Peter Stuge | dad1e30 | 2008-11-22 17:13:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of msrtool. |
| 3 | * |
| 4 | * Copyright (c) 2008 Peter Stuge <peter@stuge.se> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | */ |
| 19 | |
| 20 | #include <sys/types.h> |
| 21 | #include <sys/stat.h> |
| 22 | #include <fcntl.h> |
| 23 | #include <unistd.h> |
| 24 | #include <string.h> |
| 25 | #include <errno.h> |
| 26 | |
| 27 | #include "msrtool.h" |
| 28 | |
| 29 | static int msr_fd[MAX_CORES] = {-1, -1, -1, -1, -1, -1, -1, -1}; |
| 30 | |
| 31 | int linux_probe(const struct sysdef *system) { |
| 32 | struct stat st; |
| 33 | return 0 == stat("/dev/cpu/0/msr", &st); |
| 34 | } |
| 35 | |
| 36 | int linux_open(uint8_t cpu, enum SysModes mode) { |
| 37 | int fmode; |
| 38 | char fn[32]; |
| 39 | switch (mode) { |
| 40 | case SYS_RDWR: |
| 41 | fmode = O_RDWR; |
| 42 | break; |
| 43 | case SYS_WRONLY: |
| 44 | fmode = O_WRONLY; |
| 45 | break; |
| 46 | case SYS_RDONLY: |
| 47 | default: |
| 48 | fmode = O_RDONLY; |
| 49 | break; |
| 50 | } |
| 51 | if (cpu >= MAX_CORES) { |
| 52 | fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu); |
| 53 | return 0; |
| 54 | } |
| 55 | if (snprintf(fn, sizeof(fn), "/dev/cpu/%d/msr", cpu) == -1) { |
| 56 | fprintf(stderr, "%s: snprintf: %s\n", __func__, strerror(errno)); |
| 57 | return 0; |
| 58 | } |
| 59 | msr_fd[cpu] = open(fn, fmode); |
| 60 | if (-1 == msr_fd[cpu]) { |
| 61 | fprintf(stderr, "open(%s): %s\n", fn, strerror(errno)); |
| 62 | return 0; |
| 63 | } |
| 64 | return 1; |
| 65 | } |
| 66 | |
| 67 | int linux_close(uint8_t cpu) { |
| 68 | int ret; |
| 69 | if (cpu >= MAX_CORES) { |
| 70 | fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu); |
| 71 | return 0; |
| 72 | } |
| 73 | ret = close(msr_fd[cpu]); |
| 74 | msr_fd[cpu] = 0; |
| 75 | return 0 == ret; |
| 76 | } |
| 77 | |
| 78 | int linux_rdmsr(uint8_t cpu, uint32_t addr, struct msr *val) { |
| 79 | if (lseek(msr_fd[cpu], addr, SEEK_SET) == -1) { |
| 80 | SYSERROR(lseek, addr); |
| 81 | return 0; |
| 82 | } |
| 83 | if (read(msr_fd[cpu], val, 8) != 8) { |
| 84 | SYSERROR(read, addr); |
| 85 | return 0; |
| 86 | } |
| 87 | return 1; |
| 88 | } |