LXR linux-bk/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/config.h>
  10#include <linux/kernel.h>
  11#include <linux/spinlock.h>
  12#include <asm/system.h>
  13#include <asm/atomic.h>
  14
  15#ifdef CONFIG_SMP
  16spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  17        [0 ... (ATOMIC_HASH_SIZE-1)]  = SPIN_LOCK_UNLOCKED
  18};
  19#endif
  20
  21#ifdef __LP64__
  22unsigned long __xchg64(unsigned long x, unsigned long *ptr)
  23{
  24        unsigned long temp, flags;
  25
  26        _atomic_spin_lock_irqsave(ptr, flags);
  27        temp = *ptr;
  28        *ptr = x;
  29        _atomic_spin_unlock_irqrestore(ptr, flags);
  30        return temp;
  31}
  32#endif
  33
  34unsigned long __xchg32(int x, int *ptr)
  35{
  36        unsigned long flags;
  37        long temp;
  38
  39        _atomic_spin_lock_irqsave(ptr, flags);
  40        temp = (long) *ptr;     /* XXX - sign extension wanted? */
  41        *ptr = x;
  42        _atomic_spin_unlock_irqrestore(ptr, flags);
  43        return (unsigned long)temp;
  44}
  45
  46
  47unsigned long __xchg8(char x, char *ptr)
  48{
  49        unsigned long flags;
  50        long temp;
  51
  52        _atomic_spin_lock_irqsave(ptr, flags);
  53        temp = (long) *ptr;     /* XXX - sign extension wanted? */
  54        *ptr = x;
  55        _atomic_spin_unlock_irqrestore(ptr, flags);
  56        return (unsigned long)temp;
  57}
  58
  59
  60#ifdef __LP64__
  61unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
  62{
  63        unsigned long flags;
  64        unsigned long prev;
  65
  66        _atomic_spin_lock_irqsave(ptr, flags);
  67        if ((prev = *ptr) == old)
  68                *ptr = new;
  69        _atomic_spin_unlock_irqrestore(ptr, flags);
  70        return prev;
  71}
  72#endif
  73
  74unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
  75{
  76        unsigned long flags;
  77        unsigned int prev;
  78
  79        _atomic_spin_lock_irqsave(ptr, flags);
  80        if ((prev = *ptr) == old)
  81                *ptr = new;
  82        _atomic_spin_unlock_irqrestore(ptr, flags);
  83        return (unsigned long)prev;
  84}
  85