On Tue, 12 Feb 2019 at 17:41, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On Tue, 12 Feb 2019 at 13:09, Sumit Garg sumit.garg@linaro.org wrote:
On Tue, 12 Feb 2019 at 16:35, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
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:
- Incorporate some nitpicks in patch #1 and #3.
- Bundle all statics in a data structure in patch #4 and use dev_* instead of pr_*.
- Add reviewed-by tags for patch #1, #2 and #3.
Changes in v5:
- Add support in module device table for TEE bus devices.
- Correct license for optee-rng module.
Changes in v4:
- Use typedef instead of single member tee_client_device_id struct.
- Incorporate TEE bus nitpicks.
Changes in v3:
- Fixed bus error path in Patch #1.
- Reversed order of Patch #2 and #3.
- Fixed miscellaneous syntax comments and memory leak.
- 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:
- Added TEE bus driver framework.
- Added OP-TEE based device enumeration.
- Register optee-rng driver as TEE bus driver.
- Removed DT dependency for optee-rng device UUID.
- 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
Thanks. BTW, Jens has created a GIT PULL[1] to incorporate this patch-set.
although I had to load optee.ko manually in order for the udev autoload of optee_rng to trigger.
Did you built OP-TEE module as out-of-tree? OP-TEE by-default is built-in kernel module as per following configs in default defconfig:
CONFIG_TEE=y CONFIG_OPTEE=y
Yes, but the distros will carry it as a module.
Hmm, I see. So in this case OP-TEE module needs to be loaded manually due to missing modalias for udev autoload.
-Sumit
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?
This change is already part of your RFC patch [2] and I agree to make OP-TEE as platform driver.
[1] https://lkml.org/lkml/2019/2/4/104 [2] https://lkml.org/lkml/2018/12/27/196
Indeed, but iirc there was a question from Jens and I wasn't sure it had been answered in the mean time.