gems-kernel/source/THIRDPARTY/xnu/bsd/sys/bitstring.h
2024-06-03 11:29:39 -05:00

180 lines
8.7 KiB
C

/*
* Copyright (c) 2013-2016 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
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*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Paul Vixie.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _SYS_BITSTRING_H_
#define _SYS_BITSTRING_H_
#ifdef XNU_KERNEL_PRIVATE
#include <sys/mcache.h>
typedef uint8_t bitstr_t;
/* internal macros */
/* byte of the bitstring bit is in */
#define _bitstr_byte(bit) \
((bit) >> 3)
/* mask for the bit within its byte */
#define _bitstr_mask(bit) \
(1 << ((bit) & 0x7))
/* external macros */
/* bytes in a bitstring of nbits bits */
#define bitstr_size(nbits) \
(((nbits) + 7) >> 3)
/* allocate a bitstring on the stack */
#define bit_decl(name, nbits) \
((name)[bitstr_size(nbits)])
/* is bit N of bitstring name set? */
#define bitstr_test(name, bit) \
((name)[_bitstr_byte(bit)] & _bitstr_mask(bit))
/* set bit N of bitstring name */
#define bitstr_set(name, bit) \
((name)[_bitstr_byte(bit)] |= _bitstr_mask(bit))
/* set bit N of bitstring name (atomic) */
#define bitstr_set_atomic(name, bit) \
(void)os_atomic_or(&((name)[_bitstr_byte(bit)]), _bitstr_mask(bit), relaxed)
/* clear bit N of bitstring name */
#define bitstr_clear(name, bit) \
((name)[_bitstr_byte(bit)] &= ~_bitstr_mask(bit))
/* clear bit N of bitstring name (atomic) */
#define bitstr_clear_atomic(name, bit) \
(void)os_atomic_andnot(&((name)[_bitstr_byte(bit)]), _bitstr_mask(bit), relaxed)
/* clear bits start ... stop in bitstring */
#define bitstr_nclear(name, start, stop) do { \
bitstr_t *_name = (name); \
int _start = (start), _stop = (stop); \
int _startbyte = _bitstr_byte(_start); \
int _stopbyte = _bitstr_byte(_stop); \
if (_startbyte == _stopbyte) { \
_name[_startbyte] &= ((0xff >> (8 - (_start & 0x7))) | \
(0xff << ((_stop & 0x7) + 1))); \
} else { \
_name[_startbyte] &= 0xff >> (8 - (_start & 0x7)); \
while (++_startbyte < _stopbyte) \
_name[_startbyte] = 0; \
_name[_stopbyte] &= 0xff << ((_stop & 0x7) + 1); \
} \
} while (0)
/* set bits start ... stop in bitstring */
#define bitstr_nset(name, start, stop) do { \
bitstr_t *_name = (name); \
int _start = (start), _stop = (stop); \
int _startbyte = _bitstr_byte(_start); \
int _stopbyte = _bitstr_byte(_stop); \
if (_startbyte == _stopbyte) { \
_name[_startbyte] |= ((0xff << (_start & 0x7)) & \
(0xff >> (7 - (_stop & 0x7)))); \
} else { \
_name[_startbyte] |= 0xff << ((_start) & 0x7); \
while (++_startbyte < _stopbyte) \
_name[_startbyte] = 0xff; \
_name[_stopbyte] |= 0xff >> (7 - (_stop & 0x7)); \
} \
} while (0)
/* find first bit clear in name */
#define bitstr_ffc(name, nbits, value) do { \
bitstr_t *_name = (name); \
int _byte, _nbits = (nbits); \
int _stopbyte = _bitstr_byte(_nbits - 1), _value = -1; \
if (_nbits > 0) \
for (_byte = 0; _byte <= _stopbyte; ++_byte) \
if (_name[_byte] != 0xff) { \
bitstr_t _lb; \
_value = _byte << 3; \
for (_lb = _name[_byte]; (_lb & 0x1); \
++_value, _lb >>= 1); \
break; \
} \
if (_value >= nbits) \
_value = -1; \
*(value) = _value; \
} while (0)
/* find first bit set in name */
#define bitstr_ffs(name, nbits, value) do { \
bitstr_t *_name = (name); \
int _byte, _nbits = (nbits); \
int _stopbyte = _bitstr_byte(_nbits - 1), _value = -1; \
if (_nbits > 0) \
for (_byte = 0; _byte <= _stopbyte; ++_byte) \
if (_name[_byte]) { \
bitstr_t _lb; \
_value = _byte << 3; \
for (_lb = _name[_byte]; !(_lb & 0x1); \
++_value, _lb >>= 1); \
break; \
} \
if (_value >= nbits) \
_value = -1; \
*(value) = _value; \
} while (0)
#endif /* XNU_KERNEL_PRIVATE */
#endif /* !_SYS_BITSTRING_H_ */