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 
17 static int dhry_run_set(const char *val, const struct kernel_param *kp);
18 static const struct kernel_param_ops run_ops = {
19 	.flags = KERNEL_PARAM_OPS_FL_NOARG,
20 	.set = dhry_run_set,
21 };
22 static bool dhry_run;
23 module_param_cb(run, &run_ops, &dhry_run, 0200);
24 MODULE_PARM_DESC(run, "Run the test (default: false)");
25 
26 static int iterations = -1;
27 module_param(iterations, int, 0644);
28 MODULE_PARM_DESC(iterations,
29 		"Number of iterations through the benchmark (default: auto)");
30 
dhry_benchmark(void)31 static void dhry_benchmark(void)
32 {
33 	unsigned int cpu = get_cpu();
34 	int i, n;
35 
36 	if (iterations > 0) {
37 		n = dhry(iterations);
38 		goto report;
39 	}
40 
41 	for (i = DHRY_VAX; i > 0; i <<= 1) {
42 		n = dhry(i);
43 		if (n != -EAGAIN)
44 			break;
45 	}
46 
47 report:
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 
dhry_run_set(const char * val,const struct kernel_param * kp)58 static 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 
dhry_init(void)76 static int __init dhry_init(void)
77 {
78 	if (dhry_run)
79 		dhry_benchmark();
80 
81 	return 0;
82 }
83 module_init(dhry_init);
84 
85 MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
86 MODULE_DESCRIPTION("Dhrystone benchmark test module");
87 MODULE_LICENSE("GPL");
88