On Thu, Jul 10, 2014 at 3:47 AM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: > I don't see a way out of adding new PCI interfaces if we want to have support in > the PCI framework for unifying existing architectures. Of course, there is the painful > alternative of changing the existing APIs and fixing arches in one go, but like you've > said is going to be messy. I don't think I (or the people and companies wanting PCIe > on arm64) should cop out and pick a quick fix that adds sysdata structure into arm64 > just to avoid new APIs, as this is not going to help anyone in long term. What I can > do is to create a set of parallel APIs for pci_{scan,create}_root_bus() that take > a pci_host_bridge pointer and start converting architectures one by one to that API > while deprecating the existing one. That way we can add arm64 easily as it would be > the first architecture to use new code without breaking things *and* we provide a > migration path. A lot of the v7 discussion was about pci_register_io_range(). I apologize, because I think I really derailed things there and it was unwarranted. Arnd was right that migrating other arches should be a separate effort. I *think* I was probably thinking about the proposal of adding pci_create_root_bus_in_domain(), and my reservations about that got transferred to the pci_register_io_range() discussion. In any case, I'm completely fine with pci_register_io_range() now. 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 haven't followed closely enough to know what other objections people had. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html