On Mon, Apr 7, 2014 at 4:07 AM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: > On Mon, Apr 07, 2014 at 10:14:18AM +0100, Benjamin Herrenschmidt wrote: >> On Mon, 2014-04-07 at 09:46 +0100, Liviu Dudau wrote: >> > >> > *My* strategy is to get rid of pci_domain_nr(). I don't see why we need >> > to have arch specific way of providing the number, specially after looking >> > at the existing implementations that return a value from a variable that >> > is never touched or incremented. My guess is that pci_domain_nr() was >> > created to work around the fact that there was no domain_nr maintainance in >> > the generic code. >> >> Well, there was no generic host bridge structure. There is one now, it should >> go there. > > Exactly! Hence my patch. After it gets accepted I will go through architectures > and remove their version of pci_domain_nr(). Currently the arch has to supply pci_domain_nr() because that's the only way for the generic code to learn the domain. After you add pci_create_root_bus_in_domain(), the arch can supply the domain that way, and we won't need the arch-specific pci_domain_nr(). Right? That makes more sense to me; thanks for the explanation. Let me try to explain my concern about the pci_create_root_bus_in_domain() interface. We currently have these interfaces: pci_scan_root_bus() pci_scan_bus() pci_scan_bus_parented() pci_create_root_bus() pci_scan_root_bus() is a higher-level interface than pci_create_root_bus(), so I'm trying to migrate toward it because it lets us remove a little code from the arch, e.g., pci_scan_child_bus() and pci_bus_add_devices(). I think we can only remove the arch-specific pci_domain_nr() if that arch uses pci_create_root_bus_in_domain(). When we convert an arch from using scan_bus interfaces to using pci_create_root_bus_in_domain(), we will have to move the rest of the scan_bus code (pci_scan_child_bus(), pci_bus_add_devices()) back into the arch code. One alternative is to add an _in_domain() variant of each of these interfaces, but that doesn't seem very convenient either. My idea of passing in a structure would also require adding variants, so there's not really an advantage there, but I am thinking of the next unification effort, e.g., for NUMA node info. I don't really want to have to change all the _in_domain() interfaces to also take yet another parameter for the node number. Bjorn -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
