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/machdep.h>
  25#include <asm/io.h>
  26
  27extern void mmu_emu_init (unsigned long bootmem_end);
  28
  29const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
  30
  31extern 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 */
  36void __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#ifdef TEST_VERIFY_AREA
  48        wp_works_ok = 0;
  49#endif
  50        empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
  51
  52        address = PAGE_OFFSET;
  53        pg_dir = swapper_pg_dir;
  54        memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
  55        memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));
  56
  57        size = num_pages * sizeof(pte_t);
  58        size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
  59
  60        next_pgtable = (unsigned long)alloc_bootmem_pages(size);
  61        bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
  62
  63        /* Map whole memory from PAGE_OFFSET (0x0E000000) */
  64        pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
  65
  66        while (address < (unsigned long)high_memory) {
  67                pg_table = (pte_t *) __pa (next_pgtable);
  68                next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
  69                pgd_val(*pg_dir) = (unsigned long) pg_table;
  70                pg_dir++;
  71
  72                /* now change pg_table to kernel virtual addresses */
  73                pg_table = (pte_t *) __va ((unsigned long) pg_table);
  74                for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
  75                        pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
  76                        if (address >= (unsigned long)high_memory)
  77                                pte_val (pte) = 0;
  78                        set_pte (pg_table, pte);
  79                        address += PAGE_SIZE;
  80                }
  81        }
  82
  83        mmu_emu_init(bootmem_end);
  84
  85        current->mm = NULL;
  86
  87        /* memory sizing is a hack stolen from motorola.c..  hope it works for us */
  88        zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
  89
  90        /* I really wish I knew why the following change made things better...  -- Sam */
  91/*      free_area_init(zones_size); */
  92        free_area_init_node(0, zones_size,
  93                            (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);
  94
  95
  96}
  97
  98
  99