diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 83aae47475940b383fe89c5fd3cf30c7c7cb3ec4..ffe22bc3ac8eda872625bd178370c0e98de83fff 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -1456,7 +1456,7 @@ int dmar_reenable_qi(struct intel_iommu *iommu)
 /*
  * Check interrupt remapping support in DMAR table description.
  */
-int dmar_ir_support(void)
+int __init dmar_ir_support(void)
 {
 	struct acpi_table_dmar *dmar;
 	dmar = (struct acpi_table_dmar *)dmar_tbl;