On Tue, Jul 17, 2012 at 11:14:51AM -0600, Bjorn Helgaas wrote: > On Tue, Jul 17, 2012 at 4:38 AM, Benjamin Herrenschmidt > <benh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 2012-07-17 at 18:03 +0800, Ram Pai wrote: > >> Lets say we passed that 'type' flag to size the minimum > >> alignment constraints for that b_res. And window_alignment(bus, > >> type) of your platform used that 'type' information to > >> determine whether to use the alignment constraints of 32-bit > >> window or 64-bit window. > >> > >> However, later when the b_res is actually allocated a resource, > >> the pci_assign_resource() has no idea whether to allocate 32-bit > >> window resource or 64-bit window resource, because the 'type' > >> information is not captured anywhere in b_res. > >> > >> You would basically have a disconnect between what is sized and > >> what is allocated. Unless offcourse you pass that 'type' to > >> the b_res->flags, which is currently not the case. > > > > Right, we ideally would need the core to query the alignment once per > > "apertures" it tries as a candidate to allocate a given resource... but > > that's for later. > > > > For now we can probably live with giving out the max of the minimum > > alignment we support for M64 and our M32 segment size. > > We already know the aperture we're proposing to allocate from (the > result of find_free_bus_resource()), don't we? What if we passed it > to pcibios_window_alignment() along with the struct pci_bus *, e.g.: > > resource_size_t pcibios_window_alignment(struct pci_bus *bus, struct > resource *window) Hmm..'struct resource *window' may not yet know which aperature it is allocated from. Will it? We are still in the sizing process, the allocation will be done much later. RP -- 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
