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)
45 "1: lwarx %0,0,%2 # atomic_add_return\n\
51 : "r" (a), "r" (&v->counter)
57 static __inline__ void atomic_sub(int a, atomic_t *v)
62 "1: lwarx %0,0,%3 # atomic_sub\n\
66 : "=&r" (t), "=m" (v->counter)
67 : "r" (a), "r" (&v->counter), "m" (v->counter)
71 static __inline__ int atomic_sub_return(int a, atomic_t *v)
77 "1: lwarx %0,0,%2 # atomic_sub_return\n\
83 : "r" (a), "r" (&v->counter)
89 static __inline__ void atomic_inc(atomic_t *v)
94 "1: lwarx %0,0,%2 # atomic_inc\n\
98 : "=&r" (t), "=m" (v->counter)
99 : "r" (&v->counter), "m" (v->counter)
103 static __inline__ int atomic_inc_return(atomic_t *v)
107 __asm__ __volatile__(
109 "1: lwarx %0,0,%1 # atomic_inc_return\n\
121 static __inline__ void atomic_dec(atomic_t *v)
125 __asm__ __volatile__(
126 "1: lwarx %0,0,%2 # atomic_dec\n\
130 : "=&r" (t), "=m" (v->counter)
131 : "r" (&v->counter), "m" (v->counter)
135 static __inline__ int atomic_dec_return(atomic_t *v)
139 __asm__ __volatile__(
141 "1: lwarx %0,0,%1 # atomic_dec_return\n\
153 #define atomic_sub_and_test(a, v) (atomic_sub_return((a), (v)) == 0)
154 #define atomic_dec_and_test(v) (atomic_dec_return((v)) == 0)
157 * Atomically test *v and decrement if it is greater than 0.
158 * The function returns the old value of *v minus 1.
160 static __inline__ int atomic_dec_if_positive(atomic_t *v)
164 __asm__ __volatile__(
166 "1: lwarx %0,0,%1 # atomic_dec_if_positive\n\
180 #define smp_mb__before_atomic_dec() smp_mb()
181 #define smp_mb__after_atomic_dec() smp_mb()
182 #define smp_mb__before_atomic_inc() smp_mb()
183 #define smp_mb__after_atomic_inc() smp_mb()
185 #endif /* _ASM_PPC64_ATOMIC_H_ */