1// SPDX-License-Identifier: GPL-2.0
2/*
3 * IOMMU helper functions for the free area management
4 */
5
6#include <linux/bitmap.h>
7#include <linux/iommu-helper.h>
8
9unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
10			       unsigned long start, unsigned int nr,
11			       unsigned long shift, unsigned long boundary_size,
12			       unsigned long align_mask)
13{
14	unsigned long index;
15
16	/* We don't want the last of the limit */
17	size -= 1;
18again:
19	index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
20	if (index < size) {
21		if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
22			start = ALIGN(shift + index, boundary_size) - shift;
23			goto again;
24		}
25		bitmap_set(map, index, nr);
26		return index;
27	}
28	return -1;
29}
30