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
|
/*
* This file is part of msrtool.
*
* Copyright (c) 2008 Peter Stuge <peter@stuge.se>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "msrtool.h"
static int msr_fd[MAX_CORES] = {-1, -1, -1, -1, -1, -1, -1, -1};
int linux_probe(const struct sysdef *system) {
struct stat st;
return 0 == stat("/dev/cpu/0/msr", &st);
}
int linux_open(uint8_t cpu, enum SysModes mode) {
int fmode;
char fn[32];
switch (mode) {
case SYS_RDWR:
fmode = O_RDWR;
break;
case SYS_WRONLY:
fmode = O_WRONLY;
break;
case SYS_RDONLY:
default:
fmode = O_RDONLY;
break;
}
if (cpu >= MAX_CORES) {
fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu);
return 0;
}
if (snprintf(fn, sizeof(fn), "/dev/cpu/%d/msr", cpu) == -1) {
fprintf(stderr, "%s: snprintf: %s\n", __func__, strerror(errno));
return 0;
}
msr_fd[cpu] = open(fn, fmode);
if (-1 == msr_fd[cpu]) {
fprintf(stderr, "open(%s): %s\n", fn, strerror(errno));
return 0;
}
return 1;
}
int linux_close(uint8_t cpu) {
int ret;
if (cpu >= MAX_CORES) {
fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu);
return 0;
}
ret = close(msr_fd[cpu]);
msr_fd[cpu] = 0;
return 0 == ret;
}
int linux_rdmsr(uint8_t cpu, uint32_t addr, struct msr *val) {
struct msr tmp;
if (lseek(msr_fd[cpu], addr, SEEK_SET) == -1) {
SYSERROR(lseek, addr);
return 0;
}
if (read(msr_fd[cpu], &tmp, 8) != 8) {
SYSERROR(read, addr);
return 0;
}
val->hi = tmp.lo;
val->lo = tmp.hi;
return 1;
}
|
