extern void __kunmap(struct page *page);
extern void *__kmap_atomic(struct page *page, enum km_type type);
extern void __kunmap_atomic(void *kvaddr, enum km_type type);
extern void __kunmap(struct page *page);
extern void *__kmap_atomic(struct page *page, enum km_type type);
extern void __kunmap_atomic(void *kvaddr, enum km_type type);