extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
static inline int io_remap_pfn_range(struct vm_area_struct *vma,
extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
static inline int io_remap_pfn_range(struct vm_area_struct *vma,