[PATCH v3 12/12] iommu/arm-smmu-v3: Add HWDBM device feature reporting

[Keqian Zhu <zhukeqian1@huawei.com>]

From: Kunkun Jiang <jiangkunkun@huawei.com>

We have implemented these interfaces required to support iommu
dirty log tracking. The last step is reporting this feature to
upper user, then the user can perform higher policy base on it.

There is a new dev feature named IOMMU_DEV_FEAT_HWDBM in iommu
layer. For arm smmuv3, it is equal to ARM_SMMU_FEAT_HD and it is
enabled by default if supported. Other types of IOMMU can enable
it by default or when user invokes enable_feature.

Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 59bb1d198631..2d716ee5621f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2712,6 +2712,9 @@ static bool arm_smmu_dev_has_feature(struct device *dev,
 	switch (feat) {
 	case IOMMU_DEV_FEAT_SVA:
 		return arm_smmu_master_sva_supported(master);
+	case IOMMU_DEV_FEAT_HWDBM:
+		/* No requirement for device, require HTTU HD of smmu */
+		return !!(master->smmu->features & ARM_SMMU_FEAT_HD);
 	default:
 		return false;
 	}
@@ -2728,6 +2731,9 @@ static bool arm_smmu_dev_feature_enabled(struct device *dev,
 	switch (feat) {
 	case IOMMU_DEV_FEAT_SVA:
 		return arm_smmu_master_sva_enabled(master);
+	case IOMMU_DEV_FEAT_HWDBM:
+		/* HTTU HD is enabled if supported */
+		return arm_smmu_dev_has_feature(dev, feat);
 	default:
 		return false;
 	}
-- 
2.19.1