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 <linux/atomic.h>
  12
  13 #ifdef CONFIG_SMP
  14 arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  15         [0 ... (ATOMIC_HASH_SIZE-1)]  = __ARCH_SPIN_LOCK_UNLOCKED
  16 };
  17 #endif
  18
  19 #ifdef CONFIG_64BIT
  20 unsigned long __xchg64(unsigned long x, unsigned long *ptr)
  21 {
  22         unsigned long temp, flags;
  23
  24         _atomic_spin_lock_irqsave(ptr, flags);
  25         temp = *ptr;
  26         *ptr = x;
  27         _atomic_spin_unlock_irqrestore(ptr, flags);
  28         return temp;
  29 }
  30 #endif
  31
  32 unsigned long __xchg32(int x, int *ptr)
  33 {
  34         unsigned long flags;
  35         long temp;
  36
  37         _atomic_spin_lock_irqsave(ptr, flags);
  38         temp = (long) *ptr;     /* XXX - sign extension wanted? */
  39         *ptr = x;
  40         _atomic_spin_unlock_irqrestore(ptr, flags);
  41         return (unsigned long)temp;
  42 }
  43
  44
  45 unsigned long __xchg8(char x, char *ptr)
  46 {
  47         unsigned long flags;
  48         long temp;
  49
  50         _atomic_spin_lock_irqsave(ptr, flags);
  51         temp = (long) *ptr;     /* XXX - sign extension wanted? */
  52         *ptr = x;
  53         _atomic_spin_unlock_irqrestore(ptr, flags);
  54         return (unsigned long)temp;
  55 }
  56
  57
  58 u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new)
  59 {
  60         unsigned long flags;
  61         u64 prev;
  62
  63         _atomic_spin_lock_irqsave(ptr, flags);
  64         if ((prev = *ptr) == old)
  65                 *ptr = new;
  66         _atomic_spin_unlock_irqrestore(ptr, flags);
  67         return prev;
  68 }
  69
  70 unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
  71 {
  72         unsigned long flags;
  73         unsigned int prev;
  74
  75         _atomic_spin_lock_irqsave(ptr, flags);
  76         if ((prev = *ptr) == old)
  77                 *ptr = new;
  78         _atomic_spin_unlock_irqrestore(ptr, flags);
  79         return (unsigned long)prev;
  80 }