swiotlb: Remove duplicate swiotlb_force extern declarations

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: tony.luck@intel.com
LKML-Reference: <1258199198-16657-4-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/ia64/include/asm/swiotlb.h b/arch/ia64/include/asm/swiotlb.h
index dcbaea7..f0acde6 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 940f13a..87ffcb1 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 eb9bdb4..febedcf 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -7,6 +7,8 @@
 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 ?