#ifndef _I386_PGTABLE_3LEVEL_H#define _I386_PGTABLE_3LEVEL_H/* * Intel Physical Address Extension (PAE) Mode - three-level page * tables on PPro+ CPUs. * * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> *//* * PGDIR_SHIFT determines what a top-level page table entry can map */#define PGDIR_SHIFT	30#define PTRS_PER_PGD	4/* * PMD_SHIFT determines the size of the area a middle-level * page table can map */#define PMD_SHIFT	21#define PTRS_PER_PMD	512/* * entries per page directory level */#define PTRS_PER_PTE	512#define pte_ERROR(e) \	printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)#define pmd_ERROR(e) \	printk("%s:%d: bad pmd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))#define pgd_ERROR(e) \	printk("%s:%d: bad pgd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))static inline int pgd_none(pgd_t pgd)		{ return 0; }static inline int pgd_bad(pgd_t pgd)		{ return 0; }static inline int pgd_present(pgd_t pgd)	{ return 1; }/* Rules for using set_pte: the pte being assigned *must* be * either not present or in a state where the hardware will * not attempt to update the pte.  In places where this is * not possible, use pte_get_and_clear to obtain the old pte * value and then use set_pte to update it.  -ben */static inline void set_pte(pte_t *ptep, pte_t pte){	ptep->pte_high = pte.pte_high;	smp_wmb();	ptep->pte_low = pte.pte_low;}#define set_pmd(pmdptr,pmdval) \		set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))#define set_pgd(pgdptr,pgdval) \		set_64bit((unsigned long long *)(pgdptr),pgd_val(pgdval))/* * Pentium-II erratum A13: in PAE mode we explicitly have to flush * the TLB via cr3 if the top-level pgd is changed... * We do not let the generic code free and clear pgd entries due to * this erratum. */static inline void pgd_clear (pgd_t * pgd) { }#define pgd_page(pgd) \((unsigned long) __va(pgd_val(pgd) & PAGE_MASK))/* Find an entry in the second-level page table.. */#define pmd_offset(dir, address) ((pmd_t *) pgd_page(*(dir)) + \			__pmd_offset(address))static inline pte_t ptep_get_and_clear(pte_t *ptep){	pte_t res;	/* xchg acts as a barrier before the setting of the high bits */	res.pte_low = xchg(&ptep->pte_low, 0);	res.pte_high = ptep->pte_high;	ptep->pte_high = 0;	return res;}static inline int pte_same(pte_t a, pte_t b){	return a.pte_low == b.pte_low && a.pte_high == b.pte_high;}#define pte_page(x)	(mem_map+(((x).pte_low >> PAGE_SHIFT) | ((x).pte_high << (32 - PAGE_SHIFT))))#define pte_none(x)	(!(x).pte_low && !(x).pte_high)static inline pte_t __mk_pte(unsigned long page_nr, pgprot_t pgprot){	pte_t pte;	pte.pte_high = page_nr >> (32 - PAGE_SHIFT);	pte.pte_low = (page_nr << PAGE_SHIFT) | pgprot_val(pgprot);	return pte;}#endif /* _I386_PGTABLE_3LEVEL_H */