[+cc David] I forgot to mention that I'm also hoping for an ack from David, since he's listed as the maintainer of the ThunderX drivers. On Mon, Apr 03, 2017 at 01:15:02PM +0000, Jayachandran C wrote: > Hi Bjorn, Alex, > > Sending this again (with a trivial fix to author name), please review. > Updated summary below: > > Here is v4 of the patchset to handle the PCIe topology quirk of Cavium > ThunderX2 systems (previously known as Broadcom Vulcan). > > The earlier discussions on this can be seen at: > http://www.spinics.net/lists/linux-pci/msg51001.html > https://patchwork.ozlabs.org/patch/582633/ and > https://lists.linuxfoundation.org/pipermail/iommu/2016-June/017681.html > > The earlier discussion on this patchset ended with a suggestion that it > may be possible to fix up this quirk by handling the issue in the > function argument of pci_for_each_dma_alias(). But at that point we did > not have the codebase to make the changes since the full ACPI and OF code > for SMMU and GIC ITS was not upstream. > > Now that the changes are upstream, I tried to fix it in both the SMMU > and the GIC ITS code based on this suggestion, the changes needed are at: > https://github.com/jchandra-cavm/linux/commits/rid-xlate-fixup > > The problems with this approach are: > - of the 14 uses of pci_for_each_dma_alias in the function in the kernel > tree, I have to fixup 6 callers (which is all but one ofthe callers > outside x86) > - 4 of these can be reasonably handled (please see the github repo above), > but the calls in drivers/irqchip/irq-gic-v3-its-pci-msi.c and > drivers/iommu/iommu.c cannot be reasonably fixed up. > - Even without the 2 above two changes I can get it to work for now. > But pci_for_each_dma_alias does not work as expected on this platform > and we have to be aware of that for all future uses of the function. > > For now, I have ruled out the approach, and I have rebased the earlier > patch on to 4.11-rc and submitting again for review. The changes are: > > v3->v4: > - new address of author > > v2>v3: > - changed device flag name from PCI_DEV_FLAGS_DMA_ALIAS_ROOT to > PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT > - updated commit message to make the quirk clearer. > > Let me know your comments and suggestions. > > Thanks, > JC. > > > Jayachandran C (2): > PCI: Add device flag PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT > PCI: quirks: Fix ThunderX2 dma alias handling > > drivers/pci/quirks.c | 14 ++++++++++++++ > drivers/pci/search.c | 4 ++++ > include/linux/pci.h | 2 ++ > 3 files changed, 20 insertions(+) > > -- > 2.7.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
