1// SPDX-License-Identifier: GPL-2.0+
2//
3// Linux performance counter support for ARC CPUs.
4// This code is inspired by the perf support of various other architectures.
5//
6// Copyright (C) 2013-2018 Synopsys, Inc. (www.synopsys.com)
7
8#include <linux/errno.h>
9#include <linux/interrupt.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/perf_event.h>
13#include <linux/platform_device.h>
14#include <asm/arcregs.h>
15#include <asm/stacktrace.h>
16
17/* HW holds 8 symbols + one for null terminator */
18#define ARCPMU_EVENT_NAME_LEN 9
19
20/*
21 * Some ARC pct quirks:
22 *
23 * PERF_COUNT_HW_STALLED_CYCLES_BACKEND
24 * PERF_COUNT_HW_STALLED_CYCLES_FRONTEND
25 * The ARC 700 can either measure stalls per pipeline stage, or all stalls
26 * combined; for now we assign all stalls to STALLED_CYCLES_BACKEND
27 * and all pipeline flushes (e.g. caused by mispredicts, etc.) to
28 * STALLED_CYCLES_FRONTEND.
29 *
30 * We could start multiple performance counters and combine everything
31 * afterwards, but that makes it complicated.
32 *
33 * Note that I$ cache misses aren't counted by either of the two!
34 */
35
36/*
37 * ARC PCT has hardware conditions with fixed "names" but variable "indexes"
38 * (based on a specific RTL build)
39 * Below is the static map between perf generic/arc specific event_id and
40 * h/w condition names.
41 * At the time of probe, we loop thru each index and find its name to
42 * complete the mapping of perf event_id to h/w index as latter is needed
43 * to program the counter really
44 */
45static const char * const arc_pmu_ev_hw_map[] = {
46 /* count cycles */
47 [PERF_COUNT_HW_CPU_CYCLES] = "crun",
48 [PERF_COUNT_HW_REF_CPU_CYCLES] = "crun",
49 [PERF_COUNT_HW_BUS_CYCLES] = "crun",
50
51 [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = "bflush",
52 [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = "bstall",
53
54 /* counts condition */
55 [PERF_COUNT_HW_INSTRUCTIONS] = "iall",
56 /* All jump instructions that are taken */
57 [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = "ijmptak",
58#ifdef CONFIG_ISA_ARCV2
59 [PERF_COUNT_HW_BRANCH_MISSES] = "bpmp",
60#else
61 [PERF_COUNT_ARC_BPOK] = "bpok", /* NP-NT, PT-T, PNT-NT */
62 [PERF_COUNT_HW_BRANCH_MISSES] = "bpfail", /* NP-T, PT-NT, PNT-T */
63#endif
64 [PERF_COUNT_ARC_LDC] = "imemrdc", /* Instr: mem read cached */
65 [PERF_COUNT_ARC_STC] = "imemwrc", /* Instr: mem write cached */
66
67 [PERF_COUNT_ARC_DCLM] = "dclm", /* D-cache Load Miss */
68 [PERF_COUNT_ARC_DCSM] = "dcsm", /* D-cache Store Miss */
69 [PERF_COUNT_ARC_ICM] = "icm", /* I-cache Miss */
70 [PERF_COUNT_ARC_EDTLB] = "edtlb", /* D-TLB Miss */
71 [PERF_COUNT_ARC_EITLB] = "eitlb", /* I-TLB Miss */
72
73 [PERF_COUNT_HW_CACHE_REFERENCES] = "imemrdc", /* Instr: mem read cached */
74 [PERF_COUNT_HW_CACHE_MISSES] = "dclm", /* D-cache Load Miss */
75};
76
77#define C(_x) PERF_COUNT_HW_CACHE_##_x
78#define CACHE_OP_UNSUPPORTED 0xffff
79
80static const unsigned int arc_pmu_cache_map[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
81 [C(L1D)] = {
82 [C(OP_READ)] = {
83 [C(RESULT_ACCESS)] = PERF_COUNT_ARC_LDC,
84 [C(RESULT_MISS)] = PERF_COUNT_ARC_DCLM,
85 },
86 [C(OP_WRITE)] = {
87 [C(RESULT_ACCESS)] = PERF_COUNT_ARC_STC,
88 [C(RESULT_MISS)] = PERF_COUNT_ARC_DCSM,
89 },
90 [C(OP_PREFETCH)] = {
91 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
92 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
93 },
94 },
95 [C(L1I)] = {
96 [C(OP_READ)] = {
97 [C(RESULT_ACCESS)] = PERF_COUNT_HW_INSTRUCTIONS,
98 [C(RESULT_MISS)] = PERF_COUNT_ARC_ICM,
99 },
100 [C(OP_WRITE)] = {
101 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
102 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
103 },
104 [C(OP_PREFETCH)] = {
105 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
106 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
107 },
108 },
109 [C(LL)] = {
110 [C(OP_READ)] = {
111 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
112 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
113 },
114 [C(OP_WRITE)] = {
115 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
116 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
117 },
118 [C(OP_PREFETCH)] = {
119 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
120 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
121 },
122 },
123 [C(DTLB)] = {
124 [C(OP_READ)] = {
125 [C(RESULT_ACCESS)] = PERF_COUNT_ARC_LDC,
126 [C(RESULT_MISS)] = PERF_COUNT_ARC_EDTLB,
127 },
128 /* DTLB LD/ST Miss not segregated by h/w*/
129 [C(OP_WRITE)] = {
130 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
131 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
132 },
133 [C(OP_PREFETCH)] = {
134 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
135 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
136 },
137 },
138 [C(ITLB)] = {
139 [C(OP_READ)] = {
140 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
141 [C(RESULT_MISS)] = PERF_COUNT_ARC_EITLB,
142 },
143 [C(OP_WRITE)] = {
144 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
145 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
146 },
147 [C(OP_PREFETCH)] = {
148 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
149 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
150 },
151 },
152 [C(BPU)] = {
153 [C(OP_READ)] = {
154 [C(RESULT_ACCESS)] = PERF_COUNT_HW_BRANCH_INSTRUCTIONS,
155 [C(RESULT_MISS)] = PERF_COUNT_HW_BRANCH_MISSES,
156 },
157 [C(OP_WRITE)] = {
158 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
159 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
160 },
161 [C(OP_PREFETCH)] = {
162 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
163 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
164 },
165 },
166 [C(NODE)] = {
167 [C(OP_READ)] = {
168 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
169 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
170 },
171 [C(OP_WRITE)] = {
172 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
173 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
174 },
175 [C(OP_PREFETCH)] = {
176 [C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
177 [C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
178 },
179 },
180};
181
182enum arc_pmu_attr_groups {
183 ARCPMU_ATTR_GR_EVENTS,
184 ARCPMU_ATTR_GR_FORMATS,
185 ARCPMU_NR_ATTR_GR
186};
187
188struct arc_pmu_raw_event_entry {
189 char name[ARCPMU_EVENT_NAME_LEN];
190};
191
192struct arc_pmu {
193 struct pmu pmu;
194 unsigned int irq;
195 int n_counters;
196 int n_events;
197 u64 max_period;
198 int ev_hw_idx[PERF_COUNT_ARC_HW_MAX];
199
200 struct arc_pmu_raw_event_entry *raw_entry;
201 struct attribute **attrs;
202 struct perf_pmu_events_attr *attr;
203 const struct attribute_group *attr_groups[ARCPMU_NR_ATTR_GR + 1];
204};
205
206struct arc_pmu_cpu {
207 /*
208 * A 1 bit for an index indicates that the counter is being used for
209 * an event. A 0 means that the counter can be used.
210 */
211 unsigned long used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];
212
213 /*
214 * The events that are active on the PMU for the given index.
215 */
216 struct perf_event *act_counter[ARC_PERF_MAX_COUNTERS];
217};
218
219struct arc_callchain_trace {
220 int depth;
221 void *perf_stuff;
222};
223
224static int callchain_trace(unsigned int addr, void *data)
225{
226 struct arc_callchain_trace *ctrl = data;
227 struct perf_callchain_entry_ctx *entry = ctrl->perf_stuff;
228
229 perf_callchain_store(ctx: entry, ip: addr);
230
231 if (ctrl->depth++ < 3)
232 return 0;
233
234 return -1;
235}
236
237void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
238 struct pt_regs *regs)
239{
240 struct arc_callchain_trace ctrl = {
241 .depth = 0,
242 .perf_stuff = entry,
243 };
244
245 arc_unwind_core(NULL, regs, callchain_trace, &ctrl);
246}
247
248void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
249 struct pt_regs *regs)
250{
251 /*
252 * User stack can't be unwound trivially with kernel dwarf unwinder
253 * So for now just record the user PC
254 */
255 perf_callchain_store(ctx: entry, ip: instruction_pointer(regs));
256}
257
258static struct arc_pmu *arc_pmu;
259static DEFINE_PER_CPU(struct arc_pmu_cpu, arc_pmu_cpu);
260
261/* read counter #idx; note that counter# != event# on ARC! */
262static u64 arc_pmu_read_counter(int idx)
263{
264 u32 tmp;
265 u64 result;
266
267 /*
268 * ARC supports making 'snapshots' of the counters, so we don't
269 * need to care about counters wrapping to 0 underneath our feet
270 */
271 write_aux_reg(ARC_REG_PCT_INDEX, idx);
272 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
273 write_aux_reg(ARC_REG_PCT_CONTROL, tmp | ARC_REG_PCT_CONTROL_SN);
274 result = (u64) (read_aux_reg(ARC_REG_PCT_SNAPH)) << 32;
275 result |= read_aux_reg(ARC_REG_PCT_SNAPL);
276
277 return result;
278}
279
280static void arc_perf_event_update(struct perf_event *event,
281 struct hw_perf_event *hwc, int idx)
282{
283 u64 prev_raw_count = local64_read(&hwc->prev_count);
284 u64 new_raw_count = arc_pmu_read_counter(idx);
285 s64 delta = new_raw_count - prev_raw_count;
286
287 /*
288 * We aren't afraid of hwc->prev_count changing beneath our feet
289 * because there's no way for us to re-enter this function anytime.
290 */
291 local64_set(&hwc->prev_count, new_raw_count);
292 local64_add(delta, &event->count);
293 local64_sub(delta, &hwc->period_left);
294}
295
296static void arc_pmu_read(struct perf_event *event)
297{
298 arc_perf_event_update(event, hwc: &event->hw, idx: event->hw.idx);
299}
300
301static int arc_pmu_cache_event(u64 config)
302{
303 unsigned int cache_type, cache_op, cache_result;
304 int ret;
305
306 cache_type = (config >> 0) & 0xff;
307 cache_op = (config >> 8) & 0xff;
308 cache_result = (config >> 16) & 0xff;
309 if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
310 return -EINVAL;
311 if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
312 return -EINVAL;
313 if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
314 return -EINVAL;
315
316 ret = arc_pmu_cache_map[cache_type][cache_op][cache_result];
317
318 if (ret == CACHE_OP_UNSUPPORTED)
319 return -ENOENT;
320
321 pr_debug("init cache event: type/op/result %d/%d/%d with h/w %d \'%s\'\n",
322 cache_type, cache_op, cache_result, ret,
323 arc_pmu_ev_hw_map[ret]);
324
325 return ret;
326}
327
328/* initializes hw_perf_event structure if event is supported */
329static int arc_pmu_event_init(struct perf_event *event)
330{
331 struct hw_perf_event *hwc = &event->hw;
332 int ret;
333
334 if (!is_sampling_event(event)) {
335 hwc->sample_period = arc_pmu->max_period;
336 hwc->last_period = hwc->sample_period;
337 local64_set(&hwc->period_left, hwc->sample_period);
338 }
339
340 hwc->config = 0;
341
342 if (is_isa_arcv2()) {
343 /* "exclude user" means "count only kernel" */
344 if (event->attr.exclude_user)
345 hwc->config |= ARC_REG_PCT_CONFIG_KERN;
346
347 /* "exclude kernel" means "count only user" */
348 if (event->attr.exclude_kernel)
349 hwc->config |= ARC_REG_PCT_CONFIG_USER;
350 }
351
352 switch (event->attr.type) {
353 case PERF_TYPE_HARDWARE:
354 if (event->attr.config >= PERF_COUNT_HW_MAX)
355 return -ENOENT;
356 if (arc_pmu->ev_hw_idx[event->attr.config] < 0)
357 return -ENOENT;
358 hwc->config |= arc_pmu->ev_hw_idx[event->attr.config];
359 pr_debug("init event %d with h/w %08x \'%s\'\n",
360 (int)event->attr.config, (int)hwc->config,
361 arc_pmu_ev_hw_map[event->attr.config]);
362 return 0;
363
364 case PERF_TYPE_HW_CACHE:
365 ret = arc_pmu_cache_event(config: event->attr.config);
366 if (ret < 0)
367 return ret;
368 hwc->config |= arc_pmu->ev_hw_idx[ret];
369 pr_debug("init cache event with h/w %08x \'%s\'\n",
370 (int)hwc->config, arc_pmu_ev_hw_map[ret]);
371 return 0;
372
373 case PERF_TYPE_RAW:
374 if (event->attr.config >= arc_pmu->n_events)
375 return -ENOENT;
376
377 hwc->config |= event->attr.config;
378 pr_debug("init raw event with idx %lld \'%s\'\n",
379 event->attr.config,
380 arc_pmu->raw_entry[event->attr.config].name);
381
382 return 0;
383
384 default:
385 return -ENOENT;
386 }
387}
388
389/* starts all counters */
390static void arc_pmu_enable(struct pmu *pmu)
391{
392 u32 tmp;
393 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
394 write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x1);
395}
396
397/* stops all counters */
398static void arc_pmu_disable(struct pmu *pmu)
399{
400 u32 tmp;
401 tmp = read_aux_reg(ARC_REG_PCT_CONTROL);
402 write_aux_reg(ARC_REG_PCT_CONTROL, (tmp & 0xffff0000) | 0x0);
403}
404
405static int arc_pmu_event_set_period(struct perf_event *event)
406{
407 struct hw_perf_event *hwc = &event->hw;
408 s64 left = local64_read(&hwc->period_left);
409 s64 period = hwc->sample_period;
410 int idx = hwc->idx;
411 int overflow = 0;
412 u64 value;
413
414 if (unlikely(left <= -period)) {
415 /* left underflowed by more than period. */
416 left = period;
417 local64_set(&hwc->period_left, left);
418 hwc->last_period = period;
419 overflow = 1;
420 } else if (unlikely(left <= 0)) {
421 /* left underflowed by less than period. */
422 left += period;
423 local64_set(&hwc->period_left, left);
424 hwc->last_period = period;
425 overflow = 1;
426 }
427
428 if (left > arc_pmu->max_period)
429 left = arc_pmu->max_period;
430
431 value = arc_pmu->max_period - left;
432 local64_set(&hwc->prev_count, value);
433
434 /* Select counter */
435 write_aux_reg(ARC_REG_PCT_INDEX, idx);
436
437 /* Write value */
438 write_aux_reg(ARC_REG_PCT_COUNTL, lower_32_bits(value));
439 write_aux_reg(ARC_REG_PCT_COUNTH, upper_32_bits(value));
440
441 perf_event_update_userpage(event);
442
443 return overflow;
444}
445
446/*
447 * Assigns hardware counter to hardware condition.
448 * Note that there is no separate start/stop mechanism;
449 * stopping is achieved by assigning the 'never' condition
450 */
451static void arc_pmu_start(struct perf_event *event, int flags)
452{
453 struct hw_perf_event *hwc = &event->hw;
454 int idx = hwc->idx;
455
456 if (WARN_ON_ONCE(idx == -1))
457 return;
458
459 if (flags & PERF_EF_RELOAD)
460 WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
461
462 hwc->state = 0;
463
464 arc_pmu_event_set_period(event);
465
466 /* Enable interrupt for this counter */
467 if (is_sampling_event(event))
468 write_aux_reg(ARC_REG_PCT_INT_CTRL,
469 read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));
470
471 /* enable ARC pmu here */
472 write_aux_reg(ARC_REG_PCT_INDEX, idx); /* counter # */
473 write_aux_reg(ARC_REG_PCT_CONFIG, hwc->config); /* condition */
474}
475
476static void arc_pmu_stop(struct perf_event *event, int flags)
477{
478 struct hw_perf_event *hwc = &event->hw;
479 int idx = hwc->idx;
480
481 /* Disable interrupt for this counter */
482 if (is_sampling_event(event)) {
483 /*
484 * Reset interrupt flag by writing of 1. This is required
485 * to make sure pending interrupt was not left.
486 */
487 write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));
488 write_aux_reg(ARC_REG_PCT_INT_CTRL,
489 read_aux_reg(ARC_REG_PCT_INT_CTRL) & ~BIT(idx));
490 }
491
492 if (!(event->hw.state & PERF_HES_STOPPED)) {
493 /* stop hw counter here */
494 write_aux_reg(ARC_REG_PCT_INDEX, idx);
495
496 /* condition code #0 is always "never" */
497 write_aux_reg(ARC_REG_PCT_CONFIG, 0);
498
499 event->hw.state |= PERF_HES_STOPPED;
500 }
501
502 if ((flags & PERF_EF_UPDATE) &&
503 !(event->hw.state & PERF_HES_UPTODATE)) {
504 arc_perf_event_update(event, hwc: &event->hw, idx);
505 event->hw.state |= PERF_HES_UPTODATE;
506 }
507}
508
509static void arc_pmu_del(struct perf_event *event, int flags)
510{
511 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
512
513 arc_pmu_stop(event, PERF_EF_UPDATE);
514 __clear_bit(event->hw.idx, pmu_cpu->used_mask);
515
516 pmu_cpu->act_counter[event->hw.idx] = 0;
517
518 perf_event_update_userpage(event);
519}
520
521/* allocate hardware counter and optionally start counting */
522static int arc_pmu_add(struct perf_event *event, int flags)
523{
524 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
525 struct hw_perf_event *hwc = &event->hw;
526 int idx;
527
528 idx = ffz(pmu_cpu->used_mask[0]);
529 if (idx == arc_pmu->n_counters)
530 return -EAGAIN;
531
532 __set_bit(idx, pmu_cpu->used_mask);
533 hwc->idx = idx;
534
535 write_aux_reg(ARC_REG_PCT_INDEX, idx);
536
537 pmu_cpu->act_counter[idx] = event;
538
539 if (is_sampling_event(event)) {
540 /* Mimic full counter overflow as other arches do */
541 write_aux_reg(ARC_REG_PCT_INT_CNTL,
542 lower_32_bits(arc_pmu->max_period));
543 write_aux_reg(ARC_REG_PCT_INT_CNTH,
544 upper_32_bits(arc_pmu->max_period));
545 }
546
547 write_aux_reg(ARC_REG_PCT_CONFIG, 0);
548 write_aux_reg(ARC_REG_PCT_COUNTL, 0);
549 write_aux_reg(ARC_REG_PCT_COUNTH, 0);
550 local64_set(&hwc->prev_count, 0);
551
552 hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
553 if (flags & PERF_EF_START)
554 arc_pmu_start(event, PERF_EF_RELOAD);
555
556 perf_event_update_userpage(event);
557
558 return 0;
559}
560
561#ifdef CONFIG_ISA_ARCV2
562static irqreturn_t arc_pmu_intr(int irq, void *dev)
563{
564 struct perf_sample_data data;
565 struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
566 struct pt_regs *regs;
567 unsigned int active_ints;
568 int idx;
569
570 arc_pmu_disable(&arc_pmu->pmu);
571
572 active_ints = read_aux_reg(ARC_REG_PCT_INT_ACT);
573 if (!active_ints)
574 goto done;
575
576 regs = get_irq_regs();
577
578 do {
579 struct perf_event *event;
580 struct hw_perf_event *hwc;
581
582 idx = __ffs(active_ints);
583
584 /* Reset interrupt flag by writing of 1 */
585 write_aux_reg(ARC_REG_PCT_INT_ACT, BIT(idx));
586
587 /*
588 * On reset of "interrupt active" bit corresponding
589 * "interrupt enable" bit gets automatically reset as well.
590 * Now we need to re-enable interrupt for the counter.
591 */
592 write_aux_reg(ARC_REG_PCT_INT_CTRL,
593 read_aux_reg(ARC_REG_PCT_INT_CTRL) | BIT(idx));
594
595 event = pmu_cpu->act_counter[idx];
596 hwc = &event->hw;
597
598 WARN_ON_ONCE(hwc->idx != idx);
599
600 arc_perf_event_update(event, &event->hw, event->hw.idx);
601 perf_sample_data_init(&data, 0, hwc->last_period);
602 if (arc_pmu_event_set_period(event))
603 perf_event_overflow(event, &data, regs);
604
605 active_ints &= ~BIT(idx);
606 } while (active_ints);
607
608done:
609 arc_pmu_enable(&arc_pmu->pmu);
610
611 return IRQ_HANDLED;
612}
613#else
614
615static irqreturn_t arc_pmu_intr(int irq, void *dev)
616{
617 return IRQ_NONE;
618}
619
620#endif /* CONFIG_ISA_ARCV2 */
621
622static void arc_cpu_pmu_irq_init(void *data)
623{
624 int irq = *(int *)data;
625
626 enable_percpu_irq(irq, IRQ_TYPE_NONE);
627
628 /* Clear all pending interrupt flags */
629 write_aux_reg(ARC_REG_PCT_INT_ACT, 0xffffffff);
630}
631
632/* Event field occupies the bottom 15 bits of our config field */
633PMU_FORMAT_ATTR(event, "config:0-14");
634static struct attribute *arc_pmu_format_attrs[] = {
635 &format_attr_event.attr,
636 NULL,
637};
638
639static struct attribute_group arc_pmu_format_attr_gr = {
640 .name = "format",
641 .attrs = arc_pmu_format_attrs,
642};
643
644static ssize_t arc_pmu_events_sysfs_show(struct device *dev,
645 struct device_attribute *attr,
646 char *page)
647{
648 struct perf_pmu_events_attr *pmu_attr;
649
650 pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
651 return sprintf(buf: page, fmt: "event=0x%04llx\n", pmu_attr->id);
652}
653
654/*
655 * We don't add attrs here as we don't have pre-defined list of perf events.
656 * We will generate and add attrs dynamically in probe() after we read HW
657 * configuration.
658 */
659static struct attribute_group arc_pmu_events_attr_gr = {
660 .name = "events",
661};
662
663static void arc_pmu_add_raw_event_attr(int j, char *str)
664{
665 memmove(arc_pmu->raw_entry[j].name, str, ARCPMU_EVENT_NAME_LEN - 1);
666 arc_pmu->attr[j].attr.attr.name = arc_pmu->raw_entry[j].name;
667 arc_pmu->attr[j].attr.attr.mode = VERIFY_OCTAL_PERMISSIONS(0444);
668 arc_pmu->attr[j].attr.show = arc_pmu_events_sysfs_show;
669 arc_pmu->attr[j].id = j;
670 arc_pmu->attrs[j] = &(arc_pmu->attr[j].attr.attr);
671}
672
673static int arc_pmu_raw_alloc(struct device *dev)
674{
675 arc_pmu->attr = devm_kmalloc_array(dev, n: arc_pmu->n_events + 1,
676 size: sizeof(*arc_pmu->attr), GFP_KERNEL | __GFP_ZERO);
677 if (!arc_pmu->attr)
678 return -ENOMEM;
679
680 arc_pmu->attrs = devm_kmalloc_array(dev, n: arc_pmu->n_events + 1,
681 size: sizeof(*arc_pmu->attrs), GFP_KERNEL | __GFP_ZERO);
682 if (!arc_pmu->attrs)
683 return -ENOMEM;
684
685 arc_pmu->raw_entry = devm_kmalloc_array(dev, n: arc_pmu->n_events,
686 size: sizeof(*arc_pmu->raw_entry), GFP_KERNEL | __GFP_ZERO);
687 if (!arc_pmu->raw_entry)
688 return -ENOMEM;
689
690 return 0;
691}
692
693static inline bool event_in_hw_event_map(int i, char *name)
694{
695 if (!arc_pmu_ev_hw_map[i])
696 return false;
697
698 if (!strlen(arc_pmu_ev_hw_map[i]))
699 return false;
700
701 if (strcmp(arc_pmu_ev_hw_map[i], name))
702 return false;
703
704 return true;
705}
706
707static void arc_pmu_map_hw_event(int j, char *str)
708{
709 int i;
710
711 /* See if HW condition has been mapped to a perf event_id */
712 for (i = 0; i < ARRAY_SIZE(arc_pmu_ev_hw_map); i++) {
713 if (event_in_hw_event_map(i, str)) {
714 pr_debug("mapping perf event %2d to h/w event \'%8s\' (idx %d)\n",
715 i, str, j);
716 arc_pmu->ev_hw_idx[i] = j;
717 }
718 }
719}
720
721static int arc_pmu_device_probe(struct platform_device *pdev)
722{
723 struct arc_reg_pct_build pct_bcr;
724 struct arc_reg_cc_build cc_bcr;
725 int i, has_interrupts, irq = -1;
726 int counter_size; /* in bits */
727
728 union cc_name {
729 struct {
730 u32 word0, word1;
731 char sentinel;
732 } indiv;
733 char str[ARCPMU_EVENT_NAME_LEN];
734 } cc_name;
735
736
737 READ_BCR(ARC_REG_PCT_BUILD, pct_bcr);
738 if (!pct_bcr.v) {
739 pr_err("This core does not have performance counters!\n");
740 return -ENODEV;
741 }
742 BUILD_BUG_ON(ARC_PERF_MAX_COUNTERS > 32);
743 if (WARN_ON(pct_bcr.c > ARC_PERF_MAX_COUNTERS))
744 return -EINVAL;
745
746 READ_BCR(ARC_REG_CC_BUILD, cc_bcr);
747 if (WARN(!cc_bcr.v, "Counters exist but No countable conditions?"))
748 return -EINVAL;
749
750 arc_pmu = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct arc_pmu), GFP_KERNEL);
751 if (!arc_pmu)
752 return -ENOMEM;
753
754 arc_pmu->n_events = cc_bcr.c;
755
756 if (arc_pmu_raw_alloc(dev: &pdev->dev))
757 return -ENOMEM;
758
759 has_interrupts = is_isa_arcv2() ? pct_bcr.i : 0;
760
761 arc_pmu->n_counters = pct_bcr.c;
762 counter_size = 32 + (pct_bcr.s << 4);
763
764 arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL;
765
766 pr_info("ARC perf\t: %d counters (%d bits), %d conditions%s\n",
767 arc_pmu->n_counters, counter_size, cc_bcr.c,
768 has_interrupts ? ", [overflow IRQ support]" : "");
769
770 cc_name.str[ARCPMU_EVENT_NAME_LEN - 1] = 0;
771 for (i = 0; i < PERF_COUNT_ARC_HW_MAX; i++)
772 arc_pmu->ev_hw_idx[i] = -1;
773
774 /* loop thru all available h/w condition indexes */
775 for (i = 0; i < cc_bcr.c; i++) {
776 write_aux_reg(ARC_REG_CC_INDEX, i);
777 cc_name.indiv.word0 = le32_to_cpu(read_aux_reg(ARC_REG_CC_NAME0));
778 cc_name.indiv.word1 = le32_to_cpu(read_aux_reg(ARC_REG_CC_NAME1));
779
780 arc_pmu_map_hw_event(j: i, str: cc_name.str);
781 arc_pmu_add_raw_event_attr(j: i, str: cc_name.str);
782 }
783
784 arc_pmu_events_attr_gr.attrs = arc_pmu->attrs;
785 arc_pmu->attr_groups[ARCPMU_ATTR_GR_EVENTS] = &arc_pmu_events_attr_gr;
786 arc_pmu->attr_groups[ARCPMU_ATTR_GR_FORMATS] = &arc_pmu_format_attr_gr;
787
788 arc_pmu->pmu = (struct pmu) {
789 .pmu_enable = arc_pmu_enable,
790 .pmu_disable = arc_pmu_disable,
791 .event_init = arc_pmu_event_init,
792 .add = arc_pmu_add,
793 .del = arc_pmu_del,
794 .start = arc_pmu_start,
795 .stop = arc_pmu_stop,
796 .read = arc_pmu_read,
797 .attr_groups = arc_pmu->attr_groups,
798 };
799
800 if (has_interrupts) {
801 irq = platform_get_irq(pdev, 0);
802 if (irq >= 0) {
803 int ret;
804
805 arc_pmu->irq = irq;
806
807 /* intc map function ensures irq_set_percpu_devid() called */
808 ret = request_percpu_irq(irq, handler: arc_pmu_intr, devname: "ARC perf counters",
809 this_cpu_ptr(&arc_pmu_cpu));
810
811 if (!ret)
812 on_each_cpu(func: arc_cpu_pmu_irq_init, info: &irq, wait: 1);
813 else
814 irq = -1;
815 }
816
817 }
818
819 if (irq == -1)
820 arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
821
822 /*
823 * perf parser doesn't really like '-' symbol in events name, so let's
824 * use '_' in arc pct name as it goes to kernel PMU event prefix.
825 */
826 return perf_pmu_register(pmu: &arc_pmu->pmu, name: "arc_pct", type: PERF_TYPE_RAW);
827}
828
829static const struct of_device_id arc_pmu_match[] = {
830 { .compatible = "snps,arc700-pct" },
831 { .compatible = "snps,archs-pct" },
832 {},
833};
834MODULE_DEVICE_TABLE(of, arc_pmu_match);
835
836static struct platform_driver arc_pmu_driver = {
837 .driver = {
838 .name = "arc-pct",
839 .of_match_table = of_match_ptr(arc_pmu_match),
840 },
841 .probe = arc_pmu_device_probe,
842};
843
844module_platform_driver(arc_pmu_driver);
845
846MODULE_LICENSE("GPL");
847MODULE_AUTHOR("Mischa Jonker <mjonker@synopsys.com>");
848MODULE_DESCRIPTION("ARC PMU driver");
849

source code of linux/arch/arc/kernel/perf_event.c