Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / tools / power / cpupower / utils / helpers / msr.c

diff --git a/kernel/tools/power/cpupower/utils/helpers/msr.c b/kernel/tools/power/cpupower/utils/helpers/msr.c
new file mode 100644 (file)
index 0000000..31a4b24
--- /dev/null
+++ b/kernel/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