[PATCH 12/27] mm: refactor the ZONE_DEVICE handling in migrate_vma_pages

[Christoph Hellwig]

Make the flow a little more clear and prepare for adding a new
ZONE_DEVICE memory type.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 mm/migrate.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 30ecd7223656c1..746e1230886ddb 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2788,24 +2788,21 @@ void migrate_vma_pages(struct migrate_vma *migrate)
 
 		mapping = page_mapping(page);
 
-		if (is_zone_device_page(newpage)) {
-			if (is_device_private_page(newpage)) {
-				/*
-				 * For now only support private anonymous when
-				 * migrating to un-addressable device memory.
-				 */
-				if (mapping) {
-					migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
-					continue;
-				}
-			} else {
-				/*
-				 * Other types of ZONE_DEVICE page are not
-				 * supported.
-				 */
+		if (is_device_private_page(newpage)) {
+			/*
+			 * For now only support private anonymous when migrating
+			 * to un-addressable device memory.
+			 */
+			if (mapping) {
 				migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
 				continue;
 			}
+		} else if (is_zone_device_page(newpage)) {
+			/*
+			 * Other types of ZONE_DEVICE page are not supported.
+			 */
+			migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
+			continue;
 		}
 
 		r = migrate_page(mapping, newpage, page, MIGRATE_SYNC_NO_COPY);
-- 
2.30.2