From 2f320521a0d2d11fb857be09d05e2fbbf3ef8c13 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 21 Jan 2012 02:08:22 -0800 Subject: [PATCH] PCI: Make rescan bus increase bridge resource size if needed Current rescan will not touch bridge MMIO and IO. Try to reuse pci_assign_unassigned_bridge_resources(bridge) to update bridge resources, if child devices need more resources. Only do that for bridges whose children are all removed already; i.e. don't release resources that could already be in use by drivers on child devices. Signed-off-by: Yinghai Lu Signed-off-by: Jesse Barnes --- drivers/pci/pci-sysfs.c | 5 ++++- drivers/pci/probe.c | 25 +++++++++++++++++++++++++ include/linux/pci.h | 1 + 3 files changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index a3cd8cad532..d9723039e99 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -366,7 +366,10 @@ dev_bus_rescan_store(struct device *dev, struct device_attribute *attr, if (val) { mutex_lock(&pci_remove_rescan_mutex); - pci_rescan_bus(bus); + if (!pci_is_root_bus(bus) && list_empty(&bus->devices)) + pci_rescan_bus_bridge_resize(bus->self); + else + pci_rescan_bus(bus); mutex_unlock(&pci_remove_rescan_mutex); } return count; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 71eac9cd724..0e84e8c2a6d 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1666,6 +1666,31 @@ struct pci_bus * __devinit pci_scan_bus(int bus, struct pci_ops *ops, EXPORT_SYMBOL(pci_scan_bus); #ifdef CONFIG_HOTPLUG +/** + * pci_rescan_bus_bridge_resize - scan a PCI bus for devices. + * @bridge: PCI bridge for the bus to scan + * + * Scan a PCI bus and child buses for new devices, add them, + * and enable them, resizing bridge mmio/io resource if necessary + * and possible. The caller must ensure the child devices are already + * removed for resizing to occur. + * + * Returns the max number of subordinate bus discovered. + */ +unsigned int __ref pci_rescan_bus_bridge_resize(struct pci_dev *bridge) +{ + unsigned int max; + struct pci_bus *bus = bridge->subordinate; + + max = pci_scan_child_bus(bus); + + pci_assign_unassigned_bridge_resources(bridge); + + pci_bus_add_devices(bus); + + return max; +} + /** * pci_rescan_bus - scan a PCI bus for devices. * @bus: PCI bus to scan diff --git a/include/linux/pci.h b/include/linux/pci.h index f44276049f4..87507aadf9a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -882,6 +882,7 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev); /* Functions for PCI Hotplug drivers to use */ int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap); #ifdef CONFIG_HOTPLUG +unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge); unsigned int pci_rescan_bus(struct pci_bus *bus); #endif -- 2.20.1