2 * PowerPC64 atomic operations
4 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
5 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #ifndef _ASM_PPC64_ATOMIC_H_
14 #define _ASM_PPC64_ATOMIC_H_
16 #include <asm/memory.h>
18 typedef struct { volatile int counter; } atomic_t;
20 #define ATOMIC_INIT(i) { (i) }
22 #define atomic_read(v) ((v)->counter)
23 #define atomic_set(v,i) (((v)->counter) = (i))
25 static __inline__ void atomic_add(int a, atomic_t *v)
30 "1: lwarx %0,0,%3 # atomic_add\n\
34 : "=&r" (t), "=m" (v->counter)
35 : "r" (a), "r" (&v->counter), "m" (v->counter)
39 static __inline__ int atomic_add_return(int a, atomic_t *v)
44 "1: lwarx %0,0,%2 # atomic_add_return\n\
50 : "r" (a), "r" (&v->counter)
56 static __inline__ void atomic_sub(int a, atomic_t *v)
61 "1: lwarx %0,0,%3 # atomic_sub\n\
65 : "=&r" (t), "=m" (v->counter)
66 : "r" (a), "r" (&v->counter), "m" (v->counter)
70 static __inline__ int atomic_sub_return(int a, atomic_t *v)
75 "1: lwarx %0,0,%2 # atomic_sub_return\n\
81 : "r" (a), "r" (&v->counter)
87 static __inline__ void atomic_inc(atomic_t *v)
92 "1: lwarx %0,0,%2 # atomic_inc\n\
96 : "=&r" (t), "=m" (v->counter)
97 : "r" (&v->counter), "m" (v->counter)
101 static __inline__ int atomic_inc_return(atomic_t *v)
105 __asm__ __volatile__(
106 "1: lwarx %0,0,%1 # atomic_inc_return\n\
118 static __inline__ void atomic_dec(atomic_t *v)
122 __asm__ __volatile__(
123 "1: lwarx %0,0,%2 # atomic_dec\n\
127 : "=&r" (t), "=m" (v->counter)
128 : "r" (&v->counter), "m" (v->counter)
132 static __inline__ int atomic_dec_return(atomic_t *v)
136 __asm__ __volatile__(
137 "1: lwarx %0,0,%1 # atomic_dec_return\n\
149 #define atomic_sub_and_test(a, v) (atomic_sub_return((a), (v)) == 0)
150 #define atomic_dec_and_test(v) (atomic_dec_return((v)) == 0)
153 * Atomically test *v and decrement if it is greater than 0.
154 * The function returns the old value of *v minus 1.
156 static __inline__ int atomic_dec_if_positive(atomic_t *v)
160 __asm__ __volatile__(
161 "1: lwarx %0,0,%1 # atomic_dec_if_positive\n\
175 #define smp_mb__before_atomic_dec() smp_mb()
176 #define smp_mb__after_atomic_dec() smp_mb()
177 #define smp_mb__before_atomic_inc() smp_mb()
178 #define smp_mb__after_atomic_inc() smp_mb()
180 #endif /* _ASM_PPC64_ATOMIC_H_ */