On Tue, Oct 08, 2013 at 05:32:57PM +0100, Bjorn Helgaas wrote:
> [+cc Grant, Rob, devicetree list]
>
> On Tue, Oct 8, 2013 at 8:42 AM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote:
> > Hello,
> >
> > I am working on adding PCIe support for a new architecture and looking
> > at various existing implementations of pcibios functions I've realised
> > that some architectures share a lot of common code. As I don't like to
> > repeat the pattern again without any good reasons, I am wondering if
> > there is any appetite for carving out those common functions into
> > a generic place under drivers/pci/pcibios.c where they can be reused.
> >
> > Things that I am specifically looking at are pcibios_{alloc,free}_controller,
> > pci_process_bridge_OF_ranges and anything that will make adding support
> > for PCI/PCIe in a new architecture easier. Candidates for promoting
> > to a generic place are the functions found in both powerpc and microblaze
> > as they seem to be mostly identical, they support DT bindings and are
> > 64bits ready.
>
> I'm very much in favor of unifying code to reduce duplication across
> architectures.
>
> In general, the pcibios_*() interfaces are things used by the PCI core
> (drivers/pci) but implemented by the architecture. The specific cases
> you mentioned are not actually used by the PCI core, so my inclination
> would be to name them something else and possibly put them somewhere
> other than drivers/pci.
There are at least a handful of architectures that seem to share the same
implementation for most (all?) of the pcibios_*() functions. (PowerPC and
microblaze the most obvious offenders, x86 to a certain extent).
>
> 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.
Andrew Murray did sent a patch that was placing pci_process_bridge_OF_ranges()
in the drivers/of. I can update that, as I have taken over his work.
>
> pcibios_alloc_controller() is implemented by microblaze, powerpc, and
> xtensa. Each of those arches defines its own "struct pci_controller",
> so it won't be completely trivial to unify this. I tried to start
> some unification with the "struct pci_host_bridge" in the core, but
> haven't made much progress there.
Do you have anything that you could share? I would pretty much like to take
on that as well, as I don't want to create yet another
"struct pci_controller." BTW, powerpc and microblaze again share a very
similarly looking structure.
Best regards,
Liviu
>
> Bjorn
>
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
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