Message-ID: <6ddeba6f-9816-730e-28ce-0f1efbc11367@linaro.org>
Date:   Tue, 7 Mar 2023 17:36:26 +0200
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Subject: Re: [PATCH v3 2/4] firmware: Add support for Qualcomm Secure
 Execution Environment SCM interface
Content-Language: en-GB
To:     Maximilian Luz <luzmaximilian@gmail.com>,
        Bjorn Andersson <andersson@kernel.org>
Cc:     Andy Gross <agross@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Ard Biesheuvel <ardb@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Johan Hovold <johan@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Sumit Garg <sumit.garg@linaro.org>,
        Steev Klimaszewski <steev@kali.org>,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230305022119.1331495-1-luzmaximilian@gmail.com>
 <20230305022119.1331495-3-luzmaximilian@gmail.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <20230305022119.1331495-3-luzmaximilian@gmail.com>
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Precedence: bulk

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@gmail.com>
> ---
> 
> 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@gmail.com>
> +L:	linux-arm-msm@vger.kernel.org
> +S:	Maintained
> +F:	drivers/firmware/qcom_qseecom.c
> +F:	include/linux/firmware/qcom/qcom_qseecom.h
> +
>   QUALCOMM TSENS THERMAL DRIVER
>   M:	Amit Kucheria <amitk@kernel.org>
>   M:	Thara Gopinath <thara.gopinath@gmail.com>


> +
> +
> +/* -- 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