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1/*
2 * SPDX-License-Identifier: MIT
3 *
4 * Copyright © 2017-2018 Intel Corporation
5 */
6
7#include <linux/pm_runtime.h>
8
9#include "gt/intel_engine.h"
10#include "gt/intel_engine_pm.h"
11#include "gt/intel_engine_regs.h"
12#include "gt/intel_engine_user.h"
13#include "gt/intel_gt.h"
14#include "gt/intel_gt_pm.h"
15#include "gt/intel_gt_regs.h"
16#include "gt/intel_rc6.h"
17#include "gt/intel_rps.h"
18
19#include "i915_drv.h"
20#include "i915_pmu.h"
21
22/* Frequency for the sampling timer for events which need it. */
23#define FREQUENCY 200
24#define PERIOD max_t(u64, 10000, NSEC_PER_SEC / FREQUENCY)
25
26#define ENGINE_SAMPLE_MASK \
27 (BIT(I915_SAMPLE_BUSY) | \
28 BIT(I915_SAMPLE_WAIT) | \
29 BIT(I915_SAMPLE_SEMA))
30
31static cpumask_t i915_pmu_cpumask;
32static unsigned int i915_pmu_target_cpu = -1;
33
34static struct i915_pmu *event_to_pmu(struct perf_event *event)
35{
36 return container_of(event->pmu, struct i915_pmu, base);
37}
38
39static struct drm_i915_private *pmu_to_i915(struct i915_pmu *pmu)
40{
41 return container_of(pmu, struct drm_i915_private, pmu);
42}
43
44static u8 engine_config_sample(u64 config)
45{
46 return config & I915_PMU_SAMPLE_MASK;
47}
48
49static u8 engine_event_sample(struct perf_event *event)
50{
51 return engine_config_sample(event->attr.config);
52}
53
54static u8 engine_event_class(struct perf_event *event)
55{
56 return (event->attr.config >> I915_PMU_CLASS_SHIFT) & 0xff;
57}
58
59static u8 engine_event_instance(struct perf_event *event)
60{
61 return (event->attr.config >> I915_PMU_SAMPLE_BITS) & 0xff;
62}
63
64static bool is_engine_config(const u64 config)
65{
66 return config < __I915_PMU_OTHER(0);
67}
68
69static unsigned int config_gt_id(const u64 config)
70{
71 return config >> __I915_PMU_GT_SHIFT;
72}
73
74static u64 config_counter(const u64 config)
75{
76 return config & ~(~0ULL << __I915_PMU_GT_SHIFT);
77}
78
79static unsigned int other_bit(const u64 config)
80{
81 unsigned int val;
82
83 switch (config_counter(config)) {
84 case I915_PMU_ACTUAL_FREQUENCY:
85 val = __I915_PMU_ACTUAL_FREQUENCY_ENABLED;
86 break;
87 case I915_PMU_REQUESTED_FREQUENCY:
88 val = __I915_PMU_REQUESTED_FREQUENCY_ENABLED;
89 break;
90 case I915_PMU_RC6_RESIDENCY:
91 val = __I915_PMU_RC6_RESIDENCY_ENABLED;
92 break;
93 default:
94 /*
95 * Events that do not require sampling, or tracking state
96 * transitions between enabled and disabled can be ignored.
97 */
98 return -1;
99 }
100
101 return I915_ENGINE_SAMPLE_COUNT +
102 config_gt_id(config) * __I915_PMU_TRACKED_EVENT_COUNT +
103 val;
104}
105
106static unsigned int config_bit(const u64 config)
107{
108 if (is_engine_config(config))
109 return engine_config_sample(config);
110 else
111 return other_bit(config);
112}
113
114static u32 config_mask(const u64 config)
115{
116 unsigned int bit = config_bit(config);
117
118 if (__builtin_constant_p(config))
119 BUILD_BUG_ON(bit >
120 BITS_PER_TYPE(typeof_member(struct i915_pmu,
121 enable)) - 1);
122 else
123 WARN_ON_ONCE(bit >
124 BITS_PER_TYPE(typeof_member(struct i915_pmu,
125 enable)) - 1);
126
127 return BIT(config_bit(config));
128}
129
130static bool is_engine_event(struct perf_event *event)
131{
132 return is_engine_config(event->attr.config);
133}
134
135static unsigned int event_bit(struct perf_event *event)
136{
137 return config_bit(event->attr.config);
138}
139
140static u32 frequency_enabled_mask(void)
141{
142 unsigned int i;
143 u32 mask = 0;
144
145 for (i = 0; i < I915_PMU_MAX_GT; i++)
146 mask |= config_mask(__I915_PMU_ACTUAL_FREQUENCY(i)) |
147 config_mask(__I915_PMU_REQUESTED_FREQUENCY(i));
148
149 return mask;
150}
151
152static bool pmu_needs_timer(struct i915_pmu *pmu)
153{
154 struct drm_i915_private *i915 = pmu_to_i915(pmu);
155 u32 enable;
156
157 /*
158 * Only some counters need the sampling timer.
159 *
160 * We start with a bitmask of all currently enabled events.
161 */
162 enable = pmu->enable;
163
164 /*
165 * Mask out all the ones which do not need the timer, or in
166 * other words keep all the ones that could need the timer.
167 */
168 enable &= frequency_enabled_mask() | ENGINE_SAMPLE_MASK;
169
170 /*
171 * Also there is software busyness tracking available we do not
172 * need the timer for I915_SAMPLE_BUSY counter.
173 */
174 if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
175 enable &= ~BIT(I915_SAMPLE_BUSY);
176
177 /*
178 * If some bits remain it means we need the sampling timer running.
179 */
180 return enable;
181}
182
183static u64 __get_rc6(struct intel_gt *gt)
184{
185 struct drm_i915_private *i915 = gt->i915;
186 u64 val;
187
188 val = intel_rc6_residency_ns(>->rc6, INTEL_RC6_RES_RC6);
189
190 if (HAS_RC6p(i915))
191 val += intel_rc6_residency_ns(>->rc6, INTEL_RC6_RES_RC6p);
192
193 if (HAS_RC6pp(i915))
194 val += intel_rc6_residency_ns(>->rc6, INTEL_RC6_RES_RC6pp);
195
196 return val;
197}
198
199static inline s64 ktime_since_raw(const ktime_t kt)
200{
201 return ktime_to_ns(ktime_sub(ktime_get_raw(), kt));
202}
203
204static u64 read_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample)
205{
206 return pmu->sample[gt_id][sample].cur;
207}
208
209static void
210store_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample, u64 val)
211{
212 pmu->sample[gt_id][sample].cur = val;
213}
214
215static void
216add_sample_mult(struct i915_pmu *pmu, unsigned int gt_id, int sample, u32 val, u32 mul)
217{
218 pmu->sample[gt_id][sample].cur += mul_u32_u32(val, mul);
219}
220
221static u64 get_rc6(struct intel_gt *gt)
222{
223 struct drm_i915_private *i915 = gt->i915;
224 const unsigned int gt_id = gt->info.id;
225 struct i915_pmu *pmu = &i915->pmu;
226 intel_wakeref_t wakeref;
227 unsigned long flags;
228 u64 val;
229
230 wakeref = intel_gt_pm_get_if_awake(gt);
231 if (wakeref) {
232 val = __get_rc6(gt);
233 intel_gt_pm_put_async(gt, wakeref);
234 }
235
236 spin_lock_irqsave(&pmu->lock, flags);
237
238 if (wakeref) {
239 store_sample(pmu, gt_id, __I915_SAMPLE_RC6, val);
240 } else {
241 /*
242 * We think we are runtime suspended.
243 *
244 * Report the delta from when the device was suspended to now,
245 * on top of the last known real value, as the approximated RC6
246 * counter value.
247 */
248 val = ktime_since_raw(pmu->sleep_last[gt_id]);
249 val += read_sample(pmu, gt_id, __I915_SAMPLE_RC6);
250 }
251
252 if (val < read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED))
253 val = read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED);
254 else
255 store_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED, val);
256
257 spin_unlock_irqrestore(&pmu->lock, flags);
258
259 return val;
260}
261
262static void init_rc6(struct i915_pmu *pmu)
263{
264 struct drm_i915_private *i915 = pmu_to_i915(pmu);
265 struct intel_gt *gt;
266 unsigned int i;
267
268 for_each_gt(gt, i915, i) {
269 intel_wakeref_t wakeref;
270
271 with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
272 u64 val = __get_rc6(gt);
273
274 store_sample(pmu, i, __I915_SAMPLE_RC6, val);
275 store_sample(pmu, i, __I915_SAMPLE_RC6_LAST_REPORTED,
276 val);
277 pmu->sleep_last[i] = ktime_get_raw();
278 }
279 }
280}
281
282static void park_rc6(struct intel_gt *gt)
283{
284 struct i915_pmu *pmu = >->i915->pmu;
285
286 store_sample(pmu, gt->info.id, __I915_SAMPLE_RC6, __get_rc6(gt));
287 pmu->sleep_last[gt->info.id] = ktime_get_raw();
288}
289
290static void __i915_pmu_maybe_start_timer(struct i915_pmu *pmu)
291{
292 if (!pmu->timer_enabled && pmu_needs_timer(pmu)) {
293 pmu->timer_enabled = true;
294 pmu->timer_last = ktime_get();
295 hrtimer_start_range_ns(&pmu->timer,
296 ns_to_ktime(PERIOD), 0,
297 HRTIMER_MODE_REL_PINNED);
298 }
299}
300
301void i915_pmu_gt_parked(struct intel_gt *gt)
302{
303 struct i915_pmu *pmu = >->i915->pmu;
304
305 if (!pmu->base.event_init)
306 return;
307
308 spin_lock_irq(&pmu->lock);
309
310 park_rc6(gt);
311
312 /*
313 * Signal sampling timer to stop if only engine events are enabled and
314 * GPU went idle.
315 */
316 pmu->unparked &= ~BIT(gt->info.id);
317 if (pmu->unparked == 0)
318 pmu->timer_enabled = false;
319
320 spin_unlock_irq(&pmu->lock);
321}
322
323void i915_pmu_gt_unparked(struct intel_gt *gt)
324{
325 struct i915_pmu *pmu = >->i915->pmu;
326
327 if (!pmu->base.event_init)
328 return;
329
330 spin_lock_irq(&pmu->lock);
331
332 /*
333 * Re-enable sampling timer when GPU goes active.
334 */
335 if (pmu->unparked == 0)
336 __i915_pmu_maybe_start_timer(pmu);
337
338 pmu->unparked |= BIT(gt->info.id);
339
340 spin_unlock_irq(&pmu->lock);
341}
342
343static void
344add_sample(struct i915_pmu_sample *sample, u32 val)
345{
346 sample->cur += val;
347}
348
349static bool exclusive_mmio_access(const struct drm_i915_private *i915)
350{
351 /*
352 * We have to avoid concurrent mmio cache line access on gen7 or
353 * risk a machine hang. For a fun history lesson dig out the old
354 * userspace intel_gpu_top and run it on Ivybridge or Haswell!
355 */
356 return GRAPHICS_VER(i915) == 7;
357}
358
359static void gen3_engine_sample(struct intel_engine_cs *engine, unsigned int period_ns)
360{
361 struct intel_engine_pmu *pmu = &engine->pmu;
362 bool busy;
363 u32 val;
364
365 val = ENGINE_READ_FW(engine, RING_CTL);
366 if (val == 0) /* powerwell off => engine idle */
367 return;
368
369 if (val & RING_WAIT)
370 add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
371 if (val & RING_WAIT_SEMAPHORE)
372 add_sample(&pmu->sample[I915_SAMPLE_SEMA], period_ns);
373
374 /* No need to sample when busy stats are supported. */
375 if (intel_engine_supports_stats(engine))
376 return;
377
378 /*
379 * While waiting on a semaphore or event, MI_MODE reports the
380 * ring as idle. However, previously using the seqno, and with
381 * execlists sampling, we account for the ring waiting as the
382 * engine being busy. Therefore, we record the sample as being
383 * busy if either waiting or !idle.
384 */
385 busy = val & (RING_WAIT_SEMAPHORE | RING_WAIT);
386 if (!busy) {
387 val = ENGINE_READ_FW(engine, RING_MI_MODE);
388 busy = !(val & MODE_IDLE);
389 }
390 if (busy)
391 add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
392}
393
394static void gen2_engine_sample(struct intel_engine_cs *engine, unsigned int period_ns)
395{
396 struct intel_engine_pmu *pmu = &engine->pmu;
397 u32 tail, head, acthd;
398
399 tail = ENGINE_READ_FW(engine, RING_TAIL);
400 head = ENGINE_READ_FW(engine, RING_HEAD);
401 acthd = ENGINE_READ_FW(engine, ACTHD);
402
403 if (head & HEAD_WAIT_I8XX)
404 add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
405
406 if (head & HEAD_WAIT_I8XX || head != acthd ||
407 (head & HEAD_ADDR) != (tail & TAIL_ADDR))
408 add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
409}
410
411static void engine_sample(struct intel_engine_cs *engine, unsigned int period_ns)
412{
413 if (GRAPHICS_VER(engine->i915) >= 3)
414 gen3_engine_sample(engine, period_ns);
415 else
416 gen2_engine_sample(engine, period_ns);
417}
418
419static void
420engines_sample(struct intel_gt *gt, unsigned int period_ns)
421{
422 struct drm_i915_private *i915 = gt->i915;
423 struct intel_engine_cs *engine;
424 enum intel_engine_id id;
425 unsigned long flags;
426
427 if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
428 return;
429
430 if (!intel_gt_pm_is_awake(gt))
431 return;
432
433 for_each_engine(engine, gt, id) {
434 if (!engine->pmu.enable)
435 continue;
436
437 if (!intel_engine_pm_get_if_awake(engine))
438 continue;
439
440 if (exclusive_mmio_access(i915)) {
441 spin_lock_irqsave(&engine->uncore->lock, flags);
442 engine_sample(engine, period_ns);
443 spin_unlock_irqrestore(&engine->uncore->lock, flags);
444 } else {
445 engine_sample(engine, period_ns);
446 }
447
448 intel_engine_pm_put_async(engine);
449 }
450}
451
452static bool
453frequency_sampling_enabled(struct i915_pmu *pmu, unsigned int gt)
454{
455 return pmu->enable &
456 (config_mask(__I915_PMU_ACTUAL_FREQUENCY(gt)) |
457 config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt)));
458}
459
460static void
461frequency_sample(struct intel_gt *gt, unsigned int period_ns)
462{
463 struct drm_i915_private *i915 = gt->i915;
464 const unsigned int gt_id = gt->info.id;
465 struct i915_pmu *pmu = &i915->pmu;
466 struct intel_rps *rps = >->rps;
467 intel_wakeref_t wakeref;
468
469 if (!frequency_sampling_enabled(pmu, gt_id))
470 return;
471
472 /* Report 0/0 (actual/requested) frequency while parked. */
473 wakeref = intel_gt_pm_get_if_awake(gt);
474 if (!wakeref)
475 return;
476
477 if (pmu->enable & config_mask(__I915_PMU_ACTUAL_FREQUENCY(gt_id))) {
478 u32 val;
479
480 /*
481 * We take a quick peek here without using forcewake
482 * so that we don't perturb the system under observation
483 * (forcewake => !rc6 => increased power use). We expect
484 * that if the read fails because it is outside of the
485 * mmio power well, then it will return 0 -- in which
486 * case we assume the system is running at the intended
487 * frequency. Fortunately, the read should rarely fail!
488 */
489 val = intel_rps_read_actual_frequency_fw(rps);
490 if (!val)
491 val = intel_gpu_freq(rps, rps->cur_freq);
492
493 add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_ACT,
494 val, period_ns / 1000);
495 }
496
497 if (pmu->enable & config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt_id))) {
498 add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_REQ,
499 intel_rps_get_requested_frequency(rps),
500 period_ns / 1000);
501 }
502
503 intel_gt_pm_put_async(gt, wakeref);
504}
505
506static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer)
507{
508 struct i915_pmu *pmu = container_of(hrtimer, struct i915_pmu, timer);
509 struct drm_i915_private *i915 = pmu_to_i915(pmu);
510 unsigned int period_ns;
511 struct intel_gt *gt;
512 unsigned int i;
513 ktime_t now;
514
515 if (!READ_ONCE(pmu->timer_enabled))
516 return HRTIMER_NORESTART;
517
518 now = ktime_get();
519 period_ns = ktime_to_ns(ktime_sub(now, pmu->timer_last));
520 pmu->timer_last = now;
521
522 /*
523 * Strictly speaking the passed in period may not be 100% accurate for
524 * all internal calculation, since some amount of time can be spent on
525 * grabbing the forcewake. However the potential error from timer call-
526 * back delay greatly dominates this so we keep it simple.
527 */
528
529 for_each_gt(gt, i915, i) {
530 if (!(pmu->unparked & BIT(i)))
531 continue;
532
533 engines_sample(gt, period_ns);
534 frequency_sample(gt, period_ns);
535 }
536
537 hrtimer_forward(hrtimer, now, ns_to_ktime(PERIOD));
538
539 return HRTIMER_RESTART;
540}
541
542static void i915_pmu_event_destroy(struct perf_event *event)
543{
544 struct i915_pmu *pmu = event_to_pmu(event);
545 struct drm_i915_private *i915 = pmu_to_i915(pmu);
546
547 drm_WARN_ON(&i915->drm, event->parent);
548
549 drm_dev_put(&i915->drm);
550}
551
552static int
553engine_event_status(struct intel_engine_cs *engine,
554 enum drm_i915_pmu_engine_sample sample)
555{
556 switch (sample) {
557 case I915_SAMPLE_BUSY:
558 case I915_SAMPLE_WAIT:
559 break;
560 case I915_SAMPLE_SEMA:
561 if (GRAPHICS_VER(engine->i915) < 6)
562 return -ENODEV;
563 break;
564 default:
565 return -ENOENT;
566 }
567
568 return 0;
569}
570
571static int
572config_status(struct drm_i915_private *i915, u64 config)
573{
574 struct intel_gt *gt = to_gt(i915);
575
576 unsigned int gt_id = config_gt_id(config);
577 unsigned int max_gt_id = HAS_EXTRA_GT_LIST(i915) ? 1 : 0;
578
579 if (gt_id > max_gt_id)
580 return -ENOENT;
581
582 switch (config_counter(config)) {
583 case I915_PMU_ACTUAL_FREQUENCY:
584 if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
585 /* Requires a mutex for sampling! */
586 return -ENODEV;
587 fallthrough;
588 case I915_PMU_REQUESTED_FREQUENCY:
589 if (GRAPHICS_VER(i915) < 6)
590 return -ENODEV;
591 break;
592 case I915_PMU_INTERRUPTS:
593 if (gt_id)
594 return -ENOENT;
595 break;
596 case I915_PMU_RC6_RESIDENCY:
597 if (!gt->rc6.supported)
598 return -ENODEV;
599 break;
600 case I915_PMU_SOFTWARE_GT_AWAKE_TIME:
601 break;
602 default:
603 return -ENOENT;
604 }
605
606 return 0;
607}
608
609static int engine_event_init(struct perf_event *event)
610{
611 struct i915_pmu *pmu = event_to_pmu(event);
612 struct drm_i915_private *i915 = pmu_to_i915(pmu);
613 struct intel_engine_cs *engine;
614
615 engine = intel_engine_lookup_user(i915, engine_event_class(event),
616 engine_event_instance(event));
617 if (!engine)
618 return -ENODEV;
619
620 return engine_event_status(engine, engine_event_sample(event));
621}
622
623static int i915_pmu_event_init(struct perf_event *event)
624{
625 struct i915_pmu *pmu = event_to_pmu(event);
626 struct drm_i915_private *i915 = pmu_to_i915(pmu);
627 int ret;
628
629 if (pmu->closed)
630 return -ENODEV;
631
632 if (event->attr.type != event->pmu->type)
633 return -ENOENT;
634
635 /* unsupported modes and filters */
636 if (event->attr.sample_period) /* no sampling */
637 return -EINVAL;
638
639 if (has_branch_stack(event))
640 return -EOPNOTSUPP;
641
642 if (event->cpu < 0)
643 return -EINVAL;
644
645 /* only allow running on one cpu at a time */
646 if (!cpumask_test_cpu(event->cpu, &i915_pmu_cpumask))
647 return -EINVAL;
648
649 if (is_engine_event(event))
650 ret = engine_event_init(event);
651 else
652 ret = config_status(i915, event->attr.config);
653 if (ret)
654 return ret;
655
656 if (!event->parent) {
657 drm_dev_get(&i915->drm);
658 event->destroy = i915_pmu_event_destroy;
659 }
660
661 return 0;
662}
663
664static u64 __i915_pmu_event_read(struct perf_event *event)
665{
666 struct i915_pmu *pmu = event_to_pmu(event);
667 struct drm_i915_private *i915 = pmu_to_i915(pmu);
668 u64 val = 0;
669
670 if (is_engine_event(event)) {
671 u8 sample = engine_event_sample(event);
672 struct intel_engine_cs *engine;
673
674 engine = intel_engine_lookup_user(i915,
675 engine_event_class(event),
676 engine_event_instance(event));
677
678 if (drm_WARN_ON_ONCE(&i915->drm, !engine)) {
679 /* Do nothing */
680 } else if (sample == I915_SAMPLE_BUSY &&
681 intel_engine_supports_stats(engine)) {
682 ktime_t unused;
683
684 val = ktime_to_ns(intel_engine_get_busy_time(engine,
685 &unused));
686 } else {
687 val = engine->pmu.sample[sample].cur;
688 }
689 } else {
690 const unsigned int gt_id = config_gt_id(event->attr.config);
691 const u64 config = config_counter(event->attr.config);
692
693 switch (config) {
694 case I915_PMU_ACTUAL_FREQUENCY:
695 val =
696 div_u64(read_sample(pmu, gt_id,
697 __I915_SAMPLE_FREQ_ACT),
698 USEC_PER_SEC /* to MHz */);
699 break;
700 case I915_PMU_REQUESTED_FREQUENCY:
701 val =
702 div_u64(read_sample(pmu, gt_id,
703 __I915_SAMPLE_FREQ_REQ),
704 USEC_PER_SEC /* to MHz */);
705 break;
706 case I915_PMU_INTERRUPTS:
707 val = READ_ONCE(pmu->irq_count);
708 break;
709 case I915_PMU_RC6_RESIDENCY:
710 val = get_rc6(i915->gt[gt_id]);
711 break;
712 case I915_PMU_SOFTWARE_GT_AWAKE_TIME:
713 val = ktime_to_ns(intel_gt_get_awake_time(to_gt(i915)));
714 break;
715 }
716 }
717
718 return val;
719}
720
721static void i915_pmu_event_read(struct perf_event *event)
722{
723 struct i915_pmu *pmu = event_to_pmu(event);
724 struct hw_perf_event *hwc = &event->hw;
725 u64 prev, new;
726
727 if (pmu->closed) {
728 event->hw.state = PERF_HES_STOPPED;
729 return;
730 }
731
732 prev = local64_read(&hwc->prev_count);
733 do {
734 new = __i915_pmu_event_read(event);
735 } while (!local64_try_cmpxchg(&hwc->prev_count, &prev, new));
736
737 local64_add(new - prev, &event->count);
738}
739
740static void i915_pmu_enable(struct perf_event *event)
741{
742 struct i915_pmu *pmu = event_to_pmu(event);
743 struct drm_i915_private *i915 = pmu_to_i915(pmu);
744 const unsigned int bit = event_bit(event);
745 unsigned long flags;
746
747 if (bit == -1)
748 goto update;
749
750 spin_lock_irqsave(&pmu->lock, flags);
751
752 /*
753 * Update the bitmask of enabled events and increment
754 * the event reference counter.
755 */
756 BUILD_BUG_ON(ARRAY_SIZE(pmu->enable_count) != I915_PMU_MASK_BITS);
757 GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
758 GEM_BUG_ON(pmu->enable_count[bit] == ~0);
759
760 pmu->enable |= BIT(bit);
761 pmu->enable_count[bit]++;
762
763 /*
764 * Start the sampling timer if needed and not already enabled.
765 */
766 __i915_pmu_maybe_start_timer(pmu);
767
768 /*
769 * For per-engine events the bitmask and reference counting
770 * is stored per engine.
771 */
772 if (is_engine_event(event)) {
773 u8 sample = engine_event_sample(event);
774 struct intel_engine_cs *engine;
775
776 engine = intel_engine_lookup_user(i915,
777 engine_event_class(event),
778 engine_event_instance(event));
779
780 BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.enable_count) !=
781 I915_ENGINE_SAMPLE_COUNT);
782 BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.sample) !=
783 I915_ENGINE_SAMPLE_COUNT);
784 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
785 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
786 GEM_BUG_ON(engine->pmu.enable_count[sample] == ~0);
787
788 engine->pmu.enable |= BIT(sample);
789 engine->pmu.enable_count[sample]++;
790 }
791
792 spin_unlock_irqrestore(&pmu->lock, flags);
793
794update:
795 /*
796 * Store the current counter value so we can report the correct delta
797 * for all listeners. Even when the event was already enabled and has
798 * an existing non-zero value.
799 */
800 local64_set(&event->hw.prev_count, __i915_pmu_event_read(event));
801}
802
803static void i915_pmu_disable(struct perf_event *event)
804{
805 struct i915_pmu *pmu = event_to_pmu(event);
806 struct drm_i915_private *i915 = pmu_to_i915(pmu);
807 const unsigned int bit = event_bit(event);
808 unsigned long flags;
809
810 if (bit == -1)
811 return;
812
813 spin_lock_irqsave(&pmu->lock, flags);
814
815 if (is_engine_event(event)) {
816 u8 sample = engine_event_sample(event);
817 struct intel_engine_cs *engine;
818
819 engine = intel_engine_lookup_user(i915,
820 engine_event_class(event),
821 engine_event_instance(event));
822
823 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
824 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
825 GEM_BUG_ON(engine->pmu.enable_count[sample] == 0);
826
827 /*
828 * Decrement the reference count and clear the enabled
829 * bitmask when the last listener on an event goes away.
830 */
831 if (--engine->pmu.enable_count[sample] == 0)
832 engine->pmu.enable &= ~BIT(sample);
833 }
834
835 GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
836 GEM_BUG_ON(pmu->enable_count[bit] == 0);
837 /*
838 * Decrement the reference count and clear the enabled
839 * bitmask when the last listener on an event goes away.
840 */
841 if (--pmu->enable_count[bit] == 0) {
842 pmu->enable &= ~BIT(bit);
843 pmu->timer_enabled &= pmu_needs_timer(pmu);
844 }
845
846 spin_unlock_irqrestore(&pmu->lock, flags);
847}
848
849static void i915_pmu_event_start(struct perf_event *event, int flags)
850{
851 struct i915_pmu *pmu = event_to_pmu(event);
852
853 if (pmu->closed)
854 return;
855
856 i915_pmu_enable(event);
857 event->hw.state = 0;
858}
859
860static void i915_pmu_event_stop(struct perf_event *event, int flags)
861{
862 struct i915_pmu *pmu = event_to_pmu(event);
863
864 if (pmu->closed)
865 goto out;
866
867 if (flags & PERF_EF_UPDATE)
868 i915_pmu_event_read(event);
869
870 i915_pmu_disable(event);
871
872out:
873 event->hw.state = PERF_HES_STOPPED;
874}
875
876static int i915_pmu_event_add(struct perf_event *event, int flags)
877{
878 struct i915_pmu *pmu = event_to_pmu(event);
879
880 if (pmu->closed)
881 return -ENODEV;
882
883 if (flags & PERF_EF_START)
884 i915_pmu_event_start(event, flags);
885
886 return 0;
887}
888
889static void i915_pmu_event_del(struct perf_event *event, int flags)
890{
891 i915_pmu_event_stop(event, PERF_EF_UPDATE);
892}
893
894static int i915_pmu_event_event_idx(struct perf_event *event)
895{
896 return 0;
897}
898
899struct i915_str_attribute {
900 struct device_attribute attr;
901 const char *str;
902};
903
904static ssize_t i915_pmu_format_show(struct device *dev,
905 struct device_attribute *attr, char *buf)
906{
907 struct i915_str_attribute *eattr;
908
909 eattr = container_of(attr, struct i915_str_attribute, attr);
910 return sprintf(buf, "%s\n", eattr->str);
911}
912
913#define I915_PMU_FORMAT_ATTR(_name, _config) \
914 (&((struct i915_str_attribute[]) { \
915 { .attr = __ATTR(_name, 0444, i915_pmu_format_show, NULL), \
916 .str = _config, } \
917 })[0].attr.attr)
918
919static struct attribute *i915_pmu_format_attrs[] = {
920 I915_PMU_FORMAT_ATTR(i915_eventid, "config:0-20"),
921 NULL,
922};
923
924static const struct attribute_group i915_pmu_format_attr_group = {
925 .name = "format",
926 .attrs = i915_pmu_format_attrs,
927};
928
929struct i915_ext_attribute {
930 struct device_attribute attr;
931 unsigned long val;
932};
933
934static ssize_t i915_pmu_event_show(struct device *dev,
935 struct device_attribute *attr, char *buf)
936{
937 struct i915_ext_attribute *eattr;
938
939 eattr = container_of(attr, struct i915_ext_attribute, attr);
940 return sprintf(buf, "config=0x%lx\n", eattr->val);
941}
942
943static ssize_t cpumask_show(struct device *dev,
944 struct device_attribute *attr, char *buf)
945{
946 return cpumap_print_to_pagebuf(true, buf, &i915_pmu_cpumask);
947}
948
949static DEVICE_ATTR_RO(cpumask);
950
951static struct attribute *i915_cpumask_attrs[] = {
952 &dev_attr_cpumask.attr,
953 NULL,
954};
955
956static const struct attribute_group i915_pmu_cpumask_attr_group = {
957 .attrs = i915_cpumask_attrs,
958};
959
960#define __event(__counter, __name, __unit) \
961{ \
962 .counter = (__counter), \
963 .name = (__name), \
964 .unit = (__unit), \
965 .global = false, \
966}
967
968#define __global_event(__counter, __name, __unit) \
969{ \
970 .counter = (__counter), \
971 .name = (__name), \
972 .unit = (__unit), \
973 .global = true, \
974}
975
976#define __engine_event(__sample, __name) \
977{ \
978 .sample = (__sample), \
979 .name = (__name), \
980}
981
982static struct i915_ext_attribute *
983add_i915_attr(struct i915_ext_attribute *attr, const char *name, u64 config)
984{
985 sysfs_attr_init(&attr->attr.attr);
986 attr->attr.attr.name = name;
987 attr->attr.attr.mode = 0444;
988 attr->attr.show = i915_pmu_event_show;
989 attr->val = config;
990
991 return ++attr;
992}
993
994static struct perf_pmu_events_attr *
995add_pmu_attr(struct perf_pmu_events_attr *attr, const char *name,
996 const char *str)
997{
998 sysfs_attr_init(&attr->attr.attr);
999 attr->attr.attr.name = name;
1000 attr->attr.attr.mode = 0444;
1001 attr->attr.show = perf_event_sysfs_show;
1002 attr->event_str = str;
1003
1004 return ++attr;
1005}
1006
1007static struct attribute **
1008create_event_attributes(struct i915_pmu *pmu)
1009{
1010 struct drm_i915_private *i915 = pmu_to_i915(pmu);
1011 static const struct {
1012 unsigned int counter;
1013 const char *name;
1014 const char *unit;
1015 bool global;
1016 } events[] = {
1017 __event(0, "actual-frequency", "M"),
1018 __event(1, "requested-frequency", "M"),
1019 __global_event(2, "interrupts", NULL),
1020 __event(3, "rc6-residency", "ns"),
1021 __event(4, "software-gt-awake-time", "ns"),
1022 };
1023 static const struct {
1024 enum drm_i915_pmu_engine_sample sample;
1025 char *name;
1026 } engine_events[] = {
1027 __engine_event(I915_SAMPLE_BUSY, "busy"),
1028 __engine_event(I915_SAMPLE_SEMA, "sema"),
1029 __engine_event(I915_SAMPLE_WAIT, "wait"),
1030 };
1031 unsigned int count = 0;
1032 struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
1033 struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
1034 struct attribute **attr = NULL, **attr_iter;
1035 struct intel_engine_cs *engine;
1036 struct intel_gt *gt;
1037 unsigned int i, j;
1038
1039 /* Count how many counters we will be exposing. */
1040 for_each_gt(gt, i915, j) {
1041 for (i = 0; i < ARRAY_SIZE(events); i++) {
1042 u64 config = ___I915_PMU_OTHER(j, events[i].counter);
1043
1044 if (!config_status(i915, config))
1045 count++;
1046 }
1047 }
1048
1049 for_each_uabi_engine(engine, i915) {
1050 for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
1051 if (!engine_event_status(engine,
1052 engine_events[i].sample))
1053 count++;
1054 }
1055 }
1056
1057 /* Allocate attribute objects and table. */
1058 i915_attr = kcalloc(count, sizeof(*i915_attr), GFP_KERNEL);
1059 if (!i915_attr)
1060 goto err_alloc;
1061
1062 pmu_attr = kcalloc(count, sizeof(*pmu_attr), GFP_KERNEL);
1063 if (!pmu_attr)
1064 goto err_alloc;
1065
1066 /* Max one pointer of each attribute type plus a termination entry. */
1067 attr = kcalloc(count * 2 + 1, sizeof(*attr), GFP_KERNEL);
1068 if (!attr)
1069 goto err_alloc;
1070
1071 i915_iter = i915_attr;
1072 pmu_iter = pmu_attr;
1073 attr_iter = attr;
1074
1075 /* Initialize supported non-engine counters. */
1076 for_each_gt(gt, i915, j) {
1077 for (i = 0; i < ARRAY_SIZE(events); i++) {
1078 u64 config = ___I915_PMU_OTHER(j, events[i].counter);
1079 char *str;
1080
1081 if (config_status(i915, config))
1082 continue;
1083
1084 if (events[i].global || !HAS_EXTRA_GT_LIST(i915))
1085 str = kstrdup(events[i].name, GFP_KERNEL);
1086 else
1087 str = kasprintf(GFP_KERNEL, "%s-gt%u",
1088 events[i].name, j);
1089 if (!str)
1090 goto err;
1091
1092 *attr_iter++ = &i915_iter->attr.attr;
1093 i915_iter = add_i915_attr(i915_iter, str, config);
1094
1095 if (events[i].unit) {
1096 if (events[i].global || !HAS_EXTRA_GT_LIST(i915))
1097 str = kasprintf(GFP_KERNEL, "%s.unit",
1098 events[i].name);
1099 else
1100 str = kasprintf(GFP_KERNEL, "%s-gt%u.unit",
1101 events[i].name, j);
1102 if (!str)
1103 goto err;
1104
1105 *attr_iter++ = &pmu_iter->attr.attr;
1106 pmu_iter = add_pmu_attr(pmu_iter, str,
1107 events[i].unit);
1108 }
1109 }
1110 }
1111
1112 /* Initialize supported engine counters. */
1113 for_each_uabi_engine(engine, i915) {
1114 for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
1115 char *str;
1116
1117 if (engine_event_status(engine,
1118 engine_events[i].sample))
1119 continue;
1120
1121 str = kasprintf(GFP_KERNEL, "%s-%s",
1122 engine->name, engine_events[i].name);
1123 if (!str)
1124 goto err;
1125
1126 *attr_iter++ = &i915_iter->attr.attr;
1127 i915_iter =
1128 add_i915_attr(i915_iter, str,
1129 __I915_PMU_ENGINE(engine->uabi_class,
1130 engine->uabi_instance,
1131 engine_events[i].sample));
1132
1133 str = kasprintf(GFP_KERNEL, "%s-%s.unit",
1134 engine->name, engine_events[i].name);
1135 if (!str)
1136 goto err;
1137
1138 *attr_iter++ = &pmu_iter->attr.attr;
1139 pmu_iter = add_pmu_attr(pmu_iter, str, "ns");
1140 }
1141 }
1142
1143 pmu->i915_attr = i915_attr;
1144 pmu->pmu_attr = pmu_attr;
1145
1146 return attr;
1147
1148err:;
1149 for (attr_iter = attr; *attr_iter; attr_iter++)
1150 kfree((*attr_iter)->name);
1151
1152err_alloc:
1153 kfree(attr);
1154 kfree(i915_attr);
1155 kfree(pmu_attr);
1156
1157 return NULL;
1158}
1159
1160static void free_event_attributes(struct i915_pmu *pmu)
1161{
1162 struct attribute **attr_iter = pmu->events_attr_group.attrs;
1163
1164 for (; *attr_iter; attr_iter++)
1165 kfree((*attr_iter)->name);
1166
1167 kfree(pmu->events_attr_group.attrs);
1168 kfree(pmu->i915_attr);
1169 kfree(pmu->pmu_attr);
1170
1171 pmu->events_attr_group.attrs = NULL;
1172 pmu->i915_attr = NULL;
1173 pmu->pmu_attr = NULL;
1174}
1175
1176static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
1177{
1178 struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
1179
1180 GEM_BUG_ON(!pmu->base.event_init);
1181
1182 /* Select the first online CPU as a designated reader. */
1183 if (cpumask_empty(&i915_pmu_cpumask))
1184 cpumask_set_cpu(cpu, &i915_pmu_cpumask);
1185
1186 return 0;
1187}
1188
1189static int i915_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
1190{
1191 struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
1192 unsigned int target = i915_pmu_target_cpu;
1193
1194 GEM_BUG_ON(!pmu->base.event_init);
1195
1196 /*
1197 * Unregistering an instance generates a CPU offline event which we must
1198 * ignore to avoid incorrectly modifying the shared i915_pmu_cpumask.
1199 */
1200 if (pmu->closed)
1201 return 0;
1202
1203 if (cpumask_test_and_clear_cpu(cpu, &i915_pmu_cpumask)) {
1204 target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
1205
1206 /* Migrate events if there is a valid target */
1207 if (target < nr_cpu_ids) {
1208 cpumask_set_cpu(target, &i915_pmu_cpumask);
1209 i915_pmu_target_cpu = target;
1210 }
1211 }
1212
1213 if (target < nr_cpu_ids && target != pmu->cpuhp.cpu) {
1214 perf_pmu_migrate_context(&pmu->base, cpu, target);
1215 pmu->cpuhp.cpu = target;
1216 }
1217
1218 return 0;
1219}
1220
1221static enum cpuhp_state cpuhp_slot = CPUHP_INVALID;
1222
1223int i915_pmu_init(void)
1224{
1225 int ret;
1226
1227 ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
1228 "perf/x86/intel/i915:online",
1229 i915_pmu_cpu_online,
1230 i915_pmu_cpu_offline);
1231 if (ret < 0)
1232 pr_notice("Failed to setup cpuhp state for i915 PMU! (%d)\n",
1233 ret);
1234 else
1235 cpuhp_slot = ret;
1236
1237 return 0;
1238}
1239
1240void i915_pmu_exit(void)
1241{
1242 if (cpuhp_slot != CPUHP_INVALID)
1243 cpuhp_remove_multi_state(cpuhp_slot);
1244}
1245
1246static int i915_pmu_register_cpuhp_state(struct i915_pmu *pmu)
1247{
1248 if (cpuhp_slot == CPUHP_INVALID)
1249 return -EINVAL;
1250
1251 return cpuhp_state_add_instance(cpuhp_slot, &pmu->cpuhp.node);
1252}
1253
1254static void i915_pmu_unregister_cpuhp_state(struct i915_pmu *pmu)
1255{
1256 cpuhp_state_remove_instance(cpuhp_slot, &pmu->cpuhp.node);
1257}
1258
1259void i915_pmu_register(struct drm_i915_private *i915)
1260{
1261 struct i915_pmu *pmu = &i915->pmu;
1262 const struct attribute_group *attr_groups[] = {
1263 &i915_pmu_format_attr_group,
1264 &pmu->events_attr_group,
1265 &i915_pmu_cpumask_attr_group,
1266 NULL
1267 };
1268
1269 int ret = -ENOMEM;
1270
1271 spin_lock_init(&pmu->lock);
1272 hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1273 pmu->timer.function = i915_sample;
1274 pmu->cpuhp.cpu = -1;
1275 init_rc6(pmu);
1276
1277 if (IS_DGFX(i915)) {
1278 pmu->name = kasprintf(GFP_KERNEL,
1279 "i915_%s",
1280 dev_name(i915->drm.dev));
1281 if (pmu->name) {
1282 /* tools/perf reserves colons as special. */
1283 strreplace((char *)pmu->name, ':', '_');
1284 }
1285 } else {
1286 pmu->name = "i915";
1287 }
1288 if (!pmu->name)
1289 goto err;
1290
1291 pmu->events_attr_group.name = "events";
1292 pmu->events_attr_group.attrs = create_event_attributes(pmu);
1293 if (!pmu->events_attr_group.attrs)
1294 goto err_name;
1295
1296 pmu->base.attr_groups = kmemdup(attr_groups, sizeof(attr_groups),
1297 GFP_KERNEL);
1298 if (!pmu->base.attr_groups)
1299 goto err_attr;
1300
1301 pmu->base.module = THIS_MODULE;
1302 pmu->base.task_ctx_nr = perf_invalid_context;
1303 pmu->base.event_init = i915_pmu_event_init;
1304 pmu->base.add = i915_pmu_event_add;
1305 pmu->base.del = i915_pmu_event_del;
1306 pmu->base.start = i915_pmu_event_start;
1307 pmu->base.stop = i915_pmu_event_stop;
1308 pmu->base.read = i915_pmu_event_read;
1309 pmu->base.event_idx = i915_pmu_event_event_idx;
1310
1311 ret = perf_pmu_register(&pmu->base, pmu->name, -1);
1312 if (ret)
1313 goto err_groups;
1314
1315 ret = i915_pmu_register_cpuhp_state(pmu);
1316 if (ret)
1317 goto err_unreg;
1318
1319 return;
1320
1321err_unreg:
1322 perf_pmu_unregister(&pmu->base);
1323err_groups:
1324 kfree(pmu->base.attr_groups);
1325err_attr:
1326 pmu->base.event_init = NULL;
1327 free_event_attributes(pmu);
1328err_name:
1329 if (IS_DGFX(i915))
1330 kfree(pmu->name);
1331err:
1332 drm_notice(&i915->drm, "Failed to register PMU!\n");
1333}
1334
1335void i915_pmu_unregister(struct drm_i915_private *i915)
1336{
1337 struct i915_pmu *pmu = &i915->pmu;
1338
1339 if (!pmu->base.event_init)
1340 return;
1341
1342 /*
1343 * "Disconnect" the PMU callbacks - since all are atomic synchronize_rcu
1344 * ensures all currently executing ones will have exited before we
1345 * proceed with unregistration.
1346 */
1347 pmu->closed = true;
1348 synchronize_rcu();
1349
1350 hrtimer_cancel(&pmu->timer);
1351
1352 i915_pmu_unregister_cpuhp_state(pmu);
1353
1354 perf_pmu_unregister(&pmu->base);
1355 pmu->base.event_init = NULL;
1356 kfree(pmu->base.attr_groups);
1357 if (IS_DGFX(i915))
1358 kfree(pmu->name);
1359 free_event_attributes(pmu);
1360}