[Intel-gfx] [PATCH 2/3] drm/i915: Split GEM resetting into 3 phases

[Chris Wilson]

Currently we do a reset prepare/finish around the call to reset the GPU,
but it looks like we need a later stage after the hw has been
reinitialised to allow GEM to restart itself. Start by splitting the 2
GEM phases into 3:

  prepare - before the reset, check if GEM recovered, then stop GEM

  reset - after the reset, update GEM bookkeeping

  finish - after the re-initialisation following the reset, restart GEM

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c |  3 ++-
 drivers/gpu/drm/i915/i915_drv.h |  1 +
 drivers/gpu/drm/i915/i915_gem.c | 11 ++++++++---
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index acbd772837b5..0aa4ac2b43ca 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1836,7 +1836,7 @@ void i915_reset(struct drm_i915_private *dev_priv)
 		goto error;
 	}
 
-	i915_gem_reset_finish(dev_priv);
+	i915_gem_reset(dev_priv);
 	intel_overlay_reset(dev_priv);
 
 	/* Ok, now get things going again... */
@@ -1859,6 +1859,7 @@ void i915_reset(struct drm_i915_private *dev_priv)
 		goto error;
 	}
 
+	i915_gem_reset_finish(dev_priv);
 	i915_queue_hangcheck(dev_priv);
 
 wakeup:
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0cbd289da4ba..972d35259883 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3353,6 +3353,7 @@ static inline u32 i915_reset_count(struct i915_gpu_error *error)
 }
 
 int i915_gem_reset_prepare(struct drm_i915_private *dev_priv);
+void i915_gem_reset(struct drm_i915_private *dev_priv);
 void i915_gem_reset_finish(struct drm_i915_private *dev_priv);
 void i915_gem_set_wedged(struct drm_i915_private *dev_priv);
 void i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 17bcec9f1321..e125c0d61ce9 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2760,7 +2760,7 @@ static void i915_gem_reset_engine(struct intel_engine_cs *engine)
 		engine_skip_context(request);
 }
 
-void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
+void i915_gem_reset(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
@@ -2772,8 +2772,6 @@ void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
 	for_each_engine(engine, dev_priv, id)
 		i915_gem_reset_engine(engine);
 
-	i915_gem_restore_fences(dev_priv);
-
 	if (dev_priv->gt.awake) {
 		intel_sanitize_gt_powersave(dev_priv);
 		intel_enable_gt_powersave(dev_priv);
@@ -2782,6 +2780,13 @@ void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
 	}
 }
 
+void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
+{
+	lockdep_assert_held(&dev_priv->drm.struct_mutex);
+
+	i915_gem_restore_fences(dev_priv);
+}
+
 static void nop_submit_request(struct drm_i915_gem_request *request)
 {
 	dma_fence_set_error(&request->fence, -EIO);
-- 
2.11.0