LXR linux/arch/m68knommu/mm/init.c

   1/*
   2 *  linux/arch/m68knommu/mm/init.c
   3 *
   4 *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
   5 *                      Kenneth Albanowski <kjahds@kjahds.com>,
   6 *  Copyright (C) 2000  Lineo, Inc.  (www.lineo.com) 
   7 *
   8 *  Based on:
   9 *
  10 *  linux/arch/m68k/mm/init.c
  11 *
  12 *  Copyright (C) 1995  Hamish Macdonald
  13 *
  14 *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
  15 *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
  16 */
  17
  18#include <linux/signal.h>
  19#include <linux/sched.h>
  20#include <linux/kernel.h>
  21#include <linux/errno.h>
  22#include <linux/string.h>
  23#include <linux/types.h>
  24#include <linux/ptrace.h>
  25#include <linux/mman.h>
  26#include <linux/mm.h>
  27#include <linux/swap.h>
  28#include <linux/init.h>
  29#include <linux/highmem.h>
  30#include <linux/pagemap.h>
  31#include <linux/bootmem.h>
  32#include <linux/slab.h>
  33
  34#include <asm/setup.h>
  35#include <asm/segment.h>
  36#include <asm/page.h>
  37#include <asm/pgtable.h>
  38#include <asm/system.h>
  39#include <asm/machdep.h>
  40
  41#undef DEBUG
  42
  43extern void die_if_kernel(char *,struct pt_regs *,long);
  44extern void free_initmem(void);
  45
  46/*
  47 * BAD_PAGE is the page that is used for page faults when linux
  48 * is out-of-memory. Older versions of linux just did a
  49 * do_exit(), but using this instead means there is less risk
  50 * for a process dying in kernel mode, possibly leaving a inode
  51 * unused etc..
  52 *
  53 * BAD_PAGETABLE is the accompanying page-table: it is initialized
  54 * to point to BAD_PAGE entries.
  55 *
  56 * ZERO_PAGE is a special page that is used for zero-initialized
  57 * data and COW.
  58 */
  59static unsigned long empty_bad_page_table;
  60
  61static unsigned long empty_bad_page;
  62
  63unsigned long empty_zero_page;
  64
  65void show_mem(void)
  66{
  67    unsigned long i;
  68    int free = 0, total = 0, reserved = 0, shared = 0;
  69    int cached = 0;
  70
  71    printk(KERN_INFO "\nMem-info:\n");
  72    show_free_areas();
  73    i = max_mapnr;
  74    while (i-- > 0) {
  75        total++;
  76        if (PageReserved(mem_map+i))
  77            reserved++;
  78        else if (PageSwapCache(mem_map+i))
  79            cached++;
  80        else if (!page_count(mem_map+i))
  81            free++;
  82        else
  83            shared += page_count(mem_map+i) - 1;
  84    }
  85    printk(KERN_INFO "%d pages of RAM\n",total);
  86    printk(KERN_INFO "%d free pages\n",free);
  87    printk(KERN_INFO "%d reserved pages\n",reserved);
  88    printk(KERN_INFO "%d pages shared\n",shared);
  89    printk(KERN_INFO "%d pages swap cached\n",cached);
  90}
  91
  92extern unsigned long memory_start;
  93extern unsigned long memory_end;
  94
  95/*
  96 * paging_init() continues the virtual memory environment setup which
  97 * was begun by the code in arch/head.S.
  98 * The parameters are pointers to where to stick the starting and ending
  99 * addresses of available kernel virtual memory.
 100 */
 101void paging_init(void)
 102{
 103        /*
 104         * Make sure start_mem is page aligned, otherwise bootmem and
 105         * page_alloc get different views of the world.
 106         */
 107#ifdef DEBUG
 108        unsigned long start_mem = PAGE_ALIGN(memory_start);
 109#endif
 110        unsigned long end_mem   = memory_end & PAGE_MASK;
 111
 112#ifdef DEBUG
 113        printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
 114                start_mem, end_mem);
 115#endif
 116
 117        /*
 118         * Initialize the bad page table and bad page to point
 119         * to a couple of allocated pages.
 120         */
 121        empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 122        empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 123        empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 124        memset((void *)empty_zero_page, 0, PAGE_SIZE);
 125
 126        /*
 127         * Set up SFC/DFC registers (user data space).
 128         */
 129        set_fs (USER_DS);
 130
 131#ifdef DEBUG
 132        printk (KERN_DEBUG "before free_area_init\n");
 133
 134        printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 135                start_mem, end_mem);
 136#endif
 137
 138        {
 139                unsigned long zones_size[MAX_NR_ZONES] = {0, };
 140
 141                zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
 142                zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 143#ifdef CONFIG_HIGHMEM
 144                zones_size[ZONE_HIGHMEM] = 0;
 145#endif
 146                free_area_init(zones_size);
 147        }
 148}
 149
 150void mem_init(void)
 151{
 152        int codek = 0, datak = 0, initk = 0;
 153        unsigned long tmp;
 154        extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 155        extern unsigned int _ramend, _rambase;
 156        unsigned long len = _ramend - _rambase;
 157        unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 158        unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 159
 160#ifdef DEBUG
 161        printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 162#endif
 163
 164        end_mem &= PAGE_MASK;
 165        high_memory = (void *) end_mem;
 166
 167        start_mem = PAGE_ALIGN(start_mem);
 168        max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
 169
 170        /* this will put all memory onto the freelists */
 171        totalram_pages = free_all_bootmem();
 172
 173        codek = (&_etext - &_stext) >> 10;
 174        datak = (&_ebss - &_sdata) >> 10;
 175        initk = (&__init_begin - &__init_end) >> 10;
 176
 177        tmp = nr_free_pages() << PAGE_SHIFT;
 178        printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
 179               tmp >> 10,
 180               len >> 10,
 181               codek,
 182               datak
 183               );
 184}
 185
 186
 187#ifdef CONFIG_BLK_DEV_INITRD
 188void free_initrd_mem(unsigned long start, unsigned long end)
 189{
 190        int pages = 0;
 191        for (; start < end; start += PAGE_SIZE) {
 192                ClearPageReserved(virt_to_page(start));
 193                init_page_count(virt_to_page(start));
 194                free_page(start);
 195                totalram_pages++;
 196                pages++;
 197        }
 198        printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 199}
 200#endif
 201
 202void
 203free_initmem()
 204{
 205#ifdef CONFIG_RAMKERNEL
 206        unsigned long addr;
 207        extern char __init_begin, __init_end;
 208        /*
 209         * The following code should be cool even if these sections
 210         * are not page aligned.
 211         */
 212        addr = PAGE_ALIGN((unsigned long)(&__init_begin));
 213        /* next to check that the page we free is not a partial page */
 214        for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
 215                ClearPageReserved(virt_to_page(addr));
 216                init_page_count(virt_to_page(addr));
 217                free_page(addr);
 218                totalram_pages++;
 219        }
 220        printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
 221                        (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
 222                        (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
 223                        (int)(addr - PAGE_SIZE));
 224#endif
 225}
 226
 227