arch/sh64/mm/init.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/mm/init.c
   7  *
   8  * Copyright (C) 2000, 2001  Paolo Alberelli
   9  * Copyright (C) 2003, 2004  Paul Mundt
  10  *
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/rwsem.h>
  15 #include <linux/mm.h>
  16 #include <linux/swap.h>
  17 #include <linux/bootmem.h>
  18
  19 #include <asm/mmu_context.h>
  20 #include <asm/page.h>
  21 #include <asm/pgalloc.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/tlb.h>
  24
  25 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  26
  27 /*
  28  * Cache of MMU context last used.
  29  */
  30 unsigned long mmu_context_cache;
  31 pgd_t * mmu_pdtp_cache;
  32 int after_bootmem = 0;
  33
  34 /*
  35  * BAD_PAGE is the page that is used for page faults when linux
  36  * is out-of-memory. Older versions of linux just did a
  37  * do_exit(), but using this instead means there is less risk
  38  * for a process dying in kernel mode, possibly leaving an inode
  39  * unused etc..
  40  *
  41  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  42  * to point to BAD_PAGE entries.
  43  *
  44  * ZERO_PAGE is a special page that is used for zero-initialized
  45  * data and COW.
  46  */
  47
  48 extern unsigned char empty_zero_page[PAGE_SIZE];
  49 extern unsigned char empty_bad_page[PAGE_SIZE];
  50 extern pte_t empty_bad_pte_table[PTRS_PER_PTE];
  51 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  52
  53 extern char _text, _etext, _edata, __bss_start, _end;
  54 extern char __init_begin, __init_end;
  55
  56 /* It'd be good if these lines were in the standard header file. */
  57 #define START_PFN       (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
  58 #define MAX_LOW_PFN     (NODE_DATA(0)->bdata->node_low_pfn)
  59
  60
  61 void show_mem(void)
  62 {
  63         int i, total = 0, reserved = 0;
  64         int shared = 0, cached = 0;
  65
  66         printk("Mem-info:\n");
  67         show_free_areas();
  68         printk("Free swap:       %6ldkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
  69         i = max_mapnr;
  70         while (i-- > 0) {
  71                 total++;
  72                 if (PageReserved(mem_map+i))
  73                         reserved++;
  74                 else if (PageSwapCache(mem_map+i))
  75                         cached++;
  76                 else if (page_count(mem_map+i))
  77                         shared += page_count(mem_map+i) - 1;
  78         }
  79         printk("%d pages of RAM\n",total);
  80         printk("%d reserved pages\n",reserved);
  81         printk("%d pages shared\n",shared);
  82         printk("%d pages swap cached\n",cached);
  83         printk("%ld pages in page table cache\n", quicklist_total_size());
  84 }
  85
  86 /*
  87  * paging_init() sets up the page tables.
  88  *
  89  * head.S already did a lot to set up address translation for the kernel.
  90  * Here we comes with:
  91  * . MMU enabled
  92  * . ASID set (SR)
  93  * .  some 512MB regions being mapped of which the most relevant here is:
  94  *   . CACHED segment (ASID 0 [irrelevant], shared AND NOT user)
  95  * . possible variable length regions being mapped as:
  96  *   . UNCACHED segment (ASID 0 [irrelevant], shared AND NOT user)
  97  * . All of the memory regions are placed, independently from the platform
  98  *   on high addresses, above 0x80000000.
  99  * . swapper_pg_dir is already cleared out by the .space directive
 100  *   in any case swapper does not require a real page directory since
 101  *   it's all kernel contained.
 102  *
 103  * Those pesky NULL-reference errors in the kernel are then
 104  * dealt with by not mapping address 0x00000000 at all.
 105  *
 106  */
 107 void __init paging_init(void)
 108 {
 109         unsigned long zones_size[MAX_NR_ZONES] = {0, };
 110
 111         pgd_init((unsigned long)swapper_pg_dir);
 112         pgd_init((unsigned long)swapper_pg_dir +
 113                  sizeof(pgd_t) * USER_PTRS_PER_PGD);
 114
 115         mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
 116
 117         zones_size[ZONE_NORMAL] = MAX_LOW_PFN - START_PFN;
 118         NODE_DATA(0)->node_mem_map = NULL;
 119         free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
 120 }
 121
 122 void __init mem_init(void)
 123 {
 124         int codesize, reservedpages, datasize, initsize;
 125         int tmp;
 126
 127         max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
 128         high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
 129
 130         /*
 131          * Clear the zero-page.
 132          * This is not required but we might want to re-use
 133          * this very page to pass boot parameters, one day.
 134          */
 135         memset(empty_zero_page, 0, PAGE_SIZE);
 136
 137         /* this will put all low memory onto the freelists */
 138         totalram_pages += free_all_bootmem_node(NODE_DATA(0));
 139         reservedpages = 0;
 140         for (tmp = 0; tmp < num_physpages; tmp++)
 141                 /*
 142                  * Only count reserved RAM pages
 143                  */
 144                 if (PageReserved(mem_map+tmp))
 145                         reservedpages++;
 146
 147         after_bootmem = 1;
 148
 149         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 150         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 151         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 152
 153         printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
 154                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 155                 max_mapnr << (PAGE_SHIFT-10),
 156                 codesize >> 10,
 157                 reservedpages << (PAGE_SHIFT-10),
 158                 datasize >> 10,
 159                 initsize >> 10);
 160 }
 161
 162 void free_initmem(void)
 163 {
 164         unsigned long addr;
 165
 166         addr = (unsigned long)(&__init_begin);
 167         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 168                 ClearPageReserved(virt_to_page(addr));
 169                 init_page_count(virt_to_page(addr));
 170                 free_page(addr);
 171                 totalram_pages++;
 172         }
 173         printk ("Freeing unused kernel memory: %ldk freed\n", (&__init_end - &__init_begin) >> 10);
 174 }
 175
 176 #ifdef CONFIG_BLK_DEV_INITRD
 177 void free_initrd_mem(unsigned long start, unsigned long end)
 178 {
 179         unsigned long p;
 180         for (p = start; p < end; p += PAGE_SIZE) {
 181                 ClearPageReserved(virt_to_page(p));
 182                 init_page_count(virt_to_page(p));
 183                 free_page(p);
 184                 totalram_pages++;
 185         }
 186         printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 187 }
 188 #endif
 189