> @@ -432,6 +432,7 @@ config ARM_SMMU_V3 > tristate "ARM Ltd. System MMU Version 3 (SMMUv3) Support" > depends on ARM64 > select IOMMU_API > + select IOMMU_SVA > select IOMMU_IO_PGTABLE_LPAE > select GENERIC_MSI_IRQ_DOMAIN Doesn't this need to select MMU_NOTIFIER now? > + struct mmu_notifier_ops mn_ops; Note: not a pointer. > + /* If bind() was already called for this (dev, mm) pair, reuse it. */ > + list_for_each_entry(bond, &master->bonds, list) { > + if (bond->mm == mm) { > + refcount_inc(&bond->refs); > + return &bond->sva; > + } > + } > + > + mn = mmu_notifier_get(&smmu_domain->mn_ops, mm); > + if (IS_ERR(mn)) > + return ERR_CAST(mn); Which seems to be to avoid mmu_notifier_get reusing notifiers registered by other arm_smmu_master instance right? Either you could just use plain old mmu_notifier_register to avoid the reuse. Or we could enhance the mmu_notifier_get to pass a private oaque instance ID pointer, which is checked in addition to the ops, and you could probably kill off the bonds list and lookup.