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

From: Robin Murphy
Date: Tue Nov 14 2023 - 08:18:52 EST


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.