| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * IOMMU helper functions for the free area management |
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| 4 | */ |
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| 5 | |
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| 6 | #include <linux/bitmap.h> |
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| 7 | #include <linux/iommu-helper.h> |
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| 8 | |
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| 9 | unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, |
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| 10 | unsigned long start, unsigned int nr, |
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| 11 | unsigned long shift, unsigned long boundary_size, |
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| 12 | unsigned long align_mask) |
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| 13 | { |
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| 14 | unsigned long index; |
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| 15 | |
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| 16 | /* We don't want the last of the limit */ |
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| 17 | size -= 1; |
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| 18 | again: |
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| 19 | index = bitmap_find_next_zero_area(map, size, start, nr, align_mask); |
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| 20 | if (index < size) { |
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| 21 | if (iommu_is_span_boundary(index, nr, shift, boundary_size)) { |
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| 22 | start = ALIGN(shift + index, boundary_size) - shift; |
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| 23 | goto again; |
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| 24 | } |
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| 25 | bitmap_set(map, start: index, nbits: nr); |
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| 26 | return index; |
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| 27 | } |
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| 28 | return -1; |
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| 29 | } |
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| 30 | |
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