sun3mmu.c

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/*
 * linux/arch/m68k/mm/sun3mmu.c
 *
 * Implementations of mm routines specific to the sun3 MMU.
 *
 * Moved here 8/20/1999 Sam Creasey
 *
 */

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>

#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/io.h>

extern void mmu_emu_init (unsigned long bootmem_end);

const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";

extern unsigned long num_pages;

void free_initmem(void)
{
}

/* For the sun3 we try to follow the i386 paging_init() more closely */
/* start_mem and end_mem have PAGE_OFFSET added already */
/* now sets up tables using sun3 PTEs rather than i386 as before. --m */
void __init paging_init(void)
{
    pgd_t * pg_dir;
    pte_t * pg_table;
    int i;
    unsigned long address;
    unsigned long next_pgtable;
    unsigned long bootmem_end;
    unsigned long zones_size[MAX_NR_ZONES] = { 0, };
    unsigned long size;

#ifdef TEST_VERIFY_AREA
    wp_works_ok = 0;
#endif
    empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);

    address = PAGE_OFFSET;
    pg_dir = swapper_pg_dir;
    memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
    memset (kernel_pg_dir,  0, sizeof (kernel_pg_dir));

    size = num_pages * sizeof(pte_t);
    size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);

    next_pgtable = (unsigned long)alloc_bootmem_pages(size);
    bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;

    /* Map whole memory from PAGE_OFFSET (0x0E000000) */
    pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;

    while (address < (unsigned long)high_memory) {
        pg_table = (pte_t *) __pa (next_pgtable);
        next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
        pgd_val(*pg_dir) = (unsigned long) pg_table;
        pg_dir++;

        /* now change pg_table to kernel virtual addresses */
        pg_table = (pte_t *) __va ((unsigned long) pg_table);
        for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
            pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
            if (address >= (unsigned long)high_memory)
                pte_val (pte) = 0;
            set_pte (pg_table, pte);
            address += PAGE_SIZE;
        }
    }

    mmu_emu_init(bootmem_end);

    current->mm = NULL;

    /* memory sizing is a hack stolen from motorola.c..  hope it works for us */
    zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;

    /* I really wish I knew why the following change made things better...  -- Sam */
/*  free_area_init(zones_size); */
    free_area_init_node(0, zones_size,
                (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);


}