diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 5d1ae854bfda..2d9cd1327a06 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -162,6 +162,9 @@ config NO_IOPORT
 config IO_TRAPPED
 	bool
 
+config SWAP_IO_SPACE
+	bool
+
 config DMA_COHERENT
 	bool
 
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 28c5aa58bb45..eb76cb32f49f 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -24,6 +24,7 @@
 #define __IO_PREFIX     generic
 #include <asm/io_generic.h>
 #include <asm/io_trapped.h>
+#include <mach/mangle-port.h>
 
 #define __raw_writeb(v,a)	(__chk_io_ptr(a), *(volatile u8  __force *)(a) = (v))
 #define __raw_writew(v,a)	(__chk_io_ptr(a), *(volatile u16 __force *)(a) = (v))
@@ -35,21 +36,15 @@
 #define __raw_readl(a)		(__chk_io_ptr(a), *(volatile u32 __force *)(a))
 #define __raw_readq(a)		(__chk_io_ptr(a), *(volatile u64 __force *)(a))
 
-#define readb_relaxed(c)	({ u8  __v = __raw_readb(c); __v; })
-#define readw_relaxed(c)	({ u16 __v = le16_to_cpu((__force __le16) \
-					__raw_readw(c)); __v; })
-#define readl_relaxed(c)	({ u32 __v = le32_to_cpu((__force __le32) \
-					__raw_readl(c)); __v; })
-#define readq_relaxed(c)	({ u64 __v = le64_to_cpu((__force __le64) \
-					__raw_readq(c)); __v; })
+#define readb_relaxed(c)	({ u8  __v = ioswabb(__raw_readb(c)); __v; })
+#define readw_relaxed(c)	({ u16 __v = ioswabw(__raw_readw(c)); __v; })
+#define readl_relaxed(c)	({ u32 __v = ioswabl(__raw_readl(c)); __v; })
+#define readq_relaxed(c)	({ u64 __v = ioswabq(__raw_readq(c)); __v; })
 
-#define writeb_relaxed(v,c)	((void)__raw_writeb(v,c))
-#define writew_relaxed(v,c)	((void)__raw_writew((__force u16) \
-					cpu_to_le16(v),c))
-#define writel_relaxed(v,c)	((void)__raw_writel((__force u32) \
-					cpu_to_le32(v),c))
-#define writeq_relaxed(v,c)	((void)__raw_writeq((__force u64) \
-					cpu_to_le64(v),c))
+#define writeb_relaxed(v,c)	((void)__raw_writeb((__force  u8)ioswabb(v),c))
+#define writew_relaxed(v,c)	((void)__raw_writew((__force u16)ioswabw(v),c))
+#define writel_relaxed(v,c)	((void)__raw_writel((__force u32)ioswabl(v),c))
+#define writeq_relaxed(v,c)	((void)__raw_writeq((__force u64)ioswabq(v),c))
 
 #define readb(a)		({ u8  r_ = readb_relaxed(a); rmb(); r_; })
 #define readw(a)		({ u16 r_ = readw_relaxed(a); rmb(); r_; })
diff --git a/arch/sh/include/mach-common/mach/mangle-port.h b/arch/sh/include/mach-common/mach/mangle-port.h
new file mode 100644
index 000000000000..4ca1769a0f12
--- /dev/null
+++ b/arch/sh/include/mach-common/mach/mangle-port.h
@@ -0,0 +1,49 @@
+/*
+ * SH version cribbed from the MIPS copy:
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003, 2004 Ralf Baechle
+ */
+#ifndef __MACH_COMMON_MANGLE_PORT_H
+#define __MACH_COMMON_MANGLE_PORT_H
+
+/*
+ * Sane hardware offers swapping of PCI/ISA I/O space accesses in hardware;
+ * less sane hardware forces software to fiddle with this...
+ *
+ * Regardless, if the host bus endianness mismatches that of PCI/ISA, then
+ * you can't have the numerical value of data and byte addresses within
+ * multibyte quantities both preserved at the same time.  Hence two
+ * variations of functions: non-prefixed ones that preserve the value
+ * and prefixed ones that preserve byte addresses.  The latters are
+ * typically used for moving raw data between a peripheral and memory (cf.
+ * string I/O functions), hence the "__mem_" prefix.
+ */
+#if defined(CONFIG_SWAP_IO_SPACE)
+
+# define ioswabb(x)		(x)
+# define __mem_ioswabb(x)	(x)
+# define ioswabw(x)		le16_to_cpu(x)
+# define __mem_ioswabw(x)	(x)
+# define ioswabl(x)		le32_to_cpu(x)
+# define __mem_ioswabl(x)	(x)
+# define ioswabq(x)		le64_to_cpu(x)
+# define __mem_ioswabq(x)	(x)
+
+#else
+
+# define ioswabb(x)		(x)
+# define __mem_ioswabb(x)	(x)
+# define ioswabw(x)		(x)
+# define __mem_ioswabw(x)	cpu_to_le16(x)
+# define ioswabl(x)		(x)
+# define __mem_ioswabl(x)	cpu_to_le32(x)
+# define ioswabq(x)		(x)
+# define __mem_ioswabq(x)	cpu_to_le32(x)
+
+#endif
+
+#endif /* __MACH_COMMON_MANGLE_PORT_H */