mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-11-01 10:33:27 +00:00
46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
|
/* find_last_bit.c: fallback find next bit implementation
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008 IBM Corporation
|
||
|
|
* Written by Rusty Russell <rusty@rustcorp.com.au>
|
||
|
|
* (Inspired by David Howell's find_next_bit implementation)
|
||
|
|
*
|
||
|
|
* 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>
|
||
|
|
#include <asm/types.h>
|
||
|
|
#include <asm/byteorder.h>
|
||
|
|
|
||
|
|
unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
|
||
|
|
{
|
||
|
|
unsigned long words;
|
||
|
|
unsigned long tmp;
|
||
|
|
|
||
|
|
/* Start at final word. */
|
||
|
|
words = size / BITS_PER_LONG;
|
||
|
|
|
||
|
|
/* Partial final word? */
|
||
|
|
if (size & (BITS_PER_LONG-1)) {
|
||
|
|
tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
|
||
|
|
- (size & (BITS_PER_LONG-1)))));
|
||
|
|
if (tmp)
|
||
|
|
goto found;
|
||
|
|
}
|
||
|
|
|
||
|
|
while (words) {
|
||
|
|
tmp = addr[--words];
|
||
|
|
if (tmp) {
|
||
|
|
found:
|
||
|
|
return words * BITS_PER_LONG + __fls(tmp);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Not found */
|
||
|
|
return size;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(find_last_bit);
|