LXR linux/tools/perf/arch/x86/util/header.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <sys/types.h>
   3#include <unistd.h>
   4#include <stdio.h>
   5#include <stdlib.h>
   6#include <string.h>
   7
   8#include "../../util/header.h"
   9
  10static inline void
  11cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
  12      unsigned int *d)
  13{
  14        __asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
  15                              "movl %%ebx, %%esi\n\t.byte 0x5b"
  16                        : "=a" (*a),
  17                        "=S" (*b),
  18                        "=c" (*c),
  19                        "=d" (*d)
  20                        : "a" (op));
  21}
  22
  23static int
  24__get_cpuid(char *buffer, size_t sz, const char *fmt)
  25{
  26        unsigned int a, b, c, d, lvl;
  27        int family = -1, model = -1, step = -1;
  28        int nb;
  29        char vendor[16];
  30
  31        cpuid(0, &lvl, &b, &c, &d);
  32        strncpy(&vendor[0], (char *)(&b), 4);
  33        strncpy(&vendor[4], (char *)(&d), 4);
  34        strncpy(&vendor[8], (char *)(&c), 4);
  35        vendor[12] = '\0';
  36
  37        if (lvl >= 1) {
  38                cpuid(1, &a, &b, &c, &d);
  39
  40                family = (a >> 8) & 0xf;  /* bits 11 - 8 */
  41                model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
  42                step   = a & 0xf;
  43
  44                /* extended family */
  45                if (family == 0xf)
  46                        family += (a >> 20) & 0xff;
  47
  48                /* extended model */
  49                if (family >= 0x6)
  50                        model += ((a >> 16) & 0xf) << 4;
  51        }
  52        nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
  53
  54        /* look for end marker to ensure the entire data fit */
  55        if (strchr(buffer, '$')) {
  56                buffer[nb-1] = '\0';
  57                return 0;
  58        }
  59        return -1;
  60}
  61
  62int
  63get_cpuid(char *buffer, size_t sz)
  64{
  65        return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  66}
  67
  68char *
  69get_cpuid_str(void)
  70{
  71        char *buf = malloc(128);
  72
  73        if (__get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
  74                free(buf);
  75                return NULL;
  76        }
  77        return buf;
  78}
  79