linux/drivers/gpu/drm/i915/gt/intel_reset.c
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   1// SPDX-License-Identifier: MIT
   2/*
   3 * Copyright © 2008-2018 Intel Corporation
   4 */
   5
   6#include <linux/sched/mm.h>
   7#include <linux/stop_machine.h>
   8
   9#include "display/intel_display_types.h"
  10#include "display/intel_overlay.h"
  11
  12#include "gem/i915_gem_context.h"
  13
  14#include "i915_drv.h"
  15#include "i915_gpu_error.h"
  16#include "i915_irq.h"
  17#include "intel_breadcrumbs.h"
  18#include "intel_engine_pm.h"
  19#include "intel_gt.h"
  20#include "intel_gt_pm.h"
  21#include "intel_gt_requests.h"
  22#include "intel_reset.h"
  23
  24#include "uc/intel_guc.h"
  25
  26#define RESET_MAX_RETRIES 3
  27
  28/* XXX How to handle concurrent GGTT updates using tiling registers? */
  29#define RESET_UNDER_STOP_MACHINE 0
  30
  31static void rmw_set_fw(struct intel_uncore *uncore, i915_reg_t reg, u32 set)
  32{
  33        intel_uncore_rmw_fw(uncore, reg, 0, set);
  34}
  35
  36static void rmw_clear_fw(struct intel_uncore *uncore, i915_reg_t reg, u32 clr)
  37{
  38        intel_uncore_rmw_fw(uncore, reg, clr, 0);
  39}
  40
  41static void client_mark_guilty(struct i915_gem_context *ctx, bool banned)
  42{
  43        struct drm_i915_file_private *file_priv = ctx->file_priv;
  44        unsigned long prev_hang;
  45        unsigned int score;
  46
  47        if (IS_ERR_OR_NULL(file_priv))
  48                return;
  49
  50        score = 0;
  51        if (banned)
  52                score = I915_CLIENT_SCORE_CONTEXT_BAN;
  53
  54        prev_hang = xchg(&file_priv->hang_timestamp, jiffies);
  55        if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES))
  56                score += I915_CLIENT_SCORE_HANG_FAST;
  57
  58        if (score) {
  59                atomic_add(score, &file_priv->ban_score);
  60
  61                drm_dbg(&ctx->i915->drm,
  62                        "client %s: gained %u ban score, now %u\n",
  63                        ctx->name, score,
  64                        atomic_read(&file_priv->ban_score));
  65        }
  66}
  67
  68static bool mark_guilty(struct i915_request *rq)
  69{
  70        struct i915_gem_context *ctx;
  71        unsigned long prev_hang;
  72        bool banned;
  73        int i;
  74
  75        if (intel_context_is_closed(rq->context))
  76                return true;
  77
  78        rcu_read_lock();
  79        ctx = rcu_dereference(rq->context->gem_context);
  80        if (ctx && !kref_get_unless_zero(&ctx->ref))
  81                ctx = NULL;
  82        rcu_read_unlock();
  83        if (!ctx)
  84                return intel_context_is_banned(rq->context);
  85
  86        atomic_inc(&ctx->guilty_count);
  87
  88        /* Cool contexts are too cool to be banned! (Used for reset testing.) */
  89        if (!i915_gem_context_is_bannable(ctx)) {
  90                banned = false;
  91                goto out;
  92        }
  93
  94        drm_notice(&ctx->i915->drm,
  95                   "%s context reset due to GPU hang\n",
  96                   ctx->name);
  97
  98        /* Record the timestamp for the last N hangs */
  99        prev_hang = ctx->hang_timestamp[0];
 100        for (i = 0; i < ARRAY_SIZE(ctx->hang_timestamp) - 1; i++)
 101                ctx->hang_timestamp[i] = ctx->hang_timestamp[i + 1];
 102        ctx->hang_timestamp[i] = jiffies;
 103
 104        /* If we have hung N+1 times in rapid succession, we ban the context! */
 105        banned = !i915_gem_context_is_recoverable(ctx);
 106        if (time_before(jiffies, prev_hang + CONTEXT_FAST_HANG_JIFFIES))
 107                banned = true;
 108        if (banned)
 109                drm_dbg(&ctx->i915->drm, "context %s: guilty %d, banned\n",
 110                        ctx->name, atomic_read(&ctx->guilty_count));
 111
 112        client_mark_guilty(ctx, banned);
 113
 114out:
 115        i915_gem_context_put(ctx);
 116        return banned;
 117}
 118
 119static void mark_innocent(struct i915_request *rq)
 120{
 121        struct i915_gem_context *ctx;
 122
 123        rcu_read_lock();
 124        ctx = rcu_dereference(rq->context->gem_context);
 125        if (ctx)
 126                atomic_inc(&ctx->active_count);
 127        rcu_read_unlock();
 128}
 129
 130void __i915_request_reset(struct i915_request *rq, bool guilty)
 131{
 132        bool banned = false;
 133
 134        RQ_TRACE(rq, "guilty? %s\n", yesno(guilty));
 135        GEM_BUG_ON(__i915_request_is_complete(rq));
 136
 137        rcu_read_lock(); /* protect the GEM context */
 138        if (guilty) {
 139                i915_request_set_error_once(rq, -EIO);
 140                __i915_request_skip(rq);
 141                banned = mark_guilty(rq);
 142        } else {
 143                i915_request_set_error_once(rq, -EAGAIN);
 144                mark_innocent(rq);
 145        }
 146        rcu_read_unlock();
 147
 148        if (banned)
 149                intel_context_ban(rq->context, rq);
 150}
 151
 152static bool i915_in_reset(struct pci_dev *pdev)
 153{
 154        u8 gdrst;
 155
 156        pci_read_config_byte(pdev, I915_GDRST, &gdrst);
 157        return gdrst & GRDOM_RESET_STATUS;
 158}
 159
 160static int i915_do_reset(struct intel_gt *gt,
 161                         intel_engine_mask_t engine_mask,
 162                         unsigned int retry)
 163{
 164        struct pci_dev *pdev = to_pci_dev(gt->i915->drm.dev);
 165        int err;
 166
 167        /* Assert reset for at least 20 usec, and wait for acknowledgement. */
 168        pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 169        udelay(50);
 170        err = wait_for_atomic(i915_in_reset(pdev), 50);
 171
 172        /* Clear the reset request. */
 173        pci_write_config_byte(pdev, I915_GDRST, 0);
 174        udelay(50);
 175        if (!err)
 176                err = wait_for_atomic(!i915_in_reset(pdev), 50);
 177
 178        return err;
 179}
 180
 181static bool g4x_reset_complete(struct pci_dev *pdev)
 182{
 183        u8 gdrst;
 184
 185        pci_read_config_byte(pdev, I915_GDRST, &gdrst);
 186        return (gdrst & GRDOM_RESET_ENABLE) == 0;
 187}
 188
 189static int g33_do_reset(struct intel_gt *gt,
 190                        intel_engine_mask_t engine_mask,
 191                        unsigned int retry)
 192{
 193        struct pci_dev *pdev = to_pci_dev(gt->i915->drm.dev);
 194
 195        pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
 196        return wait_for_atomic(g4x_reset_complete(pdev), 50);
 197}
 198
 199static int g4x_do_reset(struct intel_gt *gt,
 200                        intel_engine_mask_t engine_mask,
 201                        unsigned int retry)
 202{
 203        struct pci_dev *pdev = to_pci_dev(gt->i915->drm.dev);
 204        struct intel_uncore *uncore = gt->uncore;
 205        int ret;
 206
 207        /* WaVcpClkGateDisableForMediaReset:ctg,elk */
 208        rmw_set_fw(uncore, VDECCLK_GATE_D, VCP_UNIT_CLOCK_GATE_DISABLE);
 209        intel_uncore_posting_read_fw(uncore, VDECCLK_GATE_D);
 210
 211        pci_write_config_byte(pdev, I915_GDRST,
 212                              GRDOM_MEDIA | GRDOM_RESET_ENABLE);
 213        ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
 214        if (ret) {
 215                GT_TRACE(gt, "Wait for media reset failed\n");
 216                goto out;
 217        }
 218
 219        pci_write_config_byte(pdev, I915_GDRST,
 220                              GRDOM_RENDER | GRDOM_RESET_ENABLE);
 221        ret =  wait_for_atomic(g4x_reset_complete(pdev), 50);
 222        if (ret) {
 223                GT_TRACE(gt, "Wait for render reset failed\n");
 224                goto out;
 225        }
 226
 227out:
 228        pci_write_config_byte(pdev, I915_GDRST, 0);
 229
 230        rmw_clear_fw(uncore, VDECCLK_GATE_D, VCP_UNIT_CLOCK_GATE_DISABLE);
 231        intel_uncore_posting_read_fw(uncore, VDECCLK_GATE_D);
 232
 233        return ret;
 234}
 235
 236static int ilk_do_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask,
 237                        unsigned int retry)
 238{
 239        struct intel_uncore *uncore = gt->uncore;
 240        int ret;
 241
 242        intel_uncore_write_fw(uncore, ILK_GDSR,
 243                              ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
 244        ret = __intel_wait_for_register_fw(uncore, ILK_GDSR,
 245                                           ILK_GRDOM_RESET_ENABLE, 0,
 246                                           5000, 0,
 247                                           NULL);
 248        if (ret) {
 249                GT_TRACE(gt, "Wait for render reset failed\n");
 250                goto out;
 251        }
 252
 253        intel_uncore_write_fw(uncore, ILK_GDSR,
 254                              ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
 255        ret = __intel_wait_for_register_fw(uncore, ILK_GDSR,
 256                                           ILK_GRDOM_RESET_ENABLE, 0,
 257                                           5000, 0,
 258                                           NULL);
 259        if (ret) {
 260                GT_TRACE(gt, "Wait for media reset failed\n");
 261                goto out;
 262        }
 263
 264out:
 265        intel_uncore_write_fw(uncore, ILK_GDSR, 0);
 266        intel_uncore_posting_read_fw(uncore, ILK_GDSR);
 267        return ret;
 268}
 269
 270/* Reset the hardware domains (GENX_GRDOM_*) specified by mask */
 271static int gen6_hw_domain_reset(struct intel_gt *gt, u32 hw_domain_mask)
 272{
 273        struct intel_uncore *uncore = gt->uncore;
 274        int err;
 275
 276        /*
 277         * GEN6_GDRST is not in the gt power well, no need to check
 278         * for fifo space for the write or forcewake the chip for
 279         * the read
 280         */
 281        intel_uncore_write_fw(uncore, GEN6_GDRST, hw_domain_mask);
 282
 283        /* Wait for the device to ack the reset requests */
 284        err = __intel_wait_for_register_fw(uncore,
 285                                           GEN6_GDRST, hw_domain_mask, 0,
 286                                           500, 0,
 287                                           NULL);
 288        if (err)
 289                GT_TRACE(gt,
 290                         "Wait for 0x%08x engines reset failed\n",
 291                         hw_domain_mask);
 292
 293        return err;
 294}
 295
 296static int gen6_reset_engines(struct intel_gt *gt,
 297                              intel_engine_mask_t engine_mask,
 298                              unsigned int retry)
 299{
 300        static const u32 hw_engine_mask[] = {
 301                [RCS0]  = GEN6_GRDOM_RENDER,
 302                [BCS0]  = GEN6_GRDOM_BLT,
 303                [VCS0]  = GEN6_GRDOM_MEDIA,
 304                [VCS1]  = GEN8_GRDOM_MEDIA2,
 305                [VECS0] = GEN6_GRDOM_VECS,
 306        };
 307        struct intel_engine_cs *engine;
 308        u32 hw_mask;
 309
 310        if (engine_mask == ALL_ENGINES) {
 311                hw_mask = GEN6_GRDOM_FULL;
 312        } else {
 313                intel_engine_mask_t tmp;
 314
 315                hw_mask = 0;
 316                for_each_engine_masked(engine, gt, engine_mask, tmp) {
 317                        GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
 318                        hw_mask |= hw_engine_mask[engine->id];
 319                }
 320        }
 321
 322        return gen6_hw_domain_reset(gt, hw_mask);
 323}
 324
 325static struct intel_engine_cs *find_sfc_paired_vecs_engine(struct intel_engine_cs *engine)
 326{
 327        int vecs_id;
 328
 329        GEM_BUG_ON(engine->class != VIDEO_DECODE_CLASS);
 330
 331        vecs_id = _VECS((engine->instance) / 2);
 332
 333        return engine->gt->engine[vecs_id];
 334}
 335
 336struct sfc_lock_data {
 337        i915_reg_t lock_reg;
 338        i915_reg_t ack_reg;
 339        i915_reg_t usage_reg;
 340        u32 lock_bit;
 341        u32 ack_bit;
 342        u32 usage_bit;
 343        u32 reset_bit;
 344};
 345
 346static void get_sfc_forced_lock_data(struct intel_engine_cs *engine,
 347                                     struct sfc_lock_data *sfc_lock)
 348{
 349        switch (engine->class) {
 350        default:
 351                MISSING_CASE(engine->class);
 352                fallthrough;
 353        case VIDEO_DECODE_CLASS:
 354                sfc_lock->lock_reg = GEN11_VCS_SFC_FORCED_LOCK(engine);
 355                sfc_lock->lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
 356
 357                sfc_lock->ack_reg = GEN11_VCS_SFC_LOCK_STATUS(engine);
 358                sfc_lock->ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
 359
 360                sfc_lock->usage_reg = GEN11_VCS_SFC_LOCK_STATUS(engine);
 361                sfc_lock->usage_bit = GEN11_VCS_SFC_USAGE_BIT;
 362                sfc_lock->reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
 363
 364                break;
 365        case VIDEO_ENHANCEMENT_CLASS:
 366                sfc_lock->lock_reg = GEN11_VECS_SFC_FORCED_LOCK(engine);
 367                sfc_lock->lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
 368
 369                sfc_lock->ack_reg = GEN11_VECS_SFC_LOCK_ACK(engine);
 370                sfc_lock->ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
 371
 372                sfc_lock->usage_reg = GEN11_VECS_SFC_USAGE(engine);
 373                sfc_lock->usage_bit = GEN11_VECS_SFC_USAGE_BIT;
 374                sfc_lock->reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
 375
 376                break;
 377        }
 378}
 379
 380static int gen11_lock_sfc(struct intel_engine_cs *engine,
 381                          u32 *reset_mask,
 382                          u32 *unlock_mask)
 383{
 384        struct intel_uncore *uncore = engine->uncore;
 385        u8 vdbox_sfc_access = engine->gt->info.vdbox_sfc_access;
 386        struct sfc_lock_data sfc_lock;
 387        bool lock_obtained, lock_to_other = false;
 388        int ret;
 389
 390        switch (engine->class) {
 391        case VIDEO_DECODE_CLASS:
 392                if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
 393                        return 0;
 394
 395                fallthrough;
 396        case VIDEO_ENHANCEMENT_CLASS:
 397                get_sfc_forced_lock_data(engine, &sfc_lock);
 398
 399                break;
 400        default:
 401                return 0;
 402        }
 403
 404        if (!(intel_uncore_read_fw(uncore, sfc_lock.usage_reg) & sfc_lock.usage_bit)) {
 405                struct intel_engine_cs *paired_vecs;
 406
 407                if (engine->class != VIDEO_DECODE_CLASS ||
 408                    GRAPHICS_VER(engine->i915) != 12)
 409                        return 0;
 410
 411                /*
 412                 * Wa_14010733141
 413                 *
 414                 * If the VCS-MFX isn't using the SFC, we also need to check
 415                 * whether VCS-HCP is using it.  If so, we need to issue a *VE*
 416                 * forced lock on the VE engine that shares the same SFC.
 417                 */
 418                if (!(intel_uncore_read_fw(uncore,
 419                                           GEN12_HCP_SFC_LOCK_STATUS(engine)) &
 420                      GEN12_HCP_SFC_USAGE_BIT))
 421                        return 0;
 422
 423                paired_vecs = find_sfc_paired_vecs_engine(engine);
 424                get_sfc_forced_lock_data(paired_vecs, &sfc_lock);
 425                lock_to_other = true;
 426                *unlock_mask |= paired_vecs->mask;
 427        } else {
 428                *unlock_mask |= engine->mask;
 429        }
 430
 431        /*
 432         * If the engine is using an SFC, tell the engine that a software reset
 433         * is going to happen. The engine will then try to force lock the SFC.
 434         * If SFC ends up being locked to the engine we want to reset, we have
 435         * to reset it as well (we will unlock it once the reset sequence is
 436         * completed).
 437         */
 438        rmw_set_fw(uncore, sfc_lock.lock_reg, sfc_lock.lock_bit);
 439
 440        ret = __intel_wait_for_register_fw(uncore,
 441                                           sfc_lock.ack_reg,
 442                                           sfc_lock.ack_bit,
 443                                           sfc_lock.ack_bit,
 444                                           1000, 0, NULL);
 445
 446        /*
 447         * Was the SFC released while we were trying to lock it?
 448         *
 449         * We should reset both the engine and the SFC if:
 450         *  - We were locking the SFC to this engine and the lock succeeded
 451         *       OR
 452         *  - We were locking the SFC to a different engine (Wa_14010733141)
 453         *    but the SFC was released before the lock was obtained.
 454         *
 455         * Otherwise we need only reset the engine by itself and we can
 456         * leave the SFC alone.
 457         */
 458        lock_obtained = (intel_uncore_read_fw(uncore, sfc_lock.usage_reg) &
 459                        sfc_lock.usage_bit) != 0;
 460        if (lock_obtained == lock_to_other)
 461                return 0;
 462
 463        if (ret) {
 464                ENGINE_TRACE(engine, "Wait for SFC forced lock ack failed\n");
 465                return ret;
 466        }
 467
 468        *reset_mask |= sfc_lock.reset_bit;
 469        return 0;
 470}
 471
 472static void gen11_unlock_sfc(struct intel_engine_cs *engine)
 473{
 474        struct intel_uncore *uncore = engine->uncore;
 475        u8 vdbox_sfc_access = engine->gt->info.vdbox_sfc_access;
 476        struct sfc_lock_data sfc_lock = {};
 477
 478        if (engine->class != VIDEO_DECODE_CLASS &&
 479            engine->class != VIDEO_ENHANCEMENT_CLASS)
 480                return;
 481
 482        if (engine->class == VIDEO_DECODE_CLASS &&
 483            (BIT(engine->instance) & vdbox_sfc_access) == 0)
 484                return;
 485
 486        get_sfc_forced_lock_data(engine, &sfc_lock);
 487
 488        rmw_clear_fw(uncore, sfc_lock.lock_reg, sfc_lock.lock_bit);
 489}
 490
 491static int gen11_reset_engines(struct intel_gt *gt,
 492                               intel_engine_mask_t engine_mask,
 493                               unsigned int retry)
 494{
 495        static const u32 hw_engine_mask[] = {
 496                [RCS0]  = GEN11_GRDOM_RENDER,
 497                [BCS0]  = GEN11_GRDOM_BLT,
 498                [VCS0]  = GEN11_GRDOM_MEDIA,
 499                [VCS1]  = GEN11_GRDOM_MEDIA2,
 500                [VCS2]  = GEN11_GRDOM_MEDIA3,
 501                [VCS3]  = GEN11_GRDOM_MEDIA4,
 502                [VCS4]  = GEN11_GRDOM_MEDIA5,
 503                [VCS5]  = GEN11_GRDOM_MEDIA6,
 504                [VCS6]  = GEN11_GRDOM_MEDIA7,
 505                [VCS7]  = GEN11_GRDOM_MEDIA8,
 506                [VECS0] = GEN11_GRDOM_VECS,
 507                [VECS1] = GEN11_GRDOM_VECS2,
 508                [VECS2] = GEN11_GRDOM_VECS3,
 509                [VECS3] = GEN11_GRDOM_VECS4,
 510        };
 511        struct intel_engine_cs *engine;
 512        intel_engine_mask_t tmp;
 513        u32 reset_mask, unlock_mask = 0;
 514        int ret;
 515
 516        if (engine_mask == ALL_ENGINES) {
 517                reset_mask = GEN11_GRDOM_FULL;
 518        } else {
 519                reset_mask = 0;
 520                for_each_engine_masked(engine, gt, engine_mask, tmp) {
 521                        GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
 522                        reset_mask |= hw_engine_mask[engine->id];
 523                        ret = gen11_lock_sfc(engine, &reset_mask, &unlock_mask);
 524                        if (ret)
 525                                goto sfc_unlock;
 526                }
 527        }
 528
 529        ret = gen6_hw_domain_reset(gt, reset_mask);
 530
 531sfc_unlock:
 532        /*
 533         * We unlock the SFC based on the lock status and not the result of
 534         * gen11_lock_sfc to make sure that we clean properly if something
 535         * wrong happened during the lock (e.g. lock acquired after timeout
 536         * expiration).
 537         *
 538         * Due to Wa_14010733141, we may have locked an SFC to an engine that
 539         * wasn't being reset.  So instead of calling gen11_unlock_sfc()
 540         * on engine_mask, we instead call it on the mask of engines that our
 541         * gen11_lock_sfc() calls told us actually had locks attempted.
 542         */
 543        for_each_engine_masked(engine, gt, unlock_mask, tmp)
 544                gen11_unlock_sfc(engine);
 545
 546        return ret;
 547}
 548
 549static int gen8_engine_reset_prepare(struct intel_engine_cs *engine)
 550{
 551        struct intel_uncore *uncore = engine->uncore;
 552        const i915_reg_t reg = RING_RESET_CTL(engine->mmio_base);
 553        u32 request, mask, ack;
 554        int ret;
 555
 556        if (I915_SELFTEST_ONLY(should_fail(&engine->reset_timeout, 1)))
 557                return -ETIMEDOUT;
 558
 559        ack = intel_uncore_read_fw(uncore, reg);
 560        if (ack & RESET_CTL_CAT_ERROR) {
 561                /*
 562                 * For catastrophic errors, ready-for-reset sequence
 563                 * needs to be bypassed: HAS#396813
 564                 */
 565                request = RESET_CTL_CAT_ERROR;
 566                mask = RESET_CTL_CAT_ERROR;
 567
 568                /* Catastrophic errors need to be cleared by HW */
 569                ack = 0;
 570        } else if (!(ack & RESET_CTL_READY_TO_RESET)) {
 571                request = RESET_CTL_REQUEST_RESET;
 572                mask = RESET_CTL_READY_TO_RESET;
 573                ack = RESET_CTL_READY_TO_RESET;
 574        } else {
 575                return 0;
 576        }
 577
 578        intel_uncore_write_fw(uncore, reg, _MASKED_BIT_ENABLE(request));
 579        ret = __intel_wait_for_register_fw(uncore, reg, mask, ack,
 580                                           700, 0, NULL);
 581        if (ret)
 582                drm_err(&engine->i915->drm,
 583                        "%s reset request timed out: {request: %08x, RESET_CTL: %08x}\n",
 584                        engine->name, request,
 585                        intel_uncore_read_fw(uncore, reg));
 586
 587        return ret;
 588}
 589
 590static void gen8_engine_reset_cancel(struct intel_engine_cs *engine)
 591{
 592        intel_uncore_write_fw(engine->uncore,
 593                              RING_RESET_CTL(engine->mmio_base),
 594                              _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
 595}
 596
 597static int gen8_reset_engines(struct intel_gt *gt,
 598                              intel_engine_mask_t engine_mask,
 599                              unsigned int retry)
 600{
 601        struct intel_engine_cs *engine;
 602        const bool reset_non_ready = retry >= 1;
 603        intel_engine_mask_t tmp;
 604        int ret;
 605
 606        for_each_engine_masked(engine, gt, engine_mask, tmp) {
 607                ret = gen8_engine_reset_prepare(engine);
 608                if (ret && !reset_non_ready)
 609                        goto skip_reset;
 610
 611                /*
 612                 * If this is not the first failed attempt to prepare,
 613                 * we decide to proceed anyway.
 614                 *
 615                 * By doing so we risk context corruption and with
 616                 * some gens (kbl), possible system hang if reset
 617                 * happens during active bb execution.
 618                 *
 619                 * We rather take context corruption instead of
 620                 * failed reset with a wedged driver/gpu. And
 621                 * active bb execution case should be covered by
 622                 * stop_engines() we have before the reset.
 623                 */
 624        }
 625
 626        if (GRAPHICS_VER(gt->i915) >= 11)
 627                ret = gen11_reset_engines(gt, engine_mask, retry);
 628        else
 629                ret = gen6_reset_engines(gt, engine_mask, retry);
 630
 631skip_reset:
 632        for_each_engine_masked(engine, gt, engine_mask, tmp)
 633                gen8_engine_reset_cancel(engine);
 634
 635        return ret;
 636}
 637
 638static int mock_reset(struct intel_gt *gt,
 639                      intel_engine_mask_t mask,
 640                      unsigned int retry)
 641{
 642        return 0;
 643}
 644
 645typedef int (*reset_func)(struct intel_gt *,
 646                          intel_engine_mask_t engine_mask,
 647                          unsigned int retry);
 648
 649static reset_func intel_get_gpu_reset(const struct intel_gt *gt)
 650{
 651        struct drm_i915_private *i915 = gt->i915;
 652
 653        if (is_mock_gt(gt))
 654                return mock_reset;
 655        else if (GRAPHICS_VER(i915) >= 8)
 656                return gen8_reset_engines;
 657        else if (GRAPHICS_VER(i915) >= 6)
 658                return gen6_reset_engines;
 659        else if (GRAPHICS_VER(i915) >= 5)
 660                return ilk_do_reset;
 661        else if (IS_G4X(i915))
 662                return g4x_do_reset;
 663        else if (IS_G33(i915) || IS_PINEVIEW(i915))
 664                return g33_do_reset;
 665        else if (GRAPHICS_VER(i915) >= 3)
 666                return i915_do_reset;
 667        else
 668                return NULL;
 669}
 670
 671int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 672{
 673        const int retries = engine_mask == ALL_ENGINES ? RESET_MAX_RETRIES : 1;
 674        reset_func reset;
 675        int ret = -ETIMEDOUT;
 676        int retry;
 677
 678        reset = intel_get_gpu_reset(gt);
 679        if (!reset)
 680                return -ENODEV;
 681
 682        /*
 683         * If the power well sleeps during the reset, the reset
 684         * request may be dropped and never completes (causing -EIO).
 685         */
 686        intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 687        for (retry = 0; ret == -ETIMEDOUT && retry < retries; retry++) {
 688                GT_TRACE(gt, "engine_mask=%x\n", engine_mask);
 689                preempt_disable();
 690                ret = reset(gt, engine_mask, retry);
 691                preempt_enable();
 692        }
 693        intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 694
 695        return ret;
 696}
 697
 698bool intel_has_gpu_reset(const struct intel_gt *gt)
 699{
 700        if (!gt->i915->params.reset)
 701                return NULL;
 702
 703        return intel_get_gpu_reset(gt);
 704}
 705
 706bool intel_has_reset_engine(const struct intel_gt *gt)
 707{
 708        if (gt->i915->params.reset < 2)
 709                return false;
 710
 711        return INTEL_INFO(gt->i915)->has_reset_engine;
 712}
 713
 714int intel_reset_guc(struct intel_gt *gt)
 715{
 716        u32 guc_domain =
 717                GRAPHICS_VER(gt->i915) >= 11 ? GEN11_GRDOM_GUC : GEN9_GRDOM_GUC;
 718        int ret;
 719
 720        GEM_BUG_ON(!HAS_GT_UC(gt->i915));
 721
 722        intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 723        ret = gen6_hw_domain_reset(gt, guc_domain);
 724        intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 725
 726        return ret;
 727}
 728
 729/*
 730 * Ensure irq handler finishes, and not run again.
 731 * Also return the active request so that we only search for it once.
 732 */
 733static void reset_prepare_engine(struct intel_engine_cs *engine)
 734{
 735        /*
 736         * During the reset sequence, we must prevent the engine from
 737         * entering RC6. As the context state is undefined until we restart
 738         * the engine, if it does enter RC6 during the reset, the state
 739         * written to the powercontext is undefined and so we may lose
 740         * GPU state upon resume, i.e. fail to restart after a reset.
 741         */
 742        intel_uncore_forcewake_get(engine->uncore, FORCEWAKE_ALL);
 743        if (engine->reset.prepare)
 744                engine->reset.prepare(engine);
 745}
 746
 747static void revoke_mmaps(struct intel_gt *gt)
 748{
 749        int i;
 750
 751        for (i = 0; i < gt->ggtt->num_fences; i++) {
 752                struct drm_vma_offset_node *node;
 753                struct i915_vma *vma;
 754                u64 vma_offset;
 755
 756                vma = READ_ONCE(gt->ggtt->fence_regs[i].vma);
 757                if (!vma)
 758                        continue;
 759
 760                if (!i915_vma_has_userfault(vma))
 761                        continue;
 762
 763                GEM_BUG_ON(vma->fence != &gt->ggtt->fence_regs[i]);
 764
 765                if (!vma->mmo)
 766                        continue;
 767
 768                node = &vma->mmo->vma_node;
 769                vma_offset = vma->ggtt_view.partial.offset << PAGE_SHIFT;
 770
 771                unmap_mapping_range(gt->i915->drm.anon_inode->i_mapping,
 772                                    drm_vma_node_offset_addr(node) + vma_offset,
 773                                    vma->size,
 774                                    1);
 775        }
 776}
 777
 778static intel_engine_mask_t reset_prepare(struct intel_gt *gt)
 779{
 780        struct intel_engine_cs *engine;
 781        intel_engine_mask_t awake = 0;
 782        enum intel_engine_id id;
 783
 784        for_each_engine(engine, gt, id) {
 785                if (intel_engine_pm_get_if_awake(engine))
 786                        awake |= engine->mask;
 787                reset_prepare_engine(engine);
 788        }
 789
 790        intel_uc_reset_prepare(&gt->uc);
 791
 792        return awake;
 793}
 794
 795static void gt_revoke(struct intel_gt *gt)
 796{
 797        revoke_mmaps(gt);
 798}
 799
 800static int gt_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask)
 801{
 802        struct intel_engine_cs *engine;
 803        enum intel_engine_id id;
 804        int err;
 805
 806        /*
 807         * Everything depends on having the GTT running, so we need to start
 808         * there.
 809         */
 810        err = i915_ggtt_enable_hw(gt->i915);
 811        if (err)
 812                return err;
 813
 814        local_bh_disable();
 815        for_each_engine(engine, gt, id)
 816                __intel_engine_reset(engine, stalled_mask & engine->mask);
 817        local_bh_enable();
 818
 819        intel_uc_reset(&gt->uc, true);
 820
 821        intel_ggtt_restore_fences(gt->ggtt);
 822
 823        return err;
 824}
 825
 826static void reset_finish_engine(struct intel_engine_cs *engine)
 827{
 828        if (engine->reset.finish)
 829                engine->reset.finish(engine);
 830        intel_uncore_forcewake_put(engine->uncore, FORCEWAKE_ALL);
 831
 832        intel_engine_signal_breadcrumbs(engine);
 833}
 834
 835static void reset_finish(struct intel_gt *gt, intel_engine_mask_t awake)
 836{
 837        struct intel_engine_cs *engine;
 838        enum intel_engine_id id;
 839
 840        for_each_engine(engine, gt, id) {
 841                reset_finish_engine(engine);
 842                if (awake & engine->mask)
 843                        intel_engine_pm_put(engine);
 844        }
 845
 846        intel_uc_reset_finish(&gt->uc);
 847}
 848
 849static void nop_submit_request(struct i915_request *request)
 850{
 851        RQ_TRACE(request, "-EIO\n");
 852
 853        request = i915_request_mark_eio(request);
 854        if (request) {
 855                i915_request_submit(request);
 856                intel_engine_signal_breadcrumbs(request->engine);
 857
 858                i915_request_put(request);
 859        }
 860}
 861
 862static void __intel_gt_set_wedged(struct intel_gt *gt)
 863{
 864        struct intel_engine_cs *engine;
 865        intel_engine_mask_t awake;
 866        enum intel_engine_id id;
 867
 868        if (test_bit(I915_WEDGED, &gt->reset.flags))
 869                return;
 870
 871        GT_TRACE(gt, "start\n");
 872
 873        /*
 874         * First, stop submission to hw, but do not yet complete requests by
 875         * rolling the global seqno forward (since this would complete requests
 876         * for which we haven't set the fence error to EIO yet).
 877         */
 878        awake = reset_prepare(gt);
 879
 880        /* Even if the GPU reset fails, it should still stop the engines */
 881        if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 882                __intel_gt_reset(gt, ALL_ENGINES);
 883
 884        for_each_engine(engine, gt, id)
 885                engine->submit_request = nop_submit_request;
 886
 887        /*
 888         * Make sure no request can slip through without getting completed by
 889         * either this call here to intel_engine_write_global_seqno, or the one
 890         * in nop_submit_request.
 891         */
 892        synchronize_rcu_expedited();
 893        set_bit(I915_WEDGED, &gt->reset.flags);
 894
 895        /* Mark all executing requests as skipped */
 896        local_bh_disable();
 897        for_each_engine(engine, gt, id)
 898                if (engine->reset.cancel)
 899                        engine->reset.cancel(engine);
 900        intel_uc_cancel_requests(&gt->uc);
 901        local_bh_enable();
 902
 903        reset_finish(gt, awake);
 904
 905        GT_TRACE(gt, "end\n");
 906}
 907
 908void intel_gt_set_wedged(struct intel_gt *gt)
 909{
 910        intel_wakeref_t wakeref;
 911
 912        if (test_bit(I915_WEDGED, &gt->reset.flags))
 913                return;
 914
 915        wakeref = intel_runtime_pm_get(gt->uncore->rpm);
 916        mutex_lock(&gt->reset.mutex);
 917
 918        if (GEM_SHOW_DEBUG()) {
 919                struct drm_printer p = drm_debug_printer(__func__);
 920                struct intel_engine_cs *engine;
 921                enum intel_engine_id id;
 922
 923                drm_printf(&p, "called from %pS\n", (void *)_RET_IP_);
 924                for_each_engine(engine, gt, id) {
 925                        if (intel_engine_is_idle(engine))
 926                                continue;
 927
 928                        intel_engine_dump(engine, &p, "%s\n", engine->name);
 929                }
 930        }
 931
 932        __intel_gt_set_wedged(gt);
 933
 934        mutex_unlock(&gt->reset.mutex);
 935        intel_runtime_pm_put(gt->uncore->rpm, wakeref);
 936}
 937
 938static bool __intel_gt_unset_wedged(struct intel_gt *gt)
 939{
 940        struct intel_gt_timelines *timelines = &gt->timelines;
 941        struct intel_timeline *tl;
 942        bool ok;
 943
 944        if (!test_bit(I915_WEDGED, &gt->reset.flags))
 945                return true;
 946
 947        /* Never fully initialised, recovery impossible */
 948        if (intel_gt_has_unrecoverable_error(gt))
 949                return false;
 950
 951        GT_TRACE(gt, "start\n");
 952
 953        /*
 954         * Before unwedging, make sure that all pending operations
 955         * are flushed and errored out - we may have requests waiting upon
 956         * third party fences. We marked all inflight requests as EIO, and
 957         * every execbuf since returned EIO, for consistency we want all
 958         * the currently pending requests to also be marked as EIO, which
 959         * is done inside our nop_submit_request - and so we must wait.
 960         *
 961         * No more can be submitted until we reset the wedged bit.
 962         */
 963        spin_lock(&timelines->lock);
 964        list_for_each_entry(tl, &timelines->active_list, link) {
 965                struct dma_fence *fence;
 966
 967                fence = i915_active_fence_get(&tl->last_request);
 968                if (!fence)
 969                        continue;
 970
 971                spin_unlock(&timelines->lock);
 972
 973                /*
 974                 * All internal dependencies (i915_requests) will have
 975                 * been flushed by the set-wedge, but we may be stuck waiting
 976                 * for external fences. These should all be capped to 10s
 977                 * (I915_FENCE_TIMEOUT) so this wait should not be unbounded
 978                 * in the worst case.
 979                 */
 980                dma_fence_default_wait(fence, false, MAX_SCHEDULE_TIMEOUT);
 981                dma_fence_put(fence);
 982
 983                /* Restart iteration after droping lock */
 984                spin_lock(&timelines->lock);
 985                tl = list_entry(&timelines->active_list, typeof(*tl), link);
 986        }
 987        spin_unlock(&timelines->lock);
 988
 989        /* We must reset pending GPU events before restoring our submission */
 990        ok = !HAS_EXECLISTS(gt->i915); /* XXX better agnosticism desired */
 991        if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 992                ok = __intel_gt_reset(gt, ALL_ENGINES) == 0;
 993        if (!ok) {
 994                /*
 995                 * Warn CI about the unrecoverable wedged condition.
 996                 * Time for a reboot.
 997                 */
 998                add_taint_for_CI(gt->i915, TAINT_WARN);
 999                return false;
1000        }
1001
1002        /*
1003         * Undo nop_submit_request. We prevent all new i915 requests from
1004         * being queued (by disallowing execbuf whilst wedged) so having
1005         * waited for all active requests above, we know the system is idle
1006         * and do not have to worry about a thread being inside
1007         * engine->submit_request() as we swap over. So unlike installing
1008         * the nop_submit_request on reset, we can do this from normal
1009         * context and do not require stop_machine().
1010         */
1011        intel_engines_reset_default_submission(gt);
1012
1013        GT_TRACE(gt, "end\n");
1014
1015        smp_mb__before_atomic(); /* complete takeover before enabling execbuf */
1016        clear_bit(I915_WEDGED, &gt->reset.flags);
1017
1018        return true;
1019}
1020
1021bool intel_gt_unset_wedged(struct intel_gt *gt)
1022{
1023        bool result;
1024
1025        mutex_lock(&gt->reset.mutex);
1026        result = __intel_gt_unset_wedged(gt);
1027        mutex_unlock(&gt->reset.mutex);
1028
1029        return result;
1030}
1031
1032static int do_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask)
1033{
1034        int err, i;
1035
1036        err = __intel_gt_reset(gt, ALL_ENGINES);
1037        for (i = 0; err && i < RESET_MAX_RETRIES; i++) {
1038                msleep(10 * (i + 1));
1039                err = __intel_gt_reset(gt, ALL_ENGINES);
1040        }
1041        if (err)
1042                return err;
1043
1044        return gt_reset(gt, stalled_mask);
1045}
1046
1047static int resume(struct intel_gt *gt)
1048{
1049        struct intel_engine_cs *engine;
1050        enum intel_engine_id id;
1051        int ret;
1052
1053        for_each_engine(engine, gt, id) {
1054                ret = intel_engine_resume(engine);
1055                if (ret)
1056                        return ret;
1057        }
1058
1059        return 0;
1060}
1061
1062/**
1063 * intel_gt_reset - reset chip after a hang
1064 * @gt: #intel_gt to reset
1065 * @stalled_mask: mask of the stalled engines with the guilty requests
1066 * @reason: user error message for why we are resetting
1067 *
1068 * Reset the chip.  Useful if a hang is detected. Marks the device as wedged
1069 * on failure.
1070 *
1071 * Procedure is fairly simple:
1072 *   - reset the chip using the reset reg
1073 *   - re-init context state
1074 *   - re-init hardware status page
1075 *   - re-init ring buffer
1076 *   - re-init interrupt state
1077 *   - re-init display
1078 */
1079void intel_gt_reset(struct intel_gt *gt,
1080                    intel_engine_mask_t stalled_mask,
1081                    const char *reason)
1082{
1083        intel_engine_mask_t awake;
1084        int ret;
1085
1086        GT_TRACE(gt, "flags=%lx\n", gt->reset.flags);
1087
1088        might_sleep();
1089        GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &gt->reset.flags));
1090
1091        /*
1092         * FIXME: Revoking cpu mmap ptes cannot be done from a dma_fence
1093         * critical section like gpu reset.
1094         */
1095        gt_revoke(gt);
1096
1097        mutex_lock(&gt->reset.mutex);
1098
1099        /* Clear any previous failed attempts at recovery. Time to try again. */
1100        if (!__intel_gt_unset_wedged(gt))
1101                goto unlock;
1102
1103        if (reason)
1104                drm_notice(&gt->i915->drm,
1105                           "Resetting chip for %s\n", reason);
1106        atomic_inc(&gt->i915->gpu_error.reset_count);
1107
1108        awake = reset_prepare(gt);
1109
1110        if (!intel_has_gpu_reset(gt)) {
1111                if (gt->i915->params.reset)
1112                        drm_err(&gt->i915->drm, "GPU reset not supported\n");
1113                else
1114                        drm_dbg(&gt->i915->drm, "GPU reset disabled\n");
1115                goto error;
1116        }
1117
1118        if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
1119                intel_runtime_pm_disable_interrupts(gt->i915);
1120
1121        if (do_reset(gt, stalled_mask)) {
1122                drm_err(&gt->i915->drm, "Failed to reset chip\n");
1123                goto taint;
1124        }
1125
1126        if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
1127                intel_runtime_pm_enable_interrupts(gt->i915);
1128
1129        intel_overlay_reset(gt->i915);
1130
1131        /*
1132         * Next we need to restore the context, but we don't use those
1133         * yet either...
1134         *
1135         * Ring buffer needs to be re-initialized in the KMS case, or if X
1136         * was running at the time of the reset (i.e. we weren't VT
1137         * switched away).
1138         */
1139        ret = intel_gt_init_hw(gt);
1140        if (ret) {
1141                drm_err(&gt->i915->drm,
1142                        "Failed to initialise HW following reset (%d)\n",
1143                        ret);
1144                goto taint;
1145        }
1146
1147        ret = resume(gt);
1148        if (ret)
1149                goto taint;
1150
1151finish:
1152        reset_finish(gt, awake);
1153unlock:
1154        mutex_unlock(&gt->reset.mutex);
1155        return;
1156
1157taint:
1158        /*
1159         * History tells us that if we cannot reset the GPU now, we
1160         * never will. This then impacts everything that is run
1161         * subsequently. On failing the reset, we mark the driver
1162         * as wedged, preventing further execution on the GPU.
1163         * We also want to go one step further and add a taint to the
1164         * kernel so that any subsequent faults can be traced back to
1165         * this failure. This is important for CI, where if the
1166         * GPU/driver fails we would like to reboot and restart testing
1167         * rather than continue on into oblivion. For everyone else,
1168         * the system should still plod along, but they have been warned!
1169         */
1170        add_taint_for_CI(gt->i915, TAINT_WARN);
1171error:
1172        __intel_gt_set_wedged(gt);
1173        goto finish;
1174}
1175
1176static int intel_gt_reset_engine(struct intel_engine_cs *engine)
1177{
1178        return __intel_gt_reset(engine->gt, engine->mask);
1179}
1180
1181int __intel_engine_reset_bh(struct intel_engine_cs *engine, const char *msg)
1182{
1183        struct intel_gt *gt = engine->gt;
1184        int ret;
1185
1186        ENGINE_TRACE(engine, "flags=%lx\n", gt->reset.flags);
1187        GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &gt->reset.flags));
1188
1189        if (intel_engine_uses_guc(engine))
1190                return -ENODEV;
1191
1192        if (!intel_engine_pm_get_if_awake(engine))
1193                return 0;
1194
1195        reset_prepare_engine(engine);
1196
1197        if (msg)
1198                drm_notice(&engine->i915->drm,
1199                           "Resetting %s for %s\n", engine->name, msg);
1200        atomic_inc(&engine->i915->gpu_error.reset_engine_count[engine->uabi_class]);
1201
1202        ret = intel_gt_reset_engine(engine);
1203        if (ret) {
1204                /* If we fail here, we expect to fallback to a global reset */
1205                ENGINE_TRACE(engine, "Failed to reset %s, err: %d\n", engine->name, ret);
1206                goto out;
1207        }
1208
1209        /*
1210         * The request that caused the hang is stuck on elsp, we know the
1211         * active request and can drop it, adjust head to skip the offending
1212         * request to resume executing remaining requests in the queue.
1213         */
1214        __intel_engine_reset(engine, true);
1215
1216        /*
1217         * The engine and its registers (and workarounds in case of render)
1218         * have been reset to their default values. Follow the init_ring
1219         * process to program RING_MODE, HWSP and re-enable submission.
1220         */
1221        ret = intel_engine_resume(engine);
1222
1223out:
1224        intel_engine_cancel_stop_cs(engine);
1225        reset_finish_engine(engine);
1226        intel_engine_pm_put_async(engine);
1227        return ret;
1228}
1229
1230/**
1231 * intel_engine_reset - reset GPU engine to recover from a hang
1232 * @engine: engine to reset
1233 * @msg: reason for GPU reset; or NULL for no drm_notice()
1234 *
1235 * Reset a specific GPU engine. Useful if a hang is detected.
1236 * Returns zero on successful reset or otherwise an error code.
1237 *
1238 * Procedure is:
1239 *  - identifies the request that caused the hang and it is dropped
1240 *  - reset engine (which will force the engine to idle)
1241 *  - re-init/configure engine
1242 */
1243int intel_engine_reset(struct intel_engine_cs *engine, const char *msg)
1244{
1245        int err;
1246
1247        local_bh_disable();
1248        err = __intel_engine_reset_bh(engine, msg);
1249        local_bh_enable();
1250
1251        return err;
1252}
1253
1254static void intel_gt_reset_global(struct intel_gt *gt,
1255                                  u32 engine_mask,
1256                                  const char *reason)
1257{
1258        struct kobject *kobj = &gt->i915->drm.primary->kdev->kobj;
1259        char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
1260        char *reset_event[] = { I915_RESET_UEVENT "=1", NULL };
1261        char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL };
1262        struct intel_wedge_me w;
1263
1264        kobject_uevent_env(kobj, KOBJ_CHANGE, error_event);
1265
1266        GT_TRACE(gt, "resetting chip, engines=%x\n", engine_mask);
1267        kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
1268
1269        /* Use a watchdog to ensure that our reset completes */
1270        intel_wedge_on_timeout(&w, gt, 5 * HZ) {
1271                intel_display_prepare_reset(gt->i915);
1272
1273                /* Flush everyone using a resource about to be clobbered */
1274                synchronize_srcu_expedited(&gt->reset.backoff_srcu);
1275
1276                intel_gt_reset(gt, engine_mask, reason);
1277
1278                intel_display_finish_reset(gt->i915);
1279        }
1280
1281        if (!test_bit(I915_WEDGED, &gt->reset.flags))
1282                kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event);
1283}
1284
1285/**
1286 * intel_gt_handle_error - handle a gpu error
1287 * @gt: the intel_gt
1288 * @engine_mask: mask representing engines that are hung
1289 * @flags: control flags
1290 * @fmt: Error message format string
1291 *
1292 * Do some basic checking of register state at error time and
1293 * dump it to the syslog.  Also call i915_capture_error_state() to make
1294 * sure we get a record and make it available in debugfs.  Fire a uevent
1295 * so userspace knows something bad happened (should trigger collection
1296 * of a ring dump etc.).
1297 */
1298void intel_gt_handle_error(struct intel_gt *gt,
1299                           intel_engine_mask_t engine_mask,
1300                           unsigned long flags,
1301                           const char *fmt, ...)
1302{
1303        struct intel_engine_cs *engine;
1304        intel_wakeref_t wakeref;
1305        intel_engine_mask_t tmp;
1306        char error_msg[80];
1307        char *msg = NULL;
1308
1309        if (fmt) {
1310                va_list args;
1311
1312                va_start(args, fmt);
1313                vscnprintf(error_msg, sizeof(error_msg), fmt, args);
1314                va_end(args);
1315
1316                msg = error_msg;
1317        }
1318
1319        /*
1320         * In most cases it's guaranteed that we get here with an RPM
1321         * reference held, for example because there is a pending GPU
1322         * request that won't finish until the reset is done. This
1323         * isn't the case at least when we get here by doing a
1324         * simulated reset via debugfs, so get an RPM reference.
1325         */
1326        wakeref = intel_runtime_pm_get(gt->uncore->rpm);
1327
1328        engine_mask &= gt->info.engine_mask;
1329
1330        if (flags & I915_ERROR_CAPTURE) {
1331                i915_capture_error_state(gt, engine_mask);
1332                intel_gt_clear_error_registers(gt, engine_mask);
1333        }
1334
1335        /*
1336         * Try engine reset when available. We fall back to full reset if
1337         * single reset fails.
1338         */
1339        if (!intel_uc_uses_guc_submission(&gt->uc) &&
1340            intel_has_reset_engine(gt) && !intel_gt_is_wedged(gt)) {
1341                local_bh_disable();
1342                for_each_engine_masked(engine, gt, engine_mask, tmp) {
1343                        BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
1344                        if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
1345                                             &gt->reset.flags))
1346                                continue;
1347
1348                        if (__intel_engine_reset_bh(engine, msg) == 0)
1349                                engine_mask &= ~engine->mask;
1350
1351                        clear_and_wake_up_bit(I915_RESET_ENGINE + engine->id,
1352                                              &gt->reset.flags);
1353                }
1354                local_bh_enable();
1355        }
1356
1357        if (!engine_mask)
1358                goto out;
1359
1360        /* Full reset needs the mutex, stop any other user trying to do so. */
1361        if (test_and_set_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
1362                wait_event(gt->reset.queue,
1363                           !test_bit(I915_RESET_BACKOFF, &gt->reset.flags));
1364                goto out; /* piggy-back on the other reset */
1365        }
1366
1367        /* Make sure i915_reset_trylock() sees the I915_RESET_BACKOFF */
1368        synchronize_rcu_expedited();
1369
1370        /* Prevent any other reset-engine attempt. */
1371        for_each_engine(engine, gt, tmp) {
1372                while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
1373                                        &gt->reset.flags))
1374                        wait_on_bit(&gt->reset.flags,
1375                                    I915_RESET_ENGINE + engine->id,
1376                                    TASK_UNINTERRUPTIBLE);
1377        }
1378
1379        intel_gt_reset_global(gt, engine_mask, msg);
1380
1381        for_each_engine(engine, gt, tmp)
1382                clear_bit_unlock(I915_RESET_ENGINE + engine->id,
1383                                 &gt->reset.flags);
1384        clear_bit_unlock(I915_RESET_BACKOFF, &gt->reset.flags);
1385        smp_mb__after_atomic();
1386        wake_up_all(&gt->reset.queue);
1387
1388out:
1389        intel_runtime_pm_put(gt->uncore->rpm, wakeref);
1390}
1391
1392int intel_gt_reset_trylock(struct intel_gt *gt, int *srcu)
1393{
1394        might_lock(&gt->reset.backoff_srcu);
1395        might_sleep();
1396
1397        rcu_read_lock();
1398        while (test_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
1399                rcu_read_unlock();
1400
1401                if (wait_event_interruptible(gt->reset.queue,
1402                                             !test_bit(I915_RESET_BACKOFF,
1403                                                       &gt->reset.flags)))
1404                        return -EINTR;
1405
1406                rcu_read_lock();
1407        }
1408        *srcu = srcu_read_lock(&gt->reset.backoff_srcu);
1409        rcu_read_unlock();
1410
1411        return 0;
1412}
1413
1414void intel_gt_reset_unlock(struct intel_gt *gt, int tag)
1415__releases(&gt->reset.backoff_srcu)
1416{
1417        srcu_read_unlock(&gt->reset.backoff_srcu, tag);
1418}
1419
1420int intel_gt_terminally_wedged(struct intel_gt *gt)
1421{
1422        might_sleep();
1423
1424        if (!intel_gt_is_wedged(gt))
1425                return 0;
1426
1427        if (intel_gt_has_unrecoverable_error(gt))
1428                return -EIO;
1429
1430        /* Reset still in progress? Maybe we will recover? */
1431        if (wait_event_interruptible(gt->reset.queue,
1432                                     !test_bit(I915_RESET_BACKOFF,
1433                                               &gt->reset.flags)))
1434                return -EINTR;
1435
1436        return intel_gt_is_wedged(gt) ? -EIO : 0;
1437}
1438
1439void intel_gt_set_wedged_on_init(struct intel_gt *gt)
1440{
1441        BUILD_BUG_ON(I915_RESET_ENGINE + I915_NUM_ENGINES >
1442                     I915_WEDGED_ON_INIT);
1443        intel_gt_set_wedged(gt);
1444        set_bit(I915_WEDGED_ON_INIT, &gt->reset.flags);
1445
1446        /* Wedged on init is non-recoverable */
1447        add_taint_for_CI(gt->i915, TAINT_WARN);
1448}
1449
1450void intel_gt_set_wedged_on_fini(struct intel_gt *gt)
1451{
1452        intel_gt_set_wedged(gt);
1453        set_bit(I915_WEDGED_ON_FINI, &gt->reset.flags);
1454        intel_gt_retire_requests(gt); /* cleanup any wedged requests */
1455}
1456
1457void intel_gt_init_reset(struct intel_gt *gt)
1458{
1459        init_waitqueue_head(&gt->reset.queue);
1460        mutex_init(&gt->reset.mutex);
1461        init_srcu_struct(&gt->reset.backoff_srcu);
1462
1463        /*
1464         * While undesirable to wait inside the shrinker, complain anyway.
1465         *
1466         * If we have to wait during shrinking, we guarantee forward progress
1467         * by forcing the reset. Therefore during the reset we must not
1468         * re-enter the shrinker. By declaring that we take the reset mutex
1469         * within the shrinker, we forbid ourselves from performing any
1470         * fs-reclaim or taking related locks during reset.
1471         */
1472        i915_gem_shrinker_taints_mutex(gt->i915, &gt->reset.mutex);
1473
1474        /* no GPU until we are ready! */
1475        __set_bit(I915_WEDGED, &gt->reset.flags);
1476}
1477
1478void intel_gt_fini_reset(struct intel_gt *gt)
1479{
1480        cleanup_srcu_struct(&gt->reset.backoff_srcu);
1481}
1482
1483static void intel_wedge_me(struct work_struct *work)
1484{
1485        struct intel_wedge_me *w = container_of(work, typeof(*w), work.work);
1486
1487        drm_err(&w->gt->i915->drm,
1488                "%s timed out, cancelling all in-flight rendering.\n",
1489                w->name);
1490        intel_gt_set_wedged(w->gt);
1491}
1492
1493void __intel_init_wedge(struct intel_wedge_me *w,
1494                        struct intel_gt *gt,
1495                        long timeout,
1496                        const char *name)
1497{
1498        w->gt = gt;
1499        w->name = name;
1500
1501        INIT_DELAYED_WORK_ONSTACK(&w->work, intel_wedge_me);
1502        schedule_delayed_work(&w->work, timeout);
1503}
1504
1505void __intel_fini_wedge(struct intel_wedge_me *w)
1506{
1507        cancel_delayed_work_sync(&w->work);
1508        destroy_delayed_work_on_stack(&w->work);
1509        w->gt = NULL;
1510}
1511
1512#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
1513#include "selftest_reset.c"
1514#include "selftest_hangcheck.c"
1515#endif
1516