1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2016 Intel Corporation
4  */
5 
6 #include <drm/drm_print.h>
7 
8 #include "gem/i915_gem_context.h"
9 
10 #include "i915_drv.h"
11 
12 #include "intel_breadcrumbs.h"
13 #include "intel_context.h"
14 #include "intel_engine.h"
15 #include "intel_engine_pm.h"
16 #include "intel_engine_user.h"
17 #include "intel_execlists_submission.h"
18 #include "intel_gt.h"
19 #include "intel_gt_requests.h"
20 #include "intel_gt_pm.h"
21 #include "intel_lrc_reg.h"
22 #include "intel_reset.h"
23 #include "intel_ring.h"
24 #include "uc/intel_guc_submission.h"
25 
26 /* Haswell does have the CXT_SIZE register however it does not appear to be
27  * valid. Now, docs explain in dwords what is in the context object. The full
28  * size is 70720 bytes, however, the power context and execlist context will
29  * never be saved (power context is stored elsewhere, and execlists don't work
30  * on HSW) - so the final size, including the extra state required for the
31  * Resource Streamer, is 66944 bytes, which rounds to 17 pages.
32  */
33 #define HSW_CXT_TOTAL_SIZE		(17 * PAGE_SIZE)
34 
35 #define DEFAULT_LR_CONTEXT_RENDER_SIZE	(22 * PAGE_SIZE)
36 #define GEN8_LR_CONTEXT_RENDER_SIZE	(20 * PAGE_SIZE)
37 #define GEN9_LR_CONTEXT_RENDER_SIZE	(22 * PAGE_SIZE)
38 #define GEN11_LR_CONTEXT_RENDER_SIZE	(14 * PAGE_SIZE)
39 
40 #define GEN8_LR_CONTEXT_OTHER_SIZE	( 2 * PAGE_SIZE)
41 
42 #define MAX_MMIO_BASES 3
43 struct engine_info {
44 	u8 class;
45 	u8 instance;
46 	/* mmio bases table *must* be sorted in reverse graphics_ver order */
47 	struct engine_mmio_base {
48 		u32 graphics_ver : 8;
49 		u32 base : 24;
50 	} mmio_bases[MAX_MMIO_BASES];
51 };
52 
53 static const struct engine_info intel_engines[] = {
54 	[RCS0] = {
55 		.class = RENDER_CLASS,
56 		.instance = 0,
57 		.mmio_bases = {
58 			{ .graphics_ver = 1, .base = RENDER_RING_BASE }
59 		},
60 	},
61 	[BCS0] = {
62 		.class = COPY_ENGINE_CLASS,
63 		.instance = 0,
64 		.mmio_bases = {
65 			{ .graphics_ver = 6, .base = BLT_RING_BASE }
66 		},
67 	},
68 	[VCS0] = {
69 		.class = VIDEO_DECODE_CLASS,
70 		.instance = 0,
71 		.mmio_bases = {
72 			{ .graphics_ver = 11, .base = GEN11_BSD_RING_BASE },
73 			{ .graphics_ver = 6, .base = GEN6_BSD_RING_BASE },
74 			{ .graphics_ver = 4, .base = BSD_RING_BASE }
75 		},
76 	},
77 	[VCS1] = {
78 		.class = VIDEO_DECODE_CLASS,
79 		.instance = 1,
80 		.mmio_bases = {
81 			{ .graphics_ver = 11, .base = GEN11_BSD2_RING_BASE },
82 			{ .graphics_ver = 8, .base = GEN8_BSD2_RING_BASE }
83 		},
84 	},
85 	[VCS2] = {
86 		.class = VIDEO_DECODE_CLASS,
87 		.instance = 2,
88 		.mmio_bases = {
89 			{ .graphics_ver = 11, .base = GEN11_BSD3_RING_BASE }
90 		},
91 	},
92 	[VCS3] = {
93 		.class = VIDEO_DECODE_CLASS,
94 		.instance = 3,
95 		.mmio_bases = {
96 			{ .graphics_ver = 11, .base = GEN11_BSD4_RING_BASE }
97 		},
98 	},
99 	[VCS4] = {
100 		.class = VIDEO_DECODE_CLASS,
101 		.instance = 4,
102 		.mmio_bases = {
103 			{ .graphics_ver = 12, .base = XEHP_BSD5_RING_BASE }
104 		},
105 	},
106 	[VCS5] = {
107 		.class = VIDEO_DECODE_CLASS,
108 		.instance = 5,
109 		.mmio_bases = {
110 			{ .graphics_ver = 12, .base = XEHP_BSD6_RING_BASE }
111 		},
112 	},
113 	[VCS6] = {
114 		.class = VIDEO_DECODE_CLASS,
115 		.instance = 6,
116 		.mmio_bases = {
117 			{ .graphics_ver = 12, .base = XEHP_BSD7_RING_BASE }
118 		},
119 	},
120 	[VCS7] = {
121 		.class = VIDEO_DECODE_CLASS,
122 		.instance = 7,
123 		.mmio_bases = {
124 			{ .graphics_ver = 12, .base = XEHP_BSD8_RING_BASE }
125 		},
126 	},
127 	[VECS0] = {
128 		.class = VIDEO_ENHANCEMENT_CLASS,
129 		.instance = 0,
130 		.mmio_bases = {
131 			{ .graphics_ver = 11, .base = GEN11_VEBOX_RING_BASE },
132 			{ .graphics_ver = 7, .base = VEBOX_RING_BASE }
133 		},
134 	},
135 	[VECS1] = {
136 		.class = VIDEO_ENHANCEMENT_CLASS,
137 		.instance = 1,
138 		.mmio_bases = {
139 			{ .graphics_ver = 11, .base = GEN11_VEBOX2_RING_BASE }
140 		},
141 	},
142 	[VECS2] = {
143 		.class = VIDEO_ENHANCEMENT_CLASS,
144 		.instance = 2,
145 		.mmio_bases = {
146 			{ .graphics_ver = 12, .base = XEHP_VEBOX3_RING_BASE }
147 		},
148 	},
149 	[VECS3] = {
150 		.class = VIDEO_ENHANCEMENT_CLASS,
151 		.instance = 3,
152 		.mmio_bases = {
153 			{ .graphics_ver = 12, .base = XEHP_VEBOX4_RING_BASE }
154 		},
155 	},
156 };
157 
158 /**
159  * intel_engine_context_size() - return the size of the context for an engine
160  * @gt: the gt
161  * @class: engine class
162  *
163  * Each engine class may require a different amount of space for a context
164  * image.
165  *
166  * Return: size (in bytes) of an engine class specific context image
167  *
168  * Note: this size includes the HWSP, which is part of the context image
169  * in LRC mode, but does not include the "shared data page" used with
170  * GuC submission. The caller should account for this if using the GuC.
171  */
172 u32 intel_engine_context_size(struct intel_gt *gt, u8 class)
173 {
174 	struct intel_uncore *uncore = gt->uncore;
175 	u32 cxt_size;
176 
177 	BUILD_BUG_ON(I915_GTT_PAGE_SIZE != PAGE_SIZE);
178 
179 	switch (class) {
180 	case RENDER_CLASS:
181 		switch (GRAPHICS_VER(gt->i915)) {
182 		default:
183 			MISSING_CASE(GRAPHICS_VER(gt->i915));
184 			return DEFAULT_LR_CONTEXT_RENDER_SIZE;
185 		case 12:
186 		case 11:
187 			return GEN11_LR_CONTEXT_RENDER_SIZE;
188 		case 9:
189 			return GEN9_LR_CONTEXT_RENDER_SIZE;
190 		case 8:
191 			return GEN8_LR_CONTEXT_RENDER_SIZE;
192 		case 7:
193 			if (IS_HASWELL(gt->i915))
194 				return HSW_CXT_TOTAL_SIZE;
195 
196 			cxt_size = intel_uncore_read(uncore, GEN7_CXT_SIZE);
197 			return round_up(GEN7_CXT_TOTAL_SIZE(cxt_size) * 64,
198 					PAGE_SIZE);
199 		case 6:
200 			cxt_size = intel_uncore_read(uncore, CXT_SIZE);
201 			return round_up(GEN6_CXT_TOTAL_SIZE(cxt_size) * 64,
202 					PAGE_SIZE);
203 		case 5:
204 		case 4:
205 			/*
206 			 * There is a discrepancy here between the size reported
207 			 * by the register and the size of the context layout
208 			 * in the docs. Both are described as authorative!
209 			 *
210 			 * The discrepancy is on the order of a few cachelines,
211 			 * but the total is under one page (4k), which is our
212 			 * minimum allocation anyway so it should all come
213 			 * out in the wash.
214 			 */
215 			cxt_size = intel_uncore_read(uncore, CXT_SIZE) + 1;
216 			drm_dbg(&gt->i915->drm,
217 				"graphics_ver = %d CXT_SIZE = %d bytes [0x%08x]\n",
218 				GRAPHICS_VER(gt->i915), cxt_size * 64,
219 				cxt_size - 1);
220 			return round_up(cxt_size * 64, PAGE_SIZE);
221 		case 3:
222 		case 2:
223 		/* For the special day when i810 gets merged. */
224 		case 1:
225 			return 0;
226 		}
227 		break;
228 	default:
229 		MISSING_CASE(class);
230 		fallthrough;
231 	case VIDEO_DECODE_CLASS:
232 	case VIDEO_ENHANCEMENT_CLASS:
233 	case COPY_ENGINE_CLASS:
234 		if (GRAPHICS_VER(gt->i915) < 8)
235 			return 0;
236 		return GEN8_LR_CONTEXT_OTHER_SIZE;
237 	}
238 }
239 
240 static u32 __engine_mmio_base(struct drm_i915_private *i915,
241 			      const struct engine_mmio_base *bases)
242 {
243 	int i;
244 
245 	for (i = 0; i < MAX_MMIO_BASES; i++)
246 		if (GRAPHICS_VER(i915) >= bases[i].graphics_ver)
247 			break;
248 
249 	GEM_BUG_ON(i == MAX_MMIO_BASES);
250 	GEM_BUG_ON(!bases[i].base);
251 
252 	return bases[i].base;
253 }
254 
255 static void __sprint_engine_name(struct intel_engine_cs *engine)
256 {
257 	/*
258 	 * Before we know what the uABI name for this engine will be,
259 	 * we still would like to keep track of this engine in the debug logs.
260 	 * We throw in a ' here as a reminder that this isn't its final name.
261 	 */
262 	GEM_WARN_ON(snprintf(engine->name, sizeof(engine->name), "%s'%u",
263 			     intel_engine_class_repr(engine->class),
264 			     engine->instance) >= sizeof(engine->name));
265 }
266 
267 void intel_engine_set_hwsp_writemask(struct intel_engine_cs *engine, u32 mask)
268 {
269 	/*
270 	 * Though they added more rings on g4x/ilk, they did not add
271 	 * per-engine HWSTAM until gen6.
272 	 */
273 	if (GRAPHICS_VER(engine->i915) < 6 && engine->class != RENDER_CLASS)
274 		return;
275 
276 	if (GRAPHICS_VER(engine->i915) >= 3)
277 		ENGINE_WRITE(engine, RING_HWSTAM, mask);
278 	else
279 		ENGINE_WRITE16(engine, RING_HWSTAM, mask);
280 }
281 
282 static void intel_engine_sanitize_mmio(struct intel_engine_cs *engine)
283 {
284 	/* Mask off all writes into the unknown HWSP */
285 	intel_engine_set_hwsp_writemask(engine, ~0u);
286 }
287 
288 static void nop_irq_handler(struct intel_engine_cs *engine, u16 iir)
289 {
290 	GEM_DEBUG_WARN_ON(iir);
291 }
292 
293 static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
294 {
295 	const struct engine_info *info = &intel_engines[id];
296 	struct drm_i915_private *i915 = gt->i915;
297 	struct intel_engine_cs *engine;
298 	u8 guc_class;
299 
300 	BUILD_BUG_ON(MAX_ENGINE_CLASS >= BIT(GEN11_ENGINE_CLASS_WIDTH));
301 	BUILD_BUG_ON(MAX_ENGINE_INSTANCE >= BIT(GEN11_ENGINE_INSTANCE_WIDTH));
302 	BUILD_BUG_ON(I915_MAX_VCS > (MAX_ENGINE_INSTANCE + 1));
303 	BUILD_BUG_ON(I915_MAX_VECS > (MAX_ENGINE_INSTANCE + 1));
304 
305 	if (GEM_DEBUG_WARN_ON(id >= ARRAY_SIZE(gt->engine)))
306 		return -EINVAL;
307 
308 	if (GEM_DEBUG_WARN_ON(info->class > MAX_ENGINE_CLASS))
309 		return -EINVAL;
310 
311 	if (GEM_DEBUG_WARN_ON(info->instance > MAX_ENGINE_INSTANCE))
312 		return -EINVAL;
313 
314 	if (GEM_DEBUG_WARN_ON(gt->engine_class[info->class][info->instance]))
315 		return -EINVAL;
316 
317 	engine = kzalloc(sizeof(*engine), GFP_KERNEL);
318 	if (!engine)
319 		return -ENOMEM;
320 
321 	BUILD_BUG_ON(BITS_PER_TYPE(engine->mask) < I915_NUM_ENGINES);
322 
323 	engine->id = id;
324 	engine->legacy_idx = INVALID_ENGINE;
325 	engine->mask = BIT(id);
326 	engine->i915 = i915;
327 	engine->gt = gt;
328 	engine->uncore = gt->uncore;
329 	guc_class = engine_class_to_guc_class(info->class);
330 	engine->guc_id = MAKE_GUC_ID(guc_class, info->instance);
331 	engine->mmio_base = __engine_mmio_base(i915, info->mmio_bases);
332 
333 	engine->irq_handler = nop_irq_handler;
334 
335 	engine->class = info->class;
336 	engine->instance = info->instance;
337 	__sprint_engine_name(engine);
338 
339 	engine->props.heartbeat_interval_ms =
340 		CONFIG_DRM_I915_HEARTBEAT_INTERVAL;
341 	engine->props.max_busywait_duration_ns =
342 		CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT;
343 	engine->props.preempt_timeout_ms =
344 		CONFIG_DRM_I915_PREEMPT_TIMEOUT;
345 	engine->props.stop_timeout_ms =
346 		CONFIG_DRM_I915_STOP_TIMEOUT;
347 	engine->props.timeslice_duration_ms =
348 		CONFIG_DRM_I915_TIMESLICE_DURATION;
349 
350 	/* Override to uninterruptible for OpenCL workloads. */
351 	if (GRAPHICS_VER(i915) == 12 && engine->class == RENDER_CLASS)
352 		engine->props.preempt_timeout_ms = 0;
353 
354 	engine->defaults = engine->props; /* never to change again */
355 
356 	engine->context_size = intel_engine_context_size(gt, engine->class);
357 	if (WARN_ON(engine->context_size > BIT(20)))
358 		engine->context_size = 0;
359 	if (engine->context_size)
360 		DRIVER_CAPS(i915)->has_logical_contexts = true;
361 
362 	ewma__engine_latency_init(&engine->latency);
363 	seqcount_init(&engine->stats.lock);
364 
365 	ATOMIC_INIT_NOTIFIER_HEAD(&engine->context_status_notifier);
366 
367 	/* Scrub mmio state on takeover */
368 	intel_engine_sanitize_mmio(engine);
369 
370 	gt->engine_class[info->class][info->instance] = engine;
371 	gt->engine[id] = engine;
372 
373 	return 0;
374 }
375 
376 static void __setup_engine_capabilities(struct intel_engine_cs *engine)
377 {
378 	struct drm_i915_private *i915 = engine->i915;
379 
380 	if (engine->class == VIDEO_DECODE_CLASS) {
381 		/*
382 		 * HEVC support is present on first engine instance
383 		 * before Gen11 and on all instances afterwards.
384 		 */
385 		if (GRAPHICS_VER(i915) >= 11 ||
386 		    (GRAPHICS_VER(i915) >= 9 && engine->instance == 0))
387 			engine->uabi_capabilities |=
388 				I915_VIDEO_CLASS_CAPABILITY_HEVC;
389 
390 		/*
391 		 * SFC block is present only on even logical engine
392 		 * instances.
393 		 */
394 		if ((GRAPHICS_VER(i915) >= 11 &&
395 		     (engine->gt->info.vdbox_sfc_access &
396 		      BIT(engine->instance))) ||
397 		    (GRAPHICS_VER(i915) >= 9 && engine->instance == 0))
398 			engine->uabi_capabilities |=
399 				I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC;
400 	} else if (engine->class == VIDEO_ENHANCEMENT_CLASS) {
401 		if (GRAPHICS_VER(i915) >= 9)
402 			engine->uabi_capabilities |=
403 				I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC;
404 	}
405 }
406 
407 static void intel_setup_engine_capabilities(struct intel_gt *gt)
408 {
409 	struct intel_engine_cs *engine;
410 	enum intel_engine_id id;
411 
412 	for_each_engine(engine, gt, id)
413 		__setup_engine_capabilities(engine);
414 }
415 
416 /**
417  * intel_engines_release() - free the resources allocated for Command Streamers
418  * @gt: pointer to struct intel_gt
419  */
420 void intel_engines_release(struct intel_gt *gt)
421 {
422 	struct intel_engine_cs *engine;
423 	enum intel_engine_id id;
424 
425 	/*
426 	 * Before we release the resources held by engine, we must be certain
427 	 * that the HW is no longer accessing them -- having the GPU scribble
428 	 * to or read from a page being used for something else causes no end
429 	 * of fun.
430 	 *
431 	 * The GPU should be reset by this point, but assume the worst just
432 	 * in case we aborted before completely initialising the engines.
433 	 */
434 	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
435 	if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
436 		__intel_gt_reset(gt, ALL_ENGINES);
437 
438 	/* Decouple the backend; but keep the layout for late GPU resets */
439 	for_each_engine(engine, gt, id) {
440 		if (!engine->release)
441 			continue;
442 
443 		intel_wakeref_wait_for_idle(&engine->wakeref);
444 		GEM_BUG_ON(intel_engine_pm_is_awake(engine));
445 
446 		engine->release(engine);
447 		engine->release = NULL;
448 
449 		memset(&engine->reset, 0, sizeof(engine->reset));
450 	}
451 }
452 
453 void intel_engine_free_request_pool(struct intel_engine_cs *engine)
454 {
455 	if (!engine->request_pool)
456 		return;
457 
458 	kmem_cache_free(i915_request_slab_cache(), engine->request_pool);
459 }
460 
461 void intel_engines_free(struct intel_gt *gt)
462 {
463 	struct intel_engine_cs *engine;
464 	enum intel_engine_id id;
465 
466 	/* Free the requests! dma-resv keeps fences around for an eternity */
467 	rcu_barrier();
468 
469 	for_each_engine(engine, gt, id) {
470 		intel_engine_free_request_pool(engine);
471 		kfree(engine);
472 		gt->engine[id] = NULL;
473 	}
474 }
475 
476 static
477 bool gen11_vdbox_has_sfc(struct drm_i915_private *i915,
478 			 unsigned int physical_vdbox,
479 			 unsigned int logical_vdbox, u16 vdbox_mask)
480 {
481 	/*
482 	 * In Gen11, only even numbered logical VDBOXes are hooked
483 	 * up to an SFC (Scaler & Format Converter) unit.
484 	 * In Gen12, Even numbered physical instance always are connected
485 	 * to an SFC. Odd numbered physical instances have SFC only if
486 	 * previous even instance is fused off.
487 	 */
488 	if (GRAPHICS_VER(i915) == 12)
489 		return (physical_vdbox % 2 == 0) ||
490 			!(BIT(physical_vdbox - 1) & vdbox_mask);
491 	else if (GRAPHICS_VER(i915) == 11)
492 		return logical_vdbox % 2 == 0;
493 
494 	MISSING_CASE(GRAPHICS_VER(i915));
495 	return false;
496 }
497 
498 /*
499  * Determine which engines are fused off in our particular hardware.
500  * Note that we have a catch-22 situation where we need to be able to access
501  * the blitter forcewake domain to read the engine fuses, but at the same time
502  * we need to know which engines are available on the system to know which
503  * forcewake domains are present. We solve this by intializing the forcewake
504  * domains based on the full engine mask in the platform capabilities before
505  * calling this function and pruning the domains for fused-off engines
506  * afterwards.
507  */
508 static intel_engine_mask_t init_engine_mask(struct intel_gt *gt)
509 {
510 	struct drm_i915_private *i915 = gt->i915;
511 	struct intel_gt_info *info = &gt->info;
512 	struct intel_uncore *uncore = gt->uncore;
513 	unsigned int logical_vdbox = 0;
514 	unsigned int i;
515 	u32 media_fuse;
516 	u16 vdbox_mask;
517 	u16 vebox_mask;
518 
519 	info->engine_mask = INTEL_INFO(i915)->platform_engine_mask;
520 
521 	if (GRAPHICS_VER(i915) < 11)
522 		return info->engine_mask;
523 
524 	/*
525 	 * On newer platforms the fusing register is called 'enable' and has
526 	 * enable semantics, while on older platforms it is called 'disable'
527 	 * and bits have disable semantices.
528 	 */
529 	media_fuse = intel_uncore_read(uncore, GEN11_GT_VEBOX_VDBOX_DISABLE);
530 	if (GRAPHICS_VER_FULL(i915) < IP_VER(12, 50))
531 		media_fuse = ~media_fuse;
532 
533 	vdbox_mask = media_fuse & GEN11_GT_VDBOX_DISABLE_MASK;
534 	vebox_mask = (media_fuse & GEN11_GT_VEBOX_DISABLE_MASK) >>
535 		      GEN11_GT_VEBOX_DISABLE_SHIFT;
536 
537 	for (i = 0; i < I915_MAX_VCS; i++) {
538 		if (!HAS_ENGINE(gt, _VCS(i))) {
539 			vdbox_mask &= ~BIT(i);
540 			continue;
541 		}
542 
543 		if (!(BIT(i) & vdbox_mask)) {
544 			info->engine_mask &= ~BIT(_VCS(i));
545 			drm_dbg(&i915->drm, "vcs%u fused off\n", i);
546 			continue;
547 		}
548 
549 		if (gen11_vdbox_has_sfc(i915, i, logical_vdbox, vdbox_mask))
550 			gt->info.vdbox_sfc_access |= BIT(i);
551 		logical_vdbox++;
552 	}
553 	drm_dbg(&i915->drm, "vdbox enable: %04x, instances: %04lx\n",
554 		vdbox_mask, VDBOX_MASK(gt));
555 	GEM_BUG_ON(vdbox_mask != VDBOX_MASK(gt));
556 
557 	for (i = 0; i < I915_MAX_VECS; i++) {
558 		if (!HAS_ENGINE(gt, _VECS(i))) {
559 			vebox_mask &= ~BIT(i);
560 			continue;
561 		}
562 
563 		if (!(BIT(i) & vebox_mask)) {
564 			info->engine_mask &= ~BIT(_VECS(i));
565 			drm_dbg(&i915->drm, "vecs%u fused off\n", i);
566 		}
567 	}
568 	drm_dbg(&i915->drm, "vebox enable: %04x, instances: %04lx\n",
569 		vebox_mask, VEBOX_MASK(gt));
570 	GEM_BUG_ON(vebox_mask != VEBOX_MASK(gt));
571 
572 	return info->engine_mask;
573 }
574 
575 /**
576  * intel_engines_init_mmio() - allocate and prepare the Engine Command Streamers
577  * @gt: pointer to struct intel_gt
578  *
579  * Return: non-zero if the initialization failed.
580  */
581 int intel_engines_init_mmio(struct intel_gt *gt)
582 {
583 	struct drm_i915_private *i915 = gt->i915;
584 	const unsigned int engine_mask = init_engine_mask(gt);
585 	unsigned int mask = 0;
586 	unsigned int i;
587 	int err;
588 
589 	drm_WARN_ON(&i915->drm, engine_mask == 0);
590 	drm_WARN_ON(&i915->drm, engine_mask &
591 		    GENMASK(BITS_PER_TYPE(mask) - 1, I915_NUM_ENGINES));
592 
593 	if (i915_inject_probe_failure(i915))
594 		return -ENODEV;
595 
596 	for (i = 0; i < ARRAY_SIZE(intel_engines); i++) {
597 		if (!HAS_ENGINE(gt, i))
598 			continue;
599 
600 		err = intel_engine_setup(gt, i);
601 		if (err)
602 			goto cleanup;
603 
604 		mask |= BIT(i);
605 	}
606 
607 	/*
608 	 * Catch failures to update intel_engines table when the new engines
609 	 * are added to the driver by a warning and disabling the forgotten
610 	 * engines.
611 	 */
612 	if (drm_WARN_ON(&i915->drm, mask != engine_mask))
613 		gt->info.engine_mask = mask;
614 
615 	gt->info.num_engines = hweight32(mask);
616 
617 	intel_gt_check_and_clear_faults(gt);
618 
619 	intel_setup_engine_capabilities(gt);
620 
621 	intel_uncore_prune_engine_fw_domains(gt->uncore, gt);
622 
623 	return 0;
624 
625 cleanup:
626 	intel_engines_free(gt);
627 	return err;
628 }
629 
630 void intel_engine_init_execlists(struct intel_engine_cs *engine)
631 {
632 	struct intel_engine_execlists * const execlists = &engine->execlists;
633 
634 	execlists->port_mask = 1;
635 	GEM_BUG_ON(!is_power_of_2(execlists_num_ports(execlists)));
636 	GEM_BUG_ON(execlists_num_ports(execlists) > EXECLIST_MAX_PORTS);
637 
638 	memset(execlists->pending, 0, sizeof(execlists->pending));
639 	execlists->active =
640 		memset(execlists->inflight, 0, sizeof(execlists->inflight));
641 }
642 
643 static void cleanup_status_page(struct intel_engine_cs *engine)
644 {
645 	struct i915_vma *vma;
646 
647 	/* Prevent writes into HWSP after returning the page to the system */
648 	intel_engine_set_hwsp_writemask(engine, ~0u);
649 
650 	vma = fetch_and_zero(&engine->status_page.vma);
651 	if (!vma)
652 		return;
653 
654 	if (!HWS_NEEDS_PHYSICAL(engine->i915))
655 		i915_vma_unpin(vma);
656 
657 	i915_gem_object_unpin_map(vma->obj);
658 	i915_gem_object_put(vma->obj);
659 }
660 
661 static int pin_ggtt_status_page(struct intel_engine_cs *engine,
662 				struct i915_gem_ww_ctx *ww,
663 				struct i915_vma *vma)
664 {
665 	unsigned int flags;
666 
667 	if (!HAS_LLC(engine->i915) && i915_ggtt_has_aperture(engine->gt->ggtt))
668 		/*
669 		 * On g33, we cannot place HWS above 256MiB, so
670 		 * restrict its pinning to the low mappable arena.
671 		 * Though this restriction is not documented for
672 		 * gen4, gen5, or byt, they also behave similarly
673 		 * and hang if the HWS is placed at the top of the
674 		 * GTT. To generalise, it appears that all !llc
675 		 * platforms have issues with us placing the HWS
676 		 * above the mappable region (even though we never
677 		 * actually map it).
678 		 */
679 		flags = PIN_MAPPABLE;
680 	else
681 		flags = PIN_HIGH;
682 
683 	return i915_ggtt_pin(vma, ww, 0, flags);
684 }
685 
686 static int init_status_page(struct intel_engine_cs *engine)
687 {
688 	struct drm_i915_gem_object *obj;
689 	struct i915_gem_ww_ctx ww;
690 	struct i915_vma *vma;
691 	void *vaddr;
692 	int ret;
693 
694 	INIT_LIST_HEAD(&engine->status_page.timelines);
695 
696 	/*
697 	 * Though the HWS register does support 36bit addresses, historically
698 	 * we have had hangs and corruption reported due to wild writes if
699 	 * the HWS is placed above 4G. We only allow objects to be allocated
700 	 * in GFP_DMA32 for i965, and no earlier physical address users had
701 	 * access to more than 4G.
702 	 */
703 	obj = i915_gem_object_create_internal(engine->i915, PAGE_SIZE);
704 	if (IS_ERR(obj)) {
705 		drm_err(&engine->i915->drm,
706 			"Failed to allocate status page\n");
707 		return PTR_ERR(obj);
708 	}
709 
710 	i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);
711 
712 	vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
713 	if (IS_ERR(vma)) {
714 		ret = PTR_ERR(vma);
715 		goto err_put;
716 	}
717 
718 	i915_gem_ww_ctx_init(&ww, true);
719 retry:
720 	ret = i915_gem_object_lock(obj, &ww);
721 	if (!ret && !HWS_NEEDS_PHYSICAL(engine->i915))
722 		ret = pin_ggtt_status_page(engine, &ww, vma);
723 	if (ret)
724 		goto err;
725 
726 	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
727 	if (IS_ERR(vaddr)) {
728 		ret = PTR_ERR(vaddr);
729 		goto err_unpin;
730 	}
731 
732 	engine->status_page.addr = memset(vaddr, 0, PAGE_SIZE);
733 	engine->status_page.vma = vma;
734 
735 err_unpin:
736 	if (ret)
737 		i915_vma_unpin(vma);
738 err:
739 	if (ret == -EDEADLK) {
740 		ret = i915_gem_ww_ctx_backoff(&ww);
741 		if (!ret)
742 			goto retry;
743 	}
744 	i915_gem_ww_ctx_fini(&ww);
745 err_put:
746 	if (ret)
747 		i915_gem_object_put(obj);
748 	return ret;
749 }
750 
751 static int engine_setup_common(struct intel_engine_cs *engine)
752 {
753 	int err;
754 
755 	init_llist_head(&engine->barrier_tasks);
756 
757 	err = init_status_page(engine);
758 	if (err)
759 		return err;
760 
761 	engine->breadcrumbs = intel_breadcrumbs_create(engine);
762 	if (!engine->breadcrumbs) {
763 		err = -ENOMEM;
764 		goto err_status;
765 	}
766 
767 	engine->sched_engine = i915_sched_engine_create(ENGINE_PHYSICAL);
768 	if (!engine->sched_engine) {
769 		err = -ENOMEM;
770 		goto err_sched_engine;
771 	}
772 	engine->sched_engine->private_data = engine;
773 
774 	err = intel_engine_init_cmd_parser(engine);
775 	if (err)
776 		goto err_cmd_parser;
777 
778 	intel_engine_init_execlists(engine);
779 	intel_engine_init__pm(engine);
780 	intel_engine_init_retire(engine);
781 
782 	/* Use the whole device by default */
783 	engine->sseu =
784 		intel_sseu_from_device_info(&engine->gt->info.sseu);
785 
786 	intel_engine_init_workarounds(engine);
787 	intel_engine_init_whitelist(engine);
788 	intel_engine_init_ctx_wa(engine);
789 
790 	if (GRAPHICS_VER(engine->i915) >= 12)
791 		engine->flags |= I915_ENGINE_HAS_RELATIVE_MMIO;
792 
793 	return 0;
794 
795 err_cmd_parser:
796 	i915_sched_engine_put(engine->sched_engine);
797 err_sched_engine:
798 	intel_breadcrumbs_put(engine->breadcrumbs);
799 err_status:
800 	cleanup_status_page(engine);
801 	return err;
802 }
803 
804 struct measure_breadcrumb {
805 	struct i915_request rq;
806 	struct intel_ring ring;
807 	u32 cs[2048];
808 };
809 
810 static int measure_breadcrumb_dw(struct intel_context *ce)
811 {
812 	struct intel_engine_cs *engine = ce->engine;
813 	struct measure_breadcrumb *frame;
814 	int dw;
815 
816 	GEM_BUG_ON(!engine->gt->scratch);
817 
818 	frame = kzalloc(sizeof(*frame), GFP_KERNEL);
819 	if (!frame)
820 		return -ENOMEM;
821 
822 	frame->rq.engine = engine;
823 	frame->rq.context = ce;
824 	rcu_assign_pointer(frame->rq.timeline, ce->timeline);
825 	frame->rq.hwsp_seqno = ce->timeline->hwsp_seqno;
826 
827 	frame->ring.vaddr = frame->cs;
828 	frame->ring.size = sizeof(frame->cs);
829 	frame->ring.wrap =
830 		BITS_PER_TYPE(frame->ring.size) - ilog2(frame->ring.size);
831 	frame->ring.effective_size = frame->ring.size;
832 	intel_ring_update_space(&frame->ring);
833 	frame->rq.ring = &frame->ring;
834 
835 	mutex_lock(&ce->timeline->mutex);
836 	spin_lock_irq(&engine->sched_engine->lock);
837 
838 	dw = engine->emit_fini_breadcrumb(&frame->rq, frame->cs) - frame->cs;
839 
840 	spin_unlock_irq(&engine->sched_engine->lock);
841 	mutex_unlock(&ce->timeline->mutex);
842 
843 	GEM_BUG_ON(dw & 1); /* RING_TAIL must be qword aligned */
844 
845 	kfree(frame);
846 	return dw;
847 }
848 
849 struct intel_context *
850 intel_engine_create_pinned_context(struct intel_engine_cs *engine,
851 				   struct i915_address_space *vm,
852 				   unsigned int ring_size,
853 				   unsigned int hwsp,
854 				   struct lock_class_key *key,
855 				   const char *name)
856 {
857 	struct intel_context *ce;
858 	int err;
859 
860 	ce = intel_context_create(engine);
861 	if (IS_ERR(ce))
862 		return ce;
863 
864 	__set_bit(CONTEXT_BARRIER_BIT, &ce->flags);
865 	ce->timeline = page_pack_bits(NULL, hwsp);
866 	ce->ring = NULL;
867 	ce->ring_size = ring_size;
868 
869 	i915_vm_put(ce->vm);
870 	ce->vm = i915_vm_get(vm);
871 
872 	err = intel_context_pin(ce); /* perma-pin so it is always available */
873 	if (err) {
874 		intel_context_put(ce);
875 		return ERR_PTR(err);
876 	}
877 
878 	/*
879 	 * Give our perma-pinned kernel timelines a separate lockdep class,
880 	 * so that we can use them from within the normal user timelines
881 	 * should we need to inject GPU operations during their request
882 	 * construction.
883 	 */
884 	lockdep_set_class_and_name(&ce->timeline->mutex, key, name);
885 
886 	return ce;
887 }
888 
889 void intel_engine_destroy_pinned_context(struct intel_context *ce)
890 {
891 	struct intel_engine_cs *engine = ce->engine;
892 	struct i915_vma *hwsp = engine->status_page.vma;
893 
894 	GEM_BUG_ON(ce->timeline->hwsp_ggtt != hwsp);
895 
896 	mutex_lock(&hwsp->vm->mutex);
897 	list_del(&ce->timeline->engine_link);
898 	mutex_unlock(&hwsp->vm->mutex);
899 
900 	intel_context_unpin(ce);
901 	intel_context_put(ce);
902 }
903 
904 static struct intel_context *
905 create_kernel_context(struct intel_engine_cs *engine)
906 {
907 	static struct lock_class_key kernel;
908 
909 	return intel_engine_create_pinned_context(engine, engine->gt->vm, SZ_4K,
910 						  I915_GEM_HWS_SEQNO_ADDR,
911 						  &kernel, "kernel_context");
912 }
913 
914 /**
915  * intel_engines_init_common - initialize cengine state which might require hw access
916  * @engine: Engine to initialize.
917  *
918  * Initializes @engine@ structure members shared between legacy and execlists
919  * submission modes which do require hardware access.
920  *
921  * Typcally done at later stages of submission mode specific engine setup.
922  *
923  * Returns zero on success or an error code on failure.
924  */
925 static int engine_init_common(struct intel_engine_cs *engine)
926 {
927 	struct intel_context *ce;
928 	int ret;
929 
930 	engine->set_default_submission(engine);
931 
932 	/*
933 	 * We may need to do things with the shrinker which
934 	 * require us to immediately switch back to the default
935 	 * context. This can cause a problem as pinning the
936 	 * default context also requires GTT space which may not
937 	 * be available. To avoid this we always pin the default
938 	 * context.
939 	 */
940 	ce = create_kernel_context(engine);
941 	if (IS_ERR(ce))
942 		return PTR_ERR(ce);
943 
944 	ret = measure_breadcrumb_dw(ce);
945 	if (ret < 0)
946 		goto err_context;
947 
948 	engine->emit_fini_breadcrumb_dw = ret;
949 	engine->kernel_context = ce;
950 
951 	return 0;
952 
953 err_context:
954 	intel_engine_destroy_pinned_context(ce);
955 	return ret;
956 }
957 
958 int intel_engines_init(struct intel_gt *gt)
959 {
960 	int (*setup)(struct intel_engine_cs *engine);
961 	struct intel_engine_cs *engine;
962 	enum intel_engine_id id;
963 	int err;
964 
965 	if (intel_uc_uses_guc_submission(&gt->uc)) {
966 		gt->submission_method = INTEL_SUBMISSION_GUC;
967 		setup = intel_guc_submission_setup;
968 	} else if (HAS_EXECLISTS(gt->i915)) {
969 		gt->submission_method = INTEL_SUBMISSION_ELSP;
970 		setup = intel_execlists_submission_setup;
971 	} else {
972 		gt->submission_method = INTEL_SUBMISSION_RING;
973 		setup = intel_ring_submission_setup;
974 	}
975 
976 	for_each_engine(engine, gt, id) {
977 		err = engine_setup_common(engine);
978 		if (err)
979 			return err;
980 
981 		err = setup(engine);
982 		if (err)
983 			return err;
984 
985 		err = engine_init_common(engine);
986 		if (err)
987 			return err;
988 
989 		intel_engine_add_user(engine);
990 	}
991 
992 	return 0;
993 }
994 
995 /**
996  * intel_engines_cleanup_common - cleans up the engine state created by
997  *                                the common initiailizers.
998  * @engine: Engine to cleanup.
999  *
1000  * This cleans up everything created by the common helpers.
1001  */
1002 void intel_engine_cleanup_common(struct intel_engine_cs *engine)
1003 {
1004 	GEM_BUG_ON(!list_empty(&engine->sched_engine->requests));
1005 
1006 	i915_sched_engine_put(engine->sched_engine);
1007 	intel_breadcrumbs_put(engine->breadcrumbs);
1008 
1009 	intel_engine_fini_retire(engine);
1010 	intel_engine_cleanup_cmd_parser(engine);
1011 
1012 	if (engine->default_state)
1013 		fput(engine->default_state);
1014 
1015 	if (engine->kernel_context)
1016 		intel_engine_destroy_pinned_context(engine->kernel_context);
1017 
1018 	GEM_BUG_ON(!llist_empty(&engine->barrier_tasks));
1019 	cleanup_status_page(engine);
1020 
1021 	intel_wa_list_free(&engine->ctx_wa_list);
1022 	intel_wa_list_free(&engine->wa_list);
1023 	intel_wa_list_free(&engine->whitelist);
1024 }
1025 
1026 /**
1027  * intel_engine_resume - re-initializes the HW state of the engine
1028  * @engine: Engine to resume.
1029  *
1030  * Returns zero on success or an error code on failure.
1031  */
1032 int intel_engine_resume(struct intel_engine_cs *engine)
1033 {
1034 	intel_engine_apply_workarounds(engine);
1035 	intel_engine_apply_whitelist(engine);
1036 
1037 	return engine->resume(engine);
1038 }
1039 
1040 u64 intel_engine_get_active_head(const struct intel_engine_cs *engine)
1041 {
1042 	struct drm_i915_private *i915 = engine->i915;
1043 
1044 	u64 acthd;
1045 
1046 	if (GRAPHICS_VER(i915) >= 8)
1047 		acthd = ENGINE_READ64(engine, RING_ACTHD, RING_ACTHD_UDW);
1048 	else if (GRAPHICS_VER(i915) >= 4)
1049 		acthd = ENGINE_READ(engine, RING_ACTHD);
1050 	else
1051 		acthd = ENGINE_READ(engine, ACTHD);
1052 
1053 	return acthd;
1054 }
1055 
1056 u64 intel_engine_get_last_batch_head(const struct intel_engine_cs *engine)
1057 {
1058 	u64 bbaddr;
1059 
1060 	if (GRAPHICS_VER(engine->i915) >= 8)
1061 		bbaddr = ENGINE_READ64(engine, RING_BBADDR, RING_BBADDR_UDW);
1062 	else
1063 		bbaddr = ENGINE_READ(engine, RING_BBADDR);
1064 
1065 	return bbaddr;
1066 }
1067 
1068 static unsigned long stop_timeout(const struct intel_engine_cs *engine)
1069 {
1070 	if (in_atomic() || irqs_disabled()) /* inside atomic preempt-reset? */
1071 		return 0;
1072 
1073 	/*
1074 	 * If we are doing a normal GPU reset, we can take our time and allow
1075 	 * the engine to quiesce. We've stopped submission to the engine, and
1076 	 * if we wait long enough an innocent context should complete and
1077 	 * leave the engine idle. So they should not be caught unaware by
1078 	 * the forthcoming GPU reset (which usually follows the stop_cs)!
1079 	 */
1080 	return READ_ONCE(engine->props.stop_timeout_ms);
1081 }
1082 
1083 static int __intel_engine_stop_cs(struct intel_engine_cs *engine,
1084 				  int fast_timeout_us,
1085 				  int slow_timeout_ms)
1086 {
1087 	struct intel_uncore *uncore = engine->uncore;
1088 	const i915_reg_t mode = RING_MI_MODE(engine->mmio_base);
1089 	int err;
1090 
1091 	intel_uncore_write_fw(uncore, mode, _MASKED_BIT_ENABLE(STOP_RING));
1092 	err = __intel_wait_for_register_fw(engine->uncore, mode,
1093 					   MODE_IDLE, MODE_IDLE,
1094 					   fast_timeout_us,
1095 					   slow_timeout_ms,
1096 					   NULL);
1097 
1098 	/* A final mmio read to let GPU writes be hopefully flushed to memory */
1099 	intel_uncore_posting_read_fw(uncore, mode);
1100 	return err;
1101 }
1102 
1103 int intel_engine_stop_cs(struct intel_engine_cs *engine)
1104 {
1105 	int err = 0;
1106 
1107 	if (GRAPHICS_VER(engine->i915) < 3)
1108 		return -ENODEV;
1109 
1110 	ENGINE_TRACE(engine, "\n");
1111 	if (__intel_engine_stop_cs(engine, 1000, stop_timeout(engine))) {
1112 		ENGINE_TRACE(engine,
1113 			     "timed out on STOP_RING -> IDLE; HEAD:%04x, TAIL:%04x\n",
1114 			     ENGINE_READ_FW(engine, RING_HEAD) & HEAD_ADDR,
1115 			     ENGINE_READ_FW(engine, RING_TAIL) & TAIL_ADDR);
1116 
1117 		/*
1118 		 * Sometimes we observe that the idle flag is not
1119 		 * set even though the ring is empty. So double
1120 		 * check before giving up.
1121 		 */
1122 		if ((ENGINE_READ_FW(engine, RING_HEAD) & HEAD_ADDR) !=
1123 		    (ENGINE_READ_FW(engine, RING_TAIL) & TAIL_ADDR))
1124 			err = -ETIMEDOUT;
1125 	}
1126 
1127 	return err;
1128 }
1129 
1130 void intel_engine_cancel_stop_cs(struct intel_engine_cs *engine)
1131 {
1132 	ENGINE_TRACE(engine, "\n");
1133 
1134 	ENGINE_WRITE_FW(engine, RING_MI_MODE, _MASKED_BIT_DISABLE(STOP_RING));
1135 }
1136 
1137 const char *i915_cache_level_str(struct drm_i915_private *i915, int type)
1138 {
1139 	switch (type) {
1140 	case I915_CACHE_NONE: return " uncached";
1141 	case I915_CACHE_LLC: return HAS_LLC(i915) ? " LLC" : " snooped";
1142 	case I915_CACHE_L3_LLC: return " L3+LLC";
1143 	case I915_CACHE_WT: return " WT";
1144 	default: return "";
1145 	}
1146 }
1147 
1148 static u32
1149 read_subslice_reg(const struct intel_engine_cs *engine,
1150 		  int slice, int subslice, i915_reg_t reg)
1151 {
1152 	return intel_uncore_read_with_mcr_steering(engine->uncore, reg,
1153 						   slice, subslice);
1154 }
1155 
1156 /* NB: please notice the memset */
1157 void intel_engine_get_instdone(const struct intel_engine_cs *engine,
1158 			       struct intel_instdone *instdone)
1159 {
1160 	struct drm_i915_private *i915 = engine->i915;
1161 	const struct sseu_dev_info *sseu = &engine->gt->info.sseu;
1162 	struct intel_uncore *uncore = engine->uncore;
1163 	u32 mmio_base = engine->mmio_base;
1164 	int slice;
1165 	int subslice;
1166 
1167 	memset(instdone, 0, sizeof(*instdone));
1168 
1169 	switch (GRAPHICS_VER(i915)) {
1170 	default:
1171 		instdone->instdone =
1172 			intel_uncore_read(uncore, RING_INSTDONE(mmio_base));
1173 
1174 		if (engine->id != RCS0)
1175 			break;
1176 
1177 		instdone->slice_common =
1178 			intel_uncore_read(uncore, GEN7_SC_INSTDONE);
1179 		if (GRAPHICS_VER(i915) >= 12) {
1180 			instdone->slice_common_extra[0] =
1181 				intel_uncore_read(uncore, GEN12_SC_INSTDONE_EXTRA);
1182 			instdone->slice_common_extra[1] =
1183 				intel_uncore_read(uncore, GEN12_SC_INSTDONE_EXTRA2);
1184 		}
1185 		for_each_instdone_slice_subslice(i915, sseu, slice, subslice) {
1186 			instdone->sampler[slice][subslice] =
1187 				read_subslice_reg(engine, slice, subslice,
1188 						  GEN7_SAMPLER_INSTDONE);
1189 			instdone->row[slice][subslice] =
1190 				read_subslice_reg(engine, slice, subslice,
1191 						  GEN7_ROW_INSTDONE);
1192 		}
1193 		break;
1194 	case 7:
1195 		instdone->instdone =
1196 			intel_uncore_read(uncore, RING_INSTDONE(mmio_base));
1197 
1198 		if (engine->id != RCS0)
1199 			break;
1200 
1201 		instdone->slice_common =
1202 			intel_uncore_read(uncore, GEN7_SC_INSTDONE);
1203 		instdone->sampler[0][0] =
1204 			intel_uncore_read(uncore, GEN7_SAMPLER_INSTDONE);
1205 		instdone->row[0][0] =
1206 			intel_uncore_read(uncore, GEN7_ROW_INSTDONE);
1207 
1208 		break;
1209 	case 6:
1210 	case 5:
1211 	case 4:
1212 		instdone->instdone =
1213 			intel_uncore_read(uncore, RING_INSTDONE(mmio_base));
1214 		if (engine->id == RCS0)
1215 			/* HACK: Using the wrong struct member */
1216 			instdone->slice_common =
1217 				intel_uncore_read(uncore, GEN4_INSTDONE1);
1218 		break;
1219 	case 3:
1220 	case 2:
1221 		instdone->instdone = intel_uncore_read(uncore, GEN2_INSTDONE);
1222 		break;
1223 	}
1224 }
1225 
1226 static bool ring_is_idle(struct intel_engine_cs *engine)
1227 {
1228 	bool idle = true;
1229 
1230 	if (I915_SELFTEST_ONLY(!engine->mmio_base))
1231 		return true;
1232 
1233 	if (!intel_engine_pm_get_if_awake(engine))
1234 		return true;
1235 
1236 	/* First check that no commands are left in the ring */
1237 	if ((ENGINE_READ(engine, RING_HEAD) & HEAD_ADDR) !=
1238 	    (ENGINE_READ(engine, RING_TAIL) & TAIL_ADDR))
1239 		idle = false;
1240 
1241 	/* No bit for gen2, so assume the CS parser is idle */
1242 	if (GRAPHICS_VER(engine->i915) > 2 &&
1243 	    !(ENGINE_READ(engine, RING_MI_MODE) & MODE_IDLE))
1244 		idle = false;
1245 
1246 	intel_engine_pm_put(engine);
1247 
1248 	return idle;
1249 }
1250 
1251 void __intel_engine_flush_submission(struct intel_engine_cs *engine, bool sync)
1252 {
1253 	struct tasklet_struct *t = &engine->sched_engine->tasklet;
1254 
1255 	if (!t->callback)
1256 		return;
1257 
1258 	local_bh_disable();
1259 	if (tasklet_trylock(t)) {
1260 		/* Must wait for any GPU reset in progress. */
1261 		if (__tasklet_is_enabled(t))
1262 			t->callback(t);
1263 		tasklet_unlock(t);
1264 	}
1265 	local_bh_enable();
1266 
1267 	/* Synchronise and wait for the tasklet on another CPU */
1268 	if (sync)
1269 		tasklet_unlock_wait(t);
1270 }
1271 
1272 /**
1273  * intel_engine_is_idle() - Report if the engine has finished process all work
1274  * @engine: the intel_engine_cs
1275  *
1276  * Return true if there are no requests pending, nothing left to be submitted
1277  * to hardware, and that the engine is idle.
1278  */
1279 bool intel_engine_is_idle(struct intel_engine_cs *engine)
1280 {
1281 	/* More white lies, if wedged, hw state is inconsistent */
1282 	if (intel_gt_is_wedged(engine->gt))
1283 		return true;
1284 
1285 	if (!intel_engine_pm_is_awake(engine))
1286 		return true;
1287 
1288 	/* Waiting to drain ELSP? */
1289 	intel_synchronize_hardirq(engine->i915);
1290 	intel_engine_flush_submission(engine);
1291 
1292 	/* ELSP is empty, but there are ready requests? E.g. after reset */
1293 	if (!i915_sched_engine_is_empty(engine->sched_engine))
1294 		return false;
1295 
1296 	/* Ring stopped? */
1297 	return ring_is_idle(engine);
1298 }
1299 
1300 bool intel_engines_are_idle(struct intel_gt *gt)
1301 {
1302 	struct intel_engine_cs *engine;
1303 	enum intel_engine_id id;
1304 
1305 	/*
1306 	 * If the driver is wedged, HW state may be very inconsistent and
1307 	 * report that it is still busy, even though we have stopped using it.
1308 	 */
1309 	if (intel_gt_is_wedged(gt))
1310 		return true;
1311 
1312 	/* Already parked (and passed an idleness test); must still be idle */
1313 	if (!READ_ONCE(gt->awake))
1314 		return true;
1315 
1316 	for_each_engine(engine, gt, id) {
1317 		if (!intel_engine_is_idle(engine))
1318 			return false;
1319 	}
1320 
1321 	return true;
1322 }
1323 
1324 bool intel_engine_irq_enable(struct intel_engine_cs *engine)
1325 {
1326 	if (!engine->irq_enable)
1327 		return false;
1328 
1329 	/* Caller disables interrupts */
1330 	spin_lock(&engine->gt->irq_lock);
1331 	engine->irq_enable(engine);
1332 	spin_unlock(&engine->gt->irq_lock);
1333 
1334 	return true;
1335 }
1336 
1337 void intel_engine_irq_disable(struct intel_engine_cs *engine)
1338 {
1339 	if (!engine->irq_disable)
1340 		return;
1341 
1342 	/* Caller disables interrupts */
1343 	spin_lock(&engine->gt->irq_lock);
1344 	engine->irq_disable(engine);
1345 	spin_unlock(&engine->gt->irq_lock);
1346 }
1347 
1348 void intel_engines_reset_default_submission(struct intel_gt *gt)
1349 {
1350 	struct intel_engine_cs *engine;
1351 	enum intel_engine_id id;
1352 
1353 	for_each_engine(engine, gt, id) {
1354 		if (engine->sanitize)
1355 			engine->sanitize(engine);
1356 
1357 		engine->set_default_submission(engine);
1358 	}
1359 }
1360 
1361 bool intel_engine_can_store_dword(struct intel_engine_cs *engine)
1362 {
1363 	switch (GRAPHICS_VER(engine->i915)) {
1364 	case 2:
1365 		return false; /* uses physical not virtual addresses */
1366 	case 3:
1367 		/* maybe only uses physical not virtual addresses */
1368 		return !(IS_I915G(engine->i915) || IS_I915GM(engine->i915));
1369 	case 4:
1370 		return !IS_I965G(engine->i915); /* who knows! */
1371 	case 6:
1372 		return engine->class != VIDEO_DECODE_CLASS; /* b0rked */
1373 	default:
1374 		return true;
1375 	}
1376 }
1377 
1378 static struct intel_timeline *get_timeline(struct i915_request *rq)
1379 {
1380 	struct intel_timeline *tl;
1381 
1382 	/*
1383 	 * Even though we are holding the engine->sched_engine->lock here, there
1384 	 * is no control over the submission queue per-se and we are
1385 	 * inspecting the active state at a random point in time, with an
1386 	 * unknown queue. Play safe and make sure the timeline remains valid.
1387 	 * (Only being used for pretty printing, one extra kref shouldn't
1388 	 * cause a camel stampede!)
1389 	 */
1390 	rcu_read_lock();
1391 	tl = rcu_dereference(rq->timeline);
1392 	if (!kref_get_unless_zero(&tl->kref))
1393 		tl = NULL;
1394 	rcu_read_unlock();
1395 
1396 	return tl;
1397 }
1398 
1399 static int print_ring(char *buf, int sz, struct i915_request *rq)
1400 {
1401 	int len = 0;
1402 
1403 	if (!i915_request_signaled(rq)) {
1404 		struct intel_timeline *tl = get_timeline(rq);
1405 
1406 		len = scnprintf(buf, sz,
1407 				"ring:{start:%08x, hwsp:%08x, seqno:%08x, runtime:%llums}, ",
1408 				i915_ggtt_offset(rq->ring->vma),
1409 				tl ? tl->hwsp_offset : 0,
1410 				hwsp_seqno(rq),
1411 				DIV_ROUND_CLOSEST_ULL(intel_context_get_total_runtime_ns(rq->context),
1412 						      1000 * 1000));
1413 
1414 		if (tl)
1415 			intel_timeline_put(tl);
1416 	}
1417 
1418 	return len;
1419 }
1420 
1421 static void hexdump(struct drm_printer *m, const void *buf, size_t len)
1422 {
1423 	const size_t rowsize = 8 * sizeof(u32);
1424 	const void *prev = NULL;
1425 	bool skip = false;
1426 	size_t pos;
1427 
1428 	for (pos = 0; pos < len; pos += rowsize) {
1429 		char line[128];
1430 
1431 		if (prev && !memcmp(prev, buf + pos, rowsize)) {
1432 			if (!skip) {
1433 				drm_printf(m, "*\n");
1434 				skip = true;
1435 			}
1436 			continue;
1437 		}
1438 
1439 		WARN_ON_ONCE(hex_dump_to_buffer(buf + pos, len - pos,
1440 						rowsize, sizeof(u32),
1441 						line, sizeof(line),
1442 						false) >= sizeof(line));
1443 		drm_printf(m, "[%04zx] %s\n", pos, line);
1444 
1445 		prev = buf + pos;
1446 		skip = false;
1447 	}
1448 }
1449 
1450 static const char *repr_timer(const struct timer_list *t)
1451 {
1452 	if (!READ_ONCE(t->expires))
1453 		return "inactive";
1454 
1455 	if (timer_pending(t))
1456 		return "active";
1457 
1458 	return "expired";
1459 }
1460 
1461 static void intel_engine_print_registers(struct intel_engine_cs *engine,
1462 					 struct drm_printer *m)
1463 {
1464 	struct drm_i915_private *dev_priv = engine->i915;
1465 	struct intel_engine_execlists * const execlists = &engine->execlists;
1466 	u64 addr;
1467 
1468 	if (engine->id == RENDER_CLASS && IS_GRAPHICS_VER(dev_priv, 4, 7))
1469 		drm_printf(m, "\tCCID: 0x%08x\n", ENGINE_READ(engine, CCID));
1470 	if (HAS_EXECLISTS(dev_priv)) {
1471 		drm_printf(m, "\tEL_STAT_HI: 0x%08x\n",
1472 			   ENGINE_READ(engine, RING_EXECLIST_STATUS_HI));
1473 		drm_printf(m, "\tEL_STAT_LO: 0x%08x\n",
1474 			   ENGINE_READ(engine, RING_EXECLIST_STATUS_LO));
1475 	}
1476 	drm_printf(m, "\tRING_START: 0x%08x\n",
1477 		   ENGINE_READ(engine, RING_START));
1478 	drm_printf(m, "\tRING_HEAD:  0x%08x\n",
1479 		   ENGINE_READ(engine, RING_HEAD) & HEAD_ADDR);
1480 	drm_printf(m, "\tRING_TAIL:  0x%08x\n",
1481 		   ENGINE_READ(engine, RING_TAIL) & TAIL_ADDR);
1482 	drm_printf(m, "\tRING_CTL:   0x%08x%s\n",
1483 		   ENGINE_READ(engine, RING_CTL),
1484 		   ENGINE_READ(engine, RING_CTL) & (RING_WAIT | RING_WAIT_SEMAPHORE) ? " [waiting]" : "");
1485 	if (GRAPHICS_VER(engine->i915) > 2) {
1486 		drm_printf(m, "\tRING_MODE:  0x%08x%s\n",
1487 			   ENGINE_READ(engine, RING_MI_MODE),
1488 			   ENGINE_READ(engine, RING_MI_MODE) & (MODE_IDLE) ? " [idle]" : "");
1489 	}
1490 
1491 	if (GRAPHICS_VER(dev_priv) >= 6) {
1492 		drm_printf(m, "\tRING_IMR:   0x%08x\n",
1493 			   ENGINE_READ(engine, RING_IMR));
1494 		drm_printf(m, "\tRING_ESR:   0x%08x\n",
1495 			   ENGINE_READ(engine, RING_ESR));
1496 		drm_printf(m, "\tRING_EMR:   0x%08x\n",
1497 			   ENGINE_READ(engine, RING_EMR));
1498 		drm_printf(m, "\tRING_EIR:   0x%08x\n",
1499 			   ENGINE_READ(engine, RING_EIR));
1500 	}
1501 
1502 	addr = intel_engine_get_active_head(engine);
1503 	drm_printf(m, "\tACTHD:  0x%08x_%08x\n",
1504 		   upper_32_bits(addr), lower_32_bits(addr));
1505 	addr = intel_engine_get_last_batch_head(engine);
1506 	drm_printf(m, "\tBBADDR: 0x%08x_%08x\n",
1507 		   upper_32_bits(addr), lower_32_bits(addr));
1508 	if (GRAPHICS_VER(dev_priv) >= 8)
1509 		addr = ENGINE_READ64(engine, RING_DMA_FADD, RING_DMA_FADD_UDW);
1510 	else if (GRAPHICS_VER(dev_priv) >= 4)
1511 		addr = ENGINE_READ(engine, RING_DMA_FADD);
1512 	else
1513 		addr = ENGINE_READ(engine, DMA_FADD_I8XX);
1514 	drm_printf(m, "\tDMA_FADDR: 0x%08x_%08x\n",
1515 		   upper_32_bits(addr), lower_32_bits(addr));
1516 	if (GRAPHICS_VER(dev_priv) >= 4) {
1517 		drm_printf(m, "\tIPEIR: 0x%08x\n",
1518 			   ENGINE_READ(engine, RING_IPEIR));
1519 		drm_printf(m, "\tIPEHR: 0x%08x\n",
1520 			   ENGINE_READ(engine, RING_IPEHR));
1521 	} else {
1522 		drm_printf(m, "\tIPEIR: 0x%08x\n", ENGINE_READ(engine, IPEIR));
1523 		drm_printf(m, "\tIPEHR: 0x%08x\n", ENGINE_READ(engine, IPEHR));
1524 	}
1525 
1526 	if (intel_engine_uses_guc(engine)) {
1527 		/* nothing to print yet */
1528 	} else if (HAS_EXECLISTS(dev_priv)) {
1529 		struct i915_request * const *port, *rq;
1530 		const u32 *hws =
1531 			&engine->status_page.addr[I915_HWS_CSB_BUF0_INDEX];
1532 		const u8 num_entries = execlists->csb_size;
1533 		unsigned int idx;
1534 		u8 read, write;
1535 
1536 		drm_printf(m, "\tExeclist tasklet queued? %s (%s), preempt? %s, timeslice? %s\n",
1537 			   yesno(test_bit(TASKLET_STATE_SCHED,
1538 					  &engine->sched_engine->tasklet.state)),
1539 			   enableddisabled(!atomic_read(&engine->sched_engine->tasklet.count)),
1540 			   repr_timer(&engine->execlists.preempt),
1541 			   repr_timer(&engine->execlists.timer));
1542 
1543 		read = execlists->csb_head;
1544 		write = READ_ONCE(*execlists->csb_write);
1545 
1546 		drm_printf(m, "\tExeclist status: 0x%08x %08x; CSB read:%d, write:%d, entries:%d\n",
1547 			   ENGINE_READ(engine, RING_EXECLIST_STATUS_LO),
1548 			   ENGINE_READ(engine, RING_EXECLIST_STATUS_HI),
1549 			   read, write, num_entries);
1550 
1551 		if (read >= num_entries)
1552 			read = 0;
1553 		if (write >= num_entries)
1554 			write = 0;
1555 		if (read > write)
1556 			write += num_entries;
1557 		while (read < write) {
1558 			idx = ++read % num_entries;
1559 			drm_printf(m, "\tExeclist CSB[%d]: 0x%08x, context: %d\n",
1560 				   idx, hws[idx * 2], hws[idx * 2 + 1]);
1561 		}
1562 
1563 		i915_sched_engine_active_lock_bh(engine->sched_engine);
1564 		rcu_read_lock();
1565 		for (port = execlists->active; (rq = *port); port++) {
1566 			char hdr[160];
1567 			int len;
1568 
1569 			len = scnprintf(hdr, sizeof(hdr),
1570 					"\t\tActive[%d]:  ccid:%08x%s%s, ",
1571 					(int)(port - execlists->active),
1572 					rq->context->lrc.ccid,
1573 					intel_context_is_closed(rq->context) ? "!" : "",
1574 					intel_context_is_banned(rq->context) ? "*" : "");
1575 			len += print_ring(hdr + len, sizeof(hdr) - len, rq);
1576 			scnprintf(hdr + len, sizeof(hdr) - len, "rq: ");
1577 			i915_request_show(m, rq, hdr, 0);
1578 		}
1579 		for (port = execlists->pending; (rq = *port); port++) {
1580 			char hdr[160];
1581 			int len;
1582 
1583 			len = scnprintf(hdr, sizeof(hdr),
1584 					"\t\tPending[%d]: ccid:%08x%s%s, ",
1585 					(int)(port - execlists->pending),
1586 					rq->context->lrc.ccid,
1587 					intel_context_is_closed(rq->context) ? "!" : "",
1588 					intel_context_is_banned(rq->context) ? "*" : "");
1589 			len += print_ring(hdr + len, sizeof(hdr) - len, rq);
1590 			scnprintf(hdr + len, sizeof(hdr) - len, "rq: ");
1591 			i915_request_show(m, rq, hdr, 0);
1592 		}
1593 		rcu_read_unlock();
1594 		i915_sched_engine_active_unlock_bh(engine->sched_engine);
1595 	} else if (GRAPHICS_VER(dev_priv) > 6) {
1596 		drm_printf(m, "\tPP_DIR_BASE: 0x%08x\n",
1597 			   ENGINE_READ(engine, RING_PP_DIR_BASE));
1598 		drm_printf(m, "\tPP_DIR_BASE_READ: 0x%08x\n",
1599 			   ENGINE_READ(engine, RING_PP_DIR_BASE_READ));
1600 		drm_printf(m, "\tPP_DIR_DCLV: 0x%08x\n",
1601 			   ENGINE_READ(engine, RING_PP_DIR_DCLV));
1602 	}
1603 }
1604 
1605 static void print_request_ring(struct drm_printer *m, struct i915_request *rq)
1606 {
1607 	void *ring;
1608 	int size;
1609 
1610 	drm_printf(m,
1611 		   "[head %04x, postfix %04x, tail %04x, batch 0x%08x_%08x]:\n",
1612 		   rq->head, rq->postfix, rq->tail,
1613 		   rq->batch ? upper_32_bits(rq->batch->node.start) : ~0u,
1614 		   rq->batch ? lower_32_bits(rq->batch->node.start) : ~0u);
1615 
1616 	size = rq->tail - rq->head;
1617 	if (rq->tail < rq->head)
1618 		size += rq->ring->size;
1619 
1620 	ring = kmalloc(size, GFP_ATOMIC);
1621 	if (ring) {
1622 		const void *vaddr = rq->ring->vaddr;
1623 		unsigned int head = rq->head;
1624 		unsigned int len = 0;
1625 
1626 		if (rq->tail < head) {
1627 			len = rq->ring->size - head;
1628 			memcpy(ring, vaddr + head, len);
1629 			head = 0;
1630 		}
1631 		memcpy(ring + len, vaddr + head, size - len);
1632 
1633 		hexdump(m, ring, size);
1634 		kfree(ring);
1635 	}
1636 }
1637 
1638 static unsigned long list_count(struct list_head *list)
1639 {
1640 	struct list_head *pos;
1641 	unsigned long count = 0;
1642 
1643 	list_for_each(pos, list)
1644 		count++;
1645 
1646 	return count;
1647 }
1648 
1649 static unsigned long read_ul(void *p, size_t x)
1650 {
1651 	return *(unsigned long *)(p + x);
1652 }
1653 
1654 static void print_properties(struct intel_engine_cs *engine,
1655 			     struct drm_printer *m)
1656 {
1657 	static const struct pmap {
1658 		size_t offset;
1659 		const char *name;
1660 	} props[] = {
1661 #define P(x) { \
1662 	.offset = offsetof(typeof(engine->props), x), \
1663 	.name = #x \
1664 }
1665 		P(heartbeat_interval_ms),
1666 		P(max_busywait_duration_ns),
1667 		P(preempt_timeout_ms),
1668 		P(stop_timeout_ms),
1669 		P(timeslice_duration_ms),
1670 
1671 		{},
1672 #undef P
1673 	};
1674 	const struct pmap *p;
1675 
1676 	drm_printf(m, "\tProperties:\n");
1677 	for (p = props; p->name; p++)
1678 		drm_printf(m, "\t\t%s: %lu [default %lu]\n",
1679 			   p->name,
1680 			   read_ul(&engine->props, p->offset),
1681 			   read_ul(&engine->defaults, p->offset));
1682 }
1683 
1684 static void engine_dump_request(struct i915_request *rq, struct drm_printer *m, const char *msg)
1685 {
1686 	struct intel_timeline *tl = get_timeline(rq);
1687 
1688 	i915_request_show(m, rq, msg, 0);
1689 
1690 	drm_printf(m, "\t\tring->start:  0x%08x\n",
1691 		   i915_ggtt_offset(rq->ring->vma));
1692 	drm_printf(m, "\t\tring->head:   0x%08x\n",
1693 		   rq->ring->head);
1694 	drm_printf(m, "\t\tring->tail:   0x%08x\n",
1695 		   rq->ring->tail);
1696 	drm_printf(m, "\t\tring->emit:   0x%08x\n",
1697 		   rq->ring->emit);
1698 	drm_printf(m, "\t\tring->space:  0x%08x\n",
1699 		   rq->ring->space);
1700 
1701 	if (tl) {
1702 		drm_printf(m, "\t\tring->hwsp:   0x%08x\n",
1703 			   tl->hwsp_offset);
1704 		intel_timeline_put(tl);
1705 	}
1706 
1707 	print_request_ring(m, rq);
1708 
1709 	if (rq->context->lrc_reg_state) {
1710 		drm_printf(m, "Logical Ring Context:\n");
1711 		hexdump(m, rq->context->lrc_reg_state, PAGE_SIZE);
1712 	}
1713 }
1714 
1715 void intel_engine_dump_active_requests(struct list_head *requests,
1716 				       struct i915_request *hung_rq,
1717 				       struct drm_printer *m)
1718 {
1719 	struct i915_request *rq;
1720 	const char *msg;
1721 	enum i915_request_state state;
1722 
1723 	list_for_each_entry(rq, requests, sched.link) {
1724 		if (rq == hung_rq)
1725 			continue;
1726 
1727 		state = i915_test_request_state(rq);
1728 		if (state < I915_REQUEST_QUEUED)
1729 			continue;
1730 
1731 		if (state == I915_REQUEST_ACTIVE)
1732 			msg = "\t\tactive on engine";
1733 		else
1734 			msg = "\t\tactive in queue";
1735 
1736 		engine_dump_request(rq, m, msg);
1737 	}
1738 }
1739 
1740 static void engine_dump_active_requests(struct intel_engine_cs *engine, struct drm_printer *m)
1741 {
1742 	struct i915_request *hung_rq = NULL;
1743 	struct intel_context *ce;
1744 	bool guc;
1745 
1746 	/*
1747 	 * No need for an engine->irq_seqno_barrier() before the seqno reads.
1748 	 * The GPU is still running so requests are still executing and any
1749 	 * hardware reads will be out of date by the time they are reported.
1750 	 * But the intention here is just to report an instantaneous snapshot
1751 	 * so that's fine.
1752 	 */
1753 	lockdep_assert_held(&engine->sched_engine->lock);
1754 
1755 	drm_printf(m, "\tRequests:\n");
1756 
1757 	guc = intel_uc_uses_guc_submission(&engine->gt->uc);
1758 	if (guc) {
1759 		ce = intel_engine_get_hung_context(engine);
1760 		if (ce)
1761 			hung_rq = intel_context_find_active_request(ce);
1762 	} else {
1763 		hung_rq = intel_engine_execlist_find_hung_request(engine);
1764 	}
1765 
1766 	if (hung_rq)
1767 		engine_dump_request(hung_rq, m, "\t\thung");
1768 
1769 	if (guc)
1770 		intel_guc_dump_active_requests(engine, hung_rq, m);
1771 	else
1772 		intel_engine_dump_active_requests(&engine->sched_engine->requests,
1773 						  hung_rq, m);
1774 }
1775 
1776 void intel_engine_dump(struct intel_engine_cs *engine,
1777 		       struct drm_printer *m,
1778 		       const char *header, ...)
1779 {
1780 	struct i915_gpu_error * const error = &engine->i915->gpu_error;
1781 	struct i915_request *rq;
1782 	intel_wakeref_t wakeref;
1783 	unsigned long flags;
1784 	ktime_t dummy;
1785 
1786 	if (header) {
1787 		va_list ap;
1788 
1789 		va_start(ap, header);
1790 		drm_vprintf(m, header, &ap);
1791 		va_end(ap);
1792 	}
1793 
1794 	if (intel_gt_is_wedged(engine->gt))
1795 		drm_printf(m, "*** WEDGED ***\n");
1796 
1797 	drm_printf(m, "\tAwake? %d\n", atomic_read(&engine->wakeref.count));
1798 	drm_printf(m, "\tBarriers?: %s\n",
1799 		   yesno(!llist_empty(&engine->barrier_tasks)));
1800 	drm_printf(m, "\tLatency: %luus\n",
1801 		   ewma__engine_latency_read(&engine->latency));
1802 	if (intel_engine_supports_stats(engine))
1803 		drm_printf(m, "\tRuntime: %llums\n",
1804 			   ktime_to_ms(intel_engine_get_busy_time(engine,
1805 								  &dummy)));
1806 	drm_printf(m, "\tForcewake: %x domains, %d active\n",
1807 		   engine->fw_domain, READ_ONCE(engine->fw_active));
1808 
1809 	rcu_read_lock();
1810 	rq = READ_ONCE(engine->heartbeat.systole);
1811 	if (rq)
1812 		drm_printf(m, "\tHeartbeat: %d ms ago\n",
1813 			   jiffies_to_msecs(jiffies - rq->emitted_jiffies));
1814 	rcu_read_unlock();
1815 	drm_printf(m, "\tReset count: %d (global %d)\n",
1816 		   i915_reset_engine_count(error, engine),
1817 		   i915_reset_count(error));
1818 	print_properties(engine, m);
1819 
1820 	spin_lock_irqsave(&engine->sched_engine->lock, flags);
1821 	engine_dump_active_requests(engine, m);
1822 
1823 	drm_printf(m, "\tOn hold?: %lu\n",
1824 		   list_count(&engine->sched_engine->hold));
1825 	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);
1826 
1827 	drm_printf(m, "\tMMIO base:  0x%08x\n", engine->mmio_base);
1828 	wakeref = intel_runtime_pm_get_if_in_use(engine->uncore->rpm);
1829 	if (wakeref) {
1830 		intel_engine_print_registers(engine, m);
1831 		intel_runtime_pm_put(engine->uncore->rpm, wakeref);
1832 	} else {
1833 		drm_printf(m, "\tDevice is asleep; skipping register dump\n");
1834 	}
1835 
1836 	intel_execlists_show_requests(engine, m, i915_request_show, 8);
1837 
1838 	drm_printf(m, "HWSP:\n");
1839 	hexdump(m, engine->status_page.addr, PAGE_SIZE);
1840 
1841 	drm_printf(m, "Idle? %s\n", yesno(intel_engine_is_idle(engine)));
1842 
1843 	intel_engine_print_breadcrumbs(engine, m);
1844 }
1845 
1846 static ktime_t __intel_engine_get_busy_time(struct intel_engine_cs *engine,
1847 					    ktime_t *now)
1848 {
1849 	ktime_t total = engine->stats.total;
1850 
1851 	/*
1852 	 * If the engine is executing something at the moment
1853 	 * add it to the total.
1854 	 */
1855 	*now = ktime_get();
1856 	if (READ_ONCE(engine->stats.active))
1857 		total = ktime_add(total, ktime_sub(*now, engine->stats.start));
1858 
1859 	return total;
1860 }
1861 
1862 /**
1863  * intel_engine_get_busy_time() - Return current accumulated engine busyness
1864  * @engine: engine to report on
1865  * @now: monotonic timestamp of sampling
1866  *
1867  * Returns accumulated time @engine was busy since engine stats were enabled.
1868  */
1869 ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
1870 {
1871 	unsigned int seq;
1872 	ktime_t total;
1873 
1874 	do {
1875 		seq = read_seqcount_begin(&engine->stats.lock);
1876 		total = __intel_engine_get_busy_time(engine, now);
1877 	} while (read_seqcount_retry(&engine->stats.lock, seq));
1878 
1879 	return total;
1880 }
1881 
1882 struct intel_context *
1883 intel_engine_create_virtual(struct intel_engine_cs **siblings,
1884 			    unsigned int count)
1885 {
1886 	if (count == 0)
1887 		return ERR_PTR(-EINVAL);
1888 
1889 	if (count == 1)
1890 		return intel_context_create(siblings[0]);
1891 
1892 	GEM_BUG_ON(!siblings[0]->cops->create_virtual);
1893 	return siblings[0]->cops->create_virtual(siblings, count);
1894 }
1895 
1896 struct i915_request *
1897 intel_engine_execlist_find_hung_request(struct intel_engine_cs *engine)
1898 {
1899 	struct i915_request *request, *active = NULL;
1900 
1901 	/*
1902 	 * This search does not work in GuC submission mode. However, the GuC
1903 	 * will report the hanging context directly to the driver itself. So
1904 	 * the driver should never get here when in GuC mode.
1905 	 */
1906 	GEM_BUG_ON(intel_uc_uses_guc_submission(&engine->gt->uc));
1907 
1908 	/*
1909 	 * We are called by the error capture, reset and to dump engine
1910 	 * state at random points in time. In particular, note that neither is
1911 	 * crucially ordered with an interrupt. After a hang, the GPU is dead
1912 	 * and we assume that no more writes can happen (we waited long enough
1913 	 * for all writes that were in transaction to be flushed) - adding an
1914 	 * extra delay for a recent interrupt is pointless. Hence, we do
1915 	 * not need an engine->irq_seqno_barrier() before the seqno reads.
1916 	 * At all other times, we must assume the GPU is still running, but
1917 	 * we only care about the snapshot of this moment.
1918 	 */
1919 	lockdep_assert_held(&engine->sched_engine->lock);
1920 
1921 	rcu_read_lock();
1922 	request = execlists_active(&engine->execlists);
1923 	if (request) {
1924 		struct intel_timeline *tl = request->context->timeline;
1925 
1926 		list_for_each_entry_from_reverse(request, &tl->requests, link) {
1927 			if (__i915_request_is_complete(request))
1928 				break;
1929 
1930 			active = request;
1931 		}
1932 	}
1933 	rcu_read_unlock();
1934 	if (active)
1935 		return active;
1936 
1937 	list_for_each_entry(request, &engine->sched_engine->requests,
1938 			    sched.link) {
1939 		if (i915_test_request_state(request) != I915_REQUEST_ACTIVE)
1940 			continue;
1941 
1942 		active = request;
1943 		break;
1944 	}
1945 
1946 	return active;
1947 }
1948 
1949 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
1950 #include "mock_engine.c"
1951 #include "selftest_engine.c"
1952 #include "selftest_engine_cs.c"
1953 #endif
1954