drm/msm/gpu: simplify tracking in-flight bo's

Since we already track the array of bo's in the submit object, just
unconditionally take and drop ref's per submit (rather than only taking
ref's if bo is not already active).  This simplifies later patches.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_gpu.c

@@ -432,6 +432,22 @@ int msm_gpu_perfcntr_sample(struct msm_gpu *gpu, uint32_t *activetime,
  * Cmdstream submission/retirement:
  */
 
+static void retire_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
+{
+	int i;
+
+	for (i = 0; i < submit->nr_bos; i++) {
+		struct msm_gem_object *msm_obj = submit->bos[i].obj;
+		/* move to inactive: */
+		msm_gem_move_to_inactive(&msm_obj->base);
+		msm_gem_put_iova(&msm_obj->base, gpu->id);
+		drm_gem_object_unreference(&msm_obj->base);
+	}
+
+	list_del(&submit->node);
+	kfree(submit);
+}
+
 static void retire_submits(struct msm_gpu *gpu, uint32_t fence)
 {
 	struct drm_device *dev = gpu->dev;
@@ -445,8 +461,7 @@ static void retire_submits(struct msm_gpu *gpu, uint32_t fence)
 				struct msm_gem_submit, node);
 
 		if (submit->fence <= fence) {
-			list_del(&submit->node);
-			kfree(submit);
+			retire_submit(gpu, submit);
 		} else {
 			break;
 		}
@@ -462,26 +477,7 @@ static void retire_worker(struct work_struct *work)
 	msm_update_fence(gpu->dev, fence);
 
 	mutex_lock(&dev->struct_mutex);
-
 	retire_submits(gpu, fence);
-
-	while (!list_empty(&gpu->active_list)) {
-		struct msm_gem_object *obj;
-
-		obj = list_first_entry(&gpu->active_list,
-				struct msm_gem_object, mm_list);
-
-		if ((obj->read_fence <= fence) &&
-				(obj->write_fence <= fence)) {
-			/* move to inactive: */
-			msm_gem_move_to_inactive(&obj->base);
-			msm_gem_put_iova(&obj->base, gpu->id);
-			drm_gem_object_unreference(&obj->base);
-		} else {
-			break;
-		}
-	}
-
 	mutex_unlock(&dev->struct_mutex);
 
 	if (!msm_gpu_active(gpu))
@@ -522,20 +518,17 @@ int msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
 
 	for (i = 0; i < submit->nr_bos; i++) {
 		struct msm_gem_object *msm_obj = submit->bos[i].obj;
+		uint32_t iova;
 
 		/* can't happen yet.. but when we add 2d support we'll have
 		 * to deal w/ cross-ring synchronization:
 		 */
 		WARN_ON(is_active(msm_obj) && (msm_obj->gpu != gpu));
 
-		if (!is_active(msm_obj)) {
-			uint32_t iova;
-
-			/* ring takes a reference to the bo and iova: */
-			drm_gem_object_reference(&msm_obj->base);
-			msm_gem_get_iova_locked(&msm_obj->base,
-					submit->gpu->id, &iova);
-		}
+		/* submit takes a reference to the bo and iova until retired: */
+		drm_gem_object_reference(&msm_obj->base);
+		msm_gem_get_iova_locked(&msm_obj->base,
+				submit->gpu->id, &iova);
 
 		if (submit->bos[i].flags & MSM_SUBMIT_BO_READ)
 			msm_gem_move_to_active(&msm_obj->base, gpu, false, submit->fence);