arch/arm26/mm/init.c

   1 /*
   2  *  linux/arch/arm26/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/signal.h>
  11 #include <linux/sched.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/string.h>
  15 #include <linux/types.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/mman.h>
  18 #include <linux/mm.h>
  19 #include <linux/swap.h>
  20 #include <linux/smp.h>
  21 #include <linux/init.h>
  22 #include <linux/initrd.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/pfn.h>
  26
  27 #include <asm/segment.h>
  28 #include <asm/mach-types.h>
  29 #include <asm/dma.h>
  30 #include <asm/hardware.h>
  31 #include <asm/setup.h>
  32 #include <asm/tlb.h>
  33
  34 #include <asm/map.h>
  35
  36
  37 #define TABLE_SIZE      PTRS_PER_PTE * sizeof(pte_t))
  38
  39 struct mmu_gather mmu_gathers[NR_CPUS];
  40
  41 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  42 extern char _stext, _text, _etext, _end, __init_begin, __init_end;
  43 #ifdef CONFIG_XIP_KERNEL
  44 extern char _endtext, _sdata;
  45 #endif
  46 extern unsigned long phys_initrd_start;
  47 extern unsigned long phys_initrd_size;
  48
  49 /*
  50  * The sole use of this is to pass memory configuration
  51  * data from paging_init to mem_init.
  52  */
  53 static struct meminfo meminfo __initdata = { 0, };
  54
  55 /*
  56  * empty_zero_page is a special page that is used for
  57  * zero-initialized data and COW.
  58  */
  59 struct page *empty_zero_page;
  60
  61 void show_mem(void)
  62 {
  63         int free = 0, total = 0, reserved = 0;
  64         int shared = 0, cached = 0, slab = 0;
  65         struct page *page, *end;
  66
  67         printk("Mem-info:\n");
  68         show_free_areas();
  69         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  70
  71
  72         page = NODE_MEM_MAP(0);
  73         end  = page + NODE_DATA(0)->node_spanned_pages;
  74
  75         do {
  76                 total++;
  77                 if (PageReserved(page))
  78                         reserved++;
  79                 else if (PageSwapCache(page))
  80                         cached++;
  81                 else if (PageSlab(page))
  82                         slab++;
  83                 else if (!page_count(page))
  84                         free++;
  85                 else
  86                         shared += page_count(page) - 1;
  87                 page++;
  88         } while (page < end);
  89
  90         printk("%d pages of RAM\n", total);
  91         printk("%d free pages\n", free);
  92         printk("%d reserved pages\n", reserved);
  93         printk("%d slab pages\n", slab);
  94         printk("%d pages shared\n", shared);
  95         printk("%d pages swap cached\n", cached);
  96 }
  97
  98 struct node_info {
  99         unsigned int start;
 100         unsigned int end;
 101         int bootmap_pages;
 102 };
 103
 104 /*
 105  * FIXME: We really want to avoid allocating the bootmap bitmap
 106  * over the top of the initrd.  Hopefully, this is located towards
 107  * the start of a bank, so if we allocate the bootmap bitmap at
 108  * the end, we won't clash.
 109  */
 110 static unsigned int __init
 111 find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
 112 {
 113         unsigned int start_pfn, bootmap_pfn;
 114         unsigned int start, end;
 115
 116         start_pfn   = PFN_UP((unsigned long)&_end);
 117         bootmap_pfn = 0;
 118
 119         /* ARM26 machines only have one node */
 120         if (mi->bank->node != 0)
 121                 BUG();
 122
 123         start = PFN_UP(mi->bank->start);
 124         end   = PFN_DOWN(mi->bank->size + mi->bank->start);
 125
 126         if (start < start_pfn)
 127                 start = start_pfn;
 128
 129         if (end <= start)
 130                 BUG();
 131
 132         if (end - start >= bootmap_pages)
 133                 bootmap_pfn = start;
 134         else
 135                 BUG();
 136
 137         return bootmap_pfn;
 138 }
 139
 140 /*
 141  * Scan the memory info structure and pull out:
 142  *  - the end of memory
 143  *  - the number of nodes
 144  *  - the pfn range of each node
 145  *  - the number of bootmem bitmap pages
 146  */
 147 static void __init
 148 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 149 {
 150         unsigned int memend_pfn = 0;
 151
 152         nodes_clear(node_online_map);
 153         node_set_online(0);
 154
 155         np->bootmap_pages = 0;
 156
 157         if (mi->bank->size == 0) {
 158                 BUG();
 159         }
 160
 161         /*
 162          * Get the start and end pfns for this bank
 163          */
 164         np->start = PFN_UP(mi->bank->start);
 165         np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
 166
 167         if (memend_pfn < np->end)
 168                 memend_pfn = np->end;
 169
 170         /*
 171          * Calculate the number of pages we require to
 172          * store the bootmem bitmaps.
 173          */
 174         np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
 175
 176         /*
 177          * This doesn't seem to be used by the Linux memory
 178          * manager any more.  If we can get rid of it, we
 179          * also get rid of some of the stuff above as well.
 180          */
 181         max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 182         max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 183         mi->end = memend_pfn << PAGE_SHIFT;
 184
 185 }
 186
 187 /*
 188  * Initialise the bootmem allocator for all nodes.  This is called
 189  * early during the architecture specific initialisation.
 190  */
 191 void __init bootmem_init(struct meminfo *mi)
 192 {
 193         struct node_info node_info;
 194         unsigned int bootmap_pfn;
 195         pg_data_t *pgdat = NODE_DATA(0);
 196
 197         find_memend_and_nodes(mi, &node_info);
 198
 199         bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
 200
 201         /*
 202          * Note that node 0 must always have some pages.
 203          */
 204         if (node_info.end == 0)
 205                 BUG();
 206
 207         /*
 208          * Initialise the bootmem allocator.
 209          */
 210         init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
 211
 212         /*
 213          * Register all available RAM in this node with the bootmem allocator.
 214          */
 215         free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
 216
 217         /*
 218          * Register the kernel text and data with bootmem.
 219          * Note: with XIP we dont register .text since
 220          * its in ROM.
 221          */
 222 #ifdef CONFIG_XIP_KERNEL
 223         reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
 224 #else
 225         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 226 #endif
 227
 228         /*
 229          * And don't forget to reserve the allocator bitmap,
 230          * which will be freed later.
 231          */
 232         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
 233                              node_info.bootmap_pages << PAGE_SHIFT);
 234
 235         /*
 236          * These should likewise go elsewhere.  They pre-reserve
 237          * the screen memory region at the start of main system
 238          * memory. FIXME - screen RAM is not 512K!
 239          */
 240         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
 241
 242 #ifdef CONFIG_BLK_DEV_INITRD
 243         initrd_start = phys_initrd_start;
 244         initrd_end = initrd_start + phys_initrd_size;
 245
 246         /* Achimedes machines only have one node, so initrd is in node 0 */
 247 #ifdef CONFIG_XIP_KERNEL
 248         /* Only reserve initrd space if it is in RAM */
 249         if(initrd_start && initrd_start < 0x03000000){
 250 #else
 251         if(initrd_start){
 252 #endif
 253                 reserve_bootmem_node(pgdat, __pa(initrd_start),
 254                                              initrd_end - initrd_start);
 255         }
 256 #endif   /* CONFIG_BLK_DEV_INITRD */
 257
 258
 259 }
 260
 261 /*
 262  * paging_init() sets up the page tables, initialises the zone memory
 263  * maps, and sets up the zero page, bad page and bad page tables.
 264  */
 265 void __init paging_init(struct meminfo *mi)
 266 {
 267         void *zero_page;
 268         unsigned long zone_size[MAX_NR_ZONES];
 269         unsigned long zhole_size[MAX_NR_ZONES];
 270         struct bootmem_data *bdata;
 271         pg_data_t *pgdat;
 272         int i;
 273
 274         memcpy(&meminfo, mi, sizeof(meminfo));
 275
 276         /*
 277          * allocate the zero page.  Note that we count on this going ok.
 278          */
 279         zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
 280
 281         /*
 282          * initialise the page tables.
 283          */
 284         memtable_init(mi);
 285         flush_tlb_all();
 286
 287         /*
 288          * initialise the zones in node 0 (archimedes have only 1 node)
 289          */
 290
 291         for (i = 0; i < MAX_NR_ZONES; i++) {
 292                 zone_size[i]  = 0;
 293                 zhole_size[i] = 0;
 294         }
 295
 296         pgdat = NODE_DATA(0);
 297         bdata = pgdat->bdata;
 298         zone_size[0] = bdata->node_low_pfn -
 299                         (bdata->node_boot_start >> PAGE_SHIFT);
 300         if (!zone_size[0])
 301                 BUG();
 302         pgdat->node_mem_map = NULL;
 303         free_area_init_node(0, pgdat, zone_size,
 304                         bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
 305
 306         /*
 307          * finish off the bad pages once
 308          * the mem_map is initialised
 309          */
 310         memzero(zero_page, PAGE_SIZE);
 311         empty_zero_page = virt_to_page(zero_page);
 312 }
 313
 314 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 315 {
 316         unsigned int size = (end - addr) >> 10;
 317
 318         for (; addr < end; addr += PAGE_SIZE) {
 319                 struct page *page = virt_to_page(addr);
 320                 ClearPageReserved(page);
 321                 init_page_count(page);
 322                 free_page(addr);
 323                 totalram_pages++;
 324         }
 325
 326         if (size && s)
 327                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 328 }
 329
 330 /*
 331  * mem_init() marks the free areas in the mem_map and tells us how much
 332  * memory is free.  This is done after various parts of the system have
 333  * claimed their memory after the kernel image.
 334  */
 335 void __init mem_init(void)
 336 {
 337         unsigned int codepages, datapages, initpages;
 338         pg_data_t *pgdat = NODE_DATA(0);
 339         extern int sysctl_overcommit_memory;
 340
 341
 342         /* Note: data pages includes BSS */
 343 #ifdef CONFIG_XIP_KERNEL
 344         codepages = &_endtext - &_text;
 345         datapages = &_end - &_sdata;
 346 #else
 347         codepages = &_etext - &_text;
 348         datapages = &_end - &_etext;
 349 #endif
 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         num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
 360
 361         printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 362         printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 363                 "%dK data, %dK init)\n",
 364                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 365                 codepages >> 10, datapages >> 10, initpages >> 10);
 366
 367         /*
 368          * Turn on overcommit on tiny machines
 369          */
 370         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 371                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 372                 printk("Turning on overcommit\n");
 373         }
 374 }
 375
 376 void free_initmem(void){
 377 #ifndef CONFIG_XIP_KERNEL
 378         free_area((unsigned long)(&__init_begin),
 379                   (unsigned long)(&__init_end),
 380                   "init");
 381 #endif
 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 #ifdef CONFIG_XIP_KERNEL
 391         /* Only bin initrd if it is in RAM... */
 392         if(!keep_initrd && start < 0x03000000)
 393 #else
 394         if (!keep_initrd)
 395 #endif
 396                 free_area(start, end, "initrd");
 397 }
 398
 399 static int __init keepinitrd_setup(char *__unused)
 400 {
 401         keep_initrd = 1;
 402         return 1;
 403 }
 404
 405 __setup("keepinitrd", keepinitrd_setup);
 406 #endif