iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets
authorNeil Horman <nhorman@tuxdriver.com>
Tue, 16 Apr 2013 20:38:32 +0000 (16:38 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 3 Jul 2013 17:55:22 +0000 (10:55 -0700)
commitc45180b29474509662e45d051a2448fd2e60feba
treeec91280e2e1923da5910861fe4d91abb83d2bf57
parenta31da56adfdbc020f1edbc308be17599a465ee6d
iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets

commit 03bbcb2e7e292838bb0244f5a7816d194c911d62 upstream.

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 ]

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 Miƛkiewicz <arekm@maven.pl>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/include/asm/irq_remapping.h
arch/x86/kernel/early-quirks.c
drivers/iommu/intel_irq_remapping.c
drivers/iommu/irq_remapping.c
drivers/iommu/irq_remapping.h