[PATCH 23/30] drm/i915/execlists: Refactor out can_merge_rq()

[Chris Wilson]

In the next patch, we add another user that wants to check whether
requests can be merge into a single HW execution, and in the future we
want to add more conditions under which requests from the same context
cannot be merge. In preparation, extract out can_merge_rq().

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_lrc.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 88fe3ec8ac70..3b9030fe07e8 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -280,12 +280,11 @@ static inline bool need_preempt(const struct intel_engine_cs *engine,
 }
 
 __maybe_unused static inline bool
-assert_priority_queue(const struct intel_engine_execlists *execlists,
-		      const struct i915_request *prev,
+assert_priority_queue(const struct i915_request *prev,
 		      const struct i915_request *next)
 {
-	if (!prev)
-		return true;
+	const struct intel_engine_execlists *execlists =
+		&prev->engine->execlists;
 
 	/*
 	 * Without preemption, the prev may refer to the still active element
@@ -590,6 +589,17 @@ static bool can_merge_ctx(const struct intel_context *prev,
 	return true;
 }
 
+static bool can_merge_rq(const struct i915_request *prev,
+			 const struct i915_request *next)
+{
+	GEM_BUG_ON(!assert_priority_queue(prev, next));
+
+	if (!can_merge_ctx(prev->hw_context, next->hw_context))
+		return false;
+
+	return true;
+}
+
 static void port_assign(struct execlist_port *port, struct i915_request *rq)
 {
 	GEM_BUG_ON(rq == port_request(port));
@@ -740,8 +750,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 		int i;
 
 		priolist_for_each_request_consume(rq, rn, p, i) {
-			GEM_BUG_ON(!assert_priority_queue(execlists, last, rq));
-
 			/*
 			 * Can we combine this request with the current port?
 			 * It has to be the same context/ringbuffer and not
@@ -753,8 +761,10 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 			 * second request, and so we never need to tell the
 			 * hardware about the first.
 			 */
-			if (last &&
-			    !can_merge_ctx(rq->hw_context, last->hw_context)) {
+			if (last && !can_merge_rq(last, rq)) {
+				if (last->hw_context == rq->hw_context)
+					goto done;
+
 				/*
 				 * If we are on the second port and cannot
 				 * combine this request with the last, then we
@@ -774,7 +784,6 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 				    ctx_single_port_submission(rq->hw_context))
 					goto done;
 
-				GEM_BUG_ON(last->hw_context == rq->hw_context);
 
 				if (submit)
 					port_assign(port, last);
-- 
2.20.1