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/*
* IOMMU helper functions for the free area management
*/
#include <linux/module.h>
#include <linux/bitops.h>
static unsigned long find_next_zero_area(unsigned long *map,
unsigned long size,
unsigned long start,
unsigned int nr,
unsigned long align_mask)
{
unsigned long index, end, i;
again:
index = find_next_zero_bit(map, size, start);
/* Align allocation */
index = (index + align_mask) & ~align_mask;
end = index + nr;
if (end >= size)
return -1;
for (i = index; i < end; i++) {
if (test_bit(i, map)) {
start = i+1;
goto again;
}
}
return index;
}
static inline void set_bit_area(unsigned long *map, unsigned long i,
int len)
{
unsigned long end = i + len;
while (i < end) {
__set_bit(i, map);
i++;
}
}
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;
again:
index = find_next_zero_area(map, size, start, nr, align_mask);
if (index != -1) {
if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
/* we could do more effectively */
start = index + 1;
goto again;
}
set_bit_area(map, index, nr);
}
return index;
}
EXPORT_SYMBOL(iommu_area_alloc);
void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
{
unsigned long end = start + nr;
while (start < end) {
__clear_bit(start, map);
start++;
}
}
EXPORT_SYMBOL(iommu_area_free);
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