I'm trying to understand PCI I/O addressing in the kernel... (again) I understand that ideally you want to give PCI bus addresses to PCI devices in the range of 0K to 64K. This seems to be achieved in pcibios_init_resources in arm's kernel/bios32.c implementation. What happens if you want to add another root bus? In this implementation the start address of the io_res is now 64K and as sys->io_offset is set to 0 the bus addresses under this second root bus will be 64K-128K - which I assume may break some things. Am I correct that for ARM there are no implementations where subsequent root buses allocate I/O starting from 0? And to allow subsequent busses to use I/O starting from 0, you'd have to set sys->io_offset to 64K*nr and adapt functions such as pci_iomap to use the offset? Are there any other archiectures that do give I/O ranges starting from 0 in subsequent root busses? Or am I missing something here? Andrew Murray -- 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
