tree ee13b5125001f49fc162719cf5412f87707df54a
parent 32e1d0a0651004f5fe47f85a2a5c725ad579a90c
author Suresh Siddha <suresh.b.siddha@intel.com> 1215713811 -0700
committer Ingo Molnar <mingo@elte.hu> 1215845100 +0200

x64, x2apic/intr-remap: disable DMA-remapping if Interrupt-remapping is detected (temporary quirk)

Interrupt-remapping enables queued invalidation. And once queued invalidation
is enabled, IOTLB invalidation also needs to use the queued invalidation
mechanism and the register based IOTLB invalidation doesn't work.

For now, Support for IOTLB invalidation using queued invalidation is
missing. Meanwhile, disable DMA-remapping, if Interrupt-remapping
support is detected.

For the meanwhile, if someone wants to really enable DMA-remapping, they
can use nox2apic, which will disable interrupt-remapping and as such
doesn't enable queued invalidation.

And given that none of the release platforms support intr-remapping yet,
we should be ok for this temporary hack.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>