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