drm/scheduler: Scheduler priority fixes (v2)

Remove DRM_SCHED_PRIORITY_LOW, as it was used
in only one place.

Rename and separate by a line
DRM_SCHED_PRIORITY_MAX to DRM_SCHED_PRIORITY_COUNT
as it represents a (total) count of said
priorities and it is used as such in loops
throughout the code. (0-based indexing is the
the count number.)

Remove redundant word HIGH in priority names,
and rename *KERNEL* to *HIGH*, as it really
means that, high.

v2: Add back KERNEL and remove SW and HW,
    in lieu of a single HIGH between NORMAL and KERNEL.
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -46,7 +46,7 @@ const unsigned int amdgpu_ctx_num_entities[AMDGPU_HW_IP_NUM] = {
 static int amdgpu_ctx_priority_permit(struct drm_file *filp,
 				      enum drm_sched_priority priority)
 {
-	if (priority < 0 || priority >= DRM_SCHED_PRIORITY_MAX)
+	if (priority < 0 || priority >= DRM_SCHED_PRIORITY_COUNT)
 		return -EINVAL;
 
 	/* NORMAL and below are accessible by everyone */
@@ -65,7 +65,7 @@ static int amdgpu_ctx_priority_permit(struct drm_file *filp,
 static enum gfx_pipe_priority amdgpu_ctx_sched_prio_to_compute_prio(enum drm_sched_priority prio)
 {
 	switch (prio) {
-	case DRM_SCHED_PRIORITY_HIGH_HW:
+	case DRM_SCHED_PRIORITY_HIGH:
 	case DRM_SCHED_PRIORITY_KERNEL:
 		return AMDGPU_GFX_PIPE_PRIO_HIGH;
 	default:

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

@@ -251,7 +251,7 @@ void amdgpu_job_stop_all_jobs_on_sched(struct drm_gpu_scheduler *sched)
 	int i;
 
 	/* Signal all jobs not yet scheduled */
-	for (i = DRM_SCHED_PRIORITY_MAX - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+	for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
 		struct drm_sched_rq *rq = &sched->sched_rq[i];
 
 		if (!rq)

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

@@ -267,7 +267,7 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 			&ring->sched;
 	}
 
-	for (i = 0; i < DRM_SCHED_PRIORITY_MAX; ++i)
+	for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; ++i)
 		atomic_set(&ring->num_jobs[i], 0);
 
 	return 0;

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h

@@ -243,7 +243,7 @@ struct amdgpu_ring {
 	bool			has_compute_vm_bug;
 	bool			no_scheduler;
 
-	atomic_t		num_jobs[DRM_SCHED_PRIORITY_MAX];
+	atomic_t		num_jobs[DRM_SCHED_PRIORITY_COUNT];
 	struct mutex		priority_mutex;
 	/* protected by priority_mutex */
 	int			priority;

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

@@ -36,14 +36,14 @@ enum drm_sched_priority amdgpu_to_sched_priority(int amdgpu_priority)
 {
 	switch (amdgpu_priority) {
 	case AMDGPU_CTX_PRIORITY_VERY_HIGH:
-		return DRM_SCHED_PRIORITY_HIGH_HW;
+		return DRM_SCHED_PRIORITY_HIGH;
 	case AMDGPU_CTX_PRIORITY_HIGH:
-		return DRM_SCHED_PRIORITY_HIGH_SW;
+		return DRM_SCHED_PRIORITY_HIGH;
 	case AMDGPU_CTX_PRIORITY_NORMAL:
 		return DRM_SCHED_PRIORITY_NORMAL;
 	case AMDGPU_CTX_PRIORITY_LOW:
 	case AMDGPU_CTX_PRIORITY_VERY_LOW:
-		return DRM_SCHED_PRIORITY_LOW;
+		return DRM_SCHED_PRIORITY_MIN;
 	case AMDGPU_CTX_PRIORITY_UNSET:
 		return DRM_SCHED_PRIORITY_UNSET;
 	default:

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

@@ -2109,7 +2109,7 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
 		ring = adev->mman.buffer_funcs_ring;
 		sched = &ring->sched;
 		r = drm_sched_entity_init(&adev->mman.entity,
-				          DRM_SCHED_PRIORITY_KERNEL, &sched,
+					  DRM_SCHED_PRIORITY_KERNEL, &sched,
 					  1, NULL);
 		if (r) {
 			DRM_ERROR("Failed setting up TTM BO move entity (%d)\n",

drivers/gpu/drm/scheduler/sched_main.c

@@ -623,7 +623,7 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched)
 		return NULL;
 
 	/* Kernel run queue has higher priority than normal run queue*/
-	for (i = DRM_SCHED_PRIORITY_MAX - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+	for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
 		entity = drm_sched_rq_select_entity(&sched->sched_rq[i]);
 		if (entity)
 			break;
@@ -851,7 +851,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched,
 	sched->name = name;
 	sched->timeout = timeout;
 	sched->hang_limit = hang_limit;
-	for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_MAX; i++)
+	for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++)
 		drm_sched_rq_init(sched, &sched->sched_rq[i]);
 
 	init_waitqueue_head(&sched->wake_up_worker);

include/drm/gpu_scheduler.h

@@ -33,14 +33,16 @@
 struct drm_gpu_scheduler;
 struct drm_sched_rq;
 
+/* These are often used as an (initial) index
+ * to an array, and as such should start at 0.
+ */
 enum drm_sched_priority {
 	DRM_SCHED_PRIORITY_MIN,
-	DRM_SCHED_PRIORITY_LOW = DRM_SCHED_PRIORITY_MIN,
 	DRM_SCHED_PRIORITY_NORMAL,
-	DRM_SCHED_PRIORITY_HIGH_SW,
-	DRM_SCHED_PRIORITY_HIGH_HW,
+	DRM_SCHED_PRIORITY_HIGH,
 	DRM_SCHED_PRIORITY_KERNEL,
-	DRM_SCHED_PRIORITY_MAX,
+
+	DRM_SCHED_PRIORITY_COUNT,
 	DRM_SCHED_PRIORITY_INVALID = -1,
 	DRM_SCHED_PRIORITY_UNSET = -2
 };
@@ -274,7 +276,7 @@ struct drm_gpu_scheduler {
 	uint32_t			hw_submission_limit;
 	long				timeout;
 	const char			*name;
-	struct drm_sched_rq		sched_rq[DRM_SCHED_PRIORITY_MAX];
+	struct drm_sched_rq		sched_rq[DRM_SCHED_PRIORITY_COUNT];
 	wait_queue_head_t		wake_up_worker;
 	wait_queue_head_t		job_scheduled;
 	atomic_t			hw_rq_count;