1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2008, Jeffrey Roberson <jeff@freebsd.org>
5 * All rights reserved.
6 *
7 * Copyright (c) 2008 Nokia Corporation
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice unmodified, this list of conditions, and the following
15 * disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _SYS__BITSET_H_
33#define _SYS__BITSET_H_
34
35/*
36 * Macros addressing word and bit within it, tuned to make compiler
37 * optimize cases when SETSIZE fits into single machine word.
38 */
39#define _BITSET_BITS (sizeof(unsigned long) * 8)
40
41#define __howmany(x, y) (((x) + ((y) - 1)) / (y))
42
43#define __bitset_words(_s) (__howmany(_s, _BITSET_BITS))
44
45#define __BITSET_DEFINE(_t, _s) \
46struct _t { \
47 unsigned long __bits[__bitset_words((_s))]; \
48}
49
50/*
51 * Helper to declare a bitset without it's size being a constant.
52 *
53 * Sadly we cannot declare a bitset struct with 'bits[]', because it's
54 * the only member of the struct and the compiler complains.
55 */
56#define __BITSET_DEFINE_VAR(_t) __BITSET_DEFINE(_t, 1)
57
58/*
59 * Define a default type that can be used while manually specifying size
60 * to every call.
61 */
62
63#if defined(_KERNEL) || defined(_WANT_FREEBSD_BITSET)
64__BITSET_DEFINE(bitset, 1);
65
66#define BITSET_DEFINE(_t, _s) __BITSET_DEFINE(_t, _s)
67#define BITSET_DEFINE_VAR(_t) __BITSET_DEFINE_VAR(_t)
68#endif /* defined(_KERNEL) || defined(_WANT_FREEBSD_BITSET) */
69
70#endif /* !_SYS__BITSET_H_ */