Re: [PATCH v2 17/17] devicetree: Add bindings for ftrace KHO

From: Rob Herring
Date: Tue Jan 02 2024 - 09:53:30 EST


On Sun, Dec 24, 2023 at 12:20:17AM +0100, Alexander Graf wrote:
> Hi Krzysztof!
>
> Thanks a lot for the fast review!
>
> On 23.12.23 15:30, Krzysztof Kozlowski wrote:
> > On 22/12/2023 20:51, Alexander Graf wrote:
> > > With ftrace in KHO, we are creating an ABI between old kernel and new
> > > kernel about the state that they transfer. To ensure that we document
> > > that state and catch any breaking change, let's add its schema to the
> > > common devicetree bindings. This way, we can quickly reason about the
> > > state that gets passed.
> > Please use scripts/get_maintainers.pl to get a list of necessary people
> > and lists to CC (and consider --no-git-fallback argument). It might
> > happen, that command when run on an older kernel, gives you outdated
> > entries. Therefore please be sure you base your patches on recent Linux
> > kernel.

[...]

> >
> > > + mem = < 0x101000000ULL 0x38ULL 0x101000100ULL 0x1000ULL 0x101000038ULL 0x38ULL 0x101002000ULL 0x1000ULL>;
> > ? Do you see any of such syntax in DTS?
>
>
> I was trying to make it easy to reason to readers about 64bit numbers - and
> then potentially extend dtc to consume that new syntax. KHO DTs are
> native/little endian, so dtc already has some difficulties interpreting it
> which I'll need to fix up with patches to it eventually :). I'll change it
> to something that looks more 32bit'y for now.

"/bits/ 64 <0x0 ...>" is what you are looking for.

Rob