Re: [PATCH v4 18/23] iommu/arm-smmu-v3-iommufd: Support implementation-defined hw_info
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2025-05-15 17:17:09
Also in:
linux-doc, linux-iommu, linux-kselftest, linux-patches, linux-tegra, lkml
On Thu, May 08, 2025 at 08:02:39PM -0700, Nicolin Chen wrote:
Repurpose the @__reserved field in the struct iommu_hw_info_arm_smmuv3, to an HW implementation-defined field @impl.
It would be nicer to have a tegra/cmdq specific struct and a way for iommu_hw_info to select it. 'impl' isn't going to scale very well if something else wants to use this. We have out_data_type but we could have an input sub_data_type too. 0 means what we have today, then a simple enum to select another info struct.
quoted hunk ↗ jump to hunk
@@ -726,6 +726,7 @@ struct arm_smmu_impl_ops { struct arm_smmu_domain *smmu_domain, struct iommufd_ctx *ictx, unsigned int viommu_type, const struct iommu_user_data *user_data); + u32 (*hw_info)(struct arm_smmu_device *smmu, u32 *impl); };
Then the dispatch here is just having a sub-struct enum # in arm_smmu_impl_ops for dispatching. Jason