Re: [PATCH v3 2/4] firmware: Add support for Qualcomm Secure Execution Environment SCM interface

[Dmitry Baryshkov]

On 05/03/2023 04:21, Maximilian Luz wrote:
> Add support for SCM calls to Secure OS and the Secure Execution
> Environment (SEE) residing in the TrustZone (TZ) via the QSEECOM
> interface. This allows communication with Secure/TZ applications, for
> example 'uefisecapp' managing access to UEFI variables.
>
> The interface is managed by a platform device to ensure correct lifetime
> and establish a device link to the Qualcomm SCM device.
>
> While this patch introduces only a very basic interface without the more
> advanced features (such as re-entrant and blocking SCM calls and
> listeners/callbacks), this is enough to talk to the aforementioned
> 'uefisecapp'.
>
> Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> ---
>
> Changes in v3:
>   - Rebase ontop of latest qcom_scm changes (qcom_scm.h moved).
>   - Move qcom_qseecom.h in accordance with qcom_scm.
>
> Changes in v2:
>   - Bind the interface to a device.
>   - Establish a device link to the SCM device to ensure proper ordering.
>   - Register client apps as child devices instead of requiring them to be
>     specified in the device tree.
>   - Rename (qctree -> qseecom) to allow differentiation between old
>     (qseecom) and new (smcinvoke) interfaces to the trusted execution
>     environment.
>
> ---
>   MAINTAINERS                                |   7 +
>   drivers/firmware/Kconfig                   |  15 +
>   drivers/firmware/Makefile                  |   1 +
>   drivers/firmware/qcom_qseecom.c            | 314 +++++++++++++++++++++
>   include/linux/firmware/qcom/qcom_qseecom.h | 190 +++++++++++++
>   5 files changed, 527 insertions(+)
>   create mode 100644 drivers/firmware/qcom_qseecom.c
>   create mode 100644 include/linux/firmware/qcom/qcom_qseecom.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9201967d198d..1545914a592c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17380,6 +17380,13 @@ F:	Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst
>   F:	drivers/net/ethernet/qualcomm/rmnet/
>   F:	include/linux/if_rmnet.h
>   
> +QUALCOMM SECURE EXECUTION ENVIRONMENT COMMUNICATION DRIVER
> +M:	Maximilian Luz <luzmaximilian@xxxxxxxxx>
> +L:	linux-arm-msm@xxxxxxxxxxxxxxx
> +S:	Maintained
> +F:	drivers/firmware/qcom_qseecom.c
> +F:	include/linux/firmware/qcom/qcom_qseecom.h
> +
>   QUALCOMM TSENS THERMAL DRIVER
>   M:	Amit Kucheria <amitk@xxxxxxxxxx>
>   M:	Thara Gopinath <thara.gopinath@xxxxxxxxx>



> +
> +
> +/* -- Platform specific data. ----------------------------------------------- */
> +
> +struct qseecom_data {
> +	const struct mfd_cell *cells;

The child qseecom devices are not platform devices, so MFD should not be 
used here. Please use aux devices instead.

> +	int num_cells;
> +};
> +
> +static const struct of_device_id qseecom_dt_match[] = {
> +	{ .compatible = "qcom,qseecom-sc8280xp", },

Forgot to mention, while doign review. There is no need for this compat 
until you provide the actual data. Please move it to the patch 4.

> +	{ .compatible = "qcom,qseecom", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, qseecom_dt_match);


--
With best wishes
Dmitry