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 #include <asm/sections.h>
  40
  41 #undef DEBUG
  42
  43 /*
  44  * BAD_PAGE is the page that is used for page faults when linux
  45  * is out-of-memory. Older versions of linux just did a
  46  * do_exit(), but using this instead means there is less risk
  47  * for a process dying in kernel mode, possibly leaving a inode
  48  * unused etc..
  49  *
  50  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  51  * to point to BAD_PAGE entries.
  52  *
  53  * ZERO_PAGE is a special page that is used for zero-initialized
  54  * data and COW.
  55  */
  56 static unsigned long empty_bad_page_table;
  57
  58 static unsigned long empty_bad_page;
  59
  60 unsigned long empty_zero_page;
  61
  62 extern unsigned long rom_length;
  63
  64 extern unsigned long memory_start;
  65 extern unsigned long memory_end;
  66
  67 /*
  68  * paging_init() continues the virtual memory environment setup which
  69  * was begun by the code in arch/head.S.
  70  * The parameters are pointers to where to stick the starting and ending
  71  * addresses of available kernel virtual memory.
  72  */
  73 void __init paging_init(void)
  74 {
  75         /*
  76          * Make sure start_mem is page aligned,  otherwise bootmem and
  77          * page_alloc get different views og the world.
  78          */
  79 #ifdef DEBUG
  80         unsigned long start_mem = PAGE_ALIGN(memory_start);
  81 #endif
  82         unsigned long end_mem   = memory_end & PAGE_MASK;
  83
  84 #ifdef DEBUG
  85         printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
  86                 start_mem, end_mem);
  87 #endif
  88
  89         /*
  90          * Initialize the bad page table and bad page to point
  91          * to a couple of allocated pages.
  92          */
  93         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  94         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  95         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  96         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  97
  98         /*
  99          * Set up SFC/DFC registers (user data space).
 100          */
 101         set_fs (USER_DS);
 102
 103 #ifdef DEBUG
 104         printk ("before free_area_init\n");
 105
 106         printk ("free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 107                 start_mem, end_mem);
 108 #endif
 109
 110         {
 111                 unsigned long zones_size[MAX_NR_ZONES] = {0, };
 112
 113                 zones_size[ZONE_DMA]     = 0 >> PAGE_SHIFT;
 114                 zones_size[ZONE_NORMAL]  = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 115 #ifdef CONFIG_HIGHMEM
 116                 zones_size[ZONE_HIGHMEM] = 0;
 117 #endif
 118                 free_area_init(zones_size);
 119         }
 120 }
 121
 122 void __init mem_init(void)
 123 {
 124         unsigned long codesize = _etext - _stext;
 125
 126         pr_devel("Mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
 127
 128         high_memory = (void *) (memory_end & PAGE_MASK);
 129         max_mapnr = MAP_NR(high_memory);
 130
 131         /* this will put all low memory onto the freelists */
 132         free_all_bootmem();
 133
 134         mem_init_print_info(NULL);
 135         if (rom_length > 0 && rom_length > codesize)
 136                 pr_info("Memory available: %luK/%luK ROM\n",
 137                         (rom_length - codesize) >> 10, rom_length >> 10);
 138 }
 139
 140
 141 #ifdef CONFIG_BLK_DEV_INITRD
 142 void free_initrd_mem(unsigned long start, unsigned long end)
 143 {
 144         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 145 }
 146 #endif
 147
 148 void
 149 free_initmem(void)
 150 {
 151 #ifdef CONFIG_RAMKERNEL
 152         free_initmem_default(-1);
 153 #endif
 154 }
 155