Messages in this thread Patch in this message | | | Date | Tue, 10 May 2005 18:12:55 +0300 | From | Mihai Rusu <> | Subject | [RFC][PATCH 2.4 1/4] inotify 0.22 2.4.x backport - find_next_bit |
| |
Hi
This is the find_next_bit implementation from 2.6.11 vanilla. Needed by "idr.c".
-- Mihai Rusu Linux System Development
Schlund + Partner AG Tel : +40-21-231-2544 Str Mircea Eliade 18 EMail : dizzy@schlund.ro Sect 1, Bucuresti 71295, Romania
include/linux/bitops.h | 2 + lib/Makefile | 2 - lib/find_next_bit.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+), 1 deletion(-)
diff -uNr linux-2.4.30.orig/include/linux/bitops.h linux-2.4.30/include/linux/bitops.h --- linux-2.4.30.orig/include/linux/bitops.h 2001-11-22 21:46:18.000000000 +0200 +++ linux-2.4.30/include/linux/bitops.h 2005-05-09 13:13:18.000000000 +0300 @@ -66,6 +66,8 @@ return (res & 0x0F) + ((res >> 4) & 0x0F); } +int find_next_bit(const unsigned long *addr, int size, int offset); + #include <asm/bitops.h> diff -uNr linux-2.4.30.orig/lib/Makefile linux-2.4.30/lib/Makefile --- linux-2.4.30.orig/lib/Makefile 2004-04-14 16:05:40.000000000 +0300 +++ linux-2.4.30/lib/Makefile 2005-05-09 13:16:49.000000000 +0300 @@ -12,7 +12,7 @@ rbtree.o crc32.o firmware_class.o obj-y := errno.o ctype.o string.o vsprintf.o brlock.o cmdline.o \ - bust_spinlocks.o rbtree.o dump_stack.o + bust_spinlocks.o rbtree.o dump_stack.o find_next_bit.o obj-$(CONFIG_FW_LOADER) += firmware_class.o obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o diff -uNr linux-2.4.30.orig/lib/find_next_bit.c linux-2.4.30/lib/find_next_bit.c --- linux-2.4.30.orig/lib/find_next_bit.c 1970-01-01 02:00:00.000000000 +0200 +++ linux-2.4.30/lib/find_next_bit.c 2005-05-09 13:13:18.000000000 +0300 @@ -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; +}
| |