LXR linux/lib/iommu-helper.c

   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
   9unsigned 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;
  18again:
  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