[3.16.y-ckt stable] Patch "iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt26.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 58ce73411ca02c6fa317ceba7a99a83011e0567e Mon Sep 17 00:00:00 2001
From: CQ Tang <cq.tang at intel.com>
Date: Wed, 13 Jan 2016 21:15:03 +0000
Subject: iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG

commit fda3bec12d0979aae3f02ee645913d66fbc8a26e upstream.

This is a 32-bit register. Apparently harmless on real hardware, but
causing justified warnings in simulation.

Signed-off-by: CQ Tang <cq.tang at intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/iommu/dmar.c                | 2 +-
 drivers/iommu/intel_irq_remapping.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 55f1515d54c9..04a5e5366ac0 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1246,7 +1246,7 @@ void dmar_disable_qi(struct intel_iommu *iommu)

 	raw_spin_lock_irqsave(&iommu->register_lock, flags);

-	sts =  dmar_readq(iommu->reg + DMAR_GSTS_REG);
+	sts =  readl(iommu->reg + DMAR_GSTS_REG);
 	if (!(sts & DMA_GSTS_QIES))
 		goto end;

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 9b174893f0f5..c21e80461d2d 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -504,7 +504,7 @@ static void iommu_disable_irq_remapping(struct intel_iommu *iommu)

 	raw_spin_lock_irqsave(&iommu->register_lock, flags);

-	sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
+	sts = readl(iommu->reg + DMAR_GSTS_REG);
 	if (!(sts & DMA_GSTS_IRES))
 		goto end;