arch/sh/mm/init.c

   1 /* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $
   2  *
   3  *  linux/arch/sh/mm/init.c
   4  *
   5  *  Copyright (C) 1999  Niibe Yutaka
   6  *  Copyright (C) 2002, 2004  Paul Mundt
   7  *
   8  *  Based on linux/arch/i386/mm/init.c:
   9  *   Copyright (C) 1995  Linus Torvalds
  10  */
  11
  12 #include <linux/signal.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/types.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/mman.h>
  20 #include <linux/mm.h>
  21 #include <linux/swap.h>
  22 #include <linux/smp.h>
  23 #include <linux/init.h>
  24 #include <linux/highmem.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/proc_fs.h>
  28 #include <asm/processor.h>
  29 #include <asm/system.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/pgalloc.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/io.h>
  35 #include <asm/tlb.h>
  36 #include <asm/cacheflush.h>
  37 #include <asm/cache.h>
  38
  39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  40 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  41
  42 #ifdef CONFIG_MMU
  43 /* It'd be good if these lines were in the standard header file. */
  44 #define START_PFN       (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
  45 #define MAX_LOW_PFN     (NODE_DATA(0)->bdata->node_low_pfn)
  46 #endif
  47
  48 void (*copy_page)(void *from, void *to);
  49 void (*clear_page)(void *to);
  50
  51 void show_mem(void)
  52 {
  53         int i, total = 0, reserved = 0;
  54         int shared = 0, cached = 0;
  55
  56         printk("Mem-info:\n");
  57         show_free_areas();
  58         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  59         i = max_mapnr;
  60         while (i-- > 0) {
  61                 total++;
  62                 if (PageReserved(mem_map+i))
  63                         reserved++;
  64                 else if (PageSwapCache(mem_map+i))
  65                         cached++;
  66                 else if (page_count(mem_map+i))
  67                         shared += page_count(mem_map+i) - 1;
  68         }
  69         printk("%d pages of RAM\n",total);
  70         printk("%d reserved pages\n",reserved);
  71         printk("%d pages shared\n",shared);
  72         printk("%d pages swap cached\n",cached);
  73 }
  74
  75 #ifdef CONFIG_MMU
  76 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  77 {
  78         pgd_t *pgd;
  79         pud_t *pud;
  80         pmd_t *pmd;
  81         pte_t *pte;
  82
  83         pgd = pgd_offset_k(addr);
  84         if (pgd_none(*pgd)) {
  85                 pgd_ERROR(*pgd);
  86                 return;
  87         }
  88
  89         pud = pud_alloc(NULL, pgd, addr);
  90         if (unlikely(!pud)) {
  91                 pud_ERROR(*pud);
  92                 return;
  93         }
  94
  95         pmd = pmd_alloc(NULL, pud, addr);
  96         if (unlikely(!pmd)) {
  97                 pmd_ERROR(*pmd);
  98                 return;
  99         }
 100
 101         pte = pte_offset_kernel(pmd, addr);
 102         if (!pte_none(*pte)) {
 103                 pte_ERROR(*pte);
 104                 return;
 105         }
 106
 107         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
 108
 109         flush_tlb_one(get_asid(), addr);
 110 }
 111
 112 /*
 113  * As a performance optimization, other platforms preserve the fixmap mapping
 114  * across a context switch, we don't presently do this, but this could be done
 115  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
 116  * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
 117  * give up a TLB entry for each mapping we want to preserve. While this may be
 118  * viable for a small number of fixmaps, it's not particularly useful for
 119  * everything and needs to be carefully evaluated. (ie, we may want this for
 120  * the vsyscall page).
 121  *
 122  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
 123  * in at __set_fixmap() time to determine the appropriate behavior to follow.
 124  *
 125  *                                       -- PFM.
 126  */
 127 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 128 {
 129         unsigned long address = __fix_to_virt(idx);
 130
 131         if (idx >= __end_of_fixed_addresses) {
 132                 BUG();
 133                 return;
 134         }
 135
 136         set_pte_phys(address, phys, prot);
 137 }
 138 #endif  /* CONFIG_MMU */
 139
 140 /* References to section boundaries */
 141
 142 extern char _text, _etext, _edata, __bss_start, _end;
 143 extern char __init_begin, __init_end;
 144
 145 /*
 146  * paging_init() sets up the page tables
 147  */
 148 void __init paging_init(void)
 149 {
 150         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 151
 152         /*
 153          * Setup some defaults for the zone sizes.. these should be safe
 154          * regardless of distcontiguous memory or MMU settings.
 155          */
 156         zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
 157 #ifdef CONFIG_HIGHMEM
 158         zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
 159 #endif
 160
 161 #ifdef CONFIG_MMU
 162         /*
 163          * If we have an MMU, and want to be using it .. we need to adjust
 164          * the zone sizes accordingly, in addition to turning it on.
 165          */
 166         {
 167                 /* We don't need to map the kernel through the TLB, as
 168                  * it is permanatly mapped using P1. So clear the
 169                  * entire pgd. */
 170                 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 171
 172                 /* Turn on the MMU */
 173                 enable_mmu();
 174                 zones_size[ZONE_NORMAL] = MAX_LOW_PFN - START_PFN;
 175         }
 176
 177         /* Set an initial value for the MMU.TTB so we don't have to
 178          * check for a null value. */
 179         set_TTB(swapper_pg_dir);
 180
 181 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
 182         /*
 183          * If we don't have CONFIG_MMU set and the processor in question
 184          * still has an MMU, care needs to be taken to make sure it doesn't
 185          * stay on.. Since the boot loader could have potentially already
 186          * turned it on, and we clearly don't want it, we simply turn it off.
 187          *
 188          * We don't need to do anything special for the zone sizes, since the
 189          * default values that were already configured up above should be
 190          * satisfactory.
 191          */
 192         disable_mmu();
 193 #endif
 194         NODE_DATA(0)->node_mem_map = NULL;
 195         free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
 196 }
 197
 198 static struct kcore_list kcore_mem, kcore_vmalloc;
 199
 200 void __init mem_init(void)
 201 {
 202         int codesize, reservedpages, datasize, initsize;
 203         int tmp;
 204         extern unsigned long memory_start;
 205
 206 #ifdef CONFIG_MMU
 207         high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
 208 #else
 209         extern unsigned long memory_end;
 210
 211         high_memory = (void *)(memory_end & PAGE_MASK);
 212 #endif
 213
 214         max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);
 215
 216         /* clear the zero-page */
 217         memset(empty_zero_page, 0, PAGE_SIZE);
 218         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 219
 220         /*
 221          * Setup wrappers for copy/clear_page(), these will get overridden
 222          * later in the boot process if a better method is available.
 223          */
 224 #ifdef CONFIG_MMU
 225         copy_page = copy_page_slow;
 226         clear_page = clear_page_slow;
 227 #else
 228         copy_page = copy_page_nommu;
 229         clear_page = clear_page_nommu;
 230 #endif
 231
 232         /* this will put all low memory onto the freelists */
 233         totalram_pages += free_all_bootmem_node(NODE_DATA(0));
 234         reservedpages = 0;
 235         for (tmp = 0; tmp < num_physpages; tmp++)
 236                 /*
 237                  * Only count reserved RAM pages
 238                  */
 239                 if (PageReserved(mem_map+tmp))
 240                         reservedpages++;
 241
 242         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 243         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 244         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 245
 246         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 247         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 248                    VMALLOC_END - VMALLOC_START);
 249
 250         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 251                "%dk reserved, %dk data, %dk init)\n",
 252                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 253                 max_mapnr << (PAGE_SHIFT-10),
 254                 codesize >> 10,
 255                 reservedpages << (PAGE_SHIFT-10),
 256                 datasize >> 10,
 257                 initsize >> 10);
 258
 259         p3_cache_init();
 260
 261         /* Initialize the vDSO */
 262         vsyscall_init();
 263 }
 264
 265 void free_initmem(void)
 266 {
 267         unsigned long addr;
 268
 269         addr = (unsigned long)(&__init_begin);
 270         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 271                 ClearPageReserved(virt_to_page(addr));
 272                 init_page_count(virt_to_page(addr));
 273                 free_page(addr);
 274                 totalram_pages++;
 275         }
 276         printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 277 }
 278
 279 #ifdef CONFIG_BLK_DEV_INITRD
 280 void free_initrd_mem(unsigned long start, unsigned long end)
 281 {
 282         unsigned long p;
 283         for (p = start; p < end; p += PAGE_SIZE) {
 284                 ClearPageReserved(virt_to_page(p));
 285                 init_page_count(virt_to_page(p));
 286                 free_page(p);
 287                 totalram_pages++;
 288         }
 289         printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 290 }
 291 #endif
 292