kernel/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 #ifdef CONFIG_64BIT
  59 unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
  60 {
  61         unsigned long flags;
  62         unsigned long prev;
  63
  64         _atomic_spin_lock_irqsave(ptr, flags);
  65         if ((prev = *ptr) == old)
  66                 *ptr = new;
  67         _atomic_spin_unlock_irqrestore(ptr, flags);
  68         return prev;
  69 }
  70 #endif
  71
  72 unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
  73 {
  74         unsigned long flags;
  75         unsigned int prev;
  76
  77         _atomic_spin_lock_irqsave(ptr, flags);
  78         if ((prev = *ptr) == old)
  79                 *ptr = new;
  80         _atomic_spin_unlock_irqrestore(ptr, flags);
  81         return (unsigned long)prev;
  82 }