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
10 static 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
20 static 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
29 extern 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
35 static 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
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