git.zerfleddert.de Git - ms2-kexec/blob - mmu.c

   1 /*
   2  *  linux/arch/arm/mm/mmu.c
   3  *
   4  *  Copyright (C) 1995-2005 Russell King
   5  * This Edition is maintained by Matthew Veety (aliasxerog) <mveety@gmail.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/init.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/mman.h>
  17 #include <linux/nodemask.h>
  18 #include <linux/ioport.h>
  19 #include <linux/lttlite-events.h>
  20
  21 #include <asm/cputype.h>
  22 #include <asm/mach-types.h>
  23 #include <asm/sections.h>
  24 #include <asm/setup.h>
  25 #include <asm/sizes.h>
  26 #include <asm/tlb.h>
  27 #include <asm/pgtable.h>
  28
  29 #include <asm/mach/arch.h>
  30 #include <asm/mach/map.h>
  31
  32 #include "mm.h"
  33
  34 /*
  35  * In order to soft-boot, we need to insert a 1:1 mapping in place of
  36  * the user-mode pages.  This will then ensure that we have predictable
  37  * results when turning the mmu off
  38  */
  39 void setup_mm_for_reboot(char mode)
  40 {
  41         unsigned long base_pmdval;
  42         pgd_t *pgd;
  43         int i;
  44
  45         if (current->mm && current->mm->pgd)
  46                 pgd = current->mm->pgd;
  47         else
  48                 pgd = init_mm.pgd;
  49
  50         base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT;
  51
  52         for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {
  53                 unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;
  54                 pmd_t *pmd;
  55
  56                 pmd = pmd_off(pgd, i << PGDIR_SHIFT);
  57                 pmd[0] = __pmd(pmdval);
  58                 pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));
  59                 flush_pmd_entry(pmd);
  60         }
  61 }