[PATCH 4/5] iommu/arm-smmu-v3: Add set_dirty_tracking() support

[Shameer Kolothum]

From: Joao Martins <joao.m.martins at oracle.com>

Dirty tracking will always be enabled with DBM=1 modifier enabled
by default when HD is supported.

Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 22 +++++++++++++++++++++
 1 file changed, 22 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 8331a2c70a0c..c5eabdc29ba5 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3402,6 +3402,27 @@ static int arm_smmu_read_and_clear_dirty(struct iommu_domain *domain,
 	return ret;
 }
 
+static int arm_smmu_set_dirty_tracking(struct iommu_domain *domain,
+				       bool enabled)
+{
+	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
+
+	if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+		return -EINVAL;
+
+	if (!ops) {
+		pr_err_once("io-pgtable don't support dirty tracking\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Always enabled and the dirty bitmap is cleared prior to
+	 * set_dirty_tracking().
+	 */
+	return 0;
+}
+
 static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
 {
 	return iommu_fwspec_add_ids(dev, args->args, 1);
@@ -3529,6 +3550,7 @@ static struct iommu_ops arm_smmu_ops = {
 
 static struct iommu_dirty_ops arm_smmu_dirty_ops = {
 	.read_and_clear_dirty	= arm_smmu_read_and_clear_dirty,
+	.set_dirty_tracking     = arm_smmu_set_dirty_tracking,
 };
 
 /* Probing and initialisation functions */
-- 
2.34.1