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 <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index a3cd8ca..d972303 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -366,7 +366,10 @@
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 71eac9c..0e84e8c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1667,6 +1667,31 @@
#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 f442760..87507aa 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -882,6 +882,7 @@
/* 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