drivers/gpu/drm/i915/gt/intel_reset.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright © 2008-2018 Intel Corporation
   5  */
   6
   7 #include <linux/sched/mm.h>
   8 #include <linux/stop_machine.h>
   9
  10 #include "display/intel_display_types.h"
  11 #include "display/intel_overlay.h"
  12
  13 #include "gem/i915_gem_context.h"
  14
  15 #include "i915_drv.h"
  16 #include "i915_gpu_error.h"
  17 #include "i915_irq.h"
  18 #include "intel_engine_pm.h"
  19 #include "intel_gt.h"
  20 #include "intel_gt_pm.h"
  21 #include "intel_reset.h"
  22
  23 #include "uc/intel_guc.h"
  24
  25 #define RESET_MAX_RETRIES 3
  26
  27 /* XXX How to handle concurrent GGTT updates using tiling registers? */
  28 #define RESET_UNDER_STOP_MACHINE 0
  29
  30 static void rmw_set_fw(struct intel_uncore *uncore, i915_reg_t reg, u32 set)
  31 {
  32         intel_uncore_rmw_fw(uncore, reg, 0, set);
  33 }
  34
  35 static void rmw_clear_fw(struct intel_uncore *uncore, i915_reg_t reg, u32 clr)
  36 {
  37         intel_uncore_rmw_fw(uncore, reg, clr, 0);
  38 }
  39
  40 static void engine_skip_context(struct i915_request *rq)
  41 {
  42         struct intel_engine_cs *engine = rq->engine;
  43         struct i915_gem_context *hung_ctx = rq->gem_context;
  44
  45         lockdep_assert_held(&engine->active.lock);
  46
  47         if (!i915_request_is_active(rq))
  48                 return;
  49
  50         list_for_each_entry_continue(rq, &engine->active.requests, sched.link)
  51                 if (rq->gem_context == hung_ctx)
  52                         i915_request_skip(rq, -EIO);
  53 }
  54
  55 static void client_mark_guilty(struct drm_i915_file_private *file_priv,
  56                                const struct i915_gem_context *ctx)
  57 {
  58         unsigned int score;
  59         unsigned long prev_hang;
  60
  61         if (i915_gem_context_is_banned(ctx))
  62                 score = I915_CLIENT_SCORE_CONTEXT_BAN;
  63         else
  64                 score = 0;
  65
  66         prev_hang = xchg(&file_priv->hang_timestamp, jiffies);
  67         if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES))
  68                 score += I915_CLIENT_SCORE_HANG_FAST;
  69
  70         if (score) {
  71                 atomic_add(score, &file_priv->ban_score);
  72
  73                 DRM_DEBUG_DRIVER("client %s: gained %u ban score, now %u\n",
  74                                  ctx->name, score,
  75                                  atomic_read(&file_priv->ban_score));
  76         }
  77 }
  78
  79 static bool context_mark_guilty(struct i915_gem_context *ctx)
  80 {
  81         unsigned long prev_hang;
  82         bool banned;
  83         int i;
  84
  85         atomic_inc(&ctx->guilty_count);
  86
  87         /* Cool contexts are too cool to be banned! (Used for reset testing.) */
  88         if (!i915_gem_context_is_bannable(ctx))
  89                 return false;
  90
  91         /* Record the timestamp for the last N hangs */
  92         prev_hang = ctx->hang_timestamp[0];
  93         for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp) - 1; i++)
  94                 ctx->hang_timestamp[i] = ctx->hang_timestamp[i + 1];
  95         ctx->hang_timestamp[i] = jiffies;
  96
  97         /* If we have hung N+1 times in rapid succession, we ban the context! */
  98         banned = !i915_gem_context_is_recoverable(ctx);
  99         if (time_before(jiffies, prev_hang + CONTEXT_FAST_HANG_JIFFIES))
 100                 banned = true;
 101         if (banned) {
 102                 DRM_DEBUG_DRIVER("context %s: guilty %d, banned\n",
 103                                  ctx->name, atomic_read(&ctx->guilty_count));
 104                 i915_gem_context_set_banned(ctx);
 105         }
 106
 107         if (!IS_ERR_OR_NULL(ctx->file_priv))
 108                 client_mark_guilty(ctx->file_priv, ctx);
 109
 110         return banned;
 111 }
 112
 113 static void context_mark_innocent(struct i915_gem_context *ctx)
 114 {
 115         atomic_inc(&ctx->active_count);
 116 }
 117
 118 void __i915_request_reset(struct i915_request *rq, bool guilty)
 119 {
 120         GEM_TRACE("%s rq=%llx:%lld, guilty? %s\n",
 121                   rq->engine->name,
 122                   rq->fence.context,
 123                   rq->fence.seqno,
 124                   yesno(guilty));
 125
 126         lockdep_assert_held(&rq->engine->active.lock);
 127         GEM_BUG_ON(i915_request_completed(rq));
 128
 129         if (guilty) {
 130                 i915_request_skip(rq, -EIO);
 131                 if (context_mark_guilty(rq->gem_context))
 132                         engine_skip_context(rq);
 133         } else {
 134                 dma_fence_set_error(&rq->fence, -EAGAIN);
 135                 context_mark_innocent(rq->gem_context);
 136         }
 137 }
 138
 139 static bool i915_in_reset(struct pci_dev *pdev)
 140 {
 141         u8 gdrst;
 142
 143         pci_read_config_byte(pdev, I915_GDRST, &gdrst);
 144         return gdrst & GRDOM_RESET_STATUS;
 145 }
 146
 147 static int i915_do_reset(struct intel_gt *gt,
 148                          intel_engine_mask_t engine_mask,
 149                          unsigned int retry)
 150 {
 151         struct pci_dev *pdev = gt->i915->drm.pdev;
 152         int err;
 153
 154         /* Assert reset for at least 20 usec, and wait for acknowledgement. */
 155         pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 156         udelay(50);
 157         err = wait_for_atomic(i915_in_reset(pdev), 50);
 158
 159         /* Clear the reset request. */
 160         pci_write_config_byte(pdev, I915_GDRST, 0);
 161         udelay(50);
 162         if (!err)
 163                 err = wait_for_atomic(!i915_in_reset(pdev), 50);
 164
 165         return err;
 166 }
 167
 168 static bool g4x_reset_complete(struct pci_dev *pdev)
 169 {
 170         u8 gdrst;
 171
 172         pci_read_config_byte(pdev, I915_GDRST, &gdrst);
 173         return (gdrst & GRDOM_RESET_ENABLE) == 0;
 174 }
 175
 176 static int g33_do_reset(struct intel_gt *gt,
 177                         intel_engine_mask_t engine_mask,
 178                         unsigned int retry)
 179 {
 180         struct pci_dev *pdev = gt->i915->drm.pdev;
 181
 182         pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 183         return wait_for_atomic(g4x_reset_complete(pdev), 50);
 184 }
 185
 186 static int g4x_do_reset(struct intel_gt *gt,
 187                         intel_engine_mask_t engine_mask,
 188                         unsigned int retry)
 189 {
 190         struct pci_dev *pdev = gt->i915->drm.pdev;
 191         struct intel_uncore *uncore = gt->uncore;
 192         int ret;
 193
 194         /* WaVcpClkGateDisableForMediaReset:ctg,elk */
 195         rmw_set_fw(uncore, VDECCLK_GATE_D, VCP_UNIT_CLOCK_GATE_DISABLE);
 196         intel_uncore_posting_read_fw(uncore, VDECCLK_GATE_D);
 197
 198         pci_write_config_byte(pdev, I915_GDRST,
 199                               GRDOM_MEDIA | GRDOM_RESET_ENABLE);
 200         ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
 201         if (ret) {
 202                 DRM_DEBUG_DRIVER("Wait for media reset failed\n");
 203                 goto out;
 204         }
 205
 206         pci_write_config_byte(pdev, I915_GDRST,
 207                               GRDOM_RENDER | GRDOM_RESET_ENABLE);
 208         ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
 209         if (ret) {
 210                 DRM_DEBUG_DRIVER("Wait for render reset failed\n");
 211                 goto out;
 212         }
 213
 214 out:
 215         pci_write_config_byte(pdev, I915_GDRST, 0);
 216
 217         rmw_clear_fw(uncore, VDECCLK_GATE_D, VCP_UNIT_CLOCK_GATE_DISABLE);
 218         intel_uncore_posting_read_fw(uncore, VDECCLK_GATE_D);
 219
 220         return ret;
 221 }
 222
 223 static int ironlake_do_reset(struct intel_gt *gt,
 224                              intel_engine_mask_t engine_mask,
 225                              unsigned int retry)
 226 {
 227         struct intel_uncore *uncore = gt->uncore;
 228         int ret;
 229
 230         intel_uncore_write_fw(uncore, ILK_GDSR,
 231                               ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
 232         ret = __intel_wait_for_register_fw(uncore, ILK_GDSR,
 233                                            ILK_GRDOM_RESET_ENABLE, 0,
 234                                            5000, 0,
 235                                            NULL);
 236         if (ret) {
 237                 DRM_DEBUG_DRIVER("Wait for render reset failed\n");
 238                 goto out;
 239         }
 240
 241         intel_uncore_write_fw(uncore, ILK_GDSR,
 242                               ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
 243         ret = __intel_wait_for_register_fw(uncore, ILK_GDSR,
 244                                            ILK_GRDOM_RESET_ENABLE, 0,
 245                                            5000, 0,
 246                                            NULL);
 247         if (ret) {
 248                 DRM_DEBUG_DRIVER("Wait for media reset failed\n");
 249                 goto out;
 250         }
 251
 252 out:
 253         intel_uncore_write_fw(uncore, ILK_GDSR, 0);
 254         intel_uncore_posting_read_fw(uncore, ILK_GDSR);
 255         return ret;
 256 }
 257
 258 /* Reset the hardware domains (GENX_GRDOM_*) specified by mask */
 259 static int gen6_hw_domain_reset(struct intel_gt *gt, u32 hw_domain_mask)
 260 {
 261         struct intel_uncore *uncore = gt->uncore;
 262         int err;
 263
 264         /*
 265          * GEN6_GDRST is not in the gt power well, no need to check
 266          * for fifo space for the write or forcewake the chip for
 267          * the read
 268          */
 269         intel_uncore_write_fw(uncore, GEN6_GDRST, hw_domain_mask);
 270
 271         /* Wait for the device to ack the reset requests */
 272         err = __intel_wait_for_register_fw(uncore,
 273                                            GEN6_GDRST, hw_domain_mask, 0,
 274                                            500, 0,
 275                                            NULL);
 276         if (err)
 277                 DRM_DEBUG_DRIVER("Wait for 0x%08x engines reset failed\n",
 278                                  hw_domain_mask);
 279
 280         return err;
 281 }
 282
 283 static int gen6_reset_engines(struct intel_gt *gt,
 284                               intel_engine_mask_t engine_mask,
 285                               unsigned int retry)
 286 {
 287         struct intel_engine_cs *engine;
 288         const u32 hw_engine_mask[] = {
 289                 [RCS0]  = GEN6_GRDOM_RENDER,
 290                 [BCS0]  = GEN6_GRDOM_BLT,
 291                 [VCS0]  = GEN6_GRDOM_MEDIA,
 292                 [VCS1]  = GEN8_GRDOM_MEDIA2,
 293                 [VECS0] = GEN6_GRDOM_VECS,
 294         };
 295         u32 hw_mask;
 296
 297         if (engine_mask == ALL_ENGINES) {
 298                 hw_mask = GEN6_GRDOM_FULL;
 299         } else {
 300                 intel_engine_mask_t tmp;
 301
 302                 hw_mask = 0;
 303                 for_each_engine_masked(engine, gt->i915, engine_mask, tmp) {
 304                         GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
 305                         hw_mask |= hw_engine_mask[engine->id];
 306                 }
 307         }
 308
 309         return gen6_hw_domain_reset(gt, hw_mask);
 310 }
 311
 312 static u32 gen11_lock_sfc(struct intel_engine_cs *engine)
 313 {
 314         struct intel_uncore *uncore = engine->uncore;
 315         u8 vdbox_sfc_access = RUNTIME_INFO(engine->i915)->vdbox_sfc_access;
 316         i915_reg_t sfc_forced_lock, sfc_forced_lock_ack;
 317         u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit;
 318         i915_reg_t sfc_usage;
 319         u32 sfc_usage_bit;
 320         u32 sfc_reset_bit;
 321
 322         switch (engine->class) {
 323         case VIDEO_DECODE_CLASS:
 324                 if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
 325                         return 0;
 326
 327                 sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
 328                 sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
 329
 330                 sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine);
 331                 sfc_forced_lock_ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
 332
 333                 sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine);
 334                 sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT;
 335                 sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
 336                 break;
 337
 338         case VIDEO_ENHANCEMENT_CLASS:
 339                 sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
 340                 sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
 341
 342                 sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine);
 343                 sfc_forced_lock_ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
 344
 345                 sfc_usage = GEN11_VECS_SFC_USAGE(engine);
 346                 sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT;
 347                 sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
 348                 break;
 349
 350         default:
 351                 return 0;
 352         }
 353
 354         /*
 355          * Tell the engine that a software reset is going to happen. The engine
 356          * will then try to force lock the SFC (if currently locked, it will
 357          * remain so until we tell the engine it is safe to unlock; if currently
 358          * unlocked, it will ignore this and all new lock requests). If SFC
 359          * ends up being locked to the engine we want to reset, we have to reset
 360          * it as well (we will unlock it once the reset sequence is completed).
 361          */
 362         rmw_set_fw(uncore, sfc_forced_lock, sfc_forced_lock_bit);
 363
 364         if (__intel_wait_for_register_fw(uncore,
 365                                          sfc_forced_lock_ack,
 366                                          sfc_forced_lock_ack_bit,
 367                                          sfc_forced_lock_ack_bit,
 368                                          1000, 0, NULL)) {
 369                 DRM_DEBUG_DRIVER("Wait for SFC forced lock ack failed\n");
 370                 return 0;
 371         }
 372
 373         if (intel_uncore_read_fw(uncore, sfc_usage) & sfc_usage_bit)
 374                 return sfc_reset_bit;
 375
 376         return 0;
 377 }
 378
 379 static void gen11_unlock_sfc(struct intel_engine_cs *engine)
 380 {
 381         struct intel_uncore *uncore = engine->uncore;
 382         u8 vdbox_sfc_access = RUNTIME_INFO(engine->i915)->vdbox_sfc_access;
 383         i915_reg_t sfc_forced_lock;
 384         u32 sfc_forced_lock_bit;
 385
 386         switch (engine->class) {
 387         case VIDEO_DECODE_CLASS:
 388                 if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
 389                         return;
 390
 391                 sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
 392                 sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
 393                 break;
 394
 395         case VIDEO_ENHANCEMENT_CLASS:
 396                 sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
 397                 sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
 398                 break;
 399
 400         default:
 401                 return;
 402         }
 403
 404         rmw_clear_fw(uncore, sfc_forced_lock, sfc_forced_lock_bit);
 405 }
 406
 407 static int gen11_reset_engines(struct intel_gt *gt,
 408                                intel_engine_mask_t engine_mask,
 409                                unsigned int retry)
 410 {
 411         const u32 hw_engine_mask[] = {
 412                 [RCS0]  = GEN11_GRDOM_RENDER,
 413                 [BCS0]  = GEN11_GRDOM_BLT,
 414                 [VCS0]  = GEN11_GRDOM_MEDIA,
 415                 [VCS1]  = GEN11_GRDOM_MEDIA2,
 416                 [VCS2]  = GEN11_GRDOM_MEDIA3,
 417                 [VCS3]  = GEN11_GRDOM_MEDIA4,
 418                 [VECS0] = GEN11_GRDOM_VECS,
 419                 [VECS1] = GEN11_GRDOM_VECS2,
 420         };
 421         struct intel_engine_cs *engine;
 422         intel_engine_mask_t tmp;
 423         u32 hw_mask;
 424         int ret;
 425
 426         if (engine_mask == ALL_ENGINES) {
 427                 hw_mask = GEN11_GRDOM_FULL;
 428         } else {
 429                 hw_mask = 0;
 430                 for_each_engine_masked(engine, gt->i915, engine_mask, tmp) {
 431                         GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
 432                         hw_mask |= hw_engine_mask[engine->id];
 433                         hw_mask |= gen11_lock_sfc(engine);
 434                 }
 435         }
 436
 437         ret = gen6_hw_domain_reset(gt, hw_mask);
 438
 439         if (engine_mask != ALL_ENGINES)
 440                 for_each_engine_masked(engine, gt->i915, engine_mask, tmp)
 441                         gen11_unlock_sfc(engine);
 442
 443         return ret;
 444 }
 445
 446 static int gen8_engine_reset_prepare(struct intel_engine_cs *engine)
 447 {
 448         struct intel_uncore *uncore = engine->uncore;
 449         const i915_reg_t reg = RING_RESET_CTL(engine->mmio_base);
 450         u32 request, mask, ack;
 451         int ret;
 452
 453         ack = intel_uncore_read_fw(uncore, reg);
 454         if (ack & RESET_CTL_CAT_ERROR) {
 455                 /*
 456                  * For catastrophic errors, ready-for-reset sequence
 457                  * needs to be bypassed: HAS#396813
 458                  */
 459                 request = RESET_CTL_CAT_ERROR;
 460                 mask = RESET_CTL_CAT_ERROR;
 461
 462                 /* Catastrophic errors need to be cleared by HW */
 463                 ack = 0;
 464         } else if (!(ack & RESET_CTL_READY_TO_RESET)) {
 465                 request = RESET_CTL_REQUEST_RESET;
 466                 mask = RESET_CTL_READY_TO_RESET;
 467                 ack = RESET_CTL_READY_TO_RESET;
 468         } else {
 469                 return 0;
 470         }
 471
 472         intel_uncore_write_fw(uncore, reg, _MASKED_BIT_ENABLE(request));
 473         ret = __intel_wait_for_register_fw(uncore, reg, mask, ack,
 474                                            700, 0, NULL);
 475         if (ret)
 476                 DRM_ERROR("%s reset request timed out: {request: %08x, RESET_CTL: %08x}\n",
 477                           engine->name, request,
 478                           intel_uncore_read_fw(uncore, reg));
 479
 480         return ret;
 481 }
 482
 483 static void gen8_engine_reset_cancel(struct intel_engine_cs *engine)
 484 {
 485         intel_uncore_write_fw(engine->uncore,
 486                               RING_RESET_CTL(engine->mmio_base),
 487                               _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
 488 }
 489
 490 static int gen8_reset_engines(struct intel_gt *gt,
 491                               intel_engine_mask_t engine_mask,
 492                               unsigned int retry)
 493 {
 494         struct intel_engine_cs *engine;
 495         const bool reset_non_ready = retry >= 1;
 496         intel_engine_mask_t tmp;
 497         int ret;
 498
 499         for_each_engine_masked(engine, gt->i915, engine_mask, tmp) {
 500                 ret = gen8_engine_reset_prepare(engine);
 501                 if (ret && !reset_non_ready)
 502                         goto skip_reset;
 503
 504                 /*
 505                  * If this is not the first failed attempt to prepare,
 506                  * we decide to proceed anyway.
 507                  *
 508                  * By doing so we risk context corruption and with
 509                  * some gens (kbl), possible system hang if reset
 510                  * happens during active bb execution.
 511                  *
 512                  * We rather take context corruption instead of
 513                  * failed reset with a wedged driver/gpu. And
 514                  * active bb execution case should be covered by
 515                  * stop_engines() we have before the reset.
 516                  */
 517         }
 518
 519         if (INTEL_GEN(gt->i915) >= 11)
 520                 ret = gen11_reset_engines(gt, engine_mask, retry);
 521         else
 522                 ret = gen6_reset_engines(gt, engine_mask, retry);
 523
 524 skip_reset:
 525         for_each_engine_masked(engine, gt->i915, engine_mask, tmp)
 526                 gen8_engine_reset_cancel(engine);
 527
 528         return ret;
 529 }
 530
 531 typedef int (*reset_func)(struct intel_gt *,
 532                           intel_engine_mask_t engine_mask,
 533                           unsigned int retry);
 534
 535 static reset_func intel_get_gpu_reset(struct drm_i915_private *i915)
 536 {
 537         if (INTEL_GEN(i915) >= 8)
 538                 return gen8_reset_engines;
 539         else if (INTEL_GEN(i915) >= 6)
 540                 return gen6_reset_engines;
 541         else if (INTEL_GEN(i915) >= 5)
 542                 return ironlake_do_reset;
 543         else if (IS_G4X(i915))
 544                 return g4x_do_reset;
 545         else if (IS_G33(i915) || IS_PINEVIEW(i915))
 546                 return g33_do_reset;
 547         else if (INTEL_GEN(i915) >= 3)
 548                 return i915_do_reset;
 549         else
 550                 return NULL;
 551 }
 552
 553 int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 554 {
 555         const int retries = engine_mask == ALL_ENGINES ? RESET_MAX_RETRIES : 1;
 556         reset_func reset;
 557         int ret = -ETIMEDOUT;
 558         int retry;
 559
 560         reset = intel_get_gpu_reset(gt->i915);
 561         if (!reset)
 562                 return -ENODEV;
 563
 564         /*
 565          * If the power well sleeps during the reset, the reset
 566          * request may be dropped and never completes (causing -EIO).
 567          */
 568         intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 569         for (retry = 0; ret == -ETIMEDOUT && retry < retries; retry++) {
 570                 GEM_TRACE("engine_mask=%x\n", engine_mask);
 571                 preempt_disable();
 572                 ret = reset(gt, engine_mask, retry);
 573                 preempt_enable();
 574         }
 575         intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 576
 577         return ret;
 578 }
 579
 580 bool intel_has_gpu_reset(struct drm_i915_private *i915)
 581 {
 582         if (!i915_modparams.reset)
 583                 return NULL;
 584
 585         return intel_get_gpu_reset(i915);
 586 }
 587
 588 bool intel_has_reset_engine(struct drm_i915_private *i915)
 589 {
 590         return INTEL_INFO(i915)->has_reset_engine && i915_modparams.reset >= 2;
 591 }
 592
 593 int intel_reset_guc(struct intel_gt *gt)
 594 {
 595         u32 guc_domain =
 596                 INTEL_GEN(gt->i915) >= 11 ? GEN11_GRDOM_GUC : GEN9_GRDOM_GUC;
 597         int ret;
 598
 599         GEM_BUG_ON(!HAS_GT_UC(gt->i915));
 600
 601         intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 602         ret = gen6_hw_domain_reset(gt, guc_domain);
 603         intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 604
 605         return ret;
 606 }
 607
 608 /*
 609  * Ensure irq handler finishes, and not run again.
 610  * Also return the active request so that we only search for it once.
 611  */
 612 static void reset_prepare_engine(struct intel_engine_cs *engine)
 613 {
 614         /*
 615          * During the reset sequence, we must prevent the engine from
 616          * entering RC6. As the context state is undefined until we restart
 617          * the engine, if it does enter RC6 during the reset, the state
 618          * written to the powercontext is undefined and so we may lose
 619          * GPU state upon resume, i.e. fail to restart after a reset.
 620          */
 621         intel_uncore_forcewake_get(engine->uncore, FORCEWAKE_ALL);
 622         engine->reset.prepare(engine);
 623 }
 624
 625 static void revoke_mmaps(struct intel_gt *gt)
 626 {
 627         int i;
 628
 629         for (i = 0; i < gt->ggtt->num_fences; i++) {
 630                 struct drm_vma_offset_node *node;
 631                 struct i915_vma *vma;
 632                 u64 vma_offset;
 633
 634                 vma = READ_ONCE(gt->ggtt->fence_regs[i].vma);
 635                 if (!vma)
 636                         continue;
 637
 638                 if (!i915_vma_has_userfault(vma))
 639                         continue;
 640
 641                 GEM_BUG_ON(vma->fence != &gt->ggtt->fence_regs[i]);
 642                 node = &vma->obj->base.vma_node;
 643                 vma_offset = vma->ggtt_view.partial.offset << PAGE_SHIFT;
 644                 unmap_mapping_range(gt->i915->drm.anon_inode->i_mapping,
 645                                     drm_vma_node_offset_addr(node) + vma_offset,
 646                                     vma->size,
 647                                     1);
 648         }
 649 }
 650
 651 static intel_engine_mask_t reset_prepare(struct intel_gt *gt)
 652 {
 653         struct intel_engine_cs *engine;
 654         intel_engine_mask_t awake = 0;
 655         enum intel_engine_id id;
 656
 657         for_each_engine(engine, gt->i915, id) {
 658                 if (intel_engine_pm_get_if_awake(engine))
 659                         awake |= engine->mask;
 660                 reset_prepare_engine(engine);
 661         }
 662
 663         intel_uc_reset_prepare(&gt->uc);
 664
 665         return awake;
 666 }
 667
 668 static void gt_revoke(struct intel_gt *gt)
 669 {
 670         revoke_mmaps(gt);
 671 }
 672
 673 static int gt_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask)
 674 {
 675         struct intel_engine_cs *engine;
 676         enum intel_engine_id id;
 677         int err;
 678
 679         /*
 680          * Everything depends on having the GTT running, so we need to start
 681          * there.
 682          */
 683         err = i915_ggtt_enable_hw(gt->i915);
 684         if (err)
 685                 return err;
 686
 687         for_each_engine(engine, gt->i915, id)
 688                 __intel_engine_reset(engine, stalled_mask & engine->mask);
 689
 690         i915_gem_restore_fences(gt->i915);
 691
 692         return err;
 693 }
 694
 695 static void reset_finish_engine(struct intel_engine_cs *engine)
 696 {
 697         engine->reset.finish(engine);
 698         intel_uncore_forcewake_put(engine->uncore, FORCEWAKE_ALL);
 699
 700         intel_engine_signal_breadcrumbs(engine);
 701 }
 702
 703 static void reset_finish(struct intel_gt *gt, intel_engine_mask_t awake)
 704 {
 705         struct intel_engine_cs *engine;
 706         enum intel_engine_id id;
 707
 708         for_each_engine(engine, gt->i915, id) {
 709                 reset_finish_engine(engine);
 710                 if (awake & engine->mask)
 711                         intel_engine_pm_put(engine);
 712         }
 713 }
 714
 715 static void nop_submit_request(struct i915_request *request)
 716 {
 717         struct intel_engine_cs *engine = request->engine;
 718         unsigned long flags;
 719
 720         GEM_TRACE("%s fence %llx:%lld -> -EIO\n",
 721                   engine->name, request->fence.context, request->fence.seqno);
 722         dma_fence_set_error(&request->fence, -EIO);
 723
 724         spin_lock_irqsave(&engine->active.lock, flags);
 725         __i915_request_submit(request);
 726         i915_request_mark_complete(request);
 727         spin_unlock_irqrestore(&engine->active.lock, flags);
 728
 729         intel_engine_queue_breadcrumbs(engine);
 730 }
 731
 732 static void __intel_gt_set_wedged(struct intel_gt *gt)
 733 {
 734         struct intel_engine_cs *engine;
 735         intel_engine_mask_t awake;
 736         enum intel_engine_id id;
 737
 738         if (test_bit(I915_WEDGED, &gt->reset.flags))
 739                 return;
 740
 741         if (GEM_SHOW_DEBUG() && !intel_engines_are_idle(gt)) {
 742                 struct drm_printer p = drm_debug_printer(__func__);
 743
 744                 for_each_engine(engine, gt->i915, id)
 745                         intel_engine_dump(engine, &p, "%s\n", engine->name);
 746         }
 747
 748         GEM_TRACE("start\n");
 749
 750         /*
 751          * First, stop submission to hw, but do not yet complete requests by
 752          * rolling the global seqno forward (since this would complete requests
 753          * for which we haven't set the fence error to EIO yet).
 754          */
 755         awake = reset_prepare(gt);
 756
 757         /* Even if the GPU reset fails, it should still stop the engines */
 758         if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 759                 __intel_gt_reset(gt, ALL_ENGINES);
 760
 761         for_each_engine(engine, gt->i915, id)
 762                 engine->submit_request = nop_submit_request;
 763
 764         /*
 765          * Make sure no request can slip through without getting completed by
 766          * either this call here to intel_engine_write_global_seqno, or the one
 767          * in nop_submit_request.
 768          */
 769         synchronize_rcu_expedited();
 770         set_bit(I915_WEDGED, &gt->reset.flags);
 771
 772         /* Mark all executing requests as skipped */
 773         for_each_engine(engine, gt->i915, id)
 774                 engine->cancel_requests(engine);
 775
 776         reset_finish(gt, awake);
 777
 778         GEM_TRACE("end\n");
 779 }
 780
 781 void intel_gt_set_wedged(struct intel_gt *gt)
 782 {
 783         intel_wakeref_t wakeref;
 784
 785         mutex_lock(&gt->reset.mutex);
 786         with_intel_runtime_pm(&gt->i915->runtime_pm, wakeref)
 787                 __intel_gt_set_wedged(gt);
 788         mutex_unlock(&gt->reset.mutex);
 789 }
 790
 791 static bool __intel_gt_unset_wedged(struct intel_gt *gt)
 792 {
 793         struct intel_gt_timelines *timelines = &gt->timelines;
 794         struct intel_timeline *tl;
 795
 796         if (!test_bit(I915_WEDGED, &gt->reset.flags))
 797                 return true;
 798
 799         if (!gt->scratch) /* Never full initialised, recovery impossible */
 800                 return false;
 801
 802         GEM_TRACE("start\n");
 803
 804         /*
 805          * Before unwedging, make sure that all pending operations
 806          * are flushed and errored out - we may have requests waiting upon
 807          * third party fences. We marked all inflight requests as EIO, and
 808          * every execbuf since returned EIO, for consistency we want all
 809          * the currently pending requests to also be marked as EIO, which
 810          * is done inside our nop_submit_request - and so we must wait.
 811          *
 812          * No more can be submitted until we reset the wedged bit.
 813          */
 814         mutex_lock(&timelines->mutex);
 815         list_for_each_entry(tl, &timelines->active_list, link) {
 816                 struct i915_request *rq;
 817
 818                 rq = i915_active_request_get_unlocked(&tl->last_request);
 819                 if (!rq)
 820                         continue;
 821
 822                 /*
 823                  * All internal dependencies (i915_requests) will have
 824                  * been flushed by the set-wedge, but we may be stuck waiting
 825                  * for external fences. These should all be capped to 10s
 826                  * (I915_FENCE_TIMEOUT) so this wait should not be unbounded
 827                  * in the worst case.
 828                  */
 829                 dma_fence_default_wait(&rq->fence, false, MAX_SCHEDULE_TIMEOUT);
 830                 i915_request_put(rq);
 831         }
 832         mutex_unlock(&timelines->mutex);
 833
 834         intel_gt_sanitize(gt, false);
 835
 836         /*
 837          * Undo nop_submit_request. We prevent all new i915 requests from
 838          * being queued (by disallowing execbuf whilst wedged) so having
 839          * waited for all active requests above, we know the system is idle
 840          * and do not have to worry about a thread being inside
 841          * engine->submit_request() as we swap over. So unlike installing
 842          * the nop_submit_request on reset, we can do this from normal
 843          * context and do not require stop_machine().
 844          */
 845         intel_engines_reset_default_submission(gt);
 846
 847         GEM_TRACE("end\n");
 848
 849         smp_mb__before_atomic(); /* complete takeover before enabling execbuf */
 850         clear_bit(I915_WEDGED, &gt->reset.flags);
 851
 852         return true;
 853 }
 854
 855 bool intel_gt_unset_wedged(struct intel_gt *gt)
 856 {
 857         bool result;
 858
 859         mutex_lock(&gt->reset.mutex);
 860         result = __intel_gt_unset_wedged(gt);
 861         mutex_unlock(&gt->reset.mutex);
 862
 863         return result;
 864 }
 865
 866 static int do_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask)
 867 {
 868         int err, i;
 869
 870         gt_revoke(gt);
 871
 872         err = __intel_gt_reset(gt, ALL_ENGINES);
 873         for (i = 0; err && i < RESET_MAX_RETRIES; i++) {
 874                 msleep(10 * (i + 1));
 875                 err = __intel_gt_reset(gt, ALL_ENGINES);
 876         }
 877         if (err)
 878                 return err;
 879
 880         return gt_reset(gt, stalled_mask);
 881 }
 882
 883 static int resume(struct intel_gt *gt)
 884 {
 885         struct intel_engine_cs *engine;
 886         enum intel_engine_id id;
 887         int ret;
 888
 889         for_each_engine(engine, gt->i915, id) {
 890                 ret = engine->resume(engine);
 891                 if (ret)
 892                         return ret;
 893         }
 894
 895         return 0;
 896 }
 897
 898 /**
 899  * intel_gt_reset - reset chip after a hang
 900  * @gt: #intel_gt to reset
 901  * @stalled_mask: mask of the stalled engines with the guilty requests
 902  * @reason: user error message for why we are resetting
 903  *
 904  * Reset the chip.  Useful if a hang is detected. Marks the device as wedged
 905  * on failure.
 906  *
 907  * Procedure is fairly simple:
 908  *   - reset the chip using the reset reg
 909  *   - re-init context state
 910  *   - re-init hardware status page
 911  *   - re-init ring buffer
 912  *   - re-init interrupt state
 913  *   - re-init display
 914  */
 915 void intel_gt_reset(struct intel_gt *gt,
 916                     intel_engine_mask_t stalled_mask,
 917                     const char *reason)
 918 {
 919         intel_engine_mask_t awake;
 920         int ret;
 921
 922         GEM_TRACE("flags=%lx\n", gt->reset.flags);
 923
 924         might_sleep();
 925         GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &gt->reset.flags));
 926         mutex_lock(&gt->reset.mutex);
 927
 928         /* Clear any previous failed attempts at recovery. Time to try again. */
 929         if (!__intel_gt_unset_wedged(gt))
 930                 goto unlock;
 931
 932         if (reason)
 933                 dev_notice(gt->i915->drm.dev,
 934                            "Resetting chip for %s\n", reason);
 935         atomic_inc(&gt->i915->gpu_error.reset_count);
 936
 937         awake = reset_prepare(gt);
 938
 939         if (!intel_has_gpu_reset(gt->i915)) {
 940                 if (i915_modparams.reset)
 941                         dev_err(gt->i915->drm.dev, "GPU reset not supported\n");
 942                 else
 943                         DRM_DEBUG_DRIVER("GPU reset disabled\n");
 944                 goto error;
 945         }
 946
 947         if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 948                 intel_runtime_pm_disable_interrupts(gt->i915);
 949
 950         if (do_reset(gt, stalled_mask)) {
 951                 dev_err(gt->i915->drm.dev, "Failed to reset chip\n");
 952                 goto taint;
 953         }
 954
 955         if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 956                 intel_runtime_pm_enable_interrupts(gt->i915);
 957
 958         intel_overlay_reset(gt->i915);
 959
 960         /*
 961          * Next we need to restore the context, but we don't use those
 962          * yet either...
 963          *
 964          * Ring buffer needs to be re-initialized in the KMS case, or if X
 965          * was running at the time of the reset (i.e. we weren't VT
 966          * switched away).
 967          */
 968         ret = i915_gem_init_hw(gt->i915);
 969         if (ret) {
 970                 DRM_ERROR("Failed to initialise HW following reset (%d)\n",
 971                           ret);
 972                 goto taint;
 973         }
 974
 975         ret = resume(gt);
 976         if (ret)
 977                 goto taint;
 978
 979         intel_gt_queue_hangcheck(gt);
 980
 981 finish:
 982         reset_finish(gt, awake);
 983 unlock:
 984         mutex_unlock(&gt->reset.mutex);
 985         return;
 986
 987 taint:
 988         /*
 989          * History tells us that if we cannot reset the GPU now, we
 990          * never will. This then impacts everything that is run
 991          * subsequently. On failing the reset, we mark the driver
 992          * as wedged, preventing further execution on the GPU.
 993          * We also want to go one step further and add a taint to the
 994          * kernel so that any subsequent faults can be traced back to
 995          * this failure. This is important for CI, where if the
 996          * GPU/driver fails we would like to reboot and restart testing
 997          * rather than continue on into oblivion. For everyone else,
 998          * the system should still plod along, but they have been warned!
 999          */
1000         add_taint_for_CI(TAINT_WARN);
1001 error:
1002         __intel_gt_set_wedged(gt);
1003         goto finish;
1004 }
1005
1006 static inline int intel_gt_reset_engine(struct intel_engine_cs *engine)
1007 {
1008         return __intel_gt_reset(engine->gt, engine->mask);
1009 }
1010
1011 /**
1012  * intel_engine_reset - reset GPU engine to recover from a hang
1013  * @engine: engine to reset
1014  * @msg: reason for GPU reset; or NULL for no dev_notice()
1015  *
1016  * Reset a specific GPU engine. Useful if a hang is detected.
1017  * Returns zero on successful reset or otherwise an error code.
1018  *
1019  * Procedure is:
1020  *  - identifies the request that caused the hang and it is dropped
1021  *  - reset engine (which will force the engine to idle)
1022  *  - re-init/configure engine
1023  */
1024 int intel_engine_reset(struct intel_engine_cs *engine, const char *msg)
1025 {
1026         struct intel_gt *gt = engine->gt;
1027         int ret;
1028
1029         GEM_TRACE("%s flags=%lx\n", engine->name, gt->reset.flags);
1030         GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &gt->reset.flags));
1031
1032         if (!intel_engine_pm_get_if_awake(engine))
1033                 return 0;
1034
1035         reset_prepare_engine(engine);
1036
1037         if (msg)
1038                 dev_notice(engine->i915->drm.dev,
1039                            "Resetting %s for %s\n", engine->name, msg);
1040         atomic_inc(&engine->i915->gpu_error.reset_engine_count[engine->uabi_class]);
1041
1042         if (!engine->gt->uc.guc.execbuf_client)
1043                 ret = intel_gt_reset_engine(engine);
1044         else
1045                 ret = intel_guc_reset_engine(&engine->gt->uc.guc, engine);
1046         if (ret) {
1047                 /* If we fail here, we expect to fallback to a global reset */
1048                 DRM_DEBUG_DRIVER("%sFailed to reset %s, ret=%d\n",
1049                                  engine->gt->uc.guc.execbuf_client ? "GuC " : "",
1050                                  engine->name, ret);
1051                 goto out;
1052         }
1053
1054         /*
1055          * The request that caused the hang is stuck on elsp, we know the
1056          * active request and can drop it, adjust head to skip the offending
1057          * request to resume executing remaining requests in the queue.
1058          */
1059         __intel_engine_reset(engine, true);
1060
1061         /*
1062          * The engine and its registers (and workarounds in case of render)
1063          * have been reset to their default values. Follow the init_ring
1064          * process to program RING_MODE, HWSP and re-enable submission.
1065          */
1066         ret = engine->resume(engine);
1067
1068 out:
1069         intel_engine_cancel_stop_cs(engine);
1070         reset_finish_engine(engine);
1071         intel_engine_pm_put(engine);
1072         return ret;
1073 }
1074
1075 static void intel_gt_reset_global(struct intel_gt *gt,
1076                                   u32 engine_mask,
1077                                   const char *reason)
1078 {
1079         struct kobject *kobj = &gt->i915->drm.primary->kdev->kobj;
1080         char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
1081         char *reset_event[] = { I915_RESET_UEVENT "=1", NULL };
1082         char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL };
1083         struct intel_wedge_me w;
1084
1085         kobject_uevent_env(kobj, KOBJ_CHANGE, error_event);
1086
1087         DRM_DEBUG_DRIVER("resetting chip\n");
1088         kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
1089
1090         /* Use a watchdog to ensure that our reset completes */
1091         intel_wedge_on_timeout(&w, gt, 5 * HZ) {
1092                 intel_prepare_reset(gt->i915);
1093
1094                 /* Flush everyone using a resource about to be clobbered */
1095                 synchronize_srcu_expedited(&gt->reset.backoff_srcu);
1096
1097                 intel_gt_reset(gt, engine_mask, reason);
1098
1099                 intel_finish_reset(gt->i915);
1100         }
1101
1102         if (!test_bit(I915_WEDGED, &gt->reset.flags))
1103                 kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event);
1104 }
1105
1106 /**
1107  * intel_gt_handle_error - handle a gpu error
1108  * @gt: the intel_gt
1109  * @engine_mask: mask representing engines that are hung
1110  * @flags: control flags
1111  * @fmt: Error message format string
1112  *
1113  * Do some basic checking of register state at error time and
1114  * dump it to the syslog.  Also call i915_capture_error_state() to make
1115  * sure we get a record and make it available in debugfs.  Fire a uevent
1116  * so userspace knows something bad happened (should trigger collection
1117  * of a ring dump etc.).
1118  */
1119 void intel_gt_handle_error(struct intel_gt *gt,
1120                            intel_engine_mask_t engine_mask,
1121                            unsigned long flags,
1122                            const char *fmt, ...)
1123 {
1124         struct intel_engine_cs *engine;
1125         intel_wakeref_t wakeref;
1126         intel_engine_mask_t tmp;
1127         char error_msg[80];
1128         char *msg = NULL;
1129
1130         if (fmt) {
1131                 va_list args;
1132
1133                 va_start(args, fmt);
1134                 vscnprintf(error_msg, sizeof(error_msg), fmt, args);
1135                 va_end(args);
1136
1137                 msg = error_msg;
1138         }
1139
1140         /*
1141          * In most cases it's guaranteed that we get here with an RPM
1142          * reference held, for example because there is a pending GPU
1143          * request that won't finish until the reset is done. This
1144          * isn't the case at least when we get here by doing a
1145          * simulated reset via debugfs, so get an RPM reference.
1146          */
1147         wakeref = intel_runtime_pm_get(&gt->i915->runtime_pm);
1148
1149         engine_mask &= INTEL_INFO(gt->i915)->engine_mask;
1150
1151         if (flags & I915_ERROR_CAPTURE) {
1152                 i915_capture_error_state(gt->i915, engine_mask, msg);
1153                 intel_gt_clear_error_registers(gt, engine_mask);
1154         }
1155
1156         /*
1157          * Try engine reset when available. We fall back to full reset if
1158          * single reset fails.
1159          */
1160         if (intel_has_reset_engine(gt->i915) && !intel_gt_is_wedged(gt)) {
1161                 for_each_engine_masked(engine, gt->i915, engine_mask, tmp) {
1162                         BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
1163                         if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
1164                                              &gt->reset.flags))
1165                                 continue;
1166
1167                         if (intel_engine_reset(engine, msg) == 0)
1168                                 engine_mask &= ~engine->mask;
1169
1170                         clear_and_wake_up_bit(I915_RESET_ENGINE + engine->id,
1171                                               &gt->reset.flags);
1172                 }
1173         }
1174
1175         if (!engine_mask)
1176                 goto out;
1177
1178         /* Full reset needs the mutex, stop any other user trying to do so. */
1179         if (test_and_set_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
1180                 wait_event(gt->reset.queue,
1181                            !test_bit(I915_RESET_BACKOFF, &gt->reset.flags));
1182                 goto out; /* piggy-back on the other reset */
1183         }
1184
1185         /* Make sure i915_reset_trylock() sees the I915_RESET_BACKOFF */
1186         synchronize_rcu_expedited();
1187
1188         /* Prevent any other reset-engine attempt. */
1189         for_each_engine(engine, gt->i915, tmp) {
1190                 while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
1191                                         &gt->reset.flags))
1192                         wait_on_bit(&gt->reset.flags,
1193                                     I915_RESET_ENGINE + engine->id,
1194                                     TASK_UNINTERRUPTIBLE);
1195         }
1196
1197         intel_gt_reset_global(gt, engine_mask, msg);
1198
1199         for_each_engine(engine, gt->i915, tmp)
1200                 clear_bit_unlock(I915_RESET_ENGINE + engine->id,
1201                                  &gt->reset.flags);
1202         clear_bit_unlock(I915_RESET_BACKOFF, &gt->reset.flags);
1203         smp_mb__after_atomic();
1204         wake_up_all(&gt->reset.queue);
1205
1206 out:
1207         intel_runtime_pm_put(&gt->i915->runtime_pm, wakeref);
1208 }
1209
1210 int intel_gt_reset_trylock(struct intel_gt *gt)
1211 {
1212         int srcu;
1213
1214         might_lock(&gt->reset.backoff_srcu);
1215         might_sleep();
1216
1217         rcu_read_lock();
1218         while (test_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
1219                 rcu_read_unlock();
1220
1221                 if (wait_event_interruptible(gt->reset.queue,
1222                                              !test_bit(I915_RESET_BACKOFF,
1223                                                        &gt->reset.flags)))
1224                         return -EINTR;
1225
1226                 rcu_read_lock();
1227         }
1228         srcu = srcu_read_lock(&gt->reset.backoff_srcu);
1229         rcu_read_unlock();
1230
1231         return srcu;
1232 }
1233
1234 void intel_gt_reset_unlock(struct intel_gt *gt, int tag)
1235 __releases(&gt->reset.backoff_srcu)
1236 {
1237         srcu_read_unlock(&gt->reset.backoff_srcu, tag);
1238 }
1239
1240 int intel_gt_terminally_wedged(struct intel_gt *gt)
1241 {
1242         might_sleep();
1243
1244         if (!intel_gt_is_wedged(gt))
1245                 return 0;
1246
1247         /* Reset still in progress? Maybe we will recover? */
1248         if (!test_bit(I915_RESET_BACKOFF, &gt->reset.flags))
1249                 return -EIO;
1250
1251         /* XXX intel_reset_finish() still takes struct_mutex!!! */
1252         if (mutex_is_locked(&gt->i915->drm.struct_mutex))
1253                 return -EAGAIN;
1254
1255         if (wait_event_interruptible(gt->reset.queue,
1256                                      !test_bit(I915_RESET_BACKOFF,
1257                                                &gt->reset.flags)))
1258                 return -EINTR;
1259
1260         return intel_gt_is_wedged(gt) ? -EIO : 0;
1261 }
1262
1263 void intel_gt_init_reset(struct intel_gt *gt)
1264 {
1265         init_waitqueue_head(&gt->reset.queue);
1266         mutex_init(&gt->reset.mutex);
1267         init_srcu_struct(&gt->reset.backoff_srcu);
1268 }
1269
1270 void intel_gt_fini_reset(struct intel_gt *gt)
1271 {
1272         cleanup_srcu_struct(&gt->reset.backoff_srcu);
1273 }
1274
1275 static void intel_wedge_me(struct work_struct *work)
1276 {
1277         struct intel_wedge_me *w = container_of(work, typeof(*w), work.work);
1278
1279         dev_err(w->gt->i915->drm.dev,
1280                 "%s timed out, cancelling all in-flight rendering.\n",
1281                 w->name);
1282         intel_gt_set_wedged(w->gt);
1283 }
1284
1285 void __intel_init_wedge(struct intel_wedge_me *w,
1286                         struct intel_gt *gt,
1287                         long timeout,
1288                         const char *name)
1289 {
1290         w->gt = gt;
1291         w->name = name;
1292
1293         INIT_DELAYED_WORK_ONSTACK(&w->work, intel_wedge_me);
1294         schedule_delayed_work(&w->work, timeout);
1295 }
1296
1297 void __intel_fini_wedge(struct intel_wedge_me *w)
1298 {
1299         cancel_delayed_work_sync(&w->work);
1300         destroy_delayed_work_on_stack(&w->work);
1301         w->gt = NULL;
1302 }
1303
1304 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
1305 #include "selftest_reset.c"
1306 #endif