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author | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
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committer | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
commit | 97327692361306d1e6259021bc425e32832fdb50 (patch) | |
tree | fe9088f3248ec61e24f404f21b9793cb644b7f01 /tools/power/cpupower/utils/helpers/msr.c | |
parent | 2d05a8f663478a44e088d122e0d62109bbc801d0 (diff) | |
parent | a3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff) | |
download | FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.tar.gz FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.tar.bz2 FOSSEE-netbook-kernel-source-97327692361306d1e6259021bc425e32832fdb50.zip |
dirty fix to merging
Diffstat (limited to 'tools/power/cpupower/utils/helpers/msr.c')
-rw-r--r-- | tools/power/cpupower/utils/helpers/msr.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/tools/power/cpupower/utils/helpers/msr.c b/tools/power/cpupower/utils/helpers/msr.c new file mode 100644 index 00000000..31a4b24a --- /dev/null +++ b/tools/power/cpupower/utils/helpers/msr.c @@ -0,0 +1,115 @@ +#if defined(__i386__) || defined(__x86_64__) + +#include <fcntl.h> +#include <stdio.h> +#include <unistd.h> +#include <stdint.h> + +#include "helpers/helpers.h" + +/* Intel specific MSRs */ +#define MSR_IA32_PERF_STATUS 0x198 +#define MSR_IA32_MISC_ENABLES 0x1a0 +#define MSR_IA32_ENERGY_PERF_BIAS 0x1b0 +#define MSR_NEHALEM_TURBO_RATIO_LIMIT 0x1ad + +/* + * read_msr + * + * Will return 0 on success and -1 on failure. + * Possible errno values could be: + * EFAULT -If the read/write did not fully complete + * EIO -If the CPU does not support MSRs + * ENXIO -If the CPU does not exist + */ + +int read_msr(int cpu, unsigned int idx, unsigned long long *val) +{ + int fd; + char msr_file_name[64]; + + sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); + fd = open(msr_file_name, O_RDONLY); + if (fd < 0) + return -1; + if (lseek(fd, idx, SEEK_CUR) == -1) + goto err; + if (read(fd, val, sizeof *val) != sizeof *val) + goto err; + close(fd); + return 0; + err: + close(fd); + return -1; +} + +/* + * write_msr + * + * Will return 0 on success and -1 on failure. + * Possible errno values could be: + * EFAULT -If the read/write did not fully complete + * EIO -If the CPU does not support MSRs + * ENXIO -If the CPU does not exist + */ +int write_msr(int cpu, unsigned int idx, unsigned long long val) +{ + int fd; + char msr_file_name[64]; + + sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu); + fd = open(msr_file_name, O_WRONLY); + if (fd < 0) + return -1; + if (lseek(fd, idx, SEEK_CUR) == -1) + goto err; + if (write(fd, &val, sizeof val) != sizeof val) + goto err; + close(fd); + return 0; + err: + close(fd); + return -1; +} + +int msr_intel_get_perf_bias(unsigned int cpu) +{ + unsigned long long val; + int ret; + + if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) + return -1; + + ret = read_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &val); + if (ret) + return ret; + return val; +} + +int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val) +{ + int ret; + + if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS)) + return -1; + + ret = write_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, val); + if (ret) + return ret; + return 0; +} + +unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu) +{ + unsigned long long val; + int ret; + + if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_HAS_TURBO_RATIO)) + return -1; + + ret = read_msr(cpu, MSR_NEHALEM_TURBO_RATIO_LIMIT, &val); + if (ret) + return ret; + return val; +} +#endif |