/include/asm-generic/atomic64.h

 1/*
 2 * Generic implementation of 64-bit atomics using spinlocks,
 3 * useful on processors that don't have 64-bit atomic instructions.
 4 *
 5 * Copyright Š 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  */