iommu/vt-d: Introduce __mapping_notify_one()

Introduce this new helper to notify one newly created mapping on one
single IOMMU.  We can further leverage this helper in the next patch.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

@@ -1606,6 +1606,18 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
 		iommu_flush_dev_iotlb(domain, addr, mask);
 }
 
+/* Notification for newly created mappings */
+static inline void __mapping_notify_one(struct intel_iommu *iommu,
+					struct dmar_domain *domain,
+					unsigned long pfn, unsigned int pages)
+{
+	/* It's a non-present to present mapping. Only flush if caching mode */
+	if (cap_caching_mode(iommu->cap))
+		iommu_flush_iotlb_psi(iommu, domain, pfn, pages, 0, 1);
+	else
+		iommu_flush_write_buffer(iommu);
+}
+
 static void iommu_flush_iova(struct iova_domain *iovad)
 {
 	struct dmar_domain *domain;
@@ -3625,13 +3637,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
 	if (ret)
 		goto error;
 
-	/* it's a non-present to present mapping. Only flush if caching mode */
-	if (cap_caching_mode(iommu->cap))
-		iommu_flush_iotlb_psi(iommu, domain,
-				      mm_to_dma_pfn(iova_pfn),
-				      size, 0, 1);
-	else
-		iommu_flush_write_buffer(iommu);
+	__mapping_notify_one(iommu, domain, mm_to_dma_pfn(iova_pfn), size);
 
 	start_paddr = (phys_addr_t)iova_pfn << PAGE_SHIFT;
 	start_paddr += paddr & ~PAGE_MASK;
@@ -3819,11 +3825,7 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
 		return 0;
 	}
 
-	/* it's a non-present to present mapping. Only flush if caching mode */
-	if (cap_caching_mode(iommu->cap))
-		iommu_flush_iotlb_psi(iommu, domain, start_vpfn, size, 0, 1);
-	else
-		iommu_flush_write_buffer(iommu);
+	__mapping_notify_one(iommu, domain, start_vpfn, size);
 
 	return nelems;
 }