--- /dev/null
+++ b/arch/mips/include/asm/mach-ath79/mangle-port.h
@@ -0,0 +1,37 @@
+/*
+ *  Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This file was derived from: inlude/asm-mips/mach-generic/mangle-port.h
+ *      Copyright (C) 2003, 2004 Ralf Baechle
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#ifndef __ASM_MACH_ATH79_MANGLE_PORT_H
+#define __ASM_MACH_ATH79_MANGLE_PORT_H
+
+#ifdef CONFIG_PCI
+extern unsigned long (ath79_pci_swizzle_b)(unsigned long port);
+extern unsigned long (ath79_pci_swizzle_w)(unsigned long port);
+#else
+#define ath79_pci_swizzle_b(port) (port)
+#define ath79_pci_swizzle_w(port) (port)
+#endif
+
+#define __swizzle_addr_b(port)	ath79_pci_swizzle_b(port)
+#define __swizzle_addr_w(port)	ath79_pci_swizzle_w(port)
+#define __swizzle_addr_l(port)	(port)
+#define __swizzle_addr_q(port)	(port)
+
+# define ioswabb(a, x)           (x)
+# define __mem_ioswabb(a, x)     (x)
+# define ioswabw(a, x)           (x)
+# define __mem_ioswabw(a, x)     cpu_to_le16(x)
+# define ioswabl(a, x)           (x)
+# define __mem_ioswabl(a, x)     cpu_to_le32(x)
+# define ioswabq(a, x)           (x)
+# define __mem_ioswabq(a, x)     cpu_to_le64(x)
+
+#endif /* __ASM_MACH_ATH79_MANGLE_PORT_H */
--- a/arch/mips/ath79/pci.c
+++ b/arch/mips/ath79/pci.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/resource.h>
 #include <linux/platform_device.h>
@@ -25,6 +26,9 @@ static int (*ath79_pci_plat_dev_init)(st
 static const struct ath79_pci_irq *ath79_pci_irq_map __initdata;
 static unsigned ath79_pci_nr_irqs __initdata;
 
+static unsigned long (*__ath79_pci_swizzle_b)(unsigned long port);
+static unsigned long (*__ath79_pci_swizzle_w)(unsigned long port);
+
 static const struct ath79_pci_irq ar71xx_pci_irq_map[] __initconst = {
 	{
 		.slot	= 17,
@@ -202,12 +206,50 @@ ath79_register_pci_ar724x(int id,
 	return pdev;
 }
 
+static inline bool ar71xx_is_pci_addr(unsigned long port)
+{
+	unsigned long phys = CPHYSADDR(port);
+
+	return (phys >= AR71XX_PCI_MEM_BASE &&
+		phys < AR71XX_PCI_MEM_BASE + AR71XX_PCI_MEM_SIZE);
+}
+
+static unsigned long ar71xx_pci_swizzle_b(unsigned long port)
+{
+	return ar71xx_is_pci_addr(port) ? port ^ 3 : port;
+}
+
+static unsigned long ar71xx_pci_swizzle_w(unsigned long port)
+{
+	return ar71xx_is_pci_addr(port) ? port ^ 2 : port;
+}
+
+unsigned long ath79_pci_swizzle_b(unsigned long port)
+{
+	if (__ath79_pci_swizzle_b)
+		return __ath79_pci_swizzle_b(port);
+
+	return port;
+}
+EXPORT_SYMBOL(ath79_pci_swizzle_b);
+
+unsigned long ath79_pci_swizzle_w(unsigned long port)
+{
+	if (__ath79_pci_swizzle_w)
+		return __ath79_pci_swizzle_w(port);
+
+	return port;
+}
+EXPORT_SYMBOL(ath79_pci_swizzle_w);
+
 int __init ath79_register_pci(void)
 {
 	struct platform_device *pdev = NULL;
 
 	if (soc_is_ar71xx()) {
 		pdev = ath79_register_pci_ar71xx();
+		__ath79_pci_swizzle_b = ar71xx_pci_swizzle_b;
+		__ath79_pci_swizzle_w = ar71xx_pci_swizzle_w;
 	} else if (soc_is_ar724x()) {
 		pdev = ath79_register_pci_ar724x(-1,
 						 AR724X_PCI_CFG_BASE,
