2 * Generic implementation of 64-bit atomics using spinlocks,
3 * useful on processors that don't have 64-bit atomic instructions.
5 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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.
12 #ifndef _ASM_GENERIC_ATOMIC64_H
13 #define _ASM_GENERIC_ATOMIC64_H
19 #define ATOMIC64_INIT(i) { (i) }
21 extern long long atomic64_read(const atomic64_t *v);
22 extern void atomic64_set(atomic64_t *v, long long i);
24 #define ATOMIC64_OP(op) \
25 extern void atomic64_##op(long long a, atomic64_t *v);
27 #define ATOMIC64_OP_RETURN(op) \
28 extern long long atomic64_##op##_return(long long a, atomic64_t *v);
30 #define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
36 #undef ATOMIC64_OP_RETURN
39 extern long long atomic64_dec_if_positive(atomic64_t *v);
40 extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
41 extern long long atomic64_xchg(atomic64_t *v, long long new);
42 extern int atomic64_add_unless(atomic64_t *v, long long a, long long u);
44 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
45 #define atomic64_inc(v) atomic64_add(1LL, (v))
46 #define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
47 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
48 #define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
49 #define atomic64_dec(v) atomic64_sub(1LL, (v))
50 #define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
51 #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
52 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
54 #endif /* _ASM_GENERIC_ATOMIC64_H */