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 /** 25 * DOC: Overview 26 * 27 * The GPU scheduler provides entities which allow userspace to push jobs 28 * into software queues which are then scheduled on a hardware run queue. 29 * The software queues have a priority among them. The scheduler selects the entities 30 * from the run queue using a FIFO. The scheduler provides dependency handling 31 * features among jobs. The driver is supposed to provide callback functions for 32 * backend operations to the scheduler like submitting a job to hardware run queue, 33 * returning the dependencies of a job etc. 34 * 35 * The organisation of the scheduler is the following: 36 * 37 * 1. Each hw run queue has one scheduler 38 * 2. Each scheduler has multiple run queues with different priorities 39 * (e.g., HIGH_HW,HIGH_SW, KERNEL, NORMAL) 40 * 3. Each scheduler run queue has a queue of entities to schedule 41 * 4. Entities themselves maintain a queue of jobs that will be scheduled on 42 * the hardware. 43 * 44 * The jobs in an entity are always scheduled in the order in which they were pushed. 45 * 46 * Note that once a job was taken from the entities queue and pushed to the 47 * hardware, i.e. the pending queue, the entity must not be referenced anymore 48 * through the jobs entity pointer. 49 */ 50 51 /** 52 * DOC: Flow Control 53 * 54 * The DRM GPU scheduler provides a flow control mechanism to regulate the rate 55 * in which the jobs fetched from scheduler entities are executed. 56 * 57 * In this context the &drm_gpu_scheduler keeps track of a driver specified 58 * credit limit representing the capacity of this scheduler and a credit count; 59 * every &drm_sched_job carries a driver specified number of credits. 60 * 61 * Once a job is executed (but not yet finished), the job's credits contribute 62 * to the scheduler's credit count until the job is finished. If by executing 63 * one more job the scheduler's credit count would exceed the scheduler's 64 * credit limit, the job won't be executed. Instead, the scheduler will wait 65 * until the credit count has decreased enough to not overflow its credit limit. 66 * This implies waiting for previously executed jobs. 67 */ 68 69 #include <linux/export.h> 70 #include <linux/wait.h> 71 #include <linux/sched.h> 72 #include <linux/completion.h> 73 #include <linux/dma-resv.h> 74 #include <uapi/linux/sched/types.h> 75 76 #include <drm/drm_print.h> 77 #include <drm/drm_gem.h> 78 #include <drm/drm_syncobj.h> 79 #include <drm/gpu_scheduler.h> 80 #include <drm/spsc_queue.h> 81 82 #include "sched_internal.h" 83 84 #define CREATE_TRACE_POINTS 85 #include "gpu_scheduler_trace.h" 86 87 int drm_sched_policy = DRM_SCHED_POLICY_FIFO; 88 89 /** 90 * DOC: sched_policy (int) 91 * Used to override default entities scheduling policy in a run queue. 92 */ 93 MODULE_PARM_DESC(sched_policy, "Specify the scheduling policy for entities on a run-queue, " __stringify(DRM_SCHED_POLICY_RR) " = Round Robin, " __stringify(DRM_SCHED_POLICY_FIFO) " = FIFO (default)."); 94 module_param_named(sched_policy, drm_sched_policy, int, 0444); 95 96 static u32 drm_sched_available_credits(struct drm_gpu_scheduler *sched) 97 { 98 u32 credits; 99 100 WARN_ON(check_sub_overflow(sched->credit_limit, 101 atomic_read(&sched->credit_count), 102 &credits)); 103 104 return credits; 105 } 106 107 /** 108 * drm_sched_can_queue -- Can we queue more to the hardware? 109 * @sched: scheduler instance 110 * @entity: the scheduler entity 111 * 112 * Return true if we can push at least one more job from @entity, false 113 * otherwise. 114 */ 115 static bool drm_sched_can_queue(struct drm_gpu_scheduler *sched, 116 struct drm_sched_entity *entity) 117 { 118 struct drm_sched_job *s_job; 119 120 s_job = drm_sched_entity_queue_peek(entity); 121 if (!s_job) 122 return false; 123 124 /* If a job exceeds the credit limit, truncate it to the credit limit 125 * itself to guarantee forward progress. 126 */ 127 if (s_job->credits > sched->credit_limit) { 128 dev_WARN(sched->dev, 129 "Jobs may not exceed the credit limit, truncate.\n"); 130 s_job->credits = sched->credit_limit; 131 } 132 133 return drm_sched_available_credits(sched) >= s_job->credits; 134 } 135 136 static __always_inline bool drm_sched_entity_compare_before(struct rb_node *a, 137 const struct rb_node *b) 138 { 139 struct drm_sched_entity *ent_a = rb_entry((a), struct drm_sched_entity, rb_tree_node); 140 struct drm_sched_entity *ent_b = rb_entry((b), struct drm_sched_entity, rb_tree_node); 141 142 return ktime_before(ent_a->oldest_job_waiting, ent_b->oldest_job_waiting); 143 } 144 145 static void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity, 146 struct drm_sched_rq *rq) 147 { 148 if (!RB_EMPTY_NODE(&entity->rb_tree_node)) { 149 rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root); 150 RB_CLEAR_NODE(&entity->rb_tree_node); 151 } 152 } 153 154 void drm_sched_rq_update_fifo_locked(struct drm_sched_entity *entity, 155 struct drm_sched_rq *rq, 156 ktime_t ts) 157 { 158 /* 159 * Both locks need to be grabbed, one to protect from entity->rq change 160 * for entity from within concurrent drm_sched_entity_select_rq and the 161 * other to update the rb tree structure. 162 */ 163 lockdep_assert_held(&entity->lock); 164 lockdep_assert_held(&rq->lock); 165 166 drm_sched_rq_remove_fifo_locked(entity, rq); 167 168 entity->oldest_job_waiting = ts; 169 170 rb_add_cached(&entity->rb_tree_node, &rq->rb_tree_root, 171 drm_sched_entity_compare_before); 172 } 173 174 /** 175 * drm_sched_rq_init - initialize a given run queue struct 176 * 177 * @sched: scheduler instance to associate with this run queue 178 * @rq: scheduler run queue 179 * 180 * Initializes a scheduler runqueue. 181 */ 182 static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, 183 struct drm_sched_rq *rq) 184 { 185 spin_lock_init(&rq->lock); 186 INIT_LIST_HEAD(&rq->entities); 187 rq->rb_tree_root = RB_ROOT_CACHED; 188 rq->current_entity = NULL; 189 rq->sched = sched; 190 } 191 192 /** 193 * drm_sched_rq_add_entity - add an entity 194 * 195 * @rq: scheduler run queue 196 * @entity: scheduler entity 197 * 198 * Adds a scheduler entity to the run queue. 199 */ 200 void drm_sched_rq_add_entity(struct drm_sched_rq *rq, 201 struct drm_sched_entity *entity) 202 { 203 lockdep_assert_held(&entity->lock); 204 lockdep_assert_held(&rq->lock); 205 206 if (!list_empty(&entity->list)) 207 return; 208 209 atomic_inc(rq->sched->score); 210 list_add_tail(&entity->list, &rq->entities); 211 } 212 213 /** 214 * drm_sched_rq_remove_entity - remove an entity 215 * 216 * @rq: scheduler run queue 217 * @entity: scheduler entity 218 * 219 * Removes a scheduler entity from the run queue. 220 */ 221 void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, 222 struct drm_sched_entity *entity) 223 { 224 lockdep_assert_held(&entity->lock); 225 226 if (list_empty(&entity->list)) 227 return; 228 229 spin_lock(&rq->lock); 230 231 atomic_dec(rq->sched->score); 232 list_del_init(&entity->list); 233 234 if (rq->current_entity == entity) 235 rq->current_entity = NULL; 236 237 if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) 238 drm_sched_rq_remove_fifo_locked(entity, rq); 239 240 spin_unlock(&rq->lock); 241 } 242 243 /** 244 * drm_sched_rq_select_entity_rr - Select an entity which could provide a job to run 245 * 246 * @sched: the gpu scheduler 247 * @rq: scheduler run queue to check. 248 * 249 * Try to find the next ready entity. 250 * 251 * Return an entity if one is found; return an error-pointer (!NULL) if an 252 * entity was ready, but the scheduler had insufficient credits to accommodate 253 * its job; return NULL, if no ready entity was found. 254 */ 255 static struct drm_sched_entity * 256 drm_sched_rq_select_entity_rr(struct drm_gpu_scheduler *sched, 257 struct drm_sched_rq *rq) 258 { 259 struct drm_sched_entity *entity; 260 261 spin_lock(&rq->lock); 262 263 entity = rq->current_entity; 264 if (entity) { 265 list_for_each_entry_continue(entity, &rq->entities, list) { 266 if (drm_sched_entity_is_ready(entity)) { 267 /* If we can't queue yet, preserve the current 268 * entity in terms of fairness. 269 */ 270 if (!drm_sched_can_queue(sched, entity)) { 271 spin_unlock(&rq->lock); 272 return ERR_PTR(-ENOSPC); 273 } 274 275 rq->current_entity = entity; 276 reinit_completion(&entity->entity_idle); 277 spin_unlock(&rq->lock); 278 return entity; 279 } 280 } 281 } 282 283 list_for_each_entry(entity, &rq->entities, list) { 284 if (drm_sched_entity_is_ready(entity)) { 285 /* If we can't queue yet, preserve the current entity in 286 * terms of fairness. 287 */ 288 if (!drm_sched_can_queue(sched, entity)) { 289 spin_unlock(&rq->lock); 290 return ERR_PTR(-ENOSPC); 291 } 292 293 rq->current_entity = entity; 294 reinit_completion(&entity->entity_idle); 295 spin_unlock(&rq->lock); 296 return entity; 297 } 298 299 if (entity == rq->current_entity) 300 break; 301 } 302 303 spin_unlock(&rq->lock); 304 305 return NULL; 306 } 307 308 /** 309 * drm_sched_rq_select_entity_fifo - Select an entity which provides a job to run 310 * 311 * @sched: the gpu scheduler 312 * @rq: scheduler run queue to check. 313 * 314 * Find oldest waiting ready entity. 315 * 316 * Return an entity if one is found; return an error-pointer (!NULL) if an 317 * entity was ready, but the scheduler had insufficient credits to accommodate 318 * its job; return NULL, if no ready entity was found. 319 */ 320 static struct drm_sched_entity * 321 drm_sched_rq_select_entity_fifo(struct drm_gpu_scheduler *sched, 322 struct drm_sched_rq *rq) 323 { 324 struct rb_node *rb; 325 326 spin_lock(&rq->lock); 327 for (rb = rb_first_cached(&rq->rb_tree_root); rb; rb = rb_next(rb)) { 328 struct drm_sched_entity *entity; 329 330 entity = rb_entry(rb, struct drm_sched_entity, rb_tree_node); 331 if (drm_sched_entity_is_ready(entity)) { 332 /* If we can't queue yet, preserve the current entity in 333 * terms of fairness. 334 */ 335 if (!drm_sched_can_queue(sched, entity)) { 336 spin_unlock(&rq->lock); 337 return ERR_PTR(-ENOSPC); 338 } 339 340 reinit_completion(&entity->entity_idle); 341 break; 342 } 343 } 344 spin_unlock(&rq->lock); 345 346 return rb ? rb_entry(rb, struct drm_sched_entity, rb_tree_node) : NULL; 347 } 348 349 /** 350 * drm_sched_run_job_queue - enqueue run-job work 351 * @sched: scheduler instance 352 */ 353 static void drm_sched_run_job_queue(struct drm_gpu_scheduler *sched) 354 { 355 if (!READ_ONCE(sched->pause_submit)) 356 queue_work(sched->submit_wq, &sched->work_run_job); 357 } 358 359 /** 360 * __drm_sched_run_free_queue - enqueue free-job work 361 * @sched: scheduler instance 362 */ 363 static void __drm_sched_run_free_queue(struct drm_gpu_scheduler *sched) 364 { 365 if (!READ_ONCE(sched->pause_submit)) 366 queue_work(sched->submit_wq, &sched->work_free_job); 367 } 368 369 /** 370 * drm_sched_run_free_queue - enqueue free-job work if ready 371 * @sched: scheduler instance 372 */ 373 static void drm_sched_run_free_queue(struct drm_gpu_scheduler *sched) 374 { 375 struct drm_sched_job *job; 376 377 spin_lock(&sched->job_list_lock); 378 job = list_first_entry_or_null(&sched->pending_list, 379 struct drm_sched_job, list); 380 if (job && dma_fence_is_signaled(&job->s_fence->finished)) 381 __drm_sched_run_free_queue(sched); 382 spin_unlock(&sched->job_list_lock); 383 } 384 385 /** 386 * drm_sched_job_done - complete a job 387 * @s_job: pointer to the job which is done 388 * 389 * Finish the job's fence and resubmit the work items. 390 */ 391 static void drm_sched_job_done(struct drm_sched_job *s_job, int result) 392 { 393 struct drm_sched_fence *s_fence = s_job->s_fence; 394 struct drm_gpu_scheduler *sched = s_fence->sched; 395 396 atomic_sub(s_job->credits, &sched->credit_count); 397 atomic_dec(sched->score); 398 399 trace_drm_sched_job_done(s_fence); 400 401 dma_fence_get(&s_fence->finished); 402 drm_sched_fence_finished(s_fence, result); 403 dma_fence_put(&s_fence->finished); 404 __drm_sched_run_free_queue(sched); 405 } 406 407 /** 408 * drm_sched_job_done_cb - the callback for a done job 409 * @f: fence 410 * @cb: fence callbacks 411 */ 412 static void drm_sched_job_done_cb(struct dma_fence *f, struct dma_fence_cb *cb) 413 { 414 struct drm_sched_job *s_job = container_of(cb, struct drm_sched_job, cb); 415 416 drm_sched_job_done(s_job, f->error); 417 } 418 419 /** 420 * drm_sched_start_timeout - start timeout for reset worker 421 * 422 * @sched: scheduler instance to start the worker for 423 * 424 * Start the timeout for the given scheduler. 425 */ 426 static void drm_sched_start_timeout(struct drm_gpu_scheduler *sched) 427 { 428 lockdep_assert_held(&sched->job_list_lock); 429 430 if (sched->timeout != MAX_SCHEDULE_TIMEOUT && 431 !list_empty(&sched->pending_list)) 432 mod_delayed_work(sched->timeout_wq, &sched->work_tdr, sched->timeout); 433 } 434 435 static void drm_sched_start_timeout_unlocked(struct drm_gpu_scheduler *sched) 436 { 437 spin_lock(&sched->job_list_lock); 438 drm_sched_start_timeout(sched); 439 spin_unlock(&sched->job_list_lock); 440 } 441 442 /** 443 * drm_sched_tdr_queue_imm: - immediately start job timeout handler 444 * 445 * @sched: scheduler for which the timeout handling should be started. 446 * 447 * Start timeout handling immediately for the named scheduler. 448 */ 449 void drm_sched_tdr_queue_imm(struct drm_gpu_scheduler *sched) 450 { 451 spin_lock(&sched->job_list_lock); 452 sched->timeout = 0; 453 drm_sched_start_timeout(sched); 454 spin_unlock(&sched->job_list_lock); 455 } 456 EXPORT_SYMBOL(drm_sched_tdr_queue_imm); 457 458 /** 459 * drm_sched_fault - immediately start timeout handler 460 * 461 * @sched: scheduler where the timeout handling should be started. 462 * 463 * Start timeout handling immediately when the driver detects a hardware fault. 464 */ 465 void drm_sched_fault(struct drm_gpu_scheduler *sched) 466 { 467 if (sched->timeout_wq) 468 mod_delayed_work(sched->timeout_wq, &sched->work_tdr, 0); 469 } 470 EXPORT_SYMBOL(drm_sched_fault); 471 472 /** 473 * drm_sched_suspend_timeout - Suspend scheduler job timeout 474 * 475 * @sched: scheduler instance for which to suspend the timeout 476 * 477 * Suspend the delayed work timeout for the scheduler. This is done by 478 * modifying the delayed work timeout to an arbitrary large value, 479 * MAX_SCHEDULE_TIMEOUT in this case. 480 * 481 * Returns the timeout remaining 482 * 483 */ 484 unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched) 485 { 486 unsigned long sched_timeout, now = jiffies; 487 488 sched_timeout = sched->work_tdr.timer.expires; 489 490 /* 491 * Modify the timeout to an arbitrarily large value. This also prevents 492 * the timeout to be restarted when new submissions arrive 493 */ 494 if (mod_delayed_work(sched->timeout_wq, &sched->work_tdr, MAX_SCHEDULE_TIMEOUT) 495 && time_after(sched_timeout, now)) 496 return sched_timeout - now; 497 else 498 return sched->timeout; 499 } 500 EXPORT_SYMBOL(drm_sched_suspend_timeout); 501 502 /** 503 * drm_sched_resume_timeout - Resume scheduler job timeout 504 * 505 * @sched: scheduler instance for which to resume the timeout 506 * @remaining: remaining timeout 507 * 508 * Resume the delayed work timeout for the scheduler. 509 */ 510 void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched, 511 unsigned long remaining) 512 { 513 spin_lock(&sched->job_list_lock); 514 515 if (list_empty(&sched->pending_list)) 516 cancel_delayed_work(&sched->work_tdr); 517 else 518 mod_delayed_work(sched->timeout_wq, &sched->work_tdr, remaining); 519 520 spin_unlock(&sched->job_list_lock); 521 } 522 EXPORT_SYMBOL(drm_sched_resume_timeout); 523 524 static void drm_sched_job_begin(struct drm_sched_job *s_job) 525 { 526 struct drm_gpu_scheduler *sched = s_job->sched; 527 528 spin_lock(&sched->job_list_lock); 529 list_add_tail(&s_job->list, &sched->pending_list); 530 drm_sched_start_timeout(sched); 531 spin_unlock(&sched->job_list_lock); 532 } 533 534 static void drm_sched_job_timedout(struct work_struct *work) 535 { 536 struct drm_gpu_scheduler *sched; 537 struct drm_sched_job *job; 538 enum drm_gpu_sched_stat status = DRM_GPU_SCHED_STAT_NOMINAL; 539 540 sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work); 541 542 /* Protects against concurrent deletion in drm_sched_get_finished_job */ 543 spin_lock(&sched->job_list_lock); 544 job = list_first_entry_or_null(&sched->pending_list, 545 struct drm_sched_job, list); 546 547 if (job) { 548 /* 549 * Remove the bad job so it cannot be freed by a concurrent 550 * &struct drm_sched_backend_ops.free_job. It will be 551 * reinserted after the scheduler's work items have been 552 * cancelled, at which point it's safe. 553 */ 554 list_del_init(&job->list); 555 spin_unlock(&sched->job_list_lock); 556 557 status = job->sched->ops->timedout_job(job); 558 559 /* 560 * Guilty job did complete and hence needs to be manually removed 561 * See drm_sched_stop doc. 562 */ 563 if (sched->free_guilty) { 564 job->sched->ops->free_job(job); 565 sched->free_guilty = false; 566 } 567 } else { 568 spin_unlock(&sched->job_list_lock); 569 } 570 571 if (status != DRM_GPU_SCHED_STAT_ENODEV) 572 drm_sched_start_timeout_unlocked(sched); 573 } 574 575 /** 576 * drm_sched_stop - stop the scheduler 577 * 578 * @sched: scheduler instance 579 * @bad: job which caused the time out 580 * 581 * Stop the scheduler and also removes and frees all completed jobs. 582 * Note: bad job will not be freed as it might be used later and so it's 583 * callers responsibility to release it manually if it's not part of the 584 * pending list any more. 585 * 586 * This function is typically used for reset recovery (see the docu of 587 * drm_sched_backend_ops.timedout_job() for details). Do not call it for 588 * scheduler teardown, i.e., before calling drm_sched_fini(). 589 */ 590 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad) 591 { 592 struct drm_sched_job *s_job, *tmp; 593 594 drm_sched_wqueue_stop(sched); 595 596 /* 597 * Reinsert back the bad job here - now it's safe as 598 * drm_sched_get_finished_job() cannot race against us and release the 599 * bad job at this point - we parked (waited for) any in progress 600 * (earlier) cleanups and drm_sched_get_finished_job() will not be 601 * called now until the scheduler's work items are submitted again. 602 */ 603 if (bad && bad->sched == sched) 604 /* 605 * Add at the head of the queue to reflect it was the earliest 606 * job extracted. 607 */ 608 list_add(&bad->list, &sched->pending_list); 609 610 /* 611 * Iterate the job list from later to earlier one and either deactive 612 * their HW callbacks or remove them from pending list if they already 613 * signaled. 614 * This iteration is thread safe as the scheduler's work items have been 615 * cancelled. 616 */ 617 list_for_each_entry_safe_reverse(s_job, tmp, &sched->pending_list, 618 list) { 619 if (s_job->s_fence->parent && 620 dma_fence_remove_callback(s_job->s_fence->parent, 621 &s_job->cb)) { 622 dma_fence_put(s_job->s_fence->parent); 623 s_job->s_fence->parent = NULL; 624 atomic_sub(s_job->credits, &sched->credit_count); 625 } else { 626 /* 627 * remove job from pending_list. 628 * Locking here is for concurrent resume timeout 629 */ 630 spin_lock(&sched->job_list_lock); 631 list_del_init(&s_job->list); 632 spin_unlock(&sched->job_list_lock); 633 634 /* 635 * Wait for job's HW fence callback to finish using s_job 636 * before releasing it. 637 * 638 * Job is still alive so fence refcount at least 1 639 */ 640 dma_fence_wait(&s_job->s_fence->finished, false); 641 642 /* 643 * We must keep bad job alive for later use during 644 * recovery by some of the drivers but leave a hint 645 * that the guilty job must be released. 646 */ 647 if (bad != s_job) 648 sched->ops->free_job(s_job); 649 else 650 sched->free_guilty = true; 651 } 652 } 653 654 /* 655 * Stop pending timer in flight as we rearm it in drm_sched_start. This 656 * avoids the pending timeout work in progress to fire right away after 657 * this TDR finished and before the newly restarted jobs had a 658 * chance to complete. 659 */ 660 cancel_delayed_work(&sched->work_tdr); 661 } 662 EXPORT_SYMBOL(drm_sched_stop); 663 664 /** 665 * drm_sched_start - recover jobs after a reset 666 * 667 * @sched: scheduler instance 668 * @errno: error to set on the pending fences 669 * 670 * This function is typically used for reset recovery (see the docu of 671 * drm_sched_backend_ops.timedout_job() for details). Do not call it for 672 * scheduler startup. The scheduler itself is fully operational after 673 * drm_sched_init() succeeded. 674 */ 675 void drm_sched_start(struct drm_gpu_scheduler *sched, int errno) 676 { 677 struct drm_sched_job *s_job, *tmp; 678 679 /* 680 * Locking the list is not required here as the scheduler's work items 681 * are currently not running, so no new jobs are being inserted or 682 * removed. Also concurrent GPU recovers can't run in parallel. 683 */ 684 list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) { 685 struct dma_fence *fence = s_job->s_fence->parent; 686 687 atomic_add(s_job->credits, &sched->credit_count); 688 689 if (!fence) { 690 drm_sched_job_done(s_job, errno ?: -ECANCELED); 691 continue; 692 } 693 694 if (dma_fence_add_callback(fence, &s_job->cb, 695 drm_sched_job_done_cb)) 696 drm_sched_job_done(s_job, fence->error ?: errno); 697 } 698 699 drm_sched_start_timeout_unlocked(sched); 700 drm_sched_wqueue_start(sched); 701 } 702 EXPORT_SYMBOL(drm_sched_start); 703 704 /** 705 * drm_sched_resubmit_jobs - Deprecated, don't use in new code! 706 * 707 * @sched: scheduler instance 708 * 709 * Re-submitting jobs was a concept AMD came up as cheap way to implement 710 * recovery after a job timeout. 711 * 712 * This turned out to be not working very well. First of all there are many 713 * problem with the dma_fence implementation and requirements. Either the 714 * implementation is risking deadlocks with core memory management or violating 715 * documented implementation details of the dma_fence object. 716 * 717 * Drivers can still save and restore their state for recovery operations, but 718 * we shouldn't make this a general scheduler feature around the dma_fence 719 * interface. 720 */ 721 void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched) 722 { 723 struct drm_sched_job *s_job, *tmp; 724 uint64_t guilty_context; 725 bool found_guilty = false; 726 struct dma_fence *fence; 727 728 list_for_each_entry_safe(s_job, tmp, &sched->pending_list, list) { 729 struct drm_sched_fence *s_fence = s_job->s_fence; 730 731 if (!found_guilty && atomic_read(&s_job->karma) > sched->hang_limit) { 732 found_guilty = true; 733 guilty_context = s_job->s_fence->scheduled.context; 734 } 735 736 if (found_guilty && s_job->s_fence->scheduled.context == guilty_context) 737 dma_fence_set_error(&s_fence->finished, -ECANCELED); 738 739 fence = sched->ops->run_job(s_job); 740 741 if (IS_ERR_OR_NULL(fence)) { 742 if (IS_ERR(fence)) 743 dma_fence_set_error(&s_fence->finished, PTR_ERR(fence)); 744 745 s_job->s_fence->parent = NULL; 746 } else { 747 748 s_job->s_fence->parent = dma_fence_get(fence); 749 750 /* Drop for orignal kref_init */ 751 dma_fence_put(fence); 752 } 753 } 754 } 755 EXPORT_SYMBOL(drm_sched_resubmit_jobs); 756 757 /** 758 * drm_sched_job_init - init a scheduler job 759 * @job: scheduler job to init 760 * @entity: scheduler entity to use 761 * @credits: the number of credits this job contributes to the schedulers 762 * credit limit 763 * @owner: job owner for debugging 764 * @drm_client_id: &struct drm_file.client_id of the owner (used by trace 765 * events) 766 * 767 * Refer to drm_sched_entity_push_job() documentation 768 * for locking considerations. 769 * 770 * Drivers must make sure drm_sched_job_cleanup() if this function returns 771 * successfully, even when @job is aborted before drm_sched_job_arm() is called. 772 * 773 * Note that this function does not assign a valid value to each struct member 774 * of struct drm_sched_job. Take a look at that struct's documentation to see 775 * who sets which struct member with what lifetime. 776 * 777 * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware 778 * has died, which can mean that there's no valid runqueue for a @entity. 779 * This function returns -ENOENT in this case (which probably should be -EIO as 780 * a more meanigful return value). 781 * 782 * Returns 0 for success, negative error code otherwise. 783 */ 784 int drm_sched_job_init(struct drm_sched_job *job, 785 struct drm_sched_entity *entity, 786 u32 credits, void *owner, 787 uint64_t drm_client_id) 788 { 789 if (!entity->rq) { 790 /* This will most likely be followed by missing frames 791 * or worse--a blank screen--leave a trail in the 792 * logs, so this can be debugged easier. 793 */ 794 dev_err(job->sched->dev, "%s: entity has no rq!\n", __func__); 795 return -ENOENT; 796 } 797 798 if (unlikely(!credits)) { 799 pr_err("*ERROR* %s: credits cannot be 0!\n", __func__); 800 return -EINVAL; 801 } 802 803 /* 804 * We don't know for sure how the user has allocated. Thus, zero the 805 * struct so that unallowed (i.e., too early) usage of pointers that 806 * this function does not set is guaranteed to lead to a NULL pointer 807 * exception instead of UB. 808 */ 809 memset(job, 0, sizeof(*job)); 810 811 job->entity = entity; 812 job->credits = credits; 813 job->s_fence = drm_sched_fence_alloc(entity, owner, drm_client_id); 814 if (!job->s_fence) 815 return -ENOMEM; 816 817 INIT_LIST_HEAD(&job->list); 818 819 xa_init_flags(&job->dependencies, XA_FLAGS_ALLOC); 820 821 return 0; 822 } 823 EXPORT_SYMBOL(drm_sched_job_init); 824 825 /** 826 * drm_sched_job_arm - arm a scheduler job for execution 827 * @job: scheduler job to arm 828 * 829 * This arms a scheduler job for execution. Specifically it initializes the 830 * &drm_sched_job.s_fence of @job, so that it can be attached to struct dma_resv 831 * or other places that need to track the completion of this job. It also 832 * initializes sequence numbers, which are fundamental for fence ordering. 833 * 834 * Refer to drm_sched_entity_push_job() documentation for locking 835 * considerations. 836 * 837 * Once this function was called, you *must* submit @job with 838 * drm_sched_entity_push_job(). 839 * 840 * This can only be called if drm_sched_job_init() succeeded. 841 */ 842 void drm_sched_job_arm(struct drm_sched_job *job) 843 { 844 struct drm_gpu_scheduler *sched; 845 struct drm_sched_entity *entity = job->entity; 846 847 BUG_ON(!entity); 848 drm_sched_entity_select_rq(entity); 849 sched = entity->rq->sched; 850 851 job->sched = sched; 852 job->s_priority = entity->priority; 853 854 drm_sched_fence_init(job->s_fence, job->entity); 855 } 856 EXPORT_SYMBOL(drm_sched_job_arm); 857 858 /** 859 * drm_sched_job_add_dependency - adds the fence as a job dependency 860 * @job: scheduler job to add the dependencies to 861 * @fence: the dma_fence to add to the list of dependencies. 862 * 863 * Note that @fence is consumed in both the success and error cases. 864 * 865 * Returns: 866 * 0 on success, or an error on failing to expand the array. 867 */ 868 int drm_sched_job_add_dependency(struct drm_sched_job *job, 869 struct dma_fence *fence) 870 { 871 struct dma_fence *entry; 872 unsigned long index; 873 u32 id = 0; 874 int ret; 875 876 if (!fence) 877 return 0; 878 879 /* Deduplicate if we already depend on a fence from the same context. 880 * This lets the size of the array of deps scale with the number of 881 * engines involved, rather than the number of BOs. 882 */ 883 xa_for_each(&job->dependencies, index, entry) { 884 if (entry->context != fence->context) 885 continue; 886 887 if (dma_fence_is_later(fence, entry)) { 888 dma_fence_put(entry); 889 xa_store(&job->dependencies, index, fence, GFP_KERNEL); 890 } else { 891 dma_fence_put(fence); 892 } 893 return 0; 894 } 895 896 ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b, GFP_KERNEL); 897 if (ret != 0) 898 dma_fence_put(fence); 899 900 return ret; 901 } 902 EXPORT_SYMBOL(drm_sched_job_add_dependency); 903 904 /** 905 * drm_sched_job_add_syncobj_dependency - adds a syncobj's fence as a job dependency 906 * @job: scheduler job to add the dependencies to 907 * @file: drm file private pointer 908 * @handle: syncobj handle to lookup 909 * @point: timeline point 910 * 911 * This adds the fence matching the given syncobj to @job. 912 * 913 * Returns: 914 * 0 on success, or an error on failing to expand the array. 915 */ 916 int drm_sched_job_add_syncobj_dependency(struct drm_sched_job *job, 917 struct drm_file *file, 918 u32 handle, 919 u32 point) 920 { 921 struct dma_fence *fence; 922 int ret; 923 924 ret = drm_syncobj_find_fence(file, handle, point, 0, &fence); 925 if (ret) 926 return ret; 927 928 return drm_sched_job_add_dependency(job, fence); 929 } 930 EXPORT_SYMBOL(drm_sched_job_add_syncobj_dependency); 931 932 /** 933 * drm_sched_job_add_resv_dependencies - add all fences from the resv to the job 934 * @job: scheduler job to add the dependencies to 935 * @resv: the dma_resv object to get the fences from 936 * @usage: the dma_resv_usage to use to filter the fences 937 * 938 * This adds all fences matching the given usage from @resv to @job. 939 * Must be called with the @resv lock held. 940 * 941 * Returns: 942 * 0 on success, or an error on failing to expand the array. 943 */ 944 int drm_sched_job_add_resv_dependencies(struct drm_sched_job *job, 945 struct dma_resv *resv, 946 enum dma_resv_usage usage) 947 { 948 struct dma_resv_iter cursor; 949 struct dma_fence *fence; 950 int ret; 951 952 dma_resv_assert_held(resv); 953 954 dma_resv_for_each_fence(&cursor, resv, usage, fence) { 955 /* Make sure to grab an additional ref on the added fence */ 956 dma_fence_get(fence); 957 ret = drm_sched_job_add_dependency(job, fence); 958 if (ret) { 959 dma_fence_put(fence); 960 return ret; 961 } 962 } 963 return 0; 964 } 965 EXPORT_SYMBOL(drm_sched_job_add_resv_dependencies); 966 967 /** 968 * drm_sched_job_add_implicit_dependencies - adds implicit dependencies as job 969 * dependencies 970 * @job: scheduler job to add the dependencies to 971 * @obj: the gem object to add new dependencies from. 972 * @write: whether the job might write the object (so we need to depend on 973 * shared fences in the reservation object). 974 * 975 * This should be called after drm_gem_lock_reservations() on your array of 976 * GEM objects used in the job but before updating the reservations with your 977 * own fences. 978 * 979 * Returns: 980 * 0 on success, or an error on failing to expand the array. 981 */ 982 int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job, 983 struct drm_gem_object *obj, 984 bool write) 985 { 986 return drm_sched_job_add_resv_dependencies(job, obj->resv, 987 dma_resv_usage_rw(write)); 988 } 989 EXPORT_SYMBOL(drm_sched_job_add_implicit_dependencies); 990 991 /** 992 * drm_sched_job_has_dependency - check whether fence is the job's dependency 993 * @job: scheduler job to check 994 * @fence: fence to look for 995 * 996 * Returns: 997 * True if @fence is found within the job's dependencies, or otherwise false. 998 */ 999 bool drm_sched_job_has_dependency(struct drm_sched_job *job, 1000 struct dma_fence *fence) 1001 { 1002 struct dma_fence *f; 1003 unsigned long index; 1004 1005 xa_for_each(&job->dependencies, index, f) { 1006 if (f == fence) 1007 return true; 1008 } 1009 1010 return false; 1011 } 1012 EXPORT_SYMBOL(drm_sched_job_has_dependency); 1013 1014 /** 1015 * drm_sched_job_cleanup - clean up scheduler job resources 1016 * @job: scheduler job to clean up 1017 * 1018 * Cleans up the resources allocated with drm_sched_job_init(). 1019 * 1020 * Drivers should call this from their error unwind code if @job is aborted 1021 * before drm_sched_job_arm() is called. 1022 * 1023 * drm_sched_job_arm() is a point of no return since it initializes the fences 1024 * and their sequence number etc. Once that function has been called, you *must* 1025 * submit it with drm_sched_entity_push_job() and cannot simply abort it by 1026 * calling drm_sched_job_cleanup(). 1027 * 1028 * This function should be called in the &drm_sched_backend_ops.free_job callback. 1029 */ 1030 void drm_sched_job_cleanup(struct drm_sched_job *job) 1031 { 1032 struct dma_fence *fence; 1033 unsigned long index; 1034 1035 if (kref_read(&job->s_fence->finished.refcount)) { 1036 /* The job has been processed by the scheduler, i.e., 1037 * drm_sched_job_arm() and drm_sched_entity_push_job() have 1038 * been called. 1039 */ 1040 dma_fence_put(&job->s_fence->finished); 1041 } else { 1042 /* The job was aborted before it has been committed to be run; 1043 * notably, drm_sched_job_arm() has not been called. 1044 */ 1045 drm_sched_fence_free(job->s_fence); 1046 } 1047 1048 job->s_fence = NULL; 1049 1050 xa_for_each(&job->dependencies, index, fence) { 1051 dma_fence_put(fence); 1052 } 1053 xa_destroy(&job->dependencies); 1054 1055 } 1056 EXPORT_SYMBOL(drm_sched_job_cleanup); 1057 1058 /** 1059 * drm_sched_wakeup - Wake up the scheduler if it is ready to queue 1060 * @sched: scheduler instance 1061 * 1062 * Wake up the scheduler if we can queue jobs. 1063 */ 1064 void drm_sched_wakeup(struct drm_gpu_scheduler *sched) 1065 { 1066 drm_sched_run_job_queue(sched); 1067 } 1068 1069 /** 1070 * drm_sched_select_entity - Select next entity to process 1071 * 1072 * @sched: scheduler instance 1073 * 1074 * Return an entity to process or NULL if none are found. 1075 * 1076 * Note, that we break out of the for-loop when "entity" is non-null, which can 1077 * also be an error-pointer--this assures we don't process lower priority 1078 * run-queues. See comments in the respectively called functions. 1079 */ 1080 static struct drm_sched_entity * 1081 drm_sched_select_entity(struct drm_gpu_scheduler *sched) 1082 { 1083 struct drm_sched_entity *entity; 1084 int i; 1085 1086 /* Start with the highest priority. 1087 */ 1088 for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) { 1089 entity = drm_sched_policy == DRM_SCHED_POLICY_FIFO ? 1090 drm_sched_rq_select_entity_fifo(sched, sched->sched_rq[i]) : 1091 drm_sched_rq_select_entity_rr(sched, sched->sched_rq[i]); 1092 if (entity) 1093 break; 1094 } 1095 1096 return IS_ERR(entity) ? NULL : entity; 1097 } 1098 1099 /** 1100 * drm_sched_get_finished_job - fetch the next finished job to be destroyed 1101 * 1102 * @sched: scheduler instance 1103 * 1104 * Returns the next finished job from the pending list (if there is one) 1105 * ready for it to be destroyed. 1106 */ 1107 static struct drm_sched_job * 1108 drm_sched_get_finished_job(struct drm_gpu_scheduler *sched) 1109 { 1110 struct drm_sched_job *job, *next; 1111 1112 spin_lock(&sched->job_list_lock); 1113 1114 job = list_first_entry_or_null(&sched->pending_list, 1115 struct drm_sched_job, list); 1116 1117 if (job && dma_fence_is_signaled(&job->s_fence->finished)) { 1118 /* remove job from pending_list */ 1119 list_del_init(&job->list); 1120 1121 /* cancel this job's TO timer */ 1122 cancel_delayed_work(&sched->work_tdr); 1123 /* make the scheduled timestamp more accurate */ 1124 next = list_first_entry_or_null(&sched->pending_list, 1125 typeof(*next), list); 1126 1127 if (next) { 1128 if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, 1129 &next->s_fence->scheduled.flags)) 1130 next->s_fence->scheduled.timestamp = 1131 dma_fence_timestamp(&job->s_fence->finished); 1132 /* start TO timer for next job */ 1133 drm_sched_start_timeout(sched); 1134 } 1135 } else { 1136 job = NULL; 1137 } 1138 1139 spin_unlock(&sched->job_list_lock); 1140 1141 return job; 1142 } 1143 1144 /** 1145 * drm_sched_pick_best - Get a drm sched from a sched_list with the least load 1146 * @sched_list: list of drm_gpu_schedulers 1147 * @num_sched_list: number of drm_gpu_schedulers in the sched_list 1148 * 1149 * Returns pointer of the sched with the least load or NULL if none of the 1150 * drm_gpu_schedulers are ready 1151 */ 1152 struct drm_gpu_scheduler * 1153 drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, 1154 unsigned int num_sched_list) 1155 { 1156 struct drm_gpu_scheduler *sched, *picked_sched = NULL; 1157 int i; 1158 unsigned int min_score = UINT_MAX, num_score; 1159 1160 for (i = 0; i < num_sched_list; ++i) { 1161 sched = sched_list[i]; 1162 1163 if (!sched->ready) { 1164 DRM_WARN("scheduler %s is not ready, skipping", 1165 sched->name); 1166 continue; 1167 } 1168 1169 num_score = atomic_read(sched->score); 1170 if (num_score < min_score) { 1171 min_score = num_score; 1172 picked_sched = sched; 1173 } 1174 } 1175 1176 return picked_sched; 1177 } 1178 EXPORT_SYMBOL(drm_sched_pick_best); 1179 1180 /** 1181 * drm_sched_free_job_work - worker to call free_job 1182 * 1183 * @w: free job work 1184 */ 1185 static void drm_sched_free_job_work(struct work_struct *w) 1186 { 1187 struct drm_gpu_scheduler *sched = 1188 container_of(w, struct drm_gpu_scheduler, work_free_job); 1189 struct drm_sched_job *job; 1190 1191 job = drm_sched_get_finished_job(sched); 1192 if (job) 1193 sched->ops->free_job(job); 1194 1195 drm_sched_run_free_queue(sched); 1196 drm_sched_run_job_queue(sched); 1197 } 1198 1199 /** 1200 * drm_sched_run_job_work - worker to call run_job 1201 * 1202 * @w: run job work 1203 */ 1204 static void drm_sched_run_job_work(struct work_struct *w) 1205 { 1206 struct drm_gpu_scheduler *sched = 1207 container_of(w, struct drm_gpu_scheduler, work_run_job); 1208 struct drm_sched_entity *entity; 1209 struct dma_fence *fence; 1210 struct drm_sched_fence *s_fence; 1211 struct drm_sched_job *sched_job; 1212 int r; 1213 1214 /* Find entity with a ready job */ 1215 entity = drm_sched_select_entity(sched); 1216 if (!entity) 1217 return; /* No more work */ 1218 1219 sched_job = drm_sched_entity_pop_job(entity); 1220 if (!sched_job) { 1221 complete_all(&entity->entity_idle); 1222 drm_sched_run_job_queue(sched); 1223 return; 1224 } 1225 1226 s_fence = sched_job->s_fence; 1227 1228 atomic_add(sched_job->credits, &sched->credit_count); 1229 drm_sched_job_begin(sched_job); 1230 1231 trace_drm_sched_job_run(sched_job, entity); 1232 /* 1233 * The run_job() callback must by definition return a fence whose 1234 * refcount has been incremented for the scheduler already. 1235 */ 1236 fence = sched->ops->run_job(sched_job); 1237 complete_all(&entity->entity_idle); 1238 drm_sched_fence_scheduled(s_fence, fence); 1239 1240 if (!IS_ERR_OR_NULL(fence)) { 1241 r = dma_fence_add_callback(fence, &sched_job->cb, 1242 drm_sched_job_done_cb); 1243 if (r == -ENOENT) 1244 drm_sched_job_done(sched_job, fence->error); 1245 else if (r) 1246 DRM_DEV_ERROR(sched->dev, "fence add callback failed (%d)\n", r); 1247 1248 dma_fence_put(fence); 1249 } else { 1250 drm_sched_job_done(sched_job, IS_ERR(fence) ? 1251 PTR_ERR(fence) : 0); 1252 } 1253 1254 wake_up(&sched->job_scheduled); 1255 drm_sched_run_job_queue(sched); 1256 } 1257 1258 static struct workqueue_struct *drm_sched_alloc_wq(const char *name) 1259 { 1260 #if (IS_ENABLED(CONFIG_LOCKDEP)) 1261 static struct lockdep_map map = { 1262 .name = "drm_sched_lockdep_map" 1263 }; 1264 1265 /* 1266 * Avoid leaking a lockdep map on each drm sched creation and 1267 * destruction by using a single lockdep map for all drm sched 1268 * allocated submit_wq. 1269 */ 1270 1271 return alloc_ordered_workqueue_lockdep_map(name, WQ_MEM_RECLAIM, &map); 1272 #else 1273 return alloc_ordered_workqueue(name, WQ_MEM_RECLAIM); 1274 #endif 1275 } 1276 1277 /** 1278 * drm_sched_init - Init a gpu scheduler instance 1279 * 1280 * @sched: scheduler instance 1281 * @args: scheduler initialization arguments 1282 * 1283 * Return 0 on success, otherwise error code. 1284 */ 1285 int drm_sched_init(struct drm_gpu_scheduler *sched, const struct drm_sched_init_args *args) 1286 { 1287 int i; 1288 1289 sched->ops = args->ops; 1290 sched->credit_limit = args->credit_limit; 1291 sched->name = args->name; 1292 sched->timeout = args->timeout; 1293 sched->hang_limit = args->hang_limit; 1294 sched->timeout_wq = args->timeout_wq ? args->timeout_wq : system_wq; 1295 sched->score = args->score ? args->score : &sched->_score; 1296 sched->dev = args->dev; 1297 1298 if (args->num_rqs > DRM_SCHED_PRIORITY_COUNT) { 1299 /* This is a gross violation--tell drivers what the problem is. 1300 */ 1301 dev_err(sched->dev, "%s: num_rqs cannot be greater than DRM_SCHED_PRIORITY_COUNT\n", 1302 __func__); 1303 return -EINVAL; 1304 } else if (sched->sched_rq) { 1305 /* Not an error, but warn anyway so drivers can 1306 * fine-tune their DRM calling order, and return all 1307 * is good. 1308 */ 1309 dev_warn(sched->dev, "%s: scheduler already initialized!\n", __func__); 1310 return 0; 1311 } 1312 1313 if (args->submit_wq) { 1314 sched->submit_wq = args->submit_wq; 1315 sched->own_submit_wq = false; 1316 } else { 1317 sched->submit_wq = drm_sched_alloc_wq(args->name); 1318 if (!sched->submit_wq) 1319 return -ENOMEM; 1320 1321 sched->own_submit_wq = true; 1322 } 1323 1324 sched->sched_rq = kmalloc_array(args->num_rqs, sizeof(*sched->sched_rq), 1325 GFP_KERNEL | __GFP_ZERO); 1326 if (!sched->sched_rq) 1327 goto Out_check_own; 1328 sched->num_rqs = args->num_rqs; 1329 for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) { 1330 sched->sched_rq[i] = kzalloc(sizeof(*sched->sched_rq[i]), GFP_KERNEL); 1331 if (!sched->sched_rq[i]) 1332 goto Out_unroll; 1333 drm_sched_rq_init(sched, sched->sched_rq[i]); 1334 } 1335 1336 init_waitqueue_head(&sched->job_scheduled); 1337 INIT_LIST_HEAD(&sched->pending_list); 1338 spin_lock_init(&sched->job_list_lock); 1339 atomic_set(&sched->credit_count, 0); 1340 INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout); 1341 INIT_WORK(&sched->work_run_job, drm_sched_run_job_work); 1342 INIT_WORK(&sched->work_free_job, drm_sched_free_job_work); 1343 atomic_set(&sched->_score, 0); 1344 atomic64_set(&sched->job_id_count, 0); 1345 sched->pause_submit = false; 1346 1347 sched->ready = true; 1348 return 0; 1349 Out_unroll: 1350 for (--i ; i >= DRM_SCHED_PRIORITY_KERNEL; i--) 1351 kfree(sched->sched_rq[i]); 1352 1353 kfree(sched->sched_rq); 1354 sched->sched_rq = NULL; 1355 Out_check_own: 1356 if (sched->own_submit_wq) 1357 destroy_workqueue(sched->submit_wq); 1358 dev_err(sched->dev, "%s: Failed to setup GPU scheduler--out of memory\n", __func__); 1359 return -ENOMEM; 1360 } 1361 EXPORT_SYMBOL(drm_sched_init); 1362 1363 /** 1364 * drm_sched_fini - Destroy a gpu scheduler 1365 * 1366 * @sched: scheduler instance 1367 * 1368 * Tears down and cleans up the scheduler. 1369 * 1370 * This stops submission of new jobs to the hardware through 1371 * drm_sched_backend_ops.run_job(). Consequently, drm_sched_backend_ops.free_job() 1372 * will not be called for all jobs still in drm_gpu_scheduler.pending_list. 1373 * There is no solution for this currently. Thus, it is up to the driver to make 1374 * sure that: 1375 * 1376 * a) drm_sched_fini() is only called after for all submitted jobs 1377 * drm_sched_backend_ops.free_job() has been called or that 1378 * b) the jobs for which drm_sched_backend_ops.free_job() has not been called 1379 * after drm_sched_fini() ran are freed manually. 1380 * 1381 * FIXME: Take care of the above problem and prevent this function from leaking 1382 * the jobs in drm_gpu_scheduler.pending_list under any circumstances. 1383 */ 1384 void drm_sched_fini(struct drm_gpu_scheduler *sched) 1385 { 1386 struct drm_sched_entity *s_entity; 1387 int i; 1388 1389 drm_sched_wqueue_stop(sched); 1390 1391 for (i = DRM_SCHED_PRIORITY_KERNEL; i < sched->num_rqs; i++) { 1392 struct drm_sched_rq *rq = sched->sched_rq[i]; 1393 1394 spin_lock(&rq->lock); 1395 list_for_each_entry(s_entity, &rq->entities, list) 1396 /* 1397 * Prevents reinsertion and marks job_queue as idle, 1398 * it will be removed from the rq in drm_sched_entity_fini() 1399 * eventually 1400 */ 1401 s_entity->stopped = true; 1402 spin_unlock(&rq->lock); 1403 kfree(sched->sched_rq[i]); 1404 } 1405 1406 /* Wakeup everyone stuck in drm_sched_entity_flush for this scheduler */ 1407 wake_up_all(&sched->job_scheduled); 1408 1409 /* Confirm no work left behind accessing device structures */ 1410 cancel_delayed_work_sync(&sched->work_tdr); 1411 1412 if (sched->own_submit_wq) 1413 destroy_workqueue(sched->submit_wq); 1414 sched->ready = false; 1415 kfree(sched->sched_rq); 1416 sched->sched_rq = NULL; 1417 } 1418 EXPORT_SYMBOL(drm_sched_fini); 1419 1420 /** 1421 * drm_sched_increase_karma - Update sched_entity guilty flag 1422 * 1423 * @bad: The job guilty of time out 1424 * 1425 * Increment on every hang caused by the 'bad' job. If this exceeds the hang 1426 * limit of the scheduler then the respective sched entity is marked guilty and 1427 * jobs from it will not be scheduled further 1428 */ 1429 void drm_sched_increase_karma(struct drm_sched_job *bad) 1430 { 1431 int i; 1432 struct drm_sched_entity *tmp; 1433 struct drm_sched_entity *entity; 1434 struct drm_gpu_scheduler *sched = bad->sched; 1435 1436 /* don't change @bad's karma if it's from KERNEL RQ, 1437 * because sometimes GPU hang would cause kernel jobs (like VM updating jobs) 1438 * corrupt but keep in mind that kernel jobs always considered good. 1439 */ 1440 if (bad->s_priority != DRM_SCHED_PRIORITY_KERNEL) { 1441 atomic_inc(&bad->karma); 1442 1443 for (i = DRM_SCHED_PRIORITY_HIGH; i < sched->num_rqs; i++) { 1444 struct drm_sched_rq *rq = sched->sched_rq[i]; 1445 1446 spin_lock(&rq->lock); 1447 list_for_each_entry_safe(entity, tmp, &rq->entities, list) { 1448 if (bad->s_fence->scheduled.context == 1449 entity->fence_context) { 1450 if (entity->guilty) 1451 atomic_set(entity->guilty, 1); 1452 break; 1453 } 1454 } 1455 spin_unlock(&rq->lock); 1456 if (&entity->list != &rq->entities) 1457 break; 1458 } 1459 } 1460 } 1461 EXPORT_SYMBOL(drm_sched_increase_karma); 1462 1463 /** 1464 * drm_sched_wqueue_ready - Is the scheduler ready for submission 1465 * 1466 * @sched: scheduler instance 1467 * 1468 * Returns true if submission is ready 1469 */ 1470 bool drm_sched_wqueue_ready(struct drm_gpu_scheduler *sched) 1471 { 1472 return sched->ready; 1473 } 1474 EXPORT_SYMBOL(drm_sched_wqueue_ready); 1475 1476 /** 1477 * drm_sched_wqueue_stop - stop scheduler submission 1478 * @sched: scheduler instance 1479 * 1480 * Stops the scheduler from pulling new jobs from entities. It also stops 1481 * freeing jobs automatically through drm_sched_backend_ops.free_job(). 1482 */ 1483 void drm_sched_wqueue_stop(struct drm_gpu_scheduler *sched) 1484 { 1485 WRITE_ONCE(sched->pause_submit, true); 1486 cancel_work_sync(&sched->work_run_job); 1487 cancel_work_sync(&sched->work_free_job); 1488 } 1489 EXPORT_SYMBOL(drm_sched_wqueue_stop); 1490 1491 /** 1492 * drm_sched_wqueue_start - start scheduler submission 1493 * @sched: scheduler instance 1494 * 1495 * Restarts the scheduler after drm_sched_wqueue_stop() has stopped it. 1496 * 1497 * This function is not necessary for 'conventional' startup. The scheduler is 1498 * fully operational after drm_sched_init() succeeded. 1499 */ 1500 void drm_sched_wqueue_start(struct drm_gpu_scheduler *sched) 1501 { 1502 WRITE_ONCE(sched->pause_submit, false); 1503 queue_work(sched->submit_wq, &sched->work_run_job); 1504 queue_work(sched->submit_wq, &sched->work_free_job); 1505 } 1506 EXPORT_SYMBOL(drm_sched_wqueue_start); 1507