On Fri, Jul 11, 2014 at 8:11 AM, Catalin Marinas
[off-list ref] wrote:

On Thu, Jul 10, 2014 at 11:36:10PM +0100, Bjorn Helgaas wrote:

quoted

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?

Bjorn