Merge tag 'powerpc-6.6-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[platform/kernel/linux-starfive.git] / drivers / gpu / drm / i915 / i915_pmu.c
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
31 static cpumask_t i915_pmu_cpumask;
32 static unsigned int i915_pmu_target_cpu = -1;
33
34 static u8 engine_config_sample(u64 config)
35 {
36         return config & I915_PMU_SAMPLE_MASK;
37 }
38
39 static u8 engine_event_sample(struct perf_event *event)
40 {
41         return engine_config_sample(event->attr.config);
42 }
43
44 static u8 engine_event_class(struct perf_event *event)
45 {
46         return (event->attr.config >> I915_PMU_CLASS_SHIFT) & 0xff;
47 }
48
49 static u8 engine_event_instance(struct perf_event *event)
50 {
51         return (event->attr.config >> I915_PMU_SAMPLE_BITS) & 0xff;
52 }
53
54 static bool is_engine_config(const u64 config)
55 {
56         return config < __I915_PMU_OTHER(0);
57 }
58
59 static unsigned int config_gt_id(const u64 config)
60 {
61         return config >> __I915_PMU_GT_SHIFT;
62 }
63
64 static u64 config_counter(const u64 config)
65 {
66         return config & ~(~0ULL << __I915_PMU_GT_SHIFT);
67 }
68
69 static unsigned int other_bit(const u64 config)
70 {
71         unsigned int val;
72
73         switch (config_counter(config)) {
74         case I915_PMU_ACTUAL_FREQUENCY:
75                 val =  __I915_PMU_ACTUAL_FREQUENCY_ENABLED;
76                 break;
77         case I915_PMU_REQUESTED_FREQUENCY:
78                 val = __I915_PMU_REQUESTED_FREQUENCY_ENABLED;
79                 break;
80         case I915_PMU_RC6_RESIDENCY:
81                 val = __I915_PMU_RC6_RESIDENCY_ENABLED;
82                 break;
83         default:
84                 /*
85                  * Events that do not require sampling, or tracking state
86                  * transitions between enabled and disabled can be ignored.
87                  */
88                 return -1;
89         }
90
91         return I915_ENGINE_SAMPLE_COUNT +
92                config_gt_id(config) * __I915_PMU_TRACKED_EVENT_COUNT +
93                val;
94 }
95
96 static unsigned int config_bit(const u64 config)
97 {
98         if (is_engine_config(config))
99                 return engine_config_sample(config);
100         else
101                 return other_bit(config);
102 }
103
104 static u32 config_mask(const u64 config)
105 {
106         unsigned int bit = config_bit(config);
107
108         if (__builtin_constant_p(config))
109                 BUILD_BUG_ON(bit >
110                              BITS_PER_TYPE(typeof_member(struct i915_pmu,
111                                                          enable)) - 1);
112         else
113                 WARN_ON_ONCE(bit >
114                              BITS_PER_TYPE(typeof_member(struct i915_pmu,
115                                                          enable)) - 1);
116
117         return BIT(config_bit(config));
118 }
119
120 static bool is_engine_event(struct perf_event *event)
121 {
122         return is_engine_config(event->attr.config);
123 }
124
125 static unsigned int event_bit(struct perf_event *event)
126 {
127         return config_bit(event->attr.config);
128 }
129
130 static u32 frequency_enabled_mask(void)
131 {
132         unsigned int i;
133         u32 mask = 0;
134
135         for (i = 0; i < I915_PMU_MAX_GT; i++)
136                 mask |= config_mask(__I915_PMU_ACTUAL_FREQUENCY(i)) |
137                         config_mask(__I915_PMU_REQUESTED_FREQUENCY(i));
138
139         return mask;
140 }
141
142 static bool pmu_needs_timer(struct i915_pmu *pmu)
143 {
144         struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
145         u32 enable;
146
147         /*
148          * Only some counters need the sampling timer.
149          *
150          * We start with a bitmask of all currently enabled events.
151          */
152         enable = pmu->enable;
153
154         /*
155          * Mask out all the ones which do not need the timer, or in
156          * other words keep all the ones that could need the timer.
157          */
158         enable &= frequency_enabled_mask() | ENGINE_SAMPLE_MASK;
159
160         /*
161          * Also there is software busyness tracking available we do not
162          * need the timer for I915_SAMPLE_BUSY counter.
163          */
164         if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
165                 enable &= ~BIT(I915_SAMPLE_BUSY);
166
167         /*
168          * If some bits remain it means we need the sampling timer running.
169          */
170         return enable;
171 }
172
173 static u64 __get_rc6(struct intel_gt *gt)
174 {
175         struct drm_i915_private *i915 = gt->i915;
176         u64 val;
177
178         val = intel_rc6_residency_ns(&gt->rc6, INTEL_RC6_RES_RC6);
179
180         if (HAS_RC6p(i915))
181                 val += intel_rc6_residency_ns(&gt->rc6, INTEL_RC6_RES_RC6p);
182
183         if (HAS_RC6pp(i915))
184                 val += intel_rc6_residency_ns(&gt->rc6, INTEL_RC6_RES_RC6pp);
185
186         return val;
187 }
188
189 static inline s64 ktime_since_raw(const ktime_t kt)
190 {
191         return ktime_to_ns(ktime_sub(ktime_get_raw(), kt));
192 }
193
194 static u64 read_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample)
195 {
196         return pmu->sample[gt_id][sample].cur;
197 }
198
199 static void
200 store_sample(struct i915_pmu *pmu, unsigned int gt_id, int sample, u64 val)
201 {
202         pmu->sample[gt_id][sample].cur = val;
203 }
204
205 static void
206 add_sample_mult(struct i915_pmu *pmu, unsigned int gt_id, int sample, u32 val, u32 mul)
207 {
208         pmu->sample[gt_id][sample].cur += mul_u32_u32(val, mul);
209 }
210
211 static u64 get_rc6(struct intel_gt *gt)
212 {
213         struct drm_i915_private *i915 = gt->i915;
214         const unsigned int gt_id = gt->info.id;
215         struct i915_pmu *pmu = &i915->pmu;
216         unsigned long flags;
217         bool awake = false;
218         u64 val;
219
220         if (intel_gt_pm_get_if_awake(gt)) {
221                 val = __get_rc6(gt);
222                 intel_gt_pm_put_async(gt);
223                 awake = true;
224         }
225
226         spin_lock_irqsave(&pmu->lock, flags);
227
228         if (awake) {
229                 store_sample(pmu, gt_id, __I915_SAMPLE_RC6, val);
230         } else {
231                 /*
232                  * We think we are runtime suspended.
233                  *
234                  * Report the delta from when the device was suspended to now,
235                  * on top of the last known real value, as the approximated RC6
236                  * counter value.
237                  */
238                 val = ktime_since_raw(pmu->sleep_last[gt_id]);
239                 val += read_sample(pmu, gt_id, __I915_SAMPLE_RC6);
240         }
241
242         if (val < read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED))
243                 val = read_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED);
244         else
245                 store_sample(pmu, gt_id, __I915_SAMPLE_RC6_LAST_REPORTED, val);
246
247         spin_unlock_irqrestore(&pmu->lock, flags);
248
249         return val;
250 }
251
252 static void init_rc6(struct i915_pmu *pmu)
253 {
254         struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
255         struct intel_gt *gt;
256         unsigned int i;
257
258         for_each_gt(gt, i915, i) {
259                 intel_wakeref_t wakeref;
260
261                 with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
262                         u64 val = __get_rc6(gt);
263
264                         store_sample(pmu, i, __I915_SAMPLE_RC6, val);
265                         store_sample(pmu, i, __I915_SAMPLE_RC6_LAST_REPORTED,
266                                      val);
267                         pmu->sleep_last[i] = ktime_get_raw();
268                 }
269         }
270 }
271
272 static void park_rc6(struct intel_gt *gt)
273 {
274         struct i915_pmu *pmu = &gt->i915->pmu;
275
276         store_sample(pmu, gt->info.id, __I915_SAMPLE_RC6, __get_rc6(gt));
277         pmu->sleep_last[gt->info.id] = ktime_get_raw();
278 }
279
280 static void __i915_pmu_maybe_start_timer(struct i915_pmu *pmu)
281 {
282         if (!pmu->timer_enabled && pmu_needs_timer(pmu)) {
283                 pmu->timer_enabled = true;
284                 pmu->timer_last = ktime_get();
285                 hrtimer_start_range_ns(&pmu->timer,
286                                        ns_to_ktime(PERIOD), 0,
287                                        HRTIMER_MODE_REL_PINNED);
288         }
289 }
290
291 void i915_pmu_gt_parked(struct intel_gt *gt)
292 {
293         struct i915_pmu *pmu = &gt->i915->pmu;
294
295         if (!pmu->base.event_init)
296                 return;
297
298         spin_lock_irq(&pmu->lock);
299
300         park_rc6(gt);
301
302         /*
303          * Signal sampling timer to stop if only engine events are enabled and
304          * GPU went idle.
305          */
306         pmu->unparked &= ~BIT(gt->info.id);
307         if (pmu->unparked == 0)
308                 pmu->timer_enabled = false;
309
310         spin_unlock_irq(&pmu->lock);
311 }
312
313 void i915_pmu_gt_unparked(struct intel_gt *gt)
314 {
315         struct i915_pmu *pmu = &gt->i915->pmu;
316
317         if (!pmu->base.event_init)
318                 return;
319
320         spin_lock_irq(&pmu->lock);
321
322         /*
323          * Re-enable sampling timer when GPU goes active.
324          */
325         if (pmu->unparked == 0)
326                 __i915_pmu_maybe_start_timer(pmu);
327
328         pmu->unparked |= BIT(gt->info.id);
329
330         spin_unlock_irq(&pmu->lock);
331 }
332
333 static void
334 add_sample(struct i915_pmu_sample *sample, u32 val)
335 {
336         sample->cur += val;
337 }
338
339 static bool exclusive_mmio_access(const struct drm_i915_private *i915)
340 {
341         /*
342          * We have to avoid concurrent mmio cache line access on gen7 or
343          * risk a machine hang. For a fun history lesson dig out the old
344          * userspace intel_gpu_top and run it on Ivybridge or Haswell!
345          */
346         return GRAPHICS_VER(i915) == 7;
347 }
348
349 static void engine_sample(struct intel_engine_cs *engine, unsigned int period_ns)
350 {
351         struct intel_engine_pmu *pmu = &engine->pmu;
352         bool busy;
353         u32 val;
354
355         val = ENGINE_READ_FW(engine, RING_CTL);
356         if (val == 0) /* powerwell off => engine idle */
357                 return;
358
359         if (val & RING_WAIT)
360                 add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
361         if (val & RING_WAIT_SEMAPHORE)
362                 add_sample(&pmu->sample[I915_SAMPLE_SEMA], period_ns);
363
364         /* No need to sample when busy stats are supported. */
365         if (intel_engine_supports_stats(engine))
366                 return;
367
368         /*
369          * While waiting on a semaphore or event, MI_MODE reports the
370          * ring as idle. However, previously using the seqno, and with
371          * execlists sampling, we account for the ring waiting as the
372          * engine being busy. Therefore, we record the sample as being
373          * busy if either waiting or !idle.
374          */
375         busy = val & (RING_WAIT_SEMAPHORE | RING_WAIT);
376         if (!busy) {
377                 val = ENGINE_READ_FW(engine, RING_MI_MODE);
378                 busy = !(val & MODE_IDLE);
379         }
380         if (busy)
381                 add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
382 }
383
384 static void
385 engines_sample(struct intel_gt *gt, unsigned int period_ns)
386 {
387         struct drm_i915_private *i915 = gt->i915;
388         struct intel_engine_cs *engine;
389         enum intel_engine_id id;
390         unsigned long flags;
391
392         if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
393                 return;
394
395         if (!intel_gt_pm_is_awake(gt))
396                 return;
397
398         for_each_engine(engine, gt, id) {
399                 if (!engine->pmu.enable)
400                         continue;
401
402                 if (!intel_engine_pm_get_if_awake(engine))
403                         continue;
404
405                 if (exclusive_mmio_access(i915)) {
406                         spin_lock_irqsave(&engine->uncore->lock, flags);
407                         engine_sample(engine, period_ns);
408                         spin_unlock_irqrestore(&engine->uncore->lock, flags);
409                 } else {
410                         engine_sample(engine, period_ns);
411                 }
412
413                 intel_engine_pm_put_async(engine);
414         }
415 }
416
417 static bool
418 frequency_sampling_enabled(struct i915_pmu *pmu, unsigned int gt)
419 {
420         return pmu->enable &
421                (config_mask(__I915_PMU_ACTUAL_FREQUENCY(gt)) |
422                 config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt)));
423 }
424
425 static void
426 frequency_sample(struct intel_gt *gt, unsigned int period_ns)
427 {
428         struct drm_i915_private *i915 = gt->i915;
429         const unsigned int gt_id = gt->info.id;
430         struct i915_pmu *pmu = &i915->pmu;
431         struct intel_rps *rps = &gt->rps;
432
433         if (!frequency_sampling_enabled(pmu, gt_id))
434                 return;
435
436         /* Report 0/0 (actual/requested) frequency while parked. */
437         if (!intel_gt_pm_get_if_awake(gt))
438                 return;
439
440         if (pmu->enable & config_mask(__I915_PMU_ACTUAL_FREQUENCY(gt_id))) {
441                 u32 val;
442
443                 /*
444                  * We take a quick peek here without using forcewake
445                  * so that we don't perturb the system under observation
446                  * (forcewake => !rc6 => increased power use). We expect
447                  * that if the read fails because it is outside of the
448                  * mmio power well, then it will return 0 -- in which
449                  * case we assume the system is running at the intended
450                  * frequency. Fortunately, the read should rarely fail!
451                  */
452                 val = intel_rps_read_actual_frequency_fw(rps);
453                 if (!val)
454                         val = intel_gpu_freq(rps, rps->cur_freq);
455
456                 add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_ACT,
457                                 val, period_ns / 1000);
458         }
459
460         if (pmu->enable & config_mask(__I915_PMU_REQUESTED_FREQUENCY(gt_id))) {
461                 add_sample_mult(pmu, gt_id, __I915_SAMPLE_FREQ_REQ,
462                                 intel_rps_get_requested_frequency(rps),
463                                 period_ns / 1000);
464         }
465
466         intel_gt_pm_put_async(gt);
467 }
468
469 static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer)
470 {
471         struct drm_i915_private *i915 =
472                 container_of(hrtimer, struct drm_i915_private, pmu.timer);
473         struct i915_pmu *pmu = &i915->pmu;
474         unsigned int period_ns;
475         struct intel_gt *gt;
476         unsigned int i;
477         ktime_t now;
478
479         if (!READ_ONCE(pmu->timer_enabled))
480                 return HRTIMER_NORESTART;
481
482         now = ktime_get();
483         period_ns = ktime_to_ns(ktime_sub(now, pmu->timer_last));
484         pmu->timer_last = now;
485
486         /*
487          * Strictly speaking the passed in period may not be 100% accurate for
488          * all internal calculation, since some amount of time can be spent on
489          * grabbing the forcewake. However the potential error from timer call-
490          * back delay greatly dominates this so we keep it simple.
491          */
492
493         for_each_gt(gt, i915, i) {
494                 if (!(pmu->unparked & BIT(i)))
495                         continue;
496
497                 engines_sample(gt, period_ns);
498                 frequency_sample(gt, period_ns);
499         }
500
501         hrtimer_forward(hrtimer, now, ns_to_ktime(PERIOD));
502
503         return HRTIMER_RESTART;
504 }
505
506 static void i915_pmu_event_destroy(struct perf_event *event)
507 {
508         struct drm_i915_private *i915 =
509                 container_of(event->pmu, typeof(*i915), pmu.base);
510
511         drm_WARN_ON(&i915->drm, event->parent);
512
513         drm_dev_put(&i915->drm);
514 }
515
516 static int
517 engine_event_status(struct intel_engine_cs *engine,
518                     enum drm_i915_pmu_engine_sample sample)
519 {
520         switch (sample) {
521         case I915_SAMPLE_BUSY:
522         case I915_SAMPLE_WAIT:
523                 break;
524         case I915_SAMPLE_SEMA:
525                 if (GRAPHICS_VER(engine->i915) < 6)
526                         return -ENODEV;
527                 break;
528         default:
529                 return -ENOENT;
530         }
531
532         return 0;
533 }
534
535 static int
536 config_status(struct drm_i915_private *i915, u64 config)
537 {
538         struct intel_gt *gt = to_gt(i915);
539
540         unsigned int gt_id = config_gt_id(config);
541         unsigned int max_gt_id = HAS_EXTRA_GT_LIST(i915) ? 1 : 0;
542
543         if (gt_id > max_gt_id)
544                 return -ENOENT;
545
546         switch (config_counter(config)) {
547         case I915_PMU_ACTUAL_FREQUENCY:
548                 if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
549                         /* Requires a mutex for sampling! */
550                         return -ENODEV;
551                 fallthrough;
552         case I915_PMU_REQUESTED_FREQUENCY:
553                 if (GRAPHICS_VER(i915) < 6)
554                         return -ENODEV;
555                 break;
556         case I915_PMU_INTERRUPTS:
557                 if (gt_id)
558                         return -ENOENT;
559                 break;
560         case I915_PMU_RC6_RESIDENCY:
561                 if (!gt->rc6.supported)
562                         return -ENODEV;
563                 break;
564         case I915_PMU_SOFTWARE_GT_AWAKE_TIME:
565                 break;
566         default:
567                 return -ENOENT;
568         }
569
570         return 0;
571 }
572
573 static int engine_event_init(struct perf_event *event)
574 {
575         struct drm_i915_private *i915 =
576                 container_of(event->pmu, typeof(*i915), pmu.base);
577         struct intel_engine_cs *engine;
578
579         engine = intel_engine_lookup_user(i915, engine_event_class(event),
580                                           engine_event_instance(event));
581         if (!engine)
582                 return -ENODEV;
583
584         return engine_event_status(engine, engine_event_sample(event));
585 }
586
587 static int i915_pmu_event_init(struct perf_event *event)
588 {
589         struct drm_i915_private *i915 =
590                 container_of(event->pmu, typeof(*i915), pmu.base);
591         struct i915_pmu *pmu = &i915->pmu;
592         int ret;
593
594         if (pmu->closed)
595                 return -ENODEV;
596
597         if (event->attr.type != event->pmu->type)
598                 return -ENOENT;
599
600         /* unsupported modes and filters */
601         if (event->attr.sample_period) /* no sampling */
602                 return -EINVAL;
603
604         if (has_branch_stack(event))
605                 return -EOPNOTSUPP;
606
607         if (event->cpu < 0)
608                 return -EINVAL;
609
610         /* only allow running on one cpu at a time */
611         if (!cpumask_test_cpu(event->cpu, &i915_pmu_cpumask))
612                 return -EINVAL;
613
614         if (is_engine_event(event))
615                 ret = engine_event_init(event);
616         else
617                 ret = config_status(i915, event->attr.config);
618         if (ret)
619                 return ret;
620
621         if (!event->parent) {
622                 drm_dev_get(&i915->drm);
623                 event->destroy = i915_pmu_event_destroy;
624         }
625
626         return 0;
627 }
628
629 static u64 __i915_pmu_event_read(struct perf_event *event)
630 {
631         struct drm_i915_private *i915 =
632                 container_of(event->pmu, typeof(*i915), pmu.base);
633         struct i915_pmu *pmu = &i915->pmu;
634         u64 val = 0;
635
636         if (is_engine_event(event)) {
637                 u8 sample = engine_event_sample(event);
638                 struct intel_engine_cs *engine;
639
640                 engine = intel_engine_lookup_user(i915,
641                                                   engine_event_class(event),
642                                                   engine_event_instance(event));
643
644                 if (drm_WARN_ON_ONCE(&i915->drm, !engine)) {
645                         /* Do nothing */
646                 } else if (sample == I915_SAMPLE_BUSY &&
647                            intel_engine_supports_stats(engine)) {
648                         ktime_t unused;
649
650                         val = ktime_to_ns(intel_engine_get_busy_time(engine,
651                                                                      &unused));
652                 } else {
653                         val = engine->pmu.sample[sample].cur;
654                 }
655         } else {
656                 const unsigned int gt_id = config_gt_id(event->attr.config);
657                 const u64 config = config_counter(event->attr.config);
658
659                 switch (config) {
660                 case I915_PMU_ACTUAL_FREQUENCY:
661                         val =
662                            div_u64(read_sample(pmu, gt_id,
663                                                __I915_SAMPLE_FREQ_ACT),
664                                    USEC_PER_SEC /* to MHz */);
665                         break;
666                 case I915_PMU_REQUESTED_FREQUENCY:
667                         val =
668                            div_u64(read_sample(pmu, gt_id,
669                                                __I915_SAMPLE_FREQ_REQ),
670                                    USEC_PER_SEC /* to MHz */);
671                         break;
672                 case I915_PMU_INTERRUPTS:
673                         val = READ_ONCE(pmu->irq_count);
674                         break;
675                 case I915_PMU_RC6_RESIDENCY:
676                         val = get_rc6(i915->gt[gt_id]);
677                         break;
678                 case I915_PMU_SOFTWARE_GT_AWAKE_TIME:
679                         val = ktime_to_ns(intel_gt_get_awake_time(to_gt(i915)));
680                         break;
681                 }
682         }
683
684         return val;
685 }
686
687 static void i915_pmu_event_read(struct perf_event *event)
688 {
689         struct drm_i915_private *i915 =
690                 container_of(event->pmu, typeof(*i915), pmu.base);
691         struct hw_perf_event *hwc = &event->hw;
692         struct i915_pmu *pmu = &i915->pmu;
693         u64 prev, new;
694
695         if (pmu->closed) {
696                 event->hw.state = PERF_HES_STOPPED;
697                 return;
698         }
699 again:
700         prev = local64_read(&hwc->prev_count);
701         new = __i915_pmu_event_read(event);
702
703         if (local64_cmpxchg(&hwc->prev_count, prev, new) != prev)
704                 goto again;
705
706         local64_add(new - prev, &event->count);
707 }
708
709 static void i915_pmu_enable(struct perf_event *event)
710 {
711         struct drm_i915_private *i915 =
712                 container_of(event->pmu, typeof(*i915), pmu.base);
713         const unsigned int bit = event_bit(event);
714         struct i915_pmu *pmu = &i915->pmu;
715         unsigned long flags;
716
717         if (bit == -1)
718                 goto update;
719
720         spin_lock_irqsave(&pmu->lock, flags);
721
722         /*
723          * Update the bitmask of enabled events and increment
724          * the event reference counter.
725          */
726         BUILD_BUG_ON(ARRAY_SIZE(pmu->enable_count) != I915_PMU_MASK_BITS);
727         GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
728         GEM_BUG_ON(pmu->enable_count[bit] == ~0);
729
730         pmu->enable |= BIT(bit);
731         pmu->enable_count[bit]++;
732
733         /*
734          * Start the sampling timer if needed and not already enabled.
735          */
736         __i915_pmu_maybe_start_timer(pmu);
737
738         /*
739          * For per-engine events the bitmask and reference counting
740          * is stored per engine.
741          */
742         if (is_engine_event(event)) {
743                 u8 sample = engine_event_sample(event);
744                 struct intel_engine_cs *engine;
745
746                 engine = intel_engine_lookup_user(i915,
747                                                   engine_event_class(event),
748                                                   engine_event_instance(event));
749
750                 BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.enable_count) !=
751                              I915_ENGINE_SAMPLE_COUNT);
752                 BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.sample) !=
753                              I915_ENGINE_SAMPLE_COUNT);
754                 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
755                 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
756                 GEM_BUG_ON(engine->pmu.enable_count[sample] == ~0);
757
758                 engine->pmu.enable |= BIT(sample);
759                 engine->pmu.enable_count[sample]++;
760         }
761
762         spin_unlock_irqrestore(&pmu->lock, flags);
763
764 update:
765         /*
766          * Store the current counter value so we can report the correct delta
767          * for all listeners. Even when the event was already enabled and has
768          * an existing non-zero value.
769          */
770         local64_set(&event->hw.prev_count, __i915_pmu_event_read(event));
771 }
772
773 static void i915_pmu_disable(struct perf_event *event)
774 {
775         struct drm_i915_private *i915 =
776                 container_of(event->pmu, typeof(*i915), pmu.base);
777         const unsigned int bit = event_bit(event);
778         struct i915_pmu *pmu = &i915->pmu;
779         unsigned long flags;
780
781         if (bit == -1)
782                 return;
783
784         spin_lock_irqsave(&pmu->lock, flags);
785
786         if (is_engine_event(event)) {
787                 u8 sample = engine_event_sample(event);
788                 struct intel_engine_cs *engine;
789
790                 engine = intel_engine_lookup_user(i915,
791                                                   engine_event_class(event),
792                                                   engine_event_instance(event));
793
794                 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
795                 GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
796                 GEM_BUG_ON(engine->pmu.enable_count[sample] == 0);
797
798                 /*
799                  * Decrement the reference count and clear the enabled
800                  * bitmask when the last listener on an event goes away.
801                  */
802                 if (--engine->pmu.enable_count[sample] == 0)
803                         engine->pmu.enable &= ~BIT(sample);
804         }
805
806         GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
807         GEM_BUG_ON(pmu->enable_count[bit] == 0);
808         /*
809          * Decrement the reference count and clear the enabled
810          * bitmask when the last listener on an event goes away.
811          */
812         if (--pmu->enable_count[bit] == 0) {
813                 pmu->enable &= ~BIT(bit);
814                 pmu->timer_enabled &= pmu_needs_timer(pmu);
815         }
816
817         spin_unlock_irqrestore(&pmu->lock, flags);
818 }
819
820 static void i915_pmu_event_start(struct perf_event *event, int flags)
821 {
822         struct drm_i915_private *i915 =
823                 container_of(event->pmu, typeof(*i915), pmu.base);
824         struct i915_pmu *pmu = &i915->pmu;
825
826         if (pmu->closed)
827                 return;
828
829         i915_pmu_enable(event);
830         event->hw.state = 0;
831 }
832
833 static void i915_pmu_event_stop(struct perf_event *event, int flags)
834 {
835         struct drm_i915_private *i915 =
836                 container_of(event->pmu, typeof(*i915), pmu.base);
837         struct i915_pmu *pmu = &i915->pmu;
838
839         if (pmu->closed)
840                 goto out;
841
842         if (flags & PERF_EF_UPDATE)
843                 i915_pmu_event_read(event);
844         i915_pmu_disable(event);
845
846 out:
847         event->hw.state = PERF_HES_STOPPED;
848 }
849
850 static int i915_pmu_event_add(struct perf_event *event, int flags)
851 {
852         struct drm_i915_private *i915 =
853                 container_of(event->pmu, typeof(*i915), pmu.base);
854         struct i915_pmu *pmu = &i915->pmu;
855
856         if (pmu->closed)
857                 return -ENODEV;
858
859         if (flags & PERF_EF_START)
860                 i915_pmu_event_start(event, flags);
861
862         return 0;
863 }
864
865 static void i915_pmu_event_del(struct perf_event *event, int flags)
866 {
867         i915_pmu_event_stop(event, PERF_EF_UPDATE);
868 }
869
870 static int i915_pmu_event_event_idx(struct perf_event *event)
871 {
872         return 0;
873 }
874
875 struct i915_str_attribute {
876         struct device_attribute attr;
877         const char *str;
878 };
879
880 static ssize_t i915_pmu_format_show(struct device *dev,
881                                     struct device_attribute *attr, char *buf)
882 {
883         struct i915_str_attribute *eattr;
884
885         eattr = container_of(attr, struct i915_str_attribute, attr);
886         return sprintf(buf, "%s\n", eattr->str);
887 }
888
889 #define I915_PMU_FORMAT_ATTR(_name, _config) \
890         (&((struct i915_str_attribute[]) { \
891                 { .attr = __ATTR(_name, 0444, i915_pmu_format_show, NULL), \
892                   .str = _config, } \
893         })[0].attr.attr)
894
895 static struct attribute *i915_pmu_format_attrs[] = {
896         I915_PMU_FORMAT_ATTR(i915_eventid, "config:0-20"),
897         NULL,
898 };
899
900 static const struct attribute_group i915_pmu_format_attr_group = {
901         .name = "format",
902         .attrs = i915_pmu_format_attrs,
903 };
904
905 struct i915_ext_attribute {
906         struct device_attribute attr;
907         unsigned long val;
908 };
909
910 static ssize_t i915_pmu_event_show(struct device *dev,
911                                    struct device_attribute *attr, char *buf)
912 {
913         struct i915_ext_attribute *eattr;
914
915         eattr = container_of(attr, struct i915_ext_attribute, attr);
916         return sprintf(buf, "config=0x%lx\n", eattr->val);
917 }
918
919 static ssize_t cpumask_show(struct device *dev,
920                             struct device_attribute *attr, char *buf)
921 {
922         return cpumap_print_to_pagebuf(true, buf, &i915_pmu_cpumask);
923 }
924
925 static DEVICE_ATTR_RO(cpumask);
926
927 static struct attribute *i915_cpumask_attrs[] = {
928         &dev_attr_cpumask.attr,
929         NULL,
930 };
931
932 static const struct attribute_group i915_pmu_cpumask_attr_group = {
933         .attrs = i915_cpumask_attrs,
934 };
935
936 #define __event(__counter, __name, __unit) \
937 { \
938         .counter = (__counter), \
939         .name = (__name), \
940         .unit = (__unit), \
941         .global = false, \
942 }
943
944 #define __global_event(__counter, __name, __unit) \
945 { \
946         .counter = (__counter), \
947         .name = (__name), \
948         .unit = (__unit), \
949         .global = true, \
950 }
951
952 #define __engine_event(__sample, __name) \
953 { \
954         .sample = (__sample), \
955         .name = (__name), \
956 }
957
958 static struct i915_ext_attribute *
959 add_i915_attr(struct i915_ext_attribute *attr, const char *name, u64 config)
960 {
961         sysfs_attr_init(&attr->attr.attr);
962         attr->attr.attr.name = name;
963         attr->attr.attr.mode = 0444;
964         attr->attr.show = i915_pmu_event_show;
965         attr->val = config;
966
967         return ++attr;
968 }
969
970 static struct perf_pmu_events_attr *
971 add_pmu_attr(struct perf_pmu_events_attr *attr, const char *name,
972              const char *str)
973 {
974         sysfs_attr_init(&attr->attr.attr);
975         attr->attr.attr.name = name;
976         attr->attr.attr.mode = 0444;
977         attr->attr.show = perf_event_sysfs_show;
978         attr->event_str = str;
979
980         return ++attr;
981 }
982
983 static struct attribute **
984 create_event_attributes(struct i915_pmu *pmu)
985 {
986         struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
987         static const struct {
988                 unsigned int counter;
989                 const char *name;
990                 const char *unit;
991                 bool global;
992         } events[] = {
993                 __event(0, "actual-frequency", "M"),
994                 __event(1, "requested-frequency", "M"),
995                 __global_event(2, "interrupts", NULL),
996                 __event(3, "rc6-residency", "ns"),
997                 __event(4, "software-gt-awake-time", "ns"),
998         };
999         static const struct {
1000                 enum drm_i915_pmu_engine_sample sample;
1001                 char *name;
1002         } engine_events[] = {
1003                 __engine_event(I915_SAMPLE_BUSY, "busy"),
1004                 __engine_event(I915_SAMPLE_SEMA, "sema"),
1005                 __engine_event(I915_SAMPLE_WAIT, "wait"),
1006         };
1007         unsigned int count = 0;
1008         struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
1009         struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
1010         struct attribute **attr = NULL, **attr_iter;
1011         struct intel_engine_cs *engine;
1012         struct intel_gt *gt;
1013         unsigned int i, j;
1014
1015         /* Count how many counters we will be exposing. */
1016         for_each_gt(gt, i915, j) {
1017                 for (i = 0; i < ARRAY_SIZE(events); i++) {
1018                         u64 config = ___I915_PMU_OTHER(j, events[i].counter);
1019
1020                         if (!config_status(i915, config))
1021                                 count++;
1022                 }
1023         }
1024
1025         for_each_uabi_engine(engine, i915) {
1026                 for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
1027                         if (!engine_event_status(engine,
1028                                                  engine_events[i].sample))
1029                                 count++;
1030                 }
1031         }
1032
1033         /* Allocate attribute objects and table. */
1034         i915_attr = kcalloc(count, sizeof(*i915_attr), GFP_KERNEL);
1035         if (!i915_attr)
1036                 goto err_alloc;
1037
1038         pmu_attr = kcalloc(count, sizeof(*pmu_attr), GFP_KERNEL);
1039         if (!pmu_attr)
1040                 goto err_alloc;
1041
1042         /* Max one pointer of each attribute type plus a termination entry. */
1043         attr = kcalloc(count * 2 + 1, sizeof(*attr), GFP_KERNEL);
1044         if (!attr)
1045                 goto err_alloc;
1046
1047         i915_iter = i915_attr;
1048         pmu_iter = pmu_attr;
1049         attr_iter = attr;
1050
1051         /* Initialize supported non-engine counters. */
1052         for_each_gt(gt, i915, j) {
1053                 for (i = 0; i < ARRAY_SIZE(events); i++) {
1054                         u64 config = ___I915_PMU_OTHER(j, events[i].counter);
1055                         char *str;
1056
1057                         if (config_status(i915, config))
1058                                 continue;
1059
1060                         if (events[i].global || !HAS_EXTRA_GT_LIST(i915))
1061                                 str = kstrdup(events[i].name, GFP_KERNEL);
1062                         else
1063                                 str = kasprintf(GFP_KERNEL, "%s-gt%u",
1064                                                 events[i].name, j);
1065                         if (!str)
1066                                 goto err;
1067
1068                         *attr_iter++ = &i915_iter->attr.attr;
1069                         i915_iter = add_i915_attr(i915_iter, str, config);
1070
1071                         if (events[i].unit) {
1072                                 if (events[i].global || !HAS_EXTRA_GT_LIST(i915))
1073                                         str = kasprintf(GFP_KERNEL, "%s.unit",
1074                                                         events[i].name);
1075                                 else
1076                                         str = kasprintf(GFP_KERNEL, "%s-gt%u.unit",
1077                                                         events[i].name, j);
1078                                 if (!str)
1079                                         goto err;
1080
1081                                 *attr_iter++ = &pmu_iter->attr.attr;
1082                                 pmu_iter = add_pmu_attr(pmu_iter, str,
1083                                                         events[i].unit);
1084                         }
1085                 }
1086         }
1087
1088         /* Initialize supported engine counters. */
1089         for_each_uabi_engine(engine, i915) {
1090                 for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
1091                         char *str;
1092
1093                         if (engine_event_status(engine,
1094                                                 engine_events[i].sample))
1095                                 continue;
1096
1097                         str = kasprintf(GFP_KERNEL, "%s-%s",
1098                                         engine->name, engine_events[i].name);
1099                         if (!str)
1100                                 goto err;
1101
1102                         *attr_iter++ = &i915_iter->attr.attr;
1103                         i915_iter =
1104                                 add_i915_attr(i915_iter, str,
1105                                               __I915_PMU_ENGINE(engine->uabi_class,
1106                                                                 engine->uabi_instance,
1107                                                                 engine_events[i].sample));
1108
1109                         str = kasprintf(GFP_KERNEL, "%s-%s.unit",
1110                                         engine->name, engine_events[i].name);
1111                         if (!str)
1112                                 goto err;
1113
1114                         *attr_iter++ = &pmu_iter->attr.attr;
1115                         pmu_iter = add_pmu_attr(pmu_iter, str, "ns");
1116                 }
1117         }
1118
1119         pmu->i915_attr = i915_attr;
1120         pmu->pmu_attr = pmu_attr;
1121
1122         return attr;
1123
1124 err:;
1125         for (attr_iter = attr; *attr_iter; attr_iter++)
1126                 kfree((*attr_iter)->name);
1127
1128 err_alloc:
1129         kfree(attr);
1130         kfree(i915_attr);
1131         kfree(pmu_attr);
1132
1133         return NULL;
1134 }
1135
1136 static void free_event_attributes(struct i915_pmu *pmu)
1137 {
1138         struct attribute **attr_iter = pmu->events_attr_group.attrs;
1139
1140         for (; *attr_iter; attr_iter++)
1141                 kfree((*attr_iter)->name);
1142
1143         kfree(pmu->events_attr_group.attrs);
1144         kfree(pmu->i915_attr);
1145         kfree(pmu->pmu_attr);
1146
1147         pmu->events_attr_group.attrs = NULL;
1148         pmu->i915_attr = NULL;
1149         pmu->pmu_attr = NULL;
1150 }
1151
1152 static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
1153 {
1154         struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
1155
1156         GEM_BUG_ON(!pmu->base.event_init);
1157
1158         /* Select the first online CPU as a designated reader. */
1159         if (cpumask_empty(&i915_pmu_cpumask))
1160                 cpumask_set_cpu(cpu, &i915_pmu_cpumask);
1161
1162         return 0;
1163 }
1164
1165 static int i915_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
1166 {
1167         struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
1168         unsigned int target = i915_pmu_target_cpu;
1169
1170         GEM_BUG_ON(!pmu->base.event_init);
1171
1172         /*
1173          * Unregistering an instance generates a CPU offline event which we must
1174          * ignore to avoid incorrectly modifying the shared i915_pmu_cpumask.
1175          */
1176         if (pmu->closed)
1177                 return 0;
1178
1179         if (cpumask_test_and_clear_cpu(cpu, &i915_pmu_cpumask)) {
1180                 target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
1181
1182                 /* Migrate events if there is a valid target */
1183                 if (target < nr_cpu_ids) {
1184                         cpumask_set_cpu(target, &i915_pmu_cpumask);
1185                         i915_pmu_target_cpu = target;
1186                 }
1187         }
1188
1189         if (target < nr_cpu_ids && target != pmu->cpuhp.cpu) {
1190                 perf_pmu_migrate_context(&pmu->base, cpu, target);
1191                 pmu->cpuhp.cpu = target;
1192         }
1193
1194         return 0;
1195 }
1196
1197 static enum cpuhp_state cpuhp_slot = CPUHP_INVALID;
1198
1199 int i915_pmu_init(void)
1200 {
1201         int ret;
1202
1203         ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
1204                                       "perf/x86/intel/i915:online",
1205                                       i915_pmu_cpu_online,
1206                                       i915_pmu_cpu_offline);
1207         if (ret < 0)
1208                 pr_notice("Failed to setup cpuhp state for i915 PMU! (%d)\n",
1209                           ret);
1210         else
1211                 cpuhp_slot = ret;
1212
1213         return 0;
1214 }
1215
1216 void i915_pmu_exit(void)
1217 {
1218         if (cpuhp_slot != CPUHP_INVALID)
1219                 cpuhp_remove_multi_state(cpuhp_slot);
1220 }
1221
1222 static int i915_pmu_register_cpuhp_state(struct i915_pmu *pmu)
1223 {
1224         if (cpuhp_slot == CPUHP_INVALID)
1225                 return -EINVAL;
1226
1227         return cpuhp_state_add_instance(cpuhp_slot, &pmu->cpuhp.node);
1228 }
1229
1230 static void i915_pmu_unregister_cpuhp_state(struct i915_pmu *pmu)
1231 {
1232         cpuhp_state_remove_instance(cpuhp_slot, &pmu->cpuhp.node);
1233 }
1234
1235 static bool is_igp(struct drm_i915_private *i915)
1236 {
1237         struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
1238
1239         /* IGP is 0000:00:02.0 */
1240         return pci_domain_nr(pdev->bus) == 0 &&
1241                pdev->bus->number == 0 &&
1242                PCI_SLOT(pdev->devfn) == 2 &&
1243                PCI_FUNC(pdev->devfn) == 0;
1244 }
1245
1246 void i915_pmu_register(struct drm_i915_private *i915)
1247 {
1248         struct i915_pmu *pmu = &i915->pmu;
1249         const struct attribute_group *attr_groups[] = {
1250                 &i915_pmu_format_attr_group,
1251                 &pmu->events_attr_group,
1252                 &i915_pmu_cpumask_attr_group,
1253                 NULL
1254         };
1255
1256         int ret = -ENOMEM;
1257
1258         if (GRAPHICS_VER(i915) <= 2) {
1259                 drm_info(&i915->drm, "PMU not supported for this GPU.");
1260                 return;
1261         }
1262
1263         spin_lock_init(&pmu->lock);
1264         hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1265         pmu->timer.function = i915_sample;
1266         pmu->cpuhp.cpu = -1;
1267         init_rc6(pmu);
1268
1269         if (!is_igp(i915)) {
1270                 pmu->name = kasprintf(GFP_KERNEL,
1271                                       "i915_%s",
1272                                       dev_name(i915->drm.dev));
1273                 if (pmu->name) {
1274                         /* tools/perf reserves colons as special. */
1275                         strreplace((char *)pmu->name, ':', '_');
1276                 }
1277         } else {
1278                 pmu->name = "i915";
1279         }
1280         if (!pmu->name)
1281                 goto err;
1282
1283         pmu->events_attr_group.name = "events";
1284         pmu->events_attr_group.attrs = create_event_attributes(pmu);
1285         if (!pmu->events_attr_group.attrs)
1286                 goto err_name;
1287
1288         pmu->base.attr_groups = kmemdup(attr_groups, sizeof(attr_groups),
1289                                         GFP_KERNEL);
1290         if (!pmu->base.attr_groups)
1291                 goto err_attr;
1292
1293         pmu->base.module        = THIS_MODULE;
1294         pmu->base.task_ctx_nr   = perf_invalid_context;
1295         pmu->base.event_init    = i915_pmu_event_init;
1296         pmu->base.add           = i915_pmu_event_add;
1297         pmu->base.del           = i915_pmu_event_del;
1298         pmu->base.start         = i915_pmu_event_start;
1299         pmu->base.stop          = i915_pmu_event_stop;
1300         pmu->base.read          = i915_pmu_event_read;
1301         pmu->base.event_idx     = i915_pmu_event_event_idx;
1302
1303         ret = perf_pmu_register(&pmu->base, pmu->name, -1);
1304         if (ret)
1305                 goto err_groups;
1306
1307         ret = i915_pmu_register_cpuhp_state(pmu);
1308         if (ret)
1309                 goto err_unreg;
1310
1311         return;
1312
1313 err_unreg:
1314         perf_pmu_unregister(&pmu->base);
1315 err_groups:
1316         kfree(pmu->base.attr_groups);
1317 err_attr:
1318         pmu->base.event_init = NULL;
1319         free_event_attributes(pmu);
1320 err_name:
1321         if (!is_igp(i915))
1322                 kfree(pmu->name);
1323 err:
1324         drm_notice(&i915->drm, "Failed to register PMU!\n");
1325 }
1326
1327 void i915_pmu_unregister(struct drm_i915_private *i915)
1328 {
1329         struct i915_pmu *pmu = &i915->pmu;
1330
1331         if (!pmu->base.event_init)
1332                 return;
1333
1334         /*
1335          * "Disconnect" the PMU callbacks - since all are atomic synchronize_rcu
1336          * ensures all currently executing ones will have exited before we
1337          * proceed with unregistration.
1338          */
1339         pmu->closed = true;
1340         synchronize_rcu();
1341
1342         hrtimer_cancel(&pmu->timer);
1343
1344         i915_pmu_unregister_cpuhp_state(pmu);
1345
1346         perf_pmu_unregister(&pmu->base);
1347         pmu->base.event_init = NULL;
1348         kfree(pmu->base.attr_groups);
1349         if (!is_igp(i915))
1350                 kfree(pmu->name);
1351         free_event_attributes(pmu);
1352 }