Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
14void 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
25static 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, '$')) {
54 buffer[nb-1] = '\0';
55 return 0;
56 }
57 return ENOBUFS;
58}
59
60int
61get_cpuid(char *buffer, size_t sz, struct perf_cpu cpu __maybe_unused)
62{
63 return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
64}
65
66char *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 */
78static 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
94int 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}