On Fri, Jun 27, 2014 at 01:44:21AM +0100, Rob Herring wrote: > On Thu, Jun 26, 2014 at 3:59 AM, Catalin Marinas > <catalin.marinas@xxxxxxx> wrote: > > Although a bit late, I'm raising this now and hopefully we'll come to a > > conclusion soon. Delaying arm64 PCIe support even further is not a real > > option, which leaves us with: > > > > 1. Someone else (with enough PCIe knowledge) volunteering to take over > > soon or > > 2. Dropping Liviu's work and going for an arm64-specific implementation > > (most likely based on the arm32 implementation, see below) > > 3. Keeping Liviu's patches leaving some of the architecture specific > bits. I know Arnd and I both commented on it still needing more common > pieces, but compared to option 2 that would be way better. > > Let's look at the patches in question: > > 3e71867 pci: Introduce pci_register_io_range() helper function. > 6681dff pci: OF: Fix the conversion of IO ranges into IO resources. > > Both OF patches. I'll happily merge them. We just need to make sure they don't break other users of of_pci_range_to_resource() that the second patch introduces. > 2d5dd85 pci: Create pci_host_bridge before its associated bus in > pci_create_root_bus. > f6f2854 pci: Introduce a domain number for pci_host_bridge. > 524a9f5 pci: Export find_pci_host_bridge() function. > > These don't seem to be too controversial. I think here there were discussions around introducing domain_nr to pci_host_bridge, particularly to the pci_create_root_bus_in_domain() API change. I don't think we reached any conclusion. > fb75718 pci: of: Parse and map the IRQ when adding the PCI device. > > 6 LOC. Hardly controversial. I agree. > 920a685 pci: Add support for creating a generic host_bridge from device tree > > This function could be moved to drivers/of/of_pci.c if having it in > drivers/pci is too much maintenance burden. I think it makes sense. Currently drivers/pci/host-bridge.c doesn't have anything OF related, so of_pci.c looks more appropriate. > However, nearly the same > code is already being duplicated in every DT enabled ARM PCI host > driver and will continue as more PCI hosts are added. So this isn't > really a question of converting other architectures to common PCI host > infrastructure, but converting DT based PCI hosts to common > infrastructure. ARM is the only arch moving host drivers to > drivers/pci ATM. Until other architectures start doing that, > converting them is pointless. I agree. It's probably more important to convert some of the drivers/pci/host implementations to using the common parsing rather than a new architecture (this way we avoid even more code duplication). > bcf5c10 Fix ioport_map() for !CONFIG_GENERIC_IOMAP cases. > > Seems like an independent fix that should be applied regardless. Indeed. But it got stuck at the top of this series and hasn't been pushed upstream. > 7cfde80 arm64: Add architecture support for PCI > > What is here is really just a function of which option we pick. With Liviu's latest version (not posted) and with of_create_pci_host_bridge() function moved to of_pci.c, I don't think there is much new functionality added to drivers/pci/. What I think we need is clarifying the domain_nr patch (and API change) and more users of the new generic code. As you said, it doesn't need to be a separate architecture but rather existing pci host drivers under drivers/pci. Of course, other arch conversion should follow shortly as well but even without an immediate conversion, I don't see too much additional maintenance burden for the core PCIe code (and code sharing between new PCIe host drivers is even more beneficial). -- Catalin -- 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
