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

[ Upstream commit 38d0b1c9cec71e6d0f3bddef0bbce41d05a3e796 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
index 561917fa54a8a0cb86a880ebcede34a2fdd460e7..afca4b737e80fd27222a169263840e73c05c1ec7 100644 (file)
--- a/arch/powerpc/platforms/pseries/pci_dlpar.c
+++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
@@ -66,6 +66,7 @@ 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;
 
@@ -92,7 +93,8 @@ 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)