hpte_update(mm, addr, old, 0);
hpte_update(mm, addr, ptep, old, 0);
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep){	unsigned long old;       	if ((pte_val(*ptep) & _PAGE_RW) == 0)       		return;	old = pte_update(ptep, _PAGE_RW);	if (old & _PAGE_HASHPTE)		hpte_update(mm, addr, old, 0);}