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/* find_next_bit.c: fallback find next bit implementation
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/bitops.h>
#include <linux/module.h>
int find_next_bit(const unsigned long *addr, int size, int offset)
{
const unsigned long *base;
const int NBITS = sizeof(*addr) * 8;
unsigned long tmp;
base = addr;
if (offset) {
int suboffset;
addr += offset / NBITS;
suboffset = offset % NBITS;
if (suboffset) {
tmp = *addr;
tmp >>= suboffset;
if (tmp)
goto finish;
}
addr++;
}
while ((tmp = *addr) == 0)
addr++;
offset = (addr - base) * NBITS;
finish:
/* count the remaining bits without using __ffs() since that takes a 32-bit arg */
while (!(tmp & 0xff)) {
offset += 8;
tmp >>= 8;
}
while (!(tmp & 1)) {
offset++;
tmp >>= 1;
}
return offset;
}
EXPORT_SYMBOL(find_next_bit);
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