LXR linux/arch/parisc/lib/bitops.c

   1/*
   2 * bitops.c: atomic operations which got too long to be inlined all over
   3 *      the place.
   4 * 
   5 * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
   6 * Copyright 2000 Grant Grundler (grundler@cup.hp.com)
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/spinlock.h>
  11#include <asm/system.h>
  12#include <asm/atomic.h>
  13
  14#ifdef CONFIG_SMP
  15arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  16        [0 ... (ATOMIC_HASH_SIZE-1)]  = __ARCH_SPIN_LOCK_UNLOCKED
  17};
  18#endif
  19
  20#ifdef CONFIG_64BIT
  21unsigned long __xchg64(unsigned long x, unsigned long *ptr)
  22{
  23        unsigned long temp, flags;
  24
  25        _atomic_spin_lock_irqsave(ptr, flags);
  26        temp = *ptr;
  27        *ptr = x;
  28        _atomic_spin_unlock_irqrestore(ptr, flags);
  29        return temp;
  30}
  31#endif
  32
  33unsigned long __xchg32(int x, int *ptr)
  34{
  35        unsigned long flags;
  36        long temp;
  37
  38        _atomic_spin_lock_irqsave(ptr, flags);
  39        temp = (long) *ptr;     /* XXX - sign extension wanted? */
  40        *ptr = x;
  41        _atomic_spin_unlock_irqrestore(ptr, flags);
  42        return (unsigned long)temp;
  43}
  44
  45
  46unsigned long __xchg8(char x, char *ptr)
  47{
  48        unsigned long flags;
  49        long temp;
  50
  51        _atomic_spin_lock_irqsave(ptr, flags);
  52        temp = (long) *ptr;     /* XXX - sign extension wanted? */
  53        *ptr = x;
  54        _atomic_spin_unlock_irqrestore(ptr, flags);
  55        return (unsigned long)temp;
  56}
  57
  58
  59#ifdef CONFIG_64BIT
  60unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
  61{
  62        unsigned long flags;
  63        unsigned long prev;
  64
  65        _atomic_spin_lock_irqsave(ptr, flags);
  66        if ((prev = *ptr) == old)
  67                *ptr = new;
  68        _atomic_spin_unlock_irqrestore(ptr, flags);
  69        return prev;
  70}
  71#endif
  72
  73unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
  74{
  75        unsigned long flags;
  76        unsigned int prev;
  77
  78        _atomic_spin_lock_irqsave(ptr, flags);
  79        if ((prev = *ptr) == old)
  80                *ptr = new;
  81        _atomic_spin_unlock_irqrestore(ptr, flags);
  82        return (unsigned long)prev;
  83}
  84