On Wed, Apr 20, 2016 at 01:00:38PM +1000, Alexey Kardashevskiy wrote: >On 04/20/2016 11:12 AM, Gavin Shan wrote: >>On Tue, Apr 19, 2016 at 02:16:42PM +1000, Alexey Kardashevskiy wrote: >>>On 02/17/2016 02:44 PM, Gavin Shan wrote: >>>>Currently, the PEs and their associated resources are assigned >>>>in ppc_md.pcibios_fixup() except those used by SRIOV VFs. >>> >>>But this new code does not affect IOV and VF's PEs will still be created >>>somewhere else rather than pnv_pci_setup_bridge()? >>> >> >>Correct. VF PEs cannot be created in pnv_pci_setup_bridge() as the PF's >>IOV capability isn't enabled at that point. >> >>> >>>>The >>>>function is called for once after PCI probing and resources >>>>assignment is completed. So it isn't hotplug friendly. >>>> >>>>This creates PEs dynamically by ppc_md.pcibios_setup_bridge(), which >>>>is called on the event during system bootup and PCI hotplug: updating >>>>PCI bridge's windows after resource assignment/reassignment are done. >>>>For partial hotplug case, where not all PCI devices belonging to the >>>>PE are unplugged and plugged again, we just need unbinding/binding >>>>the affected PCI devices with the corresponding PE without creating >>>>new one. >>>> >>>>As there is no upstream bridge for root bus that needs to be covered >>>>by PE, we have to create PE for root bus in ppc_md.pcibios_setup_bridge() >>>>before any other PEs can be created, as PE for root bus is the ancestor >>>>to anyone else. >>> >>>We did not need a root bus PE before? What is the other PE reserved for? >>>Comments only say "reserved"... >>> >> >>No, A PE for root bus is needed before. > >Ok. We needed a PE for the root bus and we need it now. What changed? Why do >you reserve another PE? > Originally, all PEs (include the one for root bus) were created at PHB fixup time in pnv_pci_ioda_fixup(). With this patch, all PEs are created in pnv_pci_setup_bridge(). pnv_pci_setup_bridge() is called for every PCI buses other than root bus. It means pnv_pci_setup_bridge() isn't called for root bus. So we have to create PE for root bus before the left PEs are created there. The PE# for root bus is reserved in advance and used in pnv_pci_setup_bridge() at that point. > >> >other PEs can be for the PCI bus >>originated from root port and the subordinate domains. >> >>>> >>>>Also, the windows of root port or the upstream port of PCIe switch behind >>>>root port are extended to be PHB's apertures to accommodate the additional >>>>resources needed by newly plugged devices based on the fact: hotpluggable >>>>slot is behind root port or downstream port of the PCIe switch behind >>>>root port. The extension for those PCI brdiges' windows is done in >>>>ppc_md.pcibios_setup_bridge() as well. >>> >>> >>>This patch seems to be doing way too many things, hard to follow. >>> >>>Could you please split the patch into smaller chunks? For example (you can do >>>it totally different): >>>- move pnv_pci_ioda_setup_opal_tce_kill() >>>- move PE creation from pnv_pci_ioda_fixup() to pnv_pci_setup_bridge(); >>>- add pnv_pci_fixup_bridge_resources() >>>- add an extra reserved PE for the root bus (and all this magic with >>>root_pe_idx/root_pe_populated) >>>- ... >>> >> >>I'll evaluate it later. It's always nice to have small patches. Thanks >>for the comments. >> >>> >>> >>> >>>-- >>>Alexey >>> >> >>-- >>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 >> > > >-- >Alexey > -- 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
