From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 225666B009B for ; Wed, 15 Dec 2010 15:38:42 -0500 (EST) Received: from eu_spt1 (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTP id <0LDH003FTLCCO0@mailout1.w1.samsung.com> for linux-mm@kvack.org; Wed, 15 Dec 2010 20:38:39 +0000 (GMT) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LDH0095LLCBDD@spt1.w1.samsung.com> for linux-mm@kvack.org; Wed, 15 Dec 2010 20:38:36 +0000 (GMT) Date: Wed, 15 Dec 2010 21:34:22 +0100 From: Michal Nazarewicz Subject: [PATCHv8 02/12] lib: bitmap: Added alignment offset for bitmap_find_next_zero_area() In-reply-to: Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN Content-transfer-encoding: 7BIT References: Sender: owner-linux-mm@kvack.org To: Michal Nazarewicz Cc: Andrew Morton , Ankita Garg , Daniel Walker , Johan MOSSBERG , KAMEZAWA Hiroyuki , Marek Szyprowski , Mel Gorman , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org List-ID: From: Michal Nazarewicz This commit adds a bitmap_find_next_zero_area_off() function which works like bitmap_find_next_zero_area() function expect it allows an offset to be specified when alignment is checked. This lets caller request a bit such that its number plus the offset is aligned according to the mask. Signed-off-by: Michal Nazarewicz --- include/linux/bitmap.h | 24 +++++++++++++++++++----- lib/bitmap.c | 22 ++++++++++++---------- 2 files changed, 31 insertions(+), 15 deletions(-) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index daf8c48..c0528d1 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -45,6 +45,7 @@ * bitmap_set(dst, pos, nbits) Set specified bit area * bitmap_clear(dst, pos, nbits) Clear specified bit area * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area + * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) @@ -113,11 +114,24 @@ extern int __bitmap_weight(const unsigned long *bitmap, int bits); extern void bitmap_set(unsigned long *map, int i, int len); extern void bitmap_clear(unsigned long *map, int start, int nr); -extern unsigned long bitmap_find_next_zero_area(unsigned long *map, - unsigned long size, - unsigned long start, - unsigned int nr, - unsigned long align_mask); + +extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask, + unsigned long align_offset); + +static inline unsigned long +bitmap_find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask) +{ + return bitmap_find_next_zero_area_off(map, size, start, nr, + align_mask, 0); +} extern int bitmap_scnprintf(char *buf, unsigned int len, const unsigned long *src, int nbits); diff --git a/lib/bitmap.c b/lib/bitmap.c index 741fae9..8e75a6f 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -315,30 +315,32 @@ void bitmap_clear(unsigned long *map, int start, int nr) } EXPORT_SYMBOL(bitmap_clear); -/* +/** * bitmap_find_next_zero_area - find a contiguous aligned zero area * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @align_mask: Alignment mask for zero area + * @align_offset: Alignment offset for zero area. * * The @align_mask should be one less than a power of 2; the effect is that - * the bit offset of all zero areas this function finds is multiples of that - * power of 2. A @align_mask of 0 means no alignment is required. + * the bit offset of all zero areas this function finds plus @align_offset + * is multiple of that power of 2. */ -unsigned long bitmap_find_next_zero_area(unsigned long *map, - unsigned long size, - unsigned long start, - unsigned int nr, - unsigned long align_mask) +unsigned long bitmap_find_next_zero_area_off(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr, + unsigned long align_mask, + unsigned long align_offset) { unsigned long index, end, i; again: index = find_next_zero_bit(map, size, start); /* Align allocation */ - index = __ALIGN_MASK(index, align_mask); + index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; end = index + nr; if (end > size) @@ -350,7 +352,7 @@ again: } return index; } -EXPORT_SYMBOL(bitmap_find_next_zero_area); +EXPORT_SYMBOL(bitmap_find_next_zero_area_off); /* * Bitmap printing & parsing functions: first version by Bill Irwin, -- 1.7.2.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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