bug.h: add include of it to various implicit C users
[linux-3.10.git] / lib / iommu-helper.c
1 /*
2  * IOMMU helper functions for the free area management
3  */
4
5 #include <linux/module.h>
6 #include <linux/bitmap.h>
7 #include <linux/bug.h>
8
9 int 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
19 unsigned 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;
28 again:
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 }
41 EXPORT_SYMBOL(iommu_area_alloc);