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
  16 spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  17         [0 ... (ATOMIC_HASH_SIZE-1)]  = SPIN_LOCK_UNLOCKED
  18 };
  19 #endif
  20
  21 #ifdef __LP64__
  22 unsigned 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
  34 unsigned 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
  47 unsigned 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__
  61 unsigned 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
  74 unsigned 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 }