linux-2.6/include/asm-x86/io.h

#define ARCH_HAS_IOREMAP_WC

#ifdef CONFIG_X86_32
# include "io_32.h"
#else
# include "io_64.h"
#endif
extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
				unsigned long prot_val);
extern void __iomem * ioremap_wc(unsigned long offset, unsigned long size);