Commit 98c2aaf8 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86, perfcounters: add atomic64_xchg() 



Complete atomic64_t support on the 32-bit side by adding atomic64_xch().

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090406094518.445450972@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 6278af66

arch/x86/include/asm/atomic_32.h

+21 −3
Original line number Diff line number Diff line
@@ -291,19 +291,37 @@ atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val, 
}



/**

 * atomic64_set - set atomic64 variable

 * atomic64_xchg - xchg atomic64 variable

 * @ptr:      pointer to type atomic64_t

 * @new_val:  value to assign

 * @old_val:  old value that was there

 *

 * Atomically sets the value of @ptr to @new_val.

 * Atomically xchgs the value of @ptr to @new_val and returns

 * the old value.

 */

static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val)



static inline unsigned long long

atomic64_xchg(atomic64_t *ptr, unsigned long long new_val)

{

	unsigned long long old_val;



	do {

		old_val = atomic_read(ptr);

	} while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);



	return old_val;

}



/**

 * atomic64_set - set atomic64 variable

 * @ptr:      pointer to type atomic64_t

 * @new_val:  value to assign

 *

 * Atomically sets the value of @ptr to @new_val.

 */

static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val)

{

	atomic64_xchg(ptr, new_val);

}



/**

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