Logo Search packages:      
Sourcecode: linux version File versions

bitops.c

/*
 * 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 <asm/system.h>
#include <asm/atomic.h>

#ifdef CONFIG_SMP
raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
      [0 ... (ATOMIC_HASH_SIZE-1)]  = __RAW_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;
}


#ifdef CONFIG_64BIT
unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
{
      unsigned long flags;
      unsigned long prev;

      _atomic_spin_lock_irqsave(ptr, flags);
      if ((prev = *ptr) == old)
            *ptr = new;
      _atomic_spin_unlock_irqrestore(ptr, flags);
      return prev;
}
#endif

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;
}

Generated by  Doxygen 1.6.0   Back to index