drm/amd/sched: allow clients to edit an entity's rq v2

This is useful for changing an entity's priority at runtime.

v2: don't modify the order of amd_sched_entity members
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Andres Rodriguez <andresx7@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/scheduler/gpu_scheduler.c

@@ -133,6 +133,7 @@ int amd_sched_entity_init(struct amd_gpu_scheduler *sched,
 	entity->rq = rq;
 	entity->sched = sched;
 
+	spin_lock_init(&entity->rq_lock);
 	spin_lock_init(&entity->queue_lock);
 	r = kfifo_alloc(&entity->job_queue, jobs * sizeof(void *), GFP_KERNEL);
 	if (r)
@@ -204,7 +205,6 @@ static bool amd_sched_entity_is_ready(struct amd_sched_entity *entity)
 void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 			   struct amd_sched_entity *entity)
 {
-	struct amd_sched_rq *rq = entity->rq;
 	int r;
 
 	if (!amd_sched_entity_is_initialized(sched, entity))
@@ -218,7 +218,7 @@ void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 	else
 		r = wait_event_killable(sched->job_scheduled,
 					amd_sched_entity_is_idle(entity));
-	amd_sched_rq_remove_entity(rq, entity);
+	amd_sched_entity_set_rq(entity, NULL);
 	if (r) {
 		struct amd_sched_job *job;
 
@@ -257,6 +257,24 @@ static void amd_sched_entity_clear_dep(struct dma_fence *f, struct dma_fence_cb
 	dma_fence_put(f);
 }
 
+void amd_sched_entity_set_rq(struct amd_sched_entity *entity,
+			     struct amd_sched_rq *rq)
+{
+	if (entity->rq == rq)
+		return;
+
+	spin_lock(&entity->rq_lock);
+
+	if (entity->rq)
+		amd_sched_rq_remove_entity(entity->rq, entity);
+
+	entity->rq = rq;
+	if (rq)
+		amd_sched_rq_add_entity(rq, entity);
+
+	spin_unlock(&entity->rq_lock);
+}
+
 bool amd_sched_dependency_optimized(struct dma_fence* fence,
 				    struct amd_sched_entity *entity)
 {
@@ -354,7 +372,9 @@ static bool amd_sched_entity_in(struct amd_sched_job *sched_job)
 	/* first job wakes up scheduler */
 	if (first) {
 		/* Add the entity to the run queue */
+		spin_lock(&entity->rq_lock);
 		amd_sched_rq_add_entity(entity->rq, entity);
+		spin_unlock(&entity->rq_lock);
 		amd_sched_wakeup(sched);
 	}
 	return added;

drivers/gpu/drm/amd/scheduler/gpu_scheduler.h

@@ -39,6 +39,7 @@ struct amd_sched_rq;
 struct amd_sched_entity {
 	struct list_head		list;
 	struct amd_sched_rq		*rq;
+	spinlock_t			rq_lock;
 	struct amd_gpu_scheduler	*sched;
 
 	spinlock_t			queue_lock;
@@ -154,6 +155,8 @@ int amd_sched_entity_init(struct amd_gpu_scheduler *sched,
 void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
 			   struct amd_sched_entity *entity);
 void amd_sched_entity_push_job(struct amd_sched_job *sched_job);
+void amd_sched_entity_set_rq(struct amd_sched_entity *entity,
+			     struct amd_sched_rq *rq);
 
 int amd_sched_fence_slab_init(void);
 void amd_sched_fence_slab_fini(void);