[PATCH v5 20/29] iommu: Allow an input type in hw_info op

[Tian, Kevin]

> From: Nicolin Chen <nicolinc at nvidia.com>
> Sent: Sunday, May 18, 2025 11:22 AM
> 
> The hw_info uAPI will support a bidirectional data_type field that can be
> used as an input field for user space to request for a specific info data.
> 
> To prepare for the uAPI update, change the iommu layer first:
>  - Add a new IOMMU_HW_INFO_TYPE_DEFAULT as an input, for which driver
> can
>    output its only (or firstly) supported type
>  - Update the kdoc accordingly
>  - Roll out the type validation in the existing drivers
> 
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian at intel.com>