107 lines
2.2 KiB
C
107 lines
2.2 KiB
C
/*
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* bits.h
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*
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* Copyright (C) 2014 Arnaud Andre
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*
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* This file is part of uvrrpd.
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*
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* uvrrpd is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* uvrrpd is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with uvrrpd. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef _BITS_H_
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#define _BITS_H_
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#include <limits.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdint.h>
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#include <sys/stat.h>
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/**
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* BIT_MASK(nr) - bit mask
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*/
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#define BIT_MASK(nr) (1 << (nr))
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/**
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* set_bit - Set a bit in memory
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*/
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static inline void set_bit(int nr, unsigned long *addr)
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{
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*addr |= BIT_MASK(nr);
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}
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/**
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* clear_bit - Clear a bit in memory
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*/
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static inline void clear_bit(int nr, unsigned long *addr)
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{
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*addr &= ~BIT_MASK(nr);
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}
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/**
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* change_bit - Toggle a bit in memory
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*/
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static inline void change_bit(int nr, unsigned long *addr)
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{
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*addr ^= BIT_MASK(nr);
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}
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/**
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* test_and_set_bit - Set a bit and return its old value
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*/
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static inline int test_and_set_bit(int nr, unsigned long *addr)
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{
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unsigned long mask = BIT_MASK(nr);
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unsigned long old = *addr;
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*addr = old | mask;
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return (old & mask) != 0;
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}
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/**
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* test_and_clear_bit - Clear a bit and return its old value
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*/
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static inline int test_and_clear_bit(int nr, unsigned long *addr)
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{
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unsigned long mask = BIT_MASK(nr);
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unsigned long old = *addr;
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*addr = old & ~mask;
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return (old & mask) != 0;
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}
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/**
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* test_and_change_bit - Toggle a bit and return its old value
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*/
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static inline int test_and_change_bit(int nr, unsigned long *addr)
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{
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unsigned long mask = BIT_MASK(nr);
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unsigned long old = *addr;
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*addr = old ^ mask;
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return (old & mask) != 0;
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}
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/**
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* test_bit - Determine whether a bit is set
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*/
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static inline int test_bit(int nr, const unsigned long *addr)
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{
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return 1UL & (*addr >> nr);
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}
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#endif /* _BITS_H_ */
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