urcu/arch_x86.h

   1 #ifndef _URCU_ARCH_X86_H
   2 #define _URCU_ARCH_X86_H
   3
   4 /*
   5  * arch_x86.h: trivial definitions for the x86 architecture.
   6  *
   7  * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
   8  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14 *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include <urcu/compiler.h>
  26 #include "config.h"
  27
  28 /* Assume P4 or newer */
  29 #define CONFIG_HAVE_FENCE 1
  30 #define CONFIG_HAVE_MEM_COHERENCY
  31
  32 #define CACHE_LINE_SIZE 128
  33
  34 #ifndef BITS_PER_LONG
  35 #define BITS_PER_LONG   (__SIZEOF_LONG__ * 8)
  36 #endif
  37
  38 #ifdef CONFIG_HAVE_FENCE
  39 #define mb()    asm volatile("mfence":::"memory")
  40 #define rmb()   asm volatile("lfence":::"memory")
  41 #define wmb()   asm volatile("sfence"::: "memory")
  42 #else
  43 /*
  44  * Some non-Intel clones support out of order store. wmb() ceases to be a
  45  * nop for these.
  46  */
  47 #define mb()    asm volatile("lock; addl $0,0(%%esp)":::"memory")
  48 #define rmb()   asm volatile("lock; addl $0,0(%%esp)":::"memory")
  49 #define wmb()   asm volatile("lock; addl $0,0(%%esp)"::: "memory")
  50 #endif
  51
  52 /*
  53  * Architectures without cache coherency need something like the following:
  54  *
  55  * #define mb()         mc()
  56  * #define rmb()        rmc()
  57  * #define wmb()        wmc()
  58  * #define mc()         arch_cache_flush()
  59  * #define rmc()        arch_cache_flush_read()
  60  * #define wmc()        arch_cache_flush_write()
  61  */
  62
  63 #define mc()    barrier()
  64 #define rmc()   barrier()
  65 #define wmc()   barrier()
  66
  67 #ifdef CONFIG_SMP
  68 #define smp_mb()        mb()
  69 #define smp_rmb()       rmb()
  70 #define smp_wmb()       wmb()
  71 #define smp_mc()        mc()
  72 #define smp_rmc()       rmc()
  73 #define smp_wmc()       wmc()
  74 #else
  75 #define smp_mb()        barrier()
  76 #define smp_rmb()       barrier()
  77 #define smp_wmb()       barrier()
  78 #define smp_mc()        barrier()
  79 #define smp_rmc()       barrier()
  80 #define smp_wmc()       barrier()
  81 #endif
  82
  83 /* Nop everywhere except on alpha. */
  84 #define smp_read_barrier_depends()
  85
  86 static inline void rep_nop(void)
  87 {
  88         asm volatile("rep; nop" : : : "memory");
  89 }
  90
  91 static inline void cpu_relax(void)
  92 {
  93         rep_nop();
  94 }
  95
  96 /*
  97  * Serialize core instruction execution. Also acts as a compiler barrier.
  98  */
  99 #ifdef __PIC__
 100 /*
 101  * Cannot use cpuid because it clobbers the ebx register and clashes
 102  * with -fPIC :
 103  * error: PIC register 'ebx' clobbered in 'asm'
 104  */
 105 static inline void sync_core(void)
 106 {
 107         mb();
 108 }
 109 #else
 110 static inline void sync_core(void)
 111 {
 112         asm volatile("cpuid" : : : "memory", "eax", "ebx", "ecx", "edx");
 113 }
 114 #endif
 115
 116 #define rdtscll(val)                                                      \
 117         do {                                                              \
 118              unsigned int __a, __d;                                       \
 119              asm volatile("rdtsc" : "=a" (__a), "=d" (__d));              \
 120              (val) = ((unsigned long long)__a)                            \
 121                         | (((unsigned long long)__d) << 32);              \
 122         } while(0)
 123
 124 typedef unsigned long long cycles_t;
 125
 126 static inline cycles_t get_cycles(void)
 127 {
 128         cycles_t ret = 0;
 129
 130         rdtscll(ret);
 131         return ret;
 132 }
 133
 134 #endif /* _URCU_ARCH_X86_H */