Commit fc1d4be6 authored by David Howells's avatar David Howells Committed by Linus Torvalds

[PATCH] out-of-line implementation of find_next_bit()

The attached patch provides an out-of-line implementation of find_next_bit()
and rearranges linux/bitops.h to avoid a dependency loop between inline
functions in there and in asm/bitops.h trying to include one another.
Signed-Off-By: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent cc07552d
#ifndef _LINUX_BITOPS_H
#define _LINUX_BITOPS_H
#include <asm/types.h>
#include <asm/bitops.h>
/*
* ffs: find first bit set. This is defined the same way as
......@@ -71,6 +70,12 @@ static __inline__ int generic_fls(int x)
return r;
}
/*
* Include this here because some architectures need generic_ffs/fls in
* scope
*/
#include <asm/bitops.h>
static __inline__ int get_bitmask_order(unsigned int count)
{
int order;
......
......@@ -14,6 +14,7 @@ endif
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
......
/* 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;
}
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