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/*
* bitops.c: atomic operations which got too long to be inlined all over
* the place.
*
* Copyright 1999 Philipp Rumpf (prumpf@tux.org)
* Copyright 2000 Grant Grundler (grundler@cup.hp.com)
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
#ifdef CONFIG_SMP
arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
[0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED
};
#endif
#ifdef CONFIG_64BIT
unsigned long __xchg64(unsigned long x, unsigned long *ptr)
{
unsigned long temp, flags;
_atomic_spin_lock_irqsave(ptr, flags);
temp = *ptr;
*ptr = x;
_atomic_spin_unlock_irqrestore(ptr, flags);
return temp;
}
#endif
unsigned long __xchg32(int x, int *ptr)
{
unsigned long flags;
long temp;
_atomic_spin_lock_irqsave(ptr, flags);
temp = (long) *ptr; /* XXX - sign extension wanted? */
*ptr = x;
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)temp;
}
unsigned long __xchg8(char x, char *ptr)
{
unsigned long flags;
long temp;
_atomic_spin_lock_irqsave(ptr, flags);
temp = (long) *ptr; /* XXX - sign extension wanted? */
*ptr = x;
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)temp;
}
u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new)
{
unsigned long flags;
u64 prev;
_atomic_spin_lock_irqsave(ptr, flags);
if ((prev = *ptr) == old)
*ptr = new;
_atomic_spin_unlock_irqrestore(ptr, flags);
return prev;
}
unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
{
unsigned long flags;
unsigned int prev;
_atomic_spin_lock_irqsave(ptr, flags);
if ((prev = *ptr) == old)
*ptr = new;
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)prev;
}
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