drm/sched: Further optimise drm_sched_entity_push_job

Having removed one re-lock cycle on the entity->lock in a patch titled
"drm/sched: Optimise drm_sched_entity_push_job", with only a tiny bit
larger refactoring we can do the same optimisation on the rq->lock.
(Currently both drm_sched_rq_add_entity() and
drm_sched_rq_update_fifo_locked() take and release the same lock.)

To achieve this we make drm_sched_rq_update_fifo_locked() and
drm_sched_rq_add_entity() expect the rq->lock to be held.

We also align drm_sched_rq_update_fifo_locked(),
drm_sched_rq_add_entity() and
drm_sched_rq_remove_fifo_locked() function signatures, by adding rq as a
parameter to the latter.

v2:
 * Fix after rebase of the series.
 * Avoid naming inconsistency between drm_sched_rq_add/remove. (Christian)

Signed-off-by: Tvrtko Ursulin <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: Luben Tuikov <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Philipp Stanner <[email protected]>
Reviewed-by: Christian König <[email protected]>
Reviewed-by: Philipp Stanner <[email protected]>
Signed-off-by: Philipp Stanner <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index c013c2b49aa5..69bcf0e99d57 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -515,9 +515,14 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
 
 		next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
 		if (next) {
+			struct drm_sched_rq *rq;
+
 			spin_lock(&entity->lock);
-			drm_sched_rq_update_fifo_locked(entity,
+			rq = entity->rq;
+			spin_lock(&rq->lock);
+			drm_sched_rq_update_fifo_locked(entity, rq,
 							next->submit_ts);
+			spin_unlock(&rq->lock);
 			spin_unlock(&entity->lock);
 		}
 	}
@@ -616,11 +621,13 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
 		rq = entity->rq;
 		sched = rq->sched;
 
+		spin_lock(&rq->lock);
 		drm_sched_rq_add_entity(rq, entity);
 
 		if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
-			drm_sched_rq_update_fifo_locked(entity, submit_ts);
+			drm_sched_rq_update_fifo_locked(entity, rq, submit_ts);
 
+		spin_unlock(&rq->lock);
 		spin_unlock(&entity->lock);
 
 		drm_sched_wakeup(sched);