[PATCH 11/27] mm: refactor the ZONE_DEVICE handling in migrate_vma_insert_page

[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 at lst.de>
---
 mm/migrate.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 8e0370a73f8a43..30ecd7223656c1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2670,26 +2670,25 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 	 */
 	__SetPageUptodate(page);
 
-	if (is_zone_device_page(page)) {
-		if (is_device_private_page(page)) {
-			swp_entry_t swp_entry;
+	if (is_device_private_page(page)) {
+		swp_entry_t swp_entry;
 
-			if (vma->vm_flags & VM_WRITE)
-				swp_entry = make_writable_device_private_entry(
-							page_to_pfn(page));
-			else
-				swp_entry = make_readable_device_private_entry(
-							page_to_pfn(page));
-			entry = swp_entry_to_pte(swp_entry);
-		} else {
-			/*
-			 * For now we only support migrating to un-addressable
-			 * device memory.
-			 */
+		if (vma->vm_flags & VM_WRITE)
+			swp_entry = make_writable_device_private_entry(
+						page_to_pfn(page));
+		else
+			swp_entry = make_readable_device_private_entry(
+						page_to_pfn(page));
+		entry = swp_entry_to_pte(swp_entry);
+	} else {
+		/*
+		 * For now we only support migrating to un-addressable device
+		 * memory.
+		 */
+		if (is_zone_device_page(page)) {
 			pr_warn_once("Unsupported ZONE_DEVICE page type.\n");
 			goto abort;
 		}
-	} else {
 		entry = mk_pte(page, vma->vm_page_prot);
 		if (vma->vm_flags & VM_WRITE)
 			entry = pte_mkwrite(pte_mkdirty(entry));
-- 
2.30.2