arch/mips/include/asm/barrier.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org)
   7  */
   8 #ifndef __ASM_BARRIER_H
   9 #define __ASM_BARRIER_H
  10
  11 #include <asm/addrspace.h>
  12
  13 #ifdef CONFIG_CPU_HAS_SYNC
  14 #define __sync()                                \
  15         __asm__ __volatile__(                   \
  16                 ".set   push\n\t"               \
  17                 ".set   noreorder\n\t"          \
  18                 ".set   mips2\n\t"              \
  19                 "sync\n\t"                      \
  20                 ".set   pop"                    \
  21                 : /* no output */               \
  22                 : /* no input */                \
  23                 : "memory")
  24 #else
  25 #define __sync()        do { } while(0)
  26 #endif
  27
  28 #define __fast_iob()                            \
  29         __asm__ __volatile__(                   \
  30                 ".set   push\n\t"               \
  31                 ".set   noreorder\n\t"          \
  32                 "lw     $0,%0\n\t"              \
  33                 "nop\n\t"                       \
  34                 ".set   pop"                    \
  35                 : /* no output */               \
  36                 : "m" (*(int *)CKSEG1)          \
  37                 : "memory")
  38 #ifdef CONFIG_CPU_CAVIUM_OCTEON
  39 # define OCTEON_SYNCW_STR       ".set push\n.set arch=octeon\nsyncw\nsyncw\n.set pop\n"
  40 # define __syncw()      __asm__ __volatile__(OCTEON_SYNCW_STR : : : "memory")
  41
  42 # define fast_wmb()     __syncw()
  43 # define fast_rmb()     barrier()
  44 # define fast_mb()      __sync()
  45 # define fast_iob()     do { } while (0)
  46 #else /* ! CONFIG_CPU_CAVIUM_OCTEON */
  47 # define fast_wmb()     __sync()
  48 # define fast_rmb()     __sync()
  49 # define fast_mb()      __sync()
  50 # ifdef CONFIG_SGI_IP28
  51 #  define fast_iob()                            \
  52         __asm__ __volatile__(                   \
  53                 ".set   push\n\t"               \
  54                 ".set   noreorder\n\t"          \
  55                 "lw     $0,%0\n\t"              \
  56                 "sync\n\t"                      \
  57                 "lw     $0,%0\n\t"              \
  58                 ".set   pop"                    \
  59                 : /* no output */               \
  60                 : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \
  61                 : "memory")
  62 # else
  63 #  define fast_iob()                            \
  64         do {                                    \
  65                 __sync();                       \
  66                 __fast_iob();                   \
  67         } while (0)
  68 # endif
  69 #endif /* CONFIG_CPU_CAVIUM_OCTEON */
  70
  71 #ifdef CONFIG_CPU_HAS_WB
  72
  73 #include <asm/wbflush.h>
  74
  75 #define mb()            wbflush()
  76 #define iob()           wbflush()
  77
  78 #else /* !CONFIG_CPU_HAS_WB */
  79
  80 #define mb()            fast_mb()
  81 #define iob()           fast_iob()
  82
  83 #endif /* !CONFIG_CPU_HAS_WB */
  84
  85 #define wmb()           fast_wmb()
  86 #define rmb()           fast_rmb()
  87
  88 #if defined(CONFIG_WEAK_ORDERING)
  89 # ifdef CONFIG_CPU_CAVIUM_OCTEON
  90 #  define __smp_mb()    __sync()
  91 #  define __smp_rmb()   barrier()
  92 #  define __smp_wmb()   __syncw()
  93 # else
  94 #  define __smp_mb()    __asm__ __volatile__("sync" : : :"memory")
  95 #  define __smp_rmb()   __asm__ __volatile__("sync" : : :"memory")
  96 #  define __smp_wmb()   __asm__ __volatile__("sync" : : :"memory")
  97 # endif
  98 #else
  99 #define __smp_mb()      barrier()
 100 #define __smp_rmb()     barrier()
 101 #define __smp_wmb()     barrier()
 102 #endif
 103
 104 #if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP)
 105 #define __WEAK_LLSC_MB          "       sync    \n"
 106 #else
 107 #define __WEAK_LLSC_MB          "               \n"
 108 #endif
 109
 110 #define smp_llsc_mb()   __asm__ __volatile__(__WEAK_LLSC_MB : : :"memory")
 111
 112 #ifdef CONFIG_CPU_CAVIUM_OCTEON
 113 #define smp_mb__before_llsc() smp_wmb()
 114 #define __smp_mb__before_llsc() __smp_wmb()
 115 /* Cause previous writes to become visible on all CPUs as soon as possible */
 116 #define nudge_writes() __asm__ __volatile__(".set push\n\t"             \
 117                                             ".set arch=octeon\n\t"      \
 118                                             "syncw\n\t"                 \
 119                                             ".set pop" : : : "memory")
 120 #else
 121 #define smp_mb__before_llsc() smp_llsc_mb()
 122 #define __smp_mb__before_llsc() smp_llsc_mb()
 123 #define nudge_writes() mb()
 124 #endif
 125
 126 #define __smp_mb__before_atomic()       __smp_mb__before_llsc()
 127 #define __smp_mb__after_atomic()        smp_llsc_mb()
 128
 129 #include <asm-generic/barrier.h>
 130
 131 #endif /* __ASM_BARRIER_H */