Re: [PATCH RFC 0/3] firmware: arm_firme: introduce FIRME support for host attestation

[Yeoreum Yun <yeoreum.yun@arm.com>]

> On Tue, Oct 20, 2026 at 06:05:35PM +0100, Yeoreum Yun wrote:
> > > 
> > > > If we implments this with library, are you thinking that file should
> > > > be located at driver/firmware/arm_firme or other place? though we make it
> > > > with library, I still think it should be located at
> > > > driver/firmware/arm_firme or some place in arch/arm64, but as
> > > > perspective abstraction to mange firme helpers in one place,
> > > > I think this design seems good.
> > > 
> > > Will has indicated a preference for driver/firwmare
> > 
> > Okay. with this let me make a driver/firmware/arm_firme as library not
> > a module format and make this library APIs (base, attestation) to be used
> > attestation and other. This means device / driver registeration with
> > smccc and done in driver/attestation/provider but use the APIs from
> > /driver/firmware/arm_firme.
> 
> You should try to structure it with a firme headerfile, and some
> inline helpers to invoke the smcs and then a very small set of out of
> line functions that *are used by multiple firme drivers*.

Might some could be, but want to reduce the time of calling of smc call
for example, to get a shared buffer information, it doesn't need to call
multiple times but enough to call FIRME_SERVICE_FEATURE with BASE
service and cache the result in some where.

That's why I think to provide base service helper, add the arm_firme.c
in /driver/firmeware while all attestation relevant will be located in
/driver/attestation/provider/firme.c

> 
> Don't put attestation in driver/firmware/arm_firme..

Acked.

> 
> You can look at what I did for DRTM for some inspiration
> 
> https://lore.kernel.org/all/11-v2-989a18390eb1+486-arm64_drtm_jgg@nvidia.com/
> 
> After some feedback from Jonathon I think it turned out fairly well.

Thanks.

-- 
Sincerely,
Yeoreum Yun