arch/h8300/mm/init.c

   1 /*
   2  *  linux/arch/h8300/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/m68knommu/mm/init.c
  11  *  linux/arch/m68k/mm/init.c
  12  *
  13  *  Copyright (C) 1995  Hamish Macdonald
  14  *
  15  *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
  16  *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
  17  */
  18
  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
  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 extern unsigned long rom_length;
  66
  67 void show_mem(void)
  68 {
  69     unsigned long i;
  70     int free = 0, total = 0, reserved = 0, shared = 0;
  71     int cached = 0;
  72
  73     printk("\nMem-info:\n");
  74     show_free_areas();
  75     i = max_mapnr;
  76     while (i-- > 0) {
  77         total++;
  78         if (PageReserved(mem_map+i))
  79             reserved++;
  80         else if (PageSwapCache(mem_map+i))
  81             cached++;
  82         else if (!page_count(mem_map+i))
  83             free++;
  84         else
  85             shared += page_count(mem_map+i) - 1;
  86     }
  87     printk("%d pages of RAM\n",total);
  88     printk("%d free pages\n",free);
  89     printk("%d reserved pages\n",reserved);
  90     printk("%d pages shared\n",shared);
  91     printk("%d pages swap cached\n",cached);
  92 }
  93
  94 extern unsigned long memory_start;
  95 extern unsigned long memory_end;
  96
  97 /*
  98  * paging_init() continues the virtual memory environment setup which
  99  * was begun by the code in arch/head.S.
 100  * The parameters are pointers to where to stick the starting and ending
 101  * addresses of available kernel virtual memory.
 102  */
 103 void paging_init(void)
 104 {
 105         /*
 106          * Make sure start_mem is page aligned,  otherwise bootmem and
 107          * page_alloc get different views og the world.
 108          */
 109 #ifdef DEBUG
 110         unsigned long start_mem = PAGE_ALIGN(memory_start);
 111 #endif
 112         unsigned long end_mem   = memory_end & PAGE_MASK;
 113
 114 #ifdef DEBUG
 115         printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
 116                 start_mem, end_mem);
 117 #endif
 118
 119         /*
 120          * Initialize the bad page table and bad page to point
 121          * to a couple of allocated pages.
 122          */
 123         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 124         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 125         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 126         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 127
 128         /*
 129          * Set up SFC/DFC registers (user data space).
 130          */
 131         set_fs (USER_DS);
 132
 133 #ifdef DEBUG
 134         printk ("before free_area_init\n");
 135
 136         printk ("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 137                 start_mem, end_mem);
 138 #endif
 139
 140         {
 141                 unsigned long zones_size[MAX_NR_ZONES] = {0, };
 142
 143                 zones_size[ZONE_DMA]     = 0 >> PAGE_SHIFT;
 144                 zones_size[ZONE_NORMAL]  = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 145 #ifdef CONFIG_HIGHMEM
 146                 zones_size[ZONE_HIGHMEM] = 0;
 147 #endif
 148                 free_area_init(zones_size);
 149         }
 150 }
 151
 152 void mem_init(void)
 153 {
 154         int codek = 0, datak = 0, initk = 0;
 155         /* DAVIDM look at setup memory map generically with reserved area */
 156         unsigned long tmp;
 157         extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 158         extern unsigned long  _ramend, _ramstart;
 159         unsigned long len = &_ramend - &_ramstart;
 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 = MAP_NR(high_memory);
 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                 init_page_count(virt_to_page(start));
 199                 free_page(start);
 200                 totalram_pages++;
 201                 pages++;
 202         }
 203         printk ("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                 init_page_count(virt_to_page(addr));
 222                 free_page(addr);
 223                 totalram_pages++;
 224         }
 225         printk(KERN_INFO "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