ubuntu-linux-kernel/tools/testing/selftests/intel_pstate/msr.c

41 lines
679 B
C

// SPDX-License-Identifier: GPL-2.0
#include <math.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/timeb.h>
#include <sched.h>
#include <errno.h>
int main(int argc, char **argv) {
int cpu, fd;
long long msr;
char msr_file_name[64];
if (argc != 2)
return 1;
errno = 0;
cpu = strtol(argv[1], (char **) NULL, 10);
if (errno)
return 1;
sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);
fd = open(msr_file_name, O_RDONLY);
if (fd == -1) {
perror("Failed to open");
return 1;
}
pread(fd, &msr, sizeof(msr), 0x199);
printf("msr 0x199: 0x%llx\n", msr);
return 0;
}