xref: /openbmc/linux/include/linux/iommu-helper.h (revision 95298d63)
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/kernel.h>
7 
8 static inline unsigned long iommu_device_max_index(unsigned long size,
9 						   unsigned long offset,
10 						   u64 dma_mask)
11 {
12 	if (size + offset > dma_mask)
13 		return dma_mask - offset + 1;
14 	else
15 		return size;
16 }
17 
18 static inline int iommu_is_span_boundary(unsigned int index, unsigned int nr,
19 		unsigned long shift, unsigned long boundary_size)
20 {
21 	BUG_ON(!is_power_of_2(boundary_size));
22 
23 	shift = (shift + index) & (boundary_size - 1);
24 	return shift + nr > boundary_size;
25 }
26 
27 extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
28 				      unsigned long start, unsigned int nr,
29 				      unsigned long shift,
30 				      unsigned long boundary_size,
31 				      unsigned long align_mask);
32 
33 static inline unsigned long iommu_num_pages(unsigned long addr,
34 					    unsigned long len,
35 					    unsigned long io_page_size)
36 {
37 	unsigned long size = (addr & (io_page_size - 1)) + len;
38 
39 	return DIV_ROUND_UP(size, io_page_size);
40 }
41 
42 #endif
43