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 pasidwill 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.