void kunmap(struct page *page);
void *kmap_atomic(struct page *page, enum km_type type);
void kunmap_atomic(void *kvaddr, enum km_type type);
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
struct page *kmap_atomic_to_page(void *ptr);
#define flush_cache_kmaps() do { } while (0)