- /*
- * DMA cannot cross 4 GB boundary. Mark last entry of each 4
- * GB chunk as reserved.
- */
- if (protect4gb) {
- entries_per_4g = 0x100000000l >> IOMMU_PAGE_SHIFT;
-
- /* Mark the last bit before a 4GB boundary as used */
- start_index = tbl->it_offset | (entries_per_4g - 1);
- start_index -= tbl->it_offset;
-
- end_index = tbl->it_size;
-
- for (index = start_index; index < end_index - 1; index += entries_per_4g)
- __set_bit(index, tbl->it_map);
- }
-