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, '$')) {
54 buffer[nb-1] = '\0';
55 return 0;
56 }
57 return ENOBUFS;
58 }
59
60 int
61 get_cpuid(char *buffer, size_t sz)
62 {
63 return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
64 }
65
66 char *
67 get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
68 {
69 char *buf = malloc(128);
70
71 if (buf && __get_cpuid(buf, 128, "%s-%u-%X-%X$") < 0) {
72 free(buf);
73 return NULL;
74 }
75 return buf;
76 }
77
78 /* Full CPUID format for x86 is vendor-family-model-stepping */
79 static bool is_full_cpuid(const char *id)
80 {
81 const char *tmp = id;
82 int count = 0;
83
84 while ((tmp = strchr(tmp, '-')) != NULL) {
85 count++;
86 tmp++;
87 }
88
89 if (count == 3)
90 return true;
91
92 return false;
93 }
94
95 int strcmp_cpuid_str(const char *mapcpuid, const char *id)
96 {
97 regex_t re;
98 regmatch_t pmatch[1];
99 int match;
100 bool full_mapcpuid = is_full_cpuid(mapcpuid);
101 bool full_cpuid = is_full_cpuid(id);
102
103 /*
104 * Full CPUID format is required to identify a platform.
105 * Error out if the cpuid string is incomplete.
106 */
107 if (full_mapcpuid && !full_cpuid) {
108 pr_info("Invalid CPUID %s. Full CPUID is required, "
109 "vendor-family-model-stepping\n", id);
110 return 1;
111 }
112
113 if (regcomp(&re, mapcpuid, REG_EXTENDED) != 0) {
114 /* Warn unable to generate match particular string. */
115 pr_info("Invalid regular expression %s\n", mapcpuid);
116 return 1;
117 }
118
119 match = !regexec(&re, id, 1, pmatch, 0);
120 regfree(&re);
121 if (match) {
122 size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);
123 size_t cpuid_len;
124
125 /* If the full CPUID format isn't required,
126 * ignoring the stepping.
127 */
128 if (!full_mapcpuid && full_cpuid)
129 cpuid_len = strrchr(id, '-') - id;
130 else
131 cpuid_len = strlen(id);
132
133 /* Verify the entire string matched. */
134 if (match_len == cpuid_len)
135 return 0;
136 }
137
138 return 1;
139 }
140
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