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PCI: Make rescan bus increase bridge resource size if needed

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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 <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Yinghai Lu 2012-01-21 02:08:22 -08:00 committed by Jesse Barnes
parent 8424d7592e
commit 2f320521a0
3 changed files with 30 additions and 1 deletions
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5
drivers/pci/pci-sysfs.c
View File

@ -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;

25
drivers/pci/probe.c
View File

@ -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

1
include/linux/pci.h
View File

@ -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