[RFC PATCH v1 3/5] locking/atomic: mips: Refactor xchg_small to use atomic_fetch_and_or

[Rui Wang <wangrui@loongson.cn>]

From: wangrui <wangrui@loongson.cn>

Signed-by-off: Rui Wang <wangrui@loongson.cn>
Signed-by-off: hev <r@hev.cc>
---
 arch/mips/kernel/cmpxchg.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/mips/kernel/cmpxchg.c b/arch/mips/kernel/cmpxchg.c
index ac9c8cfb2ba9..34ef35194cbe 100644
--- a/arch/mips/kernel/cmpxchg.c
+++ b/arch/mips/kernel/cmpxchg.c
@@ -9,7 +9,7 @@
 
 unsigned long __xchg_small(volatile void *ptr, unsigned long val, unsigned int size)
 {
-	u32 old32, new32, load32, mask;
+	u32 old32, mask;
 	volatile u32 *ptr32;
 	unsigned int shift;
 
@@ -36,15 +36,9 @@ unsigned long __xchg_small(volatile void *ptr, unsigned long val, unsigned int s
 	 * includes our byte of interest, and load its value.
 	 */
 	ptr32 = (volatile u32 *)((unsigned long)ptr & ~0x3);
-	load32 = *ptr32;
-
-	do {
-		old32 = load32;
-		new32 = (load32 & ~mask) | (val << shift);
-		load32 = arch_cmpxchg(ptr32, old32, new32);
-	} while (load32 != old32);
+	old32 = atomic_fetch_and_or(ptr32, ~mask, val << shift);
 
-	return (load32 & mask) >> shift;
+	return (old32 & mask) >> shift;
 }
 
 unsigned long __cmpxchg_small(volatile void *ptr, unsigned long old,
-- 
2.32.0