According to memory-barriers.txt, xchg and its atomic{,64}_ versions
need to imply a full barrier, however they are now just RELEASE+ACQUIRE,
which is not a full barrier.
So remove the definition of xchg(), and let __atomic_op_fence() build
the full-barrier versions of these operations.
Signed-off-by: Boqun Feng <boqun.f...@gmail.com>
---
arch/powerpc/include/asm/cmpxchg.h | 64 --------------------------------------
1 file changed, 64 deletions(-)
diff --git a/arch/powerpc/include/asm/cmpxchg.h
b/arch/powerpc/include/asm/cmpxchg.h
index f40f295..9f0379a 100644
--- a/arch/powerpc/include/asm/cmpxchg.h
+++ b/arch/powerpc/include/asm/cmpxchg.h
@@ -12,31 +12,7 @@
* Changes the memory location '*ptr' to be val and returns
* the previous value stored there.
*/
-static __always_inline unsigned long
-__xchg_u32(volatile void *p, unsigned long val)
-{
- unsigned long prev;
- __asm__ __volatile__(
- PPC_RELEASE_BARRIER
-"1: lwarx %0,0,%2 \n"
- PPC405_ERR77(0,%2)
-" stwcx. %3,0,%2 \n\
- bne- 1b"
- PPC_ACQUIRE_BARRIER
- : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
- : "r" (p), "r" (val)
- : "cc", "memory");
-
- return prev;
-}
-
-/*
- * Atomic exchange
- *
- * Changes the memory location '*ptr' to be val and returns
- * the previous value stored there.
- */
static __always_inline unsigned long
__xchg_u32_local(volatile void *p, unsigned long val)
{
@@ -82,25 +58,6 @@ __xchg_u32_relaxed(u32 *p, unsigned long val)
#ifdef CONFIG_PPC64
static __always_inline unsigned long
-__xchg_u64(volatile void *p, unsigned long val)
-{
- unsigned long prev;
-
- __asm__ __volatile__(
- PPC_RELEASE_BARRIER
-"1: ldarx %0,0,%2 \n"
- PPC405_ERR77(0,%2)
-" stdcx. %3,0,%2 \n\
- bne- 1b"
- PPC_ACQUIRE_BARRIER
- : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
- : "r" (p), "r" (val)
- : "cc", "memory");
-
- return prev;
-}
-
-static __always_inline unsigned long
__xchg_u64_local(volatile void *p, unsigned long val)
{
unsigned long prev;
@@ -142,21 +99,6 @@ __xchg_u64_relaxed(u64 *p, unsigned long val)
extern void __xchg_called_with_bad_pointer(void);
static __always_inline unsigned long
-__xchg(volatile void *ptr, unsigned long x, unsigned int size)
-{
- switch (size) {
- case 4:
- return __xchg_u32(ptr, x);
-#ifdef CONFIG_PPC64
- case 8:
- return __xchg_u64(ptr, x);
-#endif
- }
- __xchg_called_with_bad_pointer();
- return x;
-}
-
-static __always_inline unsigned long
__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
{
switch (size) {
@@ -185,12 +127,6 @@ __xchg_relaxed(void *ptr, unsigned long x, unsigned int
size)
__xchg_called_with_bad_pointer();
return x;
}
-#define xchg(ptr,x) \
- ({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
- })
-
#define xchg_local(ptr,x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
--
2.5.1
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