blob: b18ce4f9ee3d8330c9bbd884bcd772dcc172d268 [file] [log] [blame]
Paul Mackerras09d4e0e2009-06-12 21:10:05 +00001/*
2 * Generic implementation of 64-bit atomics using spinlocks,
3 * useful on processors that don't have 64-bit atomic instructions.
4 *
5 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
6 *
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.
11 */
12#ifndef _ASM_GENERIC_ATOMIC64_H
13#define _ASM_GENERIC_ATOMIC64_H
14
15typedef struct {
16 long long counter;
17} atomic64_t;
18
19#define ATOMIC64_INIT(i) { (i) }
20
21extern long long atomic64_read(const atomic64_t *v);
22extern void atomic64_set(atomic64_t *v, long long i);
23extern void atomic64_add(long long a, atomic64_t *v);
24extern long long atomic64_add_return(long long a, atomic64_t *v);
25extern void atomic64_sub(long long a, atomic64_t *v);
26extern long long atomic64_sub_return(long long a, atomic64_t *v);
27extern long long atomic64_dec_if_positive(atomic64_t *v);
28extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
29extern long long atomic64_xchg(atomic64_t *v, long long new);
30extern int atomic64_add_unless(atomic64_t *v, long long a, long long u);
31
32#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
33#define atomic64_inc(v) atomic64_add(1LL, (v))
34#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
35#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
36#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
37#define atomic64_dec(v) atomic64_sub(1LL, (v))
38#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
39#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
40#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
41
42#endif /* _ASM_GENERIC_ATOMIC64_H */