source: GPL/trunk/include/asm/atomic.h@ 260

#ifndef __ARCH_I386_ATOMIC__
#define __ARCH_I386_ATOMIC__

#define LOCK

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))

void atomic_add(int i, volatile atomic_t *v);
void atomic_sub(int i, volatile atomic_t *v);

void atomic_inc(volatile atomic_t *v);
#pragma aux atomic_inc =       \
  "lock inc dword ptr [eax]"                  \
  parm [eax];

void atomic_dec(volatile atomic_t *v);
#pragma aux atomic_dec =       \
  "lock dec dword ptr [eax]"                  \
  parm [eax];

/**
 * atomic_dec_and_test - decrement and test
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and
 * returns true if the result is 0, or false for all other
 * cases.  Note that the guaranteed
 * useful range of an atomic_t is only 24 bits.
 */
static inline int atomic_dec_and_test(volatile atomic_t *v)
{
    atomic_dec(v);
    if (v->counter == 0)
        return 1;
    return 0;
}

extern int atomic_add_negative(int i, volatile atomic_t *v);

/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) 

#define atomic_set_mask(mask, addr) 

#endif