arch/blackfin/include/asm/atomic.h

/*
 * Copyright 2004-2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#ifndef __ARCH_BLACKFIN_ATOMIC__
#define __ARCH_BLACKFIN_ATOMIC__

#ifndef CONFIG_SMP
# include <asm-generic/atomic.h>
#else

#include <linux/types.h>
#include <asm/system.h>	/* local_irq_XXX() */

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

#define ATOMIC_INIT(i)	{ (i) }
#define atomic_set(v, i)	(((v)->counter) = i)

#define atomic_read(v)	__raw_uncached_fetch_asm(&(v)->counter)

asmlinkage int __raw_uncached_fetch_asm(const volatile int *ptr);

asmlinkage int __raw_atomic_update_asm(volatile int *ptr, int value);

asmlinkage int __raw_atomic_clear_asm(volatile int *ptr, int value);

asmlinkage int __raw_atomic_set_asm(volatile int *ptr, int value);

asmlinkage int __raw_atomic_xor_asm(volatile int *ptr, int value);

asmlinkage int __raw_atomic_test_asm(const volatile int *ptr, int value);

static inline void atomic_add(int i, atomic_t *v)
{
	__raw_atomic_update_asm(&v->counter, i);
}

static inline void atomic_sub(int i, atomic_t *v)
{
	__raw_atomic_update_asm(&v->counter, -i);
}

static inline int atomic_add_return(int i, atomic_t *v)
{
	return __raw_atomic_update_asm(&v->counter, i);
}

static inline int atomic_sub_return(int i, atomic_t *v)
{
	return __raw_atomic_update_asm(&v->counter, -i);
}

static inline void atomic_inc(volatile atomic_t *v)
{
	__raw_atomic_update_asm(&v->counter, 1);
}

static inline void atomic_dec(volatile atomic_t *v)
{
	__raw_atomic_update_asm(&v->counter, -1);
}

static inline void atomic_clear_mask(int mask, atomic_t *v)
{
	__raw_atomic_clear_asm(&v->counter, mask);
}

static inline void atomic_set_mask(int mask, atomic_t *v)
{
	__raw_atomic_set_asm(&v->counter, mask);
}

/* 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()

#define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)
#define atomic_dec_return(v) atomic_sub_return(1,(v))
#define atomic_inc_return(v) atomic_add_return(1,(v))

#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

#define __atomic_add_unless(v, a, u)				\
({								\
	int c, old;						\
	c = atomic_read(v);					\
	while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
		c = old;					\
	c;							\
})

/*
 * atomic_inc_and_test - increment and test
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1
 * and returns true if the result is zero, or false for all
 * other cases.
 */
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)

#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)


#endif

#endif