[PATCH v7 23/28] iommu/arm-smmu-v3-iommufd: Add hw_info to impl_ops

Nicolin Chen
2025-06-26T20:40:18Z

This will be used by Tegra241 CMDQV implementation to report a non-default
HW info data.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 7 +++++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 8 ++++++--
2 files changed, 13 insertions(+), 2 deletions(-)

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 07589350b2a1..836d5556008e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -721,6 +721,13 @@ struct arm_smmu_impl_ops {
int (*init_structures)(struct arm_smmu_device *smmu);
struct arm_smmu_cmdq *(*get_secondary_cmdq)(
struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
+ /*
+ * An implementation should define its own type other than the default
+ * IOMMU_HW_INFO_TYPE_ARM_SMMUV3. And it must validate the input @type
+ * to return its own structure.
+ */
+ void *(*hw_info)(struct arm_smmu_device *smmu, u32 *length,
+ enum iommu_hw_info_type *type);
const size_t vsmmu_size;
const enum iommu_viommu_type vsmmu_type;
int (*vsmmu_init)(struct arm_vsmmu *vsmmu,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index 2ab1c6cf4aac..1cf9646e776f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -11,13 +11,17 @@ void *arm_smmu_hw_info(struct device *dev, u32 *length,
enum iommu_hw_info_type *type)
{
struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+ const struct arm_smmu_impl_ops *impl_ops = master->smmu->impl_ops;
struct iommu_hw_info_arm_smmuv3 *info;
u32 __iomem *base_idr;
unsigned int i;

if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&
- *type != IOMMU_HW_INFO_TYPE_ARM_SMMUV3)
- return ERR_PTR(-EOPNOTSUPP);
+ *type != IOMMU_HW_INFO_TYPE_ARM_SMMUV3) {
+ if (!impl_ops || !impl_ops->hw_info)
+ return ERR_PTR(-EOPNOTSUPP);
+ return impl_ops->hw_info(master->smmu, length, type);
+ }

info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
--
2.43.0