#define MAP_NR(addr) (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)
#define virt_to_page(addr) (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))
#define MAP_NR(addr) (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)
#define virt_to_page(addr) (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))