Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755651Ab3DOQ2V (ORCPT ); Mon, 15 Apr 2013 12:28:21 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:48586 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752548Ab3DOQ2R (ORCPT ); Mon, 15 Apr 2013 12:28:17 -0400 Date: Mon, 15 Apr 2013 12:28:06 -0400 From: Neil Horman To: Bjorn Helgaas Cc: "linux-kernel@vger.kernel.org" , Prarit Bhargava , Don Zickus , Don Dutile , Asit Mallick , David Woodhouse , "linux-pci@vger.kernel.org" , Joerg Roedel , Konrad Rzeszutek Wilk Subject: Re: [PATCH v7] irq: add quirk for broken interrupt remapping on 55XX chipsets Message-ID: <20130415162806.GB3505@hmsreliant.think-freely.org> References: <1362158276-4901-1-git-send-email-nhorman@tuxdriver.com> <1366024734-12011-1-git-send-email-nhorman@tuxdriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Score: -2.9 (--) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8039 Lines: 189 On Mon, Apr 15, 2013 at 09:30:36AM -0600, Bjorn Helgaas wrote: > On Mon, Apr 15, 2013 at 5:18 AM, 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. For > > details of those that reported the problem, please see: > > https://bugzilla.redhat.com/show_bug.cgi?id=887006 > > > > Signed-off-by: Neil Horman > > CC: Prarit Bhargava > > CC: Don Zickus > > CC: Don Dutile > > CC: Bjorn Helgaas > > CC: Asit Mallick > > CC: David Woodhouse > > CC: linux-pci@vger.kernel.org > > CC: Joerg Roedel > > CC: Konrad Rzeszutek Wilk > > --- > > > > 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. > > > > v3) > > > > * Removed defines from pci_ids.h, and used direct id values as per request from > > Bjorn. > > > > v4) > > > > * Converted pr_warn to WARN_TAINT(TAINT_FIRMWARE_WORKAROUND) as per David > > Woodhouse > > > > v5) > > > > * Moved check to an early quirk, and flagged the broken chip, so we could > > reasonably disable irq remapping during bootup. > > > > v6) > > > > * Clean up of stupid extra thrash in quirks.c > > > > v7) > > > > * Move broken check to intel_irq_remapping.c > > * Fixed another typo > > * Finally made the reference bugzilla public > > --- > > arch/x86/kernel/early-quirks.c | 25 +++++++++++++++++++++++++ > > drivers/iommu/intel_irq_remapping.c | 10 ++++++++++ > > drivers/iommu/irq_remapping.c | 12 ++++++++++++ > > drivers/iommu/irq_remapping.h | 1 + > > 4 files changed, 48 insertions(+) > > > > diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c > > index 3755ef4..bfa3139 100644 > > --- a/arch/x86/kernel/early-quirks.c > > +++ b/arch/x86/kernel/early-quirks.c > > @@ -192,6 +192,27 @@ static void __init ati_bugs_contd(int num, int slot, int func) > > } > > #endif > > > > +#ifdef CONFIG_IRQ_REMAP > > +static void __init intel_remapping_check(int num, int slot, int func) > > +{ > > + u8 revision; > > + > > + revision = pci_read_config_byte(num, slot, func , PCI_REVISION_ID); > > + > > + /* > > + * Revision 0x13 of this chipset supports irq remapping > > + * but has an erratum that breaks its behavior, flag it as such > > + */ > > + if (revision == 0x13) > > + irq_remap_broken = 1; > > + > > +} > > +#else > > +static void __init intel_remapping_check(int num, int slot, int func) > > +{ > > +} > > +#endif > > + > > #define QFLAG_APPLY_ONCE 0x1 > > #define QFLAG_APPLIED 0x2 > > #define QFLAG_DONE (QFLAG_APPLY_ONCE|QFLAG_APPLIED) > > @@ -221,6 +242,10 @@ static struct chipset early_qrk[] __initdata = { > > PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs }, > > { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, > > PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs_contd }, > > + { PCI_VENDOR_ID_INTEL, 0x3403, PCI_CLASS_BRIDGE_HOST, > > + PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check }, > > + { PCI_VENDOR_ID_INTEL, 0x3406, PCI_CLASS_BRIDGE_HOST, > > + PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check }, > > {} > > }; > > > > diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c > > index f3b8f23..5b19b2d 100644 > > --- a/drivers/iommu/intel_irq_remapping.c > > +++ b/drivers/iommu/intel_irq_remapping.c > > @@ -524,6 +524,16 @@ static int __init intel_irq_remapping_supported(void) > > > > if (disable_irq_remap) > > return 0; > > + if (irq_remap_broken) { > > + WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND, > > + "This system BIOS has enabled interrupt remapping\n" > > + "on a chipset that contains an erratum making that\n" > > + "feature unstable. To maintain system stability\n" > > + "interrupt remapping is being disabled. Please\n" > > + "contact your BIOS vendor for an update\n"); > > + disable_irq_remap = 1; > > + return 0; > > + } > > > > if (!dmar_ir_support()) > > return 0; > > diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c > > index d56f8c1..2b56e92 100644 > > --- a/drivers/iommu/irq_remapping.c > > +++ b/drivers/iommu/irq_remapping.c > > @@ -19,6 +19,7 @@ > > int irq_remapping_enabled; > > > > int disable_irq_remap; > > +int irq_remap_broken; > > int disable_sourceid_checking; > > int no_x2apic_optout; > > > > @@ -216,6 +217,17 @@ int irq_remapping_supported(void) > > if (disable_irq_remap) > > return 0; > > > > + if (irq_remap_broken) { > > + WARN_TAINT(1, TAIN_FIRMWARE_WORKAROUND, > > + "This system BIOS has enabled interrupt remapping\n" > > + "on a chipset that contains an erratum 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"); > > + disable_irq_remap = 1; > > + return 0; > > + } > > + > > I think you probably intended to drop the change to this file, since > you moved it to intel_irq_remapping.c. If you did intend to keep it, > s/TAIN_/TAINT_/. Damnit, yes, sorry. Not sure how that snuck back in there. I know I had removed it. Perhaps I forgot to commit that part of the change. Neil -- 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/