[PATCH] cmpxchg: Discard unnecessary cast to volatile

From: Pranith Kumar
Date: Wed Oct 01 2014 - 13:57:25 EST


Generating a volatile pointer is really not necessary here. This is the only
location where a volatile pointer is being generated for use in asm.

This commit removes the unnecessary volatile pointer being created.

Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
arch/x86/include/asm/cmpxchg.h | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 99c105d7..f0baea8 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -90,36 +90,32 @@ extern void __add_wrong_size(void)
switch (size) { \
case __X86_CASE_B: \
{ \
- volatile u8 *__ptr = (volatile u8 *)(ptr); \
asm volatile(lock "cmpxchgb %2,%1" \
- : "=a" (__ret), "+m" (*__ptr) \
+ : "=a" (__ret), "+m" (*ptr) \
: "q" (__new), "0" (__old) \
: "memory"); \
break; \
} \
case __X86_CASE_W: \
{ \
- volatile u16 *__ptr = (volatile u16 *)(ptr); \
asm volatile(lock "cmpxchgw %2,%1" \
- : "=a" (__ret), "+m" (*__ptr) \
+ : "=a" (__ret), "+m" (*ptr) \
: "r" (__new), "0" (__old) \
: "memory"); \
break; \
} \
case __X86_CASE_L: \
{ \
- volatile u32 *__ptr = (volatile u32 *)(ptr); \
asm volatile(lock "cmpxchgl %2,%1" \
- : "=a" (__ret), "+m" (*__ptr) \
+ : "=a" (__ret), "+m" (*ptr) \
: "r" (__new), "0" (__old) \
: "memory"); \
break; \
} \
case __X86_CASE_Q: \
{ \
- volatile u64 *__ptr = (volatile u64 *)(ptr); \
asm volatile(lock "cmpxchgq %2,%1" \
- : "=a" (__ret), "+m" (*__ptr) \
+ : "=a" (__ret), "+m" (*ptr) \
: "r" (__new), "0" (__old) \
: "memory"); \
break; \
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/