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// SPDX-License-Identifier: GPL-2.0
/*
* Realizations of bit operations.
*/
#include "bitops.h"
#include "defs.h"
/*
* This is a common helper function for find_next_bit and
* find_next_zero_bit. The difference is the "invert" argument, which
* is XORed with each fetched word before searching it for one bits.
*/
unsigned long _find_next_bit(const unsigned long *addr,
unsigned long nbits, unsigned long start, unsigned long invert)
{
unsigned long tmp;
if (!nbits || start >= nbits)
return nbits;
tmp = addr[start / BITS_PER_LONG] ^ invert;
/* Handle 1st word. */
tmp &= BITMAP_FIRST_WORD_MASK(start);
start = round_down(start, BITS_PER_LONG);
while (!tmp) {
start += BITS_PER_LONG;
if (start >= nbits)
return nbits;
tmp = addr[start / BITS_PER_LONG] ^ invert;
}
return min(start + __ffs(tmp), nbits);
}
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