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 struct mmu_gather mmu_gathers[NR_CPUS];
  37
  38 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  39 extern char _stext, _text, _etext, _end, __init_begin, __init_end;
  40 #ifdef CONFIG_XIP_KERNEL
  41 extern char _endtext, _sdata;
  42 #endif
  43 extern unsigned long phys_initrd_start;
  44 extern unsigned long phys_initrd_size;
  45
  46 /*
  47  * The sole use of this is to pass memory configuration
  48  * data from paging_init to mem_init.
  49  */
  50 static struct meminfo meminfo __initdata = { 0, };
  51
  52 /*
  53  * empty_zero_page is a special page that is used for
  54  * zero-initialized data and COW.
  55  */
  56 struct page *empty_zero_page;
  57
  58 void show_mem(void)
  59 {
  60         int free = 0, total = 0, reserved = 0;
  61         int shared = 0, cached = 0, slab = 0;
  62         struct page *page, *end;
  63
  64         printk("Mem-info:\n");
  65         show_free_areas();
  66         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  67
  68
  69         page = NODE_MEM_MAP(0);
  70         end  = page + NODE_DATA(0)->node_spanned_pages;
  71
  72         do {
  73                 total++;
  74                 if (PageReserved(page))
  75                         reserved++;
  76                 else if (PageSwapCache(page))
  77                         cached++;
  78                 else if (PageSlab(page))
  79                         slab++;
  80                 else if (!page_count(page))
  81                         free++;
  82                 else
  83                         shared += page_count(page) - 1;
  84                 page++;
  85         } while (page < end);
  86
  87         printk("%d pages of RAM\n", total);
  88         printk("%d free pages\n", free);
  89         printk("%d reserved pages\n", reserved);
  90         printk("%d slab pages\n", slab);
  91         printk("%d pages shared\n", shared);
  92         printk("%d pages swap cached\n", cached);
  93 }
  94
  95 struct node_info {
  96         unsigned int start;
  97         unsigned int end;
  98         int bootmap_pages;
  99 };
 100
 101 /*
 102  * FIXME: We really want to avoid allocating the bootmap bitmap
 103  * over the top of the initrd.  Hopefully, this is located towards
 104  * the start of a bank, so if we allocate the bootmap bitmap at
 105  * the end, we won't clash.
 106  */
 107 static unsigned int __init
 108 find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
 109 {
 110         unsigned int start_pfn, bootmap_pfn;
 111         unsigned int start, end;
 112
 113         start_pfn   = PFN_UP((unsigned long)&_end);
 114         bootmap_pfn = 0;
 115
 116         /* ARM26 machines only have one node */
 117         if (mi->bank->node != 0)
 118                 BUG();
 119
 120         start = PFN_UP(mi->bank->start);
 121         end   = PFN_DOWN(mi->bank->size + mi->bank->start);
 122
 123         if (start < start_pfn)
 124                 start = start_pfn;
 125
 126         if (end <= start)
 127                 BUG();
 128
 129         if (end - start >= bootmap_pages)
 130                 bootmap_pfn = start;
 131         else
 132                 BUG();
 133
 134         return bootmap_pfn;
 135 }
 136
 137 /*
 138  * Scan the memory info structure and pull out:
 139  *  - the end of memory
 140  *  - the number of nodes
 141  *  - the pfn range of each node
 142  *  - the number of bootmem bitmap pages
 143  */
 144 static void __init
 145 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 146 {
 147         unsigned int memend_pfn = 0;
 148
 149         nodes_clear(node_online_map);
 150         node_set_online(0);
 151
 152         np->bootmap_pages = 0;
 153
 154         if (mi->bank->size == 0) {
 155                 BUG();
 156         }
 157
 158         /*
 159          * Get the start and end pfns for this bank
 160          */
 161         np->start = PFN_UP(mi->bank->start);
 162         np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
 163
 164         if (memend_pfn < np->end)
 165                 memend_pfn = np->end;
 166
 167         /*
 168          * Calculate the number of pages we require to
 169          * store the bootmem bitmaps.
 170          */
 171         np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
 172
 173         /*
 174          * This doesn't seem to be used by the Linux memory
 175          * manager any more.  If we can get rid of it, we
 176          * also get rid of some of the stuff above as well.
 177          */
 178         max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 179         max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 180         mi->end = memend_pfn << PAGE_SHIFT;
 181
 182 }
 183
 184 /*
 185  * Initialise the bootmem allocator for all nodes.  This is called
 186  * early during the architecture specific initialisation.
 187  */
 188 void __init bootmem_init(struct meminfo *mi)
 189 {
 190         struct node_info node_info;
 191         unsigned int bootmap_pfn;
 192         pg_data_t *pgdat = NODE_DATA(0);
 193
 194         find_memend_and_nodes(mi, &node_info);
 195
 196         bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
 197
 198         /*
 199          * Note that node 0 must always have some pages.
 200          */
 201         if (node_info.end == 0)
 202                 BUG();
 203
 204         /*
 205          * Initialise the bootmem allocator.
 206          */
 207         init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
 208
 209         /*
 210          * Register all available RAM in this node with the bootmem allocator.
 211          */
 212         free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
 213
 214         /*
 215          * Register the kernel text and data with bootmem.
 216          * Note: with XIP we dont register .text since
 217          * its in ROM.
 218          */
 219 #ifdef CONFIG_XIP_KERNEL
 220         reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
 221 #else
 222         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 223 #endif
 224
 225         /*
 226          * And don't forget to reserve the allocator bitmap,
 227          * which will be freed later.
 228          */
 229         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
 230                              node_info.bootmap_pages << PAGE_SHIFT);
 231
 232         /*
 233          * These should likewise go elsewhere.  They pre-reserve
 234          * the screen memory region at the start of main system
 235          * memory. FIXME - screen RAM is not 512K!
 236          */
 237         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
 238
 239 #ifdef CONFIG_BLK_DEV_INITRD
 240         initrd_start = phys_initrd_start;
 241         initrd_end = initrd_start + phys_initrd_size;
 242
 243         /* Achimedes machines only have one node, so initrd is in node 0 */
 244 #ifdef CONFIG_XIP_KERNEL
 245         /* Only reserve initrd space if it is in RAM */
 246         if(initrd_start && initrd_start < 0x03000000){
 247 #else
 248         if(initrd_start){
 249 #endif
 250                 reserve_bootmem_node(pgdat, __pa(initrd_start),
 251                                              initrd_end - initrd_start);
 252         }
 253 #endif   /* CONFIG_BLK_DEV_INITRD */
 254
 255
 256 }
 257
 258 /*
 259  * paging_init() sets up the page tables, initialises the zone memory
 260  * maps, and sets up the zero page, bad page and bad page tables.
 261  */
 262 void __init paging_init(struct meminfo *mi)
 263 {
 264         void *zero_page;
 265         unsigned long zone_size[MAX_NR_ZONES];
 266         unsigned long zhole_size[MAX_NR_ZONES];
 267         struct bootmem_data *bdata;
 268         pg_data_t *pgdat;
 269         int i;
 270
 271         memcpy(&meminfo, mi, sizeof(meminfo));
 272
 273         /*
 274          * allocate the zero page.  Note that we count on this going ok.
 275          */
 276         zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
 277
 278         /*
 279          * initialise the page tables.
 280          */
 281         memtable_init(mi);
 282         flush_tlb_all();
 283
 284         /*
 285          * initialise the zones in node 0 (archimedes have only 1 node)
 286          */
 287
 288         for (i = 0; i < MAX_NR_ZONES; i++) {
 289                 zone_size[i]  = 0;
 290                 zhole_size[i] = 0;
 291         }
 292
 293         pgdat = NODE_DATA(0);
 294         bdata = pgdat->bdata;
 295         zone_size[0] = bdata->node_low_pfn -
 296                         (bdata->node_boot_start >> PAGE_SHIFT);
 297         if (!zone_size[0])
 298                 BUG();
 299         pgdat->node_mem_map = NULL;
 300         free_area_init_node(0, pgdat, zone_size,
 301                         bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
 302
 303         /*
 304          * finish off the bad pages once
 305          * the mem_map is initialised
 306          */
 307         memzero(zero_page, PAGE_SIZE);
 308         empty_zero_page = virt_to_page(zero_page);
 309 }
 310
 311 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 312 {
 313         unsigned int size = (end - addr) >> 10;
 314
 315         for (; addr < end; addr += PAGE_SIZE) {
 316                 struct page *page = virt_to_page(addr);
 317                 ClearPageReserved(page);
 318                 init_page_count(page);
 319                 free_page(addr);
 320                 totalram_pages++;
 321         }
 322
 323         if (size && s)
 324                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 325 }
 326
 327 /*
 328  * mem_init() marks the free areas in the mem_map and tells us how much
 329  * memory is free.  This is done after various parts of the system have
 330  * claimed their memory after the kernel image.
 331  */
 332 void __init mem_init(void)
 333 {
 334         unsigned int codepages, datapages, initpages;
 335         pg_data_t *pgdat = NODE_DATA(0);
 336         extern int sysctl_overcommit_memory;
 337
 338
 339         /* Note: data pages includes BSS */
 340 #ifdef CONFIG_XIP_KERNEL
 341         codepages = &_endtext - &_text;
 342         datapages = &_end - &_sdata;
 343 #else
 344         codepages = &_etext - &_text;
 345         datapages = &_end - &_etext;
 346 #endif
 347         initpages = &__init_end - &__init_begin;
 348
 349         high_memory = (void *)__va(meminfo.end);
 350         max_mapnr   = virt_to_page(high_memory) - mem_map;
 351
 352         /* this will put all unused low memory onto the freelists */
 353         if (pgdat->node_spanned_pages != 0)
 354                 totalram_pages += free_all_bootmem_node(pgdat);
 355
 356         num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
 357
 358         printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 359         printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 360                 "%dK data, %dK init)\n",
 361                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 362                 codepages >> 10, datapages >> 10, initpages >> 10);
 363
 364         /*
 365          * Turn on overcommit on tiny machines
 366          */
 367         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 368                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 369                 printk("Turning on overcommit\n");
 370         }
 371 }
 372
 373 void free_initmem(void){
 374 #ifndef CONFIG_XIP_KERNEL
 375         free_area((unsigned long)(&__init_begin),
 376                   (unsigned long)(&__init_end),
 377                   "init");
 378 #endif
 379 }
 380
 381 #ifdef CONFIG_BLK_DEV_INITRD
 382
 383 static int keep_initrd;
 384
 385 void free_initrd_mem(unsigned long start, unsigned long end)
 386 {
 387 #ifdef CONFIG_XIP_KERNEL
 388         /* Only bin initrd if it is in RAM... */
 389         if(!keep_initrd && start < 0x03000000)
 390 #else
 391         if (!keep_initrd)
 392 #endif
 393                 free_area(start, end, "initrd");
 394 }
 395
 396 static int __init keepinitrd_setup(char *__unused)
 397 {
 398         keep_initrd = 1;
 399         return 1;
 400 }
 401
 402 __setup("keepinitrd", keepinitrd_setup);
 403 #endif