+int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, int write_access);
+int hugetlb_reserve_pages(struct inode *inode, long from, long to);
+void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
+
+extern unsigned long max_huge_pages;
+extern const unsigned long hugetlb_zero, hugetlb_infinity;
+extern int sysctl_hugetlb_shm_group;
+
+/* arch callbacks */
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr);
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);