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> CC: Arkadiusz Miśkiewicz <arekm@xxxxxxxx> --- 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 v8) * Removed extraneous code from irq_remapping_enabled v9) * Fix stupid build break from rushing to shuffle simmilar header files about Thanks to Arkadiusz Miśkiewicz for pointing it out v10) * Rewrite to hide the irq_remap_broken variable so we don't need to pull in a private header file --- arch/x86/include/asm/irq_remapping.h | 1 + arch/x86/kernel/early-quirks.c | 26 ++++++++++++++++++++++++++ drivers/iommu/intel_irq_remapping.c | 10 ++++++++++ drivers/iommu/irq_remapping.c | 6 ++++++ drivers/iommu/irq_remapping.h | 2 ++ 5 files changed, 45 insertions(+) diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h index 95fd352..d740cb4 100644 --- a/arch/x86/include/asm/irq_remapping.h +++ b/arch/x86/include/asm/irq_remapping.h @@ -28,6 +28,7 @@ extern void setup_irq_remapping_ops(void); extern int irq_remapping_supported(void); +extern void set_irq_remapping_broken(void); extern int irq_remapping_prepare(void); extern int irq_remapping_enable(void); extern void irq_remapping_disable(void); diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index 3755ef4..589092d 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -18,6 +18,7 @@ #include <asm/apic.h> #include <asm/iommu.h> #include <asm/gart.h> +#include <asm/irq_remapping.h> static void __init fix_hypertransport_config(int num, int slot, int func) { @@ -192,6 +193,27 @@ 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 = read_pci_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) + set_irq_remapping_broken(); + +} +#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 +243,10 @@ 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..3c11043 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; @@ -211,6 +212,11 @@ void __init setup_irq_remapping_ops(void) #endif } +void set_irq_remapping_broken(void) +{ + irq_remap_broken = 1; +} + int irq_remapping_supported(void) { if (disable_irq_remap) diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h index ecb6376..90c4dae 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; @@ -89,6 +90,7 @@ extern struct irq_remap_ops amd_iommu_irq_ops; #define irq_remapping_enabled 0 #define disable_irq_remap 1 +#define irq_remap_broken 0 #endif /* CONFIG_IRQ_REMAP */ -- 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
