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From:   Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date:   Tue, 12 Feb 2019 12:05:44 +0100
Message-ID: <CAKv+Gu_RJHb_FwTz+R1bXNQQMsoi0xxcKzn54NF5ib3z2xnH0w@mail.gmail.com>
Subject: Re: [PATCH v6 0/4] Introduce TEE bus driver framework
To:     Sumit Garg <sumit.garg@linaro.org>
Cc:     Jens Wiklander <jens.wiklander@linaro.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
        <linux-crypto@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Michal Marek <michal.lkml@markovi.net>, mpm@selenic.com,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Bhupesh Sharma <bhsharma@redhat.com>, tee-dev@lists.linaro.org
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On Tue, 29 Jan 2019 at 06:50, Sumit Garg <sumit.garg@linaro.org> wrote:
>
> This series introduces a generic TEE bus driver concept for TEE based
> kernel drivers which would like to communicate with TEE based devices/
> services.
>
> Patch #1 adds TEE bus concept where devices/services are identified via
> Universally Unique Identifier (UUID) and drivers register a table of
> device UUIDs which they can support. This concept also allows for device
> enumeration to be specific to corresponding TEE implementation like
> OP-TEE etc.
>
> Patch #2 adds supp_nowait flag for non-blocking requests arising via
> TEE internal client interface.
>
> Patch #3 adds TEE bus device enumeration support for OP-TEE. OP-TEE
> provides a pseudo TA to enumerate TAs which can act as devices/services
> for TEE bus.
>
> Patch #4 adds OP-TEE based hwrng driver which act as TEE bus driver.
> On ARM SoC's with TrustZone enabled, peripherals like entropy sources
> might not be accessible to normal world (linux in this case) and rather
> accessible to secure world (OP-TEE in this case) only. So this driver
> aims to provides a generic interface to OP-TEE based random number
> generator service.
>
> Example case is Developerbox based on Socionext's Synquacer SoC [1]
> which provides 7 thermal sensors accessible from secure world only which
> could be used as entropy sources (thermal/measurement noise).
>
> [1] https://www.96boards.org/product/developerbox/
>
> Changes in v6:
>
> 1. Incorporate some nitpicks in patch #1 and #3.
> 2. Bundle all statics in a data structure in patch #4 and use dev_*
>    instead of pr_*.
> 3. Add reviewed-by tags for patch #1, #2 and #3.
>
> Changes in v5:
>
> 1. Add support in module device table for TEE bus devices.
> 2. Correct license for optee-rng module.
>
> Changes in v4:
>
> 1. Use typedef instead of single member tee_client_device_id struct.
> 2. Incorporate TEE bus nitpicks.
>
> Changes in v3:
>
> 1. Fixed bus error path in Patch #1.
> 2. Reversed order of Patch #2 and #3.
> 3. Fixed miscellaneous syntax comments and memory leak.
> 4. Added comments in Patch #2 for supp_nowait flag.
>
> Changes in v2:
>
> Based on review comments, the scope of this series has increased as
> follows:
>
> 1. Added TEE bus driver framework.
> 2. Added OP-TEE based device enumeration.
> 3. Register optee-rng driver as TEE bus driver.
> 4. Removed DT dependency for optee-rng device UUID.
> 5. Added supp_nowait flag.
>
> Sumit Garg (4):
>   tee: add bus driver framework for TEE based devices
>   tee: add supp_nowait flag in tee_context struct
>   tee: optee: add TEE bus device enumeration support
>   hwrng: add OP-TEE based rng driver
>

For this series

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

although I had to load optee.ko manually in order for the udev
autoload of optee_rng to trigger. Not sure where the discussion went
last time, but could we please add "linaro,optee-tz" as a DT modalias
to the optee.ko module in any case?

>  MAINTAINERS                        |   5 +
>  drivers/char/hw_random/Kconfig     |  15 ++
>  drivers/char/hw_random/Makefile    |   1 +
>  drivers/char/hw_random/optee-rng.c | 298 +++++++++++++++++++++++++++++++++++++
>  drivers/tee/optee/Makefile         |   1 +
>  drivers/tee/optee/core.c           |   4 +
>  drivers/tee/optee/device.c         | 155 +++++++++++++++++++
>  drivers/tee/optee/optee_private.h  |   3 +
>  drivers/tee/optee/supp.c           |  10 +-
>  drivers/tee/tee_core.c             |  67 ++++++++-
>  include/linux/mod_devicetable.h    |   9 ++
>  include/linux/tee_drv.h            |  38 ++++-
>  scripts/mod/devicetable-offsets.c  |   3 +
>  scripts/mod/file2alias.c           |  19 +++
>  14 files changed, 622 insertions(+), 6 deletions(-)
>  create mode 100644 drivers/char/hw_random/optee-rng.c
>  create mode 100644 drivers/tee/optee/device.c
>
> --
> 2.7.4
>