| Dominik Brodowski | 7fe2f63 | 2011-03-30 16:30:11 +0200 | [diff] [blame] | 1 | #if defined(__i386__) || defined(__x86_64__) |
| 2 | |
| 3 | #include <fcntl.h> |
| 4 | #include <stdio.h> |
| 5 | #include <unistd.h> |
| 6 | #include <stdint.h> |
| 7 | |
| 8 | #include "helpers/helpers.h" |
| 9 | |
| 10 | /* Intel specific MSRs */ |
| 11 | #define MSR_IA32_PERF_STATUS 0x198 |
| 12 | #define MSR_IA32_MISC_ENABLES 0x1a0 |
| 13 | #define MSR_IA32_ENERGY_PERF_BIAS 0x1b0 |
| Thomas Renninger | 8fb2e44 | 2011-07-21 11:54:53 +0200 | [diff] [blame] | 14 | #define MSR_NEHALEM_TURBO_RATIO_LIMIT 0x1ad |
| Dominik Brodowski | 7fe2f63 | 2011-03-30 16:30:11 +0200 | [diff] [blame] | 15 | |
| 16 | /* |
| 17 | * read_msr |
| 18 | * |
| 19 | * Will return 0 on success and -1 on failure. |
| 20 | * Possible errno values could be: |
| 21 | * EFAULT -If the read/write did not fully complete |
| 22 | * EIO -If the CPU does not support MSRs |
| 23 | * ENXIO -If the CPU does not exist |
| 24 | */ |
| 25 | |
| 26 | int read_msr(int cpu, unsigned int idx, unsigned long long *val) |
| 27 | { |
| 28 | int fd; |
| 29 | char msr_file_name[64]; |
| 30 | |
| 31 | sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); |
| 32 | fd = open(msr_file_name, O_RDONLY); |
| 33 | if (fd < 0) |
| 34 | return -1; |
| 35 | if (lseek(fd, idx, SEEK_CUR) == -1) |
| 36 | goto err; |
| 37 | if (read(fd, val, sizeof *val) != sizeof *val) |
| 38 | goto err; |
| 39 | close(fd); |
| 40 | return 0; |
| 41 | err: |
| 42 | close(fd); |
| 43 | return -1; |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * write_msr |
| 48 | * |
| 49 | * Will return 0 on success and -1 on failure. |
| 50 | * Possible errno values could be: |
| 51 | * EFAULT -If the read/write did not fully complete |
| 52 | * EIO -If the CPU does not support MSRs |
| 53 | * ENXIO -If the CPU does not exist |
| 54 | */ |
| 55 | int write_msr(int cpu, unsigned int idx, unsigned long long val) |
| 56 | { |
| 57 | int fd; |
| 58 | char msr_file_name[64]; |
| 59 | |
| 60 | sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); |
| 61 | fd = open(msr_file_name, O_WRONLY); |
| 62 | if (fd < 0) |
| 63 | return -1; |
| 64 | if (lseek(fd, idx, SEEK_CUR) == -1) |
| 65 | goto err; |
| 66 | if (write(fd, &val, sizeof val) != sizeof val) |
| 67 | goto err; |
| 68 | close(fd); |
| 69 | return 0; |
| 70 | err: |
| 71 | close(fd); |
| 72 | return -1; |
| 73 | } |
| 74 | |
| Dominik Brodowski | 7fe2f63 | 2011-03-30 16:30:11 +0200 | [diff] [blame] | 75 | int msr_intel_get_perf_bias(unsigned int cpu) |
| 76 | { |
| 77 | unsigned long long val; |
| 78 | int ret; |
| 79 | |
| 80 | if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) |
| 81 | return -1; |
| 82 | |
| 83 | ret = read_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &val); |
| 84 | if (ret) |
| 85 | return ret; |
| 86 | return val; |
| 87 | } |
| 88 | |
| 89 | int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val) |
| 90 | { |
| 91 | int ret; |
| 92 | |
| 93 | if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) |
| 94 | return -1; |
| 95 | |
| 96 | ret = write_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, val); |
| 97 | if (ret) |
| 98 | return ret; |
| 99 | return 0; |
| 100 | } |
| Thomas Renninger | 8fb2e44 | 2011-07-21 11:54:53 +0200 | [diff] [blame] | 101 | |
| 102 | unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu) |
| 103 | { |
| 104 | unsigned long long val; |
| 105 | int ret; |
| 106 | |
| 107 | if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_HAS_TURBO_RATIO)) |
| 108 | return -1; |
| 109 | |
| 110 | ret = read_msr(cpu, MSR_NEHALEM_TURBO_RATIO_LIMIT, &val); |
| 111 | if (ret) |
| 112 | return ret; |
| 113 | return val; |
| 114 | } |
| Dominik Brodowski | 7fe2f63 | 2011-03-30 16:30:11 +0200 | [diff] [blame] | 115 | #endif |