diff options
Diffstat (limited to 'arch/s390/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/s390/include/asm/cmpxchg.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/s390/include/asm/cmpxchg.h b/arch/s390/include/asm/cmpxchg.h index 587529673399..05f123d39bc3 100644 --- a/arch/s390/include/asm/cmpxchg.h +++ b/arch/s390/include/asm/cmpxchg.h @@ -11,6 +11,7 @@ #include <linux/mmdebug.h> #include <linux/types.h> #include <linux/bug.h> +#include <asm/asm.h> void __xchg_called_with_bad_pointer(void); @@ -174,6 +175,57 @@ static __always_inline u64 __arch_cmpxchg(u64 ptr, u64 old, u64 new, int size) #define arch_cmpxchg_local arch_cmpxchg #define arch_cmpxchg64_local arch_cmpxchg +#ifdef __HAVE_ASM_FLAG_OUTPUTS__ + +#define arch_try_cmpxchg(ptr, oldp, new) \ +({ \ + __typeof__(ptr) __oldp = (__typeof__(ptr))(oldp); \ + __typeof__(*(ptr)) __old = *__oldp; \ + __typeof__(*(ptr)) __new = (new); \ + __typeof__(*(ptr)) __prev; \ + int __cc; \ + \ + switch (sizeof(*(ptr))) { \ + case 1: \ + case 2: { \ + __prev = arch_cmpxchg((ptr), (__old), (__new)); \ + __cc = (__prev != __old); \ + if (unlikely(__cc)) \ + *__oldp = __prev; \ + break; \ + } \ + case 4: { \ + asm volatile( \ + " cs %[__old],%[__new],%[__ptr]\n" \ + : [__old] "+d" (*__oldp), \ + [__ptr] "+Q" (*(ptr)), \ + "=@cc" (__cc) \ + : [__new] "d" (__new) \ + : "memory"); \ + break; \ + } \ + case 8: { \ + asm volatile( \ + " csg %[__old],%[__new],%[__ptr]\n" \ + : [__old] "+d" (*__oldp), \ + [__ptr] "+QS" (*(ptr)), \ + "=@cc" (__cc) \ + : [__new] "d" (__new) \ + : "memory"); \ + break; \ + } \ + default: \ + __cmpxchg_called_with_bad_pointer(); \ + } \ + likely(__cc == 0); \ +}) + +#define arch_try_cmpxchg64 arch_try_cmpxchg +#define arch_try_cmpxchg_local arch_try_cmpxchg +#define arch_try_cmpxchg64_local arch_try_cmpxchg + +#endif /* __HAVE_ASM_FLAG_OUTPUTS__ */ + #define system_has_cmpxchg128() 1 static __always_inline u128 arch_cmpxchg128(volatile u128 *ptr, u128 old, u128 new) |