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| author | Heiko Carstens | 2013-09-16 10:44:54 +0200 |
|---|---|---|
| committer | Martin Schwidefsky | 2013-10-24 17:16:51 +0200 |
| commit | 5692e4d11cf5b51045a41daf295626c7fcbb698a (patch) | |
| tree | c1c26e0633e3a71ecdd09be0569b19452e6141c2 /arch/s390 | |
| parent | s390/qdio: fix atomic_sub() misusage (diff) | |
| download | kernel-qcow2-linux-5692e4d11cf5b51045a41daf295626c7fcbb698a.tar.gz kernel-qcow2-linux-5692e4d11cf5b51045a41daf295626c7fcbb698a.tar.xz kernel-qcow2-linux-5692e4d11cf5b51045a41daf295626c7fcbb698a.zip | |
s390/atomic: optimize atomic_add() for constant values
If the interlocked-access facility 1 is available we can use the asi
and agsi instructions for interlocked updates if the to be added
value is a contanst and small (in the range of -128..127).
asi and agsi do not not return the old or new value, therefore these
instructions can only be used for atomic_(add|sub|inc|dec)[64].
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/atomic.h | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h index 823ec99cf426..b58ea97b176f 100644 --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -82,15 +82,31 @@ static inline int atomic_add_return(int i, atomic_t *v) return __ATOMIC_LOOP(v, i, __ATOMIC_ADD) + i; } -#define atomic_add(_i, _v) atomic_add_return(_i, _v) +static inline void atomic_add(int i, atomic_t *v) +{ +#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES + if (__builtin_constant_p(i) && (i > -129) && (i < 128)) { + asm volatile( + "asi %0,%1\n" + : "+Q" (v->counter) + : "i" (i) + : "cc", "memory"); + } else { + atomic_add_return(i, v); + } +#else + atomic_add_return(i, v); +#endif +} + #define atomic_add_negative(_i, _v) (atomic_add_return(_i, _v) < 0) -#define atomic_inc(_v) atomic_add_return(1, _v) +#define atomic_inc(_v) atomic_add(1, _v) #define atomic_inc_return(_v) atomic_add_return(1, _v) #define atomic_inc_and_test(_v) (atomic_add_return(1, _v) == 0) +#define atomic_sub(_i, _v) atomic_add(-(int)(_i), _v) #define atomic_sub_return(_i, _v) atomic_add_return(-(int)(_i), _v) -#define atomic_sub(_i, _v) atomic_sub_return(_i, _v) #define atomic_sub_and_test(_i, _v) (atomic_sub_return(_i, _v) == 0) -#define atomic_dec(_v) atomic_sub_return(1, _v) +#define atomic_dec(_v) atomic_sub(1, _v) #define atomic_dec_return(_v) atomic_sub_return(1, _v) #define atomic_dec_and_test(_v) (atomic_sub_return(1, _v) == 0) @@ -314,6 +330,23 @@ static inline void atomic64_clear_mask(unsigned long long mask, atomic64_t *v) #endif /* CONFIG_64BIT */ +static inline void atomic64_add(long long i, atomic64_t *v) +{ +#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES + if (__builtin_constant_p(i) && (i > -129) && (i < 128)) { + asm volatile( + "agsi %0,%1\n" + : "+Q" (v->counter) + : "i" (i) + : "cc", "memory"); + } else { + atomic64_add_return(i, v); + } +#else + atomic64_add_return(i, v); +#endif +} + static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) { long long c, old; @@ -347,15 +380,14 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v) return dec; } -#define atomic64_add(_i, _v) atomic64_add_return(_i, _v) #define atomic64_add_negative(_i, _v) (atomic64_add_return(_i, _v) < 0) -#define atomic64_inc(_v) atomic64_add_return(1, _v) +#define atomic64_inc(_v) atomic64_add(1, _v) #define atomic64_inc_return(_v) atomic64_add_return(1, _v) #define atomic64_inc_and_test(_v) (atomic64_add_return(1, _v) == 0) #define atomic64_sub_return(_i, _v) atomic64_add_return(-(long long)(_i), _v) -#define atomic64_sub(_i, _v) atomic64_sub_return(_i, _v) +#define atomic64_sub(_i, _v) atomic64_add(-(long long)(_i), _v) #define atomic64_sub_and_test(_i, _v) (atomic64_sub_return(_i, _v) == 0) -#define atomic64_dec(_v) atomic64_sub_return(1, _v) +#define atomic64_dec(_v) atomic64_sub(1, _v) #define atomic64_dec_return(_v) atomic64_sub_return(1, _v) #define atomic64_dec_and_test(_v) (atomic64_sub_return(1, _v) == 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) |