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