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| author | David S. Miller <davem@davemloft.net> | 2010-06-26 10:27:00 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-06-26 10:27:00 -0700 |
| commit | c67dda14389205f0a223c5089307495290939b3b (patch) | |
| tree | fad0bb26b28703d02a22ebdd44d94eabac4a2ade /arch/s390/include/asm/atomic.h | |
| parent | 43bc2db47292a824152145253b1dd2847e7312a3 (diff) | |
| parent | 7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff) | |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'arch/s390/include/asm/atomic.h')
| -rw-r--r-- | arch/s390/include/asm/atomic.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h index 451bfbb9db3d..76daea117181 100644 --- a/arch/s390/include/asm/atomic.h +++ b/arch/s390/include/asm/atomic.h @@ -15,6 +15,7 @@ #include <linux/compiler.h> #include <linux/types.h> +#include <asm/system.h> #define ATOMIC_INIT(i) { (i) } @@ -274,6 +275,7 @@ static inline void atomic64_clear_mask(unsigned long long mask, atomic64_t *v) static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) { long long c, old; + c = atomic64_read(v); for (;;) { if (unlikely(c == u)) @@ -286,6 +288,23 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) return c != u; } +static inline long long atomic64_dec_if_positive(atomic64_t *v) +{ + long long c, old, dec; + + c = atomic64_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic64_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + 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) |