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

DEFINITIONS

1. cpuid
2. __get_cpuid
3. get_cpuid
4. get_cpuid_str
5. is_full_cpuid
6. strcmp_cpuid_str

   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 
  13 static inline void
  14 cpuid(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 
  26 static 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, '$')) {
  59                 buffer[nb-1] = '\0';
  60                 return 0;
  61         }
  62         return ENOBUFS;
  63 }
  64 
  65 int
  66 get_cpuid(char *buffer, size_t sz)
  67 {
  68         return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
  69 }
  70 
  71 char *
  72 get_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 */
  84 static 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 
 100 int 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 }