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
  10 static inline void
  11 cpuid(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
  23 static 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, '$')) {
  56                 buffer[nb-1] = '\0';
  57                 return 0;
  58         }
  59         return -1;
  60 }
  61
  62 int
  63 get_cpuid(char *buffer, size_t sz)
  64 {
  65         return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  66 }
  67
  68 char *
  69 get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
  70 {
  71         char *buf = malloc(128);
  72
  73         if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
  74                 free(buf);
  75                 return NULL;
  76         }
  77         return buf;
  78 }