1 files changed, 83 insertions, 0 deletions
diff --git a/tools/testing/selftests/intel_pstate/aperf.c b/tools/testing/selftests/intel_pstate/aperf.c
new file mode 100644
index 000000000..f6cd03a87
--- /dev/null
+++ b/tools/testing/selftests/intel_pstate/aperf.c
@@ -0,0 +1,83 @@
+// 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>
+#include <string.h>
+#include "../kselftest.h"
+
+void usage(char *name) {
+	printf ("Usage: %s cpunum\n", name);
+}
+
+int main(int argc, char **argv) {
+	unsigned int i, cpu, fd;
+	char msr_file_name[64];
+	long long tsc, old_tsc, new_tsc;
+	long long aperf, old_aperf, new_aperf;
+	long long mperf, old_mperf, new_mperf;
+	struct timeb before, after;
+	long long int start, finish, total;
+	cpu_set_t cpuset;
+
+	if (argc != 2) {
+		usage(argv[0]);
+		return 1;
+	}
+
+	errno = 0;
+	cpu = strtol(argv[1], (char **) NULL, 10);
+
+	if (errno) {
+		usage(argv[0]);
+		return 1;
+	}
+
+	sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);
+	fd = open(msr_file_name, O_RDONLY);
+
+	if (fd == -1) {
+		printf("/dev/cpu/%d/msr: %s\n", cpu, strerror(errno));
+		return KSFT_SKIP;
+	}
+
+	CPU_ZERO(&cpuset);
+	CPU_SET(cpu, &cpuset);
+
+	if (sched_setaffinity(0, sizeof(cpu_set_t), &cpuset)) {
+		perror("Failed to set cpu affinity");
+		return 1;
+	}
+
+	ftime(&before);
+	pread(fd, &old_tsc,  sizeof(old_tsc), 0x10);
+	pread(fd, &old_aperf,  sizeof(old_mperf), 0xe7);
+	pread(fd, &old_mperf,  sizeof(old_aperf), 0xe8);
+
+	for (i=0; i<0x8fffffff; i++) {
+		sqrt(i);
+	}
+
+	ftime(&after);
+	pread(fd, &new_tsc,  sizeof(new_tsc), 0x10);
+	pread(fd, &new_aperf,  sizeof(new_mperf), 0xe7);
+	pread(fd, &new_mperf,  sizeof(new_aperf), 0xe8);
+
+	tsc = new_tsc-old_tsc;
+	aperf = new_aperf-old_aperf;
+	mperf = new_mperf-old_mperf;
+
+	start = before.time*1000 + before.millitm;
+	finish = after.time*1000 + after.millitm;
+	total = finish - start;
+
+	printf("runTime: %4.2f\n", 1.0*total/1000);
+	printf("freq: %7.0f\n", tsc / (1.0*aperf / (1.0 * mperf)) / total);
+	return 0;
+}