LXR linux-old/arch/m68k/mm/sun3mmu.c

   1/* 
   2 * linux/arch/m68k/mm/sun3mmu.c
   3 *
   4 * Implementations of mm routines specific to the sun3 MMU.
   5 *
   6 * Moved here 8/20/1999 Sam Creasey
   7 *
   8 */
   9
  10#include <linux/config.h>
  11#include <linux/signal.h>
  12#include <linux/sched.h>
  13#include <linux/mm.h>
  14#include <linux/swap.h>
  15#include <linux/kernel.h>
  16#include <linux/string.h>
  17#include <linux/types.h>
  18#include <linux/init.h>
  19#ifdef CONFIG_BLK_DEV_RAM
  20#include <linux/blk.h>
  21#endif
  22#include <linux/bootmem.h>
  23
  24#include <asm/setup.h>
  25#include <asm/uaccess.h>
  26#include <asm/page.h>
  27#include <asm/pgtable.h>
  28#include <asm/system.h>
  29#include <asm/machdep.h>
  30#include <asm/io.h>
  31
  32extern void mmu_emu_init (unsigned long bootmem_end);
  33
  34const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  35
  36extern unsigned long empty_bad_page_table;
  37extern unsigned long empty_bad_page;
  38extern unsigned long num_pages;
  39
  40void free_initmem(void)
  41{
  42}
  43
  44/* For the sun3 we try to follow the i386 paging_init() more closely */
  45/* start_mem and end_mem have PAGE_OFFSET added already */
  46/* now sets up tables using sun3 PTEs rather than i386 as before. --m */
  47void __init paging_init(void)
  48{
  49        pgd_t * pg_dir;
  50        pte_t * pg_table;
  51        int i;
  52        unsigned long address;
  53        unsigned long next_pgtable;
  54        unsigned long bootmem_end;
  55        unsigned long zones_size[3] = {0, 0, 0};
  56        unsigned long size;
  57
  58
  59#ifdef TEST_VERIFY_AREA
  60        wp_works_ok = 0;
  61#endif
  62        empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  63        empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  64        empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  65        memset((void *)empty_zero_page, 0, PAGE_SIZE);
  66
  67        address = PAGE_OFFSET;
  68        pg_dir = swapper_pg_dir;
  69        memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
  70        memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));
  71
  72        size = num_pages * sizeof(pte_t);
  73        size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
  74        
  75        next_pgtable = (unsigned long)alloc_bootmem_pages(size);
  76        bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
  77
  78        /* Map whole memory from PAGE_OFFSET (0x0E000000) */
  79        pg_dir += PAGE_OFFSET >> PGDIR_SHIFT; 
  80
  81        while (address < (unsigned long)high_memory) {
  82                pg_table = (pte_t *) __pa (next_pgtable);
  83                next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
  84                pgd_val(*pg_dir) = (unsigned long) pg_table;
  85                pg_dir++;
  86
  87                /* now change pg_table to kernel virtual addresses */
  88                pg_table = (pte_t *) __va ((unsigned long) pg_table);
  89                for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
  90                        pte_t pte = __mk_pte(address, PAGE_INIT);
  91                        if (address >= (unsigned long)high_memory)
  92                                pte_val (pte) = 0;
  93                        set_pte (pg_table, pte);
  94                        address += PAGE_SIZE;
  95                }
  96        }
  97
  98        mmu_emu_init(bootmem_end);
  99
 100        current->mm = NULL;
 101
 102        /* memory sizing is a hack stolen from motorola.c..  hope it works for us */
 103        zones_size[0] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
 104        zones_size[1] = 0;
 105        
 106        free_area_init(zones_size);
 107
 108}
 109
 110
 111