[PATCH v3 02/11] s390x/mm: Fail when an altmap is used for arch_add_memory()

[David Hildenbrand <david@xxxxxxxxxx>]

ZONE_DEVICE is not yet supported, fail if an altmap is passed, so we
don't forget arch_add_memory()/arch_remove_memory() when unlocking
support.

Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxxx>
Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 arch/s390/mm/init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 14d1eae9fe43..d552e330fbcc 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -226,6 +226,9 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	unsigned long size_pages = PFN_DOWN(size);
 	int rc;
 
+	if (WARN_ON_ONCE(restrictions->altmap))
+		return -EINVAL;
+
 	rc = vmem_add_mapping(start, size);
 	if (rc)
 		return rc;
-- 
2.20.1