[Intel-gfx] [PATCH v2 03/11] drm/i915: Update reset path to fix incomplete requests

Arun Siluvery arun.siluvery at linux.intel.com
Fri Aug 5 16:29:59 UTC 2016


From: Chris Wilson <chris at chris-wilson.co.uk>

Update reset path in preparation for engine reset which requires
identification of incomplete requests and associated context and fixing
their state so that engine can resume correctly after reset.

The request that caused the hang will be skipped and head is reset to the
start of breadcrumb. This allows us to resume from where we left-off.
Since this request didn't complete normally we also need to cleanup elsp
queue manually.

Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Cc: Arun Siluvery <arun.siluvery at linux.intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.c         |  4 +-
 drivers/gpu/drm/i915/i915_drv.h         |  2 +-
 drivers/gpu/drm/i915/i915_gem.c         | 68 ++++++++++++++++++++++-----------
 drivers/gpu/drm/i915/i915_gem_context.c | 16 --------
 drivers/gpu/drm/i915/intel_lrc.c        | 34 ++++++++++++++++-
 drivers/gpu/drm/i915/intel_ringbuffer.c | 32 ++++++++++------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  2 +
 7 files changed, 104 insertions(+), 54 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8cfc264..09f7372 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1578,7 +1578,7 @@ static int i915_drm_resume(struct drm_device *dev)
 	mutex_lock(&dev->struct_mutex);
 	if (i915_gem_init_hw(dev)) {
 		DRM_ERROR("failed to re-initialize GPU, declaring wedged!\n");
-		atomic_or(I915_WEDGED, &dev_priv->gpu_error.reset_counter);
+		i915_gem_set_wedged(dev_priv);
 	}
 	mutex_unlock(&dev->struct_mutex);
 
@@ -1802,7 +1802,7 @@ int i915_reset(struct drm_i915_private *dev_priv)
 	return 0;
 
 error:
-	atomic_or(I915_WEDGED, &error->reset_counter);
+	i915_gem_set_wedged(dev_priv);
 	mutex_unlock(&dev->struct_mutex);
 	return ret;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 040c3b6..fa1b6e6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3245,6 +3245,7 @@ static inline u32 i915_reset_count(struct i915_gpu_error *error)
 }
 
 void i915_gem_reset(struct drm_device *dev);
+void i915_gem_set_wedged(struct drm_i915_private *dev_priv);
 bool i915_gem_clflush_object(struct drm_i915_gem_object *obj, bool force);
 int __must_check i915_gem_init(struct drm_device *dev);
 int __must_check i915_gem_init_hw(struct drm_device *dev);
@@ -3364,7 +3365,6 @@ void i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj);
 int __must_check i915_gem_context_init(struct drm_device *dev);
 void i915_gem_context_lost(struct drm_i915_private *dev_priv);
 void i915_gem_context_fini(struct drm_device *dev);
-void i915_gem_context_reset(struct drm_device *dev);
 int i915_gem_context_open(struct drm_device *dev, struct drm_file *file);
 void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
 int i915_switch_context(struct drm_i915_gem_request *req);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 19715f5..d4bcf88 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2402,23 +2402,61 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
 	return NULL;
 }
 
-static void i915_gem_reset_engine_status(struct intel_engine_cs *engine)
+static void i915_gem_reset_engine(struct intel_engine_cs *engine)
 {
 	struct drm_i915_gem_request *request;
+	struct i915_gem_context *incomplete_ctx;
 	bool ring_hung;
 
+	/* Ensure irq handler finishes or is cancelled. */
+	if (i915.enable_execlists)
+		tasklet_kill(&engine->irq_tasklet);
+
 	request = i915_gem_find_active_request(engine);
-	if (request == NULL)
+	if (!request)
 		return;
 
 	ring_hung = engine->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG;
 
 	i915_set_reset_status(request->ctx, ring_hung);
-	list_for_each_entry_continue(request, &engine->request_list, link)
+
+	engine->reset_hw(engine, request);
+
+	incomplete_ctx = request->ctx;
+	if (i915_gem_context_is_default(incomplete_ctx))
+		incomplete_ctx = NULL;
+
+	list_for_each_entry_continue(request, &engine->request_list, link) {
+		void *vaddr = request->ring->vaddr;
+		u32 head;
+
+		if (request->ctx != incomplete_ctx)
+			continue;
+
+		head = request->head;
+		if (request->postfix < head) {
+			memset(vaddr + head, 0, request->ring->size - head);
+			head = 0;
+		}
+		memset(vaddr + head, 0, request->postfix - head);
+
 		i915_set_reset_status(request->ctx, false);
+	}
 }
 
-static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
+void i915_gem_reset(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct intel_engine_cs *engine;
+
+	for_each_engine(engine, dev_priv)
+		i915_gem_reset_engine(engine);
+
+	i915_gem_context_lost(dev_priv);
+	i915_gem_restore_fences(dev);
+}
+
+static void i915_gem_cleanup_engine(struct intel_engine_cs *engine)
 {
 	struct drm_i915_gem_request *request;
 	struct intel_ring *ring;
@@ -2440,9 +2478,6 @@ static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
 	 */
 
 	if (i915.enable_execlists) {
-		/* Ensure irq handler finishes or is cancelled. */
-		tasklet_kill(&engine->irq_tasklet);
-
 		INIT_LIST_HEAD(&engine->execlist_queue);
 		i915_gem_request_assign(&engine->execlist_port[0].request,
 					NULL);
@@ -2476,26 +2511,15 @@ static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
 	engine->i915->gt.active_engines &= ~intel_engine_flag(engine);
 }
 
-void i915_gem_reset(struct drm_device *dev)
+void i915_gem_set_wedged(struct drm_i915_private *dev_priv)
 {
-	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine;
 
-	/*
-	 * Before we free the objects from the requests, we need to inspect
-	 * them for finding the guilty party. As the requests only borrow
-	 * their reference to the objects, the inspection must be done first.
-	 */
-	for_each_engine(engine, dev_priv)
-		i915_gem_reset_engine_status(engine);
+	atomic_or(I915_WEDGED, &dev_priv->gpu_error.reset_counter);
 
 	for_each_engine(engine, dev_priv)
-		i915_gem_reset_engine_cleanup(engine);
+		i915_gem_cleanup_engine(engine);
 	mod_delayed_work(dev_priv->wq, &dev_priv->gt.idle_work, 0);
-
-	i915_gem_context_reset(dev);
-
-	i915_gem_restore_fences(dev);
 }
 
 static void
@@ -4356,7 +4380,7 @@ int i915_gem_init(struct drm_device *dev)
 		 * for all other failure, such as an allocation failure, bail.
 		 */
 		DRM_ERROR("Failed to initialize GPU, declaring it wedged\n");
-		atomic_or(I915_WEDGED, &dev_priv->gpu_error.reset_counter);
+		i915_gem_set_wedged(dev_priv);
 		ret = 0;
 	}
 
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index bb72af5..a5b3ba4 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -405,22 +405,6 @@ static void i915_gem_context_unpin(struct i915_gem_context *ctx,
 	}
 }
 
-void i915_gem_context_reset(struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = to_i915(dev);
-
-	lockdep_assert_held(&dev->struct_mutex);
-
-	if (i915.enable_execlists) {
-		struct i915_gem_context *ctx;
-
-		list_for_each_entry(ctx, &dev_priv->context_list, link)
-			intel_lr_context_reset(dev_priv, ctx);
-	}
-
-	i915_gem_context_lost(dev_priv);
-}
-
 int i915_gem_context_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index e376ed3..efd3773 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1171,6 +1171,7 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
 
+	intel_mocs_init_engine(engine);
 	lrc_init_hws(engine);
 
 	I915_WRITE_IMR(engine,
@@ -1186,7 +1187,10 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
 
 	intel_engine_init_hangcheck(engine);
 
-	return intel_mocs_init_engine(engine);
+	if (engine->execlist_port[0].request)
+		execlists_submit_ports(engine);
+
+	return 0;
 }
 
 static int gen8_init_render_ring(struct intel_engine_cs *engine)
@@ -1222,6 +1226,33 @@ static int gen9_init_render_ring(struct intel_engine_cs *engine)
 	return init_workarounds_ring(engine);
 }
 
+static void reset_common_ring(struct intel_engine_cs *engine,
+			      struct drm_i915_gem_request *request)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+	struct i915_gem_context *ctx = request->ctx;
+	struct intel_context *ce = &ctx->engine[engine->id];
+	u32 *reg_state;
+
+	reg_state = ce->lrc_reg_state;
+	reg_state[CTX_RING_HEAD+1] = request->postfix;
+
+	request->ring->head = request->postfix;
+	request->ring->last_retired_head = -1;
+	intel_ring_update_space(request->ring);
+
+	if (request == engine->execlist_port[1].request) {
+		i915_gem_request_put(engine->execlist_port[0].request);
+		engine->execlist_port[0] = engine->execlist_port[1];
+		memset(&engine->execlist_port[1], 0,
+		       sizeof(engine->execlist_port[1]));
+	}
+
+	engine->execlist_port[0].count = 0;
+
+	I915_WRITE(RING_CONTEXT_STATUS_PTR(engine), _MASKED_FIELD(0xffff, 0));
+}
+
 static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req)
 {
 	struct i915_hw_ppgtt *ppgtt = req->ctx->ppgtt;
@@ -1586,6 +1617,7 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 {
 	/* Default vfuncs which can be overriden by each engine. */
 	engine->init_hw = gen8_init_common_ring;
+	engine->reset_hw = reset_common_ring;
 	engine->emit_flush = gen8_emit_flush;
 	engine->emit_request = gen8_emit_request;
 	engine->submit_request = execlists_submit_request;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index e08a1e1..cd60e15 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -577,34 +577,31 @@ static int init_ring_common(struct intel_engine_cs *engine)
 	if (I915_READ_HEAD(engine))
 		DRM_DEBUG("%s initialization failed [head=%08x], fudging\n",
 			  engine->name, I915_READ_HEAD(engine));
-	I915_WRITE_HEAD(engine, 0);
-	(void)I915_READ_HEAD(engine);
+	I915_WRITE_HEAD(engine, ring->head);
+	I915_WRITE_TAIL(engine, ring->tail);
+	(void)I915_READ_TAIL(engine);
 
 	I915_WRITE_CTL(engine,
 			((ring->size - PAGE_SIZE) & RING_NR_PAGES)
 			| RING_VALID);
 
 	/* If the head is still not zero, the ring is dead */
-	if (wait_for((I915_READ_CTL(engine) & RING_VALID) != 0 &&
-		     I915_READ_START(engine) == i915_gem_obj_ggtt_offset(obj) &&
-		     (I915_READ_HEAD(engine) & HEAD_ADDR) == 0, 50)) {
+	if (intel_wait_for_register_fw(dev_priv, RING_CTL(engine->mmio_base),
+				       RING_VALID, RING_VALID,
+				       50)) {
 		DRM_ERROR("%s initialization failed "
-			  "ctl %08x (valid? %d) head %08x tail %08x start %08x [expected %08lx]\n",
+			  "ctl %08x (valid? %d) head %08x [%08x] tail %08x [%08x] start %08x [expected %08lx]\n",
 			  engine->name,
 			  I915_READ_CTL(engine),
 			  I915_READ_CTL(engine) & RING_VALID,
-			  I915_READ_HEAD(engine), I915_READ_TAIL(engine),
+			  I915_READ_HEAD(engine), ring->head,
+			  I915_READ_TAIL(engine), ring->tail,
 			  I915_READ_START(engine),
 			  (unsigned long)i915_gem_obj_ggtt_offset(obj));
 		ret = -EIO;
 		goto out;
 	}
 
-	ring->last_retired_head = -1;
-	ring->head = I915_READ_HEAD(engine);
-	ring->tail = I915_READ_TAIL(engine) & TAIL_ADDR;
-	intel_ring_update_space(ring);
-
 	intel_engine_init_hangcheck(engine);
 
 out:
@@ -613,6 +610,16 @@ out:
 	return ret;
 }
 
+static void reset_ring_common(struct intel_engine_cs *engine,
+			      struct drm_i915_gem_request *request)
+{
+	struct intel_ring *ring = request->ring;
+
+	ring->head = request->postfix;
+	ring->last_retired_head = -1;
+	intel_ring_update_space(ring);
+}
+
 void intel_fini_pipe_control(struct intel_engine_cs *engine)
 {
 	if (engine->scratch.obj == NULL)
@@ -2748,6 +2755,7 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 	intel_ring_init_semaphores(dev_priv, engine);
 
 	engine->init_hw = init_ring_common;
+	engine->reset_hw = reset_ring_common;
 
 	engine->emit_request = i9xx_emit_request;
 	if (i915.semaphores)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index de3cec8..789e04d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -204,6 +204,8 @@ struct intel_engine_cs {
 	void		(*irq_disable)(struct intel_engine_cs *engine);
 
 	int		(*init_hw)(struct intel_engine_cs *engine);
+	void		(*reset_hw)(struct intel_engine_cs *engine,
+				    struct drm_i915_gem_request *req);
 
 	int		(*init_context)(struct drm_i915_gem_request *req);
 
-- 
1.9.1



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