Messages in this thread Patch in this message | | | Date | Mon, 8 Nov 2004 14:32:41 GMT | From | dhowells@redhat ... | Subject | [PATCH] Bit operations |
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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: dhowells@redhat.com --- diffstat bitops-2610rc1mm3.diff include/linux/bitops.h | 3 +- lib/Makefile | 1 lib/find_next_bit.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+), 1 deletion(-)
diff -uNrp /warthog/kernels/linux-2.6.10-rc1-mm3/include/linux/bitops.h linux-2.6.10-rc1-mm3-frv/include/linux/bitops.h --- /warthog/kernels/linux-2.6.10-rc1-mm3/include/linux/bitops.h 2004-06-18 13:42:16.000000000 +0100 +++ linux-2.6.10-rc1-mm3-frv/include/linux/bitops.h 2004-11-05 14:13:04.362457008 +0000 @@ -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 +70,8 @@ extern __inline__ int generic_fls(int x) return r; } +#include <asm/bitops.h> + extern __inline__ int get_bitmask_order(unsigned int count) { int order; diff -uNrp /warthog/kernels/linux-2.6.10-rc1-mm3/lib/find_next_bit.c linux-2.6.10-rc1-mm3-frv/lib/find_next_bit.c --- /warthog/kernels/linux-2.6.10-rc1-mm3/lib/find_next_bit.c 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.6.10-rc1-mm3-frv/lib/find_next_bit.c 2004-11-05 14:13:04.571439356 +0000 @@ -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 -uNrp /warthog/kernels/linux-2.6.10-rc1-mm3/lib/Makefile linux-2.6.10-rc1-mm3-frv/lib/Makefile --- /warthog/kernels/linux-2.6.10-rc1-mm3/lib/Makefile 2004-11-05 13:15:52.000000000 +0000 +++ linux-2.6.10-rc1-mm3-frv/lib/Makefile 2004-11-05 14:13:04.574439103 +0000 @@ -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) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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