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
Reviewed-by: Kevin Tian<kevin.tian@xxxxxxxxx>
Reviewed-by: Jason Gunthorpe<jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen<nicolinc@xxxxxxxxxx>