mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 10:56:40 +00:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
/* 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>
|
|
|
|
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;
|
|
}
|