1// SPDX-License-Identifier: GPL-2.0
2#include <math.h>
3#include <unistd.h>
4#include <stdio.h>
5#include <stdlib.h>
6#include <sys/types.h>
7#include <sys/stat.h>
8#include <fcntl.h>
9#include <sys/timeb.h>
10#include <sched.h>
11#include <errno.h>
12#include <string.h>
13#include <time.h>
14#include "../kselftest.h"
15
16#define MSEC_PER_SEC	1000L
17#define NSEC_PER_MSEC	1000000L
18
19void usage(char *name) {
20	printf ("Usage: %s cpunum\n", name);
21}
22
23int main(int argc, char **argv) {
24	unsigned int i, cpu, fd;
25	char msr_file_name[64];
26	long long tsc, old_tsc, new_tsc;
27	long long aperf, old_aperf, new_aperf;
28	long long mperf, old_mperf, new_mperf;
29	struct timespec before, after;
30	long long int start, finish, total;
31	cpu_set_t cpuset;
32
33	if (argc != 2) {
34		usage(argv[0]);
35		return 1;
36	}
37
38	errno = 0;
39	cpu = strtol(argv[1], (char **) NULL, 10);
40
41	if (errno) {
42		usage(argv[0]);
43		return 1;
44	}
45
46	sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);
47	fd = open(msr_file_name, O_RDONLY);
48
49	if (fd == -1) {
50		printf("/dev/cpu/%d/msr: %s\n", cpu, strerror(errno));
51		return KSFT_SKIP;
52	}
53
54	CPU_ZERO(&cpuset);
55	CPU_SET(cpu, &cpuset);
56
57	if (sched_setaffinity(0, sizeof(cpu_set_t), &cpuset)) {
58		perror("Failed to set cpu affinity");
59		return 1;
60	}
61
62	if (clock_gettime(CLOCK_MONOTONIC, &before) < 0) {
63		perror("clock_gettime");
64		return 1;
65	}
66	pread(fd, &old_tsc,  sizeof(old_tsc), 0x10);
67	pread(fd, &old_aperf,  sizeof(old_mperf), 0xe7);
68	pread(fd, &old_mperf,  sizeof(old_aperf), 0xe8);
69
70	for (i=0; i<0x8fffffff; i++) {
71		sqrt(i);
72	}
73
74	if (clock_gettime(CLOCK_MONOTONIC, &after) < 0) {
75		perror("clock_gettime");
76		return 1;
77	}
78	pread(fd, &new_tsc,  sizeof(new_tsc), 0x10);
79	pread(fd, &new_aperf,  sizeof(new_mperf), 0xe7);
80	pread(fd, &new_mperf,  sizeof(new_aperf), 0xe8);
81
82	tsc = new_tsc-old_tsc;
83	aperf = new_aperf-old_aperf;
84	mperf = new_mperf-old_mperf;
85
86	start = before.tv_sec*MSEC_PER_SEC + before.tv_nsec/NSEC_PER_MSEC;
87	finish = after.tv_sec*MSEC_PER_SEC + after.tv_nsec/NSEC_PER_MSEC;
88	total = finish - start;
89
90	printf("runTime: %4.2f\n", 1.0*total/MSEC_PER_SEC);
91	printf("freq: %7.0f\n", tsc / (1.0*aperf / (1.0 * mperf)) / total);
92	return 0;
93}
94