| Matthew Wilcox | 58d6ea3 | 2017-11-10 15:15:08 -0500 | [diff] [blame] | 1 | /* lib/bitmap.c pulls in at least two other files. */ |
| 2 | |
| 3 | #include <linux/bitmap.h> |
| 4 | |
| 5 | void bitmap_clear(unsigned long *map, unsigned int start, int len) |
| 6 | { |
| 7 | unsigned long *p = map + BIT_WORD(start); |
| 8 | const unsigned int size = start + len; |
| 9 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
| 10 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
| 11 | |
| 12 | while (len - bits_to_clear >= 0) { |
| 13 | *p &= ~mask_to_clear; |
| 14 | len -= bits_to_clear; |
| 15 | bits_to_clear = BITS_PER_LONG; |
| 16 | mask_to_clear = ~0UL; |
| 17 | p++; |
| 18 | } |
| 19 | if (len) { |
| 20 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
| 21 | *p &= ~mask_to_clear; |
| 22 | } |
| 23 | } |