On Tue, Mar 10, 2015 at 09:47:37PM -0500, Bjorn Helgaas wrote: >On Mon, Mar 02, 2015 at 03:50:37PM +0800, Wei Yang wrote: >> On Tue, Feb 24, 2015 at 02:46:53AM -0600, Bjorn Helgaas wrote: >> >On Tue, Feb 24, 2015 at 02:34:35AM -0600, Bjorn Helgaas wrote: >> >> From: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx> >> >> >> >> Current iommu_table of a PE is a static field. This will have a problem >> >> when iommu_free_table() is called. >> >> >> >> Allocate iommu_table dynamically. >> > >> >I'd like a little more explanation about why we're calling >> >iommu_free_table() now when we didn't call it before. Maybe this happens >> >when we disable SR-IOV and the VFs go away? >> >> Yes, it is called in disable path. >> >> pcibios_sriov_disable >> pnv_pci_sriov_disable >> pnv_ioda_release_vf_PE >> pnv_pci_ioda2_release_dma_pe >> iommu_free_table <--- here it is invoked >> >> >> > >> >Is there a hotplug remove path where we should also be calling >> >iommu_free_table()? >> >> When VF is not introduced, no one calls this on powernv platform. >> >> Each PCI bus is a PE and it has its own iommu table, even a device is >> hotpluged, the iommu table will not be released. > >None of this explanation made it into the v13 patch. And I don't quite >understand it anyway. > >Something like "Previously the iommu_table had the same lifetime as a >struct pnv_ioda_pe and was embedded in it. The pnv_ioda_pe was allocated >when XXX and freed when YYY. This no longer works: we can't allocate the >iommu_table at the same time as the pnv_ioda_pe because XXX, so we allocate >it when XXX and free it when YYY." Got it, I have put the explanation in change log in next version. > >Bjorn >_______________________________________________ >Linuxppc-dev mailing list >Linuxppc-dev@xxxxxxxxxxxxxxxx >https://lists.ozlabs.org/listinfo/linuxppc-dev -- Richard Yang Help you, Help me -- 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
