drm/nouveau: fence: separate fence alloc and emit

The new (VM_BIND) UAPI exports DMA fences through DRM syncobjs. Hence,
in order to emit fences within DMA fence signalling critical sections
(e.g. as typically done in the DRM GPU schedulers run_job() callback) we
need to separate fence allocation and fence emitting.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-8-dakr@redhat.com

1 files changed, 31 insertions, 21 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 6130c99b6b2c..e38e448d9632 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -823,29 +823,39 @@ nouveau_bo_move_m2mf(struct ttm_buffer_object *bo, int evict,
 		mutex_lock(&cli->mutex);
 	else
 		mutex_lock_nested(&cli->mutex, SINGLE_DEPTH_NESTING);
+
 	ret = nouveau_fence_sync(nouveau_bo(bo), chan, true, ctx->interruptible);
-	if (ret == 0) {
-		ret = drm->ttm.move(chan, bo, bo->resource, new_reg);
-		if (ret == 0) {
-			ret = nouveau_fence_new(chan, false, &fence);
-			if (ret == 0) {
-				/* TODO: figure out a better solution here
-				 *
-				 * wait on the fence here explicitly as going through
-				 * ttm_bo_move_accel_cleanup somehow doesn't seem to do it.
-				 *
-				 * Without this the operation can timeout and we'll fallback to a
-				 * software copy, which might take several minutes to finish.
-				 */
-				nouveau_fence_wait(fence, false, false);
-				ret = ttm_bo_move_accel_cleanup(bo,
-								&fence->base,
-								evict, false,
-								new_reg);
-				nouveau_fence_unref(&fence);
-			}
-		}
+	if (ret)
+		goto out_unlock;
+
+	ret = drm->ttm.move(chan, bo, bo->resource, new_reg);
+	if (ret)
+		goto out_unlock;
+
+	ret = nouveau_fence_new(&fence);
+	if (ret)
+		goto out_unlock;
+
+	ret = nouveau_fence_emit(fence, chan);
+	if (ret) {
+		nouveau_fence_unref(&fence);
+		goto out_unlock;
 	}
+
+	/* TODO: figure out a better solution here
+	 *
+	 * wait on the fence here explicitly as going through
+	 * ttm_bo_move_accel_cleanup somehow doesn't seem to do it.
+	 *
+	 * Without this the operation can timeout and we'll fallback to a
+	 * software copy, which might take several minutes to finish.
+	 */
+	nouveau_fence_wait(fence, false, false);
+	ret = ttm_bo_move_accel_cleanup(bo, &fence->base, evict, false,
+					new_reg);
+	nouveau_fence_unref(&fence);
+
+out_unlock:
 	mutex_unlock(&cli->mutex);
 	return ret;
 }