From e2413a7dae52fab290b7a8d11ec8579657bab95b Mon Sep 17 00:00:00 2001 From: Tyrel Datwyler Date: Mon, 11 Jul 2016 17:16:27 -0500 Subject: [PATCH] PCI: rpaphp: Fix slot registration for multiple slots under a PHB 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: Tyrel Datwyler Reviewed-by: Nathan Fontenot [mpe: Massage changelog] Signed-off-by: Michael Ellerman --- drivers/pci/hotplug/rpaphp_slot.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/pci/hotplug/rpaphp_slot.c b/drivers/pci/hotplug/rpaphp_slot.c index 6937c725b00b..388c4d8fcdd1 100644 --- a/drivers/pci/hotplug/rpaphp_slot.c +++ b/drivers/pci/hotplug/rpaphp_slot.c @@ -117,8 +117,10 @@ EXPORT_SYMBOL_GPL(rpaphp_deregister_slot); int rpaphp_register_slot(struct slot *slot) { struct hotplug_slot *php_slot = slot->hotplug_slot; + struct device_node *child; + u32 my_index; int retval; - int slotno; + int slotno = -1; dbg("%s registering slot:path[%s] index[%x], name[%s] pdomain[%x] type[%d]\n", __func__, slot->dn->full_name, slot->index, slot->name, @@ -130,10 +132,15 @@ int rpaphp_register_slot(struct slot *slot) return -EAGAIN; } - if (slot->dn->child) - slotno = PCI_SLOT(PCI_DN(slot->dn->child)->devfn); - else - slotno = -1; + for_each_child_of_node(slot->dn, child) { + retval = of_property_read_u32(child, "ibm,my-drc-index", &my_index); + if (my_index == slot->index) { + slotno = PCI_SLOT(PCI_DN(child)->devfn); + of_node_put(child); + break; + } + } + retval = pci_hp_register(php_slot, slot->bus, slotno, slot->name); if (retval) { err("pci_hp_register failed with error %d\n", retval); -- 2.30.2