[PATCH v5 23/29] iommu/arm-smmu-v3-iommufd: Add vsmmu_alloc impl op

Nicolin Chen
2025-05-18T04:07:34Z

An impl driver might want to allocate its own type of vIOMMU object or the
standard IOMMU_VIOMMU_TYPE_ARM_SMMUV3 by setting up its own SW/HW bits, as
the tegra241-cmdqv driver will add IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV.

Add a vsmmu_alloc op and prioritize it in arm_vsmmu_alloc().

Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 7 +++++++
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 14 ++++++++------
2 files changed, 15 insertions(+), 6 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 cb93eff4d9ab..a455ff97e53e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -16,6 +16,7 @@
#include <linux/sizes.h>

struct arm_smmu_device;
+struct arm_smmu_domain;

/* MMIO registers */
#define ARM_SMMU_IDR0 0x0
@@ -715,11 +716,17 @@ struct arm_smmu_strtab_cfg {
};

struct arm_smmu_impl_ops {
+ const unsigned int supported_vsmmu_type;
int (*device_reset)(struct arm_smmu_device *smmu);
void (*device_remove)(struct arm_smmu_device *smmu);
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);
+ struct arm_vsmmu *(*vsmmu_alloc)(
+ struct arm_smmu_device *smmu,
+ struct arm_smmu_domain *smmu_domain, struct iommufd_ucmd *ucmd,
+ unsigned int viommu_type,
+ const struct iommu_user_data *user_data);
};

/* An SMMUv3 instance */
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 61a3f9134a9b..8a13d0102c05 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
@@ -396,10 +396,7 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
iommu_get_iommu_dev(dev, struct arm_smmu_device, iommu);
struct arm_smmu_master *master = dev_iommu_priv_get(dev);
struct arm_smmu_domain *s2_parent = to_smmu_domain(parent);
- struct arm_vsmmu *vsmmu;
-
- if (viommu_type != IOMMU_VIOMMU_TYPE_ARM_SMMUV3)
- return ERR_PTR(-EOPNOTSUPP);
+ struct arm_vsmmu *vsmmu = ERR_PTR(-EOPNOTSUPP);

if (!(smmu->features & ARM_SMMU_FEAT_NESTING))
return ERR_PTR(-EOPNOTSUPP);
@@ -427,8 +424,13 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev,
!(smmu->features & ARM_SMMU_FEAT_S2FWB))
return ERR_PTR(-EOPNOTSUPP);

- vsmmu = iommufd_viommu_alloc(ucmd, struct arm_vsmmu, core,
- &arm_vsmmu_ops);
+ if (smmu->impl_ops && smmu->impl_ops->vsmmu_alloc &&
+ viommu_type == smmu->impl_ops->supported_vsmmu_type)
+ vsmmu = smmu->impl_ops->vsmmu_alloc(smmu, s2_parent, ucmd,
+ viommu_type, user_data);
+ else if (viommu_type == IOMMU_VIOMMU_TYPE_ARM_SMMUV3)
+ vsmmu = iommufd_viommu_alloc(ucmd, struct arm_vsmmu, core,
+ &arm_vsmmu_ops);
if (IS_ERR(vsmmu))
return ERR_CAST(vsmmu);

--
2.43.0