[RFC PATCH v2 1/2] topology: Represent clusters of CPUs within a die.

[Sudeep Holla]

On Tue, Dec 01, 2020 at 04:03:46PM +0000, Valentin Schneider wrote:
> 
> On 01/12/20 02:59, Barry Song wrote:
> > Currently the ID provided is the offset of the Processor
> > Hierarchy Nodes Structure within PPTT.  Whilst this is unique
> > it is not terribly elegant so alternative suggestions welcome.
> >

I had already mentioned that you need to fix the firmware/PPTT on your
platform. If you fill only mandatory fields, then yes this is optional
and we resort to use offset as unique number in the kernel.

>
> Skimming through the spec, this sounds like something the ID structure
> (Type 2) could be used for. However in v1 Jonathan and Sudeep talked about
> UID's / DSDT, any news on that?
>

FYI, type 2 is for SoC identification which is being deprecated(still
need to check if that progressed and made to the official release yet)
in favour of Arm SMCCC v1.2 SOC_ID. Anyways it is irrelevant in this
context. They need to use UIDs and mark the corresponding flag as valid
for OSPM/kernel to use it.

> > Note that arm64 / ACPI does not provide any means of identifying
> > a die level in the topology but that may be unrelate to the cluster
> > level.
> >

May need spec extension if there are no ways to identify the same.

-- 
Regards,
Sudeep