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/cleanup.h>
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/printk.h>
12#include <linux/slab.h>
13
14/* a tiny module only meant to test
15 *
16 * set/clear_bit
17 * get_count_order/long
18 */
19
20/* use an enum because that's the most common BITMAP usage */
21enum bitops_fun {
22 BITOPS_4 = 4,
23 BITOPS_7 = 7,
24 BITOPS_11 = 11,
25 BITOPS_31 = 31,
26 BITOPS_88 = 88,
27 BITOPS_LAST = 255,
28 BITOPS_LENGTH = 256
29};
30
31static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
32
33static unsigned int order_comb[][2] = {
34 {0x00000003, 2},
35 {0x00000004, 2},
36 {0x00001fff, 13},
37 {0x00002000, 13},
38 {0x50000000, 31},
39 {0x80000000, 31},
40 {0x80003000, 32},
41};
42
43#ifdef CONFIG_64BIT
44static unsigned long order_comb_long[][2] = {
45 {0x0000000300000000, 34},
46 {0x0000000400000000, 34},
47 {0x00001fff00000000, 45},
48 {0x0000200000000000, 45},
49 {0x5000000000000000, 63},
50 {0x8000000000000000, 63},
51 {0x8000300000000000, 64},
52};
53#endif
54
55static int __init test_fns(void)
56{
57 static volatile __always_used unsigned long tmp __initdata;
58 unsigned long *buf __free(kfree) = NULL;
59 unsigned int i, n;
60 ktime_t time;
61
62 buf = kmalloc_array(10000, sizeof(unsigned long), GFP_KERNEL);
63 if (!buf)
64 return -ENOMEM;
65
66 get_random_bytes(buf, len: 10000 * sizeof(unsigned long));
67 time = ktime_get();
68
69 for (n = 0; n < BITS_PER_LONG; n++)
70 for (i = 0; i < 10000; i++)
71 tmp = fns(word: buf[i], n);
72
73 time = ktime_get() - time;
74 pr_err("fns: %18llu ns\n", time);
75
76 return 0;
77}
78
79static int __init test_bitops_startup(void)
80{
81 int i, bit_set;
82
83 pr_info("Starting bitops test\n");
84 set_bit(nr: BITOPS_4, addr: g_bitmap);
85 set_bit(nr: BITOPS_7, addr: g_bitmap);
86 set_bit(nr: BITOPS_11, addr: g_bitmap);
87 set_bit(nr: BITOPS_31, addr: g_bitmap);
88 set_bit(nr: BITOPS_88, addr: g_bitmap);
89
90 for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
91 if (order_comb[i][1] != get_count_order(count: order_comb[i][0]))
92 pr_warn("get_count_order wrong for %x\n",
93 order_comb[i][0]);
94 }
95
96 for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
97 if (order_comb[i][1] != get_count_order_long(l: order_comb[i][0]))
98 pr_warn("get_count_order_long wrong for %x\n",
99 order_comb[i][0]);
100 }
101
102#ifdef CONFIG_64BIT
103 for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) {
104 if (order_comb_long[i][1] !=
105 get_count_order_long(l: order_comb_long[i][0]))
106 pr_warn("get_count_order_long wrong for %lx\n",
107 order_comb_long[i][0]);
108 }
109#endif
110
111 barrier();
112
113 clear_bit(nr: BITOPS_4, addr: g_bitmap);
114 clear_bit(nr: BITOPS_7, addr: g_bitmap);
115 clear_bit(nr: BITOPS_11, addr: g_bitmap);
116 clear_bit(nr: BITOPS_31, addr: g_bitmap);
117 clear_bit(nr: BITOPS_88, addr: g_bitmap);
118
119 bit_set = find_first_bit(addr: g_bitmap, size: BITOPS_LAST);
120 if (bit_set != BITOPS_LAST)
121 pr_err("ERROR: FOUND SET BIT %d\n", bit_set);
122
123 test_fns();
124
125 pr_info("Completed bitops test\n");
126
127 return 0;
128}
129
130static void __exit test_bitops_unstartup(void)
131{
132}
133
134module_init(test_bitops_startup);
135module_exit(test_bitops_unstartup);
136
137MODULE_AUTHOR("Jesse Brandeburg <jesse.brandeburg@intel.com>, Wei Yang <richard.weiyang@gmail.com>");
138MODULE_LICENSE("GPL");
139MODULE_DESCRIPTION("Bit testing module");
140

source code of linux/lib/test_bitops.c