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
  43 extern void die_if_kernel(char *,struct pt_regs *,long);
  44 extern 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  */
  59 static unsigned long empty_bad_page_table;
  60
  61 static unsigned long empty_bad_page;
  62
  63 unsigned long empty_zero_page;
  64
  65 void 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
  92 extern unsigned long memory_start;
  93 extern 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  */
 101 void 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
 150 void 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
 188 void 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
 202 void
 203 free_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