[v1 resend 02/12] mm/migrate_device: flags for selecting device private THP pages

[Balbir Singh]

Add flags to mark zone device migration pages.

MIGRATE_VMA_SELECT_COMPOUND will be used to select THP pages during
migrate_vma_setup() and MIGRATE_PFN_COMPOUND will make migrating
device pages as compound pages during device pfn migration.

Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Simona Vetter <simona@xxxxxxxx>
Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Barry Song <baohua@xxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Donet Tom <donettom@xxxxxxxxxxxxx>

Signed-off-by: Balbir Singh <balbirs@xxxxxxxxxx>
---
 include/linux/migrate.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index aaa2114498d6..1661e2d5479a 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -167,6 +167,7 @@ static inline int migrate_misplaced_folio(struct folio *folio, int node)
 #define MIGRATE_PFN_VALID	(1UL << 0)
 #define MIGRATE_PFN_MIGRATE	(1UL << 1)
 #define MIGRATE_PFN_WRITE	(1UL << 3)
+#define MIGRATE_PFN_COMPOUND	(1UL << 4)
 #define MIGRATE_PFN_SHIFT	6
 
 static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
@@ -185,6 +186,7 @@ enum migrate_vma_direction {
 	MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
 	MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
 	MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2,
+	MIGRATE_VMA_SELECT_COMPOUND = 1 << 3,
 };
 
 struct migrate_vma {
-- 
2.49.0