On Tue, 07 Aug 2007 18:20:12 +0300, Scott Wood <[EMAIL PROTECTED]> wrote:
> Alexandros Kostopoulos wrote: >> Except from some macros arch/powerpc/include/asm/io.h / mpc8260_pci9.h, >> I can seem to find anywhere the code regarding PCI Erratum 9. The >> defined macros(in io.h) for read/write are sufficient as a workaround >> for PCI9? Who does DMA and register initialization for this (it used >> to be done in arch/ppc/syslib/m8260_pci_erratum9.c in arc/ppc). Maybe >> u-boot or the bootwrapper? > > I don't think the workaround exists yet in arch/powerpc, despite the > config option. > Is there a plan to be implemented on arch/powerpc, or devices with the erratum will have to keep on using the legacy arch/ppc code? >> Another question regarding resource allocation: when >> alloc_resource(pci_32.c), called from pcibios_allocate_resources(), >> during pcibios init, attempts to allocate resources using >> request_resource(), the request fails. This seems to happen because >> the previously scanned PCI devices request resources in the form, e.g. >> 00000- 0000f (i.e. starting from zero), and this should be mapped >> somewhere else in cpu mem space. My question (in order to find my bug) >> is, who performs this mapping, from PCI space to CPU space, the kernel >> (and if yes, where?) or the host bridge (in which case, I've probably >> failed to configure it properly). > > If the error message is the one I'm thinking of (it always helps to post > the actual messages), that's normal for when the PCI bus hasn't been > probed by the firmware. Linux first tries to use the BARs as they're > already set, which will obviously fail because they haven't been set, > and then it will properly allocated them. It's harmless verbosity, > though it'd be nice to have a flag to tell the PCI layer to not bother > trying to preserve any existing BARs. > Well, the error message is: PCI:0000:00:16.0: Resource 0: 0000000000000000-0000000000000fff (f=200) PCI: Cannot allocate resource region 0 of device 0000:00:16.0 PCI: parent is c03c4058: 0000000080000000-00000000bfffffff (f=200) The thing is, POBARs are already setup by uboot. However the resource allocation for the PCI devices (not the host bridge) fails in request_resource (which seems to use the region requested by the device as is and not some mapped region in the cpu address space), and I can not find where in the code happens the mapping from PCI to local bus mem region. I mean, each PCI device requests some region, e.g. from 0000-00ff and this is mapped to some region in the PCI outbound window, right. For some reason this fails in my case, and I cannot find where in the code this mapping should happen. Thank you for your help Alex > -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
