arch/parisc/lib/bitops.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * bitops.c: atomic operations which got too long to be inlined all over
   4  *      the place.
   5  *
   6  * Copyright 1999 Philipp Rumpf ([email protected])
   7  * Copyright 2000 Grant Grundler ([email protected])
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/atomic.h>
  13
  14 #ifdef CONFIG_SMP
  15 arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
  16         [0 ... (ATOMIC_HASH_SIZE-1)]  = __ARCH_SPIN_LOCK_UNLOCKED
  17 };
  18 #endif
  19
  20 #ifdef CONFIG_64BIT
  21 unsigned long notrace __xchg64(unsigned long x, volatile 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 notrace __xchg32(int x, volatile 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 notrace __xchg8(char x, volatile 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 #define CMPXCHG(T)                                              \
  60         T notrace __cmpxchg_##T(volatile T *ptr, T old, T new)  \
  61         {                                                       \
  62                 unsigned long flags;                            \
  63                 T 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
  72 CMPXCHG(u64)
  73 CMPXCHG(u32)
  74 CMPXCHG(u16)
  75 CMPXCHG(u8)