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40 lines
1.0 KiB
40 lines
1.0 KiB
/* |
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* IOMMU helper functions for the free area management |
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*/ |
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#include <linux/export.h> |
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#include <linux/bitmap.h> |
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#include <linux/bug.h> |
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int iommu_is_span_boundary(unsigned int index, unsigned int nr, |
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unsigned long shift, |
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unsigned long boundary_size) |
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{ |
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BUG_ON(!is_power_of_2(boundary_size)); |
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shift = (shift + index) & (boundary_size - 1); |
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return shift + nr > boundary_size; |
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} |
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unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, |
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unsigned long start, unsigned int nr, |
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unsigned long shift, unsigned long boundary_size, |
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unsigned long align_mask) |
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{ |
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unsigned long index; |
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/* We don't want the last of the limit */ |
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size -= 1; |
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again: |
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index = bitmap_find_next_zero_area(map, size, start, nr, align_mask); |
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if (index < size) { |
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if (iommu_is_span_boundary(index, nr, shift, boundary_size)) { |
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start = ALIGN(shift + index, boundary_size) - shift; |
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goto again; |
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} |
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bitmap_set(map, index, nr); |
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return index; |
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} |
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return -1; |
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} |
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EXPORT_SYMBOL(iommu_area_alloc);
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