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#include <regex.h>
   8
   9#include "../../util/header.h"
  10
  11static inline void
  12cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
  13      unsigned int *d)
  14{
  15        __asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
  16                              "movl %%ebx, %%esi\n\t.byte 0x5b"
  17                        : "=a" (*a),
  18                        "=S" (*b),
  19                        "=c" (*c),
  20                        "=d" (*d)
  21                        : "a" (op));
  22}
  23
  24static int
  25__get_cpuid(char *buffer, size_t sz, const char *fmt)
  26{
  27        unsigned int a, b, c, d, lvl;
  28        int family = -1, model = -1, step = -1;
  29        int nb;
  30        char vendor[16];
  31
  32        cpuid(0, &lvl, &b, &c, &d);
  33        strncpy(&vendor[0], (char *)(&b), 4);
  34        strncpy(&vendor[4], (char *)(&d), 4);
  35        strncpy(&vendor[8], (char *)(&c), 4);
  36        vendor[12] = '\0';
  37
  38        if (lvl >= 1) {
  39                cpuid(1, &a, &b, &c, &d);
  40
  41                family = (a >> 8) & 0xf;  /* bits 11 - 8 */
  42                model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
  43                step   = a & 0xf;
  44
  45                /* extended family */
  46                if (family == 0xf)
  47                        family += (a >> 20) & 0xff;
  48
  49                /* extended model */
  50                if (family >= 0x6)
  51                        model += ((a >> 16) & 0xf) << 4;
  52        }
  53        nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
  54
  55        /* look for end marker to ensure the entire data fit */
  56        if (strchr(buffer, '$')) {
  57                buffer[nb-1] = '\0';
  58                return 0;
  59        }
  60        return -1;
  61}
  62
  63int
  64get_cpuid(char *buffer, size_t sz)
  65{
  66        return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  67}
  68
  69char *
  70get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
  71{
  72        char *buf = malloc(128);
  73
  74        if (buf && __get_cpuid(buf, 128, "%s-%u-%X-%X$") < 0) {
  75                free(buf);
  76                return NULL;
  77        }
  78        return buf;
  79}
  80
  81/* Full CPUID format for x86 is vendor-family-model-stepping */
  82static bool is_full_cpuid(const char *id)
  83{
  84        const char *tmp = id;
  85        int count = 0;
  86
  87        while ((tmp = strchr(tmp, '-')) != NULL) {
  88                count++;
  89                tmp++;
  90        }
  91
  92        if (count == 3)
  93                return true;
  94
  95        return false;
  96}
  97
  98int strcmp_cpuid_str(const char *mapcpuid, const char *id)
  99{
 100        regex_t re;
 101        regmatch_t pmatch[1];
 102        int match;
 103        bool full_mapcpuid = is_full_cpuid(mapcpuid);
 104        bool full_cpuid = is_full_cpuid(id);
 105
 106        /*
 107         * Full CPUID format is required to identify a platform.
 108         * Error out if the cpuid string is incomplete.
 109         */
 110        if (full_mapcpuid && !full_cpuid) {
 111                pr_info("Invalid CPUID %s. Full CPUID is required, "
 112                        "vendor-family-model-stepping\n", id);
 113                return 1;
 114        }
 115
 116        if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) {
 117                /* Warn unable to generate match particular string. */
 118                pr_info("Invalid regular expression %s\n", mapcpuid);
 119                return 1;
 120        }
 121
 122        match = !regexec(&re, id, 1, pmatch, 0);
 123        regfree(&re);
 124        if (match) {
 125                size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);
 126                size_t cpuid_len;
 127
 128                /* If the full CPUID format isn't required,
 129                 * ignoring the stepping.
 130                 */
 131                if (!full_mapcpuid && full_cpuid)
 132                        cpuid_len = strrchr(id, '-') - id;
 133                else
 134                        cpuid_len = strlen(id);
 135
 136                /* Verify the entire string matched. */
 137                if (match_len == cpuid_len)
 138                        return 0;
 139        }
 140
 141        return 1;
 142}
 143