iommu/arm-smmu: Restrict domain attributes to UNMANAGED domains

The ARM SMMU drivers provide a DOMAIN_ATTR_NESTING domain attribute,
which allows callers of the IOMMU API to request that the page table
for a domain is installed at stage-2, if supported by the hardware.

Since setting this attribute only makes sense for UNMANAGED domains,
this patch returns -ENODEV if the domain_{get,set}_attr operations are
called on other domain types.

Signed-off-by: Will Deacon <will.deacon@arm.com>

2 files changed, 12 insertions, 0 deletions

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 591bb96047c9..b47a88757c18 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1837,6 +1837,9 @@ 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:
                 *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1852,6 +1855,9 @@ 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) {
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 6560c4a34b96..099215bbff89 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1603,6 +1603,9 @@ 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:
                 *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1618,6 +1621,9 @@ 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) {