[PATCH 4/6] migrate: Expand the use of folio in __migrate_device_pages()

[Matthew Wilcox (Oracle)]

Removes a few calls to compound_head() and a call to page_mapping().

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 mm/migrate_device.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index a68616c1965f..aecc71972a87 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -692,6 +692,7 @@ static void __migrate_device_pages(unsigned long *src_pfns,
                struct page *newpage = migrate_pfn_to_page(dst_pfns[i]);
                struct page *page = migrate_pfn_to_page(src_pfns[i]);
                struct address_space *mapping;
+               struct folio *folio;
                int r;
 
                if (!newpage) {
@@ -726,15 +727,12 @@ static void __migrate_device_pages(unsigned long 
*src_pfns,
                        continue;
                }
 
-               mapping = page_mapping(page);
+               folio = page_folio(page);
+               mapping = folio_mapping(folio);
 
                if (is_device_private_page(newpage) ||
                    is_device_coherent_page(newpage)) {
                        if (mapping) {
-                               struct folio *folio;
-
-                               folio = page_folio(page);
-
                                /*
                                 * For now only support anonymous memory 
migrating to
                                 * device private or coherent memory.
@@ -757,11 +755,10 @@ static void __migrate_device_pages(unsigned long 
*src_pfns,
 
                if (migrate && migrate->fault_page == page)
                        r = migrate_folio_extra(mapping, page_folio(newpage),
-                                               page_folio(page),
-                                               MIGRATE_SYNC_NO_COPY, 1);
+                                               folio, MIGRATE_SYNC_NO_COPY, 1);
                else
                        r = migrate_folio(mapping, page_folio(newpage),
-                                       page_folio(page), MIGRATE_SYNC_NO_COPY);
+                                       folio, MIGRATE_SYNC_NO_COPY);
                if (r != MIGRATEPAGE_SUCCESS)
                        src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
        }
-- 
2.43.0