header.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Implementation of get_cpuid().
 4 *
 5 * Author: Nikita Shubin <n.shubin@yadro.com>
 6 *         Bibo Mao <maobibo@loongson.cn>
 7 *         Huacai Chen <chenhuacai@loongson.cn>
 8 */
 9
10#include <stdio.h>
11#include <stdlib.h>
12#include <api/fs/fs.h>
13#include <errno.h>
14#include "util/debug.h"
15#include "util/header.h"
16
17/*
18 * Output example from /proc/cpuinfo
19 *   CPU Family              : Loongson-64bit
20 *   Model Name              : Loongson-3C5000
21 *   CPU Revision            : 0x10
22 *   FPU Revision            : 0x01
23 */
24#define CPUINFO_MODEL	"Model Name"
25#define CPUINFO		"/proc/cpuinfo"
26
27static char *_get_field(const char *line)
28{
29	char *line2, *nl;
30
31	line2 = strrchr(line, ' ');
32	if (!line2)
33		return NULL;
34
35	line2++;
36	nl = strrchr(line, '\n');
37	if (!nl)
38		return NULL;
39
40	return strndup(line2, nl - line2);
41}
42
43static char *_get_cpuid(void)
44{
45	unsigned long line_sz;
46	char *line, *model, *cpuid;
47	FILE *file;
48
49	file = fopen(CPUINFO, "r");
50	if (file == NULL)
51		return NULL;
52
53	line = model = cpuid = NULL;
54	while (getline(&line, &line_sz, file) != -1) {
55		if (strncmp(line, CPUINFO_MODEL, strlen(CPUINFO_MODEL)))
56			continue;
57
58		model = _get_field(line);
59		if (!model)
60			goto out_free;
61		break;
62	}
63
64	if (model && (asprintf(&cpuid, "%s", model) < 0))
65		cpuid = NULL;
66
67out_free:
68	fclose(file);
69	free(model);
70	return cpuid;
71}
72
73int get_cpuid(char *buffer, size_t sz, struct perf_cpu cpu __maybe_unused)
74{
75	int ret = 0;
76	char *cpuid = _get_cpuid();
77
78	if (!cpuid)
79		return EINVAL;
80
81	if (sz < strlen(cpuid)) {
82		ret = ENOBUFS;
83		goto out_free;
84	}
85
86	scnprintf(buffer, sz, "%s", cpuid);
87
88out_free:
89	free(cpuid);
90	return ret;
91}
92
93char *get_cpuid_str(struct perf_cpu cpu __maybe_unused)
94{
95	return _get_cpuid();
96}