#ifndef __ARCH_I386_ATOMIC__
#define __ARCH_I386_ATOMIC__

#include <linux/compiler.h>
#include <asm/processor.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.
 */
typedef struct { volatile int counter; } atomic_t;

#define ATOMIC_INIT(i)  { (i) }

/**
 * atomic_read - read atomic variable
 * @v: pointer of type atomic_t
 * 
 * Atomically reads the value of @v.
 */ 
#define atomic_read(v)          ((v)->counter)

/**
 * atomic_set - set atomic variable
 * @v: pointer of type atomic_t
 * @i: required value
 * 
 * Atomically sets the value of @v to @i.
 */ 
#define atomic_set(v,i)         (((v)->counter) = (i))

/**
 * atomic_add - add integer to atomic variable
 * @i: integer value to add
 * @v: pointer of type atomic_t
 * 
 * Atomically adds @i to @v.
 */
static __inline__ void atomic_add(int i, atomic_t *v)
{
        __asm__ __volatile__(
                LOCK_PREFIX "addl %1,%0"
                :"+m" (v->counter)
                :"ir" (i));
}

/**
 * atomic_sub - subtract the atomic variable
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 * 
 * Atomically subtracts @i from @v.
 */
static __inline__ void atomic_sub(int i, atomic_t *v)
{
        __asm__ __volatile__(
                LOCK_PREFIX "subl %1,%0"
                :"+m" (v->counter)
                :"ir" (i));
}

/**
 * atomic_sub_and_test - subtract value from variable and test result
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 * 
 * Atomically subtracts @i from @v and returns
 * true if the result is zero, or false for all
 * other cases.
 */
static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
{
        unsigned char c;

        __asm__ __volatile__(
                LOCK_PREFIX "subl %2,%0; sete %1"
                :"+m" (v->counter), "=qm" (c)
                :"ir" (i) : "memory");
        return c;
}

/**
 * atomic_inc - increment atomic variable
 * @v: pointer of type atomic_t
 * 
 * Atomically increments @v by 1.
 */ 
static __inline__ void atomic_inc(atomic_t *v)
{
        __asm__ __volatile__(
                LOCK_PREFIX "incl %0"
                :"+m" (v->counter));
}

/**
 * atomic_dec - decrement atomic variable
 * @v: pointer of type atomic_t
 * 
 * Atomically decrements @v by 1.
 */ 
static __inline__ void atomic_dec(atomic_t *v)
{
        __asm__ __volatile__(
                LOCK_PREFIX "decl %0"
                :"+m" (v->counter));
}

/**
 * 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.
 */ 
static __inline__ int atomic_dec_and_test(atomic_t *v)
{
        unsigned char c;

        __asm__ __volatile__(
                LOCK_PREFIX "decl %0; sete %1"
                :"+m" (v->counter), "=qm" (c)
                : : "memory");
        return c != 0;
}

/**
 * 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.
 */ 
static __inline__ int atomic_inc_and_test(atomic_t *v)
{
        unsigned char c;

        __asm__ __volatile__(
                LOCK_PREFIX "incl %0; sete %1"
                :"+m" (v->counter), "=qm" (c)
                : : "memory");
        return c != 0;
}

/**
 * atomic_add_negative - add and test if negative
 * @v: pointer of type atomic_t
 * @i: integer value to add
 * 
 * Atomically adds @i to @v and returns true
 * if the result is negative, or false when
 * result is greater than or equal to zero.
 */ 
static __inline__ int atomic_add_negative(int i, atomic_t *v)
{
        unsigned char c;

        __asm__ __volatile__(
                LOCK_PREFIX "addl %2,%0; sets %1"
                :"+m" (v->counter), "=qm" (c)
                :"ir" (i) : "memory");
        return c;
}

/**
 * atomic_add_return - add and return
 * @v: pointer of type atomic_t
 * @i: integer value to add
 *
 * Atomically adds @i to @v and returns @i + @v
 */
static __inline__ int atomic_add_return(int i, atomic_t *v)
{
        int __i;
#ifdef CONFIG_M386
        unsigned long flags;
        if(unlikely(boot_cpu_data.x86==3))
                goto no_xadd;
#endif
        /* Modern 486+ processor */
        __i = i;
        __asm__ __volatile__(
                LOCK_PREFIX "xaddl %0, %1;"
                :"=r"(i)
                :"m"(v->counter), "0"(i));
        return i + __i;

#ifdef CONFIG_M386
no_xadd: /* Legacy 386 processor */
        local_irq_save(flags);
        __i = atomic_read(v);
        atomic_set(v, i + __i);
        local_irq_restore(flags);
        return i + __i;
#endif
}

static __inline__ int atomic_sub_return(int i, atomic_t *v)
{
        return atomic_add_return(-i,v);
}

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

/**
 * atomic_add_unless - add unless the number is a given value
 * @v: pointer of type atomic_t
 * @a: the amount to add to v...
 * @u: ...unless v is equal to u.
 *
 * Atomically adds @a to @v, so long as it was not @u.
 * Returns non-zero if @v was not @u, and zero otherwise.
 */
#define atomic_add_unless(v, a, u)                              \
({                                                              \
        int c, old;                                             \
        c = atomic_read(v);                                     \
        for (;;) {                                              \
                if (unlikely(c == (u)))                         \
                        break;                                  \
                old = atomic_cmpxchg((v), c, c + (a));          \
                if (likely(old == c))                           \
                        break;                                  \
                c = old;                                        \
        }                                                       \
        c != (u);                                               \
})
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

#define atomic_inc_return(v)  (atomic_add_return(1,v))
#define atomic_dec_return(v)  (atomic_sub_return(1,v))

/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \
: : "r" (~(mask)),"m" (*addr) : "memory")

#define atomic_set_mask(mask, addr) \
__asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \
: : "r" (mask),"m" (*(addr)) : "memory")

/* Atomic operations are already serializing on x86 */
#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()

#include <asm-generic/atomic.h>
#endif