1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 047905dc3e14..28b078133688 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -137,6 +137,7 @@ int amd_iommus_present;
 
 /* IOMMUs have a non-present cache? */
 bool amd_iommu_np_cache __read_mostly;
+bool amd_iommu_iotlb_sup __read_mostly = true;
 
 /*
  * The ACPI table parsing functions set this variable on an error
@@ -687,6 +688,9 @@ static void __init init_iommu_from_pci(struct amd_iommu *iommu)
                                         MMIO_GET_LD(range));
         iommu->evt_msi_num = MMIO_MSI_NUM(misc);
 
+        if (!(iommu->cap & (1 << IOMMU_CAP_IOTLB)))
+                amd_iommu_iotlb_sup = false;
+
         /* read extended feature bits */
         low  = readl(iommu->mmio_base + MMIO_EXT_FEATURES);
         high = readl(iommu->mmio_base + MMIO_EXT_FEATURES + 4);