include/asm-um/pgtable.h - linux - Git at Google

 /*
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgtable.h
  * Licensed under the GPL
  */

 #ifndef __UM_PGTABLE_H
 #define __UM_PGTABLE_H

 #include "linux/sched.h"
 #include "linux/linkage.h"
 #include "asm/processor.h"
 #include "asm/page.h"
 #include "asm/fixmap.h"

 #define _PAGE_PRESENT	0x001
 #define _PAGE_NEWPAGE	0x002
 #define _PAGE_NEWPROT   0x004
 #define _PAGE_FILE	0x008   /* set:pagecache unset:swap */
 #define _PAGE_PROTNONE	0x010	/* If not present */
 #define _PAGE_RW	0x020
 #define _PAGE_USER	0x040
 #define _PAGE_ACCESSED	0x080
 #define _PAGE_DIRTY	0x100

 #ifdef CONFIG_3_LEVEL_PGTABLES
 #include "asm/pgtable-3level.h"
 #else
 #include "asm/pgtable-2level.h"
 #endif

 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

 extern void *um_virt_to_phys(struct task_struct *task, unsigned long virt,
 			     pte_t *pte_out);

 /* zero page used for uninitialized stuff */
 extern unsigned long *empty_zero_page;

 #define pgtable_cache_init() do ; while (0)

 /*
  * pgd entries used up by user/kernel:
  */

 #define USER_PGD_PTRS (TASK_SIZE >> PGDIR_SHIFT)
 #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)

 #ifndef __ASSEMBLY__
 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  * current 8MB value just means that there will be a 8MB "hole" after the
  * physical memory until the kernel virtual memory starts.  That means that
  * any out-of-bounds memory accesses will hopefully be caught.
  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  * area for the same reason. ;)
  */

 extern unsigned long end_iomem;

 #define VMALLOC_OFFSET	(__va_space)
 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))

 #ifdef CONFIG_HIGHMEM
 # define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
 #else
 # define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
 #endif

 #define REGION_SHIFT	(sizeof(pte_t) * 8 - 4)
 #define REGION_MASK	(((unsigned long) 0xf) << REGION_SHIFT)

 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)

 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
 #define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED)

 /*
  * The i386 can't do page protection for execute, and considers that the same are read.
  * Also, write permissions imply read permissions. This is the closest we can get..
  */
 #define __P000	PAGE_NONE
 #define __P001	PAGE_READONLY
 #define __P010	PAGE_COPY
 #define __P011	PAGE_COPY
 #define __P100	PAGE_READONLY
 #define __P101	PAGE_READONLY
 #define __P110	PAGE_COPY
 #define __P111	PAGE_COPY

 #define __S000	PAGE_NONE
 #define __S001	PAGE_READONLY
 #define __S010	PAGE_SHARED
 #define __S011	PAGE_SHARED
 #define __S100	PAGE_READONLY
 #define __S101	PAGE_READONLY
 #define __S110	PAGE_SHARED
 #define __S111	PAGE_SHARED

 /*
  * Define this if things work differently on an i386 and an i486:
  * it will (on an i486) warn about kernel memory accesses that are
  * done without a 'verify_area(VERIFY_WRITE,..)'
  */
 #undef TEST_VERIFY_AREA

 /* page table for 0-4MB for everybody */
 extern unsigned long pg0[1024];

 /*
  * BAD_PAGETABLE is used when we need a bogus page-table, while
  * BAD_PAGE is used for a bogus page.
  *
  * ZERO_PAGE is a global shared page that is always zero: used
  * for zero-mapped memory areas etc..
  */
 extern pte_t __bad_page(void);
 extern pte_t * __bad_pagetable(void);

 #define BAD_PAGETABLE __bad_pagetable()
 #define BAD_PAGE __bad_page()

 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)

 /* number of bits that fit into a memory pointer */
 #define BITS_PER_PTR			(8*sizeof(unsigned long))

 /* to align the pointer to a pointer address */
 #define PTR_MASK			(~(sizeof(void*)-1))

 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 /* 64-bit machines, beware!  SRB. */
 #define SIZEOF_PTR_LOG2			3

 /* to find an entry in a page-table */
 #define PAGE_PTR(address) \
 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)

 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))

 #define pmd_none(x)	(!(pmd_val(x) & ~_PAGE_NEWPAGE))
 #define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
 #define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)

 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)

 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)

 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))

 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)

 #define pte_address(x) (__va(pte_val(x) & PAGE_MASK))
 #define mk_phys(a, r) ((a) + (((unsigned long) r) << REGION_SHIFT))
 #define phys_addr(p) ((p) & ~REGION_MASK)

 /*
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
  */
 static inline int pte_user(pte_t pte)
 {
 	return((pte_get_bits(pte, _PAGE_USER)) &&
 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
 }

 static inline int pte_read(pte_t pte)
 {
 	return((pte_get_bits(pte, _PAGE_USER)) &&
 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
 }

 static inline int pte_exec(pte_t pte){
 	return((pte_get_bits(pte, _PAGE_USER)) &&
 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
 }

 static inline int pte_write(pte_t pte)
 {
 	return((pte_get_bits(pte, _PAGE_RW)) &&
 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
 }

 /*
  * The following only works if pte_present() is not true.
  */
 static inline int pte_file(pte_t pte)
 {
 	return pte_get_bits(pte, _PAGE_FILE);
 }

 static inline int pte_dirty(pte_t pte)
 {
 	return pte_get_bits(pte, _PAGE_DIRTY);
 }

 static inline int pte_young(pte_t pte)
 {
 	return pte_get_bits(pte, _PAGE_ACCESSED);
 }

 static inline int pte_newpage(pte_t pte)
 {
 	return pte_get_bits(pte, _PAGE_NEWPAGE);
 }

 static inline int pte_newprot(pte_t pte)
 {
 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 }

 static inline pte_t pte_rdprotect(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_USER);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_exprotect(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_USER);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_mkclean(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_DIRTY);
 	return(pte);
 }

 static inline pte_t pte_mkold(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_ACCESSED);
 	return(pte);
 }

 static inline pte_t pte_wrprotect(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_RW);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_mkread(pte_t pte)
 {
 	pte_set_bits(pte, _PAGE_RW);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_mkexec(pte_t pte)
 {
 	pte_set_bits(pte, _PAGE_USER);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_mkdirty(pte_t pte)
 {
 	pte_set_bits(pte, _PAGE_DIRTY);
 	return(pte);
 }

 static inline pte_t pte_mkyoung(pte_t pte)
 {
 	pte_set_bits(pte, _PAGE_ACCESSED);
 	return(pte);
 }

 static inline pte_t pte_mkwrite(pte_t pte)
 {
 	pte_set_bits(pte, _PAGE_RW);
 	return(pte_mknewprot(pte));
 }

 static inline pte_t pte_mkuptodate(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_NEWPAGE);
 	if(pte_present(pte))
 		pte_clear_bits(pte, _PAGE_NEWPROT);
 	return(pte);
 }

 extern phys_t page_to_phys(struct page *page);

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

 extern pte_t mk_pte(struct page *page, pgprot_t pgprot);

 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 	if(pte_present(pte)) pte = pte_mknewpage(pte_mknewprot(pte));
 	return pte;
 }

 #define pmd_page_kernel(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))

 /*
  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
  *
  * this macro returns the index of the entry in the pgd page which would
  * control the given virtual address
  */
 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))

 #define pgd_index_k(addr) pgd_index(addr)

 /*
  * pgd_offset() returns a (pgd_t *)
  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
  */
 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))

 /*
  * a shortcut which implies the use of the kernel's pgd, instead
  * of a process's
  */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)

 /*
  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
  *
  * this macro returns the index of the entry in the pmd page which would
  * control the given virtual address
  */
 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

 /*
  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
  *
  * this macro returns the index of the entry in the pte page which would
  * control the given virtual address
  */
 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 #define pte_offset_kernel(dir, address) \
 	((pte_t *) pmd_page_kernel(*(dir)) +  pte_index(address))
 #define pte_offset_map(dir, address) \
 	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
 #define pte_unmap(pte) do { } while (0)
 #define pte_unmap_nested(pte) do { } while (0)

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

 /* Encode and de-code a swap entry */
 #define __swp_type(x)			(((x).val >> 4) & 0x3f)
 #define __swp_offset(x)			((x).val >> 11)

 #define __swp_entry(type, offset) \
 	((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
 #define __pte_to_swp_entry(pte) \
 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })

 #define kern_addr_valid(addr) (1)

 #include <asm-generic/pgtable.h>

 #include <asm-generic/pgtable-nopud.h>

 #endif
 #endif

 extern struct page *phys_to_page(const unsigned long phys);
 extern struct page *__virt_to_page(const unsigned long virt);
 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)

 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically
  * adjust the settings for this buffer only.  This must remain at the end
  * of the file.
  * ---------------------------------------------------------------------------
  * Local variables:
  * c-file-style: "linux"
  * End:
  */
	/*
	* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
	* Copyright 2003 PathScale, Inc.
	* Derived from include/asm-i386/pgtable.h
	* Licensed under the GPL
	*/

	#ifndef __UM_PGTABLE_H
	#define __UM_PGTABLE_H

	#include "linux/sched.h"
	#include "linux/linkage.h"
	#include "asm/processor.h"
	#include "asm/page.h"
	#include "asm/fixmap.h"

	#define _PAGE_PRESENT 0x001
	#define _PAGE_NEWPAGE 0x002
	#define _PAGE_NEWPROT 0x004
	#define _PAGE_FILE 0x008 /* set:pagecache unset:swap */
	#define _PAGE_PROTNONE 0x010 /* If not present */
	#define _PAGE_RW 0x020
	#define _PAGE_USER 0x040
	#define _PAGE_ACCESSED 0x080
	#define _PAGE_DIRTY 0x100

	#ifdef CONFIG_3_LEVEL_PGTABLES
	#include "asm/pgtable-3level.h"
	#else
	#include "asm/pgtable-2level.h"
	#endif

	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

	extern void um_virt_to_phys(struct task_struct task, unsigned long virt,
	pte_t *pte_out);

	/* zero page used for uninitialized stuff */
	extern unsigned long *empty_zero_page;

	#define pgtable_cache_init() do ; while (0)

	/*
	* pgd entries used up by user/kernel:
	*/

	#define USER_PGD_PTRS (TASK_SIZE >> PGDIR_SHIFT)
	#define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)

	#ifndef __ASSEMBLY__
	/* Just any arbitrary offset to the start of the vmalloc VM area: the
	* current 8MB value just means that there will be a 8MB "hole" after the
	* physical memory until the kernel virtual memory starts. That means that
	* any out-of-bounds memory accesses will hopefully be caught.
	* The vmalloc() routines leaves a hole of 4kB between each vmalloced
	* area for the same reason. ;)
	*/

	extern unsigned long end_iomem;

	#define VMALLOC_OFFSET (__va_space)
	#define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))

	#ifdef CONFIG_HIGHMEM
	# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
	#else
	# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
	#endif

	#define REGION_SHIFT (sizeof(pte_t) * 8 - 4)
	#define REGION_MASK (((unsigned long) 0xf) << REGION_SHIFT)

	#define _PAGE_TABLE (_PAGE_PRESENT \| _PAGE_RW \| _PAGE_USER \| _PAGE_ACCESSED \| _PAGE_DIRTY)
	#define _KERNPG_TABLE (_PAGE_PRESENT \| _PAGE_RW \| _PAGE_ACCESSED \| _PAGE_DIRTY)
	#define _PAGE_CHG_MASK (PAGE_MASK \| _PAGE_ACCESSED \| _PAGE_DIRTY)

	#define PAGE_NONE __pgprot(_PAGE_PROTNONE \| _PAGE_ACCESSED)
	#define PAGE_SHARED __pgprot(_PAGE_PRESENT \| _PAGE_RW \| _PAGE_USER \| _PAGE_ACCESSED)
	#define PAGE_COPY __pgprot(_PAGE_PRESENT \| _PAGE_USER \| _PAGE_ACCESSED)
	#define PAGE_READONLY __pgprot(_PAGE_PRESENT \| _PAGE_USER \| _PAGE_ACCESSED)
	#define PAGE_KERNEL __pgprot(_PAGE_PRESENT \| _PAGE_RW \| _PAGE_DIRTY \| _PAGE_ACCESSED)
	#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT \| _PAGE_DIRTY \| _PAGE_ACCESSED)

	/*
	* The i386 can't do page protection for execute, and considers that the same are read.
	* Also, write permissions imply read permissions. This is the closest we can get..
	*/
	#define __P000 PAGE_NONE
	#define __P001 PAGE_READONLY
	#define __P010 PAGE_COPY
	#define __P011 PAGE_COPY
	#define __P100 PAGE_READONLY
	#define __P101 PAGE_READONLY
	#define __P110 PAGE_COPY
	#define __P111 PAGE_COPY

	#define __S000 PAGE_NONE
	#define __S001 PAGE_READONLY
	#define __S010 PAGE_SHARED
	#define __S011 PAGE_SHARED
	#define __S100 PAGE_READONLY
	#define __S101 PAGE_READONLY
	#define __S110 PAGE_SHARED
	#define __S111 PAGE_SHARED

	/*
	* Define this if things work differently on an i386 and an i486:
	* it will (on an i486) warn about kernel memory accesses that are
	* done without a 'verify_area(VERIFY_WRITE,..)'
	*/
	#undef TEST_VERIFY_AREA

	/* page table for 0-4MB for everybody */
	extern unsigned long pg0[1024];

	/*
	* BAD_PAGETABLE is used when we need a bogus page-table, while
	* BAD_PAGE is used for a bogus page.
	*
	* ZERO_PAGE is a global shared page that is always zero: used
	* for zero-mapped memory areas etc..
	*/
	extern pte_t __bad_page(void);
	extern pte_t * __bad_pagetable(void);

	#define BAD_PAGETABLE __bad_pagetable()
	#define BAD_PAGE __bad_page()

	#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)

	/* number of bits that fit into a memory pointer */
	#define BITS_PER_PTR (8*sizeof(unsigned long))

	/* to align the pointer to a pointer address */
	#define PTR_MASK (~(sizeof(void*)-1))

	/* sizeof(void)==1<<SIZEOF_PTR_LOG2 /
	/* 64-bit machines, beware! SRB. */
	#define SIZEOF_PTR_LOG2 3

	/* to find an entry in a page-table */
	#define PAGE_PTR(address) \
	((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)

	#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))

	#define pmd_none(x) (!(pmd_val(x) & ~_PAGE_NEWPAGE))
	#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
	#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
	#define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)

	#define pmd_newpage(x) (pmd_val(x) & _PAGE_NEWPAGE)
	#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)

	#define pud_newpage(x) (pud_val(x) & _PAGE_NEWPAGE)
	#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)

	#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))

	#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)

	#define pte_address(x) (__va(pte_val(x) & PAGE_MASK))
	#define mk_phys(a, r) ((a) + (((unsigned long) r) << REGION_SHIFT))
	#define phys_addr(p) ((p) & ~REGION_MASK)

	/*
	* The following only work if pte_present() is true.
	* Undefined behaviour if not..
	*/
	static inline int pte_user(pte_t pte)
	{
	return((pte_get_bits(pte, _PAGE_USER)) &&
	!(pte_get_bits(pte, _PAGE_PROTNONE)));
	}

	static inline int pte_read(pte_t pte)
	{
	return((pte_get_bits(pte, _PAGE_USER)) &&
	!(pte_get_bits(pte, _PAGE_PROTNONE)));
	}

	static inline int pte_exec(pte_t pte){
	return((pte_get_bits(pte, _PAGE_USER)) &&
	!(pte_get_bits(pte, _PAGE_PROTNONE)));
	}

	static inline int pte_write(pte_t pte)
	{
	return((pte_get_bits(pte, _PAGE_RW)) &&
	!(pte_get_bits(pte, _PAGE_PROTNONE)));
	}

	/*
	* The following only works if pte_present() is not true.
	*/
	static inline int pte_file(pte_t pte)
	{
	return pte_get_bits(pte, _PAGE_FILE);
	}

	static inline int pte_dirty(pte_t pte)
	{
	return pte_get_bits(pte, _PAGE_DIRTY);
	}

	static inline int pte_young(pte_t pte)
	{
	return pte_get_bits(pte, _PAGE_ACCESSED);
	}

	static inline int pte_newpage(pte_t pte)
	{
	return pte_get_bits(pte, _PAGE_NEWPAGE);
	}

	static inline int pte_newprot(pte_t pte)
	{
	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
	}

	static inline pte_t pte_rdprotect(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_USER);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_exprotect(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_USER);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_mkclean(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_DIRTY);
	return(pte);
	}

	static inline pte_t pte_mkold(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_ACCESSED);
	return(pte);
	}

	static inline pte_t pte_wrprotect(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_RW);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_mkread(pte_t pte)
	{
	pte_set_bits(pte, _PAGE_RW);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_mkexec(pte_t pte)
	{
	pte_set_bits(pte, _PAGE_USER);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_mkdirty(pte_t pte)
	{
	pte_set_bits(pte, _PAGE_DIRTY);
	return(pte);
	}

	static inline pte_t pte_mkyoung(pte_t pte)
	{
	pte_set_bits(pte, _PAGE_ACCESSED);
	return(pte);
	}

	static inline pte_t pte_mkwrite(pte_t pte)
	{
	pte_set_bits(pte, _PAGE_RW);
	return(pte_mknewprot(pte));
	}

	static inline pte_t pte_mkuptodate(pte_t pte)
	{
	pte_clear_bits(pte, _PAGE_NEWPAGE);
	if(pte_present(pte))
	pte_clear_bits(pte, _PAGE_NEWPROT);
	return(pte);
	}

	extern phys_t page_to_phys(struct page *page);

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

	extern pte_t mk_pte(struct page *page, pgprot_t pgprot);

	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	{
	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
	if(pte_present(pte)) pte = pte_mknewpage(pte_mknewprot(pte));
	return pte;
	}

	#define pmd_page_kernel(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))

	/*
	* the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
	*
	* this macro returns the index of the entry in the pgd page which would
	* control the given virtual address
	*/
	#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))

	#define pgd_index_k(addr) pgd_index(addr)

	/*
	* pgd_offset() returns a (pgd_t *)
	* pgd_index() is used get the offset into the pgd page's array of pgd_t's;
	*/
	#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))

	/*
	* a shortcut which implies the use of the kernel's pgd, instead
	* of a process's
	*/
	#define pgd_offset_k(address) pgd_offset(&init_mm, address)

	/*
	* the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
	*
	* this macro returns the index of the entry in the pmd page which would
	* control the given virtual address
	*/
	#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

	/*
	* the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
	*
	* this macro returns the index of the entry in the pte page which would
	* control the given virtual address
	*/
	#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
	#define pte_offset_kernel(dir, address) \
	((pte_t ) pmd_page_kernel((dir)) + pte_index(address))
	#define pte_offset_map(dir, address) \
	((pte_t )page_address(pmd_page((dir))) + pte_index(address))
	#define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
	#define pte_unmap(pte) do { } while (0)
	#define pte_unmap_nested(pte) do { } while (0)

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

	/* Encode and de-code a swap entry */
	#define __swp_type(x) (((x).val >> 4) & 0x3f)
	#define __swp_offset(x) ((x).val >> 11)

	#define __swp_entry(type, offset) \
	((swp_entry_t) { ((type) << 4) \| ((offset) << 11) })
	#define __pte_to_swp_entry(pte) \
	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
	#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

	#define kern_addr_valid(addr) (1)

	#include <asm-generic/pgtable.h>

	#include <asm-generic/pgtable-nopud.h>

	#endif
	#endif

	extern struct page *phys_to_page(const unsigned long phys);
	extern struct page *__virt_to_page(const unsigned long virt);
	#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)

	/*
	* Overrides for Emacs so that we follow Linus's tabbing style.
	* Emacs will notice this stuff at the end of the file and automatically
	* adjust the settings for this buffer only. This must remain at the end
	* of the file.
	* ---------------------------------------------------------------------------
	* Local variables:
	* c-file-style: "linux"
	* End:
	*/