Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754693AbbBBQPe (ORCPT ); Mon, 2 Feb 2015 11:15:34 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:40638 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753186AbbBBQPd (ORCPT ); Mon, 2 Feb 2015 11:15:33 -0500 Message-ID: <54CFA29B.9000200@arm.com> Date: Mon, 02 Feb 2015 16:15:23 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Bjorn Helgaas CC: Jiang Liu , Thomas Gleixner , Lorenzo Pieralisi , Andre Przywara , "linux-pci@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] PCI: Fix pcibios_update_irq misuse of irq number References: <1422456683-797-1-git-send-email-marc.zyngier@arm.com> <54C8FE61.1030304@linux.intel.com> <54C8FFE0.3030007@arm.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3471 Lines: 93 On 28/01/15 15:43, Bjorn Helgaas wrote: > On Wed, Jan 28, 2015 at 9:27 AM, Marc Zyngier wrote: >> Hi Gerry, >> >> On 28/01/15 15:21, Jiang Liu wrote: >>> >>> >>> On 2015/1/28 22:51, Marc Zyngier wrote: >>>> pcibios_update_irq writes an irq number into the config space >>>> of a given PCI device, but ignores the fact that this number >>>> is a virtual interrupt number, which might be a very different >>>> value from what the underlying hardware is using. >>>> >>>> The obvious fix is to fetch the HW interrupt number from the >>>> corresponding irq_data structure. This is slightly complicated >>>> by the fact that this interrupt might be services by a stacked >>>> domain. >>>> >>>> This has been tested on KVM with kvmtool. >>>> >>>> Reported-by: Lorenzo Pieralisi >>>> Tested-by: Andre Przywara >>>> Signed-off-by: Marc Zyngier >>>> --- >>>> drivers/pci/setup-irq.c | 12 ++++++++++-- >>>> 1 file changed, 10 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c >>>> index 4e2d595..828cbc9 100644 >>>> --- a/drivers/pci/setup-irq.c >>>> +++ b/drivers/pci/setup-irq.c >>>> @@ -15,11 +15,19 @@ >>>> #include >>>> #include >>>> #include >>>> +#include >>>> >>>> void __weak pcibios_update_irq(struct pci_dev *dev, int irq) >>>> { >>>> - dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq); >>>> - pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq); >>>> + struct irq_data *d; >>>> + >>>> + d = irq_get_irq_data(irq); >>>> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY >>>> + while (d->parent_data) >>>> + d = d->parent_data; >>>> +#endif >>>> + dev_dbg(&dev->dev, "assigning IRQ %02ld\n", d->hwirq); >>>> + pci_write_config_byte(dev, PCI_INTERRUPT_LINE, d->hwirq); >>>> } >>> Hi Mark, >>> Instead of modifying the common version, how about >>> implementing an arch specific version? Arch may have different >>> way to determine the irq number. Above implementation doesn't >>> work with x86, for example. >> >> If you look at the Makefile, this file is used on: >> >> obj-$(CONFIG_ALPHA) += setup-irq.o >> obj-$(CONFIG_ARM) += setup-irq.o >> obj-$(CONFIG_UNICORE32) += setup-irq.o >> obj-$(CONFIG_SUPERH) += setup-irq.o >> obj-$(CONFIG_MIPS) += setup-irq.o >> obj-$(CONFIG_TILE) += setup-irq.o >> obj-$(CONFIG_SPARC_LEON) += setup-irq.o >> obj-$(CONFIG_M68K) += setup-irq.o >> >> x86 doesn't use that at all. > > Since you're looking at this, Marc, do you see a nice way to get rid > of these arch dependencies in the Makefile and unify this a bit? We > still have this pci_fixup_irqs() ugliness -- it's not really > arch-specific at all, but it's called from arch code, and it uses > for_each_pci_dev(), which obviously only works for things present at > boot and not for things hot-added later. I can have a look at this in the next cycle - I'm a bit strapped for time just now. As for for_each_pci_dev(), I'm not completely clear about what it should be replaced for. Do we have some form of notifier for this? 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/