From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43720 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756172AbcGHXT6 (ORCPT ); Fri, 8 Jul 2016 19:19:58 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u68NJI0I100253 for ; Fri, 8 Jul 2016 19:19:57 -0400 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2415xpddqr-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 08 Jul 2016 19:19:57 -0400 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 8 Jul 2016 17:19:56 -0600 From: Tyrel Datwyler To: linux-pci@vger.kernel.org Cc: bhelgaas@google.com, mpe@ellerman.id.au, benh@kernel.crashing.org, nfont@linux.vnet.ibm.com, mdroth@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Tyrel Datwyler Subject: [PATCH] rpaphp: fix slot registration for multiple slots under a PHB Date: Fri, 8 Jul 2016 18:19:47 -0500 Message-Id: <1468019987-1733-1-git-send-email-tyreld@linux.vnet.ibm.com> Sender: linux-pci-owner@vger.kernel.org List-ID: PowerVM seems to only ever provide a single hotplug slot per PHB. The under lying slot hotplug registration code assumed multiple slots, but the actual implementation is broken for multiple slots. This went unnoticed for years due to the nature of PowerVM as mentioned previously. 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. [ 6.492291] rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1 [ 6.492569] rpaphp: Slot [Slot 0] registered [ 6.492577] rpaphp: pci_hp_register failed with error -16 [ 6.493082] rpaphp: pci_hp_register failed with error -16 [ 6.493138] rpaphp: pci_hp_register failed with error -16 [ 6.493161] 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. [ 38.481750] rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1 [ 38.482004] rpaphp: Slot [C0] registered [ 38.482127] rpaphp: Slot [C1] registered [ 38.482241] rpaphp: Slot [C2] registered [ 38.482356] rpaphp: Slot [C3] registered [ 38.482495] rpaphp: Slot [C4] registered Signed-off-by: Tyrel Datwyler --- 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 6937c72..c90fa8d 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, "my,ibm-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); -- 2.7.4