[RFC PATCH 2/7] iommu/amd: Update sanity check when enable PRI/ATS

[Suravee Suthikulpanit]

Currently, PPR/ATS can be enabled only if the domain is type
identity mapping. However, when we allow the IOMMU v2 page table
to be used for DMA-API, the sanity check needs to be updated to
only apply for the case when using AMD_IOMMU_V1 page table mode.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
 drivers/iommu/amd/iommu.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 6f3e42495709..f3800efdbb29 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1549,7 +1549,7 @@ static int pri_reset_while_enabled(struct pci_dev *pdev)
 	return 0;
 }
 
-static int pdev_iommuv2_enable(struct pci_dev *pdev)
+static int pdev_pri_ats_enable(struct pci_dev *pdev)
 {
 	bool reset_enable;
 	int reqs, ret;
@@ -1624,11 +1624,19 @@ static int attach_device(struct device *dev,
 		struct iommu_domain *def_domain = iommu_get_dma_domain(dev);
 
 		ret = -EINVAL;
-		if (def_domain->type != IOMMU_DOMAIN_IDENTITY)
+
+		/*
+		 * In case of using AMD_IOMMU_V1 page table mode, and the device
+		 * is enabling for PPR/ATS support (using v2 table),
+		 * we need to make sure that the domain type is identity map.
+		 */
+		if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
+		    def_domain->type != IOMMU_DOMAIN_IDENTITY) {
 			goto out;
+		}
 
 		if (dev_data->iommu_v2) {
-			if (pdev_iommuv2_enable(pdev) != 0)
+			if (pdev_pri_ats_enable(pdev) != 0)
 				goto out;
 
 			dev_data->ats.enabled = true;
-- 
2.17.1