release/src-rt-6.x/linux/linux-2.6/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
  15 raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  16         [0 ... (ATOMIC_HASH_SIZE-1)]  = __RAW_SPIN_LOCK_UNLOCKED
  17 };
  18 #endif
  19
  20 #ifdef CONFIG_64BIT
  21 unsigned 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
  33 unsigned 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
  46 unsigned 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
  60 unsigned 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
  73 unsigned 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 }