drm/msm: Utilize gpu scheduler priorities

The drm/scheduler provides additional prioritization on top of that
provided by however many number of ringbuffers (each with their own
priority level) is supported on a given generation.  Expose the
additional levels of priority to userspace and map the userspace
priority back to ring (first level of priority) and schedular priority
(additional priority levels within the ring).

Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20210728010632.2633470-13-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 15 insertions, 20 deletions

diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c
index 682ba2a7c0ec..32a55d81b58b 100644
--- a/drivers/gpu/drm/msm/msm_submitqueue.c
+++ b/drivers/gpu/drm/msm/msm_submitqueue.c
@@ -68,6 +68,8 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 	struct msm_gpu_submitqueue *queue;
 	struct msm_ringbuffer *ring;
 	struct drm_gpu_scheduler *sched;
+	enum drm_sched_priority sched_prio;
+	unsigned ring_nr;
 	int ret;
 
 	if (!ctx)
@@ -76,8 +78,9 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 	if (!priv->gpu)
 		return -ENODEV;
 
-	if (prio >= priv->gpu->nr_rings)
-		return -EINVAL;
+	ret = msm_gpu_convert_priority(priv->gpu, prio, &ring_nr, &sched_prio);
+	if (ret)
+		return ret;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 
@@ -86,24 +89,13 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 
 	kref_init(&queue->ref);
 	queue->flags = flags;
-	queue->prio = prio;
+	queue->ring_nr = ring_nr;
 
-	ring = priv->gpu->rb[prio];
+	ring = priv->gpu->rb[ring_nr];
 	sched = &ring->sched;
 
-	/*
-	 * TODO we can allow more priorities than we have ringbuffers by
-	 * mapping:
-	 *
-	 *    ring = prio / 3;
-	 *    ent_prio = DRM_SCHED_PRIORITY_MIN + (prio % 3);
-	 *
-	 * Probably avoid using DRM_SCHED_PRIORITY_KERNEL as that is
-	 * treated specially in places.
-	 */
 	ret = drm_sched_entity_init(&queue->entity,
-			DRM_SCHED_PRIORITY_NORMAL,
-			&sched, 1, NULL);
+			sched_prio, &sched, 1, NULL);
 	if (ret) {
 		kfree(queue);
 		return ret;
@@ -134,16 +126,19 @@ int msm_submitqueue_create(struct drm_device *drm, struct msm_file_private *ctx,
 int msm_submitqueue_init(struct drm_device *drm, struct msm_file_private *ctx)
 {
 	struct msm_drm_private *priv = drm->dev_private;
-	int default_prio;
+	int default_prio, max_priority;
 
 	if (!priv->gpu)
 		return -ENODEV;
 
+	max_priority = (priv->gpu->nr_rings * NR_SCHED_PRIORITIES) - 1;
+
 	/*
-	 * Select priority 2 as the "default priority" unless nr_rings is less
-	 * than 2 and then pick the lowest priority
+	 * Pick a medium priority level as default.  Lower numeric value is
+	 * higher priority, so round-up to pick a priority that is not higher
+	 * than the middle priority level.
 	 */
-	default_prio = clamp_t(uint32_t, 2, 0, priv->gpu->nr_rings - 1);
+	default_prio = DIV_ROUND_UP(max_priority, 2);
 
 	INIT_LIST_HEAD(&ctx->submitqueues);