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| author |   Dennis Zhou <dennis@kernel.org> | 2019-12-13 16:22:10 -0800 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2020-01-20 16:40:56 +0100 |
| commit | e837dfde15a49c97dcbb059757d96c71e9e7bd54 (patch) | |
| tree | f45361c5f298b423cf168db94d81b1c70cd85681 /include/linux/bitmap.h | |
| parent | btrfs: tree-checker: Verify location key for DIR_ITEM/DIR_INDEX (diff) | |
| download | linux-dev-e837dfde15a49c97dcbb059757d96c71e9e7bd54.tar.xz linux-dev-e837dfde15a49c97dcbb059757d96c71e9e7bd54.zip | |
bitmap: genericize percpu bitmap region iterators
Bitmaps are fairly popular for their space efficiency, but we don't have
generic iterators available. Make percpu's bitmap region iterators
available to everyone.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'include/linux/bitmap.h')
| -rw-r--r-- | include/linux/bitmap.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index ff335b22f23c..cb63feb3cfbe 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -456,6 +456,41 @@ static inline int bitmap_parse(const char *buf, unsigned int buflen, return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); } +static inline void bitmap_next_clear_region(unsigned long *bitmap, + unsigned int *rs, unsigned int *re, + unsigned int end) +{ + *rs = find_next_zero_bit(bitmap, end, *rs); + *re = find_next_bit(bitmap, end, *rs + 1); +} + +static inline void bitmap_next_set_region(unsigned long *bitmap, + unsigned int *rs, unsigned int *re, + unsigned int end) +{ + *rs = find_next_bit(bitmap, end, *rs); + *re = find_next_zero_bit(bitmap, end, *rs + 1); +} + +/* + * Bitmap region iterators. Iterates over the bitmap between [@start, @end). + * @rs and @re should be integer variables and will be set to start and end + * index of the current clear or set region. + */ +#define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \ + for ((rs) = (start), \ + bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \ + (rs) < (re); \ + (rs) = (re) + 1, \ + bitmap_next_clear_region((bitmap), &(rs), &(re), (end))) + +#define bitmap_for_each_set_region(bitmap, rs, re, start, end) \ + for ((rs) = (start), \ + bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \ + (rs) < (re); \ + (rs) = (re) + 1, \ + bitmap_next_set_region((bitmap), &(rs), &(re), (end))) + /** * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. * @n: u64 value |