1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2a165010a1c1..4c780efff169 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -78,6 +78,24 @@
 #define LEVEL_STRIDE            (9)
 #define LEVEL_MASK              (((u64)1 << LEVEL_STRIDE) - 1)
 
+/*
+ * This bitmap is used to advertise the page sizes our hardware support
+ * to the IOMMU core, which will then use this information to split
+ * physically contiguous memory regions it is mapping into page sizes
+ * that we support.
+ *
+ * Traditionally the IOMMU core just handed us the mappings directly,
+ * after making sure the size is an order of a 4KiB page and that the
+ * mapping has natural alignment.
+ *
+ * To retain this behavior, we currently advertise that we support
+ * all page sizes that are an order of 4KiB.
+ *
+ * If at some point we'd like to utilize the IOMMU core's new behavior,
+ * we could change this to advertise the real page sizes we support.
+ */
+#define INTEL_IOMMU_PGSIZES     (~0xFFFUL)
+
 static inline int agaw_to_level(int agaw)
 {
         return agaw + 2;
@@ -4066,6 +4084,7 @@ static struct iommu_ops intel_iommu_ops = {
         .unmap          = intel_iommu_unmap,
         .iova_to_phys   = intel_iommu_iova_to_phys,
         .domain_has_cap = intel_iommu_domain_has_cap,
+        .pgsize_bitmap  = INTEL_IOMMU_PGSIZES,
 };
 
 static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)