+ while (unmapped < page_size) {
+
+ pte = fetch_pte(dom, bus_addr);
+
+ if (!pte) {
+ /*
+ * No PTE for this address
+ * move forward in 4kb steps
+ */
+ unmap_size = PAGE_SIZE;
+ } else if (PM_PTE_LEVEL(*pte) == 0) {
+ /* 4kb PTE found for this address */
+ unmap_size = PAGE_SIZE;
+ *pte = 0ULL;
+ } else {
+ int count, i;
+
+ /* Large PTE found which maps this address */
+ unmap_size = PTE_PAGE_SIZE(*pte);
+ count = PAGE_SIZE_PTE_COUNT(unmap_size);
+ for (i = 0; i < count; i++)
+ pte[i] = 0ULL;
+ }
+
+ bus_addr = (bus_addr & ~(unmap_size - 1)) + unmap_size;
+ unmapped += unmap_size;
+ }
+
+ BUG_ON(!is_power_of_2(unmapped));
+
+ return unmapped;