intel-iommu: add map_page and unmap_page

This is a preparation of struct dma_mapping_ops unification. We use
map_page and unmap_page instead of map_single and unmap_single.

This uses a temporary workaround, ifdef X86_64 to avoid IA64
build. The workaround will be removed after the unification. Well,
changing x86's struct dma_mapping_ops could break IA64. It's just
wrong. It's one of problems that this patchset fixes.

We will remove map_single and unmap_single hooks in the last patch in
this patchset.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

drivers/pci/intel-iommu.c

@@ -2273,6 +2273,15 @@ static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
 	return 0;
 }
 
+static dma_addr_t intel_map_page(struct device *dev, struct page *page,
+				 unsigned long offset, size_t size,
+				 enum dma_data_direction dir,
+				 struct dma_attrs *attrs)
+{
+	return __intel_map_single(dev, page_to_phys(page) + offset, size,
+				  dir, to_pci_dev(dev)->dma_mask);
+}
+
 dma_addr_t intel_map_single(struct device *hwdev, phys_addr_t paddr,
 			    size_t size, int dir)
 {
@@ -2341,8 +2350,9 @@ static void add_unmap(struct dmar_domain *dom, struct iova *iova)
 	spin_unlock_irqrestore(&async_umap_flush_lock, flags);
 }
 
-void intel_unmap_single(struct device *dev, dma_addr_t dev_addr, size_t size,
-			int dir)
+static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
+			     size_t size, enum dma_data_direction dir,
+			     struct dma_attrs *attrs)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct dmar_domain *domain;
@@ -2386,6 +2396,12 @@ void intel_unmap_single(struct device *dev, dma_addr_t dev_addr, size_t size,
 	}
 }
 
+void intel_unmap_single(struct device *dev, dma_addr_t dev_addr, size_t size,
+			int dir)
+{
+	intel_unmap_page(dev, dev_addr, size, dir, NULL);
+}
+
 void *intel_alloc_coherent(struct device *hwdev, size_t size,
 			   dma_addr_t *dma_handle, gfp_t flags)
 {
@@ -2570,6 +2586,10 @@ static struct dma_mapping_ops intel_dma_ops = {
 	.unmap_single = intel_unmap_single,
 	.map_sg = intel_map_sg,
 	.unmap_sg = intel_unmap_sg,
+#ifdef CONFIG_X86_64
+	.map_page = intel_map_page,
+	.unmap_page = intel_unmap_page,
+#endif
 };
 
 static inline int iommu_domain_cache_init(void)