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