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 */
19enum 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
29static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
30
31static 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
42static 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
53static 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
102static void __exit test_bitops_unstartup(void)
103{
104}
105
106module_init(test_bitops_startup);
107module_exit(test_bitops_unstartup);
108
109MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>, Wei Yang <richard.weiyang@gmail.com>");
110MODULE_LICENSE("GPL");
111MODULE_DESCRIPTION("Bit testing module");
112