From: mark gross <mgross@linux.intel.com>

I screwed up with my earlier patch to enable the portected memroy.  The
macro IOMMU_WAIT, exits when the condition goes true.  Without this
patch the code will hang at boot and some ( all?) vtd enabled systems.

Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/pci/intel-iommu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/pci/intel-iommu.c~intel-iommu-pmen-support-fix drivers/pci/intel-iommu.c
--- a/drivers/pci/intel-iommu.c~intel-iommu-pmen-support-fix
+++ a/drivers/pci/intel-iommu.c
@@ -704,7 +704,7 @@ static void iommu_disable_protect_mem_re
 
 	/* wait for the protected region status bit to clear */
 	IOMMU_WAIT_OP(iommu, DMAR_PMEN_REG,
-		readl, (pmen & DMA_PMEN_PRS), pmen);
+		readl, !(pmen & DMA_PMEN_PRS), pmen);
 
 	spin_unlock_irqrestore(&iommu->register_lock, flags);
 }
_