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torvalds
GitHub Repository: torvalds/linux
Path: blob/master/arch/x86/events/core.c
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1
/*
2
* Performance events x86 architecture code
3
*
4
* Copyright (C) 2008 Thomas Gleixner <[email protected]>
5
* Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6
* Copyright (C) 2009 Jaswinder Singh Rajput
7
* Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
8
* Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
9
* Copyright (C) 2009 Intel Corporation, <[email protected]>
10
* Copyright (C) 2009 Google, Inc., Stephane Eranian
11
*
12
* For licencing details see kernel-base/COPYING
13
*/
14
15
#include <linux/perf_event.h>
16
#include <linux/capability.h>
17
#include <linux/notifier.h>
18
#include <linux/hardirq.h>
19
#include <linux/kprobes.h>
20
#include <linux/export.h>
21
#include <linux/init.h>
22
#include <linux/kdebug.h>
23
#include <linux/sched/mm.h>
24
#include <linux/sched/clock.h>
25
#include <linux/uaccess.h>
26
#include <linux/slab.h>
27
#include <linux/cpu.h>
28
#include <linux/bitops.h>
29
#include <linux/device.h>
30
#include <linux/nospec.h>
31
#include <linux/static_call.h>
32
33
#include <asm/apic.h>
34
#include <asm/stacktrace.h>
35
#include <asm/msr.h>
36
#include <asm/nmi.h>
37
#include <asm/smp.h>
38
#include <asm/alternative.h>
39
#include <asm/mmu_context.h>
40
#include <asm/tlbflush.h>
41
#include <asm/timer.h>
42
#include <asm/desc.h>
43
#include <asm/ldt.h>
44
#include <asm/unwind.h>
45
#include <asm/uprobes.h>
46
#include <asm/ibt.h>
47
48
#include "perf_event.h"
49
50
struct x86_pmu x86_pmu __read_mostly;
51
static struct pmu pmu;
52
53
DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
54
.enabled = 1,
55
.pmu = &pmu,
56
};
57
58
DEFINE_STATIC_KEY_FALSE(rdpmc_never_available_key);
59
DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key);
60
DEFINE_STATIC_KEY_FALSE(perf_is_hybrid);
61
62
/*
63
* This here uses DEFINE_STATIC_CALL_NULL() to get a static_call defined
64
* from just a typename, as opposed to an actual function.
65
*/
66
DEFINE_STATIC_CALL_NULL(x86_pmu_handle_irq, *x86_pmu.handle_irq);
67
DEFINE_STATIC_CALL_NULL(x86_pmu_disable_all, *x86_pmu.disable_all);
68
DEFINE_STATIC_CALL_NULL(x86_pmu_enable_all, *x86_pmu.enable_all);
69
DEFINE_STATIC_CALL_NULL(x86_pmu_enable, *x86_pmu.enable);
70
DEFINE_STATIC_CALL_NULL(x86_pmu_disable, *x86_pmu.disable);
71
72
DEFINE_STATIC_CALL_NULL(x86_pmu_assign, *x86_pmu.assign);
73
74
DEFINE_STATIC_CALL_NULL(x86_pmu_add, *x86_pmu.add);
75
DEFINE_STATIC_CALL_NULL(x86_pmu_del, *x86_pmu.del);
76
DEFINE_STATIC_CALL_NULL(x86_pmu_read, *x86_pmu.read);
77
78
DEFINE_STATIC_CALL_NULL(x86_pmu_set_period, *x86_pmu.set_period);
79
DEFINE_STATIC_CALL_NULL(x86_pmu_update, *x86_pmu.update);
80
DEFINE_STATIC_CALL_NULL(x86_pmu_limit_period, *x86_pmu.limit_period);
81
82
DEFINE_STATIC_CALL_NULL(x86_pmu_schedule_events, *x86_pmu.schedule_events);
83
DEFINE_STATIC_CALL_NULL(x86_pmu_get_event_constraints, *x86_pmu.get_event_constraints);
84
DEFINE_STATIC_CALL_NULL(x86_pmu_put_event_constraints, *x86_pmu.put_event_constraints);
85
86
DEFINE_STATIC_CALL_NULL(x86_pmu_start_scheduling, *x86_pmu.start_scheduling);
87
DEFINE_STATIC_CALL_NULL(x86_pmu_commit_scheduling, *x86_pmu.commit_scheduling);
88
DEFINE_STATIC_CALL_NULL(x86_pmu_stop_scheduling, *x86_pmu.stop_scheduling);
89
90
DEFINE_STATIC_CALL_NULL(x86_pmu_sched_task, *x86_pmu.sched_task);
91
92
DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs, *x86_pmu.drain_pebs);
93
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);
94
95
DEFINE_STATIC_CALL_NULL(x86_pmu_filter, *x86_pmu.filter);
96
97
DEFINE_STATIC_CALL_NULL(x86_pmu_late_setup, *x86_pmu.late_setup);
98
99
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable, *x86_pmu.pebs_enable);
100
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable, *x86_pmu.pebs_disable);
101
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable_all, *x86_pmu.pebs_enable_all);
102
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable_all, *x86_pmu.pebs_disable_all);
103
104
/*
105
* This one is magic, it will get called even when PMU init fails (because
106
* there is no PMU), in which case it should simply return NULL.
107
*/
108
DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs);
109
110
u64 __read_mostly hw_cache_event_ids
111
[PERF_COUNT_HW_CACHE_MAX]
112
[PERF_COUNT_HW_CACHE_OP_MAX]
113
[PERF_COUNT_HW_CACHE_RESULT_MAX];
114
u64 __read_mostly hw_cache_extra_regs
115
[PERF_COUNT_HW_CACHE_MAX]
116
[PERF_COUNT_HW_CACHE_OP_MAX]
117
[PERF_COUNT_HW_CACHE_RESULT_MAX];
118
119
/*
120
* Propagate event elapsed time into the generic event.
121
* Can only be executed on the CPU where the event is active.
122
* Returns the delta events processed.
123
*/
124
u64 x86_perf_event_update(struct perf_event *event)
125
{
126
struct hw_perf_event *hwc = &event->hw;
127
int shift = 64 - x86_pmu.cntval_bits;
128
u64 prev_raw_count, new_raw_count;
129
u64 delta;
130
131
if (unlikely(!hwc->event_base))
132
return 0;
133
134
/*
135
* Careful: an NMI might modify the previous event value.
136
*
137
* Our tactic to handle this is to first atomically read and
138
* exchange a new raw count - then add that new-prev delta
139
* count to the generic event atomically:
140
*/
141
prev_raw_count = local64_read(&hwc->prev_count);
142
do {
143
new_raw_count = rdpmc(hwc->event_base_rdpmc);
144
} while (!local64_try_cmpxchg(&hwc->prev_count,
145
&prev_raw_count, new_raw_count));
146
147
/*
148
* Now we have the new raw value and have updated the prev
149
* timestamp already. We can now calculate the elapsed delta
150
* (event-)time and add that to the generic event.
151
*
152
* Careful, not all hw sign-extends above the physical width
153
* of the count.
154
*/
155
delta = (new_raw_count << shift) - (prev_raw_count << shift);
156
delta >>= shift;
157
158
local64_add(delta, &event->count);
159
local64_sub(delta, &hwc->period_left);
160
161
return new_raw_count;
162
}
163
164
/*
165
* Find and validate any extra registers to set up.
166
*/
167
static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
168
{
169
struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
170
struct hw_perf_event_extra *reg;
171
struct extra_reg *er;
172
173
reg = &event->hw.extra_reg;
174
175
if (!extra_regs)
176
return 0;
177
178
for (er = extra_regs; er->msr; er++) {
179
if (er->event != (config & er->config_mask))
180
continue;
181
if (event->attr.config1 & ~er->valid_mask)
182
return -EINVAL;
183
/* Check if the extra msrs can be safely accessed*/
184
if (!er->extra_msr_access)
185
return -ENXIO;
186
187
reg->idx = er->idx;
188
reg->config = event->attr.config1;
189
reg->reg = er->msr;
190
break;
191
}
192
return 0;
193
}
194
195
static atomic_t active_events;
196
static atomic_t pmc_refcount;
197
static DEFINE_MUTEX(pmc_reserve_mutex);
198
199
#ifdef CONFIG_X86_LOCAL_APIC
200
201
static inline u64 get_possible_counter_mask(void)
202
{
203
u64 cntr_mask = x86_pmu.cntr_mask64;
204
int i;
205
206
if (!is_hybrid())
207
return cntr_mask;
208
209
for (i = 0; i < x86_pmu.num_hybrid_pmus; i++)
210
cntr_mask |= x86_pmu.hybrid_pmu[i].cntr_mask64;
211
212
return cntr_mask;
213
}
214
215
static bool reserve_pmc_hardware(void)
216
{
217
u64 cntr_mask = get_possible_counter_mask();
218
int i, end;
219
220
for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
221
if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
222
goto perfctr_fail;
223
}
224
225
for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
226
if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
227
goto eventsel_fail;
228
}
229
230
return true;
231
232
eventsel_fail:
233
end = i;
234
for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
235
release_evntsel_nmi(x86_pmu_config_addr(i));
236
i = X86_PMC_IDX_MAX;
237
238
perfctr_fail:
239
end = i;
240
for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
241
release_perfctr_nmi(x86_pmu_event_addr(i));
242
243
return false;
244
}
245
246
static void release_pmc_hardware(void)
247
{
248
u64 cntr_mask = get_possible_counter_mask();
249
int i;
250
251
for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
252
release_perfctr_nmi(x86_pmu_event_addr(i));
253
release_evntsel_nmi(x86_pmu_config_addr(i));
254
}
255
}
256
257
#else
258
259
static bool reserve_pmc_hardware(void) { return true; }
260
static void release_pmc_hardware(void) {}
261
262
#endif
263
264
bool check_hw_exists(struct pmu *pmu, unsigned long *cntr_mask,
265
unsigned long *fixed_cntr_mask)
266
{
267
u64 val, val_fail = -1, val_new= ~0;
268
int i, reg, reg_fail = -1, ret = 0;
269
int bios_fail = 0;
270
int reg_safe = -1;
271
272
/*
273
* Check to see if the BIOS enabled any of the counters, if so
274
* complain and bail.
275
*/
276
for_each_set_bit(i, cntr_mask, X86_PMC_IDX_MAX) {
277
reg = x86_pmu_config_addr(i);
278
ret = rdmsrq_safe(reg, &val);
279
if (ret)
280
goto msr_fail;
281
if (val & ARCH_PERFMON_EVENTSEL_ENABLE) {
282
bios_fail = 1;
283
val_fail = val;
284
reg_fail = reg;
285
} else {
286
reg_safe = i;
287
}
288
}
289
290
if (*(u64 *)fixed_cntr_mask) {
291
reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
292
ret = rdmsrq_safe(reg, &val);
293
if (ret)
294
goto msr_fail;
295
for_each_set_bit(i, fixed_cntr_mask, X86_PMC_IDX_MAX) {
296
if (fixed_counter_disabled(i, pmu))
297
continue;
298
if (val & (0x03ULL << i*4)) {
299
bios_fail = 1;
300
val_fail = val;
301
reg_fail = reg;
302
}
303
}
304
}
305
306
/*
307
* If all the counters are enabled, the below test will always
308
* fail. The tools will also become useless in this scenario.
309
* Just fail and disable the hardware counters.
310
*/
311
312
if (reg_safe == -1) {
313
reg = reg_safe;
314
goto msr_fail;
315
}
316
317
/*
318
* Read the current value, change it and read it back to see if it
319
* matches, this is needed to detect certain hardware emulators
320
* (qemu/kvm) that don't trap on the MSR access and always return 0s.
321
*/
322
reg = x86_pmu_event_addr(reg_safe);
323
if (rdmsrq_safe(reg, &val))
324
goto msr_fail;
325
val ^= 0xffffUL;
326
ret = wrmsrq_safe(reg, val);
327
ret |= rdmsrq_safe(reg, &val_new);
328
if (ret || val != val_new)
329
goto msr_fail;
330
331
/*
332
* We still allow the PMU driver to operate:
333
*/
334
if (bios_fail) {
335
pr_cont("Broken BIOS detected, complain to your hardware vendor.\n");
336
pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n",
337
reg_fail, val_fail);
338
}
339
340
return true;
341
342
msr_fail:
343
if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
344
pr_cont("PMU not available due to virtualization, using software events only.\n");
345
} else {
346
pr_cont("Broken PMU hardware detected, using software events only.\n");
347
pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n",
348
reg, val_new);
349
}
350
351
return false;
352
}
353
354
static void hw_perf_event_destroy(struct perf_event *event)
355
{
356
x86_release_hardware();
357
atomic_dec(&active_events);
358
}
359
360
void hw_perf_lbr_event_destroy(struct perf_event *event)
361
{
362
hw_perf_event_destroy(event);
363
364
/* undo the lbr/bts event accounting */
365
x86_del_exclusive(x86_lbr_exclusive_lbr);
366
}
367
368
static inline int x86_pmu_initialized(void)
369
{
370
return x86_pmu.handle_irq != NULL;
371
}
372
373
static inline int
374
set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
375
{
376
struct perf_event_attr *attr = &event->attr;
377
unsigned int cache_type, cache_op, cache_result;
378
u64 config, val;
379
380
config = attr->config;
381
382
cache_type = (config >> 0) & 0xff;
383
if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
384
return -EINVAL;
385
cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);
386
387
cache_op = (config >> 8) & 0xff;
388
if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
389
return -EINVAL;
390
cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);
391
392
cache_result = (config >> 16) & 0xff;
393
if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
394
return -EINVAL;
395
cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);
396
397
val = hybrid_var(event->pmu, hw_cache_event_ids)[cache_type][cache_op][cache_result];
398
if (val == 0)
399
return -ENOENT;
400
401
if (val == -1)
402
return -EINVAL;
403
404
hwc->config |= val;
405
attr->config1 = hybrid_var(event->pmu, hw_cache_extra_regs)[cache_type][cache_op][cache_result];
406
return x86_pmu_extra_regs(val, event);
407
}
408
409
int x86_reserve_hardware(void)
410
{
411
int err = 0;
412
413
if (!atomic_inc_not_zero(&pmc_refcount)) {
414
mutex_lock(&pmc_reserve_mutex);
415
if (atomic_read(&pmc_refcount) == 0) {
416
if (!reserve_pmc_hardware()) {
417
err = -EBUSY;
418
} else {
419
reserve_ds_buffers();
420
reserve_lbr_buffers();
421
}
422
}
423
if (!err)
424
atomic_inc(&pmc_refcount);
425
mutex_unlock(&pmc_reserve_mutex);
426
}
427
428
return err;
429
}
430
431
void x86_release_hardware(void)
432
{
433
if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
434
release_pmc_hardware();
435
release_ds_buffers();
436
release_lbr_buffers();
437
mutex_unlock(&pmc_reserve_mutex);
438
}
439
}
440
441
/*
442
* Check if we can create event of a certain type (that no conflicting events
443
* are present).
444
*/
445
int x86_add_exclusive(unsigned int what)
446
{
447
int i;
448
449
/*
450
* When lbr_pt_coexist we allow PT to coexist with either LBR or BTS.
451
* LBR and BTS are still mutually exclusive.
452
*/
453
if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
454
goto out;
455
456
if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
457
mutex_lock(&pmc_reserve_mutex);
458
for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
459
if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
460
goto fail_unlock;
461
}
462
atomic_inc(&x86_pmu.lbr_exclusive[what]);
463
mutex_unlock(&pmc_reserve_mutex);
464
}
465
466
out:
467
atomic_inc(&active_events);
468
return 0;
469
470
fail_unlock:
471
mutex_unlock(&pmc_reserve_mutex);
472
return -EBUSY;
473
}
474
475
void x86_del_exclusive(unsigned int what)
476
{
477
atomic_dec(&active_events);
478
479
/*
480
* See the comment in x86_add_exclusive().
481
*/
482
if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
483
return;
484
485
atomic_dec(&x86_pmu.lbr_exclusive[what]);
486
}
487
488
int x86_setup_perfctr(struct perf_event *event)
489
{
490
struct perf_event_attr *attr = &event->attr;
491
struct hw_perf_event *hwc = &event->hw;
492
u64 config;
493
494
if (!is_sampling_event(event)) {
495
hwc->sample_period = x86_pmu.max_period;
496
hwc->last_period = hwc->sample_period;
497
local64_set(&hwc->period_left, hwc->sample_period);
498
}
499
500
if (attr->type == event->pmu->type)
501
return x86_pmu_extra_regs(event->attr.config, event);
502
503
if (attr->type == PERF_TYPE_HW_CACHE)
504
return set_ext_hw_attr(hwc, event);
505
506
if (attr->config >= x86_pmu.max_events)
507
return -EINVAL;
508
509
attr->config = array_index_nospec((unsigned long)attr->config, x86_pmu.max_events);
510
511
/*
512
* The generic map:
513
*/
514
config = x86_pmu.event_map(attr->config);
515
516
if (config == 0)
517
return -ENOENT;
518
519
if (config == -1LL)
520
return -EINVAL;
521
522
hwc->config |= config;
523
524
return 0;
525
}
526
527
/*
528
* check that branch_sample_type is compatible with
529
* settings needed for precise_ip > 1 which implies
530
* using the LBR to capture ALL taken branches at the
531
* priv levels of the measurement
532
*/
533
static inline int precise_br_compat(struct perf_event *event)
534
{
535
u64 m = event->attr.branch_sample_type;
536
u64 b = 0;
537
538
/* must capture all branches */
539
if (!(m & PERF_SAMPLE_BRANCH_ANY))
540
return 0;
541
542
m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;
543
544
if (!event->attr.exclude_user)
545
b |= PERF_SAMPLE_BRANCH_USER;
546
547
if (!event->attr.exclude_kernel)
548
b |= PERF_SAMPLE_BRANCH_KERNEL;
549
550
/*
551
* ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
552
*/
553
554
return m == b;
555
}
556
557
int x86_pmu_max_precise(void)
558
{
559
int precise = 0;
560
561
/* Support for constant skid */
562
if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
563
precise++;
564
565
/* Support for IP fixup */
566
if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
567
precise++;
568
569
if (x86_pmu.pebs_prec_dist)
570
precise++;
571
}
572
return precise;
573
}
574
575
int x86_pmu_hw_config(struct perf_event *event)
576
{
577
if (event->attr.precise_ip) {
578
int precise = x86_pmu_max_precise();
579
580
if (event->attr.precise_ip > precise)
581
return -EOPNOTSUPP;
582
583
/* There's no sense in having PEBS for non sampling events: */
584
if (!is_sampling_event(event))
585
return -EINVAL;
586
}
587
/*
588
* check that PEBS LBR correction does not conflict with
589
* whatever the user is asking with attr->branch_sample_type
590
*/
591
if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) {
592
u64 *br_type = &event->attr.branch_sample_type;
593
594
if (has_branch_stack(event)) {
595
if (!precise_br_compat(event))
596
return -EOPNOTSUPP;
597
598
/* branch_sample_type is compatible */
599
600
} else {
601
/*
602
* user did not specify branch_sample_type
603
*
604
* For PEBS fixups, we capture all
605
* the branches at the priv level of the
606
* event.
607
*/
608
*br_type = PERF_SAMPLE_BRANCH_ANY;
609
610
if (!event->attr.exclude_user)
611
*br_type |= PERF_SAMPLE_BRANCH_USER;
612
613
if (!event->attr.exclude_kernel)
614
*br_type |= PERF_SAMPLE_BRANCH_KERNEL;
615
}
616
}
617
618
if (branch_sample_call_stack(event))
619
event->attach_state |= PERF_ATTACH_TASK_DATA;
620
621
/*
622
* Generate PMC IRQs:
623
* (keep 'enabled' bit clear for now)
624
*/
625
event->hw.config = ARCH_PERFMON_EVENTSEL_INT;
626
627
/*
628
* Count user and OS events unless requested not to
629
*/
630
if (!event->attr.exclude_user)
631
event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
632
if (!event->attr.exclude_kernel)
633
event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;
634
635
if (event->attr.type == event->pmu->type)
636
event->hw.config |= x86_pmu_get_event_config(event);
637
638
if (is_sampling_event(event) && !event->attr.freq && x86_pmu.limit_period) {
639
s64 left = event->attr.sample_period;
640
x86_pmu.limit_period(event, &left);
641
if (left > event->attr.sample_period)
642
return -EINVAL;
643
}
644
645
/* sample_regs_user never support XMM registers */
646
if (unlikely(event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK))
647
return -EINVAL;
648
/*
649
* Besides the general purpose registers, XMM registers may
650
* be collected in PEBS on some platforms, e.g. Icelake
651
*/
652
if (unlikely(event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK)) {
653
if (!(event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS))
654
return -EINVAL;
655
656
if (!event->attr.precise_ip)
657
return -EINVAL;
658
}
659
660
return x86_setup_perfctr(event);
661
}
662
663
/*
664
* Setup the hardware configuration for a given attr_type
665
*/
666
static int __x86_pmu_event_init(struct perf_event *event)
667
{
668
int err;
669
670
if (!x86_pmu_initialized())
671
return -ENODEV;
672
673
err = x86_reserve_hardware();
674
if (err)
675
return err;
676
677
atomic_inc(&active_events);
678
event->destroy = hw_perf_event_destroy;
679
680
event->hw.idx = -1;
681
event->hw.last_cpu = -1;
682
event->hw.last_tag = ~0ULL;
683
event->hw.dyn_constraint = ~0ULL;
684
685
/* mark unused */
686
event->hw.extra_reg.idx = EXTRA_REG_NONE;
687
event->hw.branch_reg.idx = EXTRA_REG_NONE;
688
689
return x86_pmu.hw_config(event);
690
}
691
692
void x86_pmu_disable_all(void)
693
{
694
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
695
int idx;
696
697
for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
698
struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
699
u64 val;
700
701
if (!test_bit(idx, cpuc->active_mask))
702
continue;
703
rdmsrq(x86_pmu_config_addr(idx), val);
704
if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
705
continue;
706
val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
707
wrmsrq(x86_pmu_config_addr(idx), val);
708
if (is_counter_pair(hwc))
709
wrmsrq(x86_pmu_config_addr(idx + 1), 0);
710
}
711
}
712
713
struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
714
{
715
return static_call(x86_pmu_guest_get_msrs)(nr, data);
716
}
717
EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
718
719
/*
720
* There may be PMI landing after enabled=0. The PMI hitting could be before or
721
* after disable_all.
722
*
723
* If PMI hits before disable_all, the PMU will be disabled in the NMI handler.
724
* It will not be re-enabled in the NMI handler again, because enabled=0. After
725
* handling the NMI, disable_all will be called, which will not change the
726
* state either. If PMI hits after disable_all, the PMU is already disabled
727
* before entering NMI handler. The NMI handler will not change the state
728
* either.
729
*
730
* So either situation is harmless.
731
*/
732
static void x86_pmu_disable(struct pmu *pmu)
733
{
734
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
735
736
if (!x86_pmu_initialized())
737
return;
738
739
if (!cpuc->enabled)
740
return;
741
742
cpuc->n_added = 0;
743
cpuc->enabled = 0;
744
barrier();
745
746
static_call(x86_pmu_disable_all)();
747
}
748
749
void x86_pmu_enable_all(int added)
750
{
751
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
752
int idx;
753
754
for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
755
struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
756
757
if (!test_bit(idx, cpuc->active_mask))
758
continue;
759
760
__x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
761
}
762
}
763
764
int is_x86_event(struct perf_event *event)
765
{
766
/*
767
* For a non-hybrid platforms, the type of X86 pmu is
768
* always PERF_TYPE_RAW.
769
* For a hybrid platform, the PERF_PMU_CAP_EXTENDED_HW_TYPE
770
* is a unique capability for the X86 PMU.
771
* Use them to detect a X86 event.
772
*/
773
if (event->pmu->type == PERF_TYPE_RAW ||
774
event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE)
775
return true;
776
777
return false;
778
}
779
780
struct pmu *x86_get_pmu(unsigned int cpu)
781
{
782
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
783
784
/*
785
* All CPUs of the hybrid type have been offline.
786
* The x86_get_pmu() should not be invoked.
787
*/
788
if (WARN_ON_ONCE(!cpuc->pmu))
789
return &pmu;
790
791
return cpuc->pmu;
792
}
793
/*
794
* Event scheduler state:
795
*
796
* Assign events iterating over all events and counters, beginning
797
* with events with least weights first. Keep the current iterator
798
* state in struct sched_state.
799
*/
800
struct sched_state {
801
int weight;
802
int event; /* event index */
803
int counter; /* counter index */
804
int unassigned; /* number of events to be assigned left */
805
int nr_gp; /* number of GP counters used */
806
u64 used;
807
};
808
809
/* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */
810
#define SCHED_STATES_MAX 2
811
812
struct perf_sched {
813
int max_weight;
814
int max_events;
815
int max_gp;
816
int saved_states;
817
struct event_constraint **constraints;
818
struct sched_state state;
819
struct sched_state saved[SCHED_STATES_MAX];
820
};
821
822
/*
823
* Initialize iterator that runs through all events and counters.
824
*/
825
static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
826
int num, int wmin, int wmax, int gpmax)
827
{
828
int idx;
829
830
memset(sched, 0, sizeof(*sched));
831
sched->max_events = num;
832
sched->max_weight = wmax;
833
sched->max_gp = gpmax;
834
sched->constraints = constraints;
835
836
for (idx = 0; idx < num; idx++) {
837
if (constraints[idx]->weight == wmin)
838
break;
839
}
840
841
sched->state.event = idx; /* start with min weight */
842
sched->state.weight = wmin;
843
sched->state.unassigned = num;
844
}
845
846
static void perf_sched_save_state(struct perf_sched *sched)
847
{
848
if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX))
849
return;
850
851
sched->saved[sched->saved_states] = sched->state;
852
sched->saved_states++;
853
}
854
855
static bool perf_sched_restore_state(struct perf_sched *sched)
856
{
857
if (!sched->saved_states)
858
return false;
859
860
sched->saved_states--;
861
sched->state = sched->saved[sched->saved_states];
862
863
/* this assignment didn't work out */
864
/* XXX broken vs EVENT_PAIR */
865
sched->state.used &= ~BIT_ULL(sched->state.counter);
866
867
/* try the next one */
868
sched->state.counter++;
869
870
return true;
871
}
872
873
/*
874
* Select a counter for the current event to schedule. Return true on
875
* success.
876
*/
877
static bool __perf_sched_find_counter(struct perf_sched *sched)
878
{
879
struct event_constraint *c;
880
int idx;
881
882
if (!sched->state.unassigned)
883
return false;
884
885
if (sched->state.event >= sched->max_events)
886
return false;
887
888
c = sched->constraints[sched->state.event];
889
/* Prefer fixed purpose counters */
890
if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
891
idx = INTEL_PMC_IDX_FIXED;
892
for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) {
893
u64 mask = BIT_ULL(idx);
894
895
if (sched->state.used & mask)
896
continue;
897
898
sched->state.used |= mask;
899
goto done;
900
}
901
}
902
903
/* Grab the first unused counter starting with idx */
904
idx = sched->state.counter;
905
for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
906
u64 mask = BIT_ULL(idx);
907
908
if (c->flags & PERF_X86_EVENT_PAIR)
909
mask |= mask << 1;
910
911
if (sched->state.used & mask)
912
continue;
913
914
if (sched->state.nr_gp++ >= sched->max_gp)
915
return false;
916
917
sched->state.used |= mask;
918
goto done;
919
}
920
921
return false;
922
923
done:
924
sched->state.counter = idx;
925
926
if (c->overlap)
927
perf_sched_save_state(sched);
928
929
return true;
930
}
931
932
static bool perf_sched_find_counter(struct perf_sched *sched)
933
{
934
while (!__perf_sched_find_counter(sched)) {
935
if (!perf_sched_restore_state(sched))
936
return false;
937
}
938
939
return true;
940
}
941
942
/*
943
* Go through all unassigned events and find the next one to schedule.
944
* Take events with the least weight first. Return true on success.
945
*/
946
static bool perf_sched_next_event(struct perf_sched *sched)
947
{
948
struct event_constraint *c;
949
950
if (!sched->state.unassigned || !--sched->state.unassigned)
951
return false;
952
953
do {
954
/* next event */
955
sched->state.event++;
956
if (sched->state.event >= sched->max_events) {
957
/* next weight */
958
sched->state.event = 0;
959
sched->state.weight++;
960
if (sched->state.weight > sched->max_weight)
961
return false;
962
}
963
c = sched->constraints[sched->state.event];
964
} while (c->weight != sched->state.weight);
965
966
sched->state.counter = 0; /* start with first counter */
967
968
return true;
969
}
970
971
/*
972
* Assign a counter for each event.
973
*/
974
int perf_assign_events(struct event_constraint **constraints, int n,
975
int wmin, int wmax, int gpmax, int *assign)
976
{
977
struct perf_sched sched;
978
979
perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
980
981
do {
982
if (!perf_sched_find_counter(&sched))
983
break; /* failed */
984
if (assign)
985
assign[sched.state.event] = sched.state.counter;
986
} while (perf_sched_next_event(&sched));
987
988
return sched.state.unassigned;
989
}
990
EXPORT_SYMBOL_GPL(perf_assign_events);
991
992
int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
993
{
994
struct event_constraint *c;
995
struct perf_event *e;
996
int n0, i, wmin, wmax, unsched = 0;
997
struct hw_perf_event *hwc;
998
u64 used_mask = 0;
999
1000
/*
1001
* Compute the number of events already present; see x86_pmu_add(),
1002
* validate_group() and x86_pmu_commit_txn(). For the former two
1003
* cpuc->n_events hasn't been updated yet, while for the latter
1004
* cpuc->n_txn contains the number of events added in the current
1005
* transaction.
1006
*/
1007
n0 = cpuc->n_events;
1008
if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1009
n0 -= cpuc->n_txn;
1010
1011
static_call_cond(x86_pmu_start_scheduling)(cpuc);
1012
1013
for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
1014
c = cpuc->event_constraint[i];
1015
1016
/*
1017
* Previously scheduled events should have a cached constraint,
1018
* while new events should not have one.
1019
*/
1020
WARN_ON_ONCE((c && i >= n0) || (!c && i < n0));
1021
1022
/*
1023
* Request constraints for new events; or for those events that
1024
* have a dynamic constraint -- for those the constraint can
1025
* change due to external factors (sibling state, allow_tfa).
1026
*/
1027
if (!c || (c->flags & PERF_X86_EVENT_DYNAMIC)) {
1028
c = static_call(x86_pmu_get_event_constraints)(cpuc, i, cpuc->event_list[i]);
1029
cpuc->event_constraint[i] = c;
1030
}
1031
1032
wmin = min(wmin, c->weight);
1033
wmax = max(wmax, c->weight);
1034
}
1035
1036
/*
1037
* fastpath, try to reuse previous register
1038
*/
1039
for (i = 0; i < n; i++) {
1040
u64 mask;
1041
1042
hwc = &cpuc->event_list[i]->hw;
1043
c = cpuc->event_constraint[i];
1044
1045
/* never assigned */
1046
if (hwc->idx == -1)
1047
break;
1048
1049
/* constraint still honored */
1050
if (!test_bit(hwc->idx, c->idxmsk))
1051
break;
1052
1053
mask = BIT_ULL(hwc->idx);
1054
if (is_counter_pair(hwc))
1055
mask |= mask << 1;
1056
1057
/* not already used */
1058
if (used_mask & mask)
1059
break;
1060
1061
used_mask |= mask;
1062
1063
if (assign)
1064
assign[i] = hwc->idx;
1065
}
1066
1067
/* slow path */
1068
if (i != n) {
1069
int gpmax = x86_pmu_max_num_counters(cpuc->pmu);
1070
1071
/*
1072
* Do not allow scheduling of more than half the available
1073
* generic counters.
1074
*
1075
* This helps avoid counter starvation of sibling thread by
1076
* ensuring at most half the counters cannot be in exclusive
1077
* mode. There is no designated counters for the limits. Any
1078
* N/2 counters can be used. This helps with events with
1079
* specific counter constraints.
1080
*/
1081
if (is_ht_workaround_enabled() && !cpuc->is_fake &&
1082
READ_ONCE(cpuc->excl_cntrs->exclusive_present))
1083
gpmax /= 2;
1084
1085
/*
1086
* Reduce the amount of available counters to allow fitting
1087
* the extra Merge events needed by large increment events.
1088
*/
1089
if (x86_pmu.flags & PMU_FL_PAIR) {
1090
gpmax -= cpuc->n_pair;
1091
WARN_ON(gpmax <= 0);
1092
}
1093
1094
unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
1095
wmax, gpmax, assign);
1096
}
1097
1098
/*
1099
* In case of success (unsched = 0), mark events as committed,
1100
* so we do not put_constraint() in case new events are added
1101
* and fail to be scheduled
1102
*
1103
* We invoke the lower level commit callback to lock the resource
1104
*
1105
* We do not need to do all of this in case we are called to
1106
* validate an event group (assign == NULL)
1107
*/
1108
if (!unsched && assign) {
1109
for (i = 0; i < n; i++)
1110
static_call_cond(x86_pmu_commit_scheduling)(cpuc, i, assign[i]);
1111
} else {
1112
for (i = n0; i < n; i++) {
1113
e = cpuc->event_list[i];
1114
1115
/*
1116
* release events that failed scheduling
1117
*/
1118
static_call_cond(x86_pmu_put_event_constraints)(cpuc, e);
1119
1120
cpuc->event_constraint[i] = NULL;
1121
}
1122
}
1123
1124
static_call_cond(x86_pmu_stop_scheduling)(cpuc);
1125
1126
return unsched ? -EINVAL : 0;
1127
}
1128
1129
static int add_nr_metric_event(struct cpu_hw_events *cpuc,
1130
struct perf_event *event)
1131
{
1132
if (is_metric_event(event)) {
1133
if (cpuc->n_metric == INTEL_TD_METRIC_NUM)
1134
return -EINVAL;
1135
cpuc->n_metric++;
1136
cpuc->n_txn_metric++;
1137
}
1138
1139
return 0;
1140
}
1141
1142
static void del_nr_metric_event(struct cpu_hw_events *cpuc,
1143
struct perf_event *event)
1144
{
1145
if (is_metric_event(event))
1146
cpuc->n_metric--;
1147
}
1148
1149
static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event,
1150
int max_count, int n)
1151
{
1152
union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);
1153
1154
if (intel_cap.perf_metrics && add_nr_metric_event(cpuc, event))
1155
return -EINVAL;
1156
1157
if (n >= max_count + cpuc->n_metric)
1158
return -EINVAL;
1159
1160
cpuc->event_list[n] = event;
1161
if (is_counter_pair(&event->hw)) {
1162
cpuc->n_pair++;
1163
cpuc->n_txn_pair++;
1164
}
1165
1166
return 0;
1167
}
1168
1169
/*
1170
* dogrp: true if must collect siblings events (group)
1171
* returns total number of events and error code
1172
*/
1173
static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
1174
{
1175
struct perf_event *event;
1176
int n, max_count;
1177
1178
max_count = x86_pmu_num_counters(cpuc->pmu) + x86_pmu_num_counters_fixed(cpuc->pmu);
1179
1180
/* current number of events already accepted */
1181
n = cpuc->n_events;
1182
if (!cpuc->n_events)
1183
cpuc->pebs_output = 0;
1184
1185
if (!cpuc->is_fake && leader->attr.precise_ip) {
1186
/*
1187
* For PEBS->PT, if !aux_event, the group leader (PT) went
1188
* away, the group was broken down and this singleton event
1189
* can't schedule any more.
1190
*/
1191
if (is_pebs_pt(leader) && !leader->aux_event)
1192
return -EINVAL;
1193
1194
/*
1195
* pebs_output: 0: no PEBS so far, 1: PT, 2: DS
1196
*/
1197
if (cpuc->pebs_output &&
1198
cpuc->pebs_output != is_pebs_pt(leader) + 1)
1199
return -EINVAL;
1200
1201
cpuc->pebs_output = is_pebs_pt(leader) + 1;
1202
}
1203
1204
if (is_x86_event(leader)) {
1205
if (collect_event(cpuc, leader, max_count, n))
1206
return -EINVAL;
1207
n++;
1208
}
1209
1210
if (!dogrp)
1211
return n;
1212
1213
for_each_sibling_event(event, leader) {
1214
if (!is_x86_event(event) || event->state <= PERF_EVENT_STATE_OFF)
1215
continue;
1216
1217
if (collect_event(cpuc, event, max_count, n))
1218
return -EINVAL;
1219
1220
n++;
1221
}
1222
return n;
1223
}
1224
1225
static inline void x86_assign_hw_event(struct perf_event *event,
1226
struct cpu_hw_events *cpuc, int i)
1227
{
1228
struct hw_perf_event *hwc = &event->hw;
1229
int idx;
1230
1231
idx = hwc->idx = cpuc->assign[i];
1232
hwc->last_cpu = smp_processor_id();
1233
hwc->last_tag = ++cpuc->tags[i];
1234
1235
static_call_cond(x86_pmu_assign)(event, idx);
1236
1237
switch (hwc->idx) {
1238
case INTEL_PMC_IDX_FIXED_BTS:
1239
case INTEL_PMC_IDX_FIXED_VLBR:
1240
hwc->config_base = 0;
1241
hwc->event_base = 0;
1242
break;
1243
1244
case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
1245
/* All the metric events are mapped onto the fixed counter 3. */
1246
idx = INTEL_PMC_IDX_FIXED_SLOTS;
1247
fallthrough;
1248
case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS-1:
1249
hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
1250
hwc->event_base = x86_pmu_fixed_ctr_addr(idx - INTEL_PMC_IDX_FIXED);
1251
hwc->event_base_rdpmc = (idx - INTEL_PMC_IDX_FIXED) |
1252
INTEL_PMC_FIXED_RDPMC_BASE;
1253
break;
1254
1255
default:
1256
hwc->config_base = x86_pmu_config_addr(hwc->idx);
1257
hwc->event_base = x86_pmu_event_addr(hwc->idx);
1258
hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx);
1259
break;
1260
}
1261
}
1262
1263
/**
1264
* x86_perf_rdpmc_index - Return PMC counter used for event
1265
* @event: the perf_event to which the PMC counter was assigned
1266
*
1267
* The counter assigned to this performance event may change if interrupts
1268
* are enabled. This counter should thus never be used while interrupts are
1269
* enabled. Before this function is used to obtain the assigned counter the
1270
* event should be checked for validity using, for example,
1271
* perf_event_read_local(), within the same interrupt disabled section in
1272
* which this counter is planned to be used.
1273
*
1274
* Return: The index of the performance monitoring counter assigned to
1275
* @perf_event.
1276
*/
1277
int x86_perf_rdpmc_index(struct perf_event *event)
1278
{
1279
lockdep_assert_irqs_disabled();
1280
1281
return event->hw.event_base_rdpmc;
1282
}
1283
1284
static inline int match_prev_assignment(struct hw_perf_event *hwc,
1285
struct cpu_hw_events *cpuc,
1286
int i)
1287
{
1288
return hwc->idx == cpuc->assign[i] &&
1289
hwc->last_cpu == smp_processor_id() &&
1290
hwc->last_tag == cpuc->tags[i];
1291
}
1292
1293
static void x86_pmu_start(struct perf_event *event, int flags);
1294
1295
static void x86_pmu_enable(struct pmu *pmu)
1296
{
1297
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1298
struct perf_event *event;
1299
struct hw_perf_event *hwc;
1300
int i, added = cpuc->n_added;
1301
1302
if (!x86_pmu_initialized())
1303
return;
1304
1305
if (cpuc->enabled)
1306
return;
1307
1308
if (cpuc->n_added) {
1309
int n_running = cpuc->n_events - cpuc->n_added;
1310
1311
/*
1312
* The late setup (after counters are scheduled)
1313
* is required for some cases, e.g., PEBS counters
1314
* snapshotting. Because an accurate counter index
1315
* is needed.
1316
*/
1317
static_call_cond(x86_pmu_late_setup)();
1318
1319
/*
1320
* apply assignment obtained either from
1321
* hw_perf_group_sched_in() or x86_pmu_enable()
1322
*
1323
* step1: save events moving to new counters
1324
*/
1325
for (i = 0; i < n_running; i++) {
1326
event = cpuc->event_list[i];
1327
hwc = &event->hw;
1328
1329
/*
1330
* we can avoid reprogramming counter if:
1331
* - assigned same counter as last time
1332
* - running on same CPU as last time
1333
* - no other event has used the counter since
1334
*/
1335
if (hwc->idx == -1 ||
1336
match_prev_assignment(hwc, cpuc, i))
1337
continue;
1338
1339
/*
1340
* Ensure we don't accidentally enable a stopped
1341
* counter simply because we rescheduled.
1342
*/
1343
if (hwc->state & PERF_HES_STOPPED)
1344
hwc->state |= PERF_HES_ARCH;
1345
1346
x86_pmu_stop(event, PERF_EF_UPDATE);
1347
}
1348
1349
/*
1350
* step2: reprogram moved events into new counters
1351
*/
1352
for (i = 0; i < cpuc->n_events; i++) {
1353
event = cpuc->event_list[i];
1354
hwc = &event->hw;
1355
1356
if (!match_prev_assignment(hwc, cpuc, i))
1357
x86_assign_hw_event(event, cpuc, i);
1358
else if (i < n_running)
1359
continue;
1360
1361
if (hwc->state & PERF_HES_ARCH)
1362
continue;
1363
1364
/*
1365
* if cpuc->enabled = 0, then no wrmsr as
1366
* per x86_pmu_enable_event()
1367
*/
1368
x86_pmu_start(event, PERF_EF_RELOAD);
1369
}
1370
cpuc->n_added = 0;
1371
perf_events_lapic_init();
1372
}
1373
1374
cpuc->enabled = 1;
1375
barrier();
1376
1377
static_call(x86_pmu_enable_all)(added);
1378
}
1379
1380
DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
1381
1382
/*
1383
* Set the next IRQ period, based on the hwc->period_left value.
1384
* To be called with the event disabled in hw:
1385
*/
1386
int x86_perf_event_set_period(struct perf_event *event)
1387
{
1388
struct hw_perf_event *hwc = &event->hw;
1389
s64 left = local64_read(&hwc->period_left);
1390
s64 period = hwc->sample_period;
1391
int ret = 0, idx = hwc->idx;
1392
1393
if (unlikely(!hwc->event_base))
1394
return 0;
1395
1396
/*
1397
* If we are way outside a reasonable range then just skip forward:
1398
*/
1399
if (unlikely(left <= -period)) {
1400
left = period;
1401
local64_set(&hwc->period_left, left);
1402
hwc->last_period = period;
1403
ret = 1;
1404
}
1405
1406
if (unlikely(left <= 0)) {
1407
left += period;
1408
local64_set(&hwc->period_left, left);
1409
hwc->last_period = period;
1410
ret = 1;
1411
}
1412
/*
1413
* Quirk: certain CPUs dont like it if just 1 hw_event is left:
1414
*/
1415
if (unlikely(left < 2))
1416
left = 2;
1417
1418
if (left > x86_pmu.max_period)
1419
left = x86_pmu.max_period;
1420
1421
static_call_cond(x86_pmu_limit_period)(event, &left);
1422
1423
this_cpu_write(pmc_prev_left[idx], left);
1424
1425
/*
1426
* The hw event starts counting from this event offset,
1427
* mark it to be able to extra future deltas:
1428
*/
1429
local64_set(&hwc->prev_count, (u64)-left);
1430
1431
wrmsrq(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask);
1432
1433
/*
1434
* Sign extend the Merge event counter's upper 16 bits since
1435
* we currently declare a 48-bit counter width
1436
*/
1437
if (is_counter_pair(hwc))
1438
wrmsrq(x86_pmu_event_addr(idx + 1), 0xffff);
1439
1440
perf_event_update_userpage(event);
1441
1442
return ret;
1443
}
1444
1445
void x86_pmu_enable_event(struct perf_event *event)
1446
{
1447
if (__this_cpu_read(cpu_hw_events.enabled))
1448
__x86_pmu_enable_event(&event->hw,
1449
ARCH_PERFMON_EVENTSEL_ENABLE);
1450
}
1451
1452
/*
1453
* Add a single event to the PMU.
1454
*
1455
* The event is added to the group of enabled events
1456
* but only if it can be scheduled with existing events.
1457
*/
1458
static int x86_pmu_add(struct perf_event *event, int flags)
1459
{
1460
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1461
struct hw_perf_event *hwc;
1462
int assign[X86_PMC_IDX_MAX];
1463
int n, n0, ret;
1464
1465
hwc = &event->hw;
1466
1467
n0 = cpuc->n_events;
1468
ret = n = collect_events(cpuc, event, false);
1469
if (ret < 0)
1470
goto out;
1471
1472
hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
1473
if (!(flags & PERF_EF_START))
1474
hwc->state |= PERF_HES_ARCH;
1475
1476
/*
1477
* If group events scheduling transaction was started,
1478
* skip the schedulability test here, it will be performed
1479
* at commit time (->commit_txn) as a whole.
1480
*
1481
* If commit fails, we'll call ->del() on all events
1482
* for which ->add() was called.
1483
*/
1484
if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1485
goto done_collect;
1486
1487
ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
1488
if (ret)
1489
goto out;
1490
/*
1491
* copy new assignment, now we know it is possible
1492
* will be used by hw_perf_enable()
1493
*/
1494
memcpy(cpuc->assign, assign, n*sizeof(int));
1495
1496
done_collect:
1497
/*
1498
* Commit the collect_events() state. See x86_pmu_del() and
1499
* x86_pmu_*_txn().
1500
*/
1501
cpuc->n_events = n;
1502
cpuc->n_added += n - n0;
1503
cpuc->n_txn += n - n0;
1504
1505
/*
1506
* This is before x86_pmu_enable() will call x86_pmu_start(),
1507
* so we enable LBRs before an event needs them etc..
1508
*/
1509
static_call_cond(x86_pmu_add)(event);
1510
1511
ret = 0;
1512
out:
1513
return ret;
1514
}
1515
1516
static void x86_pmu_start(struct perf_event *event, int flags)
1517
{
1518
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1519
int idx = event->hw.idx;
1520
1521
if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
1522
return;
1523
1524
if (WARN_ON_ONCE(idx == -1))
1525
return;
1526
1527
if (flags & PERF_EF_RELOAD) {
1528
WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
1529
static_call(x86_pmu_set_period)(event);
1530
}
1531
1532
event->hw.state = 0;
1533
1534
cpuc->events[idx] = event;
1535
__set_bit(idx, cpuc->active_mask);
1536
static_call(x86_pmu_enable)(event);
1537
perf_event_update_userpage(event);
1538
}
1539
1540
void perf_event_print_debug(void)
1541
{
1542
u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
1543
unsigned long *cntr_mask, *fixed_cntr_mask;
1544
struct event_constraint *pebs_constraints;
1545
struct cpu_hw_events *cpuc;
1546
u64 pebs, debugctl;
1547
int cpu, idx;
1548
1549
guard(irqsave)();
1550
1551
cpu = smp_processor_id();
1552
cpuc = &per_cpu(cpu_hw_events, cpu);
1553
cntr_mask = hybrid(cpuc->pmu, cntr_mask);
1554
fixed_cntr_mask = hybrid(cpuc->pmu, fixed_cntr_mask);
1555
pebs_constraints = hybrid(cpuc->pmu, pebs_constraints);
1556
1557
if (!*(u64 *)cntr_mask)
1558
return;
1559
1560
if (x86_pmu.version >= 2) {
1561
rdmsrq(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
1562
rdmsrq(MSR_CORE_PERF_GLOBAL_STATUS, status);
1563
rdmsrq(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
1564
rdmsrq(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
1565
1566
pr_info("\n");
1567
pr_info("CPU#%d: ctrl: %016llx\n", cpu, ctrl);
1568
pr_info("CPU#%d: status: %016llx\n", cpu, status);
1569
pr_info("CPU#%d: overflow: %016llx\n", cpu, overflow);
1570
pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed);
1571
if (pebs_constraints) {
1572
rdmsrq(MSR_IA32_PEBS_ENABLE, pebs);
1573
pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs);
1574
}
1575
if (x86_pmu.lbr_nr) {
1576
rdmsrq(MSR_IA32_DEBUGCTLMSR, debugctl);
1577
pr_info("CPU#%d: debugctl: %016llx\n", cpu, debugctl);
1578
}
1579
}
1580
pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask);
1581
1582
for_each_set_bit(idx, cntr_mask, X86_PMC_IDX_MAX) {
1583
rdmsrq(x86_pmu_config_addr(idx), pmc_ctrl);
1584
rdmsrq(x86_pmu_event_addr(idx), pmc_count);
1585
1586
prev_left = per_cpu(pmc_prev_left[idx], cpu);
1587
1588
pr_info("CPU#%d: gen-PMC%d ctrl: %016llx\n",
1589
cpu, idx, pmc_ctrl);
1590
pr_info("CPU#%d: gen-PMC%d count: %016llx\n",
1591
cpu, idx, pmc_count);
1592
pr_info("CPU#%d: gen-PMC%d left: %016llx\n",
1593
cpu, idx, prev_left);
1594
}
1595
for_each_set_bit(idx, fixed_cntr_mask, X86_PMC_IDX_MAX) {
1596
if (fixed_counter_disabled(idx, cpuc->pmu))
1597
continue;
1598
rdmsrq(x86_pmu_fixed_ctr_addr(idx), pmc_count);
1599
1600
pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
1601
cpu, idx, pmc_count);
1602
}
1603
}
1604
1605
void x86_pmu_stop(struct perf_event *event, int flags)
1606
{
1607
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1608
struct hw_perf_event *hwc = &event->hw;
1609
1610
if (test_bit(hwc->idx, cpuc->active_mask)) {
1611
static_call(x86_pmu_disable)(event);
1612
__clear_bit(hwc->idx, cpuc->active_mask);
1613
cpuc->events[hwc->idx] = NULL;
1614
WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
1615
hwc->state |= PERF_HES_STOPPED;
1616
}
1617
1618
if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
1619
/*
1620
* Drain the remaining delta count out of a event
1621
* that we are disabling:
1622
*/
1623
static_call(x86_pmu_update)(event);
1624
hwc->state |= PERF_HES_UPTODATE;
1625
}
1626
}
1627
1628
static void x86_pmu_del(struct perf_event *event, int flags)
1629
{
1630
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
1631
union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);
1632
int i;
1633
1634
/*
1635
* If we're called during a txn, we only need to undo x86_pmu.add.
1636
* The events never got scheduled and ->cancel_txn will truncate
1637
* the event_list.
1638
*
1639
* XXX assumes any ->del() called during a TXN will only be on
1640
* an event added during that same TXN.
1641
*/
1642
if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
1643
goto do_del;
1644
1645
__set_bit(event->hw.idx, cpuc->dirty);
1646
1647
/*
1648
* Not a TXN, therefore cleanup properly.
1649
*/
1650
x86_pmu_stop(event, PERF_EF_UPDATE);
1651
1652
for (i = 0; i < cpuc->n_events; i++) {
1653
if (event == cpuc->event_list[i])
1654
break;
1655
}
1656
1657
if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */
1658
return;
1659
1660
/* If we have a newly added event; make sure to decrease n_added. */
1661
if (i >= cpuc->n_events - cpuc->n_added)
1662
--cpuc->n_added;
1663
1664
static_call_cond(x86_pmu_put_event_constraints)(cpuc, event);
1665
1666
/* Delete the array entry. */
1667
while (++i < cpuc->n_events) {
1668
cpuc->event_list[i-1] = cpuc->event_list[i];
1669
cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
1670
cpuc->assign[i-1] = cpuc->assign[i];
1671
}
1672
cpuc->event_constraint[i-1] = NULL;
1673
--cpuc->n_events;
1674
if (intel_cap.perf_metrics)
1675
del_nr_metric_event(cpuc, event);
1676
1677
perf_event_update_userpage(event);
1678
1679
do_del:
1680
1681
/*
1682
* This is after x86_pmu_stop(); so we disable LBRs after any
1683
* event can need them etc..
1684
*/
1685
static_call_cond(x86_pmu_del)(event);
1686
}
1687
1688
int x86_pmu_handle_irq(struct pt_regs *regs)
1689
{
1690
struct perf_sample_data data;
1691
struct cpu_hw_events *cpuc;
1692
struct perf_event *event;
1693
int idx, handled = 0;
1694
u64 last_period;
1695
u64 val;
1696
1697
cpuc = this_cpu_ptr(&cpu_hw_events);
1698
1699
/*
1700
* Some chipsets need to unmask the LVTPC in a particular spot
1701
* inside the nmi handler. As a result, the unmasking was pushed
1702
* into all the nmi handlers.
1703
*
1704
* This generic handler doesn't seem to have any issues where the
1705
* unmasking occurs so it was left at the top.
1706
*/
1707
apic_write(APIC_LVTPC, APIC_DM_NMI);
1708
1709
for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
1710
if (!test_bit(idx, cpuc->active_mask))
1711
continue;
1712
1713
event = cpuc->events[idx];
1714
last_period = event->hw.last_period;
1715
1716
val = static_call(x86_pmu_update)(event);
1717
if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
1718
continue;
1719
1720
/*
1721
* event overflow
1722
*/
1723
handled++;
1724
1725
if (!static_call(x86_pmu_set_period)(event))
1726
continue;
1727
1728
perf_sample_data_init(&data, 0, last_period);
1729
1730
perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
1731
1732
perf_event_overflow(event, &data, regs);
1733
}
1734
1735
if (handled)
1736
inc_irq_stat(apic_perf_irqs);
1737
1738
return handled;
1739
}
1740
1741
void perf_events_lapic_init(void)
1742
{
1743
if (!x86_pmu.apic || !x86_pmu_initialized())
1744
return;
1745
1746
/*
1747
* Always use NMI for PMU
1748
*/
1749
apic_write(APIC_LVTPC, APIC_DM_NMI);
1750
}
1751
1752
static int
1753
perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
1754
{
1755
u64 start_clock;
1756
u64 finish_clock;
1757
int ret;
1758
1759
/*
1760
* All PMUs/events that share this PMI handler should make sure to
1761
* increment active_events for their events.
1762
*/
1763
if (!atomic_read(&active_events))
1764
return NMI_DONE;
1765
1766
start_clock = sched_clock();
1767
ret = static_call(x86_pmu_handle_irq)(regs);
1768
finish_clock = sched_clock();
1769
1770
perf_sample_event_took(finish_clock - start_clock);
1771
1772
return ret;
1773
}
1774
NOKPROBE_SYMBOL(perf_event_nmi_handler);
1775
1776
struct event_constraint emptyconstraint;
1777
struct event_constraint unconstrained;
1778
1779
static int x86_pmu_prepare_cpu(unsigned int cpu)
1780
{
1781
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1782
int i;
1783
1784
for (i = 0 ; i < X86_PERF_KFREE_MAX; i++)
1785
cpuc->kfree_on_online[i] = NULL;
1786
if (x86_pmu.cpu_prepare)
1787
return x86_pmu.cpu_prepare(cpu);
1788
return 0;
1789
}
1790
1791
static int x86_pmu_dead_cpu(unsigned int cpu)
1792
{
1793
if (x86_pmu.cpu_dead)
1794
x86_pmu.cpu_dead(cpu);
1795
return 0;
1796
}
1797
1798
static int x86_pmu_online_cpu(unsigned int cpu)
1799
{
1800
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
1801
int i;
1802
1803
for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) {
1804
kfree(cpuc->kfree_on_online[i]);
1805
cpuc->kfree_on_online[i] = NULL;
1806
}
1807
return 0;
1808
}
1809
1810
static int x86_pmu_starting_cpu(unsigned int cpu)
1811
{
1812
if (x86_pmu.cpu_starting)
1813
x86_pmu.cpu_starting(cpu);
1814
return 0;
1815
}
1816
1817
static int x86_pmu_dying_cpu(unsigned int cpu)
1818
{
1819
if (x86_pmu.cpu_dying)
1820
x86_pmu.cpu_dying(cpu);
1821
return 0;
1822
}
1823
1824
static void __init pmu_check_apic(void)
1825
{
1826
if (boot_cpu_has(X86_FEATURE_APIC))
1827
return;
1828
1829
x86_pmu.apic = 0;
1830
pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
1831
pr_info("no hardware sampling interrupt available.\n");
1832
1833
/*
1834
* If we have a PMU initialized but no APIC
1835
* interrupts, we cannot sample hardware
1836
* events (user-space has to fall back and
1837
* sample via a hrtimer based software event):
1838
*/
1839
pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1840
1841
}
1842
1843
static struct attribute_group x86_pmu_format_group __ro_after_init = {
1844
.name = "format",
1845
.attrs = NULL,
1846
};
1847
1848
ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page)
1849
{
1850
struct perf_pmu_events_attr *pmu_attr =
1851
container_of(attr, struct perf_pmu_events_attr, attr);
1852
u64 config = 0;
1853
1854
if (pmu_attr->id < x86_pmu.max_events)
1855
config = x86_pmu.event_map(pmu_attr->id);
1856
1857
/* string trumps id */
1858
if (pmu_attr->event_str)
1859
return sprintf(page, "%s\n", pmu_attr->event_str);
1860
1861
return x86_pmu.events_sysfs_show(page, config);
1862
}
1863
EXPORT_SYMBOL_GPL(events_sysfs_show);
1864
1865
ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute *attr,
1866
char *page)
1867
{
1868
struct perf_pmu_events_ht_attr *pmu_attr =
1869
container_of(attr, struct perf_pmu_events_ht_attr, attr);
1870
1871
/*
1872
* Report conditional events depending on Hyper-Threading.
1873
*
1874
* This is overly conservative as usually the HT special
1875
* handling is not needed if the other CPU thread is idle.
1876
*
1877
* Note this does not (and cannot) handle the case when thread
1878
* siblings are invisible, for example with virtualization
1879
* if they are owned by some other guest. The user tool
1880
* has to re-read when a thread sibling gets onlined later.
1881
*/
1882
return sprintf(page, "%s",
1883
topology_max_smt_threads() > 1 ?
1884
pmu_attr->event_str_ht :
1885
pmu_attr->event_str_noht);
1886
}
1887
1888
ssize_t events_hybrid_sysfs_show(struct device *dev,
1889
struct device_attribute *attr,
1890
char *page)
1891
{
1892
struct perf_pmu_events_hybrid_attr *pmu_attr =
1893
container_of(attr, struct perf_pmu_events_hybrid_attr, attr);
1894
struct x86_hybrid_pmu *pmu;
1895
const char *str, *next_str;
1896
int i;
1897
1898
if (hweight64(pmu_attr->pmu_type) == 1)
1899
return sprintf(page, "%s", pmu_attr->event_str);
1900
1901
/*
1902
* Hybrid PMUs may support the same event name, but with different
1903
* event encoding, e.g., the mem-loads event on an Atom PMU has
1904
* different event encoding from a Core PMU.
1905
*
1906
* The event_str includes all event encodings. Each event encoding
1907
* is divided by ";". The order of the event encodings must follow
1908
* the order of the hybrid PMU index.
1909
*/
1910
pmu = container_of(dev_get_drvdata(dev), struct x86_hybrid_pmu, pmu);
1911
1912
str = pmu_attr->event_str;
1913
for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
1914
if (!(x86_pmu.hybrid_pmu[i].pmu_type & pmu_attr->pmu_type))
1915
continue;
1916
if (x86_pmu.hybrid_pmu[i].pmu_type & pmu->pmu_type) {
1917
next_str = strchr(str, ';');
1918
if (next_str)
1919
return snprintf(page, next_str - str + 1, "%s", str);
1920
else
1921
return sprintf(page, "%s", str);
1922
}
1923
str = strchr(str, ';');
1924
str++;
1925
}
1926
1927
return 0;
1928
}
1929
EXPORT_SYMBOL_GPL(events_hybrid_sysfs_show);
1930
1931
EVENT_ATTR(cpu-cycles, CPU_CYCLES );
1932
EVENT_ATTR(instructions, INSTRUCTIONS );
1933
EVENT_ATTR(cache-references, CACHE_REFERENCES );
1934
EVENT_ATTR(cache-misses, CACHE_MISSES );
1935
EVENT_ATTR(branch-instructions, BRANCH_INSTRUCTIONS );
1936
EVENT_ATTR(branch-misses, BRANCH_MISSES );
1937
EVENT_ATTR(bus-cycles, BUS_CYCLES );
1938
EVENT_ATTR(stalled-cycles-frontend, STALLED_CYCLES_FRONTEND );
1939
EVENT_ATTR(stalled-cycles-backend, STALLED_CYCLES_BACKEND );
1940
EVENT_ATTR(ref-cycles, REF_CPU_CYCLES );
1941
1942
static struct attribute *empty_attrs;
1943
1944
static struct attribute *events_attr[] = {
1945
EVENT_PTR(CPU_CYCLES),
1946
EVENT_PTR(INSTRUCTIONS),
1947
EVENT_PTR(CACHE_REFERENCES),
1948
EVENT_PTR(CACHE_MISSES),
1949
EVENT_PTR(BRANCH_INSTRUCTIONS),
1950
EVENT_PTR(BRANCH_MISSES),
1951
EVENT_PTR(BUS_CYCLES),
1952
EVENT_PTR(STALLED_CYCLES_FRONTEND),
1953
EVENT_PTR(STALLED_CYCLES_BACKEND),
1954
EVENT_PTR(REF_CPU_CYCLES),
1955
NULL,
1956
};
1957
1958
/*
1959
* Remove all undefined events (x86_pmu.event_map(id) == 0)
1960
* out of events_attr attributes.
1961
*/
1962
static umode_t
1963
is_visible(struct kobject *kobj, struct attribute *attr, int idx)
1964
{
1965
struct perf_pmu_events_attr *pmu_attr;
1966
1967
if (idx >= x86_pmu.max_events)
1968
return 0;
1969
1970
pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
1971
/* str trumps id */
1972
return pmu_attr->event_str || x86_pmu.event_map(idx) ? attr->mode : 0;
1973
}
1974
1975
static struct attribute_group x86_pmu_events_group __ro_after_init = {
1976
.name = "events",
1977
.attrs = events_attr,
1978
.is_visible = is_visible,
1979
};
1980
1981
ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
1982
{
1983
u64 umask = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
1984
u64 cmask = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
1985
bool edge = (config & ARCH_PERFMON_EVENTSEL_EDGE);
1986
bool pc = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
1987
bool any = (config & ARCH_PERFMON_EVENTSEL_ANY);
1988
bool inv = (config & ARCH_PERFMON_EVENTSEL_INV);
1989
ssize_t ret;
1990
1991
/*
1992
* We have whole page size to spend and just little data
1993
* to write, so we can safely use sprintf.
1994
*/
1995
ret = sprintf(page, "event=0x%02llx", event);
1996
1997
if (umask)
1998
ret += sprintf(page + ret, ",umask=0x%02llx", umask);
1999
2000
if (edge)
2001
ret += sprintf(page + ret, ",edge");
2002
2003
if (pc)
2004
ret += sprintf(page + ret, ",pc");
2005
2006
if (any)
2007
ret += sprintf(page + ret, ",any");
2008
2009
if (inv)
2010
ret += sprintf(page + ret, ",inv");
2011
2012
if (cmask)
2013
ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);
2014
2015
ret += sprintf(page + ret, "\n");
2016
2017
return ret;
2018
}
2019
2020
static struct attribute_group x86_pmu_attr_group;
2021
static struct attribute_group x86_pmu_caps_group;
2022
2023
static void x86_pmu_static_call_update(void)
2024
{
2025
static_call_update(x86_pmu_handle_irq, x86_pmu.handle_irq);
2026
static_call_update(x86_pmu_disable_all, x86_pmu.disable_all);
2027
static_call_update(x86_pmu_enable_all, x86_pmu.enable_all);
2028
static_call_update(x86_pmu_enable, x86_pmu.enable);
2029
static_call_update(x86_pmu_disable, x86_pmu.disable);
2030
2031
static_call_update(x86_pmu_assign, x86_pmu.assign);
2032
2033
static_call_update(x86_pmu_add, x86_pmu.add);
2034
static_call_update(x86_pmu_del, x86_pmu.del);
2035
static_call_update(x86_pmu_read, x86_pmu.read);
2036
2037
static_call_update(x86_pmu_set_period, x86_pmu.set_period);
2038
static_call_update(x86_pmu_update, x86_pmu.update);
2039
static_call_update(x86_pmu_limit_period, x86_pmu.limit_period);
2040
2041
static_call_update(x86_pmu_schedule_events, x86_pmu.schedule_events);
2042
static_call_update(x86_pmu_get_event_constraints, x86_pmu.get_event_constraints);
2043
static_call_update(x86_pmu_put_event_constraints, x86_pmu.put_event_constraints);
2044
2045
static_call_update(x86_pmu_start_scheduling, x86_pmu.start_scheduling);
2046
static_call_update(x86_pmu_commit_scheduling, x86_pmu.commit_scheduling);
2047
static_call_update(x86_pmu_stop_scheduling, x86_pmu.stop_scheduling);
2048
2049
static_call_update(x86_pmu_sched_task, x86_pmu.sched_task);
2050
2051
static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);
2052
static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);
2053
2054
static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs);
2055
static_call_update(x86_pmu_filter, x86_pmu.filter);
2056
2057
static_call_update(x86_pmu_late_setup, x86_pmu.late_setup);
2058
2059
static_call_update(x86_pmu_pebs_enable, x86_pmu.pebs_enable);
2060
static_call_update(x86_pmu_pebs_disable, x86_pmu.pebs_disable);
2061
static_call_update(x86_pmu_pebs_enable_all, x86_pmu.pebs_enable_all);
2062
static_call_update(x86_pmu_pebs_disable_all, x86_pmu.pebs_disable_all);
2063
}
2064
2065
static void _x86_pmu_read(struct perf_event *event)
2066
{
2067
static_call(x86_pmu_update)(event);
2068
}
2069
2070
void x86_pmu_show_pmu_cap(struct pmu *pmu)
2071
{
2072
pr_info("... version: %d\n", x86_pmu.version);
2073
pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
2074
pr_info("... generic registers: %d\n", x86_pmu_num_counters(pmu));
2075
pr_info("... value mask: %016Lx\n", x86_pmu.cntval_mask);
2076
pr_info("... max period: %016Lx\n", x86_pmu.max_period);
2077
pr_info("... fixed-purpose events: %d\n", x86_pmu_num_counters_fixed(pmu));
2078
pr_info("... event mask: %016Lx\n", hybrid(pmu, intel_ctrl));
2079
}
2080
2081
static int __init init_hw_perf_events(void)
2082
{
2083
struct x86_pmu_quirk *quirk;
2084
int err;
2085
2086
pr_info("Performance Events: ");
2087
2088
switch (boot_cpu_data.x86_vendor) {
2089
case X86_VENDOR_INTEL:
2090
err = intel_pmu_init();
2091
break;
2092
case X86_VENDOR_AMD:
2093
err = amd_pmu_init();
2094
break;
2095
case X86_VENDOR_HYGON:
2096
err = amd_pmu_init();
2097
x86_pmu.name = "HYGON";
2098
break;
2099
case X86_VENDOR_ZHAOXIN:
2100
case X86_VENDOR_CENTAUR:
2101
err = zhaoxin_pmu_init();
2102
break;
2103
default:
2104
err = -ENOTSUPP;
2105
}
2106
if (err != 0) {
2107
pr_cont("no PMU driver, software events only.\n");
2108
err = 0;
2109
goto out_bad_pmu;
2110
}
2111
2112
pmu_check_apic();
2113
2114
/* sanity check that the hardware exists or is emulated */
2115
if (!check_hw_exists(&pmu, x86_pmu.cntr_mask, x86_pmu.fixed_cntr_mask))
2116
goto out_bad_pmu;
2117
2118
pr_cont("%s PMU driver.\n", x86_pmu.name);
2119
2120
x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
2121
2122
for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
2123
quirk->func();
2124
2125
if (!x86_pmu.intel_ctrl)
2126
x86_pmu.intel_ctrl = x86_pmu.cntr_mask64;
2127
2128
if (!x86_pmu.config_mask)
2129
x86_pmu.config_mask = X86_RAW_EVENT_MASK;
2130
2131
perf_events_lapic_init();
2132
register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");
2133
2134
unconstrained = (struct event_constraint)
2135
__EVENT_CONSTRAINT(0, x86_pmu.cntr_mask64,
2136
0, x86_pmu_num_counters(NULL), 0, 0);
2137
2138
x86_pmu_format_group.attrs = x86_pmu.format_attrs;
2139
2140
if (!x86_pmu.events_sysfs_show)
2141
x86_pmu_events_group.attrs = &empty_attrs;
2142
2143
pmu.attr_update = x86_pmu.attr_update;
2144
2145
if (!is_hybrid())
2146
x86_pmu_show_pmu_cap(NULL);
2147
2148
if (!x86_pmu.read)
2149
x86_pmu.read = _x86_pmu_read;
2150
2151
if (!x86_pmu.guest_get_msrs)
2152
x86_pmu.guest_get_msrs = (void *)&__static_call_return0;
2153
2154
if (!x86_pmu.set_period)
2155
x86_pmu.set_period = x86_perf_event_set_period;
2156
2157
if (!x86_pmu.update)
2158
x86_pmu.update = x86_perf_event_update;
2159
2160
x86_pmu_static_call_update();
2161
2162
/*
2163
* Install callbacks. Core will call them for each online
2164
* cpu.
2165
*/
2166
err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare",
2167
x86_pmu_prepare_cpu, x86_pmu_dead_cpu);
2168
if (err)
2169
return err;
2170
2171
err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING,
2172
"perf/x86:starting", x86_pmu_starting_cpu,
2173
x86_pmu_dying_cpu);
2174
if (err)
2175
goto out;
2176
2177
err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online",
2178
x86_pmu_online_cpu, NULL);
2179
if (err)
2180
goto out1;
2181
2182
if (!is_hybrid()) {
2183
err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
2184
if (err)
2185
goto out2;
2186
} else {
2187
struct x86_hybrid_pmu *hybrid_pmu;
2188
int i, j;
2189
2190
for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
2191
hybrid_pmu = &x86_pmu.hybrid_pmu[i];
2192
2193
hybrid_pmu->pmu = pmu;
2194
hybrid_pmu->pmu.type = -1;
2195
hybrid_pmu->pmu.attr_update = x86_pmu.attr_update;
2196
hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE;
2197
2198
err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name,
2199
(hybrid_pmu->pmu_type == hybrid_big) ? PERF_TYPE_RAW : -1);
2200
if (err)
2201
break;
2202
}
2203
2204
if (i < x86_pmu.num_hybrid_pmus) {
2205
for (j = 0; j < i; j++)
2206
perf_pmu_unregister(&x86_pmu.hybrid_pmu[j].pmu);
2207
pr_warn("Failed to register hybrid PMUs\n");
2208
kfree(x86_pmu.hybrid_pmu);
2209
x86_pmu.hybrid_pmu = NULL;
2210
x86_pmu.num_hybrid_pmus = 0;
2211
goto out2;
2212
}
2213
}
2214
2215
return 0;
2216
2217
out2:
2218
cpuhp_remove_state(CPUHP_AP_PERF_X86_ONLINE);
2219
out1:
2220
cpuhp_remove_state(CPUHP_AP_PERF_X86_STARTING);
2221
out:
2222
cpuhp_remove_state(CPUHP_PERF_X86_PREPARE);
2223
out_bad_pmu:
2224
memset(&x86_pmu, 0, sizeof(x86_pmu));
2225
return err;
2226
}
2227
early_initcall(init_hw_perf_events);
2228
2229
static void x86_pmu_read(struct perf_event *event)
2230
{
2231
static_call(x86_pmu_read)(event);
2232
}
2233
2234
/*
2235
* Start group events scheduling transaction
2236
* Set the flag to make pmu::enable() not perform the
2237
* schedulability test, it will be performed at commit time
2238
*
2239
* We only support PERF_PMU_TXN_ADD transactions. Save the
2240
* transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
2241
* transactions.
2242
*/
2243
static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
2244
{
2245
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2246
2247
WARN_ON_ONCE(cpuc->txn_flags); /* txn already in flight */
2248
2249
cpuc->txn_flags = txn_flags;
2250
if (txn_flags & ~PERF_PMU_TXN_ADD)
2251
return;
2252
2253
perf_pmu_disable(pmu);
2254
__this_cpu_write(cpu_hw_events.n_txn, 0);
2255
__this_cpu_write(cpu_hw_events.n_txn_pair, 0);
2256
__this_cpu_write(cpu_hw_events.n_txn_metric, 0);
2257
}
2258
2259
/*
2260
* Stop group events scheduling transaction
2261
* Clear the flag and pmu::enable() will perform the
2262
* schedulability test.
2263
*/
2264
static void x86_pmu_cancel_txn(struct pmu *pmu)
2265
{
2266
unsigned int txn_flags;
2267
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2268
2269
WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
2270
2271
txn_flags = cpuc->txn_flags;
2272
cpuc->txn_flags = 0;
2273
if (txn_flags & ~PERF_PMU_TXN_ADD)
2274
return;
2275
2276
/*
2277
* Truncate collected array by the number of events added in this
2278
* transaction. See x86_pmu_add() and x86_pmu_*_txn().
2279
*/
2280
__this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
2281
__this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
2282
__this_cpu_sub(cpu_hw_events.n_pair, __this_cpu_read(cpu_hw_events.n_txn_pair));
2283
__this_cpu_sub(cpu_hw_events.n_metric, __this_cpu_read(cpu_hw_events.n_txn_metric));
2284
perf_pmu_enable(pmu);
2285
}
2286
2287
/*
2288
* Commit group events scheduling transaction
2289
* Perform the group schedulability test as a whole
2290
* Return 0 if success
2291
*
2292
* Does not cancel the transaction on failure; expects the caller to do this.
2293
*/
2294
static int x86_pmu_commit_txn(struct pmu *pmu)
2295
{
2296
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2297
int assign[X86_PMC_IDX_MAX];
2298
int n, ret;
2299
2300
WARN_ON_ONCE(!cpuc->txn_flags); /* no txn in flight */
2301
2302
if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) {
2303
cpuc->txn_flags = 0;
2304
return 0;
2305
}
2306
2307
n = cpuc->n_events;
2308
2309
if (!x86_pmu_initialized())
2310
return -EAGAIN;
2311
2312
ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
2313
if (ret)
2314
return ret;
2315
2316
/*
2317
* copy new assignment, now we know it is possible
2318
* will be used by hw_perf_enable()
2319
*/
2320
memcpy(cpuc->assign, assign, n*sizeof(int));
2321
2322
cpuc->txn_flags = 0;
2323
perf_pmu_enable(pmu);
2324
return 0;
2325
}
2326
/*
2327
* a fake_cpuc is used to validate event groups. Due to
2328
* the extra reg logic, we need to also allocate a fake
2329
* per_core and per_cpu structure. Otherwise, group events
2330
* using extra reg may conflict without the kernel being
2331
* able to catch this when the last event gets added to
2332
* the group.
2333
*/
2334
static void free_fake_cpuc(struct cpu_hw_events *cpuc)
2335
{
2336
intel_cpuc_finish(cpuc);
2337
kfree(cpuc);
2338
}
2339
2340
static struct cpu_hw_events *allocate_fake_cpuc(struct pmu *event_pmu)
2341
{
2342
struct cpu_hw_events *cpuc;
2343
int cpu;
2344
2345
cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL);
2346
if (!cpuc)
2347
return ERR_PTR(-ENOMEM);
2348
cpuc->is_fake = 1;
2349
2350
if (is_hybrid()) {
2351
struct x86_hybrid_pmu *h_pmu;
2352
2353
h_pmu = hybrid_pmu(event_pmu);
2354
if (cpumask_empty(&h_pmu->supported_cpus))
2355
goto error;
2356
cpu = cpumask_first(&h_pmu->supported_cpus);
2357
} else
2358
cpu = raw_smp_processor_id();
2359
cpuc->pmu = event_pmu;
2360
2361
if (intel_cpuc_prepare(cpuc, cpu))
2362
goto error;
2363
2364
return cpuc;
2365
error:
2366
free_fake_cpuc(cpuc);
2367
return ERR_PTR(-ENOMEM);
2368
}
2369
2370
/*
2371
* validate that we can schedule this event
2372
*/
2373
static int validate_event(struct perf_event *event)
2374
{
2375
struct cpu_hw_events *fake_cpuc;
2376
struct event_constraint *c;
2377
int ret = 0;
2378
2379
fake_cpuc = allocate_fake_cpuc(event->pmu);
2380
if (IS_ERR(fake_cpuc))
2381
return PTR_ERR(fake_cpuc);
2382
2383
c = x86_pmu.get_event_constraints(fake_cpuc, 0, event);
2384
2385
if (!c || !c->weight)
2386
ret = -EINVAL;
2387
2388
if (x86_pmu.put_event_constraints)
2389
x86_pmu.put_event_constraints(fake_cpuc, event);
2390
2391
free_fake_cpuc(fake_cpuc);
2392
2393
return ret;
2394
}
2395
2396
/*
2397
* validate a single event group
2398
*
2399
* validation include:
2400
* - check events are compatible which each other
2401
* - events do not compete for the same counter
2402
* - number of events <= number of counters
2403
*
2404
* validation ensures the group can be loaded onto the
2405
* PMU if it was the only group available.
2406
*/
2407
static int validate_group(struct perf_event *event)
2408
{
2409
struct perf_event *leader = event->group_leader;
2410
struct cpu_hw_events *fake_cpuc;
2411
int ret = -EINVAL, n;
2412
2413
/*
2414
* Reject events from different hybrid PMUs.
2415
*/
2416
if (is_hybrid()) {
2417
struct perf_event *sibling;
2418
struct pmu *pmu = NULL;
2419
2420
if (is_x86_event(leader))
2421
pmu = leader->pmu;
2422
2423
for_each_sibling_event(sibling, leader) {
2424
if (!is_x86_event(sibling))
2425
continue;
2426
if (!pmu)
2427
pmu = sibling->pmu;
2428
else if (pmu != sibling->pmu)
2429
return ret;
2430
}
2431
}
2432
2433
fake_cpuc = allocate_fake_cpuc(event->pmu);
2434
if (IS_ERR(fake_cpuc))
2435
return PTR_ERR(fake_cpuc);
2436
/*
2437
* the event is not yet connected with its
2438
* siblings therefore we must first collect
2439
* existing siblings, then add the new event
2440
* before we can simulate the scheduling
2441
*/
2442
n = collect_events(fake_cpuc, leader, true);
2443
if (n < 0)
2444
goto out;
2445
2446
fake_cpuc->n_events = n;
2447
n = collect_events(fake_cpuc, event, false);
2448
if (n < 0)
2449
goto out;
2450
2451
fake_cpuc->n_events = 0;
2452
ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);
2453
2454
out:
2455
free_fake_cpuc(fake_cpuc);
2456
return ret;
2457
}
2458
2459
static int x86_pmu_event_init(struct perf_event *event)
2460
{
2461
struct x86_hybrid_pmu *pmu = NULL;
2462
int err;
2463
2464
if ((event->attr.type != event->pmu->type) &&
2465
(event->attr.type != PERF_TYPE_HARDWARE) &&
2466
(event->attr.type != PERF_TYPE_HW_CACHE))
2467
return -ENOENT;
2468
2469
if (is_hybrid() && (event->cpu != -1)) {
2470
pmu = hybrid_pmu(event->pmu);
2471
if (!cpumask_test_cpu(event->cpu, &pmu->supported_cpus))
2472
return -ENOENT;
2473
}
2474
2475
err = __x86_pmu_event_init(event);
2476
if (!err) {
2477
if (event->group_leader != event)
2478
err = validate_group(event);
2479
else
2480
err = validate_event(event);
2481
}
2482
if (err) {
2483
if (event->destroy)
2484
event->destroy(event);
2485
event->destroy = NULL;
2486
}
2487
2488
if (READ_ONCE(x86_pmu.attr_rdpmc) &&
2489
!(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
2490
event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
2491
2492
return err;
2493
}
2494
2495
void perf_clear_dirty_counters(void)
2496
{
2497
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
2498
int i;
2499
2500
/* Don't need to clear the assigned counter. */
2501
for (i = 0; i < cpuc->n_events; i++)
2502
__clear_bit(cpuc->assign[i], cpuc->dirty);
2503
2504
if (bitmap_empty(cpuc->dirty, X86_PMC_IDX_MAX))
2505
return;
2506
2507
for_each_set_bit(i, cpuc->dirty, X86_PMC_IDX_MAX) {
2508
if (i >= INTEL_PMC_IDX_FIXED) {
2509
/* Metrics and fake events don't have corresponding HW counters. */
2510
if (!test_bit(i - INTEL_PMC_IDX_FIXED, hybrid(cpuc->pmu, fixed_cntr_mask)))
2511
continue;
2512
2513
wrmsrq(x86_pmu_fixed_ctr_addr(i - INTEL_PMC_IDX_FIXED), 0);
2514
} else {
2515
wrmsrq(x86_pmu_event_addr(i), 0);
2516
}
2517
}
2518
2519
bitmap_zero(cpuc->dirty, X86_PMC_IDX_MAX);
2520
}
2521
2522
static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
2523
{
2524
if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2525
return;
2526
2527
/*
2528
* This function relies on not being called concurrently in two
2529
* tasks in the same mm. Otherwise one task could observe
2530
* perf_rdpmc_allowed > 1 and return all the way back to
2531
* userspace with CR4.PCE clear while another task is still
2532
* doing on_each_cpu_mask() to propagate CR4.PCE.
2533
*
2534
* For now, this can't happen because all callers hold mmap_lock
2535
* for write. If this changes, we'll need a different solution.
2536
*/
2537
mmap_assert_write_locked(mm);
2538
2539
if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1)
2540
on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
2541
}
2542
2543
static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
2544
{
2545
if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
2546
return;
2547
2548
if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
2549
on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
2550
}
2551
2552
static int x86_pmu_event_idx(struct perf_event *event)
2553
{
2554
struct hw_perf_event *hwc = &event->hw;
2555
2556
if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
2557
return 0;
2558
2559
if (is_metric_idx(hwc->idx))
2560
return INTEL_PMC_FIXED_RDPMC_METRICS + 1;
2561
else
2562
return hwc->event_base_rdpmc + 1;
2563
}
2564
2565
static ssize_t get_attr_rdpmc(struct device *cdev,
2566
struct device_attribute *attr,
2567
char *buf)
2568
{
2569
return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
2570
}
2571
2572
static ssize_t set_attr_rdpmc(struct device *cdev,
2573
struct device_attribute *attr,
2574
const char *buf, size_t count)
2575
{
2576
static DEFINE_MUTEX(rdpmc_mutex);
2577
unsigned long val;
2578
ssize_t ret;
2579
2580
ret = kstrtoul(buf, 0, &val);
2581
if (ret)
2582
return ret;
2583
2584
if (val > 2)
2585
return -EINVAL;
2586
2587
if (x86_pmu.attr_rdpmc_broken)
2588
return -ENOTSUPP;
2589
2590
guard(mutex)(&rdpmc_mutex);
2591
2592
if (val != x86_pmu.attr_rdpmc) {
2593
/*
2594
* Changing into or out of never available or always available,
2595
* aka perf-event-bypassing mode. This path is extremely slow,
2596
* but only root can trigger it, so it's okay.
2597
*/
2598
if (val == 0)
2599
static_branch_inc(&rdpmc_never_available_key);
2600
else if (x86_pmu.attr_rdpmc == 0)
2601
static_branch_dec(&rdpmc_never_available_key);
2602
2603
if (val == 2)
2604
static_branch_inc(&rdpmc_always_available_key);
2605
else if (x86_pmu.attr_rdpmc == 2)
2606
static_branch_dec(&rdpmc_always_available_key);
2607
2608
on_each_cpu(cr4_update_pce, NULL, 1);
2609
x86_pmu.attr_rdpmc = val;
2610
}
2611
2612
return count;
2613
}
2614
2615
static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);
2616
2617
static struct attribute *x86_pmu_attrs[] = {
2618
&dev_attr_rdpmc.attr,
2619
NULL,
2620
};
2621
2622
static struct attribute_group x86_pmu_attr_group __ro_after_init = {
2623
.attrs = x86_pmu_attrs,
2624
};
2625
2626
static ssize_t max_precise_show(struct device *cdev,
2627
struct device_attribute *attr,
2628
char *buf)
2629
{
2630
return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
2631
}
2632
2633
static DEVICE_ATTR_RO(max_precise);
2634
2635
static struct attribute *x86_pmu_caps_attrs[] = {
2636
&dev_attr_max_precise.attr,
2637
NULL
2638
};
2639
2640
static struct attribute_group x86_pmu_caps_group __ro_after_init = {
2641
.name = "caps",
2642
.attrs = x86_pmu_caps_attrs,
2643
};
2644
2645
static const struct attribute_group *x86_pmu_attr_groups[] = {
2646
&x86_pmu_attr_group,
2647
&x86_pmu_format_group,
2648
&x86_pmu_events_group,
2649
&x86_pmu_caps_group,
2650
NULL,
2651
};
2652
2653
static void x86_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
2654
struct task_struct *task, bool sched_in)
2655
{
2656
static_call_cond(x86_pmu_sched_task)(pmu_ctx, task, sched_in);
2657
}
2658
2659
void perf_check_microcode(void)
2660
{
2661
if (x86_pmu.check_microcode)
2662
x86_pmu.check_microcode();
2663
}
2664
2665
static int x86_pmu_check_period(struct perf_event *event, u64 value)
2666
{
2667
if (x86_pmu.check_period && x86_pmu.check_period(event, value))
2668
return -EINVAL;
2669
2670
if (value && x86_pmu.limit_period) {
2671
s64 left = value;
2672
x86_pmu.limit_period(event, &left);
2673
if (left > value)
2674
return -EINVAL;
2675
}
2676
2677
return 0;
2678
}
2679
2680
static int x86_pmu_aux_output_match(struct perf_event *event)
2681
{
2682
if (!(pmu.capabilities & PERF_PMU_CAP_AUX_OUTPUT))
2683
return 0;
2684
2685
if (x86_pmu.aux_output_match)
2686
return x86_pmu.aux_output_match(event);
2687
2688
return 0;
2689
}
2690
2691
static bool x86_pmu_filter(struct pmu *pmu, int cpu)
2692
{
2693
bool ret = false;
2694
2695
static_call_cond(x86_pmu_filter)(pmu, cpu, &ret);
2696
2697
return ret;
2698
}
2699
2700
static struct pmu pmu = {
2701
.pmu_enable = x86_pmu_enable,
2702
.pmu_disable = x86_pmu_disable,
2703
2704
.attr_groups = x86_pmu_attr_groups,
2705
2706
.event_init = x86_pmu_event_init,
2707
2708
.event_mapped = x86_pmu_event_mapped,
2709
.event_unmapped = x86_pmu_event_unmapped,
2710
2711
.add = x86_pmu_add,
2712
.del = x86_pmu_del,
2713
.start = x86_pmu_start,
2714
.stop = x86_pmu_stop,
2715
.read = x86_pmu_read,
2716
2717
.start_txn = x86_pmu_start_txn,
2718
.cancel_txn = x86_pmu_cancel_txn,
2719
.commit_txn = x86_pmu_commit_txn,
2720
2721
.event_idx = x86_pmu_event_idx,
2722
.sched_task = x86_pmu_sched_task,
2723
.check_period = x86_pmu_check_period,
2724
2725
.aux_output_match = x86_pmu_aux_output_match,
2726
2727
.filter = x86_pmu_filter,
2728
};
2729
2730
void arch_perf_update_userpage(struct perf_event *event,
2731
struct perf_event_mmap_page *userpg, u64 now)
2732
{
2733
struct cyc2ns_data data;
2734
u64 offset;
2735
2736
userpg->cap_user_time = 0;
2737
userpg->cap_user_time_zero = 0;
2738
userpg->cap_user_rdpmc =
2739
!!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);
2740
userpg->pmc_width = x86_pmu.cntval_bits;
2741
2742
if (!using_native_sched_clock() || !sched_clock_stable())
2743
return;
2744
2745
cyc2ns_read_begin(&data);
2746
2747
offset = data.cyc2ns_offset + __sched_clock_offset;
2748
2749
/*
2750
* Internal timekeeping for enabled/running/stopped times
2751
* is always in the local_clock domain.
2752
*/
2753
userpg->cap_user_time = 1;
2754
userpg->time_mult = data.cyc2ns_mul;
2755
userpg->time_shift = data.cyc2ns_shift;
2756
userpg->time_offset = offset - now;
2757
2758
/*
2759
* cap_user_time_zero doesn't make sense when we're using a different
2760
* time base for the records.
2761
*/
2762
if (!event->attr.use_clockid) {
2763
userpg->cap_user_time_zero = 1;
2764
userpg->time_zero = offset;
2765
}
2766
2767
cyc2ns_read_end();
2768
}
2769
2770
/*
2771
* Determine whether the regs were taken from an irq/exception handler rather
2772
* than from perf_arch_fetch_caller_regs().
2773
*/
2774
static bool perf_hw_regs(struct pt_regs *regs)
2775
{
2776
return regs->flags & X86_EFLAGS_FIXED;
2777
}
2778
2779
void
2780
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2781
{
2782
struct unwind_state state;
2783
unsigned long addr;
2784
2785
if (perf_guest_state()) {
2786
/* TODO: We don't support guest os callchain now */
2787
return;
2788
}
2789
2790
if (perf_callchain_store(entry, regs->ip))
2791
return;
2792
2793
if (perf_hw_regs(regs))
2794
unwind_start(&state, current, regs, NULL);
2795
else
2796
unwind_start(&state, current, NULL, (void *)regs->sp);
2797
2798
for (; !unwind_done(&state); unwind_next_frame(&state)) {
2799
addr = unwind_get_return_address(&state);
2800
if (!addr || perf_callchain_store(entry, addr))
2801
return;
2802
}
2803
}
2804
2805
static inline int
2806
valid_user_frame(const void __user *fp, unsigned long size)
2807
{
2808
return __access_ok(fp, size);
2809
}
2810
2811
static unsigned long get_segment_base(unsigned int segment)
2812
{
2813
struct desc_struct *desc;
2814
unsigned int idx = segment >> 3;
2815
2816
if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
2817
#ifdef CONFIG_MODIFY_LDT_SYSCALL
2818
struct ldt_struct *ldt;
2819
2820
/*
2821
* If we're not in a valid context with a real (not just lazy)
2822
* user mm, then don't even try.
2823
*/
2824
if (!nmi_uaccess_okay())
2825
return 0;
2826
2827
/* IRQs are off, so this synchronizes with smp_store_release */
2828
ldt = smp_load_acquire(&current->mm->context.ldt);
2829
if (!ldt || idx >= ldt->nr_entries)
2830
return 0;
2831
2832
desc = &ldt->entries[idx];
2833
#else
2834
return 0;
2835
#endif
2836
} else {
2837
if (idx >= GDT_ENTRIES)
2838
return 0;
2839
2840
desc = raw_cpu_ptr(gdt_page.gdt) + idx;
2841
}
2842
2843
return get_desc_base(desc);
2844
}
2845
2846
#ifdef CONFIG_UPROBES
2847
/*
2848
* Heuristic-based check if uprobe is installed at the function entry.
2849
*
2850
* Under assumption of user code being compiled with frame pointers,
2851
* `push %rbp/%ebp` is a good indicator that we indeed are.
2852
*
2853
* Similarly, `endbr64` (assuming 64-bit mode) is also a common pattern.
2854
* If we get this wrong, captured stack trace might have one extra bogus
2855
* entry, but the rest of stack trace will still be meaningful.
2856
*/
2857
static bool is_uprobe_at_func_entry(struct pt_regs *regs)
2858
{
2859
struct arch_uprobe *auprobe;
2860
2861
if (!current->utask)
2862
return false;
2863
2864
auprobe = current->utask->auprobe;
2865
if (!auprobe)
2866
return false;
2867
2868
/* push %rbp/%ebp */
2869
if (auprobe->insn[0] == 0x55)
2870
return true;
2871
2872
/* endbr64 (64-bit only) */
2873
if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
2874
return true;
2875
2876
return false;
2877
}
2878
2879
#else
2880
static bool is_uprobe_at_func_entry(struct pt_regs *regs)
2881
{
2882
return false;
2883
}
2884
#endif /* CONFIG_UPROBES */
2885
2886
#ifdef CONFIG_IA32_EMULATION
2887
2888
#include <linux/compat.h>
2889
2890
static inline int
2891
perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2892
{
2893
/* 32-bit process in 64-bit kernel. */
2894
unsigned long ss_base, cs_base;
2895
struct stack_frame_ia32 frame;
2896
const struct stack_frame_ia32 __user *fp;
2897
u32 ret_addr;
2898
2899
if (user_64bit_mode(regs))
2900
return 0;
2901
2902
cs_base = get_segment_base(regs->cs);
2903
ss_base = get_segment_base(regs->ss);
2904
2905
fp = compat_ptr(ss_base + regs->bp);
2906
pagefault_disable();
2907
2908
/* see perf_callchain_user() below for why we do this */
2909
if (is_uprobe_at_func_entry(regs) &&
2910
!get_user(ret_addr, (const u32 __user *)regs->sp))
2911
perf_callchain_store(entry, ret_addr);
2912
2913
while (entry->nr < entry->max_stack) {
2914
if (!valid_user_frame(fp, sizeof(frame)))
2915
break;
2916
2917
if (__get_user(frame.next_frame, &fp->next_frame))
2918
break;
2919
if (__get_user(frame.return_address, &fp->return_address))
2920
break;
2921
2922
perf_callchain_store(entry, cs_base + frame.return_address);
2923
fp = compat_ptr(ss_base + frame.next_frame);
2924
}
2925
pagefault_enable();
2926
return 1;
2927
}
2928
#else
2929
static inline int
2930
perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
2931
{
2932
return 0;
2933
}
2934
#endif
2935
2936
void
2937
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
2938
{
2939
struct stack_frame frame;
2940
const struct stack_frame __user *fp;
2941
unsigned long ret_addr;
2942
2943
if (perf_guest_state()) {
2944
/* TODO: We don't support guest os callchain now */
2945
return;
2946
}
2947
2948
/*
2949
* We don't know what to do with VM86 stacks.. ignore them for now.
2950
*/
2951
if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
2952
return;
2953
2954
fp = (void __user *)regs->bp;
2955
2956
perf_callchain_store(entry, regs->ip);
2957
2958
if (!nmi_uaccess_okay())
2959
return;
2960
2961
if (perf_callchain_user32(regs, entry))
2962
return;
2963
2964
pagefault_disable();
2965
2966
/*
2967
* If we are called from uprobe handler, and we are indeed at the very
2968
* entry to user function (which is normally a `push %rbp` instruction,
2969
* under assumption of application being compiled with frame pointers),
2970
* we should read return address from *regs->sp before proceeding
2971
* to follow frame pointers, otherwise we'll skip immediate caller
2972
* as %rbp is not yet setup.
2973
*/
2974
if (is_uprobe_at_func_entry(regs) &&
2975
!get_user(ret_addr, (const unsigned long __user *)regs->sp))
2976
perf_callchain_store(entry, ret_addr);
2977
2978
while (entry->nr < entry->max_stack) {
2979
if (!valid_user_frame(fp, sizeof(frame)))
2980
break;
2981
2982
if (__get_user(frame.next_frame, &fp->next_frame))
2983
break;
2984
if (__get_user(frame.return_address, &fp->return_address))
2985
break;
2986
2987
perf_callchain_store(entry, frame.return_address);
2988
fp = (void __user *)frame.next_frame;
2989
}
2990
pagefault_enable();
2991
}
2992
2993
/*
2994
* Deal with code segment offsets for the various execution modes:
2995
*
2996
* VM86 - the good olde 16 bit days, where the linear address is
2997
* 20 bits and we use regs->ip + 0x10 * regs->cs.
2998
*
2999
* IA32 - Where we need to look at GDT/LDT segment descriptor tables
3000
* to figure out what the 32bit base address is.
3001
*
3002
* X32 - has TIF_X32 set, but is running in x86_64
3003
*
3004
* X86_64 - CS,DS,SS,ES are all zero based.
3005
*/
3006
static unsigned long code_segment_base(struct pt_regs *regs)
3007
{
3008
/*
3009
* For IA32 we look at the GDT/LDT segment base to convert the
3010
* effective IP to a linear address.
3011
*/
3012
3013
#ifdef CONFIG_X86_32
3014
/*
3015
* If we are in VM86 mode, add the segment offset to convert to a
3016
* linear address.
3017
*/
3018
if (regs->flags & X86_VM_MASK)
3019
return 0x10 * regs->cs;
3020
3021
if (user_mode(regs) && regs->cs != __USER_CS)
3022
return get_segment_base(regs->cs);
3023
#else
3024
if (user_mode(regs) && !user_64bit_mode(regs) &&
3025
regs->cs != __USER32_CS)
3026
return get_segment_base(regs->cs);
3027
#endif
3028
return 0;
3029
}
3030
3031
unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
3032
{
3033
return regs->ip + code_segment_base(regs);
3034
}
3035
3036
static unsigned long common_misc_flags(struct pt_regs *regs)
3037
{
3038
if (regs->flags & PERF_EFLAGS_EXACT)
3039
return PERF_RECORD_MISC_EXACT_IP;
3040
3041
return 0;
3042
}
3043
3044
static unsigned long guest_misc_flags(struct pt_regs *regs)
3045
{
3046
unsigned long guest_state = perf_guest_state();
3047
3048
if (!(guest_state & PERF_GUEST_ACTIVE))
3049
return 0;
3050
3051
if (guest_state & PERF_GUEST_USER)
3052
return PERF_RECORD_MISC_GUEST_USER;
3053
else
3054
return PERF_RECORD_MISC_GUEST_KERNEL;
3055
3056
}
3057
3058
static unsigned long host_misc_flags(struct pt_regs *regs)
3059
{
3060
if (user_mode(regs))
3061
return PERF_RECORD_MISC_USER;
3062
else
3063
return PERF_RECORD_MISC_KERNEL;
3064
}
3065
3066
unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
3067
{
3068
unsigned long flags = common_misc_flags(regs);
3069
3070
flags |= guest_misc_flags(regs);
3071
3072
return flags;
3073
}
3074
3075
unsigned long perf_arch_misc_flags(struct pt_regs *regs)
3076
{
3077
unsigned long flags = common_misc_flags(regs);
3078
3079
flags |= host_misc_flags(regs);
3080
3081
return flags;
3082
}
3083
3084
void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
3085
{
3086
/* This API doesn't currently support enumerating hybrid PMUs. */
3087
if (WARN_ON_ONCE(cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) ||
3088
!x86_pmu_initialized()) {
3089
memset(cap, 0, sizeof(*cap));
3090
return;
3091
}
3092
3093
/*
3094
* Note, hybrid CPU models get tracked as having hybrid PMUs even when
3095
* all E-cores are disabled via BIOS. When E-cores are disabled, the
3096
* base PMU holds the correct number of counters for P-cores.
3097
*/
3098
cap->version = x86_pmu.version;
3099
cap->num_counters_gp = x86_pmu_num_counters(NULL);
3100
cap->num_counters_fixed = x86_pmu_num_counters_fixed(NULL);
3101
cap->bit_width_gp = x86_pmu.cntval_bits;
3102
cap->bit_width_fixed = x86_pmu.cntval_bits;
3103
cap->events_mask = (unsigned int)x86_pmu.events_maskl;
3104
cap->events_mask_len = x86_pmu.events_mask_len;
3105
cap->pebs_ept = x86_pmu.pebs_ept;
3106
}
3107
EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);
3108
3109
u64 perf_get_hw_event_config(int hw_event)
3110
{
3111
int max = x86_pmu.max_events;
3112
3113
if (hw_event < max)
3114
return x86_pmu.event_map(array_index_nospec(hw_event, max));
3115
3116
return 0;
3117
}
3118
EXPORT_SYMBOL_GPL(perf_get_hw_event_config);
3119
3120