powerpc/pseries: extract host bridge from pci_bus prior to bus removal

The pci_bus->bridge reference may no longer be valid after
pci_bus_remove() resulting in passing a bad value to device_unregister()
for the associated bridge device.

Store the host_bridge reference in a separate variable prior to
pci_bus_remove().

Fixes: 7340056567e3 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210211182435.47968-1-tyreld@linux.ibm.com

diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
index f9ae17e..a8f9140 100644 (file)
--- a/arch/powerpc/platforms/pseries/pci_dlpar.c
+++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
@@ -50,6 +50,7 @@ EXPORT_SYMBOL_GPL(init_phb_dynamic);
 int remove_phb_dynamic(struct pci_controller *phb)
 {
        struct pci_bus *b = phb->bus;
+       struct pci_host_bridge *host_bridge = to_pci_host_bridge(b->bridge);
        struct resource *res;
        int rc, i;
 
@@ -76,7 +77,8 @@ int remove_phb_dynamic(struct pci_controller *phb)
        /* Remove the PCI bus and unregister the bridge device from sysfs */
        phb->bus = NULL;
        pci_remove_bus(b);
-       device_unregister(b->bridge);
+       host_bridge->bus = NULL;
+       device_unregister(&host_bridge->dev);
 
        /* Now release the IO resource */
        if (res->flags & IORESOURCE_IO)