• Tyrel Datwyler's avatar
    PCI: rpaphp: Fix slot registration for multiple slots under a PHB · e2413a7d
    Tyrel Datwyler authored
    The underlying slot hotplug registration code assumed multiple slots, but
    the actual implementation is broken for multiple slots.
    
    This went unnoticed for years do to the fact that PowerVM seems to only
    ever provide a single hotplug slot per PHB.
    
    Under qemu/kvm the hotplug slot model aligns more with x86 where
    multiple slots are presented under a single PHB. As seen in the
    following each additional slot after the first fails to register due to
    each slot always being compared against the first child node of the PHB
    in the device tree.
    
      rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1
      rpaphp: Slot [Slot 0] registered
      rpaphp: pci_hp_register failed with error -16
      rpaphp: pci_hp_register failed with error -16
      rpaphp: pci_hp_register failed with error -16
      rpaphp: pci_hp_register failed with error -16
    
    The registration logic is fixed so that each slot is compared
    against the existing child devices of the PHB in the device tree to
    determine present slots vs empty slots.
    
      rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1
      rpaphp: Slot [C0] registered
      rpaphp: Slot [C1] registered
      rpaphp: Slot [C2] registered
      rpaphp: Slot [C3] registered
      rpaphp: Slot [C4] registered
    Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.vnet.ibm.com>
    Reviewed-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
    [mpe: Massage changelog]
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    e2413a7d
rpaphp_slot.c 4.01 KB