1 /* 2 * Copyright © 2008-2015 Intel Corporation 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 (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #include <linux/prefetch.h> 26 #include <linux/dma-fence-array.h> 27 #include <linux/sched.h> 28 #include <linux/sched/clock.h> 29 #include <linux/sched/signal.h> 30 31 #include "i915_drv.h" 32 33 static const char *i915_fence_get_driver_name(struct dma_fence *fence) 34 { 35 return "i915"; 36 } 37 38 static const char *i915_fence_get_timeline_name(struct dma_fence *fence) 39 { 40 /* 41 * The timeline struct (as part of the ppgtt underneath a context) 42 * may be freed when the request is no longer in use by the GPU. 43 * We could extend the life of a context to beyond that of all 44 * fences, possibly keeping the hw resource around indefinitely, 45 * or we just give them a false name. Since 46 * dma_fence_ops.get_timeline_name is a debug feature, the occasional 47 * lie seems justifiable. 48 */ 49 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) 50 return "signaled"; 51 52 return to_request(fence)->timeline->name; 53 } 54 55 static bool i915_fence_signaled(struct dma_fence *fence) 56 { 57 return i915_request_completed(to_request(fence)); 58 } 59 60 static bool i915_fence_enable_signaling(struct dma_fence *fence) 61 { 62 return intel_engine_enable_signaling(to_request(fence), true); 63 } 64 65 static signed long i915_fence_wait(struct dma_fence *fence, 66 bool interruptible, 67 signed long timeout) 68 { 69 return i915_request_wait(to_request(fence), interruptible, timeout); 70 } 71 72 static void i915_fence_release(struct dma_fence *fence) 73 { 74 struct i915_request *rq = to_request(fence); 75 76 /* 77 * The request is put onto a RCU freelist (i.e. the address 78 * is immediately reused), mark the fences as being freed now. 79 * Otherwise the debugobjects for the fences are only marked as 80 * freed when the slab cache itself is freed, and so we would get 81 * caught trying to reuse dead objects. 82 */ 83 i915_sw_fence_fini(&rq->submit); 84 85 kmem_cache_free(rq->i915->requests, rq); 86 } 87 88 const struct dma_fence_ops i915_fence_ops = { 89 .get_driver_name = i915_fence_get_driver_name, 90 .get_timeline_name = i915_fence_get_timeline_name, 91 .enable_signaling = i915_fence_enable_signaling, 92 .signaled = i915_fence_signaled, 93 .wait = i915_fence_wait, 94 .release = i915_fence_release, 95 }; 96 97 static inline void 98 i915_request_remove_from_client(struct i915_request *request) 99 { 100 struct drm_i915_file_private *file_priv; 101 102 file_priv = request->file_priv; 103 if (!file_priv) 104 return; 105 106 spin_lock(&file_priv->mm.lock); 107 if (request->file_priv) { 108 list_del(&request->client_link); 109 request->file_priv = NULL; 110 } 111 spin_unlock(&file_priv->mm.lock); 112 } 113 114 static struct i915_dependency * 115 i915_dependency_alloc(struct drm_i915_private *i915) 116 { 117 return kmem_cache_alloc(i915->dependencies, GFP_KERNEL); 118 } 119 120 static void 121 i915_dependency_free(struct drm_i915_private *i915, 122 struct i915_dependency *dep) 123 { 124 kmem_cache_free(i915->dependencies, dep); 125 } 126 127 static void 128 __i915_sched_node_add_dependency(struct i915_sched_node *node, 129 struct i915_sched_node *signal, 130 struct i915_dependency *dep, 131 unsigned long flags) 132 { 133 INIT_LIST_HEAD(&dep->dfs_link); 134 list_add(&dep->wait_link, &signal->waiters_list); 135 list_add(&dep->signal_link, &node->signalers_list); 136 dep->signaler = signal; 137 dep->flags = flags; 138 } 139 140 static int 141 i915_sched_node_add_dependency(struct drm_i915_private *i915, 142 struct i915_sched_node *node, 143 struct i915_sched_node *signal) 144 { 145 struct i915_dependency *dep; 146 147 dep = i915_dependency_alloc(i915); 148 if (!dep) 149 return -ENOMEM; 150 151 __i915_sched_node_add_dependency(node, signal, dep, 152 I915_DEPENDENCY_ALLOC); 153 return 0; 154 } 155 156 static void 157 i915_sched_node_fini(struct drm_i915_private *i915, 158 struct i915_sched_node *node) 159 { 160 struct i915_dependency *dep, *tmp; 161 162 GEM_BUG_ON(!list_empty(&node->link)); 163 164 /* 165 * Everyone we depended upon (the fences we wait to be signaled) 166 * should retire before us and remove themselves from our list. 167 * However, retirement is run independently on each timeline and 168 * so we may be called out-of-order. 169 */ 170 list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) { 171 GEM_BUG_ON(!i915_sched_node_signaled(dep->signaler)); 172 GEM_BUG_ON(!list_empty(&dep->dfs_link)); 173 174 list_del(&dep->wait_link); 175 if (dep->flags & I915_DEPENDENCY_ALLOC) 176 i915_dependency_free(i915, dep); 177 } 178 179 /* Remove ourselves from everyone who depends upon us */ 180 list_for_each_entry_safe(dep, tmp, &node->waiters_list, wait_link) { 181 GEM_BUG_ON(dep->signaler != node); 182 GEM_BUG_ON(!list_empty(&dep->dfs_link)); 183 184 list_del(&dep->signal_link); 185 if (dep->flags & I915_DEPENDENCY_ALLOC) 186 i915_dependency_free(i915, dep); 187 } 188 } 189 190 static void 191 i915_sched_node_init(struct i915_sched_node *node) 192 { 193 INIT_LIST_HEAD(&node->signalers_list); 194 INIT_LIST_HEAD(&node->waiters_list); 195 INIT_LIST_HEAD(&node->link); 196 node->attr.priority = I915_PRIORITY_INVALID; 197 } 198 199 static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno) 200 { 201 struct intel_engine_cs *engine; 202 struct i915_timeline *timeline; 203 enum intel_engine_id id; 204 int ret; 205 206 /* Carefully retire all requests without writing to the rings */ 207 ret = i915_gem_wait_for_idle(i915, 208 I915_WAIT_INTERRUPTIBLE | 209 I915_WAIT_LOCKED, 210 MAX_SCHEDULE_TIMEOUT); 211 if (ret) 212 return ret; 213 214 GEM_BUG_ON(i915->gt.active_requests); 215 216 /* If the seqno wraps around, we need to clear the breadcrumb rbtree */ 217 for_each_engine(engine, i915, id) { 218 GEM_TRACE("%s seqno %d (current %d) -> %d\n", 219 engine->name, 220 engine->timeline.seqno, 221 intel_engine_get_seqno(engine), 222 seqno); 223 224 if (!i915_seqno_passed(seqno, engine->timeline.seqno)) { 225 /* Flush any waiters before we reuse the seqno */ 226 intel_engine_disarm_breadcrumbs(engine); 227 intel_engine_init_hangcheck(engine); 228 GEM_BUG_ON(!list_empty(&engine->breadcrumbs.signals)); 229 } 230 231 /* Check we are idle before we fiddle with hw state! */ 232 GEM_BUG_ON(!intel_engine_is_idle(engine)); 233 GEM_BUG_ON(i915_gem_active_isset(&engine->timeline.last_request)); 234 235 /* Finally reset hw state */ 236 intel_engine_init_global_seqno(engine, seqno); 237 engine->timeline.seqno = seqno; 238 } 239 240 list_for_each_entry(timeline, &i915->gt.timelines, link) 241 memset(timeline->global_sync, 0, sizeof(timeline->global_sync)); 242 243 i915->gt.request_serial = seqno; 244 245 return 0; 246 } 247 248 int i915_gem_set_global_seqno(struct drm_device *dev, u32 seqno) 249 { 250 struct drm_i915_private *i915 = to_i915(dev); 251 252 lockdep_assert_held(&i915->drm.struct_mutex); 253 254 if (seqno == 0) 255 return -EINVAL; 256 257 /* HWS page needs to be set less than what we will inject to ring */ 258 return reset_all_global_seqno(i915, seqno - 1); 259 } 260 261 static int reserve_gt(struct drm_i915_private *i915) 262 { 263 int ret; 264 265 /* 266 * Reservation is fine until we may need to wrap around 267 * 268 * By incrementing the serial for every request, we know that no 269 * individual engine may exceed that serial (as each is reset to 0 270 * on any wrap). This protects even the most pessimistic of migrations 271 * of every request from all engines onto just one. 272 */ 273 while (unlikely(++i915->gt.request_serial == 0)) { 274 ret = reset_all_global_seqno(i915, 0); 275 if (ret) { 276 i915->gt.request_serial--; 277 return ret; 278 } 279 } 280 281 if (!i915->gt.active_requests++) 282 i915_gem_unpark(i915); 283 284 return 0; 285 } 286 287 static void unreserve_gt(struct drm_i915_private *i915) 288 { 289 GEM_BUG_ON(!i915->gt.active_requests); 290 if (!--i915->gt.active_requests) 291 i915_gem_park(i915); 292 } 293 294 void i915_gem_retire_noop(struct i915_gem_active *active, 295 struct i915_request *request) 296 { 297 /* Space left intentionally blank */ 298 } 299 300 static void advance_ring(struct i915_request *request) 301 { 302 struct intel_ring *ring = request->ring; 303 unsigned int tail; 304 305 /* 306 * We know the GPU must have read the request to have 307 * sent us the seqno + interrupt, so use the position 308 * of tail of the request to update the last known position 309 * of the GPU head. 310 * 311 * Note this requires that we are always called in request 312 * completion order. 313 */ 314 GEM_BUG_ON(!list_is_first(&request->ring_link, &ring->request_list)); 315 if (list_is_last(&request->ring_link, &ring->request_list)) { 316 /* 317 * We may race here with execlists resubmitting this request 318 * as we retire it. The resubmission will move the ring->tail 319 * forwards (to request->wa_tail). We either read the 320 * current value that was written to hw, or the value that 321 * is just about to be. Either works, if we miss the last two 322 * noops - they are safe to be replayed on a reset. 323 */ 324 GEM_TRACE("marking %s as inactive\n", ring->timeline->name); 325 tail = READ_ONCE(request->tail); 326 list_del(&ring->active_link); 327 } else { 328 tail = request->postfix; 329 } 330 list_del_init(&request->ring_link); 331 332 ring->head = tail; 333 } 334 335 static void free_capture_list(struct i915_request *request) 336 { 337 struct i915_capture_list *capture; 338 339 capture = request->capture_list; 340 while (capture) { 341 struct i915_capture_list *next = capture->next; 342 343 kfree(capture); 344 capture = next; 345 } 346 } 347 348 static void __retire_engine_request(struct intel_engine_cs *engine, 349 struct i915_request *rq) 350 { 351 GEM_TRACE("%s(%s) fence %llx:%d, global=%d, current %d\n", 352 __func__, engine->name, 353 rq->fence.context, rq->fence.seqno, 354 rq->global_seqno, 355 intel_engine_get_seqno(engine)); 356 357 GEM_BUG_ON(!i915_request_completed(rq)); 358 359 local_irq_disable(); 360 361 spin_lock(&engine->timeline.lock); 362 GEM_BUG_ON(!list_is_first(&rq->link, &engine->timeline.requests)); 363 list_del_init(&rq->link); 364 spin_unlock(&engine->timeline.lock); 365 366 spin_lock(&rq->lock); 367 if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags)) 368 dma_fence_signal_locked(&rq->fence); 369 if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags)) 370 intel_engine_cancel_signaling(rq); 371 if (rq->waitboost) { 372 GEM_BUG_ON(!atomic_read(&rq->i915->gt_pm.rps.num_waiters)); 373 atomic_dec(&rq->i915->gt_pm.rps.num_waiters); 374 } 375 spin_unlock(&rq->lock); 376 377 local_irq_enable(); 378 379 /* 380 * The backing object for the context is done after switching to the 381 * *next* context. Therefore we cannot retire the previous context until 382 * the next context has already started running. However, since we 383 * cannot take the required locks at i915_request_submit() we 384 * defer the unpinning of the active context to now, retirement of 385 * the subsequent request. 386 */ 387 if (engine->last_retired_context) 388 intel_context_unpin(engine->last_retired_context); 389 engine->last_retired_context = rq->hw_context; 390 } 391 392 static void __retire_engine_upto(struct intel_engine_cs *engine, 393 struct i915_request *rq) 394 { 395 struct i915_request *tmp; 396 397 if (list_empty(&rq->link)) 398 return; 399 400 do { 401 tmp = list_first_entry(&engine->timeline.requests, 402 typeof(*tmp), link); 403 404 GEM_BUG_ON(tmp->engine != engine); 405 __retire_engine_request(engine, tmp); 406 } while (tmp != rq); 407 } 408 409 static void i915_request_retire(struct i915_request *request) 410 { 411 struct i915_gem_active *active, *next; 412 413 GEM_TRACE("%s fence %llx:%d, global=%d, current %d\n", 414 request->engine->name, 415 request->fence.context, request->fence.seqno, 416 request->global_seqno, 417 intel_engine_get_seqno(request->engine)); 418 419 lockdep_assert_held(&request->i915->drm.struct_mutex); 420 GEM_BUG_ON(!i915_sw_fence_signaled(&request->submit)); 421 GEM_BUG_ON(!i915_request_completed(request)); 422 423 trace_i915_request_retire(request); 424 425 advance_ring(request); 426 free_capture_list(request); 427 428 /* 429 * Walk through the active list, calling retire on each. This allows 430 * objects to track their GPU activity and mark themselves as idle 431 * when their *last* active request is completed (updating state 432 * tracking lists for eviction, active references for GEM, etc). 433 * 434 * As the ->retire() may free the node, we decouple it first and 435 * pass along the auxiliary information (to avoid dereferencing 436 * the node after the callback). 437 */ 438 list_for_each_entry_safe(active, next, &request->active_list, link) { 439 /* 440 * In microbenchmarks or focusing upon time inside the kernel, 441 * we may spend an inordinate amount of time simply handling 442 * the retirement of requests and processing their callbacks. 443 * Of which, this loop itself is particularly hot due to the 444 * cache misses when jumping around the list of i915_gem_active. 445 * So we try to keep this loop as streamlined as possible and 446 * also prefetch the next i915_gem_active to try and hide 447 * the likely cache miss. 448 */ 449 prefetchw(next); 450 451 INIT_LIST_HEAD(&active->link); 452 RCU_INIT_POINTER(active->request, NULL); 453 454 active->retire(active, request); 455 } 456 457 i915_request_remove_from_client(request); 458 459 /* Retirement decays the ban score as it is a sign of ctx progress */ 460 atomic_dec_if_positive(&request->gem_context->ban_score); 461 intel_context_unpin(request->hw_context); 462 463 __retire_engine_upto(request->engine, request); 464 465 unreserve_gt(request->i915); 466 467 i915_sched_node_fini(request->i915, &request->sched); 468 i915_request_put(request); 469 } 470 471 void i915_request_retire_upto(struct i915_request *rq) 472 { 473 struct intel_ring *ring = rq->ring; 474 struct i915_request *tmp; 475 476 GEM_TRACE("%s fence %llx:%d, global=%d, current %d\n", 477 rq->engine->name, 478 rq->fence.context, rq->fence.seqno, 479 rq->global_seqno, 480 intel_engine_get_seqno(rq->engine)); 481 482 lockdep_assert_held(&rq->i915->drm.struct_mutex); 483 GEM_BUG_ON(!i915_request_completed(rq)); 484 485 if (list_empty(&rq->ring_link)) 486 return; 487 488 do { 489 tmp = list_first_entry(&ring->request_list, 490 typeof(*tmp), ring_link); 491 492 i915_request_retire(tmp); 493 } while (tmp != rq); 494 } 495 496 static u32 timeline_get_seqno(struct i915_timeline *tl) 497 { 498 return ++tl->seqno; 499 } 500 501 static void move_to_timeline(struct i915_request *request, 502 struct i915_timeline *timeline) 503 { 504 GEM_BUG_ON(request->timeline == &request->engine->timeline); 505 lockdep_assert_held(&request->engine->timeline.lock); 506 507 spin_lock(&request->timeline->lock); 508 list_move_tail(&request->link, &timeline->requests); 509 spin_unlock(&request->timeline->lock); 510 } 511 512 void __i915_request_submit(struct i915_request *request) 513 { 514 struct intel_engine_cs *engine = request->engine; 515 u32 seqno; 516 517 GEM_TRACE("%s fence %llx:%d -> global=%d, current %d\n", 518 engine->name, 519 request->fence.context, request->fence.seqno, 520 engine->timeline.seqno + 1, 521 intel_engine_get_seqno(engine)); 522 523 GEM_BUG_ON(!irqs_disabled()); 524 lockdep_assert_held(&engine->timeline.lock); 525 526 GEM_BUG_ON(request->global_seqno); 527 528 seqno = timeline_get_seqno(&engine->timeline); 529 GEM_BUG_ON(!seqno); 530 GEM_BUG_ON(intel_engine_signaled(engine, seqno)); 531 532 /* We may be recursing from the signal callback of another i915 fence */ 533 spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING); 534 request->global_seqno = seqno; 535 if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) 536 intel_engine_enable_signaling(request, false); 537 spin_unlock(&request->lock); 538 539 engine->emit_breadcrumb(request, 540 request->ring->vaddr + request->postfix); 541 542 /* Transfer from per-context onto the global per-engine timeline */ 543 move_to_timeline(request, &engine->timeline); 544 545 trace_i915_request_execute(request); 546 547 wake_up_all(&request->execute); 548 } 549 550 void i915_request_submit(struct i915_request *request) 551 { 552 struct intel_engine_cs *engine = request->engine; 553 unsigned long flags; 554 555 /* Will be called from irq-context when using foreign fences. */ 556 spin_lock_irqsave(&engine->timeline.lock, flags); 557 558 __i915_request_submit(request); 559 560 spin_unlock_irqrestore(&engine->timeline.lock, flags); 561 } 562 563 void __i915_request_unsubmit(struct i915_request *request) 564 { 565 struct intel_engine_cs *engine = request->engine; 566 567 GEM_TRACE("%s fence %llx:%d <- global=%d, current %d\n", 568 engine->name, 569 request->fence.context, request->fence.seqno, 570 request->global_seqno, 571 intel_engine_get_seqno(engine)); 572 573 GEM_BUG_ON(!irqs_disabled()); 574 lockdep_assert_held(&engine->timeline.lock); 575 576 /* 577 * Only unwind in reverse order, required so that the per-context list 578 * is kept in seqno/ring order. 579 */ 580 GEM_BUG_ON(!request->global_seqno); 581 GEM_BUG_ON(request->global_seqno != engine->timeline.seqno); 582 GEM_BUG_ON(intel_engine_has_completed(engine, request->global_seqno)); 583 engine->timeline.seqno--; 584 585 /* We may be recursing from the signal callback of another i915 fence */ 586 spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING); 587 request->global_seqno = 0; 588 if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags)) 589 intel_engine_cancel_signaling(request); 590 spin_unlock(&request->lock); 591 592 /* Transfer back from the global per-engine timeline to per-context */ 593 move_to_timeline(request, request->timeline); 594 595 /* 596 * We don't need to wake_up any waiters on request->execute, they 597 * will get woken by any other event or us re-adding this request 598 * to the engine timeline (__i915_request_submit()). The waiters 599 * should be quite adapt at finding that the request now has a new 600 * global_seqno to the one they went to sleep on. 601 */ 602 } 603 604 void i915_request_unsubmit(struct i915_request *request) 605 { 606 struct intel_engine_cs *engine = request->engine; 607 unsigned long flags; 608 609 /* Will be called from irq-context when using foreign fences. */ 610 spin_lock_irqsave(&engine->timeline.lock, flags); 611 612 __i915_request_unsubmit(request); 613 614 spin_unlock_irqrestore(&engine->timeline.lock, flags); 615 } 616 617 static int __i915_sw_fence_call 618 submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state) 619 { 620 struct i915_request *request = 621 container_of(fence, typeof(*request), submit); 622 623 switch (state) { 624 case FENCE_COMPLETE: 625 trace_i915_request_submit(request); 626 /* 627 * We need to serialize use of the submit_request() callback 628 * with its hotplugging performed during an emergency 629 * i915_gem_set_wedged(). We use the RCU mechanism to mark the 630 * critical section in order to force i915_gem_set_wedged() to 631 * wait until the submit_request() is completed before 632 * proceeding. 633 */ 634 rcu_read_lock(); 635 request->engine->submit_request(request); 636 rcu_read_unlock(); 637 break; 638 639 case FENCE_FREE: 640 i915_request_put(request); 641 break; 642 } 643 644 return NOTIFY_DONE; 645 } 646 647 /** 648 * i915_request_alloc - allocate a request structure 649 * 650 * @engine: engine that we wish to issue the request on. 651 * @ctx: context that the request will be associated with. 652 * 653 * Returns a pointer to the allocated request if successful, 654 * or an error code if not. 655 */ 656 struct i915_request * 657 i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx) 658 { 659 struct drm_i915_private *i915 = engine->i915; 660 struct i915_request *rq; 661 struct intel_context *ce; 662 int ret; 663 664 lockdep_assert_held(&i915->drm.struct_mutex); 665 666 /* 667 * Preempt contexts are reserved for exclusive use to inject a 668 * preemption context switch. They are never to be used for any trivial 669 * request! 670 */ 671 GEM_BUG_ON(ctx == i915->preempt_context); 672 673 /* 674 * ABI: Before userspace accesses the GPU (e.g. execbuffer), report 675 * EIO if the GPU is already wedged. 676 */ 677 if (i915_terminally_wedged(&i915->gpu_error)) 678 return ERR_PTR(-EIO); 679 680 /* 681 * Pinning the contexts may generate requests in order to acquire 682 * GGTT space, so do this first before we reserve a seqno for 683 * ourselves. 684 */ 685 ce = intel_context_pin(ctx, engine); 686 if (IS_ERR(ce)) 687 return ERR_CAST(ce); 688 689 ret = reserve_gt(i915); 690 if (ret) 691 goto err_unpin; 692 693 ret = intel_ring_wait_for_space(ce->ring, MIN_SPACE_FOR_ADD_REQUEST); 694 if (ret) 695 goto err_unreserve; 696 697 /* Move our oldest request to the slab-cache (if not in use!) */ 698 rq = list_first_entry(&ce->ring->request_list, typeof(*rq), ring_link); 699 if (!list_is_last(&rq->ring_link, &ce->ring->request_list) && 700 i915_request_completed(rq)) 701 i915_request_retire(rq); 702 703 /* 704 * Beware: Dragons be flying overhead. 705 * 706 * We use RCU to look up requests in flight. The lookups may 707 * race with the request being allocated from the slab freelist. 708 * That is the request we are writing to here, may be in the process 709 * of being read by __i915_gem_active_get_rcu(). As such, 710 * we have to be very careful when overwriting the contents. During 711 * the RCU lookup, we change chase the request->engine pointer, 712 * read the request->global_seqno and increment the reference count. 713 * 714 * The reference count is incremented atomically. If it is zero, 715 * the lookup knows the request is unallocated and complete. Otherwise, 716 * it is either still in use, or has been reallocated and reset 717 * with dma_fence_init(). This increment is safe for release as we 718 * check that the request we have a reference to and matches the active 719 * request. 720 * 721 * Before we increment the refcount, we chase the request->engine 722 * pointer. We must not call kmem_cache_zalloc() or else we set 723 * that pointer to NULL and cause a crash during the lookup. If 724 * we see the request is completed (based on the value of the 725 * old engine and seqno), the lookup is complete and reports NULL. 726 * If we decide the request is not completed (new engine or seqno), 727 * then we grab a reference and double check that it is still the 728 * active request - which it won't be and restart the lookup. 729 * 730 * Do not use kmem_cache_zalloc() here! 731 */ 732 rq = kmem_cache_alloc(i915->requests, 733 GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN); 734 if (unlikely(!rq)) { 735 i915_retire_requests(i915); 736 737 /* Ratelimit ourselves to prevent oom from malicious clients */ 738 rq = i915_gem_active_raw(&ce->ring->timeline->last_request, 739 &i915->drm.struct_mutex); 740 if (rq) 741 cond_synchronize_rcu(rq->rcustate); 742 743 /* 744 * We've forced the client to stall and catch up with whatever 745 * backlog there might have been. As we are assuming that we 746 * caused the mempressure, now is an opportune time to 747 * recover as much memory from the request pool as is possible. 748 * Having already penalized the client to stall, we spend 749 * a little extra time to re-optimise page allocation. 750 */ 751 kmem_cache_shrink(i915->requests); 752 rcu_barrier(); /* Recover the TYPESAFE_BY_RCU pages */ 753 754 rq = kmem_cache_alloc(i915->requests, GFP_KERNEL); 755 if (!rq) { 756 ret = -ENOMEM; 757 goto err_unreserve; 758 } 759 } 760 761 rq->rcustate = get_state_synchronize_rcu(); 762 763 INIT_LIST_HEAD(&rq->active_list); 764 rq->i915 = i915; 765 rq->engine = engine; 766 rq->gem_context = ctx; 767 rq->hw_context = ce; 768 rq->ring = ce->ring; 769 rq->timeline = ce->ring->timeline; 770 GEM_BUG_ON(rq->timeline == &engine->timeline); 771 772 spin_lock_init(&rq->lock); 773 dma_fence_init(&rq->fence, 774 &i915_fence_ops, 775 &rq->lock, 776 rq->timeline->fence_context, 777 timeline_get_seqno(rq->timeline)); 778 779 /* We bump the ref for the fence chain */ 780 i915_sw_fence_init(&i915_request_get(rq)->submit, submit_notify); 781 init_waitqueue_head(&rq->execute); 782 783 i915_sched_node_init(&rq->sched); 784 785 /* No zalloc, must clear what we need by hand */ 786 rq->global_seqno = 0; 787 rq->signaling.wait.seqno = 0; 788 rq->file_priv = NULL; 789 rq->batch = NULL; 790 rq->capture_list = NULL; 791 rq->waitboost = false; 792 793 /* 794 * Reserve space in the ring buffer for all the commands required to 795 * eventually emit this request. This is to guarantee that the 796 * i915_request_add() call can't fail. Note that the reserve may need 797 * to be redone if the request is not actually submitted straight 798 * away, e.g. because a GPU scheduler has deferred it. 799 */ 800 rq->reserved_space = MIN_SPACE_FOR_ADD_REQUEST; 801 GEM_BUG_ON(rq->reserved_space < engine->emit_breadcrumb_sz); 802 803 /* 804 * Record the position of the start of the request so that 805 * should we detect the updated seqno part-way through the 806 * GPU processing the request, we never over-estimate the 807 * position of the head. 808 */ 809 rq->head = rq->ring->emit; 810 811 /* Unconditionally invalidate GPU caches and TLBs. */ 812 ret = engine->emit_flush(rq, EMIT_INVALIDATE); 813 if (ret) 814 goto err_unwind; 815 816 ret = engine->request_alloc(rq); 817 if (ret) 818 goto err_unwind; 819 820 /* Keep a second pin for the dual retirement along engine and ring */ 821 __intel_context_pin(ce); 822 823 rq->infix = rq->ring->emit; /* end of header; start of user payload */ 824 825 /* Check that we didn't interrupt ourselves with a new request */ 826 GEM_BUG_ON(rq->timeline->seqno != rq->fence.seqno); 827 return rq; 828 829 err_unwind: 830 ce->ring->emit = rq->head; 831 832 /* Make sure we didn't add ourselves to external state before freeing */ 833 GEM_BUG_ON(!list_empty(&rq->active_list)); 834 GEM_BUG_ON(!list_empty(&rq->sched.signalers_list)); 835 GEM_BUG_ON(!list_empty(&rq->sched.waiters_list)); 836 837 kmem_cache_free(i915->requests, rq); 838 err_unreserve: 839 unreserve_gt(i915); 840 err_unpin: 841 intel_context_unpin(ce); 842 return ERR_PTR(ret); 843 } 844 845 static int 846 i915_request_await_request(struct i915_request *to, struct i915_request *from) 847 { 848 int ret; 849 850 GEM_BUG_ON(to == from); 851 GEM_BUG_ON(to->timeline == from->timeline); 852 853 if (i915_request_completed(from)) 854 return 0; 855 856 if (to->engine->schedule) { 857 ret = i915_sched_node_add_dependency(to->i915, 858 &to->sched, 859 &from->sched); 860 if (ret < 0) 861 return ret; 862 } 863 864 if (to->engine == from->engine) { 865 ret = i915_sw_fence_await_sw_fence_gfp(&to->submit, 866 &from->submit, 867 I915_FENCE_GFP); 868 return ret < 0 ? ret : 0; 869 } 870 871 if (to->engine->semaphore.sync_to) { 872 u32 seqno; 873 874 GEM_BUG_ON(!from->engine->semaphore.signal); 875 876 seqno = i915_request_global_seqno(from); 877 if (!seqno) 878 goto await_dma_fence; 879 880 if (seqno <= to->timeline->global_sync[from->engine->id]) 881 return 0; 882 883 trace_i915_gem_ring_sync_to(to, from); 884 ret = to->engine->semaphore.sync_to(to, from); 885 if (ret) 886 return ret; 887 888 to->timeline->global_sync[from->engine->id] = seqno; 889 return 0; 890 } 891 892 await_dma_fence: 893 ret = i915_sw_fence_await_dma_fence(&to->submit, 894 &from->fence, 0, 895 I915_FENCE_GFP); 896 return ret < 0 ? ret : 0; 897 } 898 899 int 900 i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence) 901 { 902 struct dma_fence **child = &fence; 903 unsigned int nchild = 1; 904 int ret; 905 906 /* 907 * Note that if the fence-array was created in signal-on-any mode, 908 * we should *not* decompose it into its individual fences. However, 909 * we don't currently store which mode the fence-array is operating 910 * in. Fortunately, the only user of signal-on-any is private to 911 * amdgpu and we should not see any incoming fence-array from 912 * sync-file being in signal-on-any mode. 913 */ 914 if (dma_fence_is_array(fence)) { 915 struct dma_fence_array *array = to_dma_fence_array(fence); 916 917 child = array->fences; 918 nchild = array->num_fences; 919 GEM_BUG_ON(!nchild); 920 } 921 922 do { 923 fence = *child++; 924 if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) 925 continue; 926 927 /* 928 * Requests on the same timeline are explicitly ordered, along 929 * with their dependencies, by i915_request_add() which ensures 930 * that requests are submitted in-order through each ring. 931 */ 932 if (fence->context == rq->fence.context) 933 continue; 934 935 /* Squash repeated waits to the same timelines */ 936 if (fence->context != rq->i915->mm.unordered_timeline && 937 i915_timeline_sync_is_later(rq->timeline, fence)) 938 continue; 939 940 if (dma_fence_is_i915(fence)) 941 ret = i915_request_await_request(rq, to_request(fence)); 942 else 943 ret = i915_sw_fence_await_dma_fence(&rq->submit, fence, 944 I915_FENCE_TIMEOUT, 945 I915_FENCE_GFP); 946 if (ret < 0) 947 return ret; 948 949 /* Record the latest fence used against each timeline */ 950 if (fence->context != rq->i915->mm.unordered_timeline) 951 i915_timeline_sync_set(rq->timeline, fence); 952 } while (--nchild); 953 954 return 0; 955 } 956 957 /** 958 * i915_request_await_object - set this request to (async) wait upon a bo 959 * @to: request we are wishing to use 960 * @obj: object which may be in use on another ring. 961 * @write: whether the wait is on behalf of a writer 962 * 963 * This code is meant to abstract object synchronization with the GPU. 964 * Conceptually we serialise writes between engines inside the GPU. 965 * We only allow one engine to write into a buffer at any time, but 966 * multiple readers. To ensure each has a coherent view of memory, we must: 967 * 968 * - If there is an outstanding write request to the object, the new 969 * request must wait for it to complete (either CPU or in hw, requests 970 * on the same ring will be naturally ordered). 971 * 972 * - If we are a write request (pending_write_domain is set), the new 973 * request must wait for outstanding read requests to complete. 974 * 975 * Returns 0 if successful, else propagates up the lower layer error. 976 */ 977 int 978 i915_request_await_object(struct i915_request *to, 979 struct drm_i915_gem_object *obj, 980 bool write) 981 { 982 struct dma_fence *excl; 983 int ret = 0; 984 985 if (write) { 986 struct dma_fence **shared; 987 unsigned int count, i; 988 989 ret = reservation_object_get_fences_rcu(obj->resv, 990 &excl, &count, &shared); 991 if (ret) 992 return ret; 993 994 for (i = 0; i < count; i++) { 995 ret = i915_request_await_dma_fence(to, shared[i]); 996 if (ret) 997 break; 998 999 dma_fence_put(shared[i]); 1000 } 1001 1002 for (; i < count; i++) 1003 dma_fence_put(shared[i]); 1004 kfree(shared); 1005 } else { 1006 excl = reservation_object_get_excl_rcu(obj->resv); 1007 } 1008 1009 if (excl) { 1010 if (ret == 0) 1011 ret = i915_request_await_dma_fence(to, excl); 1012 1013 dma_fence_put(excl); 1014 } 1015 1016 return ret; 1017 } 1018 1019 void i915_request_skip(struct i915_request *rq, int error) 1020 { 1021 void *vaddr = rq->ring->vaddr; 1022 u32 head; 1023 1024 GEM_BUG_ON(!IS_ERR_VALUE((long)error)); 1025 dma_fence_set_error(&rq->fence, error); 1026 1027 /* 1028 * As this request likely depends on state from the lost 1029 * context, clear out all the user operations leaving the 1030 * breadcrumb at the end (so we get the fence notifications). 1031 */ 1032 head = rq->infix; 1033 if (rq->postfix < head) { 1034 memset(vaddr + head, 0, rq->ring->size - head); 1035 head = 0; 1036 } 1037 memset(vaddr + head, 0, rq->postfix - head); 1038 } 1039 1040 /* 1041 * NB: This function is not allowed to fail. Doing so would mean the the 1042 * request is not being tracked for completion but the work itself is 1043 * going to happen on the hardware. This would be a Bad Thing(tm). 1044 */ 1045 void i915_request_add(struct i915_request *request) 1046 { 1047 struct intel_engine_cs *engine = request->engine; 1048 struct i915_timeline *timeline = request->timeline; 1049 struct intel_ring *ring = request->ring; 1050 struct i915_request *prev; 1051 u32 *cs; 1052 1053 GEM_TRACE("%s fence %llx:%d\n", 1054 engine->name, request->fence.context, request->fence.seqno); 1055 1056 lockdep_assert_held(&request->i915->drm.struct_mutex); 1057 trace_i915_request_add(request); 1058 1059 /* 1060 * Make sure that no request gazumped us - if it was allocated after 1061 * our i915_request_alloc() and called __i915_request_add() before 1062 * us, the timeline will hold its seqno which is later than ours. 1063 */ 1064 GEM_BUG_ON(timeline->seqno != request->fence.seqno); 1065 1066 /* 1067 * To ensure that this call will not fail, space for its emissions 1068 * should already have been reserved in the ring buffer. Let the ring 1069 * know that it is time to use that space up. 1070 */ 1071 request->reserved_space = 0; 1072 engine->emit_flush(request, EMIT_FLUSH); 1073 1074 /* 1075 * Record the position of the start of the breadcrumb so that 1076 * should we detect the updated seqno part-way through the 1077 * GPU processing the request, we never over-estimate the 1078 * position of the ring's HEAD. 1079 */ 1080 cs = intel_ring_begin(request, engine->emit_breadcrumb_sz); 1081 GEM_BUG_ON(IS_ERR(cs)); 1082 request->postfix = intel_ring_offset(request, cs); 1083 1084 /* 1085 * Seal the request and mark it as pending execution. Note that 1086 * we may inspect this state, without holding any locks, during 1087 * hangcheck. Hence we apply the barrier to ensure that we do not 1088 * see a more recent value in the hws than we are tracking. 1089 */ 1090 1091 prev = i915_gem_active_raw(&timeline->last_request, 1092 &request->i915->drm.struct_mutex); 1093 if (prev && !i915_request_completed(prev)) { 1094 i915_sw_fence_await_sw_fence(&request->submit, &prev->submit, 1095 &request->submitq); 1096 if (engine->schedule) 1097 __i915_sched_node_add_dependency(&request->sched, 1098 &prev->sched, 1099 &request->dep, 1100 0); 1101 } 1102 1103 spin_lock_irq(&timeline->lock); 1104 list_add_tail(&request->link, &timeline->requests); 1105 spin_unlock_irq(&timeline->lock); 1106 1107 GEM_BUG_ON(timeline->seqno != request->fence.seqno); 1108 i915_gem_active_set(&timeline->last_request, request); 1109 1110 list_add_tail(&request->ring_link, &ring->request_list); 1111 if (list_is_first(&request->ring_link, &ring->request_list)) { 1112 GEM_TRACE("marking %s as active\n", ring->timeline->name); 1113 list_add(&ring->active_link, &request->i915->gt.active_rings); 1114 } 1115 request->emitted_jiffies = jiffies; 1116 1117 /* 1118 * Let the backend know a new request has arrived that may need 1119 * to adjust the existing execution schedule due to a high priority 1120 * request - i.e. we may want to preempt the current request in order 1121 * to run a high priority dependency chain *before* we can execute this 1122 * request. 1123 * 1124 * This is called before the request is ready to run so that we can 1125 * decide whether to preempt the entire chain so that it is ready to 1126 * run at the earliest possible convenience. 1127 */ 1128 local_bh_disable(); 1129 rcu_read_lock(); /* RCU serialisation for set-wedged protection */ 1130 if (engine->schedule) 1131 engine->schedule(request, &request->gem_context->sched); 1132 rcu_read_unlock(); 1133 i915_sw_fence_commit(&request->submit); 1134 local_bh_enable(); /* Kick the execlists tasklet if just scheduled */ 1135 1136 /* 1137 * In typical scenarios, we do not expect the previous request on 1138 * the timeline to be still tracked by timeline->last_request if it 1139 * has been completed. If the completed request is still here, that 1140 * implies that request retirement is a long way behind submission, 1141 * suggesting that we haven't been retiring frequently enough from 1142 * the combination of retire-before-alloc, waiters and the background 1143 * retirement worker. So if the last request on this timeline was 1144 * already completed, do a catch up pass, flushing the retirement queue 1145 * up to this client. Since we have now moved the heaviest operations 1146 * during retirement onto secondary workers, such as freeing objects 1147 * or contexts, retiring a bunch of requests is mostly list management 1148 * (and cache misses), and so we should not be overly penalizing this 1149 * client by performing excess work, though we may still performing 1150 * work on behalf of others -- but instead we should benefit from 1151 * improved resource management. (Well, that's the theory at least.) 1152 */ 1153 if (prev && i915_request_completed(prev)) 1154 i915_request_retire_upto(prev); 1155 } 1156 1157 static unsigned long local_clock_us(unsigned int *cpu) 1158 { 1159 unsigned long t; 1160 1161 /* 1162 * Cheaply and approximately convert from nanoseconds to microseconds. 1163 * The result and subsequent calculations are also defined in the same 1164 * approximate microseconds units. The principal source of timing 1165 * error here is from the simple truncation. 1166 * 1167 * Note that local_clock() is only defined wrt to the current CPU; 1168 * the comparisons are no longer valid if we switch CPUs. Instead of 1169 * blocking preemption for the entire busywait, we can detect the CPU 1170 * switch and use that as indicator of system load and a reason to 1171 * stop busywaiting, see busywait_stop(). 1172 */ 1173 *cpu = get_cpu(); 1174 t = local_clock() >> 10; 1175 put_cpu(); 1176 1177 return t; 1178 } 1179 1180 static bool busywait_stop(unsigned long timeout, unsigned int cpu) 1181 { 1182 unsigned int this_cpu; 1183 1184 if (time_after(local_clock_us(&this_cpu), timeout)) 1185 return true; 1186 1187 return this_cpu != cpu; 1188 } 1189 1190 static bool __i915_spin_request(const struct i915_request *rq, 1191 u32 seqno, int state, unsigned long timeout_us) 1192 { 1193 struct intel_engine_cs *engine = rq->engine; 1194 unsigned int irq, cpu; 1195 1196 GEM_BUG_ON(!seqno); 1197 1198 /* 1199 * Only wait for the request if we know it is likely to complete. 1200 * 1201 * We don't track the timestamps around requests, nor the average 1202 * request length, so we do not have a good indicator that this 1203 * request will complete within the timeout. What we do know is the 1204 * order in which requests are executed by the engine and so we can 1205 * tell if the request has started. If the request hasn't started yet, 1206 * it is a fair assumption that it will not complete within our 1207 * relatively short timeout. 1208 */ 1209 if (!intel_engine_has_started(engine, seqno)) 1210 return false; 1211 1212 /* 1213 * When waiting for high frequency requests, e.g. during synchronous 1214 * rendering split between the CPU and GPU, the finite amount of time 1215 * required to set up the irq and wait upon it limits the response 1216 * rate. By busywaiting on the request completion for a short while we 1217 * can service the high frequency waits as quick as possible. However, 1218 * if it is a slow request, we want to sleep as quickly as possible. 1219 * The tradeoff between waiting and sleeping is roughly the time it 1220 * takes to sleep on a request, on the order of a microsecond. 1221 */ 1222 1223 irq = READ_ONCE(engine->breadcrumbs.irq_count); 1224 timeout_us += local_clock_us(&cpu); 1225 do { 1226 if (intel_engine_has_completed(engine, seqno)) 1227 return seqno == i915_request_global_seqno(rq); 1228 1229 /* 1230 * Seqno are meant to be ordered *before* the interrupt. If 1231 * we see an interrupt without a corresponding seqno advance, 1232 * assume we won't see one in the near future but require 1233 * the engine->seqno_barrier() to fixup coherency. 1234 */ 1235 if (READ_ONCE(engine->breadcrumbs.irq_count) != irq) 1236 break; 1237 1238 if (signal_pending_state(state, current)) 1239 break; 1240 1241 if (busywait_stop(timeout_us, cpu)) 1242 break; 1243 1244 cpu_relax(); 1245 } while (!need_resched()); 1246 1247 return false; 1248 } 1249 1250 static bool __i915_wait_request_check_and_reset(struct i915_request *request) 1251 { 1252 struct i915_gpu_error *error = &request->i915->gpu_error; 1253 1254 if (likely(!i915_reset_handoff(error))) 1255 return false; 1256 1257 __set_current_state(TASK_RUNNING); 1258 i915_reset(request->i915, error->stalled_mask, error->reason); 1259 return true; 1260 } 1261 1262 /** 1263 * i915_request_wait - wait until execution of request has finished 1264 * @rq: the request to wait upon 1265 * @flags: how to wait 1266 * @timeout: how long to wait in jiffies 1267 * 1268 * i915_request_wait() waits for the request to be completed, for a 1269 * maximum of @timeout jiffies (with MAX_SCHEDULE_TIMEOUT implying an 1270 * unbounded wait). 1271 * 1272 * If the caller holds the struct_mutex, the caller must pass I915_WAIT_LOCKED 1273 * in via the flags, and vice versa if the struct_mutex is not held, the caller 1274 * must not specify that the wait is locked. 1275 * 1276 * Returns the remaining time (in jiffies) if the request completed, which may 1277 * be zero or -ETIME if the request is unfinished after the timeout expires. 1278 * May return -EINTR is called with I915_WAIT_INTERRUPTIBLE and a signal is 1279 * pending before the request completes. 1280 */ 1281 long i915_request_wait(struct i915_request *rq, 1282 unsigned int flags, 1283 long timeout) 1284 { 1285 const int state = flags & I915_WAIT_INTERRUPTIBLE ? 1286 TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE; 1287 wait_queue_head_t *errq = &rq->i915->gpu_error.wait_queue; 1288 DEFINE_WAIT_FUNC(reset, default_wake_function); 1289 DEFINE_WAIT_FUNC(exec, default_wake_function); 1290 struct intel_wait wait; 1291 1292 might_sleep(); 1293 #if IS_ENABLED(CONFIG_LOCKDEP) 1294 GEM_BUG_ON(debug_locks && 1295 !!lockdep_is_held(&rq->i915->drm.struct_mutex) != 1296 !!(flags & I915_WAIT_LOCKED)); 1297 #endif 1298 GEM_BUG_ON(timeout < 0); 1299 1300 if (i915_request_completed(rq)) 1301 return timeout; 1302 1303 if (!timeout) 1304 return -ETIME; 1305 1306 trace_i915_request_wait_begin(rq, flags); 1307 1308 add_wait_queue(&rq->execute, &exec); 1309 if (flags & I915_WAIT_LOCKED) 1310 add_wait_queue(errq, &reset); 1311 1312 intel_wait_init(&wait); 1313 1314 restart: 1315 do { 1316 set_current_state(state); 1317 if (intel_wait_update_request(&wait, rq)) 1318 break; 1319 1320 if (flags & I915_WAIT_LOCKED && 1321 __i915_wait_request_check_and_reset(rq)) 1322 continue; 1323 1324 if (signal_pending_state(state, current)) { 1325 timeout = -ERESTARTSYS; 1326 goto complete; 1327 } 1328 1329 if (!timeout) { 1330 timeout = -ETIME; 1331 goto complete; 1332 } 1333 1334 timeout = io_schedule_timeout(timeout); 1335 } while (1); 1336 1337 GEM_BUG_ON(!intel_wait_has_seqno(&wait)); 1338 GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit)); 1339 1340 /* Optimistic short spin before touching IRQs */ 1341 if (__i915_spin_request(rq, wait.seqno, state, 5)) 1342 goto complete; 1343 1344 set_current_state(state); 1345 if (intel_engine_add_wait(rq->engine, &wait)) 1346 /* 1347 * In order to check that we haven't missed the interrupt 1348 * as we enabled it, we need to kick ourselves to do a 1349 * coherent check on the seqno before we sleep. 1350 */ 1351 goto wakeup; 1352 1353 if (flags & I915_WAIT_LOCKED) 1354 __i915_wait_request_check_and_reset(rq); 1355 1356 for (;;) { 1357 if (signal_pending_state(state, current)) { 1358 timeout = -ERESTARTSYS; 1359 break; 1360 } 1361 1362 if (!timeout) { 1363 timeout = -ETIME; 1364 break; 1365 } 1366 1367 timeout = io_schedule_timeout(timeout); 1368 1369 if (intel_wait_complete(&wait) && 1370 intel_wait_check_request(&wait, rq)) 1371 break; 1372 1373 set_current_state(state); 1374 1375 wakeup: 1376 /* 1377 * Carefully check if the request is complete, giving time 1378 * for the seqno to be visible following the interrupt. 1379 * We also have to check in case we are kicked by the GPU 1380 * reset in order to drop the struct_mutex. 1381 */ 1382 if (__i915_request_irq_complete(rq)) 1383 break; 1384 1385 /* 1386 * If the GPU is hung, and we hold the lock, reset the GPU 1387 * and then check for completion. On a full reset, the engine's 1388 * HW seqno will be advanced passed us and we are complete. 1389 * If we do a partial reset, we have to wait for the GPU to 1390 * resume and update the breadcrumb. 1391 * 1392 * If we don't hold the mutex, we can just wait for the worker 1393 * to come along and update the breadcrumb (either directly 1394 * itself, or indirectly by recovering the GPU). 1395 */ 1396 if (flags & I915_WAIT_LOCKED && 1397 __i915_wait_request_check_and_reset(rq)) 1398 continue; 1399 1400 /* Only spin if we know the GPU is processing this request */ 1401 if (__i915_spin_request(rq, wait.seqno, state, 2)) 1402 break; 1403 1404 if (!intel_wait_check_request(&wait, rq)) { 1405 intel_engine_remove_wait(rq->engine, &wait); 1406 goto restart; 1407 } 1408 } 1409 1410 intel_engine_remove_wait(rq->engine, &wait); 1411 complete: 1412 __set_current_state(TASK_RUNNING); 1413 if (flags & I915_WAIT_LOCKED) 1414 remove_wait_queue(errq, &reset); 1415 remove_wait_queue(&rq->execute, &exec); 1416 trace_i915_request_wait_end(rq); 1417 1418 return timeout; 1419 } 1420 1421 static void ring_retire_requests(struct intel_ring *ring) 1422 { 1423 struct i915_request *request, *next; 1424 1425 list_for_each_entry_safe(request, next, 1426 &ring->request_list, ring_link) { 1427 if (!i915_request_completed(request)) 1428 break; 1429 1430 i915_request_retire(request); 1431 } 1432 } 1433 1434 void i915_retire_requests(struct drm_i915_private *i915) 1435 { 1436 struct intel_ring *ring, *tmp; 1437 1438 lockdep_assert_held(&i915->drm.struct_mutex); 1439 1440 if (!i915->gt.active_requests) 1441 return; 1442 1443 list_for_each_entry_safe(ring, tmp, &i915->gt.active_rings, active_link) 1444 ring_retire_requests(ring); 1445 } 1446 1447 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 1448 #include "selftests/mock_request.c" 1449 #include "selftests/i915_request.c" 1450 #endif 1451