intel-iommu: Make dma_pte_clear_range() use pfns

/* clear last level pte, a tlb flush should be followed */

static void dma_pte_clear_range(struct dmar_domain *domain, u64 start, u64 end)

{

	int addr_width = agaw_to_width(domain->agaw);

	int npages;

	BUG_ON(start >> addr_width);

	BUG_ON((end-1) >> addr_width);

	unsigned long start_pfn = IOVA_PFN(start);

	unsigned long end_pfn = IOVA_PFN(end-1);

	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;

	/* in case it's partial page */

	start &= PAGE_MASK;

	end = PAGE_ALIGN(end);

	npages = (end - start) / VTD_PAGE_SIZE;

	BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);

	BUG_ON(addr_width < BITS_PER_LONG && end_pfn >> addr_width);

	/* we don't need lock here, nobody else touches the iova range */

	while (npages--) {

		dma_pte_clear_one(domain, start >> VTD_PAGE_SHIFT);

		start += VTD_PAGE_SIZE;

	/* we don't need lock here; nobody else touches the iova range */

	while (start_pfn <= end_pfn) {

		dma_pte_clear_one(domain, start_pfn);

		start_pfn++;

	}

}