projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 0291df8c FT |
1 | /* |
| 2 | * IOMMU helper functions for the free area management | |
| 3 | */ | |
| 4 | ||
| 5 | #include <linux/module.h> | |
| 6 | #include <linux/bitops.h> | |
| 7 | ||
| 8 | static unsigned long find_next_zero_area(unsigned long *map, | |
| 9 | unsigned long size, | |
| 10 | unsigned long start, | |
| 11 | unsigned int nr, | |
| 12 | unsigned long align_mask) | |
| 13 | { | |
| 14 | unsigned long index, end, i; | |
| 15 | again: | |
| 16 | index = find_next_zero_bit(map, size, start); | |
| 17 | ||
| 18 | /* Align allocation */ | |
| 19 | index = (index + align_mask) & ~align_mask; | |
| 20 | ||
| 21 | end = index + nr; | |
| 22 | if (end >= size) | |
| 23 | return -1; | |
| 24 | for (i = index; i < end; i++) { | |
| 25 | if (test_bit(i, map)) { | |
| 26 | start = i+1; | |
| 27 | goto again; | |
| 28 | } | |
| 29 | } | |
| 30 | return index; | |
| 31 | } | |
| 32 | ||
| d26dbc5c | 33 | void iommu_area_reserve(unsigned long *map, unsigned long i, int len) |
| 0291df8c FT |
34 | { |
| 35 | unsigned long end = i + len; | |
| 36 | while (i < end) { | |
| 37 | __set_bit(i, map); | |
| 38 | i++; | |
| 39 | } | |
| 40 | } | |
| 41 | ||
| 3715863a FT |
42 | int iommu_is_span_boundary(unsigned int index, unsigned int nr, |
| 43 | unsigned long shift, | |
| 44 | unsigned long boundary_size) | |
| 0291df8c | 45 | { |
| 3715863a FT |
46 | BUG_ON(!is_power_of_2(boundary_size)); |
| 47 | ||
| 0291df8c FT |
48 | shift = (shift + index) & (boundary_size - 1); |
| 49 | return shift + nr > boundary_size; | |
| 50 | } | |
| 51 | ||
| 52 | unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, | |
| 53 | unsigned long start, unsigned int nr, | |
| 54 | unsigned long shift, unsigned long boundary_size, | |
| 55 | unsigned long align_mask) | |
| 56 | { | |
| 57 | unsigned long index; | |
| 58 | again: | |
| 59 | index = find_next_zero_area(map, size, start, nr, align_mask); | |
| 60 | if (index != -1) { | |
| 3715863a | 61 | if (iommu_is_span_boundary(index, nr, shift, boundary_size)) { |
| 0291df8c FT |
62 | /* we could do more effectively */ |
| 63 | start = index + 1; | |
| 64 | goto again; | |
| 65 | } | |
| d26dbc5c | 66 | iommu_area_reserve(map, index, nr); |
| 0291df8c FT |
67 | } |
| 68 | return index; | |
| 69 | } | |
| 70 | EXPORT_SYMBOL(iommu_area_alloc); | |
| 71 | ||
| 72 | void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr) | |
| 73 | { | |
| 74 | unsigned long end = start + nr; | |
| 75 | ||
| 76 | while (start < end) { | |
| 77 | __clear_bit(start, map); | |
| 78 | start++; | |
| 79 | } | |
| 80 | } | |
| 81 | EXPORT_SYMBOL(iommu_area_free); | |
| 56d93660 JR |
82 | |
| 83 | unsigned long iommu_num_pages(unsigned long addr, unsigned long len, | |
| 84 | unsigned long io_page_size) | |
| 85 | { | |
| 86 | unsigned long size = (addr & (io_page_size - 1)) + len; | |
| 87 | ||
| 88 | return DIV_ROUND_UP(size, io_page_size); | |
| 89 | } | |
| 90 | EXPORT_SYMBOL(iommu_num_pages); |