On Mon, Apr 15, 2013 at 5:18 AM, Neil Horman <nhorman@xxxxxxxxxxxxx> 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 <nhorman@xxxxxxxxxxxxx> > CC: Prarit Bhargava <prarit@xxxxxxxxxx> > CC: Don Zickus <dzickus@xxxxxxxxxx> > CC: Don Dutile <ddutile@xxxxxxxxxx> > CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > CC: Asit Mallick <asit.k.mallick@xxxxxxxxx> > CC: David Woodhouse <dwmw2@xxxxxxxxxxxxx> > CC: linux-pci@xxxxxxxxxxxxxxx > CC: Joerg Roedel <joro@xxxxxxxxxx> > CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> > --- > > 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_/. > if (!remap_ops || !remap_ops->supported) > return 0; > > diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h > index ecb6376..d7537e4 100644 > --- a/drivers/iommu/irq_remapping.h > +++ b/drivers/iommu/irq_remapping.h > @@ -32,6 +32,7 @@ struct pci_dev; > struct msi_msg; > > extern int disable_irq_remap; > +extern int irq_remap_broken; > extern int disable_sourceid_checking; > extern int no_x2apic_optout; > extern int irq_remapping_enabled; > -- > 1.8.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
