iommu/vt-d: Implement apply_resv_region iommu ops entry

Used by iommu.c before creating identity mappings for reserved
ranges to ensure dma-ops won't ever remap these ranges.

Signed-off-by: James Sewart <jamessewart@arista.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

@@ -5549,6 +5549,19 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev)
 	return ret;
 }
 
+static void intel_iommu_apply_resv_region(struct device *dev,
+					  struct iommu_domain *domain,
+					  struct iommu_resv_region *region)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	unsigned long start, end;
+
+	start = IOVA_PFN(region->start);
+	end   = IOVA_PFN(region->start + region->length - 1);
+
+	WARN_ON_ONCE(!reserve_iova(&dmar_domain->iovad, start, end));
+}
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
 {
@@ -5714,6 +5727,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.remove_device		= intel_iommu_remove_device,
 	.get_resv_regions	= intel_iommu_get_resv_regions,
 	.put_resv_regions	= intel_iommu_put_resv_regions,
+	.apply_resv_region	= intel_iommu_apply_resv_region,
 	.device_group		= pci_device_group,
 	.dev_has_feat		= intel_iommu_dev_has_feat,
 	.dev_feat_enabled	= intel_iommu_dev_feat_enabled,