include/asm-x86/pgtable_64.h - fp2-dev/kernel/msm - Gitiles

 #ifndef _X86_64_PGTABLE_H
 #define _X86_64_PGTABLE_H

 #include <linux/const.h>
 #ifndef __ASSEMBLY__

 /*
  * This file contains the functions and defines necessary to modify and use
  * the x86-64 page table tree.
  */
 #include <asm/processor.h>
 #include <linux/bitops.h>
 #include <linux/threads.h>
 #include <asm/pda.h>

 extern pud_t level3_kernel_pgt[512];
 extern pud_t level3_ident_pgt[512];
 extern pmd_t level2_kernel_pgt[512];
 extern pgd_t init_level4_pgt[];
 extern unsigned long __supported_pte_mask;

 #define swapper_pg_dir init_level4_pgt

 extern void paging_init(void);
 extern void clear_kernel_mapping(unsigned long addr, unsigned long size);

 /*
  * ZERO_PAGE is a global shared page that is always zero: used
  * for zero-mapped memory areas etc..
  */
 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

 #endif /* !__ASSEMBLY__ */

 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */
 #define PGDIR_SHIFT	39
 #define PTRS_PER_PGD	512

 /*
  * 3rd level page
  */
 #define PUD_SHIFT	30
 #define PTRS_PER_PUD	512

 /*
  * 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

 #ifndef __ASSEMBLY__

 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
 #define pmd_ERROR(e) \
 	printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
 #define pud_ERROR(e) \
 	printk("%s:%d: bad pud %p(%016lx).\n", __FILE__, __LINE__, &(e), pud_val(e))
 #define pgd_ERROR(e) \
 	printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))

 #define pgd_none(x)	(!pgd_val(x))
 #define pud_none(x)	(!pud_val(x))

 static inline void set_pte(pte_t *dst, pte_t val)
 {
 	pte_val(*dst) = pte_val(val);
 }
 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)

 static inline void set_pmd(pmd_t *dst, pmd_t val)
 {
 	*dst = val;
 }

 static inline void set_pud(pud_t *dst, pud_t val)
 {
 	*dst = val;
 }

 static inline void pud_clear (pud_t *pud)
 {
 	set_pud(pud, __pud(0));
 }

 static inline void set_pgd(pgd_t *dst, pgd_t val)
 {
 	*dst = val;
 }

 static inline void pgd_clear (pgd_t * pgd)
 {
 	set_pgd(pgd, __pgd(0));
 }

 #define ptep_get_and_clear(mm,addr,xp)	__pte(xchg(&(xp)->pte, 0))

 struct mm_struct;

 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full)
 {
 	pte_t pte;
 	if (full) {
 		pte = *ptep;
 		*ptep = __pte(0);
 	} else {
 		pte = ptep_get_and_clear(mm, addr, ptep);
 	}
 	return pte;
 }

 #define pte_same(a, b)		((a).pte == (b).pte)

 #define pte_pgprot(a)	(__pgprot((a).pte & ~PHYSICAL_PAGE_MASK))

 #endif /* !__ASSEMBLY__ */

 #define PMD_SIZE	(_AC(1,UL) << PMD_SHIFT)
 #define PMD_MASK	(~(PMD_SIZE-1))
 #define PUD_SIZE	(_AC(1,UL) << PUD_SHIFT)
 #define PUD_MASK	(~(PUD_SIZE-1))
 #define PGDIR_SIZE	(_AC(1,UL) << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))


 #define MAXMEM		 _AC(0x3fffffffffff, UL)
 #define VMALLOC_START    _AC(0xffffc20000000000, UL)
 #define VMALLOC_END      _AC(0xffffe1ffffffffff, UL)
 #define VMEMMAP_START	 _AC(0xffffe20000000000, UL)
 #define MODULES_VADDR    _AC(0xffffffff88000000, UL)
 #define MODULES_END      _AC(0xfffffffffff00000, UL)
 #define MODULES_LEN   (MODULES_END - MODULES_VADDR)

 #ifndef __ASSEMBLY__

 static inline unsigned long pgd_bad(pgd_t pgd)
 {
 	return pgd_val(pgd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
 }

 static inline unsigned long pud_bad(pud_t pud)
 {
 	return pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
 }

 static inline unsigned long pmd_bad(pmd_t pmd)
 {
 	return pmd_val(pmd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
 }

 #define pte_none(x)	(!pte_val(x))
 #define pte_present(x)	(pte_val(x) & (_PAGE_PRESENT | _PAGE_PROTNONE))
 #define pte_clear(mm,addr,xp)	do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)

 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))	/* FIXME: is this right? */
 #define pte_page(x)	pfn_to_page(pte_pfn(x))
 #define pte_pfn(x)  ((pte_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
 	pte_t pte;
 	pte_val(pte) = (page_nr << PAGE_SHIFT);
 	pte_val(pte) |= pgprot_val(pgprot);
 	pte_val(pte) &= __supported_pte_mask;
 	return pte;
 }

 /*
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
  */
 #define __LARGE_PTE (_PAGE_PSE|_PAGE_PRESENT)
 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
 static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_RW; }
 static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
 static inline int pte_huge(pte_t pte)		{ return pte_val(pte) & _PAGE_PSE; }

 static inline pte_t pte_mkclean(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_DIRTY)); return pte; }
 static inline pte_t pte_mkold(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_ACCESSED)); return pte; }
 static inline pte_t pte_wrprotect(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_RW)); return pte; }
 static inline pte_t pte_mkexec(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_NX)); return pte; }
 static inline pte_t pte_mkdirty(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_DIRTY)); return pte; }
 static inline pte_t pte_mkyoung(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_ACCESSED)); return pte; }
 static inline pte_t pte_mkwrite(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_RW)); return pte; }
 static inline pte_t pte_mkhuge(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_PSE)); return pte; }
 static inline pte_t pte_clrhuge(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_PSE)); return pte; }

 struct vm_area_struct;

 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 {
 	if (!pte_young(*ptep))
 		return 0;
 	return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte);
 }

 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	clear_bit(_PAGE_BIT_RW, &ptep->pte);
 }

 /*
  * Macro to mark a page protection value as "uncacheable".
  */
 #define pgprot_noncached(prot)	(__pgprot(pgprot_val(prot) | _PAGE_PCD | _PAGE_PWT))

 static inline int pmd_large(pmd_t pte) {
 	return (pmd_val(pte) & __LARGE_PTE) == __LARGE_PTE;
 }


 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  */

 /*
  * Level 4 access.
  */
 #define pgd_page_vaddr(pgd) ((unsigned long) __va((unsigned long)pgd_val(pgd) & PTE_MASK))
 #define pgd_page(pgd)		(pfn_to_page(pgd_val(pgd) >> PAGE_SHIFT))
 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
 #define pgd_offset_k(address) (init_level4_pgt + pgd_index(address))
 #define pgd_present(pgd) (pgd_val(pgd) & _PAGE_PRESENT)
 #define mk_kernel_pgd(address) ((pgd_t){ (address) | _KERNPG_TABLE })

 /* PUD - Level3 access */
 /* to find an entry in a page-table-directory. */
 #define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PHYSICAL_PAGE_MASK))
 #define pud_page(pud)		(pfn_to_page(pud_val(pud) >> PAGE_SHIFT))
 #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 #define pud_offset(pgd, address) ((pud_t *) pgd_page_vaddr(*(pgd)) + pud_index(address))
 #define pud_present(pud) (pud_val(pud) & _PAGE_PRESENT)

 /* PMD  - Level 2 access */
 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PTE_MASK))
 #define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 #define pmd_offset(dir, address) ((pmd_t *) pud_page_vaddr(*(dir)) + \
 			pmd_index(address))
 #define pmd_none(x)	(!pmd_val(x))
 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
 #define pmd_clear(xp)	do { set_pmd(xp, __pmd(0)); } while (0)
 #define pfn_pmd(nr,prot) (__pmd(((nr) << PAGE_SHIFT) | pgprot_val(prot)))
 #define pmd_pfn(x)  ((pmd_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

 #define pte_to_pgoff(pte) ((pte_val(pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
 #define pgoff_to_pte(off) ((pte_t) { ((off) << PAGE_SHIFT) | _PAGE_FILE })
 #define PTE_FILE_MAX_BITS __PHYSICAL_MASK_SHIFT

 /* PTE - Level 1 access. */

 /* page, protection -> pte */
 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))

 /* Change flags of a PTE */
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	pte_val(pte) &= _PAGE_CHG_MASK;
 	pte_val(pte) |= pgprot_val(newprot);
 	pte_val(pte) &= __supported_pte_mask;
        return pte;
 }

 #define pte_index(address) \
 		(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 #define pte_offset_kernel(dir, address) ((pte_t *) pmd_page_vaddr(*(dir)) + \
 			pte_index(address))

 /* x86-64 always has all page tables mapped. */
 #define pte_offset_map(dir,address) pte_offset_kernel(dir,address)
 #define pte_offset_map_nested(dir,address) pte_offset_kernel(dir,address)
 #define pte_unmap(pte) /* NOP */
 #define pte_unmap_nested(pte) /* NOP */

 #define update_mmu_cache(vma,address,pte) do { } while (0)

 /* We only update the dirty/accessed state if we set
  * the dirty bit by hand in the kernel, since the hardware
  * will do the accessed bit for us, and we don't want to
  * race with other CPU's that might be updating the dirty
  * bit at the same time. */
 #define  __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
 ({									  \
 	int __changed = !pte_same(*(__ptep), __entry);			  \
 	if (__changed && __dirty) {					  \
 		set_pte(__ptep, __entry);			  	  \
 		flush_tlb_page(__vma, __address);		  	  \
 	}								  \
 	__changed;							  \
 })

 /* Encode and de-code a swap entry */
 #define __swp_type(x)			(((x).val >> 1) & 0x3f)
 #define __swp_offset(x)			((x).val >> 8)
 #define __swp_entry(type, offset)	((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })

 extern spinlock_t pgd_lock;
 extern struct list_head pgd_list;

 extern int kern_addr_valid(unsigned long addr);

 pte_t *lookup_address(unsigned long addr);

 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
 		remap_pfn_range(vma, vaddr, pfn, size, prot)

 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

 #define pgtable_cache_init()   do { } while (0)
 #define check_pgt_cache()      do { } while (0)

 #define PAGE_AGP    PAGE_KERNEL_NOCACHE
 #define HAVE_PAGE_AGP 1

 /* fs/proc/kcore.c */
 #define	kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
 #define	kc_offset_to_vaddr(o) \
    (((o) & (1UL << (__VIRTUAL_MASK_SHIFT-1))) ? ((o) | (~__VIRTUAL_MASK)) : (o))

 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 #define __HAVE_ARCH_PTE_SAME
 #include <asm-generic/pgtable.h>
 #endif /* !__ASSEMBLY__ */

 #endif /* _X86_64_PGTABLE_H */
	#ifndef _X86_64_PGTABLE_H
	#define _X86_64_PGTABLE_H

	#include <linux/const.h>
	#ifndef __ASSEMBLY__

	/*
	* This file contains the functions and defines necessary to modify and use
	* the x86-64 page table tree.
	*/
	#include <asm/processor.h>
	#include <linux/bitops.h>
	#include <linux/threads.h>
	#include <asm/pda.h>

	extern pud_t level3_kernel_pgt[512];
	extern pud_t level3_ident_pgt[512];
	extern pmd_t level2_kernel_pgt[512];
	extern pgd_t init_level4_pgt[];
	extern unsigned long __supported_pte_mask;

	#define swapper_pg_dir init_level4_pgt

	extern void paging_init(void);
	extern void clear_kernel_mapping(unsigned long addr, unsigned long size);

	/*
	* ZERO_PAGE is a global shared page that is always zero: used
	* for zero-mapped memory areas etc..
	*/
	extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
	#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

	#endif /* !__ASSEMBLY__ */

	/*
	* PGDIR_SHIFT determines what a top-level page table entry can map
	*/
	#define PGDIR_SHIFT 39
	#define PTRS_PER_PGD 512

	/*
	* 3rd level page
	*/
	#define PUD_SHIFT 30
	#define PTRS_PER_PUD 512

	/*
	* 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

	#ifndef __ASSEMBLY__

	#define pte_ERROR(e) \
	printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
	#define pmd_ERROR(e) \
	printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
	#define pud_ERROR(e) \
	printk("%s:%d: bad pud %p(%016lx).\n", __FILE__, __LINE__, &(e), pud_val(e))
	#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))

	#define pgd_none(x) (!pgd_val(x))
	#define pud_none(x) (!pud_val(x))

	static inline void set_pte(pte_t *dst, pte_t val)
	{
	pte_val(*dst) = pte_val(val);
	}
	#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)

	static inline void set_pmd(pmd_t *dst, pmd_t val)
	{
	*dst = val;
	}

	static inline void set_pud(pud_t *dst, pud_t val)
	{
	*dst = val;
	}

	static inline void pud_clear (pud_t *pud)
	{
	set_pud(pud, __pud(0));
	}

	static inline void set_pgd(pgd_t *dst, pgd_t val)
	{
	*dst = val;
	}

	static inline void pgd_clear (pgd_t * pgd)
	{
	set_pgd(pgd, __pgd(0));
	}

	#define ptep_get_and_clear(mm,addr,xp) __pte(xchg(&(xp)->pte, 0))

	struct mm_struct;

	static inline pte_t ptep_get_and_clear_full(struct mm_struct mm, unsigned long addr, pte_t ptep, int full)
	{
	pte_t pte;
	if (full) {
	pte = *ptep;
	*ptep = __pte(0);
	} else {
	pte = ptep_get_and_clear(mm, addr, ptep);
	}
	return pte;
	}

	#define pte_same(a, b) ((a).pte == (b).pte)

	#define pte_pgprot(a) (__pgprot((a).pte & ~PHYSICAL_PAGE_MASK))

	#endif /* !__ASSEMBLY__ */

	#define PMD_SIZE (_AC(1,UL) << PMD_SHIFT)
	#define PMD_MASK (~(PMD_SIZE-1))
	#define PUD_SIZE (_AC(1,UL) << PUD_SHIFT)
	#define PUD_MASK (~(PUD_SIZE-1))
	#define PGDIR_SIZE (_AC(1,UL) << PGDIR_SHIFT)
	#define PGDIR_MASK (~(PGDIR_SIZE-1))


	#define MAXMEM _AC(0x3fffffffffff, UL)
	#define VMALLOC_START _AC(0xffffc20000000000, UL)
	#define VMALLOC_END _AC(0xffffe1ffffffffff, UL)
	#define VMEMMAP_START _AC(0xffffe20000000000, UL)
	#define MODULES_VADDR _AC(0xffffffff88000000, UL)
	#define MODULES_END _AC(0xfffffffffff00000, UL)
	#define MODULES_LEN (MODULES_END - MODULES_VADDR)

	#ifndef __ASSEMBLY__

	static inline unsigned long pgd_bad(pgd_t pgd)
	{
	return pgd_val(pgd) & ~(PTE_MASK \| _KERNPG_TABLE \| _PAGE_USER);
	}

	static inline unsigned long pud_bad(pud_t pud)
	{
	return pud_val(pud) & ~(PTE_MASK \| _KERNPG_TABLE \| _PAGE_USER);
	}

	static inline unsigned long pmd_bad(pmd_t pmd)
	{
	return pmd_val(pmd) & ~(PTE_MASK \| _KERNPG_TABLE \| _PAGE_USER);
	}

	#define pte_none(x) (!pte_val(x))
	#define pte_present(x) (pte_val(x) & (_PAGE_PRESENT \| _PAGE_PROTNONE))
	#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)

	#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT)) /* FIXME: is this right? */
	#define pte_page(x) pfn_to_page(pte_pfn(x))
	#define pte_pfn(x) ((pte_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

	static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
	{
	pte_t pte;
	pte_val(pte) = (page_nr << PAGE_SHIFT);
	pte_val(pte) \|= pgprot_val(pgprot);
	pte_val(pte) &= __supported_pte_mask;
	return pte;
	}

	/*
	* The following only work if pte_present() is true.
	* Undefined behaviour if not..
	*/
	#define __LARGE_PTE (_PAGE_PSE\|_PAGE_PRESENT)
	static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
	static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
	static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
	static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
	static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_PSE; }

	static inline pte_t pte_mkclean(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_DIRTY)); return pte; }
	static inline pte_t pte_mkold(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_ACCESSED)); return pte; }
	static inline pte_t pte_wrprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_RW)); return pte; }
	static inline pte_t pte_mkexec(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_NX)); return pte; }
	static inline pte_t pte_mkdirty(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) \| _PAGE_DIRTY)); return pte; }
	static inline pte_t pte_mkyoung(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) \| _PAGE_ACCESSED)); return pte; }
	static inline pte_t pte_mkwrite(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) \| _PAGE_RW)); return pte; }
	static inline pte_t pte_mkhuge(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) \| _PAGE_PSE)); return pte; }
	static inline pte_t pte_clrhuge(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_PSE)); return pte; }

	struct vm_area_struct;

	static inline int ptep_test_and_clear_young(struct vm_area_struct vma, unsigned long addr, pte_t ptep)
	{
	if (!pte_young(*ptep))
	return 0;
	return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte);
	}

	static inline void ptep_set_wrprotect(struct mm_struct mm, unsigned long addr, pte_t ptep)
	{
	clear_bit(_PAGE_BIT_RW, &ptep->pte);
	}

	/*
	* Macro to mark a page protection value as "uncacheable".
	*/
	#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) \| _PAGE_PCD \| _PAGE_PWT))

	static inline int pmd_large(pmd_t pte) {
	return (pmd_val(pte) & __LARGE_PTE) == __LARGE_PTE;
	}


	/*
	* Conversion functions: convert a page and protection to a page entry,
	* and a page entry and page directory to the page they refer to.
	*/

	/*
	* Level 4 access.
	*/
	#define pgd_page_vaddr(pgd) ((unsigned long) __va((unsigned long)pgd_val(pgd) & PTE_MASK))
	#define pgd_page(pgd) (pfn_to_page(pgd_val(pgd) >> PAGE_SHIFT))
	#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
	#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
	#define pgd_offset_k(address) (init_level4_pgt + pgd_index(address))
	#define pgd_present(pgd) (pgd_val(pgd) & _PAGE_PRESENT)
	#define mk_kernel_pgd(address) ((pgd_t){ (address) \| _KERNPG_TABLE })

	/* PUD - Level3 access */
	/* to find an entry in a page-table-directory. */
	#define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PHYSICAL_PAGE_MASK))
	#define pud_page(pud) (pfn_to_page(pud_val(pud) >> PAGE_SHIFT))
	#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
	#define pud_offset(pgd, address) ((pud_t ) pgd_page_vaddr((pgd)) + pud_index(address))
	#define pud_present(pud) (pud_val(pud) & _PAGE_PRESENT)

	/* PMD - Level 2 access */
	#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PTE_MASK))
	#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

	#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
	#define pmd_offset(dir, address) ((pmd_t ) pud_page_vaddr((dir)) + \
	pmd_index(address))
	#define pmd_none(x) (!pmd_val(x))
	#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
	#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
	#define pfn_pmd(nr,prot) (__pmd(((nr) << PAGE_SHIFT) \| pgprot_val(prot)))
	#define pmd_pfn(x) ((pmd_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

	#define pte_to_pgoff(pte) ((pte_val(pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
	#define pgoff_to_pte(off) ((pte_t) { ((off) << PAGE_SHIFT) \| _PAGE_FILE })
	#define PTE_FILE_MAX_BITS __PHYSICAL_MASK_SHIFT

	/* PTE - Level 1 access. */

	/* page, protection -> pte */
	#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))

	/* Change flags of a PTE */
	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	{
	pte_val(pte) &= _PAGE_CHG_MASK;
	pte_val(pte) \|= pgprot_val(newprot);
	pte_val(pte) &= __supported_pte_mask;
	return pte;
	}

	#define pte_index(address) \
	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
	#define pte_offset_kernel(dir, address) ((pte_t ) pmd_page_vaddr((dir)) + \
	pte_index(address))

	/* x86-64 always has all page tables mapped. */
	#define pte_offset_map(dir,address) pte_offset_kernel(dir,address)
	#define pte_offset_map_nested(dir,address) pte_offset_kernel(dir,address)
	#define pte_unmap(pte) /* NOP */
	#define pte_unmap_nested(pte) /* NOP */

	#define update_mmu_cache(vma,address,pte) do { } while (0)

	/* We only update the dirty/accessed state if we set
	* the dirty bit by hand in the kernel, since the hardware
	* will do the accessed bit for us, and we don't want to
	* race with other CPU's that might be updating the dirty
	* bit at the same time. */
	#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
	#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
	({ \
	int __changed = !pte_same(*(__ptep), __entry); \
	if (__changed && __dirty) { \
	set_pte(__ptep, __entry); \
	flush_tlb_page(__vma, __address); \
	} \
	__changed; \
	})

	/* Encode and de-code a swap entry */
	#define __swp_type(x) (((x).val >> 1) & 0x3f)
	#define __swp_offset(x) ((x).val >> 8)
	#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) \| ((offset) << 8) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

	extern spinlock_t pgd_lock;
	extern struct list_head pgd_list;

	extern int kern_addr_valid(unsigned long addr);

	pte_t *lookup_address(unsigned long addr);

	#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
	remap_pfn_range(vma, vaddr, pfn, size, prot)

	#define HAVE_ARCH_UNMAPPED_AREA
	#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

	#define pgtable_cache_init() do { } while (0)
	#define check_pgt_cache() do { } while (0)

	#define PAGE_AGP PAGE_KERNEL_NOCACHE
	#define HAVE_PAGE_AGP 1

	/* fs/proc/kcore.c */
	#define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
	#define kc_offset_to_vaddr(o) \
	(((o) & (1UL << (__VIRTUAL_MASK_SHIFT-1))) ? ((o) \| (~__VIRTUAL_MASK)) : (o))

	#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
	#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
	#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
	#define __HAVE_ARCH_PTEP_SET_WRPROTECT
	#define __HAVE_ARCH_PTE_SAME
	#include <asm-generic/pgtable.h>
	#endif /* !__ASSEMBLY__ */

	#endif /* _X86_64_PGTABLE_H */