[PATCH v2 10/17] iommu/arm-smmu-v3: Allow ARM_SMMU_DOMAIN_S1 stage to access s2_cfg

[Nicolin Chen <nicolinc@nvidia.com>]

In a nested translation setup, the device is attached to a stage-1 domain
that represents the guest-level Context Descriptor table. A Stream Table
Entry for a 2-stage translation needs both the stage-1 Context Descriptor
table info and the stage-2 Translation table information, i.e. a pair of
s1_cfg and s2_cfg.

Add an "s2" pointer in struct arm_smmu_domain, so a nested stage-1 domain
can simply navigate its stage-2 domain for the s2_cfg pointer, upon the
availability of a domain->s2 pointer.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 ++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 +
 2 files changed, 3 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 74e38abf5f4c..fd3ac4802907 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1289,6 +1289,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 		switch (smmu_domain->stage) {
 		case ARM_SMMU_DOMAIN_S1:
 			s1_cfg = &smmu_domain->s1_cfg;
+			if (smmu_domain->s2)
+				s2_cfg = &smmu_domain->s2->s2_cfg;
 			break;
 		case ARM_SMMU_DOMAIN_S2:
 			s2_cfg = &smmu_domain->s2_cfg;
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 e73707479119..232a2dda5d24 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -711,6 +711,7 @@ enum arm_smmu_domain_stage {
 };
 
 struct arm_smmu_domain {
+	struct arm_smmu_domain		*s2;
 	struct arm_smmu_device		*smmu;
 	struct mutex			init_mutex; /* Protects smmu pointer */
 
-- 
2.40.1