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#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) (*(volatile struct { int a[100]; } *)x)
#ifdef __SMP__
typedef struct { volatile int counter; } atomic_t;
#else
typedef struct { int counter; } atomic_t;
#endif
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) ((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
static __inline__ void atomic_add(int i, volatile 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(int i, volatile 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(volatile atomic_t *v)
{
__asm__ __volatile__(
LOCK "incl %0"
:"=m" (__atomic_fool_gcc(v))
:"m" (__atomic_fool_gcc(v)));
}
static __inline__ void atomic_dec(volatile 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(volatile 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;
}
/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
__asm__ __volatile__(LOCK "andl %0,%1" \
: : "r" (~(mask)),"m" (__atomic_fool_gcc(addr)) : "memory")
#define atomic_set_mask(mask, addr) \
__asm__ __volatile__(LOCK "orl %0,%1" \
: : "r" (mask),"m" (__atomic_fool_gcc(addr)) : "memory")
#endif
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