467 lines
10 KiB
C
467 lines
10 KiB
C
#ifndef __ARCH_X86_64_ATOMIC__
|
|
#define __ARCH_X86_64_ATOMIC__
|
|
|
|
#include <asm/alternative.h>
|
|
#include <asm/cmpxchg.h>
|
|
|
|
/* atomic_t should be 32 bit signed type */
|
|
|
|
/*
|
|
* 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 { 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), "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.
|
|
*/
|
|
static __inline__ void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "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.
|
|
*/
|
|
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), "m" (v->counter) : "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)
|
|
:"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)
|
|
:"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)
|
|
:"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.
|
|
*/
|
|
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)
|
|
:"m" (v->counter) : "memory");
|
|
return c != 0;
|
|
}
|
|
|
|
/**
|
|
* atomic_add_negative - add and test if negative
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* 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), "m" (v->counter) : "memory");
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* atomic_add_return - add and return
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v and returns @i + @v
|
|
*/
|
|
static __inline__ int atomic_add_return(int i, atomic_t *v)
|
|
{
|
|
int __i = i;
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "xaddl %0, %1"
|
|
:"+r" (i), "+m" (v->counter)
|
|
: : "memory");
|
|
return i + __i;
|
|
}
|
|
|
|
static __inline__ int atomic_sub_return(int i, atomic_t *v)
|
|
{
|
|
return atomic_add_return(-i,v);
|
|
}
|
|
|
|
#define atomic_inc_return(v) (atomic_add_return(1,v))
|
|
#define atomic_dec_return(v) (atomic_sub_return(1,v))
|
|
|
|
/* An 64bit atomic type */
|
|
|
|
typedef struct { long counter; } atomic64_t;
|
|
|
|
#define ATOMIC64_INIT(i) { (i) }
|
|
|
|
/**
|
|
* atomic64_read - read atomic64 variable
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically reads the value of @v.
|
|
* Doesn't imply a read memory barrier.
|
|
*/
|
|
#define atomic64_read(v) ((v)->counter)
|
|
|
|
/**
|
|
* atomic64_set - set atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i.
|
|
*/
|
|
#define atomic64_set(v,i) (((v)->counter) = (i))
|
|
|
|
/**
|
|
* atomic64_add - add integer to atomic64 variable
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @i to @v.
|
|
*/
|
|
static __inline__ void atomic64_add(long i, atomic64_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "addq %1,%0"
|
|
:"=m" (v->counter)
|
|
:"ir" (i), "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_sub - subtract the atomic64 variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static __inline__ void atomic64_sub(long i, atomic64_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "subq %1,%0"
|
|
:"=m" (v->counter)
|
|
:"ir" (i), "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_sub_and_test - subtract value from variable and test result
|
|
* @i: integer value to subtract
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "subq %2,%0; sete %1"
|
|
:"=m" (v->counter), "=qm" (c)
|
|
:"ir" (i), "m" (v->counter) : "memory");
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* atomic64_inc - increment atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
static __inline__ void atomic64_inc(atomic64_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "incq %0"
|
|
:"=m" (v->counter)
|
|
:"m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_dec - decrement atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
static __inline__ void atomic64_dec(atomic64_t *v)
|
|
{
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "decq %0"
|
|
:"=m" (v->counter)
|
|
:"m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_dec_and_test - decrement and test
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
static __inline__ int atomic64_dec_and_test(atomic64_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "decq %0; sete %1"
|
|
:"=m" (v->counter), "=qm" (c)
|
|
:"m" (v->counter) : "memory");
|
|
return c != 0;
|
|
}
|
|
|
|
/**
|
|
* atomic64_inc_and_test - increment and test
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static __inline__ int atomic64_inc_and_test(atomic64_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "incq %0; sete %1"
|
|
:"=m" (v->counter), "=qm" (c)
|
|
:"m" (v->counter) : "memory");
|
|
return c != 0;
|
|
}
|
|
|
|
/**
|
|
* atomic64_add_negative - add and test if negative
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* 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 atomic64_add_negative(long i, atomic64_t *v)
|
|
{
|
|
unsigned char c;
|
|
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "addq %2,%0; sets %1"
|
|
:"=m" (v->counter), "=qm" (c)
|
|
:"ir" (i), "m" (v->counter) : "memory");
|
|
return c;
|
|
}
|
|
|
|
/**
|
|
* atomic64_add_return - add and return
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @i to @v and returns @i + @v
|
|
*/
|
|
static __inline__ long atomic64_add_return(long i, atomic64_t *v)
|
|
{
|
|
long __i = i;
|
|
__asm__ __volatile__(
|
|
LOCK_PREFIX "xaddq %0, %1;"
|
|
:"+r" (i), "+m" (v->counter)
|
|
: : "memory");
|
|
return i + __i;
|
|
}
|
|
|
|
static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
|
|
{
|
|
return atomic64_add_return(-i,v);
|
|
}
|
|
|
|
#define atomic64_inc_return(v) (atomic64_add_return(1,v))
|
|
#define atomic64_dec_return(v) (atomic64_sub_return(1,v))
|
|
|
|
#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
|
|
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
|
|
|
|
#define atomic_cmpxchg(v, old, new) (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.
|
|
*/
|
|
static __inline__ int atomic_add_unless(atomic_t *v, int a, int 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;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
|
|
|
|
/**
|
|
* atomic64_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic64_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.
|
|
*/
|
|
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
|
|
{
|
|
long c, old;
|
|
c = atomic64_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic64_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
|
|
|
|
/* 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" ((unsigned)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
|