diff --git a/arch/ia64/include/asm/swiotlb.h b/arch/ia64/include/asm/swiotlb.h
index dcbaea7ce12868436a39d4f2bd31a406a6d3a704..f0acde68aaea5c3dd685b853f542647393bbbd6b 100644
--- a/arch/ia64/include/asm/swiotlb.h
+++ b/arch/ia64/include/asm/swiotlb.h
@@ -4,8 +4,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/swiotlb.h>
 
-extern int swiotlb_force;
-
 #ifdef CONFIG_SWIOTLB
 extern int swiotlb;
 extern void pci_swiotlb_init(void);
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index 940f13a213f864a07a64f3494b17d258b4907394..87ffcb12a1b87c91b3ad9fd6f459b97ad222aa5c 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -3,10 +3,6 @@
 
 #include <linux/swiotlb.h>
 
-/* SWIOTLB interface */
-
-extern int swiotlb_force;
-
 #ifdef CONFIG_SWIOTLB
 extern int swiotlb;
 extern int pci_swiotlb_init(void);
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index eb9bdb4d4854d6d12101c9d645a7bbdf691f02aa..febedcf67c7ec38464add407881e0351f6352ca5 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -7,6 +7,8 @@ struct device;
 struct dma_attrs;
 struct scatterlist;
 
+extern int swiotlb_force;
+
 /*
  * Maximum allowable number of contiguous slabs to map,
  * must be a power of 2.  What is the appropriate value ?