1/*
2 * Copyright 2015 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 */
23
24/**
25 * DOC: Overview
26 *
27 * The GPU scheduler provides entities which allow userspace to push jobs
28 * into software queues which are then scheduled on a hardware run queue.
29 * The software queues have a priority among them. The scheduler selects the entities
30 * from the run queue using a FIFO. The scheduler provides dependency handling
31 * features among jobs. The driver is supposed to provide callback functions for
32 * backend operations to the scheduler like submitting a job to hardware run queue,
33 * returning the dependencies of a job etc.
34 *
35 * The organisation of the scheduler is the following:
36 *
37 * 1. Each hw run queue has one scheduler
38 * 2. Each scheduler has multiple run queues with different priorities
39 *    (e.g., HIGH_HW,HIGH_SW, KERNEL, NORMAL)
40 * 3. Each scheduler run queue has a queue of entities to schedule
41 * 4. Entities themselves maintain a queue of jobs that will be scheduled on
42 *    the hardware.
43 *
44 * The jobs in a entity are always scheduled in the order that they were pushed.
45 *
46 * Note that once a job was taken from the entities queue and pushed to the
47 * hardware, i.e. the pending queue, the entity must not be referenced anymore
48 * through the jobs entity pointer.
49 */
50
51/**
52 * DOC: Flow Control
53 *
54 * The DRM GPU scheduler provides a flow control mechanism to regulate the rate
55 * in which the jobs fetched from scheduler entities are executed.
56 *
57 * In this context the &drm_gpu_scheduler keeps track of a driver specified
58 * credit limit representing the capacity of this scheduler and a credit count;
59 * every &drm_sched_job carries a driver specified number of credits.
60 *
61 * Once a job is executed (but not yet finished), the job's credits contribute
62 * to the scheduler's credit count until the job is finished. If by executing
63 * one more job the scheduler's credit count would exceed the scheduler's
64 * credit limit, the job won't be executed. Instead, the scheduler will wait
65 * until the credit count has decreased enough to not overflow its credit limit.
66 * This implies waiting for previously executed jobs.
67 *
68 * Optionally, drivers may register a callback (update_job_credits) provided by
69 * struct drm_sched_backend_ops to update the job's credits dynamically. The
70 * scheduler executes this callback every time the scheduler considers a job for
71 * execution and subsequently checks whether the job fits the scheduler's credit
72 * limit.
73 */
74
75#include <linux/wait.h>
76#include <linux/sched.h>
77#include <linux/completion.h>
78#include <linux/dma-resv.h>
79#include <uapi/linux/sched/types.h>
80
81#include <drm/drm_print.h>
82#include <drm/drm_gem.h>
83#include <drm/drm_syncobj.h>
84#include <drm/gpu_scheduler.h>
85#include <drm/spsc_queue.h>
86
87#define CREATE_TRACE_POINTS
88#include "gpu_scheduler_trace.h"
89
90#define to_drm_sched_job(sched_job)		\
91		container_of((sched_job), struct drm_sched_job, queue_node)
92
93int drm_sched_policy = DRM_SCHED_POLICY_FIFO;
94
95/**
96 * DOC: sched_policy (int)
97 * Used to override default entities scheduling policy in a run queue.
98 */
99MODULE_PARM_DESC(sched_policy, "Specify the scheduling policy for entities on a run-queue, " __stringify(DRM_SCHED_POLICY_RR) " = Round Robin, " __stringify(DRM_SCHED_POLICY_FIFO) " = FIFO (default).");
100module_param_named(sched_policy, drm_sched_policy, int, 0444);
101
102static u32 drm_sched_available_credits(struct drm_gpu_scheduler *sched)
103{
104	u32 credits;
105
106	drm_WARN_ON(sched, check_sub_overflow(sched->credit_limit,
107					      atomic_read(&sched->credit_count),
108					      &credits));
109
110	return credits;
111}
112
113/**
114 * drm_sched_can_queue -- Can we queue more to the hardware?
115 * @sched: scheduler instance
116 * @entity: the scheduler entity
117 *
118 * Return true if we can push at least one more job from @entity, false
119 * otherwise.
120 */
121static bool drm_sched_can_queue(struct drm_gpu_scheduler *sched,
122				struct drm_sched_entity *entity)
123{
124	struct drm_sched_job *s_job;
125
126	s_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
127	if (!s_job)
128		return false;
129
130	if (sched->ops->update_job_credits) {
131		s_job->credits = sched->ops->update_job_credits(s_job);
132
133		drm_WARN(sched, !s_job->credits,
134			 "Jobs with zero credits bypass job-flow control.\n");
135	}
136
137	/* If a job exceeds the credit limit, truncate it to the credit limit
138	 * itself to guarantee forward progress.
139	 */
140	if (drm_WARN(sched, s_job->credits > sched->credit_limit,
141		     "Jobs may not exceed the credit limit, truncate.\n"))
142		s_job->credits = sched->credit_limit;
143
144	return drm_sched_available_credits(sched) >= s_job->credits;
145}
146
147static __always_inline bool drm_sched_entity_compare_before(struct rb_node *a,
148							    const struct rb_node *b)
149{
150	struct drm_sched_entity *ent_a =  rb_entry((a), struct drm_sched_entity, rb_tree_node);
151	struct drm_sched_entity *ent_b =  rb_entry((b), struct drm_sched_entity, rb_tree_node);
152
153	return ktime_before(ent_a->oldest_job_waiting, ent_b->oldest_job_waiting);
154}
155
156static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity)
157{
158	struct drm_sched_rq *rq = entity->rq;
159
160	if (!RB_EMPTY_NODE(&entity->rb_tree_node)) {
161		rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root);
162		RB_CLEAR_NODE(&entity->rb_tree_node);
163	}
164}
165
166void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
167{
168	/*
169	 * Both locks need to be grabbed, one to protect from entity->rq change
170	 * for entity from within concurrent drm_sched_entity_select_rq and the
171	 * other to update the rb tree structure.
172	 */
173	spin_lock(&entity->rq_lock);
174	spin_lock(&entity->rq->lock);
175
176	drm_sched_rq_remove_fifo_locked(entity);
177
178	entity->oldest_job_waiting = ts;
179
180	rb_add_cached(&entity->rb_tree_node, &entity->rq->rb_tree_root,
181		      drm_sched_entity_compare_before);
182
183	spin_unlock(&entity->rq->lock);
184	spin_unlock(&entity->rq_lock);
185}
186
187/**
188 * drm_sched_rq_init - initialize a given run queue struct
189 *
190 * @sched: scheduler instance to associate with this run queue
191 * @rq: scheduler run queue
192 *
193 * Initializes a scheduler runqueue.
194 */
195static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
196			      struct drm_sched_rq *rq)
197{
198	spin_lock_init(&rq->lock);
199	INIT_LIST_HEAD(&rq->entities);
200	rq->rb_tree_root = RB_ROOT_CACHED;
201	rq->current_entity = NULL;
202	rq->sched = sched;
203}
204
205/**
206 * drm_sched_rq_add_entity - add an entity
207 *
208 * @rq: scheduler run queue
209 * @entity: scheduler entity
210 *
211 * Adds a scheduler entity to the run queue.
212 */
213void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
214			     struct drm_sched_entity *entity)
215{
216	if (!list_empty(&entity->list))
217		return;
218
219	spin_lock(&rq->lock);
220
221	atomic_inc(rq->sched->score);
222	list_add_tail(&entity->list, &rq->entities);
223
224	spin_unlock(&rq->lock);
225}
226
227/**
228 * drm_sched_rq_remove_entity - remove an entity
229 *
230 * @rq: scheduler run queue
231 * @entity: scheduler entity
232 *
233 * Removes a scheduler entity from the run queue.
234 */
235void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
236				struct drm_sched_entity *entity)
237{
238	if (list_empty(&entity->list))
239		return;
240
241	spin_lock(&rq->lock);
242
243	atomic_dec(rq->sched->score);
244	list_del_init(&entity->list);
245
246	if (rq->current_entity == entity)
247		rq->current_entity = NULL;
248
249	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
250		drm_sched_rq_remove_fifo_locked(entity);
251
252	spin_unlock(&rq->lock);
253}
254
255/**
256 * drm_sched_rq_select_entity_rr - Select an entity which could provide a job to run
257 *
258 * @sched: the gpu scheduler
259 * @rq: scheduler run queue to check.
260 *
261 * Try to find the next ready entity.
262 *
263 * Return an entity if one is found; return an error-pointer (!NULL) if an
264 * entity was ready, but the scheduler had insufficient credits to accommodate
265 * its job; return NULL, if no ready entity was found.
266 */
267static struct drm_sched_entity *
268drm_sched_rq_select_entity_rr(struct drm_gpu_scheduler *sched,
269			      struct drm_sched_rq *rq)
270{
271	struct drm_sched_entity *entity;
272
273	spin_lock(&rq->lock);
274
275	entity = rq->current_entity;
276	if (entity) {
277		list_for_each_entry_continue(entity, &rq->entities, list) {
278			if (drm_sched_entity_is_ready(entity)) {
279				/* If we can't queue yet, preserve the current
280				 * entity in terms of fairness.
281				 */
282				if (!drm_sched_can_queue(sched, entity)) {
283					spin_unlock(&rq->lock);
284					return ERR_PTR(-ENOSPC);
285				}
286
287				rq->current_entity = entity;
288				reinit_completion(&entity->entity_idle);
289				spin_unlock(&rq->lock);
290				return entity;
291			}
292		}
293	}
294
295	list_for_each_entry(entity, &rq->entities, list) {
296		if (drm_sched_entity_is_ready(entity)) {
297			/* If we can't queue yet, preserve the current entity in
298			 * terms of fairness.
299			 */
300			if (!drm_sched_can_queue(sched, entity)) {
301				spin_unlock(&rq->lock);
302				return ERR_PTR(-ENOSPC);
303			}
304
305			rq->current_entity = entity;
306			reinit_completion(&entity->entity_idle);
307			spin_unlock(&rq->lock);
308			return entity;
309		}
310
311		if (entity == rq->current_entity)
312			break;
313	}
314
315	spin_unlock(&rq->lock);
316
317	return NULL;
318}
319
320/**
321 * drm_sched_rq_select_entity_fifo - Select an entity which provides a job to run
322 *
323 * @sched: the gpu scheduler
324 * @rq: scheduler run queue to check.
325 *
326 * Find oldest waiting ready entity.
327 *
328 * Return an entity if one is found; return an error-pointer (!NULL) if an
329 * entity was ready, but the scheduler had insufficient credits to accommodate
330 * its job; return NULL, if no ready entity was found.
331 */
332static struct drm_sched_entity *
333drm_sched_rq_select_entity_fifo(struct drm_gpu_scheduler *sched,
334				struct drm_sched_rq *rq)
335{
336	struct rb_node *rb;
337
338	spin_lock(&rq->lock);
339	for (rb = rb_first_cached(&rq->rb_tree_root); rb; rb = rb_next(rb)) {
340		struct drm_sched_entity *entity;
341
342		entity = rb_entry(rb, struct drm_sched_entity, rb_tree_node);
343		if (drm_sched_entity_is_ready(entity)) {
344			/* If we can't queue yet, preserve the current entity in
345			 * terms of fairness.
346			 */
347			if (!drm_sched_can_queue(sched, entity)) {
348				spin_unlock(&rq->lock);
349				return ERR_PTR(-ENOSPC);
350			}
351
352			rq->current_entity = entity;
353			reinit_completion(&entity->entity_idle);
354			break;
355		}
356	}
357	spin_unlock(&rq->lock);
358
359	return rb ? rb_entry(rb, struct drm_sched_entity, rb_tree_node) : NULL;
360}
361
362/**
363 * drm_sched_run_job_queue - enqueue run-job work
364 * @sched: scheduler instance
365 */
366static void drm_sched_run_job_queue(struct drm_gpu_scheduler *sched)
367{
368	if (!READ_ONCE(sched->pause_submit))
369		queue_work(sched->submit_wq, &sched->work_run_job);
370}
371
372/**
373 * __drm_sched_run_free_queue - enqueue free-job work
374 * @sched: scheduler instance
375 */
376static void __drm_sched_run_free_queue(struct drm_gpu_scheduler *sched)
377{
378	if (!READ_ONCE(sched->pause_submit))
379		queue_work(sched->submit_wq, &sched->work_free_job);
380}
381
382/**
383 * drm_sched_run_free_queue - enqueue free-job work if ready
384 * @sched: scheduler instance
385 */
386static void drm_sched_run_free_queue(struct drm_gpu_scheduler *sched)
387{
388	struct drm_sched_job *job;
389
390	spin_lock(&sched->job_list_lock);
391	job = list_first_entry_or_null(&sched->pending_list,
392				       struct drm_sched_job, list);
393	if (job && dma_fence_is_signaled(&job->s_fence->finished))
394		__drm_sched_run_free_queue(sched);
395	spin_unlock(&sched->job_list_lock);
396}
397
398/**
399 * drm_sched_job_done - complete a job
400 * @s_job: pointer to the job which is done
401 *
402 * Finish the job's fence and wake up the worker thread.
403 */
404static void drm_sched_job_done(struct drm_sched_job *s_job, int result)
405{
406	struct drm_sched_fence *s_fence = s_job->s_fence;
407	struct drm_gpu_scheduler *sched = s_fence->sched;
408
409	atomic_sub(s_job->credits, &sched->credit_count);
410	atomic_dec(sched->score);
411
412	trace_drm_sched_process_job(s_fence);
413
414	dma_fence_get(&s_fence->finished);
415	drm_sched_fence_finished(s_fence, result);
416	dma_fence_put(&s_fence->finished);
417	__drm_sched_run_free_queue(sched);
418}
419
420/**
421 * drm_sched_job_done_cb - the callback for a done job
422 * @f: fence
423 * @cb: fence callbacks
424 */
425static void drm_sched_job_done_cb(struct dma_fence *f, struct dma_fence_cb *cb)
426{
427	struct drm_sched_job *s_job = container_of(cb, struct drm_sched_job, cb);
428
429	drm_sched_job_done(s_job, f->error);
430}
431
432/**
433 * drm_sched_start_timeout - start timeout for reset worker
434 *
435 * @sched: scheduler instance to start the worker for
436 *
437 * Start the timeout for the given scheduler.
438 */
439static void drm_sched_start_timeout(struct drm_gpu_scheduler *sched)
440{
441	lockdep_assert_held(&sched->job_list_lock);
442
443	if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
444	    !list_empty(&sched->pending_list))
445		mod_delayed_work(sched->timeout_wq, &sched->work_tdr, sched->timeout);
446}
447
448static void drm_sched_start_timeout_unlocked(struct drm_gpu_scheduler *sched)
449{
450	spin_lock(&sched->job_list_lock);
451	drm_sched_start_timeout(sched);
452	spin_unlock(&sched->job_list_lock);
453}
454
455/**
456 * drm_sched_tdr_queue_imm: - immediately start job timeout handler
457 *
458 * @sched: scheduler for which the timeout handling should be started.
459 *
460 * Start timeout handling immediately for the named scheduler.
461 */
462void drm_sched_tdr_queue_imm(struct drm_gpu_scheduler *sched)
463{
464	spin_lock(&sched->job_list_lock);
465	sched->timeout = 0;
466	drm_sched_start_timeout(sched);
467	spin_unlock(&sched->job_list_lock);
468}
469EXPORT_SYMBOL(drm_sched_tdr_queue_imm);
470
471/**
472 * drm_sched_fault - immediately start timeout handler
473 *
474 * @sched: scheduler where the timeout handling should be started.
475 *
476 * Start timeout handling immediately when the driver detects a hardware fault.
477 */
478void drm_sched_fault(struct drm_gpu_scheduler *sched)
479{
480	if (sched->timeout_wq)
481		mod_delayed_work(sched->timeout_wq, &sched->work_tdr, 0);
482}
483EXPORT_SYMBOL(drm_sched_fault);
484
485/**
486 * drm_sched_suspend_timeout - Suspend scheduler job timeout
487 *
488 * @sched: scheduler instance for which to suspend the timeout
489 *
490 * Suspend the delayed work timeout for the scheduler. This is done by
491 * modifying the delayed work timeout to an arbitrary large value,
492 * MAX_SCHEDULE_TIMEOUT in this case.
493 *
494 * Returns the timeout remaining
495 *
496 */
497unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched)
498{
499	unsigned long sched_timeout, now = jiffies;
500
501	sched_timeout = sched->work_tdr.timer.expires;
502
503	/*
504	 * Modify the timeout to an arbitrarily large value. This also prevents
505	 * the timeout to be restarted when new submissions arrive
506	 */
507	if (mod_delayed_work(sched->timeout_wq, &sched->work_tdr, MAX_SCHEDULE_TIMEOUT)
508			&& time_after(sched_timeout, now))
509		return sched_timeout - now;
510	else
511		return sched->timeout;
512}
513EXPORT_SYMBOL(drm_sched_suspend_timeout);
514
515/**
516 * drm_sched_resume_timeout - Resume scheduler job timeout
517 *
518 * @sched: scheduler instance for which to resume the timeout
519 * @remaining: remaining timeout
520 *
521 * Resume the delayed work timeout for the scheduler.
522 */
523void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
524		unsigned long remaining)
525{
526	spin_lock(&sched->job_list_lock);
527
528	if (list_empty(&sched->pending_list))
529		cancel_delayed_work(&sched->work_tdr);
530	else
531		mod_delayed_work(sched->timeout_wq, &sched->work_tdr, remaining);
532
533	spin_unlock(&sched->job_list_lock);
534}
535EXPORT_SYMBOL(drm_sched_resume_timeout);
536
537static void drm_sched_job_begin(struct drm_sched_job *s_job)
538{
539	struct drm_gpu_scheduler *sched = s_job->sched;
540
541	spin_lock(&sched->job_list_lock);
542	list_add_tail(&s_job->list, &sched->pending_list);
543	drm_sched_start_timeout(sched);
544	spin_unlock(&sched->job_list_lock);
545}
546
547static void drm_sched_job_timedout(struct work_struct *work)
548{
549	struct drm_gpu_scheduler *sched;
550	struct drm_sched_job *job;
551	enum drm_gpu_sched_stat status = DRM_GPU_SCHED_STAT_NOMINAL;
552
553	sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work);
554
555	/* Protects against concurrent deletion in drm_sched_get_finished_job */
556	spin_lock(&sched->job_list_lock);
557	job = list_first_entry_or_null(&sched->pending_list,
558				       struct drm_sched_job, list);
559
560	if (job) {
561		/*
562		 * Remove the bad job so it cannot be freed by concurrent
563		 * drm_sched_cleanup_jobs. It will be reinserted back after sched->thread
564		 * is parked at which point it's safe.
565		 */
566		list_del_init(&job->list);
567		spin_unlock(&sched->job_list_lock);
568
569		status = job->sched->ops->timedout_job(job);
570
571		/*
572		 * Guilty job did complete and hence needs to be manually removed
573		 * See drm_sched_stop doc.
574		 */
575		if (sched->free_guilty) {
576			job->sched->ops->free_job(job);
577			sched->free_guilty = false;
578		}
579	} else {
580		spin_unlock(&sched->job_list_lock);
581	}
582
583	if (status != DRM_GPU_SCHED_STAT_ENODEV)
584		drm_sched_start_timeout_unlocked(sched);
585}
586
587/**
588 * drm_sched_stop - stop the scheduler
589 *
590 * @sched: scheduler instance
591 * @bad: job which caused the time out
592 *
593 * Stop the scheduler and also removes and frees all completed jobs.
594 * Note: bad job will not be freed as it might be used later and so it's
595 * callers responsibility to release it manually if it's not part of the
596 * pending list any more.
597 *
598 */
599void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad)
600{
601	struct drm_sched_job *s_job, *tmp;
602
603	drm_sched_wqueue_stop(sched);
604
605	/*
606	 * Reinsert back the bad job here - now it's safe as
607	 * drm_sched_get_finished_job cannot race against us and release the
608	 * bad job at this point - we parked (waited for) any in progress
609	 * (earlier) cleanups and drm_sched_get_finished_job will not be called
610	 * now until the scheduler thread is unparked.
611	 */
612	if (bad && bad->sched == sched)
613		/*
614		 * Add at the head of the queue to reflect it was the earliest
615		 * job extracted.
616		 */
617		list_add(&bad->list, &sched->pending_list);
618
619	/*
620	 * Iterate the job list from later to  earlier one and either deactive
621	 * their HW callbacks or remove them from pending list if they already
622	 * signaled.
623	 * This iteration is thread safe as sched thread is stopped.
624	 */
625	list_for_each_entry_safe_reverse(s_job, tmp, &sched->pending_list,
626					 list) {
627		if (s_job->s_fence->parent &&
628		    dma_fence_remove_callback(s_job->s_fence->parent,
629					      &s_job->cb)) {
630			dma_fence_put(s_job->s_fence->parent);
631			s_job->s_fence->parent = NULL;
632			atomic_sub(s_job->credits, &sched->credit_count);
633		} else {
634			/*
635			 * remove job from pending_list.
636			 * Locking here is for concurrent resume timeout
637			 */
638			spin_lock(&sched->job_list_lock);
639			list_del_init(&s_job->list);
640			spin_unlock(&sched->job_list_lock);
641
642			/*
643			 * Wait for job's HW fence callback to finish using s_job
644			 * before releasing it.
645			 *
646			 * Job is still alive so fence refcount at least 1
647			 */
648			dma_fence_wait(&s_job->s_fence->finished, false);
649
650			/*
651			 * We must keep bad job alive for later use during
652			 * recovery by some of the drivers but leave a hint
653			 * that the guilty job must be released.
654			 */
655			if (bad != s_job)
656				sched->ops->free_job(s_job);
657			else
658				sched->free_guilty = true;
659		}
660	}
661
662	/*
663	 * Stop pending timer in flight as we rearm it in  drm_sched_start. This
664	 * avoids the pending timeout work in progress to fire right away after
665	 * this TDR finished and before the newly restarted jobs had a
666	 * chance to complete.
667	 */
668	cancel_delayed_work(&sched->work_tdr);
669}
670
671EXPORT_SYMBOL(drm_sched_stop);
672
673/**
674 * drm_sched_start - recover jobs after a reset
675 *
676 * @sched: scheduler instance
677 * @full_recovery: proceed with complete sched restart
678 *
679 */
680void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery)
681{
682	struct drm_sched_job *s_job, *tmp;
683	int r;
684
685	/*
686	 * Locking the list is not required here as the sched thread is parked
687	 * so no new jobs are being inserted or removed. Also concurrent
688	 * GPU recovers can't run in parallel.
689	 */
690	list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) {
691		struct dma_fence *fence = s_job->s_fence->parent;
692
693		atomic_add(s_job->credits, &sched->credit_count);
694
695		if (!full_recovery)
696			continue;
697
698		if (fence) {
699			r = dma_fence_add_callback(fence, &s_job->cb,
700						   drm_sched_job_done_cb);
701			if (r == -ENOENT)
702				drm_sched_job_done(s_job, fence->error);
703			else if (r)
704				DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n",
705					  r);
706		} else
707			drm_sched_job_done(s_job, -ECANCELED);
708	}
709
710	if (full_recovery)
711		drm_sched_start_timeout_unlocked(sched);
712
713	drm_sched_wqueue_start(sched);
714}
715EXPORT_SYMBOL(drm_sched_start);
716
717/**
718 * drm_sched_resubmit_jobs - Deprecated, don't use in new code!
719 *
720 * @sched: scheduler instance
721 *
722 * Re-submitting jobs was a concept AMD came up as cheap way to implement
723 * recovery after a job timeout.
724 *
725 * This turned out to be not working very well. First of all there are many
726 * problem with the dma_fence implementation and requirements. Either the
727 * implementation is risking deadlocks with core memory management or violating
728 * documented implementation details of the dma_fence object.
729 *
730 * Drivers can still save and restore their state for recovery operations, but
731 * we shouldn't make this a general scheduler feature around the dma_fence
732 * interface.
733 */
734void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched)
735{
736	struct drm_sched_job *s_job, *tmp;
737	uint64_t guilty_context;
738	bool found_guilty = false;
739	struct dma_fence *fence;
740
741	list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) {
742		struct drm_sched_fence *s_fence = s_job->s_fence;
743
744		if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) {
745			found_guilty = true;
746			guilty_context = s_job->s_fence->scheduled.context;
747		}
748
749		if (found_guilty && s_job->s_fence->scheduled.context == guilty_context)
750			dma_fence_set_error(&s_fence->finished, -ECANCELED);
751
752		fence = sched->ops->run_job(s_job);
753
754		if (IS_ERR_OR_NULL(fence)) {
755			if (IS_ERR(fence))
756				dma_fence_set_error(&s_fence->finished, PTR_ERR(fence));
757
758			s_job->s_fence->parent = NULL;
759		} else {
760
761			s_job->s_fence->parent = dma_fence_get(fence);
762
763			/* Drop for orignal kref_init */
764			dma_fence_put(fence);
765		}
766	}
767}
768EXPORT_SYMBOL(drm_sched_resubmit_jobs);
769
770/**
771 * drm_sched_job_init - init a scheduler job
772 * @job: scheduler job to init
773 * @entity: scheduler entity to use
774 * @credits: the number of credits this job contributes to the schedulers
775 * credit limit
776 * @owner: job owner for debugging
777 *
778 * Refer to drm_sched_entity_push_job() documentation
779 * for locking considerations.
780 *
781 * Drivers must make sure drm_sched_job_cleanup() if this function returns
782 * successfully, even when @job is aborted before drm_sched_job_arm() is called.
783 *
784 * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware
785 * has died, which can mean that there's no valid runqueue for a @entity.
786 * This function returns -ENOENT in this case (which probably should be -EIO as
787 * a more meanigful return value).
788 *
789 * Returns 0 for success, negative error code otherwise.
790 */
791int drm_sched_job_init(struct drm_sched_job *job,
792		       struct drm_sched_entity *entity,
793		       u32 credits, void *owner)
794{
795	if (!entity->rq) {
796		/* This will most likely be followed by missing frames
797		 * or worse--a blank screen--leave a trail in the
798		 * logs, so this can be debugged easier.
799		 */
800		drm_err(job->sched, "%s: entity has no rq!\n", __func__);
801		return -ENOENT;
802	}
803
804	if (unlikely(!credits)) {
805		pr_err("*ERROR* %s: credits cannot be 0!\n", __func__);
806		return -EINVAL;
807	}
808
809	job->entity = entity;
810	job->credits = credits;
811	job->s_fence = drm_sched_fence_alloc(entity, owner);
812	if (!job->s_fence)
813		return -ENOMEM;
814
815	INIT_LIST_HEAD(&job->list);
816
817	xa_init_flags(&job->dependencies, XA_FLAGS_ALLOC);
818
819	return 0;
820}
821EXPORT_SYMBOL(drm_sched_job_init);
822
823/**
824 * drm_sched_job_arm - arm a scheduler job for execution
825 * @job: scheduler job to arm
826 *
827 * This arms a scheduler job for execution. Specifically it initializes the
828 * &drm_sched_job.s_fence of @job, so that it can be attached to struct dma_resv
829 * or other places that need to track the completion of this job.
830 *
831 * Refer to drm_sched_entity_push_job() documentation for locking
832 * considerations.
833 *
834 * This can only be called if drm_sched_job_init() succeeded.
835 */
836void drm_sched_job_arm(struct drm_sched_job *job)
837{
838	struct drm_gpu_scheduler *sched;
839	struct drm_sched_entity *entity = job->entity;
840
841	BUG_ON(!entity);
842	drm_sched_entity_select_rq(entity);
843	sched = entity->rq->sched;
844
845	job->sched = sched;
846	job->s_priority = entity->priority;
847	job->id = atomic64_inc_return(&sched->job_id_count);
848
849	drm_sched_fence_init(job->s_fence, job->entity);
850}
851EXPORT_SYMBOL(drm_sched_job_arm);
852
853/**
854 * drm_sched_job_add_dependency - adds the fence as a job dependency
855 * @job: scheduler job to add the dependencies to
856 * @fence: the dma_fence to add to the list of dependencies.
857 *
858 * Note that @fence is consumed in both the success and error cases.
859 *
860 * Returns:
861 * 0 on success, or an error on failing to expand the array.
862 */
863int drm_sched_job_add_dependency(struct drm_sched_job *job,
864				 struct dma_fence *fence)
865{
866	struct dma_fence *entry;
867	unsigned long index;
868	u32 id = 0;
869	int ret;
870
871	if (!fence)
872		return 0;
873
874	/* Deduplicate if we already depend on a fence from the same context.
875	 * This lets the size of the array of deps scale with the number of
876	 * engines involved, rather than the number of BOs.
877	 */
878	xa_for_each(&job->dependencies, index, entry) {
879		if (entry->context != fence->context)
880			continue;
881
882		if (dma_fence_is_later(fence, entry)) {
883			dma_fence_put(entry);
884			xa_store(&job->dependencies, index, fence, GFP_KERNEL);
885		} else {
886			dma_fence_put(fence);
887		}
888		return 0;
889	}
890
891	ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b, GFP_KERNEL);
892	if (ret != 0)
893		dma_fence_put(fence);
894
895	return ret;
896}
897EXPORT_SYMBOL(drm_sched_job_add_dependency);
898
899/**
900 * drm_sched_job_add_syncobj_dependency - adds a syncobj's fence as a job dependency
901 * @job: scheduler job to add the dependencies to
902 * @file: drm file private pointer
903 * @handle: syncobj handle to lookup
904 * @point: timeline point
905 *
906 * This adds the fence matching the given syncobj to @job.
907 *
908 * Returns:
909 * 0 on success, or an error on failing to expand the array.
910 */
911int drm_sched_job_add_syncobj_dependency(struct drm_sched_job *job,
912					 struct drm_file *file,
913					 u32 handle,
914					 u32 point)
915{
916	struct dma_fence *fence;
917	int ret;
918
919	ret = drm_syncobj_find_fence(file, handle, point, 0, &fence);
920	if (ret)
921		return ret;
922
923	return drm_sched_job_add_dependency(job, fence);
924}
925EXPORT_SYMBOL(drm_sched_job_add_syncobj_dependency);
926
927/**
928 * drm_sched_job_add_resv_dependencies - add all fences from the resv to the job
929 * @job: scheduler job to add the dependencies to
930 * @resv: the dma_resv object to get the fences from
931 * @usage: the dma_resv_usage to use to filter the fences
932 *
933 * This adds all fences matching the given usage from @resv to @job.
934 * Must be called with the @resv lock held.
935 *
936 * Returns:
937 * 0 on success, or an error on failing to expand the array.
938 */
939int drm_sched_job_add_resv_dependencies(struct drm_sched_job *job,
940					struct dma_resv *resv,
941					enum dma_resv_usage usage)
942{
943	struct dma_resv_iter cursor;
944	struct dma_fence *fence;
945	int ret;
946
947	dma_resv_assert_held(resv);
948
949	dma_resv_for_each_fence(&cursor, resv, usage, fence) {
950		/* Make sure to grab an additional ref on the added fence */
951		dma_fence_get(fence);
952		ret = drm_sched_job_add_dependency(job, fence);
953		if (ret) {
954			dma_fence_put(fence);
955			return ret;
956		}
957	}
958	return 0;
959}
960EXPORT_SYMBOL(drm_sched_job_add_resv_dependencies);
961
962/**
963 * drm_sched_job_add_implicit_dependencies - adds implicit dependencies as job
964 *   dependencies
965 * @job: scheduler job to add the dependencies to
966 * @obj: the gem object to add new dependencies from.
967 * @write: whether the job might write the object (so we need to depend on
968 * shared fences in the reservation object).
969 *
970 * This should be called after drm_gem_lock_reservations() on your array of
971 * GEM objects used in the job but before updating the reservations with your
972 * own fences.
973 *
974 * Returns:
975 * 0 on success, or an error on failing to expand the array.
976 */
977int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job,
978					    struct drm_gem_object *obj,
979					    bool write)
980{
981	return drm_sched_job_add_resv_dependencies(job, obj->resv,
982						   dma_resv_usage_rw(write));
983}
984EXPORT_SYMBOL(drm_sched_job_add_implicit_dependencies);
985
986/**
987 * drm_sched_job_cleanup - clean up scheduler job resources
988 * @job: scheduler job to clean up
989 *
990 * Cleans up the resources allocated with drm_sched_job_init().
991 *
992 * Drivers should call this from their error unwind code if @job is aborted
993 * before drm_sched_job_arm() is called.
994 *
995 * After that point of no return @job is committed to be executed by the
996 * scheduler, and this function should be called from the
997 * &drm_sched_backend_ops.free_job callback.
998 */
999void drm_sched_job_cleanup(struct drm_sched_job *job)
1000{
1001	struct dma_fence *fence;
1002	unsigned long index;
1003
1004	if (kref_read(&job->s_fence->finished.refcount)) {
1005		/* drm_sched_job_arm() has been called */
1006		dma_fence_put(&job->s_fence->finished);
1007	} else {
1008		/* aborted job before committing to run it */
1009		drm_sched_fence_free(job->s_fence);
1010	}
1011
1012	job->s_fence = NULL;
1013
1014	xa_for_each(&job->dependencies, index, fence) {
1015		dma_fence_put(fence);
1016	}
1017	xa_destroy(&job->dependencies);
1018
1019}
1020EXPORT_SYMBOL(drm_sched_job_cleanup);
1021
1022/**
1023 * drm_sched_wakeup - Wake up the scheduler if it is ready to queue
1024 * @sched: scheduler instance
1025 * @entity: the scheduler entity
1026 *
1027 * Wake up the scheduler if we can queue jobs.
1028 */
1029void drm_sched_wakeup(struct drm_gpu_scheduler *sched,
1030		      struct drm_sched_entity *entity)
1031{
1032	if (drm_sched_can_queue(sched, entity))
1033		drm_sched_run_job_queue(sched);
1034}
1035
1036/**
1037 * drm_sched_select_entity - Select next entity to process
1038 *
1039 * @sched: scheduler instance
1040 *
1041 * Return an entity to process or NULL if none are found.
1042 *
1043 * Note, that we break out of the for-loop when "entity" is non-null, which can
1044 * also be an error-pointer--this assures we don't process lower priority
1045 * run-queues. See comments in the respectively called functions.
1046 */
1047static struct drm_sched_entity *
1048drm_sched_select_entity(struct drm_gpu_scheduler *sched)
1049{
1050	struct drm_sched_entity *entity;
1051	int i;
1052
1053	/* Start with the highest priority.
1054	 */
1055	for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) {
1056		entity = drm_sched_policy == DRM_SCHED_POLICY_FIFO ?
1057			drm_sched_rq_select_entity_fifo(sched, sched->sched_rq[i]) :
1058			drm_sched_rq_select_entity_rr(sched, sched->sched_rq[i]);
1059		if (entity)
1060			break;
1061	}
1062
1063	return IS_ERR(entity) ? NULL : entity;
1064}
1065
1066/**
1067 * drm_sched_get_finished_job - fetch the next finished job to be destroyed
1068 *
1069 * @sched: scheduler instance
1070 *
1071 * Returns the next finished job from the pending list (if there is one)
1072 * ready for it to be destroyed.
1073 */
1074static struct drm_sched_job *
1075drm_sched_get_finished_job(struct drm_gpu_scheduler *sched)
1076{
1077	struct drm_sched_job *job, *next;
1078
1079	spin_lock(&sched->job_list_lock);
1080
1081	job = list_first_entry_or_null(&sched->pending_list,
1082				       struct drm_sched_job, list);
1083
1084	if (job && dma_fence_is_signaled(&job->s_fence->finished)) {
1085		/* remove job from pending_list */
1086		list_del_init(&job->list);
1087
1088		/* cancel this job's TO timer */
1089		cancel_delayed_work(&sched->work_tdr);
1090		/* make the scheduled timestamp more accurate */
1091		next = list_first_entry_or_null(&sched->pending_list,
1092						typeof(*next), list);
1093
1094		if (next) {
1095			if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT,
1096				     &next->s_fence->scheduled.flags))
1097				next->s_fence->scheduled.timestamp =
1098					dma_fence_timestamp(&job->s_fence->finished);
1099			/* start TO timer for next job */
1100			drm_sched_start_timeout(sched);
1101		}
1102	} else {
1103		job = NULL;
1104	}
1105
1106	spin_unlock(&sched->job_list_lock);
1107
1108	return job;
1109}
1110
1111/**
1112 * drm_sched_pick_best - Get a drm sched from a sched_list with the least load
1113 * @sched_list: list of drm_gpu_schedulers
1114 * @num_sched_list: number of drm_gpu_schedulers in the sched_list
1115 *
1116 * Returns pointer of the sched with the least load or NULL if none of the
1117 * drm_gpu_schedulers are ready
1118 */
1119struct drm_gpu_scheduler *
1120drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
1121		     unsigned int num_sched_list)
1122{
1123	struct drm_gpu_scheduler *sched, *picked_sched = NULL;
1124	int i;
1125	unsigned int min_score = UINT_MAX, num_score;
1126
1127	for (i = 0; i < num_sched_list; ++i) {
1128		sched = sched_list[i];
1129
1130		if (!sched->ready) {
1131			DRM_WARN("scheduler %s is not ready, skipping",
1132				 sched->name);
1133			continue;
1134		}
1135
1136		num_score = atomic_read(sched->score);
1137		if (num_score < min_score) {
1138			min_score = num_score;
1139			picked_sched = sched;
1140		}
1141	}
1142
1143	return picked_sched;
1144}
1145EXPORT_SYMBOL(drm_sched_pick_best);
1146
1147/**
1148 * drm_sched_free_job_work - worker to call free_job
1149 *
1150 * @w: free job work
1151 */
1152static void drm_sched_free_job_work(struct work_struct *w)
1153{
1154	struct drm_gpu_scheduler *sched =
1155		container_of(w, struct drm_gpu_scheduler, work_free_job);
1156	struct drm_sched_job *job;
1157
1158	if (READ_ONCE(sched->pause_submit))
1159		return;
1160
1161	job = drm_sched_get_finished_job(sched);
1162	if (job)
1163		sched->ops->free_job(job);
1164
1165	drm_sched_run_free_queue(sched);
1166	drm_sched_run_job_queue(sched);
1167}
1168
1169/**
1170 * drm_sched_run_job_work - worker to call run_job
1171 *
1172 * @w: run job work
1173 */
1174static void drm_sched_run_job_work(struct work_struct *w)
1175{
1176	struct drm_gpu_scheduler *sched =
1177		container_of(w, struct drm_gpu_scheduler, work_run_job);
1178	struct drm_sched_entity *entity;
1179	struct dma_fence *fence;
1180	struct drm_sched_fence *s_fence;
1181	struct drm_sched_job *sched_job;
1182	int r;
1183
1184	if (READ_ONCE(sched->pause_submit))
1185		return;
1186
1187	/* Find entity with a ready job */
1188	entity = drm_sched_select_entity(sched);
1189	if (!entity)
1190		return;	/* No more work */
1191
1192	sched_job = drm_sched_entity_pop_job(entity);
1193	if (!sched_job) {
1194		complete_all(&entity->entity_idle);
1195		drm_sched_run_job_queue(sched);
1196		return;
1197	}
1198
1199	s_fence = sched_job->s_fence;
1200
1201	atomic_add(sched_job->credits, &sched->credit_count);
1202	drm_sched_job_begin(sched_job);
1203
1204	trace_drm_run_job(sched_job, entity);
1205	fence = sched->ops->run_job(sched_job);
1206	complete_all(&entity->entity_idle);
1207	drm_sched_fence_scheduled(s_fence, fence);
1208
1209	if (!IS_ERR_OR_NULL(fence)) {
1210		/* Drop for original kref_init of the fence */
1211		dma_fence_put(fence);
1212
1213		r = dma_fence_add_callback(fence, &sched_job->cb,
1214					   drm_sched_job_done_cb);
1215		if (r == -ENOENT)
1216			drm_sched_job_done(sched_job, fence->error);
1217		else if (r)
1218			DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n", r);
1219	} else {
1220		drm_sched_job_done(sched_job, IS_ERR(fence) ?
1221				   PTR_ERR(fence) : 0);
1222	}
1223
1224	wake_up(&sched->job_scheduled);
1225	drm_sched_run_job_queue(sched);
1226}
1227
1228/**
1229 * drm_sched_init - Init a gpu scheduler instance
1230 *
1231 * @sched: scheduler instance
1232 * @ops: backend operations for this scheduler
1233 * @submit_wq: workqueue to use for submission. If NULL, an ordered wq is
1234 *	       allocated and used
1235 * @num_rqs: number of runqueues, one for each priority, up to DRM_SCHED_PRIORITY_COUNT
1236 * @credit_limit: the number of credits this scheduler can hold from all jobs
1237 * @hang_limit: number of times to allow a job to hang before dropping it
1238 * @timeout: timeout value in jiffies for the scheduler
1239 * @timeout_wq: workqueue to use for timeout work. If NULL, the system_wq is
1240 *		used
1241 * @score: optional score atomic shared with other schedulers
1242 * @name: name used for debugging
1243 * @dev: target &struct device
1244 *
1245 * Return 0 on success, otherwise error code.
1246 */
1247int drm_sched_init(struct drm_gpu_scheduler *sched,
1248		   const struct drm_sched_backend_ops *ops,
1249		   struct workqueue_struct *submit_wq,
1250		   u32 num_rqs, u32 credit_limit, unsigned int hang_limit,
1251		   long timeout, struct workqueue_struct *timeout_wq,
1252		   atomic_t *score, const char *name, struct device *dev)
1253{
1254	int i;
1255
1256	sched->ops = ops;
1257	sched->credit_limit = credit_limit;
1258	sched->name = name;
1259	sched->timeout = timeout;
1260	sched->timeout_wq = timeout_wq ? : system_wq;
1261	sched->hang_limit = hang_limit;
1262	sched->score = score ? score : &sched->_score;
1263	sched->dev = dev;
1264
1265	if (num_rqs > DRM_SCHED_PRIORITY_COUNT) {
1266		/* This is a gross violation--tell drivers what the  problem is.
1267		 */
1268		drm_err(sched, "%s: num_rqs cannot be greater than DRM_SCHED_PRIORITY_COUNT\n",
1269			__func__);
1270		return -EINVAL;
1271	} else if (sched->sched_rq) {
1272		/* Not an error, but warn anyway so drivers can
1273		 * fine-tune their DRM calling order, and return all
1274		 * is good.
1275		 */
1276		drm_warn(sched, "%s: scheduler already initialized!\n", __func__);
1277		return 0;
1278	}
1279
1280	if (submit_wq) {
1281		sched->submit_wq = submit_wq;
1282		sched->own_submit_wq = false;
1283	} else {
1284		sched->submit_wq = alloc_ordered_workqueue(name, 0);
1285		if (!sched->submit_wq)
1286			return -ENOMEM;
1287
1288		sched->own_submit_wq = true;
1289	}
1290
1291	sched->sched_rq = kmalloc_array(num_rqs, sizeof(*sched->sched_rq),
1292					GFP_KERNEL | __GFP_ZERO);
1293	if (!sched->sched_rq)
1294		goto Out_check_own;
1295	sched->num_rqs = num_rqs;
1296	for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) {
1297		sched->sched_rq[i] = kzalloc(sizeof(*sched->sched_rq[i]), GFP_KERNEL);
1298		if (!sched->sched_rq[i])
1299			goto Out_unroll;
1300		drm_sched_rq_init(sched, sched->sched_rq[i]);
1301	}
1302
1303	init_waitqueue_head(&sched->job_scheduled);
1304	INIT_LIST_HEAD(&sched->pending_list);
1305	spin_lock_init(&sched->job_list_lock);
1306	atomic_set(&sched->credit_count, 0);
1307	INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout);
1308	INIT_WORK(&sched->work_run_job, drm_sched_run_job_work);
1309	INIT_WORK(&sched->work_free_job, drm_sched_free_job_work);
1310	atomic_set(&sched->_score, 0);
1311	atomic64_set(&sched->job_id_count, 0);
1312	sched->pause_submit = false;
1313
1314	sched->ready = true;
1315	return 0;
1316Out_unroll:
1317	for (--i ; i >= DRM_SCHED_PRIORITY_KERNEL; i--)
1318		kfree(sched->sched_rq[i]);
1319
1320	kfree(sched->sched_rq);
1321	sched->sched_rq = NULL;
1322Out_check_own:
1323	if (sched->own_submit_wq)
1324		destroy_workqueue(sched->submit_wq);
1325	drm_err(sched, "%s: Failed to setup GPU scheduler--out of memory\n", __func__);
1326	return -ENOMEM;
1327}
1328EXPORT_SYMBOL(drm_sched_init);
1329
1330/**
1331 * drm_sched_fini - Destroy a gpu scheduler
1332 *
1333 * @sched: scheduler instance
1334 *
1335 * Tears down and cleans up the scheduler.
1336 */
1337void drm_sched_fini(struct drm_gpu_scheduler *sched)
1338{
1339	struct drm_sched_entity *s_entity;
1340	int i;
1341
1342	drm_sched_wqueue_stop(sched);
1343
1344	for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) {
1345		struct drm_sched_rq *rq = sched->sched_rq[i];
1346
1347		spin_lock(&rq->lock);
1348		list_for_each_entry(s_entity, &rq->entities, list)
1349			/*
1350			 * Prevents reinsertion and marks job_queue as idle,
1351			 * it will removed from rq in drm_sched_entity_fini
1352			 * eventually
1353			 */
1354			s_entity->stopped = true;
1355		spin_unlock(&rq->lock);
1356		kfree(sched->sched_rq[i]);
1357	}
1358
1359	/* Wakeup everyone stuck in drm_sched_entity_flush for this scheduler */
1360	wake_up_all(&sched->job_scheduled);
1361
1362	/* Confirm no work left behind accessing device structures */
1363	cancel_delayed_work_sync(&sched->work_tdr);
1364
1365	if (sched->own_submit_wq)
1366		destroy_workqueue(sched->submit_wq);
1367	sched->ready = false;
1368	kfree(sched->sched_rq);
1369	sched->sched_rq = NULL;
1370}
1371EXPORT_SYMBOL(drm_sched_fini);
1372
1373/**
1374 * drm_sched_increase_karma - Update sched_entity guilty flag
1375 *
1376 * @bad: The job guilty of time out
1377 *
1378 * Increment on every hang caused by the 'bad' job. If this exceeds the hang
1379 * limit of the scheduler then the respective sched entity is marked guilty and
1380 * jobs from it will not be scheduled further
1381 */
1382void drm_sched_increase_karma(struct drm_sched_job *bad)
1383{
1384	int i;
1385	struct drm_sched_entity *tmp;
1386	struct drm_sched_entity *entity;
1387	struct drm_gpu_scheduler *sched = bad->sched;
1388
1389	/* don't change @bad's karma if it's from KERNEL RQ,
1390	 * because sometimes GPU hang would cause kernel jobs (like VM updating jobs)
1391	 * corrupt but keep in mind that kernel jobs always considered good.
1392	 */
1393	if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) {
1394		atomic_inc(&bad->karma);
1395
1396		for (i = DRM_SCHED_PRIORITY_HIGH; i < sched->num_rqs; i++) {
1397			struct drm_sched_rq *rq = sched->sched_rq[i];
1398
1399			spin_lock(&rq->lock);
1400			list_for_each_entry_safe(entity, tmp, &rq->entities, list) {
1401				if (bad->s_fence->scheduled.context ==
1402				    entity->fence_context) {
1403					if (entity->guilty)
1404						atomic_set(entity->guilty, 1);
1405					break;
1406				}
1407			}
1408			spin_unlock(&rq->lock);
1409			if (&entity->list != &rq->entities)
1410				break;
1411		}
1412	}
1413}
1414EXPORT_SYMBOL(drm_sched_increase_karma);
1415
1416/**
1417 * drm_sched_wqueue_ready - Is the scheduler ready for submission
1418 *
1419 * @sched: scheduler instance
1420 *
1421 * Returns true if submission is ready
1422 */
1423bool drm_sched_wqueue_ready(struct drm_gpu_scheduler *sched)
1424{
1425	return sched->ready;
1426}
1427EXPORT_SYMBOL(drm_sched_wqueue_ready);
1428
1429/**
1430 * drm_sched_wqueue_stop - stop scheduler submission
1431 *
1432 * @sched: scheduler instance
1433 */
1434void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched)
1435{
1436	WRITE_ONCE(sched->pause_submit, true);
1437	cancel_work_sync(&sched->work_run_job);
1438	cancel_work_sync(&sched->work_free_job);
1439}
1440EXPORT_SYMBOL(drm_sched_wqueue_stop);
1441
1442/**
1443 * drm_sched_wqueue_start - start scheduler submission
1444 *
1445 * @sched: scheduler instance
1446 */
1447void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched)
1448{
1449	WRITE_ONCE(sched->pause_submit, false);
1450	queue_work(sched->submit_wq, &sched->work_run_job);
1451	queue_work(sched->submit_wq, &sched->work_free_job);
1452}
1453EXPORT_SYMBOL(drm_sched_wqueue_start);
1454