1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * IOMMU helper functions for the free area management
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/bitmap.h>
7*4882a593Smuzhiyun #include <linux/iommu-helper.h>
8*4882a593Smuzhiyun
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*4882a593Smuzhiyun unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
10*4882a593Smuzhiyun unsigned long start, unsigned int nr,
11*4882a593Smuzhiyun unsigned long shift, unsigned long boundary_size,
12*4882a593Smuzhiyun unsigned long align_mask)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun unsigned long index;
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /* We don't want the last of the limit */
17*4882a593Smuzhiyun size -= 1;
18*4882a593Smuzhiyun again:
19*4882a593Smuzhiyun index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
20*4882a593Smuzhiyun if (index < size) {
21*4882a593Smuzhiyun if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
22*4882a593Smuzhiyun start = ALIGN(shift + index, boundary_size) - shift;
23*4882a593Smuzhiyun goto again;
24*4882a593Smuzhiyun }
25*4882a593Smuzhiyun bitmap_set(map, index, nr);
26*4882a593Smuzhiyun return index;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun return -1;
29*4882a593Smuzhiyun }
30