1/* 2 * Copyright (c) 2013 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29/*- 30 * Copyright (c) 1989, 1993 31 * The Regents of the University of California. All rights reserved. 32 * 33 * This code is derived from software contributed to Berkeley by 34 * Paul Vixie. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 */ 60 61#ifndef _SYS_BITSTRING_H_ 62#define _SYS_BITSTRING_H_ 63 64#ifdef XNU_KERNEL_PRIVATE 65#include <sys/mcache.h> 66 67typedef uint8_t bitstr_t; 68 69/* internal macros */ 70 /* byte of the bitstring bit is in */ 71#define _bit_byte(bit) \ 72 ((bit) >> 3) 73 74 /* mask for the bit within its byte */ 75#define _bit_mask(bit) \ 76 (1 << ((bit) & 0x7)) 77 78/* external macros */ 79 /* bytes in a bitstring of nbits bits */ 80#define bitstr_size(nbits) \ 81 (((nbits) + 7) >> 3) 82 83 /* allocate a bitstring on the stack */ 84#define bit_decl(name, nbits) \ 85 ((name)[bitstr_size(nbits)]) 86 87 /* is bit N of bitstring name set? */ 88#define bit_test(name, bit) \ 89 ((name)[_bit_byte(bit)] & _bit_mask(bit)) 90 91 /* set bit N of bitstring name */ 92#define bit_set(name, bit) \ 93 ((name)[_bit_byte(bit)] |= _bit_mask(bit)) 94 95 /* set bit N of bitstring name (atomic) */ 96#define bit_set_atomic(name, bit) \ 97 atomic_bitset_8(&((name)[_bit_byte(bit)]), _bit_mask(bit)) 98 99 /* clear bit N of bitstring name */ 100#define bit_clear(name, bit) \ 101 ((name)[_bit_byte(bit)] &= ~_bit_mask(bit)) 102 103 /* clear bit N of bitstring name (atomic) */ 104#define bit_clear_atomic(name, bit) \ 105 atomic_bitclear_8(&((name)[_bit_byte(bit)]), _bit_mask(bit)) 106 107 /* clear bits start ... stop in bitstring */ 108#define bit_nclear(name, start, stop) do { \ 109 bitstr_t *_name = (name); \ 110 int _start = (start), _stop = (stop); \ 111 int _startbyte = _bit_byte(_start); \ 112 int _stopbyte = _bit_byte(_stop); \ 113 if (_startbyte == _stopbyte) { \ 114 _name[_startbyte] &= ((0xff >> (8 - (_start & 0x7))) | \ 115 (0xff << ((_stop & 0x7) + 1))); \ 116 } else { \ 117 _name[_startbyte] &= 0xff >> (8 - (_start & 0x7)); \ 118 while (++_startbyte < _stopbyte) \ 119 _name[_startbyte] = 0; \ 120 _name[_stopbyte] &= 0xff << ((_stop & 0x7) + 1); \ 121 } \ 122} while (0) 123 124 /* set bits start ... stop in bitstring */ 125#define bit_nset(name, start, stop) do { \ 126 bitstr_t *_name = (name); \ 127 int _start = (start), _stop = (stop); \ 128 int _startbyte = _bit_byte(_start); \ 129 int _stopbyte = _bit_byte(_stop); \ 130 if (_startbyte == _stopbyte) { \ 131 _name[_startbyte] |= ((0xff << (_start & 0x7)) & \ 132 (0xff >> (7 - (_stop & 0x7)))); \ 133 } else { \ 134 _name[_startbyte] |= 0xff << ((_start) & 0x7); \ 135 while (++_startbyte < _stopbyte) \ 136 _name[_startbyte] = 0xff; \ 137 _name[_stopbyte] |= 0xff >> (7 - (_stop & 0x7)); \ 138 } \ 139} while (0) 140 141 /* find first bit clear in name */ 142#define bit_ffc(name, nbits, value) do { \ 143 bitstr_t *_name = (name); \ 144 int _byte, _nbits = (nbits); \ 145 int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 146 if (_nbits > 0) \ 147 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 148 if (_name[_byte] != 0xff) { \ 149 bitstr_t _lb; \ 150 _value = _byte << 3; \ 151 for (_lb = _name[_byte]; (_lb & 0x1); \ 152 ++_value, _lb >>= 1); \ 153 break; \ 154 } \ 155 if (_value >= nbits) \ 156 _value = -1; \ 157 *(value) = _value; \ 158} while (0) 159 160 /* find first bit set in name */ 161#define bit_ffs(name, nbits, value) do { \ 162 bitstr_t *_name = (name); \ 163 int _byte, _nbits = (nbits); \ 164 int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \ 165 if (_nbits > 0) \ 166 for (_byte = 0; _byte <= _stopbyte; ++_byte) \ 167 if (_name[_byte]) { \ 168 bitstr_t _lb; \ 169 _value = _byte << 3; \ 170 for (_lb = _name[_byte]; !(_lb & 0x1); \ 171 ++_value, _lb >>= 1); \ 172 break; \ 173 } \ 174 if (_value >= nbits) \ 175 _value = -1; \ 176 *(value) = _value; \ 177} while (0) 178 179#endif /* XNU_KERNEL_PRIVATE */ 180#endif /* !_SYS_BITSTRING_H_ */ 181