arch/frv/mm/init.c

   1 /* init.c: memory initialisation for FRV
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  *
  11  * Derived from:
  12  *  - linux/arch/m68knommu/mm/init.c
  13  *    - Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>, Kenneth Albanowski <kjahds@kjahds.com>,
  14  *    - Copyright (C) 2000  Lineo, Inc.  (www.lineo.com)
  15  *  - linux/arch/m68k/mm/init.c
  16  *    - Copyright (C) 1995  Hamish Macdonald
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/signal.h>
  21 #include <linux/sched.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/swap.h>
  24 #include <linux/mm.h>
  25 #include <linux/kernel.h>
  26 #include <linux/string.h>
  27 #include <linux/types.h>
  28 #include <linux/bootmem.h>
  29 #include <linux/highmem.h>
  30
  31 #include <asm/setup.h>
  32 #include <asm/segment.h>
  33 #include <asm/page.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/system.h>
  36 #include <asm/mmu_context.h>
  37 #include <asm/virtconvert.h>
  38 #include <asm/sections.h>
  39 #include <asm/tlb.h>
  40
  41 #undef DEBUG
  42
  43 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  44
  45 /*
  46  * BAD_PAGE is the page that is used for page faults when linux
  47  * is out-of-memory. Older versions of linux just did a
  48  * do_exit(), but using this instead means there is less risk
  49  * for a process dying in kernel mode, possibly leaving a inode
  50  * unused etc..
  51  *
  52  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  53  * to point to BAD_PAGE entries.
  54  *
  55  * ZERO_PAGE is a special page that is used for zero-initialized
  56  * data and COW.
  57  */
  58 static unsigned long empty_bad_page_table;
  59 static unsigned long empty_bad_page;
  60 unsigned long empty_zero_page;
  61
  62 /*****************************************************************************/
  63 /*
  64  *
  65  */
  66 void show_mem(void)
  67 {
  68         unsigned long i;
  69         int free = 0, total = 0, reserved = 0, shared = 0;
  70
  71         printk("\nMem-info:\n");
  72         show_free_areas();
  73         i = max_mapnr;
  74         while (i-- > 0) {
  75                 struct page *page = &mem_map[i];
  76
  77                 total++;
  78                 if (PageReserved(page))
  79                         reserved++;
  80                 else if (!page_count(page))
  81                         free++;
  82                 else
  83                         shared += page_count(page) - 1;
  84         }
  85
  86         printk("%d pages of RAM\n",total);
  87         printk("%d free pages\n",free);
  88         printk("%d reserved pages\n",reserved);
  89         printk("%d pages shared\n",shared);
  90
  91 } /* end show_mem() */
  92
  93 /*****************************************************************************/
  94 /*
  95  * paging_init() continues the virtual memory environment setup which
  96  * was begun by the code in arch/head.S.
  97  * The parameters are pointers to where to stick the starting and ending
  98  * addresses  of available kernel virtual memory.
  99  */
 100 void __init paging_init(void)
 101 {
 102         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 103
 104         /* allocate some pages for kernel housekeeping tasks */
 105         empty_bad_page_table    = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
 106         empty_bad_page          = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
 107         empty_zero_page         = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
 108
 109         memset((void *) empty_zero_page, 0, PAGE_SIZE);
 110
 111 #if CONFIG_HIGHMEM
 112         if (num_physpages - num_mappedpages) {
 113                 pgd_t *pge;
 114                 pud_t *pue;
 115                 pmd_t *pme;
 116
 117                 pkmap_page_table = alloc_bootmem_pages(PAGE_SIZE);
 118
 119                 memset(pkmap_page_table, 0, PAGE_SIZE);
 120
 121                 pge = swapper_pg_dir + pgd_index_k(PKMAP_BASE);
 122                 pue = pud_offset(pge, PKMAP_BASE);
 123                 pme = pmd_offset(pue, PKMAP_BASE);
 124                 __set_pmd(pme, virt_to_phys(pkmap_page_table) | _PAGE_TABLE);
 125         }
 126 #endif
 127
 128         /* distribute the allocatable pages across the various zones and pass them to the allocator
 129          */
 130         zones_size[ZONE_DMA]     = max_low_pfn - min_low_pfn;
 131         zones_size[ZONE_NORMAL]  = 0;
 132 #ifdef CONFIG_HIGHMEM
 133         zones_size[ZONE_HIGHMEM] = num_physpages - num_mappedpages;
 134 #endif
 135
 136         free_area_init(zones_size);
 137
 138 #ifdef CONFIG_MMU
 139         /* initialise init's MMU context */
 140         init_new_context(&init_task, &init_mm);
 141 #endif
 142
 143 } /* end paging_init() */
 144
 145 /*****************************************************************************/
 146 /*
 147  *
 148  */
 149 void __init mem_init(void)
 150 {
 151         unsigned long npages = (memory_end - memory_start) >> PAGE_SHIFT;
 152         unsigned long tmp;
 153 #ifdef CONFIG_MMU
 154         unsigned long loop, pfn;
 155         int datapages = 0;
 156 #endif
 157         int codek = 0, datak = 0;
 158
 159         /* this will put all memory onto the freelists */
 160         totalram_pages = free_all_bootmem();
 161
 162 #ifdef CONFIG_MMU
 163         for (loop = 0 ; loop < npages ; loop++)
 164                 if (PageReserved(&mem_map[loop]))
 165                         datapages++;
 166
 167 #ifdef CONFIG_HIGHMEM
 168         for (pfn = num_physpages - 1; pfn >= num_mappedpages; pfn--) {
 169                 struct page *page = &mem_map[pfn];
 170
 171                 ClearPageReserved(page);
 172                 set_page_count(page, 1);
 173                 __free_page(page);
 174                 totalram_pages++;
 175         }
 176 #endif
 177
 178         codek = ((unsigned long) &_etext - (unsigned long) &_stext) >> 10;
 179         datak = datapages << (PAGE_SHIFT - 10);
 180
 181 #else
 182         codek = (_etext - _stext) >> 10;
 183         datak = 0; //(_ebss - _sdata) >> 10;
 184 #endif
 185
 186         tmp = nr_free_pages() << PAGE_SHIFT;
 187         printk("Memory available: %luKiB/%luKiB RAM, %luKiB/%luKiB ROM (%dKiB kernel code, %dKiB data)\n",
 188                tmp >> 10,
 189                npages << (PAGE_SHIFT - 10),
 190                (rom_length > 0) ? ((rom_length >> 10) - codek) : 0,
 191                rom_length >> 10,
 192                codek,
 193                datak
 194                );
 195
 196 } /* end mem_init() */
 197
 198 /*****************************************************************************/
 199 /*
 200  * free the memory that was only required for initialisation
 201  */
 202 void __init free_initmem(void)
 203 {
 204 #if defined(CONFIG_RAMKERNEL) && !defined(CONFIG_PROTECT_KERNEL)
 205         unsigned long start, end, addr;
 206
 207         start = PAGE_ALIGN((unsigned long) &__init_begin);      /* round up */
 208         end   = ((unsigned long) &__init_end) & PAGE_MASK;      /* round down */
 209
 210         /* next to check that the page we free is not a partial page */
 211         for (addr = start; addr < end; addr += PAGE_SIZE) {
 212                 ClearPageReserved(virt_to_page(addr));
 213                 set_page_count(virt_to_page(addr), 1);
 214                 free_page(addr);
 215                 totalram_pages++;
 216         }
 217
 218         printk("Freeing unused kernel memory: %ldKiB freed (0x%lx - 0x%lx)\n",
 219                (end - start) >> 10, start, end);
 220 #endif
 221 } /* end free_initmem() */
 222
 223 /*****************************************************************************/
 224 /*
 225  * free the initial ramdisk memory
 226  */
 227 #ifdef CONFIG_BLK_DEV_INITRD
 228 void __init free_initrd_mem(unsigned long start, unsigned long end)
 229 {
 230         int pages = 0;
 231         for (; start < end; start += PAGE_SIZE) {
 232                 ClearPageReserved(virt_to_page(start));
 233                 set_page_count(virt_to_page(start), 1);
 234                 free_page(start);
 235                 totalram_pages++;
 236                 pages++;
 237         }
 238         printk("Freeing initrd memory: %dKiB freed\n", (pages * PAGE_SIZE) >> 10);
 239 } /* end free_initrd_mem() */
 240 #endif