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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#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 entity->last_scheduled = NULL;
76 RB_CLEAR_NODE(&entity->rb_tree_node);
77
78 if(num_sched_list)
79 entity->rq = &sched_list[0]->sched_rq[entity->priority];
80
81 init_completion(&entity->entity_idle);
82
83 /* We start in an idle state. */
84 complete_all(&entity->entity_idle);
85
86 spin_lock_init(&entity->rq_lock);
87 spsc_queue_init(&entity->job_queue);
88
89 atomic_set(&entity->fence_seq, 0);
90 entity->fence_context = dma_fence_context_alloc(2);
91
92 return 0;
93}
94EXPORT_SYMBOL(drm_sched_entity_init);
95
96/**
97 * drm_sched_entity_modify_sched - Modify sched of an entity
98 * @entity: scheduler entity to init
99 * @sched_list: the list of new drm scheds which will replace
100 * existing entity->sched_list
101 * @num_sched_list: number of drm sched in sched_list
102 *
103 * Note that this must be called under the same common lock for @entity as
104 * drm_sched_job_arm() and drm_sched_entity_push_job(), or the driver needs to
105 * guarantee through some other means that this is never called while new jobs
106 * can be pushed to @entity.
107 */
108void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
109 struct drm_gpu_scheduler **sched_list,
110 unsigned int num_sched_list)
111{
112 WARN_ON(!num_sched_list || !sched_list);
113
114 entity->sched_list = sched_list;
115 entity->num_sched_list = num_sched_list;
116}
117EXPORT_SYMBOL(drm_sched_entity_modify_sched);
118
119static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
120{
121 rmb(); /* for list_empty to work without lock */
122
123 if (list_empty(&entity->list) ||
124 spsc_queue_count(&entity->job_queue) == 0 ||
125 entity->stopped)
126 return true;
127
128 return false;
129}
130
131/* Return true if entity could provide a job. */
132bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
133{
134 if (spsc_queue_peek(&entity->job_queue) == NULL)
135 return false;
136
137 if (READ_ONCE(entity->dependency))
138 return false;
139
140 return true;
141}
142
143static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)
144{
145 struct drm_sched_job *job = container_of(wrk, typeof(*job), work);
146
147 drm_sched_fence_finished(job->s_fence);
148 WARN_ON(job->s_fence->parent);
149 job->sched->ops->free_job(job);
150}
151
152/* Signal the scheduler finished fence when the entity in question is killed. */
153static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
154 struct dma_fence_cb *cb)
155{
156 struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
157 finish_cb);
158 int r;
159
160 dma_fence_put(f);
161
162 /* Wait for all dependencies to avoid data corruptions */
163 while (!xa_empty(&job->dependencies)) {
164 f = xa_erase(&job->dependencies, job->last_dependency++);
165 r = dma_fence_add_callback(f, &job->finish_cb,
166 drm_sched_entity_kill_jobs_cb);
167 if (!r)
168 return;
169
170 dma_fence_put(f);
171 }
172
173 INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
174 schedule_work(&job->work);
175}
176
177/* Remove the entity from the scheduler and kill all pending jobs */
178static void drm_sched_entity_kill(struct drm_sched_entity *entity)
179{
180 struct drm_sched_job *job;
181 struct dma_fence *prev;
182
183 if (!entity->rq)
184 return;
185
186 spin_lock(&entity->rq_lock);
187 entity->stopped = true;
188 drm_sched_rq_remove_entity(entity->rq, entity);
189 spin_unlock(&entity->rq_lock);
190
191 /* Make sure this entity is not used by the scheduler at the moment */
192 wait_for_completion(&entity->entity_idle);
193
194 prev = dma_fence_get(entity->last_scheduled);
195 while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
196 struct drm_sched_fence *s_fence = job->s_fence;
197
198 dma_fence_set_error(&s_fence->finished, -ESRCH);
199
200 dma_fence_get(&s_fence->finished);
201 if (!prev || dma_fence_add_callback(prev, &job->finish_cb,
202 drm_sched_entity_kill_jobs_cb))
203 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
204
205 prev = &s_fence->finished;
206 }
207 dma_fence_put(prev);
208}
209
210/**
211 * drm_sched_entity_flush - Flush a context entity
212 *
213 * @entity: scheduler entity
214 * @timeout: time to wait in for Q to become empty in jiffies.
215 *
216 * Splitting drm_sched_entity_fini() into two functions, The first one does the
217 * waiting, removes the entity from the runqueue and returns an error when the
218 * process was killed.
219 *
220 * Returns the remaining time in jiffies left from the input timeout
221 */
222long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
223{
224 struct drm_gpu_scheduler *sched;
225 struct task_struct *last_user;
226 long ret = timeout;
227
228 if (!entity->rq)
229 return 0;
230
231 sched = entity->rq->sched;
232 /**
233 * The client will not queue more IBs during this fini, consume existing
234 * queued IBs or discard them on SIGKILL
235 */
236 if (current->flags & PF_EXITING) {
237 if (timeout)
238 ret = wait_event_timeout(
239 sched->job_scheduled,
240 drm_sched_entity_is_idle(entity),
241 timeout);
242 } else {
243 wait_event_killable(sched->job_scheduled,
244 drm_sched_entity_is_idle(entity));
245 }
246
247 /* For killed process disable any more IBs enqueue right now */
248 last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
249 if ((!last_user || last_user == current->group_leader) &&
250 (current->flags & PF_EXITING) && (current->exit_code == SIGKILL))
251 drm_sched_entity_kill(entity);
252
253 return ret;
254}
255EXPORT_SYMBOL(drm_sched_entity_flush);
256
257/**
258 * drm_sched_entity_fini - Destroy a context entity
259 *
260 * @entity: scheduler entity
261 *
262 * Cleanups up @entity which has been initialized by drm_sched_entity_init().
263 *
264 * If there are potentially job still in flight or getting newly queued
265 * drm_sched_entity_flush() must be called first. This function then goes over
266 * the entity and signals all jobs with an error code if the process was killed.
267 */
268void drm_sched_entity_fini(struct drm_sched_entity *entity)
269{
270 /*
271 * If consumption of existing IBs wasn't completed. Forcefully remove
272 * them here. Also makes sure that the scheduler won't touch this entity
273 * any more.
274 */
275 drm_sched_entity_kill(entity);
276
277 if (entity->dependency) {
278 dma_fence_remove_callback(entity->dependency, &entity->cb);
279 dma_fence_put(entity->dependency);
280 entity->dependency = NULL;
281 }
282
283 dma_fence_put(entity->last_scheduled);
284 entity->last_scheduled = NULL;
285}
286EXPORT_SYMBOL(drm_sched_entity_fini);
287
288/**
289 * drm_sched_entity_destroy - Destroy a context entity
290 * @entity: scheduler entity
291 *
292 * Calls drm_sched_entity_flush() and drm_sched_entity_fini() as a
293 * convenience wrapper.
294 */
295void drm_sched_entity_destroy(struct drm_sched_entity *entity)
296{
297 drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
298 drm_sched_entity_fini(entity);
299}
300EXPORT_SYMBOL(drm_sched_entity_destroy);
301
302/* drm_sched_entity_clear_dep - callback to clear the entities dependency */
303static void drm_sched_entity_clear_dep(struct dma_fence *f,
304 struct dma_fence_cb *cb)
305{
306 struct drm_sched_entity *entity =
307 container_of(cb, struct drm_sched_entity, cb);
308
309 entity->dependency = NULL;
310 dma_fence_put(f);
311}
312
313/*
314 * drm_sched_entity_clear_dep - callback to clear the entities dependency and
315 * wake up scheduler
316 */
317static void drm_sched_entity_wakeup(struct dma_fence *f,
318 struct dma_fence_cb *cb)
319{
320 struct drm_sched_entity *entity =
321 container_of(cb, struct drm_sched_entity, cb);
322
323 drm_sched_entity_clear_dep(f, cb);
324 drm_sched_wakeup(entity->rq->sched);
325}
326
327/**
328 * drm_sched_entity_set_priority - Sets priority of the entity
329 *
330 * @entity: scheduler entity
331 * @priority: scheduler priority
332 *
333 * Update the priority of runqueus used for the entity.
334 */
335void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
336 enum drm_sched_priority priority)
337{
338 spin_lock(&entity->rq_lock);
339 entity->priority = priority;
340 spin_unlock(&entity->rq_lock);
341}
342EXPORT_SYMBOL(drm_sched_entity_set_priority);
343
344/*
345 * Add a callback to the current dependency of the entity to wake up the
346 * scheduler when the entity becomes available.
347 */
348static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
349{
350 struct drm_gpu_scheduler *sched = entity->rq->sched;
351 struct dma_fence *fence = entity->dependency;
352 struct drm_sched_fence *s_fence;
353
354 if (fence->context == entity->fence_context ||
355 fence->context == entity->fence_context + 1) {
356 /*
357 * Fence is a scheduled/finished fence from a job
358 * which belongs to the same entity, we can ignore
359 * fences from ourself
360 */
361 dma_fence_put(entity->dependency);
362 return false;
363 }
364
365 s_fence = to_drm_sched_fence(fence);
366 if (s_fence && s_fence->sched == sched &&
367 !test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) {
368
369 /*
370 * Fence is from the same scheduler, only need to wait for
371 * it to be scheduled
372 */
373 fence = dma_fence_get(&s_fence->scheduled);
374 dma_fence_put(entity->dependency);
375 entity->dependency = fence;
376 if (!dma_fence_add_callback(fence, &entity->cb,
377 drm_sched_entity_clear_dep))
378 return true;
379
380 /* Ignore it when it is already scheduled */
381 dma_fence_put(fence);
382 return false;
383 }
384
385 if (!dma_fence_add_callback(entity->dependency, &entity->cb,
386 drm_sched_entity_wakeup))
387 return true;
388
389 dma_fence_put(entity->dependency);
390 return false;
391}
392
393static struct dma_fence *
394drm_sched_job_dependency(struct drm_sched_job *job,
395 struct drm_sched_entity *entity)
396{
397 if (!xa_empty(&job->dependencies))
398 return xa_erase(&job->dependencies, job->last_dependency++);
399
400 if (job->sched->ops->prepare_job)
401 return job->sched->ops->prepare_job(job, entity);
402
403 return NULL;
404}
405
406struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
407{
408 struct drm_sched_job *sched_job;
409
410 sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
411 if (!sched_job)
412 return NULL;
413
414 while ((entity->dependency =
415 drm_sched_job_dependency(sched_job, entity))) {
416 trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
417
418 if (drm_sched_entity_add_dependency_cb(entity))
419 return NULL;
420 }
421
422 /* skip jobs from entity that marked guilty */
423 if (entity->guilty && atomic_read(entity->guilty))
424 dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
425
426 dma_fence_put(entity->last_scheduled);
427
428 entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
429
430 /*
431 * If the queue is empty we allow drm_sched_entity_select_rq() to
432 * locklessly access ->last_scheduled. This only works if we set the
433 * pointer before we dequeue and if we a write barrier here.
434 */
435 smp_wmb();
436
437 spsc_queue_pop(&entity->job_queue);
438
439 /*
440 * Update the entity's location in the min heap according to
441 * the timestamp of the next job, if any.
442 */
443 if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) {
444 struct drm_sched_job *next;
445
446 next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
447 if (next)
448 drm_sched_rq_update_fifo(entity, next->submit_ts);
449 }
450
451 return sched_job;
452}
453
454void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
455{
456 struct dma_fence *fence;
457 struct drm_gpu_scheduler *sched;
458 struct drm_sched_rq *rq;
459
460 /* single possible engine and already selected */
461 if (!entity->sched_list)
462 return;
463
464 /* queue non-empty, stay on the same engine */
465 if (spsc_queue_count(&entity->job_queue))
466 return;
467
468 /*
469 * Only when the queue is empty are we guaranteed that the scheduler
470 * thread cannot change ->last_scheduled. To enforce ordering we need
471 * a read barrier here. See drm_sched_entity_pop_job() for the other
472 * side.
473 */
474 smp_rmb();
475
476 fence = entity->last_scheduled;
477
478 /* stay on the same engine if the previous job hasn't finished */
479 if (fence && !dma_fence_is_signaled(fence))
480 return;
481
482 spin_lock(&entity->rq_lock);
483 sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
484 rq = sched ? &sched->sched_rq[entity->priority] : NULL;
485 if (rq != entity->rq) {
486 drm_sched_rq_remove_entity(entity->rq, entity);
487 entity->rq = rq;
488 }
489 spin_unlock(&entity->rq_lock);
490
491 if (entity->num_sched_list == 1)
492 entity->sched_list = NULL;
493}
494
495/**
496 * drm_sched_entity_push_job - Submit a job to the entity's job queue
497 * @sched_job: job to submit
498 *
499 * Note: To guarantee that the order of insertion to queue matches the job's
500 * fence sequence number this function should be called with drm_sched_job_arm()
501 * under common lock for the struct drm_sched_entity that was set up for
502 * @sched_job in drm_sched_job_init().
503 *
504 * Returns 0 for success, negative error code otherwise.
505 */
506void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
507{
508 struct drm_sched_entity *entity = sched_job->entity;
509 bool first;
510
511 trace_drm_sched_job(sched_job, entity);
512 atomic_inc(entity->rq->sched->score);
513 WRITE_ONCE(entity->last_user, current->group_leader);
514 first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
515 sched_job->submit_ts = ktime_get();
516
517 /* first job wakes up scheduler */
518 if (first) {
519 /* Add the entity to the run queue */
520 spin_lock(&entity->rq_lock);
521 if (entity->stopped) {
522 spin_unlock(&entity->rq_lock);
523
524 DRM_ERROR("Trying to push to a killed entity\n");
525 return;
526 }
527
528 drm_sched_rq_add_entity(entity->rq, entity);
529 spin_unlock(&entity->rq_lock);
530
531 if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
532 drm_sched_rq_update_fifo(entity, sched_job->submit_ts);
533
534 drm_sched_wakeup(entity->rq->sched);
535 }
536}
537EXPORT_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
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);