target/linux/ubicom32/files/arch/ubicom32/mm/init.c

   1 /*
   2  * arch/ubicom32/mm/init.c
   3  *   Ubicom32 architecture virtual memory initialization.
   4  *
   5  * (C) Copyright 2009, Ubicom, Inc.
   6  *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
   7  *                      Kenneth Albanowski <kjahds@kjahds.com>,
   8  *  Copyright (C) 2000  Lineo, Inc.  (www.lineo.com)
   9  *
  10  *  Based on:
  11  *
  12  *  linux/arch/m68k/mm/init.c
  13  *
  14  *  Copyright (C) 1995  Hamish Macdonald
  15  *
  16  *  JAN/1999 -- hacked to support ColdFire (gerg@snapgear.com)
  17  *  DEC/2000 -- linux 2.4 support <davidm@snapgear.com>
  18  *
  19  * This file is part of the Ubicom32 Linux Kernel Port.
  20  *
  21  * The Ubicom32 Linux Kernel Port is free software: you can redistribute
  22  * it and/or modify it under the terms of the GNU General Public License
  23  * as published by the Free Software Foundation, either version 2 of the
  24  * License, or (at your option) any later version.
  25  *
  26  * The Ubicom32 Linux Kernel Port is distributed in the hope that it
  27  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  28  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  29  * the GNU General Public License for more details.
  30  *
  31  * You should have received a copy of the GNU General Public License
  32  * along with the Ubicom32 Linux Kernel Port.  If not,
  33  * see <http://www.gnu.org/licenses/>.
  34  *
  35  * Ubicom32 implementation derived from (with many thanks):
  36  *   arch/m68knommu
  37  *   arch/blackfin
  38  *   arch/parisc
  39  */
  40
  41 #include <linux/signal.h>
  42 #include <linux/sched.h>
  43 #include <linux/kernel.h>
  44 #include <linux/errno.h>
  45 #include <linux/string.h>
  46 #include <linux/types.h>
  47 #include <linux/ptrace.h>
  48 #include <linux/mman.h>
  49 #include <linux/mm.h>
  50 #include <linux/swap.h>
  51 #include <linux/init.h>
  52 #include <linux/highmem.h>
  53 #include <linux/pagemap.h>
  54 #include <linux/bootmem.h>
  55 #include <linux/slab.h>
  56
  57 #include <asm/setup.h>
  58 #include <asm/segment.h>
  59 #include <asm/page.h>
  60 #include <asm/pgtable.h>
  61 #include <asm/system.h>
  62 #include <asm/machdep.h>
  63 #include <asm/ocm-alloc.h>
  64 #include <asm/processor.h>
  65
  66 #undef DEBUG
  67
  68 extern void die_if_kernel(char *,struct pt_regs *,long);
  69 extern void free_initmem(void);
  70
  71 /*
  72  * BAD_PAGE is the page that is used for page faults when linux
  73  * is out-of-memory. Older versions of linux just did a
  74  * do_exit(), but using this instead means there is less risk
  75  * for a process dying in kernel mode, possibly leaving a inode
  76  * unused etc..
  77  *
  78  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  79  * to point to BAD_PAGE entries.
  80  *
  81  * ZERO_PAGE is a special page that is used for zero-initialized
  82  * data and COW.
  83  */
  84 static unsigned long empty_bad_page_table;
  85
  86 static unsigned long empty_bad_page;
  87
  88 unsigned long empty_zero_page;
  89
  90 void show_mem(void)
  91 {
  92     unsigned long i;
  93     int free = 0, total = 0, reserved = 0, shared = 0;
  94     int cached = 0;
  95
  96     printk(KERN_INFO "\nMem-info:\n");
  97     show_free_areas();
  98     i = max_mapnr;
  99     while (i-- > 0) {
 100         total++;
 101         if (PageReserved(mem_map+i))
 102             reserved++;
 103         else if (PageSwapCache(mem_map+i))
 104             cached++;
 105         else if (!page_count(mem_map+i))
 106             free++;
 107         else
 108             shared += page_count(mem_map+i) - 1;
 109     }
 110     printk(KERN_INFO "%d pages of RAM\n",total);
 111     printk(KERN_INFO "%d free pages\n",free);
 112     printk(KERN_INFO "%d reserved pages\n",reserved);
 113     printk(KERN_INFO "%d pages shared\n",shared);
 114     printk(KERN_INFO "%d pages swap cached\n",cached);
 115 }
 116
 117 extern unsigned long memory_start;
 118 extern unsigned long memory_end;
 119 extern char __ocm_free_begin;
 120 extern char __ocm_free_end;
 121
 122 /*
 123  * paging_init() continues the virtual memory environment setup which
 124  * was begun by the code in arch/head.S.
 125  * The parameters are pointers to where to stick the starting and ending
 126  * addresses of available kernel virtual memory.
 127  */
 128 void __init paging_init(void)
 129 {
 130         /*
 131          * Make sure start_mem is page aligned, otherwise bootmem and
 132          * page_alloc get different views of the world.
 133          */
 134 #ifdef DEBUG
 135         unsigned long start_mem = PAGE_ALIGN(memory_start);
 136 #endif
 137         unsigned long end_mem   = memory_end & PAGE_MASK;
 138
 139 #ifdef DEBUG
 140         printk (KERN_DEBUG "start_mem is %#lx\nvirtual_end is %#lx\n",
 141                 start_mem, end_mem);
 142 #endif
 143
 144         /*
 145          * Initialize the bad page table and bad page to point
 146          * to a couple of allocated pages.
 147          */
 148         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 149         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 150         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 151         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 152
 153         /*
 154          * TODO: enable setting up for user memory management interface.
 155          */
 156
 157 #ifdef DEBUG
 158         printk (KERN_DEBUG "before free_area_init\n");
 159
 160         printk (KERN_DEBUG "free_area_init -> start_mem is %#lx\nvirtual_end is %#lx\n",
 161                 start_mem, end_mem);
 162 #endif
 163
 164         {
 165                 unsigned long zones_size[MAX_NR_ZONES] = {0, };
 166 #ifdef CONFIG_ZONE_DMA
 167                 zones_size[ZONE_DMA] = OCMSIZE >> PAGE_SHIFT;
 168 #endif
 169                 zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 170 #ifdef CONFIG_HIGHMEM
 171                 zones_size[ZONE_HIGHMEM] = 0;
 172 #endif
 173                 free_area_init(zones_size);
 174         }
 175 }
 176
 177 void __init mem_init(void)
 178 {
 179         int codek = 0, datak = 0, initk = 0;
 180         unsigned long tmp, ram_start, ram_end, len;
 181         extern char _etext, _stext, _sdata, _ebss, __init_begin, __init_end;
 182
 183         unsigned long start_mem = memory_start; /* DAVIDM - these must start at end of kernel */
 184         unsigned long end_mem   = memory_end; /* DAVIDM - this must not include kernel stack at top */
 185         processor_dram(&ram_start, &ram_end);
 186         len = (ram_end - ram_start) + OCMSIZE;
 187 #ifdef DEBUG
 188         printk(KERN_DEBUG "Mem_init: start=%lx, end=%lx\n", start_mem, end_mem);
 189 #endif
 190
 191         end_mem &= PAGE_MASK;
 192         high_memory = (void *) end_mem;
 193
 194         start_mem = PAGE_ALIGN(start_mem);
 195         max_mapnr = num_physpages = (((unsigned long) high_memory) - PAGE_OFFSET) >> PAGE_SHIFT;
 196
 197         /* this will put all memory onto the freelists */
 198 #ifdef CONFIG_ZONE_DMA
 199         {
 200                 unsigned long ocm_free_begin = (unsigned long)&__ocm_free_begin;
 201                 unsigned long ocm_free_end = (unsigned long)&__ocm_free_end;
 202                 unsigned long zone_dma_begin = (ocm_free_begin + PAGE_SIZE - 1) & PAGE_MASK;
 203                 unsigned long zone_dma_end = ocm_free_end & PAGE_MASK;
 204                 if (zone_dma_end > zone_dma_begin)
 205                         free_bootmem(zone_dma_begin, zone_dma_end-zone_dma_begin);
 206         }
 207 #endif
 208         totalram_pages = free_all_bootmem();
 209
 210         codek = (&_etext - &_stext) >> 10;
 211         datak = (&_ebss - &_sdata) >> 10;
 212         initk = (&__init_begin - &__init_end) >> 10;
 213
 214         tmp = nr_free_pages() << PAGE_SHIFT;
 215         printk(KERN_INFO "Memory available: %luk/%luk RAM, (%dk kernel code, %dk data)\n",
 216                tmp >> 10,
 217                len >> 10,
 218                codek,
 219                datak
 220                );
 221
 222 }
 223
 224 #ifdef CONFIG_BLK_DEV_INITRD
 225 void free_initrd_mem(unsigned long start, unsigned long end)
 226 {
 227         int pages = 0;
 228         for (; start < end; start += PAGE_SIZE) {
 229                 ClearPageReserved(virt_to_page(start));
 230                 init_page_count(virt_to_page(start));
 231                 free_page(start);
 232                 totalram_pages++;
 233                 pages++;
 234         }
 235         printk (KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 236 }
 237 #endif
 238
 239 void
 240 free_initmem()
 241 {
 242 #ifdef CONFIG_RAMKERNEL
 243         unsigned long addr;
 244         extern char __init_begin, __init_end;
 245         /*
 246          * The following code should be cool even if these sections
 247          * are not page aligned.
 248          */
 249         addr = PAGE_ALIGN((unsigned long)(&__init_begin));
 250         /* next to check that the page we free is not a partial page */
 251         for (; addr + PAGE_SIZE < (unsigned long)(&__init_end); addr +=PAGE_SIZE) {
 252                 ClearPageReserved(virt_to_page(addr));
 253                 init_page_count(virt_to_page(addr));
 254                 free_page(addr);
 255                 totalram_pages++;
 256         }
 257         printk(KERN_NOTICE "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
 258                         (addr - PAGE_ALIGN((long) &__init_begin)) >> 10,
 259                         (int)(PAGE_ALIGN((unsigned long)(&__init_begin))),
 260                         (int)(addr - PAGE_SIZE));
 261 #endif
 262 }