#ifndef __ASM_ARM_ARCH_IO_H
#define __ASM_ARM_ARCH_IO_H
+#include <asm/hardware.h>
+
#define IO_SPACE_LIMIT 0xffffffff
#define __mem_pci(a) (a)
-#define ___io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
/*
- * The IXP2400 before revision B0 asserts byte lanes for PCI I/O
+ * The A? revisions of the IXP2000s assert byte lanes for PCI I/O
* transactions the other way round (MEM transactions don't have this
- * issue), so we need to override the standard functions. B0 and later
- * have a bit that can be set to 1 to get the 'proper' behavior, but
- * since that isn't available on the A? revisions we just keep doing
- * things manually.
+ * issue), so if we want to support those models, we need to override
+ * the standard I/O functions.
+ *
+ * B0 and later have a bit that can be set to 1 to get the proper
+ * behavior for I/O transactions, which then allows us to use the
+ * standard I/O functions. This is what we do if the user does not
+ * explicitly ask for support for pre-B0.
*/
+#ifdef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
+#define ___io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
+
#define alignb(addr) (void __iomem *)((unsigned long)(addr) ^ 3)
#define alignw(addr) (void __iomem *)((unsigned long)(addr) ^ 2)
#define ioport_map(port, nr) ___io(port)
#define ioport_unmap(addr)
+#else
+#define __io(p) ((void __iomem *)((p)+IXP2000_PCI_IO_VIRT_BASE))
+#endif
#ifdef CONFIG_ARCH_IXDP2X01