Commit 2f320521 authored by Yinghai Lu's avatar Yinghai Lu Committed by Jesse Barnes
Browse files

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: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 8424d759

drivers/pci/pci-sysfs.c

+4 −1
Original line number Diff line number Diff line
@@ -366,6 +366,9 @@ dev_bus_rescan_store(struct device *dev, struct device_attribute *attr, 


	if (val) {

		mutex_lock(&pci_remove_rescan_mutex);

		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);

	}

drivers/pci/probe.c

+25 −0
Original line number Diff line number Diff line
@@ -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

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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

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