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Commit 79d365a3 authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Linus Torvalds
Browse files

atomic.h: add atomic64 cmpxchg, xchg and add_unless to x86_64 



Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2549c858

include/asm-x86_64/atomic.h

+32 −4
Original line number Diff line number Diff line
@@ -375,8 +375,8 @@ 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), "0"(i));

		:"+r" (i), "+m" (v->counter)

		: : "memory");

	return i + __i;

}
@@ -388,7 +388,10 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v) 
#define atomic64_inc_return(v)  (atomic64_add_return(1,v))

#define atomic64_dec_return(v)  (atomic64_sub_return(1,v))



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

#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))



/**
@@ -402,7 +405,7 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v) 
 */

#define atomic_add_unless(v, a, u)				\

({								\

	int c, old;						\

	__typeof__((v)->counter) c, old;			\

	c = atomic_read(v);					\

	for (;;) {						\

		if (unlikely(c == (u)))				\
@@ -416,6 +419,31 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v) 
})

#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.

 */

#define atomic64_add_unless(v, a, u)				\

({								\

	__typeof__((v)->counter) 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;					\

	}							\

	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" \