diff mbox

[stable] iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets

Message ID 1373303174-21977-1-git-send-email-nhorman@tuxdriver.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Neil Horman July 8, 2013, 5:06 p.m. UTC
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

[ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]

Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
isn't needed in the upstream tree

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Prarit Bhargava <prarit@redhat.com>
CC: Don Zickus <dzickus@redhat.com>
CC: Don Dutile <ddutile@redhat.com>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Asit Mallick <asit.k.mallick@intel.com>
CC: David Woodhouse <dwmw2@infradead.org>
CC: linux-pci@vger.kernel.org
CC: Joerg Roedel <joro@8bytes.org>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
CC: Jean Delvare <jdelvare@suse.de>
CC: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
(cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)
---
 arch/x86/include/asm/irq_remapping.h |  2 ++
 arch/x86/kernel/early-quirks.c       | 21 +++++++++++++++++++++
 drivers/iommu/intel_irq_remapping.c  | 10 ++++++++++
 drivers/iommu/irq_remapping.c        |  6 ++++++
 drivers/iommu/irq_remapping.h        |  2 ++
 5 files changed, 41 insertions(+)

Comments

Greg Kroah-Hartman July 23, 2013, 5:06 p.m. UTC | #1
On Mon, Jul 08, 2013 at 01:06:14PM -0400, 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
> 
> [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> 
> Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
> isn't needed in the upstream tree
> 
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> CC: Prarit Bhargava <prarit@redhat.com>
> CC: Don Zickus <dzickus@redhat.com>
> CC: Don Dutile <ddutile@redhat.com>
> CC: Bjorn Helgaas <bhelgaas@google.com>
> CC: Asit Mallick <asit.k.mallick@intel.com>
> CC: David Woodhouse <dwmw2@infradead.org>
> CC: linux-pci@vger.kernel.org
> CC: Joerg Roedel <joro@8bytes.org>
> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
> CC: Jean Delvare <jdelvare@suse.de>
> CC: Greg KH <gregkh@linuxfoundation.org>
> Signed-off-by: Joerg Roedel <joro@8bytes.org>
> (cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)

As 3.9-stable is now dead, this one missed that window, sorry about
that.

greg k-h
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Neil Horman July 23, 2013, 8:03 p.m. UTC | #2
On Tue, Jul 23, 2013 at 10:06:02AM -0700, Greg KH wrote:
> On Mon, Jul 08, 2013 at 01:06:14PM -0400, 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
> > 
> > [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> > 
> > Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
> > isn't needed in the upstream tree
> > 
> > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> > CC: Prarit Bhargava <prarit@redhat.com>
> > CC: Don Zickus <dzickus@redhat.com>
> > CC: Don Dutile <ddutile@redhat.com>
> > CC: Bjorn Helgaas <bhelgaas@google.com>
> > CC: Asit Mallick <asit.k.mallick@intel.com>
> > CC: David Woodhouse <dwmw2@infradead.org>
> > CC: linux-pci@vger.kernel.org
> > CC: Joerg Roedel <joro@8bytes.org>
> > CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
> > CC: Jean Delvare <jdelvare@suse.de>
> > CC: Greg KH <gregkh@linuxfoundation.org>
> > Signed-off-by: Joerg Roedel <joro@8bytes.org>
> > (cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)
> 
> As 3.9-stable is now dead, this one missed that window, sorry about
> that.
> 
Thanks for the heads up, we tried our best :).
Neil

> greg k-h
> 
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Jean Delvare Oct. 8, 2013, 8:45 p.m. UTC | #3
Hi Greg, hi Neil,

Le Tuesday 23 July 2013 à 10:06 -0700, Greg KH a écrit :
> On Mon, Jul 08, 2013 at 01:06:14PM -0400, 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
> > 
> > [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> > 
> > Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
> > isn't needed in the upstream tree
> > 
> > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> > CC: Prarit Bhargava <prarit@redhat.com>
> > CC: Don Zickus <dzickus@redhat.com>
> > CC: Don Dutile <ddutile@redhat.com>
> > CC: Bjorn Helgaas <bhelgaas@google.com>
> > CC: Asit Mallick <asit.k.mallick@intel.com>
> > CC: David Woodhouse <dwmw2@infradead.org>
> > CC: linux-pci@vger.kernel.org
> > CC: Joerg Roedel <joro@8bytes.org>
> > CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
> > CC: Jean Delvare <jdelvare@suse.de>
> > CC: Greg KH <gregkh@linuxfoundation.org>
> > Signed-off-by: Joerg Roedel <joro@8bytes.org>
> > (cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)
> 
> As 3.9-stable is now dead, this one missed that window, sorry about
> that.

Sorry for jumping in a little late, but I am looking into this again
because one customer of ours requested this fix. I'm a bit confused now,
by two different things:

1* Why did Greg claim that the fix missed the 3.9-stable window while I
can see Neil's backport of the fix made it into 3.9.9?

2* Why was the backport only added to 3.9-stable and not also
3.4-longterm and 3.0 longterm?

I need the fix for the SLE11 SP3 kernel which is based on 3.0. Neil, do
you have a backport of the fix for this kernel? The 3.9 doesn't apply :(

Thanks,
Neil Horman Oct. 8, 2013, 9 p.m. UTC | #4
On Tue, Oct 08, 2013 at 10:45:32PM +0200, Jean Delvare wrote:
> Hi Greg, hi Neil,
> 
> Le Tuesday 23 July 2013 à 10:06 -0700, Greg KH a écrit :
> > On Mon, Jul 08, 2013 at 01:06:14PM -0400, 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
> > > 
> > > [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> > > 
> > > Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
> > > isn't needed in the upstream tree
> > > 
> > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> > > CC: Prarit Bhargava <prarit@redhat.com>
> > > CC: Don Zickus <dzickus@redhat.com>
> > > CC: Don Dutile <ddutile@redhat.com>
> > > CC: Bjorn Helgaas <bhelgaas@google.com>
> > > CC: Asit Mallick <asit.k.mallick@intel.com>
> > > CC: David Woodhouse <dwmw2@infradead.org>
> > > CC: linux-pci@vger.kernel.org
> > > CC: Joerg Roedel <joro@8bytes.org>
> > > CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > > CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
> > > CC: Jean Delvare <jdelvare@suse.de>
> > > CC: Greg KH <gregkh@linuxfoundation.org>
> > > Signed-off-by: Joerg Roedel <joro@8bytes.org>
> > > (cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)
> > 
> > As 3.9-stable is now dead, this one missed that window, sorry about
> > that.
> 
> Sorry for jumping in a little late, but I am looking into this again
> because one customer of ours requested this fix. I'm a bit confused now,
> by two different things:
> 
> 1* Why did Greg claim that the fix missed the 3.9-stable window while I
> can see Neil's backport of the fix made it into 3.9.9?
> 
> 2* Why was the backport only added to 3.9-stable and not also
> 3.4-longterm and 3.0 longterm?
> 
These are questions that you should ask Greg I think.

> I need the fix for the SLE11 SP3 kernel which is based on 3.0. Neil, do
> you have a backport of the fix for this kernel? The 3.9 doesn't apply :(
> 
I don't.  I've backported it to RHEL6.5 (which is 2.6.32 based), so it shouldn't
be that hard to massage into place.

Neil

> Thanks,
> -- 
> Jean Delvare
> Suse L3 Support
> 
> 
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Greg Kroah-Hartman Oct. 8, 2013, 9:30 p.m. UTC | #5
On Tue, Oct 08, 2013 at 10:45:32PM +0200, Jean Delvare wrote:
> Hi Greg, hi Neil,
> 
> Le Tuesday 23 July 2013 à 10:06 -0700, Greg KH a écrit :
> > On Mon, Jul 08, 2013 at 01:06:14PM -0400, 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
> > > 
> > > [ Joerg: Removed CONFIG_IRQ_REMAP ifdef from early-quirks.c ]
> > > 
> > > Notes: Modified early-quirks.c to include linux/irq.h, to fix warnings.  This
> > > isn't needed in the upstream tree
> > > 
> > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
> > > CC: Prarit Bhargava <prarit@redhat.com>
> > > CC: Don Zickus <dzickus@redhat.com>
> > > CC: Don Dutile <ddutile@redhat.com>
> > > CC: Bjorn Helgaas <bhelgaas@google.com>
> > > CC: Asit Mallick <asit.k.mallick@intel.com>
> > > CC: David Woodhouse <dwmw2@infradead.org>
> > > CC: linux-pci@vger.kernel.org
> > > CC: Joerg Roedel <joro@8bytes.org>
> > > CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > > CC: Arkadiusz Mi?kiewicz <arekm@maven.pl>
> > > CC: Jean Delvare <jdelvare@suse.de>
> > > CC: Greg KH <gregkh@linuxfoundation.org>
> > > Signed-off-by: Joerg Roedel <joro@8bytes.org>
> > > (cherry picked from commit 03bbcb2e7e292838bb0244f5a7816d194c911d62)
> > 
> > As 3.9-stable is now dead, this one missed that window, sorry about
> > that.
> 
> Sorry for jumping in a little late, but I am looking into this again
> because one customer of ours requested this fix. I'm a bit confused now,
> by two different things:
> 
> 1* Why did Greg claim that the fix missed the 3.9-stable window while I
> can see Neil's backport of the fix made it into 3.9.9?

Greg doesn't remember what patches he applied to what stable tree, nor
if he had applied them to a previous stable release at all.  His
short-term memory is almost non-existant given the huge rate of patches
flowing through him, and he is feeling strange referring to himself in
the third person...

> 2* Why was the backport only added to 3.9-stable and not also
> 3.4-longterm and 3.0 longterm?

Probably because the patch sent to me didn't apply there?

> I need the fix for the SLE11 SP3 kernel which is based on 3.0. Neil, do
> you have a backport of the fix for this kernel? The 3.9 doesn't apply :(

Ah, yes, that's why I didn't apply it.

If someone sends me a version that does, I will add it to those trees.

thanks,

greg k-h
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diff mbox

Patch

diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h
index 95fd352..aca6aa2 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);
@@ -54,6 +55,7 @@  void irq_remap_modify_chip_defaults(struct irq_chip *chip);
 
 static inline void setup_irq_remapping_ops(void) { }
 static inline int irq_remapping_supported(void) { return 0; }
+static inline void set_irq_remapping_broken(void) { }
 static inline int irq_remapping_prepare(void) { return -ENODEV; }
 static inline int irq_remapping_enable(void) { return -ENODEV; }
 static inline void irq_remapping_disable(void) { }
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index 3755ef4..28bd4a1 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -12,12 +12,14 @@ 
 #include <linux/pci.h>
 #include <linux/acpi.h>
 #include <linux/pci_ids.h>
+#include <linux/irq.h>
 #include <asm/pci-direct.h>
 #include <asm/dma.h>
 #include <asm/io_apic.h>
 #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 +194,21 @@  static void __init ati_bugs_contd(int num, int slot, int func)
 }
 #endif
 
+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();
+
+}
+
 #define QFLAG_APPLY_ONCE 	0x1
 #define QFLAG_APPLIED		0x2
 #define QFLAG_DONE		(QFLAG_APPLY_ONCE|QFLAG_APPLIED)
@@ -221,6 +238,10 @@  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 7c11ff3..dcfea4e 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -18,6 +18,7 @@ 
 int irq_remapping_enabled;
 
 int disable_irq_remap;
+int irq_remap_broken;
 int disable_sourceid_checking;
 int no_x2apic_optout;
 
@@ -210,6 +211,11 @@  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 */