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   1/*
   2 * SPDX-License-Identifier: MIT
   3 *
   4 * Copyright © 2017-2018 Intel Corporation
   5 */
   6
   7#include <linux/irq.h>
   8#include <linux/pm_runtime.h>
   9
  10#include "gt/intel_engine.h"
  11#include "gt/intel_engine_pm.h"
  12#include "gt/intel_engine_user.h"
  13#include "gt/intel_gt_pm.h"
  14
  15#include "i915_drv.h"
  16#include "i915_pmu.h"
  17#include "intel_pm.h"
  18
  19/* Frequency for the sampling timer for events which need it. */
  20#define FREQUENCY 200
  21#define PERIOD max_t(u64, 10000, NSEC_PER_SEC / FREQUENCY)
  22
  23#define ENGINE_SAMPLE_MASK \
  24	(BIT(I915_SAMPLE_BUSY) | \
  25	 BIT(I915_SAMPLE_WAIT) | \
  26	 BIT(I915_SAMPLE_SEMA))
  27
  28#define ENGINE_SAMPLE_BITS (1 << I915_PMU_SAMPLE_BITS)
  29
  30static cpumask_t i915_pmu_cpumask;
  31
  32static u8 engine_config_sample(u64 config)
  33{
  34	return config & I915_PMU_SAMPLE_MASK;
  35}
  36
  37static u8 engine_event_sample(struct perf_event *event)
  38{
  39	return engine_config_sample(event->attr.config);
  40}
  41
  42static u8 engine_event_class(struct perf_event *event)
  43{
  44	return (event->attr.config >> I915_PMU_CLASS_SHIFT) & 0xff;
  45}
  46
  47static u8 engine_event_instance(struct perf_event *event)
  48{
  49	return (event->attr.config >> I915_PMU_SAMPLE_BITS) & 0xff;
  50}
  51
  52static bool is_engine_config(u64 config)
  53{
  54	return config < __I915_PMU_OTHER(0);
  55}
  56
  57static unsigned int config_enabled_bit(u64 config)
  58{
  59	if (is_engine_config(config))
  60		return engine_config_sample(config);
  61	else
  62		return ENGINE_SAMPLE_BITS + (config - __I915_PMU_OTHER(0));
  63}
  64
  65static u64 config_enabled_mask(u64 config)
  66{
  67	return BIT_ULL(config_enabled_bit(config));
  68}
  69
  70static bool is_engine_event(struct perf_event *event)
  71{
  72	return is_engine_config(event->attr.config);
  73}
  74
  75static unsigned int event_enabled_bit(struct perf_event *event)
  76{
  77	return config_enabled_bit(event->attr.config);
  78}
  79
  80static bool pmu_needs_timer(struct i915_pmu *pmu, bool gpu_active)
  81{
  82	struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
  83	u64 enable;
  84
  85	/*
  86	 * Only some counters need the sampling timer.
  87	 *
  88	 * We start with a bitmask of all currently enabled events.
  89	 */
  90	enable = pmu->enable;
  91
  92	/*
  93	 * Mask out all the ones which do not need the timer, or in
  94	 * other words keep all the ones that could need the timer.
  95	 */
  96	enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) |
  97		  config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) |
  98		  ENGINE_SAMPLE_MASK;
  99
 100	/*
 101	 * When the GPU is idle per-engine counters do not need to be
 102	 * running so clear those bits out.
 103	 */
 104	if (!gpu_active)
 105		enable &= ~ENGINE_SAMPLE_MASK;
 106	/*
 107	 * Also there is software busyness tracking available we do not
 108	 * need the timer for I915_SAMPLE_BUSY counter.
 109	 */
 110	else if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
 111		enable &= ~BIT(I915_SAMPLE_BUSY);
 112
 113	/*
 114	 * If some bits remain it means we need the sampling timer running.
 115	 */
 116	return enable;
 117}
 118
 119void i915_pmu_gt_parked(struct drm_i915_private *i915)
 120{
 121	struct i915_pmu *pmu = &i915->pmu;
 122
 123	if (!pmu->base.event_init)
 124		return;
 125
 126	spin_lock_irq(&pmu->lock);
 127	/*
 128	 * Signal sampling timer to stop if only engine events are enabled and
 129	 * GPU went idle.
 130	 */
 131	pmu->timer_enabled = pmu_needs_timer(pmu, false);
 132	spin_unlock_irq(&pmu->lock);
 133}
 134
 135static void __i915_pmu_maybe_start_timer(struct i915_pmu *pmu)
 136{
 137	if (!pmu->timer_enabled && pmu_needs_timer(pmu, true)) {
 138		pmu->timer_enabled = true;
 139		pmu->timer_last = ktime_get();
 140		hrtimer_start_range_ns(&pmu->timer,
 141				       ns_to_ktime(PERIOD), 0,
 142				       HRTIMER_MODE_REL_PINNED);
 143	}
 144}
 145
 146void i915_pmu_gt_unparked(struct drm_i915_private *i915)
 147{
 148	struct i915_pmu *pmu = &i915->pmu;
 149
 150	if (!pmu->base.event_init)
 151		return;
 152
 153	spin_lock_irq(&pmu->lock);
 154	/*
 155	 * Re-enable sampling timer when GPU goes active.
 156	 */
 157	__i915_pmu_maybe_start_timer(pmu);
 158	spin_unlock_irq(&pmu->lock);
 159}
 160
 161static void
 162add_sample(struct i915_pmu_sample *sample, u32 val)
 163{
 164	sample->cur += val;
 165}
 166
 167static void
 168engines_sample(struct intel_gt *gt, unsigned int period_ns)
 169{
 170	struct drm_i915_private *i915 = gt->i915;
 171	struct intel_engine_cs *engine;
 172	enum intel_engine_id id;
 173
 174	if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
 175		return;
 176
 177	for_each_engine(engine, i915, id) {
 178		struct intel_engine_pmu *pmu = &engine->pmu;
 179		unsigned long flags;
 180		bool busy;
 181		u32 val;
 182
 183		if (!intel_engine_pm_get_if_awake(engine))
 184			continue;
 185
 186		spin_lock_irqsave(&engine->uncore->lock, flags);
 187
 188		val = ENGINE_READ_FW(engine, RING_CTL);
 189		if (val == 0) /* powerwell off => engine idle */
 190			goto skip;
 191
 192		if (val & RING_WAIT)
 193			add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
 194		if (val & RING_WAIT_SEMAPHORE)
 195			add_sample(&pmu->sample[I915_SAMPLE_SEMA], period_ns);
 196
 197		/*
 198		 * While waiting on a semaphore or event, MI_MODE reports the
 199		 * ring as idle. However, previously using the seqno, and with
 200		 * execlists sampling, we account for the ring waiting as the
 201		 * engine being busy. Therefore, we record the sample as being
 202		 * busy if either waiting or !idle.
 203		 */
 204		busy = val & (RING_WAIT_SEMAPHORE | RING_WAIT);
 205		if (!busy) {
 206			val = ENGINE_READ_FW(engine, RING_MI_MODE);
 207			busy = !(val & MODE_IDLE);
 208		}
 209		if (busy)
 210			add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
 211
 212skip:
 213		spin_unlock_irqrestore(&engine->uncore->lock, flags);
 214		intel_engine_pm_put(engine);
 215	}
 216}
 217
 218static void
 219add_sample_mult(struct i915_pmu_sample *sample, u32 val, u32 mul)
 220{
 221	sample->cur += mul_u32_u32(val, mul);
 222}
 223
 224static void
 225frequency_sample(struct intel_gt *gt, unsigned int period_ns)
 226{
 227	struct drm_i915_private *i915 = gt->i915;
 228	struct intel_uncore *uncore = gt->uncore;
 229	struct i915_pmu *pmu = &i915->pmu;
 230
 231	if (pmu->enable & config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY)) {
 232		u32 val;
 233
 234		val = i915->gt_pm.rps.cur_freq;
 235		if (intel_gt_pm_get_if_awake(gt)) {
 236			val = intel_uncore_read_notrace(uncore, GEN6_RPSTAT1);
 237			val = intel_get_cagf(i915, val);
 238			intel_gt_pm_put(gt);
 239		}
 240
 241		add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_ACT],
 242				intel_gpu_freq(i915, val),
 243				period_ns / 1000);
 244	}
 245
 246	if (pmu->enable & config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY)) {
 247		add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_REQ],
 248				intel_gpu_freq(i915, i915->gt_pm.rps.cur_freq),
 249				period_ns / 1000);
 250	}
 251}
 252
 253static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer)
 254{
 255	struct drm_i915_private *i915 =
 256		container_of(hrtimer, struct drm_i915_private, pmu.timer);
 257	struct i915_pmu *pmu = &i915->pmu;
 258	struct intel_gt *gt = &i915->gt;
 259	unsigned int period_ns;
 260	ktime_t now;
 261
 262	if (!READ_ONCE(pmu->timer_enabled))
 263		return HRTIMER_NORESTART;
 264
 265	now = ktime_get();
 266	period_ns = ktime_to_ns(ktime_sub(now, pmu->timer_last));
 267	pmu->timer_last = now;
 268
 269	/*
 270	 * Strictly speaking the passed in period may not be 100% accurate for
 271	 * all internal calculation, since some amount of time can be spent on
 272	 * grabbing the forcewake. However the potential error from timer call-
 273	 * back delay greatly dominates this so we keep it simple.
 274	 */
 275	engines_sample(gt, period_ns);
 276	frequency_sample(gt, period_ns);
 277
 278	hrtimer_forward(hrtimer, now, ns_to_ktime(PERIOD));
 279
 280	return HRTIMER_RESTART;
 281}
 282
 283static u64 count_interrupts(struct drm_i915_private *i915)
 284{
 285	/* open-coded kstat_irqs() */
 286	struct irq_desc *desc = irq_to_desc(i915->drm.pdev->irq);
 287	u64 sum = 0;
 288	int cpu;
 289
 290	if (!desc || !desc->kstat_irqs)
 291		return 0;
 292
 293	for_each_possible_cpu(cpu)
 294		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
 295
 296	return sum;
 297}
 298
 299static void engine_event_destroy(struct perf_event *event)
 300{
 301	struct drm_i915_private *i915 =
 302		container_of(event->pmu, typeof(*i915), pmu.base);
 303	struct intel_engine_cs *engine;
 304
 305	engine = intel_engine_lookup_user(i915,
 306					  engine_event_class(event),
 307					  engine_event_instance(event));
 308	if (WARN_ON_ONCE(!engine))
 309		return;
 310
 311	if (engine_event_sample(event) == I915_SAMPLE_BUSY &&
 312	    intel_engine_supports_stats(engine))
 313		intel_disable_engine_stats(engine);
 314}
 315
 316static void i915_pmu_event_destroy(struct perf_event *event)
 317{
 318	WARN_ON(event->parent);
 319
 320	if (is_engine_event(event))
 321		engine_event_destroy(event);
 322}
 323
 324static int
 325engine_event_status(struct intel_engine_cs *engine,
 326		    enum drm_i915_pmu_engine_sample sample)
 327{
 328	switch (sample) {
 329	case I915_SAMPLE_BUSY:
 330	case I915_SAMPLE_WAIT:
 331		break;
 332	case I915_SAMPLE_SEMA:
 333		if (INTEL_GEN(engine->i915) < 6)
 334			return -ENODEV;
 335		break;
 336	default:
 337		return -ENOENT;
 338	}
 339
 340	return 0;
 341}
 342
 343static int
 344config_status(struct drm_i915_private *i915, u64 config)
 345{
 346	switch (config) {
 347	case I915_PMU_ACTUAL_FREQUENCY:
 348		if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
 349			/* Requires a mutex for sampling! */
 350			return -ENODEV;
 351		/* Fall-through. */
 352	case I915_PMU_REQUESTED_FREQUENCY:
 353		if (INTEL_GEN(i915) < 6)
 354			return -ENODEV;
 355		break;
 356	case I915_PMU_INTERRUPTS:
 357		break;
 358	case I915_PMU_RC6_RESIDENCY:
 359		if (!HAS_RC6(i915))
 360			return -ENODEV;
 361		break;
 362	default:
 363		return -ENOENT;
 364	}
 365
 366	return 0;
 367}
 368
 369static int engine_event_init(struct perf_event *event)
 370{
 371	struct drm_i915_private *i915 =
 372		container_of(event->pmu, typeof(*i915), pmu.base);
 373	struct intel_engine_cs *engine;
 374	u8 sample;
 375	int ret;
 376
 377	engine = intel_engine_lookup_user(i915, engine_event_class(event),
 378					  engine_event_instance(event));
 379	if (!engine)
 380		return -ENODEV;
 381
 382	sample = engine_event_sample(event);
 383	ret = engine_event_status(engine, sample);
 384	if (ret)
 385		return ret;
 386
 387	if (sample == I915_SAMPLE_BUSY && intel_engine_supports_stats(engine))
 388		ret = intel_enable_engine_stats(engine);
 389
 390	return ret;
 391}
 392
 393static int i915_pmu_event_init(struct perf_event *event)
 394{
 395	struct drm_i915_private *i915 =
 396		container_of(event->pmu, typeof(*i915), pmu.base);
 397	int ret;
 398
 399	if (event->attr.type != event->pmu->type)
 400		return -ENOENT;
 401
 402	/* unsupported modes and filters */
 403	if (event->attr.sample_period) /* no sampling */
 404		return -EINVAL;
 405
 406	if (has_branch_stack(event))
 407		return -EOPNOTSUPP;
 408
 409	if (event->cpu < 0)
 410		return -EINVAL;
 411
 412	/* only allow running on one cpu at a time */
 413	if (!cpumask_test_cpu(event->cpu, &i915_pmu_cpumask))
 414		return -EINVAL;
 415
 416	if (is_engine_event(event))
 417		ret = engine_event_init(event);
 418	else
 419		ret = config_status(i915, event->attr.config);
 420	if (ret)
 421		return ret;
 422
 423	if (!event->parent)
 424		event->destroy = i915_pmu_event_destroy;
 425
 426	return 0;
 427}
 428
 429static u64 __get_rc6(struct intel_gt *gt)
 430{
 431	struct drm_i915_private *i915 = gt->i915;
 432	u64 val;
 433
 434	val = intel_rc6_residency_ns(i915,
 435				     IS_VALLEYVIEW(i915) ?
 436				     VLV_GT_RENDER_RC6 :
 437				     GEN6_GT_GFX_RC6);
 438
 439	if (HAS_RC6p(i915))
 440		val += intel_rc6_residency_ns(i915, GEN6_GT_GFX_RC6p);
 441
 442	if (HAS_RC6pp(i915))
 443		val += intel_rc6_residency_ns(i915, GEN6_GT_GFX_RC6pp);
 444
 445	return val;
 446}
 447
 448static u64 get_rc6(struct intel_gt *gt)
 449{
 450#if IS_ENABLED(CONFIG_PM)
 451	struct drm_i915_private *i915 = gt->i915;
 452	struct intel_runtime_pm *rpm = &i915->runtime_pm;
 453	struct i915_pmu *pmu = &i915->pmu;
 454	intel_wakeref_t wakeref;
 455	unsigned long flags;
 456	u64 val;
 457
 458	wakeref = intel_runtime_pm_get_if_in_use(rpm);
 459	if (wakeref) {
 460		val = __get_rc6(gt);
 461		intel_runtime_pm_put(rpm, wakeref);
 462
 463		/*
 464		 * If we are coming back from being runtime suspended we must
 465		 * be careful not to report a larger value than returned
 466		 * previously.
 467		 */
 468
 469		spin_lock_irqsave(&pmu->lock, flags);
 470
 471		if (val >= pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur) {
 472			pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur = 0;
 473			pmu->sample[__I915_SAMPLE_RC6].cur = val;
 474		} else {
 475			val = pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur;
 476		}
 477
 478		spin_unlock_irqrestore(&pmu->lock, flags);
 479	} else {
 480		struct device *kdev = rpm->kdev;
 481
 482		/*
 483		 * We are runtime suspended.
 484		 *
 485		 * Report the delta from when the device was suspended to now,
 486		 * on top of the last known real value, as the approximated RC6
 487		 * counter value.
 488		 */
 489		spin_lock_irqsave(&pmu->lock, flags);
 490
 491		/*
 492		 * After the above branch intel_runtime_pm_get_if_in_use failed
 493		 * to get the runtime PM reference we cannot assume we are in
 494		 * runtime suspend since we can either: a) race with coming out
 495		 * of it before we took the power.lock, or b) there are other
 496		 * states than suspended which can bring us here.
 497		 *
 498		 * We need to double-check that we are indeed currently runtime
 499		 * suspended and if not we cannot do better than report the last
 500		 * known RC6 value.
 501		 */
 502		if (pm_runtime_status_suspended(kdev)) {
 503			val = pm_runtime_suspended_time(kdev);
 504
 505			if (!pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur)
 506				pmu->suspended_time_last = val;
 507
 508			val -= pmu->suspended_time_last;
 509			val += pmu->sample[__I915_SAMPLE_RC6].cur;
 510
 511			pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur = val;
 512		} else if (pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur) {
 513			val = pmu->sample[__I915_SAMPLE_RC6_ESTIMATED].cur;
 514		} else {
 515			val = pmu->sample[__I915_SAMPLE_RC6].cur;
 516		}
 517
 518		spin_unlock_irqrestore(&pmu->lock, flags);
 519	}
 520
 521	return val;
 522#else
 523	return __get_rc6(gt);
 524#endif
 525}
 526
 527static u64 __i915_pmu_event_read(struct perf_event *event)
 528{
 529	struct drm_i915_private *i915 =
 530		container_of(event->pmu, typeof(*i915), pmu.base);
 531	struct i915_pmu *pmu = &i915->pmu;
 532	u64 val = 0;
 533
 534	if (is_engine_event(event)) {
 535		u8 sample = engine_event_sample(event);
 536		struct intel_engine_cs *engine;
 537
 538		engine = intel_engine_lookup_user(i915,
 539						  engine_event_class(event),
 540						  engine_event_instance(event));
 541
 542		if (WARN_ON_ONCE(!engine)) {
 543			/* Do nothing */
 544		} else if (sample == I915_SAMPLE_BUSY &&
 545			   intel_engine_supports_stats(engine)) {
 546			val = ktime_to_ns(intel_engine_get_busy_time(engine));
 547		} else {
 548			val = engine->pmu.sample[sample].cur;
 549		}
 550	} else {
 551		switch (event->attr.config) {
 552		case I915_PMU_ACTUAL_FREQUENCY:
 553			val =
 554			   div_u64(pmu->sample[__I915_SAMPLE_FREQ_ACT].cur,
 555				   USEC_PER_SEC /* to MHz */);
 556			break;
 557		case I915_PMU_REQUESTED_FREQUENCY:
 558			val =
 559			   div_u64(pmu->sample[__I915_SAMPLE_FREQ_REQ].cur,
 560				   USEC_PER_SEC /* to MHz */);
 561			break;
 562		case I915_PMU_INTERRUPTS:
 563			val = count_interrupts(i915);
 564			break;
 565		case I915_PMU_RC6_RESIDENCY:
 566			val = get_rc6(&i915->gt);
 567			break;
 568		}
 569	}
 570
 571	return val;
 572}
 573
 574static void i915_pmu_event_read(struct perf_event *event)
 575{
 576	struct hw_perf_event *hwc = &event->hw;
 577	u64 prev, new;
 578
 579again:
 580	prev = local64_read(&hwc->prev_count);
 581	new = __i915_pmu_event_read(event);
 582
 583	if (local64_cmpxchg(&hwc->prev_count, prev, new) != prev)
 584		goto again;
 585
 586	local64_add(new - prev, &event->count);
 587}
 588
 589static void i915_pmu_enable(struct perf_event *event)
 590{
 591	struct drm_i915_private *i915 =
 592		container_of(event->pmu, typeof(*i915), pmu.base);
 593	unsigned int bit = event_enabled_bit(event);
 594	struct i915_pmu *pmu = &i915->pmu;
 595	unsigned long flags;
 596
 597	spin_lock_irqsave(&pmu->lock, flags);
 598
 599	/*
 600	 * Update the bitmask of enabled events and increment
 601	 * the event reference counter.
 602	 */
 603	BUILD_BUG_ON(ARRAY_SIZE(pmu->enable_count) != I915_PMU_MASK_BITS);
 604	GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
 605	GEM_BUG_ON(pmu->enable_count[bit] == ~0);
 606	pmu->enable |= BIT_ULL(bit);
 607	pmu->enable_count[bit]++;
 608
 609	/*
 610	 * Start the sampling timer if needed and not already enabled.
 611	 */
 612	__i915_pmu_maybe_start_timer(pmu);
 613
 614	/*
 615	 * For per-engine events the bitmask and reference counting
 616	 * is stored per engine.
 617	 */
 618	if (is_engine_event(event)) {
 619		u8 sample = engine_event_sample(event);
 620		struct intel_engine_cs *engine;
 621
 622		engine = intel_engine_lookup_user(i915,
 623						  engine_event_class(event),
 624						  engine_event_instance(event));
 625
 626		BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.enable_count) !=
 627			     I915_ENGINE_SAMPLE_COUNT);
 628		BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.sample) !=
 629			     I915_ENGINE_SAMPLE_COUNT);
 630		GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
 631		GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
 632		GEM_BUG_ON(engine->pmu.enable_count[sample] == ~0);
 633
 634		engine->pmu.enable |= BIT(sample);
 635		engine->pmu.enable_count[sample]++;
 636	}
 637
 638	spin_unlock_irqrestore(&pmu->lock, flags);
 639
 640	/*
 641	 * Store the current counter value so we can report the correct delta
 642	 * for all listeners. Even when the event was already enabled and has
 643	 * an existing non-zero value.
 644	 */
 645	local64_set(&event->hw.prev_count, __i915_pmu_event_read(event));
 646}
 647
 648static void i915_pmu_disable(struct perf_event *event)
 649{
 650	struct drm_i915_private *i915 =
 651		container_of(event->pmu, typeof(*i915), pmu.base);
 652	unsigned int bit = event_enabled_bit(event);
 653	struct i915_pmu *pmu = &i915->pmu;
 654	unsigned long flags;
 655
 656	spin_lock_irqsave(&pmu->lock, flags);
 657
 658	if (is_engine_event(event)) {
 659		u8 sample = engine_event_sample(event);
 660		struct intel_engine_cs *engine;
 661
 662		engine = intel_engine_lookup_user(i915,
 663						  engine_event_class(event),
 664						  engine_event_instance(event));
 665
 666		GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
 667		GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
 668		GEM_BUG_ON(engine->pmu.enable_count[sample] == 0);
 669
 670		/*
 671		 * Decrement the reference count and clear the enabled
 672		 * bitmask when the last listener on an event goes away.
 673		 */
 674		if (--engine->pmu.enable_count[sample] == 0)
 675			engine->pmu.enable &= ~BIT(sample);
 676	}
 677
 678	GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
 679	GEM_BUG_ON(pmu->enable_count[bit] == 0);
 680	/*
 681	 * Decrement the reference count and clear the enabled
 682	 * bitmask when the last listener on an event goes away.
 683	 */
 684	if (--pmu->enable_count[bit] == 0) {
 685		pmu->enable &= ~BIT_ULL(bit);
 686		pmu->timer_enabled &= pmu_needs_timer(pmu, true);
 687	}
 688
 689	spin_unlock_irqrestore(&pmu->lock, flags);
 690}
 691
 692static void i915_pmu_event_start(struct perf_event *event, int flags)
 693{
 694	i915_pmu_enable(event);
 695	event->hw.state = 0;
 696}
 697
 698static void i915_pmu_event_stop(struct perf_event *event, int flags)
 699{
 700	if (flags & PERF_EF_UPDATE)
 701		i915_pmu_event_read(event);
 702	i915_pmu_disable(event);
 703	event->hw.state = PERF_HES_STOPPED;
 704}
 705
 706static int i915_pmu_event_add(struct perf_event *event, int flags)
 707{
 708	if (flags & PERF_EF_START)
 709		i915_pmu_event_start(event, flags);
 710
 711	return 0;
 712}
 713
 714static void i915_pmu_event_del(struct perf_event *event, int flags)
 715{
 716	i915_pmu_event_stop(event, PERF_EF_UPDATE);
 717}
 718
 719static int i915_pmu_event_event_idx(struct perf_event *event)
 720{
 721	return 0;
 722}
 723
 724struct i915_str_attribute {
 725	struct device_attribute attr;
 726	const char *str;
 727};
 728
 729static ssize_t i915_pmu_format_show(struct device *dev,
 730				    struct device_attribute *attr, char *buf)
 731{
 732	struct i915_str_attribute *eattr;
 733
 734	eattr = container_of(attr, struct i915_str_attribute, attr);
 735	return sprintf(buf, "%s\n", eattr->str);
 736}
 737
 738#define I915_PMU_FORMAT_ATTR(_name, _config) \
 739	(&((struct i915_str_attribute[]) { \
 740		{ .attr = __ATTR(_name, 0444, i915_pmu_format_show, NULL), \
 741		  .str = _config, } \
 742	})[0].attr.attr)
 743
 744static struct attribute *i915_pmu_format_attrs[] = {
 745	I915_PMU_FORMAT_ATTR(i915_eventid, "config:0-20"),
 746	NULL,
 747};
 748
 749static const struct attribute_group i915_pmu_format_attr_group = {
 750	.name = "format",
 751	.attrs = i915_pmu_format_attrs,
 752};
 753
 754struct i915_ext_attribute {
 755	struct device_attribute attr;
 756	unsigned long val;
 757};
 758
 759static ssize_t i915_pmu_event_show(struct device *dev,
 760				   struct device_attribute *attr, char *buf)
 761{
 762	struct i915_ext_attribute *eattr;
 763
 764	eattr = container_of(attr, struct i915_ext_attribute, attr);
 765	return sprintf(buf, "config=0x%lx\n", eattr->val);
 766}
 767
 768static struct attribute_group i915_pmu_events_attr_group = {
 769	.name = "events",
 770	/* Patch in attrs at runtime. */
 771};
 772
 773static ssize_t
 774i915_pmu_get_attr_cpumask(struct device *dev,
 775			  struct device_attribute *attr,
 776			  char *buf)
 777{
 778	return cpumap_print_to_pagebuf(true, buf, &i915_pmu_cpumask);
 779}
 780
 781static DEVICE_ATTR(cpumask, 0444, i915_pmu_get_attr_cpumask, NULL);
 782
 783static struct attribute *i915_cpumask_attrs[] = {
 784	&dev_attr_cpumask.attr,
 785	NULL,
 786};
 787
 788static const struct attribute_group i915_pmu_cpumask_attr_group = {
 789	.attrs = i915_cpumask_attrs,
 790};
 791
 792static const struct attribute_group *i915_pmu_attr_groups[] = {
 793	&i915_pmu_format_attr_group,
 794	&i915_pmu_events_attr_group,
 795	&i915_pmu_cpumask_attr_group,
 796	NULL
 797};
 798
 799#define __event(__config, __name, __unit) \
 800{ \
 801	.config = (__config), \
 802	.name = (__name), \
 803	.unit = (__unit), \
 804}
 805
 806#define __engine_event(__sample, __name) \
 807{ \
 808	.sample = (__sample), \
 809	.name = (__name), \
 810}
 811
 812static struct i915_ext_attribute *
 813add_i915_attr(struct i915_ext_attribute *attr, const char *name, u64 config)
 814{
 815	sysfs_attr_init(&attr->attr.attr);
 816	attr->attr.attr.name = name;
 817	attr->attr.attr.mode = 0444;
 818	attr->attr.show = i915_pmu_event_show;
 819	attr->val = config;
 820
 821	return ++attr;
 822}
 823
 824static struct perf_pmu_events_attr *
 825add_pmu_attr(struct perf_pmu_events_attr *attr, const char *name,
 826	     const char *str)
 827{
 828	sysfs_attr_init(&attr->attr.attr);
 829	attr->attr.attr.name = name;
 830	attr->attr.attr.mode = 0444;
 831	attr->attr.show = perf_event_sysfs_show;
 832	attr->event_str = str;
 833
 834	return ++attr;
 835}
 836
 837static struct attribute **
 838create_event_attributes(struct i915_pmu *pmu)
 839{
 840	struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
 841	static const struct {
 842		u64 config;
 843		const char *name;
 844		const char *unit;
 845	} events[] = {
 846		__event(I915_PMU_ACTUAL_FREQUENCY, "actual-frequency", "M"),
 847		__event(I915_PMU_REQUESTED_FREQUENCY, "requested-frequency", "M"),
 848		__event(I915_PMU_INTERRUPTS, "interrupts", NULL),
 849		__event(I915_PMU_RC6_RESIDENCY, "rc6-residency", "ns"),
 850	};
 851	static const struct {
 852		enum drm_i915_pmu_engine_sample sample;
 853		char *name;
 854	} engine_events[] = {
 855		__engine_event(I915_SAMPLE_BUSY, "busy"),
 856		__engine_event(I915_SAMPLE_SEMA, "sema"),
 857		__engine_event(I915_SAMPLE_WAIT, "wait"),
 858	};
 859	unsigned int count = 0;
 860	struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
 861	struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
 862	struct attribute **attr = NULL, **attr_iter;
 863	struct intel_engine_cs *engine;
 864	unsigned int i;
 865
 866	/* Count how many counters we will be exposing. */
 867	for (i = 0; i < ARRAY_SIZE(events); i++) {
 868		if (!config_status(i915, events[i].config))
 869			count++;
 870	}
 871
 872	for_each_uabi_engine(engine, i915) {
 873		for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
 874			if (!engine_event_status(engine,
 875						 engine_events[i].sample))
 876				count++;
 877		}
 878	}
 879
 880	/* Allocate attribute objects and table. */
 881	i915_attr = kcalloc(count, sizeof(*i915_attr), GFP_KERNEL);
 882	if (!i915_attr)
 883		goto err_alloc;
 884
 885	pmu_attr = kcalloc(count, sizeof(*pmu_attr), GFP_KERNEL);
 886	if (!pmu_attr)
 887		goto err_alloc;
 888
 889	/* Max one pointer of each attribute type plus a termination entry. */
 890	attr = kcalloc(count * 2 + 1, sizeof(*attr), GFP_KERNEL);
 891	if (!attr)
 892		goto err_alloc;
 893
 894	i915_iter = i915_attr;
 895	pmu_iter = pmu_attr;
 896	attr_iter = attr;
 897
 898	/* Initialize supported non-engine counters. */
 899	for (i = 0; i < ARRAY_SIZE(events); i++) {
 900		char *str;
 901
 902		if (config_status(i915, events[i].config))
 903			continue;
 904
 905		str = kstrdup(events[i].name, GFP_KERNEL);
 906		if (!str)
 907			goto err;
 908
 909		*attr_iter++ = &i915_iter->attr.attr;
 910		i915_iter = add_i915_attr(i915_iter, str, events[i].config);
 911
 912		if (events[i].unit) {
 913			str = kasprintf(GFP_KERNEL, "%s.unit", events[i].name);
 914			if (!str)
 915				goto err;
 916
 917			*attr_iter++ = &pmu_iter->attr.attr;
 918			pmu_iter = add_pmu_attr(pmu_iter, str, events[i].unit);
 919		}
 920	}
 921
 922	/* Initialize supported engine counters. */
 923	for_each_uabi_engine(engine, i915) {
 924		for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
 925			char *str;
 926
 927			if (engine_event_status(engine,
 928						engine_events[i].sample))
 929				continue;
 930
 931			str = kasprintf(GFP_KERNEL, "%s-%s",
 932					engine->name, engine_events[i].name);
 933			if (!str)
 934				goto err;
 935
 936			*attr_iter++ = &i915_iter->attr.attr;
 937			i915_iter =
 938				add_i915_attr(i915_iter, str,
 939					      __I915_PMU_ENGINE(engine->uabi_class,
 940								engine->uabi_instance,
 941								engine_events[i].sample));
 942
 943			str = kasprintf(GFP_KERNEL, "%s-%s.unit",
 944					engine->name, engine_events[i].name);
 945			if (!str)
 946				goto err;
 947
 948			*attr_iter++ = &pmu_iter->attr.attr;
 949			pmu_iter = add_pmu_attr(pmu_iter, str, "ns");
 950		}
 951	}
 952
 953	pmu->i915_attr = i915_attr;
 954	pmu->pmu_attr = pmu_attr;
 955
 956	return attr;
 957
 958err:;
 959	for (attr_iter = attr; *attr_iter; attr_iter++)
 960		kfree((*attr_iter)->name);
 961
 962err_alloc:
 963	kfree(attr);
 964	kfree(i915_attr);
 965	kfree(pmu_attr);
 966
 967	return NULL;
 968}
 969
 970static void free_event_attributes(struct i915_pmu *pmu)
 971{
 972	struct attribute **attr_iter = i915_pmu_events_attr_group.attrs;
 973
 974	for (; *attr_iter; attr_iter++)
 975		kfree((*attr_iter)->name);
 976
 977	kfree(i915_pmu_events_attr_group.attrs);
 978	kfree(pmu->i915_attr);
 979	kfree(pmu->pmu_attr);
 980
 981	i915_pmu_events_attr_group.attrs = NULL;
 982	pmu->i915_attr = NULL;
 983	pmu->pmu_attr = NULL;
 984}
 985
 986static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
 987{
 988	struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), node);
 989
 990	GEM_BUG_ON(!pmu->base.event_init);
 991
 992	/* Select the first online CPU as a designated reader. */
 993	if (!cpumask_weight(&i915_pmu_cpumask))
 994		cpumask_set_cpu(cpu, &i915_pmu_cpumask);
 995
 996	return 0;
 997}
 998
 999static int i915_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
1000{
1001	struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), node);
1002	unsigned int target;
1003
1004	GEM_BUG_ON(!pmu->base.event_init);
1005
1006	if (cpumask_test_and_clear_cpu(cpu, &i915_pmu_cpumask)) {
1007		target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
1008		/* Migrate events if there is a valid target */
1009		if (target < nr_cpu_ids) {
1010			cpumask_set_cpu(target, &i915_pmu_cpumask);
1011			perf_pmu_migrate_context(&pmu->base, cpu, target);
1012		}
1013	}
1014
1015	return 0;
1016}
1017
1018static enum cpuhp_state cpuhp_slot = CPUHP_INVALID;
1019
1020static int i915_pmu_register_cpuhp_state(struct i915_pmu *pmu)
1021{
1022	enum cpuhp_state slot;
1023	int ret;
1024
1025	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
1026				      "perf/x86/intel/i915:online",
1027				      i915_pmu_cpu_online,
1028				      i915_pmu_cpu_offline);
1029	if (ret < 0)
1030		return ret;
1031
1032	slot = ret;
1033	ret = cpuhp_state_add_instance(slot, &pmu->node);
1034	if (ret) {
1035		cpuhp_remove_multi_state(slot);
1036		return ret;
1037	}
1038
1039	cpuhp_slot = slot;
1040	return 0;
1041}
1042
1043static void i915_pmu_unregister_cpuhp_state(struct i915_pmu *pmu)
1044{
1045	WARN_ON(cpuhp_slot == CPUHP_INVALID);
1046	WARN_ON(cpuhp_state_remove_instance(cpuhp_slot, &pmu->node));
1047	cpuhp_remove_multi_state(cpuhp_slot);
1048}
1049
1050void i915_pmu_register(struct drm_i915_private *i915)
1051{
1052	struct i915_pmu *pmu = &i915->pmu;
1053	int ret;
1054
1055	if (INTEL_GEN(i915) <= 2) {
1056		dev_info(i915->drm.dev, "PMU not supported for this GPU.");
1057		return;
1058	}
1059
1060	i915_pmu_events_attr_group.attrs = create_event_attributes(pmu);
1061	if (!i915_pmu_events_attr_group.attrs) {
1062		ret = -ENOMEM;
1063		goto err;
1064	}
1065
1066	pmu->base.attr_groups	= i915_pmu_attr_groups;
1067	pmu->base.task_ctx_nr	= perf_invalid_context;
1068	pmu->base.event_init	= i915_pmu_event_init;
1069	pmu->base.add		= i915_pmu_event_add;
1070	pmu->base.del		= i915_pmu_event_del;
1071	pmu->base.start		= i915_pmu_event_start;
1072	pmu->base.stop		= i915_pmu_event_stop;
1073	pmu->base.read		= i915_pmu_event_read;
1074	pmu->base.event_idx	= i915_pmu_event_event_idx;
1075
1076	spin_lock_init(&pmu->lock);
1077	hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1078	pmu->timer.function = i915_sample;
1079
1080	ret = perf_pmu_register(&pmu->base, "i915", -1);
1081	if (ret)
1082		goto err;
1083
1084	ret = i915_pmu_register_cpuhp_state(pmu);
1085	if (ret)
1086		goto err_unreg;
1087
1088	return;
1089
1090err_unreg:
1091	perf_pmu_unregister(&pmu->base);
1092err:
1093	pmu->base.event_init = NULL;
1094	free_event_attributes(pmu);
1095	DRM_NOTE("Failed to register PMU! (err=%d)\n", ret);
1096}
1097
1098void i915_pmu_unregister(struct drm_i915_private *i915)
1099{
1100	struct i915_pmu *pmu = &i915->pmu;
1101
1102	if (!pmu->base.event_init)
1103		return;
1104
1105	WARN_ON(pmu->enable);
1106
1107	hrtimer_cancel(&pmu->timer);
1108
1109	i915_pmu_unregister_cpuhp_state(pmu);
1110
1111	perf_pmu_unregister(&pmu->base);
1112	pmu->base.event_init = NULL;
1113	free_event_attributes(pmu);
1114}