Re: [PATCH v3 00/15] firmware: qcom: Add OP-TEE PAS service support

Bjorn Andersson
2026-04-06T15:09:37Z

On Fri, Mar 27, 2026 at 06:40:28PM +0530, Sumit Garg wrote:
> From: Sumit Garg <sumit.garg@oss.qualcomm.com>
>
> Qcom platforms has the legacy of using non-standard SCM calls
> splintered over the various kernel drivers. These SCM calls aren't
> compliant with the standard SMC calling conventions which is a
> prerequisite to enable migration to the FF-A specifications from Arm.
>

Please get our colleagues involved in this discussion, because this
non-SCM interface does not match the direction we are taking.

Regards,
Bjorn

> OP-TEE as an alternative trusted OS to Qualcomm TEE (QTEE) can't
> support these non-standard SCM calls. And even for newer architectures
> using S-EL2 with Hafnium support, QTEE won't be able to support SCM
> calls either with FF-A requirements coming in. And with both OP-TEE
> and QTEE drivers well integrated in the TEE subsystem, it makes further
> sense to reuse the TEE bus client drivers infrastructure.
>
> The added benefit of TEE bus infrastructure is that there is support
> for discoverable/enumerable services. With that client drivers don't
> have to manually invoke a special SCM call to know the service status.
>
> So enable the generic Peripheral Authentication Service (PAS) provided
> by the firmware. It acts as the common layer with different TZ
> backends plugged in whether it's an SCM implementation or a proper
> TEE bus based PAS service implementation.
>
> The TEE PAS service ABI is designed to be extensible with additional API
> as PTA_QCOM_PAS_CAPABILITIES. This allows to accommodate any future
> extensions of the PAS service needed while still maintaining backwards
> compatibility.
>
> Currently OP-TEE support is being added to provide the backend PAS
> service implementation which can be found as part of this PR [1].
> This implementation has been tested on Kodiak/RB3Gen2 board with lemans
> EVK board being the next target. In addition to that WIN/IPQ targets
> planning to use OP-TEE will use this service too. Surely the backwards
> compatibility is maintained and tested for SCM backend.
>
> Patch summary:
> - Patch #1: adds Kodiak EL2 overlay since boot stack with TF-A/OP-TEE
> only allow UEFI and Linux to boot in EL2.
> - Patch #2: adds generic PAS service.
> - Patch #3: migrates SCM backend to generic PAS service.
> - Patch #4: adds TEE/OP-TEE backend for generic PAS service.
> - Patch #5-#13: migrates all client drivers to generic PAS service.
> - Patch #14: drops legacy PAS SCM exported APIs.
>
> The patch-set is based on v7.0-rc5 tag and can be found in git tree here
> [2].
>
> Merge strategy:
>
> It is expected due to APIs dependency, the entire patch-set to go via
> the Qcom tree. All other subsystem maintainers, it will be great if I
> can get acks for the corresponding subsystem patches.
>
> [1] https://github.com/OP-TEE/optee_os/pull/7721
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/sumit.garg/linux.git/log/?h=qcom-pas-v3
>
> ---
> Changes in v3:
> - Incorporated some style and misc. comments for patch #2, #3 and #4.
> - Add QCOM_PAS Kconfig dependency for various subsystems.
> - Switch from pseudo TA to proper TA invoke commands.
>
> Changes in v2:
> - Fixed kernel doc warnings.
> - Polish commit message and comments for patch #2.
> - Pass proper PAS ID in set_remote_state API for media firmware drivers.
> - Added Maintainer entry and dropped MODULE_AUTHOR.
>
> Mukesh Ojha (1):
> arm64: dts: qcom: kodiak: Add EL2 overlay
>
> Sumit Garg (14):
> firmware: qcom: Add a generic PAS service
> firmware: qcom_scm: Migrate to generic PAS service
> firmware: qcom: Add a PAS TEE service
> remoteproc: qcom_q6v5_pas: Switch over to generic PAS TZ APIs
> remoteproc: qcom_q6v5_mss: Switch to generic PAS TZ APIs
> soc: qcom: mdtloader: Switch to generic PAS TZ APIs
> remoteproc: qcom_wcnss: Switch to generic PAS TZ APIs
> remoteproc: qcom: Select QCOM_PAS generic service
> drm/msm: Switch to generic PAS TZ APIs
> media: qcom: Switch to generic PAS TZ APIs
> net: ipa: Switch to generic PAS TZ APIs
> wifi: ath12k: Switch to generic PAS TZ APIs
> firmware: qcom_scm: Remove SCM PAS wrappers
> MAINTAINERS: Add maintainer entry for Qualcomm PAS TZ service
>
> MAINTAINERS | 9 +
> arch/arm64/boot/dts/qcom/Makefile | 2 +
> arch/arm64/boot/dts/qcom/kodiak-el2.dtso | 35 ++
> drivers/firmware/qcom/Kconfig | 19 +
> drivers/firmware/qcom/Makefile | 2 +
> drivers/firmware/qcom/qcom_pas.c | 288 +++++++++++
> drivers/firmware/qcom/qcom_pas.h | 50 ++
> drivers/firmware/qcom/qcom_pas_tee.c | 478 ++++++++++++++++++
> drivers/firmware/qcom/qcom_scm.c | 302 ++++-------
> drivers/gpu/drm/msm/Kconfig | 1 +
> drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 4 +-
> drivers/gpu/drm/msm/adreno/adreno_gpu.c | 11 +-
> drivers/media/platform/qcom/iris/Kconfig | 25 +-
> .../media/platform/qcom/iris/iris_firmware.c | 9 +-
> drivers/media/platform/qcom/venus/Kconfig | 1 +
> drivers/media/platform/qcom/venus/firmware.c | 11 +-
> drivers/net/ipa/Kconfig | 2 +-
> drivers/net/ipa/ipa_main.c | 13 +-
> drivers/net/wireless/ath/ath12k/Kconfig | 2 +-
> drivers/net/wireless/ath/ath12k/ahb.c | 8 +-
> drivers/remoteproc/Kconfig | 1 +
> drivers/remoteproc/qcom_q6v5_mss.c | 5 +-
> drivers/remoteproc/qcom_q6v5_pas.c | 51 +-
> drivers/remoteproc/qcom_wcnss.c | 12 +-
> drivers/soc/qcom/mdt_loader.c | 12 +-
> include/linux/firmware/qcom/qcom_pas.h | 43 ++
> include/linux/firmware/qcom/qcom_scm.h | 29 --
> include/linux/soc/qcom/mdt_loader.h | 6 +-
> 28 files changed, 1114 insertions(+), 317 deletions(-)
> create mode 100644 arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> create mode 100644 drivers/firmware/qcom/qcom_pas.c
> create mode 100644 drivers/firmware/qcom/qcom_pas.h
> create mode 100644 drivers/firmware/qcom/qcom_pas_tee.c
> create mode 100644 include/linux/firmware/qcom/qcom_pas.h
>
> --
> 2.51.0
>