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

[Jason Gunthorpe]

On Sat, May 17, 2025 at 08:21:37PM -0700, Nicolin Chen wrote:
> 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>
> ---
>  include/linux/iommu.h                               | 6 ++++--
>  include/uapi/linux/iommufd.h                        | 4 +++-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 4 ++++
>  drivers/iommu/intel/iommu.c                         | 4 ++++
>  drivers/iommu/iommufd/device.c                      | 3 +++
>  drivers/iommu/iommufd/selftest.c                    | 4 ++++
>  6 files changed, 22 insertions(+), 3 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>

Jason