1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_IOMMU_HELPER_H
3#define _LINUX_IOMMU_HELPER_H
4
5#include <linux/bug.h>
6#include <linux/log2.h>
7#include <linux/math.h>
8#include <linux/types.h>
9
10static inline unsigned long iommu_device_max_index(unsigned long size,
11 unsigned long offset,
12 u64 dma_mask)
13{
14 if (size + offset > dma_mask)
15 return dma_mask - offset + 1;
16 else
17 return size;
18}
19
20static inline int iommu_is_span_boundary(unsigned int index, unsigned int nr,
21 unsigned long shift, unsigned long boundary_size)
22{
23 BUG_ON(!is_power_of_2(boundary_size));
24
25 shift = (shift + index) & (boundary_size - 1);
26 return shift + nr > boundary_size;
27}
28
29extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
30 unsigned long start, unsigned int nr,
31 unsigned long shift,
32 unsigned long boundary_size,
33 unsigned long align_mask);
34
35static inline unsigned long iommu_num_pages(unsigned long addr,
36 unsigned long len,
37 unsigned long io_page_size)
38{
39 unsigned long size = (addr & (io_page_size - 1)) + len;
40
41 return DIV_ROUND_UP(size, io_page_size);
42}
43
44#endif
45