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/* atomic.h: atomic operation emulation for FR-V
*
* For an explanation of how atomic ops work in this arch, see:
* Documentation/frv/atomic-ops.txt
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.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_ATOMIC_H
#define _ASM_ATOMIC_H
#include <linux/types.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#ifdef CONFIG_SMP
#error not SMP safe
#endif
#include <asm/atomic_defs.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* We do not have SMP systems, so we don't have to deal with that.
*/
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) READ_ONCE((v)->counter)
#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
static inline int atomic_inc_return(atomic_t *v)
{
return __atomic_add_return(1, &v->counter);
}
static inline int atomic_dec_return(atomic_t *v)
{
return __atomic_sub_return(1, &v->counter);
}
static inline int atomic_add_return(int i, atomic_t *v)
{
return __atomic_add_return(i, &v->counter);
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
return __atomic_sub_return(i, &v->counter);
}
static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}
static inline void atomic_inc(atomic_t *v)
{
atomic_inc_return(v);
}
static inline void atomic_dec(atomic_t *v)
{
atomic_dec_return(v);
}
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
/*
* 64-bit atomic ops
*/
typedef struct {
long long counter;
} atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
static inline long long atomic64_read(const atomic64_t *v)
{
long long counter;
asm("ldd%I1 %M1,%0"
: "=e"(counter)
: "m"(v->counter));
return counter;
}
static inline void atomic64_set(atomic64_t *v, long long i)
{
asm volatile("std%I0 %1,%M0"
: "=m"(v->counter)
: "e"(i));
}
static inline long long atomic64_inc_return(atomic64_t *v)
{
return __atomic64_add_return(1, &v->counter);
}
static inline long long atomic64_dec_return(atomic64_t *v)
{
return __atomic64_sub_return(1, &v->counter);
}
static inline long long atomic64_add_return(long long i, atomic64_t *v)
{
return __atomic64_add_return(i, &v->counter);
}
static inline long long atomic64_sub_return(long long i, atomic64_t *v)
{
return __atomic64_sub_return(i, &v->counter);
}
static inline long long atomic64_add_negative(long long i, atomic64_t *v)
{
return atomic64_add_return(i, v) < 0;
}
static inline void atomic64_inc(atomic64_t *v)
{
atomic64_inc_return(v);
}
static inline void atomic64_dec(atomic64_t *v)
{
atomic64_dec_return(v);
}
#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
#define atomic64_inc_and_test(v) (atomic64_inc_return((v)) == 0)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#define atomic_cmpxchg(v, old, new) (cmpxchg(&(v)->counter, old, new))
#define atomic_xchg(v, new) (xchg(&(v)->counter, new))
#define atomic64_cmpxchg(v, old, new) (__cmpxchg_64(old, new, &(v)->counter))
#define atomic64_xchg(v, new) (__xchg_64(new, &(v)->counter))
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c;
}
static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u)
{
long long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == u))
break;
old = atomic64_cmpxchg(v, c, c + i);
if (likely(old == c))
break;
c = old;
}
return c != u;
}
static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
long long c, old, dec;
c = atomic64_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic64_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
#define ATOMIC_OP(op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
return __atomic32_fetch_##op(i, &v->counter); \
} \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
(void)__atomic32_fetch_##op(i, &v->counter); \
} \
\
static inline long long atomic64_fetch_##op(long long i, atomic64_t *v) \
{ \
return __atomic64_fetch_##op(i, &v->counter); \
} \
static inline void atomic64_##op(long long i, atomic64_t *v) \
{ \
(void)__atomic64_fetch_##op(i, &v->counter); \
}
ATOMIC_OP(or)
ATOMIC_OP(and)
ATOMIC_OP(xor)
ATOMIC_OP(add)
ATOMIC_OP(sub)
#undef ATOMIC_OP
#endif /* _ASM_ATOMIC_H */
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