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/mman.h>
  15 #include <linux/sched/signal.h>
  16 #include <linux/sched/task.h>
  17 #include <linux/export.h>
  18 #include <linux/nodemask.h>
  19 #include <linux/initrd.h>
  20 #include <linux/of_fdt.h>
  21 #include <linux/highmem.h>
  22 #include <linux/gfp.h>
  23 #include <linux/memblock.h>
  24 #include <linux/dma-contiguous.h>
  25 #include <linux/sizes.h>
  26 #include <linux/stop_machine.h>
  27
  28 #include <asm/cp15.h>
  29 #include <asm/mach-types.h>
  30 #include <asm/memblock.h>
  31 #include <asm/memory.h>
  32 #include <asm/prom.h>
  33 #include <asm/sections.h>
  34 #include <asm/setup.h>
  35 #include <asm/system_info.h>
  36 #include <asm/tlb.h>
  37 #include <asm/fixmap.h>
  38 #include <asm/ptdump.h>
  39
  40 #include <asm/mach/arch.h>
  41 #include <asm/mach/map.h>
  42
  43 #include "mm.h"
  44
  45 #ifdef CONFIG_CPU_CP15_MMU
  46 unsigned long __init __clear_cr(unsigned long mask)
  47 {
  48         cr_alignment = cr_alignment & ~mask;
  49         return cr_alignment;
  50 }
  51 #endif
  52
  53 #ifdef CONFIG_BLK_DEV_INITRD
  54 static int __init parse_tag_initrd(const struct tag *tag)
  55 {
  56         pr_warn("ATAG_INITRD is deprecated; "
  57                 "please update your bootloader.\n");
  58         phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
  59         phys_initrd_size = tag->u.initrd.size;
  60         return 0;
  61 }
  62
  63 __tagtable(ATAG_INITRD, parse_tag_initrd);
  64
  65 static int __init parse_tag_initrd2(const struct tag *tag)
  66 {
  67         phys_initrd_start = tag->u.initrd.start;
  68         phys_initrd_size = tag->u.initrd.size;
  69         return 0;
  70 }
  71
  72 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
  73 #endif
  74
  75 static void __init find_limits(unsigned long *min, unsigned long *max_low,
  76                                unsigned long *max_high)
  77 {
  78         *max_low = PFN_DOWN(memblock_get_current_limit());
  79         *min = PFN_UP(memblock_start_of_DRAM());
  80         *max_high = PFN_DOWN(memblock_end_of_DRAM());
  81 }
  82
  83 #ifdef CONFIG_ZONE_DMA
  84
  85 phys_addr_t arm_dma_zone_size __read_mostly;
  86 EXPORT_SYMBOL(arm_dma_zone_size);
  87
  88 /*
  89  * The DMA mask corresponding to the maximum bus address allocatable
  90  * using GFP_DMA.  The default here places no restriction on DMA
  91  * allocations.  This must be the smallest DMA mask in the system,
  92  * so a successful GFP_DMA allocation will always satisfy this.
  93  */
  94 phys_addr_t arm_dma_limit;
  95 unsigned long arm_dma_pfn_limit;
  96
  97 static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
  98         unsigned long dma_size)
  99 {
 100         if (size[0] <= dma_size)
 101                 return;
 102
 103         size[ZONE_NORMAL] = size[0] - dma_size;
 104         size[ZONE_DMA] = dma_size;
 105         hole[ZONE_NORMAL] = hole[0];
 106         hole[ZONE_DMA] = 0;
 107 }
 108 #endif
 109
 110 void __init setup_dma_zone(const struct machine_desc *mdesc)
 111 {
 112 #ifdef CONFIG_ZONE_DMA
 113         if (mdesc->dma_zone_size) {
 114                 arm_dma_zone_size = mdesc->dma_zone_size;
 115                 arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
 116         } else
 117                 arm_dma_limit = 0xffffffff;
 118         arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
 119 #endif
 120 }
 121
 122 static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
 123         unsigned long max_high)
 124 {
 125         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
 126         struct memblock_region *reg;
 127
 128         /*
 129          * initialise the zones.
 130          */
 131         memset(zone_size, 0, sizeof(zone_size));
 132
 133         /*
 134          * The memory size has already been determined.  If we need
 135          * to do anything fancy with the allocation of this memory
 136          * to the zones, now is the time to do it.
 137          */
 138         zone_size[0] = max_low - min;
 139 #ifdef CONFIG_HIGHMEM
 140         zone_size[ZONE_HIGHMEM] = max_high - max_low;
 141 #endif
 142
 143         /*
 144          * Calculate the size of the holes.
 145          *  holes = node_size - sum(bank_sizes)
 146          */
 147         memcpy(zhole_size, zone_size, sizeof(zhole_size));
 148         for_each_memblock(memory, reg) {
 149                 unsigned long start = memblock_region_memory_base_pfn(reg);
 150                 unsigned long end = memblock_region_memory_end_pfn(reg);
 151
 152                 if (start < max_low) {
 153                         unsigned long low_end = min(end, max_low);
 154                         zhole_size[0] -= low_end - start;
 155                 }
 156 #ifdef CONFIG_HIGHMEM
 157                 if (end > max_low) {
 158                         unsigned long high_start = max(start, max_low);
 159                         zhole_size[ZONE_HIGHMEM] -= end - high_start;
 160                 }
 161 #endif
 162         }
 163
 164 #ifdef CONFIG_ZONE_DMA
 165         /*
 166          * Adjust the sizes according to any special requirements for
 167          * this machine type.
 168          */
 169         if (arm_dma_zone_size)
 170                 arm_adjust_dma_zone(zone_size, zhole_size,
 171                         arm_dma_zone_size >> PAGE_SHIFT);
 172 #endif
 173
 174         free_area_init_node(0, zone_size, min, zhole_size);
 175 }
 176
 177 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 178 int pfn_valid(unsigned long pfn)
 179 {
 180         return memblock_is_map_memory(__pfn_to_phys(pfn));
 181 }
 182 EXPORT_SYMBOL(pfn_valid);
 183 #endif
 184
 185 #ifndef CONFIG_SPARSEMEM
 186 static void __init arm_memory_present(void)
 187 {
 188 }
 189 #else
 190 static void __init arm_memory_present(void)
 191 {
 192         struct memblock_region *reg;
 193
 194         for_each_memblock(memory, reg)
 195                 memory_present(0, memblock_region_memory_base_pfn(reg),
 196                                memblock_region_memory_end_pfn(reg));
 197 }
 198 #endif
 199
 200 static bool arm_memblock_steal_permitted = true;
 201
 202 phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
 203 {
 204         phys_addr_t phys;
 205
 206         BUG_ON(!arm_memblock_steal_permitted);
 207
 208         phys = memblock_phys_alloc(size, align);
 209         if (!phys)
 210                 panic("Failed to steal %pa bytes at %pS\n",
 211                       &size, (void *)_RET_IP_);
 212
 213         memblock_free(phys, size);
 214         memblock_remove(phys, size);
 215
 216         return phys;
 217 }
 218
 219 static void __init arm_initrd_init(void)
 220 {
 221 #ifdef CONFIG_BLK_DEV_INITRD
 222         phys_addr_t start;
 223         unsigned long size;
 224
 225         initrd_start = initrd_end = 0;
 226
 227         if (!phys_initrd_size)
 228                 return;
 229
 230         /*
 231          * Round the memory region to page boundaries as per free_initrd_mem()
 232          * This allows us to detect whether the pages overlapping the initrd
 233          * are in use, but more importantly, reserves the entire set of pages
 234          * as we don't want these pages allocated for other purposes.
 235          */
 236         start = round_down(phys_initrd_start, PAGE_SIZE);
 237         size = phys_initrd_size + (phys_initrd_start - start);
 238         size = round_up(size, PAGE_SIZE);
 239
 240         if (!memblock_is_region_memory(start, size)) {
 241                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
 242                        (u64)start, size);
 243                 return;
 244         }
 245
 246         if (memblock_is_region_reserved(start, size)) {
 247                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
 248                        (u64)start, size);
 249                 return;
 250         }
 251
 252         memblock_reserve(start, size);
 253
 254         /* Now convert initrd to virtual addresses */
 255         initrd_start = __phys_to_virt(phys_initrd_start);
 256         initrd_end = initrd_start + phys_initrd_size;
 257 #endif
 258 }
 259
 260 void __init arm_memblock_init(const struct machine_desc *mdesc)
 261 {
 262         /* Register the kernel text, kernel data and initrd with memblock. */
 263         memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
 264
 265         arm_initrd_init();
 266
 267         arm_mm_memblock_reserve();
 268
 269         /* reserve any platform specific memblock areas */
 270         if (mdesc->reserve)
 271                 mdesc->reserve();
 272
 273         early_init_fdt_reserve_self();
 274         early_init_fdt_scan_reserved_mem();
 275
 276         /* reserve memory for DMA contiguous allocations */
 277         dma_contiguous_reserve(arm_dma_limit);
 278
 279         arm_memblock_steal_permitted = false;
 280         memblock_dump_all();
 281 }
 282
 283 void __init bootmem_init(void)
 284 {
 285         memblock_allow_resize();
 286
 287         find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
 288
 289         early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
 290                       (phys_addr_t)max_low_pfn << PAGE_SHIFT);
 291
 292         /*
 293          * Sparsemem tries to allocate bootmem in memory_present(),
 294          * so must be done after the fixed reservations
 295          */
 296         arm_memory_present();
 297
 298         /*
 299          * sparse_init() needs the bootmem allocator up and running.
 300          */
 301         sparse_init();
 302
 303         /*
 304          * Now free the memory - free_area_init_node needs
 305          * the sparse mem_map arrays initialized by sparse_init()
 306          * for memmap_init_zone(), otherwise all PFNs are invalid.
 307          */
 308         zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
 309 }
 310
 311 /*
 312  * Poison init memory with an undefined instruction (ARM) or a branch to an
 313  * undefined instruction (Thumb).
 314  */
 315 static inline void poison_init_mem(void *s, size_t count)
 316 {
 317         u32 *p = (u32 *)s;
 318         for (; count != 0; count -= 4)
 319                 *p++ = 0xe7fddef0;
 320 }
 321
 322 static inline void
 323 free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 324 {
 325         struct page *start_pg, *end_pg;
 326         phys_addr_t pg, pgend;
 327
 328         /*
 329          * Convert start_pfn/end_pfn to a struct page pointer.
 330          */
 331         start_pg = pfn_to_page(start_pfn - 1) + 1;
 332         end_pg = pfn_to_page(end_pfn - 1) + 1;
 333
 334         /*
 335          * Convert to physical addresses, and
 336          * round start upwards and end downwards.
 337          */
 338         pg = PAGE_ALIGN(__pa(start_pg));
 339         pgend = __pa(end_pg) & PAGE_MASK;
 340
 341         /*
 342          * If there are free pages between these,
 343          * free the section of the memmap array.
 344          */
 345         if (pg < pgend)
 346                 memblock_free_early(pg, pgend - pg);
 347 }
 348
 349 /*
 350  * The mem_map array can get very big.  Free the unused area of the memory map.
 351  */
 352 static void __init free_unused_memmap(void)
 353 {
 354         unsigned long start, prev_end = 0;
 355         struct memblock_region *reg;
 356
 357         /*
 358          * This relies on each bank being in address order.
 359          * The banks are sorted previously in bootmem_init().
 360          */
 361         for_each_memblock(memory, reg) {
 362                 start = memblock_region_memory_base_pfn(reg);
 363
 364 #ifdef CONFIG_SPARSEMEM
 365                 /*
 366                  * Take care not to free memmap entries that don't exist
 367                  * due to SPARSEMEM sections which aren't present.
 368                  */
 369                 start = min(start,
 370                                  ALIGN(prev_end, PAGES_PER_SECTION));
 371 #else
 372                 /*
 373                  * Align down here since the VM subsystem insists that the
 374                  * memmap entries are valid from the bank start aligned to
 375                  * MAX_ORDER_NR_PAGES.
 376                  */
 377                 start = round_down(start, MAX_ORDER_NR_PAGES);
 378 #endif
 379                 /*
 380                  * If we had a previous bank, and there is a space
 381                  * between the current bank and the previous, free it.
 382                  */
 383                 if (prev_end && prev_end < start)
 384                         free_memmap(prev_end, start);
 385
 386                 /*
 387                  * Align up here since the VM subsystem insists that the
 388                  * memmap entries are valid from the bank end aligned to
 389                  * MAX_ORDER_NR_PAGES.
 390                  */
 391                 prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
 392                                  MAX_ORDER_NR_PAGES);
 393         }
 394
 395 #ifdef CONFIG_SPARSEMEM
 396         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 397                 free_memmap(prev_end,
 398                             ALIGN(prev_end, PAGES_PER_SECTION));
 399 #endif
 400 }
 401
 402 #ifdef CONFIG_HIGHMEM
 403 static inline void free_area_high(unsigned long pfn, unsigned long end)
 404 {
 405         for (; pfn < end; pfn++)
 406                 free_highmem_page(pfn_to_page(pfn));
 407 }
 408 #endif
 409
 410 static void __init free_highpages(void)
 411 {
 412 #ifdef CONFIG_HIGHMEM
 413         unsigned long max_low = max_low_pfn;
 414         struct memblock_region *mem, *res;
 415
 416         /* set highmem page free */
 417         for_each_memblock(memory, mem) {
 418                 unsigned long start = memblock_region_memory_base_pfn(mem);
 419                 unsigned long end = memblock_region_memory_end_pfn(mem);
 420
 421                 /* Ignore complete lowmem entries */
 422                 if (end <= max_low)
 423                         continue;
 424
 425                 if (memblock_is_nomap(mem))
 426                         continue;
 427
 428                 /* Truncate partial highmem entries */
 429                 if (start < max_low)
 430                         start = max_low;
 431
 432                 /* Find and exclude any reserved regions */
 433                 for_each_memblock(reserved, res) {
 434                         unsigned long res_start, res_end;
 435
 436                         res_start = memblock_region_reserved_base_pfn(res);
 437                         res_end = memblock_region_reserved_end_pfn(res);
 438
 439                         if (res_end < start)
 440                                 continue;
 441                         if (res_start < start)
 442                                 res_start = start;
 443                         if (res_start > end)
 444                                 res_start = end;
 445                         if (res_end > end)
 446                                 res_end = end;
 447                         if (res_start != start)
 448                                 free_area_high(start, res_start);
 449                         start = res_end;
 450                         if (start == end)
 451                                 break;
 452                 }
 453
 454                 /* And now free anything which remains */
 455                 if (start < end)
 456                         free_area_high(start, end);
 457         }
 458 #endif
 459 }
 460
 461 /*
 462  * mem_init() marks the free areas in the mem_map and tells us how much
 463  * memory is free.  This is done after various parts of the system have
 464  * claimed their memory after the kernel image.
 465  */
 466 void __init mem_init(void)
 467 {
 468 #ifdef CONFIG_HAVE_TCM
 469         /* These pointers are filled in on TCM detection */
 470         extern u32 dtcm_end;
 471         extern u32 itcm_end;
 472 #endif
 473
 474         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 475
 476         /* this will put all unused low memory onto the freelists */
 477         free_unused_memmap();
 478         memblock_free_all();
 479
 480 #ifdef CONFIG_SA1111
 481         /* now that our DMA memory is actually so designated, we can free it */
 482         free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
 483 #endif
 484
 485         free_highpages();
 486
 487         mem_init_print_info(NULL);
 488
 489         /*
 490          * Check boundaries twice: Some fundamental inconsistencies can
 491          * be detected at build time already.
 492          */
 493 #ifdef CONFIG_MMU
 494         BUILD_BUG_ON(TASK_SIZE                          > MODULES_VADDR);
 495         BUG_ON(TASK_SIZE                                > MODULES_VADDR);
 496 #endif
 497
 498 #ifdef CONFIG_HIGHMEM
 499         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
 500         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
 501 #endif
 502 }
 503
 504 #ifdef CONFIG_STRICT_KERNEL_RWX
 505 struct section_perm {
 506         const char *name;
 507         unsigned long start;
 508         unsigned long end;
 509         pmdval_t mask;
 510         pmdval_t prot;
 511         pmdval_t clear;
 512 };
 513
 514 /* First section-aligned location at or after __start_rodata. */
 515 extern char __start_rodata_section_aligned[];
 516
 517 static struct section_perm nx_perms[] = {
 518         /* Make pages tables, etc before _stext RW (set NX). */
 519         {
 520                 .name   = "pre-text NX",
 521                 .start  = PAGE_OFFSET,
 522                 .end    = (unsigned long)_stext,
 523                 .mask   = ~PMD_SECT_XN,
 524                 .prot   = PMD_SECT_XN,
 525         },
 526         /* Make init RW (set NX). */
 527         {
 528                 .name   = "init NX",
 529                 .start  = (unsigned long)__init_begin,
 530                 .end    = (unsigned long)_sdata,
 531                 .mask   = ~PMD_SECT_XN,
 532                 .prot   = PMD_SECT_XN,
 533         },
 534         /* Make rodata NX (set RO in ro_perms below). */
 535         {
 536                 .name   = "rodata NX",
 537                 .start  = (unsigned long)__start_rodata_section_aligned,
 538                 .end    = (unsigned long)__init_begin,
 539                 .mask   = ~PMD_SECT_XN,
 540                 .prot   = PMD_SECT_XN,
 541         },
 542 };
 543
 544 static struct section_perm ro_perms[] = {
 545         /* Make kernel code and rodata RX (set RO). */
 546         {
 547                 .name   = "text/rodata RO",
 548                 .start  = (unsigned long)_stext,
 549                 .end    = (unsigned long)__init_begin,
 550 #ifdef CONFIG_ARM_LPAE
 551                 .mask   = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
 552                 .prot   = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
 553 #else
 554                 .mask   = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
 555                 .prot   = PMD_SECT_APX | PMD_SECT_AP_WRITE,
 556                 .clear  = PMD_SECT_AP_WRITE,
 557 #endif
 558         },
 559 };
 560
 561 /*
 562  * Updates section permissions only for the current mm (sections are
 563  * copied into each mm). During startup, this is the init_mm. Is only
 564  * safe to be called with preemption disabled, as under stop_machine().
 565  */
 566 static inline void section_update(unsigned long addr, pmdval_t mask,
 567                                   pmdval_t prot, struct mm_struct *mm)
 568 {
 569         pmd_t *pmd;
 570
 571         pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
 572
 573 #ifdef CONFIG_ARM_LPAE
 574         pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 575 #else
 576         if (addr & SECTION_SIZE)
 577                 pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
 578         else
 579                 pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
 580 #endif
 581         flush_pmd_entry(pmd);
 582         local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
 583 }
 584
 585 /* Make sure extended page tables are in use. */
 586 static inline bool arch_has_strict_perms(void)
 587 {
 588         if (cpu_architecture() < CPU_ARCH_ARMv6)
 589                 return false;
 590
 591         return !!(get_cr() & CR_XP);
 592 }
 593
 594 void set_section_perms(struct section_perm *perms, int n, bool set,
 595                         struct mm_struct *mm)
 596 {
 597         size_t i;
 598         unsigned long addr;
 599
 600         if (!arch_has_strict_perms())
 601                 return;
 602
 603         for (i = 0; i < n; i++) {
 604                 if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
 605                     !IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
 606                         pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
 607                                 perms[i].name, perms[i].start, perms[i].end,
 608                                 SECTION_SIZE);
 609                         continue;
 610                 }
 611
 612                 for (addr = perms[i].start;
 613                      addr < perms[i].end;
 614                      addr += SECTION_SIZE)
 615                         section_update(addr, perms[i].mask,
 616                                 set ? perms[i].prot : perms[i].clear, mm);
 617         }
 618
 619 }
 620
 621 /**
 622  * update_sections_early intended to be called only through stop_machine
 623  * framework and executed by only one CPU while all other CPUs will spin and
 624  * wait, so no locking is required in this function.
 625  */
 626 static void update_sections_early(struct section_perm perms[], int n)
 627 {
 628         struct task_struct *t, *s;
 629
 630         for_each_process(t) {
 631                 if (t->flags & PF_KTHREAD)
 632                         continue;
 633                 for_each_thread(t, s)
 634                         set_section_perms(perms, n, true, s->mm);
 635         }
 636         set_section_perms(perms, n, true, current->active_mm);
 637         set_section_perms(perms, n, true, &init_mm);
 638 }
 639
 640 static int __fix_kernmem_perms(void *unused)
 641 {
 642         update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
 643         return 0;
 644 }
 645
 646 static void fix_kernmem_perms(void)
 647 {
 648         stop_machine(__fix_kernmem_perms, NULL, NULL);
 649 }
 650
 651 static int __mark_rodata_ro(void *unused)
 652 {
 653         update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
 654         return 0;
 655 }
 656
 657 static int kernel_set_to_readonly __read_mostly;
 658
 659 void mark_rodata_ro(void)
 660 {
 661         kernel_set_to_readonly = 1;
 662         stop_machine(__mark_rodata_ro, NULL, NULL);
 663         debug_checkwx();
 664 }
 665
 666 void set_kernel_text_rw(void)
 667 {
 668         if (!kernel_set_to_readonly)
 669                 return;
 670
 671         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
 672                                 current->active_mm);
 673 }
 674
 675 void set_kernel_text_ro(void)
 676 {
 677         if (!kernel_set_to_readonly)
 678                 return;
 679
 680         set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
 681                                 current->active_mm);
 682 }
 683
 684 #else
 685 static inline void fix_kernmem_perms(void) { }
 686 #endif /* CONFIG_STRICT_KERNEL_RWX */
 687
 688 void free_initmem(void)
 689 {
 690         fix_kernmem_perms();
 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                 if (start == initrd_start)
 705                         start = round_down(start, PAGE_SIZE);
 706                 if (end == initrd_end)
 707                         end = round_up(end, PAGE_SIZE);
 708
 709                 poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 710                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 711         }
 712 }
 713
 714 static int __init keepinitrd_setup(char *__unused)
 715 {
 716         keep_initrd = 1;
 717         return 1;
 718 }
 719
 720 __setup("keepinitrd", keepinitrd_setup);
 721 #endif