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/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */
#ifndef __ASM_CRIS_ATOMIC__
#define __ASM_CRIS_ATOMIC__
#include <asm/system.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
* not some alias that contains the same information.
*/
#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
typedef struct { int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) ((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
/* These should be written in asm but we do it in C for now. */
static __inline__ void atomic_add(int i, volatile atomic_t *v)
{
unsigned long flags;
save_flags(flags);
cli();
v->counter += i;
restore_flags(flags);
}
static __inline__ void atomic_sub(int i, volatile atomic_t *v)
{
unsigned long flags;
save_flags(flags);
cli();
v->counter -= i;
restore_flags(flags);
}
static __inline__ int atomic_add_return(int i, volatile atomic_t *v)
{
unsigned long flags;
int retval;
save_flags(flags);
cli();
retval = (v->counter += i);
restore_flags(flags);
return retval;
}
static __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
{
unsigned long flags;
int retval;
save_flags(flags);
cli();
retval = (v->counter -= i);
restore_flags(flags);
return retval;
}
static __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
{
int retval;
unsigned long flags;
save_flags(flags);
cli();
retval = (v->counter -= i) == 0;
restore_flags(flags);
return retval;
}
static __inline__ void atomic_inc(volatile atomic_t *v)
{
unsigned long flags;
save_flags(flags);
cli();
(v->counter)++;
restore_flags(flags);
}
static __inline__ void atomic_dec(volatile atomic_t *v)
{
unsigned long flags;
save_flags(flags);
cli();
(v->counter)--;
restore_flags(flags);
}
static __inline__ int atomic_inc_return(volatile atomic_t *v)
{
unsigned long flags;
int retval;
save_flags(flags);
cli();
retval = (v->counter)++;
restore_flags(flags);
return retval;
}
static __inline__ int atomic_dec_return(volatile atomic_t *v)
{
unsigned long flags;
int retval;
save_flags(flags);
cli();
retval = (v->counter)--;
restore_flags(flags);
return retval;
}
static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
{
int retval;
unsigned long flags;
save_flags(flags);
cli();
retval = --(v->counter) == 0;
restore_flags(flags);
return retval;
}
static __inline__ int atomic_inc_and_test(volatile atomic_t *v)
{
int retval;
unsigned long flags;
save_flags(flags);
cli();
retval = ++(v->counter) == 0;
restore_flags(flags);
return retval;
}
/* Atomic operations are already serializing */
#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
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