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
iommu_area_alloc(unsigned long * map,unsigned long size,unsigned long start,unsigned int nr,unsigned long shift,unsigned long boundary_size,unsigned long align_mask)9 unsigned 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;
18 again:
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