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 #ifdef CONFIG_OF_FLATTREE 80 void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end) 81 { 82 phys_initrd_start = start; 83 phys_initrd_size = end - start; 84 } 85 #endif /* CONFIG_OF_FLATTREE */ 86 87 /* 88 * This keeps memory configuration data used by a couple memory 89 * initialization functions, as well as show_mem() for the skipping 90 * of holes in the memory map. It is populated by arm_add_memory(). 91 */ 92 struct meminfo meminfo; 93 94 void show_mem(unsigned int filter) 95 { 96 int free = 0, total = 0, reserved = 0; 97 int shared = 0, cached = 0, slab = 0, i; 98 struct meminfo * mi = &meminfo; 99 100 printk("Mem-info:\n"); 101 show_free_areas(filter); 102 103 if (filter & SHOW_MEM_FILTER_PAGE_COUNT) 104 return; 105 106 for_each_bank (i, mi) { 107 struct membank *bank = &mi->bank[i]; 108 unsigned int pfn1, pfn2; 109 struct page *page, *end; 110 111 pfn1 = bank_pfn_start(bank); 112 pfn2 = bank_pfn_end(bank); 113 114 page = pfn_to_page(pfn1); 115 end = pfn_to_page(pfn2 - 1) + 1; 116 117 do { 118 total++; 119 if (PageReserved(page)) 120 reserved++; 121 else if (PageSwapCache(page)) 122 cached++; 123 else if (PageSlab(page)) 124 slab++; 125 else if (!page_count(page)) 126 free++; 127 else 128 shared += page_count(page) - 1; 129 page++; 130 } while (page < end); 131 } 132 133 printk("%d pages of RAM\n", total); 134 printk("%d free pages\n", free); 135 printk("%d reserved pages\n", reserved); 136 printk("%d slab pages\n", slab); 137 printk("%d pages shared\n", shared); 138 printk("%d pages swap cached\n", cached); 139 } 140 141 static void __init find_limits(unsigned long *min, unsigned long *max_low, 142 unsigned long *max_high) 143 { 144 struct meminfo *mi = &meminfo; 145 int i; 146 147 /* This assumes the meminfo array is properly sorted */ 148 *min = bank_pfn_start(&mi->bank[0]); 149 for_each_bank (i, mi) 150 if (mi->bank[i].highmem) 151 break; 152 *max_low = bank_pfn_end(&mi->bank[i - 1]); 153 *max_high = bank_pfn_end(&mi->bank[mi->nr_banks - 1]); 154 } 155 156 static void __init arm_bootmem_init(unsigned long start_pfn, 157 unsigned long end_pfn) 158 { 159 struct memblock_region *reg; 160 unsigned int boot_pages; 161 phys_addr_t bitmap; 162 pg_data_t *pgdat; 163 164 /* 165 * Allocate the bootmem bitmap page. This must be in a region 166 * of memory which has already been mapped. 167 */ 168 boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn); 169 bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES, 170 __pfn_to_phys(end_pfn)); 171 172 /* 173 * Initialise the bootmem allocator, handing the 174 * memory banks over to bootmem. 175 */ 176 node_set_online(0); 177 pgdat = NODE_DATA(0); 178 init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn); 179 180 /* Free the lowmem regions from memblock into bootmem. */ 181 for_each_memblock(memory, reg) { 182 unsigned long start = memblock_region_memory_base_pfn(reg); 183 unsigned long end = memblock_region_memory_end_pfn(reg); 184 185 if (end >= end_pfn) 186 end = end_pfn; 187 if (start >= end) 188 break; 189 190 free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT); 191 } 192 193 /* Reserve the lowmem memblock reserved regions in bootmem. */ 194 for_each_memblock(reserved, reg) { 195 unsigned long start = memblock_region_reserved_base_pfn(reg); 196 unsigned long end = memblock_region_reserved_end_pfn(reg); 197 198 if (end >= end_pfn) 199 end = end_pfn; 200 if (start >= end) 201 break; 202 203 reserve_bootmem(__pfn_to_phys(start), 204 (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT); 205 } 206 } 207 208 #ifdef CONFIG_ZONE_DMA 209 210 unsigned long arm_dma_zone_size __read_mostly; 211 EXPORT_SYMBOL(arm_dma_zone_size); 212 213 /* 214 * The DMA mask corresponding to the maximum bus address allocatable 215 * using GFP_DMA. The default here places no restriction on DMA 216 * allocations. This must be the smallest DMA mask in the system, 217 * so a successful GFP_DMA allocation will always satisfy this. 218 */ 219 phys_addr_t arm_dma_limit; 220 221 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole, 222 unsigned long dma_size) 223 { 224 if (size[0] <= dma_size) 225 return; 226 227 size[ZONE_NORMAL] = size[0] - dma_size; 228 size[ZONE_DMA] = dma_size; 229 hole[ZONE_NORMAL] = hole[0]; 230 hole[ZONE_DMA] = 0; 231 } 232 #endif 233 234 void __init setup_dma_zone(const struct machine_desc *mdesc) 235 { 236 #ifdef CONFIG_ZONE_DMA 237 if (mdesc->dma_zone_size) { 238 arm_dma_zone_size = mdesc->dma_zone_size; 239 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1; 240 } else 241 arm_dma_limit = 0xffffffff; 242 #endif 243 } 244 245 static void __init arm_bootmem_free(unsigned long min, unsigned long max_low, 246 unsigned long max_high) 247 { 248 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 249 struct memblock_region *reg; 250 251 /* 252 * initialise the zones. 253 */ 254 memset(zone_size, 0, sizeof(zone_size)); 255 256 /* 257 * The memory size has already been determined. If we need 258 * to do anything fancy with the allocation of this memory 259 * to the zones, now is the time to do it. 260 */ 261 zone_size[0] = max_low - min; 262 #ifdef CONFIG_HIGHMEM 263 zone_size[ZONE_HIGHMEM] = max_high - max_low; 264 #endif 265 266 /* 267 * Calculate the size of the holes. 268 * holes = node_size - sum(bank_sizes) 269 */ 270 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 271 for_each_memblock(memory, reg) { 272 unsigned long start = memblock_region_memory_base_pfn(reg); 273 unsigned long end = memblock_region_memory_end_pfn(reg); 274 275 if (start < max_low) { 276 unsigned long low_end = min(end, max_low); 277 zhole_size[0] -= low_end - start; 278 } 279 #ifdef CONFIG_HIGHMEM 280 if (end > max_low) { 281 unsigned long high_start = max(start, max_low); 282 zhole_size[ZONE_HIGHMEM] -= end - high_start; 283 } 284 #endif 285 } 286 287 #ifdef CONFIG_ZONE_DMA 288 /* 289 * Adjust the sizes according to any special requirements for 290 * this machine type. 291 */ 292 if (arm_dma_zone_size) 293 arm_adjust_dma_zone(zone_size, zhole_size, 294 arm_dma_zone_size >> PAGE_SHIFT); 295 #endif 296 297 free_area_init_node(0, zone_size, min, zhole_size); 298 } 299 300 #ifdef CONFIG_HAVE_ARCH_PFN_VALID 301 int pfn_valid(unsigned long pfn) 302 { 303 return memblock_is_memory(__pfn_to_phys(pfn)); 304 } 305 EXPORT_SYMBOL(pfn_valid); 306 #endif 307 308 #ifndef CONFIG_SPARSEMEM 309 static void __init arm_memory_present(void) 310 { 311 } 312 #else 313 static void __init arm_memory_present(void) 314 { 315 struct memblock_region *reg; 316 317 for_each_memblock(memory, reg) 318 memory_present(0, memblock_region_memory_base_pfn(reg), 319 memblock_region_memory_end_pfn(reg)); 320 } 321 #endif 322 323 static bool arm_memblock_steal_permitted = true; 324 325 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align) 326 { 327 phys_addr_t phys; 328 329 BUG_ON(!arm_memblock_steal_permitted); 330 331 phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE); 332 memblock_free(phys, size); 333 memblock_remove(phys, size); 334 335 return phys; 336 } 337 338 void __init arm_memblock_init(struct meminfo *mi, 339 const struct machine_desc *mdesc) 340 { 341 int i; 342 343 for (i = 0; i < mi->nr_banks; i++) 344 memblock_add(mi->bank[i].start, mi->bank[i].size); 345 346 /* Register the kernel text, kernel data and initrd with memblock. */ 347 #ifdef CONFIG_XIP_KERNEL 348 memblock_reserve(__pa(_sdata), _end - _sdata); 349 #else 350 memblock_reserve(__pa(_stext), _end - _stext); 351 #endif 352 #ifdef CONFIG_BLK_DEV_INITRD 353 if (phys_initrd_size && 354 !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) { 355 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", 356 (u64)phys_initrd_start, phys_initrd_size); 357 phys_initrd_start = phys_initrd_size = 0; 358 } 359 if (phys_initrd_size && 360 memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) { 361 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", 362 (u64)phys_initrd_start, phys_initrd_size); 363 phys_initrd_start = phys_initrd_size = 0; 364 } 365 if (phys_initrd_size) { 366 memblock_reserve(phys_initrd_start, phys_initrd_size); 367 368 /* Now convert initrd to virtual addresses */ 369 initrd_start = __phys_to_virt(phys_initrd_start); 370 initrd_end = initrd_start + phys_initrd_size; 371 } 372 #endif 373 374 arm_mm_memblock_reserve(); 375 arm_dt_memblock_reserve(); 376 377 /* reserve any platform specific memblock areas */ 378 if (mdesc->reserve) 379 mdesc->reserve(); 380 381 /* 382 * reserve memory for DMA contigouos allocations, 383 * must come from DMA area inside low memory 384 */ 385 dma_contiguous_reserve(min(arm_dma_limit, arm_lowmem_limit)); 386 387 arm_memblock_steal_permitted = false; 388 memblock_allow_resize(); 389 memblock_dump_all(); 390 } 391 392 void __init bootmem_init(void) 393 { 394 unsigned long min, max_low, max_high; 395 396 max_low = max_high = 0; 397 398 find_limits(&min, &max_low, &max_high); 399 400 arm_bootmem_init(min, max_low); 401 402 /* 403 * Sparsemem tries to allocate bootmem in memory_present(), 404 * so must be done after the fixed reservations 405 */ 406 arm_memory_present(); 407 408 /* 409 * sparse_init() needs the bootmem allocator up and running. 410 */ 411 sparse_init(); 412 413 /* 414 * Now free the memory - free_area_init_node needs 415 * the sparse mem_map arrays initialized by sparse_init() 416 * for memmap_init_zone(), otherwise all PFNs are invalid. 417 */ 418 arm_bootmem_free(min, max_low, max_high); 419 420 /* 421 * This doesn't seem to be used by the Linux memory manager any 422 * more, but is used by ll_rw_block. If we can get rid of it, we 423 * also get rid of some of the stuff above as well. 424 * 425 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in 426 * the system, not the maximum PFN. 427 */ 428 max_low_pfn = max_low - PHYS_PFN_OFFSET; 429 max_pfn = max_high - PHYS_PFN_OFFSET; 430 } 431 432 /* 433 * Poison init memory with an undefined instruction (ARM) or a branch to an 434 * undefined instruction (Thumb). 435 */ 436 static inline void poison_init_mem(void *s, size_t count) 437 { 438 u32 *p = (u32 *)s; 439 for (; count != 0; count -= 4) 440 *p++ = 0xe7fddef0; 441 } 442 443 static inline void 444 free_memmap(unsigned long start_pfn, unsigned long end_pfn) 445 { 446 struct page *start_pg, *end_pg; 447 phys_addr_t pg, pgend; 448 449 /* 450 * Convert start_pfn/end_pfn to a struct page pointer. 451 */ 452 start_pg = pfn_to_page(start_pfn - 1) + 1; 453 end_pg = pfn_to_page(end_pfn - 1) + 1; 454 455 /* 456 * Convert to physical addresses, and 457 * round start upwards and end downwards. 458 */ 459 pg = PAGE_ALIGN(__pa(start_pg)); 460 pgend = __pa(end_pg) & PAGE_MASK; 461 462 /* 463 * If there are free pages between these, 464 * free the section of the memmap array. 465 */ 466 if (pg < pgend) 467 free_bootmem(pg, pgend - pg); 468 } 469 470 /* 471 * The mem_map array can get very big. Free the unused area of the memory map. 472 */ 473 static void __init free_unused_memmap(struct meminfo *mi) 474 { 475 unsigned long bank_start, prev_bank_end = 0; 476 unsigned int i; 477 478 /* 479 * This relies on each bank being in address order. 480 * The banks are sorted previously in bootmem_init(). 481 */ 482 for_each_bank(i, mi) { 483 struct membank *bank = &mi->bank[i]; 484 485 bank_start = bank_pfn_start(bank); 486 487 #ifdef CONFIG_SPARSEMEM 488 /* 489 * Take care not to free memmap entries that don't exist 490 * due to SPARSEMEM sections which aren't present. 491 */ 492 bank_start = min(bank_start, 493 ALIGN(prev_bank_end, PAGES_PER_SECTION)); 494 #else 495 /* 496 * Align down here since the VM subsystem insists that the 497 * memmap entries are valid from the bank start aligned to 498 * MAX_ORDER_NR_PAGES. 499 */ 500 bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES); 501 #endif 502 /* 503 * If we had a previous bank, and there is a space 504 * between the current bank and the previous, free it. 505 */ 506 if (prev_bank_end && prev_bank_end < bank_start) 507 free_memmap(prev_bank_end, bank_start); 508 509 /* 510 * Align up here since the VM subsystem insists that the 511 * memmap entries are valid from the bank end aligned to 512 * MAX_ORDER_NR_PAGES. 513 */ 514 prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES); 515 } 516 517 #ifdef CONFIG_SPARSEMEM 518 if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION)) 519 free_memmap(prev_bank_end, 520 ALIGN(prev_bank_end, PAGES_PER_SECTION)); 521 #endif 522 } 523 524 #ifdef CONFIG_HIGHMEM 525 static inline void free_area_high(unsigned long pfn, unsigned long end) 526 { 527 for (; pfn < end; pfn++) 528 free_highmem_page(pfn_to_page(pfn)); 529 } 530 #endif 531 532 static void __init free_highpages(void) 533 { 534 #ifdef CONFIG_HIGHMEM 535 unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET; 536 struct memblock_region *mem, *res; 537 538 /* set highmem page free */ 539 for_each_memblock(memory, mem) { 540 unsigned long start = memblock_region_memory_base_pfn(mem); 541 unsigned long end = memblock_region_memory_end_pfn(mem); 542 543 /* Ignore complete lowmem entries */ 544 if (end <= max_low) 545 continue; 546 547 /* Truncate partial highmem entries */ 548 if (start < max_low) 549 start = max_low; 550 551 /* Find and exclude any reserved regions */ 552 for_each_memblock(reserved, res) { 553 unsigned long res_start, res_end; 554 555 res_start = memblock_region_reserved_base_pfn(res); 556 res_end = memblock_region_reserved_end_pfn(res); 557 558 if (res_end < start) 559 continue; 560 if (res_start < start) 561 res_start = start; 562 if (res_start > end) 563 res_start = end; 564 if (res_end > end) 565 res_end = end; 566 if (res_start != start) 567 free_area_high(start, res_start); 568 start = res_end; 569 if (start == end) 570 break; 571 } 572 573 /* And now free anything which remains */ 574 if (start < end) 575 free_area_high(start, end); 576 } 577 #endif 578 } 579 580 /* 581 * mem_init() marks the free areas in the mem_map and tells us how much 582 * memory is free. This is done after various parts of the system have 583 * claimed their memory after the kernel image. 584 */ 585 void __init mem_init(void) 586 { 587 #ifdef CONFIG_HAVE_TCM 588 /* These pointers are filled in on TCM detection */ 589 extern u32 dtcm_end; 590 extern u32 itcm_end; 591 #endif 592 593 max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map; 594 595 /* this will put all unused low memory onto the freelists */ 596 free_unused_memmap(&meminfo); 597 free_all_bootmem(); 598 599 #ifdef CONFIG_SA1111 600 /* now that our DMA memory is actually so designated, we can free it */ 601 free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL); 602 #endif 603 604 free_highpages(); 605 606 mem_init_print_info(NULL); 607 608 #define MLK(b, t) b, t, ((t) - (b)) >> 10 609 #define MLM(b, t) b, t, ((t) - (b)) >> 20 610 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 611 612 printk(KERN_NOTICE "Virtual kernel memory layout:\n" 613 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n" 614 #ifdef CONFIG_HAVE_TCM 615 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 616 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 617 #endif 618 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 619 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 620 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 621 #ifdef CONFIG_HIGHMEM 622 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n" 623 #endif 624 #ifdef CONFIG_MODULES 625 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n" 626 #endif 627 " .text : 0x%p" " - 0x%p" " (%4d kB)\n" 628 " .init : 0x%p" " - 0x%p" " (%4d kB)\n" 629 " .data : 0x%p" " - 0x%p" " (%4d kB)\n" 630 " .bss : 0x%p" " - 0x%p" " (%4d kB)\n", 631 632 MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) + 633 (PAGE_SIZE)), 634 #ifdef CONFIG_HAVE_TCM 635 MLK(DTCM_OFFSET, (unsigned long) dtcm_end), 636 MLK(ITCM_OFFSET, (unsigned long) itcm_end), 637 #endif 638 MLK(FIXADDR_START, FIXADDR_TOP), 639 MLM(VMALLOC_START, VMALLOC_END), 640 MLM(PAGE_OFFSET, (unsigned long)high_memory), 641 #ifdef CONFIG_HIGHMEM 642 MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) * 643 (PAGE_SIZE)), 644 #endif 645 #ifdef CONFIG_MODULES 646 MLM(MODULES_VADDR, MODULES_END), 647 #endif 648 649 MLK_ROUNDUP(_text, _etext), 650 MLK_ROUNDUP(__init_begin, __init_end), 651 MLK_ROUNDUP(_sdata, _edata), 652 MLK_ROUNDUP(__bss_start, __bss_stop)); 653 654 #undef MLK 655 #undef MLM 656 #undef MLK_ROUNDUP 657 658 /* 659 * Check boundaries twice: Some fundamental inconsistencies can 660 * be detected at build time already. 661 */ 662 #ifdef CONFIG_MMU 663 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); 664 BUG_ON(TASK_SIZE > MODULES_VADDR); 665 #endif 666 667 #ifdef CONFIG_HIGHMEM 668 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 669 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 670 #endif 671 672 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { 673 extern int sysctl_overcommit_memory; 674 /* 675 * On a machine this small we won't get 676 * anywhere without overcommit, so turn 677 * it on by default. 678 */ 679 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 680 } 681 } 682 683 void free_initmem(void) 684 { 685 #ifdef CONFIG_HAVE_TCM 686 extern char __tcm_start, __tcm_end; 687 688 poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start); 689 free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link"); 690 #endif 691 692 poison_init_mem(__init_begin, __init_end - __init_begin); 693 if (!machine_is_integrator() && !machine_is_cintegrator()) 694 free_initmem_default(-1); 695 } 696 697 #ifdef CONFIG_BLK_DEV_INITRD 698 699 static int keep_initrd; 700 701 void free_initrd_mem(unsigned long start, unsigned long end) 702 { 703 if (!keep_initrd) { 704 poison_init_mem((void *)start, PAGE_ALIGN(end) - start); 705 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 706 } 707 } 708 709 static int __init keepinitrd_setup(char *__unused) 710 { 711 keep_initrd = 1; 712 return 1; 713 } 714 715 __setup("keepinitrd", keepinitrd_setup); 716 #endif 717