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/cp15.h>
  27 #include <asm/mach-types.h>
  28 #include <asm/memblock.h>
  29 #include <asm/prom.h>
  30 #include <asm/sections.h>
  31 #include <asm/setup.h>
  32 #include <asm/tlb.h>
  33 #include <asm/fixmap.h>
  34
  35 #include <asm/mach/arch.h>
  36 #include <asm/mach/map.h>
  37
  38 #include "mm.h"
  39
  40 #ifdef CONFIG_CPU_CP15_MMU
  41 unsigned long __init __clear_cr(unsigned long mask)
  42 {
  43         cr_alignment = cr_alignment & ~mask;
  44         return cr_alignment;
  45 }
  46 #endif
  47
  48 static phys_addr_t phys_initrd_start __initdata = 0;
  49 static unsigned long phys_initrd_size __initdata = 0;
  50
  51 static int __init early_initrd(char *p)
  52 {
  53         phys_addr_t start;
  54         unsigned long size;
  55         char *endp;
  56
  57         start = memparse(p, &endp);
  58         if (*endp == ',') {
  59                 size = memparse(endp + 1, NULL);
  60
  61                 phys_initrd_start = start;
  62                 phys_initrd_size = size;
  63         }
  64         return 0;
  65 }
  66 early_param("initrd", early_initrd);
  67
  68 static int __init parse_tag_initrd(const struct tag *tag)
  69 {
  70         printk(KERN_WARNING "ATAG_INITRD is deprecated; "
  71                 "please update your bootloader.\n");
  72         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  73         phys_initrd_size = tag->u.initrd.size;
  74         return 0;
  75 }
  76
  77 __tagtable(ATAG_INITRD, parse_tag_initrd);
  78
  79 static int __init parse_tag_initrd2(const struct tag *tag)
  80 {
  81         phys_initrd_start = tag->u.initrd.start;
  82         phys_initrd_size = tag->u.initrd.size;
  83         return 0;
  84 }
  85
  86 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  87
  88 /*
  89  * This keeps memory configuration data used by a couple memory
  90  * initialization functions, as well as show_mem() for the skipping
  91  * of holes in the memory map.  It is populated by arm_add_memory().
  92  */
  93 void show_mem(unsigned int filter)
  94 {
  95         int free = 0, total = 0, reserved = 0;
  96         int shared = 0, cached = 0, slab = 0;
  97         struct memblock_region *reg;
  98
  99         printk("Mem-info:\n");
 100         show_free_areas(filter);
 101
 102         for_each_memblock (memory, reg) {
 103                 unsigned int pfn1, pfn2;
 104                 struct page *page, *end;
 105
 106                 pfn1 = memblock_region_memory_base_pfn(reg);
 107                 pfn2 = memblock_region_memory_end_pfn(reg);
 108
 109                 page = pfn_to_page(pfn1);
 110                 end  = pfn_to_page(pfn2 - 1) + 1;
 111
 112                 do {
 113                         total++;
 114                         if (PageReserved(page))
 115                                 reserved++;
 116                         else if (PageSwapCache(page))
 117                                 cached++;
 118                         else if (PageSlab(page))
 119                                 slab++;
 120                         else if (!page_count(page))
 121                                 free++;
 122                         else
 123                                 shared += page_count(page) - 1;
 124                         pfn1++;
 125                         page = pfn_to_page(pfn1);
 126                 } while (pfn1 < pfn2);
 127         }
 128
 129         printk("%d pages of RAM\n", total);
 130         printk("%d free pages\n", free);
 131         printk("%d reserved pages\n", reserved);
 132         printk("%d slab pages\n", slab);
 133         printk("%d pages shared\n", shared);
 134         printk("%d pages swap cached\n", cached);
 135 }
 136
 137 static void __init find_limits(unsigned long *min, unsigned long *max_low,
 138                                unsigned long *max_high)
 139 {
 140         *max_low = PFN_DOWN(memblock_get_current_limit());
 141         *min = PFN_UP(memblock_start_of_DRAM());
 142         *max_high = PFN_DOWN(memblock_end_of_DRAM());
 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(const struct machine_desc *mdesc)
 278 {
 279         /* Register the kernel text, kernel data and initrd with memblock. */
 280 #ifdef CONFIG_XIP_KERNEL
 281         memblock_reserve(__pa(_sdata), _end - _sdata);
 282 #else
 283         memblock_reserve(__pa(_stext), _end - _stext);
 284 #endif
 285 #ifdef CONFIG_BLK_DEV_INITRD
 286         /* FDT scan will populate initrd_start */
 287         if (initrd_start && !phys_initrd_size) {
 288                 phys_initrd_start = __virt_to_phys(initrd_start);
 289                 phys_initrd_size = initrd_end - initrd_start;
 290         }
 291         initrd_start = initrd_end = 0;
 292         if (phys_initrd_size &&
 293             !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) {
 294                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 295                        (u64)phys_initrd_start, phys_initrd_size);
 296                 phys_initrd_start = phys_initrd_size = 0;
 297         }
 298         if (phys_initrd_size &&
 299             memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) {
 300                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use 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_reserve(phys_initrd_start, phys_initrd_size);
 306
 307                 /* Now convert initrd to virtual addresses */
 308                 initrd_start = __phys_to_virt(phys_initrd_start);
 309                 initrd_end = initrd_start + phys_initrd_size;
 310         }
 311 #endif
 312
 313         arm_mm_memblock_reserve();
 314
 315         /* reserve any platform specific memblock areas */
 316         if (mdesc->reserve)
 317                 mdesc->reserve();
 318
 319         early_init_fdt_scan_reserved_mem();
 320
 321         /*
 322          * reserve memory for DMA contigouos allocations,
 323          * must come from DMA area inside low memory
 324          */
 325         dma_contiguous_reserve(arm_dma_limit);
 326
 327         arm_memblock_steal_permitted = false;
 328         memblock_dump_all();
 329 }
 330
 331 void __init bootmem_init(void)
 332 {
 333         unsigned long min, max_low, max_high;
 334
 335         memblock_allow_resize();
 336         max_low = max_high = 0;
 337
 338         find_limits(&min, &max_low, &max_high);
 339
 340         /*
 341          * Sparsemem tries to allocate bootmem in memory_present(),
 342          * so must be done after the fixed reservations
 343          */
 344         arm_memory_present();
 345
 346         /*
 347          * sparse_init() needs the bootmem allocator up and running.
 348          */
 349         sparse_init();
 350
 351         /*
 352          * Now free the memory - free_area_init_node needs
 353          * the sparse mem_map arrays initialized by sparse_init()
 354          * for memmap_init_zone(), otherwise all PFNs are invalid.
 355          */
 356         zone_sizes_init(min, max_low, max_high);
 357
 358         /*
 359          * This doesn't seem to be used by the Linux memory manager any
 360          * more, but is used by ll_rw_block.  If we can get rid of it, we
 361          * also get rid of some of the stuff above as well.
 362          */
 363         min_low_pfn = min;
 364         max_low_pfn = max_low;
 365         max_pfn = max_high;
 366 }
 367
 368 /*
 369  * Poison init memory with an undefined instruction (ARM) or a branch to an
 370  * undefined instruction (Thumb).
 371  */
 372 static inline void poison_init_mem(void *s, size_t count)
 373 {
 374         u32 *p = (u32 *)s;
 375         for (; count != 0; count -= 4)
 376                 *p++ = 0xe7fddef0;
 377 }
 378
 379 static inline void
 380 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 381 {
 382         struct page *start_pg, *end_pg;
 383         phys_addr_t pg, pgend;
 384
 385         /*
 386          * Convert start_pfn/end_pfn to a struct page pointer.
 387          */
 388         start_pg = pfn_to_page(start_pfn - 1) + 1;
 389         end_pg = pfn_to_page(end_pfn - 1) + 1;
 390
 391         /*
 392          * Convert to physical addresses, and
 393          * round start upwards and end downwards.
 394          */
 395         pg = PAGE_ALIGN(__pa(start_pg));
 396         pgend = __pa(end_pg) & PAGE_MASK;
 397
 398         /*
 399          * If there are free pages between these,
 400          * free the section of the memmap array.
 401          */
 402         if (pg < pgend)
 403                 memblock_free_early(pg, pgend - pg);
 404 }
 405
 406 /*
 407  * The mem_map array can get very big.  Free the unused area of the memory map.
 408  */
 409 static void __init free_unused_memmap(void)
 410 {
 411         unsigned long start, prev_end = 0;
 412         struct memblock_region *reg;
 413
 414         /*
 415          * This relies on each bank being in address order.
 416          * The banks are sorted previously in bootmem_init().
 417          */
 418         for_each_memblock(memory, reg) {
 419                 start = memblock_region_memory_base_pfn(reg);
 420
 421 #ifdef CONFIG_SPARSEMEM
 422                 /*
 423                  * Take care not to free memmap entries that don't exist
 424                  * due to SPARSEMEM sections which aren't present.
 425                  */
 426                 start = min(start,
 427                                  ALIGN(prev_end, PAGES_PER_SECTION));
 428 #else
 429                 /*
 430                  * Align down here since the VM subsystem insists that the
 431                  * memmap entries are valid from the bank start aligned to
 432                  * MAX_ORDER_NR_PAGES.
 433                  */
 434                 start = round_down(start, MAX_ORDER_NR_PAGES);
 435 #endif
 436                 /*
 437                  * If we had a previous bank, and there is a space
 438                  * between the current bank and the previous, free it.
 439                  */
 440                 if (prev_end && prev_end < start)
 441                         free_memmap(prev_end, start);
 442
 443                 /*
 444                  * Align up here since the VM subsystem insists that the
 445                  * memmap entries are valid from the bank end aligned to
 446                  * MAX_ORDER_NR_PAGES.
 447                  */
 448                 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
 449                                  MAX_ORDER_NR_PAGES);
 450         }
 451
 452 #ifdef CONFIG_SPARSEMEM
 453         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 454                 free_memmap(prev_end,
 455                             ALIGN(prev_end, PAGES_PER_SECTION));
 456 #endif
 457 }
 458
 459 #ifdef CONFIG_HIGHMEM
 460 static inline void free_area_high(unsigned long pfn, unsigned long end)
 461 {
 462         for (; pfn < end; pfn++)
 463                 free_highmem_page(pfn_to_page(pfn));
 464 }
 465 #endif
 466
 467 static void __init free_highpages(void)
 468 {
 469 #ifdef CONFIG_HIGHMEM
 470         unsigned long max_low = max_low_pfn;
 471         struct memblock_region *mem, *res;
 472
 473         /* set highmem page free */
 474         for_each_memblock(memory, mem) {
 475                 unsigned long start = memblock_region_memory_base_pfn(mem);
 476                 unsigned long end = memblock_region_memory_end_pfn(mem);
 477
 478                 /* Ignore complete lowmem entries */
 479                 if (end <= max_low)
 480                         continue;
 481
 482                 /* Truncate partial highmem entries */
 483                 if (start < max_low)
 484                         start = max_low;
 485
 486                 /* Find and exclude any reserved regions */
 487                 for_each_memblock(reserved, res) {
 488                         unsigned long res_start, res_end;
 489
 490                         res_start = memblock_region_reserved_base_pfn(res);
 491                         res_end = memblock_region_reserved_end_pfn(res);
 492
 493                         if (res_end < start)
 494                                 continue;
 495                         if (res_start < start)
 496                                 res_start = start;
 497                         if (res_start > end)
 498                                 res_start = end;
 499                         if (res_end > end)
 500                                 res_end = end;
 501                         if (res_start != start)
 502                                 free_area_high(start, res_start);
 503                         start = res_end;
 504                         if (start == end)
 505                                 break;
 506                 }
 507
 508                 /* And now free anything which remains */
 509                 if (start < end)
 510                         free_area_high(start, end);
 511         }
 512 #endif
 513 }
 514
 515 /*
 516  * mem_init() marks the free areas in the mem_map and tells us how much
 517  * memory is free.  This is done after various parts of the system have
 518  * claimed their memory after the kernel image.
 519  */
 520 void __init mem_init(void)
 521 {
 522 #ifdef CONFIG_HAVE_TCM
 523         /* These pointers are filled in on TCM detection */
 524         extern u32 dtcm_end;
 525         extern u32 itcm_end;
 526 #endif
 527
 528         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 529
 530         /* this will put all unused low memory onto the freelists */
 531         free_unused_memmap();
 532         free_all_bootmem();
 533
 534 #ifdef CONFIG_SA1111
 535         /* now that our DMA memory is actually so designated, we can free it */
 536         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 537 #endif
 538
 539         free_highpages();
 540
 541         mem_init_print_info(NULL);
 542
 543 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 544 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 545 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 546
 547         printk(KERN_NOTICE "Virtual kernel memory layout:\n"
 548                         "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 549 #ifdef CONFIG_HAVE_TCM
 550                         "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 551                         "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 552 #endif
 553                         "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 554                         "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 555                         "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 556 #ifdef CONFIG_HIGHMEM
 557                         "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 558 #endif
 559 #ifdef CONFIG_MODULES
 560                         "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 561 #endif
 562                         "      .text : 0x%p" " - 0x%p" "   (%4td kB)\n"
 563                         "      .init : 0x%p" " - 0x%p" "   (%4td kB)\n"
 564                         "      .data : 0x%p" " - 0x%p" "   (%4td kB)\n"
 565                         "       .bss : 0x%p" " - 0x%p" "   (%4td kB)\n",
 566
 567                         MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
 568                                 (PAGE_SIZE)),
 569 #ifdef CONFIG_HAVE_TCM
 570                         MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
 571                         MLK(ITCM_OFFSET, (unsigned long) itcm_end),
 572 #endif
 573                         MLK(FIXADDR_START, FIXADDR_TOP),
 574                         MLM(VMALLOC_START, VMALLOC_END),
 575                         MLM(PAGE_OFFSET, (unsigned long)high_memory),
 576 #ifdef CONFIG_HIGHMEM
 577                         MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
 578                                 (PAGE_SIZE)),
 579 #endif
 580 #ifdef CONFIG_MODULES
 581                         MLM(MODULES_VADDR, MODULES_END),
 582 #endif
 583
 584                         MLK_ROUNDUP(_text, _etext),
 585                         MLK_ROUNDUP(__init_begin, __init_end),
 586                         MLK_ROUNDUP(_sdata, _edata),
 587                         MLK_ROUNDUP(__bss_start, __bss_stop));
 588
 589 #undef MLK
 590 #undef MLM
 591 #undef MLK_ROUNDUP
 592
 593         /*
 594          * Check boundaries twice: Some fundamental inconsistencies can
 595          * be detected at build time already.
 596          */
 597 #ifdef CONFIG_MMU
 598         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 599         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 600 #endif
 601
 602 #ifdef CONFIG_HIGHMEM
 603         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 604         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 605 #endif
 606
 607         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 608                 extern int sysctl_overcommit_memory;
 609                 /*
 610                  * On a machine this small we won't get
 611                  * anywhere without overcommit, so turn
 612                  * it on by default.
 613                  */
 614                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 615         }
 616 }
 617
 618 void free_initmem(void)
 619 {
 620 #ifdef CONFIG_HAVE_TCM
 621         extern char __tcm_start, __tcm_end;
 622
 623         poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
 624         free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
 625 #endif
 626
 627         poison_init_mem(__init_begin, __init_end - __init_begin);
 628         if (!machine_is_integrator() && !machine_is_cintegrator())
 629                 free_initmem_default(-1);
 630 }
 631
 632 #ifdef CONFIG_BLK_DEV_INITRD
 633
 634 static int keep_initrd;
 635
 636 void free_initrd_mem(unsigned long start, unsigned long end)
 637 {
 638         if (!keep_initrd) {
 639                 if (start == initrd_start)
 640                         start = round_down(start, PAGE_SIZE);
 641                 if (end == initrd_end)
 642                         end = round_up(end, PAGE_SIZE);
 643
 644                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 645                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 646         }
 647 }
 648
 649 static int __init keepinitrd_setup(char *__unused)
 650 {
 651         keep_initrd = 1;
 652         return 1;
 653 }
 654
 655 __setup("keepinitrd", keepinitrd_setup);
 656 #endif