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(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, struct machine_desc *mdesc) 339 { 340 int i; 341 342 for (i = 0; i < mi->nr_banks; i++) 343 memblock_add(mi->bank[i].start, mi->bank[i].size); 344 345 /* Register the kernel text, kernel data and initrd with memblock. */ 346 #ifdef CONFIG_XIP_KERNEL 347 memblock_reserve(__pa(_sdata), _end - _sdata); 348 #else 349 memblock_reserve(__pa(_stext), _end - _stext); 350 #endif 351 #ifdef CONFIG_BLK_DEV_INITRD 352 if (phys_initrd_size && 353 !memblock_is_region_memory(phys_initrd_start, phys_initrd_size)) { 354 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n", 355 (u64)phys_initrd_start, phys_initrd_size); 356 phys_initrd_start = phys_initrd_size = 0; 357 } 358 if (phys_initrd_size && 359 memblock_is_region_reserved(phys_initrd_start, phys_initrd_size)) { 360 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n", 361 (u64)phys_initrd_start, phys_initrd_size); 362 phys_initrd_start = phys_initrd_size = 0; 363 } 364 if (phys_initrd_size) { 365 memblock_reserve(phys_initrd_start, phys_initrd_size); 366 367 /* Now convert initrd to virtual addresses */ 368 initrd_start = __phys_to_virt(phys_initrd_start); 369 initrd_end = initrd_start + phys_initrd_size; 370 } 371 #endif 372 373 arm_mm_memblock_reserve(); 374 arm_dt_memblock_reserve(); 375 376 /* reserve any platform specific memblock areas */ 377 if (mdesc->reserve) 378 mdesc->reserve(); 379 380 /* 381 * reserve memory for DMA contigouos allocations, 382 * must come from DMA area inside low memory 383 */ 384 dma_contiguous_reserve(min(arm_dma_limit, arm_lowmem_limit)); 385 386 arm_memblock_steal_permitted = false; 387 memblock_allow_resize(); 388 memblock_dump_all(); 389 } 390 391 void __init bootmem_init(void) 392 { 393 unsigned long min, max_low, max_high; 394 395 max_low = max_high = 0; 396 397 find_limits(&min, &max_low, &max_high); 398 399 arm_bootmem_init(min, max_low); 400 401 /* 402 * Sparsemem tries to allocate bootmem in memory_present(), 403 * so must be done after the fixed reservations 404 */ 405 arm_memory_present(); 406 407 /* 408 * sparse_init() needs the bootmem allocator up and running. 409 */ 410 sparse_init(); 411 412 /* 413 * Now free the memory - free_area_init_node needs 414 * the sparse mem_map arrays initialized by sparse_init() 415 * for memmap_init_zone(), otherwise all PFNs are invalid. 416 */ 417 arm_bootmem_free(min, max_low, max_high); 418 419 /* 420 * This doesn't seem to be used by the Linux memory manager any 421 * more, but is used by ll_rw_block. If we can get rid of it, we 422 * also get rid of some of the stuff above as well. 423 * 424 * Note: max_low_pfn and max_pfn reflect the number of _pages_ in 425 * the system, not the maximum PFN. 426 */ 427 max_low_pfn = max_low - PHYS_PFN_OFFSET; 428 max_pfn = max_high - PHYS_PFN_OFFSET; 429 } 430 431 /* 432 * Poison init memory with an undefined instruction (ARM) or a branch to an 433 * undefined instruction (Thumb). 434 */ 435 static inline void poison_init_mem(void *s, size_t count) 436 { 437 u32 *p = (u32 *)s; 438 for (; count != 0; count -= 4) 439 *p++ = 0xe7fddef0; 440 } 441 442 static inline void 443 free_memmap(unsigned long start_pfn, unsigned long end_pfn) 444 { 445 struct page *start_pg, *end_pg; 446 phys_addr_t pg, pgend; 447 448 /* 449 * Convert start_pfn/end_pfn to a struct page pointer. 450 */ 451 start_pg = pfn_to_page(start_pfn - 1) + 1; 452 end_pg = pfn_to_page(end_pfn - 1) + 1; 453 454 /* 455 * Convert to physical addresses, and 456 * round start upwards and end downwards. 457 */ 458 pg = PAGE_ALIGN(__pa(start_pg)); 459 pgend = __pa(end_pg) & PAGE_MASK; 460 461 /* 462 * If there are free pages between these, 463 * free the section of the memmap array. 464 */ 465 if (pg < pgend) 466 free_bootmem(pg, pgend - pg); 467 } 468 469 /* 470 * The mem_map array can get very big. Free the unused area of the memory map. 471 */ 472 static void __init free_unused_memmap(struct meminfo *mi) 473 { 474 unsigned long bank_start, prev_bank_end = 0; 475 unsigned int i; 476 477 /* 478 * This relies on each bank being in address order. 479 * The banks are sorted previously in bootmem_init(). 480 */ 481 for_each_bank(i, mi) { 482 struct membank *bank = &mi->bank[i]; 483 484 bank_start = bank_pfn_start(bank); 485 486 #ifdef CONFIG_SPARSEMEM 487 /* 488 * Take care not to free memmap entries that don't exist 489 * due to SPARSEMEM sections which aren't present. 490 */ 491 bank_start = min(bank_start, 492 ALIGN(prev_bank_end, PAGES_PER_SECTION)); 493 #else 494 /* 495 * Align down here since the VM subsystem insists that the 496 * memmap entries are valid from the bank start aligned to 497 * MAX_ORDER_NR_PAGES. 498 */ 499 bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES); 500 #endif 501 /* 502 * If we had a previous bank, and there is a space 503 * between the current bank and the previous, free it. 504 */ 505 if (prev_bank_end && prev_bank_end < bank_start) 506 free_memmap(prev_bank_end, bank_start); 507 508 /* 509 * Align up here since the VM subsystem insists that the 510 * memmap entries are valid from the bank end aligned to 511 * MAX_ORDER_NR_PAGES. 512 */ 513 prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES); 514 } 515 516 #ifdef CONFIG_SPARSEMEM 517 if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION)) 518 free_memmap(prev_bank_end, 519 ALIGN(prev_bank_end, PAGES_PER_SECTION)); 520 #endif 521 } 522 523 #ifdef CONFIG_HIGHMEM 524 static inline void free_area_high(unsigned long pfn, unsigned long end) 525 { 526 for (; pfn < end; pfn++) 527 free_highmem_page(pfn_to_page(pfn)); 528 } 529 #endif 530 531 static void __init free_highpages(void) 532 { 533 #ifdef CONFIG_HIGHMEM 534 unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET; 535 struct memblock_region *mem, *res; 536 537 /* set highmem page free */ 538 for_each_memblock(memory, mem) { 539 unsigned long start = memblock_region_memory_base_pfn(mem); 540 unsigned long end = memblock_region_memory_end_pfn(mem); 541 542 /* Ignore complete lowmem entries */ 543 if (end <= max_low) 544 continue; 545 546 /* Truncate partial highmem entries */ 547 if (start < max_low) 548 start = max_low; 549 550 /* Find and exclude any reserved regions */ 551 for_each_memblock(reserved, res) { 552 unsigned long res_start, res_end; 553 554 res_start = memblock_region_reserved_base_pfn(res); 555 res_end = memblock_region_reserved_end_pfn(res); 556 557 if (res_end < start) 558 continue; 559 if (res_start < start) 560 res_start = start; 561 if (res_start > end) 562 res_start = end; 563 if (res_end > end) 564 res_end = end; 565 if (res_start != start) 566 free_area_high(start, res_start); 567 start = res_end; 568 if (start == end) 569 break; 570 } 571 572 /* And now free anything which remains */ 573 if (start < end) 574 free_area_high(start, end); 575 } 576 #endif 577 } 578 579 /* 580 * mem_init() marks the free areas in the mem_map and tells us how much 581 * memory is free. This is done after various parts of the system have 582 * claimed their memory after the kernel image. 583 */ 584 void __init mem_init(void) 585 { 586 #ifdef CONFIG_HAVE_TCM 587 /* These pointers are filled in on TCM detection */ 588 extern u32 dtcm_end; 589 extern u32 itcm_end; 590 #endif 591 592 max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map; 593 594 /* this will put all unused low memory onto the freelists */ 595 free_unused_memmap(&meminfo); 596 free_all_bootmem(); 597 598 #ifdef CONFIG_SA1111 599 /* now that our DMA memory is actually so designated, we can free it */ 600 free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, -1, NULL); 601 #endif 602 603 free_highpages(); 604 605 mem_init_print_info(NULL); 606 607 #define MLK(b, t) b, t, ((t) - (b)) >> 10 608 #define MLM(b, t) b, t, ((t) - (b)) >> 20 609 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 610 611 printk(KERN_NOTICE "Virtual kernel memory layout:\n" 612 " vector : 0x%08lx - 0x%08lx (%4ld kB)\n" 613 #ifdef CONFIG_HAVE_TCM 614 " DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 615 " ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n" 616 #endif 617 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 618 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 619 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 620 #ifdef CONFIG_HIGHMEM 621 " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n" 622 #endif 623 #ifdef CONFIG_MODULES 624 " modules : 0x%08lx - 0x%08lx (%4ld MB)\n" 625 #endif 626 " .text : 0x%p" " - 0x%p" " (%4d kB)\n" 627 " .init : 0x%p" " - 0x%p" " (%4d kB)\n" 628 " .data : 0x%p" " - 0x%p" " (%4d kB)\n" 629 " .bss : 0x%p" " - 0x%p" " (%4d kB)\n", 630 631 MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) + 632 (PAGE_SIZE)), 633 #ifdef CONFIG_HAVE_TCM 634 MLK(DTCM_OFFSET, (unsigned long) dtcm_end), 635 MLK(ITCM_OFFSET, (unsigned long) itcm_end), 636 #endif 637 MLK(FIXADDR_START, FIXADDR_TOP), 638 MLM(VMALLOC_START, VMALLOC_END), 639 MLM(PAGE_OFFSET, (unsigned long)high_memory), 640 #ifdef CONFIG_HIGHMEM 641 MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) * 642 (PAGE_SIZE)), 643 #endif 644 #ifdef CONFIG_MODULES 645 MLM(MODULES_VADDR, MODULES_END), 646 #endif 647 648 MLK_ROUNDUP(_text, _etext), 649 MLK_ROUNDUP(__init_begin, __init_end), 650 MLK_ROUNDUP(_sdata, _edata), 651 MLK_ROUNDUP(__bss_start, __bss_stop)); 652 653 #undef MLK 654 #undef MLM 655 #undef MLK_ROUNDUP 656 657 /* 658 * Check boundaries twice: Some fundamental inconsistencies can 659 * be detected at build time already. 660 */ 661 #ifdef CONFIG_MMU 662 BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR); 663 BUG_ON(TASK_SIZE > MODULES_VADDR); 664 #endif 665 666 #ifdef CONFIG_HIGHMEM 667 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 668 BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET); 669 #endif 670 671 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { 672 extern int sysctl_overcommit_memory; 673 /* 674 * On a machine this small we won't get 675 * anywhere without overcommit, so turn 676 * it on by default. 677 */ 678 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 679 } 680 } 681 682 void free_initmem(void) 683 { 684 #ifdef CONFIG_HAVE_TCM 685 extern char __tcm_start, __tcm_end; 686 687 poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start); 688 free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link"); 689 #endif 690 691 poison_init_mem(__init_begin, __init_end - __init_begin); 692 if (!machine_is_integrator() && !machine_is_cintegrator()) 693 free_initmem_default(-1); 694 } 695 696 #ifdef CONFIG_BLK_DEV_INITRD 697 698 static int keep_initrd; 699 700 void free_initrd_mem(unsigned long start, unsigned long end) 701 { 702 if (!keep_initrd) { 703 poison_init_mem((void *)start, PAGE_ALIGN(end) - start); 704 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 705 } 706 } 707 708 static int __init keepinitrd_setup(char *__unused) 709 { 710 keep_initrd = 1; 711 return 1; 712 } 713 714 __setup("keepinitrd", keepinitrd_setup); 715 #endif 716