Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v2 2/4] iommu: Add new iommu op to get iommu hardware information | Date | Thu, 16 Mar 2023 08:16:35 +0000 |
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> From: Liu, Yi L <yi.l.liu@intel.com> > Sent: Thursday, March 9, 2023 3:54 PM > @@ -222,6 +223,11 @@ struct iommu_iotlb_gather { > /** > * struct iommu_ops - iommu ops and capabilities > * @capable: check capability > + * @hw_info: IOMMU hardware information. The type of the returned data > is > + * defined in include/uapi/linux/iommufd.h. The data buffer is
"The type of the returned data is marked by @driver_type".
"defined in include/uapi/linux/iommufd.h" should belong to the comment of @driver_type
> + * allocated in the IOMMU driver and the caller should free it > + * after use. Return the data buffer if success, or ERR_PTR on > + * failure. > * @domain_alloc: allocate iommu domain > * @probe_device: Add device to iommu driver handling > * @release_device: Remove device from iommu driver handling > @@ -246,11 +252,17 @@ struct iommu_iotlb_gather { > * @remove_dev_pasid: Remove any translation configurations of a specific > * pasid, so that any DMA transactions with this pasid > * will be blocked by the hardware. > + * @driver_type: One of enum iommu_hw_info_type. This is used in the > hw_info > + * reporting path. For the drivers that supports it, a unique > + * type should be defined. For the driver that does not support > + * it, this field is the IOMMU_HW_INFO_TYPE_DEFAULT that is 0. > + * Hence, such drivers do not need to care this field.
The meaning of "driver_type" is much broader than reporting hw_info.
let's be accurate to call it as "hw_info_type". and while we have two separate fields for one feature where is the check enforced on whether both are provided?
Is it simpler to return the type directly in @hw_info?
btw IOMMU_HW_INFO_TYPE_DEFAULT also sounds misleading. 'default' implies hw_info still available but in a default format.
probably it's clearer to call it IOMMU_HW_INFO_TYPE_NONE.
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