From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756515AbcGHX6X (ORCPT ); Fri, 8 Jul 2016 19:58:23 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37675 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752967AbcGHX6O (ORCPT ); Fri, 8 Jul 2016 19:58:14 -0400 X-IBM-Helo: d03dlp01.boulder.ibm.com X-IBM-MailFrom: nfont@linux.vnet.ibm.com Subject: Re: [PATCH] rpaphp: fix slot registration for multiple slots under a PHB To: Tyrel Datwyler , linux-pci@vger.kernel.org References: <1468019987-1733-1-git-send-email-tyreld@linux.vnet.ibm.com> Cc: bhelgaas@google.com, mpe@ellerman.id.au, benh@kernel.crashing.org, mdroth@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org From: Nathan Fontenot Date: Fri, 8 Jul 2016 18:57:06 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <1468019987-1733-1-git-send-email-tyreld@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16070823-0004-0000-0000-00000FDE9534 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16070823-0005-0000-0000-000076E91CB2 Message-Id: <57803DD2.601@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-07-08_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607080237 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/2016 06:19 PM, Tyrel Datwyler wrote: > 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); Shouldn't this be reading ibm,my-drc-index? instead of my,ibm-drc-index. -Nathan > + 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); >