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, 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(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(BITOPS_4, g_bitmap);
 85	set_bit(BITOPS_7, g_bitmap);
 86	set_bit(BITOPS_11, g_bitmap);
 87	set_bit(BITOPS_31, g_bitmap);
 88	set_bit(BITOPS_88, g_bitmap);
 89
 90	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
 91		if (order_comb[i][1] != get_count_order(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(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(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(BITOPS_4, g_bitmap);
114	clear_bit(BITOPS_7, g_bitmap);
115	clear_bit(BITOPS_11, g_bitmap);
116	clear_bit(BITOPS_31, g_bitmap);
117	clear_bit(BITOPS_88, g_bitmap);
118
119	bit_set = find_first_bit(g_bitmap, 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");