#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) })
#define __swp_entry_to_pte(x) __pte((x).val)
-void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
-void pgtable_cache_init(void);
extern int map_kernel_page(unsigned long ea, unsigned long pa,
unsigned long flags);
extern int __meminit vmemmap_create_mapping(unsigned long start,