urcu/arch/generic.h

   1 #ifndef _URCU_ARCH_GENERIC_H
   2 #define _URCU_ARCH_GENERIC_H
   3
   4 /*
   5  * arch_generic.h: common definitions for multiple architectures.
   6  *
   7  * Copyright (c) 2010 Paolo Bonzini <pbonzini@redhat.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include <urcu/compiler.h>
  25 #include <urcu/config.h>
  26 #include <urcu/syscall-compat.h>
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 #ifndef CAA_CACHE_LINE_SIZE
  33 #define CAA_CACHE_LINE_SIZE     64
  34 #endif
  35
  36 #if !defined(cmm_mc) && !defined(cmm_rmc) && !defined(cmm_wmc)
  37 #define CONFIG_HAVE_MEM_COHERENCY
  38 /*
  39  * Architectures with cache coherency must _not_ define cmm_mc/cmm_rmc/cmm_wmc.
  40  *
  41  * For them, cmm_mc/cmm_rmc/cmm_wmc are implemented with a simple
  42  * compiler barrier; in addition, we provide defaults for cmm_mb (using
  43  * GCC builtins) as well as cmm_rmb and cmm_wmb (defaulting to cmm_mb).
  44  */
  45
  46 #ifndef cmm_mb
  47 #define cmm_mb()    __sync_synchronize()
  48 #endif
  49
  50 #ifndef cmm_rmb
  51 #define cmm_rmb()       cmm_mb()
  52 #endif
  53
  54 #ifndef cmm_wmb
  55 #define cmm_wmb()       cmm_mb()
  56 #endif
  57
  58 #define cmm_mc()        cmm_barrier()
  59 #define cmm_rmc()       cmm_barrier()
  60 #define cmm_wmc()       cmm_barrier()
  61 #else
  62 /*
  63  * Architectures without cache coherency need something like the following:
  64  *
  65  * #define cmm_mc()     arch_cache_flush()
  66  * #define cmm_rmc()    arch_cache_flush_read()
  67  * #define cmm_wmc()    arch_cache_flush_write()
  68  *
  69  * Of these, only cmm_mc is mandatory. cmm_rmc and cmm_wmc default to
  70  * cmm_mc. cmm_mb/cmm_rmb/cmm_wmb use these definitions by default:
  71  *
  72  * #define cmm_mb()     cmm_mc()
  73  * #define cmm_rmb()    cmm_rmc()
  74  * #define cmm_wmb()    cmm_wmc()
  75  */
  76
  77 #ifndef cmm_mb
  78 #define cmm_mb()        cmm_mc()
  79 #endif
  80
  81 #ifndef cmm_rmb
  82 #define cmm_rmb()       cmm_rmc()
  83 #endif
  84
  85 #ifndef cmm_wmb
  86 #define cmm_wmb()       cmm_wmc()
  87 #endif
  88
  89 #ifndef cmm_rmc
  90 #define cmm_rmc()       cmm_mc()
  91 #endif
  92
  93 #ifndef cmm_wmc
  94 #define cmm_wmc()       cmm_mc()
  95 #endif
  96 #endif
  97
  98 /* Nop everywhere except on alpha. */
  99 #ifndef cmm_read_barrier_depends
 100 #define cmm_read_barrier_depends()
 101 #endif
 102
 103 #ifdef CONFIG_RCU_SMP
 104 #ifndef cmm_smp_mb
 105 #define cmm_smp_mb()    cmm_mb()
 106 #endif
 107 #ifndef cmm_smp_rmb
 108 #define cmm_smp_rmb()   cmm_rmb()
 109 #endif
 110 #ifndef cmm_smp_wmb
 111 #define cmm_smp_wmb()   cmm_wmb()
 112 #endif
 113 #ifndef cmm_smp_mc
 114 #define cmm_smp_mc()    cmm_mc()
 115 #endif
 116 #ifndef cmm_smp_rmc
 117 #define cmm_smp_rmc()   cmm_rmc()
 118 #endif
 119 #ifndef cmm_smp_wmc
 120 #define cmm_smp_wmc()   cmm_wmc()
 121 #endif
 122 #ifndef cmm_smp_read_barrier_depends
 123 #define cmm_smp_read_barrier_depends()  cmm_read_barrier_depends()
 124 #endif
 125 #else
 126 #ifndef cmm_smp_mb
 127 #define cmm_smp_mb()    cmm_barrier()
 128 #endif
 129 #ifndef cmm_smp_rmb
 130 #define cmm_smp_rmb()   cmm_barrier()
 131 #endif
 132 #ifndef cmm_smp_wmb
 133 #define cmm_smp_wmb()   cmm_barrier()
 134 #endif
 135 #ifndef cmm_smp_mc
 136 #define cmm_smp_mc()    cmm_barrier()
 137 #endif
 138 #ifndef cmm_smp_rmc
 139 #define cmm_smp_rmc()   cmm_barrier()
 140 #endif
 141 #ifndef cmm_smp_wmc
 142 #define cmm_smp_wmc()   cmm_barrier()
 143 #endif
 144 #ifndef cmm_smp_read_barrier_depends
 145 #define cmm_smp_read_barrier_depends()
 146 #endif
 147 #endif
 148
 149 #ifndef caa_cpu_relax
 150 #define caa_cpu_relax()         cmm_barrier()
 151 #endif
 152
 153 #ifndef HAS_CAA_GET_CYCLES
 154 #define HAS_CAA_GET_CYCLES
 155 typedef unsigned long long cycles_t;
 156
 157 static inline cycles_t caa_get_cycles (void)
 158 {
 159         cycles_t thetime;
 160         struct timeval tv;
 161
 162         if (gettimeofday(&tv, NULL) != 0)
 163                 return 0;
 164         thetime = ((cycles_t)tv.tv_sec) * 1000000ULL + ((cycles_t)tv.tv_usec);
 165         return (cycles_t)thetime;
 166 }
 167 #endif /* HAS_CAA_GET_CYCLES */
 168
 169 #ifdef __cplusplus
 170 }
 171 #endif
 172
 173 #endif /* _URCU_ARCH_GENERIC_H */