nouveau: factor out dmem fence completion

Factor out the end of fencing logic from the two migration routines.

Link: https://lore.kernel.org/r/20190814075928.23766-5-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/gpu/drm/nouveau/nouveau_dmem.c

@@ -133,6 +133,19 @@ static void nouveau_dmem_page_free(struct page *page)
 	spin_unlock(&chunk->lock);
 }
 
+static void nouveau_dmem_fence_done(struct nouveau_fence **fence)
+{
+	if (fence) {
+		nouveau_fence_wait(*fence, true, false);
+		nouveau_fence_unref(fence);
+	} else {
+		/*
+		 * FIXME wait for channel to be IDLE before calling finalizing
+		 * the hmem object.
+		 */
+	}
+}
+
 static void
 nouveau_dmem_fault_alloc_and_copy(struct vm_area_struct *vma,
 				  const unsigned long *src_pfns,
@@ -236,15 +249,7 @@ nouveau_dmem_fault_finalize_and_map(struct nouveau_dmem_fault *fault)
 {
 	struct nouveau_drm *drm = fault->drm;
 
-	if (fault->fence) {
-		nouveau_fence_wait(fault->fence, true, false);
-		nouveau_fence_unref(&fault->fence);
-	} else {
-		/*
-		 * FIXME wait for channel to be IDLE before calling finalizing
-		 * the hmem object below (nouveau_migrate_hmem_fini()).
-		 */
-	}
+	nouveau_dmem_fence_done(&fault->fence);
 
 	while (fault->npages--) {
 		dma_unmap_page(drm->dev->dev, fault->dma[fault->npages],
@@ -748,15 +753,7 @@ nouveau_dmem_migrate_finalize_and_map(struct nouveau_migrate *migrate)
 {
 	struct nouveau_drm *drm = migrate->drm;
 
-	if (migrate->fence) {
-		nouveau_fence_wait(migrate->fence, true, false);
-		nouveau_fence_unref(&migrate->fence);
-	} else {
-		/*
-		 * FIXME wait for channel to be IDLE before finalizing
-		 * the hmem object below (nouveau_migrate_hmem_fini()) ?
-		 */
-	}
+	nouveau_dmem_fence_done(&migrate->fence);
 
 	while (migrate->dma_nr--) {
 		dma_unmap_page(drm->dev->dev, migrate->dma[migrate->dma_nr],