arch/arm/mm/init.c

   1 /*
   2  *  linux/arch/arm/mm/init.c
   3  *
   4  *  Copyright (C) 1995-2005 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/kernel.h>
  11 #include <linux/errno.h>
  12 #include <linux/swap.h>
  13 #include <linux/init.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/mman.h>
  16 #include <linux/nodemask.h>
  17 #include <linux/initrd.h>
  18 #include <linux/highmem.h>
  19 #include <linux/gfp.h>
  20 #include <linux/memblock.h>
  21
  22 #include <asm/mach-types.h>
  23 #include <asm/sections.h>
  24 #include <asm/setup.h>
  25 #include <asm/sizes.h>
  26 #include <asm/tlb.h>
  27 #include <asm/fixmap.h>
  28
  29 #include <asm/mach/arch.h>
  30 #include <asm/mach/map.h>
  31
  32 #include "mm.h"
  33
  34 static unsigned long phys_initrd_start __initdata = 0;
  35 static unsigned long phys_initrd_size __initdata = 0;
  36
  37 static int __init early_initrd(char *p)
  38 {
  39         unsigned long start, size;
  40         char *endp;
  41
  42         start = memparse(p, &endp);
  43         if (*endp == ',') {
  44                 size = memparse(endp + 1, NULL);
  45
  46                 phys_initrd_start = start;
  47                 phys_initrd_size = size;
  48         }
  49         return 0;
  50 }
  51 early_param("initrd", early_initrd);
  52
  53 static int __init parse_tag_initrd(const struct tag *tag)
  54 {
  55         printk(KERN_WARNING "ATAG_INITRD is deprecated; "
  56                 "please update your bootloader.\n");
  57         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  58         phys_initrd_size = tag->u.initrd.size;
  59         return 0;
  60 }
  61
  62 __tagtable(ATAG_INITRD, parse_tag_initrd);
  63
  64 static int __init parse_tag_initrd2(const struct tag *tag)
  65 {
  66         phys_initrd_start = tag->u.initrd.start;
  67         phys_initrd_size = tag->u.initrd.size;
  68         return 0;
  69 }
  70
  71 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  72
  73 /*
  74  * This keeps memory configuration data used by a couple memory
  75  * initialization functions, as well as show_mem() for the skipping
  76  * of holes in the memory map.  It is populated by arm_add_memory().
  77  */
  78 struct meminfo meminfo;
  79
  80 void show_mem(void)
  81 {
  82         int free = 0, total = 0, reserved = 0;
  83         int shared = 0, cached = 0, slab = 0, i;
  84         struct meminfo * mi = &meminfo;
  85
  86         printk("Mem-info:\n");
  87         show_free_areas();
  88
  89         for_each_bank (i, mi) {
  90                 struct membank *bank = &mi->bank[i];
  91                 unsigned int pfn1, pfn2;
  92                 struct page *page, *end;
  93
  94                 pfn1 = bank_pfn_start(bank);
  95                 pfn2 = bank_pfn_end(bank);
  96
  97                 page = pfn_to_page(pfn1);
  98                 end  = pfn_to_page(pfn2 - 1) + 1;
  99
 100                 do {
 101                         total++;
 102                         if (PageReserved(page))
 103                                 reserved++;
 104                         else if (PageSwapCache(page))
 105                                 cached++;
 106                         else if (PageSlab(page))
 107                                 slab++;
 108                         else if (!page_count(page))
 109                                 free++;
 110                         else
 111                                 shared += page_count(page) - 1;
 112                         page++;
 113                 } while (page < end);
 114         }
 115
 116         printk("%d pages of RAM\n", total);
 117         printk("%d free pages\n", free);
 118         printk("%d reserved pages\n", reserved);
 119         printk("%d slab pages\n", slab);
 120         printk("%d pages shared\n", shared);
 121         printk("%d pages swap cached\n", cached);
 122 }
 123
 124 static void __init find_limits(struct meminfo *mi,
 125         unsigned long *min, unsigned long *max_low, unsigned long *max_high)
 126 {
 127         int i;
 128
 129         *min = -1UL;
 130         *max_low = *max_high = 0;
 131
 132         for_each_bank (i, mi) {
 133                 struct membank *bank = &mi->bank[i];
 134                 unsigned long start, end;
 135
 136                 start = bank_pfn_start(bank);
 137                 end = bank_pfn_end(bank);
 138
 139                 if (*min > start)
 140                         *min = start;
 141                 if (*max_high < end)
 142                         *max_high = end;
 143                 if (bank->highmem)
 144                         continue;
 145                 if (*max_low < end)
 146                         *max_low = end;
 147         }
 148 }
 149
 150 static void __init arm_bootmem_init(unsigned long start_pfn,
 151         unsigned long end_pfn)
 152 {
 153         unsigned int boot_pages;
 154         phys_addr_t bitmap;
 155         pg_data_t *pgdat;
 156         int i;
 157
 158         /*
 159          * Allocate the bootmem bitmap page.  This must be in a region
 160          * of memory which has already been mapped.
 161          */
 162         boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
 163         bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
 164                                 __pfn_to_phys(end_pfn));
 165
 166         /*
 167          * Initialise the bootmem allocator, handing the
 168          * memory banks over to bootmem.
 169          */
 170         node_set_online(0);
 171         pgdat = NODE_DATA(0);
 172         init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
 173
 174         /* Free the lowmem regions from memblock into bootmem. */
 175         for (i = 0; i < memblock.memory.cnt; i++) {
 176                 unsigned long start = memblock_start_pfn(&memblock.memory, i);
 177                 unsigned long end = memblock_end_pfn(&memblock.memory, i);
 178
 179                 if (end >= end_pfn)
 180                         end = end_pfn;
 181                 if (start >= end)
 182                         break;
 183
 184                 free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
 185         }
 186
 187         /* Reserve the lowmem memblock reserved regions in bootmem. */
 188         for (i = 0; i < memblock.reserved.cnt; i++) {
 189                 unsigned long start = memblock_start_pfn(&memblock.reserved, i);
 190                 unsigned long size = memblock_size_bytes(&memblock.reserved, i);
 191
 192                 if (start >= end_pfn)
 193                         break;
 194                 if (start + PFN_UP(size) > end_pfn)
 195                         size = (end_pfn - start) << PAGE_SHIFT;
 196
 197                 reserve_bootmem(__pfn_to_phys(start), size, BOOTMEM_DEFAULT);
 198         }
 199 }
 200
 201 static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
 202         unsigned long max_high)
 203 {
 204         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 205         int i;
 206
 207         /*
 208          * initialise the zones.
 209          */
 210         memset(zone_size, 0, sizeof(zone_size));
 211
 212         /*
 213          * The memory size has already been determined.  If we need
 214          * to do anything fancy with the allocation of this memory
 215          * to the zones, now is the time to do it.
 216          */
 217         zone_size[0] = max_low - min;
 218 #ifdef CONFIG_HIGHMEM
 219         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 220 #endif
 221
 222         /*
 223          * Calculate the size of the holes.
 224          *  holes = node_size - sum(bank_sizes)
 225          */
 226         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 227         for (i = 0; i < memblock.memory.cnt; i++) {
 228                 unsigned long start = memblock_start_pfn(&memblock.memory, i);
 229                 unsigned long end = memblock_end_pfn(&memblock.memory, i);
 230
 231                 if (start < max_low) {
 232                         unsigned long low_end = min(end, max_low);
 233
 234                         zhole_size[0] -= low_end - start;
 235                 }
 236
 237 #ifdef CONFIG_HIGHMEM
 238                 if (end > max_low) {
 239                         unsigned long high_start = max(start, max_low);
 240
 241                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 242                 }
 243 #endif
 244         }
 245
 246         /*
 247          * Adjust the sizes according to any special requirements for
 248          * this machine type.
 249          */
 250         arch_adjust_zones(zone_size, zhole_size);
 251
 252         free_area_init_node(0, zone_size, min, zhole_size);
 253 }
 254
 255 #ifndef CONFIG_SPARSEMEM
 256 int pfn_valid(unsigned long pfn)
 257 {
 258         struct memblock_region *mem = &memblock.memory;
 259         unsigned int left = 0, right = mem->cnt;
 260
 261         do {
 262                 unsigned int mid = (right + left) / 2;
 263
 264                 if (pfn < memblock_start_pfn(mem, mid))
 265                         right = mid;
 266                 else if (pfn >= memblock_end_pfn(mem, mid))
 267                         left = mid + 1;
 268                 else
 269                         return 1;
 270         } while (left < right);
 271         return 0;
 272 }
 273 EXPORT_SYMBOL(pfn_valid);
 274
 275 static void arm_memory_present(void)
 276 {
 277 }
 278 #else
 279 static void arm_memory_present(void)
 280 {
 281         int i;
 282         for (i = 0; i < memblock.memory.cnt; i++)
 283                 memory_present(0, memblock_start_pfn(&memblock.memory, i),
 284                                   memblock_end_pfn(&memblock.memory, i));
 285 }
 286 #endif
 287
 288 void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
 289 {
 290         int i;
 291
 292         memblock_init();
 293         for (i = 0; i < mi->nr_banks; i++)
 294                 memblock_add(mi->bank[i].start, mi->bank[i].size);
 295
 296         /* Register the kernel text, kernel data and initrd with memblock. */
 297 #ifdef CONFIG_XIP_KERNEL
 298         memblock_reserve(__pa(_data), _end - _data);
 299 #else
 300         memblock_reserve(__pa(_stext), _end - _stext);
 301 #endif
 302 #ifdef CONFIG_BLK_DEV_INITRD
 303         if (phys_initrd_size) {
 304                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 305
 306                 /* Now convert initrd to virtual addresses */
 307                 initrd_start = __phys_to_virt(phys_initrd_start);
 308                 initrd_end = initrd_start + phys_initrd_size;
 309         }
 310 #endif
 311
 312         arm_mm_memblock_reserve();
 313
 314         /* reserve any platform specific memblock areas */
 315         if (mdesc->reserve)
 316                 mdesc->reserve();
 317
 318         memblock_analyze();
 319         memblock_dump_all();
 320 }
 321
 322 void __init bootmem_init(void)
 323 {
 324         struct meminfo *mi = &meminfo;
 325         unsigned long min, max_low, max_high;
 326
 327         max_low = max_high = 0;
 328
 329         find_limits(mi, &min, &max_low, &max_high);
 330
 331         arm_bootmem_init(min, max_low);
 332
 333         /*
 334          * Sparsemem tries to allocate bootmem in memory_present(),
 335          * so must be done after the fixed reservations
 336          */
 337         arm_memory_present();
 338
 339         /*
 340          * sparse_init() needs the bootmem allocator up and running.
 341          */
 342         sparse_init();
 343
 344         /*
 345          * Now free the memory - free_area_init_node needs
 346          * the sparse mem_map arrays initialized by sparse_init()
 347          * for memmap_init_zone(), otherwise all PFNs are invalid.
 348          */
 349         arm_bootmem_free(min, max_low, max_high);
 350
 351         high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;
 352
 353         /*
 354          * This doesn't seem to be used by the Linux memory manager any
 355          * more, but is used by ll_rw_block.  If we can get rid of it, we
 356          * also get rid of some of the stuff above as well.
 357          *
 358          * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
 359          * the system, not the maximum PFN.
 360          */
 361         max_low_pfn = max_low - PHYS_PFN_OFFSET;
 362         max_pfn = max_high - PHYS_PFN_OFFSET;
 363 }
 364
 365 static inline int free_area(unsigned long pfn, unsigned long end, char *s)
 366 {
 367         unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
 368
 369         for (; pfn < end; pfn++) {
 370                 struct page *page = pfn_to_page(pfn);
 371                 ClearPageReserved(page);
 372                 init_page_count(page);
 373                 __free_page(page);
 374                 pages++;
 375         }
 376
 377         if (size && s)
 378                 printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 379
 380         return pages;
 381 }
 382
 383 static inline void
 384 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 385 {
 386         struct page *start_pg, *end_pg;
 387         unsigned long pg, pgend;
 388
 389         /*
 390          * Convert start_pfn/end_pfn to a struct page pointer.
 391          */
 392         start_pg = pfn_to_page(start_pfn - 1) + 1;
 393         end_pg = pfn_to_page(end_pfn);
 394
 395         /*
 396          * Convert to physical addresses, and
 397          * round start upwards and end downwards.
 398          */
 399         pg = PAGE_ALIGN(__pa(start_pg));
 400         pgend = __pa(end_pg) & PAGE_MASK;
 401
 402         /*
 403          * If there are free pages between these,
 404          * free the section of the memmap array.
 405          */
 406         if (pg < pgend)
 407                 free_bootmem(pg, pgend - pg);
 408 }
 409
 410 /*
 411  * The mem_map array can get very big.  Free the unused area of the memory map.
 412  */
 413 static void __init free_unused_memmap(struct meminfo *mi)
 414 {
 415         unsigned long bank_start, prev_bank_end = 0;
 416         unsigned int i;
 417
 418         /*
 419          * This relies on each bank being in address order.
 420          * The banks are sorted previously in bootmem_init().
 421          */
 422         for_each_bank(i, mi) {
 423                 struct membank *bank = &mi->bank[i];
 424
 425                 bank_start = bank_pfn_start(bank);
 426
 427                 /*
 428                  * If we had a previous bank, and there is a space
 429                  * between the current bank and the previous, free it.
 430                  */
 431                 if (prev_bank_end && prev_bank_end < bank_start)
 432                         free_memmap(prev_bank_end, bank_start);
 433
 434                 /*
 435                  * Align up here since the VM subsystem insists that the
 436                  * memmap entries are valid from the bank end aligned to
 437                  * MAX_ORDER_NR_PAGES.
 438                  */
 439                 prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
 440         }
 441 }
 442
 443 static void __init free_highpages(void)
 444 {
 445 #ifdef CONFIG_HIGHMEM
 446         unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
 447         int i, j;
 448
 449         /* set highmem page free */
 450         for (i = j = 0; i < memblock.memory.cnt; i++) {
 451                 unsigned long start = memblock_start_pfn(&memblock.memory, i);
 452                 unsigned long end = memblock_end_pfn(&memblock.memory, i);
 453
 454                 /* Ignore complete lowmem entries */
 455                 if (end <= max_low)
 456                         continue;
 457
 458                 /* Truncate partial highmem entries */
 459                 if (start < max_low)
 460                         start = max_low;
 461
 462                 /* Find and exclude any reserved regions */
 463                 for (; j < memblock.reserved.cnt; j++) {
 464                         unsigned long res_start;
 465                         unsigned long res_end;
 466
 467                         res_start = memblock_start_pfn(&memblock.reserved, j);
 468                         res_end = res_start + PFN_UP(memblock_size_bytes(&memblock.reserved, j));
 469
 470                         if (res_end < start)
 471                                 continue;
 472                         if (res_start < start)
 473                                 res_start = start;
 474                         if (res_start > end)
 475                                 res_start = end;
 476                         if (res_end > end)
 477                                 res_end = end;
 478                         if (res_start != start)
 479                                 totalhigh_pages += free_area(start, res_start,
 480                                                              NULL);
 481                         start = res_end;
 482                         if (start == end)
 483                                 break;
 484                 }
 485
 486                 /* And now free anything which remains */
 487                 if (start < end)
 488                         totalhigh_pages += free_area(start, end, NULL);
 489         }
 490         totalram_pages += totalhigh_pages;
 491 #endif
 492 }
 493
 494 /*
 495  * mem_init() marks the free areas in the mem_map and tells us how much
 496  * memory is free.  This is done after various parts of the system have
 497  * claimed their memory after the kernel image.
 498  */
 499 void __init mem_init(void)
 500 {
 501         unsigned long reserved_pages, free_pages;
 502         int i;
 503 #ifdef CONFIG_HAVE_TCM
 504         /* These pointers are filled in on TCM detection */
 505         extern u32 dtcm_end;
 506         extern u32 itcm_end;
 507 #endif
 508
 509         max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 510
 511         /* this will put all unused low memory onto the freelists */
 512         free_unused_memmap(&meminfo);
 513
 514         totalram_pages += free_all_bootmem();
 515
 516 #ifdef CONFIG_SA1111
 517         /* now that our DMA memory is actually so designated, we can free it */
 518         totalram_pages += free_area(PHYS_PFN_OFFSET,
 519                                     __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
 520 #endif
 521
 522         free_highpages();
 523
 524         reserved_pages = free_pages = 0;
 525
 526         for_each_bank(i, &meminfo) {
 527                 struct membank *bank = &meminfo.bank[i];
 528                 unsigned int pfn1, pfn2;
 529                 struct page *page, *end;
 530
 531                 pfn1 = bank_pfn_start(bank);
 532                 pfn2 = bank_pfn_end(bank);
 533
 534                 page = pfn_to_page(pfn1);
 535                 end  = pfn_to_page(pfn2 - 1) + 1;
 536
 537                 do {
 538                         if (PageReserved(page))
 539                                 reserved_pages++;
 540                         else if (!page_count(page))
 541                                 free_pages++;
 542                         page++;
 543                 } while (page < end);
 544         }
 545
 546         /*
 547          * Since our memory may not be contiguous, calculate the
 548          * real number of pages we have in this system
 549          */
 550         printk(KERN_INFO "Memory:");
 551         num_physpages = 0;
 552         for (i = 0; i < memblock.memory.cnt; i++) {
 553                 unsigned long pages = memblock_size_pages(&memblock.memory, i);
 554                 num_physpages += pages;
 555                 printk(" %luMB", pages >> (20 - PAGE_SHIFT));
 556         }
 557         printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 558
 559         printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
 560                 nr_free_pages() << (PAGE_SHIFT-10),
 561                 free_pages << (PAGE_SHIFT-10),
 562                 reserved_pages << (PAGE_SHIFT-10),
 563                 totalhigh_pages << (PAGE_SHIFT-10));
 564
 565 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 566 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 567 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 568
 569         printk(KERN_NOTICE "Virtual kernel memory layout:\n"
 570                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 571 #ifdef CONFIG_HAVE_TCM
 572                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 573                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 574 #endif
 575                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 576 #ifdef CONFIG_MMU
 577                         "    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 578 #endif
 579                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 580                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 581 #ifdef CONFIG_HIGHMEM
 582                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 583 #endif
 584                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 585                         "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
 586                         "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
 587                         "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",
 588
 589                         MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
 590                                 (PAGE_SIZE)),
 591 #ifdef CONFIG_HAVE_TCM
 592                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 593                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 594 #endif
 595                         MLK(FIXADDR_START, FIXADDR_TOP),
 596 #ifdef CONFIG_MMU
 597                         MLM(CONSISTENT_BASE, CONSISTENT_END),
 598 #endif
 599                         MLM(VMALLOC_START, VMALLOC_END),
 600                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 601 #ifdef CONFIG_HIGHMEM
 602                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 603                                 (PAGE_SIZE)),
 604 #endif
 605                         MLM(MODULES_VADDR, MODULES_END),
 606
 607                         MLK_ROUNDUP(__init_begin, __init_end),
 608                         MLK_ROUNDUP(_text, _etext),
 609                         MLK_ROUNDUP(_data, _edata));
 610
 611 #undef MLK
 612 #undef MLM
 613 #undef MLK_ROUNDUP
 614
 615         /*
 616          * Check boundaries twice: Some fundamental inconsistencies can
 617          * be detected at build time already.
 618          */
 619 #ifdef CONFIG_MMU
 620         BUILD_BUG_ON(VMALLOC_END                        > CONSISTENT_BASE);
 621         BUG_ON(VMALLOC_END                              > CONSISTENT_BASE);
 622
 623         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 624         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 625 #endif
 626
 627 #ifdef CONFIG_HIGHMEM
 628         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 629         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 630 #endif
 631
 632         if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 633                 extern int sysctl_overcommit_memory;
 634                 /*
 635                  * On a machine this small we won't get
 636                  * anywhere without overcommit, so turn
 637                  * it on by default.
 638                  */
 639                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 640         }
 641 }
 642
 643 void free_initmem(void)
 644 {
 645 #ifdef CONFIG_HAVE_TCM
 646         extern char __tcm_start, __tcm_end;
 647
 648         totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
 649                                     __phys_to_pfn(__pa(&__tcm_end)),
 650                                     "TCM link");
 651 #endif
 652
 653         if (!machine_is_integrator() && !machine_is_cintegrator())
 654                 totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
 655                                             __phys_to_pfn(__pa(__init_end)),
 656                                             "init");
 657 }
 658
 659 #ifdef CONFIG_BLK_DEV_INITRD
 660
 661 static int keep_initrd;
 662
 663 void free_initrd_mem(unsigned long start, unsigned long end)
 664 {
 665         if (!keep_initrd)
 666                 totalram_pages += free_area(__phys_to_pfn(__pa(start)),
 667                                             __phys_to_pfn(__pa(end)),
 668                                             "initrd");
 669 }
 670
 671 static int __init keepinitrd_setup(char *__unused)
 672 {
 673         keep_initrd = 1;
 674         return 1;
 675 }
 676
 677 __setup("keepinitrd", keepinitrd_setup);
 678 #endif