[PATCH v9 00/14] firmware: qcom: Add OP-TEE PAS service support

Thu Jul 2 12:14:03 PDT 2026

Hey Sumit - nice hearing from you...

Is there some kind of overarching design harminisation between what
you are proposing here and what Arnaud posted back in April [1] ?

[1]. https://lists.trustedfirmware.org/archives/list/op-tee@lists.trustedfirmware.org/thread/VMKTRATYUFWL2TP7NHN5KJ37MSVZZMPK/

On Thu, 2 Jul 2026 at 05:59, Sumit Garg <sumit.garg at kernel.org> wrote:
>
> From: Sumit Garg <sumit.garg at 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.
>
> 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 and lemans
> EVK boards. In addition to that WIN/IPQ targets tested OP-TEE with
> this service too. Surely the backwards compatibility is maintained and
> tested for SCM backend.
>
> Note that kernel PAS service support while running in EL2 is at parity
> among OP-TEE vs QTEE. Especially the media (venus/iris) support depends
> on proper IOMMU support being worked out on the PAS client end.
>
> Patch summary:
> - Patch #1: adds generic PAS service.
> - Patch #2: migrates SCM backend to generic PAS service.
> - Patch #3: adds TEE/OP-TEE backend for generic PAS service.
> - Patch #4-#12: migrates all client drivers to generic PAS service.
> - Patch #13: drops legacy PAS SCM exported APIs.
>
> The patch-set is based on v7.2-rc1 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 (already merged)
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/sumit.garg/linux.git/log/?h=qcom-pas-v9
>
> ---
> Changes in v9:
> - Rebased to 7.2-rc1.
> - Enable SCM backend similar to TEE if ARCH_QCOM is set.
> - Address misc. comments from Konrad.
> - Add checks for corner cases (although not reachable as per OP-TEE ABI)
>   reported by Shashiko on patch #3.
> - Picked up review tags from Konrad.
>
> Changes in v8:
> - Rebased on mainline tip (no functional changes).
> - Now Lemans EVK is also tested to support OP-TEE PAS here:
>   https://github.com/OP-TEE/optee_os/pull/7845
> - Drop Kodiak DT patch as it is carried independently by Mukesh here:
>   https://lore.kernel.org/lkml/20260624063952.2242702-1-mukesh.ojha@oss.qualcomm.com/
> - Regarding Sashiko comments, I have already replied in v6 the ones that
>   don't apply but in v7 I got the same comments again. Specific context
>   reasoning which Shashiko ignores:
>     - ABI contract between Linux and TZ
>     - No support for multiple concurrent backends
>     - The TZ backend doesn’t detach during the entire boot cycle
>
> Changes in v7:
> - Rebased to qcom tree (for-next branch) tip.
> - Merged patch #5 and #7 due to build dependency.
> - Disabled modem for kodiak EL2 as it isn't tested yet.
> - Fix an issue found out by sashiko-bot for patch #4.
>
> Changes in v6:
> - Rebased to v7.1-rc4 tag.
> - Patch #14: fixed ret error print.
> - Add Kconfig descriptions for PAS symbols such that they are visible
>   in menuconfig to update.
>
> Changes in v5:
> - Incorporated misc. comments from Mukesh.
> - Split up patch #11 into 2 to add an independent commit for passing
>   proper PAS ID to set_remote_state API.
> - Picked up tags.
>
> Changes in v4:
> - Incorporate misc. comments on patch #4.
> - Picked up an ack for patch #10.
> - Clarify in cover letter about state of media support.
>
> 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.
>
> 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
>   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
>   media: qcom: Pass proper PAS ID to set_remote_state API
>   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 +
>  drivers/firmware/qcom/Kconfig                 |  22 +-
>  drivers/firmware/qcom/Makefile                |   2 +
>  drivers/firmware/qcom/qcom_pas.c              | 299 +++++++++++
>  drivers/firmware/qcom/qcom_pas.h              |  50 ++
>  drivers/firmware/qcom/qcom_pas_tee.c          | 479 ++++++++++++++++++
>  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      |  27 +-
>  .../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         |  10 +-
>  drivers/remoteproc/Kconfig                    |   4 +-
>  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 +-
>  26 files changed, 1095 insertions(+), 321 deletions(-)
>  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
>
> --
> 2.53.0
>