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#ifndef __ARCH_I386_ATOMIC__
#define __ARCH_I386_ATOMIC__
#include <linux/config.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*/
#ifdef CONFIG_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.
*/
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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
#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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
#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. Note that the guaranteed useful range
* of an atomic_t is only 24 bits.
*/
static __inline__ void atomic_add(int i, atomic_t *v)
{
__asm__ __volatile__(
LOCK "addl %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
/**
* atomic_sub - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ void atomic_sub(int i, atomic_t *v)
{
__asm__ __volatile__(
LOCK "subl %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
/**
* 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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
{
unsigned char c;
__asm__ __volatile__(
LOCK "subl %2,%0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
}
/**
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ void atomic_inc(atomic_t *v)
{
__asm__ __volatile__(
LOCK "incl %0"
:"=m" (v->counter)
:"m" (v->counter));
}
/**
* atomic_dec - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ void atomic_dec(atomic_t *v)
{
__asm__ __volatile__(
LOCK "decl %0"
:"=m" (v->counter)
:"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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ int atomic_dec_and_test(atomic_t *v)
{
unsigned char c;
__asm__ __volatile__(
LOCK "decl %0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ int atomic_inc_and_test(atomic_t *v)
{
unsigned char c;
__asm__ __volatile__(
LOCK "incl %0; sete %1"
:"=m" (v->counter), "=qm" (c)
:"m" (v->counter) : "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. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ int atomic_add_negative(int i, atomic_t *v)
{
unsigned char c;
__asm__ __volatile__(
LOCK "addl %2,%0; sets %1"
:"=m" (v->counter), "=qm" (c)
:"ir" (i), "m" (v->counter) : "memory");
return c;
}
/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
__asm__ __volatile__(LOCK "andl %0,%1" \
: : "r" (~(mask)),"m" (*addr) : "memory")
#define atomic_set_mask(mask, addr) \
__asm__ __volatile__(LOCK "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()
#endif
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