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-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/perf_event.c1348
3 files changed, 1357 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 74d1e767f0b7..9fb91ce106bc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1174,6 +1174,14 @@ config HIGHPTE
1174 depends on HIGHMEM 1174 depends on HIGHMEM
1175 depends on !OUTER_CACHE 1175 depends on !OUTER_CACHE
1176 1176
1177config HW_PERF_EVENTS
1178 bool "Enable hardware performance counter support for perf events"
1179 depends on PERF_EVENTS && CPU_HAS_PMU && CPU_V6
1180 default y
1181 help
1182 Enable hardware performance counter support for perf events. If
1183 disabled, perf events will use software events only.
1184
1177source "mm/Kconfig" 1185source "mm/Kconfig"
1178 1186
1179config LEDS 1187config LEDS
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 216890d804c2..c76e6d2679b8 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_CPU_XSC3) += xscale-cp0.o
47obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o 47obj-$(CONFIG_CPU_MOHAWK) += xscale-cp0.o
48obj-$(CONFIG_IWMMXT) += iwmmxt.o 48obj-$(CONFIG_IWMMXT) += iwmmxt.o
49obj-$(CONFIG_CPU_HAS_PMU) += pmu.o 49obj-$(CONFIG_CPU_HAS_PMU) += pmu.o
50obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
50AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt 51AFLAGS_iwmmxt.o := -Wa,-mcpu=iwmmxt
51 52
52ifneq ($(CONFIG_ARCH_EBSA110),y) 53ifneq ($(CONFIG_ARCH_EBSA110),y)
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
new file mode 100644
index 000000000000..7b1022b9aa52
--- /dev/null
+++ b/arch/arm/kernel/perf_event.c
@@ -0,0 +1,1348 @@
1#undef DEBUG
2
3/*
4 * ARM performance counter support.
5 *
6 * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
7 *
8 * This code is based on the sparc64 perf event code, which is in turn based
9 * on the x86 code. Callchain code is based on the ARM OProfile backtrace
10 * code.
11 */
12#define pr_fmt(fmt) "hw perfevents: " fmt
13
14#include <linux/interrupt.h>
15#include <linux/kernel.h>
16#include <linux/perf_event.h>
17#include <linux/spinlock.h>
18#include <linux/uaccess.h>
19
20#include <asm/cputype.h>
21#include <asm/irq.h>
22#include <asm/irq_regs.h>
23#include <asm/pmu.h>
24#include <asm/stacktrace.h>
25
26static const struct pmu_irqs *pmu_irqs;
27
28/*
29 * Hardware lock to serialize accesses to PMU registers. Needed for the
30 * read/modify/write sequences.
31 */
32DEFINE_SPINLOCK(pmu_lock);
33
34/*
35 * ARMv6 supports a maximum of 3 events, starting from index 1. If we add
36 * another platform that supports more, we need to increase this to be the
37 * largest of all platforms.
38 */
39#define ARMPMU_MAX_HWEVENTS 4
40
41/* The events for a given CPU. */
42struct cpu_hw_events {
43 /*
44 * The events that are active on the CPU for the given index. Index 0
45 * is reserved.
46 */
47 struct perf_event *events[ARMPMU_MAX_HWEVENTS];
48
49 /*
50 * A 1 bit for an index indicates that the counter is being used for
51 * an event. A 0 means that the counter can be used.
52 */
53 unsigned long used_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
54
55 /*
56 * A 1 bit for an index indicates that the counter is actively being
57 * used.
58 */
59 unsigned long active_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
60};
61DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
62
63struct arm_pmu {
64 const char *name;
65 irqreturn_t (*handle_irq)(int irq_num, void *dev);
66 void (*enable)(struct hw_perf_event *evt, int idx);
67 void (*disable)(struct hw_perf_event *evt, int idx);
68 int (*event_map)(int evt);
69 u64 (*raw_event)(u64);
70 int (*get_event_idx)(struct cpu_hw_events *cpuc,
71 struct hw_perf_event *hwc);
72 u32 (*read_counter)(int idx);
73 void (*write_counter)(int idx, u32 val);
74 void (*start)(void);
75 void (*stop)(void);
76 int num_events;
77 u64 max_period;
78};
79
80/* Set at runtime when we know what CPU type we are. */
81static const struct arm_pmu *armpmu;
82
83#define HW_OP_UNSUPPORTED 0xFFFF
84
85#define C(_x) \
86 PERF_COUNT_HW_CACHE_##_x
87
88#define CACHE_OP_UNSUPPORTED 0xFFFF
89
90static unsigned armpmu_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
91 [PERF_COUNT_HW_CACHE_OP_MAX]
92 [PERF_COUNT_HW_CACHE_RESULT_MAX];
93
94static int
95armpmu_map_cache_event(u64 config)
96{
97 unsigned int cache_type, cache_op, cache_result, ret;
98
99 cache_type = (config >> 0) & 0xff;
100 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
101 return -EINVAL;
102
103 cache_op = (config >> 8) & 0xff;
104 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
105 return -EINVAL;
106
107 cache_result = (config >> 16) & 0xff;
108 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
109 return -EINVAL;
110
111 ret = (int)armpmu_perf_cache_map[cache_type][cache_op][cache_result];
112
113 if (ret == CACHE_OP_UNSUPPORTED)
114 return -ENOENT;
115
116 return ret;
117}
118
119static int
120armpmu_event_set_period(struct perf_event *event,
121 struct hw_perf_event *hwc,
122 int idx)
123{
124 s64 left = atomic64_read(&hwc->period_left);
125 s64 period = hwc->sample_period;
126 int ret = 0;
127
128 if (unlikely(left <= -period)) {
129 left = period;
130 atomic64_set(&hwc->period_left, left);
131 hwc->last_period = period;
132 ret = 1;
133 }
134
135 if (unlikely(left <= 0)) {
136 left += period;
137 atomic64_set(&hwc->period_left, left);
138 hwc->last_period = period;
139 ret = 1;
140 }
141
142 if (left > (s64)armpmu->max_period)
143 left = armpmu->max_period;
144
145 atomic64_set(&hwc->prev_count, (u64)-left);
146
147 armpmu->write_counter(idx, (u64)(-left) & 0xffffffff);
148
149 perf_event_update_userpage(event);
150
151 return ret;
152}
153
154static u64
155armpmu_event_update(struct perf_event *event,
156 struct hw_perf_event *hwc,
157 int idx)
158{
159 int shift = 64 - 32;
160 s64 prev_raw_count, new_raw_count;
161 s64 delta;
162
163again:
164 prev_raw_count = atomic64_read(&hwc->prev_count);
165 new_raw_count = armpmu->read_counter(idx);
166
167 if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
168 new_raw_count) != prev_raw_count)
169 goto again;
170
171 delta = (new_raw_count << shift) - (prev_raw_count << shift);
172 delta >>= shift;
173
174 atomic64_add(delta, &event->count);
175 atomic64_sub(delta, &hwc->period_left);
176
177 return new_raw_count;
178}
179
180static void
181armpmu_disable(struct perf_event *event)
182{
183 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
184 struct hw_perf_event *hwc = &event->hw;
185 int idx = hwc->idx;
186
187 WARN_ON(idx < 0);
188
189 clear_bit(idx, cpuc->active_mask);
190 armpmu->disable(hwc, idx);
191
192 barrier();
193
194 armpmu_event_update(event, hwc, idx);
195 cpuc->events[idx] = NULL;
196 clear_bit(idx, cpuc->used_mask);
197
198 perf_event_update_userpage(event);
199}
200
201static void
202armpmu_read(struct perf_event *event)
203{
204 struct hw_perf_event *hwc = &event->hw;
205
206 /* Don't read disabled counters! */
207 if (hwc->idx < 0)
208 return;
209
210 armpmu_event_update(event, hwc, hwc->idx);
211}
212
213static void
214armpmu_unthrottle(struct perf_event *event)
215{
216 struct hw_perf_event *hwc = &event->hw;
217
218 /*
219 * Set the period again. Some counters can't be stopped, so when we
220 * were throttled we simply disabled the IRQ source and the counter
221 * may have been left counting. If we don't do this step then we may
222 * get an interrupt too soon or *way* too late if the overflow has
223 * happened since disabling.
224 */
225 armpmu_event_set_period(event, hwc, hwc->idx);
226 armpmu->enable(hwc, hwc->idx);
227}
228
229static int
230armpmu_enable(struct perf_event *event)
231{
232 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
233 struct hw_perf_event *hwc = &event->hw;
234 int idx;
235 int err = 0;
236
237 /* If we don't have a space for the counter then finish early. */
238 idx = armpmu->get_event_idx(cpuc, hwc);
239 if (idx < 0) {
240 err = idx;
241 goto out;
242 }
243
244 /*
245 * If there is an event in the counter we are going to use then make
246 * sure it is disabled.
247 */
248 event->hw.idx = idx;
249 armpmu->disable(hwc, idx);
250 cpuc->events[idx] = event;
251 set_bit(idx, cpuc->active_mask);
252
253 /* Set the period for the event. */
254 armpmu_event_set_period(event, hwc, idx);
255
256 /* Enable the event. */
257 armpmu->enable(hwc, idx);
258
259 /* Propagate our changes to the userspace mapping. */
260 perf_event_update_userpage(event);
261
262out:
263 return err;
264}
265
266static struct pmu pmu = {
267 .enable = armpmu_enable,
268 .disable = armpmu_disable,
269 .unthrottle = armpmu_unthrottle,
270 .read = armpmu_read,
271};
272
273static int
274validate_event(struct cpu_hw_events *cpuc,
275 struct perf_event *event)
276{
277 struct hw_perf_event fake_event = event->hw;
278
279 if (event->pmu && event->pmu != &pmu)
280 return 0;
281
282 return armpmu->get_event_idx(cpuc, &fake_event) >= 0;
283}
284
285static int
286validate_group(struct perf_event *event)
287{
288 struct perf_event *sibling, *leader = event->group_leader;
289 struct cpu_hw_events fake_pmu;
290
291 memset(&fake_pmu, 0, sizeof(fake_pmu));
292
293 if (!validate_event(&fake_pmu, leader))
294 return -ENOSPC;
295
296 list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
297 if (!validate_event(&fake_pmu, sibling))
298 return -ENOSPC;
299 }
300
301 if (!validate_event(&fake_pmu, event))
302 return -ENOSPC;
303
304 return 0;
305}
306
307static int
308armpmu_reserve_hardware(void)
309{
310 int i;
311 int err;
312
313 pmu_irqs = reserve_pmu();
314 if (IS_ERR(pmu_irqs)) {
315 pr_warning("unable to reserve pmu\n");
316 return PTR_ERR(pmu_irqs);
317 }
318
319 init_pmu();
320
321 if (pmu_irqs->num_irqs < 1) {
322 pr_err("no irqs for PMUs defined\n");
323 return -ENODEV;
324 }
325
326 for (i = 0; i < pmu_irqs->num_irqs; ++i) {
327 err = request_irq(pmu_irqs->irqs[i], armpmu->handle_irq,
328 IRQF_DISABLED, "armpmu", NULL);
329 if (err) {
330 pr_warning("unable to request IRQ%d for ARM "
331 "perf counters\n", pmu_irqs->irqs[i]);
332 break;
333 }
334 }
335
336 if (err) {
337 for (i = i - 1; i >= 0; --i)
338 free_irq(pmu_irqs->irqs[i], NULL);
339 release_pmu(pmu_irqs);
340 pmu_irqs = NULL;
341 }
342
343 return err;
344}
345
346static void
347armpmu_release_hardware(void)
348{
349 int i;
350
351 for (i = pmu_irqs->num_irqs - 1; i >= 0; --i)
352 free_irq(pmu_irqs->irqs[i], NULL);
353 armpmu->stop();
354
355 release_pmu(pmu_irqs);
356 pmu_irqs = NULL;
357}
358
359static atomic_t active_events = ATOMIC_INIT(0);
360static DEFINE_MUTEX(pmu_reserve_mutex);
361
362static void
363hw_perf_event_destroy(struct perf_event *event)
364{
365 if (atomic_dec_and_mutex_lock(&active_events, &pmu_reserve_mutex)) {
366 armpmu_release_hardware();
367 mutex_unlock(&pmu_reserve_mutex);
368 }
369}
370
371static int
372__hw_perf_event_init(struct perf_event *event)
373{
374 struct hw_perf_event *hwc = &event->hw;
375 int mapping, err;
376
377 /* Decode the generic type into an ARM event identifier. */
378 if (PERF_TYPE_HARDWARE == event->attr.type) {
379 mapping = armpmu->event_map(event->attr.config);
380 } else if (PERF_TYPE_HW_CACHE == event->attr.type) {
381 mapping = armpmu_map_cache_event(event->attr.config);
382 } else if (PERF_TYPE_RAW == event->attr.type) {
383 mapping = armpmu->raw_event(event->attr.config);
384 } else {
385 pr_debug("event type %x not supported\n", event->attr.type);
386 return -EOPNOTSUPP;
387 }
388
389 if (mapping < 0) {
390 pr_debug("event %x:%llx not supported\n", event->attr.type,
391 event->attr.config);
392 return mapping;
393 }
394
395 /*
396 * Check whether we need to exclude the counter from certain modes.
397 * The ARM performance counters are on all of the time so if someone
398 * has asked us for some excludes then we have to fail.
399 */
400 if (event->attr.exclude_kernel || event->attr.exclude_user ||
401 event->attr.exclude_hv || event->attr.exclude_idle) {
402 pr_debug("ARM performance counters do not support "
403 "mode exclusion\n");
404 return -EPERM;
405 }
406
407 /*
408 * We don't assign an index until we actually place the event onto
409 * hardware. Use -1 to signify that we haven't decided where to put it
410 * yet. For SMP systems, each core has it's own PMU so we can't do any
411 * clever allocation or constraints checking at this point.
412 */
413 hwc->idx = -1;
414
415 /*
416 * Store the event encoding into the config_base field. config and
417 * event_base are unused as the only 2 things we need to know are
418 * the event mapping and the counter to use. The counter to use is
419 * also the indx and the config_base is the event type.
420 */
421 hwc->config_base = (unsigned long)mapping;
422 hwc->config = 0;
423 hwc->event_base = 0;
424
425 if (!hwc->sample_period) {
426 hwc->sample_period = armpmu->max_period;
427 hwc->last_period = hwc->sample_period;
428 atomic64_set(&hwc->period_left, hwc->sample_period);
429 }
430
431 err = 0;
432 if (event->group_leader != event) {
433 err = validate_group(event);
434 if (err)
435 return -EINVAL;
436 }
437
438 return err;
439}
440
441const struct pmu *
442hw_perf_event_init(struct perf_event *event)
443{
444 int err = 0;
445
446 if (!armpmu)
447 return ERR_PTR(-ENODEV);
448
449 event->destroy = hw_perf_event_destroy;
450
451 if (!atomic_inc_not_zero(&active_events)) {
452 if (atomic_read(&active_events) > perf_max_events) {
453 atomic_dec(&active_events);
454 return ERR_PTR(-ENOSPC);
455 }
456
457 mutex_lock(&pmu_reserve_mutex);
458 if (atomic_read(&active_events) == 0) {
459 err = armpmu_reserve_hardware();
460 }
461
462 if (!err)
463 atomic_inc(&active_events);
464 mutex_unlock(&pmu_reserve_mutex);
465 }
466
467 if (err)
468 return ERR_PTR(err);
469
470 err = __hw_perf_event_init(event);
471 if (err)
472 hw_perf_event_destroy(event);
473
474 return err ? ERR_PTR(err) : &pmu;
475}
476
477void
478hw_perf_enable(void)
479{
480 /* Enable all of the perf events on hardware. */
481 int idx;
482 struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
483
484 if (!armpmu)
485 return;
486
487 for (idx = 0; idx <= armpmu->num_events; ++idx) {
488 struct perf_event *event = cpuc->events[idx];
489
490 if (!event)
491 continue;
492
493 armpmu->enable(&event->hw, idx);
494 }
495
496 armpmu->start();
497}
498
499void
500hw_perf_disable(void)
501{
502 if (armpmu)
503 armpmu->stop();
504}
505
506/*
507 * ARMv6 Performance counter handling code.
508 *
509 * ARMv6 has 2 configurable performance counters and a single cycle counter.
510 * They all share a single reset bit but can be written to zero so we can use
511 * that for a reset.
512 *
513 * The counters can't be individually enabled or disabled so when we remove
514 * one event and replace it with another we could get spurious counts from the
515 * wrong event. However, we can take advantage of the fact that the
516 * performance counters can export events to the event bus, and the event bus
517 * itself can be monitored. This requires that we *don't* export the events to
518 * the event bus. The procedure for disabling a configurable counter is:
519 * - change the counter to count the ETMEXTOUT[0] signal (0x20). This
520 * effectively stops the counter from counting.
521 * - disable the counter's interrupt generation (each counter has it's
522 * own interrupt enable bit).
523 * Once stopped, the counter value can be written as 0 to reset.
524 *
525 * To enable a counter:
526 * - enable the counter's interrupt generation.
527 * - set the new event type.
528 *
529 * Note: the dedicated cycle counter only counts cycles and can't be
530 * enabled/disabled independently of the others. When we want to disable the
531 * cycle counter, we have to just disable the interrupt reporting and start
532 * ignoring that counter. When re-enabling, we have to reset the value and
533 * enable the interrupt.
534 */
535
536enum armv6_perf_types {
537 ARMV6_PERFCTR_ICACHE_MISS = 0x0,
538 ARMV6_PERFCTR_IBUF_STALL = 0x1,
539 ARMV6_PERFCTR_DDEP_STALL = 0x2,
540 ARMV6_PERFCTR_ITLB_MISS = 0x3,
541 ARMV6_PERFCTR_DTLB_MISS = 0x4,
542 ARMV6_PERFCTR_BR_EXEC = 0x5,
543 ARMV6_PERFCTR_BR_MISPREDICT = 0x6,
544 ARMV6_PERFCTR_INSTR_EXEC = 0x7,
545 ARMV6_PERFCTR_DCACHE_HIT = 0x9,
546 ARMV6_PERFCTR_DCACHE_ACCESS = 0xA,
547 ARMV6_PERFCTR_DCACHE_MISS = 0xB,
548 ARMV6_PERFCTR_DCACHE_WBACK = 0xC,
549 ARMV6_PERFCTR_SW_PC_CHANGE = 0xD,
550 ARMV6_PERFCTR_MAIN_TLB_MISS = 0xF,
551 ARMV6_PERFCTR_EXPL_D_ACCESS = 0x10,
552 ARMV6_PERFCTR_LSU_FULL_STALL = 0x11,
553 ARMV6_PERFCTR_WBUF_DRAINED = 0x12,
554 ARMV6_PERFCTR_CPU_CYCLES = 0xFF,
555 ARMV6_PERFCTR_NOP = 0x20,
556};
557
558enum armv6_counters {
559 ARMV6_CYCLE_COUNTER = 1,
560 ARMV6_COUNTER0,
561 ARMV6_COUNTER1,
562};
563
564/*
565 * The hardware events that we support. We do support cache operations but
566 * we have harvard caches and no way to combine instruction and data
567 * accesses/misses in hardware.
568 */
569static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = {
570 [PERF_COUNT_HW_CPU_CYCLES] = ARMV6_PERFCTR_CPU_CYCLES,
571 [PERF_COUNT_HW_INSTRUCTIONS] = ARMV6_PERFCTR_INSTR_EXEC,
572 [PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
573 [PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
574 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6_PERFCTR_BR_EXEC,
575 [PERF_COUNT_HW_BRANCH_MISSES] = ARMV6_PERFCTR_BR_MISPREDICT,
576 [PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
577};
578
579static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
580 [PERF_COUNT_HW_CACHE_OP_MAX]
581 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
582 [C(L1D)] = {
583 /*
584 * The performance counters don't differentiate between read
585 * and write accesses/misses so this isn't strictly correct,
586 * but it's the best we can do. Writes and reads get
587 * combined.
588 */
589 [C(OP_READ)] = {
590 [C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS,
591 [C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
592 },
593 [C(OP_WRITE)] = {
594 [C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS,
595 [C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
596 },
597 [C(OP_PREFETCH)] = {
598 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
599 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
600 },
601 },
602 [C(L1I)] = {
603 [C(OP_READ)] = {
604 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
605 [C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
606 },
607 [C(OP_WRITE)] = {
608 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
609 [C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
610 },
611 [C(OP_PREFETCH)] = {
612 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
613 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
614 },
615 },
616 [C(LL)] = {
617 [C(OP_READ)] = {
618 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
619 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
620 },
621 [C(OP_WRITE)] = {
622 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
623 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
624 },
625 [C(OP_PREFETCH)] = {
626 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
627 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
628 },
629 },
630 [C(DTLB)] = {
631 /*
632 * The ARM performance counters can count micro DTLB misses,
633 * micro ITLB misses and main TLB misses. There isn't an event
634 * for TLB misses, so use the micro misses here and if users
635 * want the main TLB misses they can use a raw counter.
636 */
637 [C(OP_READ)] = {
638 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
639 [C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
640 },
641 [C(OP_WRITE)] = {
642 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
643 [C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
644 },
645 [C(OP_PREFETCH)] = {
646 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
647 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
648 },
649 },
650 [C(ITLB)] = {
651 [C(OP_READ)] = {
652 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
653 [C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
654 },
655 [C(OP_WRITE)] = {
656 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
657 [C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
658 },
659 [C(OP_PREFETCH)] = {
660 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
661 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
662 },
663 },
664 [C(BPU)] = {
665 [C(OP_READ)] = {
666 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
667 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
668 },
669 [C(OP_WRITE)] = {
670 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
671 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
672 },
673 [C(OP_PREFETCH)] = {
674 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
675 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
676 },
677 },
678};
679
680enum armv6mpcore_perf_types {
681 ARMV6MPCORE_PERFCTR_ICACHE_MISS = 0x0,
682 ARMV6MPCORE_PERFCTR_IBUF_STALL = 0x1,
683 ARMV6MPCORE_PERFCTR_DDEP_STALL = 0x2,
684 ARMV6MPCORE_PERFCTR_ITLB_MISS = 0x3,
685 ARMV6MPCORE_PERFCTR_DTLB_MISS = 0x4,
686 ARMV6MPCORE_PERFCTR_BR_EXEC = 0x5,
687 ARMV6MPCORE_PERFCTR_BR_NOTPREDICT = 0x6,
688 ARMV6MPCORE_PERFCTR_BR_MISPREDICT = 0x7,
689 ARMV6MPCORE_PERFCTR_INSTR_EXEC = 0x8,
690 ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA,
691 ARMV6MPCORE_PERFCTR_DCACHE_RDMISS = 0xB,
692 ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC,
693 ARMV6MPCORE_PERFCTR_DCACHE_WRMISS = 0xD,
694 ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE,
695 ARMV6MPCORE_PERFCTR_SW_PC_CHANGE = 0xF,
696 ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS = 0x10,
697 ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11,
698 ARMV6MPCORE_PERFCTR_LSU_FULL_STALL = 0x12,
699 ARMV6MPCORE_PERFCTR_WBUF_DRAINED = 0x13,
700 ARMV6MPCORE_PERFCTR_CPU_CYCLES = 0xFF,
701};
702
703/*
704 * The hardware events that we support. We do support cache operations but
705 * we have harvard caches and no way to combine instruction and data
706 * accesses/misses in hardware.
707 */
708static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = {
709 [PERF_COUNT_HW_CPU_CYCLES] = ARMV6MPCORE_PERFCTR_CPU_CYCLES,
710 [PERF_COUNT_HW_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_INSTR_EXEC,
711 [PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
712 [PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
713 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_BR_EXEC,
714 [PERF_COUNT_HW_BRANCH_MISSES] = ARMV6MPCORE_PERFCTR_BR_MISPREDICT,
715 [PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
716};
717
718static const unsigned armv6mpcore_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
719 [PERF_COUNT_HW_CACHE_OP_MAX]
720 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
721 [C(L1D)] = {
722 [C(OP_READ)] = {
723 [C(RESULT_ACCESS)] =
724 ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS,
725 [C(RESULT_MISS)] =
726 ARMV6MPCORE_PERFCTR_DCACHE_RDMISS,
727 },
728 [C(OP_WRITE)] = {
729 [C(RESULT_ACCESS)] =
730 ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS,
731 [C(RESULT_MISS)] =
732 ARMV6MPCORE_PERFCTR_DCACHE_WRMISS,
733 },
734 [C(OP_PREFETCH)] = {
735 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
736 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
737 },
738 },
739 [C(L1I)] = {
740 [C(OP_READ)] = {
741 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
742 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
743 },
744 [C(OP_WRITE)] = {
745 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
746 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
747 },
748 [C(OP_PREFETCH)] = {
749 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
750 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
751 },
752 },
753 [C(LL)] = {
754 [C(OP_READ)] = {
755 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
756 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
757 },
758 [C(OP_WRITE)] = {
759 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
760 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
761 },
762 [C(OP_PREFETCH)] = {
763 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
764 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
765 },
766 },
767 [C(DTLB)] = {
768 /*
769 * The ARM performance counters can count micro DTLB misses,
770 * micro ITLB misses and main TLB misses. There isn't an event
771 * for TLB misses, so use the micro misses here and if users
772 * want the main TLB misses they can use a raw counter.
773 */
774 [C(OP_READ)] = {
775 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
776 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
777 },
778 [C(OP_WRITE)] = {
779 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
780 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
781 },
782 [C(OP_PREFETCH)] = {
783 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
784 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
785 },
786 },
787 [C(ITLB)] = {
788 [C(OP_READ)] = {
789 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
790 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
791 },
792 [C(OP_WRITE)] = {
793 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
794 [C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
795 },
796 [C(OP_PREFETCH)] = {
797 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
798 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
799 },
800 },
801 [C(BPU)] = {
802 [C(OP_READ)] = {
803 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
804 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
805 },
806 [C(OP_WRITE)] = {
807 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
808 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
809 },
810 [C(OP_PREFETCH)] = {
811 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
812 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
813 },
814 },
815};
816
817static inline unsigned long
818armv6_pmcr_read(void)
819{
820 u32 val;
821 asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r"(val));
822 return val;
823}
824
825static inline void
826armv6_pmcr_write(unsigned long val)
827{
828 asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r"(val));
829}
830
831#define ARMV6_PMCR_ENABLE (1 << 0)
832#define ARMV6_PMCR_CTR01_RESET (1 << 1)
833#define ARMV6_PMCR_CCOUNT_RESET (1 << 2)
834#define ARMV6_PMCR_CCOUNT_DIV (1 << 3)
835#define ARMV6_PMCR_COUNT0_IEN (1 << 4)
836#define ARMV6_PMCR_COUNT1_IEN (1 << 5)
837#define ARMV6_PMCR_CCOUNT_IEN (1 << 6)
838#define ARMV6_PMCR_COUNT0_OVERFLOW (1 << 8)
839#define ARMV6_PMCR_COUNT1_OVERFLOW (1 << 9)
840#define ARMV6_PMCR_CCOUNT_OVERFLOW (1 << 10)
841#define ARMV6_PMCR_EVT_COUNT0_SHIFT 20
842#define ARMV6_PMCR_EVT_COUNT0_MASK (0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT)
843#define ARMV6_PMCR_EVT_COUNT1_SHIFT 12
844#define ARMV6_PMCR_EVT_COUNT1_MASK (0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT)
845
846#define ARMV6_PMCR_OVERFLOWED_MASK \
847 (ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \
848 ARMV6_PMCR_CCOUNT_OVERFLOW)
849
850static inline int
851armv6_pmcr_has_overflowed(unsigned long pmcr)
852{
853 return (pmcr & ARMV6_PMCR_OVERFLOWED_MASK);
854}
855
856static inline int
857armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
858 enum armv6_counters counter)
859{
860 int ret = 0;
861
862 if (ARMV6_CYCLE_COUNTER == counter)
863 ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW;
864 else if (ARMV6_COUNTER0 == counter)
865 ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW;
866 else if (ARMV6_COUNTER1 == counter)
867 ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW;
868 else
869 WARN_ONCE(1, "invalid counter number (%d)\n", counter);
870
871 return ret;
872}
873
874static inline u32
875armv6pmu_read_counter(int counter)
876{
877 unsigned long value = 0;
878
879 if (ARMV6_CYCLE_COUNTER == counter)
880 asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r"(value));
881 else if (ARMV6_COUNTER0 == counter)
882 asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r"(value));
883 else if (ARMV6_COUNTER1 == counter)
884 asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r"(value));
885 else
886 WARN_ONCE(1, "invalid counter number (%d)\n", counter);
887
888 return value;
889}
890
891static inline void
892armv6pmu_write_counter(int counter,
893 u32 value)
894{
895 if (ARMV6_CYCLE_COUNTER == counter)
896 asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r"(value));
897 else if (ARMV6_COUNTER0 == counter)
898 asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r"(value));
899 else if (ARMV6_COUNTER1 == counter)
900 asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r"(value));
901 else
902 WARN_ONCE(1, "invalid counter number (%d)\n", counter);
903}
904
905void
906armv6pmu_enable_event(struct hw_perf_event *hwc,
907 int idx)
908{
909 unsigned long val, mask, evt, flags;
910
911 if (ARMV6_CYCLE_COUNTER == idx) {
912 mask = 0;
913 evt = ARMV6_PMCR_CCOUNT_IEN;
914 } else if (ARMV6_COUNTER0 == idx) {
915 mask = ARMV6_PMCR_EVT_COUNT0_MASK;
916 evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) |
917 ARMV6_PMCR_COUNT0_IEN;
918 } else if (ARMV6_COUNTER1 == idx) {
919 mask = ARMV6_PMCR_EVT_COUNT1_MASK;
920 evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) |
921 ARMV6_PMCR_COUNT1_IEN;
922 } else {
923 WARN_ONCE(1, "invalid counter number (%d)\n", idx);
924 return;
925 }
926
927 /*
928 * Mask out the current event and set the counter to count the event
929 * that we're interested in.
930 */
931 spin_lock_irqsave(&pmu_lock, flags);
932 val = armv6_pmcr_read();
933 val &= ~mask;
934 val |= evt;
935 armv6_pmcr_write(val);
936 spin_unlock_irqrestore(&pmu_lock, flags);
937}
938
939static irqreturn_t
940armv6pmu_handle_irq(int irq_num,
941 void *dev)
942{
943 unsigned long pmcr = armv6_pmcr_read();
944 struct perf_sample_data data;
945 struct cpu_hw_events *cpuc;
946 struct pt_regs *regs;
947 int idx;
948
949 if (!armv6_pmcr_has_overflowed(pmcr))
950 return IRQ_NONE;
951
952 regs = get_irq_regs();
953
954 /*
955 * The interrupts are cleared by writing the overflow flags back to
956 * the control register. All of the other bits don't have any effect
957 * if they are rewritten, so write the whole value back.
958 */
959 armv6_pmcr_write(pmcr);
960
961 data.addr = 0;
962
963 cpuc = &__get_cpu_var(cpu_hw_events);
964 for (idx = 0; idx <= armpmu->num_events; ++idx) {
965 struct perf_event *event = cpuc->events[idx];
966 struct hw_perf_event *hwc;
967
968 if (!test_bit(idx, cpuc->active_mask))
969 continue;
970
971 /*
972 * We have a single interrupt for all counters. Check that
973 * each counter has overflowed before we process it.
974 */
975 if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
976 continue;
977
978 hwc = &event->hw;
979 armpmu_event_update(event, hwc, idx);
980 data.period = event->hw.last_period;
981 if (!armpmu_event_set_period(event, hwc, idx))
982 continue;
983
984 if (perf_event_overflow(event, 0, &data, regs))
985 armpmu->disable(hwc, idx);
986 }
987
988 /*
989 * Handle the pending perf events.
990 *
991 * Note: this call *must* be run with interrupts enabled. For
992 * platforms that can have the PMU interrupts raised as a PMI, this
993 * will not work.
994 */
995 perf_event_do_pending();
996
997 return IRQ_HANDLED;
998}
999
1000static void
1001armv6pmu_start(void)
1002{
1003 unsigned long flags, val;
1004
1005 spin_lock_irqsave(&pmu_lock, flags);
1006 val = armv6_pmcr_read();
1007 val |= ARMV6_PMCR_ENABLE;
1008 armv6_pmcr_write(val);
1009 spin_unlock_irqrestore(&pmu_lock, flags);
1010}
1011
1012void
1013armv6pmu_stop(void)
1014{
1015 unsigned long flags, val;
1016
1017 spin_lock_irqsave(&pmu_lock, flags);
1018 val = armv6_pmcr_read();
1019 val &= ~ARMV6_PMCR_ENABLE;
1020 armv6_pmcr_write(val);
1021 spin_unlock_irqrestore(&pmu_lock, flags);
1022}
1023
1024static inline int
1025armv6pmu_event_map(int config)
1026{
1027 int mapping = armv6_perf_map[config];
1028 if (HW_OP_UNSUPPORTED == mapping)
1029 mapping = -EOPNOTSUPP;
1030 return mapping;
1031}
1032
1033static inline int
1034armv6mpcore_pmu_event_map(int config)
1035{
1036 int mapping = armv6mpcore_perf_map[config];
1037 if (HW_OP_UNSUPPORTED == mapping)
1038 mapping = -EOPNOTSUPP;
1039 return mapping;
1040}
1041
1042static u64
1043armv6pmu_raw_event(u64 config)
1044{
1045 return config & 0xff;
1046}
1047
1048static int
1049armv6pmu_get_event_idx(struct cpu_hw_events *cpuc,
1050 struct hw_perf_event *event)
1051{
1052 /* Always place a cycle counter into the cycle counter. */
1053 if (ARMV6_PERFCTR_CPU_CYCLES == event->config_base) {
1054 if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
1055 return -EAGAIN;
1056
1057 return ARMV6_CYCLE_COUNTER;
1058 } else {
1059 /*
1060 * For anything other than a cycle counter, try and use
1061 * counter0 and counter1.
1062 */
1063 if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask)) {
1064 return ARMV6_COUNTER1;
1065 }
1066
1067 if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask)) {
1068 return ARMV6_COUNTER0;
1069 }
1070
1071 /* The counters are all in use. */
1072 return -EAGAIN;
1073 }
1074}
1075
1076static void
1077armv6pmu_disable_event(struct hw_perf_event *hwc,
1078 int idx)
1079{
1080 unsigned long val, mask, evt, flags;
1081
1082 if (ARMV6_CYCLE_COUNTER == idx) {
1083 mask = ARMV6_PMCR_CCOUNT_IEN;
1084 evt = 0;
1085 } else if (ARMV6_COUNTER0 == idx) {
1086 mask = ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
1087 evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
1088 } else if (ARMV6_COUNTER1 == idx) {
1089 mask = ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
1090 evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
1091 } else {
1092 WARN_ONCE(1, "invalid counter number (%d)\n", idx);
1093 return;
1094 }
1095
1096 /*
1097 * Mask out the current event and set the counter to count the number
1098 * of ETM bus signal assertion cycles. The external reporting should
1099 * be disabled and so this should never increment.
1100 */
1101 spin_lock_irqsave(&pmu_lock, flags);
1102 val = armv6_pmcr_read();
1103 val &= ~mask;
1104 val |= evt;
1105 armv6_pmcr_write(val);
1106 spin_unlock_irqrestore(&pmu_lock, flags);
1107}
1108
1109static void
1110armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc,
1111 int idx)
1112{
1113 unsigned long val, mask, flags, evt = 0;
1114
1115 if (ARMV6_CYCLE_COUNTER == idx) {
1116 mask = ARMV6_PMCR_CCOUNT_IEN;
1117 } else if (ARMV6_COUNTER0 == idx) {
1118 mask = ARMV6_PMCR_COUNT0_IEN;
1119 } else if (ARMV6_COUNTER1 == idx) {
1120 mask = ARMV6_PMCR_COUNT1_IEN;
1121 } else {
1122 WARN_ONCE(1, "invalid counter number (%d)\n", idx);
1123 return;
1124 }
1125
1126 /*
1127 * Unlike UP ARMv6, we don't have a way of stopping the counters. We
1128 * simply disable the interrupt reporting.
1129 */
1130 spin_lock_irqsave(&pmu_lock, flags);
1131 val = armv6_pmcr_read();
1132 val &= ~mask;
1133 val |= evt;
1134 armv6_pmcr_write(val);
1135 spin_unlock_irqrestore(&pmu_lock, flags);
1136}
1137
1138static const struct arm_pmu armv6pmu = {
1139 .name = "v6",
1140 .handle_irq = armv6pmu_handle_irq,
1141 .enable = armv6pmu_enable_event,
1142 .disable = armv6pmu_disable_event,
1143 .event_map = armv6pmu_event_map,
1144 .raw_event = armv6pmu_raw_event,
1145 .read_counter = armv6pmu_read_counter,
1146 .write_counter = armv6pmu_write_counter,
1147 .get_event_idx = armv6pmu_get_event_idx,
1148 .start = armv6pmu_start,
1149 .stop = armv6pmu_stop,
1150 .num_events = 3,
1151 .max_period = (1LLU << 32) - 1,
1152};
1153
1154/*
1155 * ARMv6mpcore is almost identical to single core ARMv6 with the exception
1156 * that some of the events have different enumerations and that there is no
1157 * *hack* to stop the programmable counters. To stop the counters we simply
1158 * disable the interrupt reporting and update the event. When unthrottling we
1159 * reset the period and enable the interrupt reporting.
1160 */
1161static const struct arm_pmu armv6mpcore_pmu = {
1162 .name = "v6mpcore",
1163 .handle_irq = armv6pmu_handle_irq,
1164 .enable = armv6pmu_enable_event,
1165 .disable = armv6mpcore_pmu_disable_event,
1166 .event_map = armv6mpcore_pmu_event_map,
1167 .raw_event = armv6pmu_raw_event,
1168 .read_counter = armv6pmu_read_counter,
1169 .write_counter = armv6pmu_write_counter,
1170 .get_event_idx = armv6pmu_get_event_idx,
1171 .start = armv6pmu_start,
1172 .stop = armv6pmu_stop,
1173 .num_events = 3,
1174 .max_period = (1LLU << 32) - 1,
1175};
1176
1177static int __init
1178init_hw_perf_events(void)
1179{
1180 unsigned long cpuid = read_cpuid_id();
1181 unsigned long implementor = (cpuid & 0xFF000000) >> 24;
1182 unsigned long part_number = (cpuid & 0xFFF0);
1183
1184 /* We only support ARM CPUs implemented by ARM at the moment. */
1185 if (0x41 == implementor) {
1186 switch (part_number) {
1187 case 0xB360: /* ARM1136 */
1188 case 0xB560: /* ARM1156 */
1189 case 0xB760: /* ARM1176 */
1190 armpmu = &armv6pmu;
1191 memcpy(armpmu_perf_cache_map, armv6_perf_cache_map,
1192 sizeof(armv6_perf_cache_map));
1193 perf_max_events = armv6pmu.num_events;
1194 break;
1195 case 0xB020: /* ARM11mpcore */
1196 armpmu = &armv6mpcore_pmu;
1197 memcpy(armpmu_perf_cache_map,
1198 armv6mpcore_perf_cache_map,
1199 sizeof(armv6mpcore_perf_cache_map));
1200 perf_max_events = armv6mpcore_pmu.num_events;
1201 break;
1202 default:
1203 pr_info("no hardware support available\n");
1204 perf_max_events = -1;
1205 }
1206 }
1207
1208 if (armpmu)
1209 pr_info("enabled with %s PMU driver\n",
1210 armpmu->name);
1211
1212 return 0;
1213}
1214arch_initcall(init_hw_perf_events);
1215
1216/*
1217 * Callchain handling code.
1218 */
1219static inline void
1220callchain_store(struct perf_callchain_entry *entry,
1221 u64 ip)
1222{
1223 if (entry->nr < PERF_MAX_STACK_DEPTH)
1224 entry->ip[entry->nr++] = ip;
1225}
1226
1227/*
1228 * The registers we're interested in are at the end of the variable
1229 * length saved register structure. The fp points at the end of this
1230 * structure so the address of this struct is:
1231 * (struct frame_tail *)(xxx->fp)-1
1232 *
1233 * This code has been adapted from the ARM OProfile support.
1234 */
1235struct frame_tail {
1236 struct frame_tail *fp;
1237 unsigned long sp;
1238 unsigned long lr;
1239} __attribute__((packed));
1240
1241/*
1242 * Get the return address for a single stackframe and return a pointer to the
1243 * next frame tail.
1244 */
1245static struct frame_tail *
1246user_backtrace(struct frame_tail *tail,
1247 struct perf_callchain_entry *entry)
1248{
1249 struct frame_tail buftail;
1250
1251 /* Also check accessibility of one struct frame_tail beyond */
1252 if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
1253 return NULL;
1254 if (__copy_from_user_inatomic(&buftail, tail, sizeof(buftail)))
1255 return NULL;
1256
1257 callchain_store(entry, buftail.lr);
1258
1259 /*
1260 * Frame pointers should strictly progress back up the stack
1261 * (towards higher addresses).
1262 */
1263 if (tail >= buftail.fp)
1264 return NULL;
1265
1266 return buftail.fp - 1;
1267}
1268
1269static void
1270perf_callchain_user(struct pt_regs *regs,
1271 struct perf_callchain_entry *entry)
1272{
1273 struct frame_tail *tail;
1274
1275 callchain_store(entry, PERF_CONTEXT_USER);
1276
1277 if (!user_mode(regs))
1278 regs = task_pt_regs(current);
1279
1280 tail = (struct frame_tail *)regs->ARM_fp - 1;
1281
1282 while (tail && !((unsigned long)tail & 0x3))
1283 tail = user_backtrace(tail, entry);
1284}
1285
1286/*
1287 * Gets called by walk_stackframe() for every stackframe. This will be called
1288 * whist unwinding the stackframe and is like a subroutine return so we use
1289 * the PC.
1290 */
1291static int
1292callchain_trace(struct stackframe *fr,
1293 void *data)
1294{
1295 struct perf_callchain_entry *entry = data;
1296 callchain_store(entry, fr->pc);
1297 return 0;
1298}
1299
1300static void
1301perf_callchain_kernel(struct pt_regs *regs,
1302 struct perf_callchain_entry *entry)
1303{
1304 struct stackframe fr;
1305
1306 callchain_store(entry, PERF_CONTEXT_KERNEL);
1307 fr.fp = regs->ARM_fp;
1308 fr.sp = regs->ARM_sp;
1309 fr.lr = regs->ARM_lr;
1310 fr.pc = regs->ARM_pc;
1311 walk_stackframe(&fr, callchain_trace, entry);
1312}
1313
1314static void
1315perf_do_callchain(struct pt_regs *regs,
1316 struct perf_callchain_entry *entry)
1317{
1318 int is_user;
1319
1320 if (!regs)
1321 return;
1322
1323 is_user = user_mode(regs);
1324
1325 if (!current || !current->pid)
1326 return;
1327
1328 if (is_user && current->state != TASK_RUNNING)
1329 return;
1330
1331 if (!is_user)
1332 perf_callchain_kernel(regs, entry);
1333
1334 if (current->mm)
1335 perf_callchain_user(regs, entry);
1336}
1337
1338static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
1339
1340struct perf_callchain_entry *
1341perf_callchain(struct pt_regs *regs)
1342{
1343 struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry);
1344
1345 entry->nr = 0;
1346 perf_do_callchain(regs, entry);
1347 return entry;
1348}
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-08 17:25:42 -0500