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authorHeiko Carstens <hca@linux.ibm.com>2023-03-17 16:51:41 +0300
committerHeiko Carstens <hca@linux.ibm.com>2023-03-20 13:12:49 +0300
commitd28d86a07dbca4b6e33032196ef4a9a7121181b4 (patch)
treeadb2709f82c814ccfb3dea39f903317c1c6b77aa /arch/s390
parent038c5bedbc313b55f66b26fda5a7808727c2f177 (diff)
downloadlinux-d28d86a07dbca4b6e33032196ef4a9a7121181b4.tar.xz
s390/mm: make use of atomic_fetch_xor()
Make use of atomic_fetch_xor() instead of an atomic_cmpxchg() loop to implement atomic_xor_bits() (aka atomic_xor_return()). This makes the C code more readable and in addition generates better code, since for z196 and newer a single lax instruction is generated instead of a cmpxchg() loop. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/mm/pgalloc.c8
1 files changed, 1 insertions, 7 deletions
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 0f68b7257e08..66ab68db9842 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -133,13 +133,7 @@ err_p4d:
static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
{
- unsigned int old, new;
-
- do {
- old = atomic_read(v);
- new = old ^ bits;
- } while (atomic_cmpxchg(v, old, new) != old);
- return new;
+ return atomic_fetch_xor(bits, v) ^ bits;
}
#ifdef CONFIG_PGSTE