diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_reset.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_reset.c | 1389 |
1 files changed, 1389 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c new file mode 100644 index 000000000000..342d9ee42601 --- /dev/null +++ b/drivers/gpu/drm/i915/i915_reset.c @@ -0,0 +1,1389 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2008-2018 Intel Corporation + */ + +#include <linux/sched/mm.h> + +#include "i915_drv.h" +#include "i915_gpu_error.h" +#include "i915_reset.h" + +#include "intel_guc.h" + +static void engine_skip_context(struct i915_request *rq) +{ + struct intel_engine_cs *engine = rq->engine; + struct i915_gem_context *hung_ctx = rq->gem_context; + struct i915_timeline *timeline = rq->timeline; + unsigned long flags; + + GEM_BUG_ON(timeline == &engine->timeline); + + spin_lock_irqsave(&engine->timeline.lock, flags); + spin_lock(&timeline->lock); + + list_for_each_entry_continue(rq, &engine->timeline.requests, link) + if (rq->gem_context == hung_ctx) + i915_request_skip(rq, -EIO); + + list_for_each_entry(rq, &timeline->requests, link) + i915_request_skip(rq, -EIO); + + spin_unlock(&timeline->lock); + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static void client_mark_guilty(struct drm_i915_file_private *file_priv, + const struct i915_gem_context *ctx) +{ + unsigned int score; + unsigned long prev_hang; + + if (i915_gem_context_is_banned(ctx)) + score = I915_CLIENT_SCORE_CONTEXT_BAN; + else + score = 0; + + prev_hang = xchg(&file_priv->hang_timestamp, jiffies); + if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES)) + score += I915_CLIENT_SCORE_HANG_FAST; + + if (score) { + atomic_add(score, &file_priv->ban_score); + + DRM_DEBUG_DRIVER("client %s: gained %u ban score, now %u\n", + ctx->name, score, + atomic_read(&file_priv->ban_score)); + } +} + +static void context_mark_guilty(struct i915_gem_context *ctx) +{ + unsigned int score; + bool banned, bannable; + + atomic_inc(&ctx->guilty_count); + + bannable = i915_gem_context_is_bannable(ctx); + score = atomic_add_return(CONTEXT_SCORE_GUILTY, &ctx->ban_score); + banned = score >= CONTEXT_SCORE_BAN_THRESHOLD; + + /* Cool contexts don't accumulate client ban score */ + if (!bannable) + return; + + if (banned) { + DRM_DEBUG_DRIVER("context %s: guilty %d, score %u, banned\n", + ctx->name, atomic_read(&ctx->guilty_count), + score); + i915_gem_context_set_banned(ctx); + } + + if (!IS_ERR_OR_NULL(ctx->file_priv)) + client_mark_guilty(ctx->file_priv, ctx); +} + +static void context_mark_innocent(struct i915_gem_context *ctx) +{ + atomic_inc(&ctx->active_count); +} + +static void gen3_stop_engine(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + const u32 base = engine->mmio_base; + + if (intel_engine_stop_cs(engine)) + DRM_DEBUG_DRIVER("%s: timed out on STOP_RING\n", engine->name); + + I915_WRITE_FW(RING_HEAD(base), I915_READ_FW(RING_TAIL(base))); + POSTING_READ_FW(RING_HEAD(base)); /* paranoia */ + + I915_WRITE_FW(RING_HEAD(base), 0); + I915_WRITE_FW(RING_TAIL(base), 0); + POSTING_READ_FW(RING_TAIL(base)); + + /* The ring must be empty before it is disabled */ + I915_WRITE_FW(RING_CTL(base), 0); + + /* Check acts as a post */ + if (I915_READ_FW(RING_HEAD(base)) != 0) + DRM_DEBUG_DRIVER("%s: ring head not parked\n", + engine->name); +} + +static void i915_stop_engines(struct drm_i915_private *i915, + unsigned int engine_mask) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + + if (INTEL_GEN(i915) < 3) + return; + + for_each_engine_masked(engine, i915, engine_mask, id) + gen3_stop_engine(engine); +} + +static bool i915_in_reset(struct pci_dev *pdev) +{ + u8 gdrst; + + pci_read_config_byte(pdev, I915_GDRST, &gdrst); + return gdrst & GRDOM_RESET_STATUS; +} + +static int i915_do_reset(struct drm_i915_private *i915, + unsigned int engine_mask, + unsigned int retry) +{ + struct pci_dev *pdev = i915->drm.pdev; + int err; + + /* Assert reset for at least 20 usec, and wait for acknowledgement. */ + pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE); + usleep_range(50, 200); + err = wait_for(i915_in_reset(pdev), 500); + + /* Clear the reset request. */ + pci_write_config_byte(pdev, I915_GDRST, 0); + usleep_range(50, 200); + if (!err) + err = wait_for(!i915_in_reset(pdev), 500); + + return err; +} + +static bool g4x_reset_complete(struct pci_dev *pdev) +{ + u8 gdrst; + + pci_read_config_byte(pdev, I915_GDRST, &gdrst); + return (gdrst & GRDOM_RESET_ENABLE) == 0; +} + +static int g33_do_reset(struct drm_i915_private *i915, + unsigned int engine_mask, + unsigned int retry) +{ + struct pci_dev *pdev = i915->drm.pdev; + + pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE); + return wait_for(g4x_reset_complete(pdev), 500); +} + +static int g4x_do_reset(struct drm_i915_private *dev_priv, + unsigned int engine_mask, + unsigned int retry) +{ + struct pci_dev *pdev = dev_priv->drm.pdev; + int ret; + + /* WaVcpClkGateDisableForMediaReset:ctg,elk */ + I915_WRITE(VDECCLK_GATE_D, + I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE); + POSTING_READ(VDECCLK_GATE_D); + + pci_write_config_byte(pdev, I915_GDRST, + GRDOM_MEDIA | GRDOM_RESET_ENABLE); + ret = wait_for(g4x_reset_complete(pdev), 500); + if (ret) { + DRM_DEBUG_DRIVER("Wait for media reset failed\n"); + goto out; + } + + pci_write_config_byte(pdev, I915_GDRST, + GRDOM_RENDER | GRDOM_RESET_ENABLE); + ret = wait_for(g4x_reset_complete(pdev), 500); + if (ret) { + DRM_DEBUG_DRIVER("Wait for render reset failed\n"); + goto out; + } + +out: + pci_write_config_byte(pdev, I915_GDRST, 0); + + I915_WRITE(VDECCLK_GATE_D, + I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE); + POSTING_READ(VDECCLK_GATE_D); + + return ret; +} + +static int ironlake_do_reset(struct drm_i915_private *dev_priv, + unsigned int engine_mask, + unsigned int retry) +{ + int ret; + + I915_WRITE(ILK_GDSR, ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE); + ret = intel_wait_for_register(dev_priv, + ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0, + 500); + if (ret) { + DRM_DEBUG_DRIVER("Wait for render reset failed\n"); + goto out; + } + + I915_WRITE(ILK_GDSR, ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE); + ret = intel_wait_for_register(dev_priv, + ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0, + 500); + if (ret) { + DRM_DEBUG_DRIVER("Wait for media reset failed\n"); + goto out; + } + +out: + I915_WRITE(ILK_GDSR, 0); + POSTING_READ(ILK_GDSR); + return ret; +} + +/* Reset the hardware domains (GENX_GRDOM_*) specified by mask */ +static int gen6_hw_domain_reset(struct drm_i915_private *dev_priv, + u32 hw_domain_mask) +{ + int err; + + /* + * GEN6_GDRST is not in the gt power well, no need to check + * for fifo space for the write or forcewake the chip for + * the read + */ + I915_WRITE_FW(GEN6_GDRST, hw_domain_mask); + + /* Wait for the device to ack the reset requests */ + err = __intel_wait_for_register_fw(dev_priv, + GEN6_GDRST, hw_domain_mask, 0, + 500, 0, + NULL); + if (err) + DRM_DEBUG_DRIVER("Wait for 0x%08x engines reset failed\n", + hw_domain_mask); + + return err; +} + +static int gen6_reset_engines(struct drm_i915_private *i915, + unsigned int engine_mask, + unsigned int retry) +{ + struct intel_engine_cs *engine; + const u32 hw_engine_mask[I915_NUM_ENGINES] = { + [RCS] = GEN6_GRDOM_RENDER, + [BCS] = GEN6_GRDOM_BLT, + [VCS] = GEN6_GRDOM_MEDIA, + [VCS2] = GEN8_GRDOM_MEDIA2, + [VECS] = GEN6_GRDOM_VECS, + }; + u32 hw_mask; + + if (engine_mask == ALL_ENGINES) { + hw_mask = GEN6_GRDOM_FULL; + } else { + unsigned int tmp; + + hw_mask = 0; + for_each_engine_masked(engine, i915, engine_mask, tmp) + hw_mask |= hw_engine_mask[engine->id]; + } + + return gen6_hw_domain_reset(i915, hw_mask); +} + +static u32 gen11_lock_sfc(struct drm_i915_private *dev_priv, + struct intel_engine_cs *engine) +{ + u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access; + i915_reg_t sfc_forced_lock, sfc_forced_lock_ack; + u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit; + i915_reg_t sfc_usage; + u32 sfc_usage_bit; + u32 sfc_reset_bit; + + switch (engine->class) { + case VIDEO_DECODE_CLASS: + if ((BIT(engine->instance) & vdbox_sfc_access) == 0) + return 0; + + sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine); + sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT; + + sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine); + sfc_forced_lock_ack_bit = GEN11_VCS_SFC_LOCK_ACK_BIT; + + sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine); + sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT; + sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance); + break; + + case VIDEO_ENHANCEMENT_CLASS: + sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine); + sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT; + + sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine); + sfc_forced_lock_ack_bit = GEN11_VECS_SFC_LOCK_ACK_BIT; + + sfc_usage = GEN11_VECS_SFC_USAGE(engine); + sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT; + sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance); + break; + + default: + return 0; + } + + /* + * Tell the engine that a software reset is going to happen. The engine + * will then try to force lock the SFC (if currently locked, it will + * remain so until we tell the engine it is safe to unlock; if currently + * unlocked, it will ignore this and all new lock requests). If SFC + * ends up being locked to the engine we want to reset, we have to reset + * it as well (we will unlock it once the reset sequence is completed). + */ + I915_WRITE_FW(sfc_forced_lock, + I915_READ_FW(sfc_forced_lock) | sfc_forced_lock_bit); + + if (__intel_wait_for_register_fw(dev_priv, + sfc_forced_lock_ack, + sfc_forced_lock_ack_bit, + sfc_forced_lock_ack_bit, + 1000, 0, NULL)) { + DRM_DEBUG_DRIVER("Wait for SFC forced lock ack failed\n"); + return 0; + } + + if (I915_READ_FW(sfc_usage) & sfc_usage_bit) + return sfc_reset_bit; + + return 0; +} + +static void gen11_unlock_sfc(struct drm_i915_private *dev_priv, + struct intel_engine_cs *engine) +{ + u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access; + i915_reg_t sfc_forced_lock; + u32 sfc_forced_lock_bit; + + switch (engine->class) { + case VIDEO_DECODE_CLASS: + if ((BIT(engine->instance) & vdbox_sfc_access) == 0) + return; + + sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine); + sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT; + break; + + case VIDEO_ENHANCEMENT_CLASS: + sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine); + sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT; + break; + + default: + return; + } + + I915_WRITE_FW(sfc_forced_lock, + I915_READ_FW(sfc_forced_lock) & ~sfc_forced_lock_bit); +} + +static int gen11_reset_engines(struct drm_i915_private *i915, + unsigned int engine_mask, + unsigned int retry) +{ + const u32 hw_engine_mask[I915_NUM_ENGINES] = { + [RCS] = GEN11_GRDOM_RENDER, + [BCS] = GEN11_GRDOM_BLT, + [VCS] = GEN11_GRDOM_MEDIA, + [VCS2] = GEN11_GRDOM_MEDIA2, + [VCS3] = GEN11_GRDOM_MEDIA3, + [VCS4] = GEN11_GRDOM_MEDIA4, + [VECS] = GEN11_GRDOM_VECS, + [VECS2] = GEN11_GRDOM_VECS2, + }; + struct intel_engine_cs *engine; + unsigned int tmp; + u32 hw_mask; + int ret; + + BUILD_BUG_ON(VECS2 + 1 != I915_NUM_ENGINES); + + if (engine_mask == ALL_ENGINES) { + hw_mask = GEN11_GRDOM_FULL; + } else { + hw_mask = 0; + for_each_engine_masked(engine, i915, engine_mask, tmp) { + hw_mask |= hw_engine_mask[engine->id]; + hw_mask |= gen11_lock_sfc(i915, engine); + } + } + + ret = gen6_hw_domain_reset(i915, hw_mask); + + if (engine_mask != ALL_ENGINES) + for_each_engine_masked(engine, i915, engine_mask, tmp) + gen11_unlock_sfc(i915, engine); + + return ret; +} + +static int gen8_engine_reset_prepare(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + int ret; + + I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base), + _MASKED_BIT_ENABLE(RESET_CTL_REQUEST_RESET)); + + ret = __intel_wait_for_register_fw(dev_priv, + RING_RESET_CTL(engine->mmio_base), + RESET_CTL_READY_TO_RESET, + RESET_CTL_READY_TO_RESET, + 700, 0, + NULL); + if (ret) + DRM_ERROR("%s: reset request timeout\n", engine->name); + + return ret; +} + +static void gen8_engine_reset_cancel(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + + I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base), + _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET)); +} + +static int gen8_reset_engines(struct drm_i915_private *i915, + unsigned int engine_mask, + unsigned int retry) +{ + struct intel_engine_cs *engine; + const bool reset_non_ready = retry >= 1; + unsigned int tmp; + int ret; + + for_each_engine_masked(engine, i915, engine_mask, tmp) { + ret = gen8_engine_reset_prepare(engine); + if (ret && !reset_non_ready) + goto skip_reset; + + /* + * If this is not the first failed attempt to prepare, + * we decide to proceed anyway. + * + * By doing so we risk context corruption and with + * some gens (kbl), possible system hang if reset + * happens during active bb execution. + * + * We rather take context corruption instead of + * failed reset with a wedged driver/gpu. And + * active bb execution case should be covered by + * i915_stop_engines we have before the reset. + */ + } + + if (INTEL_GEN(i915) >= 11) + ret = gen11_reset_engines(i915, engine_mask, retry); + else + ret = gen6_reset_engines(i915, engine_mask, retry); + +skip_reset: + for_each_engine_masked(engine, i915, engine_mask, tmp) + gen8_engine_reset_cancel(engine); + + return ret; +} + +typedef int (*reset_func)(struct drm_i915_private *, + unsigned int engine_mask, + unsigned int retry); + +static reset_func intel_get_gpu_reset(struct drm_i915_private *i915) +{ + if (!i915_modparams.reset) + return NULL; + + if (INTEL_GEN(i915) >= 8) + return gen8_reset_engines; + else if (INTEL_GEN(i915) >= 6) + return gen6_reset_engines; + else if (INTEL_GEN(i915) >= 5) + return ironlake_do_reset; + else if (IS_G4X(i915)) + return g4x_do_reset; + else if (IS_G33(i915) || IS_PINEVIEW(i915)) + return g33_do_reset; + else if (INTEL_GEN(i915) >= 3) + return i915_do_reset; + else + return NULL; +} + +int intel_gpu_reset(struct drm_i915_private *i915, unsigned int engine_mask) +{ + reset_func reset = intel_get_gpu_reset(i915); + int retry; + int ret; + + /* + * We want to perform per-engine reset from atomic context (e.g. + * softirq), which imposes the constraint that we cannot sleep. + * However, experience suggests that spending a bit of time waiting + * for a reset helps in various cases, so for a full-device reset + * we apply the opposite rule and wait if we want to. As we should + * always follow up a failed per-engine reset with a full device reset, + * being a little faster, stricter and more error prone for the + * atomic case seems an acceptable compromise. + * + * Unfortunately this leads to a bimodal routine, when the goal was + * to have a single reset function that worked for resetting any + * number of engines simultaneously. + */ + might_sleep_if(engine_mask == ALL_ENGINES); + + /* + * If the power well sleeps during the reset, the reset + * request may be dropped and never completes (causing -EIO). + */ + intel_uncore_forcewake_get(i915, FORCEWAKE_ALL); + for (retry = 0; retry < 3; retry++) { + /* + * We stop engines, otherwise we might get failed reset and a + * dead gpu (on elk). Also as modern gpu as kbl can suffer + * from system hang if batchbuffer is progressing when + * the reset is issued, regardless of READY_TO_RESET ack. + * Thus assume it is best to stop engines on all gens + * where we have a gpu reset. + * + * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES) + * + * WaMediaResetMainRingCleanup:ctg,elk (presumably) + * + * FIXME: Wa for more modern gens needs to be validated + */ + i915_stop_engines(i915, engine_mask); + + ret = -ENODEV; + if (reset) { + GEM_TRACE("engine_mask=%x\n", engine_mask); + ret = reset(i915, engine_mask, retry); + } + if (ret != -ETIMEDOUT || engine_mask != ALL_ENGINES) + break; + + cond_resched(); + } + intel_uncore_forcewake_put(i915, FORCEWAKE_ALL); + + return ret; +} + +bool intel_has_gpu_reset(struct drm_i915_private *i915) +{ + return intel_get_gpu_reset(i915); +} + +bool intel_has_reset_engine(struct drm_i915_private *i915) +{ + return INTEL_INFO(i915)->has_reset_engine && i915_modparams.reset >= 2; +} + +int intel_reset_guc(struct drm_i915_private *i915) +{ + u32 guc_domain = + INTEL_GEN(i915) >= 11 ? GEN11_GRDOM_GUC : GEN9_GRDOM_GUC; + int ret; + + GEM_BUG_ON(!HAS_GUC(i915)); + + intel_uncore_forcewake_get(i915, FORCEWAKE_ALL); + ret = gen6_hw_domain_reset(i915, guc_domain); + intel_uncore_forcewake_put(i915, FORCEWAKE_ALL); + + return ret; +} + +/* + * Ensure irq handler finishes, and not run again. + * Also return the active request so that we only search for it once. + */ +static struct i915_request * +reset_prepare_engine(struct intel_engine_cs *engine) +{ + struct i915_request *rq; + + /* + * During the reset sequence, we must prevent the engine from + * entering RC6. As the context state is undefined until we restart + * the engine, if it does enter RC6 during the reset, the state + * written to the powercontext is undefined and so we may lose + * GPU state upon resume, i.e. fail to restart after a reset. + */ + intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL); + + rq = engine->reset.prepare(engine); + if (rq && rq->fence.error == -EIO) + rq = ERR_PTR(-EIO); /* Previous reset failed! */ + + return rq; +} + +static int reset_prepare(struct drm_i915_private *i915) +{ + struct intel_engine_cs *engine; + struct i915_request *rq; + enum intel_engine_id id; + int err = 0; + + for_each_engine(engine, i915, id) { + rq = reset_prepare_engine(engine); + if (IS_ERR(rq)) { + err = PTR_ERR(rq); + continue; + } + + engine->hangcheck.active_request = rq; + } + + i915_gem_revoke_fences(i915); + intel_uc_sanitize(i915); + + return err; +} + +/* Returns the request if it was guilty of the hang */ +static struct i915_request * +reset_request(struct intel_engine_cs *engine, + struct i915_request *rq, + bool stalled) +{ + /* + * The guilty request will get skipped on a hung engine. + * + * Users of client default contexts do not rely on logical + * state preserved between batches so it is safe to execute + * queued requests following the hang. Non default contexts + * rely on preserved state, so skipping a batch loses the + * evolution of the state and it needs to be considered corrupted. + * Executing more queued batches on top of corrupted state is + * risky. But we take the risk by trying to advance through + * the queued requests in order to make the client behaviour + * more predictable around resets, by not throwing away random + * amount of batches it has prepared for execution. Sophisticated + * clients can use gem_reset_stats_ioctl and dma fence status + * (exported via sync_file info ioctl on explicit fences) to observe + * when it loses the context state and should rebuild accordingly. + * + * The context ban, and ultimately the client ban, mechanism are safety + * valves if client submission ends up resulting in nothing more than + * subsequent hangs. + */ + + if (i915_request_completed(rq)) { + GEM_TRACE("%s pardoned global=%d (fence %llx:%lld), current %d\n", + engine->name, rq->global_seqno, + rq->fence.context, rq->fence.seqno, + intel_engine_get_seqno(engine)); + stalled = false; + } + + if (stalled) { + context_mark_guilty(rq->gem_context); + i915_request_skip(rq, -EIO); + + /* If this context is now banned, skip all pending requests. */ + if (i915_gem_context_is_banned(rq->gem_context)) + engine_skip_context(rq); + } else { + /* + * Since this is not the hung engine, it may have advanced + * since the hang declaration. Double check by refinding + * the active request at the time of the reset. + */ + rq = i915_gem_find_active_request(engine); + if (rq) { + unsigned long flags; + + context_mark_innocent(rq->gem_context); + dma_fence_set_error(&rq->fence, -EAGAIN); + + /* Rewind the engine to replay the incomplete rq */ + spin_lock_irqsave(&engine->timeline.lock, flags); + rq = list_prev_entry(rq, link); + if (&rq->link == &engine->timeline.requests) + rq = NULL; + spin_unlock_irqrestore(&engine->timeline.lock, flags); + } + } + + return rq; +} + +static void reset_engine(struct intel_engine_cs *engine, + struct i915_request *rq, + bool stalled) +{ + if (rq) + rq = reset_request(engine, rq, stalled); + + /* Setup the CS to resume from the breadcrumb of the hung request */ + engine->reset.reset(engine, rq); +} + +static void gt_reset(struct drm_i915_private *i915, unsigned int stalled_mask) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + + lockdep_assert_held(&i915->drm.struct_mutex); + + i915_retire_requests(i915); + + for_each_engine(engine, i915, id) { + struct intel_context *ce; + + reset_engine(engine, + engine->hangcheck.active_request, + stalled_mask & ENGINE_MASK(id)); + ce = fetch_and_zero(&engine->last_retired_context); + if (ce) + intel_context_unpin(ce); + + /* + * Ostensibily, we always want a context loaded for powersaving, + * so if the engine is idle after the reset, send a request + * to load our scratch kernel_context. + * + * More mysteriously, if we leave the engine idle after a reset, + * the next userspace batch may hang, with what appears to be + * an incoherent read by the CS (presumably stale TLB). An + * empty request appears sufficient to paper over the glitch. + */ + if (intel_engine_is_idle(engine)) { + struct i915_request *rq; + + rq = i915_request_alloc(engine, i915->kernel_context); + if (!IS_ERR(rq)) + i915_request_add(rq); + } + } + + i915_gem_restore_fences(i915); +} + +static void reset_finish_engine(struct intel_engine_cs *engine) +{ + engine->reset.finish(engine); + + intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL); +} + +static void reset_finish(struct drm_i915_private *i915) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + + lockdep_assert_held(&i915->drm.struct_mutex); + + for_each_engine(engine, i915, id) { + engine->hangcheck.active_request = NULL; + reset_finish_engine(engine); + } +} + +static void nop_submit_request(struct i915_request *request) +{ + unsigned long flags; + + GEM_TRACE("%s fence %llx:%lld -> -EIO\n", + request->engine->name, + request->fence.context, request->fence.seqno); + dma_fence_set_error(&request->fence, -EIO); + + spin_lock_irqsave(&request->engine->timeline.lock, flags); + __i915_request_submit(request); + intel_engine_write_global_seqno(request->engine, request->global_seqno); + spin_unlock_irqrestore(&request->engine->timeline.lock, flags); +} + +void i915_gem_set_wedged(struct drm_i915_private *i915) +{ + struct i915_gpu_error *error = &i915->gpu_error; + struct intel_engine_cs *engine; + enum intel_engine_id id; + + mutex_lock(&error->wedge_mutex); + if (test_bit(I915_WEDGED, &error->flags)) { + mutex_unlock(&error->wedge_mutex); + return; + } + + if (GEM_SHOW_DEBUG() && !intel_engines_are_idle(i915)) { + struct drm_printer p = drm_debug_printer(__func__); + + for_each_engine(engine, i915, id) + intel_engine_dump(engine, &p, "%s\n", engine->name); + } + + GEM_TRACE("start\n"); + + /* + * First, stop submission to hw, but do not yet complete requests by + * rolling the global seqno forward (since this would complete requests + * for which we haven't set the fence error to EIO yet). + */ + for_each_engine(engine, i915, id) + reset_prepare_engine(engine); + + /* Even if the GPU reset fails, it should still stop the engines */ + if (INTEL_GEN(i915) >= 5) + intel_gpu_reset(i915, ALL_ENGINES); + + for_each_engine(engine, i915, id) { + engine->submit_request = nop_submit_request; + engine->schedule = NULL; + } + i915->caps.scheduler = 0; + + /* + * Make sure no request can slip through without getting completed by + * either this call here to intel_engine_write_global_seqno, or the one + * in nop_submit_request. + */ + synchronize_rcu(); + + /* Mark all executing requests as skipped */ + for_each_engine(engine, i915, id) + engine->cancel_requests(engine); + + for_each_engine(engine, i915, id) { + reset_finish_engine(engine); + intel_engine_wakeup(engine); + } + + smp_mb__before_atomic(); + set_bit(I915_WEDGED, &error->flags); + + GEM_TRACE("end\n"); + mutex_unlock(&error->wedge_mutex); + + wake_up_all(&error->reset_queue); +} + +bool i915_gem_unset_wedged(struct drm_i915_private *i915) +{ + struct i915_gpu_error *error = &i915->gpu_error; + struct i915_timeline *tl; + bool ret = false; + + lockdep_assert_held(&i915->drm.struct_mutex); + + if (!test_bit(I915_WEDGED, &error->flags)) + return true; + + if (!i915->gt.scratch) /* Never full initialised, recovery impossible */ + return false; + + mutex_lock(&error->wedge_mutex); + + GEM_TRACE("start\n"); + + /* + * Before unwedging, make sure that all pending operations + * are flushed and errored out - we may have requests waiting upon + * third party fences. We marked all inflight requests as EIO, and + * every execbuf since returned EIO, for consistency we want all + * the currently pending requests to also be marked as EIO, which + * is done inside our nop_submit_request - and so we must wait. + * + * No more can be submitted until we reset the wedged bit. + */ + list_for_each_entry(tl, &i915->gt.timelines, link) { + struct i915_request *rq; + + rq = i915_gem_active_peek(&tl->last_request, + &i915->drm.struct_mutex); + if (!rq) + continue; + + /* + * We can't use our normal waiter as we want to + * avoid recursively trying to handle the current + * reset. The basic dma_fence_default_wait() installs + * a callback for dma_fence_signal(), which is + * triggered by our nop handler (indirectly, the + * callback enables the signaler thread which is + * woken by the nop_submit_request() advancing the seqno + * and when the seqno passes the fence, the signaler + * then signals the fence waking us up). + */ + if (dma_fence_default_wait(&rq->fence, true, + MAX_SCHEDULE_TIMEOUT) < 0) + goto unlock; + } + i915_retire_requests(i915); + GEM_BUG_ON(i915->gt.active_requests); + + intel_engines_sanitize(i915, false); + + /* + * Undo nop_submit_request. We prevent all new i915 requests from + * being queued (by disallowing execbuf whilst wedged) so having + * waited for all active requests above, we know the system is idle + * and do not have to worry about a thread being inside + * engine->submit_request() as we swap over. So unlike installing + * the nop_submit_request on reset, we can do this from normal + * context and do not require stop_machine(). + */ + intel_engines_reset_default_submission(i915); + i915_gem_contexts_lost(i915); + + GEM_TRACE("end\n"); + + smp_mb__before_atomic(); /* complete takeover before enabling execbuf */ + clear_bit(I915_WEDGED, &i915->gpu_error.flags); + ret = true; +unlock: + mutex_unlock(&i915->gpu_error.wedge_mutex); + + return ret; +} + +/** + * i915_reset - reset chip after a hang + * @i915: #drm_i915_private to reset + * @stalled_mask: mask of the stalled engines with the guilty requests + * @reason: user error message for why we are resetting + * + * Reset the chip. Useful if a hang is detected. Marks the device as wedged + * on failure. + * + * Caller must hold the struct_mutex. + * + * Procedure is fairly simple: + * - reset the chip using the reset reg + * - re-init context state + * - re-init hardware status page + * - re-init ring buffer + * - re-init interrupt state + * - re-init display + */ +void i915_reset(struct drm_i915_private *i915, + unsigned int stalled_mask, + const char *reason) +{ + struct i915_gpu_error *error = &i915->gpu_error; + int ret; + int i; + + GEM_TRACE("flags=%lx\n", error->flags); + + might_sleep(); + lockdep_assert_held(&i915->drm.struct_mutex); + assert_rpm_wakelock_held(i915); + GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags)); + + if (!test_bit(I915_RESET_HANDOFF, &error->flags)) + return; + + /* Clear any previous failed attempts at recovery. Time to try again. */ + if (!i915_gem_unset_wedged(i915)) + goto wakeup; + + if (reason) + dev_notice(i915->drm.dev, "Resetting chip for %s\n", reason); + error->reset_count++; + + ret = reset_prepare(i915); + if (ret) { + dev_err(i915->drm.dev, "GPU recovery failed\n"); + goto taint; + } + + if (!intel_has_gpu_reset(i915)) { + if (i915_modparams.reset) + dev_err(i915->drm.dev, "GPU reset not supported\n"); + else + DRM_DEBUG_DRIVER("GPU reset disabled\n"); + goto error; + } + + for (i = 0; i < 3; i++) { + ret = intel_gpu_reset(i915, ALL_ENGINES); + if (ret == 0) + break; + + msleep(100); + } + if (ret) { + dev_err(i915->drm.dev, "Failed to reset chip\n"); + goto taint; + } + + /* Ok, now get things going again... */ + + /* + * Everything depends on having the GTT running, so we need to start + * there. + */ + ret = i915_ggtt_enable_hw(i915); + if (ret) { + DRM_ERROR("Failed to re-enable GGTT following reset (%d)\n", + ret); + goto error; + } + + gt_reset(i915, stalled_mask); + intel_overlay_reset(i915); + + /* + * Next we need to restore the context, but we don't use those + * yet either... + * + * Ring buffer needs to be re-initialized in the KMS case, or if X + * was running at the time of the reset (i.e. we weren't VT + * switched away). + */ + ret = i915_gem_init_hw(i915); + if (ret) { + DRM_ERROR("Failed to initialise HW following reset (%d)\n", + ret); + goto error; + } + + i915_queue_hangcheck(i915); + +finish: + reset_finish(i915); +wakeup: + clear_bit(I915_RESET_HANDOFF, &error->flags); + wake_up_bit(&error->flags, I915_RESET_HANDOFF); + return; + +taint: + /* + * History tells us that if we cannot reset the GPU now, we + * never will. This then impacts everything that is run + * subsequently. On failing the reset, we mark the driver + * as wedged, preventing further execution on the GPU. + * We also want to go one step further and add a taint to the + * kernel so that any subsequent faults can be traced back to + * this failure. This is important for CI, where if the + * GPU/driver fails we would like to reboot and restart testing + * rather than continue on into oblivion. For everyone else, + * the system should still plod along, but they have been warned! + */ + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); +error: + i915_gem_set_wedged(i915); + i915_retire_requests(i915); + goto finish; +} + +static inline int intel_gt_reset_engine(struct drm_i915_private *i915, + struct intel_engine_cs *engine) +{ + return intel_gpu_reset(i915, intel_engine_flag(engine)); +} + +/** + * i915_reset_engine - reset GPU engine to recover from a hang + * @engine: engine to reset + * @msg: reason for GPU reset; or NULL for no dev_notice() + * + * Reset a specific GPU engine. Useful if a hang is detected. + * Returns zero on successful reset or otherwise an error code. + * + * Procedure is: + * - identifies the request that caused the hang and it is dropped + * - reset engine (which will force the engine to idle) + * - re-init/configure engine + */ +int i915_reset_engine(struct intel_engine_cs *engine, const char *msg) +{ + struct i915_gpu_error *error = &engine->i915->gpu_error; + struct i915_request *active_request; + int ret; + + GEM_TRACE("%s flags=%lx\n", engine->name, error->flags); + GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags)); + + active_request = reset_prepare_engine(engine); + if (IS_ERR_OR_NULL(active_request)) { + /* Either the previous reset failed, or we pardon the reset. */ + ret = PTR_ERR(active_request); + goto out; + } + + if (msg) + dev_notice(engine->i915->drm.dev, + "Resetting %s for %s\n", engine->name, msg); + error->reset_engine_count[engine->id]++; + + if (!engine->i915->guc.execbuf_client) + ret = intel_gt_reset_engine(engine->i915, engine); + else + ret = intel_guc_reset_engine(&engine->i915->guc, engine); + if (ret) { + /* If we fail here, we expect to fallback to a global reset */ + DRM_DEBUG_DRIVER("%sFailed to reset %s, ret=%d\n", + engine->i915->guc.execbuf_client ? "GuC " : "", + engine->name, ret); + goto out; + } + + /* + * The request that caused the hang is stuck on elsp, we know the + * active request and can drop it, adjust head to skip the offending + * request to resume executing remaining requests in the queue. + */ + reset_engine(engine, active_request, true); + + /* + * The engine and its registers (and workarounds in case of render) + * have been reset to their default values. Follow the init_ring + * process to program RING_MODE, HWSP and re-enable submission. + */ + ret = engine->init_hw(engine); + if (ret) + goto out; + +out: + intel_engine_cancel_stop_cs(engine); + reset_finish_engine(engine); + return ret; +} + +static void i915_reset_device(struct drm_i915_private *i915, + u32 engine_mask, + const char *reason) +{ + struct i915_gpu_error *error = &i915->gpu_error; + struct kobject *kobj = &i915->drm.primary->kdev->kobj; + char *error_event[] = { I915_ERROR_UEVENT "=1", NULL }; + char *reset_event[] = { I915_RESET_UEVENT "=1", NULL }; + char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL }; + struct i915_wedge_me w; + + kobject_uevent_env(kobj, KOBJ_CHANGE, error_event); + + DRM_DEBUG_DRIVER("resetting chip\n"); + kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event); + + /* Use a watchdog to ensure that our reset completes */ + i915_wedge_on_timeout(&w, i915, 5 * HZ) { + intel_prepare_reset(i915); + + error->reason = reason; + error->stalled_mask = engine_mask; + + /* Signal that locked waiters should reset the GPU */ + smp_mb__before_atomic(); + set_bit(I915_RESET_HANDOFF, &error->flags); + wake_up_all(&error->wait_queue); + + /* + * Wait for anyone holding the lock to wakeup, without + * blocking indefinitely on struct_mutex. + */ + do { + if (mutex_trylock(&i915->drm.struct_mutex)) { + i915_reset(i915, engine_mask, reason); + mutex_unlock(&i915->drm.struct_mutex); + } + } while (wait_on_bit_timeout(&error->flags, + I915_RESET_HANDOFF, + TASK_UNINTERRUPTIBLE, + 1)); + + error->stalled_mask = 0; + error->reason = NULL; + + intel_finish_reset(i915); + } + + if (!test_bit(I915_WEDGED, &error->flags)) + kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event); +} + +void i915_clear_error_registers(struct drm_i915_private *dev_priv) +{ + u32 eir; + + if (!IS_GEN(dev_priv, 2)) + I915_WRITE(PGTBL_ER, I915_READ(PGTBL_ER)); + + if (INTEL_GEN(dev_priv) < 4) + I915_WRITE(IPEIR, I915_READ(IPEIR)); + else + I915_WRITE(IPEIR_I965, I915_READ(IPEIR_I965)); + + I915_WRITE(EIR, I915_READ(EIR)); + eir = I915_READ(EIR); + if (eir) { + /* + * some errors might have become stuck, + * mask them. + */ + DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir); + I915_WRITE(EMR, I915_READ(EMR) | eir); + I915_WRITE(IIR, I915_MASTER_ERROR_INTERRUPT); + } + + if (INTEL_GEN(dev_priv) >= 8) { + I915_WRITE(GEN8_RING_FAULT_REG, + I915_READ(GEN8_RING_FAULT_REG) & ~RING_FAULT_VALID); + POSTING_READ(GEN8_RING_FAULT_REG); + } else if (INTEL_GEN(dev_priv) >= 6) { + struct intel_engine_cs *engine; + enum intel_engine_id id; + + for_each_engine(engine, dev_priv, id) { + I915_WRITE(RING_FAULT_REG(engine), + I915_READ(RING_FAULT_REG(engine)) & + ~RING_FAULT_VALID); + } + POSTING_READ(RING_FAULT_REG(dev_priv->engine[RCS])); + } +} + +/** + * i915_handle_error - handle a gpu error + * @i915: i915 device private + * @engine_mask: mask representing engines that are hung + * @flags: control flags + * @fmt: Error message format string + * + * Do some basic checking of register state at error time and + * dump it to the syslog. Also call i915_capture_error_state() to make + * sure we get a record and make it available in debugfs. Fire a uevent + * so userspace knows something bad happened (should trigger collection + * of a ring dump etc.). + */ +void i915_handle_error(struct drm_i915_private *i915, + u32 engine_mask, + unsigned long flags, + const char *fmt, ...) +{ + struct intel_engine_cs *engine; + intel_wakeref_t wakeref; + unsigned int tmp; + char error_msg[80]; + char *msg = NULL; + + if (fmt) { + va_list args; + + va_start(args, fmt); + vscnprintf(error_msg, sizeof(error_msg), fmt, args); + va_end(args); + + msg = error_msg; + } + + /* + * In most cases it's guaranteed that we get here with an RPM + * reference held, for example because there is a pending GPU + * request that won't finish until the reset is done. This + * isn't the case at least when we get here by doing a + * simulated reset via debugfs, so get an RPM reference. + */ + wakeref = intel_runtime_pm_get(i915); + + engine_mask &= INTEL_INFO(i915)->ring_mask; + + if (flags & I915_ERROR_CAPTURE) { + i915_capture_error_state(i915, engine_mask, msg); + i915_clear_error_registers(i915); + } + + /* + * Try engine reset when available. We fall back to full reset if + * single reset fails. + */ + if (intel_has_reset_engine(i915) && + !i915_terminally_wedged(&i915->gpu_error)) { + for_each_engine_masked(engine, i915, engine_mask, tmp) { + BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE); + if (test_and_set_bit(I915_RESET_ENGINE + engine->id, + &i915->gpu_error.flags)) + continue; + + if (i915_reset_engine(engine, msg) == 0) + engine_mask &= ~intel_engine_flag(engine); + + clear_bit(I915_RESET_ENGINE + engine->id, + &i915->gpu_error.flags); + wake_up_bit(&i915->gpu_error.flags, + I915_RESET_ENGINE + engine->id); + } + } + + if (!engine_mask) + goto out; + + /* Full reset needs the mutex, stop any other user trying to do so. */ + if (test_and_set_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags)) { + wait_event(i915->gpu_error.reset_queue, + !test_bit(I915_RESET_BACKOFF, + &i915->gpu_error.flags)); + goto out; + } + + /* Prevent any other reset-engine attempt. */ + for_each_engine(engine, i915, tmp) { + while (test_and_set_bit(I915_RESET_ENGINE + engine->id, + &i915->gpu_error.flags)) + wait_on_bit(&i915->gpu_error.flags, + I915_RESET_ENGINE + engine->id, + TASK_UNINTERRUPTIBLE); + } + + i915_reset_device(i915, engine_mask, msg); + + for_each_engine(engine, i915, tmp) { + clear_bit(I915_RESET_ENGINE + engine->id, + &i915->gpu_error.flags); + } + + clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags); + wake_up_all(&i915->gpu_error.reset_queue); + +out: + intel_runtime_pm_put(i915, wakeref); +} + +static void i915_wedge_me(struct work_struct *work) +{ + struct i915_wedge_me *w = container_of(work, typeof(*w), work.work); + + dev_err(w->i915->drm.dev, + "%s timed out, cancelling all in-flight rendering.\n", + w->name); + i915_gem_set_wedged(w->i915); +} + +void __i915_init_wedge(struct i915_wedge_me *w, + struct drm_i915_private *i915, + long timeout, + const char *name) +{ + w->i915 = i915; + w->name = name; + + INIT_DELAYED_WORK_ONSTACK(&w->work, i915_wedge_me); + schedule_delayed_work(&w->work, timeout); +} + +void __i915_fini_wedge(struct i915_wedge_me *w) +{ + cancel_delayed_work_sync(&w->work); + destroy_delayed_work_on_stack(&w->work); + w->i915 = NULL; +} |