1 files changed, 12 insertions, 59 deletions
diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
index d41d7cbf0ad..7eb18c1d8d6 100644
--- a/arch/arm/include/asm/cmpxchg.h
+++ b/arch/arm/include/asm/cmpxchg.h
@@ -229,66 +229,19 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr,
 				       (unsigned long)(n),		\
 				       sizeof(*(ptr))))
 
-#ifndef CONFIG_CPU_V6	/* min ARCH >= ARMv6K */
-
-/*
- * Note : ARMv7-M (currently unsupported by Linux) does not support
- * ldrexd/strexd. If ARMv7-M is ever supported by the Linux kernel, it should
- * not be allowed to use __cmpxchg64.
- */
-static inline unsigned long long __cmpxchg64(volatile void *ptr,
-					     unsigned long long old,
-					     unsigned long long new)
-{
-	register unsigned long long oldval asm("r0");
-	register unsigned long long __old asm("r2") = old;
-	register unsigned long long __new asm("r4") = new;
-	unsigned long res;
-
-	do {
-		asm volatile(
-		"	@ __cmpxchg8\n"
-		"	ldrexd	%1, %H1, [%2]\n"
-		"	mov	%0, #0\n"
-		"	teq	%1, %3\n"
-		"	teqeq	%H1, %H3\n"
-		"	strexdeq %0, %4, %H4, [%2]\n"
-			: "=&r" (res), "=&r" (oldval)
-			: "r" (ptr), "Ir" (__old), "r" (__new)
-			: "memory", "cc");
-	} while (res);
-
-	return oldval;
-}
-
-static inline unsigned long long __cmpxchg64_mb(volatile void *ptr,
-						unsigned long long old,
-						unsigned long long new)
-{
-	unsigned long long ret;
+#define cmpxchg64(ptr, o, n)						\
+	((__typeof__(*(ptr)))atomic64_cmpxchg(container_of((ptr),	\
+						atomic64_t,		\
+						counter),		\
+					      (unsigned long)(o),	\
+					      (unsigned long)(n)))
 
-	smp_mb();
-	ret = __cmpxchg64(ptr, old, new);
-	smp_mb();
-
-	return ret;
-}
-
-#define cmpxchg64(ptr,o,n)						\
-	((__typeof__(*(ptr)))__cmpxchg64_mb((ptr),			\
-					    (unsigned long long)(o),	\
-					    (unsigned long long)(n)))
-
-#define cmpxchg64_local(ptr,o,n)					\
-	((__typeof__(*(ptr)))__cmpxchg64((ptr),				\
-					 (unsigned long long)(o),	\
-					 (unsigned long long)(n)))
-
-#else /* min ARCH = ARMv6 */
-
-#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
-
-#endif
+#define cmpxchg64_local(ptr, o, n)					\
+	((__typeof__(*(ptr)))local64_cmpxchg(container_of((ptr),	\
+						local64_t,		\
+						a),			\
+					     (unsigned long)(o),	\
+					     (unsigned long)(n)))
 
 #endif	/* __LINUX_ARM_ARCH__ >= 6 */