[PATCH 23/26] drm/i915: Make request conflict tracking understand parallel submits

[Matthew Brost <matthew.brost@xxxxxxxxx>]

If an object in the excl or shared slot is a composite fence from a
parallel submit and the current request in the conflict tracking is from
the same parallel context there is no need to enforce ordering as the
ordering already implicit. Make the request conflict tracking understand
this by comparing the parents parallel fence values and skipping the
conflict insertion if the values match.

Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_request.c | 43 +++++++++++++++++++----------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index e9bfa32f9270..cf89624020ad 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1325,6 +1325,25 @@ i915_request_await_external(struct i915_request *rq, struct dma_fence *fence)
 	return err;
 }
 
+static inline bool is_parallel_rq(struct i915_request *rq)
+{
+	return intel_context_is_parallel(rq->context);
+}
+
+static inline struct intel_context *request_to_parent(struct i915_request *rq)
+{
+	return intel_context_to_parent(rq->context);
+}
+
+static bool is_same_parallel_context(struct i915_request *to,
+				     struct i915_request *from)
+{
+	if (is_parallel_rq(to))
+		return request_to_parent(to) == request_to_parent(from);
+
+	return false;
+}
+
 int
 i915_request_await_execution(struct i915_request *rq,
 			     struct dma_fence *fence)
@@ -1356,11 +1375,14 @@ i915_request_await_execution(struct i915_request *rq,
 		 * want to run our callback in all cases.
 		 */
 
-		if (dma_fence_is_i915(fence))
+		if (dma_fence_is_i915(fence)) {
+			if (is_same_parallel_context(rq, to_request(fence)))
+				continue;
 			ret = __i915_request_await_execution(rq,
 							     to_request(fence));
-		else
+		} else {
 			ret = i915_request_await_external(rq, fence);
+		}
 		if (ret < 0)
 			return ret;
 	} while (--nchild);
@@ -1461,10 +1483,13 @@ i915_request_await_dma_fence(struct i915_request *rq, struct dma_fence *fence)
 						 fence))
 			continue;
 
-		if (dma_fence_is_i915(fence))
+		if (dma_fence_is_i915(fence)) {
+			if (is_same_parallel_context(rq, to_request(fence)))
+				continue;
 			ret = i915_request_await_request(rq, to_request(fence));
-		else
+		} else {
 			ret = i915_request_await_external(rq, fence);
+		}
 		if (ret < 0)
 			return ret;
 
@@ -1539,16 +1564,6 @@ i915_request_await_object(struct i915_request *to,
 	return ret;
 }
 
-static inline bool is_parallel_rq(struct i915_request *rq)
-{
-	return intel_context_is_parallel(rq->context);
-}
-
-static inline struct intel_context *request_to_parent(struct i915_request *rq)
-{
-	return intel_context_to_parent(rq->context);
-}
-
 static struct i915_request *
 __i915_request_ensure_parallel_ordering(struct i915_request *rq,
 					struct intel_timeline *timeline)
-- 
2.32.0