tools/power/cpupower/utils/helpers/cpuid.c

   1 #include <stdio.h>
   2 #include <errno.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6
   7 #include "helpers/helpers.h"
   8
   9 static const char *cpu_vendor_table[X86_VENDOR_MAX] = {
  10         "Unknown", "GenuineIntel", "AuthenticAMD",
  11 };
  12
  13 #if defined(__i386__) || defined(__x86_64__)
  14
  15 /* from gcc */
  16 #include <cpuid.h>
  17
  18 /*
  19  * CPUID functions returning a single datum
  20  *
  21  * Define unsigned int cpuid_e[abcd]x(unsigned int op)
  22  */
  23 #define cpuid_func(reg)                                 \
  24         unsigned int cpuid_##reg(unsigned int op)       \
  25         {                                               \
  26         unsigned int eax, ebx, ecx, edx;                \
  27         __cpuid(op, eax, ebx, ecx, edx);                \
  28         return reg;                                     \
  29         }
  30 cpuid_func(eax);
  31 cpuid_func(ebx);
  32 cpuid_func(ecx);
  33 cpuid_func(edx);
  34
  35 #endif /* defined(__i386__) || defined(__x86_64__) */
  36
  37 /* get_cpu_info
  38  *
  39  * Extract CPU vendor, family, model, stepping info from /proc/cpuinfo
  40  *
  41  * Returns 0 on success or a negativ error code
  42  *
  43  * TBD: Should there be a cpuid alternative for this if /proc is not mounted?
  44  */
  45 int get_cpu_info(unsigned int cpu, struct cpupower_cpu_info *cpu_info)
  46 {
  47         FILE *fp;
  48         char value[64];
  49         unsigned int proc, x;
  50         unsigned int unknown = 0xffffff;
  51         unsigned int cpuid_level, ext_cpuid_level;
  52
  53         int ret = -EINVAL;
  54
  55         cpu_info->vendor                = X86_VENDOR_UNKNOWN;
  56         cpu_info->family                = unknown;
  57         cpu_info->model                 = unknown;
  58         cpu_info->stepping              = unknown;
  59         cpu_info->caps                  = 0;
  60
  61         fp = fopen("/proc/cpuinfo", "r");
  62         if (!fp)
  63                 return -EIO;
  64
  65         while (!feof(fp)) {
  66                 if (!fgets(value, 64, fp))
  67                         continue;
  68                 value[63 - 1] = '\0';
  69
  70                 if (!strncmp(value, "processor\t: ", 12)) {
  71                         sscanf(value, "processor\t: %u", &proc);
  72                 }
  73                 if (proc != cpu)
  74                         continue;
  75
  76                 /* Get CPU vendor */
  77                 if (!strncmp(value, "vendor_id", 9))
  78                         for (x = 1; x < X86_VENDOR_MAX; x++) {
  79                                 if (strstr(value, cpu_vendor_table[x]))
  80                                         cpu_info->vendor = x;
  81                         }
  82                 /* Get CPU family, etc. */
  83                 else if (!strncmp(value, "cpu family\t: ", 13)) {
  84                         sscanf(value, "cpu family\t: %u",
  85                                &cpu_info->family);
  86                 }
  87                 else if (!strncmp(value, "model\t\t: ", 9)) {
  88                         sscanf(value, "model\t\t: %u",
  89                                &cpu_info->model);
  90                 }
  91                 else if (!strncmp(value, "stepping\t: ", 10)) {
  92                         sscanf(value, "stepping\t: %u",
  93                                &cpu_info->stepping);
  94
  95                         /* Exit -> all values must have been set */
  96                         if (cpu_info->vendor == X86_VENDOR_UNKNOWN ||
  97                             cpu_info->family == unknown ||
  98                             cpu_info->model == unknown ||
  99                             cpu_info->stepping == unknown) {
 100                                 ret = -EINVAL;
 101                                 goto out;
 102                         }
 103
 104                         ret = 0;
 105                         goto out;
 106                 }
 107         }
 108         ret = -ENODEV;
 109 out:
 110         fclose(fp);
 111         /* Get some useful CPU capabilities from cpuid */
 112         if (cpu_info->vendor != X86_VENDOR_AMD &&
 113             cpu_info->vendor != X86_VENDOR_INTEL)
 114                 return ret;
 115
 116         cpuid_level     = cpuid_eax(0);
 117         ext_cpuid_level = cpuid_eax(0x80000000);
 118
 119         /* Invariant TSC */
 120         if (ext_cpuid_level >= 0x80000007 &&
 121             (cpuid_edx(0x80000007) & (1 << 8)))
 122                 cpu_info->caps |= CPUPOWER_CAP_INV_TSC;
 123
 124         /* Aperf/Mperf registers support */
 125         if (cpuid_level >= 6 && (cpuid_ecx(6) & 0x1))
 126                 cpu_info->caps |= CPUPOWER_CAP_APERF;
 127
 128         /* AMD Boost state enable/disable register */
 129         if (cpu_info->vendor == X86_VENDOR_AMD) {
 130                 if (ext_cpuid_level >= 0x80000007 &&
 131                     (cpuid_edx(0x80000007) & (1 << 9)))
 132                         cpu_info->caps |= CPUPOWER_CAP_AMD_CBP;
 133         }
 134
 135         /* Intel's perf-bias MSR support */
 136         if (cpu_info->vendor == X86_VENDOR_INTEL) {
 137                 if (cpuid_level >= 6 && (cpuid_ecx(6) & (1 << 3)))
 138                         cpu_info->caps |= CPUPOWER_CAP_PERF_BIAS;
 139         }
 140
 141         /*      printf("ID: %u - Extid: 0x%x - Caps: 0x%llx\n",
 142                 cpuid_level, ext_cpuid_level, cpu_info->caps);
 143         */
 144         return ret;
 145 }