Chris Wilson <ch...@chris-wilson.co.uk> writes:

> Currently the code to reset the GPU and our state is spread widely
> across a few files. Pull the logic together into a common file.
>
> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>

Dunno how it goes but gut feeling that this would have
been better at the end of series after the dust has settled.
Regardless,

Acked-by: Mika Kuoppala <mika.kuopp...@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/Makefile                 |    3 +-
>  drivers/gpu/drm/i915/i915_debugfs.c           |    2 +
>  drivers/gpu/drm/i915/i915_drv.c               |  206 +--
>  drivers/gpu/drm/i915/i915_drv.h               |   33 +-
>  drivers/gpu/drm/i915/i915_gem.c               |  446 +-----
>  drivers/gpu/drm/i915/i915_gem_gtt.c           |    1 +
>  drivers/gpu/drm/i915/i915_irq.c               |  238 ---
>  drivers/gpu/drm/i915/i915_request.c           |    1 +
>  drivers/gpu/drm/i915/i915_reset.c             | 1389 +++++++++++++++++
>  drivers/gpu/drm/i915/i915_reset.h             |   56 +
>  drivers/gpu/drm/i915/intel_display.c          |   15 +-
>  drivers/gpu/drm/i915/intel_engine_cs.c        |    1 +
>  drivers/gpu/drm/i915/intel_guc.h              |    3 +
>  drivers/gpu/drm/i915/intel_hangcheck.c        |    1 +
>  drivers/gpu/drm/i915/intel_uc.c               |    1 +
>  drivers/gpu/drm/i915/intel_uncore.c           |  556 -------
>  drivers/gpu/drm/i915/selftests/intel_lrc.c    |    2 +
>  .../drm/i915/selftests/intel_workarounds.c    |    1 +
>  18 files changed, 1483 insertions(+), 1472 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/i915_reset.c
>  create mode 100644 drivers/gpu/drm/i915/i915_reset.h
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index c34bee16730d..611115ed00db 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -40,9 +40,10 @@ i915-y := i915_drv.o \
>         i915_mm.o \
>         i915_params.o \
>         i915_pci.o \
> +       i915_reset.o \
>         i915_suspend.o \
> -       i915_syncmap.o \
>         i915_sw_fence.o \
> +       i915_syncmap.o \
>         i915_sysfs.o \
>         intel_csr.o \
>         intel_device_info.o \
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index da6d2581cb0e..a93abb2274e6 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -32,6 +32,8 @@
>  #include "intel_drv.h"
>  #include "intel_guc_submission.h"
>  
> +#include "i915_reset.h"
> +
>  static inline struct drm_i915_private *node_to_i915(struct drm_info_node 
> *node)
>  {
>       return to_i915(node->minor->dev);
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index dafbbfadd1ad..f462a4d28af4 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -48,6 +48,7 @@
>  #include "i915_drv.h"
>  #include "i915_trace.h"
>  #include "i915_pmu.h"
> +#include "i915_reset.h"
>  #include "i915_query.h"
>  #include "i915_vgpu.h"
>  #include "intel_drv.h"
> @@ -2205,211 +2206,6 @@ static int i915_resume_switcheroo(struct drm_device 
> *dev)
>       return i915_drm_resume(dev);
>  }
>  
> -/**
> - * 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 = i915_gem_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;
> -     }
> -
> -     i915_gem_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:
> -     i915_gem_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 *dev_priv,
> -                                     struct intel_engine_cs *engine)
> -{
> -     return intel_gpu_reset(dev_priv, 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 = i915_gem_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.
> -      */
> -     i915_gem_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);
> -     i915_gem_reset_finish_engine(engine);
> -     return ret;
> -}
> -
>  static int i915_pm_prepare(struct device *kdev)
>  {
>       struct pci_dev *pdev = to_pci_dev(kdev);
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index fa99824f63b3..224d433ac7b6 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2611,19 +2611,7 @@ extern const struct dev_pm_ops i915_pm_ops;
>  extern int i915_driver_load(struct pci_dev *pdev,
>                           const struct pci_device_id *ent);
>  extern void i915_driver_unload(struct drm_device *dev);
> -extern int intel_gpu_reset(struct drm_i915_private *dev_priv, u32 
> engine_mask);
> -extern bool intel_has_gpu_reset(struct drm_i915_private *dev_priv);
> -
> -extern void i915_reset(struct drm_i915_private *i915,
> -                    unsigned int stalled_mask,
> -                    const char *reason);
> -extern int i915_reset_engine(struct intel_engine_cs *engine,
> -                          const char *reason);
> -
> -extern bool intel_has_reset_engine(struct drm_i915_private *dev_priv);
> -extern int intel_reset_guc(struct drm_i915_private *dev_priv);
> -extern int intel_guc_reset_engine(struct intel_guc *guc,
> -                               struct intel_engine_cs *engine);
> +
>  extern void intel_engine_init_hangcheck(struct intel_engine_cs *engine);
>  extern void intel_hangcheck_init(struct drm_i915_private *dev_priv);
>  extern unsigned long i915_chipset_val(struct drm_i915_private *dev_priv);
> @@ -2666,20 +2654,11 @@ static inline void i915_queue_hangcheck(struct 
> drm_i915_private *dev_priv)
>                          &dev_priv->gpu_error.hangcheck_work, delay);
>  }
>  
> -__printf(4, 5)
> -void i915_handle_error(struct drm_i915_private *dev_priv,
> -                    u32 engine_mask,
> -                    unsigned long flags,
> -                    const char *fmt, ...);
> -#define I915_ERROR_CAPTURE BIT(0)
> -
>  extern void intel_irq_init(struct drm_i915_private *dev_priv);
>  extern void intel_irq_fini(struct drm_i915_private *dev_priv);
>  int intel_irq_install(struct drm_i915_private *dev_priv);
>  void intel_irq_uninstall(struct drm_i915_private *dev_priv);
>  
> -void i915_clear_error_registers(struct drm_i915_private *dev_priv);
> -
>  static inline bool intel_gvt_active(struct drm_i915_private *dev_priv)
>  {
>       return dev_priv->gvt;
> @@ -3044,18 +3023,8 @@ static inline u32 i915_reset_engine_count(struct 
> i915_gpu_error *error,
>       return READ_ONCE(error->reset_engine_count[engine->id]);
>  }
>  
> -struct i915_request *
> -i915_gem_reset_prepare_engine(struct intel_engine_cs *engine);
> -int i915_gem_reset_prepare(struct drm_i915_private *dev_priv);
> -void i915_gem_reset(struct drm_i915_private *dev_priv,
> -                 unsigned int stalled_mask);
> -void i915_gem_reset_finish_engine(struct intel_engine_cs *engine);
> -void i915_gem_reset_finish(struct drm_i915_private *dev_priv);
>  void i915_gem_set_wedged(struct drm_i915_private *dev_priv);
>  bool i915_gem_unset_wedged(struct drm_i915_private *dev_priv);
> -void i915_gem_reset_engine(struct intel_engine_cs *engine,
> -                        struct i915_request *request,
> -                        bool stalled);
>  
>  void i915_gem_init_mmio(struct drm_i915_private *i915);
>  int __must_check i915_gem_init(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 910c49befc50..a7e0d61a45ea 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -27,15 +27,6 @@
>  
>  #include <drm/drm_vma_manager.h>
>  #include <drm/i915_drm.h>
> -#include "i915_drv.h"
> -#include "i915_gem_clflush.h"
> -#include "i915_vgpu.h"
> -#include "i915_trace.h"
> -#include "intel_drv.h"
> -#include "intel_frontbuffer.h"
> -#include "intel_mocs.h"
> -#include "intel_workarounds.h"
> -#include "i915_gemfs.h"
>  #include <linux/dma-fence-array.h>
>  #include <linux/kthread.h>
>  #include <linux/reservation.h>
> @@ -46,6 +37,18 @@
>  #include <linux/pci.h>
>  #include <linux/dma-buf.h>
>  
> +#include "i915_drv.h"
> +#include "i915_gem_clflush.h"
> +#include "i915_gemfs.h"
> +#include "i915_reset.h"
> +#include "i915_trace.h"
> +#include "i915_vgpu.h"
> +
> +#include "intel_drv.h"
> +#include "intel_frontbuffer.h"
> +#include "intel_mocs.h"
> +#include "intel_workarounds.h"
> +
>  static void i915_gem_flush_free_objects(struct drm_i915_private *i915);
>  
>  static bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj)
> @@ -2859,61 +2862,6 @@ i915_gem_object_pwrite_gtt(struct drm_i915_gem_object 
> *obj,
>       return 0;
>  }
>  
> -static void i915_gem_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 i915_gem_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))
> -             i915_gem_client_mark_guilty(ctx->file_priv, ctx);
> -}
> -
> -static void i915_gem_context_mark_innocent(struct i915_gem_context *ctx)
> -{
> -     atomic_inc(&ctx->active_count);
> -}
> -
>  struct i915_request *
>  i915_gem_find_active_request(struct intel_engine_cs *engine)
>  {
> @@ -2944,376 +2892,6 @@ i915_gem_find_active_request(struct intel_engine_cs 
> *engine)
>       return active;
>  }
>  
> -/*
> - * Ensure irq handler finishes, and not run again.
> - * Also return the active request so that we only search for it once.
> - */
> -struct i915_request *
> -i915_gem_reset_prepare_engine(struct intel_engine_cs *engine)
> -{
> -     struct i915_request *request;
> -
> -     /*
> -      * 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);
> -
> -     request = engine->reset.prepare(engine);
> -     if (request && request->fence.error == -EIO)
> -             request = ERR_PTR(-EIO); /* Previous reset failed! */
> -
> -     return request;
> -}
> -
> -int i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
> -{
> -     struct intel_engine_cs *engine;
> -     struct i915_request *request;
> -     enum intel_engine_id id;
> -     int err = 0;
> -
> -     for_each_engine(engine, dev_priv, id) {
> -             request = i915_gem_reset_prepare_engine(engine);
> -             if (IS_ERR(request)) {
> -                     err = PTR_ERR(request);
> -                     continue;
> -             }
> -
> -             engine->hangcheck.active_request = request;
> -     }
> -
> -     i915_gem_revoke_fences(dev_priv);
> -     intel_uc_sanitize(dev_priv);
> -
> -     return err;
> -}
> -
> -static void engine_skip_context(struct i915_request *request)
> -{
> -     struct intel_engine_cs *engine = request->engine;
> -     struct i915_gem_context *hung_ctx = request->gem_context;
> -     struct i915_timeline *timeline = request->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(request, &engine->timeline.requests, link)
> -             if (request->gem_context == hung_ctx)
> -                     i915_request_skip(request, -EIO);
> -
> -     list_for_each_entry(request, &timeline->requests, link)
> -             i915_request_skip(request, -EIO);
> -
> -     spin_unlock(&timeline->lock);
> -     spin_unlock_irqrestore(&engine->timeline.lock, flags);
> -}
> -
> -/* Returns the request if it was guilty of the hang */
> -static struct i915_request *
> -i915_gem_reset_request(struct intel_engine_cs *engine,
> -                    struct i915_request *request,
> -                    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(request)) {
> -             GEM_TRACE("%s pardoned global=%d (fence %llx:%lld), current 
> %d\n",
> -                       engine->name, request->global_seqno,
> -                       request->fence.context, request->fence.seqno,
> -                       intel_engine_get_seqno(engine));
> -             stalled = false;
> -     }
> -
> -     if (stalled) {
> -             i915_gem_context_mark_guilty(request->gem_context);
> -             i915_request_skip(request, -EIO);
> -
> -             /* If this context is now banned, skip all pending requests. */
> -             if (i915_gem_context_is_banned(request->gem_context))
> -                     engine_skip_context(request);
> -     } 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.
> -              */
> -             request = i915_gem_find_active_request(engine);
> -             if (request) {
> -                     unsigned long flags;
> -
> -                     i915_gem_context_mark_innocent(request->gem_context);
> -                     dma_fence_set_error(&request->fence, -EAGAIN);
> -
> -                     /* Rewind the engine to replay the incomplete rq */
> -                     spin_lock_irqsave(&engine->timeline.lock, flags);
> -                     request = list_prev_entry(request, link);
> -                     if (&request->link == &engine->timeline.requests)
> -                             request = NULL;
> -                     spin_unlock_irqrestore(&engine->timeline.lock, flags);
> -             }
> -     }
> -
> -     return request;
> -}
> -
> -void i915_gem_reset_engine(struct intel_engine_cs *engine,
> -                        struct i915_request *request,
> -                        bool stalled)
> -{
> -     if (request)
> -             request = i915_gem_reset_request(engine, request, stalled);
> -
> -     /* Setup the CS to resume from the breadcrumb of the hung request */
> -     engine->reset.reset(engine, request);
> -}
> -
> -void i915_gem_reset(struct drm_i915_private *dev_priv,
> -                 unsigned int stalled_mask)
> -{
> -     struct intel_engine_cs *engine;
> -     enum intel_engine_id id;
> -
> -     lockdep_assert_held(&dev_priv->drm.struct_mutex);
> -
> -     i915_retire_requests(dev_priv);
> -
> -     for_each_engine(engine, dev_priv, id) {
> -             struct intel_context *ce;
> -
> -             i915_gem_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,
> -                                             dev_priv->kernel_context);
> -                     if (!IS_ERR(rq))
> -                             i915_request_add(rq);
> -             }
> -     }
> -
> -     i915_gem_restore_fences(dev_priv);
> -}
> -
> -void i915_gem_reset_finish_engine(struct intel_engine_cs *engine)
> -{
> -     engine->reset.finish(engine);
> -
> -     intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
> -}
> -
> -void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
> -{
> -     struct intel_engine_cs *engine;
> -     enum intel_engine_id id;
> -
> -     lockdep_assert_held(&dev_priv->drm.struct_mutex);
> -
> -     for_each_engine(engine, dev_priv, id) {
> -             engine->hangcheck.active_request = NULL;
> -             i915_gem_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()) {
> -             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)
> -             i915_gem_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) {
> -             i915_gem_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;
> -}
> -
>  static void
>  i915_gem_retire_work_handler(struct work_struct *work)
>  {
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c 
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 74e6d02dcbbf..68e02e46186b 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -37,6 +37,7 @@
>  
>  #include "i915_drv.h"
>  #include "i915_vgpu.h"
> +#include "i915_reset.h"
>  #include "i915_trace.h"
>  #include "intel_drv.h"
>  #include "intel_frontbuffer.h"
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 94187e68d39a..1c6cf024a509 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -2930,46 +2930,6 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
>       return IRQ_HANDLED;
>  }
>  
> -struct wedge_me {
> -     struct delayed_work work;
> -     struct drm_i915_private *i915;
> -     const char *name;
> -};
> -
> -static void wedge_me(struct work_struct *work)
> -{
> -     struct 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);
> -}
> -
> -static void __init_wedge(struct 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, wedge_me);
> -     schedule_delayed_work(&w->work, timeout);
> -}
> -
> -static void __fini_wedge(struct wedge_me *w)
> -{
> -     cancel_delayed_work_sync(&w->work);
> -     destroy_delayed_work_on_stack(&w->work);
> -     w->i915 = NULL;
> -}
> -
> -#define i915_wedge_on_timeout(W, DEV, TIMEOUT)                               
> \
> -     for (__init_wedge((W), (DEV), (TIMEOUT), __func__);             \
> -          (W)->i915;                                                 \
> -          __fini_wedge((W)))
> -
>  static u32
>  gen11_gt_engine_identity(struct drm_i915_private * const i915,
>                        const unsigned int bank, const unsigned int bit)
> @@ -3180,204 +3140,6 @@ static irqreturn_t gen11_irq_handler(int irq, void 
> *arg)
>       return IRQ_HANDLED;
>  }
>  
> -static void i915_reset_device(struct drm_i915_private *dev_priv,
> -                           u32 engine_mask,
> -                           const char *reason)
> -{
> -     struct i915_gpu_error *error = &dev_priv->gpu_error;
> -     struct kobject *kobj = &dev_priv->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 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, dev_priv, 5*HZ) {
> -             intel_prepare_reset(dev_priv);
> -
> -             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(&dev_priv->drm.struct_mutex)) {
> -                             i915_reset(dev_priv, engine_mask, reason);
> -                             mutex_unlock(&dev_priv->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(dev_priv);
> -     }
> -
> -     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
> - * @dev_priv: 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 *dev_priv,
> -                    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(dev_priv);
> -
> -     engine_mask &= INTEL_INFO(dev_priv)->ring_mask;
> -
> -     if (flags & I915_ERROR_CAPTURE) {
> -             i915_capture_error_state(dev_priv, engine_mask, msg);
> -             i915_clear_error_registers(dev_priv);
> -     }
> -
> -     /*
> -      * Try engine reset when available. We fall back to full reset if
> -      * single reset fails.
> -      */
> -     if (intel_has_reset_engine(dev_priv) &&
> -         !i915_terminally_wedged(&dev_priv->gpu_error)) {
> -             for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
> -                     BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
> -                     if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
> -                                          &dev_priv->gpu_error.flags))
> -                             continue;
> -
> -                     if (i915_reset_engine(engine, msg) == 0)
> -                             engine_mask &= ~intel_engine_flag(engine);
> -
> -                     clear_bit(I915_RESET_ENGINE + engine->id,
> -                               &dev_priv->gpu_error.flags);
> -                     wake_up_bit(&dev_priv->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, &dev_priv->gpu_error.flags)) {
> -             wait_event(dev_priv->gpu_error.reset_queue,
> -                        !test_bit(I915_RESET_BACKOFF,
> -                                  &dev_priv->gpu_error.flags));
> -             goto out;
> -     }
> -
> -     /* Prevent any other reset-engine attempt. */
> -     for_each_engine(engine, dev_priv, tmp) {
> -             while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
> -                                     &dev_priv->gpu_error.flags))
> -                     wait_on_bit(&dev_priv->gpu_error.flags,
> -                                 I915_RESET_ENGINE + engine->id,
> -                                 TASK_UNINTERRUPTIBLE);
> -     }
> -
> -     i915_reset_device(dev_priv, engine_mask, msg);
> -
> -     for_each_engine(engine, dev_priv, tmp) {
> -             clear_bit(I915_RESET_ENGINE + engine->id,
> -                       &dev_priv->gpu_error.flags);
> -     }
> -
> -     clear_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags);
> -     wake_up_all(&dev_priv->gpu_error.reset_queue);
> -
> -out:
> -     intel_runtime_pm_put(dev_priv, wakeref);
> -}
> -
>  /* Called from drm generic code, passed 'crtc' which
>   * we use as a pipe index
>   */
> diff --git a/drivers/gpu/drm/i915/i915_request.c 
> b/drivers/gpu/drm/i915/i915_request.c
> index d1355154886a..5403d4e2cee0 100644
> --- a/drivers/gpu/drm/i915/i915_request.c
> +++ b/drivers/gpu/drm/i915/i915_request.c
> @@ -29,6 +29,7 @@
>  #include <linux/sched/signal.h>
>  
>  #include "i915_drv.h"
> +#include "i915_reset.h"
>  
>  static const char *i915_fence_get_driver_name(struct dma_fence *fence)
>  {
> diff --git a/drivers/gpu/drm/i915/i915_reset.c 
> b/drivers/gpu/drm/i915/i915_reset.c
> new file mode 100644
> index 000000000000..e2e40b44a9a8
> --- /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()) {
> +             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;
> +}
> diff --git a/drivers/gpu/drm/i915/i915_reset.h 
> b/drivers/gpu/drm/i915/i915_reset.h
> new file mode 100644
> index 000000000000..b6a519bde67d
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/i915_reset.h
> @@ -0,0 +1,56 @@
> +/*
> + * SPDX-License-Identifier: MIT
> + *
> + * Copyright © 2008-2018 Intel Corporation
> + */
> +
> +#ifndef I915_RESET_H
> +#define I915_RESET_H
> +
> +#include <linux/compiler.h>
> +#include <linux/types.h>
> +
> +struct drm_i915_private;
> +struct intel_engine_cs;
> +struct intel_guc;
> +
> +__printf(4, 5)
> +void i915_handle_error(struct drm_i915_private *i915,
> +                    u32 engine_mask,
> +                    unsigned long flags,
> +                    const char *fmt, ...);
> +#define I915_ERROR_CAPTURE BIT(0)
> +
> +void i915_clear_error_registers(struct drm_i915_private *i915);
> +
> +void i915_reset(struct drm_i915_private *i915,
> +             unsigned int stalled_mask,
> +             const char *reason);
> +int i915_reset_engine(struct intel_engine_cs *engine,
> +                   const char *reason);
> +
> +bool intel_has_gpu_reset(struct drm_i915_private *i915);
> +bool intel_has_reset_engine(struct drm_i915_private *i915);
> +
> +int intel_gpu_reset(struct drm_i915_private *i915, u32 engine_mask);
> +
> +int intel_reset_guc(struct drm_i915_private *i915);
> +
> +struct i915_wedge_me {
> +     struct delayed_work work;
> +     struct drm_i915_private *i915;
> +     const char *name;
> +};
> +
> +void __i915_init_wedge(struct i915_wedge_me *w,
> +                    struct drm_i915_private *i915,
> +                    long timeout,
> +                    const char *name);
> +void __i915_fini_wedge(struct i915_wedge_me *w);
> +
> +#define i915_wedge_on_timeout(W, DEV, TIMEOUT)                               
> \
> +     for (__i915_init_wedge((W), (DEV), (TIMEOUT), __func__);        \
> +          (W)->i915;                                                 \
> +          __i915_fini_wedge((W)))
> +
> +#endif /* I915_RESET_H */
> diff --git a/drivers/gpu/drm/i915/intel_display.c 
> b/drivers/gpu/drm/i915/intel_display.c
> index 64dbd06f4ffb..fbe3c3a3b675 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -31,13 +31,7 @@
>  #include <linux/slab.h>
>  #include <linux/vgaarb.h>
>  #include <drm/drm_edid.h>
> -#include "intel_drv.h"
> -#include "intel_frontbuffer.h"
>  #include <drm/i915_drm.h>
> -#include "i915_drv.h"
> -#include "i915_gem_clflush.h"
> -#include "intel_dsi.h"
> -#include "i915_trace.h"
>  #include <drm/drm_atomic.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_dp_helper.h>
> @@ -48,6 +42,15 @@
>  #include <linux/intel-iommu.h>
>  #include <linux/reservation.h>
>  
> +#include "intel_drv.h"
> +#include "intel_dsi.h"
> +#include "intel_frontbuffer.h"
> +
> +#include "i915_drv.h"
> +#include "i915_gem_clflush.h"
> +#include "i915_reset.h"
> +#include "i915_trace.h"
> +
>  /* Primary plane formats for gen <= 3 */
>  static const uint32_t i8xx_primary_formats[] = {
>       DRM_FORMAT_C8,
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c 
> b/drivers/gpu/drm/i915/intel_engine_cs.c
> index bf4dae2649ab..9c943bb95cb9 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -25,6 +25,7 @@
>  #include <drm/drm_print.h>
>  
>  #include "i915_drv.h"
> +#include "i915_reset.h"
>  #include "intel_ringbuffer.h"
>  #include "intel_lrc.h"
>  
> diff --git a/drivers/gpu/drm/i915/intel_guc.h 
> b/drivers/gpu/drm/i915/intel_guc.h
> index 0f1c4f9ebfd8..744220296653 100644
> --- a/drivers/gpu/drm/i915/intel_guc.h
> +++ b/drivers/gpu/drm/i915/intel_guc.h
> @@ -192,4 +192,7 @@ static inline void intel_guc_disable_msg(struct intel_guc 
> *guc, u32 mask)
>       spin_unlock_irq(&guc->irq_lock);
>  }
>  
> +int intel_guc_reset_engine(struct intel_guc *guc,
> +                        struct intel_engine_cs *engine);
> +
>  #endif
> diff --git a/drivers/gpu/drm/i915/intel_hangcheck.c 
> b/drivers/gpu/drm/i915/intel_hangcheck.c
> index 51e9efec5116..7dc11fcb13de 100644
> --- a/drivers/gpu/drm/i915/intel_hangcheck.c
> +++ b/drivers/gpu/drm/i915/intel_hangcheck.c
> @@ -23,6 +23,7 @@
>   */
>  
>  #include "i915_drv.h"
> +#include "i915_reset.h"
>  
>  static bool instdone_unchanged(u32 current_instdone, u32 *old_instdone)
>  {
> diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
> index 731b82afe636..e711eb3268bc 100644
> --- a/drivers/gpu/drm/i915/intel_uc.c
> +++ b/drivers/gpu/drm/i915/intel_uc.c
> @@ -26,6 +26,7 @@
>  #include "intel_guc_submission.h"
>  #include "intel_guc.h"
>  #include "i915_drv.h"
> +#include "i915_reset.h"
>  
>  static void guc_free_load_err_log(struct intel_guc *guc);
>  
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c 
> b/drivers/gpu/drm/i915/intel_uncore.c
> index 681ea532585e..e88f0252d77e 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -1715,372 +1715,6 @@ int i915_reg_read_ioctl(struct drm_device *dev,
>       return ret;
>  }
>  
> -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 *dev_priv,
> -                           unsigned int engine_mask)
> -{
> -     struct intel_engine_cs *engine;
> -     enum intel_engine_id id;
> -
> -     if (INTEL_GEN(dev_priv) < 3)
> -             return;
> -
> -     for_each_engine_masked(engine, dev_priv, 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 *dev_priv,
> -                      unsigned int engine_mask,
> -                      unsigned int retry)
> -{
> -     struct pci_dev *pdev = dev_priv->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 *dev_priv,
> -                     unsigned int engine_mask,
> -                     unsigned int retry)
> -{
> -     struct pci_dev *pdev = dev_priv->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
> -      */
> -     __raw_i915_write32(dev_priv, 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;
> -}
> -
> -/**
> - * gen6_reset_engines - reset individual engines
> - * @dev_priv: i915 device
> - * @engine_mask: mask of intel_ring_flag() engines or ALL_ENGINES for full 
> reset
> - * @retry: the count of of previous attempts to reset.
> - *
> - * This function will reset the individual engines that are set in 
> engine_mask.
> - * If you provide ALL_ENGINES as mask, full global domain reset will be 
> issued.
> - *
> - * Note: It is responsibility of the caller to handle the difference between
> - * asking full domain reset versus reset for all available individual 
> engines.
> - *
> - * Returns 0 on success, nonzero on error.
> - */
> -static int gen6_reset_engines(struct drm_i915_private *dev_priv,
> -                           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, dev_priv, engine_mask, tmp)
> -                     hw_mask |= hw_engine_mask[engine->id];
> -     }
> -
> -     return gen6_hw_domain_reset(dev_priv, 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);
> -}
> -
> -/**
> - * gen11_reset_engines - reset individual engines
> - * @dev_priv: i915 device
> - * @engine_mask: mask of intel_ring_flag() engines or ALL_ENGINES for full 
> reset
> - *
> - * This function will reset the individual engines that are set in 
> engine_mask.
> - * If you provide ALL_ENGINES as mask, full global domain reset will be 
> issued.
> - *
> - * Note: It is responsibility of the caller to handle the difference between
> - * asking full domain reset versus reset for all available individual 
> engines.
> - *
> - * Returns 0 on success, nonzero on error.
> - */
> -static int gen11_reset_engines(struct drm_i915_private *dev_priv,
> -                            unsigned int engine_mask)
> -{
> -     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, dev_priv, engine_mask, tmp) {
> -                     hw_mask |= hw_engine_mask[engine->id];
> -                     hw_mask |= gen11_lock_sfc(dev_priv, engine);
> -             }
> -     }
> -
> -     ret = gen6_hw_domain_reset(dev_priv, hw_mask);
> -
> -     if (engine_mask != ALL_ENGINES)
> -             for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
> -                     gen11_unlock_sfc(dev_priv, engine);
> -
> -     return ret;
> -}
> -
>  /**
>   * __intel_wait_for_register_fw - wait until register matches expected state
>   * @dev_priv: the i915 device
> @@ -2191,196 +1825,6 @@ int __intel_wait_for_register(struct drm_i915_private 
> *dev_priv,
>       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 reset_engines(struct drm_i915_private *i915,
> -                      unsigned int engine_mask,
> -                      unsigned int retry)
> -{
> -     if (INTEL_GEN(i915) >= 11)
> -             return gen11_reset_engines(i915, engine_mask);
> -     else
> -             return gen6_reset_engines(i915, engine_mask, retry);
> -}
> -
> -static int gen8_reset_engines(struct drm_i915_private *dev_priv,
> -                           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, dev_priv, 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.
> -              */
> -     }
> -
> -     ret = reset_engines(dev_priv, engine_mask, retry);
> -
> -skip_reset:
> -     for_each_engine_masked(engine, dev_priv, 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 *dev_priv)
> -{
> -     if (!i915_modparams.reset)
> -             return NULL;
> -
> -     if (INTEL_GEN(dev_priv) >= 8)
> -             return gen8_reset_engines;
> -     else if (INTEL_GEN(dev_priv) >= 6)
> -             return gen6_reset_engines;
> -     else if (IS_GEN(dev_priv, 5))
> -             return ironlake_do_reset;
> -     else if (IS_G4X(dev_priv))
> -             return g4x_do_reset;
> -     else if (IS_G33(dev_priv) || IS_PINEVIEW(dev_priv))
> -             return g33_do_reset;
> -     else if (INTEL_GEN(dev_priv) >= 3)
> -             return i915_do_reset;
> -     else
> -             return NULL;
> -}
> -
> -int intel_gpu_reset(struct drm_i915_private *dev_priv,
> -                 const unsigned int engine_mask)
> -{
> -     reset_func reset = intel_get_gpu_reset(dev_priv);
> -     unsigned int retry;
> -     int ret;
> -
> -     GEM_BUG_ON(!engine_mask);
> -
> -     /*
> -      * 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(dev_priv, 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(dev_priv, engine_mask);
> -
> -             ret = -ENODEV;
> -             if (reset) {
> -                     ret = reset(dev_priv, engine_mask, retry);
> -                     GEM_TRACE("engine_mask=%x, ret=%d, retry=%d\n",
> -                               engine_mask, ret, retry);
> -             }
> -             if (ret != -ETIMEDOUT || engine_mask != ALL_ENGINES)
> -                     break;
> -
> -             cond_resched();
> -     }
> -     intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
> -
> -     return ret;
> -}
> -
> -bool intel_has_gpu_reset(struct drm_i915_private *dev_priv)
> -{
> -     return intel_get_gpu_reset(dev_priv) != NULL;
> -}
> -
> -bool intel_has_reset_engine(struct drm_i915_private *dev_priv)
> -{
> -     return (INTEL_INFO(dev_priv)->has_reset_engine &&
> -             i915_modparams.reset >= 2);
> -}
> -
> -int intel_reset_guc(struct drm_i915_private *dev_priv)
> -{
> -     u32 guc_domain = INTEL_GEN(dev_priv) >= 11 ? GEN11_GRDOM_GUC :
> -                                                  GEN9_GRDOM_GUC;
> -     int ret;
> -
> -     GEM_BUG_ON(!HAS_GUC(dev_priv));
> -
> -     intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
> -     ret = gen6_hw_domain_reset(dev_priv, guc_domain);
> -     intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
> -
> -     return ret;
> -}
> -
>  bool intel_uncore_unclaimed_mmio(struct drm_i915_private *dev_priv)
>  {
>       return check_for_unclaimed_mmio(dev_priv);
> diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c 
> b/drivers/gpu/drm/i915/selftests/intel_lrc.c
> index e6073cd4719c..2b2ecd76c2ac 100644
> --- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
> @@ -4,6 +4,8 @@
>   * Copyright © 2018 Intel Corporation
>   */
>  
> +#include "../i915_reset.h"
> +
>  #include "../i915_selftest.h"
>  #include "igt_flush_test.h"
>  #include "igt_spinner.h"
> diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c 
> b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
> index 9009d7b8b136..a8cac56be835 100644
> --- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
> @@ -5,6 +5,7 @@
>   */
>  
>  #include "../i915_selftest.h"
> +#include "../i915_reset.h"
>  
>  #include "igt_flush_test.h"
>  #include "igt_reset.h"
> -- 
> 2.20.1
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