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/signal.h>
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/swap.h>
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <linux/types.h>
  17 #include <linux/init.h>
  18 #include <linux/bootmem.h>
  19
  20 #include <asm/setup.h>
  21 #include <linux/uaccess.h>
  22 #include <asm/page.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/machdep.h>
  25 #include <asm/io.h>
  26
  27 extern void mmu_emu_init (unsigned long bootmem_end);
  28
  29 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  30
  31 extern unsigned long num_pages;
  32
  33 /* For the sun3 we try to follow the i386 paging_init() more closely */
  34 /* start_mem and end_mem have PAGE_OFFSET added already */
  35 /* now sets up tables using sun3 PTEs rather than i386 as before. --m */
  36 void __init paging_init(void)
  37 {
  38         pgd_t * pg_dir;
  39         pte_t * pg_table;
  40         int i;
  41         unsigned long address;
  42         unsigned long next_pgtable;
  43         unsigned long bootmem_end;
  44         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  45         unsigned long size;
  46
  47         empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
  48
  49         address = PAGE_OFFSET;
  50         pg_dir = swapper_pg_dir;
  51         memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
  52         memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));
  53
  54         size = num_pages * sizeof(pte_t);
  55         size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
  56
  57         next_pgtable = (unsigned long)alloc_bootmem_pages(size);
  58         bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
  59
  60         /* Map whole memory from PAGE_OFFSET (0x0E000000) */
  61         pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
  62
  63         while (address < (unsigned long)high_memory) {
  64                 pg_table = (pte_t *) __pa (next_pgtable);
  65                 next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
  66                 pgd_val(*pg_dir) = (unsigned long) pg_table;
  67                 pg_dir++;
  68
  69                 /* now change pg_table to kernel virtual addresses */
  70                 pg_table = (pte_t *) __va ((unsigned long) pg_table);
  71                 for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
  72                         pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
  73                         if (address >= (unsigned long)high_memory)
  74                                 pte_val (pte) = 0;
  75                         set_pte (pg_table, pte);
  76                         address += PAGE_SIZE;
  77                 }
  78         }
  79
  80         mmu_emu_init(bootmem_end);
  81
  82         current->mm = NULL;
  83
  84         /* memory sizing is a hack stolen from motorola.c..  hope it works for us */
  85         zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
  86
  87         /* I really wish I knew why the following change made things better...  -- Sam */
  88 /*      free_area_init(zones_size); */
  89         free_area_init_node(0, zones_size,
  90                             (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);
  91
  92
  93 }
  94
  95