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().
v2: Reorder tests to decide if we can continue filling ELSP and bonus
comments.
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_lrc.c | 35 ++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index e37f207afb5a..66d465708bc6 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -285,12 +285,11 @@ 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
@@ -601,6 +600,17 @@ 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));
@@ -753,8 +763,6 @@ 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
@@ -766,8 +774,7 @@ 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 we are on the second port and cannot
* combine this request with the last, then we
@@ -776,6 +783,14 @@ static void execlists_dequeue(struct intel_engine_cs
*engine)
if (port == last_port)
goto done;
+ /*
+ * We must not populate both ELSP[] with the
+ * same LRCA, i.e. we must submit 2 different
+ * contexts if we submit 2 ELSP.
+ */
+ if (last->hw_context == rq->hw_context)
+ goto done;
+
/*
* If GVT overrides us we only ever submit
* port[0], leaving port[1] empty. Note that we
@@ -787,7 +802,6 @@ 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);
@@ -826,8 +840,7 @@ static void execlists_dequeue(struct intel_engine_cs
*engine)
* request triggering preemption on the next dequeue (or subsequent
* interrupt for secondary ports).
*/
- execlists->queue_priority_hint =
- port != execlists->port ? rq_prio(last) : INT_MIN;
+ execlists->queue_priority_hint = queue_prio(execlists);
if (submit) {
port_assign(port, last);
