Subversion Repositories or1k

#ifndef __ARCH_I386_ATOMIC__

#define __ARCH_I386_ATOMIC__

/*

 * Atomic operations that C can't guarantee us.  Useful for

 * resource counting etc..

 */

#ifdef __SMP__

#define LOCK "lock ; "

#else

#define LOCK ""

#endif

/*

 * 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 int atomic_t;

static __inline__ void atomic_add(atomic_t i, atomic_t *v)

{

        __asm__ __volatile__(

                LOCK "addl %1,%0"

                :"=m" (__atomic_fool_gcc(v))

                :"ir" (i), "m" (__atomic_fool_gcc(v)));

}

static __inline__ void atomic_sub(atomic_t i, atomic_t *v)

{

        __asm__ __volatile__(

                LOCK "subl %1,%0"

                :"=m" (__atomic_fool_gcc(v))

                :"ir" (i), "m" (__atomic_fool_gcc(v)));

}

static __inline__ void atomic_inc(atomic_t *v)

{

        __asm__ __volatile__(

                LOCK "incl %0"

                :"=m" (__atomic_fool_gcc(v))

                :"m" (__atomic_fool_gcc(v)));

}

static __inline__ void atomic_dec(atomic_t *v)

{

        __asm__ __volatile__(

                LOCK "decl %0"

                :"=m" (__atomic_fool_gcc(v))

                :"m" (__atomic_fool_gcc(v)));

}

static __inline__ int atomic_dec_and_test(atomic_t *v)

{

        unsigned char c;

        __asm__ __volatile__(

                LOCK "decl %0; sete %1"

                :"=m" (__atomic_fool_gcc(v)), "=qm" (c)

                :"m" (__atomic_fool_gcc(v)));

        return c != 0;

}

#endif