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// SPDX-License-Identifier: GPL-2.0
/*
* IOMMU helper functions for the free area management
*/
#include <linux/export.h>
#include <linux/bitmap.h>
#include <linux/bug.h>
int iommu_is_span_boundary(unsigned int index, unsigned int nr,
unsigned long shift,
unsigned long boundary_size)
{
BUG_ON(!is_power_of_2(boundary_size));
shift = (shift + index) & (boundary_size - 1);
return shift + nr > boundary_size;
}
unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
unsigned long start, unsigned int nr,
unsigned long shift, unsigned long boundary_size,
unsigned long align_mask)
{
unsigned long index;
/* We don't want the last of the limit */
size -= 1;
again:
index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
if (index < size) {
if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
start = ALIGN(shift + index, boundary_size) - shift;
goto again;
}
bitmap_set(map, index, nr);
return index;
}
return -1;
}
EXPORT_SYMBOL(iommu_area_alloc);
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