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authorHeiko Carstens <heiko.carstens@de.ibm.com>2011-03-23 10:16:06 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2011-03-23 10:16:00 +0100
commit54eaae3028e6b09de0bd2232a8176fc0d0a2397a (patch)
tree5a557243c1684ad5047614a5b2c19a43dd98b561 /arch/s390/include
parenta2c9dbe8dbb8591ae6fd142e562813cd95d06609 (diff)
[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>
Diffstat (limited to 'arch/s390/include')
-rw-r--r--arch/s390/include/asm/cmpxchg.h38
1 files changed, 29 insertions, 9 deletions
diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h
index 4052df9030c..7488e52efa9 100644
--- a/arch/s390/include/asm/cmpxchg.h
+++ b/arch/s390/include/asm/cmpxchg.h
@@ -164,6 +164,33 @@ static inline unsigned long __cmpxchg(void *ptr, unsigned long old,
((__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 @@ static inline unsigned long __cmpxchg_local(void *ptr,
#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 */