From: David Howells <dhowells@redhat.com>
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: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/bitops.h | 7 ++++-
25-akpm/lib/Makefile | 1
25-akpm/lib/find_next_bit.c | 55 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 62 insertions(+), 1 deletion(-)
diff -puN include/linux/bitops.h~out-of-line-implementation-of-find_next_bit include/linux/bitops.h
--- 25/include/linux/bitops.h~out-of-line-implementation-of-find_next_bit 2004-11-11 01:14:03.000000000 -0800
+++ 25-akpm/include/linux/bitops.h 2004-11-11 12:30:16.684071840 -0800
@@ -1,7 +1,6 @@
#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;
diff -puN /dev/null lib/find_next_bit.c
--- /dev/null 2003-09-15 06:40:47.000000000 -0700
+++ 25-akpm/lib/find_next_bit.c 2004-11-11 01:14:03.000000000 -0800
@@ -0,0 +1,55 @@
+/* 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;
+}
diff -puN lib/Makefile~out-of-line-implementation-of-find_next_bit lib/Makefile
--- 25/lib/Makefile~out-of-line-implementation-of-find_next_bit 2004-11-11 01:14:03.000000000 -0800
+++ 25-akpm/lib/Makefile 2004-11-11 01:14:03.000000000 -0800
@@ -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)
_