[PATCH 2/4] iommu/vt-d: Implement apply_resv_region for reserving IOVA ranges

[James Sewart <jamessewart@arista.com>]

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

Signed-off-by: James Sewart <jamessewart@arista.com>
---
 drivers/iommu/intel-iommu.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 78188bf7e90d..8e0a4e2ff77f 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5299,6 +5299,19 @@ static void intel_iommu_put_resv_regions(struct device *dev,
 	}
 }
 
+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) == NULL);
+}
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sdev)
 {
@@ -5392,6 +5405,7 @@ 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,
 	.pgsize_bitmap		= INTEL_IOMMU_PGSIZES,
 };
-- 
2.17.1