1 /* 2 * Copyright 2015 Advanced Micro Devices, Inc. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20 * OTHER DEALINGS IN THE SOFTWARE. 21 * 22 */ 23 24 #include <linux/kthread.h> 25 #include <linux/slab.h> 26 #include <linux/completion.h> 27 28 #include <drm/drm_print.h> 29 #include <drm/gpu_scheduler.h> 30 31 #include "gpu_scheduler_trace.h" 32 33 #define to_drm_sched_job(sched_job) \ 34 container_of((sched_job), struct drm_sched_job, queue_node) 35 36 /** 37 * drm_sched_entity_init - Init a context entity used by scheduler when 38 * submit to HW ring. 39 * 40 * @entity: scheduler entity to init 41 * @priority: priority of the entity 42 * @sched_list: the list of drm scheds on which jobs from this 43 * entity can be submitted 44 * @num_sched_list: number of drm sched in sched_list 45 * @guilty: atomic_t set to 1 when a job on this queue 46 * is found to be guilty causing a timeout 47 * 48 * Note that the &sched_list must have at least one element to schedule the entity. 49 * 50 * For changing @priority later on at runtime see 51 * drm_sched_entity_set_priority(). For changing the set of schedulers 52 * @sched_list at runtime see drm_sched_entity_modify_sched(). 53 * 54 * An entity is cleaned up by callind drm_sched_entity_fini(). See also 55 * drm_sched_entity_destroy(). 56 * 57 * Returns 0 on success or a negative error code on failure. 58 */ 59 int drm_sched_entity_init(struct drm_sched_entity *entity, 60 enum drm_sched_priority priority, 61 struct drm_gpu_scheduler **sched_list, 62 unsigned int num_sched_list, 63 atomic_t *guilty) 64 { 65 if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0]))) 66 return -EINVAL; 67 68 memset(entity, 0, sizeof(struct drm_sched_entity)); 69 INIT_LIST_HEAD(&entity->list); 70 entity->rq = NULL; 71 entity->guilty = guilty; 72 entity->num_sched_list = num_sched_list; 73 entity->priority = priority; 74 entity->sched_list = num_sched_list > 1 ? sched_list : NULL; 75 entity->last_scheduled = NULL; 76 77 if(num_sched_list) 78 entity->rq = &sched_list[0]->sched_rq[entity->priority]; 79 80 init_completion(&entity->entity_idle); 81 82 /* We start in an idle state. */ 83 complete(&entity->entity_idle); 84 85 spin_lock_init(&entity->rq_lock); 86 spsc_queue_init(&entity->job_queue); 87 88 atomic_set(&entity->fence_seq, 0); 89 entity->fence_context = dma_fence_context_alloc(2); 90 91 return 0; 92 } 93 EXPORT_SYMBOL(drm_sched_entity_init); 94 95 /** 96 * drm_sched_entity_modify_sched - Modify sched of an entity 97 * @entity: scheduler entity to init 98 * @sched_list: the list of new drm scheds which will replace 99 * existing entity->sched_list 100 * @num_sched_list: number of drm sched in sched_list 101 * 102 * Note that this must be called under the same common lock for @entity as 103 * drm_sched_job_arm() and drm_sched_entity_push_job(), or the driver needs to 104 * guarantee through some other means that this is never called while new jobs 105 * can be pushed to @entity. 106 */ 107 void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, 108 struct drm_gpu_scheduler **sched_list, 109 unsigned int num_sched_list) 110 { 111 WARN_ON(!num_sched_list || !sched_list); 112 113 entity->sched_list = sched_list; 114 entity->num_sched_list = num_sched_list; 115 } 116 EXPORT_SYMBOL(drm_sched_entity_modify_sched); 117 118 static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity) 119 { 120 rmb(); /* for list_empty to work without lock */ 121 122 if (list_empty(&entity->list) || 123 spsc_queue_count(&entity->job_queue) == 0 || 124 entity->stopped) 125 return true; 126 127 return false; 128 } 129 130 /* Return true if entity could provide a job. */ 131 bool drm_sched_entity_is_ready(struct drm_sched_entity *entity) 132 { 133 if (spsc_queue_peek(&entity->job_queue) == NULL) 134 return false; 135 136 if (READ_ONCE(entity->dependency)) 137 return false; 138 139 return true; 140 } 141 142 /** 143 * drm_sched_entity_flush - Flush a context entity 144 * 145 * @entity: scheduler entity 146 * @timeout: time to wait in for Q to become empty in jiffies. 147 * 148 * Splitting drm_sched_entity_fini() into two functions, The first one does the 149 * waiting, removes the entity from the runqueue and returns an error when the 150 * process was killed. 151 * 152 * Returns the remaining time in jiffies left from the input timeout 153 */ 154 long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) 155 { 156 struct drm_gpu_scheduler *sched; 157 struct task_struct *last_user; 158 long ret = timeout; 159 160 if (!entity->rq) 161 return 0; 162 163 sched = entity->rq->sched; 164 /** 165 * The client will not queue more IBs during this fini, consume existing 166 * queued IBs or discard them on SIGKILL 167 */ 168 if (current->flags & PF_EXITING) { 169 if (timeout) 170 ret = wait_event_timeout( 171 sched->job_scheduled, 172 drm_sched_entity_is_idle(entity), 173 timeout); 174 } else { 175 wait_event_killable(sched->job_scheduled, 176 drm_sched_entity_is_idle(entity)); 177 } 178 179 /* For killed process disable any more IBs enqueue right now */ 180 last_user = cmpxchg(&entity->last_user, current->group_leader, NULL); 181 if ((!last_user || last_user == current->group_leader) && 182 (current->flags & PF_EXITING) && (current->exit_code == SIGKILL)) { 183 spin_lock(&entity->rq_lock); 184 entity->stopped = true; 185 drm_sched_rq_remove_entity(entity->rq, entity); 186 spin_unlock(&entity->rq_lock); 187 } 188 189 return ret; 190 } 191 EXPORT_SYMBOL(drm_sched_entity_flush); 192 193 static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk) 194 { 195 struct drm_sched_job *job = container_of(wrk, typeof(*job), work); 196 197 drm_sched_fence_finished(job->s_fence); 198 WARN_ON(job->s_fence->parent); 199 job->sched->ops->free_job(job); 200 } 201 202 203 /* Signal the scheduler finished fence when the entity in question is killed. */ 204 static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, 205 struct dma_fence_cb *cb) 206 { 207 struct drm_sched_job *job = container_of(cb, struct drm_sched_job, 208 finish_cb); 209 210 INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work); 211 schedule_work(&job->work); 212 } 213 214 static struct dma_fence * 215 drm_sched_job_dependency(struct drm_sched_job *job, 216 struct drm_sched_entity *entity) 217 { 218 if (!xa_empty(&job->dependencies)) 219 return xa_erase(&job->dependencies, job->last_dependency++); 220 221 if (job->sched->ops->dependency) 222 return job->sched->ops->dependency(job, entity); 223 224 return NULL; 225 } 226 227 static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity) 228 { 229 struct drm_sched_job *job; 230 struct dma_fence *f; 231 int r; 232 233 while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue)))) { 234 struct drm_sched_fence *s_fence = job->s_fence; 235 236 /* Wait for all dependencies to avoid data corruptions */ 237 while ((f = drm_sched_job_dependency(job, entity))) 238 dma_fence_wait(f, false); 239 240 drm_sched_fence_scheduled(s_fence); 241 dma_fence_set_error(&s_fence->finished, -ESRCH); 242 243 /* 244 * When pipe is hanged by older entity, new entity might 245 * not even have chance to submit it's first job to HW 246 * and so entity->last_scheduled will remain NULL 247 */ 248 if (!entity->last_scheduled) { 249 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb); 250 continue; 251 } 252 253 r = dma_fence_add_callback(entity->last_scheduled, 254 &job->finish_cb, 255 drm_sched_entity_kill_jobs_cb); 256 if (r == -ENOENT) 257 drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb); 258 else if (r) 259 DRM_ERROR("fence add callback failed (%d)\n", r); 260 } 261 } 262 263 /** 264 * drm_sched_entity_fini - Destroy a context entity 265 * 266 * @entity: scheduler entity 267 * 268 * Cleanups up @entity which has been initialized by drm_sched_entity_init(). 269 * 270 * If there are potentially job still in flight or getting newly queued 271 * drm_sched_entity_flush() must be called first. This function then goes over 272 * the entity and signals all jobs with an error code if the process was killed. 273 */ 274 void drm_sched_entity_fini(struct drm_sched_entity *entity) 275 { 276 struct drm_gpu_scheduler *sched = NULL; 277 278 if (entity->rq) { 279 sched = entity->rq->sched; 280 drm_sched_rq_remove_entity(entity->rq, entity); 281 } 282 283 /* Consumption of existing IBs wasn't completed. Forcefully 284 * remove them here. 285 */ 286 if (spsc_queue_count(&entity->job_queue)) { 287 if (sched) { 288 /* 289 * Wait for thread to idle to make sure it isn't processing 290 * this entity. 291 */ 292 wait_for_completion(&entity->entity_idle); 293 294 } 295 if (entity->dependency) { 296 dma_fence_remove_callback(entity->dependency, 297 &entity->cb); 298 dma_fence_put(entity->dependency); 299 entity->dependency = NULL; 300 } 301 302 drm_sched_entity_kill_jobs(entity); 303 } 304 305 dma_fence_put(entity->last_scheduled); 306 entity->last_scheduled = NULL; 307 } 308 EXPORT_SYMBOL(drm_sched_entity_fini); 309 310 /** 311 * drm_sched_entity_destroy - Destroy a context entity 312 * @entity: scheduler entity 313 * 314 * Calls drm_sched_entity_flush() and drm_sched_entity_fini() as a 315 * convenience wrapper. 316 */ 317 void drm_sched_entity_destroy(struct drm_sched_entity *entity) 318 { 319 drm_sched_entity_flush(entity, MAX_WAIT_SCHED_ENTITY_Q_EMPTY); 320 drm_sched_entity_fini(entity); 321 } 322 EXPORT_SYMBOL(drm_sched_entity_destroy); 323 324 /* drm_sched_entity_clear_dep - callback to clear the entities dependency */ 325 static void drm_sched_entity_clear_dep(struct dma_fence *f, 326 struct dma_fence_cb *cb) 327 { 328 struct drm_sched_entity *entity = 329 container_of(cb, struct drm_sched_entity, cb); 330 331 entity->dependency = NULL; 332 dma_fence_put(f); 333 } 334 335 /* 336 * drm_sched_entity_clear_dep - callback to clear the entities dependency and 337 * wake up scheduler 338 */ 339 static void drm_sched_entity_wakeup(struct dma_fence *f, 340 struct dma_fence_cb *cb) 341 { 342 struct drm_sched_entity *entity = 343 container_of(cb, struct drm_sched_entity, cb); 344 345 drm_sched_entity_clear_dep(f, cb); 346 drm_sched_wakeup(entity->rq->sched); 347 } 348 349 /** 350 * drm_sched_entity_set_priority - Sets priority of the entity 351 * 352 * @entity: scheduler entity 353 * @priority: scheduler priority 354 * 355 * Update the priority of runqueus used for the entity. 356 */ 357 void drm_sched_entity_set_priority(struct drm_sched_entity *entity, 358 enum drm_sched_priority priority) 359 { 360 spin_lock(&entity->rq_lock); 361 entity->priority = priority; 362 spin_unlock(&entity->rq_lock); 363 } 364 EXPORT_SYMBOL(drm_sched_entity_set_priority); 365 366 /* 367 * Add a callback to the current dependency of the entity to wake up the 368 * scheduler when the entity becomes available. 369 */ 370 static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) 371 { 372 struct drm_gpu_scheduler *sched = entity->rq->sched; 373 struct dma_fence *fence = entity->dependency; 374 struct drm_sched_fence *s_fence; 375 376 if (fence->context == entity->fence_context || 377 fence->context == entity->fence_context + 1) { 378 /* 379 * Fence is a scheduled/finished fence from a job 380 * which belongs to the same entity, we can ignore 381 * fences from ourself 382 */ 383 dma_fence_put(entity->dependency); 384 return false; 385 } 386 387 s_fence = to_drm_sched_fence(fence); 388 if (s_fence && s_fence->sched == sched && 389 !test_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &fence->flags)) { 390 391 /* 392 * Fence is from the same scheduler, only need to wait for 393 * it to be scheduled 394 */ 395 fence = dma_fence_get(&s_fence->scheduled); 396 dma_fence_put(entity->dependency); 397 entity->dependency = fence; 398 if (!dma_fence_add_callback(fence, &entity->cb, 399 drm_sched_entity_clear_dep)) 400 return true; 401 402 /* Ignore it when it is already scheduled */ 403 dma_fence_put(fence); 404 return false; 405 } 406 407 if (!dma_fence_add_callback(entity->dependency, &entity->cb, 408 drm_sched_entity_wakeup)) 409 return true; 410 411 dma_fence_put(entity->dependency); 412 return false; 413 } 414 415 struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) 416 { 417 struct drm_sched_job *sched_job; 418 419 sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); 420 if (!sched_job) 421 return NULL; 422 423 while ((entity->dependency = 424 drm_sched_job_dependency(sched_job, entity))) { 425 trace_drm_sched_job_wait_dep(sched_job, entity->dependency); 426 427 if (drm_sched_entity_add_dependency_cb(entity)) 428 return NULL; 429 } 430 431 /* skip jobs from entity that marked guilty */ 432 if (entity->guilty && atomic_read(entity->guilty)) 433 dma_fence_set_error(&sched_job->s_fence->finished, -ECANCELED); 434 435 dma_fence_put(entity->last_scheduled); 436 437 entity->last_scheduled = dma_fence_get(&sched_job->s_fence->finished); 438 439 /* 440 * If the queue is empty we allow drm_sched_entity_select_rq() to 441 * locklessly access ->last_scheduled. This only works if we set the 442 * pointer before we dequeue and if we a write barrier here. 443 */ 444 smp_wmb(); 445 446 spsc_queue_pop(&entity->job_queue); 447 return sched_job; 448 } 449 450 void drm_sched_entity_select_rq(struct drm_sched_entity *entity) 451 { 452 struct dma_fence *fence; 453 struct drm_gpu_scheduler *sched; 454 struct drm_sched_rq *rq; 455 456 /* single possible engine and already selected */ 457 if (!entity->sched_list) 458 return; 459 460 /* queue non-empty, stay on the same engine */ 461 if (spsc_queue_count(&entity->job_queue)) 462 return; 463 464 /* 465 * Only when the queue is empty are we guaranteed that the scheduler 466 * thread cannot change ->last_scheduled. To enforce ordering we need 467 * a read barrier here. See drm_sched_entity_pop_job() for the other 468 * side. 469 */ 470 smp_rmb(); 471 472 fence = entity->last_scheduled; 473 474 /* stay on the same engine if the previous job hasn't finished */ 475 if (fence && !dma_fence_is_signaled(fence)) 476 return; 477 478 spin_lock(&entity->rq_lock); 479 sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list); 480 rq = sched ? &sched->sched_rq[entity->priority] : NULL; 481 if (rq != entity->rq) { 482 drm_sched_rq_remove_entity(entity->rq, entity); 483 entity->rq = rq; 484 } 485 spin_unlock(&entity->rq_lock); 486 487 if (entity->num_sched_list == 1) 488 entity->sched_list = NULL; 489 } 490 491 /** 492 * drm_sched_entity_push_job - Submit a job to the entity's job queue 493 * @sched_job: job to submit 494 * 495 * Note: To guarantee that the order of insertion to queue matches the job's 496 * fence sequence number this function should be called with drm_sched_job_arm() 497 * under common lock for the struct drm_sched_entity that was set up for 498 * @sched_job in drm_sched_job_init(). 499 * 500 * Returns 0 for success, negative error code otherwise. 501 */ 502 void drm_sched_entity_push_job(struct drm_sched_job *sched_job) 503 { 504 struct drm_sched_entity *entity = sched_job->entity; 505 bool first; 506 507 trace_drm_sched_job(sched_job, entity); 508 atomic_inc(entity->rq->sched->score); 509 WRITE_ONCE(entity->last_user, current->group_leader); 510 first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node); 511 512 /* first job wakes up scheduler */ 513 if (first) { 514 /* Add the entity to the run queue */ 515 spin_lock(&entity->rq_lock); 516 if (entity->stopped) { 517 spin_unlock(&entity->rq_lock); 518 519 DRM_ERROR("Trying to push to a killed entity\n"); 520 return; 521 } 522 drm_sched_rq_add_entity(entity->rq, entity); 523 spin_unlock(&entity->rq_lock); 524 drm_sched_wakeup(entity->rq->sched); 525 } 526 } 527 EXPORT_SYMBOL(drm_sched_entity_push_job); 528