Re: [PATCH v6 0/4] Introduce TEE bus driver framework

[Jens Wiklander]

Hi Matt and Herbert,

On Tue, Jan 29, 2019 at 11:19:34AM +0530, Sumit Garg 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
> 
>  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
> 

I think this patch series is good now. It has received comments which
has been addressed and have also gathered a few R-B tags.

All patches but "hwrng: add OP-TEE based rng driver" covers what I
normally send pull requests to arm-soc for.

Matt, Herbert, are you fine with the patch
"hwrng: add OP-TEE based rng driver"?
If so, is it also OK if I take it via my tree which I then will include
in a pull request to arm-soc? An Acked-By tag would be nice to have.

Thanks,
Jens