[Intel-gfx] [PATCH 45/49] drm/i915: Record the position of the start of the request

[Chris Wilson]

Not only does it make for good documentation and debugging aide, but it
is also vital for when we want to unwind requests - such as when
throwing away an incomplete request.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c         | 12 +++++++----
 drivers/gpu/drm/i915/i915_gem_context.c |  9 +--------
 drivers/gpu/drm/i915/intel_lrc.c        | 36 +--------------------------------
 drivers/gpu/drm/i915/intel_lrc.h        |  2 --
 drivers/gpu/drm/i915/intel_ringbuffer.c |  1 +
 5 files changed, 11 insertions(+), 49 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5fef69b2ce9f..706ec143ff1b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2406,7 +2406,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 	struct drm_i915_gem_request *request;
 	struct intel_ringbuffer *ringbuf;
-	u32 request_start;
 	int ret;
 
 	request = ring->outstanding_lazy_request;
@@ -2421,7 +2420,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 	} else
 		ringbuf = ring->buffer;
 
-	request_start = intel_ring_get_tail(ringbuf);
 	/*
 	 * Emit any outstanding flushes - execbuf can fail to emit the flush
 	 * after having emitted the batchbuffer command. Hence we need to fix
@@ -2449,7 +2447,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 			return ret;
 	}
 
-	request->head = request_start;
 	request->tail = intel_ring_get_tail(ringbuf);
 
 	/* Whilst this request exists, batch_obj will be on the
@@ -2658,7 +2655,14 @@ static void i915_gem_reset_ring_cleanup(struct drm_i915_private *dev_priv,
 	}
 
 	/* This may not have been flushed before the reset, so clean it now */
-	i915_gem_request_assign(&ring->outstanding_lazy_request, NULL);
+	if (ring->outstanding_lazy_request) {
+		struct drm_i915_gem_request *request;
+
+		request = ring->outstanding_lazy_request;
+		request->ringbuf->tail = request->head;
+
+		i915_gem_request_assign(&ring->outstanding_lazy_request, NULL);
+	}
 }
 
 void i915_gem_restore_fences(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index b9c6b0ad1d0f..43e58249235b 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -298,15 +298,8 @@ void i915_gem_context_reset(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int i;
 
-	if (i915.enable_execlists) {
-		struct intel_context *ctx;
-
-		list_for_each_entry(ctx, &dev_priv->context_list, link) {
-			intel_lr_context_reset(dev, ctx);
-		}
-
+	if (i915.enable_execlists)
 		return;
-	}
 
 	for (i = 0; i < I915_NUM_RINGS; i++) {
 		struct intel_engine_cs *ring = &dev_priv->ring[i];
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 8fa44c3e8c3c..f4535832cf53 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -768,6 +768,7 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 	request->ctx = ctx;
 	i915_gem_context_reference(request->ctx);
 	request->ringbuf = ctx->engine[ring->id].ringbuf;
+	request->head = intel_ring_get_tail(request->ringbuf);
 
 	ring->outstanding_lazy_request = request;
 	return 0;
@@ -1813,38 +1814,3 @@ error_unpin_ctx:
 	drm_gem_object_unreference(&ctx_obj->base);
 	return ret;
 }
-
-void intel_lr_context_reset(struct drm_device *dev,
-			    struct intel_context *ctx)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_engine_cs *ring;
-	int i;
-
-	for_each_ring(ring, dev_priv, i) {
-		struct drm_i915_gem_object *ctx_obj =
-				ctx->engine[ring->id].state;
-		struct intel_ringbuffer *ringbuf =
-				ctx->engine[ring->id].ringbuf;
-		uint32_t *reg_state;
-		struct page *page;
-
-		if (!ctx_obj)
-			continue;
-
-		if (i915_gem_object_get_pages(ctx_obj)) {
-			WARN(1, "Failed get_pages for context obj\n");
-			continue;
-		}
-		page = i915_gem_object_get_page(ctx_obj, 1);
-		reg_state = kmap_atomic(page);
-
-		reg_state[CTX_RING_HEAD+1] = 0;
-		reg_state[CTX_RING_TAIL+1] = 0;
-
-		kunmap_atomic(reg_state);
-
-		ringbuf->head = 0;
-		ringbuf->tail = 0;
-	}
-}
diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index 03e69c8636b0..b276e00773d9 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -71,8 +71,6 @@ int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf,
 void intel_lr_context_free(struct intel_context *ctx);
 int intel_lr_context_deferred_create(struct intel_context *ctx,
 				     struct intel_engine_cs *ring);
-void intel_lr_context_reset(struct drm_device *dev,
-			struct intel_context *ctx);
 
 /* Execlists */
 int intel_sanitize_enable_execlists(struct drm_device *dev, int enable_execlists);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index f44e7be17104..984bfefb8373 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2185,6 +2185,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 
 	request->ring = ring;
 	request->ringbuf = ring->buffer;
+	request->head = intel_ring_get_tail(ring->buffer);
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {
-- 
2.1.4