summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/scheduler/sched_entity.c
blob: e2942c9a11a7aeccb6710cdb7890cc56e1558d73 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
/*
 * Copyright 2015 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <linux/kthread.h>
#include <drm/gpu_scheduler.h>

#include "gpu_scheduler_trace.h"

#define to_drm_sched_job(sched_job)		\
		container_of((sched_job), struct drm_sched_job, queue_node)

/**
 * drm_sched_entity_init - Init a context entity used by scheduler when
 * submit to HW ring.
 *
 * @entity: scheduler entity to init
 * @rq_list: the list of run queue on which jobs from this
 *           entity can be submitted
 * @num_rq_list: number of run queue in rq_list
 * @guilty: atomic_t set to 1 when a job on this queue
 *          is found to be guilty causing a timeout
 *
 * Note: the rq_list should have atleast one element to schedule
 *       the entity
 *
 * Returns 0 on success or a negative error code on failure.
 */
int drm_sched_entity_init(struct drm_sched_entity *entity,
			  struct drm_sched_rq **rq_list,
			  unsigned int num_rq_list,
			  atomic_t *guilty)
{
	int i;

	if (!(entity && rq_list && num_rq_list > 0 && rq_list[0]))
		return -EINVAL;

	memset(entity, 0, sizeof(struct drm_sched_entity));
	INIT_LIST_HEAD(&entity->list);
	entity->rq = rq_list[0];
	entity->guilty = guilty;
	entity->num_rq_list = num_rq_list;
	entity->rq_list = kcalloc(num_rq_list, sizeof(struct drm_sched_rq *),
				GFP_KERNEL);
	if (!entity->rq_list)
		return -ENOMEM;

	for (i = 0; i < num_rq_list; ++i)
		entity->rq_list[i] = rq_list[i];
	entity->last_scheduled = NULL;

	spin_lock_init(&entity->rq_lock);
	spsc_queue_init(&entity->job_queue);

	atomic_set(&entity->fence_seq, 0);
	entity->fence_context = dma_fence_context_alloc(2);

	return 0;
}
EXPORT_SYMBOL(drm_sched_entity_init);

/**
 * drm_sched_entity_is_idle - Check if entity is idle
 *
 * @entity: scheduler entity
 *
 * Returns true if the entity does not have any unscheduled jobs.
 */
static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
{
	rmb(); /* for list_empty to work without lock */

	if (list_empty(&entity->list) ||
	    spsc_queue_peek(&entity->job_queue) == NULL)
		return true;

	return false;
}

/**
 * drm_sched_entity_is_ready - Check if entity is ready
 *
 * @entity: scheduler entity
 *
 * Return true if entity could provide a job.
 */
bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
{
	if (spsc_queue_peek(&entity->job_queue) == NULL)
		return false;

	if (READ_ONCE(entity->dependency))
		return false;

	return true;
}

/**
 * drm_sched_entity_get_free_sched - Get the rq from rq_list with least load
 *
 * @entity: scheduler entity
 *
 * Return the pointer to the rq with least load.
 */
static struct drm_sched_rq *
drm_sched_entity_get_free_sched(struct drm_sched_entity *entity)
{
	struct drm_sched_rq *rq = NULL;
	unsigned int min_jobs = UINT_MAX, num_jobs;
	int i;

	for (i = 0; i < entity->num_rq_list; ++i) {
		struct drm_gpu_scheduler *sched = entity->rq_list[i]->sched;

		if (!entity->rq_list[i]->sched->ready) {
			DRM_WARN("sched%s is not ready, skipping", sched->name);
			continue;
		}

		num_jobs = atomic_read(&sched->num_jobs);
		if (num_jobs < min_jobs) {
			min_jobs = num_jobs;
			rq = entity->rq_list[i];
		}
	}

	return rq;
}

/**
 * drm_sched_entity_flush - Flush a context entity
 *
 * @entity: scheduler entity
 * @timeout: time to wait in for Q to become empty in jiffies.
 *
 * Splitting drm_sched_entity_fini() into two functions, The first one does the
 * waiting, removes the entity from the runqueue and returns an error when the
 * process was killed.
 *
 * Returns the remaining time in jiffies left from the input timeout
 */
long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
{
	struct drm_gpu_scheduler *sched;
	struct task_struct *last_user;
	long ret = timeout;

	sched = entity->rq->sched;
	/**
	 * The client will not queue more IBs during this fini, consume existing
	 * queued IBs or discard them on SIGKILL
	 */
	if (current->flags & PF_EXITING) {
		if (timeout)
			ret = wait_event_timeout(
					sched->job_scheduled,
					drm_sched_entity_is_idle(entity),
					timeout);
	} else {
		wait_event_killable(sched->job_scheduled,
				    drm_sched_entity_is_idle(entity));
	}

	/* For killed process disable any more IBs enqueue right now */
	last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
	if ((!last_user || last_user == current->group_leader) &&
	    (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) {
		spin_lock(&entity->rq_lock);
		entity->stopped = true;
		drm_sched_rq_remove_entity(entity->rq, entity);
		spin_unlock(&entity->rq_lock);
	}

	return ret;
}
EXPORT_SYMBOL(drm_sched_entity_flush);

/**
 * drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
 *
 * @f: signaled fence
 * @cb: our callback structure
 *
 * Signal the scheduler finished fence when the entity in question is killed.
 */
static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
					  struct dma_fence_cb *cb)
{
	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
						 finish_cb);

	drm_sched_fence_finished(job->s_fence);
	WARN_ON(job->s_fence->parent);
	job->sched->ops->free_job(job);
}

/**
 * drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
 *
 * @entity: entity which is cleaned up
 *
 * Makes sure that all remaining jobs in an entity are killed before it is
 * destroyed.
 */
static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
{
	struct drm_sched_job *job;
	int r;

	while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
		struct drm_sched_fence *s_fence = job->s_fence;

		drm_sched_fence_scheduled(s_fence);
		dma_fence_set_error(&s_fence->finished, -ESRCH);

		/*
		 * When pipe is hanged by older entity, new entity might
		 * not even have chance to submit it's first job to HW
		 * and so entity->last_scheduled will remain NULL
		 */
		if (!entity->last_scheduled) {
			drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
			continue;
		}

		r = dma_fence_add_callback(entity->last_scheduled,
					   &job->finish_cb,
					   drm_sched_entity_kill_jobs_cb);
		if (r == -ENOENT)
			drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
		else if (r)
			DRM_ERROR("fence add callback failed (%d)\n", r);
	}
}

/**
 * drm_sched_entity_cleanup - Destroy a context entity
 *
 * @entity: scheduler entity
 *
 * This should be called after @drm_sched_entity_do_release. It goes over the
 * entity and signals all jobs with an error code if the process was killed.
 *
 */
void drm_sched_entity_fini(struct drm_sched_entity *entity)
{
	struct drm_gpu_scheduler *sched;

	sched = entity->rq->sched;
	drm_sched_rq_remove_entity(entity->rq, entity);

	/* Consumption of existing IBs wasn't completed. Forcefully
	 * remove them here.
	 */
	if (spsc_queue_peek(&entity->job_queue)) {
		/* Park the kernel for a moment to make sure it isn't processing
		 * our enity.
		 */
		kthread_park(sched->thread);
		kthread_unpark(sched->thread);
		if (entity->dependency) {
			dma_fence_remove_callback(entity->dependency,
						  &entity->cb);
			dma_fence_put(entity->dependency);
			entity->dependency = NULL;
		}

		drm_sched_entity_kill_jobs(entity);
	}

	dma_fence_put(entity->last_scheduled);
	entity->last_scheduled = NULL;
	kfree(entity->rq_list);
}
EXPORT_SYMBOL(drm_sched_entity_fini);

/**
 * drm_sched_entity_fini - Destroy a context entity
 *
 * @entity: scheduler entity
 *
 * Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup()
 */
void drm_sched_entity_destroy(struct drm_sched_entity *entity)
{
	drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
	drm_sched_entity_fini(entity);
}
EXPORT_SYMBOL(drm_sched_entity_destroy);

/**
 * drm_sched_entity_clear_dep - callback to clear the entities dependency
 */
static void drm_sched_entity_clear_dep(struct dma_fence *f,
				       struct dma_fence_cb *cb)
{
	struct drm_sched_entity *entity =
		container_of(cb, struct drm_sched_entity, cb);

	entity->dependency = NULL;
	dma_fence_put(f);
}

/**
 * drm_sched_entity_clear_dep - callback to clear the entities dependency and
 * wake up scheduler
 */
static void drm_sched_entity_wakeup(struct dma_fence *f,
				    struct dma_fence_cb *cb)
{
	struct drm_sched_entity *entity =
		container_of(cb, struct drm_sched_entity, cb);

	drm_sched_entity_clear_dep(f, cb);
	drm_sched_wakeup(entity->rq->sched);
}

/**
 * drm_sched_entity_set_rq_priority - helper for drm_sched_entity_set_priority
 */
static void drm_sched_entity_set_rq_priority(struct drm_sched_rq **rq,
					     enum drm_sched_priority priority)
{
	*rq = &(*rq)->sched->sched_rq[priority];
}

/**
 * drm_sched_entity_set_priority - Sets priority of the entity
 *
 * @entity: scheduler entity
 * @priority: scheduler priority
 *
 * Update the priority of runqueus used for the entity.
 */
void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
				   enum drm_sched_priority priority)
{
	unsigned int i;

	spin_lock(&entity->rq_lock);

	for (i = 0; i < entity->num_rq_list; ++i)
		drm_sched_entity_set_rq_priority(&entity->rq_list[i], priority);

	drm_sched_rq_remove_entity(entity->rq, entity);
	drm_sched_entity_set_rq_priority(&entity->rq, priority);
	drm_sched_rq_add_entity(entity->rq, entity);

	spin_unlock(&entity->rq_lock);
}
EXPORT_SYMBOL(drm_sched_entity_set_priority);

/**
 * drm_sched_entity_add_dependency_cb - add callback for the entities dependency
 *
 * @entity: entity with dependency
 *
 * Add a callback to the current dependency of the entity to wake up the
 * scheduler when the entity becomes available.
 */
static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
{
	struct drm_gpu_scheduler *sched = entity->rq->sched;
	struct dma_fence *fence = entity->dependency;
	struct drm_sched_fence *s_fence;

	if (fence->context == entity->fence_context ||
	    fence->context == entity->fence_context + 1) {
		/*
		 * Fence is a scheduled/finished fence from a job
		 * which belongs to the same entity, we can ignore
		 * fences from ourself
		 */
		dma_fence_put(entity->dependency);
		return false;
	}

	s_fence = to_drm_sched_fence(fence);
	if (s_fence && s_fence->sched == sched) {

		/*
		 * Fence is from the same scheduler, only need to wait for
		 * it to be scheduled
		 */
		fence = dma_fence_get(&s_fence->scheduled);
		dma_fence_put(entity->dependency);
		entity->dependency = fence;
		if (!dma_fence_add_callback(fence, &entity->cb,
					    drm_sched_entity_clear_dep))
			return true;

		/* Ignore it when it is already scheduled */
		dma_fence_put(fence);
		return false;
	}

	if (!dma_fence_add_callback(entity->dependency, &entity->cb,
				    drm_sched_entity_wakeup))
		return true;

	dma_fence_put(entity->dependency);
	return false;
}

/**
 * drm_sched_entity_pop_job - get a ready to be scheduled job from the entity
 *
 * @entity: entity to get the job from
 *
 * Process all dependencies and try to get one job from the entities queue.
 */
struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
{
	struct drm_gpu_scheduler *sched = entity->rq->sched;
	struct drm_sched_job *sched_job;

	sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
	if (!sched_job)
		return NULL;

	while ((entity->dependency =
			sched->ops->dependency(sched_job, entity))) {
		trace_drm_sched_job_wait_dep(sched_job, entity->dependency);

		if (drm_sched_entity_add_dependency_cb(entity))
			return NULL;
	}

	/* skip jobs from entity that marked guilty */
	if (entity->guilty && atomic_read(entity->guilty))
		dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);

	dma_fence_put(entity->last_scheduled);
	entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);

	spsc_queue_pop(&entity->job_queue);
	return sched_job;
}

/**
 * drm_sched_entity_select_rq - select a new rq for the entity
 *
 * @entity: scheduler entity
 *
 * Check all prerequisites and select a new rq for the entity for load
 * balancing.
 */
void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
{
	struct dma_fence *fence;
	struct drm_sched_rq *rq;

	if (spsc_queue_count(&entity->job_queue) || entity->num_rq_list <= 1)
		return;

	fence = READ_ONCE(entity->last_scheduled);
	if (fence && !dma_fence_is_signaled(fence))
		return;

	rq = drm_sched_entity_get_free_sched(entity);
	if (rq == entity->rq)
		return;

	spin_lock(&entity->rq_lock);
	drm_sched_rq_remove_entity(entity->rq, entity);
	entity->rq = rq;
	spin_unlock(&entity->rq_lock);
}

/**
 * drm_sched_entity_push_job - Submit a job to the entity's job queue
 *
 * @sched_job: job to submit
 * @entity: scheduler entity
 *
 * Note: To guarantee that the order of insertion to queue matches
 * the job's fence sequence number this function should be
 * called with drm_sched_job_init under common lock.
 *
 * Returns 0 for success, negative error code otherwise.
 */
void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
			       struct drm_sched_entity *entity)
{
	bool first;

	trace_drm_sched_job(sched_job, entity);
	atomic_inc(&entity->rq->sched->num_jobs);
	WRITE_ONCE(entity->last_user, current->group_leader);
	first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);

	/* first job wakes up scheduler */
	if (first) {
		/* Add the entity to the run queue */
		spin_lock(&entity->rq_lock);
		if (entity->stopped) {
			spin_unlock(&entity->rq_lock);

			DRM_ERROR("Trying to push to a killed entity\n");
			return;
		}
		drm_sched_rq_add_entity(entity->rq, entity);
		spin_unlock(&entity->rq_lock);
		drm_sched_wakeup(entity->rq->sched);
	}
}
EXPORT_SYMBOL(drm_sched_entity_push_job);