[PATCH v3 3/7] mm: Split device-private and coherent folios before freeing

[Francois Dugast]

From: Matthew Brost <matthew.brost@xxxxxxxxx>

Split device-private and coherent folios into individual pages before
freeing so that any order folio can be formed upon the next use of the
pages.

Cc: Balbir Singh <balbirs@xxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-cxl@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Signed-off-by: Francois Dugast <francois.dugast@xxxxxxxxx>
---
 mm/memremap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/memremap.c b/mm/memremap.c
index 63c6ab4fdf08..7289cdd6862f 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -453,6 +453,8 @@ void free_zone_device_folio(struct folio *folio)
 	case MEMORY_DEVICE_COHERENT:
 		if (WARN_ON_ONCE(!pgmap->ops || !pgmap->ops->folio_free))
 			break;
+
+		folio_split_unref(folio);
 		pgmap->ops->folio_free(folio);
 		percpu_ref_put_many(&folio->pgmap->ref, nr);
 		break;
-- 
2.43.0