From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rv1Rf5mRhzDqMf for ; Tue, 19 Jul 2016 23:41:50 +1000 (AEST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u6JDYXTv136270 for ; Tue, 19 Jul 2016 09:41:48 -0400 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0b-001b2d01.pphosted.com with ESMTP id 2495r8m41t-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 19 Jul 2016 09:41:47 -0400 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 19 Jul 2016 07:41:47 -0600 Subject: Re: [Patch v2] rpaphp: fix slot registration for multiple slots under a PHB To: Tyrel Datwyler , linux-pci@vger.kernel.org References: <1468275387-22392-1-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: Tue, 19 Jul 2016 08:41:40 -0500 MIME-Version: 1.0 In-Reply-To: <1468275387-22392-1-git-send-email-tyreld@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Message-Id: <578E2E14.2070606@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 07/11/2016 05:16 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 Reviewed-by: Nathan Fontenot > --- > > 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); >