On Thu, Oct 22, 2015 at 02:47:42PM +1100, Benjamin Herrenschmidt wrote: > On Wed, 2015-10-21 at 18:27 -0700, David Miller wrote: > > From: Yinghai Lu <yinghai@xxxxxxxxxx> > > Date: Wed, 21 Oct 2015 11:16:53 -0700 > > > > > otherwise we need to compare res with pbm->mem_space or pbm > > ->mem64_space > > > to get direct parent for request_resource_conflict() calling in > > > pci_register_legacy_regions(). > > > > Right, this is the issue. > > > > On sparc64, the cpu physical base address used for accessing 64-bit > > and non-64-bit memory spaces is different. > > > > And that's why the resource values will be different. > > This is the same on power btw, we have separate PowerBus windows to the > PHB that get mapped respectively to 32-bit PCI MMIO and 64-bit PCI > MMIO. The former gets "remapped" to generates 0-based PCI cycles, while > the latter is 1:1. So the offset between CPU and PCI changes depending > on which window you hit. Lots of architectures do this, and the PCI core supports it by keeping a list of all the host bridge windows. Each entry has a struct resource that contains the CPU address, as well as the offset from the CPU address to the PCI address. The arch or host bridge driver uses pci_add_resource_offset() to tell the core about the window and the offset. Bjorn -- 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
