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