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/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/blkdev.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 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 105 #define PFN_UP(x)       (PAGE_ALIGN(x) >> PAGE_SHIFT)
 106 #define PFN_SIZE(x)     ((x) >> PAGE_SHIFT)
 107 #define PFN_RANGE(s,e)  PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
 108                                 (((unsigned long)(s)) & PAGE_MASK))
 109
 110 /*
 111  * FIXME: We really want to avoid allocating the bootmap bitmap
 112  * over the top of the initrd.  Hopefully, this is located towards
 113  * the start of a bank, so if we allocate the bootmap bitmap at
 114  * the end, we won't clash.
 115  */
 116 static unsigned int __init
 117 find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
 118 {
 119         unsigned int start_pfn, bootmap_pfn;
 120         unsigned int start, end;
 121
 122         start_pfn   = PFN_UP((unsigned long)&_end);
 123         bootmap_pfn = 0;
 124
 125         /* ARM26 machines only have one node */
 126         if (mi->bank->node != 0)
 127                 BUG();
 128
 129         start = PFN_UP(mi->bank->start);
 130         end   = PFN_DOWN(mi->bank->size + mi->bank->start);
 131
 132         if (start < start_pfn)
 133                 start = start_pfn;
 134
 135         if (end <= start)
 136                 BUG();
 137
 138         if (end - start >= bootmap_pages)
 139                 bootmap_pfn = start;
 140         else
 141                 BUG();
 142
 143         return bootmap_pfn;
 144 }
 145
 146 /*
 147  * Scan the memory info structure and pull out:
 148  *  - the end of memory
 149  *  - the number of nodes
 150  *  - the pfn range of each node
 151  *  - the number of bootmem bitmap pages
 152  */
 153 static void __init
 154 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 155 {
 156         unsigned int memend_pfn = 0;
 157
 158         nodes_clear(node_online_map);
 159         node_set_online(0);
 160
 161         np->bootmap_pages = 0;
 162
 163         if (mi->bank->size == 0) {
 164                 BUG();
 165         }
 166
 167         /*
 168          * Get the start and end pfns for this bank
 169          */
 170         np->start = PFN_UP(mi->bank->start);
 171         np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
 172
 173         if (memend_pfn < np->end)
 174                 memend_pfn = np->end;
 175
 176         /*
 177          * Calculate the number of pages we require to
 178          * store the bootmem bitmaps.
 179          */
 180         np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
 181
 182         /*
 183          * This doesn't seem to be used by the Linux memory
 184          * manager any more.  If we can get rid of it, we
 185          * also get rid of some of the stuff above as well.
 186          */
 187         max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 188         max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 189         mi->end = memend_pfn << PAGE_SHIFT;
 190
 191 }
 192
 193 /*
 194  * Initialise the bootmem allocator for all nodes.  This is called
 195  * early during the architecture specific initialisation.
 196  */
 197 void __init bootmem_init(struct meminfo *mi)
 198 {
 199         struct node_info node_info;
 200         unsigned int bootmap_pfn;
 201         pg_data_t *pgdat = NODE_DATA(0);
 202
 203         find_memend_and_nodes(mi, &node_info);
 204
 205         bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
 206
 207         /*
 208          * Note that node 0 must always have some pages.
 209          */
 210         if (node_info.end == 0)
 211                 BUG();
 212
 213         /*
 214          * Initialise the bootmem allocator.
 215          */
 216         init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
 217
 218         /*
 219          * Register all available RAM in this node with the bootmem allocator.
 220          */
 221         free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
 222
 223         /*
 224          * Register the kernel text and data with bootmem.
 225          * Note: with XIP we dont register .text since
 226          * its in ROM.
 227          */
 228 #ifdef CONFIG_XIP_KERNEL
 229         reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
 230 #else
 231         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 232 #endif
 233
 234         /*
 235          * And don't forget to reserve the allocator bitmap,
 236          * which will be freed later.
 237          */
 238         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
 239                              node_info.bootmap_pages << PAGE_SHIFT);
 240
 241         /*
 242          * These should likewise go elsewhere.  They pre-reserve
 243          * the screen memory region at the start of main system
 244          * memory. FIXME - screen RAM is not 512K!
 245          */
 246         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
 247
 248 #ifdef CONFIG_BLK_DEV_INITRD
 249         initrd_start = phys_initrd_start;
 250         initrd_end = initrd_start + phys_initrd_size;
 251
 252         /* Achimedes machines only have one node, so initrd is in node 0 */
 253 #ifdef CONFIG_XIP_KERNEL
 254         /* Only reserve initrd space if it is in RAM */
 255         if(initrd_start && initrd_start < 0x03000000){
 256 #else
 257         if(initrd_start){
 258 #endif
 259                 reserve_bootmem_node(pgdat, __pa(initrd_start),
 260                                              initrd_end - initrd_start);
 261         }
 262 #endif   /* CONFIG_BLK_DEV_INITRD */
 263
 264
 265 }
 266
 267 /*
 268  * paging_init() sets up the page tables, initialises the zone memory
 269  * maps, and sets up the zero page, bad page and bad page tables.
 270  */
 271 void __init paging_init(struct meminfo *mi)
 272 {
 273         void *zero_page;
 274         unsigned long zone_size[MAX_NR_ZONES];
 275         unsigned long zhole_size[MAX_NR_ZONES];
 276         struct bootmem_data *bdata;
 277         pg_data_t *pgdat;
 278         int i;
 279
 280         memcpy(&meminfo, mi, sizeof(meminfo));
 281
 282         /*
 283          * allocate the zero page.  Note that we count on this going ok.
 284          */
 285         zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
 286
 287         /*
 288          * initialise the page tables.
 289          */
 290         memtable_init(mi);
 291         flush_tlb_all();
 292
 293         /*
 294          * initialise the zones in node 0 (archimedes have only 1 node)
 295          */
 296
 297         for (i = 0; i < MAX_NR_ZONES; i++) {
 298                 zone_size[i]  = 0;
 299                 zhole_size[i] = 0;
 300         }
 301
 302         pgdat = NODE_DATA(0);
 303         bdata = pgdat->bdata;
 304         zone_size[0] = bdata->node_low_pfn -
 305                         (bdata->node_boot_start >> PAGE_SHIFT);
 306         if (!zone_size[0])
 307                 BUG();
 308         pgdat->node_mem_map = NULL;
 309         free_area_init_node(0, pgdat, zone_size,
 310                         bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
 311
 312         /*
 313          * finish off the bad pages once
 314          * the mem_map is initialised
 315          */
 316         memzero(zero_page, PAGE_SIZE);
 317         empty_zero_page = virt_to_page(zero_page);
 318 }
 319
 320 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 321 {
 322         unsigned int size = (end - addr) >> 10;
 323
 324         for (; addr < end; addr += PAGE_SIZE) {
 325                 struct page *page = virt_to_page(addr);
 326                 ClearPageReserved(page);
 327                 set_page_count(page, 1);
 328                 free_page(addr);
 329                 totalram_pages++;
 330         }
 331
 332         if (size && s)
 333                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 334 }
 335
 336 /*
 337  * mem_init() marks the free areas in the mem_map and tells us how much
 338  * memory is free.  This is done after various parts of the system have
 339  * claimed their memory after the kernel image.
 340  */
 341 void __init mem_init(void)
 342 {
 343         unsigned int codepages, datapages, initpages;
 344         pg_data_t *pgdat = NODE_DATA(0);
 345         extern int sysctl_overcommit_memory;
 346
 347
 348         /* Note: data pages includes BSS */
 349 #ifdef CONFIG_XIP_KERNEL
 350         codepages = &_endtext - &_text;
 351         datapages = &_end - &_sdata;
 352 #else
 353         codepages = &_etext - &_text;
 354         datapages = &_end - &_etext;
 355 #endif
 356         initpages = &__init_end - &__init_begin;
 357
 358         high_memory = (void *)__va(meminfo.end);
 359         max_mapnr   = virt_to_page(high_memory) - mem_map;
 360
 361         /* this will put all unused low memory onto the freelists */
 362         if (pgdat->node_spanned_pages != 0)
 363                 totalram_pages += free_all_bootmem_node(pgdat);
 364
 365         num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
 366
 367         printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 368         printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 369                 "%dK data, %dK init)\n",
 370                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 371                 codepages >> 10, datapages >> 10, initpages >> 10);
 372
 373         /*
 374          * Turn on overcommit on tiny machines
 375          */
 376         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 377                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 378                 printk("Turning on overcommit\n");
 379         }
 380 }
 381
 382 void free_initmem(void){
 383 #ifndef CONFIG_XIP_KERNEL
 384         free_area((unsigned long)(&__init_begin),
 385                   (unsigned long)(&__init_end),
 386                   "init");
 387 #endif
 388 }
 389
 390 #ifdef CONFIG_BLK_DEV_INITRD
 391
 392 static int keep_initrd;
 393
 394 void free_initrd_mem(unsigned long start, unsigned long end)
 395 {
 396 #ifdef CONFIG_XIP_KERNEL
 397         /* Only bin initrd if it is in RAM... */
 398         if(!keep_initrd && start < 0x03000000)
 399 #else
 400         if (!keep_initrd)
 401 #endif
 402                 free_area(start, end, "initrd");
 403 }
 404
 405 static int __init keepinitrd_setup(char *__unused)
 406 {
 407         keep_initrd = 1;
 408         return 1;
 409 }
 410
 411 __setup("keepinitrd", keepinitrd_setup);
 412 #endif