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: the sched_list should have at least one element to schedule
49 * the entity
50 *
51 * Returns 0 on success or a negative error code on failure.
52 */
drm_sched_entity_init(struct drm_sched_entity * entity,enum drm_sched_priority priority,struct drm_gpu_scheduler ** sched_list,unsigned int num_sched_list,atomic_t * guilty)53 int drm_sched_entity_init(struct drm_sched_entity *entity,
54 enum drm_sched_priority priority,
55 struct drm_gpu_scheduler **sched_list,
56 unsigned int num_sched_list,
57 atomic_t *guilty)
58 {
59 if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0])))
60 return -EINVAL;
61
62 memset(entity, 0, sizeof(struct drm_sched_entity));
63 INIT_LIST_HEAD(&entity->list);
64 entity->rq = NULL;
65 entity->guilty = guilty;
66 entity->num_sched_list = num_sched_list;
67 entity->priority = priority;
68 entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
69 entity->last_scheduled = NULL;
70
71 if(num_sched_list)
72 entity->rq = &sched_list[0]->sched_rq[entity->priority];
73
74 init_completion(&entity->entity_idle);
75
76 spin_lock_init(&entity->rq_lock);
77 spsc_queue_init(&entity->job_queue);
78
79 atomic_set(&entity->fence_seq, 0);
80 entity->fence_context = dma_fence_context_alloc(2);
81
82 return 0;
83 }
84 EXPORT_SYMBOL(drm_sched_entity_init);
85
86 /**
87 * drm_sched_entity_modify_sched - Modify sched of an entity
88 * @entity: scheduler entity to init
89 * @sched_list: the list of new drm scheds which will replace
90 * existing entity->sched_list
91 * @num_sched_list: number of drm sched in sched_list
92 */
drm_sched_entity_modify_sched(struct drm_sched_entity * entity,struct drm_gpu_scheduler ** sched_list,unsigned int num_sched_list)93 void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
94 struct drm_gpu_scheduler **sched_list,
95 unsigned int num_sched_list)
96 {
97 WARN_ON(!num_sched_list || !sched_list);
98
99 entity->sched_list = sched_list;
100 entity->num_sched_list = num_sched_list;
101 }
102 EXPORT_SYMBOL(drm_sched_entity_modify_sched);
103
104 /**
105 * drm_sched_entity_is_idle - Check if entity is idle
106 *
107 * @entity: scheduler entity
108 *
109 * Returns true if the entity does not have any unscheduled jobs.
110 */
drm_sched_entity_is_idle(struct drm_sched_entity * entity)111 static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity)
112 {
113 rmb(); /* for list_empty to work without lock */
114
115 if (list_empty(&entity->list) ||
116 spsc_queue_count(&entity->job_queue) == 0 ||
117 entity->stopped)
118 return true;
119
120 return false;
121 }
122
123 /**
124 * drm_sched_entity_is_ready - Check if entity is ready
125 *
126 * @entity: scheduler entity
127 *
128 * Return true if entity could provide a job.
129 */
drm_sched_entity_is_ready(struct drm_sched_entity * entity)130 bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
131 {
132 if (spsc_queue_peek(&entity->job_queue) == NULL)
133 return false;
134
135 if (READ_ONCE(entity->dependency))
136 return false;
137
138 return true;
139 }
140
141 /**
142 * drm_sched_entity_flush - Flush a context entity
143 *
144 * @entity: scheduler entity
145 * @timeout: time to wait in for Q to become empty in jiffies.
146 *
147 * Splitting drm_sched_entity_fini() into two functions, The first one does the
148 * waiting, removes the entity from the runqueue and returns an error when the
149 * process was killed.
150 *
151 * Returns the remaining time in jiffies left from the input timeout
152 */
drm_sched_entity_flush(struct drm_sched_entity * entity,long timeout)153 long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
154 {
155 struct drm_gpu_scheduler *sched;
156 struct task_struct *last_user;
157 long ret = timeout;
158
159 if (!entity->rq)
160 return 0;
161
162 sched = entity->rq->sched;
163 /**
164 * The client will not queue more IBs during this fini, consume existing
165 * queued IBs or discard them on SIGKILL
166 */
167 if (current->flags & PF_EXITING) {
168 if (timeout)
169 ret = wait_event_timeout(
170 sched->job_scheduled,
171 drm_sched_entity_is_idle(entity),
172 timeout);
173 } else {
174 wait_event_killable(sched->job_scheduled,
175 drm_sched_entity_is_idle(entity));
176 }
177
178 /* For killed process disable any more IBs enqueue right now */
179 last_user = cmpxchg(&entity->last_user, current->group_leader, NULL);
180 if ((!last_user || last_user == current->group_leader) &&
181 (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) {
182 spin_lock(&entity->rq_lock);
183 entity->stopped = true;
184 drm_sched_rq_remove_entity(entity->rq, entity);
185 spin_unlock(&entity->rq_lock);
186 }
187
188 return ret;
189 }
190 EXPORT_SYMBOL(drm_sched_entity_flush);
191
192 /**
193 * drm_sched_entity_kill_jobs - helper for drm_sched_entity_kill_jobs
194 *
195 * @f: signaled fence
196 * @cb: our callback structure
197 *
198 * Signal the scheduler finished fence when the entity in question is killed.
199 */
drm_sched_entity_kill_jobs_cb(struct dma_fence * f,struct dma_fence_cb * cb)200 static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
201 struct dma_fence_cb *cb)
202 {
203 struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
204 finish_cb);
205
206 drm_sched_fence_finished(job->s_fence);
207 WARN_ON(job->s_fence->parent);
208 job->sched->ops->free_job(job);
209 }
210
211 /**
212 * drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
213 *
214 * @entity: entity which is cleaned up
215 *
216 * Makes sure that all remaining jobs in an entity are killed before it is
217 * destroyed.
218 */
drm_sched_entity_kill_jobs(struct drm_sched_entity * entity)219 static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
220 {
221 struct drm_sched_job *job;
222 struct dma_fence *f;
223 int r;
224
225 while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) {
226 struct drm_sched_fence *s_fence = job->s_fence;
227
228 /* Wait for all dependencies to avoid data corruptions */
229 while ((f = job->sched->ops->dependency(job, entity)))
230 dma_fence_wait(f, false);
231
232 drm_sched_fence_scheduled(s_fence);
233 dma_fence_set_error(&s_fence->finished, -ESRCH);
234
235 /*
236 * When pipe is hanged by older entity, new entity might
237 * not even have chance to submit it's first job to HW
238 * and so entity->last_scheduled will remain NULL
239 */
240 if (!entity->last_scheduled) {
241 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
242 continue;
243 }
244
245 r = dma_fence_add_callback(entity->last_scheduled,
246 &job->finish_cb,
247 drm_sched_entity_kill_jobs_cb);
248 if (r == -ENOENT)
249 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb);
250 else if (r)
251 DRM_ERROR("fence add callback failed (%d)\n", r);
252 }
253 }
254
255 /**
256 * drm_sched_entity_cleanup - Destroy a context entity
257 *
258 * @entity: scheduler entity
259 *
260 * This should be called after @drm_sched_entity_do_release. It goes over the
261 * entity and signals all jobs with an error code if the process was killed.
262 *
263 */
drm_sched_entity_fini(struct drm_sched_entity * entity)264 void drm_sched_entity_fini(struct drm_sched_entity *entity)
265 {
266 struct drm_gpu_scheduler *sched = NULL;
267
268 if (entity->rq) {
269 sched = entity->rq->sched;
270 drm_sched_rq_remove_entity(entity->rq, entity);
271 }
272
273 /* Consumption of existing IBs wasn't completed. Forcefully
274 * remove them here.
275 */
276 if (spsc_queue_count(&entity->job_queue)) {
277 if (sched) {
278 /*
279 * Wait for thread to idle to make sure it isn't processing
280 * this entity.
281 */
282 wait_for_completion(&entity->entity_idle);
283
284 }
285 if (entity->dependency) {
286 dma_fence_remove_callback(entity->dependency,
287 &entity->cb);
288 dma_fence_put(entity->dependency);
289 entity->dependency = NULL;
290 }
291
292 drm_sched_entity_kill_jobs(entity);
293 }
294
295 dma_fence_put(entity->last_scheduled);
296 entity->last_scheduled = NULL;
297 }
298 EXPORT_SYMBOL(drm_sched_entity_fini);
299
300 /**
301 * drm_sched_entity_fini - Destroy a context entity
302 *
303 * @entity: scheduler entity
304 *
305 * Calls drm_sched_entity_do_release() and drm_sched_entity_cleanup()
306 */
drm_sched_entity_destroy(struct drm_sched_entity * entity)307 void drm_sched_entity_destroy(struct drm_sched_entity *entity)
308 {
309 drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY);
310 drm_sched_entity_fini(entity);
311 }
312 EXPORT_SYMBOL(drm_sched_entity_destroy);
313
314 /**
315 * drm_sched_entity_clear_dep - callback to clear the entities dependency
316 */
drm_sched_entity_clear_dep(struct dma_fence * f,struct dma_fence_cb * cb)317 static void drm_sched_entity_clear_dep(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 entity->dependency = NULL;
324 dma_fence_put(f);
325 }
326
327 /**
328 * drm_sched_entity_clear_dep - callback to clear the entities dependency and
329 * wake up scheduler
330 */
drm_sched_entity_wakeup(struct dma_fence * f,struct dma_fence_cb * cb)331 static void drm_sched_entity_wakeup(struct dma_fence *f,
332 struct dma_fence_cb *cb)
333 {
334 struct drm_sched_entity *entity =
335 container_of(cb, struct drm_sched_entity, cb);
336
337 drm_sched_entity_clear_dep(f, cb);
338 drm_sched_wakeup(entity->rq->sched);
339 }
340
341 /**
342 * drm_sched_entity_set_priority - Sets priority of the entity
343 *
344 * @entity: scheduler entity
345 * @priority: scheduler priority
346 *
347 * Update the priority of runqueus used for the entity.
348 */
drm_sched_entity_set_priority(struct drm_sched_entity * entity,enum drm_sched_priority priority)349 void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
350 enum drm_sched_priority priority)
351 {
352 spin_lock(&entity->rq_lock);
353 entity->priority = priority;
354 spin_unlock(&entity->rq_lock);
355 }
356 EXPORT_SYMBOL(drm_sched_entity_set_priority);
357
358 /**
359 * drm_sched_entity_add_dependency_cb - add callback for the entities dependency
360 *
361 * @entity: entity with dependency
362 *
363 * Add a callback to the current dependency of the entity to wake up the
364 * scheduler when the entity becomes available.
365 */
drm_sched_entity_add_dependency_cb(struct drm_sched_entity * entity)366 static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
367 {
368 struct drm_gpu_scheduler *sched = entity->rq->sched;
369 struct dma_fence *fence = entity->dependency;
370 struct drm_sched_fence *s_fence;
371
372 if (fence->context == entity->fence_context ||
373 fence->context == entity->fence_context + 1) {
374 /*
375 * Fence is a scheduled/finished fence from a job
376 * which belongs to the same entity, we can ignore
377 * fences from ourself
378 */
379 dma_fence_put(entity->dependency);
380 return false;
381 }
382
383 s_fence = to_drm_sched_fence(fence);
384 if (s_fence && s_fence->sched == sched) {
385
386 /*
387 * Fence is from the same scheduler, only need to wait for
388 * it to be scheduled
389 */
390 fence = dma_fence_get(&s_fence->scheduled);
391 dma_fence_put(entity->dependency);
392 entity->dependency = fence;
393 if (!dma_fence_add_callback(fence, &entity->cb,
394 drm_sched_entity_clear_dep))
395 return true;
396
397 /* Ignore it when it is already scheduled */
398 dma_fence_put(fence);
399 return false;
400 }
401
402 if (!dma_fence_add_callback(entity->dependency, &entity->cb,
403 drm_sched_entity_wakeup))
404 return true;
405
406 dma_fence_put(entity->dependency);
407 return false;
408 }
409
410 /**
411 * drm_sched_entity_pop_job - get a ready to be scheduled job from the entity
412 *
413 * @entity: entity to get the job from
414 *
415 * Process all dependencies and try to get one job from the entities queue.
416 */
drm_sched_entity_pop_job(struct drm_sched_entity * entity)417 struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
418 {
419 struct drm_gpu_scheduler *sched = entity->rq->sched;
420 struct drm_sched_job *sched_job;
421
422 sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
423 if (!sched_job)
424 return NULL;
425
426 while ((entity->dependency =
427 sched->ops->dependency(sched_job, entity))) {
428 trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
429
430 if (drm_sched_entity_add_dependency_cb(entity))
431 return NULL;
432 }
433
434 /* skip jobs from entity that marked guilty */
435 if (entity->guilty && atomic_read(entity->guilty))
436 dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED);
437
438 dma_fence_put(entity->last_scheduled);
439 entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished);
440
441 spsc_queue_pop(&entity->job_queue);
442 return sched_job;
443 }
444
445 /**
446 * drm_sched_entity_select_rq - select a new rq for the entity
447 *
448 * @entity: scheduler entity
449 *
450 * Check all prerequisites and select a new rq for the entity for load
451 * balancing.
452 */
drm_sched_entity_select_rq(struct drm_sched_entity * entity)453 void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
454 {
455 struct dma_fence *fence;
456 struct drm_gpu_scheduler *sched;
457 struct drm_sched_rq *rq;
458
459 if (spsc_queue_count(&entity->job_queue) || entity->num_sched_list <= 1)
460 return;
461
462 fence = READ_ONCE(entity->last_scheduled);
463 if (fence && !dma_fence_is_signaled(fence))
464 return;
465
466 spin_lock(&entity->rq_lock);
467 sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list);
468 rq = sched ? &sched->sched_rq[entity->priority] : NULL;
469 if (rq != entity->rq) {
470 drm_sched_rq_remove_entity(entity->rq, entity);
471 entity->rq = rq;
472 }
473
474 spin_unlock(&entity->rq_lock);
475 }
476
477 /**
478 * drm_sched_entity_push_job - Submit a job to the entity's job queue
479 *
480 * @sched_job: job to submit
481 * @entity: scheduler entity
482 *
483 * Note: To guarantee that the order of insertion to queue matches
484 * the job's fence sequence number this function should be
485 * called with drm_sched_job_init under common lock.
486 *
487 * Returns 0 for success, negative error code otherwise.
488 */
drm_sched_entity_push_job(struct drm_sched_job * sched_job,struct drm_sched_entity * entity)489 void drm_sched_entity_push_job(struct drm_sched_job *sched_job,
490 struct drm_sched_entity *entity)
491 {
492 bool first;
493
494 trace_drm_sched_job(sched_job, entity);
495 atomic_inc(&entity->rq->sched->score);
496 WRITE_ONCE(entity->last_user, current->group_leader);
497 first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
498
499 /* first job wakes up scheduler */
500 if (first) {
501 /* Add the entity to the run queue */
502 spin_lock(&entity->rq_lock);
503 if (entity->stopped) {
504 spin_unlock(&entity->rq_lock);
505
506 DRM_ERROR("Trying to push to a killed entity\n");
507 return;
508 }
509 drm_sched_rq_add_entity(entity->rq, entity);
510 spin_unlock(&entity->rq_lock);
511 drm_sched_wakeup(entity->rq->sched);
512 }
513 }
514 EXPORT_SYMBOL(drm_sched_entity_push_job);
515