LXR linux/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
  13static inline void
  14cpuid(unsigned int op, unsigned int *a, unsigned int *b, unsigned int *c,
  15      unsigned int *d)
  16{
  17        __asm__ __volatile__ (".byte 0x53\n\tcpuid\n\t"
  18                              "movl %%ebx, %%esi\n\t.byte 0x5b"
  19                        : "=a" (*a),
  20                        "=S" (*b),
  21                        "=c" (*c),
  22                        "=d" (*d)
  23                        : "a" (op));
  24}
  25
  26static int
  27__get_cpuid(char *buffer, size_t sz, const char *fmt)
  28{
  29        unsigned int a, b, c, d, lvl;
  30        int family = -1, model = -1, step = -1;
  31        int nb;
  32        char vendor[16];
  33
  34        cpuid(0, &lvl, &b, &c, &d);
  35        strncpy(&vendor[0], (char *)(&b), 4);
  36        strncpy(&vendor[4], (char *)(&d), 4);
  37        strncpy(&vendor[8], (char *)(&c), 4);
  38        vendor[12] = '\0';
  39
  40        if (lvl >= 1) {
  41                cpuid(1, &a, &b, &c, &d);
  42
  43                family = (a >> 8) & 0xf;  /* bits 11 - 8 */
  44                model  = (a >> 4) & 0xf;  /* Bits  7 - 4 */
  45                step   = a & 0xf;
  46
  47                /* extended family */
  48                if (family == 0xf)
  49                        family += (a >> 20) & 0xff;
  50
  51                /* extended model */
  52                if (family >= 0x6)
  53                        model += ((a >> 16) & 0xf) << 4;
  54        }
  55        nb = scnprintf(buffer, sz, fmt, vendor, family, model, step);
  56
  57        /* look for end marker to ensure the entire data fit */
  58        if (strchr(buffer, '$')) {
  59                buffer[nb-1] = '\0';
  60                return 0;
  61        }
  62        return ENOBUFS;
  63}
  64
  65int
  66get_cpuid(char *buffer, size_t sz)
  67{
  68        return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  69}
  70
  71char *
  72get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
  73{
  74        char *buf = malloc(128);
  75
  76        if (buf && __get_cpuid(buf, 128, "%s-%u-%X-%X$") < 0) {
  77                free(buf);
  78                return NULL;
  79        }
  80        return buf;
  81}
  82
  83/* Full CPUID format for x86 is vendor-family-model-stepping */
  84static bool is_full_cpuid(const char *id)
  85{
  86        const char *tmp = id;
  87        int count = 0;
  88
  89        while ((tmp = strchr(tmp, '-')) != NULL) {
  90                count++;
  91                tmp++;
  92        }
  93
  94        if (count == 3)
  95                return true;
  96
  97        return false;
  98}
  99
 100int strcmp_cpuid_str(const char *mapcpuid, const char *id)
 101{
 102        regex_t re;
 103        regmatch_t pmatch[1];
 104        int match;
 105        bool full_mapcpuid = is_full_cpuid(mapcpuid);
 106        bool full_cpuid = is_full_cpuid(id);
 107
 108        /*
 109         * Full CPUID format is required to identify a platform.
 110         * Error out if the cpuid string is incomplete.
 111         */
 112        if (full_mapcpuid && !full_cpuid) {
 113                pr_info("Invalid CPUID %s. Full CPUID is required, "
 114                        "vendor-family-model-stepping\n", id);
 115                return 1;
 116        }
 117
 118        if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) {
 119                /* Warn unable to generate match particular string. */
 120                pr_info("Invalid regular expression %s\n", mapcpuid);
 121                return 1;
 122        }
 123
 124        match = !regexec(&re, id, 1, pmatch, 0);
 125        regfree(&re);
 126        if (match) {
 127                size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);
 128                size_t cpuid_len;
 129
 130                /* If the full CPUID format isn't required,
 131                 * ignoring the stepping.
 132                 */
 133                if (!full_mapcpuid && full_cpuid)
 134                        cpuid_len = strrchr(id, '-') - id;
 135                else
 136                        cpuid_len = strlen(id);
 137
 138                /* Verify the entire string matched. */
 139                if (match_len == cpuid_len)
 140                        return 0;
 141        }
 142
 143        return 1;
 144}
 145