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
  23 #include <asm/setup.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/page.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/system.h>
  28 #include <asm/machdep.h>
  29 #include <asm/io.h>
  30
  31 extern void mmu_emu_init (void);
  32
  33 extern unsigned long free_area_init(unsigned long *zones_size);
  34
  35 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  36
  37 extern unsigned long empty_bad_page_table;
  38 extern unsigned long empty_bad_page;
  39
  40 void free_initmem(void)
  41 {
  42 }
  43 /* For the sun3 we try to follow the i386 paging_init() more closely */
  44 /* start_mem and end_mem have PAGE_OFFSET added already */
  45 /* now sets up tables using sun3 PTEs rather than i386 as before. --m */
  46 unsigned long __init paging_init(unsigned long start_mem,
  47                                  unsigned long end_mem)
  48 {
  49         pgd_t * pg_dir;
  50         pte_t * pg_table;
  51         int i;
  52         unsigned long address;
  53
  54 #ifdef TEST_VERIFY_AREA
  55         wp_works_ok = 0;
  56 #endif
  57         start_mem = PAGE_ALIGN(start_mem);
  58         empty_bad_page_table = start_mem;
  59         start_mem += PAGE_SIZE;
  60         empty_bad_page = start_mem;
  61         start_mem += PAGE_SIZE;
  62         empty_zero_page = start_mem;
  63         start_mem += PAGE_SIZE;
  64         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  65
  66         address = PAGE_OFFSET;
  67         pg_dir = swapper_pg_dir;
  68         memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
  69         memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));
  70
  71         /* Map whole memory from PAGE_OFFSET (0x0E000000) */
  72         pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
  73
  74         while (address < end_mem) {
  75                 pg_table = (pte_t *) __pa (start_mem);
  76                 start_mem += PTRS_PER_PTE * sizeof (pte_t);
  77                 pgd_val(*pg_dir) = (unsigned long) pg_table;
  78                 pg_dir++;
  79
  80                 /* now change pg_table to kernel virtual addresses */
  81                 pg_table = (pte_t *) __va ((unsigned long) pg_table);
  82                 for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
  83                         pte_t pte = __mk_pte(address, PAGE_INIT);
  84                         if (address >= end_mem)
  85                                 pte_val (pte) = 0;
  86                         set_pte (pg_table, pte);
  87                         address += PAGE_SIZE;
  88                 }
  89         }
  90
  91         mmu_emu_init();
  92
  93         current->mm = NULL;
  94
  95         return PAGE_ALIGN(free_area_init(start_mem, end_mem));
  96 }
  97
  98