arch/tile/include/asm/cmpxchg.h

   1 /*
   2  * cmpxchg.h -- forked from asm/atomic.h with this copyright:
   3  *
   4  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   5  *
   6  *   This program is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU General Public License
   8  *   as published by the Free Software Foundation, version 2.
   9  *
  10  *   This program is distributed in the hope that it will be useful, but
  11  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  13  *   NON INFRINGEMENT.  See the GNU General Public License for
  14  *   more details.
  15  *
  16  */
  17
  18 #ifndef _ASM_TILE_CMPXCHG_H
  19 #define _ASM_TILE_CMPXCHG_H
  20
  21 #ifndef __ASSEMBLY__
  22
  23 /* Nonexistent functions intended to cause link errors. */
  24 extern unsigned long __xchg_called_with_bad_pointer(void);
  25 extern unsigned long __cmpxchg_called_with_bad_pointer(void);
  26
  27 #define xchg(ptr, x)                                                    \
  28         ({                                                              \
  29                 typeof(*(ptr)) __x;                                     \
  30                 switch (sizeof(*(ptr))) {                               \
  31                 case 4:                                                 \
  32                         __x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \
  33                                 (atomic_t *)(ptr),                      \
  34                                 (u32)(typeof((x)-(x)))(x));             \
  35                         break;                                          \
  36                 case 8:                                                 \
  37                         __x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \
  38                                 (atomic64_t *)(ptr),                    \
  39                                 (u64)(typeof((x)-(x)))(x));             \
  40                         break;                                          \
  41                 default:                                                \
  42                         __xchg_called_with_bad_pointer();               \
  43                 }                                                       \
  44                 __x;                                                    \
  45         })
  46
  47 #define cmpxchg(ptr, o, n)                                              \
  48         ({                                                              \
  49                 typeof(*(ptr)) __x;                                     \
  50                 switch (sizeof(*(ptr))) {                               \
  51                 case 4:                                                 \
  52                         __x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \
  53                                 (atomic_t *)(ptr),                      \
  54                                 (u32)(typeof((o)-(o)))(o),              \
  55                                 (u32)(typeof((n)-(n)))(n));             \
  56                         break;                                          \
  57                 case 8:                                                 \
  58                         __x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \
  59                                 (atomic64_t *)(ptr),                    \
  60                                 (u64)(typeof((o)-(o)))(o),              \
  61                                 (u64)(typeof((n)-(n)))(n));             \
  62                         break;                                          \
  63                 default:                                                \
  64                         __cmpxchg_called_with_bad_pointer();            \
  65                 }                                                       \
  66                 __x;                                                    \
  67         })
  68
  69 #define tas(ptr) (xchg((ptr), 1))
  70
  71 #define cmpxchg64(ptr, o, n)                                            \
  72 ({                                                                      \
  73         BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
  74         cmpxchg((ptr), (o), (n));                                       \
  75 })
  76
  77 #endif /* __ASSEMBLY__ */
  78
  79 #endif /* _ASM_TILE_CMPXCHG_H */