| // SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later |
| /* Copyright 2016 IBM Corp. */ |
| |
| #include "bitmap.h" |
| |
| static int __bitmap_find_bit(bitmap_t map, unsigned int start, unsigned int count, |
| bool value) |
| { |
| unsigned int el, first_bit; |
| unsigned int end = start + count; |
| bitmap_elem_t e, ev; |
| int b; |
| |
| ev = value ? -1ul : 0; |
| el = BITMAP_ELEM(start); |
| first_bit = BITMAP_BIT(start); |
| |
| while (start < end) { |
| e = map[el] ^ ev; |
| e |= ((1ul << first_bit) - 1); |
| if (~e) |
| break; |
| start = (start + BITMAP_ELSZ) & ~(BITMAP_ELSZ - 1); |
| first_bit = 0; |
| el++; |
| } |
| for (b = first_bit; b < BITMAP_ELSZ && start < end; b++,start++) { |
| if ((e & (1ull << b)) == 0) |
| return start; |
| } |
| |
| return -1; |
| } |
| |
| int bitmap_find_zero_bit(bitmap_t map, unsigned int start, unsigned int count) |
| { |
| return __bitmap_find_bit(map, start, count, false); |
| } |
| |
| int bitmap_find_one_bit(bitmap_t map, unsigned int start, unsigned int count) |
| { |
| return __bitmap_find_bit(map, start, count, true); |
| } |
| |