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 */
250 typedef 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 */
266 typedef 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
288 typedef 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 */
377 typedef 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 */
392 typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
393 typedef 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 */
419 typedef 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 */
447 typedef 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
454 typedef 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
462 typedef 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 */
472 typedef 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
495 typedef 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 */
510 static pfm_stats_t pfm_stats[NR_CPUS];
511 static pfm_session_t pfm_sessions; /* global sessions information */
512
513 static DEFINE_SPINLOCK(pfm_alt_install_check);
514 static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
515
516 static struct proc_dir_entry *perfmon_dir;
517 static pfm_uuid_t pfm_null_uuid = {0,};
518
519 static spinlock_t pfm_buffer_fmt_lock;
520 static LIST_HEAD(pfm_buffer_fmt_list);
521
522 static pmu_config_t *pmu_conf;
523
524 /* sysctl() controls */
525 pfm_sysctl_t pfm_sysctl;
526 EXPORT_SYMBOL(pfm_sysctl);
527
528 static 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 };
559 static struct ctl_table pfm_sysctl_dir[] = {
560 {
561 .procname = "perfmon",
562 .mode = 0555,
563 .child = pfm_ctl_table,
564 },
565 {}
566 };
567 static struct ctl_table pfm_sysctl_root[] = {
568 {
569 .procname = "kernel",
570 .mode = 0555,
571 .child = pfm_sysctl_dir,
572 },
573 {}
574 };
575 static struct ctl_table_header *pfm_sysctl_header;
576
577 static 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
582 static inline void
583 pfm_put_task(struct task_struct *task)
584 {
585 if (task != current) put_task_struct(task);
586 }
587
588 static inline unsigned long
589 pfm_protect_ctx_ctxsw(pfm_context_t *x)
590 {
591 spin_lock(&(x)->ctx_lock);
592 return 0UL;
593 }
594
595 static inline void
596 pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
597 {
598 spin_unlock(&(x)->ctx_lock);
599 }
600
601 /* forward declaration */
602 static const struct dentry_operations pfmfs_dentry_operations;
603
604 static 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
613 static 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 };
618 MODULE_ALIAS_FS("pfmfs");
619
620 DEFINE_PER_CPU(unsigned long, pfm_syst_info);
621 DEFINE_PER_CPU(struct task_struct *, pmu_owner);
622 DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
623 DEFINE_PER_CPU(unsigned long, pmu_activation_number);
624 EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
625
626
627 /* forward declaration */
628 static const struct file_operations pfm_file_ops;
629
630 /*
631 * forward declarations
632 */
633 #ifndef CONFIG_SMP
634 static void pfm_lazy_save_regs (struct task_struct *ta);
635 #endif
636
637 void dump_pmu_state(const char *);
638 static 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
645 static 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
654 static int pfm_end_notify_user(pfm_context_t *ctx);
655
656 static inline void
657 pfm_clear_psr_pp(void)
658 {
659 ia64_rsm(IA64_PSR_PP);
660 ia64_srlz_i();
661 }
662
663 static inline void
664 pfm_set_psr_pp(void)
665 {
666 ia64_ssm(IA64_PSR_PP);
667 ia64_srlz_i();
668 }
669
670 static inline void
671 pfm_clear_psr_up(void)
672 {
673 ia64_rsm(IA64_PSR_UP);
674 ia64_srlz_i();
675 }
676
677 static inline void
678 pfm_set_psr_up(void)
679 {
680 ia64_ssm(IA64_PSR_UP);
681 ia64_srlz_i();
682 }
683
684 static inline unsigned long
685 pfm_get_psr(void)
686 {
687 unsigned long tmp;
688 tmp = ia64_getreg(_IA64_REG_PSR);
689 ia64_srlz_i();
690 return tmp;
691 }
692
693 static inline void
694 pfm_set_psr_l(unsigned long val)
695 {
696 ia64_setreg(_IA64_REG_PSR_L, val);
697 ia64_srlz_i();
698 }
699
700 static inline void
701 pfm_freeze_pmu(void)
702 {
703 ia64_set_pmc(0,1UL);
704 ia64_srlz_d();
705 }
706
707 static inline void
708 pfm_unfreeze_pmu(void)
709 {
710 ia64_set_pmc(0,0UL);
711 ia64_srlz_d();
712 }
713
714 static inline void
715 pfm_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
726 static inline void
727 pfm_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 */
741 static inline unsigned long
742 pfm_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 */
750 static inline void
751 pfm_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
763 static pfm_msg_t *
764 pfm_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
781 static pfm_msg_t *
782 pfm_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
805 static void
806 pfm_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
812 static pfm_context_t *
813 pfm_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
868 static void
869 pfm_context_free(pfm_context_t *ctx)
870 {
871 if (ctx) {
872 DPRINT(("free ctx @%p\n", ctx));
873 kfree(ctx);
874 }
875 }
876
877 static void
878 pfm_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 */
951 static void
952 pfm_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
1047 static inline void
1048 pfm_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 */
1062 static inline void
1063 pfm_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 */
1079 static inline void
1080 pfm_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 */
1115 static inline void
1116 pfm_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
1132 static inline void
1133 pfm_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
1144 static inline int
1145 pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
1146 {
1147 return memcmp(a, b, sizeof(pfm_uuid_t));
1148 }
1149
1150 static inline int
1151 pfm_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
1158 static inline int
1159 pfm_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
1167 static inline int
1168 pfm_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
1176 static inline int
1177 pfm_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
1185 static inline int
1186 pfm_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
1193 static inline int
1194 pfm_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
1201 static 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 */
1218 static pfm_buffer_fmt_t *
1219 pfm_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
1228 int
1229 pfm_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
1253 out:
1254 spin_unlock(&pfm_buffer_fmt_lock);
1255 return ret;
1256 }
1257 EXPORT_SYMBOL(pfm_register_buffer_fmt);
1258
1259 int
1260 pfm_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
1276 out:
1277 spin_unlock(&pfm_buffer_fmt_lock);
1278 return ret;
1279
1280 }
1281 EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
1282
1283 static int
1284 pfm_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
1338 error_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));
1342 abort:
1343 UNLOCK_PFS(flags);
1344
1345 return -EBUSY;
1346
1347 }
1348
1349 static int
1350 pfm_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 */
1402 static int
1403 pfm_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
1434 static int
1435 pfm_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
1463 invalid_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
1469 static inline void
1470 pfm_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 */
1484 static struct vfsmount *pfmfs_mnt __read_mostly;
1485
1486 static int __init
1487 init_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
1501 static ssize_t
1502 pfm_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
1588 abort_locked:
1589 UNPROTECT_CTX(ctx, flags);
1590 abort:
1591 return ret;
1592 }
1593
1594 static ssize_t
1595 pfm_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
1602 static __poll_t
1603 pfm_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
1637 static long
1638 pfm_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 */
1647 static inline int
1648 pfm_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
1663 static int
1664 pfm_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 */
1703 static void
1704 pfm_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
1751 static void
1752 pfm_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 */
1766 static int
1767 pfm_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 */
1905 static int
1906 pfm_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
2035 doit:
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
2105 static 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
2116 static 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
2122 static const struct dentry_operations pfmfs_dentry_operations = {
2123 .d_delete = always_delete_dentry,
2124 .d_dname = pfmfs_dname,
2125 };
2126
2127
2128 static struct file *
2129 pfm_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
2173 static int
2174 pfm_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 */
2195 static int
2196 pfm_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
2299 error:
2300 vm_area_free(vma);
2301 error_kmem:
2302 vfree(smpl_buf);
2303
2304 return -ENOMEM;
2305 }
2306
2307 /*
2308 * XXX: do something better here
2309 */
2310 static int
2311 pfm_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
2342 static int
2343 pfarg_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
2367 static int
2368 pfm_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
2418 error:
2419 return ret;
2420 }
2421
2422 static void
2423 pfm_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
2478 static int
2479 pfm_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 */
2508 static int
2509 pfm_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
2554 static int
2555 pfm_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
2581 static int
2582 pfm_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
2643 buffer_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 }
2651 error_file:
2652 pfm_context_free(ctx);
2653
2654 error:
2655 put_unused_fd(fd);
2656 return ret;
2657 }
2658
2659 static inline unsigned long
2660 pfm_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
2678 static void
2679 pfm_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
2714 static void
2715 pfm_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
2765 static int
2766 pfm_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;
3000 error:
3001 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3002 return ret;
3003 }
3004
3005 static int
3006 pfm_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
3184 abort_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 */
3201 static int
3202 pfm_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
3327 error:
3328 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
3329 return ret;
3330 }
3331
3332 int
3333 pfm_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 }
3351 EXPORT_SYMBOL(pfm_mod_write_pmcs);
3352
3353 int
3354 pfm_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 }
3372 EXPORT_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 */
3378 int
3379 pfm_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 */
3433 int
3434 pfm_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
3454 static int
3455 pfm_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
3607 static int
3608 pfm_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 */
3626 static int
3627 pfm_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
3801 abort_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
3821 static int
3822 pfm_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
3827 static int
3828 pfm_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
3833 int
3834 pfm_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 }
3852 EXPORT_SYMBOL(pfm_mod_write_ibrs);
3853
3854 int
3855 pfm_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 }
3873 EXPORT_SYMBOL(pfm_mod_write_dbrs);
3874
3875
3876 static int
3877 pfm_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
3885 static int
3886 pfm_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
3974 static int
3975 pfm_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
4055 static int
4056 pfm_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
4077 abort_mission:
4078 PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
4079 return ret;
4080 }
4081
4082 static int
4083 pfm_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);
4096 out:
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
4104 static int
4105 pfm_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
4323 error_unres:
4324 if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
4325 error:
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 */
4359 static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
4360
4361 static int
4362 pfm_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 */
4494 void
4495 pfm_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
4564 static 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
4602 static int
4603 pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
4604 {
4605 struct task_struct *task;
4606 int state, old_state;
4607
4608 recheck:
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 */
4706 asmlinkage long
4707 sys_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
4754 restart_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
4831 skip_fd:
4832 ret = (*func)(ctx, args_k, count, task_pt_regs(current));
4833
4834 call_made = 1;
4835
4836 abort_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
4845 error_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
4856 static void
4857 pfm_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 */
4902 static void
4903 pfm_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
4926 static 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 */
4937 void
4938 pfm_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) {
5017 do_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
5028 skip_blocking:
5029 pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
5030 ctx->ctx_ovfl_regs[0] = 0UL;
5031
5032 nothing_to_do:
5033 /*
5034 * restore flags as they were upon entry
5035 */
5036 UNPROTECT_CTX(ctx, flags);
5037 }
5038
5039 static int
5040 pfm_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
5060 static int
5061 pfm_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
5091 static int
5092 pfm_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 */
5120 static 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
5358 sanity_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
5365 stop_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
5401 static int
5402 pfm_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
5453 report_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;
5458 report_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
5466 static irqreturn_t
5467 pfm_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
5512 static void *
5513 pfm_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
5528 static void *
5529 pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
5530 {
5531 ++*pos;
5532 return pfm_proc_start(m, pos);
5533 }
5534
5535 static void
5536 pfm_proc_stop(struct seq_file *m, void *v)
5537 {
5538 }
5539
5540 static void
5541 pfm_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
5586 static int
5587 pfm_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
5655 const 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 */
5668 void
5669 pfm_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
5716 static void
5717 pfm_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 */
5745 void
5746 pfm_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 */
5834 void
5835 pfm_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
5865 static void
5866 pfm_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 */
5927 void
5928 pfm_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 */
6090 void
6091 pfm_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