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/*

 *  linux/include/asm-arm/pgtable.h

 *

 *  Copyright (C) 2000-2002 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#ifndef _ASMARM_PGTABLE_H

#define _ASMARM_PGTABLE_H

#include <linux/config.h>

#include <asm/memory.h>

#include <asm/proc-fns.h>

/*

 * PMD_SHIFT determines the size of the area a second-level page table can map

 * PGDIR_SHIFT determines what a third-level page table entry can map

 */

#define PMD_SHIFT               20

#define PGDIR_SHIFT             20

#define LIBRARY_TEXT_START      0x0c000000

#ifndef __ASSEMBLY__

extern void __pte_error(const char *file, int line, unsigned long val);

extern void __pmd_error(const char *file, int line, unsigned long val);

extern void __pgd_error(const char *file, int line, unsigned long val);

#define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))

#define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))

#define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))

#endif /* !__ASSEMBLY__ */

#define PMD_SIZE                (1UL << PMD_SHIFT)

#define PMD_MASK                (~(PMD_SIZE-1))

#define PGDIR_SIZE              (1UL << PGDIR_SHIFT)

#define PGDIR_MASK              (~(PGDIR_SIZE-1))

#define FIRST_USER_PGD_NR       1

#define USER_PTRS_PER_PGD       ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)

/*

 * The table below defines the page protection levels that we insert into our

 * Linux page table version.  These get translated into the best that the

 * architecture can perform.  Note that on most ARM hardware:

 *  1) We cannot do execute protection

 *  2) If we could do execute protection, then read is implied

 *  3) write implies read permissions

 */

#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

#ifndef __ASSEMBLY__

/*

 * ZERO_PAGE is a global shared page that is always zero: used

 * for zero-mapped memory areas etc..

 */

extern struct page *empty_zero_page;

#define ZERO_PAGE(vaddr)        (empty_zero_page)

#define pte_pfn(pte)            (pte_val(pte) >> PAGE_SHIFT)

#define pfn_pte(pfn,prot)       (__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)))

#define pte_none(pte)           (!pte_val(pte))

#define pte_clear(ptep)         set_pte((ptep), __pte(0))

#define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))

#define pmd_none(pmd)           (!pmd_val(pmd))

#define pmd_present(pmd)        (pmd_val(pmd))

#define pmd_clear(pmdp)         set_pmd(pmdp, __pmd(0))

/*

 * Permanent address of a page. We never have highmem, so this is trivial.

 */

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

/*

 * Conversion functions: convert a page and protection to a page entry,

 * and a page entry and page directory to the page they refer to.

 */

static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)

{

        pte_t pte;

        pte_val(pte) = physpage | pgprot_val(pgprot);

        return pte;

}

#define mk_pte(page,prot)       pfn_pte(page_to_pfn(page),prot)

/*

 * The "pgd_xxx()" functions here are trivial for a folded two-level

 * setup: the pgd is never bad, and a pmd always exists (as it's folded

 * into the pgd entry)

 */

#define pgd_none(pgd)           (0)

#define pgd_bad(pgd)            (0)

#define pgd_present(pgd)        (1)

#define pgd_clear(pgdp)         do { } while (0)

#define page_pte_prot(page,prot)        mk_pte(page, prot)

#define page_pte(page)          mk_pte(page, __pgprot(0))

/* to find an entry in a page-table-directory */

#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)

#define __pgd_offset(addr)      pgd_index(addr)

#define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))

/* to find an entry in a kernel page-table-directory */

#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)

/* Find an entry in the second-level page table.. */

#define pmd_offset(dir, addr)   ((pmd_t *)(dir))

/* Find an entry in the third-level page table.. */

#define __pte_offset(addr)      (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))

#define pte_offset(dir, addr)   ((pte_t *)pmd_page(*(dir)) + __pte_offset(addr))

#include <asm/proc/pgtable.h>

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;

}

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

/* Encode and decode a swap entry.

 *

 * We support up to 32GB of swap on 4k machines

 */

#define SWP_TYPE(x)             (((x).val >> 2) & 0x7f)

#define SWP_OFFSET(x)           ((x).val >> 9)

#define SWP_ENTRY(type,offset)  ((swp_entry_t) { ((type) << 2) | ((offset) << 9) })

#define pte_to_swp_entry(pte)   ((swp_entry_t) { pte_val(pte) })

#define swp_entry_to_pte(swp)   ((pte_t) { (swp).val })

/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */

/* FIXME: this is not correct */

#define kern_addr_valid(addr)   (1)

#include <asm-generic/pgtable.h>

extern void pgtable_cache_init(void);

/*

 * remap a physical address `phys' of size `size' with page protection `prot'

 * into virtual address `from'

 */

#define io_remap_page_range(from,phys,size,prot) \

                remap_page_range(from,phys,size,prot)

#endif /* !__ASSEMBLY__ */

#endif /* _ASMARM_PGTABLE_H */