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/*
* linux/include/asm-arm26/atomic.h
*
* Copyright (c) 1996 Russell King.
* Modified for arm26 by Ian Molton
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Changelog:
* 25-11-2004 IM Updated for 2.6.9
* 27-06-1996 RMK Created
* 13-04-1997 RMK Made functions atomic!
* 07-12-1997 RMK Upgraded for v2.1.
* 26-08-1998 PJB Added #ifdef __KERNEL__
*
* FIXME - its probably worth seeing what these compile into...
*/
#ifndef __ASM_ARM_ATOMIC_H
#define __ASM_ARM_ATOMIC_H
#include <linux/config.h>
#ifdef CONFIG_SMP
#error SMP is NOT supported
#endif
typedef struct { volatile int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
#ifdef __KERNEL__
#include <asm/system.h>
#define atomic_read(v) ((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long flags;
int val;
local_irq_save(flags);
val = v->counter;
v->counter = val += i;
local_irq_restore(flags);
return val;
}
static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long flags;
int val;
local_irq_save(flags);
val = v->counter;
v->counter = val -= i;
local_irq_restore(flags);
return val;
}
static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
int ret;
unsigned long flags;
local_irq_save(flags);
ret = v->counter;
if (likely(ret == old))
v->counter = new;
local_irq_restore(flags);
return ret;
}
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
{
unsigned long flags;
local_irq_save(flags);
*addr &= ~mask;
local_irq_restore(flags);
}
#define atomic_add(i, v) (void) atomic_add_return(i, v)
#define atomic_inc(v) (void) atomic_add_return(1, v)
#define atomic_sub(i, v) (void) atomic_sub_return(i, v)
#define atomic_dec(v) (void) atomic_sub_return(1, v)
#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic_inc_return(v) (atomic_add_return(1, v))
#define atomic_dec_return(v) (atomic_sub_return(1, v))
#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
/* Atomic operations are already serializing on ARM26 */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
#endif
#endif
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