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 © 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 15 typedef struct { 16 long long counter; 17 } atomic64_t; 18 19 #define ATOMIC64_INIT(i) { (i) } 20 21 extern long long atomic64_read(const atomic64_t *v); 22 extern void atomic64_set(atomic64_t *v, long long i); 23 extern void atomic64_add(long long a, atomic64_t *v); 24 extern long long atomic64_add_return(long long a, atomic64_t *v); 25 extern void atomic64_sub(long long a, atomic64_t *v); 26 extern long long atomic64_sub_return(long long a, atomic64_t *v); 27 extern long long atomic64_dec_if_positive(atomic64_t *v); 28 extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n); 29 extern long long atomic64_xchg(atomic64_t *v, long long new); 30 extern 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 */ 43