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/smp.h>
14
15#define DHRY_VAX 1757
16
17static int dhry_run_set(const char *val, const struct kernel_param *kp);
18static const struct kernel_param_ops run_ops = {
19 .flags = KERNEL_PARAM_OPS_FL_NOARG,
20 .set = dhry_run_set,
21};
22static bool dhry_run;
23module_param_cb(run, &run_ops, &dhry_run, 0200);
24MODULE_PARM_DESC(run, "Run the test (default: false)");
25
26static int iterations = -1;
27module_param(iterations, int, 0644);
28MODULE_PARM_DESC(iterations,
29 "Number of iterations through the benchmark (default: auto)");
30
31static void dhry_benchmark(void)
32{
33 unsigned int cpu = get_cpu();
34 int i, n;
35
36 if (iterations > 0) {
37 n = dhry(n: iterations);
38 goto report;
39 }
40
41 for (i = DHRY_VAX; i > 0; i <<= 1) {
42 n = dhry(n: i);
43 if (n != -EAGAIN)
44 break;
45 }
46
47report:
48 put_cpu();
49 if (n >= 0)
50 pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", cpu,
51 n, n / DHRY_VAX);
52 else if (n == -EAGAIN)
53 pr_err("Please increase the number of iterations\n");
54 else
55 pr_err("Dhrystone benchmark failed error %pe\n", ERR_PTR(n));
56}
57
58static int dhry_run_set(const char *val, const struct kernel_param *kp)
59{
60 int ret;
61
62 if (val) {
63 ret = param_set_bool(val, kp);
64 if (ret)
65 return ret;
66 } else {
67 dhry_run = true;
68 }
69
70 if (dhry_run && system_state == SYSTEM_RUNNING)
71 dhry_benchmark();
72
73 return 0;
74}
75
76static int __init dhry_init(void)
77{
78 if (dhry_run)
79 dhry_benchmark();
80
81 return 0;
82}
83module_init(dhry_init);
84
85MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
86MODULE_DESCRIPTION("Dhrystone benchmark test module");
87MODULE_LICENSE("GPL");
88

source code of linux/lib/dhry_run.c