/* * PowerPC64 atomic operations * * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_PPC64_ATOMIC_H_ #define _ASM_PPC64_ATOMIC_H_ #include <asm/memory.h> typedef struct { volatile int counter; } atomic_t; #define ATOMIC_INIT(i) { (i) } #define atomic_read(v) ((v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) static __inline__ void atomic_add(int a, atomic_t *v) { int t; __asm__ __volatile__( "1: lwarx %0,0,%3 # atomic_add\n\ add %0,%2,%0\n\ stwcx. %0,0,%3\n\ bne- 1b" : "=&r" (t), "=m" (v->counter) : "r" (a), "r" (&v->counter), "m" (v->counter) : "cc"); } static __inline__ int atomic_add_return(int a, atomic_t *v) { int t; __asm__ __volatile__( EIEIO_ON_SMP "1: lwarx %0,0,%2 # atomic_add_return\n\ add %0,%1,%0\n\ stwcx. %0,0,%2\n\ bne- 1b" ISYNC_ON_SMP : "=&r" (t) : "r" (a), "r" (&v->counter) : "cc", "memory"); return t; } #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) static __inline__ void atomic_sub(int a, atomic_t *v) { int t; __asm__ __volatile__( "1: lwarx %0,0,%3 # atomic_sub\n\ subf %0,%2,%0\n\ stwcx. %0,0,%3\n\ bne- 1b" : "=&r" (t), "=m" (v->counter) : "r" (a), "r" (&v->counter), "m" (v->counter) : "cc"); } static __inline__ int atomic_sub_return(int a, atomic_t *v) { int t; __asm__ __volatile__( EIEIO_ON_SMP "1: lwarx %0,0,%2 # atomic_sub_return\n\ subf %0,%1,%0\n\ stwcx. %0,0,%2\n\ bne- 1b" ISYNC_ON_SMP : "=&r" (t) : "r" (a), "r" (&v->counter) : "cc", "memory"); return t; } static __inline__ void atomic_inc(atomic_t *v) { int t; __asm__ __volatile__( "1: lwarx %0,0,%2 # atomic_inc\n\ addic %0,%0,1\n\ stwcx. %0,0,%2\n\ bne- 1b" : "=&r" (t), "=m" (v->counter) : "r" (&v->counter), "m" (v->counter) : "cc"); } static __inline__ int atomic_inc_return(atomic_t *v) { int t; __asm__ __volatile__( EIEIO_ON_SMP "1: lwarx %0,0,%1 # atomic_inc_return\n\ addic %0,%0,1\n\ stwcx. %0,0,%1\n\ bne- 1b" ISYNC_ON_SMP : "=&r" (t) : "r" (&v->counter) : "cc", "memory"); return t; } /* * atomic_inc_and_test - increment and test * @v: pointer of type atomic_t * * Atomically increments @v by 1 * and returns true if the result is zero, or false for all * other cases. */ #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) static __inline__ void atomic_dec(atomic_t *v) { int t; __asm__ __volatile__( "1: lwarx %0,0,%2 # atomic_dec\n\ addic %0,%0,-1\n\ stwcx. %0,0,%2\n\ bne- 1b" : "=&r" (t), "=m" (v->counter) : "r" (&v->counter), "m" (v->counter) : "cc"); } static __inline__ int atomic_dec_return(atomic_t *v) { int t; __asm__ __volatile__( EIEIO_ON_SMP "1: lwarx %0,0,%1 # atomic_dec_return\n\ addic %0,%0,-1\n\ stwcx. %0,0,%1\n\ bne- 1b" ISYNC_ON_SMP : "=&r" (t) : "r" (&v->counter) : "cc", "memory"); return t; } #define atomic_sub_and_test(a, v) (atomic_sub_return((a), (v)) == 0) #define atomic_dec_and_test(v) (atomic_dec_return((v)) == 0) /* * Atomically test *v and decrement if it is greater than 0. * The function returns the old value of *v minus 1. */ static __inline__ int atomic_dec_if_positive(atomic_t *v) { int t; __asm__ __volatile__( EIEIO_ON_SMP "1: lwarx %0,0,%1 # atomic_dec_if_positive\n\ addic. %0,%0,-1\n\ blt- 2f\n\ stwcx. %0,0,%1\n\ bne- 1b" ISYNC_ON_SMP "\n\ 2:" : "=&r" (t) : "r" (&v->counter) : "cc", "memory"); return t; } #define smp_mb__before_atomic_dec() smp_mb() #define smp_mb__after_atomic_dec() smp_mb() #define smp_mb__before_atomic_inc() smp_mb() #define smp_mb__after_atomic_inc() smp_mb() #endif /* _ASM_PPC64_ATOMIC_H_ */