diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h
index d82517d..7580736 100644
--- a/include/asm-x86/dma-mapping.h
+++ b/include/asm-x86/dma-mapping.h
@@ -15,6 +15,7 @@
 extern struct device fallback_dev;
 extern int panic_on_overflow;
 extern int forbid_dac;
+extern int force_iommu;
 
 struct dma_mapping_ops {
 	int             (*mapping_error)(dma_addr_t dma_addr);