Revision b57f95a38233a2e73b679bea4a5453a1cc2a1cc9 authored by Linus Torvalds on 10 May 2010, 01:36:28 UTC, committed by Linus Torvalds on 10 May 2010, 01:36:28 UTC
1 parent 93cb463
iommu-helper.c
/*
* IOMMU helper functions for the free area management
*/
#include <linux/module.h>
#include <linux/bitmap.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)) {
/* we could do more effectively */
start = index + 1;
goto again;
}
bitmap_set(map, index, nr);
return index;
}
return -1;
}
EXPORT_SYMBOL(iommu_area_alloc);
unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
unsigned long io_page_size)
{
unsigned long size = (addr & (io_page_size - 1)) + len;
return DIV_ROUND_UP(size, io_page_size);
}
EXPORT_SYMBOL(iommu_num_pages);
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