[RFC PATCH v1 8/8] iommu/arm-smmu-v3: allow multi-SMMU domain installs

Michael Shavit
2023-08-17T18:24:07Z

Remove the arm_smmu_domain->smmu handle now that a domain may be
attached to devices with different upstream SMMUs.

Signed-off-by: Michael Shavit <mshavit@google.com>
---

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 ++-------
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 3 +--
2 files changed, 3 insertions(+), 9 deletions(-)

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 c9f89f4f47721..08594612a81a8 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2587,13 +2587,8 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)

mutex_lock(&smmu_domain->init_mutex);

- if (!smmu_domain->smmu) {
- smmu_domain->smmu = smmu;
- ret = arm_smmu_domain_finalise(domain, smmu);
- if (ret)
- smmu_domain->smmu = NULL;
- } else if (smmu_domain->smmu != smmu)
- ret = -EINVAL;
+ if (!smmu_domain->pgtbl_ops)
+ ret = arm_smmu_domain_finalise(&smmu_domain->domain, smmu);

mutex_unlock(&smmu_domain->init_mutex);
if (ret)
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 143b287be2f8b..342fa6ef837ab 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -726,8 +726,7 @@ enum arm_smmu_domain_stage {
};

struct arm_smmu_domain {
- struct arm_smmu_device *smmu;
- struct mutex init_mutex; /* Protects smmu pointer */
+ struct mutex init_mutex; /* Protects pgtbl_ops pointer */

struct io_pgtable_ops *pgtbl_ops;
struct io_pgtable_cfg pgtbl_cfg;
--
2.42.0.rc1.204.g551eb34607-goog