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path: root/drivers/gpu/drm/i915/i915_reset.c
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Diffstat (limited to 'drivers/gpu/drm/i915/i915_reset.c')
-rw-r--r--drivers/gpu/drm/i915/i915_reset.c1349
1 files changed, 1349 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..0e0ddf2e6815
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -0,0 +1,1349 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2008-2018 Intel Corporation
+ */
+
+#include <linux/sched/mm.h>
+#include <linux/stop_machine.h>
+
+#include "i915_drv.h"
+#include "i915_gpu_error.h"
+#include "i915_reset.h"
+
+#include "intel_guc.h"
+
+#define RESET_MAX_RETRIES 3
+
+/* XXX How to handle concurrent GGTT updates using tiling registers? */
+#define RESET_UNDER_STOP_MACHINE 0
+
+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;
+
+ lockdep_assert_held(&engine->timeline.lock);
+ GEM_BUG_ON(timeline == &engine->timeline);
+
+ spin_lock(&timeline->lock);
+
+ if (i915_request_is_active(rq)) {
+ 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);
+}
+
+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 bool 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 false;
+
+ 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);
+
+ return banned;
+}
+
+static void context_mark_innocent(struct i915_gem_context *ctx)
+{
+ atomic_inc(&ctx->active_count);
+}
+
+void i915_reset_request(struct i915_request *rq, bool guilty)
+{
+ lockdep_assert_held(&rq->engine->timeline.lock);
+ GEM_BUG_ON(i915_request_completed(rq));
+
+ if (guilty) {
+ i915_request_skip(rq, -EIO);
+ if (context_mark_guilty(rq->gem_context))
+ engine_skip_context(rq);
+ } else {
+ dma_fence_set_error(&rq->fence, -EAGAIN);
+ context_mark_innocent(rq->gem_context);
+ }
+}
+
+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);
+ udelay(50);
+ err = wait_for_atomic(i915_in_reset(pdev), 50);
+
+ /* Clear the reset request. */
+ pci_write_config_byte(pdev, I915_GDRST, 0);
+ udelay(50);
+ if (!err)
+ err = wait_for_atomic(!i915_in_reset(pdev), 50);
+
+ 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_atomic(g4x_reset_complete(pdev), 50);
+}
+
+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_FW(VDECCLK_GATE_D,
+ I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
+ POSTING_READ_FW(VDECCLK_GATE_D);
+
+ pci_write_config_byte(pdev, I915_GDRST,
+ GRDOM_MEDIA | GRDOM_RESET_ENABLE);
+ ret = wait_for_atomic(g4x_reset_complete(pdev), 50);
+ 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_atomic(g4x_reset_complete(pdev), 50);
+ if (ret) {
+ DRM_DEBUG_DRIVER("Wait for render reset failed\n");
+ goto out;
+ }
+
+out:
+ pci_write_config_byte(pdev, I915_GDRST, 0);
+
+ I915_WRITE_FW(VDECCLK_GATE_D,
+ I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
+ POSTING_READ_FW(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_FW(ILK_GDSR, ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
+ ret = __intel_wait_for_register_fw(dev_priv, ILK_GDSR,
+ ILK_GRDOM_RESET_ENABLE, 0,
+ 5000, 0,
+ NULL);
+ if (ret) {
+ DRM_DEBUG_DRIVER("Wait for render reset failed\n");
+ goto out;
+ }
+
+ I915_WRITE_FW(ILK_GDSR, ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
+ ret = __intel_wait_for_register_fw(dev_priv, ILK_GDSR,
+ ILK_GRDOM_RESET_ENABLE, 0,
+ 5000, 0,
+ NULL);
+ if (ret) {
+ DRM_DEBUG_DRIVER("Wait for media reset failed\n");
+ goto out;
+ }
+
+out:
+ I915_WRITE_FW(ILK_GDSR, 0);
+ POSTING_READ_FW(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)
+{
+ const int retries = engine_mask == ALL_ENGINES ? RESET_MAX_RETRIES : 1;
+ reset_func reset;
+ int ret = -ETIMEDOUT;
+ int retry;
+
+ reset = intel_get_gpu_reset(i915);
+ if (!reset)
+ return -ENODEV;
+
+ /*
+ * 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; ret == -ETIMEDOUT && retry < retries; 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);
+
+ GEM_TRACE("engine_mask=%x\n", engine_mask);
+ preempt_disable();
+ ret = reset(i915, engine_mask, retry);
+ preempt_enable();
+ }
+ intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
+
+ return ret;
+}
+
+bool intel_has_gpu_reset(struct drm_i915_private *i915)
+{
+ if (USES_GUC(i915))
+ return false;
+
+ 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 void reset_prepare_engine(struct intel_engine_cs *engine)
+{
+ /*
+ * 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);
+ engine->reset.prepare(engine);
+}
+
+static void reset_prepare(struct drm_i915_private *i915)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+
+ for_each_engine(engine, i915, id)
+ reset_prepare_engine(engine);
+
+ intel_uc_sanitize(i915);
+}
+
+static int gt_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ int err;
+
+ /*
+ * Everything depends on having the GTT running, so we need to start
+ * there.
+ */
+ err = i915_ggtt_enable_hw(i915);
+ if (err)
+ return err;
+
+ for_each_engine(engine, i915, id)
+ intel_engine_reset(engine, stalled_mask & ENGINE_MASK(id));
+
+ i915_gem_restore_fences(i915);
+
+ return err;
+}
+
+static void reset_finish_engine(struct intel_engine_cs *engine)
+{
+ engine->reset.finish(engine);
+ intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
+}
+
+struct i915_gpu_restart {
+ struct work_struct work;
+ struct drm_i915_private *i915;
+};
+
+static void restart_work(struct work_struct *work)
+{
+ struct i915_gpu_restart *arg = container_of(work, typeof(*arg), work);
+ struct drm_i915_private *i915 = arg->i915;
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ intel_wakeref_t wakeref;
+
+ wakeref = intel_runtime_pm_get(i915);
+ mutex_lock(&i915->drm.struct_mutex);
+ WRITE_ONCE(i915->gpu_error.restart, NULL);
+
+ for_each_engine(engine, i915, id) {
+ struct i915_request *rq;
+
+ /*
+ * 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.
+ */
+ if (!intel_engine_is_idle(engine))
+ continue;
+
+ rq = i915_request_alloc(engine, i915->kernel_context);
+ if (!IS_ERR(rq))
+ i915_request_add(rq);
+ }
+
+ mutex_unlock(&i915->drm.struct_mutex);
+ intel_runtime_pm_put(i915, wakeref);
+
+ kfree(arg);
+}
+
+static void reset_finish(struct drm_i915_private *i915)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+
+ for_each_engine(engine, i915, id)
+ reset_finish_engine(engine);
+}
+
+static void reset_restart(struct drm_i915_private *i915)
+{
+ struct i915_gpu_restart *arg;
+
+ /*
+ * Following the reset, ensure that we always reload context for
+ * powersaving, and to correct engine->last_retired_context. Since
+ * this requires us to submit a request, queue a worker to do that
+ * task for us to evade any locking here.
+ */
+ if (READ_ONCE(i915->gpu_error.restart))
+ return;
+
+ arg = kmalloc(sizeof(*arg), GFP_KERNEL);
+ if (arg) {
+ arg->i915 = i915;
+ INIT_WORK(&arg->work, restart_work);
+
+ WRITE_ONCE(i915->gpu_error.restart, arg);
+ queue_work(i915->wq, &arg->work);
+ }
+}
+
+static void nop_submit_request(struct i915_request *request)
+{
+ struct intel_engine_cs *engine = request->engine;
+ unsigned long flags;
+
+ GEM_TRACE("%s fence %llx:%lld -> -EIO\n",
+ engine->name, request->fence.context, request->fence.seqno);
+ dma_fence_set_error(&request->fence, -EIO);
+
+ spin_lock_irqsave(&engine->timeline.lock, flags);
+ __i915_request_submit(request);
+ i915_request_mark_complete(request);
+ intel_engine_write_global_seqno(engine, request->global_seqno);
+ spin_unlock_irqrestore(&engine->timeline.lock, flags);
+
+ intel_engine_queue_breadcrumbs(engine);
+}
+
+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_signal_breadcrumbs(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;
+
+ 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.
+ */
+ mutex_lock(&i915->gt.timelines.mutex);
+ list_for_each_entry(tl, &i915->gt.timelines.active_list, link) {
+ struct i915_request *rq;
+ long timeout;
+
+ rq = i915_active_request_get_unlocked(&tl->last_request);
+ 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).
+ */
+ timeout = dma_fence_default_wait(&rq->fence, true,
+ MAX_SCHEDULE_TIMEOUT);
+ i915_request_put(rq);
+ if (timeout < 0) {
+ mutex_unlock(&i915->gt.timelines.mutex);
+ goto unlock;
+ }
+ }
+ mutex_unlock(&i915->gt.timelines.mutex);
+
+ 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);
+
+ 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;
+}
+
+struct __i915_reset {
+ struct drm_i915_private *i915;
+ unsigned int stalled_mask;
+};
+
+static int __i915_reset__BKL(void *data)
+{
+ struct __i915_reset *arg = data;
+ int err;
+
+ err = intel_gpu_reset(arg->i915, ALL_ENGINES);
+ if (err)
+ return err;
+
+ return gt_reset(arg->i915, arg->stalled_mask);
+}
+
+#if RESET_UNDER_STOP_MACHINE
+/*
+ * XXX An alternative to using stop_machine would be to park only the
+ * processes that have a GGTT mmap. By remote parking the threads (SIGSTOP)
+ * we should be able to prevent their memmory accesses via the lost fence
+ * registers over the course of the reset without the potential recursive
+ * of mutexes between the pagefault handler and reset.
+ *
+ * See igt/gem_mmap_gtt/hang
+ */
+#define __do_reset(fn, arg) stop_machine(fn, arg, NULL)
+#else
+#define __do_reset(fn, arg) fn(arg)
+#endif
+
+static int do_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
+{
+ struct __i915_reset arg = { i915, stalled_mask };
+ int err, i;
+
+ err = __do_reset(__i915_reset__BKL, &arg);
+ for (i = 0; err && i < RESET_MAX_RETRIES; i++) {
+ msleep(100);
+ err = __do_reset(__i915_reset__BKL, &arg);
+ }
+
+ return err;
+}
+
+/**
+ * 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;
+
+ GEM_TRACE("flags=%lx\n", error->flags);
+
+ might_sleep();
+ assert_rpm_wakelock_held(i915);
+ GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags));
+
+ /* Clear any previous failed attempts at recovery. Time to try again. */
+ if (!i915_gem_unset_wedged(i915))
+ return;
+
+ if (reason)
+ dev_notice(i915->drm.dev, "Resetting chip for %s\n", reason);
+ error->reset_count++;
+
+ reset_prepare(i915);
+
+ 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;
+ }
+
+ if (do_reset(i915, stalled_mask)) {
+ dev_err(i915->drm.dev, "Failed to reset chip\n");
+ goto taint;
+ }
+
+ 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);
+ if (!i915_terminally_wedged(error))
+ reset_restart(i915);
+ 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);
+ 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;
+ int ret;
+
+ GEM_TRACE("%s flags=%lx\n", engine->name, error->flags);
+ GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags));
+
+ reset_prepare_engine(engine);
+
+ 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.
+ */
+ intel_engine_reset(engine, 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);
+
+ i915_reset(i915, engine_mask, reason);
+
+ 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);
+}
+
+bool i915_reset_flush(struct drm_i915_private *i915)
+{
+ int err;
+
+ cancel_delayed_work_sync(&i915->gpu_error.hangcheck_work);
+
+ flush_workqueue(i915->wq);
+ GEM_BUG_ON(READ_ONCE(i915->gpu_error.restart));
+
+ mutex_lock(&i915->drm.struct_mutex);
+ err = i915_gem_wait_for_idle(i915,
+ I915_WAIT_LOCKED |
+ I915_WAIT_FOR_IDLE_BOOST,
+ MAX_SCHEDULE_TIMEOUT);
+ mutex_unlock(&i915->drm.struct_mutex);
+
+ return !err;
+}
+
+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;
+}