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