Re: [PATCH v8 6/9] pci: Introduce a domain number for pci_host_bridge.

From: Bjorn Helgaas
Date: Fri Jul 11 2014 - 13:03:22 EST

On Fri, Jul 11, 2014 at 8:11 AM, Catalin Marinas
<catalin.marinas@xxxxxxx> wrote:
> On Thu, Jul 10, 2014 at 11:36:10PM +0100, Bjorn Helgaas wrote:
>> Most of the rest of the v7 discussion was about "Introduce a domain
>> number for pci_host_bridge." I think we should add arm64 using the
>> existing pci_scan_root_bus() and keep the domain number in the arm64
>> sysdata structure like every other arch does. Isn't that feasible?
>> We can worry about domain unification later.
> I think that's what we were trying to avoid, adding an arm64-specific
> pci_sys_data structure (and arm64-specific API). IIUC, avoiding this
> would allow the host controller drivers to use the sysdata pointer for
> their own private data structures.
> Also since you can specify the domain number via DT (and in Liviu's
> v8 patches read by of_create_pci_host_bridge), I think it would make
> sense to have it stored in some generic data structures (e.g.
> pci_host_bridge) rather than in an arm64 private sysdata.

It would definitely be nice to keep the domain in a generic data
structure rather than an arm64-specific one. But every other arch
keeps it in an arch-specific structure today, and I think following
that existing pattern is the quickest way forward.

But you mentioned arm64-specific API, too. What do you have in mind
there? I know there will be arm64 implementations of various
pcibios_*() functions (just like for every other arch), but it sounds
like there might be something else?

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