git.ozlabs.org Git - ccan/blob - ccan/cpuid/cpuid.c

   1 /*
   2  * Copyright (c) 2013 Ahmed Samy  <f.fallen45@gmail.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20  * THE SOFTWARE.
  21  *
  22  * This file has been written with some help from wikipedia:
  23  *      http://en.wikipedia.org/wiki/CPUID
  24  */
  25 #include <stdint.h>
  26
  27 #include "cpuid.h"
  28
  29 enum {
  30         CPU_PROC_BRAND_STRING_INTERNAL0                 = 0x80000003,
  31         CPU_PROC_BRAND_STRING_INTERNAL1                 = 0x80000004
  32 };
  33
  34 #ifndef _MSC_VER
  35 static void ___cpuid(cpuid_t info, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
  36 {
  37         __asm__(
  38                 "xchg %%ebx, %%edi\n\t"         /* 32bit PIC: Don't clobber ebx.  */
  39                 "cpuid\n\t"
  40                 "xchg %%ebx, %%edi\n\t"
  41                 : "=a"(*eax), "=D"(*ebx), "=c"(*ecx), "=d"(*edx)
  42                 : "0" (info)
  43         );
  44 }
  45 #else
  46 #include <intrin.h>
  47
  48 static void ___cpuid(cpuid_t info, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
  49 {
  50         uint32_t registers[4];
  51         __cpuid(registers, info);
  52
  53         *eax = registers[0];
  54         *ebx = registers[1];
  55         *ecx = registers[2];
  56         *edx = registers[3];
  57 }
  58 #endif
  59
  60 int highest_ext_func_supported(void)
  61 {
  62         static int highest;
  63
  64         if (!highest) {
  65                 asm volatile(
  66                         "cpuid\n\t"
  67                         : "=a" (highest)
  68                         : "a" (CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED)
  69                 );
  70         }
  71
  72         return highest;
  73 }
  74
  75 int cpuid_test_feature(cpuid_t feature)
  76 {
  77         if (feature > CPU_VIRT_PHYS_ADDR_SIZES || feature < CPU_EXTENDED_PROC_INFO_FEATURE_BITS)
  78                 return 0;
  79
  80         return (feature <= highest_ext_func_supported());
  81 }
  82
  83 int cpuid_has_feature(cpufeature_t feature)
  84 {
  85         uint32_t eax, ebx, ecx, edx;
  86
  87         ___cpuid(CPU_PROCINFO_AND_FEATUREBITS, &eax, &ebx, &ecx, &edx);
  88         switch (feature) {
  89                 case CF_MMX:
  90                 case CF_SSE:
  91                 case CF_SSE2:
  92                         return (edx & ((int)feature)) != 0;
  93                 case CF_SSE3:
  94                 case CF_SSSE3:
  95                 case CF_SSE41:
  96                 case CF_SSE42:
  97                 case CF_AVX:
  98                 case CF_FMA:
  99                         return (ecx & ((int)feature)) != 0;
 100         }
 101
 102         return 0;
 103 }
 104
 105 int cpuid_has_ext_feature(cpuextfeature_t extfeature)
 106 {
 107         uint32_t eax, ebx, ecx, edx;
 108         if (!cpuid_test_feature(CPU_EXTENDED_PROC_INFO_FEATURE_BITS))
 109                 return 0;
 110
 111         ___cpuid(CPU_EXTENDED_PROC_INFO_FEATURE_BITS, &eax, &ebx, &ecx, &edx);
 112         switch (extfeature) {
 113                 case CEF_x64:
 114                         return (edx & ((int)extfeature)) != 0;
 115                 case CEF_SSE4a:
 116                 case CEF_FMA4:
 117                 case CEF_XOP:
 118                         return (ecx & ((int)extfeature)) != 0;
 119         }
 120
 121         return 0;
 122 }
 123
 124 void cpuid(cpuid_t info, void *buf)
 125 {
 126         /* Sanity checks, make sure we're not trying to do something
 127          * invalid or we are trying to get information that isn't supported
 128          * by the CPU.  */
 129         if (info > CPU_VIRT_PHYS_ADDR_SIZES || (info > CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED
 130                 && !cpuid_test_feature(info)))
 131                 return;
 132
 133         uint32_t *ubuf = buf;
 134         if (info == CPU_PROC_BRAND_STRING) {
 135                 ___cpuid(CPU_PROC_BRAND_STRING,           &ubuf[0], &ubuf[1], &ubuf[2],  &ubuf[3]);
 136                 ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL0, &ubuf[4], &ubuf[5], &ubuf[6],  &ubuf[7]);
 137                 ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL1, &ubuf[8], &ubuf[9], &ubuf[10], &ubuf[11]);
 138                 return;
 139         } else if (info == CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED) {
 140                 *ubuf = highest_ext_func_supported();
 141                 return;
 142         }
 143
 144         uint32_t eax, ebx, ecx, edx;
 145         ___cpuid(info, &eax, &ebx, &ecx, &edx);
 146
 147         switch (info) {
 148                 case CPU_VENDORID:
 149                         ubuf[0] = ebx;
 150                         ubuf[1] = edx;
 151                         ubuf[2] = ecx;
 152                         break;
 153                 case CPU_PROCINFO_AND_FEATUREBITS:
 154                         ubuf[0] = eax;  /* The so called "signature" of the CPU.  */
 155                         ubuf[1] = edx;  /* Feature flags #1.  */
 156                         ubuf[2] = ecx;  /* Feature flags #2.  */
 157                         ubuf[3] = ebx;  /* Additional feature information.  */
 158                         break;
 159                 case CPU_CACHE_AND_TLBD_INFO:
 160                         ubuf[0] = eax;
 161                         ubuf[1] = ebx;
 162                         ubuf[2] = ecx;
 163                         ubuf[3] = edx;
 164                         break;
 165                 case CPU_EXTENDED_PROC_INFO_FEATURE_BITS:
 166                         ubuf[0] = edx;
 167                         ubuf[1] = ecx;
 168                         break;
 169                 case CPU_L1_CACHE_AND_TLB_IDS:
 170                         break;
 171                 case CPU_EXTENDED_L2_CACHE_FEATURES:
 172                         ubuf[0] = (ecx & 0xFF);                 /* Cache size  */
 173                         ubuf[1] = (ecx >> 12) & 0xF;            /* Line size  */
 174                         ubuf[2] = (ecx >> 16) & 0xFFFF;         /* Associativity  */
 175                         break;
 176                 case CPU_ADV_POWER_MGT_INFO:
 177                         break;
 178                 case CPU_VIRT_PHYS_ADDR_SIZES:
 179                         *ubuf = eax;
 180                         break;
 181                 default:
 182                         *ubuf = 0xbaadf00d;
 183                         break;
 184         }
 185 }
 186