From e837dfde15a49c97dcbb059757d96c71e9e7bd54 Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Fri, 13 Dec 2019 16:22:10 -0800 Subject: 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 Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba --- include/linux/bitmap.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include/linux/bitmap.h') 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 -- cgit v1.2.3