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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#include <linux/kthread.h>
25#include <linux/slab.h>
26
27#include <drm/drm_print.h>
28#include <drm/gpu_scheduler.h>
29
30#include "gpu_scheduler_trace.h"
31
32#define to_drm_sched_job(sched_job) \
33 container_of((sched_job), struct drm_sched_job, queue_node)
34
35/**
36 * drm_sched_entity_init - Init a context entity used by scheduler when
37 * submit to HW ring.
38 *
39 * @entity: scheduler entity to init
40 * @rq_list: the list of run queue on which jobs from this
41 * entity can be submitted
42 * @num_rq_list: number of run queue in rq_list
43 * @guilty: atomic_t set to 1 when a job on this queue
44 * is found to be guilty causing a timeout
45 *
46 * Note: the rq_list should have atleast one element to schedule
47 * the entity
48 *
49 * Returns 0 on success or a negative error code on failure.
50 */
51int drm_sched_entity_init(struct drm_sched_entity *entity,
52 struct drm_sched_rq **rq_list,
53 unsigned int num_rq_list,
54 atomic_t *guilty)
55{
56 int i;
57
58 if (!(entity && rq_list && (num_rq_list == 0 || rq_list[0])))
59 return -EINVAL;
60
61 memset(entity, 0, sizeof(struct drm_sched_entity));
62 INIT_LIST_HEAD(&entity->list);
63 entity->rq = NULL;
64 entity->guilty = guilty;
65 entity->num_rq_list = num_rq_list;
66 entity->rq_list = kcalloc(num_rq_list, sizeof(struct drm_sched_rq *),
67 GFP_KERNEL);
68 if (!entity->rq_list)
69 return -ENOMEM;
70
71 for (i = 0; i < num_rq_list; ++i)
72 entity->rq_list[i] = rq_list[i];
73
74 if (num_rq_list)
75 entity->rq = rq_list[0];
76
77 entity->last_scheduled = NULL;
78
79 spin_lock_init(&entity->rq_lock);
80 spsc_queue_init(&entity->job_queue);
81
82 atomic_set(&entity->fence_seq, 0);
83 entity->fence_context = dma_fence_context_alloc(2);
84
85 return 0;
86}
87EXPORT_SYMBOL(drm_sched_entity_init);
88
89/**
90 * drm_sched_entity_is_idle - Check if entity is idle
91 *
92 * @entity: scheduler entity
93 *
94 * Returns true if the entity does not have any unscheduled jobs.
95 */
96static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
97{
98 rmb(); /* for list_empty to work without lock */
99
100 if (list_empty(&entity->list) ||
101 spsc_queue_count(&entity->job_queue) == 0)
102 return true;
103
104 return false;
105}
106
107/**
108 * drm_sched_entity_is_ready - Check if entity is ready
109 *
110 * @entity: scheduler entity
111 *
112 * Return true if entity could provide a job.
113 */
114bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
115{
116 if (spsc_queue_peek(&entity->job_queue) == NULL)
117 return false;
118
119 if (READ_ONCE(entity->dependency))
120 return false;
121
122 return true;
123}
124
125/**
126 * drm_sched_entity_get_free_sched - Get the rq from rq_list with least load
127 *
128 * @entity: scheduler entity
129 *
130 * Return the pointer to the rq with least load.
131 */
132static struct drm_sched_rq *
133drm_sched_entity_get_free_sched(struct drm_sched_entity *entity)
134{
135 struct drm_sched_rq *rq = NULL;
136 unsigned int min_jobs = UINT_MAX, num_jobs;
137 int i;
138
139 for (i = 0; i < entity->num_rq_list; ++i) {
140 struct drm_gpu_scheduler *sched = entity->rq_list[i]->sched;
141
142 if (!entity->rq_list[i]->sched->ready) {
143 DRM_WARN("sched%s is not ready, skipping", sched->name);
144 continue;
145 }
146
147 num_jobs = atomic_read(&sched->num_jobs);
148 if (num_jobs < min_jobs) {
149 min_jobs = num_jobs;
150 rq = entity->rq_list[i];
151 }
152 }
153
154 return rq;
155}
156
157/**
158 * drm_sched_entity_flush - Flush a context entity
159 *
160 * @entity: scheduler entity
161 * @timeout: time to wait in for Q to become empty in jiffies.
162 *
163 * Splitting drm_sched_entity_fini() into two functions, The first one does the
164 * waiting, removes the entity from the runqueue and returns an error when the
165 * process was killed.
166 *
167 * Returns the remaining time in jiffies left from the input timeout
168 */
169long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
170{
171 struct drm_gpu_scheduler *sched;
172 struct task_struct *last_user;
173 long ret = timeout;
174
175 if (!entity->rq)
176 return 0;
177
178 sched = entity->rq->sched;
179 /**
180 * The client will not queue more IBs during this fini, consume existing
181 * queued IBs or discard them on SIGKILL
182 */
183 if (current->flags & PF_EXITING) {
184 if (timeout)
185 ret = wait_event_timeout(
186 sched->job_scheduled,
187 drm_sched_entity_is_idle(entity),
188 timeout);
189 } else {
190 wait_event_killable(sched->job_scheduled,
191 drm_sched_entity_is_idle(entity));
192 }
193
194 /* For killed process disable any more IBs enqueue right now */
195 last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
196 if ((!last_user || last_user == current->group_leader) &&
197 (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) {
198 spin_lock(&entity->rq_lock);
199 entity->stopped = true;
200 drm_sched_rq_remove_entity(entity->rq, entity);
201 spin_unlock(&entity->rq_lock);
202 }
203
204 return ret;
205}
206EXPORT_SYMBOL(drm_sched_entity_flush);
207
208/**
209 * drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
210 *
211 * @f: signaled fence
212 * @cb: our callback structure
213 *
214 * Signal the scheduler finished fence when the entity in question is killed.
215 */
216static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
217 struct dma_fence_cb *cb)
218{
219 struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
220 finish_cb);
221
222 drm_sched_fence_finished(job->s_fence);
223 WARN_ON(job->s_fence->parent);
224 job->sched->ops->free_job(job);
225}
226
227/**
228 * drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
229 *
230 * @entity: entity which is cleaned up
231 *
232 * Makes sure that all remaining jobs in an entity are killed before it is
233 * destroyed.
234 */
235static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
236{
237 struct drm_sched_job *job;
238 int r;
239
240 while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
241 struct drm_sched_fence *s_fence = job->s_fence;
242
243 drm_sched_fence_scheduled(s_fence);
244 dma_fence_set_error(&s_fence->finished, -ESRCH);
245
246 /*
247 * When pipe is hanged by older entity, new entity might
248 * not even have chance to submit it's first job to HW
249 * and so entity->last_scheduled will remain NULL
250 */
251 if (!entity->last_scheduled) {
252 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
253 continue;
254 }
255
256 r = dma_fence_add_callback(entity->last_scheduled,
257 &job->finish_cb,
258 drm_sched_entity_kill_jobs_cb);
259 if (r == -ENOENT)
260 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
261 else if (r)
262 DRM_ERROR("fence add callback failed (%d)\n", r);
263 }
264}
265
266/**
267 * drm_sched_entity_cleanup - Destroy a context entity
268 *
269 * @entity: scheduler entity
270 *
271 * This should be called after @drm_sched_entity_do_release. It goes over the
272 * entity and signals all jobs with an error code if the process was killed.
273 *
274 */
275void drm_sched_entity_fini(struct drm_sched_entity *entity)
276{
277 struct drm_gpu_scheduler *sched = NULL;
278
279 if (entity->rq) {
280 sched = entity->rq->sched;
281 drm_sched_rq_remove_entity(entity->rq, entity);
282 }
283
284 /* Consumption of existing IBs wasn't completed. Forcefully
285 * remove them here.
286 */
287 if (spsc_queue_count(&entity->job_queue)) {
288 if (sched) {
289 /* Park the kernel for a moment to make sure it isn't processing
290 * our enity.
291 */
292 kthread_park(sched->thread);
293 kthread_unpark(sched->thread);
294 }
295 if (entity->dependency) {
296 dma_fence_remove_callback(entity->dependency,
297 &entity->cb);
298 dma_fence_put(entity->dependency);
299 entity->dependency = NULL;
300 }
301
302 drm_sched_entity_kill_jobs(entity);
303 }
304
305 dma_fence_put(entity->last_scheduled);
306 entity->last_scheduled = NULL;
307 kfree(entity->rq_list);
308}
309EXPORT_SYMBOL(drm_sched_entity_fini);
310
311/**
312 * drm_sched_entity_fini - Destroy a context entity
313 *
314 * @entity: scheduler entity
315 *
316 * Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup()
317 */
318void drm_sched_entity_destroy(struct drm_sched_entity *entity)
319{
320 drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
321 drm_sched_entity_fini(entity);
322}
323EXPORT_SYMBOL(drm_sched_entity_destroy);
324
325/**
326 * drm_sched_entity_clear_dep - callback to clear the entities dependency
327 */
328static void drm_sched_entity_clear_dep(struct dma_fence *f,
329 struct dma_fence_cb *cb)
330{
331 struct drm_sched_entity *entity =
332 container_of(cb, struct drm_sched_entity, cb);
333
334 entity->dependency = NULL;
335 dma_fence_put(f);
336}
337
338/**
339 * drm_sched_entity_clear_dep - callback to clear the entities dependency and
340 * wake up scheduler
341 */
342static void drm_sched_entity_wakeup(struct dma_fence *f,
343 struct dma_fence_cb *cb)
344{
345 struct drm_sched_entity *entity =
346 container_of(cb, struct drm_sched_entity, cb);
347
348 drm_sched_entity_clear_dep(f, cb);
349 drm_sched_wakeup(entity->rq->sched);
350}
351
352/**
353 * drm_sched_entity_set_rq_priority - helper for drm_sched_entity_set_priority
354 */
355static void drm_sched_entity_set_rq_priority(struct drm_sched_rq **rq,
356 enum drm_sched_priority priority)
357{
358 *rq = &(*rq)->sched->sched_rq[priority];
359}
360
361/**
362 * drm_sched_entity_set_priority - Sets priority of the entity
363 *
364 * @entity: scheduler entity
365 * @priority: scheduler priority
366 *
367 * Update the priority of runqueus used for the entity.
368 */
369void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
370 enum drm_sched_priority priority)
371{
372 unsigned int i;
373
374 spin_lock(&entity->rq_lock);
375
376 for (i = 0; i < entity->num_rq_list; ++i)
377 drm_sched_entity_set_rq_priority(&entity->rq_list[i], priority);
378
379 if (entity->rq) {
380 drm_sched_rq_remove_entity(entity->rq, entity);
381 drm_sched_entity_set_rq_priority(&entity->rq, priority);
382 drm_sched_rq_add_entity(entity->rq, entity);
383 }
384
385 spin_unlock(&entity->rq_lock);
386}
387EXPORT_SYMBOL(drm_sched_entity_set_priority);
388
389/**
390 * drm_sched_entity_add_dependency_cb - add callback for the entities dependency
391 *
392 * @entity: entity with dependency
393 *
394 * Add a callback to the current dependency of the entity to wake up the
395 * scheduler when the entity becomes available.
396 */
397static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
398{
399 struct drm_gpu_scheduler *sched = entity->rq->sched;
400 struct dma_fence *fence = entity->dependency;
401 struct drm_sched_fence *s_fence;
402
403 if (fence->context == entity->fence_context ||
404 fence->context == entity->fence_context + 1) {
405 /*
406 * Fence is a scheduled/finished fence from a job
407 * which belongs to the same entity, we can ignore
408 * fences from ourself
409 */
410 dma_fence_put(entity->dependency);
411 return false;
412 }
413
414 s_fence = to_drm_sched_fence(fence);
415 if (s_fence && s_fence->sched == sched) {
416
417 /*
418 * Fence is from the same scheduler, only need to wait for
419 * it to be scheduled
420 */
421 fence = dma_fence_get(&s_fence->scheduled);
422 dma_fence_put(entity->dependency);
423 entity->dependency = fence;
424 if (!dma_fence_add_callback(fence, &entity->cb,
425 drm_sched_entity_clear_dep))
426 return true;
427
428 /* Ignore it when it is already scheduled */
429 dma_fence_put(fence);
430 return false;
431 }
432
433 if (!dma_fence_add_callback(entity->dependency, &entity->cb,
434 drm_sched_entity_wakeup))
435 return true;
436
437 dma_fence_put(entity->dependency);
438 return false;
439}
440
441/**
442 * drm_sched_entity_pop_job - get a ready to be scheduled job from the entity
443 *
444 * @entity: entity to get the job from
445 *
446 * Process all dependencies and try to get one job from the entities queue.
447 */
448struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
449{
450 struct drm_gpu_scheduler *sched = entity->rq->sched;
451 struct drm_sched_job *sched_job;
452
453 sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
454 if (!sched_job)
455 return NULL;
456
457 while ((entity->dependency =
458 sched->ops->dependency(sched_job, entity))) {
459 trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
460
461 if (drm_sched_entity_add_dependency_cb(entity))
462 return NULL;
463 }
464
465 /* skip jobs from entity that marked guilty */
466 if (entity->guilty && atomic_read(entity->guilty))
467 dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
468
469 dma_fence_put(entity->last_scheduled);
470 entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
471
472 spsc_queue_pop(&entity->job_queue);
473 return sched_job;
474}
475
476/**
477 * drm_sched_entity_select_rq - select a new rq for the entity
478 *
479 * @entity: scheduler entity
480 *
481 * Check all prerequisites and select a new rq for the entity for load
482 * balancing.
483 */
484void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
485{
486 struct dma_fence *fence;
487 struct drm_sched_rq *rq;
488
489 if (spsc_queue_count(&entity->job_queue) || entity->num_rq_list <= 1)
490 return;
491
492 fence = READ_ONCE(entity->last_scheduled);
493 if (fence && !dma_fence_is_signaled(fence))
494 return;
495
496 rq = drm_sched_entity_get_free_sched(entity);
497 if (rq == entity->rq)
498 return;
499
500 spin_lock(&entity->rq_lock);
501 drm_sched_rq_remove_entity(entity->rq, entity);
502 entity->rq = rq;
503 spin_unlock(&entity->rq_lock);
504}
505
506/**
507 * drm_sched_entity_push_job - Submit a job to the entity's job queue
508 *
509 * @sched_job: job to submit
510 * @entity: scheduler entity
511 *
512 * Note: To guarantee that the order of insertion to queue matches
513 * the job's fence sequence number this function should be
514 * called with drm_sched_job_init under common lock.
515 *
516 * Returns 0 for success, negative error code otherwise.
517 */
518void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
519 struct drm_sched_entity *entity)
520{
521 bool first;
522
523 trace_drm_sched_job(sched_job, entity);
524 atomic_inc(&entity->rq->sched->num_jobs);
525 WRITE_ONCE(entity->last_user, current->group_leader);
526 first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
527
528 /* first job wakes up scheduler */
529 if (first) {
530 /* Add the entity to the run queue */
531 spin_lock(&entity->rq_lock);
532 if (entity->stopped) {
533 spin_unlock(&entity->rq_lock);
534
535 DRM_ERROR("Trying to push to a killed entity\n");
536 return;
537 }
538 drm_sched_rq_add_entity(entity->rq, entity);
539 spin_unlock(&entity->rq_lock);
540 drm_sched_wakeup(entity->rq->sched);
541 }
542}
543EXPORT_SYMBOL(drm_sched_entity_push_job);
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#include <linux/kthread.h>
25#include <linux/slab.h>
26#include <linux/completion.h>
27
28#include <drm/drm_print.h>
29#include <drm/gpu_scheduler.h>
30
31#include "gpu_scheduler_trace.h"
32
33#define to_drm_sched_job(sched_job) \
34 container_of((sched_job), struct drm_sched_job, queue_node)
35
36/**
37 * drm_sched_entity_init - Init a context entity used by scheduler when
38 * submit to HW ring.
39 *
40 * @entity: scheduler entity to init
41 * @priority: priority of the entity
42 * @sched_list: the list of drm scheds on which jobs from this
43 * entity can be submitted
44 * @num_sched_list: number of drm sched in sched_list
45 * @guilty: atomic_t set to 1 when a job on this queue
46 * is found to be guilty causing a timeout
47 *
48 * Note that the &sched_list must have at least one element to schedule the entity.
49 *
50 * For changing @priority later on at runtime see
51 * drm_sched_entity_set_priority(). For changing the set of schedulers
52 * @sched_list at runtime see drm_sched_entity_modify_sched().
53 *
54 * An entity is cleaned up by callind drm_sched_entity_fini(). See also
55 * drm_sched_entity_destroy().
56 *
57 * Returns 0 on success or a negative error code on failure.
58 */
59int drm_sched_entity_init(struct drm_sched_entity *entity,
60 enum drm_sched_priority priority,
61 struct drm_gpu_scheduler **sched_list,
62 unsigned int num_sched_list,
63 atomic_t *guilty)
64{
65 if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0])))
66 return -EINVAL;
67
68 memset(entity, 0, sizeof(struct drm_sched_entity));
69 INIT_LIST_HEAD(&entity->list);
70 entity->rq = NULL;
71 entity->guilty = guilty;
72 entity->num_sched_list = num_sched_list;
73 entity->priority = priority;
74 entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
75 RCU_INIT_POINTER(entity->last_scheduled, NULL);
76 RB_CLEAR_NODE(&entity->rb_tree_node);
77
78 if (!sched_list[0]->sched_rq) {
79 /* Warn drivers not to do this and to fix their DRM
80 * calling order.
81 */
82 pr_warn("%s: called with uninitialized scheduler\n", __func__);
83 } else if (num_sched_list) {
84 /* The "priority" of an entity cannot exceed the number of run-queues of a
85 * scheduler. Protect against num_rqs being 0, by converting to signed. Choose
86 * the lowest priority available.
87 */
88 if (entity->priority >= sched_list[0]->num_rqs) {
89 drm_err(sched_list[0], "entity with out-of-bounds priority:%u num_rqs:%u\n",
90 entity->priority, sched_list[0]->num_rqs);
91 entity->priority = max_t(s32, (s32) sched_list[0]->num_rqs - 1,
92 (s32) DRM_SCHED_PRIORITY_KERNEL);
93 }
94 entity->rq = sched_list[0]->sched_rq[entity->priority];
95 }
96
97 init_completion(&entity->entity_idle);
98
99 /* We start in an idle state. */
100 complete_all(&entity->entity_idle);
101
102 spin_lock_init(&entity->rq_lock);
103 spsc_queue_init(&entity->job_queue);
104
105 atomic_set(&entity->fence_seq, 0);
106 entity->fence_context = dma_fence_context_alloc(2);
107
108 return 0;
109}
110EXPORT_SYMBOL(drm_sched_entity_init);
111
112/**
113 * drm_sched_entity_modify_sched - Modify sched of an entity
114 * @entity: scheduler entity to init
115 * @sched_list: the list of new drm scheds which will replace
116 * existing entity->sched_list
117 * @num_sched_list: number of drm sched in sched_list
118 *
119 * Note that this must be called under the same common lock for @entity as
120 * drm_sched_job_arm() and drm_sched_entity_push_job(), or the driver needs to
121 * guarantee through some other means that this is never called while new jobs
122 * can be pushed to @entity.
123 */
124void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
125 struct drm_gpu_scheduler **sched_list,
126 unsigned int num_sched_list)
127{
128 WARN_ON(!num_sched_list || !sched_list);
129
130 entity->sched_list = sched_list;
131 entity->num_sched_list = num_sched_list;
132}
133EXPORT_SYMBOL(drm_sched_entity_modify_sched);
134
135static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
136{
137 rmb(); /* for list_empty to work without lock */
138
139 if (list_empty(&entity->list) ||
140 spsc_queue_count(&entity->job_queue) == 0 ||
141 entity->stopped)
142 return true;
143
144 return false;
145}
146
147/* Return true if entity could provide a job. */
148bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
149{
150 if (spsc_queue_peek(&entity->job_queue) == NULL)
151 return false;
152
153 if (READ_ONCE(entity->dependency))
154 return false;
155
156 return true;
157}
158
159/**
160 * drm_sched_entity_error - return error of last scheduled job
161 * @entity: scheduler entity to check
162 *
163 * Opportunistically return the error of the last scheduled job. Result can
164 * change any time when new jobs are pushed to the hw.
165 */
166int drm_sched_entity_error(struct drm_sched_entity *entity)
167{
168 struct dma_fence *fence;
169 int r;
170
171 rcu_read_lock();
172 fence = rcu_dereference(entity->last_scheduled);
173 r = fence ? fence->error : 0;
174 rcu_read_unlock();
175
176 return r;
177}
178EXPORT_SYMBOL(drm_sched_entity_error);
179
180static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)
181{
182 struct drm_sched_job *job = container_of(wrk, typeof(*job), work);
183
184 drm_sched_fence_finished(job->s_fence, -ESRCH);
185 WARN_ON(job->s_fence->parent);
186 job->sched->ops->free_job(job);
187}
188
189/* Signal the scheduler finished fence when the entity in question is killed. */
190static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
191 struct dma_fence_cb *cb)
192{
193 struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
194 finish_cb);
195 unsigned long index;
196
197 dma_fence_put(f);
198
199 /* Wait for all dependencies to avoid data corruptions */
200 xa_for_each(&job->dependencies, index, f) {
201 struct drm_sched_fence *s_fence = to_drm_sched_fence(f);
202
203 if (s_fence && f == &s_fence->scheduled) {
204 /* The dependencies array had a reference on the scheduled
205 * fence, and the finished fence refcount might have
206 * dropped to zero. Use dma_fence_get_rcu() so we get
207 * a NULL fence in that case.
208 */
209 f = dma_fence_get_rcu(&s_fence->finished);
210
211 /* Now that we have a reference on the finished fence,
212 * we can release the reference the dependencies array
213 * had on the scheduled fence.
214 */
215 dma_fence_put(&s_fence->scheduled);
216 }
217
218 xa_erase(&job->dependencies, index);
219 if (f && !dma_fence_add_callback(f, &job->finish_cb,
220 drm_sched_entity_kill_jobs_cb))
221 return;
222
223 dma_fence_put(f);
224 }
225
226 INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
227 schedule_work(&job->work);
228}
229
230/* Remove the entity from the scheduler and kill all pending jobs */
231static void drm_sched_entity_kill(struct drm_sched_entity *entity)
232{
233 struct drm_sched_job *job;
234 struct dma_fence *prev;
235
236 if (!entity->rq)
237 return;
238
239 spin_lock(&entity->rq_lock);
240 entity->stopped = true;
241 drm_sched_rq_remove_entity(entity->rq, entity);
242 spin_unlock(&entity->rq_lock);
243
244 /* Make sure this entity is not used by the scheduler at the moment */
245 wait_for_completion(&entity->entity_idle);
246
247 /* The entity is guaranteed to not be used by the scheduler */
248 prev = rcu_dereference_check(entity->last_scheduled, true);
249 dma_fence_get(prev);
250 while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
251 struct drm_sched_fence *s_fence = job->s_fence;
252
253 dma_fence_get(&s_fence->finished);
254 if (!prev || dma_fence_add_callback(prev, &job->finish_cb,
255 drm_sched_entity_kill_jobs_cb))
256 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
257
258 prev = &s_fence->finished;
259 }
260 dma_fence_put(prev);
261}
262
263/**
264 * drm_sched_entity_flush - Flush a context entity
265 *
266 * @entity: scheduler entity
267 * @timeout: time to wait in for Q to become empty in jiffies.
268 *
269 * Splitting drm_sched_entity_fini() into two functions, The first one does the
270 * waiting, removes the entity from the runqueue and returns an error when the
271 * process was killed.
272 *
273 * Returns the remaining time in jiffies left from the input timeout
274 */
275long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
276{
277 struct drm_gpu_scheduler *sched;
278 struct task_struct *last_user;
279 long ret = timeout;
280
281 if (!entity->rq)
282 return 0;
283
284 sched = entity->rq->sched;
285 /**
286 * The client will not queue more IBs during this fini, consume existing
287 * queued IBs or discard them on SIGKILL
288 */
289 if (current->flags & PF_EXITING) {
290 if (timeout)
291 ret = wait_event_timeout(
292 sched->job_scheduled,
293 drm_sched_entity_is_idle(entity),
294 timeout);
295 } else {
296 wait_event_killable(sched->job_scheduled,
297 drm_sched_entity_is_idle(entity));
298 }
299
300 /* For killed process disable any more IBs enqueue right now */
301 last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
302 if ((!last_user || last_user == current->group_leader) &&
303 (current->flags & PF_EXITING) && (current->exit_code == SIGKILL))
304 drm_sched_entity_kill(entity);
305
306 return ret;
307}
308EXPORT_SYMBOL(drm_sched_entity_flush);
309
310/**
311 * drm_sched_entity_fini - Destroy a context entity
312 *
313 * @entity: scheduler entity
314 *
315 * Cleanups up @entity which has been initialized by drm_sched_entity_init().
316 *
317 * If there are potentially job still in flight or getting newly queued
318 * drm_sched_entity_flush() must be called first. This function then goes over
319 * the entity and signals all jobs with an error code if the process was killed.
320 */
321void drm_sched_entity_fini(struct drm_sched_entity *entity)
322{
323 /*
324 * If consumption of existing IBs wasn't completed. Forcefully remove
325 * them here. Also makes sure that the scheduler won't touch this entity
326 * any more.
327 */
328 drm_sched_entity_kill(entity);
329
330 if (entity->dependency) {
331 dma_fence_remove_callback(entity->dependency, &entity->cb);
332 dma_fence_put(entity->dependency);
333 entity->dependency = NULL;
334 }
335
336 dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));
337 RCU_INIT_POINTER(entity->last_scheduled, NULL);
338}
339EXPORT_SYMBOL(drm_sched_entity_fini);
340
341/**
342 * drm_sched_entity_destroy - Destroy a context entity
343 * @entity: scheduler entity
344 *
345 * Calls drm_sched_entity_flush() and drm_sched_entity_fini() as a
346 * convenience wrapper.
347 */
348void drm_sched_entity_destroy(struct drm_sched_entity *entity)
349{
350 drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
351 drm_sched_entity_fini(entity);
352}
353EXPORT_SYMBOL(drm_sched_entity_destroy);
354
355/* drm_sched_entity_clear_dep - callback to clear the entities dependency */
356static void drm_sched_entity_clear_dep(struct dma_fence *f,
357 struct dma_fence_cb *cb)
358{
359 struct drm_sched_entity *entity =
360 container_of(cb, struct drm_sched_entity, cb);
361
362 entity->dependency = NULL;
363 dma_fence_put(f);
364}
365
366/*
367 * drm_sched_entity_clear_dep - callback to clear the entities dependency and
368 * wake up scheduler
369 */
370static void drm_sched_entity_wakeup(struct dma_fence *f,
371 struct dma_fence_cb *cb)
372{
373 struct drm_sched_entity *entity =
374 container_of(cb, struct drm_sched_entity, cb);
375
376 drm_sched_entity_clear_dep(f, cb);
377 drm_sched_wakeup(entity->rq->sched, entity);
378}
379
380/**
381 * drm_sched_entity_set_priority - Sets priority of the entity
382 *
383 * @entity: scheduler entity
384 * @priority: scheduler priority
385 *
386 * Update the priority of runqueus used for the entity.
387 */
388void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
389 enum drm_sched_priority priority)
390{
391 spin_lock(&entity->rq_lock);
392 entity->priority = priority;
393 spin_unlock(&entity->rq_lock);
394}
395EXPORT_SYMBOL(drm_sched_entity_set_priority);
396
397/*
398 * Add a callback to the current dependency of the entity to wake up the
399 * scheduler when the entity becomes available.
400 */
401static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
402{
403 struct drm_gpu_scheduler *sched = entity->rq->sched;
404 struct dma_fence *fence = entity->dependency;
405 struct drm_sched_fence *s_fence;
406
407 if (fence->context == entity->fence_context ||
408 fence->context == entity->fence_context + 1) {
409 /*
410 * Fence is a scheduled/finished fence from a job
411 * which belongs to the same entity, we can ignore
412 * fences from ourself
413 */
414 dma_fence_put(entity->dependency);
415 return false;
416 }
417
418 s_fence = to_drm_sched_fence(fence);
419 if (!fence->error && s_fence && s_fence->sched == sched &&
420 !test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) {
421
422 /*
423 * Fence is from the same scheduler, only need to wait for
424 * it to be scheduled
425 */
426 fence = dma_fence_get(&s_fence->scheduled);
427 dma_fence_put(entity->dependency);
428 entity->dependency = fence;
429 if (!dma_fence_add_callback(fence, &entity->cb,
430 drm_sched_entity_clear_dep))
431 return true;
432
433 /* Ignore it when it is already scheduled */
434 dma_fence_put(fence);
435 return false;
436 }
437
438 if (!dma_fence_add_callback(entity->dependency, &entity->cb,
439 drm_sched_entity_wakeup))
440 return true;
441
442 dma_fence_put(entity->dependency);
443 return false;
444}
445
446static struct dma_fence *
447drm_sched_job_dependency(struct drm_sched_job *job,
448 struct drm_sched_entity *entity)
449{
450 struct dma_fence *f;
451
452 /* We keep the fence around, so we can iterate over all dependencies
453 * in drm_sched_entity_kill_jobs_cb() to ensure all deps are signaled
454 * before killing the job.
455 */
456 f = xa_load(&job->dependencies, job->last_dependency);
457 if (f) {
458 job->last_dependency++;
459 return dma_fence_get(f);
460 }
461
462 if (job->sched->ops->prepare_job)
463 return job->sched->ops->prepare_job(job, entity);
464
465 return NULL;
466}
467
468struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
469{
470 struct drm_sched_job *sched_job;
471
472 sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
473 if (!sched_job)
474 return NULL;
475
476 while ((entity->dependency =
477 drm_sched_job_dependency(sched_job, entity))) {
478 trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
479
480 if (drm_sched_entity_add_dependency_cb(entity))
481 return NULL;
482 }
483
484 /* skip jobs from entity that marked guilty */
485 if (entity->guilty && atomic_read(entity->guilty))
486 dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
487
488 dma_fence_put(rcu_dereference_check(entity->last_scheduled, true));
489 rcu_assign_pointer(entity->last_scheduled,
490 dma_fence_get(&sched_job->s_fence->finished));
491
492 /*
493 * If the queue is empty we allow drm_sched_entity_select_rq() to
494 * locklessly access ->last_scheduled. This only works if we set the
495 * pointer before we dequeue and if we a write barrier here.
496 */
497 smp_wmb();
498
499 spsc_queue_pop(&entity->job_queue);
500
501 /*
502 * Update the entity's location in the min heap according to
503 * the timestamp of the next job, if any.
504 */
505 if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) {
506 struct drm_sched_job *next;
507
508 next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
509 if (next)
510 drm_sched_rq_update_fifo(entity, next->submit_ts);
511 }
512
513 /* Jobs and entities might have different lifecycles. Since we're
514 * removing the job from the entities queue, set the jobs entity pointer
515 * to NULL to prevent any future access of the entity through this job.
516 */
517 sched_job->entity = NULL;
518
519 return sched_job;
520}
521
522void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
523{
524 struct dma_fence *fence;
525 struct drm_gpu_scheduler *sched;
526 struct drm_sched_rq *rq;
527
528 /* single possible engine and already selected */
529 if (!entity->sched_list)
530 return;
531
532 /* queue non-empty, stay on the same engine */
533 if (spsc_queue_count(&entity->job_queue))
534 return;
535
536 /*
537 * Only when the queue is empty are we guaranteed that the scheduler
538 * thread cannot change ->last_scheduled. To enforce ordering we need
539 * a read barrier here. See drm_sched_entity_pop_job() for the other
540 * side.
541 */
542 smp_rmb();
543
544 fence = rcu_dereference_check(entity->last_scheduled, true);
545
546 /* stay on the same engine if the previous job hasn't finished */
547 if (fence && !dma_fence_is_signaled(fence))
548 return;
549
550 spin_lock(&entity->rq_lock);
551 sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
552 rq = sched ? sched->sched_rq[entity->priority] : NULL;
553 if (rq != entity->rq) {
554 drm_sched_rq_remove_entity(entity->rq, entity);
555 entity->rq = rq;
556 }
557 spin_unlock(&entity->rq_lock);
558
559 if (entity->num_sched_list == 1)
560 entity->sched_list = NULL;
561}
562
563/**
564 * drm_sched_entity_push_job - Submit a job to the entity's job queue
565 * @sched_job: job to submit
566 *
567 * Note: To guarantee that the order of insertion to queue matches the job's
568 * fence sequence number this function should be called with drm_sched_job_arm()
569 * under common lock for the struct drm_sched_entity that was set up for
570 * @sched_job in drm_sched_job_init().
571 *
572 * Returns 0 for success, negative error code otherwise.
573 */
574void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
575{
576 struct drm_sched_entity *entity = sched_job->entity;
577 bool first;
578 ktime_t submit_ts;
579
580 trace_drm_sched_job(sched_job, entity);
581 atomic_inc(entity->rq->sched->score);
582 WRITE_ONCE(entity->last_user, current->group_leader);
583
584 /*
585 * After the sched_job is pushed into the entity queue, it may be
586 * completed and freed up at any time. We can no longer access it.
587 * Make sure to set the submit_ts first, to avoid a race.
588 */
589 sched_job->submit_ts = submit_ts = ktime_get();
590 first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
591
592 /* first job wakes up scheduler */
593 if (first) {
594 /* Add the entity to the run queue */
595 spin_lock(&entity->rq_lock);
596 if (entity->stopped) {
597 spin_unlock(&entity->rq_lock);
598
599 DRM_ERROR("Trying to push to a killed entity\n");
600 return;
601 }
602
603 drm_sched_rq_add_entity(entity->rq, entity);
604 spin_unlock(&entity->rq_lock);
605
606 if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
607 drm_sched_rq_update_fifo(entity, submit_ts);
608
609 drm_sched_wakeup(entity->rq->sched, entity);
610 }
611}
612EXPORT_SYMBOL(drm_sched_entity_push_job);