Re: [PATCH v4 00/15] firmware: qcom: Add OP-TEE PAS service support

[Sumit Garg <sumit.garg@kernel.org>]

On Wed, Apr 29, 2026 at 12:29:26PM +0530, Mukesh Ojha wrote:
> On Mon, Apr 27, 2026 at 03:25:48PM +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.
> > 
> > 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.
> > 
> > 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 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.
> 
> 
> Gave it a try to test the series on Lemans with Gunyah as well as KVM
> hypervisor and all the remote processor are coming up successfully.
> 
> Feel free to carry 
> 
> Tested-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com> # Lemans
> 
> for the Series.
>

Thanks for taking time to test this patch-set.

-Sumit

> 
> > The patch-set is based on v7.1-rc1 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-v4
> > 
> > ---
> > 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.
> > 
> > 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          | 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      |  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, 1115 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
> > 
> 
> -- 
> -Mukesh Ojha
>