Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762953Ab3DCXxt (ORCPT ); Wed, 3 Apr 2013 19:53:49 -0400 Received: from mail-oa0-f50.google.com ([209.85.219.50]:44130 "EHLO mail-oa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762898Ab3DCXxr (ORCPT ); Wed, 3 Apr 2013 19:53:47 -0400 MIME-Version: 1.0 In-Reply-To: <1362423859-18516-1-git-send-email-nhorman@tuxdriver.com> References: <1362158276-4901-1-git-send-email-nhorman@tuxdriver.com> <1362423859-18516-1-git-send-email-nhorman@tuxdriver.com> From: Bjorn Helgaas Date: Wed, 3 Apr 2013 17:53:27 -0600 Message-ID: Subject: Re: [PATCH v2] irq: add quirk for broken interrupt remapping on 55XX chipsets To: Neil Horman Cc: "linux-kernel@vger.kernel.org" , Prarit Bhargava , Don Zickus , Don Dutile , Asit Mallick , "linux-pci@vger.kernel.org" , David Woodhouse , iommu@lists.linux-foundation.org, Yinghai Lu , Jiang Liu Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5544 Lines: 126 [+cc David and iommu list, Yinghai, Jiang] On Mon, Mar 4, 2013 at 12:04 PM, Neil Horman wrote: > A few years back intel published a spec update: > http://www.intel.com/content/dam/doc/specification-update/5520-and-5500-chipset-ioh-specification-update.pdf > > For the 5520 and 5500 chipsets which contained an errata (specificially errata > 53), which noted that these chipsets can't properly do interrupt remapping, and > as a result the recommend that interrupt remapping be disabled in bios. While > many vendors have a bios update to do exactly that, not all do, and of course > not all users update their bios to a level that corrects the problem. As a > result, occasionally interrupts can arrive at a cpu even after affinity for that > interrupt has be moved, leading to lost or spurrious interrupts (usually > characterized by the message: > kernel: do_IRQ: 7.71 No irq handler for vector (irq -1) > > There have been several incidents recently of people seeing this error, and > investigation has shown that they have system for which their BIOS level is such > that this feature was not properly turned off. As such, it would be good to > give them a reminder that their systems are vulnurable to this problem. > > Signed-off-by: Neil Horman > CC: Prarit Bhargava > CC: Don Zickus > CC: Don Dutile > CC: Bjorn Helgaas > CC: Asit Mallick > CC: linux-pci@vger.kernel.org > > --- > > Change notes: > > v2) > > * Moved the quirk to the x86 arch, since consensus seems to be that the 55XX > chipset series is x86 only. I decided however to keep the quirk as a regular > quirk, not an early_quirk. Early quirks have no way currently to determine if > BIOS has properly disabled the feature in the iommu, at least not without > significant hacking, and since its quite possible this will be a short lived > quirk, should Don Z's workaround code prove successful (and it looks like it may > well), I don't think that necessecary. > > * Removed the WARNING banner from the quirk, and added the HW_ERR token to the > string, I opted to leave the newlines in place however, as I really couldnt > find a way to keep the text on a single line is still legible from a code > perspective. I think theres enough language in there that using cscope on just > about any substring however will turn it up, and again, this may be a short > lived quirk. > --- > arch/x86/kernel/quirks.c | 18 ++++++++++++++++++ > include/linux/pci_ids.h | 2 ++ > 2 files changed, 20 insertions(+) > > diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c > index 26ee48a..a718ea2 100644 > --- a/arch/x86/kernel/quirks.c > +++ b/arch/x86/kernel/quirks.c > @@ -5,6 +5,7 @@ > #include > > #include > +#include "../../../drivers/iommu/irq_remapping.h" > > #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI) > > @@ -567,3 +568,20 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F5, > quirk_amd_nb_node); > > #endif > + > +static void intel_remapping_check(struct pci_dev *dev) > +{ > + u8 revision; > + > + pci_read_config_byte(dev, PCI_REVISION_ID, &revision); > + > + if ((revision == 0x13) && irq_remapping_enabled) { > + pr_warn(HW_ERR "This system BIOS has enabled interrupt remapping\n" > + "on a chipset that contains an errata making that\n" > + "feature unstable. Please reboot with nointremap\n" > + "added to the kernel command line and contact\n" > + "your BIOS vendor for an update"); > + } > +} > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5520_IOHUB, intel_remapping_check); > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5500_IOHUB, intel_remapping_check); This started as an IOMMU change, and I'm not an expert in that area, so I added David and the IOMMU list. I'd rather have him deal with this than me. Is this something we can just *fix* in the kernel, e.g., by turning off interrupt remapping ourselves, or does it have to be done before the OS boots? > diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h > index 31717bd..54027a6 100644 > --- a/include/linux/pci_ids.h > +++ b/include/linux/pci_ids.h > @@ -2732,6 +2732,8 @@ > #define PCI_DEVICE_ID_INTEL_LYNNFIELD_MC_CH2_RANK_REV2 0x2db2 > #define PCI_DEVICE_ID_INTEL_LYNNFIELD_MC_CH2_TC_REV2 0x2db3 > #define PCI_DEVICE_ID_INTEL_82855PM_HB 0x3340 > +#define PCI_DEVICE_ID_INTEL_5500_IOHUB 0x3403 > +#define PCI_DEVICE_ID_INTEL_5520_IOHUB 0x3406 For constants only used in one place, we just use the bare constant (0x3403) in the quirk rather than editing pci_ids.h (see comment at the top of that file). > #define PCI_DEVICE_ID_INTEL_IOAT_TBG4 0x3429 > #define PCI_DEVICE_ID_INTEL_IOAT_TBG5 0x342a > #define PCI_DEVICE_ID_INTEL_IOAT_TBG6 0x342b > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/