[PATCH 3/5] arm: stm32mp: Implement support for TZC 400 controller

[Alex G.]

On 2/7/21 8:37 AM, Simon Glass wrote:
> Hi Alexandru,
> 
> On Thu, 4 Feb 2021 at 12:56, Alexandru Gagniuc <mr.nuke.me at gmail.com> wrote:
>>
>> The purpose of this change is to allow configuring TrustZone (TZC)
>> memory permissions. For example, OP-TEE expects TZC regions to be
>> configured in a very particular way. The API presented here is
>> intended to allow exactly that.
>>
>> UCLASS support is not implemented, because it would not be too useful.
>> Changing TZC permissions needs to be done with care, so as not to cut
>> off access to memory we are currently using. One place where we can
>> use this is at the end of SPL, right before jumping to OP-TEE.
>>
>> Signed-off-by: Alexandru Gagniuc <mr.nuke.me at gmail.com>
>> ---
>>   arch/arm/mach-stm32mp/Makefile           |   1 +
>>   arch/arm/mach-stm32mp/include/mach/tzc.h |  33 ++++++
>>   arch/arm/mach-stm32mp/tzc400.c           | 135 +++++++++++++++++++++++
>>   3 files changed, 169 insertions(+)
>>   create mode 100644 arch/arm/mach-stm32mp/include/mach/tzc.h
>>   create mode 100644 arch/arm/mach-stm32mp/tzc400.c
> 
> If this is an API you should add comments to the header file structs
> and functions.
> 
> Is this API specific to just this chip?

I've designed and validated this to set up stm32mp for starting up 
OP-TEE. It's a narrow use case. I can't speak for other chips.

Alex