Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932306Ab3EOAoJ (ORCPT ); Tue, 14 May 2013 20:44:09 -0400 Received: from gate.crashing.org ([63.228.1.57]:34542 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932158Ab3EOAoH (ORCPT ); Tue, 14 May 2013 20:44:07 -0400 Message-ID: <1368574202.31689.54.camel@pasglop> Subject: Re: [RFC PATCH v2, part 2 09/18] PCI, PPC: use hotplug-safe iterators to walk PCI buses From: Benjamin Herrenschmidt To: Jiang Liu Cc: Bjorn Helgaas , Yinghai Lu , Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Mackerras , Gavin Shan , Grant Likely , Bill Pemberton , linuxppc-dev@lists.ozlabs.org Date: Wed, 15 May 2013 09:30:02 +1000 In-Reply-To: <1368550322-1045-9-git-send-email-jiang.liu@huawei.com> References: <1368550322-1045-1-git-send-email-jiang.liu@huawei.com> <1368550322-1045-9-git-send-email-jiang.liu@huawei.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1870 Lines: 60 On Wed, 2013-05-15 at 00:51 +0800, Jiang Liu wrote: > Enhance PPC architecture specific code to use hotplug-safe iterators > to walk PCI buses. I was about to ack it but then I saw: > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c > index 51a133a..a41c6dd 100644 > --- a/arch/powerpc/kernel/pci_64.c > +++ b/arch/powerpc/kernel/pci_64.c > @@ -208,7 +208,6 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > unsigned long in_devfn) > { > struct pci_controller* hose; > - struct list_head *ln; > struct pci_bus *bus = NULL; > struct device_node *hose_node; > > @@ -229,18 +228,16 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > /* That syscall isn't quite compatible with PCI domains, but it's > * used on pre-domains setup. We return the first match > */ > - > - for (ln = pci_root_buses.next; ln != &pci_root_buses; ln = ln->next) { > - bus = pci_bus_b(ln); > - if (in_bus >= bus->number && in_bus <= bus->busn_res.end) > + for_each_pci_root_bus(bus) > + if (in_bus >= bus->number && in_bus <= bus->busn_res.end && > + bus->dev.of_node) > break; > - bus = NULL; > - } > - if (bus == NULL || bus->dev.of_node == NULL) > + if (bus == NULL) > return -ENODEV; You just removed the NULL check for the of_node field... > hose_node = bus->dev.of_node; > hose = PCI_DN(hose_node)->phb; Which is dereferrenced here. > + pci_bus_put(bus); On the other hand, the whole thing can probably be using pci_bus_to_host() instead.... the above code is bitrotted. > switch (which) { > case IOBASE_BRIDGE_NUMBER: Cheeers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/