/* * 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  */