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, '$')) {
54		buffer[nb-1] = '\0';
55		return 0;
56	}
57	return ENOBUFS;
58}
59
60int
61get_cpuid(char *buffer, size_t sz)
62{
63	return __get_cpuid(buffer, sz, "%s,%u,%u,%u$");
64}
65
66char *
67get_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 */
79static 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
95int 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