[Intel-gfx] [PATCH 10/10] drm/i915: Cache ringbuf pointer in request structure

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

Cache a pointer to the ringbuf so that retire requests does not need to do messy
'are we in execlist mode' decisions.

Change-Id: I75bf6b73dc8a675a5be7bbff1927aa30f393788c
For: VIZ-1587
Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h         |    3 ++-
 drivers/gpu/drm/i915/i915_gem.c         |   14 +-------------
 drivers/gpu/drm/i915/intel_lrc.c        |    3 ++-
 drivers/gpu/drm/i915/intel_ringbuffer.c |    1 +
 4 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f885a90..b340455 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2024,8 +2024,9 @@ struct drm_i915_gem_request {
 	/** Position in the ringbuffer of the end of the request */
 	u32 tail;
 
-	/** Context related to this request */
+	/** Context and ring buffer related to this request */
 	struct intel_context *ctx;
+	struct intel_ringbuffer *ringbuf;
 
 	/** Batch buffer related to this request if any */
 	struct drm_i915_gem_object *batch_obj;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 031af9d..b8ee384 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2762,7 +2762,6 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 
 	while (!list_empty(&ring->request_list)) {
 		struct drm_i915_gem_request *request;
-		struct intel_ringbuffer *ringbuf;
 
 		request = list_first_entry(&ring->request_list,
 					   struct drm_i915_gem_request,
@@ -2773,23 +2772,12 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring)
 
 		trace_i915_gem_request_retire(request);
 
-		/* This is one of the few common intersection points
-		 * between legacy ringbuffer submission and execlists:
-		 * we need to tell them apart in order to find the correct
-		 * ringbuffer to which the request belongs to.
-		 */
-		if (i915.enable_execlists) {
-			struct intel_context *ctx = request->ctx;
-			ringbuf = ctx->engine[ring->id].ringbuf;
-		} else
-			ringbuf = ring->buffer;
-
 		/* We know the GPU must have read the request to have
 		 * sent us the seqno + interrupt, so use the position
 		 * of tail of the request to update the last known position
 		 * of the GPU head.
 		 */
-		ringbuf->last_retired_head = request->tail;
+		request->ringbuf->last_retired_head = request->tail;
 
 		i915_gem_free_request(request);
 	}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 971ba0c..684eb1e 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -944,10 +944,11 @@ int intel_logical_ring_alloc_request(struct intel_engine_cs *ring,
 
 	/* Hold a reference to the context this request belongs to
 	 * (we will need it when the time comes to emit/retire the
-	 * request).
+	 * request). Likewise, the ringbuff is useful to keep track of.
 	 */
 	request->ctx = ctx;
 	i915_gem_context_reference(request->ctx);
+	request->ringbuf = ctx->engine[ring->id].ringbuf;
 
 	ring->outstanding_lazy_request = request;
 	return 0;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 65ffdd1..f0242cf 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2039,6 +2039,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring, struct intel_context *ctx
 
 	kref_init(&request->ref);
 	request->ring = ring;
+	request->ringbuf = ring->buffer;
 	request->uniq = dev_private->request_uniq++;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
-- 
1.7.9.5