Re: [PATCH v2 02/15] firmware: qcom: Add a generic PAS service

Sumit Garg
2026-03-23T13:01:18Z

On Fri, Mar 13, 2026 at 01:29:48PM +0530, Mukesh Ojha wrote:
> On Thu, Mar 12, 2026 at 11:57:43AM +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
> > with S-EL2 and 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.
> >
> > Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > ---
> > drivers/firmware/qcom/Kconfig | 8 +
> > drivers/firmware/qcom/Makefile | 1 +
> > drivers/firmware/qcom/qcom_pas.c | 298 +++++++++++++++++++++++++
> > drivers/firmware/qcom/qcom_pas.h | 53 +++++
> > include/linux/firmware/qcom/qcom_pas.h | 41 ++++
> > 5 files changed, 401 insertions(+)
> > create mode 100644 drivers/firmware/qcom/qcom_pas.c
> > create mode 100644 drivers/firmware/qcom/qcom_pas.h
> > create mode 100644 include/linux/firmware/qcom/qcom_pas.h
> >

<snip>

> > diff --git a/drivers/firmware/qcom/qcom_pas.c b/drivers/firmware/qcom/qcom_pas.c
> > new file mode 100644
> > index 000000000000..beb1bae55546
> > --- /dev/null
> > +++ b/drivers/firmware/qcom/qcom_pas.c
> > @@ -0,0 +1,298 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> > + */
>
> I know, this is new file but most of the documentation and some of the
> function are rename to reflect pas service.
>
> Should this carry original file copyright ? Not sure..
>

This file only contains the wrapper generic PAS APIs which aren't
re-used from any other file. Carrying copyrights solely based on moving
API documentation in not very clear to me. Any other thoughts?

-Sumit