2 * IOMMU helper functions for the free area management
5 #include <linux/module.h>
6 #include <linux/bitops.h>
8 static unsigned long find_next_zero_area(unsigned long *map,
12 unsigned long align_mask)
14 unsigned long index, end, i;
16 index = find_next_zero_bit(map, size, start);
18 /* Align allocation */
19 index = (index + align_mask) & ~align_mask;
24 for (i = index; i < end; i++) {
25 if (test_bit(i, map)) {
33 static inline void set_bit_area(unsigned long *map, unsigned long i,
36 unsigned long end = i + len;
43 static inline int is_span_boundary(unsigned int index, unsigned int nr,
45 unsigned long boundary_size)
47 shift = (shift + index) & (boundary_size - 1);
48 return shift + nr > boundary_size;
51 unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
52 unsigned long start, unsigned int nr,
53 unsigned long shift, unsigned long boundary_size,
54 unsigned long align_mask)
58 index = find_next_zero_area(map, size, start, nr, align_mask);
60 if (is_span_boundary(index, nr, shift, boundary_size)) {
61 /* we could do more effectively */
65 set_bit_area(map, index, nr);
69 EXPORT_SYMBOL(iommu_area_alloc);
71 void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
73 unsigned long end = start + nr;
76 __clear_bit(start, map);
80 EXPORT_SYMBOL(iommu_area_free);