/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. 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.
*
* Copyright (c) 2014 Spectra Logic Corporation
* All rights reserved.
*
* 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,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*
* $FreeBSD$
*/
#ifndef _SYS_BITSTRING_H_
#define _SYS_BITSTRING_H_
#ifdef _KERNEL
#include <sys/libkern.h>
#include <sys/malloc.h>
#endif
#include <sys/types.h>
typedef unsigned long bitstr_t;
/*---------------------- Private Implementation Details ----------------------*/
#define _BITSTR_MASK (~0UL)
#define _BITSTR_BITS (sizeof(bitstr_t) * 8)
#ifdef roundup2
#define _bit_roundup2 roundup2
#else
#define _bit_roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
#endif
/* bitstr_t in bit string containing the bit. */
static inline int
_bit_idx(int _bit)
{
return (_bit / _BITSTR_BITS);
}
/* bit number within bitstr_t at _bit_idx(_bit). */
static inline int
_bit_offset(int _bit)
{
return (_bit % _BITSTR_BITS);
}
/* Mask for the bit within its long. */
static inline bitstr_t
_bit_mask(int _bit)
{
return (1UL << _bit_offset(_bit));
}
static inline bitstr_t
_bit_make_mask(int _start, int _stop)
{
return ((_BITSTR_MASK << _bit_offset(_start)) &
(_BITSTR_MASK >> (_BITSTR_BITS - _bit_offset(_stop) - 1)));
}
/*----------------------------- Public Interface -----------------------------*/
/* Number of bytes allocated for a bit string of nbits bits */
#define bitstr_size(_nbits) (_bit_roundup2(_nbits, _BITSTR_BITS) / 8)
/* Allocate a bit string initialized with no bits set. */
#ifdef _KERNEL
static inline bitstr_t *
bit_alloc(int _nbits, struct malloc_type *type, int flags)
{
return ((bitstr_t *)malloc(bitstr_size(_nbits), type, flags | M_ZERO));
}
#else
static inline bitstr_t *
bit_alloc(int _nbits)
{
return ((bitstr_t *)calloc(bitstr_size(_nbits), 1));
}
#endif
/* Allocate a bit string on the stack */
#define bit_decl(name, nbits) \
((name)[bitstr_size(nbits) / sizeof(bitstr_t)])
/* Is bit N of bit string set? */
static inline int
bit_test(const bitstr_t *_bitstr, int _bit)
{
return ((_bitstr[_bit_idx(_bit)] & _bit_mask(_bit)) != 0);
}
/* Set bit N of bit string. */
static inline void
bit_set(bitstr_t *_bitstr, int _bit)
{
_bitstr[_bit_idx(_bit)] |= _bit_mask(_bit);
}
/* clear bit N of bit string name */
static inline void
bit_clear(bitstr_t *_bitstr, int _bit)
{
_bitstr[_bit_idx(_bit)] &= ~_bit_mask(_bit);
}
/* Set bits start ... stop inclusive in bit string. */
static inline void
bit_nset(bitstr_t *_bitstr, int _start, int _stop)
{
bitstr_t *_stopbitstr;
_stopbitstr = _bitstr + _bit_idx(_stop);
_bitstr += _bit_idx(_start);
if (_bitstr == _stopbitstr) {
*_bitstr |= _bit_make_mask(_start, _stop);
} else {
*_bitstr |= _bit_make_mask(_start, _BITSTR_BITS - 1);
while (++_bitstr < _stopbitstr)
*_bitstr = _BITSTR_MASK;
*_stopbitstr |= _bit_make_mask(0, _stop);
}
}
/* Clear bits start ... stop inclusive in bit string. */
static inline void
bit_nclear(bitstr_t *_bitstr, int _start, int _stop)
{
bitstr_t *_stopbitstr;
_stopbitstr = _bitstr + _bit_idx(_stop);
_bitstr += _bit_idx(_start);
if (_bitstr == _stopbitstr) {
*_bitstr &= ~_bit_make_mask(_start, _stop);
} else {
*_bitstr &= ~_bit_make_mask(_start, _BITSTR_BITS - 1);
while (++_bitstr < _stopbitstr)
*_bitstr = 0;
*_stopbitstr &= ~_bit_make_mask(0, _stop);
}
}
/* Find the first bit set in bit string at or after bit start. */
static inline void
bit_ffs_at(bitstr_t *_bitstr, int _start, int _nbits, int *_result)
{
bitstr_t *_curbitstr;
bitstr_t *_stopbitstr;
bitstr_t _test;
int _value, _offset;
if (_nbits > 0) {
_curbitstr = _bitstr + _bit_idx(_start);
_stopbitstr = _bitstr + _bit_idx(_nbits - 1);
_test = *_curbitstr;
if (_bit_offset(_start) != 0)
_test &= _bit_make_mask(_start, _BITSTR_BITS - 1);
while (_test == 0 && _curbitstr < _stopbitstr)
_test = *(++_curbitstr);
_offset = ffsl(_test);
_value = ((_curbitstr - _bitstr) * _BITSTR_BITS) + _offset - 1;
if (_offset == 0 || _value >= _nbits)
_value = -1;
} else {
_value = -1;
}
*_result = _value;
}
/* Find the first bit clear in bit string at or after bit start. */
static inline void
bit_ffc_at(bitstr_t *_bitstr, int _start, int _nbits, int *_result)
{
bitstr_t *_curbitstr;
bitstr_t *_stopbitstr;
bitstr_t _test;
int _value, _offset;
if (_nbits > 0) {
_curbitstr = _bitstr + _bit_idx(_start);
_stopbitstr = _bitstr + _bit_idx(_nbits - 1);
_test = *_curbitstr;
if (_bit_offset(_start) != 0)
_test |= _bit_make_mask(0, _start - 1);
while (_test == _BITSTR_MASK && _curbitstr < _stopbitstr)
_test = *(++_curbitstr);
_offset = ffsl(~_test);
_value = ((_curbitstr - _bitstr) * _BITSTR_BITS) + _offset - 1;
if (_offset == 0 || _value >= _nbits)
_value = -1;
} else {
_value = -1;
}
*_result = _value;
}
/* Find the first bit set in bit string. */
static inline void
bit_ffs(bitstr_t *_bitstr, int _nbits, int *_result)
{
bit_ffs_at(_bitstr, /*start*/0, _nbits, _result);
}
/* Find the first bit clear in bit string. */
static inline void
bit_ffc(bitstr_t *_bitstr, int _nbits, int *_result)
{
bit_ffc_at(_bitstr, /*start*/0, _nbits, _result);
}
/* Count the number of bits set in a bitstr of size _nbits at or after _start */
static inline void
bit_count(bitstr_t *_bitstr, int _start, int _nbits, int *_result)
{
bitstr_t *_curbitstr, mask;
int _value = 0, curbitstr_len;
if (_start >= _nbits)
goto out;
_curbitstr = _bitstr + _bit_idx(_start);
_nbits -= _BITSTR_BITS * _bit_idx(_start);
_start -= _BITSTR_BITS * _bit_idx(_start);
if (_start > 0) {
curbitstr_len = (int)_BITSTR_BITS < _nbits ?
(int)_BITSTR_BITS : _nbits;
mask = _bit_make_mask(_start, _bit_offset(curbitstr_len - 1));
_value += __bitcountl(*_curbitstr & mask);
_curbitstr++;
_nbits -= _BITSTR_BITS;
}
while (_nbits >= (int)_BITSTR_BITS) {
_value += __bitcountl(*_curbitstr);
_curbitstr++;
_nbits -= _BITSTR_BITS;
}
if (_nbits > 0) {
mask = _bit_make_mask(0, _bit_offset(_nbits - 1));
_value += __bitcountl(*_curbitstr & mask);
}
out:
*_result = _value;
}
#endif /* _SYS_BITSTRING_H_ */
