drm/amdgpu: add scheduler dependency callback v2

This way the scheduler doesn't wait in it's work thread any more.

v2: fix race conditions

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
index 205cb887d023..2f5d1f0da8e5 100644
--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
@@ -192,14 +192,36 @@ void amd_sched_entity_fini(struct amd_gpu_scheduler *sched,
         kfifo_free(&entity->job_queue);
 }
 
+static void amd_sched_entity_wakeup(struct fence *f, struct fence_cb *cb)
+{
+        struct amd_sched_entity *entity =
+                container_of(cb, struct amd_sched_entity, cb);
+        entity->dependency = NULL;
+        fence_put(f);
+        amd_sched_wakeup(entity->scheduler);
+}
+
 static struct amd_sched_job *
 amd_sched_entity_pop_job(struct amd_sched_entity *entity)
 {
+        struct amd_gpu_scheduler *sched = entity->scheduler;
         struct amd_sched_job *job;
 
+        if (ACCESS_ONCE(entity->dependency))
+                return NULL;
+
         if (!kfifo_out_peek(&entity->job_queue, &job, sizeof(job)))
                 return NULL;
 
+        while ((entity->dependency = sched->ops->dependency(job))) {
+
+                if (fence_add_callback(entity->dependency, &entity->cb,
+                                       amd_sched_entity_wakeup))
+                        fence_put(entity->dependency);
+                else
+                        return NULL;
+        }
+
         return job;
 }