Re: [PATCH v2 6/8] dt-bindings: reserved-memory: Add secure CMA reserved memory range

Robin Murphy
2023-11-14T13:18:57Z

On 13/11/2023 6:37 am, Yong Wu (吴勇) wrote:
[...]
>>> +properties:
>>> + compatible:
>>> + const: secure_cma_region
>>
>> Still wrong compatible. Look at other bindings - there is nowhere
>> underscore. Look at other reserved memory bindings especially.
>>
>> Also, CMA is a Linux thingy, so either not suitable for bindings at
>> all,
>> or you need Linux specific compatible. I don't quite get why do you
>> evennot
>> put CMA there - adding Linux specific stuff will get obvious
>> pushback...
>
> Thanks. I will change to: secure-region. Is this ok?

No, the previous discussion went off in entirely the wrong direction. To
reiterate, the point of the binding is not to describe the expected
usage of the thing nor the general concept of the thing, but to describe
the actual thing itself. There are any number of different ways software
may interact with a "secure region", so that is meaningless as a
compatible. It needs to describe *this* secure memory interface offered
by *this* TEE, so that software knows that to use it requires making
those particular SiP calls with that particular UUID etc.

Thanks,
Robin.