[PATCH 01/27] iommu/arm-smmu-v3: Check that the RID domain is S1 in SVA

[Jason Gunthorpe <jgg@nvidia.com>]

This code only works if the RID domain is a S1 domain and has already
installed the cdtable.

Add a to_smmu_domain_safe() which does a robust conversion from
struct iommu_domain to the struct arm_smmu_domain.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c |  7 +++++--
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c     |  7 +++----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h     | 14 ++++++++++++++
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index df66fe43a9853f..6b1896b18d54c7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -382,8 +382,11 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	int ret;
 	struct arm_smmu_bond *bond;
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct arm_smmu_domain *smmu_domain =
+		to_smmu_domain_safe(iommu_get_domain_for_dev(dev));
+
+	if (!smmu_domain || smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+		return ERR_PTR(-ENODEV);
 
 	if (!master || !master->sva_enabled)
 		return ERR_PTR(-ENODEV);
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 3952fd062c523e..b527e635a3043c 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2461,14 +2461,13 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master)
 
 static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 {
-	struct iommu_domain *domain = iommu_get_domain_for_dev(master->dev);
-	struct arm_smmu_domain *smmu_domain;
+	struct arm_smmu_domain *smmu_domain =
+		to_smmu_domain_safe(iommu_get_domain_for_dev(master->dev));
 	unsigned long flags;
 
-	if (!domain || !(domain->type & __IOMMU_DOMAIN_PAGING))
+	if (!smmu_domain)
 		return;
 
-	smmu_domain = to_smmu_domain(domain);
 	arm_smmu_disable_ats(master, smmu_domain);
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 154808f96718df..6f62184eaa2434 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -740,6 +740,20 @@ static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 	return container_of(dom, struct arm_smmu_domain, domain);
 }
 
+/*
+ * Check that the domain type has an arm_smmu_domain struct. The global static
+ * IDENTITY and BLOCKED domains do not.
+ */
+static inline struct arm_smmu_domain *
+to_smmu_domain_safe(struct iommu_domain *domain)
+{
+	if (!domain)
+		return NULL;
+	if (domain->type & __IOMMU_DOMAIN_PAGING)
+		return to_smmu_domain(domain);
+	return NULL;
+}
+
 extern struct xarray arm_smmu_asid_xa;
 extern struct mutex arm_smmu_asid_lock;
 extern struct arm_smmu_ctx_desc quiet_cd;
-- 
2.42.0