xref: /linux/drivers/gpu/drm/i915/i915_pmu.c (revision 160b8e75932fd51a49607d32dbfa1d417977b79c)
1 /*
2  * Copyright © 2017 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  */
24 
25 #include <linux/perf_event.h>
26 #include <linux/pm_runtime.h>
27 
28 #include "i915_drv.h"
29 #include "i915_pmu.h"
30 #include "intel_ringbuffer.h"
31 
32 /* Frequency for the sampling timer for events which need it. */
33 #define FREQUENCY 200
34 #define PERIOD max_t(u64, 10000, NSEC_PER_SEC / FREQUENCY)
35 
36 #define ENGINE_SAMPLE_MASK \
37 	(BIT(I915_SAMPLE_BUSY) | \
38 	 BIT(I915_SAMPLE_WAIT) | \
39 	 BIT(I915_SAMPLE_SEMA))
40 
41 #define ENGINE_SAMPLE_BITS (1 << I915_PMU_SAMPLE_BITS)
42 
43 static cpumask_t i915_pmu_cpumask;
44 
45 static u8 engine_config_sample(u64 config)
46 {
47 	return config & I915_PMU_SAMPLE_MASK;
48 }
49 
50 static u8 engine_event_sample(struct perf_event *event)
51 {
52 	return engine_config_sample(event->attr.config);
53 }
54 
55 static u8 engine_event_class(struct perf_event *event)
56 {
57 	return (event->attr.config >> I915_PMU_CLASS_SHIFT) & 0xff;
58 }
59 
60 static u8 engine_event_instance(struct perf_event *event)
61 {
62 	return (event->attr.config >> I915_PMU_SAMPLE_BITS) & 0xff;
63 }
64 
65 static bool is_engine_config(u64 config)
66 {
67 	return config < __I915_PMU_OTHER(0);
68 }
69 
70 static unsigned int config_enabled_bit(u64 config)
71 {
72 	if (is_engine_config(config))
73 		return engine_config_sample(config);
74 	else
75 		return ENGINE_SAMPLE_BITS + (config - __I915_PMU_OTHER(0));
76 }
77 
78 static u64 config_enabled_mask(u64 config)
79 {
80 	return BIT_ULL(config_enabled_bit(config));
81 }
82 
83 static bool is_engine_event(struct perf_event *event)
84 {
85 	return is_engine_config(event->attr.config);
86 }
87 
88 static unsigned int event_enabled_bit(struct perf_event *event)
89 {
90 	return config_enabled_bit(event->attr.config);
91 }
92 
93 static bool pmu_needs_timer(struct drm_i915_private *i915, bool gpu_active)
94 {
95 	u64 enable;
96 
97 	/*
98 	 * Only some counters need the sampling timer.
99 	 *
100 	 * We start with a bitmask of all currently enabled events.
101 	 */
102 	enable = i915->pmu.enable;
103 
104 	/*
105 	 * Mask out all the ones which do not need the timer, or in
106 	 * other words keep all the ones that could need the timer.
107 	 */
108 	enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) |
109 		  config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) |
110 		  ENGINE_SAMPLE_MASK;
111 
112 	/*
113 	 * When the GPU is idle per-engine counters do not need to be
114 	 * running so clear those bits out.
115 	 */
116 	if (!gpu_active)
117 		enable &= ~ENGINE_SAMPLE_MASK;
118 	/*
119 	 * Also there is software busyness tracking available we do not
120 	 * need the timer for I915_SAMPLE_BUSY counter.
121 	 *
122 	 * Use RCS as proxy for all engines.
123 	 */
124 	else if (intel_engine_supports_stats(i915->engine[RCS]))
125 		enable &= ~BIT(I915_SAMPLE_BUSY);
126 
127 	/*
128 	 * If some bits remain it means we need the sampling timer running.
129 	 */
130 	return enable;
131 }
132 
133 void i915_pmu_gt_parked(struct drm_i915_private *i915)
134 {
135 	if (!i915->pmu.base.event_init)
136 		return;
137 
138 	spin_lock_irq(&i915->pmu.lock);
139 	/*
140 	 * Signal sampling timer to stop if only engine events are enabled and
141 	 * GPU went idle.
142 	 */
143 	i915->pmu.timer_enabled = pmu_needs_timer(i915, false);
144 	spin_unlock_irq(&i915->pmu.lock);
145 }
146 
147 static void __i915_pmu_maybe_start_timer(struct drm_i915_private *i915)
148 {
149 	if (!i915->pmu.timer_enabled && pmu_needs_timer(i915, true)) {
150 		i915->pmu.timer_enabled = true;
151 		hrtimer_start_range_ns(&i915->pmu.timer,
152 				       ns_to_ktime(PERIOD), 0,
153 				       HRTIMER_MODE_REL_PINNED);
154 	}
155 }
156 
157 void i915_pmu_gt_unparked(struct drm_i915_private *i915)
158 {
159 	if (!i915->pmu.base.event_init)
160 		return;
161 
162 	spin_lock_irq(&i915->pmu.lock);
163 	/*
164 	 * Re-enable sampling timer when GPU goes active.
165 	 */
166 	__i915_pmu_maybe_start_timer(i915);
167 	spin_unlock_irq(&i915->pmu.lock);
168 }
169 
170 static bool grab_forcewake(struct drm_i915_private *i915, bool fw)
171 {
172 	if (!fw)
173 		intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
174 
175 	return true;
176 }
177 
178 static void
179 update_sample(struct i915_pmu_sample *sample, u32 unit, u32 val)
180 {
181 	sample->cur += mul_u32_u32(val, unit);
182 }
183 
184 static void engines_sample(struct drm_i915_private *dev_priv)
185 {
186 	struct intel_engine_cs *engine;
187 	enum intel_engine_id id;
188 	bool fw = false;
189 
190 	if ((dev_priv->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
191 		return;
192 
193 	if (!dev_priv->gt.awake)
194 		return;
195 
196 	if (!intel_runtime_pm_get_if_in_use(dev_priv))
197 		return;
198 
199 	for_each_engine(engine, dev_priv, id) {
200 		u32 current_seqno = intel_engine_get_seqno(engine);
201 		u32 last_seqno = intel_engine_last_submit(engine);
202 		u32 val;
203 
204 		val = !i915_seqno_passed(current_seqno, last_seqno);
205 
206 		update_sample(&engine->pmu.sample[I915_SAMPLE_BUSY],
207 			      PERIOD, val);
208 
209 		if (val && (engine->pmu.enable &
210 		    (BIT(I915_SAMPLE_WAIT) | BIT(I915_SAMPLE_SEMA)))) {
211 			fw = grab_forcewake(dev_priv, fw);
212 
213 			val = I915_READ_FW(RING_CTL(engine->mmio_base));
214 		} else {
215 			val = 0;
216 		}
217 
218 		update_sample(&engine->pmu.sample[I915_SAMPLE_WAIT],
219 			      PERIOD, !!(val & RING_WAIT));
220 
221 		update_sample(&engine->pmu.sample[I915_SAMPLE_SEMA],
222 			      PERIOD, !!(val & RING_WAIT_SEMAPHORE));
223 	}
224 
225 	if (fw)
226 		intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
227 
228 	intel_runtime_pm_put(dev_priv);
229 }
230 
231 static void frequency_sample(struct drm_i915_private *dev_priv)
232 {
233 	if (dev_priv->pmu.enable &
234 	    config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY)) {
235 		u32 val;
236 
237 		val = dev_priv->gt_pm.rps.cur_freq;
238 		if (dev_priv->gt.awake &&
239 		    intel_runtime_pm_get_if_in_use(dev_priv)) {
240 			val = intel_get_cagf(dev_priv,
241 					     I915_READ_NOTRACE(GEN6_RPSTAT1));
242 			intel_runtime_pm_put(dev_priv);
243 		}
244 
245 		update_sample(&dev_priv->pmu.sample[__I915_SAMPLE_FREQ_ACT],
246 			      1, intel_gpu_freq(dev_priv, val));
247 	}
248 
249 	if (dev_priv->pmu.enable &
250 	    config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY)) {
251 		update_sample(&dev_priv->pmu.sample[__I915_SAMPLE_FREQ_REQ], 1,
252 			      intel_gpu_freq(dev_priv,
253 					     dev_priv->gt_pm.rps.cur_freq));
254 	}
255 }
256 
257 static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer)
258 {
259 	struct drm_i915_private *i915 =
260 		container_of(hrtimer, struct drm_i915_private, pmu.timer);
261 
262 	if (!READ_ONCE(i915->pmu.timer_enabled))
263 		return HRTIMER_NORESTART;
264 
265 	engines_sample(i915);
266 	frequency_sample(i915);
267 
268 	hrtimer_forward_now(hrtimer, ns_to_ktime(PERIOD));
269 	return HRTIMER_RESTART;
270 }
271 
272 static u64 count_interrupts(struct drm_i915_private *i915)
273 {
274 	/* open-coded kstat_irqs() */
275 	struct irq_desc *desc = irq_to_desc(i915->drm.pdev->irq);
276 	u64 sum = 0;
277 	int cpu;
278 
279 	if (!desc || !desc->kstat_irqs)
280 		return 0;
281 
282 	for_each_possible_cpu(cpu)
283 		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
284 
285 	return sum;
286 }
287 
288 static void engine_event_destroy(struct perf_event *event)
289 {
290 	struct drm_i915_private *i915 =
291 		container_of(event->pmu, typeof(*i915), pmu.base);
292 	struct intel_engine_cs *engine;
293 
294 	engine = intel_engine_lookup_user(i915,
295 					  engine_event_class(event),
296 					  engine_event_instance(event));
297 	if (WARN_ON_ONCE(!engine))
298 		return;
299 
300 	if (engine_event_sample(event) == I915_SAMPLE_BUSY &&
301 	    intel_engine_supports_stats(engine))
302 		intel_disable_engine_stats(engine);
303 }
304 
305 static void i915_pmu_event_destroy(struct perf_event *event)
306 {
307 	WARN_ON(event->parent);
308 
309 	if (is_engine_event(event))
310 		engine_event_destroy(event);
311 }
312 
313 static int
314 engine_event_status(struct intel_engine_cs *engine,
315 		    enum drm_i915_pmu_engine_sample sample)
316 {
317 	switch (sample) {
318 	case I915_SAMPLE_BUSY:
319 	case I915_SAMPLE_WAIT:
320 		break;
321 	case I915_SAMPLE_SEMA:
322 		if (INTEL_GEN(engine->i915) < 6)
323 			return -ENODEV;
324 		break;
325 	default:
326 		return -ENOENT;
327 	}
328 
329 	return 0;
330 }
331 
332 static int
333 config_status(struct drm_i915_private *i915, u64 config)
334 {
335 	switch (config) {
336 	case I915_PMU_ACTUAL_FREQUENCY:
337 		if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
338 			/* Requires a mutex for sampling! */
339 			return -ENODEV;
340 		/* Fall-through. */
341 	case I915_PMU_REQUESTED_FREQUENCY:
342 		if (INTEL_GEN(i915) < 6)
343 			return -ENODEV;
344 		break;
345 	case I915_PMU_INTERRUPTS:
346 		break;
347 	case I915_PMU_RC6_RESIDENCY:
348 		if (!HAS_RC6(i915))
349 			return -ENODEV;
350 		break;
351 	default:
352 		return -ENOENT;
353 	}
354 
355 	return 0;
356 }
357 
358 static int engine_event_init(struct perf_event *event)
359 {
360 	struct drm_i915_private *i915 =
361 		container_of(event->pmu, typeof(*i915), pmu.base);
362 	struct intel_engine_cs *engine;
363 	u8 sample;
364 	int ret;
365 
366 	engine = intel_engine_lookup_user(i915, engine_event_class(event),
367 					  engine_event_instance(event));
368 	if (!engine)
369 		return -ENODEV;
370 
371 	sample = engine_event_sample(event);
372 	ret = engine_event_status(engine, sample);
373 	if (ret)
374 		return ret;
375 
376 	if (sample == I915_SAMPLE_BUSY && intel_engine_supports_stats(engine))
377 		ret = intel_enable_engine_stats(engine);
378 
379 	return ret;
380 }
381 
382 static int i915_pmu_event_init(struct perf_event *event)
383 {
384 	struct drm_i915_private *i915 =
385 		container_of(event->pmu, typeof(*i915), pmu.base);
386 	int ret;
387 
388 	if (event->attr.type != event->pmu->type)
389 		return -ENOENT;
390 
391 	/* unsupported modes and filters */
392 	if (event->attr.sample_period) /* no sampling */
393 		return -EINVAL;
394 
395 	if (has_branch_stack(event))
396 		return -EOPNOTSUPP;
397 
398 	if (event->cpu < 0)
399 		return -EINVAL;
400 
401 	/* only allow running on one cpu at a time */
402 	if (!cpumask_test_cpu(event->cpu, &i915_pmu_cpumask))
403 		return -EINVAL;
404 
405 	if (is_engine_event(event))
406 		ret = engine_event_init(event);
407 	else
408 		ret = config_status(i915, event->attr.config);
409 	if (ret)
410 		return ret;
411 
412 	if (!event->parent)
413 		event->destroy = i915_pmu_event_destroy;
414 
415 	return 0;
416 }
417 
418 static u64 __get_rc6(struct drm_i915_private *i915)
419 {
420 	u64 val;
421 
422 	val = intel_rc6_residency_ns(i915,
423 				     IS_VALLEYVIEW(i915) ?
424 				     VLV_GT_RENDER_RC6 :
425 				     GEN6_GT_GFX_RC6);
426 
427 	if (HAS_RC6p(i915))
428 		val += intel_rc6_residency_ns(i915, GEN6_GT_GFX_RC6p);
429 
430 	if (HAS_RC6pp(i915))
431 		val += intel_rc6_residency_ns(i915, GEN6_GT_GFX_RC6pp);
432 
433 	return val;
434 }
435 
436 static u64 get_rc6(struct drm_i915_private *i915, bool locked)
437 {
438 #if IS_ENABLED(CONFIG_PM)
439 	unsigned long flags;
440 	u64 val;
441 
442 	if (intel_runtime_pm_get_if_in_use(i915)) {
443 		val = __get_rc6(i915);
444 		intel_runtime_pm_put(i915);
445 
446 		/*
447 		 * If we are coming back from being runtime suspended we must
448 		 * be careful not to report a larger value than returned
449 		 * previously.
450 		 */
451 
452 		if (!locked)
453 			spin_lock_irqsave(&i915->pmu.lock, flags);
454 
455 		if (val >= i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur) {
456 			i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur = 0;
457 			i915->pmu.sample[__I915_SAMPLE_RC6].cur = val;
458 		} else {
459 			val = i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur;
460 		}
461 
462 		if (!locked)
463 			spin_unlock_irqrestore(&i915->pmu.lock, flags);
464 	} else {
465 		struct pci_dev *pdev = i915->drm.pdev;
466 		struct device *kdev = &pdev->dev;
467 		unsigned long flags2;
468 
469 		/*
470 		 * We are runtime suspended.
471 		 *
472 		 * Report the delta from when the device was suspended to now,
473 		 * on top of the last known real value, as the approximated RC6
474 		 * counter value.
475 		 */
476 		if (!locked)
477 			spin_lock_irqsave(&i915->pmu.lock, flags);
478 
479 		spin_lock_irqsave(&kdev->power.lock, flags2);
480 
481 		if (!i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur)
482 			i915->pmu.suspended_jiffies_last =
483 						kdev->power.suspended_jiffies;
484 
485 		val = kdev->power.suspended_jiffies -
486 		      i915->pmu.suspended_jiffies_last;
487 		val += jiffies - kdev->power.accounting_timestamp;
488 
489 		spin_unlock_irqrestore(&kdev->power.lock, flags2);
490 
491 		val = jiffies_to_nsecs(val);
492 		val += i915->pmu.sample[__I915_SAMPLE_RC6].cur;
493 		i915->pmu.sample[__I915_SAMPLE_RC6_ESTIMATED].cur = val;
494 
495 		if (!locked)
496 			spin_unlock_irqrestore(&i915->pmu.lock, flags);
497 	}
498 
499 	return val;
500 #else
501 	return __get_rc6(i915);
502 #endif
503 }
504 
505 static u64 __i915_pmu_event_read(struct perf_event *event, bool locked)
506 {
507 	struct drm_i915_private *i915 =
508 		container_of(event->pmu, typeof(*i915), pmu.base);
509 	u64 val = 0;
510 
511 	if (is_engine_event(event)) {
512 		u8 sample = engine_event_sample(event);
513 		struct intel_engine_cs *engine;
514 
515 		engine = intel_engine_lookup_user(i915,
516 						  engine_event_class(event),
517 						  engine_event_instance(event));
518 
519 		if (WARN_ON_ONCE(!engine)) {
520 			/* Do nothing */
521 		} else if (sample == I915_SAMPLE_BUSY &&
522 			   intel_engine_supports_stats(engine)) {
523 			val = ktime_to_ns(intel_engine_get_busy_time(engine));
524 		} else {
525 			val = engine->pmu.sample[sample].cur;
526 		}
527 	} else {
528 		switch (event->attr.config) {
529 		case I915_PMU_ACTUAL_FREQUENCY:
530 			val =
531 			   div_u64(i915->pmu.sample[__I915_SAMPLE_FREQ_ACT].cur,
532 				   FREQUENCY);
533 			break;
534 		case I915_PMU_REQUESTED_FREQUENCY:
535 			val =
536 			   div_u64(i915->pmu.sample[__I915_SAMPLE_FREQ_REQ].cur,
537 				   FREQUENCY);
538 			break;
539 		case I915_PMU_INTERRUPTS:
540 			val = count_interrupts(i915);
541 			break;
542 		case I915_PMU_RC6_RESIDENCY:
543 			val = get_rc6(i915, locked);
544 			break;
545 		}
546 	}
547 
548 	return val;
549 }
550 
551 static void i915_pmu_event_read(struct perf_event *event)
552 {
553 	struct hw_perf_event *hwc = &event->hw;
554 	u64 prev, new;
555 
556 again:
557 	prev = local64_read(&hwc->prev_count);
558 	new = __i915_pmu_event_read(event, false);
559 
560 	if (local64_cmpxchg(&hwc->prev_count, prev, new) != prev)
561 		goto again;
562 
563 	local64_add(new - prev, &event->count);
564 }
565 
566 static void i915_pmu_enable(struct perf_event *event)
567 {
568 	struct drm_i915_private *i915 =
569 		container_of(event->pmu, typeof(*i915), pmu.base);
570 	unsigned int bit = event_enabled_bit(event);
571 	unsigned long flags;
572 
573 	spin_lock_irqsave(&i915->pmu.lock, flags);
574 
575 	/*
576 	 * Update the bitmask of enabled events and increment
577 	 * the event reference counter.
578 	 */
579 	GEM_BUG_ON(bit >= I915_PMU_MASK_BITS);
580 	GEM_BUG_ON(i915->pmu.enable_count[bit] == ~0);
581 	i915->pmu.enable |= BIT_ULL(bit);
582 	i915->pmu.enable_count[bit]++;
583 
584 	/*
585 	 * Start the sampling timer if needed and not already enabled.
586 	 */
587 	__i915_pmu_maybe_start_timer(i915);
588 
589 	/*
590 	 * For per-engine events the bitmask and reference counting
591 	 * is stored per engine.
592 	 */
593 	if (is_engine_event(event)) {
594 		u8 sample = engine_event_sample(event);
595 		struct intel_engine_cs *engine;
596 
597 		engine = intel_engine_lookup_user(i915,
598 						  engine_event_class(event),
599 						  engine_event_instance(event));
600 		GEM_BUG_ON(!engine);
601 		engine->pmu.enable |= BIT(sample);
602 
603 		GEM_BUG_ON(sample >= I915_PMU_SAMPLE_BITS);
604 		GEM_BUG_ON(engine->pmu.enable_count[sample] == ~0);
605 		engine->pmu.enable_count[sample]++;
606 	}
607 
608 	/*
609 	 * Store the current counter value so we can report the correct delta
610 	 * for all listeners. Even when the event was already enabled and has
611 	 * an existing non-zero value.
612 	 */
613 	local64_set(&event->hw.prev_count, __i915_pmu_event_read(event, true));
614 
615 	spin_unlock_irqrestore(&i915->pmu.lock, flags);
616 }
617 
618 static void i915_pmu_disable(struct perf_event *event)
619 {
620 	struct drm_i915_private *i915 =
621 		container_of(event->pmu, typeof(*i915), pmu.base);
622 	unsigned int bit = event_enabled_bit(event);
623 	unsigned long flags;
624 
625 	spin_lock_irqsave(&i915->pmu.lock, flags);
626 
627 	if (is_engine_event(event)) {
628 		u8 sample = engine_event_sample(event);
629 		struct intel_engine_cs *engine;
630 
631 		engine = intel_engine_lookup_user(i915,
632 						  engine_event_class(event),
633 						  engine_event_instance(event));
634 		GEM_BUG_ON(!engine);
635 		GEM_BUG_ON(sample >= I915_PMU_SAMPLE_BITS);
636 		GEM_BUG_ON(engine->pmu.enable_count[sample] == 0);
637 		/*
638 		 * Decrement the reference count and clear the enabled
639 		 * bitmask when the last listener on an event goes away.
640 		 */
641 		if (--engine->pmu.enable_count[sample] == 0)
642 			engine->pmu.enable &= ~BIT(sample);
643 	}
644 
645 	GEM_BUG_ON(bit >= I915_PMU_MASK_BITS);
646 	GEM_BUG_ON(i915->pmu.enable_count[bit] == 0);
647 	/*
648 	 * Decrement the reference count and clear the enabled
649 	 * bitmask when the last listener on an event goes away.
650 	 */
651 	if (--i915->pmu.enable_count[bit] == 0) {
652 		i915->pmu.enable &= ~BIT_ULL(bit);
653 		i915->pmu.timer_enabled &= pmu_needs_timer(i915, true);
654 	}
655 
656 	spin_unlock_irqrestore(&i915->pmu.lock, flags);
657 }
658 
659 static void i915_pmu_event_start(struct perf_event *event, int flags)
660 {
661 	i915_pmu_enable(event);
662 	event->hw.state = 0;
663 }
664 
665 static void i915_pmu_event_stop(struct perf_event *event, int flags)
666 {
667 	if (flags & PERF_EF_UPDATE)
668 		i915_pmu_event_read(event);
669 	i915_pmu_disable(event);
670 	event->hw.state = PERF_HES_STOPPED;
671 }
672 
673 static int i915_pmu_event_add(struct perf_event *event, int flags)
674 {
675 	if (flags & PERF_EF_START)
676 		i915_pmu_event_start(event, flags);
677 
678 	return 0;
679 }
680 
681 static void i915_pmu_event_del(struct perf_event *event, int flags)
682 {
683 	i915_pmu_event_stop(event, PERF_EF_UPDATE);
684 }
685 
686 static int i915_pmu_event_event_idx(struct perf_event *event)
687 {
688 	return 0;
689 }
690 
691 struct i915_str_attribute {
692 	struct device_attribute attr;
693 	const char *str;
694 };
695 
696 static ssize_t i915_pmu_format_show(struct device *dev,
697 				    struct device_attribute *attr, char *buf)
698 {
699 	struct i915_str_attribute *eattr;
700 
701 	eattr = container_of(attr, struct i915_str_attribute, attr);
702 	return sprintf(buf, "%s\n", eattr->str);
703 }
704 
705 #define I915_PMU_FORMAT_ATTR(_name, _config) \
706 	(&((struct i915_str_attribute[]) { \
707 		{ .attr = __ATTR(_name, 0444, i915_pmu_format_show, NULL), \
708 		  .str = _config, } \
709 	})[0].attr.attr)
710 
711 static struct attribute *i915_pmu_format_attrs[] = {
712 	I915_PMU_FORMAT_ATTR(i915_eventid, "config:0-20"),
713 	NULL,
714 };
715 
716 static const struct attribute_group i915_pmu_format_attr_group = {
717 	.name = "format",
718 	.attrs = i915_pmu_format_attrs,
719 };
720 
721 struct i915_ext_attribute {
722 	struct device_attribute attr;
723 	unsigned long val;
724 };
725 
726 static ssize_t i915_pmu_event_show(struct device *dev,
727 				   struct device_attribute *attr, char *buf)
728 {
729 	struct i915_ext_attribute *eattr;
730 
731 	eattr = container_of(attr, struct i915_ext_attribute, attr);
732 	return sprintf(buf, "config=0x%lx\n", eattr->val);
733 }
734 
735 static struct attribute_group i915_pmu_events_attr_group = {
736 	.name = "events",
737 	/* Patch in attrs at runtime. */
738 };
739 
740 static ssize_t
741 i915_pmu_get_attr_cpumask(struct device *dev,
742 			  struct device_attribute *attr,
743 			  char *buf)
744 {
745 	return cpumap_print_to_pagebuf(true, buf, &i915_pmu_cpumask);
746 }
747 
748 static DEVICE_ATTR(cpumask, 0444, i915_pmu_get_attr_cpumask, NULL);
749 
750 static struct attribute *i915_cpumask_attrs[] = {
751 	&dev_attr_cpumask.attr,
752 	NULL,
753 };
754 
755 static const struct attribute_group i915_pmu_cpumask_attr_group = {
756 	.attrs = i915_cpumask_attrs,
757 };
758 
759 static const struct attribute_group *i915_pmu_attr_groups[] = {
760 	&i915_pmu_format_attr_group,
761 	&i915_pmu_events_attr_group,
762 	&i915_pmu_cpumask_attr_group,
763 	NULL
764 };
765 
766 #define __event(__config, __name, __unit) \
767 { \
768 	.config = (__config), \
769 	.name = (__name), \
770 	.unit = (__unit), \
771 }
772 
773 #define __engine_event(__sample, __name) \
774 { \
775 	.sample = (__sample), \
776 	.name = (__name), \
777 }
778 
779 static struct i915_ext_attribute *
780 add_i915_attr(struct i915_ext_attribute *attr, const char *name, u64 config)
781 {
782 	sysfs_attr_init(&attr->attr.attr);
783 	attr->attr.attr.name = name;
784 	attr->attr.attr.mode = 0444;
785 	attr->attr.show = i915_pmu_event_show;
786 	attr->val = config;
787 
788 	return ++attr;
789 }
790 
791 static struct perf_pmu_events_attr *
792 add_pmu_attr(struct perf_pmu_events_attr *attr, const char *name,
793 	     const char *str)
794 {
795 	sysfs_attr_init(&attr->attr.attr);
796 	attr->attr.attr.name = name;
797 	attr->attr.attr.mode = 0444;
798 	attr->attr.show = perf_event_sysfs_show;
799 	attr->event_str = str;
800 
801 	return ++attr;
802 }
803 
804 static struct attribute **
805 create_event_attributes(struct drm_i915_private *i915)
806 {
807 	static const struct {
808 		u64 config;
809 		const char *name;
810 		const char *unit;
811 	} events[] = {
812 		__event(I915_PMU_ACTUAL_FREQUENCY, "actual-frequency", "MHz"),
813 		__event(I915_PMU_REQUESTED_FREQUENCY, "requested-frequency", "MHz"),
814 		__event(I915_PMU_INTERRUPTS, "interrupts", NULL),
815 		__event(I915_PMU_RC6_RESIDENCY, "rc6-residency", "ns"),
816 	};
817 	static const struct {
818 		enum drm_i915_pmu_engine_sample sample;
819 		char *name;
820 	} engine_events[] = {
821 		__engine_event(I915_SAMPLE_BUSY, "busy"),
822 		__engine_event(I915_SAMPLE_SEMA, "sema"),
823 		__engine_event(I915_SAMPLE_WAIT, "wait"),
824 	};
825 	unsigned int count = 0;
826 	struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
827 	struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
828 	struct attribute **attr = NULL, **attr_iter;
829 	struct intel_engine_cs *engine;
830 	enum intel_engine_id id;
831 	unsigned int i;
832 
833 	/* Count how many counters we will be exposing. */
834 	for (i = 0; i < ARRAY_SIZE(events); i++) {
835 		if (!config_status(i915, events[i].config))
836 			count++;
837 	}
838 
839 	for_each_engine(engine, i915, id) {
840 		for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
841 			if (!engine_event_status(engine,
842 						 engine_events[i].sample))
843 				count++;
844 		}
845 	}
846 
847 	/* Allocate attribute objects and table. */
848 	i915_attr = kcalloc(count, sizeof(*i915_attr), GFP_KERNEL);
849 	if (!i915_attr)
850 		goto err_alloc;
851 
852 	pmu_attr = kcalloc(count, sizeof(*pmu_attr), GFP_KERNEL);
853 	if (!pmu_attr)
854 		goto err_alloc;
855 
856 	/* Max one pointer of each attribute type plus a termination entry. */
857 	attr = kcalloc(count * 2 + 1, sizeof(*attr), GFP_KERNEL);
858 	if (!attr)
859 		goto err_alloc;
860 
861 	i915_iter = i915_attr;
862 	pmu_iter = pmu_attr;
863 	attr_iter = attr;
864 
865 	/* Initialize supported non-engine counters. */
866 	for (i = 0; i < ARRAY_SIZE(events); i++) {
867 		char *str;
868 
869 		if (config_status(i915, events[i].config))
870 			continue;
871 
872 		str = kstrdup(events[i].name, GFP_KERNEL);
873 		if (!str)
874 			goto err;
875 
876 		*attr_iter++ = &i915_iter->attr.attr;
877 		i915_iter = add_i915_attr(i915_iter, str, events[i].config);
878 
879 		if (events[i].unit) {
880 			str = kasprintf(GFP_KERNEL, "%s.unit", events[i].name);
881 			if (!str)
882 				goto err;
883 
884 			*attr_iter++ = &pmu_iter->attr.attr;
885 			pmu_iter = add_pmu_attr(pmu_iter, str, events[i].unit);
886 		}
887 	}
888 
889 	/* Initialize supported engine counters. */
890 	for_each_engine(engine, i915, id) {
891 		for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
892 			char *str;
893 
894 			if (engine_event_status(engine,
895 						engine_events[i].sample))
896 				continue;
897 
898 			str = kasprintf(GFP_KERNEL, "%s-%s",
899 					engine->name, engine_events[i].name);
900 			if (!str)
901 				goto err;
902 
903 			*attr_iter++ = &i915_iter->attr.attr;
904 			i915_iter =
905 				add_i915_attr(i915_iter, str,
906 					      __I915_PMU_ENGINE(engine->uabi_class,
907 								engine->instance,
908 								engine_events[i].sample));
909 
910 			str = kasprintf(GFP_KERNEL, "%s-%s.unit",
911 					engine->name, engine_events[i].name);
912 			if (!str)
913 				goto err;
914 
915 			*attr_iter++ = &pmu_iter->attr.attr;
916 			pmu_iter = add_pmu_attr(pmu_iter, str, "ns");
917 		}
918 	}
919 
920 	i915->pmu.i915_attr = i915_attr;
921 	i915->pmu.pmu_attr = pmu_attr;
922 
923 	return attr;
924 
925 err:;
926 	for (attr_iter = attr; *attr_iter; attr_iter++)
927 		kfree((*attr_iter)->name);
928 
929 err_alloc:
930 	kfree(attr);
931 	kfree(i915_attr);
932 	kfree(pmu_attr);
933 
934 	return NULL;
935 }
936 
937 static void free_event_attributes(struct drm_i915_private *i915)
938 {
939 	struct attribute **attr_iter = i915_pmu_events_attr_group.attrs;
940 
941 	for (; *attr_iter; attr_iter++)
942 		kfree((*attr_iter)->name);
943 
944 	kfree(i915_pmu_events_attr_group.attrs);
945 	kfree(i915->pmu.i915_attr);
946 	kfree(i915->pmu.pmu_attr);
947 
948 	i915_pmu_events_attr_group.attrs = NULL;
949 	i915->pmu.i915_attr = NULL;
950 	i915->pmu.pmu_attr = NULL;
951 }
952 
953 static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
954 {
955 	struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), node);
956 
957 	GEM_BUG_ON(!pmu->base.event_init);
958 
959 	/* Select the first online CPU as a designated reader. */
960 	if (!cpumask_weight(&i915_pmu_cpumask))
961 		cpumask_set_cpu(cpu, &i915_pmu_cpumask);
962 
963 	return 0;
964 }
965 
966 static int i915_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
967 {
968 	struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), node);
969 	unsigned int target;
970 
971 	GEM_BUG_ON(!pmu->base.event_init);
972 
973 	if (cpumask_test_and_clear_cpu(cpu, &i915_pmu_cpumask)) {
974 		target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
975 		/* Migrate events if there is a valid target */
976 		if (target < nr_cpu_ids) {
977 			cpumask_set_cpu(target, &i915_pmu_cpumask);
978 			perf_pmu_migrate_context(&pmu->base, cpu, target);
979 		}
980 	}
981 
982 	return 0;
983 }
984 
985 static enum cpuhp_state cpuhp_slot = CPUHP_INVALID;
986 
987 static int i915_pmu_register_cpuhp_state(struct drm_i915_private *i915)
988 {
989 	enum cpuhp_state slot;
990 	int ret;
991 
992 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
993 				      "perf/x86/intel/i915:online",
994 				      i915_pmu_cpu_online,
995 				      i915_pmu_cpu_offline);
996 	if (ret < 0)
997 		return ret;
998 
999 	slot = ret;
1000 	ret = cpuhp_state_add_instance(slot, &i915->pmu.node);
1001 	if (ret) {
1002 		cpuhp_remove_multi_state(slot);
1003 		return ret;
1004 	}
1005 
1006 	cpuhp_slot = slot;
1007 	return 0;
1008 }
1009 
1010 static void i915_pmu_unregister_cpuhp_state(struct drm_i915_private *i915)
1011 {
1012 	WARN_ON(cpuhp_slot == CPUHP_INVALID);
1013 	WARN_ON(cpuhp_state_remove_instance(cpuhp_slot, &i915->pmu.node));
1014 	cpuhp_remove_multi_state(cpuhp_slot);
1015 }
1016 
1017 void i915_pmu_register(struct drm_i915_private *i915)
1018 {
1019 	int ret;
1020 
1021 	if (INTEL_GEN(i915) <= 2) {
1022 		DRM_INFO("PMU not supported for this GPU.");
1023 		return;
1024 	}
1025 
1026 	i915_pmu_events_attr_group.attrs = create_event_attributes(i915);
1027 	if (!i915_pmu_events_attr_group.attrs) {
1028 		ret = -ENOMEM;
1029 		goto err;
1030 	}
1031 
1032 	i915->pmu.base.attr_groups	= i915_pmu_attr_groups;
1033 	i915->pmu.base.task_ctx_nr	= perf_invalid_context;
1034 	i915->pmu.base.event_init	= i915_pmu_event_init;
1035 	i915->pmu.base.add		= i915_pmu_event_add;
1036 	i915->pmu.base.del		= i915_pmu_event_del;
1037 	i915->pmu.base.start		= i915_pmu_event_start;
1038 	i915->pmu.base.stop		= i915_pmu_event_stop;
1039 	i915->pmu.base.read		= i915_pmu_event_read;
1040 	i915->pmu.base.event_idx	= i915_pmu_event_event_idx;
1041 
1042 	spin_lock_init(&i915->pmu.lock);
1043 	hrtimer_init(&i915->pmu.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1044 	i915->pmu.timer.function = i915_sample;
1045 
1046 	ret = perf_pmu_register(&i915->pmu.base, "i915", -1);
1047 	if (ret)
1048 		goto err;
1049 
1050 	ret = i915_pmu_register_cpuhp_state(i915);
1051 	if (ret)
1052 		goto err_unreg;
1053 
1054 	return;
1055 
1056 err_unreg:
1057 	perf_pmu_unregister(&i915->pmu.base);
1058 err:
1059 	i915->pmu.base.event_init = NULL;
1060 	free_event_attributes(i915);
1061 	DRM_NOTE("Failed to register PMU! (err=%d)\n", ret);
1062 }
1063 
1064 void i915_pmu_unregister(struct drm_i915_private *i915)
1065 {
1066 	if (!i915->pmu.base.event_init)
1067 		return;
1068 
1069 	WARN_ON(i915->pmu.enable);
1070 
1071 	hrtimer_cancel(&i915->pmu.timer);
1072 
1073 	i915_pmu_unregister_cpuhp_state(i915);
1074 
1075 	perf_pmu_unregister(&i915->pmu.base);
1076 	i915->pmu.base.event_init = NULL;
1077 	free_event_attributes(i915);
1078 }
1079