intel-iommu: VT-d page table to support snooping control bit

The user can request to enable snooping control through VT-d page table.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0cf3a4e43f23..3af4ffd591b9 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -21,6 +21,7 @@
 
 #define IOMMU_READ      (1)
 #define IOMMU_WRITE     (2)
+#define IOMMU_CACHE     (4) /* DMA cache coherency */
 
 struct device;