LXR linux/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 <asm/uaccess.h>
  22#include <asm/page.h>
  23#include <asm/pgtable.h>
  24#include <asm/system.h>
  25#include <asm/machdep.h>
  26#include <asm/io.h>
  27
  28extern void mmu_emu_init (unsigned long bootmem_end);
  29
  30const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  31
  32extern unsigned long num_pages;
  33
  34void free_initmem(void)
  35{
  36}
  37
  38/* For the sun3 we try to follow the i386 paging_init() more closely */
  39/* start_mem and end_mem have PAGE_OFFSET added already */
  40/* now sets up tables using sun3 PTEs rather than i386 as before. --m */
  41void __init paging_init(void)
  42{
  43        pgd_t * pg_dir;
  44        pte_t * pg_table;
  45        int i;
  46        unsigned long address;
  47        unsigned long next_pgtable;
  48        unsigned long bootmem_end;
  49        unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  50        unsigned long size;
  51
  52#ifdef TEST_VERIFY_AREA
  53        wp_works_ok = 0;
  54#endif
  55        empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
  56
  57        address = PAGE_OFFSET;
  58        pg_dir = swapper_pg_dir;
  59        memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
  60        memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));
  61
  62        size = num_pages * sizeof(pte_t);
  63        size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
  64
  65        next_pgtable = (unsigned long)alloc_bootmem_pages(size);
  66        bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
  67
  68        /* Map whole memory from PAGE_OFFSET (0x0E000000) */
  69        pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
  70
  71        while (address < (unsigned long)high_memory) {
  72                pg_table = (pte_t *) __pa (next_pgtable);
  73                next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
  74                pgd_val(*pg_dir) = (unsigned long) pg_table;
  75                pg_dir++;
  76
  77                /* now change pg_table to kernel virtual addresses */
  78                pg_table = (pte_t *) __va ((unsigned long) pg_table);
  79                for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
  80                        pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
  81                        if (address >= (unsigned long)high_memory)
  82                                pte_val (pte) = 0;
  83                        set_pte (pg_table, pte);
  84                        address += PAGE_SIZE;
  85                }
  86        }
  87
  88        mmu_emu_init(bootmem_end);
  89
  90        current->mm = NULL;
  91
  92        /* memory sizing is a hack stolen from motorola.c..  hope it works for us */
  93        zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
  94
  95        /* I really wish I knew why the following change made things better...  -- Sam */
  96/*      free_area_init(zones_size); */
  97        free_area_init_node(0, zones_size,
  98                            (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);
  99
 100
 101}
 102
 103
 104