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| author | Michal Nazarewicz <mina86@mina86.com> | 2014-12-12 16:54:45 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:46 -0800 |
| commit | 5e19b013f55a884c59a14391b22138899d1cc4cc (patch) | |
| tree | 9bf703aa3539ddf0e2b9767787f112d04559ed84 /lib/bitmap.c | |
| parent | c8475d144abb1e62958cc5ec281d2a9e161c1946 (diff) | |
| download | lwn-5e19b013f55a884c59a14391b22138899d1cc4cc.tar.gz lwn-5e19b013f55a884c59a14391b22138899d1cc4cc.zip | |
lib: bitmap: add alignment offset for bitmap_find_next_zero_area()
Add a bitmap_find_next_zero_area_off() function which works like
bitmap_find_next_zero_area() function except 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.
[gregory.0xf0@gmail.com: Retrieved from https://patchwork.linuxtv.org/patch/6254/ and updated documentation]
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/bitmap.c')
| -rw-r--r-- | lib/bitmap.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c index b499ab6ada29..969ae8fbc85b 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -326,30 +326,32 @@ void bitmap_clear(unsigned long *map, unsigned int start, int len) } EXPORT_SYMBOL(bitmap_clear); -/* - * bitmap_find_next_zero_area - find a contiguous aligned zero area +/** + * bitmap_find_next_zero_area_off - 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) @@ -361,7 +363,7 @@ 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 Nadia Yvette Chambers, |