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 #include <asm/shglcore.h>
  42
  43 #undef DEBUG
  44
  45 extern void die_if_kernel(char *,struct pt_regs *,long);
  46 extern void free_initmem(void);
  47
  48 /*
  49  * BAD_PAGE is the page that is used for page faults when linux
  50  * is out-of-memory. Older versions of linux just did a
  51  * do_exit(), but using this instead means there is less risk
  52  * for a process dying in kernel mode, possibly leaving a inode
  53  * unused etc..
  54  *
  55  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  56  * to point to BAD_PAGE entries.
  57  *
  58  * ZERO_PAGE is a special page that is used for zero-initialized
  59  * data and COW.
  60  */
  61 static unsigned long empty_bad_page_table;
  62
  63 static unsigned long empty_bad_page;
  64
  65 unsigned long empty_zero_page;
  66
  67 extern unsigned long rom_length;
  68
  69 void show_mem(void)
  70 {
  71     unsigned long i;
  72     int free = 0, total = 0, reserved = 0, shared = 0;
  73     int cached = 0;
  74
  75     printk(KERN_INFO "\nMem-info:\n");
  76     show_free_areas();
  77     i = max_mapnr;
  78     while (i-- > 0) {
  79         total++;
  80         if (PageReserved(mem_map+i))
  81             reserved++;
  82         else if (PageSwapCache(mem_map+i))
  83             cached++;
  84         else if (!page_count(mem_map+i))
  85             free++;
  86         else
  87             shared += page_count(mem_map+i) - 1;
  88     }
  89     printk(KERN_INFO "%d pages of RAM\n",total);
  90     printk(KERN_INFO "%d free pages\n",free);
  91     printk(KERN_INFO "%d reserved pages\n",reserved);
  92     printk(KERN_INFO "%d pages shared\n",shared);
  93     printk(KERN_INFO "%d pages swap cached\n",cached);
  94 }
  95
  96 extern unsigned long memory_start;
  97 extern unsigned long memory_end;
  98
  99 /*
 100  * paging_init() continues the virtual memory environment setup which
 101  * was begun by the code in arch/head.S.
 102  * The parameters are pointers to where to stick the starting and ending
 103  * addresses of available kernel virtual memory.
 104  */
 105 void paging_init(void)
 106 {
 107         /*
 108          * Make sure start_mem is page aligned, otherwise bootmem and
 109          * page_alloc get different views of the world.
 110          */
 111 #ifdef DEBUG
 112         unsigned long start_mem = PAGE_ALIGN(memory_start);
 113 #endif
 114         unsigned long end_mem   = memory_end & PAGE_MASK;
 115
 116 #ifdef DEBUG
 117         printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
 118                 start_mem, end_mem);
 119 #endif
 120
 121         /*
 122          * Initialize the bad page table and bad page to point
 123          * to a couple of allocated pages.
 124          */
 125         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 126         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 127         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 128         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 129
 130         /*
 131          * Set up SFC/DFC registers (user data space).
 132          */
 133         set_fs (USER_DS);
 134
 135 #ifdef DEBUG
 136         printk (KERN_DEBUG "before free_area_init\n");
 137
 138         printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 139                 start_mem, end_mem);
 140 #endif
 141
 142         {
 143                 unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 144
 145                 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
 146                 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 147 #ifdef CONFIG_HIGHMEM
 148                 zones_size[ZONE_HIGHMEM] = 0;
 149 #endif
 150                 free_area_init(zones_size);
 151         }
 152 }
 153
 154 void mem_init(void)
 155 {
 156         int codek = 0, datak = 0, initk = 0;
 157         unsigned long tmp;
 158         extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 159         extern unsigned int _ramend, _rambase;
 160         unsigned long len = _ramend - _rambase;
 161         unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 162         unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 163
 164 #ifdef DEBUG
 165         printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 166 #endif
 167
 168         end_mem &= PAGE_MASK;
 169         high_memory = (void *) end_mem;
 170
 171         start_mem = PAGE_ALIGN(start_mem);
 172         max_mapnr = num_physpages = MAP_NR(high_memory);
 173
 174         /* this will put all memory onto the freelists */
 175         totalram_pages = free_all_bootmem();
 176
 177         codek = (&_etext - &_stext) >> 10;
 178         datak = (&_ebss - &_sdata) >> 10;
 179         initk = (&__init_begin - &__init_end) >> 10;
 180
 181         tmp = nr_free_pages() << PAGE_SHIFT;
 182         printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
 183                tmp >> 10,
 184                len >> 10,
 185                (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
 186                rom_length >> 10,
 187                codek,
 188                datak
 189                );
 190 }
 191
 192
 193 #ifdef CONFIG_BLK_DEV_INITRD
 194 void free_initrd_mem(unsigned long start, unsigned long end)
 195 {
 196         int pages = 0;
 197         for (; start < end; start += PAGE_SIZE) {
 198                 ClearPageReserved(virt_to_page(start));
 199                 set_page_count(virt_to_page(start), 1);
 200                 free_page(start);
 201                 totalram_pages++;
 202                 pages++;
 203         }
 204         printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 205 }
 206 #endif
 207
 208 void
 209 free_initmem()
 210 {
 211 #ifdef CONFIG_RAMKERNEL
 212         unsigned long addr;
 213         extern char __init_begin, __init_end;
 214         /*
 215          * The following code should be cool even if these sections
 216          * are not page aligned.
 217          */
 218         addr = PAGE_ALIGN((unsigned long)(&__init_begin));
 219         /* next to check that the page we free is not a partial page */
 220         for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
 221                 ClearPageReserved(virt_to_page(addr));
 222                 set_page_count(virt_to_page(addr), 1);
 223                 free_page(addr);
 224                 totalram_pages++;
 225         }
 226         printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
 227                         (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
 228                         (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
 229                         (int)(addr - PAGE_SIZE));
 230 #endif
 231 }
 232