Orange Pi5 kernel

 /* 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.
 */
 
/* or32 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
 * or32, 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 or32 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))
#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, 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)
#define FIRST_USER_ADDRESS      0UL
 
/*
 * 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)
 
#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)
 
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY_X
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY_X
#define __P100	PAGE_READONLY
#define __P101	PAGE_READONLY_X
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY_X
 
#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY_X
#define __S010	PAGE_SHARED
#define __S011	PAGE_SHARED_X
#define __S100	PAGE_READONLY
#define __S101	PAGE_READONLY_X
#define __S110	PAGE_SHARED
#define __S111	PAGE_SHARED_X
 
/* 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(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_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 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(struct vm_area_struct *vma,
<------>unsigned long address, pte_t *pte)
{
<------>update_tlb(vma, address, pte);
<------>update_cache(vma, address, pte);
}
 
/* __PHX__ FIXME, SWAP, this probably doesn't work */
 
/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */
 
#define __swp_type(x)			(((x).val >> 5) & 0x7f)
#define __swp_offset(x)			((x).val >> 12)
#define __swp_entry(type, offset) \
<------>((swp_entry_t) { ((type) << 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 })
 
#define kern_addr_valid(addr)           (1)
 
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.
	*/

	/* or32 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
	* or32, 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 or32 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))
	#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, 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)
	#define FIRST_USER_ADDRESS 0UL

	/*
	* 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)

	#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)

	#define __P000 PAGE_NONE
	#define __P001 PAGE_READONLY_X
	#define __P010 PAGE_COPY
	#define __P011 PAGE_COPY_X
	#define __P100 PAGE_READONLY
	#define __P101 PAGE_READONLY_X
	#define __P110 PAGE_COPY
	#define __P111 PAGE_COPY_X

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

	/* 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(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_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 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(struct vm_area_struct *vma,
	<------>unsigned long address, pte_t *pte)
	{
	<------>update_tlb(vma, address, pte);
	<------>update_cache(vma, address, pte);
	}

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

	/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
	/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */

	#define __swp_type(x) (((x).val >> 5) & 0x7f)
	#define __swp_offset(x) ((x).val >> 12)
	#define __swp_entry(type, offset) \
	<------>((swp_entry_t) { ((type) << 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 })

	#define kern_addr_valid(addr) (1)

	typedef pte_t *pte_addr_t;

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