1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Dhrystone benchmark test module
 4 *
 5 * Copyright (C) 2022 Glider bv
 6 */
 7
 8#include "dhry.h"
 9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/mutex.h>
14#include <linux/smp.h>
15
16#define DHRY_VAX	1757
17
18static int dhry_run_set(const char *val, const struct kernel_param *kp);
19static const struct kernel_param_ops run_ops = {
20	.flags = KERNEL_PARAM_OPS_FL_NOARG,
21	.set = dhry_run_set,
22};
23static bool dhry_run;
24module_param_cb(run, &run_ops, &dhry_run, 0200);
25MODULE_PARM_DESC(run, "Run the test (default: false)");
26
27static int iterations = -1;
28module_param(iterations, int, 0644);
29MODULE_PARM_DESC(iterations,
30		"Number of iterations through the benchmark (default: auto)");
31
32static void dhry_benchmark(void)
33{
34	unsigned int cpu = get_cpu();
35	int i, n;
36
37	if (iterations > 0) {
38		n = dhry(iterations);
39		goto report;
40	}
41
42	for (i = DHRY_VAX; i > 0; i <<= 1) {
43		n = dhry(i);
44		if (n != -EAGAIN)
45			break;
46	}
47
48report:
49	put_cpu();
50	if (n >= 0)
51		pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", cpu,
52			n, n / DHRY_VAX);
53	else if (n == -EAGAIN)
54		pr_err("Please increase the number of iterations\n");
55	else
56		pr_err("Dhrystone benchmark failed error %pe\n", ERR_PTR(n));
57}
58
59static int dhry_run_set(const char *val, const struct kernel_param *kp)
60{
61	int ret;
62
63	if (val) {
64		ret = param_set_bool(val, kp);
65		if (ret)
66			return ret;
67	} else {
68		dhry_run = true;
69	}
70
71	if (dhry_run && system_state == SYSTEM_RUNNING)
72		dhry_benchmark();
73
74	return 0;
75}
76
77static int __init dhry_init(void)
78{
79	if (dhry_run)
80		dhry_benchmark();
81
82	return 0;
83}
84module_init(dhry_init);
85
86MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
87MODULE_LICENSE("GPL");