[PATCH 3.16.y-ckt 002/142] iommu/vt-d: Fix 64-bit accesses to 32-bit DMAR_GSTS_REG

From: Luis Henriques
Date: Tue Mar 22 2016 - 07:24:26 EST


3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know.

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

From: CQ Tang <cq.tang@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
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;