| Message ID | 20190311133122.11417-21-s.miroshnichenko@yadro.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Allow BAR movement during hotplug | expand |
On Mon, Mar 11, 2019 at 04:31:21PM +0300, Sergey Miroshnichenko wrote: > With movable BARs, adding a hotplugged device may affect all the PCIe > domain starting from the root, so use a pci_rescan_bus() function which > handles the rearrangement of existing BARs and bridge windows. > > Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com> > --- > drivers/pci/hotplug/pciehp_pci.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c > index b9c1396db6fe..7c0871db5bae 100644 > --- a/drivers/pci/hotplug/pciehp_pci.c > +++ b/drivers/pci/hotplug/pciehp_pci.c > @@ -56,12 +56,16 @@ int pciehp_configure_device(struct controller *ctrl) > goto out; > } > > - for_each_pci_bridge(dev, parent) > - pci_hp_add_bridge(dev); > + if (pci_movable_bars_enabled()) { > + pci_rescan_bus(parent); > + } else { > + for_each_pci_bridge(dev, parent) > + pci_hp_add_bridge(dev); > > - pci_assign_unassigned_bridge_resources(bridge); > - pcie_bus_configure_settings(parent); > - pci_bus_add_devices(parent); > + pci_assign_unassigned_bridge_resources(bridge); > + pcie_bus_configure_settings(parent); > + pci_bus_add_devices(parent); > + } The addition of a second path at this level, i.e., different paths depending on whether movable BARs are enabled, seems a little problematic because it's hard to determine whether they're equivalent except for the movable BAR aspect. For example, you don't call pci_hp_add_bridge() when movable BARs are enabled, and I can't tell whether that's intentional or whether it's a problem. This looks like the sort of change that should be made in other hotplug paths, e.g., enable_slot() for acpiphp, pcibios_finish_adding_to_bus() for powerpc (maybe? I can't really tell), cpci_configure_slot() shpchp_configure_device()? If we have or could invent some top-level interface that all these places could use, and somewhere inside that we could do the movable BAR magic, I think that would make it more maintainable. > out: > pci_unlock_rescan_remove(); > -- > 2.20.1 >
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c index b9c1396db6fe..7c0871db5bae 100644 --- a/drivers/pci/hotplug/pciehp_pci.c +++ b/drivers/pci/hotplug/pciehp_pci.c @@ -56,12 +56,16 @@ int pciehp_configure_device(struct controller *ctrl) goto out; } - for_each_pci_bridge(dev, parent) - pci_hp_add_bridge(dev); + if (pci_movable_bars_enabled()) { + pci_rescan_bus(parent); + } else { + for_each_pci_bridge(dev, parent) + pci_hp_add_bridge(dev); - pci_assign_unassigned_bridge_resources(bridge); - pcie_bus_configure_settings(parent); - pci_bus_add_devices(parent); + pci_assign_unassigned_bridge_resources(bridge); + pcie_bus_configure_settings(parent); + pci_bus_add_devices(parent); + } out: pci_unlock_rescan_remove();
With movable BARs, adding a hotplugged device may affect all the PCIe domain starting from the root, so use a pci_rescan_bus() function which handles the rearrangement of existing BARs and bridge windows. Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com> --- drivers/pci/hotplug/pciehp_pci.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)