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1/*2 * Copyright © 2008-2015 Intel Corporation3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice (including the next12 * paragraph) shall be included in all copies or substantial portions of the13 * Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS21 * IN THE SOFTWARE.22 *23 */24 25#include <linux/dma-fence-array.h>26#include <linux/dma-fence-chain.h>27#include <linux/irq_work.h>28#include <linux/prefetch.h>29#include <linux/sched.h>30#include <linux/sched/clock.h>31#include <linux/sched/signal.h>32#include <linux/sched/mm.h>33 34#include "gem/i915_gem_context.h"35#include "gt/intel_breadcrumbs.h"36#include "gt/intel_context.h"37#include "gt/intel_engine.h"38#include "gt/intel_engine_heartbeat.h"39#include "gt/intel_engine_regs.h"40#include "gt/intel_gpu_commands.h"41#include "gt/intel_reset.h"42#include "gt/intel_ring.h"43#include "gt/intel_rps.h"44 45#include "i915_active.h"46#include "i915_config.h"47#include "i915_deps.h"48#include "i915_driver.h"49#include "i915_drv.h"50#include "i915_trace.h"51 52struct execute_cb {53	struct irq_work work;54	struct i915_sw_fence *fence;55};56 57static struct kmem_cache *slab_requests;58static struct kmem_cache *slab_execute_cbs;59 60static const char *i915_fence_get_driver_name(struct dma_fence *fence)61{62	return dev_name(to_request(fence)->i915->drm.dev);63}64 65static const char *i915_fence_get_timeline_name(struct dma_fence *fence)66{67	const struct i915_gem_context *ctx;68 69	/*70	 * The timeline struct (as part of the ppgtt underneath a context)71	 * may be freed when the request is no longer in use by the GPU.72	 * We could extend the life of a context to beyond that of all73	 * fences, possibly keeping the hw resource around indefinitely,74	 * or we just give them a false name. Since75	 * dma_fence_ops.get_timeline_name is a debug feature, the occasional76	 * lie seems justifiable.77	 */78	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))79		return "signaled";80 81	ctx = i915_request_gem_context(to_request(fence));82	if (!ctx)83		return "[" DRIVER_NAME "]";84 85	return ctx->name;86}87 88static bool i915_fence_signaled(struct dma_fence *fence)89{90	return i915_request_completed(to_request(fence));91}92 93static bool i915_fence_enable_signaling(struct dma_fence *fence)94{95	return i915_request_enable_breadcrumb(to_request(fence));96}97 98static signed long i915_fence_wait(struct dma_fence *fence,99				   bool interruptible,100				   signed long timeout)101{102	return i915_request_wait_timeout(to_request(fence),103					 interruptible | I915_WAIT_PRIORITY,104					 timeout);105}106 107struct kmem_cache *i915_request_slab_cache(void)108{109	return slab_requests;110}111 112static void i915_fence_release(struct dma_fence *fence)113{114	struct i915_request *rq = to_request(fence);115 116	GEM_BUG_ON(rq->guc_prio != GUC_PRIO_INIT &&117		   rq->guc_prio != GUC_PRIO_FINI);118 119	i915_request_free_capture_list(fetch_and_zero(&rq->capture_list));120	if (rq->batch_res) {121		i915_vma_resource_put(rq->batch_res);122		rq->batch_res = NULL;123	}124 125	/*126	 * The request is put onto a RCU freelist (i.e. the address127	 * is immediately reused), mark the fences as being freed now.128	 * Otherwise the debugobjects for the fences are only marked as129	 * freed when the slab cache itself is freed, and so we would get130	 * caught trying to reuse dead objects.131	 */132	i915_sw_fence_fini(&rq->submit);133	i915_sw_fence_fini(&rq->semaphore);134 135	/*136	 * Keep one request on each engine for reserved use under mempressure.137	 *138	 * We do not hold a reference to the engine here and so have to be139	 * very careful in what rq->engine we poke. The virtual engine is140	 * referenced via the rq->context and we released that ref during141	 * i915_request_retire(), ergo we must not dereference a virtual142	 * engine here. Not that we would want to, as the only consumer of143	 * the reserved engine->request_pool is the power management parking,144	 * which must-not-fail, and that is only run on the physical engines.145	 *146	 * Since the request must have been executed to be have completed,147	 * we know that it will have been processed by the HW and will148	 * not be unsubmitted again, so rq->engine and rq->execution_mask149	 * at this point is stable. rq->execution_mask will be a single150	 * bit if the last and _only_ engine it could execution on was a151	 * physical engine, if it's multiple bits then it started on and152	 * could still be on a virtual engine. Thus if the mask is not a153	 * power-of-two we assume that rq->engine may still be a virtual154	 * engine and so a dangling invalid pointer that we cannot dereference155	 *156	 * For example, consider the flow of a bonded request through a virtual157	 * engine. The request is created with a wide engine mask (all engines158	 * that we might execute on). On processing the bond, the request mask159	 * is reduced to one or more engines. If the request is subsequently160	 * bound to a single engine, it will then be constrained to only161	 * execute on that engine and never returned to the virtual engine162	 * after timeslicing away, see __unwind_incomplete_requests(). Thus we163	 * know that if the rq->execution_mask is a single bit, rq->engine164	 * can be a physical engine with the exact corresponding mask.165	 */166	if (is_power_of_2(rq->execution_mask) &&167	    !cmpxchg(&rq->engine->request_pool, NULL, rq))168		return;169 170	kmem_cache_free(slab_requests, rq);171}172 173const struct dma_fence_ops i915_fence_ops = {174	.get_driver_name = i915_fence_get_driver_name,175	.get_timeline_name = i915_fence_get_timeline_name,176	.enable_signaling = i915_fence_enable_signaling,177	.signaled = i915_fence_signaled,178	.wait = i915_fence_wait,179	.release = i915_fence_release,180};181 182static void irq_execute_cb(struct irq_work *wrk)183{184	struct execute_cb *cb = container_of(wrk, typeof(*cb), work);185 186	i915_sw_fence_complete(cb->fence);187	kmem_cache_free(slab_execute_cbs, cb);188}189 190static __always_inline void191__notify_execute_cb(struct i915_request *rq, bool (*fn)(struct irq_work *wrk))192{193	struct execute_cb *cb, *cn;194 195	if (llist_empty(&rq->execute_cb))196		return;197 198	llist_for_each_entry_safe(cb, cn,199				  llist_del_all(&rq->execute_cb),200				  work.node.llist)201		fn(&cb->work);202}203 204static void __notify_execute_cb_irq(struct i915_request *rq)205{206	__notify_execute_cb(rq, irq_work_queue);207}208 209static bool irq_work_imm(struct irq_work *wrk)210{211	wrk->func(wrk);212	return false;213}214 215void i915_request_notify_execute_cb_imm(struct i915_request *rq)216{217	__notify_execute_cb(rq, irq_work_imm);218}219 220static void __i915_request_fill(struct i915_request *rq, u8 val)221{222	void *vaddr = rq->ring->vaddr;223	u32 head;224 225	head = rq->infix;226	if (rq->postfix < head) {227		memset(vaddr + head, val, rq->ring->size - head);228		head = 0;229	}230	memset(vaddr + head, val, rq->postfix - head);231}232 233/**234 * i915_request_active_engine235 * @rq: request to inspect236 * @active: pointer in which to return the active engine237 *238 * Fills the currently active engine to the @active pointer if the request239 * is active and still not completed.240 *241 * Returns true if request was active or false otherwise.242 */243bool244i915_request_active_engine(struct i915_request *rq,245			   struct intel_engine_cs **active)246{247	struct intel_engine_cs *engine, *locked;248	bool ret = false;249 250	/*251	 * Serialise with __i915_request_submit() so that it sees252	 * is-banned?, or we know the request is already inflight.253	 *254	 * Note that rq->engine is unstable, and so we double255	 * check that we have acquired the lock on the final engine.256	 */257	locked = READ_ONCE(rq->engine);258	spin_lock_irq(&locked->sched_engine->lock);259	while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {260		spin_unlock(&locked->sched_engine->lock);261		locked = engine;262		spin_lock(&locked->sched_engine->lock);263	}264 265	if (i915_request_is_active(rq)) {266		if (!__i915_request_is_complete(rq))267			*active = locked;268		ret = true;269	}270 271	spin_unlock_irq(&locked->sched_engine->lock);272 273	return ret;274}275 276static void __rq_init_watchdog(struct i915_request *rq)277{278	rq->watchdog.timer.function = NULL;279}280 281static enum hrtimer_restart __rq_watchdog_expired(struct hrtimer *hrtimer)282{283	struct i915_request *rq =284		container_of(hrtimer, struct i915_request, watchdog.timer);285	struct intel_gt *gt = rq->engine->gt;286 287	if (!i915_request_completed(rq)) {288		if (llist_add(&rq->watchdog.link, &gt->watchdog.list))289			queue_work(gt->i915->unordered_wq, &gt->watchdog.work);290	} else {291		i915_request_put(rq);292	}293 294	return HRTIMER_NORESTART;295}296 297static void __rq_arm_watchdog(struct i915_request *rq)298{299	struct i915_request_watchdog *wdg = &rq->watchdog;300	struct intel_context *ce = rq->context;301 302	if (!ce->watchdog.timeout_us)303		return;304 305	i915_request_get(rq);306 307	hrtimer_init(&wdg->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);308	wdg->timer.function = __rq_watchdog_expired;309	hrtimer_start_range_ns(&wdg->timer,310			       ns_to_ktime(ce->watchdog.timeout_us *311					   NSEC_PER_USEC),312			       NSEC_PER_MSEC,313			       HRTIMER_MODE_REL);314}315 316static void __rq_cancel_watchdog(struct i915_request *rq)317{318	struct i915_request_watchdog *wdg = &rq->watchdog;319 320	if (wdg->timer.function && hrtimer_try_to_cancel(&wdg->timer) > 0)321		i915_request_put(rq);322}323 324#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)325 326/**327 * i915_request_free_capture_list - Free a capture list328 * @capture: Pointer to the first list item or NULL329 *330 */331void i915_request_free_capture_list(struct i915_capture_list *capture)332{333	while (capture) {334		struct i915_capture_list *next = capture->next;335 336		i915_vma_resource_put(capture->vma_res);337		kfree(capture);338		capture = next;339	}340}341 342#define assert_capture_list_is_null(_rq) GEM_BUG_ON((_rq)->capture_list)343 344#define clear_capture_list(_rq) ((_rq)->capture_list = NULL)345 346#else347 348#define i915_request_free_capture_list(_a) do {} while (0)349 350#define assert_capture_list_is_null(_a) do {} while (0)351 352#define clear_capture_list(_rq) do {} while (0)353 354#endif355 356bool i915_request_retire(struct i915_request *rq)357{358	if (!__i915_request_is_complete(rq))359		return false;360 361	RQ_TRACE(rq, "\n");362 363	GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));364	trace_i915_request_retire(rq);365	i915_request_mark_complete(rq);366 367	__rq_cancel_watchdog(rq);368 369	/*370	 * We know the GPU must have read the request to have371	 * sent us the seqno + interrupt, so use the position372	 * of tail of the request to update the last known position373	 * of the GPU head.374	 *375	 * Note this requires that we are always called in request376	 * completion order.377	 */378	GEM_BUG_ON(!list_is_first(&rq->link,379				  &i915_request_timeline(rq)->requests));380	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))381		/* Poison before we release our space in the ring */382		__i915_request_fill(rq, POISON_FREE);383	rq->ring->head = rq->postfix;384 385	if (!i915_request_signaled(rq)) {386		spin_lock_irq(&rq->lock);387		dma_fence_signal_locked(&rq->fence);388		spin_unlock_irq(&rq->lock);389	}390 391	if (test_and_set_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags))392		intel_rps_dec_waiters(&rq->engine->gt->rps);393 394	/*395	 * We only loosely track inflight requests across preemption,396	 * and so we may find ourselves attempting to retire a _completed_397	 * request that we have removed from the HW and put back on a run398	 * queue.399	 *400	 * As we set I915_FENCE_FLAG_ACTIVE on the request, this should be401	 * after removing the breadcrumb and signaling it, so that we do not402	 * inadvertently attach the breadcrumb to a completed request.403	 */404	rq->engine->remove_active_request(rq);405	GEM_BUG_ON(!llist_empty(&rq->execute_cb));406 407	__list_del_entry(&rq->link); /* poison neither prev/next (RCU walks) */408 409	intel_context_exit(rq->context);410	intel_context_unpin(rq->context);411 412	i915_sched_node_fini(&rq->sched);413	i915_request_put(rq);414 415	return true;416}417 418void i915_request_retire_upto(struct i915_request *rq)419{420	struct intel_timeline * const tl = i915_request_timeline(rq);421	struct i915_request *tmp;422 423	RQ_TRACE(rq, "\n");424	GEM_BUG_ON(!__i915_request_is_complete(rq));425 426	do {427		tmp = list_first_entry(&tl->requests, typeof(*tmp), link);428		GEM_BUG_ON(!i915_request_completed(tmp));429	} while (i915_request_retire(tmp) && tmp != rq);430}431 432static struct i915_request * const *433__engine_active(struct intel_engine_cs *engine)434{435	return READ_ONCE(engine->execlists.active);436}437 438static bool __request_in_flight(const struct i915_request *signal)439{440	struct i915_request * const *port, *rq;441	bool inflight = false;442 443	if (!i915_request_is_ready(signal))444		return false;445 446	/*447	 * Even if we have unwound the request, it may still be on448	 * the GPU (preempt-to-busy). If that request is inside an449	 * unpreemptible critical section, it will not be removed. Some450	 * GPU functions may even be stuck waiting for the paired request451	 * (__await_execution) to be submitted and cannot be preempted452	 * until the bond is executing.453	 *454	 * As we know that there are always preemption points between455	 * requests, we know that only the currently executing request456	 * may be still active even though we have cleared the flag.457	 * However, we can't rely on our tracking of ELSP[0] to know458	 * which request is currently active and so maybe stuck, as459	 * the tracking maybe an event behind. Instead assume that460	 * if the context is still inflight, then it is still active461	 * even if the active flag has been cleared.462	 *463	 * To further complicate matters, if there a pending promotion, the HW464	 * may either perform a context switch to the second inflight execlists,465	 * or it may switch to the pending set of execlists. In the case of the466	 * latter, it may send the ACK and we process the event copying the467	 * pending[] over top of inflight[], _overwriting_ our *active. Since468	 * this implies the HW is arbitrating and not struck in *active, we do469	 * not worry about complete accuracy, but we do require no read/write470	 * tearing of the pointer [the read of the pointer must be valid, even471	 * as the array is being overwritten, for which we require the writes472	 * to avoid tearing.]473	 *474	 * Note that the read of *execlists->active may race with the promotion475	 * of execlists->pending[] to execlists->inflight[], overwritting476	 * the value at *execlists->active. This is fine. The promotion implies477	 * that we received an ACK from the HW, and so the context is not478	 * stuck -- if we do not see ourselves in *active, the inflight status479	 * is valid. If instead we see ourselves being copied into *active,480	 * we are inflight and may signal the callback.481	 */482	if (!intel_context_inflight(signal->context))483		return false;484 485	rcu_read_lock();486	for (port = __engine_active(signal->engine);487	     (rq = READ_ONCE(*port)); /* may race with promotion of pending[] */488	     port++) {489		if (rq->context == signal->context) {490			inflight = i915_seqno_passed(rq->fence.seqno,491						     signal->fence.seqno);492			break;493		}494	}495	rcu_read_unlock();496 497	return inflight;498}499 500static int501__await_execution(struct i915_request *rq,502		  struct i915_request *signal,503		  gfp_t gfp)504{505	struct execute_cb *cb;506 507	if (i915_request_is_active(signal))508		return 0;509 510	cb = kmem_cache_alloc(slab_execute_cbs, gfp);511	if (!cb)512		return -ENOMEM;513 514	cb->fence = &rq->submit;515	i915_sw_fence_await(cb->fence);516	init_irq_work(&cb->work, irq_execute_cb);517 518	/*519	 * Register the callback first, then see if the signaler is already520	 * active. This ensures that if we race with the521	 * __notify_execute_cb from i915_request_submit() and we are not522	 * included in that list, we get a second bite of the cherry and523	 * execute it ourselves. After this point, a future524	 * i915_request_submit() will notify us.525	 *526	 * In i915_request_retire() we set the ACTIVE bit on a completed527	 * request (then flush the execute_cb). So by registering the528	 * callback first, then checking the ACTIVE bit, we serialise with529	 * the completed/retired request.530	 */531	if (llist_add(&cb->work.node.llist, &signal->execute_cb)) {532		if (i915_request_is_active(signal) ||533		    __request_in_flight(signal))534			i915_request_notify_execute_cb_imm(signal);535	}536 537	return 0;538}539 540static bool fatal_error(int error)541{542	switch (error) {543	case 0: /* not an error! */544	case -EAGAIN: /* innocent victim of a GT reset (__i915_request_reset) */545	case -ETIMEDOUT: /* waiting for Godot (timer_i915_sw_fence_wake) */546		return false;547	default:548		return true;549	}550}551 552void __i915_request_skip(struct i915_request *rq)553{554	GEM_BUG_ON(!fatal_error(rq->fence.error));555 556	if (rq->infix == rq->postfix)557		return;558 559	RQ_TRACE(rq, "error: %d\n", rq->fence.error);560 561	/*562	 * As this request likely depends on state from the lost563	 * context, clear out all the user operations leaving the564	 * breadcrumb at the end (so we get the fence notifications).565	 */566	__i915_request_fill(rq, 0);567	rq->infix = rq->postfix;568}569 570bool i915_request_set_error_once(struct i915_request *rq, int error)571{572	int old;573 574	GEM_BUG_ON(!IS_ERR_VALUE((long)error));575 576	if (i915_request_signaled(rq))577		return false;578 579	old = READ_ONCE(rq->fence.error);580	do {581		if (fatal_error(old))582			return false;583	} while (!try_cmpxchg(&rq->fence.error, &old, error));584 585	return true;586}587 588struct i915_request *i915_request_mark_eio(struct i915_request *rq)589{590	if (__i915_request_is_complete(rq))591		return NULL;592 593	GEM_BUG_ON(i915_request_signaled(rq));594 595	/* As soon as the request is completed, it may be retired */596	rq = i915_request_get(rq);597 598	i915_request_set_error_once(rq, -EIO);599	i915_request_mark_complete(rq);600 601	return rq;602}603 604bool __i915_request_submit(struct i915_request *request)605{606	struct intel_engine_cs *engine = request->engine;607	bool result = false;608 609	RQ_TRACE(request, "\n");610 611	GEM_BUG_ON(!irqs_disabled());612	lockdep_assert_held(&engine->sched_engine->lock);613 614	/*615	 * With the advent of preempt-to-busy, we frequently encounter616	 * requests that we have unsubmitted from HW, but left running617	 * until the next ack and so have completed in the meantime. On618	 * resubmission of that completed request, we can skip619	 * updating the payload, and execlists can even skip submitting620	 * the request.621	 *622	 * We must remove the request from the caller's priority queue,623	 * and the caller must only call us when the request is in their624	 * priority queue, under the sched_engine->lock. This ensures that the625	 * request has *not* yet been retired and we can safely move626	 * the request into the engine->active.list where it will be627	 * dropped upon retiring. (Otherwise if resubmit a *retired*628	 * request, this would be a horrible use-after-free.)629	 */630	if (__i915_request_is_complete(request)) {631		list_del_init(&request->sched.link);632		goto active;633	}634 635	if (unlikely(!intel_context_is_schedulable(request->context)))636		i915_request_set_error_once(request, -EIO);637 638	if (unlikely(fatal_error(request->fence.error)))639		__i915_request_skip(request);640 641	/*642	 * Are we using semaphores when the gpu is already saturated?643	 *644	 * Using semaphores incurs a cost in having the GPU poll a645	 * memory location, busywaiting for it to change. The continual646	 * memory reads can have a noticeable impact on the rest of the647	 * system with the extra bus traffic, stalling the cpu as it too648	 * tries to access memory across the bus (perf stat -e bus-cycles).649	 *650	 * If we installed a semaphore on this request and we only submit651	 * the request after the signaler completed, that indicates the652	 * system is overloaded and using semaphores at this time only653	 * increases the amount of work we are doing. If so, we disable654	 * further use of semaphores until we are idle again, whence we655	 * optimistically try again.656	 */657	if (request->sched.semaphores &&658	    i915_sw_fence_signaled(&request->semaphore))659		engine->saturated |= request->sched.semaphores;660 661	engine->emit_fini_breadcrumb(request,662				     request->ring->vaddr + request->postfix);663 664	trace_i915_request_execute(request);665	if (engine->bump_serial)666		engine->bump_serial(engine);667	else668		engine->serial++;669 670	result = true;671 672	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));673	engine->add_active_request(request);674active:675	clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags);676	set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);677 678	/*679	 * XXX Rollback bonded-execution on __i915_request_unsubmit()?680	 *681	 * In the future, perhaps when we have an active time-slicing scheduler,682	 * it will be interesting to unsubmit parallel execution and remove683	 * busywaits from the GPU until their master is restarted. This is684	 * quite hairy, we have to carefully rollback the fence and do a685	 * preempt-to-idle cycle on the target engine, all the while the686	 * master execute_cb may refire.687	 */688	__notify_execute_cb_irq(request);689 690	/* We may be recursing from the signal callback of another i915 fence */691	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))692		i915_request_enable_breadcrumb(request);693 694	return result;695}696 697void i915_request_submit(struct i915_request *request)698{699	struct intel_engine_cs *engine = request->engine;700	unsigned long flags;701 702	/* Will be called from irq-context when using foreign fences. */703	spin_lock_irqsave(&engine->sched_engine->lock, flags);704 705	__i915_request_submit(request);706 707	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);708}709 710void __i915_request_unsubmit(struct i915_request *request)711{712	struct intel_engine_cs *engine = request->engine;713 714	/*715	 * Only unwind in reverse order, required so that the per-context list716	 * is kept in seqno/ring order.717	 */718	RQ_TRACE(request, "\n");719 720	GEM_BUG_ON(!irqs_disabled());721	lockdep_assert_held(&engine->sched_engine->lock);722 723	/*724	 * Before we remove this breadcrumb from the signal list, we have725	 * to ensure that a concurrent dma_fence_enable_signaling() does not726	 * attach itself. We first mark the request as no longer active and727	 * make sure that is visible to other cores, and then remove the728	 * breadcrumb if attached.729	 */730	GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));731	clear_bit_unlock(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);732	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))733		i915_request_cancel_breadcrumb(request);734 735	/* We've already spun, don't charge on resubmitting. */736	if (request->sched.semaphores && __i915_request_has_started(request))737		request->sched.semaphores = 0;738 739	/*740	 * We don't need to wake_up any waiters on request->execute, they741	 * will get woken by any other event or us re-adding this request742	 * to the engine timeline (__i915_request_submit()). The waiters743	 * should be quite adapt at finding that the request now has a new744	 * global_seqno to the one they went to sleep on.745	 */746}747 748void i915_request_unsubmit(struct i915_request *request)749{750	struct intel_engine_cs *engine = request->engine;751	unsigned long flags;752 753	/* Will be called from irq-context when using foreign fences. */754	spin_lock_irqsave(&engine->sched_engine->lock, flags);755 756	__i915_request_unsubmit(request);757 758	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);759}760 761void i915_request_cancel(struct i915_request *rq, int error)762{763	if (!i915_request_set_error_once(rq, error))764		return;765 766	set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags);767 768	intel_context_cancel_request(rq->context, rq);769}770 771static int772submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)773{774	struct i915_request *request =775		container_of(fence, typeof(*request), submit);776 777	switch (state) {778	case FENCE_COMPLETE:779		trace_i915_request_submit(request);780 781		if (unlikely(fence->error))782			i915_request_set_error_once(request, fence->error);783		else784			__rq_arm_watchdog(request);785 786		/*787		 * We need to serialize use of the submit_request() callback788		 * with its hotplugging performed during an emergency789		 * i915_gem_set_wedged().  We use the RCU mechanism to mark the790		 * critical section in order to force i915_gem_set_wedged() to791		 * wait until the submit_request() is completed before792		 * proceeding.793		 */794		rcu_read_lock();795		request->engine->submit_request(request);796		rcu_read_unlock();797		break;798 799	case FENCE_FREE:800		i915_request_put(request);801		break;802	}803 804	return NOTIFY_DONE;805}806 807static int808semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)809{810	struct i915_request *rq = container_of(fence, typeof(*rq), semaphore);811 812	switch (state) {813	case FENCE_COMPLETE:814		break;815 816	case FENCE_FREE:817		i915_request_put(rq);818		break;819	}820 821	return NOTIFY_DONE;822}823 824static void retire_requests(struct intel_timeline *tl)825{826	struct i915_request *rq, *rn;827 828	list_for_each_entry_safe(rq, rn, &tl->requests, link)829		if (!i915_request_retire(rq))830			break;831}832 833static noinline struct i915_request *834request_alloc_slow(struct intel_timeline *tl,835		   struct i915_request **rsvd,836		   gfp_t gfp)837{838	struct i915_request *rq;839 840	/* If we cannot wait, dip into our reserves */841	if (!gfpflags_allow_blocking(gfp)) {842		rq = xchg(rsvd, NULL);843		if (!rq) /* Use the normal failure path for one final WARN */844			goto out;845 846		return rq;847	}848 849	if (list_empty(&tl->requests))850		goto out;851 852	/* Move our oldest request to the slab-cache (if not in use!) */853	rq = list_first_entry(&tl->requests, typeof(*rq), link);854	i915_request_retire(rq);855 856	rq = kmem_cache_alloc(slab_requests,857			      gfp | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);858	if (rq)859		return rq;860 861	/* Ratelimit ourselves to prevent oom from malicious clients */862	rq = list_last_entry(&tl->requests, typeof(*rq), link);863	cond_synchronize_rcu(rq->rcustate);864 865	/* Retire our old requests in the hope that we free some */866	retire_requests(tl);867 868out:869	return kmem_cache_alloc(slab_requests, gfp);870}871 872static void __i915_request_ctor(void *arg)873{874	struct i915_request *rq = arg;875 876	spin_lock_init(&rq->lock);877	i915_sched_node_init(&rq->sched);878	i915_sw_fence_init(&rq->submit, submit_notify);879	i915_sw_fence_init(&rq->semaphore, semaphore_notify);880 881	clear_capture_list(rq);882	rq->batch_res = NULL;883 884	init_llist_head(&rq->execute_cb);885}886 887#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)888#define clear_batch_ptr(_rq) ((_rq)->batch = NULL)889#else890#define clear_batch_ptr(_a) do {} while (0)891#endif892 893struct i915_request *894__i915_request_create(struct intel_context *ce, gfp_t gfp)895{896	struct intel_timeline *tl = ce->timeline;897	struct i915_request *rq;898	u32 seqno;899	int ret;900 901	might_alloc(gfp);902 903	/* Check that the caller provided an already pinned context */904	__intel_context_pin(ce);905 906	/*907	 * Beware: Dragons be flying overhead.908	 *909	 * We use RCU to look up requests in flight. The lookups may910	 * race with the request being allocated from the slab freelist.911	 * That is the request we are writing to here, may be in the process912	 * of being read by __i915_active_request_get_rcu(). As such,913	 * we have to be very careful when overwriting the contents. During914	 * the RCU lookup, we change chase the request->engine pointer,915	 * read the request->global_seqno and increment the reference count.916	 *917	 * The reference count is incremented atomically. If it is zero,918	 * the lookup knows the request is unallocated and complete. Otherwise,919	 * it is either still in use, or has been reallocated and reset920	 * with dma_fence_init(). This increment is safe for release as we921	 * check that the request we have a reference to and matches the active922	 * request.923	 *924	 * Before we increment the refcount, we chase the request->engine925	 * pointer. We must not call kmem_cache_zalloc() or else we set926	 * that pointer to NULL and cause a crash during the lookup. If927	 * we see the request is completed (based on the value of the928	 * old engine and seqno), the lookup is complete and reports NULL.929	 * If we decide the request is not completed (new engine or seqno),930	 * then we grab a reference and double check that it is still the931	 * active request - which it won't be and restart the lookup.932	 *933	 * Do not use kmem_cache_zalloc() here!934	 */935	rq = kmem_cache_alloc(slab_requests,936			      gfp | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);937	if (unlikely(!rq)) {938		rq = request_alloc_slow(tl, &ce->engine->request_pool, gfp);939		if (!rq) {940			ret = -ENOMEM;941			goto err_unreserve;942		}943	}944 945	rq->context = ce;946	rq->engine = ce->engine;947	rq->ring = ce->ring;948	rq->execution_mask = ce->engine->mask;949	rq->i915 = ce->engine->i915;950 951	ret = intel_timeline_get_seqno(tl, rq, &seqno);952	if (ret)953		goto err_free;954 955	dma_fence_init(&rq->fence, &i915_fence_ops, &rq->lock,956		       tl->fence_context, seqno);957 958	RCU_INIT_POINTER(rq->timeline, tl);959	rq->hwsp_seqno = tl->hwsp_seqno;960	GEM_BUG_ON(__i915_request_is_complete(rq));961 962	rq->rcustate = get_state_synchronize_rcu(); /* acts as smp_mb() */963 964	rq->guc_prio = GUC_PRIO_INIT;965 966	/* We bump the ref for the fence chain */967	i915_sw_fence_reinit(&i915_request_get(rq)->submit);968	i915_sw_fence_reinit(&i915_request_get(rq)->semaphore);969 970	i915_sched_node_reinit(&rq->sched);971 972	/* No zalloc, everything must be cleared after use */973	clear_batch_ptr(rq);974	__rq_init_watchdog(rq);975	assert_capture_list_is_null(rq);976	GEM_BUG_ON(!llist_empty(&rq->execute_cb));977	GEM_BUG_ON(rq->batch_res);978 979	/*980	 * Reserve space in the ring buffer for all the commands required to981	 * eventually emit this request. This is to guarantee that the982	 * i915_request_add() call can't fail. Note that the reserve may need983	 * to be redone if the request is not actually submitted straight984	 * away, e.g. because a GPU scheduler has deferred it.985	 *986	 * Note that due to how we add reserved_space to intel_ring_begin()987	 * we need to double our request to ensure that if we need to wrap988	 * around inside i915_request_add() there is sufficient space at989	 * the beginning of the ring as well.990	 */991	rq->reserved_space =992		2 * rq->engine->emit_fini_breadcrumb_dw * sizeof(u32);993 994	/*995	 * Record the position of the start of the request so that996	 * should we detect the updated seqno part-way through the997	 * GPU processing the request, we never over-estimate the998	 * position of the head.999	 */1000	rq->head = rq->ring->emit;1001 1002	ret = rq->engine->request_alloc(rq);1003	if (ret)1004		goto err_unwind;1005 1006	rq->infix = rq->ring->emit; /* end of header; start of user payload */1007 1008	intel_context_mark_active(ce);1009	list_add_tail_rcu(&rq->link, &tl->requests);1010 1011	return rq;1012 1013err_unwind:1014	ce->ring->emit = rq->head;1015 1016	/* Make sure we didn't add ourselves to external state before freeing */1017	GEM_BUG_ON(!list_empty(&rq->sched.signalers_list));1018	GEM_BUG_ON(!list_empty(&rq->sched.waiters_list));1019 1020err_free:1021	kmem_cache_free(slab_requests, rq);1022err_unreserve:1023	intel_context_unpin(ce);1024	return ERR_PTR(ret);1025}1026 1027struct i915_request *1028i915_request_create(struct intel_context *ce)1029{1030	struct i915_request *rq;1031	struct intel_timeline *tl;1032 1033	tl = intel_context_timeline_lock(ce);1034	if (IS_ERR(tl))1035		return ERR_CAST(tl);1036 1037	/* Move our oldest request to the slab-cache (if not in use!) */1038	rq = list_first_entry(&tl->requests, typeof(*rq), link);1039	if (!list_is_last(&rq->link, &tl->requests))1040		i915_request_retire(rq);1041 1042	intel_context_enter(ce);1043	rq = __i915_request_create(ce, GFP_KERNEL);1044	intel_context_exit(ce); /* active reference transferred to request */1045	if (IS_ERR(rq))1046		goto err_unlock;1047 1048	/* Check that we do not interrupt ourselves with a new request */1049	rq->cookie = lockdep_pin_lock(&tl->mutex);1050 1051	return rq;1052 1053err_unlock:1054	intel_context_timeline_unlock(tl);1055	return rq;1056}1057 1058static int1059i915_request_await_start(struct i915_request *rq, struct i915_request *signal)1060{1061	struct dma_fence *fence;1062	int err;1063 1064	if (i915_request_timeline(rq) == rcu_access_pointer(signal->timeline))1065		return 0;1066 1067	if (i915_request_started(signal))1068		return 0;1069 1070	/*1071	 * The caller holds a reference on @signal, but we do not serialise1072	 * against it being retired and removed from the lists.1073	 *1074	 * We do not hold a reference to the request before @signal, and1075	 * so must be very careful to ensure that it is not _recycled_ as1076	 * we follow the link backwards.1077	 */1078	fence = NULL;1079	rcu_read_lock();1080	do {1081		struct list_head *pos = READ_ONCE(signal->link.prev);1082		struct i915_request *prev;1083 1084		/* Confirm signal has not been retired, the link is valid */1085		if (unlikely(__i915_request_has_started(signal)))1086			break;1087 1088		/* Is signal the earliest request on its timeline? */1089		if (pos == &rcu_dereference(signal->timeline)->requests)1090			break;1091 1092		/*1093		 * Peek at the request before us in the timeline. That1094		 * request will only be valid before it is retired, so1095		 * after acquiring a reference to it, confirm that it is1096		 * still part of the signaler's timeline.1097		 */1098		prev = list_entry(pos, typeof(*prev), link);1099		if (!i915_request_get_rcu(prev))1100			break;1101 1102		/* After the strong barrier, confirm prev is still attached */1103		if (unlikely(READ_ONCE(prev->link.next) != &signal->link)) {1104			i915_request_put(prev);1105			break;1106		}1107 1108		fence = &prev->fence;1109	} while (0);1110	rcu_read_unlock();1111	if (!fence)1112		return 0;1113 1114	err = 0;1115	if (!intel_timeline_sync_is_later(i915_request_timeline(rq), fence))1116		err = i915_sw_fence_await_dma_fence(&rq->submit,1117						    fence, 0,1118						    I915_FENCE_GFP);1119	dma_fence_put(fence);1120 1121	return err;1122}1123 1124static intel_engine_mask_t1125already_busywaiting(struct i915_request *rq)1126{1127	/*1128	 * Polling a semaphore causes bus traffic, delaying other users of1129	 * both the GPU and CPU. We want to limit the impact on others,1130	 * while taking advantage of early submission to reduce GPU1131	 * latency. Therefore we restrict ourselves to not using more1132	 * than one semaphore from each source, and not using a semaphore1133	 * if we have detected the engine is saturated (i.e. would not be1134	 * submitted early and cause bus traffic reading an already passed1135	 * semaphore).1136	 *1137	 * See the are-we-too-late? check in __i915_request_submit().1138	 */1139	return rq->sched.semaphores | READ_ONCE(rq->engine->saturated);1140}1141 1142static int1143__emit_semaphore_wait(struct i915_request *to,1144		      struct i915_request *from,1145		      u32 seqno)1146{1147	const int has_token = GRAPHICS_VER(to->engine->i915) >= 12;1148	u32 hwsp_offset;1149	int len, err;1150	u32 *cs;1151 1152	GEM_BUG_ON(GRAPHICS_VER(to->engine->i915) < 8);1153	GEM_BUG_ON(i915_request_has_initial_breadcrumb(to));1154 1155	/* We need to pin the signaler's HWSP until we are finished reading. */1156	err = intel_timeline_read_hwsp(from, to, &hwsp_offset);1157	if (err)1158		return err;1159 1160	len = 4;1161	if (has_token)1162		len += 2;1163 1164	cs = intel_ring_begin(to, len);1165	if (IS_ERR(cs))1166		return PTR_ERR(cs);1167 1168	/*1169	 * Using greater-than-or-equal here means we have to worry1170	 * about seqno wraparound. To side step that issue, we swap1171	 * the timeline HWSP upon wrapping, so that everyone listening1172	 * for the old (pre-wrap) values do not see the much smaller1173	 * (post-wrap) values than they were expecting (and so wait1174	 * forever).1175	 */1176	*cs++ = (MI_SEMAPHORE_WAIT |1177		 MI_SEMAPHORE_GLOBAL_GTT |1178		 MI_SEMAPHORE_POLL |1179		 MI_SEMAPHORE_SAD_GTE_SDD) +1180		has_token;1181	*cs++ = seqno;1182	*cs++ = hwsp_offset;1183	*cs++ = 0;1184	if (has_token) {1185		*cs++ = 0;1186		*cs++ = MI_NOOP;1187	}1188 1189	intel_ring_advance(to, cs);1190	return 0;1191}1192 1193static bool1194can_use_semaphore_wait(struct i915_request *to, struct i915_request *from)1195{1196	return to->engine->gt->ggtt == from->engine->gt->ggtt;1197}1198 1199static int1200emit_semaphore_wait(struct i915_request *to,1201		    struct i915_request *from,1202		    gfp_t gfp)1203{1204	const intel_engine_mask_t mask = READ_ONCE(from->engine)->mask;1205	struct i915_sw_fence *wait = &to->submit;1206 1207	if (!can_use_semaphore_wait(to, from))1208		goto await_fence;1209 1210	if (!intel_context_use_semaphores(to->context))1211		goto await_fence;1212 1213	if (i915_request_has_initial_breadcrumb(to))1214		goto await_fence;1215 1216	/*1217	 * If this or its dependents are waiting on an external fence1218	 * that may fail catastrophically, then we want to avoid using1219	 * semaphores as they bypass the fence signaling metadata, and we1220	 * lose the fence->error propagation.1221	 */1222	if (from->sched.flags & I915_SCHED_HAS_EXTERNAL_CHAIN)1223		goto await_fence;1224 1225	/* Just emit the first semaphore we see as request space is limited. */1226	if (already_busywaiting(to) & mask)1227		goto await_fence;1228 1229	if (i915_request_await_start(to, from) < 0)1230		goto await_fence;1231 1232	/* Only submit our spinner after the signaler is running! */1233	if (__await_execution(to, from, gfp))1234		goto await_fence;1235 1236	if (__emit_semaphore_wait(to, from, from->fence.seqno))1237		goto await_fence;1238 1239	to->sched.semaphores |= mask;1240	wait = &to->semaphore;1241 1242await_fence:1243	return i915_sw_fence_await_dma_fence(wait,1244					     &from->fence, 0,1245					     I915_FENCE_GFP);1246}1247 1248static bool intel_timeline_sync_has_start(struct intel_timeline *tl,1249					  struct dma_fence *fence)1250{1251	return __intel_timeline_sync_is_later(tl,1252					      fence->context,1253					      fence->seqno - 1);1254}1255 1256static int intel_timeline_sync_set_start(struct intel_timeline *tl,1257					 const struct dma_fence *fence)1258{1259	return __intel_timeline_sync_set(tl, fence->context, fence->seqno - 1);1260}1261 1262static int1263__i915_request_await_execution(struct i915_request *to,1264			       struct i915_request *from)1265{1266	int err;1267 1268	GEM_BUG_ON(intel_context_is_barrier(from->context));1269 1270	/* Submit both requests at the same time */1271	err = __await_execution(to, from, I915_FENCE_GFP);1272	if (err)1273		return err;1274 1275	/* Squash repeated depenendices to the same timelines */1276	if (intel_timeline_sync_has_start(i915_request_timeline(to),1277					  &from->fence))1278		return 0;1279 1280	/*1281	 * Wait until the start of this request.1282	 *1283	 * The execution cb fires when we submit the request to HW. But in1284	 * many cases this may be long before the request itself is ready to1285	 * run (consider that we submit 2 requests for the same context, where1286	 * the request of interest is behind an indefinite spinner). So we hook1287	 * up to both to reduce our queues and keep the execution lag minimised1288	 * in the worst case, though we hope that the await_start is elided.1289	 */1290	err = i915_request_await_start(to, from);1291	if (err < 0)1292		return err;1293 1294	/*1295	 * Ensure both start together [after all semaphores in signal]1296	 *1297	 * Now that we are queued to the HW at roughly the same time (thanks1298	 * to the execute cb) and are ready to run at roughly the same time1299	 * (thanks to the await start), our signaler may still be indefinitely1300	 * delayed by waiting on a semaphore from a remote engine. If our1301	 * signaler depends on a semaphore, so indirectly do we, and we do not1302	 * want to start our payload until our signaler also starts theirs.1303	 * So we wait.1304	 *1305	 * However, there is also a second condition for which we need to wait1306	 * for the precise start of the signaler. Consider that the signaler1307	 * was submitted in a chain of requests following another context1308	 * (with just an ordinary intra-engine fence dependency between the1309	 * two). In this case the signaler is queued to HW, but not for1310	 * immediate execution, and so we must wait until it reaches the1311	 * active slot.1312	 */1313	if (can_use_semaphore_wait(to, from) &&1314	    intel_engine_has_semaphores(to->engine) &&1315	    !i915_request_has_initial_breadcrumb(to)) {1316		err = __emit_semaphore_wait(to, from, from->fence.seqno - 1);1317		if (err < 0)1318			return err;1319	}1320 1321	/* Couple the dependency tree for PI on this exposed to->fence */1322	if (to->engine->sched_engine->schedule) {1323		err = i915_sched_node_add_dependency(&to->sched,1324						     &from->sched,1325						     I915_DEPENDENCY_WEAK);1326		if (err < 0)1327			return err;1328	}1329 1330	return intel_timeline_sync_set_start(i915_request_timeline(to),1331					     &from->fence);1332}1333 1334static void mark_external(struct i915_request *rq)1335{1336	/*1337	 * The downside of using semaphores is that we lose metadata passing1338	 * along the signaling chain. This is particularly nasty when we1339	 * need to pass along a fatal error such as EFAULT or EDEADLK. For1340	 * fatal errors we want to scrub the request before it is executed,1341	 * which means that we cannot preload the request onto HW and have1342	 * it wait upon a semaphore.1343	 */1344	rq->sched.flags |= I915_SCHED_HAS_EXTERNAL_CHAIN;1345}1346 1347static int1348__i915_request_await_external(struct i915_request *rq, struct dma_fence *fence)1349{1350	mark_external(rq);1351	return i915_sw_fence_await_dma_fence(&rq->submit, fence,1352					     i915_fence_context_timeout(rq->i915,1353									fence->context),1354					     I915_FENCE_GFP);1355}1356 1357static int1358i915_request_await_external(struct i915_request *rq, struct dma_fence *fence)1359{1360	struct dma_fence *iter;1361	int err = 0;1362 1363	if (!to_dma_fence_chain(fence))1364		return __i915_request_await_external(rq, fence);1365 1366	dma_fence_chain_for_each(iter, fence) {1367		struct dma_fence_chain *chain = to_dma_fence_chain(iter);1368 1369		if (!dma_fence_is_i915(chain->fence)) {1370			err = __i915_request_await_external(rq, iter);1371			break;1372		}1373 1374		err = i915_request_await_dma_fence(rq, chain->fence);1375		if (err < 0)1376			break;1377	}1378 1379	dma_fence_put(iter);1380	return err;1381}1382 1383static inline bool is_parallel_rq(struct i915_request *rq)1384{1385	return intel_context_is_parallel(rq->context);1386}1387 1388static inline struct intel_context *request_to_parent(struct i915_request *rq)1389{1390	return intel_context_to_parent(rq->context);1391}1392 1393static bool is_same_parallel_context(struct i915_request *to,1394				     struct i915_request *from)1395{1396	if (is_parallel_rq(to))1397		return request_to_parent(to) == request_to_parent(from);1398 1399	return false;1400}1401 1402int1403i915_request_await_execution(struct i915_request *rq,1404			     struct dma_fence *fence)1405{1406	struct dma_fence **child = &fence;1407	unsigned int nchild = 1;1408	int ret;1409 1410	if (dma_fence_is_array(fence)) {1411		struct dma_fence_array *array = to_dma_fence_array(fence);1412 1413		/* XXX Error for signal-on-any fence arrays */1414 1415		child = array->fences;1416		nchild = array->num_fences;1417		GEM_BUG_ON(!nchild);1418	}1419 1420	do {1421		fence = *child++;1422		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))1423			continue;1424 1425		if (fence->context == rq->fence.context)1426			continue;1427 1428		/*1429		 * We don't squash repeated fence dependencies here as we1430		 * want to run our callback in all cases.1431		 */1432 1433		if (dma_fence_is_i915(fence)) {1434			if (is_same_parallel_context(rq, to_request(fence)))1435				continue;1436			ret = __i915_request_await_execution(rq,1437							     to_request(fence));1438		} else {1439			ret = i915_request_await_external(rq, fence);1440		}1441		if (ret < 0)1442			return ret;1443	} while (--nchild);1444 1445	return 0;1446}1447 1448static int1449await_request_submit(struct i915_request *to, struct i915_request *from)1450{1451	/*1452	 * If we are waiting on a virtual engine, then it may be1453	 * constrained to execute on a single engine *prior* to submission.1454	 * When it is submitted, it will be first submitted to the virtual1455	 * engine and then passed to the physical engine. We cannot allow1456	 * the waiter to be submitted immediately to the physical engine1457	 * as it may then bypass the virtual request.1458	 */1459	if (to->engine == READ_ONCE(from->engine))1460		return i915_sw_fence_await_sw_fence_gfp(&to->submit,1461							&from->submit,1462							I915_FENCE_GFP);1463	else1464		return __i915_request_await_execution(to, from);1465}1466 1467static int1468i915_request_await_request(struct i915_request *to, struct i915_request *from)1469{1470	int ret;1471 1472	GEM_BUG_ON(to == from);1473	GEM_BUG_ON(to->timeline == from->timeline);1474 1475	if (i915_request_completed(from)) {1476		i915_sw_fence_set_error_once(&to->submit, from->fence.error);1477		return 0;1478	}1479 1480	if (to->engine->sched_engine->schedule) {1481		ret = i915_sched_node_add_dependency(&to->sched,1482						     &from->sched,1483						     I915_DEPENDENCY_EXTERNAL);1484		if (ret < 0)1485			return ret;1486	}1487 1488	if (!intel_engine_uses_guc(to->engine) &&1489	    is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask)))1490		ret = await_request_submit(to, from);1491	else1492		ret = emit_semaphore_wait(to, from, I915_FENCE_GFP);1493	if (ret < 0)1494		return ret;1495 1496	return 0;1497}1498 1499int1500i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence)1501{1502	struct dma_fence **child = &fence;1503	unsigned int nchild = 1;1504	int ret;1505 1506	/*1507	 * Note that if the fence-array was created in signal-on-any mode,1508	 * we should *not* decompose it into its individual fences. However,1509	 * we don't currently store which mode the fence-array is operating1510	 * in. Fortunately, the only user of signal-on-any is private to1511	 * amdgpu and we should not see any incoming fence-array from1512	 * sync-file being in signal-on-any mode.1513	 */1514	if (dma_fence_is_array(fence)) {1515		struct dma_fence_array *array = to_dma_fence_array(fence);1516 1517		child = array->fences;1518		nchild = array->num_fences;1519		GEM_BUG_ON(!nchild);1520	}1521 1522	do {1523		fence = *child++;1524		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))1525			continue;1526 1527		/*1528		 * Requests on the same timeline are explicitly ordered, along1529		 * with their dependencies, by i915_request_add() which ensures1530		 * that requests are submitted in-order through each ring.1531		 */1532		if (fence->context == rq->fence.context)1533			continue;1534 1535		/* Squash repeated waits to the same timelines */1536		if (fence->context &&1537		    intel_timeline_sync_is_later(i915_request_timeline(rq),1538						 fence))1539			continue;1540 1541		if (dma_fence_is_i915(fence)) {1542			if (is_same_parallel_context(rq, to_request(fence)))1543				continue;1544			ret = i915_request_await_request(rq, to_request(fence));1545		} else {1546			ret = i915_request_await_external(rq, fence);1547		}1548		if (ret < 0)1549			return ret;1550 1551		/* Record the latest fence used against each timeline */1552		if (fence->context)1553			intel_timeline_sync_set(i915_request_timeline(rq),1554						fence);1555	} while (--nchild);1556 1557	return 0;1558}1559 1560/**1561 * i915_request_await_deps - set this request to (async) wait upon a struct1562 * i915_deps dma_fence collection1563 * @rq: request we are wishing to use1564 * @deps: The struct i915_deps containing the dependencies.1565 *1566 * Returns 0 if successful, negative error code on error.1567 */1568int i915_request_await_deps(struct i915_request *rq, const struct i915_deps *deps)1569{1570	int i, err;1571 1572	for (i = 0; i < deps->num_deps; ++i) {1573		err = i915_request_await_dma_fence(rq, deps->fences[i]);1574		if (err)1575			return err;1576	}1577 1578	return 0;1579}1580 1581/**1582 * i915_request_await_object - set this request to (async) wait upon a bo1583 * @to: request we are wishing to use1584 * @obj: object which may be in use on another ring.1585 * @write: whether the wait is on behalf of a writer1586 *1587 * This code is meant to abstract object synchronization with the GPU.1588 * Conceptually we serialise writes between engines inside the GPU.1589 * We only allow one engine to write into a buffer at any time, but1590 * multiple readers. To ensure each has a coherent view of memory, we must:1591 *1592 * - If there is an outstanding write request to the object, the new1593 *   request must wait for it to complete (either CPU or in hw, requests1594 *   on the same ring will be naturally ordered).1595 *1596 * - If we are a write request (pending_write_domain is set), the new1597 *   request must wait for outstanding read requests to complete.1598 *1599 * Returns 0 if successful, else propagates up the lower layer error.1600 */1601int1602i915_request_await_object(struct i915_request *to,1603			  struct drm_i915_gem_object *obj,1604			  bool write)1605{1606	struct dma_resv_iter cursor;1607	struct dma_fence *fence;1608	int ret = 0;1609 1610	dma_resv_for_each_fence(&cursor, obj->base.resv,1611				dma_resv_usage_rw(write), fence) {1612		ret = i915_request_await_dma_fence(to, fence);1613		if (ret)1614			break;1615	}1616 1617	return ret;1618}1619 1620static void i915_request_await_huc(struct i915_request *rq)1621{1622	struct intel_huc *huc = &rq->context->engine->gt->uc.huc;1623 1624	/* don't stall kernel submissions! */1625	if (!rcu_access_pointer(rq->context->gem_context))1626		return;1627 1628	if (intel_huc_wait_required(huc))1629		i915_sw_fence_await_sw_fence(&rq->submit,1630					     &huc->delayed_load.fence,1631					     &rq->hucq);1632}1633 1634static struct i915_request *1635__i915_request_ensure_parallel_ordering(struct i915_request *rq,1636					struct intel_timeline *timeline)1637{1638	struct i915_request *prev;1639 1640	GEM_BUG_ON(!is_parallel_rq(rq));1641 1642	prev = request_to_parent(rq)->parallel.last_rq;1643	if (prev) {1644		if (!__i915_request_is_complete(prev)) {1645			i915_sw_fence_await_sw_fence(&rq->submit,1646						     &prev->submit,1647						     &rq->submitq);1648 1649			if (rq->engine->sched_engine->schedule)1650				__i915_sched_node_add_dependency(&rq->sched,1651								 &prev->sched,1652								 &rq->dep,1653								 0);1654		}1655		i915_request_put(prev);1656	}1657 1658	request_to_parent(rq)->parallel.last_rq = i915_request_get(rq);1659 1660	/*1661	 * Users have to put a reference potentially got by1662	 * __i915_active_fence_set() to the returned request1663	 * when no longer needed1664	 */1665	return to_request(__i915_active_fence_set(&timeline->last_request,1666						  &rq->fence));1667}1668 1669static struct i915_request *1670__i915_request_ensure_ordering(struct i915_request *rq,1671			       struct intel_timeline *timeline)1672{1673	struct i915_request *prev;1674 1675	GEM_BUG_ON(is_parallel_rq(rq));1676 1677	prev = to_request(__i915_active_fence_set(&timeline->last_request,1678						  &rq->fence));1679 1680	if (prev && !__i915_request_is_complete(prev)) {1681		bool uses_guc = intel_engine_uses_guc(rq->engine);1682		bool pow2 = is_power_of_2(READ_ONCE(prev->engine)->mask |1683					  rq->engine->mask);1684		bool same_context = prev->context == rq->context;1685 1686		/*1687		 * The requests are supposed to be kept in order. However,1688		 * we need to be wary in case the timeline->last_request1689		 * is used as a barrier for external modification to this1690		 * context.1691		 */1692		GEM_BUG_ON(same_context &&1693			   i915_seqno_passed(prev->fence.seqno,1694					     rq->fence.seqno));1695 1696		if ((same_context && uses_guc) || (!uses_guc && pow2))1697			i915_sw_fence_await_sw_fence(&rq->submit,1698						     &prev->submit,1699						     &rq->submitq);1700		else1701			__i915_sw_fence_await_dma_fence(&rq->submit,1702							&prev->fence,1703							&rq->dmaq);1704		if (rq->engine->sched_engine->schedule)1705			__i915_sched_node_add_dependency(&rq->sched,1706							 &prev->sched,1707							 &rq->dep,1708							 0);1709	}1710 1711	/*1712	 * Users have to put the reference to prev potentially got1713	 * by __i915_active_fence_set() when no longer needed1714	 */1715	return prev;1716}1717 1718static struct i915_request *1719__i915_request_add_to_timeline(struct i915_request *rq)1720{1721	struct intel_timeline *timeline = i915_request_timeline(rq);1722	struct i915_request *prev;1723 1724	/*1725	 * Media workloads may require HuC, so stall them until HuC loading is1726	 * complete. Note that HuC not being loaded when a user submission1727	 * arrives can only happen when HuC is loaded via GSC and in that case1728	 * we still expect the window between us starting to accept submissions1729	 * and HuC loading completion to be small (a few hundred ms).1730	 */1731	if (rq->engine->class == VIDEO_DECODE_CLASS)1732		i915_request_await_huc(rq);1733 1734	/*1735	 * Dependency tracking and request ordering along the timeline1736	 * is special cased so that we can eliminate redundant ordering1737	 * operations while building the request (we know that the timeline1738	 * itself is ordered, and here we guarantee it).1739	 *1740	 * As we know we will need to emit tracking along the timeline,1741	 * we embed the hooks into our request struct -- at the cost of1742	 * having to have specialised no-allocation interfaces (which will1743	 * be beneficial elsewhere).1744	 *1745	 * A second benefit to open-coding i915_request_await_request is1746	 * that we can apply a slight variant of the rules specialised1747	 * for timelines that jump between engines (such as virtual engines).1748	 * If we consider the case of virtual engine, we must emit a dma-fence1749	 * to prevent scheduling of the second request until the first is1750	 * complete (to maximise our greedy late load balancing) and this1751	 * precludes optimising to use semaphores serialisation of a single1752	 * timeline across engines.1753	 *1754	 * We do not order parallel submission requests on the timeline as each1755	 * parallel submission context has its own timeline and the ordering1756	 * rules for parallel requests are that they must be submitted in the1757	 * order received from the execbuf IOCTL. So rather than using the1758	 * timeline we store a pointer to last request submitted in the1759	 * relationship in the gem context and insert a submission fence1760	 * between that request and request passed into this function or1761	 * alternatively we use completion fence if gem context has a single1762	 * timeline and this is the first submission of an execbuf IOCTL.1763	 */1764	if (likely(!is_parallel_rq(rq)))1765		prev = __i915_request_ensure_ordering(rq, timeline);1766	else1767		prev = __i915_request_ensure_parallel_ordering(rq, timeline);1768	if (prev)1769		i915_request_put(prev);1770 1771	/*1772	 * Make sure that no request gazumped us - if it was allocated after1773	 * our i915_request_alloc() and called __i915_request_add() before1774	 * us, the timeline will hold its seqno which is later than ours.1775	 */1776	GEM_BUG_ON(timeline->seqno != rq->fence.seqno);1777 1778	return prev;1779}1780 1781/*1782 * NB: This function is not allowed to fail. Doing so would mean the the1783 * request is not being tracked for completion but the work itself is1784 * going to happen on the hardware. This would be a Bad Thing(tm).1785 */1786struct i915_request *__i915_request_commit(struct i915_request *rq)1787{1788	struct intel_engine_cs *engine = rq->engine;1789	struct intel_ring *ring = rq->ring;1790	u32 *cs;1791 1792	RQ_TRACE(rq, "\n");1793 1794	/*1795	 * To ensure that this call will not fail, space for its emissions1796	 * should already have been reserved in the ring buffer. Let the ring1797	 * know that it is time to use that space up.1798	 */1799	GEM_BUG_ON(rq->reserved_space > ring->space);1800	rq->reserved_space = 0;1801	rq->emitted_jiffies = jiffies;1802 1803	/*1804	 * Record the position of the start of the breadcrumb so that1805	 * should we detect the updated seqno part-way through the1806	 * GPU processing the request, we never over-estimate the1807	 * position of the ring's HEAD.1808	 */1809	cs = intel_ring_begin(rq, engine->emit_fini_breadcrumb_dw);1810	GEM_BUG_ON(IS_ERR(cs));1811	rq->postfix = intel_ring_offset(rq, cs);1812 1813	return __i915_request_add_to_timeline(rq);1814}1815 1816void __i915_request_queue_bh(struct i915_request *rq)1817{1818	i915_sw_fence_commit(&rq->semaphore);1819	i915_sw_fence_commit(&rq->submit);1820}1821 1822void __i915_request_queue(struct i915_request *rq,1823			  const struct i915_sched_attr *attr)1824{1825	/*1826	 * Let the backend know a new request has arrived that may need1827	 * to adjust the existing execution schedule due to a high priority1828	 * request - i.e. we may want to preempt the current request in order1829	 * to run a high priority dependency chain *before* we can execute this1830	 * request.1831	 *1832	 * This is called before the request is ready to run so that we can1833	 * decide whether to preempt the entire chain so that it is ready to1834	 * run at the earliest possible convenience.1835	 */1836	if (attr && rq->engine->sched_engine->schedule)1837		rq->engine->sched_engine->schedule(rq, attr);1838 1839	local_bh_disable();1840	__i915_request_queue_bh(rq);1841	local_bh_enable(); /* kick tasklets */1842}1843 1844void i915_request_add(struct i915_request *rq)1845{1846	struct intel_timeline * const tl = i915_request_timeline(rq);1847	struct i915_sched_attr attr = {};1848	struct i915_gem_context *ctx;1849 1850	lockdep_assert_held(&tl->mutex);1851	lockdep_unpin_lock(&tl->mutex, rq->cookie);1852 1853	trace_i915_request_add(rq);1854	__i915_request_commit(rq);1855 1856	/* XXX placeholder for selftests */1857	rcu_read_lock();1858	ctx = rcu_dereference(rq->context->gem_context);1859	if (ctx)1860		attr = ctx->sched;1861	rcu_read_unlock();1862 1863	__i915_request_queue(rq, &attr);1864 1865	mutex_unlock(&tl->mutex);1866}1867 1868static unsigned long local_clock_ns(unsigned int *cpu)1869{1870	unsigned long t;1871 1872	/*1873	 * Cheaply and approximately convert from nanoseconds to microseconds.1874	 * The result and subsequent calculations are also defined in the same1875	 * approximate microseconds units. The principal source of timing1876	 * error here is from the simple truncation.1877	 *1878	 * Note that local_clock() is only defined wrt to the current CPU;1879	 * the comparisons are no longer valid if we switch CPUs. Instead of1880	 * blocking preemption for the entire busywait, we can detect the CPU1881	 * switch and use that as indicator of system load and a reason to1882	 * stop busywaiting, see busywait_stop().1883	 */1884	*cpu = get_cpu();1885	t = local_clock();1886	put_cpu();1887 1888	return t;1889}1890 1891static bool busywait_stop(unsigned long timeout, unsigned int cpu)1892{1893	unsigned int this_cpu;1894 1895	if (time_after(local_clock_ns(&this_cpu), timeout))1896		return true;1897 1898	return this_cpu != cpu;1899}1900 1901static bool __i915_spin_request(struct i915_request * const rq, int state)1902{1903	unsigned long timeout_ns;1904	unsigned int cpu;1905 1906	/*1907	 * Only wait for the request if we know it is likely to complete.1908	 *1909	 * We don't track the timestamps around requests, nor the average1910	 * request length, so we do not have a good indicator that this1911	 * request will complete within the timeout. What we do know is the1912	 * order in which requests are executed by the context and so we can1913	 * tell if the request has been started. If the request is not even1914	 * running yet, it is a fair assumption that it will not complete1915	 * within our relatively short timeout.1916	 */1917	if (!i915_request_is_running(rq))1918		return false;1919 1920	/*1921	 * When waiting for high frequency requests, e.g. during synchronous1922	 * rendering split between the CPU and GPU, the finite amount of time1923	 * required to set up the irq and wait upon it limits the response1924	 * rate. By busywaiting on the request completion for a short while we1925	 * can service the high frequency waits as quick as possible. However,1926	 * if it is a slow request, we want to sleep as quickly as possible.1927	 * The tradeoff between waiting and sleeping is roughly the time it1928	 * takes to sleep on a request, on the order of a microsecond.1929	 */1930 1931	timeout_ns = READ_ONCE(rq->engine->props.max_busywait_duration_ns);1932	timeout_ns += local_clock_ns(&cpu);1933	do {1934		if (dma_fence_is_signaled(&rq->fence))1935			return true;1936 1937		if (signal_pending_state(state, current))1938			break;1939 1940		if (busywait_stop(timeout_ns, cpu))1941			break;1942 1943		cpu_relax();1944	} while (!need_resched());1945 1946	return false;1947}1948 1949struct request_wait {1950	struct dma_fence_cb cb;1951	struct task_struct *tsk;1952};1953 1954static void request_wait_wake(struct dma_fence *fence, struct dma_fence_cb *cb)1955{1956	struct request_wait *wait = container_of(cb, typeof(*wait), cb);1957 1958	wake_up_process(fetch_and_zero(&wait->tsk));1959}1960 1961/**1962 * i915_request_wait_timeout - wait until execution of request has finished1963 * @rq: the request to wait upon1964 * @flags: how to wait1965 * @timeout: how long to wait in jiffies1966 *1967 * i915_request_wait_timeout() waits for the request to be completed, for a1968 * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an1969 * unbounded wait).1970 *1971 * Returns the remaining time (in jiffies) if the request completed, which may1972 * be zero if the request is unfinished after the timeout expires.1973 * If the timeout is 0, it will return 1 if the fence is signaled.1974 *1975 * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is1976 * pending before the request completes.1977 *1978 * NOTE: This function has the same wait semantics as dma-fence.1979 */1980long i915_request_wait_timeout(struct i915_request *rq,1981			       unsigned int flags,1982			       long timeout)1983{1984	const int state = flags & I915_WAIT_INTERRUPTIBLE ?1985		TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;1986	struct request_wait wait;1987 1988	might_sleep();1989	GEM_BUG_ON(timeout < 0);1990 1991	if (dma_fence_is_signaled(&rq->fence))1992		return timeout ?: 1;1993 1994	if (!timeout)1995		return -ETIME;1996 1997	trace_i915_request_wait_begin(rq, flags);1998 1999	/*2000	 * We must never wait on the GPU while holding a lock as we2001	 * may need to perform a GPU reset. So while we don't need to2002	 * serialise wait/reset with an explicit lock, we do want2003	 * lockdep to detect potential dependency cycles.2004	 */2005	mutex_acquire(&rq->engine->gt->reset.mutex.dep_map, 0, 0, _THIS_IP_);2006 2007	/*2008	 * Optimistic spin before touching IRQs.2009	 *2010	 * We may use a rather large value here to offset the penalty of2011	 * switching away from the active task. Frequently, the client will2012	 * wait upon an old swapbuffer to throttle itself to remain within a2013	 * frame of the gpu. If the client is running in lockstep with the gpu,2014	 * then it should not be waiting long at all, and a sleep now will incur2015	 * extra scheduler latency in producing the next frame. To try to2016	 * avoid adding the cost of enabling/disabling the interrupt to the2017	 * short wait, we first spin to see if the request would have completed2018	 * in the time taken to setup the interrupt.2019	 *2020	 * We need upto 5us to enable the irq, and upto 20us to hide the2021	 * scheduler latency of a context switch, ignoring the secondary2022	 * impacts from a context switch such as cache eviction.2023	 *2024	 * The scheme used for low-latency IO is called "hybrid interrupt2025	 * polling". The suggestion there is to sleep until just before you2026	 * expect to be woken by the device interrupt and then poll for its2027	 * completion. That requires having a good predictor for the request2028	 * duration, which we currently lack.2029	 */2030	if (CONFIG_DRM_I915_MAX_REQUEST_BUSYWAIT &&2031	    __i915_spin_request(rq, state))2032		goto out;2033 2034	/*2035	 * This client is about to stall waiting for the GPU. In many cases2036	 * this is undesirable and limits the throughput of the system, as2037	 * many clients cannot continue processing user input/output whilst2038	 * blocked. RPS autotuning may take tens of milliseconds to respond2039	 * to the GPU load and thus incurs additional latency for the client.2040	 * We can circumvent that by promoting the GPU frequency to maximum2041	 * before we sleep. This makes the GPU throttle up much more quickly2042	 * (good for benchmarks and user experience, e.g. window animations),2043	 * but at a cost of spending more power processing the workload2044	 * (bad for battery).2045	 */2046	if (flags & I915_WAIT_PRIORITY && !i915_request_started(rq))2047		intel_rps_boost(rq);2048 2049	wait.tsk = current;2050	if (dma_fence_add_callback(&rq->fence, &wait.cb, request_wait_wake))2051		goto out;2052 2053	/*2054	 * Flush the submission tasklet, but only if it may help this request.2055	 *2056	 * We sometimes experience some latency between the HW interrupts and2057	 * tasklet execution (mostly due to ksoftirqd latency, but it can also2058	 * be due to lazy CS events), so lets run the tasklet manually if there2059	 * is a chance it may submit this request. If the request is not ready2060	 * to run, as it is waiting for other fences to be signaled, flushing2061	 * the tasklet is busy work without any advantage for this client.2062	 *2063	 * If the HW is being lazy, this is the last chance before we go to2064	 * sleep to catch any pending events. We will check periodically in2065	 * the heartbeat to flush the submission tasklets as a last resort2066	 * for unhappy HW.2067	 */2068	if (i915_request_is_ready(rq))2069		__intel_engine_flush_submission(rq->engine, false);2070 2071	for (;;) {2072		set_current_state(state);2073 2074		if (dma_fence_is_signaled(&rq->fence))2075			break;2076 2077		if (signal_pending_state(state, current)) {2078			timeout = -ERESTARTSYS;2079			break;2080		}2081 2082		if (!timeout) {2083			timeout = -ETIME;2084			break;2085		}2086 2087		timeout = io_schedule_timeout(timeout);2088	}2089	__set_current_state(TASK_RUNNING);2090 2091	if (READ_ONCE(wait.tsk))2092		dma_fence_remove_callback(&rq->fence, &wait.cb);2093	GEM_BUG_ON(!list_empty(&wait.cb.node));2094 2095out:2096	mutex_release(&rq->engine->gt->reset.mutex.dep_map, _THIS_IP_);2097	trace_i915_request_wait_end(rq);2098	return timeout;2099}2100 2101/**2102 * i915_request_wait - wait until execution of request has finished2103 * @rq: the request to wait upon2104 * @flags: how to wait2105 * @timeout: how long to wait in jiffies2106 *2107 * i915_request_wait() waits for the request to be completed, for a2108 * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an2109 * unbounded wait).2110 *2111 * Returns the remaining time (in jiffies) if the request completed, which may2112 * be zero or -ETIME if the request is unfinished after the timeout expires.2113 * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is2114 * pending before the request completes.2115 *2116 * NOTE: This function behaves differently from dma-fence wait semantics for2117 * timeout = 0. It returns 0 on success, and -ETIME if not signaled.2118 */2119long i915_request_wait(struct i915_request *rq,2120		       unsigned int flags,2121		       long timeout)2122{2123	long ret = i915_request_wait_timeout(rq, flags, timeout);2124 2125	if (!ret)2126		return -ETIME;2127 2128	if (ret > 0 && !timeout)2129		return 0;2130 2131	return ret;2132}2133 2134static int print_sched_attr(const struct i915_sched_attr *attr,2135			    char *buf, int x, int len)2136{2137	if (attr->priority == I915_PRIORITY_INVALID)2138		return x;2139 2140	x += snprintf(buf + x, len - x,2141		      " prio=%d", attr->priority);2142 2143	return x;2144}2145 2146static char queue_status(const struct i915_request *rq)2147{2148	if (i915_request_is_active(rq))2149		return 'E';2150 2151	if (i915_request_is_ready(rq))2152		return intel_engine_is_virtual(rq->engine) ? 'V' : 'R';2153 2154	return 'U';2155}2156 2157static const char *run_status(const struct i915_request *rq)2158{2159	if (__i915_request_is_complete(rq))2160		return "!";2161 2162	if (__i915_request_has_started(rq))2163		return "*";2164 2165	if (!i915_sw_fence_signaled(&rq->semaphore))2166		return "&";2167 2168	return "";2169}2170 2171static const char *fence_status(const struct i915_request *rq)2172{2173	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))2174		return "+";2175 2176	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags))2177		return "-";2178 2179	return "";2180}2181 2182void i915_request_show(struct drm_printer *m,2183		       const struct i915_request *rq,2184		       const char *prefix,2185		       int indent)2186{2187	const char *name = rq->fence.ops->get_timeline_name((struct dma_fence *)&rq->fence);2188	char buf[80] = "";2189	int x = 0;2190 2191	/*2192	 * The prefix is used to show the queue status, for which we use2193	 * the following flags:2194	 *2195	 *  U [Unready]2196	 *    - initial status upon being submitted by the user2197	 *2198	 *    - the request is not ready for execution as it is waiting2199	 *      for external fences2200	 *2201	 *  R [Ready]2202	 *    - all fences the request was waiting on have been signaled,2203	 *      and the request is now ready for execution and will be2204	 *      in a backend queue2205	 *2206	 *    - a ready request may still need to wait on semaphores2207	 *      [internal fences]2208	 *2209	 *  V [Ready/virtual]2210	 *    - same as ready, but queued over multiple backends2211	 *2212	 *  E [Executing]2213	 *    - the request has been transferred from the backend queue and2214	 *      submitted for execution on HW2215	 *2216	 *    - a completed request may still be regarded as executing, its2217	 *      status may not be updated until it is retired and removed2218	 *      from the lists2219	 */2220 2221	x = print_sched_attr(&rq->sched.attr, buf, x, sizeof(buf));2222 2223	drm_printf(m, "%s%.*s%c %llx:%lld%s%s %s @ %dms: %s\n",2224		   prefix, indent, "                ",2225		   queue_status(rq),2226		   rq->fence.context, rq->fence.seqno,2227		   run_status(rq),2228		   fence_status(rq),2229		   buf,2230		   jiffies_to_msecs(jiffies - rq->emitted_jiffies),2231		   name);2232}2233 2234static bool engine_match_ring(struct intel_engine_cs *engine, struct i915_request *rq)2235{2236	u32 ring = ENGINE_READ(engine, RING_START);2237 2238	return ring == i915_ggtt_offset(rq->ring->vma);2239}2240 2241static bool match_ring(struct i915_request *rq)2242{2243	struct intel_engine_cs *engine;2244	bool found;2245	int i;2246 2247	if (!intel_engine_is_virtual(rq->engine))2248		return engine_match_ring(rq->engine, rq);2249 2250	found = false;2251	i = 0;2252	while ((engine = intel_engine_get_sibling(rq->engine, i++))) {2253		found = engine_match_ring(engine, rq);2254		if (found)2255			break;2256	}2257 2258	return found;2259}2260 2261enum i915_request_state i915_test_request_state(struct i915_request *rq)2262{2263	if (i915_request_completed(rq))2264		return I915_REQUEST_COMPLETE;2265 2266	if (!i915_request_started(rq))2267		return I915_REQUEST_PENDING;2268 2269	if (match_ring(rq))2270		return I915_REQUEST_ACTIVE;2271 2272	return I915_REQUEST_QUEUED;2273}2274 2275#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)2276#include "selftests/mock_request.c"2277#include "selftests/i915_request.c"2278#endif2279 2280void i915_request_module_exit(void)2281{2282	kmem_cache_destroy(slab_execute_cbs);2283	kmem_cache_destroy(slab_requests);2284}2285 2286int __init i915_request_module_init(void)2287{2288	slab_requests =2289		kmem_cache_create("i915_request",2290				  sizeof(struct i915_request),2291				  __alignof__(struct i915_request),2292				  SLAB_HWCACHE_ALIGN |2293				  SLAB_RECLAIM_ACCOUNT |2294				  SLAB_TYPESAFE_BY_RCU,2295				  __i915_request_ctor);2296	if (!slab_requests)2297		return -ENOMEM;2298 2299	slab_execute_cbs = KMEM_CACHE(execute_cb,2300					     SLAB_HWCACHE_ALIGN |2301					     SLAB_RECLAIM_ACCOUNT |2302					     SLAB_TYPESAFE_BY_RCU);2303	if (!slab_execute_cbs)2304		goto err_requests;2305 2306	return 0;2307 2308err_requests:2309	kmem_cache_destroy(slab_requests);2310	return -ENOMEM;2311}2312