intel-iommu: fix sg_page()

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index b3d7031..0c4ab3b 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -1962,7 +1962,7 @@
 	free_pages((unsigned long)vaddr, order);
 }
 
-#define SG_ENT_VIRT_ADDRESS(sg)	(page_address((sg)->page) + (sg)->offset)
+#define SG_ENT_VIRT_ADDRESS(sg)	(sg_virt((sg)))
 static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sglist,
 	int nelems, int dir)
 {
@@ -2010,7 +2010,7 @@
 	struct scatterlist *sg;
 
 	for_each_sg(sglist, sg, nelems, i) {
-		BUG_ON(!sg->page);
+		BUG_ON(!sg_page(sg));
 		sg->dma_address = virt_to_bus(SG_ENT_VIRT_ADDRESS(sg));
 		sg->dma_length = sg->length;
 	}