From: Michal Nazarewicz m.nazarewicz@samsung.com
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 m.nazarewicz@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com CC: Michal Nazarewicz mina86@mina86.com --- 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 dcafe0b..50e2c16 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) @@ -114,11 +115,24 @@ 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 41baf02..bad4f20 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,