[S390] cmpxchg: implement cmpxchg64()
We have a cmpxchg64_local() implementation but strange enough the
SMP capable variant cmpxchg64() is missing. So implement it.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h
index 4052df9..7488e52 100644
--- a/arch/s390/include/asm/cmpxchg.h
+++ b/arch/s390/include/asm/cmpxchg.h
@@ -164,6 +164,33 @@
((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
+#ifdef CONFIG_64BIT
+#define cmpxchg64(ptr, o, n) \
+({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg((ptr), (o), (n)); \
+})
+#else /* CONFIG_64BIT */
+static inline unsigned long long __cmpxchg64(void *ptr,
+ unsigned long long old,
+ unsigned long long new)
+{
+ register_pair rp_old = {.pair = old};
+ register_pair rp_new = {.pair = new};
+
+ asm volatile(
+ " cds %0,%2,%1"
+ : "+&d" (rp_old), "=Q" (ptr)
+ : "d" (rp_new), "Q" (ptr)
+ : "cc");
+ return rp_old.pair;
+}
+#define cmpxchg64(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg64((ptr), \
+ (unsigned long long)(o), \
+ (unsigned long long)(n)))
+#endif /* CONFIG_64BIT */
+
#include <asm-generic/cmpxchg-local.h>
static inline unsigned long __cmpxchg_local(void *ptr,
@@ -192,14 +219,7 @@
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
-#ifdef CONFIG_64BIT
-#define cmpxchg64_local(ptr, o, n) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
- cmpxchg_local((ptr), (o), (n)); \
-})
-#else
-#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
-#endif
+
+#define cmpxchg64_local(ptr, o, n) cmpxchg64((ptr), (o), (n))
#endif /* __ASM_CMPXCHG_H */