/* * Generic implementation of 64-bit atomics using spinlocks, * useful on processors that don't have 64-bit atomic instructions. * * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_GENERIC_ATOMIC64_H #define _ASM_GENERIC_ATOMIC64_H typedef struct { long long counter; } atomic64_t; #define ATOMIC64_INIT(i) { (i) } extern long long atomic64_read(const atomic64_t *v); extern void atomic64_set(atomic64_t *v, long long i); #define ATOMIC64_OP(op) \ extern void atomic64_##op(long long a, atomic64_t *v); #define ATOMIC64_OP_RETURN(op) \ extern long long atomic64_##op##_return(long long a, atomic64_t *v); #define ATOMIC64_FETCH_OP(op) \ extern long long atomic64_fetch_##op(long long a, atomic64_t *v); #define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op) ATOMIC64_OPS(add) ATOMIC64_OPS(sub) #undef ATOMIC64_OPS #define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op) ATOMIC64_OPS(and) ATOMIC64_OPS(or) ATOMIC64_OPS(xor) #undef ATOMIC64_OPS #undef ATOMIC64_FETCH_OP #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP extern long long atomic64_dec_if_positive(atomic64_t *v); extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n); extern long long atomic64_xchg(atomic64_t *v, long long new); extern int atomic64_add_unless(atomic64_t *v, long long a, long long u); #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) #define atomic64_inc(v) atomic64_add(1LL, (v)) #define atomic64_inc_return(v) atomic64_add_return(1LL, (v)) #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) #define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0) #define atomic64_dec(v) atomic64_sub(1LL, (v)) #define atomic64_dec_return(v) atomic64_sub_return(1LL, (v)) #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) #endif /* _ASM_GENERIC_ATOMIC64_H */ |