On Mon, Oct 30, 2023 at 9:48 AM Etienne Carriere
<etienne.carriere@foss.st.com> wrote:
>
> This series introduces TEE system sessions for TEE service sessions that
> require TEE to provision resources to prevent deadlock when clients call
> the TEE.
>
> This deadlock situation can happen when a TEE service is used by low
> level system resources as for example when Linux kernel uses SCMI
> service embedded in TEE for clock, reset, regulator, etc... controls.
> This case is detailled in patch 2/4:
>
> > This feature is needed to prevent a system deadlock when several TEE
> > client applications invoke TEE, consuming all TEE thread contexts
> > available in the secure world. The deadlock can happen in the OP-TEE
> > driver for example if all these TEE threads issue an RPC call from TEE
> > to Linux OS to access an eMMC RPMB partition (TEE secure storage) which
> > device clock or regulator controller is accessed through an OP-TEE SCMI
> > services. In that case, Linux SCMI driver must reach OP-TEE SCMI
> > service without waiting until one of the consumed TEE threads is freed.
>
> Etienne Carriere (4):
> tee: optee: system call property
> tee: system session
> tee: optee: support tracking system threads
> firmware: arm_scmi: optee: use optee system invocation
>
> drivers/firmware/arm_scmi/optee.c | 4 +
> drivers/tee/optee/call.c | 130 ++++++++++++++++++++++++++++--
> drivers/tee/optee/core.c | 5 +-
> drivers/tee/optee/ffa_abi.c | 14 ++--
> drivers/tee/optee/optee_private.h | 29 ++++++-
> drivers/tee/optee/smc_abi.c | 32 +++++---
> drivers/tee/tee_core.c | 8 ++
> include/linux/tee_drv.h | 16 ++++
> 8 files changed, 211 insertions(+), 27 deletions(-)
> ---
> Changes since v11:
> - Fixed inline description comments in patch 1/3 and 3/4, other patches
> are unchanged.
>
> Changes since v10:
> - Changes patch 3/4, other are unchanged.
> --
> 2.25.1
>
I'm picking up this.
Thanks,
Jens