aboutsummaryrefslogtreecommitdiffstats
path: root/tools/power/cpupower/utils/helpers/cpuid.c
blob: 732b0b41ba261664eefb9e862f7a7174bcc9fca0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>

#include "helpers/helpers.h"

static const char *cpu_vendor_table[X86_VENDOR_MAX] = {
	"Unknown", "GenuineIntel", "AuthenticAMD",
};

#if defined(__i386__) || defined(__x86_64__)

/* from gcc */
#include <cpuid.h>

/*
 * CPUID functions returning a single datum
 *
 * Define unsigned int cpuid_e[abcd]x(unsigned int op)
 */
#define cpuid_func(reg)					\
	unsigned int cpuid_##reg(unsigned int op)	\
	{						\
	unsigned int eax, ebx, ecx, edx;		\
	__cpuid(op, eax, ebx, ecx, edx);		\
	return reg;					\
	}
cpuid_func(eax);
cpuid_func(ebx);
cpuid_func(ecx);
cpuid_func(edx);

#endif /* defined(__i386__) || defined(__x86_64__) */

/* get_cpu_info
 *
 * Extract CPU vendor, family, model, stepping info from /proc/cpuinfo
 *
 * Returns 0 on success or a negativ error code
 *
 * TBD: Should there be a cpuid alternative for this if /proc is not mounted?
 */
int get_cpu_info(struct cpupower_cpu_info *cpu_info)
{
	FILE *fp;
	char value[64];
	unsigned int proc, x;
	unsigned int unknown = 0xffffff;
	unsigned int cpuid_level, ext_cpuid_level;

	int ret = -EINVAL;

	cpu_info->vendor		= X86_VENDOR_UNKNOWN;
	cpu_info->family		= unknown;
	cpu_info->model			= unknown;
	cpu_info->stepping		= unknown;
	cpu_info->caps			= 0;

	fp = fopen("/proc/cpuinfo", "r");
	if (!fp)
		return -EIO;

	while (!feof(fp)) {
		if (!fgets(value, 64, fp))
			continue;
		value[63 - 1] = '\0';

		if (!strncmp(value, "processor\t: ", 12))
			sscanf(value, "processor\t: %u", &proc);

		if (proc != (unsigned int)base_cpu)
			continue;

		/* Get CPU vendor */
		if (!strncmp(value, "vendor_id", 9)) {
			for (x = 1; x < X86_VENDOR_MAX; x++) {
				if (strstr(value, cpu_vendor_table[x]))
					cpu_info->vendor = x;
			}
		/* Get CPU family, etc. */
		} else if (!strncmp(value, "cpu family\t: ", 13)) {
			sscanf(value, "cpu family\t: %u",
			       &cpu_info->family);
		} else if (!strncmp(value, "model\t\t: ", 9)) {
			sscanf(value, "model\t\t: %u",
			       &cpu_info->model);
		} else if (!strncmp(value, "stepping\t: ", 10)) {
			sscanf(value, "stepping\t: %u",
			       &cpu_info->stepping);

			/* Exit -> all values must have been set */
			if (cpu_info->vendor == X86_VENDOR_UNKNOWN ||
			    cpu_info->family == unknown ||
			    cpu_info->model == unknown ||
			    cpu_info->stepping == unknown) {
				ret = -EINVAL;
				goto out;
			}

			ret = 0;
			goto out;
		}
	}
	ret = -ENODEV;
out:
	fclose(fp);
	/* Get some useful CPU capabilities from cpuid */
	if (cpu_info->vendor != X86_VENDOR_AMD &&
	    cpu_info->vendor != X86_VENDOR_INTEL)
		return ret;

	cpuid_level	= cpuid_eax(0);
	ext_cpuid_level	= cpuid_eax(0x80000000);

	/* Invariant TSC */
	if (ext_cpuid_level >= 0x80000007 &&
	    (cpuid_edx(0x80000007) & (1 << 8)))
		cpu_info->caps |= CPUPOWER_CAP_INV_TSC;

	/* Aperf/Mperf registers support */
	if (cpuid_level >= 6 && (cpuid_ecx(6) & 0x1))
		cpu_info->caps |= CPUPOWER_CAP_APERF;

	/* AMD Boost state enable/disable register */
	if (cpu_info->vendor == X86_VENDOR_AMD) {
		if (ext_cpuid_level >= 0x80000007 &&
		    (cpuid_edx(0x80000007) & (1 << 9)))
			cpu_info->caps |= CPUPOWER_CAP_AMD_CBP;
	}

	if (cpu_info->vendor == X86_VENDOR_INTEL) {
		if (cpuid_level >= 6 &&
		    (cpuid_eax(6) & (1 << 1)))
			cpu_info->caps |= CPUPOWER_CAP_INTEL_IDA;
	}

	if (cpu_info->vendor == X86_VENDOR_INTEL) {
		/* Intel's perf-bias MSR support */
		if (cpuid_level >= 6 && (cpuid_ecx(6) & (1 << 3)))
			cpu_info->caps |= CPUPOWER_CAP_PERF_BIAS;

		/* Intel's Turbo Ratio Limit support */
		if (cpu_info->family == 6) {
			switch (cpu_info->model) {
			case 0x1A:	/* Core i7, Xeon 5500 series
					 * Bloomfield, Gainstown NHM-EP
					 */
			case 0x1E:	/* Core i7 and i5 Processor
					 * Clarksfield, Lynnfield, Jasper Forest
					 */
			case 0x1F:	/* Core i7 and i5 Processor - Nehalem */
			case 0x25:	/* Westmere Client
					 * Clarkdale, Arrandale
					 */
			case 0x2C:	/* Westmere EP - Gulftown */
				cpu_info->caps |= CPUPOWER_CAP_HAS_TURBO_RATIO;
				break;
			case 0x2A:	/* SNB */
			case 0x2D:	/* SNB Xeon */
			case 0x3A:	/* IVB */
			case 0x3E:	/* IVB Xeon */
				cpu_info->caps |= CPUPOWER_CAP_HAS_TURBO_RATIO;
				cpu_info->caps |= CPUPOWER_CAP_IS_SNB;
				break;
			case 0x2E:	/* Nehalem-EX Xeon - Beckton */
			case 0x2F:	/* Westmere-EX Xeon - Eagleton */
			default:
				break;
			}
		}
	}

	/*	printf("ID: %u - Extid: 0x%x - Caps: 0x%llx\n",
		cpuid_level, ext_cpuid_level, cpu_info->caps);
	*/
	return ret;
}

Privacy Policy