1 files changed, 12 insertions, 2 deletions

diff --git a/kernel/drivers/iommu/amd_iommu_init.c b/kernel/drivers/iommu/amd_iommu_init.c
index bf4959f42..94f1bf772 100644
--- a/kernel/drivers/iommu/amd_iommu_init.c
+++ b/kernel/drivers/iommu/amd_iommu_init.c
@@ -1363,13 +1363,23 @@ static int __init amd_iommu_init_pci(void)
 			break;
 	}
 
+	/*
+	 * Order is important here to make sure any unity map requirements are
+	 * fulfilled. The unity mappings are created and written to the device
+	 * table during the amd_iommu_init_api() call.
+	 *
+	 * After that we call init_device_table_dma() to make sure any
+	 * uninitialized DTE will block DMA, and in the end we flush the caches
+	 * of all IOMMUs to make sure the changes to the device table are
+	 * active.
+	 */
+	ret = amd_iommu_init_api();
+
 	init_device_table_dma();
 
 	for_each_iommu(iommu)
 		iommu_flush_all_caches(iommu);
 
-	ret = amd_iommu_init_api();
-
 	if (!ret)
 		print_iommu_info();