From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752583AbcGKWQq (ORCPT ); Mon, 11 Jul 2016 18:16:46 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:52279 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750787AbcGKWQo (ORCPT ); Mon, 11 Jul 2016 18:16:44 -0400 X-IBM-Helo: d03dlp01.boulder.ibm.com X-IBM-MailFrom: tyreld@linux.vnet.ibm.com 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 v2] rpaphp: fix slot registration for multiple slots under a PHB Date: Mon, 11 Jul 2016 17:16:27 -0500 X-Mailer: git-send-email 2.7.4 X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16071122-0016-0000-0000-000004282C84 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16071122-0017-0000-0000-00003103CD02 Message-Id: <1468275387-22392-1-git-send-email-tyreld@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-07-11_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607110218 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- Changes in v2: corrected ibm,my-drc-index property name --- 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..388c4d8 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); -- 2.7.4