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/[email protected]/thread/VMKTRATYUFWL2TP7NHN5KJ37MSVZZMPK/ On Thu, 2 Jul 2026 at 05:59, Sumit Garg <[email protected]> wrote: > > From: Sumit Garg <[email protected]> > > 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/[email protected]/ > - 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 >
