diff options
Diffstat (limited to 'include/asm-powerpc/atomic.h')
| -rw-r--r-- | include/asm-powerpc/atomic.h | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h index 147a38dcc766..bb3c0ab7e667 100644 --- a/include/asm-powerpc/atomic.h +++ b/include/asm-powerpc/atomic.h @@ -8,6 +8,7 @@ typedef struct { volatile int counter; } atomic_t; #ifdef __KERNEL__ +#include <linux/compiler.h> #include <asm/synch.h> #include <asm/asm-compat.h> @@ -176,20 +177,29 @@ static __inline__ int atomic_dec_return(atomic_t *v) * Atomically adds @a to @v, so long as it was not @u. * Returns non-zero if @v was not @u, and zero otherwise. */ -#define atomic_add_unless(v, a, u) \ -({ \ - int c, old; \ - c = atomic_read(v); \ - for (;;) { \ - if (unlikely(c == (u))) \ - break; \ - old = atomic_cmpxchg((v), c, c + (a)); \ - if (likely(old == c)) \ - break; \ - c = old; \ - } \ - c != (u); \ -}) +static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) +{ + int t; + + __asm__ __volatile__ ( + LWSYNC_ON_SMP +"1: lwarx %0,0,%1 # atomic_add_unless\n\ + cmpw 0,%0,%3 \n\ + beq- 2f \n\ + add %0,%2,%0 \n" + PPC405_ERR77(0,%2) +" stwcx. %0,0,%1 \n\ + bne- 1b \n" + ISYNC_ON_SMP +" subf %0,%2,%0 \n\ +2:" + : "=&r" (t) + : "r" (&v->counter), "r" (a), "r" (u) + : "cc", "memory"); + + return t != u; +} + #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) #define atomic_sub_and_test(a, v) (atomic_sub_return((a), (v)) == 0) |