[PATCH v6 03/28] s390: Make UV folio operations work on whole folio

Claudio Imbrenda
2025-12-22T16:50:45Z

uv_destroy_folio() and uv_convert_from_secure_folio() should work on
all pages in the folio, not just the first one.

This was fine until now, but it will become a problem with upcoming
patches.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
arch/s390/kernel/uv.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index ed46950be86f..ca0849008c0d 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -134,14 +134,15 @@ static int uv_destroy(unsigned long paddr)
*/
int uv_destroy_folio(struct folio *folio)
{
+ unsigned long i;
int rc;

- /* Large folios cannot be secure */
- if (unlikely(folio_test_large(folio)))
- return 0;
-
folio_get(folio);
- rc = uv_destroy(folio_to_phys(folio));
+ for (i = 0; i < (1 << folio_order(folio)); i++) {
+ rc = uv_destroy(folio_to_phys(folio) + i * PAGE_SIZE);
+ if (rc)
+ break;
+ }
if (!rc)
clear_bit(PG_arch_1, &folio->flags.f);
folio_put(folio);
@@ -183,14 +184,15 @@ EXPORT_SYMBOL_GPL(uv_convert_from_secure);
*/
int uv_convert_from_secure_folio(struct folio *folio)
{
+ unsigned long i;
int rc;

- /* Large folios cannot be secure */
- if (unlikely(folio_test_large(folio)))
- return 0;
-
folio_get(folio);
- rc = uv_convert_from_secure(folio_to_phys(folio));
+ for (i = 0; i < (1 << folio_order(folio)); i++) {
+ rc = uv_convert_from_secure(folio_to_phys(folio) + i * PAGE_SIZE);
+ if (rc)
+ break;
+ }
if (!rc)
clear_bit(PG_arch_1, &folio->flags.f);
folio_put(folio);
--
2.52.0