[PATCH] PCI Hotplug: PCI panic on dlpar add (add pci slot to running partition)

Removing and then adding a PCI slot to a running partition results in
a kernel panic. The current code attempts to add iospace for an entire
root bus, which is inappropriate, and silently fails.  When a pci device
tries to use the iospace, a page fault is taken, as the iospace had not
been mapped, and of course the page fault cannot be resolved.

This only occurs for PCI adapters using pio, which may be why it hadn't
been seen earlier (this seems to have been broken for a while).
This patch has survived testing of dozens of slot add and removes.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Acked-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index 7d93dbaf628deda9dc32811b5c0ed95c023ea500..7f504b380f2664a4030af967f3c086bd05853bc4 100644 (file)
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -152,7 +152,7 @@ static struct pci_dev *dlpar_pci_add_bus(struct device_node *dn)
        pcibios_claim_one_bus(dev->bus);
 
        /* ioremap() for child bus, which may or may not succeed */
-       (void) remap_bus_range(dev->bus);
+       remap_bus_range(dev->subordinate);
 
        /* Add new devices to global lists.  Register in proc, sysfs. */
        pci_bus_add_devices(phb->bus);