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/export.h>
  17 #include <linux/nodemask.h>
  18 #include <linux/initrd.h>
  19 #include <linux/of_fdt.h>
  20 #include <linux/highmem.h>
  21 #include <linux/gfp.h>
  22 #include <linux/memblock.h>
  23 #include <linux/dma-contiguous.h>
  24 #include <linux/sizes.h>
  25
  26 #include <asm/mach-types.h>
  27 #include <asm/memblock.h>
  28 #include <asm/prom.h>
  29 #include <asm/sections.h>
  30 #include <asm/setup.h>
  31 #include <asm/tlb.h>
  32 #include <asm/fixmap.h>
  33
  34 #include <asm/mach/arch.h>
  35 #include <asm/mach/map.h>
  36
  37 #include "mm.h"
  38
  39 static phys_addr_t phys_initrd_start __initdata = 0;
  40 static unsigned long phys_initrd_size __initdata = 0;
  41
  42 static int __init early_initrd(char *p)
  43 {
  44         phys_addr_t start;
  45         unsigned long size;
  46         char *endp;
  47
  48         start = memparse(p, &endp);
  49         if (*endp == ',') {
  50                 size = memparse(endp + 1, NULL);
  51
  52                 phys_initrd_start = start;
  53                 phys_initrd_size = size;
  54         }
  55         return 0;
  56 }
  57 early_param("initrd", early_initrd);
  58
  59 static int __init parse_tag_initrd(const struct tag *tag)
  60 {
  61         printk(KERN_WARNING "ATAG_INITRD is deprecated; "
  62                 "please update your bootloader.\n");
  63         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  64         phys_initrd_size = tag->u.initrd.size;
  65         return 0;
  66 }
  67
  68 __tagtable(ATAG_INITRD, parse_tag_initrd);
  69
  70 static int __init parse_tag_initrd2(const struct tag *tag)
  71 {
  72         phys_initrd_start = tag->u.initrd.start;
  73         phys_initrd_size = tag->u.initrd.size;
  74         return 0;
  75 }
  76
  77 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  78
  79 /*
  80  * This keeps memory configuration data used by a couple memory
  81  * initialization functions, as well as show_mem() for the skipping
  82  * of holes in the memory map.  It is populated by arm_add_memory().
  83  */
  84 struct meminfo meminfo;
  85
  86 void show_mem(unsigned int filter)
  87 {
  88         int free = 0, total = 0, reserved = 0;
  89         int shared = 0, cached = 0, slab = 0, i;
  90         struct meminfo * mi = &meminfo;
  91
  92         printk("Mem-info:\n");
  93         show_free_areas(filter);
  94
  95         for_each_bank (i, mi) {
  96                 struct membank *bank = &mi->bank[i];
  97                 unsigned int pfn1, pfn2;
  98                 struct page *page, *end;
  99
 100                 pfn1 = bank_pfn_start(bank);
 101                 pfn2 = bank_pfn_end(bank);
 102
 103                 page = pfn_to_page(pfn1);
 104                 end  = pfn_to_page(pfn2 - 1) + 1;
 105
 106                 do {
 107                         total++;
 108                         if (PageReserved(page))
 109                                 reserved++;
 110                         else if (PageSwapCache(page))
 111                                 cached++;
 112                         else if (PageSlab(page))
 113                                 slab++;
 114                         else if (!page_count(page))
 115                                 free++;
 116                         else
 117                                 shared += page_count(page) - 1;
 118                         page++;
 119                 } while (page < end);
 120         }
 121
 122         printk("%d pages of RAM\n", total);
 123         printk("%d free pages\n", free);
 124         printk("%d reserved pages\n", reserved);
 125         printk("%d slab pages\n", slab);
 126         printk("%d pages shared\n", shared);
 127         printk("%d pages swap cached\n", cached);
 128 }
 129
 130 static void __init find_limits(unsigned long *min, unsigned long *max_low,
 131                                unsigned long *max_high)
 132 {
 133         struct meminfo *mi = &meminfo;
 134         int i;
 135
 136         /* This assumes the meminfo array is properly sorted */
 137         *min = bank_pfn_start(&mi->bank[0]);
 138         for_each_bank (i, mi)
 139                 if (mi->bank[i].highmem)
 140                                 break;
 141         *max_low = bank_pfn_end(&mi->bank[i - 1]);
 142         *max_high = bank_pfn_end(&mi->bank[mi->nr_banks - 1]);
 143 }
 144
 145 #ifdef CONFIG_ZONE_DMA
 146
 147 phys_addr_t arm_dma_zone_size __read_mostly;
 148 EXPORT_SYMBOL(arm_dma_zone_size);
 149
 150 /*
 151  * The DMA mask corresponding to the maximum bus address allocatable
 152  * using GFP_DMA.  The default here places no restriction on DMA
 153  * allocations.  This must be the smallest DMA mask in the system,
 154  * so a successful GFP_DMA allocation will always satisfy this.
 155  */
 156 phys_addr_t arm_dma_limit;
 157 unsigned long arm_dma_pfn_limit;
 158
 159 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
 160         unsigned long dma_size)
 161 {
 162         if (size[0] <= dma_size)
 163                 return;
 164
 165         size[ZONE_NORMAL] = size[0] - dma_size;
 166         size[ZONE_DMA] = dma_size;
 167         hole[ZONE_NORMAL] = hole[0];
 168         hole[ZONE_DMA] = 0;
 169 }
 170 #endif
 171
 172 void __init setup_dma_zone(const struct machine_desc *mdesc)
 173 {
 174 #ifdef CONFIG_ZONE_DMA
 175         if (mdesc->dma_zone_size) {
 176                 arm_dma_zone_size = mdesc->dma_zone_size;
 177                 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
 178         } else
 179                 arm_dma_limit = 0xffffffff;
 180         arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
 181 #endif
 182 }
 183
 184 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
 185         unsigned long max_high)
 186 {
 187         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 188         struct memblock_region *reg;
 189
 190         /*
 191          * initialise the zones.
 192          */
 193         memset(zone_size, 0, sizeof(zone_size));
 194
 195         /*
 196          * The memory size has already been determined.  If we need
 197          * to do anything fancy with the allocation of this memory
 198          * to the zones, now is the time to do it.
 199          */
 200         zone_size[0] = max_low - min;
 201 #ifdef CONFIG_HIGHMEM
 202         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 203 #endif
 204
 205         /*
 206          * Calculate the size of the holes.
 207          *  holes = node_size - sum(bank_sizes)
 208          */
 209         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 210         for_each_memblock(memory, reg) {
 211                 unsigned long start = memblock_region_memory_base_pfn(reg);
 212                 unsigned long end = memblock_region_memory_end_pfn(reg);
 213
 214                 if (start < max_low) {
 215                         unsigned long low_end = min(end, max_low);
 216                         zhole_size[0] -= low_end - start;
 217                 }
 218 #ifdef CONFIG_HIGHMEM
 219                 if (end > max_low) {
 220                         unsigned long high_start = max(start, max_low);
 221                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 222                 }
 223 #endif
 224         }
 225
 226 #ifdef CONFIG_ZONE_DMA
 227         /*
 228          * Adjust the sizes according to any special requirements for
 229          * this machine type.
 230          */
 231         if (arm_dma_zone_size)
 232                 arm_adjust_dma_zone(zone_size, zhole_size,
 233                         arm_dma_zone_size >> PAGE_SHIFT);
 234 #endif
 235
 236         free_area_init_node(0, zone_size, min, zhole_size);
 237 }
 238
 239 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 240 int pfn_valid(unsigned long pfn)
 241 {
 242         return memblock_is_memory(__pfn_to_phys(pfn));
 243 }
 244 EXPORT_SYMBOL(pfn_valid);
 245 #endif
 246
 247 #ifndef CONFIG_SPARSEMEM
 248 static void __init arm_memory_present(void)
 249 {
 250 }
 251 #else
 252 static void __init arm_memory_present(void)
 253 {
 254         struct memblock_region *reg;
 255
 256         for_each_memblock(memory, reg)
 257                 memory_present(0, memblock_region_memory_base_pfn(reg),
 258                                memblock_region_memory_end_pfn(reg));
 259 }
 260 #endif
 261
 262 static bool arm_memblock_steal_permitted = true;
 263
 264 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 265 {
 266         phys_addr_t phys;
 267
 268         BUG_ON(!arm_memblock_steal_permitted);
 269
 270         phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 271         memblock_free(phys, size);
 272         memblock_remove(phys, size);
 273
 274         return phys;
 275 }
 276
 277 void __init arm_memblock_init(struct meminfo *mi,
 278         const struct machine_desc *mdesc)
 279 {
 280         int i;
 281
 282         for (i = 0; i < mi->nr_banks; i++)
 283                 memblock_add(mi->bank[i].start, mi->bank[i].size);
 284
 285         /* Register the kernel text, kernel data and initrd with memblock. */
 286 #ifdef CONFIG_XIP_KERNEL
 287         memblock_reserve(__pa(_sdata), _end - _sdata);
 288 #else
 289         memblock_reserve(__pa(_stext), _end - _stext);
 290 #endif
 291 #ifdef CONFIG_BLK_DEV_INITRD
 292         /* FDT scan will populate initrd_start */
 293         if (initrd_start && !phys_initrd_size) {
 294                 phys_initrd_start = __virt_to_phys(initrd_start);
 295                 phys_initrd_size = initrd_end - initrd_start;
 296         }
 297         initrd_start = initrd_end = 0;
 298         if (phys_initrd_size &&
 299             !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
 300                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 301                        (u64)phys_initrd_start, phys_initrd_size);
 302                 phys_initrd_start = phys_initrd_size = 0;
 303         }
 304         if (phys_initrd_size &&
 305             memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
 306                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 307                        (u64)phys_initrd_start, phys_initrd_size);
 308                 phys_initrd_start = phys_initrd_size = 0;
 309         }
 310         if (phys_initrd_size) {
 311                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 312
 313                 /* Now convert initrd to virtual addresses */
 314                 initrd_start = __phys_to_virt(phys_initrd_start);
 315                 initrd_end = initrd_start + phys_initrd_size;
 316         }
 317 #endif
 318
 319         arm_mm_memblock_reserve();
 320         arm_dt_memblock_reserve();
 321
 322         /* reserve any platform specific memblock areas */
 323         if (mdesc->reserve)
 324                 mdesc->reserve();
 325
 326         early_init_fdt_scan_reserved_mem();
 327
 328         /*
 329          * reserve memory for DMA contigouos allocations,
 330          * must come from DMA area inside low memory
 331          */
 332         dma_contiguous_reserve(min(arm_dma_limit, arm_lowmem_limit));
 333
 334         arm_memblock_steal_permitted = false;
 335         memblock_dump_all();
 336 }
 337
 338 void __init bootmem_init(void)
 339 {
 340         unsigned long min, max_low, max_high;
 341
 342         memblock_allow_resize();
 343         max_low = max_high = 0;
 344
 345         find_limits(&min, &max_low, &max_high);
 346
 347         /*
 348          * Sparsemem tries to allocate bootmem in memory_present(),
 349          * so must be done after the fixed reservations
 350          */
 351         arm_memory_present();
 352
 353         /*
 354          * sparse_init() needs the bootmem allocator up and running.
 355          */
 356         sparse_init();
 357
 358         /*
 359          * Now free the memory - free_area_init_node needs
 360          * the sparse mem_map arrays initialized by sparse_init()
 361          * for memmap_init_zone(), otherwise all PFNs are invalid.
 362          */
 363         zone_sizes_init(min, max_low, max_high);
 364
 365         /*
 366          * This doesn't seem to be used by the Linux memory manager any
 367          * more, but is used by ll_rw_block.  If we can get rid of it, we
 368          * also get rid of some of the stuff above as well.
 369          */
 370         min_low_pfn = min;
 371         max_low_pfn = max_low;
 372         max_pfn = max_high;
 373 }
 374
 375 /*
 376  * Poison init memory with an undefined instruction (ARM) or a branch to an
 377  * undefined instruction (Thumb).
 378  */
 379 static inline void poison_init_mem(void *s, size_t count)
 380 {
 381         u32 *p = (u32 *)s;
 382         for (; count != 0; count -= 4)
 383                 *p++ = 0xe7fddef0;
 384 }
 385
 386 static inline void
 387 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 388 {
 389         struct page *start_pg, *end_pg;
 390         phys_addr_t pg, pgend;
 391
 392         /*
 393          * Convert start_pfn/end_pfn to a struct page pointer.
 394          */
 395         start_pg = pfn_to_page(start_pfn - 1) + 1;
 396         end_pg = pfn_to_page(end_pfn - 1) + 1;
 397
 398         /*
 399          * Convert to physical addresses, and
 400          * round start upwards and end downwards.
 401          */
 402         pg = PAGE_ALIGN(__pa(start_pg));
 403         pgend = __pa(end_pg) & PAGE_MASK;
 404
 405         /*
 406          * If there are free pages between these,
 407          * free the section of the memmap array.
 408          */
 409         if (pg < pgend)
 410                 memblock_free_early(pg, pgend - pg);
 411 }
 412
 413 /*
 414  * The mem_map array can get very big.  Free the unused area of the memory map.
 415  */
 416 static void __init free_unused_memmap(struct meminfo *mi)
 417 {
 418         unsigned long bank_start, prev_bank_end = 0;
 419         unsigned int i;
 420
 421         /*
 422          * This relies on each bank being in address order.
 423          * The banks are sorted previously in bootmem_init().
 424          */
 425         for_each_bank(i, mi) {
 426                 struct membank *bank = &mi->bank[i];
 427
 428                 bank_start = bank_pfn_start(bank);
 429
 430 #ifdef CONFIG_SPARSEMEM
 431                 /*
 432                  * Take care not to free memmap entries that don't exist
 433                  * due to SPARSEMEM sections which aren't present.
 434                  */
 435                 bank_start = min(bank_start,
 436                                  ALIGN(prev_bank_end, PAGES_PER_SECTION));
 437 #else
 438                 /*
 439                  * Align down here since the VM subsystem insists that the
 440                  * memmap entries are valid from the bank start aligned to
 441                  * MAX_ORDER_NR_PAGES.
 442                  */
 443                 bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES);
 444 #endif
 445                 /*
 446                  * If we had a previous bank, and there is a space
 447                  * between the current bank and the previous, free it.
 448                  */
 449                 if (prev_bank_end && prev_bank_end < bank_start)
 450                         free_memmap(prev_bank_end, bank_start);
 451
 452                 /*
 453                  * Align up here since the VM subsystem insists that the
 454                  * memmap entries are valid from the bank end aligned to
 455                  * MAX_ORDER_NR_PAGES.
 456                  */
 457                 prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
 458         }
 459
 460 #ifdef CONFIG_SPARSEMEM
 461         if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
 462                 free_memmap(prev_bank_end,
 463                             ALIGN(prev_bank_end, PAGES_PER_SECTION));
 464 #endif
 465 }
 466
 467 #ifdef CONFIG_HIGHMEM
 468 static inline void free_area_high(unsigned long pfn, unsigned long end)
 469 {
 470         for (; pfn < end; pfn++)
 471                 free_highmem_page(pfn_to_page(pfn));
 472 }
 473 #endif
 474
 475 static void __init free_highpages(void)
 476 {
 477 #ifdef CONFIG_HIGHMEM
 478         unsigned long max_low = max_low_pfn;
 479         struct memblock_region *mem, *res;
 480
 481         /* set highmem page free */
 482         for_each_memblock(memory, mem) {
 483                 unsigned long start = memblock_region_memory_base_pfn(mem);
 484                 unsigned long end = memblock_region_memory_end_pfn(mem);
 485
 486                 /* Ignore complete lowmem entries */
 487                 if (end <= max_low)
 488                         continue;
 489
 490                 /* Truncate partial highmem entries */
 491                 if (start < max_low)
 492                         start = max_low;
 493
 494                 /* Find and exclude any reserved regions */
 495                 for_each_memblock(reserved, res) {
 496                         unsigned long res_start, res_end;
 497
 498                         res_start = memblock_region_reserved_base_pfn(res);
 499                         res_end = memblock_region_reserved_end_pfn(res);
 500
 501                         if (res_end < start)
 502                                 continue;
 503                         if (res_start < start)
 504                                 res_start = start;
 505                         if (res_start > end)
 506                                 res_start = end;
 507                         if (res_end > end)
 508                                 res_end = end;
 509                         if (res_start != start)
 510                                 free_area_high(start, res_start);
 511                         start = res_end;
 512                         if (start == end)
 513                                 break;
 514                 }
 515
 516                 /* And now free anything which remains */
 517                 if (start < end)
 518                         free_area_high(start, end);
 519         }
 520 #endif
 521 }
 522
 523 /*
 524  * mem_init() marks the free areas in the mem_map and tells us how much
 525  * memory is free.  This is done after various parts of the system have
 526  * claimed their memory after the kernel image.
 527  */
 528 void __init mem_init(void)
 529 {
 530 #ifdef CONFIG_HAVE_TCM
 531         /* These pointers are filled in on TCM detection */
 532         extern u32 dtcm_end;
 533         extern u32 itcm_end;
 534 #endif
 535
 536         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 537
 538         /* this will put all unused low memory onto the freelists */
 539         free_unused_memmap(&meminfo);
 540         free_all_bootmem();
 541
 542 #ifdef CONFIG_SA1111
 543         /* now that our DMA memory is actually so designated, we can free it */
 544         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 545 #endif
 546
 547         free_highpages();
 548
 549         mem_init_print_info(NULL);
 550
 551 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 552 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 553 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 554
 555         printk(KERN_NOTICE "Virtual kernel memory layout:\n"
 556                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 557 #ifdef CONFIG_HAVE_TCM
 558                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 559                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 560 #endif
 561                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 562                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 563                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 564 #ifdef CONFIG_HIGHMEM
 565                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 566 #endif
 567 #ifdef CONFIG_MODULES
 568                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 569 #endif
 570                         "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
 571                         "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
 572                         "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n"
 573                         "       .bss : 0x%p" " - 0x%p" "   (%4d kB)\n",
 574
 575                         MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
 576                                 (PAGE_SIZE)),
 577 #ifdef CONFIG_HAVE_TCM
 578                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 579                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 580 #endif
 581                         MLK(FIXADDR_START, FIXADDR_TOP),
 582                         MLM(VMALLOC_START, VMALLOC_END),
 583                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 584 #ifdef CONFIG_HIGHMEM
 585                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 586                                 (PAGE_SIZE)),
 587 #endif
 588 #ifdef CONFIG_MODULES
 589                         MLM(MODULES_VADDR, MODULES_END),
 590 #endif
 591
 592                         MLK_ROUNDUP(_text, _etext),
 593                         MLK_ROUNDUP(__init_begin, __init_end),
 594                         MLK_ROUNDUP(_sdata, _edata),
 595                         MLK_ROUNDUP(__bss_start, __bss_stop));
 596
 597 #undef MLK
 598 #undef MLM
 599 #undef MLK_ROUNDUP
 600
 601         /*
 602          * Check boundaries twice: Some fundamental inconsistencies can
 603          * be detected at build time already.
 604          */
 605 #ifdef CONFIG_MMU
 606         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 607         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 608 #endif
 609
 610 #ifdef CONFIG_HIGHMEM
 611         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 612         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 613 #endif
 614
 615         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 616                 extern int sysctl_overcommit_memory;
 617                 /*
 618                  * On a machine this small we won't get
 619                  * anywhere without overcommit, so turn
 620                  * it on by default.
 621                  */
 622                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 623         }
 624 }
 625
 626 void free_initmem(void)
 627 {
 628 #ifdef CONFIG_HAVE_TCM
 629         extern char __tcm_start, __tcm_end;
 630
 631         poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
 632         free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 633 #endif
 634
 635         poison_init_mem(__init_begin, __init_end - __init_begin);
 636         if (!machine_is_integrator() && !machine_is_cintegrator())
 637                 free_initmem_default(-1);
 638 }
 639
 640 #ifdef CONFIG_BLK_DEV_INITRD
 641
 642 static int keep_initrd;
 643
 644 void free_initrd_mem(unsigned long start, unsigned long end)
 645 {
 646         if (!keep_initrd) {
 647                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 648                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 649         }
 650 }
 651
 652 static int __init keepinitrd_setup(char *__unused)
 653 {
 654         keep_initrd = 1;
 655         return 1;
 656 }
 657
 658 __setup("keepinitrd", keepinitrd_setup);
 659 #endif