1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 Intel Corporation
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/printk.h>
11 
12 /* a tiny module only meant to test
13  *
14  *   set/clear_bit
15  *   get_count_order/long
16  */
17 
18 /* use an enum because that's the most common BITMAP usage */
19 enum bitops_fun {
20 	BITOPS_4 = 4,
21 	BITOPS_7 = 7,
22 	BITOPS_11 = 11,
23 	BITOPS_31 = 31,
24 	BITOPS_88 = 88,
25 	BITOPS_LAST = 255,
26 	BITOPS_LENGTH = 256
27 };
28 
29 static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
30 
31 static unsigned int order_comb[][2] = {
32 	{0x00000003,  2},
33 	{0x00000004,  2},
34 	{0x00001fff, 13},
35 	{0x00002000, 13},
36 	{0x50000000, 31},
37 	{0x80000000, 31},
38 	{0x80003000, 32},
39 };
40 
41 #ifdef CONFIG_64BIT
42 static unsigned long order_comb_long[][2] = {
43 	{0x0000000300000000, 34},
44 	{0x0000000400000000, 34},
45 	{0x00001fff00000000, 45},
46 	{0x0000200000000000, 45},
47 	{0x5000000000000000, 63},
48 	{0x8000000000000000, 63},
49 	{0x8000300000000000, 64},
50 };
51 #endif
52 
test_bitops_startup(void)53 static int __init test_bitops_startup(void)
54 {
55 	int i, bit_set;
56 
57 	pr_info("Starting bitops test\n");
58 	set_bit(BITOPS_4, g_bitmap);
59 	set_bit(BITOPS_7, g_bitmap);
60 	set_bit(BITOPS_11, g_bitmap);
61 	set_bit(BITOPS_31, g_bitmap);
62 	set_bit(BITOPS_88, g_bitmap);
63 
64 	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
65 		if (order_comb[i][1] != get_count_order(order_comb[i][0]))
66 			pr_warn("get_count_order wrong for %x\n",
67 				       order_comb[i][0]);
68 	}
69 
70 	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
71 		if (order_comb[i][1] != get_count_order_long(order_comb[i][0]))
72 			pr_warn("get_count_order_long wrong for %x\n",
73 				       order_comb[i][0]);
74 	}
75 
76 #ifdef CONFIG_64BIT
77 	for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) {
78 		if (order_comb_long[i][1] !=
79 			       get_count_order_long(order_comb_long[i][0]))
80 			pr_warn("get_count_order_long wrong for %lx\n",
81 				       order_comb_long[i][0]);
82 	}
83 #endif
84 
85 	barrier();
86 
87 	clear_bit(BITOPS_4, g_bitmap);
88 	clear_bit(BITOPS_7, g_bitmap);
89 	clear_bit(BITOPS_11, g_bitmap);
90 	clear_bit(BITOPS_31, g_bitmap);
91 	clear_bit(BITOPS_88, g_bitmap);
92 
93 	bit_set = find_first_bit(g_bitmap, BITOPS_LAST);
94 	if (bit_set != BITOPS_LAST)
95 		pr_err("ERROR: FOUND SET BIT %d\n", bit_set);
96 
97 	pr_info("Completed bitops test\n");
98 
99 	return 0;
100 }
101 
test_bitops_unstartup(void)102 static void __exit test_bitops_unstartup(void)
103 {
104 }
105 
106 module_init(test_bitops_startup);
107 module_exit(test_bitops_unstartup);
108 
109 MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>, Wei Yang <richard.weiyang@gmail.com>");
110 MODULE_LICENSE("GPL");
111 MODULE_DESCRIPTION("Bit testing module");
112