projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 0291df8c FT |
2 | /* |
| 3 | * IOMMU helper functions for the free area management | |
| 4 | */ | |
| 5 | ||
| 8bc3bcc9 | 6 | #include <linux/export.h> |
| a66022c4 | 7 | #include <linux/bitmap.h> |
| 50af5ead | 8 | #include <linux/bug.h> |
| 0291df8c | 9 | |
| 3715863a FT |
10 | int iommu_is_span_boundary(unsigned int index, unsigned int nr, |
| 11 | unsigned long shift, | |
| 12 | unsigned long boundary_size) | |
| 0291df8c | 13 | { |
| 3715863a FT |
14 | BUG_ON(!is_power_of_2(boundary_size)); |
| 15 | ||
| 0291df8c FT |
16 | shift = (shift + index) & (boundary_size - 1); |
| 17 | return shift + nr > boundary_size; | |
| 18 | } | |
| 19 | ||
| 20 | unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, | |
| 21 | unsigned long start, unsigned int nr, | |
| 22 | unsigned long shift, unsigned long boundary_size, | |
| 23 | unsigned long align_mask) | |
| 24 | { | |
| 25 | unsigned long index; | |
| a66022c4 AM |
26 | |
| 27 | /* We don't want the last of the limit */ | |
| 28 | size -= 1; | |
| 0291df8c | 29 | again: |
| a66022c4 AM |
30 | index = bitmap_find_next_zero_area(map, size, start, nr, align_mask); |
| 31 | if (index < size) { | |
| 3715863a | 32 | if (iommu_is_span_boundary(index, nr, shift, boundary_size)) { |
| f003a1f1 | 33 | start = ALIGN(shift + index, boundary_size) - shift; |
| 0291df8c FT |
34 | goto again; |
| 35 | } | |
| a66022c4 AM |
36 | bitmap_set(map, index, nr); |
| 37 | return index; | |
| 0291df8c | 38 | } |
| a66022c4 | 39 | return -1; |
| 0291df8c FT |
40 | } |
| 41 | EXPORT_SYMBOL(iommu_area_alloc); |