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