On Thu, Feb 9, 2012 at 6:36 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > There's a lot of PCI-related code under arch/, but much of it is not actually > architecture-specific. This series removes some of that code by moving most > of the bus-to-resource conversions into the core. > > We currently read PCI bus addresses from BARs in the core (pci_setup_device()). > Then every arch is responsible for converting those bus addresses to CPU > resources, usually in pcibios_fixup_bus(). > > We already have a way for architectures to tell the core what the windows > through a host bridge are: > > LIST_HEAD(resources); > pci_add_resource(&resources, io_space); > pci_add_resource(&resources, mem_space); > pci_scan_root_bus(parent, bus, ops, sysdata, &resources); > > This series extends that so the arch can also tell the core about address > translation performed by the host bridge: > > LIST_HEAD(resources); > pci_add_resource_offset(&resources, io_space, io_offset); > pci_add_resource_offset(&resources, mem_space, mem_offset); > pci_scan_root_bus(parent, bus, ops, sysdata, &resources); > > Given that offset (the difference between bus address and CPU address for > each aperture), the core can do the bus-to-resource conversion immediately > when it reads the BARs. > > This removes an opportunity for bugs (some PCI fixups currently see bus > addresses in struct pci_dev resources when they're expecting CPU addresses), > but the main reason to do this is to make our PCI resource handling simpler > and more uniform. > > These patches are also available in this git repo: > git://github.com/bjorn-helgaas/linux.git pci-offset-v2-d15af52258dd > > Or you can browse them here: > https://github.com/bjorn-helgaas/linux/compare/master...pci-offset-v2-d15af52258dd > > I'd like to get these into linux-next soon to be ready for the 3.4 merge > window, so please let me know if you see any issues. > > Changes since v1: > - mips: remove Cobalt legacy IDE fixup > - show bus address range, not offset, e.g., this: > pci_bus 0000:00: root bus resource [mem 0xf0000000000-0xf007edfffff] (bus address [0x80000000-0xfedfffff]) > instead of this: > pci_bus 0000:00: root bus resource [mem 0xf0000000000-0xf007edfffff] (bus offset 0xeff80000000) > still think make pci_sysdata to generic and add one offset field to that would be more simple. Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
