Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755302AbbHNPoJ (ORCPT ); Fri, 14 Aug 2015 11:44:09 -0400 Received: from foss.arm.com ([217.140.101.70]:39056 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754994AbbHNPoH (ORCPT ); Fri, 14 Aug 2015 11:44:07 -0400 Message-ID: <55CE0CC2.7010705@arm.com> Date: Fri, 14 Aug 2015 16:44:02 +0100 From: Marc Zyngier Organization: ARM Ltd User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: Bjorn Helgaas CC: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Will Deacon , "suravee.suthikulpanit@amd.com" , Lorenzo Pieralisi , "agraf@suse.de" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-pci@vger.kernel.org" Subject: Re: [PATCH 2/3] powerpc: PCI: Fix lookup of linux,pci-probe-only property References: <1439563268-13418-1-git-send-email-marc.zyngier@arm.com> <1439563268-13418-3-git-send-email-marc.zyngier@arm.com> <20150814145755.GE26431@google.com> In-Reply-To: <20150814145755.GE26431@google.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2329 Lines: 67 Hi Bjorn, On 14/08/15 15:57, Bjorn Helgaas wrote: > Hi Marc, > > On Fri, Aug 14, 2015 at 03:41:07PM +0100, Marc Zyngier wrote: >> When find_and_init_phbs() looks for the probe-only property, it seems >> to trust the firmware to be correctly written, and assumes that there >> is a parameter to the property. >> >> It is conceivable that the firmware could not be that perfect, and it >> could expose this property naked (at least one arm64 platform seems to >> exhibit this exact behaviour). The setup code the ends up making >> a decision based on whatever the property pointer points to, which >> is likely to be junk. >> >> Instead, let's check for the validity of the property, and ignore >> it if the firmware couldn't make up its mind. >> >> Signed-off-by: Marc Zyngier >> --- >> arch/powerpc/platforms/pseries/setup.c | 15 ++++++++++----- >> 1 file changed, 10 insertions(+), 5 deletions(-) >> >> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c >> index df6a704..6bdc1f9 100644 >> --- a/arch/powerpc/platforms/pseries/setup.c >> +++ b/arch/powerpc/platforms/pseries/setup.c >> @@ -490,14 +490,19 @@ static void __init find_and_init_phbs(void) >> */ >> if (of_chosen) { >> const int *prop; >> + int len; >> >> prop = of_get_property(of_chosen, >> - "linux,pci-probe-only", NULL); >> + "linux,pci-probe-only", &len); >> if (prop) { >> - if (*prop) >> - pci_add_flags(PCI_PROBE_ONLY); >> - else >> - pci_clear_flags(PCI_PROBE_ONLY); >> + if (len) { >> + if (be32_to_cpup(prop)) >> + pci_add_flags(PCI_PROBE_ONLY); >> + else >> + pci_clear_flags(PCI_PROBE_ONLY); >> + } else { >> + pr_warn("linux,pci-probe-only set without value, ignoring\n"); >> + } > > This seems essentially identical to the pci-host-generic version. > Is there a way we can factor it out so there's only one copy? Probably. drivers/of/of_pci.c seems like a good landing place for it. I'll hack something and repost it. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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/