From e96e27fc6f7971380283768e9a734af16b1716ee Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 5 Sep 2022 11:02:30 +0300 Subject: [PATCH] PCI: Distribute available resources for root buses, too Previously we distributed spare resources only upon hot-add, so if the initial root bus scan found devices that had not been fully configured by the BIOS, we allocated only enough resources to cover what was then present. If some of those devices were hotplug bridges, we did not leave any additional resource space for future expansion. Distribute the available resources for root buses, too, to make this work the same way as the normal hotplug case. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216000 Link: https://lore.kernel.org/r/20220905080232.36087-5-mika.westerberg@linux.intel.com Reported-by: Chris Chiu Tested-by: Chris Chiu Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko --- drivers/pci/setup-bus.c | 62 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 3b981da0fb4e..df9fc974b313 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1768,7 +1768,10 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, } res->end = res->start + new_size - 1; - remove_from_list(add_list, res); + + /* If the resource is part of the add_list remove it now */ + if (add_list) + remove_from_list(add_list, res); } static void pci_bus_distribute_available_resources(struct pci_bus *bus, @@ -1923,6 +1926,8 @@ static void pci_bridge_distribute_available_resources(struct pci_dev *bridge, if (!bridge->is_hotplug_bridge) return; + pci_dbg(bridge, "distributing available resources\n"); + /* Take the initial extra resources from the hotplug port */ available_io = bridge->resource[PCI_BRIDGE_IO_WINDOW]; available_mmio = bridge->resource[PCI_BRIDGE_MEM_WINDOW]; @@ -1934,6 +1939,59 @@ static void pci_bridge_distribute_available_resources(struct pci_dev *bridge, available_mmio_pref); } +static bool pci_bridge_resources_not_assigned(struct pci_dev *dev) +{ + const struct resource *r; + + /* + * Check the child device's resources and if they are not yet + * assigned it means we are configuring them (not the boot + * firmware) so we should be able to extend the upstream + * bridge's (that's the hotplug downstream PCIe port) resources + * in the same way we do with the normal hotplug case. + */ + r = &dev->resource[PCI_BRIDGE_IO_WINDOW]; + if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN)) + return false; + r = &dev->resource[PCI_BRIDGE_MEM_WINDOW]; + if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN)) + return false; + r = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW]; + if (!r->flags || !(r->flags & IORESOURCE_STARTALIGN)) + return false; + + return true; +} + +static void pci_root_bus_distribute_available_resources(struct pci_bus *bus, + struct list_head *add_list) +{ + struct pci_dev *dev, *bridge = bus->self; + + for_each_pci_bridge(dev, bus) { + struct pci_bus *b; + + b = dev->subordinate; + if (!b) + continue; + + /* + * Need to check "bridge" here too because it is NULL + * in case of root bus. + */ + if (bridge && pci_bridge_resources_not_assigned(dev)) { + pci_bridge_distribute_available_resources(bridge, add_list); + /* + * There is only PCIe upstream port on the bus + * so we don't need to go futher. + */ + return; + } + + pci_root_bus_distribute_available_resources(b, add_list); + } +} + /* * First try will not touch PCI bridge res. * Second and later try will clear small leaf bridge res. @@ -1973,6 +2031,8 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus) */ __pci_bus_size_bridges(bus, add_list); + pci_root_bus_distribute_available_resources(bus, add_list); + /* Depth last, allocate resources and update the hardware. */ __pci_bus_assign_resources(bus, add_list, &fail_head); if (add_list)