atomic.h

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#ifndef __ARCH_H8300_ATOMIC__
#define __ARCH_H8300_ATOMIC__

#include <linux/types.h>
#include <asm/cmpxchg.h>

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

#define ATOMIC_INIT(i)  { (i) }

#define atomic_read(v)      (*(volatile int *)&(v)->counter)
#define atomic_set(v, i)    (((v)->counter) = i)

#include <linux/kernel.h>

static __inline__ int atomic_add_return(int i, atomic_t *v)
{
    unsigned long flags;
    int ret;
    local_irq_save(flags);
    ret = v->counter += i;
    local_irq_restore(flags);
    return ret;
}

#define atomic_add(i, v) atomic_add_return(i, v)
#define atomic_add_negative(a, v)   (atomic_add_return((a), (v)) < 0)

static __inline__ int atomic_sub_return(int i, atomic_t *v)
{
    unsigned long flags;
    int ret;
    local_irq_save(flags);
    ret = v->counter -= i;
    local_irq_restore(flags);
    return ret;
}

#define atomic_sub(i, v) atomic_sub_return(i, v)
#define atomic_sub_and_test(i,v) (atomic_sub_return(i, v) == 0)

static __inline__ int atomic_inc_return(atomic_t *v)
{
    unsigned long flags;
    int ret;
    local_irq_save(flags);
    v->counter++;
    ret = v->counter;
    local_irq_restore(flags);
    return ret;
}

#define atomic_inc(v) atomic_inc_return(v)

/*
 * 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)

static __inline__ int atomic_dec_return(atomic_t *v)
{
    unsigned long flags;
    int ret;
    local_irq_save(flags);
    --v->counter;
    ret = v->counter;
    local_irq_restore(flags);
    return ret;
}

#define atomic_dec(v) atomic_dec_return(v)

static __inline__ int atomic_dec_and_test(atomic_t *v)
{
    unsigned long flags;
    int ret;
    local_irq_save(flags);
    --v->counter;
    ret = v->counter;
    local_irq_restore(flags);
    return ret == 0;
}

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 int __atomic_add_unless(atomic_t *v, int a, int u)
{
    int ret;
    unsigned long flags;

    local_irq_save(flags);
    ret = v->counter;
    if (ret != u)
        v->counter += a;
    local_irq_restore(flags);
    return ret;
}

static __inline__ void atomic_clear_mask(unsigned long mask, unsigned long *v)
{
    __asm__ __volatile__("stc ccr,r1l\n\t"
                         "orc #0x80,ccr\n\t"
                         "mov.l %0,er0\n\t"
                         "and.l %1,er0\n\t"
                         "mov.l er0,%0\n\t"
                         "ldc r1l,ccr" 
                             : "=m" (*v) : "g" (~(mask)) :"er0","er1");
}

static __inline__ void atomic_set_mask(unsigned long mask, unsigned long *v)
{
    __asm__ __volatile__("stc ccr,r1l\n\t"
                         "orc #0x80,ccr\n\t"
                         "mov.l %0,er0\n\t"
                         "or.l %1,er0\n\t"
                         "mov.l er0,%0\n\t"
                         "ldc r1l,ccr" 
                             : "=m" (*v) : "g" (mask) :"er0","er1");
}

/* 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 /* __ARCH_H8300_ATOMIC __ */