via_dmablit(): use get_user_pages_fast()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/gpu/drm/via/via_dmablit.c

@@ -238,9 +238,9 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg,  drm_via_dmablit_t *xfer)
 	vsg->pages = vzalloc(sizeof(struct page *) * vsg->num_pages);
 	if (NULL == vsg->pages)
 		return -ENOMEM;
-	ret = get_user_pages_unlocked((unsigned long)xfer->mem_addr,
-			vsg->num_pages, vsg->pages,
-			(vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0);
+	ret = get_user_pages_fast((unsigned long)xfer->mem_addr,
+			vsg->num_pages, vsg->direction == DMA_FROM_DEVICE,
+			vsg->pages);
 	if (ret != vsg->num_pages) {
 		if (ret < 0)
 			return ret;