[coreboot] Resources and links

[Marc Jones]

On Thu, Dec 4, 2008 at 7:00 AM, Myles Watson <mylesgw at gmail.com> wrote:
> I've been thinking about getting rid of the links in v3, or changing their
> meaning.  I can't see anywhere that they're being used right now.
>
> The problem is how to deal with k8.  It has "multiple links", but not in the
> same sense as v3.  In v3, multiple links means logical connections to
> multiple devices.  K8 has multiple physical connections, but only one
> logical connection.
>
> This is a problem for resource allocation (the current implementation as
> well as my patch.)  The idea is that for every bridge resource gets all
> matching resources from the sub-tree packed into it.  The problem is that
> for k8 there can be multiple bridge resources of the same type, and to know
> which resources to pack into it, you have to know which physical link they
> are connected to.  At the same time, all the children are logically
> connected to the same PCI.
>
> This could be solved in several ways, but I'm hoping that there's an elegant
> way that I haven't thought of yet.  Here are a couple I was thinking of:
>
> 1. Let links have resources, and make all bridge resources live there.
>        I don't like this one because links aren't needed anywhere else, and
> this just makes links larger.
>
> 2. Give bridges a function which returns the children under a resource.
>        It's an extra function for all bridges, but most would just return
> all children.

Myles,

#2 seems like it would be useful. Would it be useful to have the link
hold pointes to the child bridge(s) or is that already handled?

Marc