1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * IOMMU helper functions for the free area management 4 */ 5 6 #include <linux/bitmap.h> 7 #include <linux/iommu-helper.h> 8 9 unsigned long iommu_area_alloc(unsigned long *map, unsigned long size, 10 unsigned long start, unsigned int nr, 11 unsigned long shift, unsigned long boundary_size, 12 unsigned long align_mask) 13 { 14 unsigned long index; 15 16 /* We don't want the last of the limit */ 17 size -= 1; 18 again: 19 index = bitmap_find_next_zero_area(map, size, start, nr, align_mask); 20 if (index < size) { 21 if (iommu_is_span_boundary(index, nr, shift, boundary_size)) { 22 start = ALIGN(shift + index, boundary_size) - shift; 23 goto again; 24 } 25 bitmap_set(map, index, nr); 26 return index; 27 } 28 return -1; 29 } 30