kernel/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 #include <asm/barrier.h>
  24
  25 /* Nonexistent functions intended to cause compile errors. */
  26 extern void __xchg_called_with_bad_pointer(void)
  27         __compiletime_error("Bad argument size for xchg");
  28 extern void __cmpxchg_called_with_bad_pointer(void)
  29         __compiletime_error("Bad argument size for cmpxchg");
  30
  31 #ifndef __tilegx__
  32
  33 /* Note the _atomic_xxx() routines include a final mb(). */
  34 int _atomic_xchg(int *ptr, int n);
  35 int _atomic_xchg_add(int *v, int i);
  36 int _atomic_xchg_add_unless(int *v, int a, int u);
  37 int _atomic_cmpxchg(int *ptr, int o, int n);
  38 long long _atomic64_xchg(long long *v, long long n);
  39 long long _atomic64_xchg_add(long long *v, long long i);
  40 long long _atomic64_xchg_add_unless(long long *v, long long a, long long u);
  41 long long _atomic64_cmpxchg(long long *v, long long o, long long n);
  42
  43 #define xchg(ptr, n)                                                    \
  44         ({                                                              \
  45                 if (sizeof(*(ptr)) != 4)                                \
  46                         __xchg_called_with_bad_pointer();               \
  47                 smp_mb();                                               \
  48                 (typeof(*(ptr)))_atomic_xchg((int *)(ptr), (int)(n));   \
  49         })
  50
  51 #define cmpxchg(ptr, o, n)                                              \
  52         ({                                                              \
  53                 if (sizeof(*(ptr)) != 4)                                \
  54                         __cmpxchg_called_with_bad_pointer();            \
  55                 smp_mb();                                               \
  56                 (typeof(*(ptr)))_atomic_cmpxchg((int *)ptr, (int)o,     \
  57                                                 (int)n);                \
  58         })
  59
  60 #define xchg64(ptr, n)                                                  \
  61         ({                                                              \
  62                 if (sizeof(*(ptr)) != 8)                                \
  63                         __xchg_called_with_bad_pointer();               \
  64                 smp_mb();                                               \
  65                 (typeof(*(ptr)))_atomic64_xchg((long long *)(ptr),      \
  66                                                 (long long)(n));        \
  67         })
  68
  69 #define cmpxchg64(ptr, o, n)                                            \
  70         ({                                                              \
  71                 if (sizeof(*(ptr)) != 8)                                \
  72                         __cmpxchg_called_with_bad_pointer();            \
  73                 smp_mb();                                               \
  74                 (typeof(*(ptr)))_atomic64_cmpxchg((long long *)ptr,     \
  75                                         (long long)o, (long long)n);    \
  76         })
  77
  78 #else
  79
  80 #define xchg(ptr, n)                                                    \
  81         ({                                                              \
  82                 typeof(*(ptr)) __x;                                     \
  83                 smp_mb();                                               \
  84                 switch (sizeof(*(ptr))) {                               \
  85                 case 4:                                                 \
  86                         __x = (typeof(__x))(unsigned long)              \
  87                                 __insn_exch4((ptr),                     \
  88                                         (u32)(unsigned long)(n));       \
  89                         break;                                          \
  90                 case 8:                                                 \
  91                         __x = (typeof(__x))                             \
  92                                 __insn_exch((ptr), (unsigned long)(n)); \
  93                         break;                                          \
  94                 default:                                                \
  95                         __xchg_called_with_bad_pointer();               \
  96                         break;                                          \
  97                 }                                                       \
  98                 smp_mb();                                               \
  99                 __x;                                                    \
 100         })
 101
 102 #define cmpxchg(ptr, o, n)                                              \
 103         ({                                                              \
 104                 typeof(*(ptr)) __x;                                     \
 105                 __insn_mtspr(SPR_CMPEXCH_VALUE, (unsigned long)(o));    \
 106                 smp_mb();                                               \
 107                 switch (sizeof(*(ptr))) {                               \
 108                 case 4:                                                 \
 109                         __x = (typeof(__x))(unsigned long)              \
 110                                 __insn_cmpexch4((ptr),                  \
 111                                         (u32)(unsigned long)(n));       \
 112                         break;                                          \
 113                 case 8:                                                 \
 114                         __x = (typeof(__x))__insn_cmpexch((ptr),        \
 115                                                 (long long)(n));        \
 116                         break;                                          \
 117                 default:                                                \
 118                         __cmpxchg_called_with_bad_pointer();            \
 119                         break;                                          \
 120                 }                                                       \
 121                 smp_mb();                                               \
 122                 __x;                                                    \
 123         })
 124
 125 #define xchg64 xchg
 126 #define cmpxchg64 cmpxchg
 127
 128 #endif
 129
 130 #define tas(ptr) xchg((ptr), 1)
 131
 132 #endif /* __ASSEMBLY__ */
 133
 134 #endif /* _ASM_TILE_CMPXCHG_H */