PCI: Allow additional bus numbers for hotplug bridges
A user may hot add a switch requiring more than one bus to enumerate. This
previously required a system reboot if BIOS did not sufficiently pad the
bus resource, which they frequently don't do.
Add a kernel parameter so a user can specify the minimum number of bus
numbers to reserve for a hotplug bridge's subordinate buses so rebooting
won't be necessary.
The default is 1, which is equivalent to previous behavior.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b67e4df..0c28325 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1706,6 +1706,7 @@
extern unsigned long pci_hotplug_io_size;
extern unsigned long pci_hotplug_mem_size;
+extern unsigned long pci_hotplug_bus_size;
/* Architecture-specific versions may override these (weak) */
void pcibios_disable_device(struct pci_dev *dev);