Re: [RFC] Architecture independent pcibios?

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Wed, 2013-10-09 at 10:09 +0100, Liviu Dudau wrote:
> On Tue, Oct 08, 2013 at 09:28:55PM +0100, Benjamin Herrenschmidt wrote:
> > On Tue, 2013-10-08 at 11:55 -0500, Rob Herring wrote:
> >
> > > > I wonder if pci_process_bridge_OF_ranges() would fit somewhere in
> > > > drivers/of?  The implementations I looked at are mostly concerned with
> > > > parsing OF resources, and they don't have much to do with PCI
> > > > directly.
> > >
> > > This was being done until Ben weighed in:
> > >
> > > https://lkml.org/lkml/2013/5/4/103
> >
> > Well, I proposed an alternative (better) approach which I of course had
> > no time to actually implement yet :-)
> 
> In order to avoid any confusion, could you please point me again to the
> relevant message(s) where you proposed your approach?

The one pointed to by the above URL ?

> > I have done the changes I needed to do to powerpc
> > pci_process_bridge_OF_ranges so it would be possible to move that now to
> > a generic place, but I still think it's not a great idea. It means the
> > pci_controller structure with its resources will have to become generic
> > which somewhat overlaps with the pci_host_bridge that Bjorn introduced,
> > so that's really not great.
> >
> > I still think an arch with DT and simpler PCI code that powerpc could
> > start looking at the transition to a better model that I hinted at...
> 
> As tempting as it is to start anew and with a cleaner code, I am wary
> that porting the existing platforms to the new code will take longer
> that way. My intentions are to make the (probably infrequent) task of
> adding a new architecture to the PCI infrastructure a simple and
> straighforward task. But adding code for my platform is no guarantee
> that new ones will have an easier job.

It still makes little sense to generalize a pci_controller with
resources & offset on top of the generic pci_host_bridge with apertures.

Ben.

> Best regards,
> Liviu
> 
> >
> > Cheers,
> > Ben.
> >
> >
> >
> 
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