diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 9676100b83ee..f8afdd271f3d 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -56,6 +56,9 @@ config MMU
 config NEED_DMA_MAP_STATE
 	def_bool y
 
+config NEED_SG_DMA_LENGTH
+	def_bool y
+
 config SWIOTLB
        bool
 
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 0e318c905eea..c5ee4ce60b57 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -186,6 +186,9 @@ config DMA_NONCOHERENT
 config NEED_DMA_MAP_STATE
 	def_bool DMA_NONCOHERENT
 
+config NEED_SG_DMA_LENGTH
+	def_bool y
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index d6781ce687e2..6f1470baa314 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -133,6 +133,9 @@ config ZONE_DMA
 config NEED_DMA_MAP_STATE
 	def_bool y
 
+config NEED_SG_DMA_LENGTH
+	def_bool y
+
 config GENERIC_ISA_DMA
 	bool
 	default y if SPARC32
diff --git a/arch/sparc/include/asm/scatterlist.h b/arch/sparc/include/asm/scatterlist.h
index 0fa0d6da2107..69d21bb052f1 100644
--- a/arch/sparc/include/asm/scatterlist.h
+++ b/arch/sparc/include/asm/scatterlist.h
@@ -1,8 +1,6 @@
 #ifndef _SPARC_SCATTERLIST_H
 #define _SPARC_SCATTERLIST_H
 
-#define sg_dma_len(sg)     	((sg)->dma_length)
-
 #define ISA_DMA_THRESHOLD	(~0UL)
 
 #include <asm-generic/scatterlist.h>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e0c619c55b4e..5bdc143b1228 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -109,6 +109,9 @@ config SBUS
 config NEED_DMA_MAP_STATE
        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 
+config NEED_SG_DMA_LENGTH
+	def_bool X86_64
+
 config GENERIC_ISA_DMA
 	def_bool y
 
diff --git a/include/asm-generic/scatterlist.h b/include/asm-generic/scatterlist.h
index 51a7a43ab0ce..5e087944a659 100644
--- a/include/asm-generic/scatterlist.h
+++ b/include/asm-generic/scatterlist.h
@@ -11,7 +11,9 @@ struct scatterlist {
 	unsigned int	offset;
 	unsigned int	length;
 	dma_addr_t	dma_address;
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
 	unsigned int	dma_length;
+#endif
 };
 
 /*
@@ -22,17 +24,12 @@ struct scatterlist {
  * is 0.
  */
 #define sg_dma_address(sg)	((sg)->dma_address)
-#ifndef sg_dma_len
-/*
- * Normally, you have an iommu on 64 bit machines, but not on 32 bit
- * machines. Architectures that are differnt should override this.
- */
-#if __BITS_PER_LONG == 64
+
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
 #define sg_dma_len(sg)		((sg)->dma_length)
 #else
 #define sg_dma_len(sg)		((sg)->length)
-#endif /* 64 bit */
-#endif /* sg_dma_len */
+#endif
 
 #define ARCH_HAS_SG_CHAIN