arch/arm26/mm/init.c

   1 /*
   2  *  linux/arch/arm/mm/init.c
   3  *
   4  *  Copyright (C) 1995-2002 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/config.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/string.h>
  16 #include <linux/types.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/mman.h>
  19 #include <linux/mm.h>
  20 #include <linux/swap.h>
  21 #include <linux/smp.h>
  22 #include <linux/init.h>
  23 #include <linux/initrd.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/blk.h>
  26
  27 #include <asm/segment.h>
  28 #include <asm/mach-types.h>
  29 #include <asm/pgalloc.h>
  30 #include <asm/dma.h>
  31 #include <asm/hardware.h>
  32 #include <asm/setup.h>
  33 #include <asm/tlb.h>
  34
  35 //#include <asm/arch.h>
  36 #include <asm/map.h>
  37
  38 #define TABLE_SIZE      PTRS_PER_PTE * sizeof(pte_t))
  39
  40 struct mmu_gather mmu_gathers[NR_CPUS];
  41
  42 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  43 extern char _stext, _text, _etext, _end, __init_begin, __init_end;
  44 extern unsigned long phys_initrd_start;
  45 extern unsigned long phys_initrd_size;
  46
  47 /*
  48  * The sole use of this is to pass memory configuration
  49  * data from paging_init to mem_init.
  50  */
  51 static struct meminfo meminfo __initdata = { 0, };
  52
  53 /*
  54  * empty_zero_page is a special page that is used for
  55  * zero-initialized data and COW.
  56  */
  57 struct page *empty_zero_page;
  58
  59 void show_mem(void)
  60 {
  61         int free = 0, total = 0, reserved = 0;
  62         int shared = 0, cached = 0, slab = 0;
  63         struct page *page, *end;
  64
  65         printk("Mem-info:\n");
  66         show_free_areas();
  67         printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
  68
  69
  70         page = NODE_MEM_MAP(0);
  71         end  = page + NODE_DATA(0)->node_spanned_pages;
  72
  73         do {
  74                 total++;
  75                 if (PageReserved(page))
  76                         reserved++;
  77                 else if (PageSwapCache(page))
  78                         cached++;
  79                 else if (PageSlab(page))
  80                         slab++;
  81                 else if (!page_count(page))
  82                         free++;
  83                 else
  84                         shared += atomic_read(&page->count) - 1;
  85                 page++;
  86         } while (page < end);
  87
  88         printk("%d pages of RAM\n", total);
  89         printk("%d free pages\n", free);
  90         printk("%d reserved pages\n", reserved);
  91         printk("%d slab pages\n", slab);
  92         printk("%d pages shared\n", shared);
  93         printk("%d pages swap cached\n", cached);
  94 }
  95
  96 struct node_info {
  97         unsigned int start;
  98         unsigned int end;
  99         int bootmap_pages;
 100 };
 101
 102 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 103 #define PFN_UP(x)       (PAGE_ALIGN(x) >> PAGE_SHIFT)
 104 #define PFN_SIZE(x)     ((x) >> PAGE_SHIFT)
 105 #define PFN_RANGE(s,e)  PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
 106                                 (((unsigned long)(s)) & PAGE_MASK))
 107
 108 /*
 109  * FIXME: We really want to avoid allocating the bootmap bitmap
 110  * over the top of the initrd.  Hopefully, this is located towards
 111  * the start of a bank, so if we allocate the bootmap bitmap at
 112  * the end, we won't clash.
 113  */
 114 static unsigned int __init
 115 find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
 116 {
 117         unsigned int start_pfn, bootmap_pfn;
 118         unsigned int start, end;
 119
 120         start_pfn   = PFN_UP((unsigned long)&_end);
 121         bootmap_pfn = 0;
 122
 123         /* ARM26 machines only have one node */
 124         if (mi->bank->node != 0)
 125                 BUG();
 126
 127         start = PFN_UP(mi->bank->start);
 128         end   = PFN_DOWN(mi->bank->size + mi->bank->start);
 129
 130         if (start < start_pfn)
 131                 start = start_pfn;
 132
 133         if (end <= start)
 134                 BUG();
 135
 136         if (end - start >= bootmap_pages)
 137                 bootmap_pfn = start;
 138         else
 139                 BUG();
 140
 141         return bootmap_pfn;
 142 }
 143
 144 /*
 145  * Scan the memory info structure and pull out:
 146  *  - the end of memory
 147  *  - the number of nodes
 148  *  - the pfn range of each node
 149  *  - the number of bootmem bitmap pages
 150  */
 151 static void __init
 152 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 153 {
 154         unsigned int memend_pfn = 0;
 155         numnodes = 1;
 156
 157         np->bootmap_pages = 0;
 158
 159         if (mi->bank->size == 0) {
 160                 BUG();
 161         }
 162
 163         /*
 164          * Get the start and end pfns for this bank
 165          */
 166         np->start = PFN_UP(mi->bank->start);
 167         np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
 168
 169         if (memend_pfn < np->end)
 170                 memend_pfn = np->end;
 171
 172         /*
 173          * Calculate the number of pages we require to
 174          * store the bootmem bitmaps.
 175          */
 176         np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
 177
 178         /*
 179          * This doesn't seem to be used by the Linux memory
 180          * manager any more.  If we can get rid of it, we
 181          * also get rid of some of the stuff above as well.
 182          */
 183         max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 184         max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 185         mi->end = memend_pfn << PAGE_SHIFT;
 186
 187 }
 188
 189 /*
 190  * Reserve the various regions of node 0
 191  */
 192 static __init void reserve_node_zero(unsigned int bootmap_pfn, unsigned int bootmap_pages)
 193 {
 194         pg_data_t *pgdat = NODE_DATA(0);
 195
 196         /*
 197          * Register the kernel text and data with bootmem.
 198          * Note that this can only be in node 0.
 199          */
 200         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 201
 202         /*
 203          * And don't forget to reserve the allocator bitmap,
 204          * which will be freed later.
 205          */
 206         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
 207                              bootmap_pages << PAGE_SHIFT);
 208
 209         /*
 210          * These should likewise go elsewhere.  They pre-reserve
 211          * the screen memory region at the start of main system
 212          * memory.
 213          */
 214         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
 215
 216 #ifdef CONFIG_BLK_DEV_INITRD
 217         initrd_start = phys_initrd_start;
 218         initrd_end = initrd_start + phys_initrd_size;
 219
 220         /* Achimedes machines only have one node, so initrd is in node 0 */
 221         reserve_bootmem_node(pgdat, __pa(initrd_start),
 222                                      initrd_end - initrd_start);
 223 #endif
 224
 225 }
 226
 227
 228 /*
 229  * Initialise the bootmem allocator for all nodes.  This is called
 230  * early during the architecture specific initialisation.
 231  */
 232 void __init bootmem_init(struct meminfo *mi)
 233 {
 234         struct node_info node_info;
 235         unsigned int bootmap_pfn;
 236
 237         find_memend_and_nodes(mi, &node_info);
 238
 239         bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
 240
 241         /*
 242          * Note that node 0 must always have some pages.
 243          */
 244         if (node_info.end == 0)
 245                 BUG();
 246
 247         /*
 248          * Initialise the bootmem allocator.
 249          */
 250         init_bootmem_node(NODE_DATA(node), bootmap_pfn, node_info.start, node_info.end);
 251
 252         /*
 253          * Register all available RAM in this node with the bootmem allocator.
 254          */
 255         free_bootmem_node(NODE_DATA(node), mi->bank->start, mi->bank->size);
 256
 257         /*
 258          * Reserve ram for stuff like initrd, video, kernel, etc.
 259          */
 260
 261         reserve_node_zero(bootmap_pfn, node_info.bootmap_pages);
 262
 263 }
 264
 265 /*
 266  * paging_init() sets up the page tables, initialises the zone memory
 267  * maps, and sets up the zero page, bad page and bad page tables.
 268  */
 269 void __init paging_init(struct meminfo *mi)
 270 {
 271         void *zero_page;
 272         unsigned long zone_size[MAX_NR_ZONES];
 273         unsigned long zhole_size[MAX_NR_ZONES];
 274         struct bootmem_data *bdata;
 275         pg_data_t *pgdat;
 276         int i;
 277
 278         memcpy(&meminfo, mi, sizeof(meminfo));
 279
 280         /*
 281          * allocate the zero page.  Note that we count on this going ok.
 282          */
 283         zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
 284
 285         /*
 286          * initialise the page tables.
 287          */
 288         memtable_init(mi);
 289         flush_tlb_all();
 290
 291         /*
 292          * initialise the zones in node 0 (archimedes have only 1 node)
 293          */
 294
 295         for (i = 0; i < MAX_NR_ZONES; i++) {
 296                 zone_size[i]  = 0;
 297                 zhole_size[i] = 0;
 298         }
 299
 300         pgdat = NODE_DATA(0);
 301         bdata = pgdat->bdata;
 302
 303         zone_size[0] = bdata->node_low_pfn -
 304                         (bdata->node_boot_start >> PAGE_SHIFT);
 305         if (!zone_size[0])
 306                 BUG();
 307
 308         free_area_init_node(0, pgdat, 0, zone_size,
 309                         bdata->node_boot_start >> PAGE_SHIFT, 0);
 310
 311         mem_map = contig_page_data.node_mem_map;
 312
 313         /*
 314          * finish off the bad pages once
 315          * the mem_map is initialised
 316          */
 317         memzero(zero_page, PAGE_SIZE);
 318         empty_zero_page = virt_to_page(zero_page);
 319 }
 320
 321 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 322 {
 323         unsigned int size = (end - addr) >> 10;
 324
 325         for (; addr < end; addr += PAGE_SIZE) {
 326                 struct page *page = virt_to_page(addr);
 327                 ClearPageReserved(page);
 328                 set_page_count(page, 1);
 329                 free_page(addr);
 330                 totalram_pages++;
 331         }
 332
 333         if (size && s)
 334                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 335 }
 336
 337 /*
 338  * mem_init() marks the free areas in the mem_map and tells us how much
 339  * memory is free.  This is done after various parts of the system have
 340  * claimed their memory after the kernel image.
 341  */
 342 void __init mem_init(void)
 343 {
 344         unsigned int codepages, datapages, initpages;
 345         pg_data_t *pgdat = NODE_DATA(0);
 346         extern int sysctl_overcommit_memory;
 347
 348         datapages = &_end - &_etext;
 349         codepages = &_etext - &_text;
 350         initpages = &__init_end - &__init_begin;
 351
 352         high_memory = (void *)__va(meminfo.end);
 353         max_mapnr   = virt_to_page(high_memory) - mem_map;
 354
 355         /* this will put all unused low memory onto the freelists */
 356         if (pgdat->node_spanned_pages != 0)
 357                 totalram_pages += free_all_bootmem_node(pgdat);
 358
 359         printk(KERN_INFO "Memory:");
 360
 361         num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
 362
 363         printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 364         printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 365                 "%dK data, %dK init)\n",
 366                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 367                 codepages >> 10, datapages >> 10, initpages >> 10);
 368         /*
 369          * Turn on overcommit on tiny machines
 370          */
 371         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 372                 sysctl_overcommit_memory = 1;
 373                 printk("Turning on overcommit\n");
 374         }
 375 }
 376
 377 void free_initmem(void)
 378 {
 379         free_area((unsigned long)(&__init_begin),
 380                   (unsigned long)(&__init_end),
 381                   "init");
 382 }
 383
 384 #ifdef CONFIG_BLK_DEV_INITRD
 385
 386 static int keep_initrd;
 387
 388 void free_initrd_mem(unsigned long start, unsigned long end)
 389 {
 390         if (!keep_initrd)
 391                 free_area(start, end, "initrd");
 392 }
 393
 394 static int __init keepinitrd_setup(char *__unused)
 395 {
 396         keep_initrd = 1;
 397         return 1;
 398 }
 399
 400 __setup("keepinitrd", keepinitrd_setup);
 401 #endif