 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3334
3335 if (can_access_pmu) ia64_srlz_d();
3336 }
3337 expert_mode = pfm_sysctl.expert_mode;
3338
3339 DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
3340 is_loaded,
3341 can_access_pmu,
3342 state));
3343
3344 /*
3345 * on both UP and SMP, we can only read the PMD from the hardware register when
3346 * the task is the owner of the local PMU.
3347 */
3348
3349 for (i = 0; i < count; i++, req++) {
3350
3351 cnum = req->reg_num;
3352 reg_flags = req->reg_flags;
3353
3354 if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
3355 /*
3356 * we can only read the register that we use. That includes
3357 * the one we explicitly initialize AND the one we want included
3358 * in the sampling buffer (smpl_regs).
3359 *
3360 * Having this restriction allows optimization in the ctxsw routine
3361 * without compromising security (leaks)
3362 */
3363 if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
3364
3365 sval = ctx->ctx_pmds[cnum].val;
3366 lval = ctx->ctx_pmds[cnum].lval;
3367 is_counting = PMD_IS_COUNTING(cnum);
3368
3369 /*
3370 * If the task is not the current one, then we check if the
3371 * PMU state is still in the local live register due to lazy ctxsw.
3372 * If true, then we read directly from the registers.
3373 */
3374 if (can_access_pmu){
3375 val = ia64_get_pmd(cnum);
3376 } else {
3377 /*
3378 * context has been saved
3379 * if context is zombie, then task does not exist anymore.
3380 * In this case, we use the full value saved in the context (pfm_flush_regs()).
3381 */
3382 val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
3383 }
3384 rd_func = pmu_conf->pmd_desc[cnum].read_check;
3385
3386 if (is_counting) {
3387 /*
3388 * XXX: need to check for overflow when loaded
3389 */
3390 val &= ovfl_mask;
3391 val += sval;
3392 }
3393
3394 /*
3395 * execute read checker, if any
3396 */
3397 if (unlikely(expert_mode == 0 && rd_func)) {
3398 unsigned long v = val;
3399 ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
3400 if (ret) goto error;
3401 val = v;
3402 ret = -EINVAL;
3403 }
3404
3405 PFM_REG_RETFLAG_SET(reg_flags, 0);
3406
3407 DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
3408
3409 /*
3410 * update register return value, abort all if problem during copy.
3411 * we only modify the reg_flags field. no check mode is fine because
3412 * access has been verified upfront in sys_perfmonctl().
3413 */
3414 req->reg_value = val;
3415 req->reg_flags = reg_flags;
3416 req->reg_last_reset_val = lval;
3417 }
3418
3419 return 0;
3420
3421error:
3422 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3423 return ret;
3424}
3425
3426int
3427pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3428{
3429 pfm_context_t *ctx;
3430
3431 if (req == NULL) return -EINVAL;
3432
3433 ctx = GET_PMU_CTX();
3434
3435 if (ctx == NULL) return -EINVAL;
3436
3437 /*
3438 * for now limit to current task, which is enough when calling
3439 * from overflow handler
3440 */
3441 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3442
3443 return pfm_write_pmcs(ctx, req, nreq, regs);
3444}
3445EXPORT_SYMBOL(pfm_mod_write_pmcs);
3446
3447int
3448pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3449{
3450 pfm_context_t *ctx;
3451
3452 if (req == NULL) return -EINVAL;
3453
3454 ctx = GET_PMU_CTX();
3455
3456 if (ctx == NULL) return -EINVAL;
3457
3458 /*
3459 * for now limit to current task, which is enough when calling
3460 * from overflow handler
3461 */
3462 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3463
3464 return pfm_read_pmds(ctx, req, nreq, regs);
3465}
3466EXPORT_SYMBOL(pfm_mod_read_pmds);
3467
3468/*
3469 * Only call this function when a process it trying to
3470 * write the debug registers (reading is always allowed)
3471 */
3472int
3473pfm_use_debug_registers(struct task_struct *task)
3474{
3475 pfm_context_t *ctx = task->thread.pfm_context;
3476 unsigned long flags;
3477 int ret = 0;
3478
3479 if (pmu_conf->use_rr_dbregs == 0) return 0;
3480
3481 DPRINT(("called for [%d]\n", task_pid_nr(task)));
3482
3483 /*
3484 * do it only once
3485 */
3486 if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
3487
3488 /*
3489 * Even on SMP, we do not need to use an atomic here because
3490 * the only way in is via ptrace() and this is possible only when the
3491 * process is stopped. Even in the case where the ctxsw out is not totally
3492 * completed by the time we come here, there is no way the 'stopped' process
3493 * could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
3494 * So this is always safe.
3495 */
3496 if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
3497
3498 LOCK_PFS(flags);
3499
3500 /*
3501 * We cannot allow setting breakpoints when system wide monitoring
3502 * sessions are using the debug registers.
3503 */
3504 if (pfm_sessions.pfs_sys_use_dbregs> 0)
3505 ret = -1;
3506 else
3507 pfm_sessions.pfs_ptrace_use_dbregs++;
3508
3509 DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
3510 pfm_sessions.pfs_ptrace_use_dbregs,
3511 pfm_sessions.pfs_sys_use_dbregs,
3512 task_pid_nr(task), ret));
3513
3514 UNLOCK_PFS(flags);
3515
3516 return ret;
3517}
3518
3519/*
3520 * This function is called for every task that exits with the
3521 * IA64_THREAD_DBG_VALID set. This indicates a task which was
3522 * able to use the debug registers for debugging purposes via
3523 * ptrace(). Therefore we know it was not using them for
3524 * performance monitoring, so we only decrement the number
3525 * of "ptraced" debug register users to keep the count up to date
3526 */
3527int
3528pfm_release_debug_registers(struct task_struct *task)
3529{
3530 unsigned long flags;
3531 int ret;
3532
3533 if (pmu_conf->use_rr_dbregs == 0) return 0;
3534
3535 LOCK_PFS(flags);
3536 if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
3537 printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
3538 ret = -1;
3539 } else {
3540 pfm_sessions.pfs_ptrace_use_dbregs--;
3541 ret = 0;
3542 }
3543 UNLOCK_PFS(flags);
3544
3545 return ret;
3546}
3547
3548static int
3549pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3550{
3551 struct task_struct *task;
3552 pfm_buffer_fmt_t *fmt;
3553 pfm_ovfl_ctrl_t rst_ctrl;
3554 int state, is_system;
3555 int ret = 0;
3556
3557 state = ctx->ctx_state;
3558 fmt = ctx->ctx_buf_fmt;
3559 is_system = ctx->ctx_fl_system;
3560 task = PFM_CTX_TASK(ctx);
3561
3562 switch(state) {
3563 case PFM_CTX_MASKED:
3564 break;
3565 case PFM_CTX_LOADED:
3566 if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
3567 /* fall through */
3568 case PFM_CTX_UNLOADED:
3569 case PFM_CTX_ZOMBIE:
3570 DPRINT(("invalid state=%d\n", state));
3571 return -EBUSY;
3572 default:
3573 DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
3574 return -EINVAL;
3575 }
3576
3577 /*
3578 * In system wide and when the context is loaded, access can only happen
3579 * when the caller is running on the CPU being monitored by the session.
3580 * It does not have to be the owner (ctx_task) of the context per se.
3581 */
3582 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
3583 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3584 return -EBUSY;
3585 }
3586
3587 /* sanity check */
3588 if (unlikely(task == NULL)) {
3589 printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
3590 return -EINVAL;
3591 }
3592
3593 if (task == current || is_system) {
3594
3595 fmt = ctx->ctx_buf_fmt;
3596
3597 DPRINT(("restarting self %d ovfl=0x%lx\n",
3598 task_pid_nr(task),
3599 ctx->ctx_ovfl_regs[0]));
3600
3601 if (CTX_HAS_SMPL(ctx)) {
3602
3603 prefetch(ctx->ctx_smpl_hdr);
3604
3605 rst_ctrl.bits.mask_monitoring = 0;
3606 rst_ctrl.bits.reset_ovfl_pmds = 0;
3607
3608 if (state == PFM_CTX_LOADED)
3609 ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3610 else
3611 ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
3612 } else {
3613 rst_ctrl.bits.mask_monitoring = 0;
3614 rst_ctrl.bits.reset_ovfl_pmds = 1;
3615 }
3616
3617 if (ret == 0) {
3618 if (rst_ctrl.bits.reset_ovfl_pmds)
3619 pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
3620
3621 if (rst_ctrl.bits.mask_monitoring == 0) {
3622 DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
3623
3624 if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
3625 } else {
3626 DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
3627
3628 // cannot use pfm_stop_monitoring(task, regs);
3629 }
3630 }
3631 /*
3632 * clear overflowed PMD mask to remove any stale information
3633 */
3634 ctx->ctx_ovfl_regs[0] = 0UL;
3635
3636 /*
3637 * back to LOADED state
3638 */
3639 ctx->ctx_state = PFM_CTX_LOADED;
3640
3641 /*
3642 * XXX: not really useful for self monitoring
3643 */
3644 ctx->ctx_fl_can_restart = 0;
3645
3646 return 0;
3647 }
3648
3649 /*
3650 * restart another task
3651 */
3652
3653 /*
3654 * When PFM_CTX_MASKED, we cannot issue a restart before the previous
3655 * one is seen by the task.
3656 */
3657 if (state == PFM_CTX_MASKED) {
3658 if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
3659 /*
3660 * will prevent subsequent restart before this one is
3661 * seen by other task
3662 */
3663 ctx->ctx_fl_can_restart = 0;
3664 }
3665
3666 /*
3667 * if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
3668 * the task is blocked or on its way to block. That's the normal
3669 * restart path. If the monitoring is not masked, then the task
3670 * can be actively monitoring and we cannot directly intervene.
3671 * Therefore we use the trap mechanism to catch the task and
3672 * force it to reset the buffer/reset PMDs.
3673 *
3674 * if non-blocking, then we ensure that the task will go into
3675 * pfm_handle_work() before returning to user mode.
3676 *
3677 * We cannot explicitly reset another task, it MUST always
3678 * be done by the task itself. This works for system wide because
3679 * the tool that is controlling the session is logically doing
3680 * "self-monitoring".
3681 */
3682 if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
3683 DPRINT(("unblocking [%d]\n", task_pid_nr(task)));
3684 complete(&ctx->ctx_restart_done);
3685 } else {
3686 DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
3687
3688 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
3689
3690 PFM_SET_WORK_PENDING(task, 1);
3691
3692 set_notify_resume(task);
3693
3694 /*
3695 * XXX: send reschedule if task runs on another CPU
3696 */
3697 }
3698 return 0;
3699}
3700
3701static int
3702pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3703{
3704 unsigned int m = *(unsigned int *)arg;
3705
3706 pfm_sysctl.debug = m == 0 ? 0 : 1;
3707
3708 printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
3709
3710 if (m == 0) {
3711 memset(pfm_stats, 0, sizeof(pfm_stats));
3712 for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
3713 }
3714 return 0;
3715}
3716
3717/*
3718 * arg can be NULL and count can be zero for this function
3719 */
3720static int
3721pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3722{
3723 struct thread_struct *thread = NULL;
3724 struct task_struct *task;
3725 pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
3726 unsigned long flags;
3727 dbreg_t dbreg;
3728 unsigned int rnum;
3729 int first_time;
3730 int ret = 0, state;
3731 int i, can_access_pmu = 0;
3732 int is_system, is_loaded;
3733
3734 if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
3735
3736 state = ctx->ctx_state;
3737 is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
3738 is_system = ctx->ctx_fl_system;
3739 task = ctx->ctx_task;
3740
3741 if (state == PFM_CTX_ZOMBIE) return -EINVAL;
3742
3743 /*
3744 * on both UP and SMP, we can only write to the PMC when the task is
3745 * the owner of the local PMU.
3746 */
3747 if (is_loaded) {
3748 thread = &task->thread;
3749 /*
3750 * In system wide and when the context is loaded, access can only happen
3751 * when the caller is running on the CPU being monitored by the session.
3752 * It does not have to be the owner (ctx_task) of the context per se.
3753 */
3754 if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
3755 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
3756 return -EBUSY;
3757 }
3758 can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
3759 }
3760
3761 /*
3762 * we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
3763 * ensuring that no real breakpoint can be installed via this call.
3764 *
3765 * IMPORTANT: regs can be NULL in this function
3766 */
3767
3768 first_time = ctx->ctx_fl_using_dbreg == 0;
3769
3770 /*
3771 * don't bother if we are loaded and task is being debugged
3772 */
3773 if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
3774 DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
3775 return -EBUSY;
3776 }
3777
3778 /*
3779 * check for debug registers in system wide mode
3780 *
3781 * If though a check is done in pfm_context_load(),
3782 * we must repeat it here, in case the registers are
3783 * written after the context is loaded
3784 */
3785 if (is_loaded) {
3786 LOCK_PFS(flags);
3787
3788 if (first_time && is_system) {
3789 if (pfm_sessions.pfs_ptrace_use_dbregs)
3790 ret = -EBUSY;
3791 else
3792 pfm_sessions.pfs_sys_use_dbregs++;
3793 }
3794 UNLOCK_PFS(flags);
3795 }
3796
3797 if (ret != 0) return ret;
3798
3799 /*
3800 * mark ourself as user of the debug registers for
3801 * perfmon purposes.
3802 */
3803 ctx->ctx_fl_using_dbreg = 1;
3804
3805 /*
3806 * clear hardware registers to make sure we don't
3807 * pick up stale state.
3808 *
3809 * for a system wide session, we do not use
3810 * thread.dbr, thread.ibr because this process
3811 * never leaves the current CPU and the state
3812 * is shared by all processes running on it
3813 */
3814 if (first_time && can_access_pmu) {
3815 DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
3816 for (i=0; i < pmu_conf->num_ibrs; i++) {
3817 ia64_set_ibr(i, 0UL);
3818 ia64_dv_serialize_instruction();
3819 }
3820 ia64_srlz_i();
3821 for (i=0; i < pmu_conf->num_dbrs; i++) {
3822 ia64_set_dbr(i, 0UL);
3823 ia64_dv_serialize_data();
3824 }
3825 ia64_srlz_d();
3826 }
3827
3828 /*
3829 * Now install the values into the registers
3830 */
3831 for (i = 0; i < count; i++, req++) {
3832
3833 rnum = req->dbreg_num;
3834 dbreg.val = req->dbreg_value;
3835
3836 ret = -EINVAL;
3837
3838 if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
3839 DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
3840 rnum, dbreg.val, mode, i, count));
3841
3842 goto abort_mission;
3843 }
3844
3845 /*
3846 * make sure we do not install enabled breakpoint
3847 */
3848 if (rnum & 0x1) {
3849 if (mode == PFM_CODE_RR)
3850 dbreg.ibr.ibr_x = 0;
3851 else
3852 dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
3853 }
3854
3855 PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
3856
3857 /*
3858 * Debug registers, just like PMC, can only be modified
3859 * by a kernel call. Moreover, perfmon() access to those
3860 * registers are centralized in this routine. The hardware
3861 * does not modify the value of these registers, therefore,
3862 * if we save them as they are written, we can avoid having
3863 * to save them on context switch out. This is made possible
3864 * by the fact that when perfmon uses debug registers, ptrace()
3865 * won't be able to modify them concurrently.
3866 */
3867 if (mode == PFM_CODE_RR) {
3868 CTX_USED_IBR(ctx, rnum);
3869
3870 if (can_access_pmu) {
3871 ia64_set_ibr(rnum, dbreg.val);
3872 ia64_dv_serialize_instruction();
3873 }
3874
3875 ctx->ctx_ibrs[rnum] = dbreg.val;
3876
3877 DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
3878 rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
3879 } else {
3880 CTX_USED_DBR(ctx, rnum);
3881
3882 if (can_access_pmu) {
3883 ia64_set_dbr(rnum, dbreg.val);
3884 ia64_dv_serialize_data();
3885 }
3886 ctx->ctx_dbrs[rnum] = dbreg.val;
3887
3888 DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
3889 rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
3890 }
3891 }
3892
3893 return 0;
3894
3895abort_mission:
3896 /*
3897 * in case it was our first attempt, we undo the global modifications
3898 */
3899 if (first_time) {
3900 LOCK_PFS(flags);
3901 if (ctx->ctx_fl_system) {
3902 pfm_sessions.pfs_sys_use_dbregs--;
3903 }
3904 UNLOCK_PFS(flags);
3905 ctx->ctx_fl_using_dbreg = 0;
3906 }
3907 /*
3908 * install error return flag
3909 */
3910 PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
3911
3912 return ret;
3913}
3914
3915static int
3916pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3917{
3918 return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
3919}
3920
3921static int
3922pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3923{
3924 return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
3925}
3926
3927int
3928pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3929{
3930 pfm_context_t *ctx;
3931
3932 if (req == NULL) return -EINVAL;
3933
3934 ctx = GET_PMU_CTX();
3935
3936 if (ctx == NULL) return -EINVAL;
3937
3938 /*
3939 * for now limit to current task, which is enough when calling
3940 * from overflow handler
3941 */
3942 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3943
3944 return pfm_write_ibrs(ctx, req, nreq, regs);
3945}
3946EXPORT_SYMBOL(pfm_mod_write_ibrs);
3947
3948int
3949pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
3950{
3951 pfm_context_t *ctx;
3952
3953 if (req == NULL) return -EINVAL;
3954
3955 ctx = GET_PMU_CTX();
3956
3957 if (ctx == NULL) return -EINVAL;
3958
3959 /*
3960 * for now limit to current task, which is enough when calling
3961 * from overflow handler
3962 */
3963 if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
3964
3965 return pfm_write_dbrs(ctx, req, nreq, regs);
3966}
3967EXPORT_SYMBOL(pfm_mod_write_dbrs);
3968
3969
3970static int
3971pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3972{
3973 pfarg_features_t *req = (pfarg_features_t *)arg;
3974
3975 req->ft_version = PFM_VERSION;
3976 return 0;
3977}
3978
3979static int
3980pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
3981{
3982 struct pt_regs *tregs;
3983 struct task_struct *task = PFM_CTX_TASK(ctx);
3984 int state, is_system;
3985
3986 state = ctx->ctx_state;
3987 is_system = ctx->ctx_fl_system;
3988
3989 /*
3990 * context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
3991 */
3992 if (state == PFM_CTX_UNLOADED) return -EINVAL;
3993
3994 /*
3995 * In system wide and when the context is loaded, access can only happen
3996 * when the caller is running on the CPU being monitored by the session.
3997 * It does not have to be the owner (ctx_task) of the context per se.
3998 */
3999 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
4000 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
4001 return -EBUSY;
4002 }
4003 DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
4004 task_pid_nr(PFM_CTX_TASK(ctx)),
4005 state,
4006 is_system));
4007 /*
4008 * in system mode, we need to update the PMU directly
4009 * and the user level state of the caller, which may not
4010 * necessarily be the creator of the context.
4011 */
4012 if (is_system) {
4013 /*
4014 * Update local PMU first
4015 *
4016 * disable dcr pp
4017 */
4018 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
4019 ia64_srlz_i();
4020
4021 /*
4022 * update local cpuinfo
4023 */
4024 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4025
4026 /*
4027 * stop monitoring, does srlz.i
4028 */
4029 pfm_clear_psr_pp();
4030
4031 /*
4032 * stop monitoring in the caller
4033 */
4034 ia64_psr(regs)->pp = 0;
4035
4036 return 0;
4037 }
4038 /*
4039 * per-task mode
4040 */
4041
4042 if (task == current) {
4043 /* stop monitoring at kernel level */
4044 pfm_clear_psr_up();
4045
4046 /*
4047 * stop monitoring at the user level
4048 */
4049 ia64_psr(regs)->up = 0;
4050 } else {
4051 tregs = task_pt_regs(task);
4052
4053 /*
4054 * stop monitoring at the user level
4055 */
4056 ia64_psr(tregs)->up = 0;
4057
4058 /*
4059 * monitoring disabled in kernel at next reschedule
4060 */
4061 ctx->ctx_saved_psr_up = 0;
4062 DPRINT(("task=[%d]\n", task_pid_nr(task)));
4063 }
4064 return 0;
4065}
4066
4067
4068static int
4069pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4070{
4071 struct pt_regs *tregs;
4072 int state, is_system;
4073
4074 state = ctx->ctx_state;
4075 is_system = ctx->ctx_fl_system;
4076
4077 if (state != PFM_CTX_LOADED) return -EINVAL;
4078
4079 /*
4080 * In system wide and when the context is loaded, access can only happen
4081 * when the caller is running on the CPU being monitored by the session.
4082 * It does not have to be the owner (ctx_task) of the context per se.
4083 */
4084 if (is_system && ctx->ctx_cpu != smp_processor_id()) {
4085 DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
4086 return -EBUSY;
4087 }
4088
4089 /*
4090 * in system mode, we need to update the PMU directly
4091 * and the user level state of the caller, which may not
4092 * necessarily be the creator of the context.
4093 */
4094 if (is_system) {
4095
4096 /*
4097 * set user level psr.pp for the caller
4098 */
4099 ia64_psr(regs)->pp = 1;
4100
4101 /*
4102 * now update the local PMU and cpuinfo
4103 */
4104 PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
4105
4106 /*
4107 * start monitoring at kernel level
4108 */
4109 pfm_set_psr_pp();
4110
4111 /* enable dcr pp */
4112 ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
4113 ia64_srlz_i();
4114
4115 return 0;
4116 }
4117
4118 /*
4119 * per-process mode
4120 */
4121
4122 if (ctx->ctx_task == current) {
4123
4124 /* start monitoring at kernel level */
4125 pfm_set_psr_up();
4126
4127 /*
4128 * activate monitoring at user level
4129 */
4130 ia64_psr(regs)->up = 1;
4131
4132 } else {
4133 tregs = task_pt_regs(ctx->ctx_task);
4134
4135 /*
4136 * start monitoring at the kernel level the next
4137 * time the task is scheduled
4138 */
4139 ctx->ctx_saved_psr_up = IA64_PSR_UP;
4140
4141 /*
4142 * activate monitoring at user level
4143 */
4144 ia64_psr(tregs)->up = 1;
4145 }
4146 return 0;
4147}
4148
4149static int
4150pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4151{
4152 pfarg_reg_t *req = (pfarg_reg_t *)arg;
4153 unsigned int cnum;
4154 int i;
4155 int ret = -EINVAL;
4156
4157 for (i = 0; i < count; i++, req++) {
4158
4159 cnum = req->reg_num;
4160
4161 if (!PMC_IS_IMPL(cnum)) goto abort_mission;
4162
4163 req->reg_value = PMC_DFL_VAL(cnum);
4164
4165 PFM_REG_RETFLAG_SET(req->reg_flags, 0);
4166
4167 DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
4168 }
4169 return 0;
4170
4171abort_mission:
4172 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
4173 return ret;
4174}
4175
4176static int
4177pfm_check_task_exist(pfm_context_t *ctx)
4178{
4179 struct task_struct *g, *t;
4180 int ret = -ESRCH;
4181
4182 read_lock(&tasklist_lock);
4183
4184 do_each_thread (g, t) {
4185 if (t->thread.pfm_context == ctx) {
4186 ret = 0;
4187 goto out;
4188 }
4189 } while_each_thread (g, t);
4190out:
4191 read_unlock(&tasklist_lock);
4192
4193 DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
4194
4195 return ret;
4196}
4197
4198static int
4199pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4200{
4201 struct task_struct *task;
4202 struct thread_struct *thread;
4203 struct pfm_context_t *old;
4204 unsigned long flags;
4205#ifndef CONFIG_SMP
4206 struct task_struct *owner_task = NULL;
4207#endif
4208 pfarg_load_t *req = (pfarg_load_t *)arg;
4209 unsigned long *pmcs_source, *pmds_source;
4210 int the_cpu;
4211 int ret = 0;
4212 int state, is_system, set_dbregs = 0;
4213
4214 state = ctx->ctx_state;
4215 is_system = ctx->ctx_fl_system;
4216 /*
4217 * can only load from unloaded or terminated state
4218 */
4219 if (state != PFM_CTX_UNLOADED) {
4220 DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
4221 req->load_pid,
4222 ctx->ctx_state));
4223 return -EBUSY;
4224 }
4225
4226 DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
4227
4228 if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
4229 DPRINT(("cannot use blocking mode on self\n"));
4230 return -EINVAL;
4231 }
4232
4233 ret = pfm_get_task(ctx, req->load_pid, &task);
4234 if (ret) {
4235 DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
4236 return ret;
4237 }
4238
4239 ret = -EINVAL;
4240
4241 /*
4242 * system wide is self monitoring only
4243 */
4244 if (is_system && task != current) {
4245 DPRINT(("system wide is self monitoring only load_pid=%d\n",
4246 req->load_pid));
4247 goto error;
4248 }
4249
4250 thread = &task->thread;
4251
4252 ret = 0;
4253 /*
4254 * cannot load a context which is using range restrictions,
4255 * into a task that is being debugged.
4256 */
4257 if (ctx->ctx_fl_using_dbreg) {
4258 if (thread->flags & IA64_THREAD_DBG_VALID) {
4259 ret = -EBUSY;
4260 DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
4261 goto error;
4262 }
4263 LOCK_PFS(flags);
4264
4265 if (is_system) {
4266 if (pfm_sessions.pfs_ptrace_use_dbregs) {
4267 DPRINT(("cannot load [%d] dbregs in use\n",
4268 task_pid_nr(task)));
4269 ret = -EBUSY;
4270 } else {
4271 pfm_sessions.pfs_sys_use_dbregs++;
4272 DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
4273 set_dbregs = 1;
4274 }
4275 }
4276
4277 UNLOCK_PFS(flags);
4278
4279 if (ret) goto error;
4280 }
4281
4282 /*
4283 * SMP system-wide monitoring implies self-monitoring.
4284 *
4285 * The programming model expects the task to
4286 * be pinned on a CPU throughout the session.
4287 * Here we take note of the current CPU at the
4288 * time the context is loaded. No call from
4289 * another CPU will be allowed.
4290 *
4291 * The pinning via shed_setaffinity()
4292 * must be done by the calling task prior
4293 * to this call.
4294 *
4295 * systemwide: keep track of CPU this session is supposed to run on
4296 */
4297 the_cpu = ctx->ctx_cpu = smp_processor_id();
4298
4299 ret = -EBUSY;
4300 /*
4301 * now reserve the session
4302 */
4303 ret = pfm_reserve_session(current, is_system, the_cpu);
4304 if (ret) goto error;
4305
4306 /*
4307 * task is necessarily stopped at this point.
4308 *
4309 * If the previous context was zombie, then it got removed in
4310 * pfm_save_regs(). Therefore we should not see it here.
4311 * If we see a context, then this is an active context
4312 *
4313 * XXX: needs to be atomic
4314 */
4315 DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
4316 thread->pfm_context, ctx));
4317
4318 ret = -EBUSY;
4319 old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
4320 if (old != NULL) {
4321 DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
4322 goto error_unres;
4323 }
4324
4325 pfm_reset_msgq(ctx);
4326
4327 ctx->ctx_state = PFM_CTX_LOADED;
4328
4329 /*
4330 * link context to task
4331 */
4332 ctx->ctx_task = task;
4333
4334 if (is_system) {
4335 /*
4336 * we load as stopped
4337 */
4338 PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
4339 PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
4340
4341 if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
4342 } else {
4343 thread->flags |= IA64_THREAD_PM_VALID;
4344 }
4345
4346 /*
4347 * propagate into thread-state
4348 */
4349 pfm_copy_pmds(task, ctx);
4350 pfm_copy_pmcs(task, ctx);
4351
4352 pmcs_source = ctx->th_pmcs;
4353 pmds_source = ctx->th_pmds;
4354
4355 /*
4356 * always the case for system-wide
4357 */
4358 if (task == current) {
4359
4360 if (is_system == 0) {
4361
4362 /* allow user level control */
4363 ia64_psr(regs)->sp = 0;
4364 DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
4365
4366 SET_LAST_CPU(ctx, smp_processor_id());
4367 INC_ACTIVATION();
4368 SET_ACTIVATION(ctx);
4369#ifndef CONFIG_SMP
4370 /*
4371 * push the other task out, if any
4372 */
4373 owner_task = GET_PMU_OWNER();
4374 if (owner_task) pfm_lazy_save_regs(owner_task);
4375#endif
4376 }
4377 /*
4378 * load all PMD from ctx to PMU (as opposed to thread state)
4379 * restore all PMC from ctx to PMU
4380 */
4381 pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
4382 pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
4383
4384 ctx->ctx_reload_pmcs[0] = 0UL;
4385 ctx->ctx_reload_pmds[0] = 0UL;
4386
4387 /*
4388 * guaranteed safe by earlier check against DBG_VALID
4389 */
4390 if (ctx->ctx_fl_using_dbreg) {
4391 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
4392 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
4393 }
4394 /*
4395 * set new ownership
4396 */
4397 SET_PMU_OWNER(task, ctx);
4398
4399 DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
4400 } else {
4401 /*
4402 * when not current, task MUST be stopped, so this is safe
4403 */
4404 regs = task_pt_regs(task);
4405
4406 /* force a full reload */
4407 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4408 SET_LAST_CPU(ctx, -1);
4409
4410 /* initial saved psr (stopped) */
4411 ctx->ctx_saved_psr_up = 0UL;
4412 ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
4413 }
4414
4415 ret = 0;
4416
4417error_unres:
4418 if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
4419error:
4420 /*
4421 * we must undo the dbregs setting (for system-wide)
4422 */
4423 if (ret && set_dbregs) {
4424 LOCK_PFS(flags);
4425 pfm_sessions.pfs_sys_use_dbregs--;
4426 UNLOCK_PFS(flags);
4427 }
4428 /*
4429 * release task, there is now a link with the context
4430 */
4431 if (is_system == 0 && task != current) {
4432 pfm_put_task(task);
4433
4434 if (ret == 0) {
4435 ret = pfm_check_task_exist(ctx);
4436 if (ret) {
4437 ctx->ctx_state = PFM_CTX_UNLOADED;
4438 ctx->ctx_task = NULL;
4439 }
4440 }
4441 }
4442 return ret;
4443}
4444
4445/*
4446 * in this function, we do not need to increase the use count
4447 * for the task via get_task_struct(), because we hold the
4448 * context lock. If the task were to disappear while having
4449 * a context attached, it would go through pfm_exit_thread()
4450 * which also grabs the context lock and would therefore be blocked
4451 * until we are here.
4452 */
4453static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
4454
4455static int
4456pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
4457{
4458 struct task_struct *task = PFM_CTX_TASK(ctx);
4459 struct pt_regs *tregs;
4460 int prev_state, is_system;
4461 int ret;
4462
4463 DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
4464
4465 prev_state = ctx->ctx_state;
4466 is_system = ctx->ctx_fl_system;
4467
4468 /*
4469 * unload only when necessary
4470 */
4471 if (prev_state == PFM_CTX_UNLOADED) {
4472 DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
4473 return 0;
4474 }
4475
4476 /*
4477 * clear psr and dcr bits
4478 */
4479 ret = pfm_stop(ctx, NULL, 0, regs);
4480 if (ret) return ret;
4481
4482 ctx->ctx_state = PFM_CTX_UNLOADED;
4483
4484 /*
4485 * in system mode, we need to update the PMU directly
4486 * and the user level state of the caller, which may not
4487 * necessarily be the creator of the context.
4488 */
4489 if (is_system) {
4490
4491 /*
4492 * Update cpuinfo
4493 *
4494 * local PMU is taken care of in pfm_stop()
4495 */
4496 PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
4497 PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
4498
4499 /*
4500 * save PMDs in context
4501 * release ownership
4502 */
4503 pfm_flush_pmds(current, ctx);
4504
4505 /*
4506 * at this point we are done with the PMU
4507 * so we can unreserve the resource.
4508 */
4509 if (prev_state != PFM_CTX_ZOMBIE)
4510 pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
4511
4512 /*
4513 * disconnect context from task
4514 */
4515 task->thread.pfm_context = NULL;
4516 /*
4517 * disconnect task from context
4518 */
4519 ctx->ctx_task = NULL;
4520
4521 /*
4522 * There is nothing more to cleanup here.
4523 */
4524 return 0;
4525 }
4526
4527 /*
4528 * per-task mode
4529 */
4530 tregs = task == current ? regs : task_pt_regs(task);
4531
4532 if (task == current) {
4533 /*
4534 * cancel user level control
4535 */
4536 ia64_psr(regs)->sp = 1;
4537
4538 DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
4539 }
4540 /*
4541 * save PMDs to context
4542 * release ownership
4543 */
4544 pfm_flush_pmds(task, ctx);
4545
4546 /*
4547 * at this point we are done with the PMU
4548 * so we can unreserve the resource.
4549 *
4550 * when state was ZOMBIE, we have already unreserved.
4551 */
4552 if (prev_state != PFM_CTX_ZOMBIE)
4553 pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
4554
4555 /*
4556 * reset activation counter and psr
4557 */
4558 ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
4559 SET_LAST_CPU(ctx, -1);
4560
4561 /*
4562 * PMU state will not be restored
4563 */
4564 task->thread.flags &= ~IA64_THREAD_PM_VALID;
4565
4566 /*
4567 * break links between context and task
4568 */
4569 task->thread.pfm_context = NULL;
4570 ctx->ctx_task = NULL;
4571
4572 PFM_SET_WORK_PENDING(task, 0);
4573
4574 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
4575 ctx->ctx_fl_can_restart = 0;
4576 ctx->ctx_fl_going_zombie = 0;
4577
4578 DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
4579
4580 return 0;
4581}
4582
4583
4584/*
4585 * called only from exit_thread(): task == current
4586 * we come here only if current has a context attached (loaded or masked)
4587 */
4588void
4589pfm_exit_thread(struct task_struct *task)
4590{
4591 pfm_context_t *ctx;
4592 unsigned long flags;
4593 struct pt_regs *regs = task_pt_regs(task);
4594 int ret, state;
4595 int free_ok = 0;
4596
4597 ctx = PFM_GET_CTX(task);
4598
4599 PROTECT_CTX(ctx, flags);
4600
4601 DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
4602
4603 state = ctx->ctx_state;
4604 switch(state) {
4605 case PFM_CTX_UNLOADED:
4606 /*
4607 * only comes to this function if pfm_context is not NULL, i.e., cannot
4608 * be in unloaded state
4609 */
4610 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
4611 break;
4612 case PFM_CTX_LOADED:
4613 case PFM_CTX_MASKED:
4614 ret = pfm_context_unload(ctx, NULL, 0, regs);
4615 if (ret) {
4616 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4617 }
4618 DPRINT(("ctx unloaded for current state was %d\n", state));
4619
4620 pfm_end_notify_user(ctx);
4621 break;
4622 case PFM_CTX_ZOMBIE:
4623 ret = pfm_context_unload(ctx, NULL, 0, regs);
4624 if (ret) {
4625 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
4626 }
4627 free_ok = 1;
4628 break;
4629 default:
4630 printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
4631 break;
4632 }
4633 UNPROTECT_CTX(ctx, flags);
4634
4635 { u64 psr = pfm_get_psr();
4636 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
4637 BUG_ON(GET_PMU_OWNER());
4638 BUG_ON(ia64_psr(regs)->up);
4639 BUG_ON(ia64_psr(regs)->pp);
4640 }
4641
4642 /*
4643 * All memory free operations (especially for vmalloc'ed memory)
4644 * MUST be done with interrupts ENABLED.
4645 */
4646 if (free_ok) pfm_context_free(ctx);
4647}
4648
4649/*
4650 * functions MUST be listed in the increasing order of their index (see permfon.h)
4651 */
4652#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
4653#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
4654#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
4655#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
4656#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
4657
4658static pfm_cmd_desc_t pfm_cmd_tab[]={
4659/* 0 */PFM_CMD_NONE,
4660/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4661/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4662/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4663/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
4664/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
4665/* 6 */PFM_CMD_NONE,
4666/* 7 */PFM_CMD_NONE,
4667/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
4668/* 9 */PFM_CMD_NONE,
4669/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
4670/* 11 */PFM_CMD_NONE,
4671/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
4672/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
4673/* 14 */PFM_CMD_NONE,
4674/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
4675/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
4676/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
4677/* 18 */PFM_CMD_NONE,
4678/* 19 */PFM_CMD_NONE,
4679/* 20 */PFM_CMD_NONE,
4680/* 21 */PFM_CMD_NONE,
4681/* 22 */PFM_CMD_NONE,
4682/* 23 */PFM_CMD_NONE,
4683/* 24 */PFM_CMD_NONE,
4684/* 25 */PFM_CMD_NONE,
4685/* 26 */PFM_CMD_NONE,
4686/* 27 */PFM_CMD_NONE,
4687/* 28 */PFM_CMD_NONE,
4688/* 29 */PFM_CMD_NONE,
4689/* 30 */PFM_CMD_NONE,
4690/* 31 */PFM_CMD_NONE,
4691/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
4692/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
4693};
4694#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
4695
4696static int
4697pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
4698{
4699 struct task_struct *task;
4700 int state, old_state;
4701
4702recheck:
4703 state = ctx->ctx_state;
4704 task = ctx->ctx_task;
4705
4706 if (task == NULL) {
4707 DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
4708 return 0;
4709 }
4710
4711 DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
4712 ctx->ctx_fd,
4713 state,
4714 task_pid_nr(task),
4715 task->state, PFM_CMD_STOPPED(cmd)));
4716
4717 /*
4718 * self-monitoring always ok.
4719 *
4720 * for system-wide the caller can either be the creator of the
4721 * context (to one to which the context is attached to) OR
4722 * a task running on the same CPU as the session.
4723 */
4724 if (task == current || ctx->ctx_fl_system) return 0;
4725
4726 /*
4727 * we are monitoring another thread
4728 */
4729 switch(state) {
4730 case PFM_CTX_UNLOADED:
4731 /*
4732 * if context is UNLOADED we are safe to go
4733 */
4734 return 0;
4735 case PFM_CTX_ZOMBIE:
4736 /*
4737 * no command can operate on a zombie context
4738 */
4739 DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
4740 return -EINVAL;
4741 case PFM_CTX_MASKED:
4742 /*
4743 * PMU state has been saved to software even though
4744 * the thread may still be running.
4745 */
4746 if (cmd != PFM_UNLOAD_CONTEXT) return 0;
4747 }
4748
4749 /*
4750 * context is LOADED or MASKED. Some commands may need to have
4751 * the task stopped.
4752 *
4753 * We could lift this restriction for UP but it would mean that
4754 * the user has no guarantee the task would not run between
4755 * two successive calls to perfmonctl(). That's probably OK.
4756 * If this user wants to ensure the task does not run, then
4757 * the task must be stopped.
4758 */
4759 if (PFM_CMD_STOPPED(cmd)) {
4760 if (!task_is_stopped_or_traced(task)) {
4761 DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
4762 return -EBUSY;
4763 }
4764 /*
4765 * task is now stopped, wait for ctxsw out
4766 *
4767 * This is an interesting point in the code.
4768 * We need to unprotect the context because
4769 * the pfm_save_regs() routines needs to grab
4770 * the same lock. There are danger in doing
4771 * this because it leaves a window open for
4772 * another task to get access to the context
4773 * and possibly change its state. The one thing
4774 * that is not possible is for the context to disappear
4775 * because we are protected by the VFS layer, i.e.,
4776 * get_fd()/put_fd().
4777 */
4778 old_state = state;
4779
4780 UNPROTECT_CTX(ctx, flags);
4781
4782 wait_task_inactive(task, 0);
4783
4784 PROTECT_CTX(ctx, flags);
4785
4786 /*
4787 * we must recheck to verify if state has changed
4788 */
4789 if (ctx->ctx_state != old_state) {
4790 DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
4791 goto recheck;
4792 }
4793 }
4794 return 0;
4795}
4796
4797/*
4798 * system-call entry point (must return long)
4799 */
4800asmlinkage long
4801sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
4802{
4803 struct file *file = NULL;
4804 pfm_context_t *ctx = NULL;
4805 unsigned long flags = 0UL;
4806 void *args_k = NULL;
4807 long ret; /* will expand int return types */
4808 size_t base_sz, sz, xtra_sz = 0;
4809 int narg, completed_args = 0, call_made = 0, cmd_flags;
4810 int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
4811 int (*getsize)(void *arg, size_t *sz);
4812#define PFM_MAX_ARGSIZE 4096
4813
4814 /*
4815 * reject any call if perfmon was disabled at initialization
4816 */
4817 if (unlikely(pmu_conf == NULL)) return -ENOSYS;
4818
4819 if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
4820 DPRINT(("invalid cmd=%d\n", cmd));
4821 return -EINVAL;
4822 }
4823
4824 func = pfm_cmd_tab[cmd].cmd_func;
4825 narg = pfm_cmd_tab[cmd].cmd_narg;
4826 base_sz = pfm_cmd_tab[cmd].cmd_argsize;
4827 getsize = pfm_cmd_tab[cmd].cmd_getsize;
4828 cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
4829
4830 if (unlikely(func == NULL)) {
4831 DPRINT(("invalid cmd=%d\n", cmd));
4832 return -EINVAL;
4833 }
4834
4835 DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
4836 PFM_CMD_NAME(cmd),
4837 cmd,
4838 narg,
4839 base_sz,
4840 count));
4841
4842 /*
4843 * check if number of arguments matches what the command expects
4844 */
4845 if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
4846 return -EINVAL;
4847
4848restart_args:
4849 sz = xtra_sz + base_sz*count;
4850 /*
4851 * limit abuse to min page size
4852 */
4853 if (unlikely(sz > PFM_MAX_ARGSIZE)) {
4854 printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
4855 return -E2BIG;
4856 }
4857
4858 /*
4859 * allocate default-sized argument buffer
4860 */
4861 if (likely(count && args_k == NULL)) {
4862 args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
4863 if (args_k == NULL) return -ENOMEM;
4864 }
4865
4866 ret = -EFAULT;
4867
4868 /*
4869 * copy arguments
4870 *
4871 * assume sz = 0 for command without parameters
4872 */
4873 if (sz && copy_from_user(args_k, arg, sz)) {
4874 DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
4875 goto error_args;
4876 }
4877
4878 /*
4879 * check if command supports extra parameters
4880 */
4881 if (completed_args == 0 && getsize) {
4882 /*
4883 * get extra parameters size (based on main argument)
4884 */
4885 ret = (*getsize)(args_k, &xtra_sz);
4886 if (ret) goto error_args;
4887
4888 completed_args = 1;
4889
4890 DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
4891
4892 /* retry if necessary */
4893 if (likely(xtra_sz)) goto restart_args;
4894 }
4895
4896 if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
4897
4898 ret = -EBADF;
4899
4900 file = fget(fd);
4901 if (unlikely(file == NULL)) {
4902 DPRINT(("invalid fd %d\n", fd));
4903 goto error_args;
4904 }
4905 if (unlikely(PFM_IS_FILE(file) == 0)) {
4906 DPRINT(("fd %d not related to perfmon\n", fd));
4907 goto error_args;
4908 }
4909
4910 ctx = file->private_data;
4911 if (unlikely(ctx == NULL)) {
4912 DPRINT(("no context for fd %d\n", fd));
4913 goto error_args;
4914 }
4915 prefetch(&ctx->ctx_state);
4916
4917 PROTECT_CTX(ctx, flags);
4918
4919 /*
4920 * check task is stopped
4921 */
4922 ret = pfm_check_task_state(ctx, cmd, flags);
4923 if (unlikely(ret)) goto abort_locked;
4924
4925skip_fd:
4926 ret = (*func)(ctx, args_k, count, task_pt_regs(current));
4927
4928 call_made = 1;
4929
4930abort_locked:
4931 if (likely(ctx)) {
4932 DPRINT(("context unlocked\n"));
4933 UNPROTECT_CTX(ctx, flags);
4934 }
4935
4936 /* copy argument back to user, if needed */
4937 if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
4938
4939error_args:
4940 if (file)
4941 fput(file);
4942
4943 kfree(args_k);
4944
4945 DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
4946
4947 return ret;
4948}
4949
4950static void
4951pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
4952{
4953 pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
4954 pfm_ovfl_ctrl_t rst_ctrl;
4955 int state;
4956 int ret = 0;
4957
4958 state = ctx->ctx_state;
4959 /*
4960 * Unlock sampling buffer and reset index atomically
4961 * XXX: not really needed when blocking
4962 */
4963 if (CTX_HAS_SMPL(ctx)) {
4964
4965 rst_ctrl.bits.mask_monitoring = 0;
4966 rst_ctrl.bits.reset_ovfl_pmds = 0;
4967
4968 if (state == PFM_CTX_LOADED)
4969 ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4970 else
4971 ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
4972 } else {
4973 rst_ctrl.bits.mask_monitoring = 0;
4974 rst_ctrl.bits.reset_ovfl_pmds = 1;
4975 }
4976
4977 if (ret == 0) {
4978 if (rst_ctrl.bits.reset_ovfl_pmds) {
4979 pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
4980 }
4981 if (rst_ctrl.bits.mask_monitoring == 0) {
4982 DPRINT(("resuming monitoring\n"));
4983 if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
4984 } else {
4985 DPRINT(("stopping monitoring\n"));
4986 //pfm_stop_monitoring(current, regs);
4987 }
4988 ctx->ctx_state = PFM_CTX_LOADED;
4989 }
4990}
4991
4992/*
4993 * context MUST BE LOCKED when calling
4994 * can only be called for current
4995 */
4996static void
4997pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
4998{
4999 int ret;
5000
5001 DPRINT(("entering for [%d]\n", task_pid_nr(current)));
5002
5003 ret = pfm_context_unload(ctx, NULL, 0, regs);
5004 if (ret) {
5005 printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
5006 }
5007
5008 /*
5009 * and wakeup controlling task, indicating we are now disconnected
5010 */
5011 wake_up_interruptible(&ctx->ctx_zombieq);
5012
5013 /*
5014 * given that context is still locked, the controlling
5015 * task will only get access when we return from
5016 * pfm_handle_work().
5017 */
5018}
5019
5020static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
5021
5022 /*
5023 * pfm_handle_work() can be called with interrupts enabled
5024 * (TIF_NEED_RESCHED) or disabled. The down_interruptible
5025 * call may sleep, therefore we must re-enable interrupts
5026 * to avoid deadlocks. It is safe to do so because this function
5027 * is called ONLY when returning to user level (pUStk=1), in which case
5028 * there is no risk of kernel stack overflow due to deep
5029 * interrupt nesting.
5030 */
5031void
5032pfm_handle_work(void)
5033{
5034 pfm_context_t *ctx;
5035 struct pt_regs *regs;
5036 unsigned long flags, dummy_flags;
5037 unsigned long ovfl_regs;
5038 unsigned int reason;
5039 int ret;
5040
5041 ctx = PFM_GET_CTX(current);
5042 if (ctx == NULL) {
5043 printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
5044 task_pid_nr(current));
5045 return;
5046 }
5047
5048 PROTECT_CTX(ctx, flags);
5049
5050 PFM_SET_WORK_PENDING(current, 0);
5051
5052 regs = task_pt_regs(current);
5053
5054 /*
5055 * extract reason for being here and clear
5056 */
5057 reason = ctx->ctx_fl_trap_reason;
5058 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
5059 ovfl_regs = ctx->ctx_ovfl_regs[0];
5060
5061 DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
5062
5063 /*
5064 * must be done before we check for simple-reset mode
5065 */
5066 if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
5067 goto do_zombie;
5068
5069 //if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
5070 if (reason == PFM_TRAP_REASON_RESET)
5071 goto skip_blocking;
5072
5073 /*
5074 * restore interrupt mask to what it was on entry.
5075 * Could be enabled/diasbled.
5076 */
5077 UNPROTECT_CTX(ctx, flags);
5078
5079 /*
5080 * force interrupt enable because of down_interruptible()
5081 */
5082 local_irq_enable();
5083
5084 DPRINT(("before block sleeping\n"));
5085
5086 /*
5087 * may go through without blocking on SMP systems
5088 * if restart has been received already by the time we call down()
5089 */
5090 ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
5091
5092 DPRINT(("after block sleeping ret=%d\n", ret));
5093
5094 /*
5095 * lock context and mask interrupts again
5096 * We save flags into a dummy because we may have
5097 * altered interrupts mask compared to entry in this
5098 * function.
5099 */
5100 PROTECT_CTX(ctx, dummy_flags);
5101
5102 /*
5103 * we need to read the ovfl_regs only after wake-up
5104 * because we may have had pfm_write_pmds() in between
5105 * and that can changed PMD values and therefore
5106 * ovfl_regs is reset for these new PMD values.
5107 */
5108 ovfl_regs = ctx->ctx_ovfl_regs[0];
5109
5110 if (ctx->ctx_fl_going_zombie) {
5111do_zombie:
5112 DPRINT(("context is zombie, bailing out\n"));
5113 pfm_context_force_terminate(ctx, regs);
5114 goto nothing_to_do;
5115 }
5116 /*
5117 * in case of interruption of down() we don't restart anything
5118 */
5119 if (ret < 0)
5120 goto nothing_to_do;
5121
5122skip_blocking:
5123 pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
5124 ctx->ctx_ovfl_regs[0] = 0UL;
5125
5126nothing_to_do:
5127 /*
5128 * restore flags as they were upon entry
5129 */
5130 UNPROTECT_CTX(ctx, flags);
5131}
5132
5133static int
5134pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
5135{
5136 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5137 DPRINT(("ignoring overflow notification, owner is zombie\n"));
5138 return 0;
5139 }
5140
5141 DPRINT(("waking up somebody\n"));
5142
5143 if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
5144
5145 /*
5146 * safe, we are not in intr handler, nor in ctxsw when
5147 * we come here
5148 */
5149 kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
5150
5151 return 0;
5152}
5153
5154static int
5155pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
5156{
5157 pfm_msg_t *msg = NULL;
5158
5159 if (ctx->ctx_fl_no_msg == 0) {
5160 msg = pfm_get_new_msg(ctx);
5161 if (msg == NULL) {
5162 printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
5163 return -1;
5164 }
5165
5166 msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
5167 msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
5168 msg->pfm_ovfl_msg.msg_active_set = 0;
5169 msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
5170 msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
5171 msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
5172 msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
5173 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5174 }
5175
5176 DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
5177 msg,
5178 ctx->ctx_fl_no_msg,
5179 ctx->ctx_fd,
5180 ovfl_pmds));
5181
5182 return pfm_notify_user(ctx, msg);
5183}
5184
5185static int
5186pfm_end_notify_user(pfm_context_t *ctx)
5187{
5188 pfm_msg_t *msg;
5189
5190 msg = pfm_get_new_msg(ctx);
5191 if (msg == NULL) {
5192 printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
5193 return -1;
5194 }
5195 /* no leak */
5196 memset(msg, 0, sizeof(*msg));
5197
5198 msg->pfm_end_msg.msg_type = PFM_MSG_END;
5199 msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
5200 msg->pfm_ovfl_msg.msg_tstamp = 0UL;
5201
5202 DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
5203 msg,
5204 ctx->ctx_fl_no_msg,
5205 ctx->ctx_fd));
5206
5207 return pfm_notify_user(ctx, msg);
5208}
5209
5210/*
5211 * main overflow processing routine.
5212 * it can be called from the interrupt path or explicitly during the context switch code
5213 */
5214static void pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx,
5215 unsigned long pmc0, struct pt_regs *regs)
5216{
5217 pfm_ovfl_arg_t *ovfl_arg;
5218 unsigned long mask;
5219 unsigned long old_val, ovfl_val, new_val;
5220 unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
5221 unsigned long tstamp;
5222 pfm_ovfl_ctrl_t ovfl_ctrl;
5223 unsigned int i, has_smpl;
5224 int must_notify = 0;
5225
5226 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
5227
5228 /*
5229 * sanity test. Should never happen
5230 */
5231 if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
5232
5233 tstamp = ia64_get_itc();
5234 mask = pmc0 >> PMU_FIRST_COUNTER;
5235 ovfl_val = pmu_conf->ovfl_val;
5236 has_smpl = CTX_HAS_SMPL(ctx);
5237
5238 DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
5239 "used_pmds=0x%lx\n",
5240 pmc0,
5241 task ? task_pid_nr(task): -1,
5242 (regs ? regs->cr_iip : 0),
5243 CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
5244 ctx->ctx_used_pmds[0]));
5245
5246
5247 /*
5248 * first we update the virtual counters
5249 * assume there was a prior ia64_srlz_d() issued
5250 */
5251 for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
5252
5253 /* skip pmd which did not overflow */
5254 if ((mask & 0x1) == 0) continue;
5255
5256 /*
5257 * Note that the pmd is not necessarily 0 at this point as qualified events
5258 * may have happened before the PMU was frozen. The residual count is not
5259 * taken into consideration here but will be with any read of the pmd via
5260 * pfm_read_pmds().
5261 */
5262 old_val = new_val = ctx->ctx_pmds[i].val;
5263 new_val += 1 + ovfl_val;
5264 ctx->ctx_pmds[i].val = new_val;
5265
5266 /*
5267 * check for overflow condition
5268 */
5269 if (likely(old_val > new_val)) {
5270 ovfl_pmds |= 1UL << i;
5271 if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
5272 }
5273
5274 DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
5275 i,
5276 new_val,
5277 old_val,
5278 ia64_get_pmd(i) & ovfl_val,
5279 ovfl_pmds,
5280 ovfl_notify));
5281 }
5282
5283 /*
5284 * there was no 64-bit overflow, nothing else to do
5285 */
5286 if (ovfl_pmds == 0UL) return;
5287
5288 /*
5289 * reset all control bits
5290 */
5291 ovfl_ctrl.val = 0;
5292 reset_pmds = 0UL;
5293
5294 /*
5295 * if a sampling format module exists, then we "cache" the overflow by
5296 * calling the module's handler() routine.
5297 */
5298 if (has_smpl) {
5299 unsigned long start_cycles, end_cycles;
5300 unsigned long pmd_mask;
5301 int j, k, ret = 0;
5302 int this_cpu = smp_processor_id();
5303
5304 pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
5305 ovfl_arg = &ctx->ctx_ovfl_arg;
5306
5307 prefetch(ctx->ctx_smpl_hdr);
5308
5309 for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
5310
5311 mask = 1UL << i;
5312
5313 if ((pmd_mask & 0x1) == 0) continue;
5314
5315 ovfl_arg->ovfl_pmd = (unsigned char )i;
5316 ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
5317 ovfl_arg->active_set = 0;
5318 ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
5319 ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
5320
5321 ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
5322 ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
5323 ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
5324
5325 /*
5326 * copy values of pmds of interest. Sampling format may copy them
5327 * into sampling buffer.
5328 */
5329 if (smpl_pmds) {
5330 for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
5331 if ((smpl_pmds & 0x1) == 0) continue;
5332 ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
5333 DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
5334 }
5335 }
5336
5337 pfm_stats[this_cpu].pfm_smpl_handler_calls++;
5338
5339 start_cycles = ia64_get_itc();
5340
5341 /*
5342 * call custom buffer format record (handler) routine
5343 */
5344 ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
5345
5346 end_cycles = ia64_get_itc();
5347
5348 /*
5349 * For those controls, we take the union because they have
5350 * an all or nothing behavior.
5351 */
5352 ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
5353 ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
5354 ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
5355 /*
5356 * build the bitmask of pmds to reset now
5357 */
5358 if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
5359
5360 pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
5361 }
5362 /*
5363 * when the module cannot handle the rest of the overflows, we abort right here
5364 */
5365 if (ret && pmd_mask) {
5366 DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
5367 pmd_mask<<PMU_FIRST_COUNTER));
5368 }
5369 /*
5370 * remove the pmds we reset now from the set of pmds to reset in pfm_restart()
5371 */
5372 ovfl_pmds &= ~reset_pmds;
5373 } else {
5374 /*
5375 * when no sampling module is used, then the default
5376 * is to notify on overflow if requested by user
5377 */
5378 ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
5379 ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
5380 ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
5381 ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
5382 /*
5383 * if needed, we reset all overflowed pmds
5384 */
5385 if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
5386 }
5387
5388 DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
5389
5390 /*
5391 * reset the requested PMD registers using the short reset values
5392 */
5393 if (reset_pmds) {
5394 unsigned long bm = reset_pmds;
5395 pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
5396 }
5397
5398 if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
5399 /*
5400 * keep track of what to reset when unblocking
5401 */
5402 ctx->ctx_ovfl_regs[0] = ovfl_pmds;
5403
5404 /*
5405 * check for blocking context
5406 */
5407 if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
5408
5409 ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
5410
5411 /*
5412 * set the perfmon specific checking pending work for the task
5413 */
5414 PFM_SET_WORK_PENDING(task, 1);
5415
5416 /*
5417 * when coming from ctxsw, current still points to the
5418 * previous task, therefore we must work with task and not current.
5419 */
5420 set_notify_resume(task);
5421 }
5422 /*
5423 * defer until state is changed (shorten spin window). the context is locked
5424 * anyway, so the signal receiver would come spin for nothing.
5425 */
5426 must_notify = 1;
5427 }
5428
5429 DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
5430 GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
5431 PFM_GET_WORK_PENDING(task),
5432 ctx->ctx_fl_trap_reason,
5433 ovfl_pmds,
5434 ovfl_notify,
5435 ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
5436 /*
5437 * in case monitoring must be stopped, we toggle the psr bits
5438 */
5439 if (ovfl_ctrl.bits.mask_monitoring) {
5440 pfm_mask_monitoring(task);
5441 ctx->ctx_state = PFM_CTX_MASKED;
5442 ctx->ctx_fl_can_restart = 1;
5443 }
5444
5445 /*
5446 * send notification now
5447 */
5448 if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
5449
5450 return;
5451
5452sanity_check:
5453 printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
5454 smp_processor_id(),
5455 task ? task_pid_nr(task) : -1,
5456 pmc0);
5457 return;
5458
5459stop_monitoring:
5460 /*
5461 * in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
5462 * Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
5463 * come here as zombie only if the task is the current task. In which case, we
5464 * can access the PMU hardware directly.
5465 *
5466 * Note that zombies do have PM_VALID set. So here we do the minimal.
5467 *
5468 * In case the context was zombified it could not be reclaimed at the time
5469 * the monitoring program exited. At this point, the PMU reservation has been
5470 * returned, the sampiing buffer has been freed. We must convert this call
5471 * into a spurious interrupt. However, we must also avoid infinite overflows
5472 * by stopping monitoring for this task. We can only come here for a per-task
5473 * context. All we need to do is to stop monitoring using the psr bits which
5474 * are always task private. By re-enabling secure montioring, we ensure that
5475 * the monitored task will not be able to re-activate monitoring.
5476 * The task will eventually be context switched out, at which point the context
5477 * will be reclaimed (that includes releasing ownership of the PMU).
5478 *
5479 * So there might be a window of time where the number of per-task session is zero
5480 * yet one PMU might have a owner and get at most one overflow interrupt for a zombie
5481 * context. This is safe because if a per-task session comes in, it will push this one
5482 * out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
5483 * session is force on that CPU, given that we use task pinning, pfm_save_regs() will
5484 * also push our zombie context out.
5485 *
5486 * Overall pretty hairy stuff....
5487 */
5488 DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
5489 pfm_clear_psr_up();
5490 ia64_psr(regs)->up = 0;
5491 ia64_psr(regs)->sp = 1;
5492 return;
5493}
5494
5495static int
5496pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
5497{
5498 struct task_struct *task;
5499 pfm_context_t *ctx;
5500 unsigned long flags;
5501 u64 pmc0;
5502 int this_cpu = smp_processor_id();
5503 int retval = 0;
5504
5505 pfm_stats[this_cpu].pfm_ovfl_intr_count++;
5506
5507 /*
5508 * srlz.d done before arriving here
5509 */
5510 pmc0 = ia64_get_pmc(0);
5511
5512 task = GET_PMU_OWNER();
5513 ctx = GET_PMU_CTX();
5514
5515 /*
5516 * if we have some pending bits set
5517 * assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
5518 */
5519 if (PMC0_HAS_OVFL(pmc0) && task) {
5520 /*
5521 * we assume that pmc0.fr is always set here
5522 */
5523
5524 /* sanity check */
5525 if (!ctx) goto report_spurious1;
5526
5527 if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
5528 goto report_spurious2;
5529
5530 PROTECT_CTX_NOPRINT(ctx, flags);
5531
5532 pfm_overflow_handler(task, ctx, pmc0, regs);
5533
5534 UNPROTECT_CTX_NOPRINT(ctx, flags);
5535
5536 } else {
5537 pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
5538 retval = -1;
5539 }
5540 /*
5541 * keep it unfrozen at all times
5542 */
5543 pfm_unfreeze_pmu();
5544
5545 return retval;
5546
5547report_spurious1:
5548 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
5549 this_cpu, task_pid_nr(task));
5550 pfm_unfreeze_pmu();
5551 return -1;
5552report_spurious2:
5553 printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
5554 this_cpu,
5555 task_pid_nr(task));
5556 pfm_unfreeze_pmu();
5557 return -1;
5558}
5559
5560static irqreturn_t
5561pfm_interrupt_handler(int irq, void *arg)
5562{
5563 unsigned long start_cycles, total_cycles;
5564 unsigned long min, max;
5565 int this_cpu;
5566 int ret;
5567 struct pt_regs *regs = get_irq_regs();
5568
5569 this_cpu = get_cpu();
5570 if (likely(!pfm_alt_intr_handler)) {
5571 min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
5572 max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
5573
5574 start_cycles = ia64_get_itc();
5575
5576 ret = pfm_do_interrupt_handler(arg, regs);
5577
5578 total_cycles = ia64_get_itc();
5579
5580 /*
5581 * don't measure spurious interrupts
5582 */
5583 if (likely(ret == 0)) {
5584 total_cycles -= start_cycles;
5585
5586 if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
5587 if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
5588
5589 pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
5590 }
5591 }
5592 else {
5593 (*pfm_alt_intr_handler->handler)(irq, arg, regs);
5594 }
5595
5596 put_cpu();
5597 return IRQ_HANDLED;
5598}
5599
5600/*
5601 * /proc/perfmon interface, for debug only
5602 */
5603
5604#define PFM_PROC_SHOW_HEADER ((void *)(long)nr_cpu_ids+1)
5605
5606static void *
5607pfm_proc_start(struct seq_file *m, loff_t *pos)
5608{
5609 if (*pos == 0) {
5610 return PFM_PROC_SHOW_HEADER;
5611 }
5612
5613 while (*pos <= nr_cpu_ids) {
5614 if (cpu_online(*pos - 1)) {
5615 return (void *)*pos;
5616 }
5617 ++*pos;
5618 }
5619 return NULL;
5620}
5621
5622static void *
5623pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
5624{
5625 ++*pos;
5626 return pfm_proc_start(m, pos);
5627}
5628
5629static void
5630pfm_proc_stop(struct seq_file *m, void *v)
5631{
5632}
5633
5634static void
5635pfm_proc_show_header(struct seq_file *m)
5636{
5637 struct list_head * pos;
5638 pfm_buffer_fmt_t * entry;
5639 unsigned long flags;
5640
5641 seq_printf(m,
5642 "perfmon version : %u.%u\n"
5643 "model : %s\n"
5644 "fastctxsw : %s\n"
5645 "expert mode : %s\n"
5646 "ovfl_mask : 0x%lx\n"
5647 "PMU flags : 0x%x\n",
5648 PFM_VERSION_MAJ, PFM_VERSION_MIN,
5649 pmu_conf->pmu_name,
5650 pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
5651 pfm_sysctl.expert_mode > 0 ? "Yes": "No",
5652 pmu_conf->ovfl_val,
5653 pmu_conf->flags);
5654
5655 LOCK_PFS(flags);
5656
5657 seq_printf(m,
5658 "proc_sessions : %u\n"
5659 "sys_sessions : %u\n"
5660 "sys_use_dbregs : %u\n"
5661 "ptrace_use_dbregs : %u\n",
5662 pfm_sessions.pfs_task_sessions,
5663 pfm_sessions.pfs_sys_sessions,
5664 pfm_sessions.pfs_sys_use_dbregs,
5665 pfm_sessions.pfs_ptrace_use_dbregs);
5666
5667 UNLOCK_PFS(flags);
5668
5669 spin_lock(&pfm_buffer_fmt_lock);
5670
5671 list_for_each(pos, &pfm_buffer_fmt_list) {
5672 entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
5673 seq_printf(m, "format : %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x %s\n",
5674 entry->fmt_uuid[0],
5675 entry->fmt_uuid[1],
5676 entry->fmt_uuid[2],
5677 entry->fmt_uuid[3],
5678 entry->fmt_uuid[4],
5679 entry->fmt_uuid[5],
5680 entry->fmt_uuid[6],
5681 entry->fmt_uuid[7],
5682 entry->fmt_uuid[8],
5683 entry->fmt_uuid[9],
5684 entry->fmt_uuid[10],
5685 entry->fmt_uuid[11],
5686 entry->fmt_uuid[12],
5687 entry->fmt_uuid[13],
5688 entry->fmt_uuid[14],
5689 entry->fmt_uuid[15],
5690 entry->fmt_name);
5691 }
5692 spin_unlock(&pfm_buffer_fmt_lock);
5693
5694}
5695
5696static int
5697pfm_proc_show(struct seq_file *m, void *v)
5698{
5699 unsigned long psr;
5700 unsigned int i;
5701 int cpu;
5702
5703 if (v == PFM_PROC_SHOW_HEADER) {
5704 pfm_proc_show_header(m);
5705 return 0;
5706 }
5707
5708 /* show info for CPU (v - 1) */
5709
5710 cpu = (long)v - 1;
5711 seq_printf(m,
5712 "CPU%-2d overflow intrs : %lu\n"
5713 "CPU%-2d overflow cycles : %lu\n"
5714 "CPU%-2d overflow min : %lu\n"
5715 "CPU%-2d overflow max : %lu\n"
5716 "CPU%-2d smpl handler calls : %lu\n"
5717 "CPU%-2d smpl handler cycles : %lu\n"
5718 "CPU%-2d spurious intrs : %lu\n"
5719 "CPU%-2d replay intrs : %lu\n"
5720 "CPU%-2d syst_wide : %d\n"
5721 "CPU%-2d dcr_pp : %d\n"
5722 "CPU%-2d exclude idle : %d\n"
5723 "CPU%-2d owner : %d\n"
5724 "CPU%-2d context : %p\n"
5725 "CPU%-2d activations : %lu\n",
5726 cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
5727 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
5728 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
5729 cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
5730 cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
5731 cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
5732 cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
5733 cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
5734 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
5735 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
5736 cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
5737 cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
5738 cpu, pfm_get_cpu_data(pmu_ctx, cpu),
5739 cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
5740
5741 if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
5742
5743 psr = pfm_get_psr();
5744
5745 ia64_srlz_d();
5746
5747 seq_printf(m,
5748 "CPU%-2d psr : 0x%lx\n"
5749 "CPU%-2d pmc0 : 0x%lx\n",
5750 cpu, psr,
5751 cpu, ia64_get_pmc(0));
5752
5753 for (i=0; PMC_IS_LAST(i) == 0; i++) {
5754 if (PMC_IS_COUNTING(i) == 0) continue;
5755 seq_printf(m,
5756 "CPU%-2d pmc%u : 0x%lx\n"
5757 "CPU%-2d pmd%u : 0x%lx\n",
5758 cpu, i, ia64_get_pmc(i),
5759 cpu, i, ia64_get_pmd(i));
5760 }
5761 }
5762 return 0;
5763}
5764
5765const struct seq_operations pfm_seq_ops = {
5766 .start = pfm_proc_start,
5767 .next = pfm_proc_next,
5768 .stop = pfm_proc_stop,
5769 .show = pfm_proc_show
5770};
5771
5772static int
5773pfm_proc_open(struct inode *inode, struct file *file)
5774{
5775 return seq_open(file, &pfm_seq_ops);
5776}
5777
5778
5779/*
5780 * we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
5781 * during pfm_enable() hence before pfm_start(). We cannot assume monitoring
5782 * is active or inactive based on mode. We must rely on the value in
5783 * local_cpu_data->pfm_syst_info
5784 */
5785void
5786pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
5787{
5788 struct pt_regs *regs;
5789 unsigned long dcr;
5790 unsigned long dcr_pp;
5791
5792 dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
5793
5794 /*
5795 * pid 0 is guaranteed to be the idle task. There is one such task with pid 0
5796 * on every CPU, so we can rely on the pid to identify the idle task.
5797 */
5798 if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
5799 regs = task_pt_regs(task);
5800 ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
5801 return;
5802 }
5803 /*
5804 * if monitoring has started
5805 */
5806 if (dcr_pp) {
5807 dcr = ia64_getreg(_IA64_REG_CR_DCR);
5808 /*
5809 * context switching in?
5810 */
5811 if (is_ctxswin) {
5812 /* mask monitoring for the idle task */
5813 ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
5814 pfm_clear_psr_pp();
5815 ia64_srlz_i();
5816 return;
5817 }
5818 /*
5819 * context switching out
5820 * restore monitoring for next task
5821 *
5822 * Due to inlining this odd if-then-else construction generates
5823 * better code.
5824 */
5825 ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
5826 pfm_set_psr_pp();
5827 ia64_srlz_i();
5828 }
5829}
5830
5831#ifdef CONFIG_SMP
5832
5833static void
5834pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
5835{
5836 struct task_struct *task = ctx->ctx_task;
5837
5838 ia64_psr(regs)->up = 0;
5839 ia64_psr(regs)->sp = 1;
5840
5841 if (GET_PMU_OWNER() == task) {
5842 DPRINT(("cleared ownership for [%d]\n",
5843 task_pid_nr(ctx->ctx_task)));
5844 SET_PMU_OWNER(NULL, NULL);
5845 }
5846
5847 /*
5848 * disconnect the task from the context and vice-versa
5849 */
5850 PFM_SET_WORK_PENDING(task, 0);
5851
5852 task->thread.pfm_context = NULL;
5853 task->thread.flags &= ~IA64_THREAD_PM_VALID;
5854
5855 DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
5856}
5857
5858
5859/*
5860 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
5861 */
5862void
5863pfm_save_regs(struct task_struct *task)
5864{
5865 pfm_context_t *ctx;
5866 unsigned long flags;
5867 u64 psr;
5868
5869
5870 ctx = PFM_GET_CTX(task);
5871 if (ctx == NULL) return;
5872
5873 /*
5874 * we always come here with interrupts ALREADY disabled by
5875 * the scheduler. So we simply need to protect against concurrent
5876 * access, not CPU concurrency.
5877 */
5878 flags = pfm_protect_ctx_ctxsw(ctx);
5879
5880 if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
5881 struct pt_regs *regs = task_pt_regs(task);
5882
5883 pfm_clear_psr_up();
5884
5885 pfm_force_cleanup(ctx, regs);
5886
5887 BUG_ON(ctx->ctx_smpl_hdr);
5888
5889 pfm_unprotect_ctx_ctxsw(ctx, flags);
5890
5891 pfm_context_free(ctx);
5892 return;
5893 }
5894
5895 /*
5896 * save current PSR: needed because we modify it
5897 */
5898 ia64_srlz_d();
5899 psr = pfm_get_psr();
5900
5901 BUG_ON(psr & (IA64_PSR_I));
5902
5903 /*
5904 * stop monitoring:
5905 * This is the last instruction which may generate an overflow
5906 *
5907 * We do not need to set psr.sp because, it is irrelevant in kernel.
5908 * It will be restored from ipsr when going back to user level
5909 */
5910 pfm_clear_psr_up();
5911
5912 /*
5913 * keep a copy of psr.up (for reload)
5914 */
5915 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5916
5917 /*
5918 * release ownership of this PMU.
5919 * PM interrupts are masked, so nothing
5920 * can happen.
5921 */
5922 SET_PMU_OWNER(NULL, NULL);
5923
5924 /*
5925 * we systematically save the PMD as we have no
5926 * guarantee we will be schedule at that same
5927 * CPU again.
5928 */
5929 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
5930
5931 /*
5932 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
5933 * we will need it on the restore path to check
5934 * for pending overflow.
5935 */
5936 ctx->th_pmcs[0] = ia64_get_pmc(0);
5937
5938 /*
5939 * unfreeze PMU if had pending overflows
5940 */
5941 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
5942
5943 /*
5944 * finally, allow context access.
5945 * interrupts will still be masked after this call.
5946 */
5947 pfm_unprotect_ctx_ctxsw(ctx, flags);
5948}
5949
5950#else /* !CONFIG_SMP */
5951void
5952pfm_save_regs(struct task_struct *task)
5953{
5954 pfm_context_t *ctx;
5955 u64 psr;
5956
5957 ctx = PFM_GET_CTX(task);
5958 if (ctx == NULL) return;
5959
5960 /*
5961 * save current PSR: needed because we modify it
5962 */
5963 psr = pfm_get_psr();
5964
5965 BUG_ON(psr & (IA64_PSR_I));
5966
5967 /*
5968 * stop monitoring:
5969 * This is the last instruction which may generate an overflow
5970 *
5971 * We do not need to set psr.sp because, it is irrelevant in kernel.
5972 * It will be restored from ipsr when going back to user level
5973 */
5974 pfm_clear_psr_up();
5975
5976 /*
5977 * keep a copy of psr.up (for reload)
5978 */
5979 ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
5980}
5981
5982static void
5983pfm_lazy_save_regs (struct task_struct *task)
5984{
5985 pfm_context_t *ctx;
5986 unsigned long flags;
5987
5988 { u64 psr = pfm_get_psr();
5989 BUG_ON(psr & IA64_PSR_UP);
5990 }
5991
5992 ctx = PFM_GET_CTX(task);
5993
5994 /*
5995 * we need to mask PMU overflow here to
5996 * make sure that we maintain pmc0 until
5997 * we save it. overflow interrupts are
5998 * treated as spurious if there is no
5999 * owner.
6000 *
6001 * XXX: I don't think this is necessary
6002 */
6003 PROTECT_CTX(ctx,flags);
6004
6005 /*
6006 * release ownership of this PMU.
6007 * must be done before we save the registers.
6008 *
6009 * after this call any PMU interrupt is treated
6010 * as spurious.
6011 */
6012 SET_PMU_OWNER(NULL, NULL);
6013
6014 /*
6015 * save all the pmds we use
6016 */
6017 pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
6018
6019 /*
6020 * save pmc0 ia64_srlz_d() done in pfm_save_pmds()
6021 * it is needed to check for pended overflow
6022 * on the restore path
6023 */
6024 ctx->th_pmcs[0] = ia64_get_pmc(0);
6025
6026 /*
6027 * unfreeze PMU if had pending overflows
6028 */
6029 if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
6030
6031 /*
6032 * now get can unmask PMU interrupts, they will
6033 * be treated as purely spurious and we will not
6034 * lose any information
6035 */
6036 UNPROTECT_CTX(ctx,flags);
6037}
6038#endif /* CONFIG_SMP */
6039
6040#ifdef CONFIG_SMP
6041/*
6042 * in 2.6, interrupts are masked when we come here and the runqueue lock is held
6043 */
6044void
6045pfm_load_regs (struct task_struct *task)
6046{
6047 pfm_context_t *ctx;
6048 unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
6049 unsigned long flags;
6050 u64 psr, psr_up;
6051 int need_irq_resend;
6052
6053 ctx = PFM_GET_CTX(task);
6054 if (unlikely(ctx == NULL)) return;
6055
6056 BUG_ON(GET_PMU_OWNER());
6057
6058 /*
6059 * possible on unload
6060 */
6061 if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
6062
6063 /*
6064 * we always come here with interrupts ALREADY disabled by
6065 * the scheduler. So we simply need to protect against concurrent
6066 * access, not CPU concurrency.
6067 */
6068 flags = pfm_protect_ctx_ctxsw(ctx);
6069 psr = pfm_get_psr();
6070
6071 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6072
6073 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6074 BUG_ON(psr & IA64_PSR_I);
6075
6076 if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
6077 struct pt_regs *regs = task_pt_regs(task);
6078
6079 BUG_ON(ctx->ctx_smpl_hdr);
6080
6081 pfm_force_cleanup(ctx, regs);
6082
6083 pfm_unprotect_ctx_ctxsw(ctx, flags);
6084
6085 /*
6086 * this one (kmalloc'ed) is fine with interrupts disabled
6087 */
6088 pfm_context_free(ctx);
6089
6090 return;
6091 }
6092
6093 /*
6094 * we restore ALL the debug registers to avoid picking up
6095 * stale state.
6096 */
6097 if (ctx->ctx_fl_using_dbreg) {
6098 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6099 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6100 }
6101 /*
6102 * retrieve saved psr.up
6103 */
6104 psr_up = ctx->ctx_saved_psr_up;
6105
6106 /*
6107 * if we were the last user of the PMU on that CPU,
6108 * then nothing to do except restore psr
6109 */
6110 if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
6111
6112 /*
6113 * retrieve partial reload masks (due to user modifications)
6114 */
6115 pmc_mask = ctx->ctx_reload_pmcs[0];
6116 pmd_mask = ctx->ctx_reload_pmds[0];
6117
6118 } else {
6119 /*
6120 * To avoid leaking information to the user level when psr.sp=0,
6121 * we must reload ALL implemented pmds (even the ones we don't use).
6122 * In the kernel we only allow PFM_READ_PMDS on registers which
6123 * we initialized or requested (sampling) so there is no risk there.
6124 */
6125 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6126
6127 /*
6128 * ALL accessible PMCs are systematically reloaded, unused registers
6129 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6130 * up stale configuration.
6131 *
6132 * PMC0 is never in the mask. It is always restored separately.
6133 */
6134 pmc_mask = ctx->ctx_all_pmcs[0];
6135 }
6136 /*
6137 * when context is MASKED, we will restore PMC with plm=0
6138 * and PMD with stale information, but that's ok, nothing
6139 * will be captured.
6140 *
6141 * XXX: optimize here
6142 */
6143 if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6144 if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6145
6146 /*
6147 * check for pending overflow at the time the state
6148 * was saved.
6149 */
6150 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6151 /*
6152 * reload pmc0 with the overflow information
6153 * On McKinley PMU, this will trigger a PMU interrupt
6154 */
6155 ia64_set_pmc(0, ctx->th_pmcs[0]);
6156 ia64_srlz_d();
6157 ctx->th_pmcs[0] = 0UL;
6158
6159 /*
6160 * will replay the PMU interrupt
6161 */
6162 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6163
6164 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6165 }
6166
6167 /*
6168 * we just did a reload, so we reset the partial reload fields
6169 */
6170 ctx->ctx_reload_pmcs[0] = 0UL;
6171 ctx->ctx_reload_pmds[0] = 0UL;
6172
6173 SET_LAST_CPU(ctx, smp_processor_id());
6174
6175 /*
6176 * dump activation value for this PMU
6177 */
6178 INC_ACTIVATION();
6179 /*
6180 * record current activation for this context
6181 */
6182 SET_ACTIVATION(ctx);
6183
6184 /*
6185 * establish new ownership.
6186 */
6187 SET_PMU_OWNER(task, ctx);
6188
6189 /*
6190 * restore the psr.up bit. measurement
6191 * is active again.
6192 * no PMU interrupt can happen at this point
6193 * because we still have interrupts disabled.
6194 */
6195 if (likely(psr_up)) pfm_set_psr_up();
6196
6197 /*
6198 * allow concurrent access to context
6199 */
6200 pfm_unprotect_ctx_ctxsw(ctx, flags);
6201}
6202#else /* !CONFIG_SMP */
6203/*
6204 * reload PMU state for UP kernels
6205 * in 2.5 we come here with interrupts disabled
6206 */
6207void
6208pfm_load_regs (struct task_struct *task)
6209{
6210 pfm_context_t *ctx;
6211 struct task_struct *owner;
6212 unsigned long pmd_mask, pmc_mask;
6213 u64 psr, psr_up;
6214 int need_irq_resend;
6215
6216 owner = GET_PMU_OWNER();
6217 ctx = PFM_GET_CTX(task);
6218 psr = pfm_get_psr();
6219
6220 BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
6221 BUG_ON(psr & IA64_PSR_I);
6222
6223 /*
6224 * we restore ALL the debug registers to avoid picking up
6225 * stale state.
6226 *
6227 * This must be done even when the task is still the owner
6228 * as the registers may have been modified via ptrace()
6229 * (not perfmon) by the previous task.
6230 */
6231 if (ctx->ctx_fl_using_dbreg) {
6232 pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
6233 pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
6234 }
6235
6236 /*
6237 * retrieved saved psr.up
6238 */
6239 psr_up = ctx->ctx_saved_psr_up;
6240 need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
6241
6242 /*
6243 * short path, our state is still there, just
6244 * need to restore psr and we go
6245 *
6246 * we do not touch either PMC nor PMD. the psr is not touched
6247 * by the overflow_handler. So we are safe w.r.t. to interrupt
6248 * concurrency even without interrupt masking.
6249 */
6250 if (likely(owner == task)) {
6251 if (likely(psr_up)) pfm_set_psr_up();
6252 return;
6253 }
6254
6255 /*
6256 * someone else is still using the PMU, first push it out and
6257 * then we'll be able to install our stuff !
6258 *
6259 * Upon return, there will be no owner for the current PMU
6260 */
6261 if (owner) pfm_lazy_save_regs(owner);
6262
6263 /*
6264 * To avoid leaking information to the user level when psr.sp=0,
6265 * we must reload ALL implemented pmds (even the ones we don't use).
6266 * In the kernel we only allow PFM_READ_PMDS on registers which
6267 * we initialized or requested (sampling) so there is no risk there.
6268 */
6269 pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
6270
6271 /*
6272 * ALL accessible PMCs are systematically reloaded, unused registers
6273 * get their default (from pfm_reset_pmu_state()) values to avoid picking
6274 * up stale configuration.
6275 *
6276 * PMC0 is never in the mask. It is always restored separately
6277 */
6278 pmc_mask = ctx->ctx_all_pmcs[0];
6279
6280 pfm_restore_pmds(ctx->th_pmds, pmd_mask);
6281 pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
6282
6283 /*
6284 * check for pending overflow at the time the state
6285 * was saved.
6286 */
6287 if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
6288 /*
6289 * reload pmc0 with the overflow information
6290 * On McKinley PMU, this will trigger a PMU interrupt
6291 */
6292 ia64_set_pmc(0, ctx->th_pmcs[0]);
6293 ia64_srlz_d();
6294
6295 ctx->th_pmcs[0] = 0UL;
6296
6297 /*
6298 * will replay the PMU interrupt
6299 */
6300 if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
6301
6302 pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
6303 }
6304
6305 /*
6306 * establish new ownership.
6307 */
6308 SET_PMU_OWNER(task, ctx);
6309
6310 /*
6311 * restore the psr.up bit. measurement
6312 * is active again.
6313 * no PMU interrupt can happen at this point
6314 * because we still have interrupts disabled.
6315 */
6316 if (likely(psr_up)) pfm_set_psr_up();
6317}
6318#endif /* CONFIG_SMP */
6319
6320/*
6321 * this function assumes monitoring is stopped
6322 */
6323static void
6324pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
6325{
6326 u64 pmc0;
6327 unsigned long mask2, val, pmd_val, ovfl_val;
6328 int i, can_access_pmu = 0;
6329 int is_self;
6330
6331 /*
6332 * is the caller the task being monitored (or which initiated the
6333 * session for system wide measurements)
6334 */
6335 is_self = ctx->ctx_task == task ? 1 : 0;
6336
6337 /*
6338 * can access PMU is task is the owner of the PMU state on the current CPU
6339 * or if we are running on the CPU bound to the context in system-wide mode
6340 * (that is not necessarily the task the context is attached to in this mode).
6341 * In system-wide we always have can_access_pmu true because a task running on an
6342 * invalid processor is flagged earlier in the call stack (see pfm_stop).
6343 */
6344 can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
6345 if (can_access_pmu) {
6346 /*
6347 * Mark the PMU as not owned
6348 * This will cause the interrupt handler to do nothing in case an overflow
6349 * interrupt was in-flight
6350 * This also guarantees that pmc0 will contain the final state
6351 * It virtually gives us full control on overflow processing from that point
6352 * on.
6353 */
6354 SET_PMU_OWNER(NULL, NULL);
6355 DPRINT(("releasing ownership\n"));
6356
6357 /*
6358 * read current overflow status:
6359 *
6360 * we are guaranteed to read the final stable state
6361 */
6362 ia64_srlz_d();
6363 pmc0 = ia64_get_pmc(0); /* slow */
6364
6365 /*
6366 * reset freeze bit, overflow status information destroyed
6367 */
6368 pfm_unfreeze_pmu();
6369 } else {
6370 pmc0 = ctx->th_pmcs[0];
6371 /*
6372 * clear whatever overflow status bits there were
6373 */
6374 ctx->th_pmcs[0] = 0;
6375 }
6376 ovfl_val = pmu_conf->ovfl_val;
6377 /*
6378 * we save all the used pmds
6379 * we take care of overflows for counting PMDs
6380 *
6381 * XXX: sampling situation is not taken into account here
6382 */
6383 mask2 = ctx->ctx_used_pmds[0];
6384
6385 DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
6386
6387 for (i = 0; mask2; i++, mask2>>=1) {
6388
6389 /* skip non used pmds */
6390 if ((mask2 & 0x1) == 0) continue;
6391
6392 /*
6393 * can access PMU always true in system wide mode
6394 */
6395 val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
6396
6397 if (PMD_IS_COUNTING(i)) {
6398 DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
6399 task_pid_nr(task),
6400 i,
6401 ctx->ctx_pmds[i].val,
6402 val & ovfl_val));
6403
6404 /*
6405 * we rebuild the full 64 bit value of the counter
6406 */
6407 val = ctx->ctx_pmds[i].val + (val & ovfl_val);
6408
6409 /*
6410 * now everything is in ctx_pmds[] and we need
6411 * to clear the saved context from save_regs() such that
6412 * pfm_read_pmds() gets the correct value
6413 */
6414 pmd_val = 0UL;
6415
6416 /*
6417 * take care of overflow inline
6418 */
6419 if (pmc0 & (1UL << i)) {
6420 val += 1 + ovfl_val;
6421 DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
6422 }
6423 }
6424
6425 DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
6426
6427 if (is_self) ctx->th_pmds[i] = pmd_val;
6428
6429 ctx->ctx_pmds[i].val = val;
6430 }
6431}
6432
6433static struct irqaction perfmon_irqaction = {
6434 .handler = pfm_interrupt_handler,
6435 .flags = IRQF_DISABLED,
6436 .name = "perfmon"
6437};
6438
6439static void
6440pfm_alt_save_pmu_state(void *data)
6441{
6442 struct pt_regs *regs;
6443
6444 regs = task_pt_regs(current);
6445
6446 DPRINT(("called\n"));
6447
6448 /*
6449 * should not be necessary but
6450 * let's take not risk
6451 */
6452 pfm_clear_psr_up();
6453 pfm_clear_psr_pp();
6454 ia64_psr(regs)->pp = 0;
6455
6456 /*
6457 * This call is required
6458 * May cause a spurious interrupt on some processors
6459 */
6460 pfm_freeze_pmu();
6461
6462 ia64_srlz_d();
6463}
6464
6465void
6466pfm_alt_restore_pmu_state(void *data)
6467{
6468 struct pt_regs *regs;
6469
6470 regs = task_pt_regs(current);
6471
6472 DPRINT(("called\n"));
6473
6474 /*
6475 * put PMU back in state expected
6476 * by perfmon
6477 */
6478 pfm_clear_psr_up();
6479 pfm_clear_psr_pp();
6480 ia64_psr(regs)->pp = 0;
6481
6482 /*
6483 * perfmon runs with PMU unfrozen at all times
6484 */
6485 pfm_unfreeze_pmu();
6486
6487 ia64_srlz_d();
6488}
6489
6490int
6491pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6492{
6493 int ret, i;
6494 int reserve_cpu;
6495
6496 /* some sanity checks */
6497 if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
6498
6499 /* do the easy test first */
6500 if (pfm_alt_intr_handler) return -EBUSY;
6501
6502 /* one at a time in the install or remove, just fail the others */
6503 if (!spin_trylock(&pfm_alt_install_check)) {
6504 return -EBUSY;
6505 }
6506
6507 /* reserve our session */
6508 for_each_online_cpu(reserve_cpu) {
6509 ret = pfm_reserve_session(NULL, 1, reserve_cpu);
6510 if (ret) goto cleanup_reserve;
6511 }
6512
6513 /* save the current system wide pmu states */
6514 ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 1);
6515 if (ret) {
6516 DPRINT(("on_each_cpu() failed: %d\n", ret));
6517 goto cleanup_reserve;
6518 }
6519
6520 /* officially change to the alternate interrupt handler */
6521 pfm_alt_intr_handler = hdl;
6522
6523 spin_unlock(&pfm_alt_install_check);
6524
6525 return 0;
6526
6527cleanup_reserve:
6528 for_each_online_cpu(i) {
6529 /* don't unreserve more than we reserved */
6530 if (i >= reserve_cpu) break;
6531
6532 pfm_unreserve_session(NULL, 1, i);
6533 }
6534
6535 spin_unlock(&pfm_alt_install_check);
6536
6537 return ret;
6538}
6539EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
6540
6541int
6542pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
6543{
6544 int i;
6545 int ret;
6546
6547 if (hdl == NULL) return -EINVAL;
6548
6549 /* cannot remove someone else's handler! */
6550 if (pfm_alt_intr_handler != hdl) return -EINVAL;
6551
6552 /* one at a time in the install or remove, just fail the others */
6553 if (!spin_trylock(&pfm_alt_install_check)) {
6554 return -EBUSY;
6555 }
6556
6557 pfm_alt_intr_handler = NULL;
6558
6559 ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 1);
6560 if (ret) {
6561 DPRINT(("on_each_cpu() failed: %d\n", ret));
6562 }
6563
6564 for_each_online_cpu(i) {
6565 pfm_unreserve_session(NULL, 1, i);
6566 }
6567
6568 spin_unlock(&pfm_alt_install_check);
6569
6570 return 0;
6571}
6572EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
6573
6574/*
6575 * perfmon initialization routine, called from the initcall() table
6576 */
6577static int init_pfm_fs(void);
6578
6579static int __init
6580pfm_probe_pmu(void)
6581{
6582 pmu_config_t **p;
6583 int family;
6584
6585 family = local_cpu_data->family;
6586 p = pmu_confs;
6587
6588 while(*p) {
6589 if ((*p)->probe) {
6590 if ((*p)->probe() == 0) goto found;
6591 } else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
6592 goto found;
6593 }
6594 p++;
6595 }
6596 return -1;
6597found:
6598 pmu_conf = *p;
6599 return 0;
6600}
6601
6602static const struct file_operations pfm_proc_fops = {
6603 .open = pfm_proc_open,
6604 .read = seq_read,
6605 .llseek = seq_lseek,
6606 .release = seq_release,
6607};
6608
6609int __init
6610pfm_init(void)
6611{
6612 unsigned int n, n_counters, i;
6613
6614 printk("perfmon: version %u.%u IRQ %u\n",
6615 PFM_VERSION_MAJ,
6616 PFM_VERSION_MIN,
6617 IA64_PERFMON_VECTOR);
6618
6619 if (pfm_probe_pmu()) {
6620 printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
6621 local_cpu_data->family);
6622 return -ENODEV;
6623 }
6624
6625 /*
6626 * compute the number of implemented PMD/PMC from the
6627 * description tables
6628 */
6629 n = 0;
6630 for (i=0; PMC_IS_LAST(i) == 0; i++) {
6631 if (PMC_IS_IMPL(i) == 0) continue;
6632 pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
6633 n++;
6634 }
6635 pmu_conf->num_pmcs = n;
6636
6637 n = 0; n_counters = 0;
6638 for (i=0; PMD_IS_LAST(i) == 0; i++) {
6639 if (PMD_IS_IMPL(i) == 0) continue;
6640 pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
6641 n++;
6642 if (PMD_IS_COUNTING(i)) n_counters++;
6643 }
6644 pmu_conf->num_pmds = n;
6645 pmu_conf->num_counters = n_counters;
6646
6647 /*
6648 * sanity checks on the number of debug registers
6649 */
6650 if (pmu_conf->use_rr_dbregs) {
6651 if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
6652 printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
6653 pmu_conf = NULL;
6654 return -1;
6655 }
6656 if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
6657 printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
6658 pmu_conf = NULL;
6659 return -1;
6660 }
6661 }
6662
6663 printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
6664 pmu_conf->pmu_name,
6665 pmu_conf->num_pmcs,
6666 pmu_conf->num_pmds,
6667 pmu_conf->num_counters,
6668 ffz(pmu_conf->ovfl_val));
6669
6670 /* sanity check */
6671 if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
6672 printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
6673 pmu_conf = NULL;
6674 return -1;
6675 }
6676
6677 /*
6678 * create /proc/perfmon (mostly for debugging purposes)
6679 */
6680 perfmon_dir = proc_create("perfmon", S_IRUGO, NULL, &pfm_proc_fops);
6681 if (perfmon_dir == NULL) {
6682 printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
6683 pmu_conf = NULL;
6684 return -1;
6685 }
6686
6687 /*
6688 * create /proc/sys/kernel/perfmon (for debugging purposes)
6689 */
6690 pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
6691
6692 /*
6693 * initialize all our spinlocks
6694 */
6695 spin_lock_init(&pfm_sessions.pfs_lock);
6696 spin_lock_init(&pfm_buffer_fmt_lock);
6697
6698 init_pfm_fs();
6699
6700 for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
6701
6702 return 0;
6703}
6704
6705__initcall(pfm_init);
6706
6707/*
6708 * this function is called before pfm_init()
6709 */
6710void
6711pfm_init_percpu (void)
6712{
6713 static int first_time=1;
6714 /*
6715 * make sure no measurement is active
6716 * (may inherit programmed PMCs from EFI).
6717 */
6718 pfm_clear_psr_pp();
6719 pfm_clear_psr_up();
6720
6721 /*
6722 * we run with the PMU not frozen at all times
6723 */
6724 pfm_unfreeze_pmu();
6725
6726 if (first_time) {
6727 register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
6728 first_time=0;
6729 }
6730
6731 ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
6732 ia64_srlz_d();
6733}
6734
6735/*
6736 * used for debug purposes only
6737 */
6738void
6739dump_pmu_state(const char *from)
6740{
6741 struct task_struct *task;
6742 struct pt_regs *regs;
6743 pfm_context_t *ctx;
6744 unsigned long psr, dcr, info, flags;
6745 int i, this_cpu;
6746
6747 local_irq_save(flags);
6748
6749 this_cpu = smp_processor_id();
6750 regs = task_pt_regs(current);
6751 info = PFM_CPUINFO_GET();
6752 dcr = ia64_getreg(_IA64_REG_CR_DCR);
6753
6754 if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
6755 local_irq_restore(flags);
6756 return;
6757 }
6758
6759 printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
6760 this_cpu,
6761 from,
6762 task_pid_nr(current),
6763 regs->cr_iip,
6764 current->comm);
6765
6766 task = GET_PMU_OWNER();
6767 ctx = GET_PMU_CTX();
6768
6769 printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
6770
6771 psr = pfm_get_psr();
6772
6773 printk("->CPU%d pmc0=0x%lx psr.pp=%d psr.up=%d dcr.pp=%d syst_info=0x%lx user_psr.up=%d user_psr.pp=%d\n",
6774 this_cpu,
6775 ia64_get_pmc(0),
6776 psr & IA64_PSR_PP ? 1 : 0,
6777 psr & IA64_PSR_UP ? 1 : 0,
6778 dcr & IA64_DCR_PP ? 1 : 0,
6779 info,
6780 ia64_psr(regs)->up,
6781 ia64_psr(regs)->pp);
6782
6783 ia64_psr(regs)->up = 0;
6784 ia64_psr(regs)->pp = 0;
6785
6786 for (i=1; PMC_IS_LAST(i) == 0; i++) {
6787 if (PMC_IS_IMPL(i) == 0) continue;
6788 printk("->CPU%d pmc[%d]=0x%lx thread_pmc[%d]=0x%lx\n", this_cpu, i, ia64_get_pmc(i), i, ctx->th_pmcs[i]);
6789 }
6790
6791 for (i=1; PMD_IS_LAST(i) == 0; i++) {
6792 if (PMD_IS_IMPL(i) == 0) continue;
6793 printk("->CPU%d pmd[%d]=0x%lx thread_pmd[%d]=0x%lx\n", this_cpu, i, ia64_get_pmd(i), i, ctx->th_pmds[i]);
6794 }
6795
6796 if (ctx) {
6797 printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
6798 this_cpu,
6799 ctx->ctx_state,
6800 ctx->ctx_smpl_vaddr,
6801 ctx->ctx_smpl_hdr,
6802 ctx->ctx_msgq_head,
6803 ctx->ctx_msgq_tail,
6804 ctx->ctx_saved_psr_up);
6805 }
6806 local_irq_restore(flags);
6807}
6808
6809/*
6810 * called from process.c:copy_thread(). task is new child.
6811 */
6812void
6813pfm_inherit(struct task_struct *task, struct pt_regs *regs)
6814{
6815 struct thread_struct *thread;
6816
6817 DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
6818
6819 thread = &task->thread;
6820
6821 /*
6822 * cut links inherited from parent (current)
6823 */
6824 thread->pfm_context = NULL;
6825
6826 PFM_SET_WORK_PENDING(task, 0);
6827
6828 /*
6829 * the psr bits are already set properly in copy_threads()
6830 */
6831}
6832#else /* !CONFIG_PERFMON */
6833asmlinkage long
6834sys_perfmonctl (int fd, int cmd, void *arg, int count)
6835{
6836 return -ENOSYS;
6837}
6838#endif /* CONFIG_PERFMON */