arch/nios2nommu/mm/init.c

   1 /*
   2  *  linux/arch/nios2nommu/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  * Copyright (C) 2004   Microtronix Datacom Ltd
   8  *
   9  *  Based on:
  10  *
  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  * Jan/20/2004          dgt         NiosII
  18  *
  19  */
  20
  21 #include <linux/signal.h>
  22 #include <linux/sched.h>
  23 #include <linux/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/string.h>
  26 #include <linux/types.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/mman.h>
  29 #include <linux/mm.h>
  30 #include <linux/swap.h>
  31 #include <linux/init.h>
  32 #include <linux/highmem.h>
  33 #include <linux/pagemap.h>
  34 #include <linux/bootmem.h>
  35 #include <linux/slab.h>
  36
  37 #include <asm/setup.h>
  38 #include <asm/segment.h>
  39 #include <asm/page.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/system.h>
  42 //;dgt2;#include <asm/machdep.h>
  43 //;dgt2;#include <asm/shglcore.h>
  44
  45 #undef DEBUG
  46
  47 extern void die_if_kernel(char *,struct pt_regs *,long);
  48 extern void free_initmem(void);
  49
  50 /*
  51  * BAD_PAGE is the page that is used for page faults when linux
  52  * is out-of-memory. Older versions of linux just did a
  53  * do_exit(), but using this instead means there is less risk
  54  * for a process dying in kernel mode, possibly leaving a inode
  55  * unused etc..
  56  *
  57  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  58  * to point to BAD_PAGE entries.
  59  *
  60  * ZERO_PAGE is a special page that is used for zero-initialized
  61  * data and COW.
  62  */
  63 static unsigned long empty_bad_page_table;
  64
  65 static unsigned long empty_bad_page;
  66
  67 unsigned long empty_zero_page;
  68
  69 extern unsigned long rom_length;
  70
  71 void show_mem(void)
  72 {
  73     unsigned long i;
  74     int free = 0, total = 0, reserved = 0, shared = 0;
  75     int cached = 0;
  76
  77     printk(KERN_INFO "\nMem-info:\n");
  78     show_free_areas();
  79     i = max_mapnr;
  80     while (i-- > 0) {
  81         total++;
  82         if (PageReserved(mem_map+i))
  83             reserved++;
  84         else if (PageSwapCache(mem_map+i))
  85             cached++;
  86         else if (!page_count(mem_map+i))
  87             free++;
  88         else
  89             shared += page_count(mem_map+i) - 1;
  90     }
  91     printk(KERN_INFO "%d pages of RAM\n",total);
  92     printk(KERN_INFO "%d free pages\n",free);
  93     printk(KERN_INFO "%d reserved pages\n",reserved);
  94     printk(KERN_INFO "%d pages shared\n",shared);
  95     printk(KERN_INFO "%d pages swap cached\n",cached);
  96 }
  97
  98 extern unsigned long memory_start;
  99 extern unsigned long memory_end;
 100
 101 /*
 102  * paging_init() continues the virtual memory environment setup which
 103  * was begun by the code in arch/head.S.
 104  * The parameters are pointers to where to stick the starting and ending
 105  * addresses of available kernel virtual memory.
 106  */
 107 void paging_init(void)
 108 {
 109         /*
 110          * Make sure start_mem is page aligned, otherwise bootmem and
 111          * page_alloc get different views of the world.
 112          */
 113 #ifdef DEBUG
 114         unsigned long start_mem = PAGE_ALIGN(memory_start);
 115 #endif
 116         unsigned long end_mem   = memory_end & PAGE_MASK;
 117
 118 #ifdef DEBUG
 119         printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
 120                 start_mem, end_mem);
 121 #endif
 122
 123         /*
 124          * Initialize the bad page table and bad page to point
 125          * to a couple of allocated pages.
 126          */
 127         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 128         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 129         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 130         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 131
 132         /*
 133          * Set up SFC/DFC registers (user data space).
 134          */
 135         set_fs (USER_DS);
 136
 137 #ifdef DEBUG
 138         printk (KERN_DEBUG "before free_area_init\n");
 139
 140         printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 141                 start_mem, end_mem);
 142 #endif
 143
 144         {
 145                 unsigned long zones_size[MAX_NR_ZONES] = {0, };
 146
 147                 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 148                 zones_size[ZONE_NORMAL] = 0;
 149 #ifdef CONFIG_HIGHMEM
 150                 zones_size[ZONE_HIGHMEM] = 0;
 151 #endif
 152                 free_area_init(zones_size);
 153         }
 154 }
 155
 156 void mem_init(void)
 157 {
 158         int codek = 0, datak = 0, initk = 0;
 159         unsigned long tmp;
 160         extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 161         extern unsigned char _ramend, _rambase;
 162         unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 163         unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 164
 165 #ifdef DEBUG
 166         printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 167 #endif
 168
 169         end_mem &= PAGE_MASK;
 170         high_memory = (void *) end_mem;
 171
 172         start_mem = PAGE_ALIGN(start_mem);
 173         max_mapnr = num_physpages = MAP_NR(high_memory);
 174
 175         /* this will put all memory onto the freelists */
 176         totalram_pages = free_all_bootmem();
 177
 178         codek = (&_etext - &_stext) >> 10;
 179         datak = (&_ebss - &_sdata) >> 10;
 180         initk = (&__init_begin - &__init_end) >> 10;
 181
 182         tmp = nr_free_pages() << PAGE_SHIFT;
 183         printk(KERN_INFO "Memory available: %luk/%luk RAM, %luk/%luk ROM (%dk kernel code, %dk data)\n",
 184                tmp >> 10,
 185                (&_ramend - &_rambase) >> 10,
 186                (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
 187                rom_length >> 10,
 188                codek,
 189                datak
 190                );
 191 }
 192
 193
 194 #ifdef CONFIG_BLK_DEV_INITRD
 195 void free_initrd_mem(unsigned long start, unsigned long end)
 196 {
 197         int pages = 0;
 198         for (; start < end; start += PAGE_SIZE) {
 199                 ClearPageReserved(virt_to_page(start));
 200                 init_page_count(virt_to_page(start));
 201                 free_page(start);
 202                 totalram_pages++;
 203                 pages++;
 204         }
 205         printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 206 }
 207 #endif
 208
 209 void
 210 free_initmem()
 211 {
 212 #ifdef CONFIG_RAMKERNEL
 213         unsigned long addr;
 214         extern char __init_begin, __init_end;
 215         /*
 216          * The following code should be cool even if these sections
 217          * are not page aligned.
 218          */
 219         addr = PAGE_ALIGN((unsigned long)(&__init_begin));
 220         /* next to check that the page we free is not a partial page */
 221         for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
 222                 ClearPageReserved(virt_to_page(addr));
 223                 init_page_count(virt_to_page(addr));
 224                 free_page(addr);
 225                 totalram_pages++;
 226         }
 227         printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
 228                         (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
 229                         (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
 230                         (int)(addr - PAGE_SIZE));
 231 #endif
 232 }
 233