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
  32 extern void mmu_emu_init (unsigned long bootmem_end);
  33
  34 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  35
  36 extern unsigned long empty_bad_page_table;
  37 extern unsigned long empty_bad_page;
  38 extern unsigned long num_pages;
  39
  40 void 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 */
  47 void __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[1] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
 104         zones_size[0] = zones_size[1]/2;
 105         zones_size[1] -= zones_size[0];
 106
 107         free_area_init(zones_size);
 108
 109 }
 110
 111