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}

 
 1/*
 2 * IOMMU helper functions for the free area management
 3 */
 4
 5#include <linux/export.h>
 6#include <linux/bitmap.h>
 7#include <linux/bug.h>
 8
 9int iommu_is_span_boundary(unsigned int index, unsigned int nr,
10			   unsigned long shift,
11			   unsigned long boundary_size)
12{
13	BUG_ON(!is_power_of_2(boundary_size));
14
15	shift = (shift + index) & (boundary_size - 1);
16	return shift + nr > boundary_size;
17}
18
19unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
20			       unsigned long start, unsigned int nr,
21			       unsigned long shift, unsigned long boundary_size,
22			       unsigned long align_mask)
23{
24	unsigned long index;
25
26	/* We don't want the last of the limit */
27	size -= 1;
28again:
29	index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
30	if (index < size) {
31		if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
32			/* we could do more effectively */
33			start = index + 1;
34			goto again;
35		}
36		bitmap_set(map, index, nr);
37		return index;
38	}
39	return -1;
40}
41EXPORT_SYMBOL(iommu_area_alloc);