[PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode

[Robin Murphy]

From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>

Dynamically choose strict or non-strict mode for page table config based
on the iommu domain type.

Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
[rm: convert to domain attribute]
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
 drivers/iommu/arm-smmu-v3.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index f10c852479fc..7bbfa5f7ce8e 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -612,6 +612,7 @@ struct arm_smmu_domain {
 	struct mutex			init_mutex; /* Protects smmu pointer */
 
 	struct io_pgtable_ops		*pgtbl_ops;
+	bool				non_strict;
 
 	enum arm_smmu_domain_stage	stage;
 	union {
@@ -1633,6 +1634,9 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
 	if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
 		pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
 
+	if (smmu_domain->non_strict)
+		pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
+
 	pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
 	if (!pgtbl_ops)
 		return -ENOMEM;
@@ -1934,13 +1938,17 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
-	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
-		return -EINVAL;
-
 	switch (attr) {
 	case DOMAIN_ATTR_NESTING:
+		if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+			return -EINVAL;
 		*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
 		return 0;
+	case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
+		if (domain->type != IOMMU_DOMAIN_DMA)
+			return -EINVAL;
+		*(int *)data = smmu_domain->non_strict;
+		return 0;
 	default:
 		return -ENODEV;
 	}
@@ -1952,13 +1960,15 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 	int ret = 0;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
-	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
-		return -EINVAL;
-
 	mutex_lock(&smmu_domain->init_mutex);
 
 	switch (attr) {
 	case DOMAIN_ATTR_NESTING:
+		if (domain->type != IOMMU_DOMAIN_UNMANAGED) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
 		if (smmu_domain->smmu) {
 			ret = -EPERM;
 			goto out_unlock;
@@ -1969,6 +1979,14 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 		else
 			smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
 
+		break;
+	case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
+		if (domain->type != IOMMU_DOMAIN_DMA) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		smmu_domain->non_strict = *(int *)data;
 		break;
 	default:
 		ret = -ENODEV;
-- 
2.19.0.dirty