linux/include/asm-cris/atomic.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

151 lines
3.3 KiB
C

/* $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. */
extern __inline__ void atomic_add(int i, volatile atomic_t *v)
{
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
v->counter += i;
local_irq_restore(flags);
}
extern __inline__ void atomic_sub(int i, volatile atomic_t *v)
{
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
v->counter -= i;
local_irq_restore(flags);
}
extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
{
unsigned long flags;
int retval;
local_save_flags(flags);
local_irq_disable();
retval = (v->counter += i);
local_irq_restore(flags);
return retval;
}
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
{
unsigned long flags;
int retval;
local_save_flags(flags);
local_irq_disable();
retval = (v->counter -= i);
local_irq_restore(flags);
return retval;
}
extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
{
int retval;
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
retval = (v->counter -= i) == 0;
local_irq_restore(flags);
return retval;
}
extern __inline__ void atomic_inc(volatile atomic_t *v)
{
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
(v->counter)++;
local_irq_restore(flags);
}
extern __inline__ void atomic_dec(volatile atomic_t *v)
{
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
(v->counter)--;
local_irq_restore(flags);
}
extern __inline__ int atomic_inc_return(volatile atomic_t *v)
{
unsigned long flags;
int retval;
local_save_flags(flags);
local_irq_disable();
retval = (v->counter)++;
local_irq_restore(flags);
return retval;
}
extern __inline__ int atomic_dec_return(volatile atomic_t *v)
{
unsigned long flags;
int retval;
local_save_flags(flags);
local_irq_disable();
retval = (v->counter)--;
local_irq_restore(flags);
return retval;
}
extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
{
int retval;
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
retval = --(v->counter) == 0;
local_irq_restore(flags);
return retval;
}
extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
{
int retval;
unsigned long flags;
local_save_flags(flags);
local_irq_disable();
retval = ++(v->counter) == 0;
local_irq_restore(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