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