[RFC PATCH v1 5/5] locking/atomic: xtensa: Refactor xchg_small to use atomic_fetch_and_or
DORMANTno replies
From: Rui Wang <hidden>
Date: 2021-07-28 11:50:11
Subsystem:
tensilica xtensa port (xtensa), the rest · Maintainers:
Chris Zankel, Max Filippov, Linus Torvalds
From: wangrui <redacted> Signed-by-off: Rui Wang [off-list ref] Signed-by-off: hev [off-list ref] --- arch/xtensa/include/asm/cmpxchg.h | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h
index 3699e2818efb..e118cfc00988 100644
--- a/arch/xtensa/include/asm/cmpxchg.h
+++ b/arch/xtensa/include/asm/cmpxchg.h@@ -182,16 +182,10 @@ static inline u32 xchg_small(volatile void *ptr, u32 x, int size) int bitoff = off * BITS_PER_BYTE; #endif u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff; - u32 oldv, newv; - u32 ret; + u32 oldv; - do { - oldv = READ_ONCE(*p); - ret = (oldv & bitmask) >> bitoff; - newv = (oldv & ~bitmask) | (x << bitoff); - } while (__cmpxchg_u32(p, oldv, newv) != oldv); - - return ret; + oldv = atomic_fetch_and_or(p, ~bitmask, x << bitoff); + return (oldv & bitmask) >> bitoff; } /*
--
2.32.0