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] = {
  17         [0 ... (ATOMIC_HASH_SIZE-1)]  = SPIN_LOCK_UNLOCKED
  18 };
  19 #endif
  20
  21 spinlock_t __atomic_lock = SPIN_LOCK_UNLOCKED;
  22
  23 #ifdef __LP64__
  24 unsigned long __xchg64(unsigned long x, unsigned long *ptr)
  25 {
  26         unsigned long temp, flags;
  27
  28         SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
  29         temp = *ptr;
  30         *ptr = x;
  31         SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
  32         return temp;
  33 }
  34 #endif
  35
  36 unsigned long __xchg32(int x, int *ptr)
  37 {
  38         unsigned long flags;
  39         unsigned long temp;
  40
  41         SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
  42         (long) temp = (long) *ptr;      /* XXX - sign extension wanted? */
  43         *ptr = x;
  44         SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
  45         return temp;
  46 }
  47
  48
  49 unsigned long __xchg8(char x, char *ptr)
  50 {
  51         unsigned long flags;
  52         unsigned long temp;
  53
  54         SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
  55         (long) temp = (long) *ptr;      /* XXX - sign extension wanted? */
  56         *ptr = x;
  57         SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
  58         return temp;
  59 }
  60
  61
  62 #ifdef __LP64__
  63 unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
  64 {
  65         unsigned long flags;
  66         unsigned long prev;
  67
  68         SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
  69         if ((prev = *ptr) == old)
  70                 *ptr = new;
  71         SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
  72         return prev;
  73 }
  74 #endif
  75
  76 unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
  77 {
  78         unsigned long flags;
  79         unsigned int prev;
  80
  81         SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
  82         if ((prev = *ptr) == old)
  83                 *ptr = new;
  84         SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
  85         return (unsigned long)prev;
  86 }