From: Seth Forshee <seth.forshee@canonical.com>
Date: Wed, 8 Aug 2012 13:27:03 +0000 (-0500)
Subject: irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU
X-Git-Tag: v3.6-rc3~25^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=32ab31e01e2def6f48294d872d9bb42573aae00f;p=pandora-kernel.git

irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU

The ACPI tables in the Macbook Air 5,1 define a single IOAPIC with id 2,
but the only remapping unit described in the DMAR table matches id 0.
Interrupt remapping fails as a result, and the kernel panics with the
message "timer doesn't work through Interrupt-remapped IO-APIC."

To fix this, check each IOAPIC for a corresponding IOMMU. If an IOMMU is
not found, do not allow IRQ remapping to be enabled.

v2: Move check to parse_ioapics_under_ir(), raise log level to KERN_ERR,
    and add FW_BUG to the log message
v3: Skip check if IOMMU doesn't support interrupt remapping and remove
    existing check that the IOMMU count equals the IOAPIC count

Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---

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