drivers/gpu/drm/amd/scheduler/gpu_scheduler.c

   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/wait.h>
  26 #include <linux/sched.h>
  27 #include <uapi/linux/sched/types.h>
  28 #include <drm/drmP.h>
  29 #include "gpu_scheduler.h"
  30
  31 #define CREATE_TRACE_POINTS
  32 #include "gpu_sched_trace.h"
  33
  34 static bool amd_sched_entity_is_ready(struct amd_sched_entity *entity);
  35 static void amd_sched_wakeup(struct amd_gpu_scheduler *sched);
  36 static void amd_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb);
  37
  38 /* Initialize a given run queue struct */
  39 static void amd_sched_rq_init(struct amd_sched_rq *rq)
  40 {
  41         spin_lock_init(&rq->lock);
  42         INIT_LIST_HEAD(&rq->entities);
  43         rq->current_entity = NULL;
  44 }
  45
  46 static void amd_sched_rq_add_entity(struct amd_sched_rq *rq,
  47                                     struct amd_sched_entity *entity)
  48 {
  49         if (!list_empty(&entity->list))
  50                 return;
  51         spin_lock(&rq->lock);
  52         list_add_tail(&entity->list, &rq->entities);
  53         spin_unlock(&rq->lock);
  54 }
  55
  56 static void amd_sched_rq_remove_entity(struct amd_sched_rq *rq,
  57                                        struct amd_sched_entity *entity)
  58 {
  59         if (list_empty(&entity->list))
  60                 return;
  61         spin_lock(&rq->lock);
  62         list_del_init(&entity->list);
  63         if (rq->current_entity == entity)
  64                 rq->current_entity = NULL;
  65         spin_unlock(&rq->lock);
  66 }
  67
  68 /**
  69  * Select an entity which could provide a job to run
  70  *
  71  * @rq          The run queue to check.
  72  *
  73  * Try to find a ready entity, returns NULL if none found.
  74  */
  75 static struct amd_sched_entity *
  76 amd_sched_rq_select_entity(struct amd_sched_rq *rq)
  77 {
  78         struct amd_sched_entity *entity;
  79
  80         spin_lock(&rq->lock);
  81
  82         entity = rq->current_entity;
  83         if (entity) {
  84                 list_for_each_entry_continue(entity, &rq->entities, list) {
  85                         if (amd_sched_entity_is_ready(entity)) {
  86                                 rq->current_entity = entity;
  87                                 spin_unlock(&rq->lock);
  88                                 return entity;
  89                         }
  90                 }
  91         }
  92
  93         list_for_each_entry(entity, &rq->entities, list) {
  94
  95                 if (amd_sched_entity_is_ready(entity)) {
  96                         rq->current_entity = entity;
  97                         spin_unlock(&rq->lock);
  98                         return entity;
  99                 }
 100
 101                 if (entity == rq->current_entity)
 102                         break;
 103         }
 104
 105         spin_unlock(&rq->lock);
 106
 107         return NULL;
 108 }
 109
 110 /**
 111  * Init a context entity used by scheduler when submit to HW ring.
 112  *
 113  * @sched       The pointer to the scheduler
 114  * @entity      The pointer to a valid amd_sched_entity
 115  * @rq          The run queue this entity belongs
 116  * @kernel      If this is an entity for the kernel
 117  * @jobs        The max number of jobs in the job queue
 118  *
 119  * return 0 if succeed. negative error code on failure
 120 */
 121 int amd_sched_entity_init(struct amd_gpu_scheduler *sched,
 122                           struct amd_sched_entity *entity,
 123                           struct amd_sched_rq *rq,
 124                           uint32_t jobs)
 125 {
 126         int r;
 127
 128         if (!(sched && entity && rq))
 129                 return -EINVAL;
 130
 131         memset(entity, 0, sizeof(struct amd_sched_entity));
 132         INIT_LIST_HEAD(&entity->list);
 133         entity->rq = rq;
 134         entity->sched = sched;
 135
 136         spin_lock_init(&entity->rq_lock);
 137         spin_lock_init(&entity->queue_lock);
 138         r = kfifo_alloc(&entity->job_queue, jobs * sizeof(void *), GFP_KERNEL);
 139         if (r)
 140                 return r;
 141
 142         atomic_set(&entity->fence_seq, 0);
 143         entity->fence_context = dma_fence_context_alloc(2);
 144
 145         return 0;
 146 }
 147
 148 /**
 149  * Query if entity is initialized
 150  *
 151  * @sched       Pointer to scheduler instance
 152  * @entity      The pointer to a valid scheduler entity
 153  *
 154  * return true if entity is initialized, false otherwise
 155 */
 156 static bool amd_sched_entity_is_initialized(struct amd_gpu_scheduler *sched,
 157                                             struct amd_sched_entity *entity)
 158 {
 159         return entity->sched == sched &&
 160                 entity->rq != NULL;
 161 }
 162
 163 /**
 164  * Check if entity is idle
 165  *
 166  * @entity      The pointer to a valid scheduler entity
 167  *
 168  * Return true if entity don't has any unscheduled jobs.
 169  */
 170 static bool amd_sched_entity_is_idle(struct amd_sched_entity *entity)
 171 {
 172         rmb();
 173         if (kfifo_is_empty(&entity->job_queue))
 174                 return true;
 175
 176         return false;
 177 }
 178
 179 /**
 180  * Check if entity is ready
 181  *
 182  * @entity      The pointer to a valid scheduler entity
 183  *
 184  * Return true if entity could provide a job.
 185  */
 186 static bool amd_sched_entity_is_ready(struct amd_sched_entity *entity)
 187 {
 188         if (kfifo_is_empty(&entity->job_queue))
 189                 return false;
 190
 191         if (READ_ONCE(entity->dependency))
 192                 return false;
 193
 194         return true;
 195 }
 196
 197 /**
 198  * Destroy a context entity
 199  *
 200  * @sched       Pointer to scheduler instance
 201  * @entity      The pointer to a valid scheduler entity
 202  *
 203  * Cleanup and free the allocated resources.
 204  */
 205 void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 206                            struct amd_sched_entity *entity)
 207 {
 208         int r;
 209
 210         if (!amd_sched_entity_is_initialized(sched, entity))
 211                 return;
 212         /**
 213          * The client will not queue more IBs during this fini, consume existing
 214          * queued IBs or discard them on SIGKILL
 215         */
 216         if ((current->flags & PF_SIGNALED) && current->exit_code == SIGKILL)
 217                 r = -ERESTARTSYS;
 218         else
 219                 r = wait_event_killable(sched->job_scheduled,
 220                                         amd_sched_entity_is_idle(entity));
 221         amd_sched_entity_set_rq(entity, NULL);
 222         if (r) {
 223                 struct amd_sched_job *job;
 224
 225                 /* Park the kernel for a moment to make sure it isn't processing
 226                  * our enity.
 227                  */
 228                 kthread_park(sched->thread);
 229                 kthread_unpark(sched->thread);
 230                 while (kfifo_out(&entity->job_queue, &job, sizeof(job))) {
 231                         struct amd_sched_fence *s_fence = job->s_fence;
 232                         amd_sched_fence_scheduled(s_fence);
 233                         dma_fence_set_error(&s_fence->finished, -ESRCH);
 234                         amd_sched_fence_finished(s_fence);
 235                         dma_fence_put(&s_fence->finished);
 236                         sched->ops->free_job(job);
 237                 }
 238
 239         }
 240         kfifo_free(&entity->job_queue);
 241 }
 242
 243 static void amd_sched_entity_wakeup(struct dma_fence *f, struct dma_fence_cb *cb)
 244 {
 245         struct amd_sched_entity *entity =
 246                 container_of(cb, struct amd_sched_entity, cb);
 247         entity->dependency = NULL;
 248         dma_fence_put(f);
 249         amd_sched_wakeup(entity->sched);
 250 }
 251
 252 static void amd_sched_entity_clear_dep(struct dma_fence *f, struct dma_fence_cb *cb)
 253 {
 254         struct amd_sched_entity *entity =
 255                 container_of(cb, struct amd_sched_entity, cb);
 256         entity->dependency = NULL;
 257         dma_fence_put(f);
 258 }
 259
 260 void amd_sched_entity_set_rq(struct amd_sched_entity *entity,
 261                              struct amd_sched_rq *rq)
 262 {
 263         if (entity->rq == rq)
 264                 return;
 265
 266         spin_lock(&entity->rq_lock);
 267
 268         if (entity->rq)
 269                 amd_sched_rq_remove_entity(entity->rq, entity);
 270
 271         entity->rq = rq;
 272         if (rq)
 273                 amd_sched_rq_add_entity(rq, entity);
 274
 275         spin_unlock(&entity->rq_lock);
 276 }
 277
 278 bool amd_sched_dependency_optimized(struct dma_fence* fence,
 279                                     struct amd_sched_entity *entity)
 280 {
 281         struct amd_gpu_scheduler *sched = entity->sched;
 282         struct amd_sched_fence *s_fence;
 283
 284         if (!fence || dma_fence_is_signaled(fence))
 285                 return false;
 286         if (fence->context == entity->fence_context)
 287                 return true;
 288         s_fence = to_amd_sched_fence(fence);
 289         if (s_fence && s_fence->sched == sched)
 290                 return true;
 291
 292         return false;
 293 }
 294
 295 static bool amd_sched_entity_add_dependency_cb(struct amd_sched_entity *entity)
 296 {
 297         struct amd_gpu_scheduler *sched = entity->sched;
 298         struct dma_fence * fence = entity->dependency;
 299         struct amd_sched_fence *s_fence;
 300
 301         if (fence->context == entity->fence_context) {
 302                 /* We can ignore fences from ourself */
 303                 dma_fence_put(entity->dependency);
 304                 return false;
 305         }
 306
 307         s_fence = to_amd_sched_fence(fence);
 308         if (s_fence && s_fence->sched == sched) {
 309
 310                 /*
 311                  * Fence is from the same scheduler, only need to wait for
 312                  * it to be scheduled
 313                  */
 314                 fence = dma_fence_get(&s_fence->scheduled);
 315                 dma_fence_put(entity->dependency);
 316                 entity->dependency = fence;
 317                 if (!dma_fence_add_callback(fence, &entity->cb,
 318                                             amd_sched_entity_clear_dep))
 319                         return true;
 320
 321                 /* Ignore it when it is already scheduled */
 322                 dma_fence_put(fence);
 323                 return false;
 324         }
 325
 326         if (!dma_fence_add_callback(entity->dependency, &entity->cb,
 327                                     amd_sched_entity_wakeup))
 328                 return true;
 329
 330         dma_fence_put(entity->dependency);
 331         return false;
 332 }
 333
 334 static struct amd_sched_job *
 335 amd_sched_entity_peek_job(struct amd_sched_entity *entity)
 336 {
 337         struct amd_gpu_scheduler *sched = entity->sched;
 338         struct amd_sched_job *sched_job;
 339
 340         if (!kfifo_out_peek(&entity->job_queue, &sched_job, sizeof(sched_job)))
 341                 return NULL;
 342
 343         while ((entity->dependency = sched->ops->dependency(sched_job)))
 344                 if (amd_sched_entity_add_dependency_cb(entity))
 345                         return NULL;
 346
 347         return sched_job;
 348 }
 349
 350 /**
 351  * Helper to submit a job to the job queue
 352  *
 353  * @sched_job           The pointer to job required to submit
 354  *
 355  * Returns true if we could submit the job.
 356  */
 357 static bool amd_sched_entity_in(struct amd_sched_job *sched_job)
 358 {
 359         struct amd_gpu_scheduler *sched = sched_job->sched;
 360         struct amd_sched_entity *entity = sched_job->s_entity;
 361         bool added, first = false;
 362
 363         spin_lock(&entity->queue_lock);
 364         added = kfifo_in(&entity->job_queue, &sched_job,
 365                         sizeof(sched_job)) == sizeof(sched_job);
 366
 367         if (added && kfifo_len(&entity->job_queue) == sizeof(sched_job))
 368                 first = true;
 369
 370         spin_unlock(&entity->queue_lock);
 371
 372         /* first job wakes up scheduler */
 373         if (first) {
 374                 /* Add the entity to the run queue */
 375                 spin_lock(&entity->rq_lock);
 376                 amd_sched_rq_add_entity(entity->rq, entity);
 377                 spin_unlock(&entity->rq_lock);
 378                 amd_sched_wakeup(sched);
 379         }
 380         return added;
 381 }
 382
 383 /* job_finish is called after hw fence signaled
 384  */
 385 static void amd_sched_job_finish(struct work_struct *work)
 386 {
 387         struct amd_sched_job *s_job = container_of(work, struct amd_sched_job,
 388                                                    finish_work);
 389         struct amd_gpu_scheduler *sched = s_job->sched;
 390
 391         /* remove job from ring_mirror_list */
 392         spin_lock(&sched->job_list_lock);
 393         list_del_init(&s_job->node);
 394         if (sched->timeout != MAX_SCHEDULE_TIMEOUT) {
 395                 struct amd_sched_job *next;
 396
 397                 spin_unlock(&sched->job_list_lock);
 398                 cancel_delayed_work_sync(&s_job->work_tdr);
 399                 spin_lock(&sched->job_list_lock);
 400
 401                 /* queue TDR for next job */
 402                 next = list_first_entry_or_null(&sched->ring_mirror_list,
 403                                                 struct amd_sched_job, node);
 404
 405                 if (next)
 406                         schedule_delayed_work(&next->work_tdr, sched->timeout);
 407         }
 408         spin_unlock(&sched->job_list_lock);
 409         dma_fence_put(&s_job->s_fence->finished);
 410         sched->ops->free_job(s_job);
 411 }
 412
 413 static void amd_sched_job_finish_cb(struct dma_fence *f,
 414                                     struct dma_fence_cb *cb)
 415 {
 416         struct amd_sched_job *job = container_of(cb, struct amd_sched_job,
 417                                                  finish_cb);
 418         schedule_work(&job->finish_work);
 419 }
 420
 421 static void amd_sched_job_begin(struct amd_sched_job *s_job)
 422 {
 423         struct amd_gpu_scheduler *sched = s_job->sched;
 424
 425         dma_fence_add_callback(&s_job->s_fence->finished, &s_job->finish_cb,
 426                                amd_sched_job_finish_cb);
 427
 428         spin_lock(&sched->job_list_lock);
 429         list_add_tail(&s_job->node, &sched->ring_mirror_list);
 430         if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
 431             list_first_entry_or_null(&sched->ring_mirror_list,
 432                                      struct amd_sched_job, node) == s_job)
 433                 schedule_delayed_work(&s_job->work_tdr, sched->timeout);
 434         spin_unlock(&sched->job_list_lock);
 435 }
 436
 437 static void amd_sched_job_timedout(struct work_struct *work)
 438 {
 439         struct amd_sched_job *job = container_of(work, struct amd_sched_job,
 440                                                  work_tdr.work);
 441
 442         job->sched->ops->timedout_job(job);
 443 }
 444
 445 void amd_sched_hw_job_reset(struct amd_gpu_scheduler *sched)
 446 {
 447         struct amd_sched_job *s_job;
 448
 449         spin_lock(&sched->job_list_lock);
 450         list_for_each_entry_reverse(s_job, &sched->ring_mirror_list, node) {
 451                 if (s_job->s_fence->parent &&
 452                     dma_fence_remove_callback(s_job->s_fence->parent,
 453                                               &s_job->s_fence->cb)) {
 454                         dma_fence_put(s_job->s_fence->parent);
 455                         s_job->s_fence->parent = NULL;
 456                         atomic_dec(&sched->hw_rq_count);
 457                 }
 458         }
 459         spin_unlock(&sched->job_list_lock);
 460 }
 461
 462 void amd_sched_job_kickout(struct amd_sched_job *s_job)
 463 {
 464         struct amd_gpu_scheduler *sched = s_job->sched;
 465
 466         spin_lock(&sched->job_list_lock);
 467         list_del_init(&s_job->node);
 468         spin_unlock(&sched->job_list_lock);
 469 }
 470
 471 void amd_sched_job_recovery(struct amd_gpu_scheduler *sched)
 472 {
 473         struct amd_sched_job *s_job, *tmp;
 474         int r;
 475
 476         spin_lock(&sched->job_list_lock);
 477         s_job = list_first_entry_or_null(&sched->ring_mirror_list,
 478                                          struct amd_sched_job, node);
 479         if (s_job && sched->timeout != MAX_SCHEDULE_TIMEOUT)
 480                 schedule_delayed_work(&s_job->work_tdr, sched->timeout);
 481
 482         list_for_each_entry_safe(s_job, tmp, &sched->ring_mirror_list, node) {
 483                 struct amd_sched_fence *s_fence = s_job->s_fence;
 484                 struct dma_fence *fence;
 485
 486                 spin_unlock(&sched->job_list_lock);
 487                 fence = sched->ops->run_job(s_job);
 488                 atomic_inc(&sched->hw_rq_count);
 489                 if (fence) {
 490                         s_fence->parent = dma_fence_get(fence);
 491                         r = dma_fence_add_callback(fence, &s_fence->cb,
 492                                                    amd_sched_process_job);
 493                         if (r == -ENOENT)
 494                                 amd_sched_process_job(fence, &s_fence->cb);
 495                         else if (r)
 496                                 DRM_ERROR("fence add callback failed (%d)\n",
 497                                           r);
 498                         dma_fence_put(fence);
 499                 } else {
 500                         DRM_ERROR("Failed to run job!\n");
 501                         amd_sched_process_job(NULL, &s_fence->cb);
 502                 }
 503                 spin_lock(&sched->job_list_lock);
 504         }
 505         spin_unlock(&sched->job_list_lock);
 506 }
 507
 508 /**
 509  * Submit a job to the job queue
 510  *
 511  * @sched_job           The pointer to job required to submit
 512  *
 513  * Returns 0 for success, negative error code otherwise.
 514  */
 515 void amd_sched_entity_push_job(struct amd_sched_job *sched_job)
 516 {
 517         struct amd_sched_entity *entity = sched_job->s_entity;
 518
 519         trace_amd_sched_job(sched_job);
 520         wait_event(entity->sched->job_scheduled,
 521                    amd_sched_entity_in(sched_job));
 522 }
 523
 524 /* init a sched_job with basic field */
 525 int amd_sched_job_init(struct amd_sched_job *job,
 526                        struct amd_gpu_scheduler *sched,
 527                        struct amd_sched_entity *entity,
 528                        void *owner)
 529 {
 530         job->sched = sched;
 531         job->s_entity = entity;
 532         job->s_fence = amd_sched_fence_create(entity, owner);
 533         if (!job->s_fence)
 534                 return -ENOMEM;
 535         job->id = atomic64_inc_return(&sched->job_id_count);
 536
 537         INIT_WORK(&job->finish_work, amd_sched_job_finish);
 538         INIT_LIST_HEAD(&job->node);
 539         INIT_DELAYED_WORK(&job->work_tdr, amd_sched_job_timedout);
 540
 541         return 0;
 542 }
 543
 544 /**
 545  * Return ture if we can push more jobs to the hw.
 546  */
 547 static bool amd_sched_ready(struct amd_gpu_scheduler *sched)
 548 {
 549         return atomic_read(&sched->hw_rq_count) <
 550                 sched->hw_submission_limit;
 551 }
 552
 553 /**
 554  * Wake up the scheduler when it is ready
 555  */
 556 static void amd_sched_wakeup(struct amd_gpu_scheduler *sched)
 557 {
 558         if (amd_sched_ready(sched))
 559                 wake_up_interruptible(&sched->wake_up_worker);
 560 }
 561
 562 /**
 563  * Select next entity to process
 564 */
 565 static struct amd_sched_entity *
 566 amd_sched_select_entity(struct amd_gpu_scheduler *sched)
 567 {
 568         struct amd_sched_entity *entity;
 569         int i;
 570
 571         if (!amd_sched_ready(sched))
 572                 return NULL;
 573
 574         /* Kernel run queue has higher priority than normal run queue*/
 575         for (i = AMD_SCHED_PRIORITY_MAX - 1; i >= AMD_SCHED_PRIORITY_MIN; i--) {
 576                 entity = amd_sched_rq_select_entity(&sched->sched_rq[i]);
 577                 if (entity)
 578                         break;
 579         }
 580
 581         return entity;
 582 }
 583
 584 static void amd_sched_process_job(struct dma_fence *f, struct dma_fence_cb *cb)
 585 {
 586         struct amd_sched_fence *s_fence =
 587                 container_of(cb, struct amd_sched_fence, cb);
 588         struct amd_gpu_scheduler *sched = s_fence->sched;
 589
 590         dma_fence_get(&s_fence->finished);
 591         atomic_dec(&sched->hw_rq_count);
 592         amd_sched_fence_finished(s_fence);
 593
 594         trace_amd_sched_process_job(s_fence);
 595         dma_fence_put(&s_fence->finished);
 596         wake_up_interruptible(&sched->wake_up_worker);
 597 }
 598
 599 static bool amd_sched_blocked(struct amd_gpu_scheduler *sched)
 600 {
 601         if (kthread_should_park()) {
 602                 kthread_parkme();
 603                 return true;
 604         }
 605
 606         return false;
 607 }
 608
 609 static int amd_sched_main(void *param)
 610 {
 611         struct sched_param sparam = {.sched_priority = 1};
 612         struct amd_gpu_scheduler *sched = (struct amd_gpu_scheduler *)param;
 613         int r, count;
 614
 615         sched_setscheduler(current, SCHED_FIFO, &sparam);
 616
 617         while (!kthread_should_stop()) {
 618                 struct amd_sched_entity *entity = NULL;
 619                 struct amd_sched_fence *s_fence;
 620                 struct amd_sched_job *sched_job;
 621                 struct dma_fence *fence;
 622
 623                 wait_event_interruptible(sched->wake_up_worker,
 624                                          (!amd_sched_blocked(sched) &&
 625                                           (entity = amd_sched_select_entity(sched))) ||
 626                                          kthread_should_stop());
 627
 628                 if (!entity)
 629                         continue;
 630
 631                 sched_job = amd_sched_entity_peek_job(entity);
 632                 if (!sched_job)
 633                         continue;
 634
 635                 s_fence = sched_job->s_fence;
 636
 637                 atomic_inc(&sched->hw_rq_count);
 638                 amd_sched_job_begin(sched_job);
 639
 640                 fence = sched->ops->run_job(sched_job);
 641                 amd_sched_fence_scheduled(s_fence);
 642
 643                 if (fence) {
 644                         s_fence->parent = dma_fence_get(fence);
 645                         r = dma_fence_add_callback(fence, &s_fence->cb,
 646                                                    amd_sched_process_job);
 647                         if (r == -ENOENT)
 648                                 amd_sched_process_job(fence, &s_fence->cb);
 649                         else if (r)
 650                                 DRM_ERROR("fence add callback failed (%d)\n",
 651                                           r);
 652                         dma_fence_put(fence);
 653                 } else {
 654                         DRM_ERROR("Failed to run job!\n");
 655                         amd_sched_process_job(NULL, &s_fence->cb);
 656                 }
 657
 658                 count = kfifo_out(&entity->job_queue, &sched_job,
 659                                 sizeof(sched_job));
 660                 WARN_ON(count != sizeof(sched_job));
 661                 wake_up(&sched->job_scheduled);
 662         }
 663         return 0;
 664 }
 665
 666 /**
 667  * Init a gpu scheduler instance
 668  *
 669  * @sched               The pointer to the scheduler
 670  * @ops                 The backend operations for this scheduler.
 671  * @hw_submissions      Number of hw submissions to do.
 672  * @name                Name used for debugging
 673  *
 674  * Return 0 on success, otherwise error code.
 675 */
 676 int amd_sched_init(struct amd_gpu_scheduler *sched,
 677                    const struct amd_sched_backend_ops *ops,
 678                    unsigned hw_submission, long timeout, const char *name)
 679 {
 680         int i;
 681         sched->ops = ops;
 682         sched->hw_submission_limit = hw_submission;
 683         sched->name = name;
 684         sched->timeout = timeout;
 685         for (i = AMD_SCHED_PRIORITY_MIN; i < AMD_SCHED_PRIORITY_MAX; i++)
 686                 amd_sched_rq_init(&sched->sched_rq[i]);
 687
 688         init_waitqueue_head(&sched->wake_up_worker);
 689         init_waitqueue_head(&sched->job_scheduled);
 690         INIT_LIST_HEAD(&sched->ring_mirror_list);
 691         spin_lock_init(&sched->job_list_lock);
 692         atomic_set(&sched->hw_rq_count, 0);
 693         atomic64_set(&sched->job_id_count, 0);
 694
 695         /* Each scheduler will run on a seperate kernel thread */
 696         sched->thread = kthread_run(amd_sched_main, sched, sched->name);
 697         if (IS_ERR(sched->thread)) {
 698                 DRM_ERROR("Failed to create scheduler for %s.\n", name);
 699                 return PTR_ERR(sched->thread);
 700         }
 701
 702         return 0;
 703 }
 704
 705 /**
 706  * Destroy a gpu scheduler
 707  *
 708  * @sched       The pointer to the scheduler
 709  */
 710 void amd_sched_fini(struct amd_gpu_scheduler *sched)
 711 {
 712         if (sched->thread)
 713                 kthread_stop(sched->thread);
 714 }