Re: [PATCH 2/4] x86/amd_nb: add support for newer PCI topologies

Woods, Brian
2018-11-06T08:54:32Z

On Mon, Nov 05, 2018 at 10:42:33PM +0100, Borislav Petkov wrote:
> Yes please. Because this is the usual kernel coding style of calling a
> function (or a loop which has some result in this case) and testing that
> result immediately after the function call.

Done.

> You say "correct" as there is a special one. But the text before it says
> they're "functionally the same" wrt DF/SMN access so it sounds to me
> like we wanna map the first one we find and ignore the others.
>
> I.e., we wanna say
>
> "... so the DF/SMN interfaces get mapped to the *first* PCI root and the
> others N-1 ignored."
>
> Or am I misreading this?
>
> Thx.
>
> --
> Regards/Gruss,
> Boris.
>
> Good mailing practices for 400: avoid top-posting and trim the reply.

Your understanding is correct. It's more so that the following DF/SMN
interface gets mapped correctly.
/*
* If there are more PCI root devices than data fabric/
* system management network interfaces, then the (N)
* PCI roots per DF/SMN interface are functionally the
* same (for DF/SMN access) and N-1 are redundant. N-1
* PCI roots should be skipped per DF/SMN interface so
* the following DF/SMN interfaces get mapped to
* correct PCI roots.
*/
Does that read clearer?

--
Brian Woods