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 extern unsigned long rom_length;
  67
  68 void show_mem(void)
  69 {
  70     unsigned long i;
  71     int free = 0, total = 0, reserved = 0, shared = 0;
  72     int cached = 0;
  73
  74     printk(KERN_INFO "\nMem-info:\n");
  75     show_free_areas();
  76     i = max_mapnr;
  77     while (i-- > 0) {
  78         total++;
  79         if (PageReserved(mem_map+i))
  80             reserved++;
  81         else if (PageSwapCache(mem_map+i))
  82             cached++;
  83         else if (!page_count(mem_map+i))
  84             free++;
  85         else
  86             shared += page_count(mem_map+i) - 1;
  87     }
  88     printk(KERN_INFO "%d pages of RAM\n",total);
  89     printk(KERN_INFO "%d free pages\n",free);
  90     printk(KERN_INFO "%d reserved pages\n",reserved);
  91     printk(KERN_INFO "%d pages shared\n",shared);
  92     printk(KERN_INFO "%d pages swap cached\n",cached);
  93 }
  94
  95 extern unsigned long memory_start;
  96 extern unsigned long memory_end;
  97
  98 /*
  99  * paging_init() continues the virtual memory environment setup which
 100  * was begun by the code in arch/head.S.
 101  * The parameters are pointers to where to stick the starting and ending
 102  * addresses of available kernel virtual memory.
 103  */
 104 void paging_init(void)
 105 {
 106         /*
 107          * Make sure start_mem is page aligned, otherwise bootmem and
 108          * page_alloc get different views of the world.
 109          */
 110 #ifdef DEBUG
 111         unsigned long start_mem = PAGE_ALIGN(memory_start);
 112 #endif
 113         unsigned long end_mem   = memory_end & PAGE_MASK;
 114
 115 #ifdef DEBUG
 116         printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
 117                 start_mem, end_mem);
 118 #endif
 119
 120         /*
 121          * Initialize the bad page table and bad page to point
 122          * to a couple of allocated pages.
 123          */
 124         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 125         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 126         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 127         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 128
 129         /*
 130          * Set up SFC/DFC registers (user data space).
 131          */
 132         set_fs (USER_DS);
 133
 134 #ifdef DEBUG
 135         printk (KERN_DEBUG "before free_area_init\n");
 136
 137         printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 138                 start_mem, end_mem);
 139 #endif
 140
 141         {
 142                 unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 143
 144                 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
 145                 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 146 #ifdef CONFIG_HIGHMEM
 147                 zones_size[ZONE_HIGHMEM] = 0;
 148 #endif
 149                 free_area_init(zones_size);
 150         }
 151 }
 152
 153 void mem_init(void)
 154 {
 155         int codek = 0, datak = 0, initk = 0;
 156         unsigned long tmp;
 157         extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 158         extern unsigned int _ramend, _rambase;
 159         unsigned long len = _ramend - _rambase;
 160         unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 161         unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 162
 163 #ifdef DEBUG
 164         printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 165 #endif
 166
 167         end_mem &= PAGE_MASK;
 168         high_memory = (void *) end_mem;
 169
 170         start_mem = PAGE_ALIGN(start_mem);
 171         max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
 172
 173         /* this will put all memory onto the freelists */
 174         totalram_pages = free_all_bootmem();
 175
 176         codek = (&_etext - &_stext) >> 10;
 177         datak = (&_ebss - &_sdata) >> 10;
 178         initk = (&__init_begin - &__init_end) >> 10;
 179
 180         tmp = nr_free_pages() << PAGE_SHIFT;
 181         printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
 182                tmp >> 10,
 183                len >> 10,
 184                (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
 185                rom_length >> 10,
 186                codek,
 187                datak
 188                );
 189 }
 190
 191
 192 #ifdef CONFIG_BLK_DEV_INITRD
 193 void free_initrd_mem(unsigned long start, unsigned long end)
 194 {
 195         int pages = 0;
 196         for (; start < end; start += PAGE_SIZE) {
 197                 ClearPageReserved(virt_to_page(start));
 198                 set_page_count(virt_to_page(start), 1);
 199                 free_page(start);
 200                 totalram_pages++;
 201                 pages++;
 202         }
 203         printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 204 }
 205 #endif
 206
 207 void
 208 free_initmem()
 209 {
 210 #ifdef CONFIG_RAMKERNEL
 211         unsigned long addr;
 212         extern char __init_begin, __init_end;
 213         /*
 214          * The following code should be cool even if these sections
 215          * are not page aligned.
 216          */
 217         addr = PAGE_ALIGN((unsigned long)(&__init_begin));
 218         /* next to check that the page we free is not a partial page */
 219         for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
 220                 ClearPageReserved(virt_to_page(addr));
 221                 set_page_count(virt_to_page(addr), 1);
 222                 free_page(addr);
 223                 totalram_pages++;
 224         }
 225         printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
 226                         (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
 227                         (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
 228                         (int)(addr - PAGE_SIZE));
 229 #endif
 230 }
 231