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