drm/amdgpu: Avoid accessing job->entity after the job is scheduled.

Bug: amdgpu_job_free_cb was accessing s_job->s_entity when the allocated
amdgpu_ctx (and the entity inside it) were already deallocated from
amdgpu_cs_parser_fini.

Fix: Save job's priority on it's creation instead of accessing it from
s_entity later on.

Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Reviewed-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -1194,8 +1194,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 	job->uf_sequence = seq;
 
 	amdgpu_job_free_resources(job);
-	amdgpu_ring_priority_get(job->ring,
-				 amd_sched_get_job_priority(&job->base));
+	amdgpu_ring_priority_get(job->ring, job->base.s_priority);
 
 	trace_amdgpu_cs_ioctl(job);
 	amd_sched_entity_push_job(&job->base);

drivers/gpu/drm/amd/amdgpu/amdgpu_job.c

@@ -104,7 +104,7 @@ static void amdgpu_job_free_cb(struct amd_sched_job *s_job)
 {
 	struct amdgpu_job *job = container_of(s_job, struct amdgpu_job, base);
 
-	amdgpu_ring_priority_put(job->ring, amd_sched_get_job_priority(s_job));
+	amdgpu_ring_priority_put(job->ring, s_job->s_priority);
 	dma_fence_put(job->fence);
 	amdgpu_sync_free(&job->sync);
 	amdgpu_sync_free(&job->dep_sync);
@@ -141,8 +141,7 @@ int amdgpu_job_submit(struct amdgpu_job *job, struct amdgpu_ring *ring,
 	job->fence_ctx = entity->fence_context;
 	*f = dma_fence_get(&job->base.s_fence->finished);
 	amdgpu_job_free_resources(job);
-	amdgpu_ring_priority_get(job->ring,
-				 amd_sched_get_job_priority(&job->base));
+	amdgpu_ring_priority_get(job->ring, job->base.s_priority);
 	amd_sched_entity_push_job(&job->base);
 
 	return 0;

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

@@ -529,6 +529,7 @@ int amd_sched_job_init(struct amd_sched_job *job,
 {
 	job->sched = sched;
 	job->s_entity = entity;
+	job->s_priority = entity->rq - sched->sched_rq;
 	job->s_fence = amd_sched_fence_create(entity, owner);
 	if (!job->s_fence)
 		return -ENOMEM;

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

@@ -30,6 +30,19 @@
 struct amd_gpu_scheduler;
 struct amd_sched_rq;
 
+enum amd_sched_priority {
+	AMD_SCHED_PRIORITY_MIN,
+	AMD_SCHED_PRIORITY_LOW = AMD_SCHED_PRIORITY_MIN,
+	AMD_SCHED_PRIORITY_NORMAL,
+	AMD_SCHED_PRIORITY_HIGH_SW,
+	AMD_SCHED_PRIORITY_HIGH_HW,
+	AMD_SCHED_PRIORITY_KERNEL,
+	AMD_SCHED_PRIORITY_MAX,
+	AMD_SCHED_PRIORITY_INVALID = -1,
+	AMD_SCHED_PRIORITY_UNSET = -2
+};
+
+
 /**
  * A scheduler entity is a wrapper around a job queue or a group
  * of other entities. Entities take turns emitting jobs from their
@@ -83,6 +96,7 @@ struct amd_sched_job {
 	struct delayed_work		work_tdr;
 	uint64_t			id;
 	atomic_t karma;
+	enum amd_sched_priority s_priority;
 };
 
 extern const struct dma_fence_ops amd_sched_fence_ops_scheduled;
@@ -114,18 +128,6 @@ struct amd_sched_backend_ops {
 	void (*free_job)(struct amd_sched_job *sched_job);
 };
 
-enum amd_sched_priority {
-	AMD_SCHED_PRIORITY_MIN,
-	AMD_SCHED_PRIORITY_LOW = AMD_SCHED_PRIORITY_MIN,
-	AMD_SCHED_PRIORITY_NORMAL,
-	AMD_SCHED_PRIORITY_HIGH_SW,
-	AMD_SCHED_PRIORITY_HIGH_HW,
-	AMD_SCHED_PRIORITY_KERNEL,
-	AMD_SCHED_PRIORITY_MAX,
-	AMD_SCHED_PRIORITY_INVALID = -1,
-	AMD_SCHED_PRIORITY_UNSET = -2
-};
-
 /**
  * One scheduler is implemented for each hardware ring
 */
@@ -176,10 +178,4 @@ bool amd_sched_dependency_optimized(struct dma_fence* fence,
 				    struct amd_sched_entity *entity);
 void amd_sched_job_kickout(struct amd_sched_job *s_job);
 
-static inline enum amd_sched_priority
-amd_sched_get_job_priority(struct amd_sched_job *job)
-{
-	return (job->s_entity->rq - job->sched->sched_rq);
-}
-
 #endif