Resguardo inicial

linux-7.2.3/tools/testing/selftests/intel_pstate/msr.c

@@ -0,0 +1,40 @@
+// 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;
+}