arch/openrisc/include/asm/pgtable.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * OpenRISC Linux
  *
  * Linux architectural port borrowing liberally from similar works of
  * others.  All original copyrights apply as per the original source
  * declaration.
  *
  * OpenRISC implementation:
  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  * et al.
  */

 /* or1k pgtable.h - macros and functions to manipulate page tables
  *
  * Based on:
  * include/asm-cris/pgtable.h
  */

 #ifndef __ASM_OPENRISC_PGTABLE_H
 #define __ASM_OPENRISC_PGTABLE_H

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

 #ifndef __ASSEMBLY__
 #include <asm/mmu.h>
 #include <asm/fixmap.h>

 /*
  * The Linux memory management assumes a three-level page table setup. On
  * or1k, we use that, but "fold" the mid level into the top-level page
  * table. Since the MMU TLB is software loaded through an interrupt, it
  * supports any page table structure, so we could have used a three-level
  * setup, but for the amounts of memory we normally use, a two-level is
  * probably more efficient.
  *
  * This file contains the functions and defines necessary to modify and use
  * the or1k page table tree.
  */

 extern void paging_init(void);

 /* Certain architectures need to do special things when pte's
  * within a page table are directly modified.  Thus, the following
  * hook is made available.
  */
 #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))

 /*
  * (pmds are folded into pgds so this doesn't get actually called,
  * but the define is needed for a generic inline function.)
  */
 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)

 #define PGDIR_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT-2))
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE-1))

 /*
  * entries per page directory level: we use a two-level, so
  * we don't really have any PMD directory physically.
  * pointers are 4 bytes so we can use the page size and
  * divide it by 4 (shift by 2).
  */
 #define PTRS_PER_PTE	(1UL << (PAGE_SHIFT-2))

 #define PTRS_PER_PGD	(1UL << (32-PGDIR_SHIFT))

 /* calculate how many PGD entries a user-level program can use
  * the first mappable virtual address is 0
  * (TASK_SIZE is the maximum virtual address space)
  */

 #define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)

 /*
  * Kernels own virtual memory area.
  */

 /*
  * The size and location of the vmalloc area are chosen so that modules
  * placed in this area aren't more than a 28-bit signed offset from any
  * kernel functions that they may need.  This greatly simplifies handling
  * of the relocations for l.j and l.jal instructions as we don't need to
  * introduce any trampolines for reaching "distant" code.
  *
  * 64 MB of vmalloc area is comparable to what's available on other arches.
  */

 #define VMALLOC_START	(PAGE_OFFSET-0x04000000UL)
 #define VMALLOC_END	(PAGE_OFFSET)
 #define VMALLOC_VMADDR(x) ((unsigned long)(x))

 /* Define some higher level generic page attributes.
  *
  * If you change _PAGE_CI definition be sure to change it in
  * io.h for ioremap() too.
  */

 /*
  * An OR32 PTE looks like this:
  *
  * |  31 ... 10 |  9  |  8 ... 6  |  5  |  4  |  3  |  2  |  1  |  0  |
  *  Phys pg.num    L     PP Index    D     A    WOM   WBC   CI    CC
  *
  *  L  : link
  *  PPI: Page protection index
  *  D  : Dirty
  *  A  : Accessed
  *  WOM: Weakly ordered memory
  *  WBC: Write-back cache
  *  CI : Cache inhibit
  *  CC : Cache coherent
  *
  * The protection bits below should correspond to the layout of the actual
  * PTE as per above
  */

 #define _PAGE_CC       0x001 /* software: pte contains a translation */
 #define _PAGE_CI       0x002 /* cache inhibit          */
 #define _PAGE_WBC      0x004 /* write back cache       */
 #define _PAGE_WOM      0x008 /* weakly ordered memory  */

 #define _PAGE_A        0x010 /* accessed               */
 #define _PAGE_D        0x020 /* dirty                  */
 #define _PAGE_URE      0x040 /* user read enable       */
 #define _PAGE_UWE      0x080 /* user write enable      */

 #define _PAGE_SRE      0x100 /* superuser read enable  */
 #define _PAGE_SWE      0x200 /* superuser write enable */
 #define _PAGE_EXEC     0x400 /* software: page is executable */
 #define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */

 /* 0x001 is cache coherency bit, which should always be set to
  *       1 - for SMP (when we support it)
  *       0 - otherwise
  *
  * we just reuse this bit in software for _PAGE_PRESENT and
  * force it to 0 when loading it into TLB.
  */
 #define _PAGE_PRESENT  _PAGE_CC
 #define _PAGE_USER     _PAGE_URE
 #define _PAGE_WRITE    (_PAGE_UWE | _PAGE_SWE)
 #define _PAGE_DIRTY    _PAGE_D
 #define _PAGE_ACCESSED _PAGE_A
 #define _PAGE_NO_CACHE _PAGE_CI
 #define _PAGE_SHARED   _PAGE_U_SHARED
 #define _PAGE_READ     (_PAGE_URE | _PAGE_SRE)

 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
 #define _PAGE_BASE     (_PAGE_PRESENT | _PAGE_ACCESSED)
 #define _PAGE_ALL      (_PAGE_PRESENT | _PAGE_ACCESSED)
 #define _KERNPG_TABLE \
 	(_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY)

 /* We borrow bit 11 to store the exclusive marker in swap PTEs. */
 #define _PAGE_SWP_EXCLUSIVE	_PAGE_U_SHARED

 #define PAGE_NONE       __pgprot(_PAGE_ALL)
 #define PAGE_READONLY   __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
 #define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)
 #define PAGE_SHARED \
 	__pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
 		 | _PAGE_SHARED)
 #define PAGE_SHARED_X \
 	__pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \
 		 | _PAGE_SHARED | _PAGE_EXEC)
 #define PAGE_COPY       __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE)
 #define PAGE_COPY_X     __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC)

 #define PAGE_KERNEL \
 	__pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
 		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
 #define PAGE_KERNEL_RO \
 	__pgprot(_PAGE_ALL | _PAGE_SRE \
 		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC)
 #define PAGE_KERNEL_NOCACHE \
 	__pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
 		 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI)

 /* zero page used for uninitialized stuff */
 extern unsigned long empty_zero_page[2048];
 #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			2

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

 /* to set the page-dir */
 #define SET_PAGE_DIR(tsk, pgdir)

 #define pte_none(x)	(!pte_val(x))
 #define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
 #define pte_clear(mm, addr, xp)	do { pte_val(*(xp)) = 0; } while (0)

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

 /*
  * The following only work if pte_present() is true.
  * Undefined behaviour if not..
  */

 static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_READ; }
 static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
 static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC; }
 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 pte_t pte_wrprotect(pte_t pte)
 {
 	pte_val(pte) &= ~(_PAGE_WRITE);
 	return pte;
 }

 static inline pte_t pte_rdprotect(pte_t pte)
 {
 	pte_val(pte) &= ~(_PAGE_READ);
 	return pte;
 }

 static inline pte_t pte_exprotect(pte_t pte)
 {
 	pte_val(pte) &= ~(_PAGE_EXEC);
 	return pte;
 }

 static inline pte_t pte_mkclean(pte_t pte)
 {
 	pte_val(pte) &= ~(_PAGE_DIRTY);
 	return pte;
 }

 static inline pte_t pte_mkold(pte_t pte)
 {
 	pte_val(pte) &= ~(_PAGE_ACCESSED);
 	return pte;
 }

 static inline pte_t pte_mkwrite_novma(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_WRITE;
 	return pte;
 }

 static inline pte_t pte_mkread(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_READ;
 	return pte;
 }

 static inline pte_t pte_mkexec(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_EXEC;
 	return pte;
 }

 static inline pte_t pte_mkdirty(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_DIRTY;
 	return pte;
 }

 static inline pte_t pte_mkyoung(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_ACCESSED;
 	return 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.
  */

 /* What actually goes as arguments to the various functions is less than
  * obvious, but a rule of thumb is that struct page's goes as struct page *,
  * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
  * addresses (the 0xc0xxxxxx's) goes as void *'s.
  */

 static inline pte_t __mk_pte(void *page, pgprot_t pgprot)
 {
 	pte_t pte;
 	/* the PTE needs a physical address */
 	pte_val(pte) = __pa(page) | pgprot_val(pgprot);
 	return pte;
 }

 #define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))

 #define mk_pte_phys(physpage, pgprot) \
 ({                                                                      \
 	pte_t __pte;                                                    \
 									\
 	pte_val(__pte) = (physpage) + pgprot_val(pgprot);               \
 	__pte;                                                          \
 })

 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
 	return pte;
 }


 /*
  * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval
  * __pte_page(pte_val) refers to the "virtual" DRAM interval
  * pte_pagenr refers to the page-number counted starting from the virtual
  * DRAM start
  */

 static inline unsigned long __pte_page(pte_t pte)
 {
 	/* the PTE contains a physical address */
 	return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
 }

 #define pte_pagenr(pte)         ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)

 /* permanent address of a page */

 #define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
 #define pte_page(pte)		(mem_map+pte_pagenr(pte))

 /*
  * only the pte's themselves need to point to physical DRAM (see above)
  * the pagetable links are purely handled within the kernel SW and thus
  * don't need the __pa and __va transformations.
  */
 static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
 {
 	pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep;
 }

 #define pmd_pfn(pmd)		(pmd_val(pmd) >> PAGE_SHIFT)
 #define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 {
 	return ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK));
 }

 #define __pmd_offset(address) \
 	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

 #define PFN_PTE_SHIFT		PAGE_SHIFT
 #define pte_pfn(x)		((unsigned long)(((x).pte)) >> PAGE_SHIFT)
 #define pfn_pte(pfn, prot)  __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot))

 #define pte_ERROR(e) \
 	printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \
 	       __FILE__, __LINE__, &(e), pte_val(e))
 #define pgd_ERROR(e) \
 	printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \
 	       __FILE__, __LINE__, &(e), pgd_val(e))

 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */

 struct vm_area_struct;

 static inline void update_tlb(struct vm_area_struct *vma,
 	unsigned long address, pte_t *pte)
 {
 }

 extern void update_cache(struct vm_area_struct *vma,
 	unsigned long address, pte_t *pte);

 static inline void update_mmu_cache_range(struct vm_fault *vmf,
 		struct vm_area_struct *vma, unsigned long address,
 		pte_t *ptep, unsigned int nr)
 {
 	update_tlb(vma, address, ptep);
 	update_cache(vma, address, ptep);
 }

 #define update_mmu_cache(vma, addr, ptep) \
 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)

 /* __PHX__ FIXME, SWAP, this probably doesn't work */

 /*
  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
  * are !pte_none() && !pte_present().
  *
  * Format of swap PTEs:
  *
  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
  *   <-------------- offset ---------------> E <- type --> 0 0 0 0 0
  *
  *   E is the exclusive marker that is not stored in swap entries.
  *   The zero'ed bits include _PAGE_PRESENT.
  */
 #define __swp_type(x)			(((x).val >> 5) & 0x3f)
 #define __swp_offset(x)			((x).val >> 12)
 #define __swp_entry(type, offset) \
 	((swp_entry_t) { (((type) & 0x3f) << 5) | ((offset) << 12) })
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })

 static inline int pte_swp_exclusive(pte_t pte)
 {
 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
 }

 static inline pte_t pte_swp_mkexclusive(pte_t pte)
 {
 	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
 	return pte;
 }

 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
 {
 	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
 	return pte;
 }

 typedef pte_t *pte_addr_t;

 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_OPENRISC_PGTABLE_H */
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	/*
	* OpenRISC Linux
	*
	* Linux architectural port borrowing liberally from similar works of
	* others. All original copyrights apply as per the original source
	* declaration.
	*
	* OpenRISC implementation:
	* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
	* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
	* et al.
	*/

	/* or1k pgtable.h - macros and functions to manipulate page tables
	*
	* Based on:
	* include/asm-cris/pgtable.h
	*/

	#ifndef __ASM_OPENRISC_PGTABLE_H
	#define __ASM_OPENRISC_PGTABLE_H

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

	#ifndef __ASSEMBLY__
	#include <asm/mmu.h>
	#include <asm/fixmap.h>

	/*
	* The Linux memory management assumes a three-level page table setup. On
	* or1k, we use that, but "fold" the mid level into the top-level page
	* table. Since the MMU TLB is software loaded through an interrupt, it
	* supports any page table structure, so we could have used a three-level
	* setup, but for the amounts of memory we normally use, a two-level is
	* probably more efficient.
	*
	* This file contains the functions and defines necessary to modify and use
	* the or1k page table tree.
	*/

	extern void paging_init(void);

	/* Certain architectures need to do special things when pte's
	* within a page table are directly modified. Thus, the following
	* hook is made available.
	*/
	#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))

	/*
	* (pmds are folded into pgds so this doesn't get actually called,
	* but the define is needed for a generic inline function.)
	*/
	#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)

	#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2))
	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
	#define PGDIR_MASK (~(PGDIR_SIZE-1))

	/*
	* entries per page directory level: we use a two-level, so
	* we don't really have any PMD directory physically.
	* pointers are 4 bytes so we can use the page size and
	* divide it by 4 (shift by 2).
	*/
	#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2))

	#define PTRS_PER_PGD (1UL << (32-PGDIR_SHIFT))

	/* calculate how many PGD entries a user-level program can use
	* the first mappable virtual address is 0
	* (TASK_SIZE is the maximum virtual address space)
	*/

	#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)

	/*
	* Kernels own virtual memory area.
	*/

	/*
	* The size and location of the vmalloc area are chosen so that modules
	* placed in this area aren't more than a 28-bit signed offset from any
	* kernel functions that they may need. This greatly simplifies handling
	* of the relocations for l.j and l.jal instructions as we don't need to
	* introduce any trampolines for reaching "distant" code.
	*
	* 64 MB of vmalloc area is comparable to what's available on other arches.
	*/

	#define VMALLOC_START (PAGE_OFFSET-0x04000000UL)
	#define VMALLOC_END (PAGE_OFFSET)
	#define VMALLOC_VMADDR(x) ((unsigned long)(x))

	/* Define some higher level generic page attributes.
	*
	* If you change _PAGE_CI definition be sure to change it in
	* io.h for ioremap() too.
	*/

	/*
	* An OR32 PTE looks like this:
	*
	* \| 31 ... 10 \| 9 \| 8 ... 6 \| 5 \| 4 \| 3 \| 2 \| 1 \| 0 \|
	* Phys pg.num L PP Index D A WOM WBC CI CC
	*
	* L : link
	* PPI: Page protection index
	* D : Dirty
	* A : Accessed
	* WOM: Weakly ordered memory
	* WBC: Write-back cache
	* CI : Cache inhibit
	* CC : Cache coherent
	*
	* The protection bits below should correspond to the layout of the actual
	* PTE as per above
	*/

	#define _PAGE_CC 0x001 /* software: pte contains a translation */
	#define _PAGE_CI 0x002 /* cache inhibit */
	#define _PAGE_WBC 0x004 /* write back cache */
	#define _PAGE_WOM 0x008 /* weakly ordered memory */

	#define _PAGE_A 0x010 /* accessed */
	#define _PAGE_D 0x020 /* dirty */
	#define _PAGE_URE 0x040 /* user read enable */
	#define _PAGE_UWE 0x080 /* user write enable */

	#define _PAGE_SRE 0x100 /* superuser read enable */
	#define _PAGE_SWE 0x200 /* superuser write enable */
	#define _PAGE_EXEC 0x400 /* software: page is executable */
	#define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */

	/* 0x001 is cache coherency bit, which should always be set to
	* 1 - for SMP (when we support it)
	* 0 - otherwise
	*
	* we just reuse this bit in software for _PAGE_PRESENT and
	* force it to 0 when loading it into TLB.
	*/
	#define _PAGE_PRESENT _PAGE_CC
	#define _PAGE_USER _PAGE_URE
	#define _PAGE_WRITE (_PAGE_UWE \| _PAGE_SWE)
	#define _PAGE_DIRTY _PAGE_D
	#define _PAGE_ACCESSED _PAGE_A
	#define _PAGE_NO_CACHE _PAGE_CI
	#define _PAGE_SHARED _PAGE_U_SHARED
	#define _PAGE_READ (_PAGE_URE \| _PAGE_SRE)

	#define _PAGE_CHG_MASK (PAGE_MASK \| _PAGE_ACCESSED \| _PAGE_DIRTY)
	#define _PAGE_BASE (_PAGE_PRESENT \| _PAGE_ACCESSED)
	#define _PAGE_ALL (_PAGE_PRESENT \| _PAGE_ACCESSED)
	#define _KERNPG_TABLE \
	(_PAGE_BASE \| _PAGE_SRE \| _PAGE_SWE \| _PAGE_ACCESSED \| _PAGE_DIRTY)

	/* We borrow bit 11 to store the exclusive marker in swap PTEs. */
	#define _PAGE_SWP_EXCLUSIVE _PAGE_U_SHARED

	#define PAGE_NONE __pgprot(_PAGE_ALL)
	#define PAGE_READONLY __pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE)
	#define PAGE_READONLY_X __pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE \| _PAGE_EXEC)
	#define PAGE_SHARED \
	__pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE \| _PAGE_UWE \| _PAGE_SWE \
	\| _PAGE_SHARED)
	#define PAGE_SHARED_X \
	__pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE \| _PAGE_UWE \| _PAGE_SWE \
	\| _PAGE_SHARED \| _PAGE_EXEC)
	#define PAGE_COPY __pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE)
	#define PAGE_COPY_X __pgprot(_PAGE_ALL \| _PAGE_URE \| _PAGE_SRE \| _PAGE_EXEC)

	#define PAGE_KERNEL \
	__pgprot(_PAGE_ALL \| _PAGE_SRE \| _PAGE_SWE \
	\| _PAGE_SHARED \| _PAGE_DIRTY \| _PAGE_EXEC)
	#define PAGE_KERNEL_RO \
	__pgprot(_PAGE_ALL \| _PAGE_SRE \
	\| _PAGE_SHARED \| _PAGE_DIRTY \| _PAGE_EXEC)
	#define PAGE_KERNEL_NOCACHE \
	__pgprot(_PAGE_ALL \| _PAGE_SRE \| _PAGE_SWE \
	\| _PAGE_SHARED \| _PAGE_DIRTY \| _PAGE_EXEC \| _PAGE_CI)

	/* zero page used for uninitialized stuff */
	extern unsigned long empty_zero_page[2048];
	#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 2

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

	/* to set the page-dir */
	#define SET_PAGE_DIR(tsk, pgdir)

	#define pte_none(x) (!pte_val(x))
	#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
	#define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0)

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

	/*
	* The following only work if pte_present() is true.
	* Undefined behaviour if not..
	*/

	static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; }
	static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
	static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; }
	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 pte_t pte_wrprotect(pte_t pte)
	{
	pte_val(pte) &= ~(_PAGE_WRITE);
	return pte;
	}

	static inline pte_t pte_rdprotect(pte_t pte)
	{
	pte_val(pte) &= ~(_PAGE_READ);
	return pte;
	}

	static inline pte_t pte_exprotect(pte_t pte)
	{
	pte_val(pte) &= ~(_PAGE_EXEC);
	return pte;
	}

	static inline pte_t pte_mkclean(pte_t pte)
	{
	pte_val(pte) &= ~(_PAGE_DIRTY);
	return pte;
	}

	static inline pte_t pte_mkold(pte_t pte)
	{
	pte_val(pte) &= ~(_PAGE_ACCESSED);
	return pte;
	}

	static inline pte_t pte_mkwrite_novma(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_WRITE;
	return pte;
	}

	static inline pte_t pte_mkread(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_READ;
	return pte;
	}

	static inline pte_t pte_mkexec(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_EXEC;
	return pte;
	}

	static inline pte_t pte_mkdirty(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_DIRTY;
	return pte;
	}

	static inline pte_t pte_mkyoung(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_ACCESSED;
	return 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.
	*/

	/* What actually goes as arguments to the various functions is less than
	* obvious, but a rule of thumb is that struct page's goes as struct page *,
	* really physical DRAM addresses are unsigned long's, and DRAM "virtual"
	* addresses (the 0xc0xxxxxx's) goes as void *'s.
	*/

	static inline pte_t __mk_pte(void *page, pgprot_t pgprot)
	{
	pte_t pte;
	/* the PTE needs a physical address */
	pte_val(pte) = __pa(page) \| pgprot_val(pgprot);
	return pte;
	}

	#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))

	#define mk_pte_phys(physpage, pgprot) \
	({ \
	pte_t __pte; \
	\
	pte_val(__pte) = (physpage) + pgprot_val(pgprot); \
	__pte; \
	})

	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	{
	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) \| pgprot_val(newprot);
	return pte;
	}


	/*
	* pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval
	* __pte_page(pte_val) refers to the "virtual" DRAM interval
	* pte_pagenr refers to the page-number counted starting from the virtual
	* DRAM start
	*/

	static inline unsigned long __pte_page(pte_t pte)
	{
	/* the PTE contains a physical address */
	return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
	}

	#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)

	/* permanent address of a page */

	#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
	#define pte_page(pte) (mem_map+pte_pagenr(pte))

	/*
	* only the pte's themselves need to point to physical DRAM (see above)
	* the pagetable links are purely handled within the kernel SW and thus
	* don't need the __pa and __va transformations.
	*/
	static inline void pmd_set(pmd_t pmdp, pte_t ptep)
	{
	pmd_val(*pmdp) = _KERNPG_TABLE \| (unsigned long) ptep;
	}

	#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
	#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

	static inline unsigned long pmd_page_vaddr(pmd_t pmd)
	{
	return ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK));
	}

	#define __pmd_offset(address) \
	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

	#define PFN_PTE_SHIFT PAGE_SHIFT
	#define pte_pfn(x) ((unsigned long)(((x).pte)) >> PAGE_SHIFT)
	#define pfn_pte(pfn, prot) __pte((((pfn) << PAGE_SHIFT)) \| pgprot_val(prot))

	#define pte_ERROR(e) \
	printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \
	__FILE__, __LINE__, &(e), pte_val(e))
	#define pgd_ERROR(e) \
	printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \
	__FILE__, __LINE__, &(e), pgd_val(e))

	extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */

	struct vm_area_struct;

	static inline void update_tlb(struct vm_area_struct *vma,
	unsigned long address, pte_t *pte)
	{
	}

	extern void update_cache(struct vm_area_struct *vma,
	unsigned long address, pte_t *pte);

	static inline void update_mmu_cache_range(struct vm_fault *vmf,
	struct vm_area_struct *vma, unsigned long address,
	pte_t *ptep, unsigned int nr)
	{
	update_tlb(vma, address, ptep);
	update_cache(vma, address, ptep);
	}

	#define update_mmu_cache(vma, addr, ptep) \
	update_mmu_cache_range(NULL, vma, addr, ptep, 1)

	/* __PHX__ FIXME, SWAP, this probably doesn't work */

	/*
	* Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
	* are !pte_none() && !pte_present().
	*
	* Format of swap PTEs:
	*
	* 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
	* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
	* <-------------- offset ---------------> E <- type --> 0 0 0 0 0
	*
	* E is the exclusive marker that is not stored in swap entries.
	* The zero'ed bits include _PAGE_PRESENT.
	*/
	#define __swp_type(x) (((x).val >> 5) & 0x3f)
	#define __swp_offset(x) ((x).val >> 12)
	#define __swp_entry(type, offset) \
	((swp_entry_t) { (((type) & 0x3f) << 5) \| ((offset) << 12) })
	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
	#define __swp_entry_to_pte(x) ((pte_t) { (x).val })

	static inline int pte_swp_exclusive(pte_t pte)
	{
	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
	}

	static inline pte_t pte_swp_mkexclusive(pte_t pte)
	{
	pte_val(pte) \|= _PAGE_SWP_EXCLUSIVE;
	return pte;
	}

	static inline pte_t pte_swp_clear_exclusive(pte_t pte)
	{
	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
	return pte;
	}

	typedef pte_t *pte_addr_t;

	#endif /* __ASSEMBLY__ */
	#endif /* __ASM_OPENRISC_PGTABLE_H */