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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <sys/types.h>
   3 #include <errno.h>
   4 #include <unistd.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <regex.h>
   9
  10 #include "../../../util/debug.h"
  11 #include "../../../util/header.h"
  12 #include "cpuid.h"
  13
  14 void get_cpuid_0(char *vendor, unsigned int *lvl)
  15 {
  16         unsigned int b, c, d;
  17
  18         cpuid(0, 0, lvl, &b, &c, &d);
  19         strncpy(&vendor[0], (char *)(&b), 4);
  20         strncpy(&vendor[4], (char *)(&d), 4);
  21         strncpy(&vendor[8], (char *)(&c), 4);
  22         vendor[12] = '\0';
  23 }
  24
  25 static int
  26 __get_cpuid(char *buffer, size_t sz, const char *fmt)
  27 {
  28         unsigned int a, b, c, d, lvl;
  29         int family = -1, model = -1, step = -1;
  30         int nb;
  31         char vendor[16];
  32
  33         get_cpuid_0(vendor, &lvl);
  34
  35         if (lvl >= 1) {
  36                 cpuid(1, 0, &a, &b, &c, &d);
  37
  38                 family = (a >> 8) & 0xf;  /* bits 11 - 8 */
  39                 model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
  40                 step   = a & 0xf;
  41
  42                 /* extended family */
  43                 if (family == 0xf)
  44                         family += (a >> 20) & 0xff;
  45
  46                 /* extended model */
  47                 if (family >= 0x6)
  48                         model += ((a >> 16) & 0xf) << 4;
  49         }
  50         nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
  51
  52         /* look for end marker to ensure the entire data fit */
  53         if (strchr(buffer, '$')) {
  54                 buffer[nb-1] = '\0';
  55                 return 0;
  56         }
  57         return ENOBUFS;
  58 }
  59
  60 int
  61 get_cpuid(char *buffer, size_t sz, struct perf_cpu cpu __maybe_unused)
  62 {
  63         return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  64 }
  65
  66 char *get_cpuid_str(struct perf_cpu cpu __maybe_unused)
  67 {
  68         char *buf = malloc(128);
  69
  70         if (buf && __get_cpuid(buf, 128, "%s-%u-%X-%X$") < 0) {
  71                 free(buf);
  72                 return NULL;
  73         }
  74         return buf;
  75 }
  76
  77 /* Full CPUID format for x86 is vendor-family-model-stepping */
  78 static bool is_full_cpuid(const char *id)
  79 {
  80         const char *tmp = id;
  81         int count = 0;
  82
  83         while ((tmp = strchr(tmp, '-')) != NULL) {
  84                 count++;
  85                 tmp++;
  86         }
  87
  88         if (count == 3)
  89                 return true;
  90
  91         return false;
  92 }
  93
  94 int strcmp_cpuid_str(const char *mapcpuid, const char *id)
  95 {
  96         regex_t re;
  97         regmatch_t pmatch[1];
  98         int match;
  99         bool full_mapcpuid = is_full_cpuid(mapcpuid);
 100         bool full_cpuid = is_full_cpuid(id);
 101
 102         /*
 103          * Full CPUID format is required to identify a platform.
 104          * Error out if the cpuid string is incomplete.
 105          */
 106         if (full_mapcpuid && !full_cpuid) {
 107                 pr_info("Invalid CPUID %s. Full CPUID is required, "
 108                         "vendor-family-model-stepping\n", id);
 109                 return 1;
 110         }
 111
 112         if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) {
 113                 /* Warn unable to generate match particular string. */
 114                 pr_info("Invalid regular expression %s\n", mapcpuid);
 115                 return 1;
 116         }
 117
 118         match = !regexec(&re, id, 1, pmatch, 0);
 119         regfree(&re);
 120         if (match) {
 121                 size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);
 122                 size_t cpuid_len;
 123
 124                 /* If the full CPUID format isn't required,
 125                  * ignoring the stepping.
 126                  */
 127                 if (!full_mapcpuid && full_cpuid)
 128                         cpuid_len = strrchr(id, '-') - id;
 129                 else
 130                         cpuid_len = strlen(id);
 131
 132                 /* Verify the entire string matched. */
 133                 if (match_len == cpuid_len)
 134                         return 0;
 135         }
 136
 137         return 1;
 138 }