iommu/arm-smmu-v3-iommufd: Add vsmmu_size/type and vsmmu_init impl ops

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 vsmmu_size/type and vsmmu_init to struct arm_smmu_impl_ops. Prioritize
them in arm_smmu_get_viommu_size() and arm_vsmmu_init().

Link: https://patch.msgid.link/r/375ac2b056764534bb7c10ecc4f34a0bae82b108.1752126748.git.nicolinc@nvidia.com
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: nicolinc

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c

@@ -416,6 +416,10 @@ size_t arm_smmu_get_viommu_size(struct device *dev,
 	    !(smmu->features & ARM_SMMU_FEAT_S2FWB))
 		return 0;
 
+	if (smmu->impl_ops && smmu->impl_ops->vsmmu_size &&
+	    viommu_type == smmu->impl_ops->vsmmu_type)
+		return smmu->impl_ops->vsmmu_size;
+
 	if (viommu_type != IOMMU_VIOMMU_TYPE_ARM_SMMUV3)
 		return 0;
 
@@ -439,6 +443,10 @@ int arm_vsmmu_init(struct iommufd_viommu *viommu,
 	/* FIXME Move VMID allocation from the S2 domain allocation to here */
 	vsmmu->vmid = s2_parent->s2_cfg.vmid;
 
+	if (smmu->impl_ops && smmu->impl_ops->vsmmu_init &&
+	    viommu->type == smmu->impl_ops->vsmmu_type)
+		return smmu->impl_ops->vsmmu_init(vsmmu, user_data);
+
 	viommu->ops = &arm_vsmmu_ops;
 	return 0;
 }

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

@@ -16,6 +16,7 @@
 #include <linux/sizes.h>
 
 struct arm_smmu_device;
+struct arm_vsmmu;
 
 /* MMIO registers */
 #define ARM_SMMU_IDR0			0x0
@@ -720,6 +721,10 @@ 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);
+	const size_t vsmmu_size;
+	const enum iommu_viommu_type vsmmu_type;
+	int (*vsmmu_init)(struct arm_vsmmu *vsmmu,
+			  const struct iommu_user_data *user_data);
 };
 
 /* An SMMUv3 instance */