arch/x86/mm/init_64.c

   1 /*
   2  *  linux/arch/x86_64/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7  */
   8
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 #include <linux/smp.h>
  20 #include <linux/init.h>
  21 #include <linux/initrd.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memblock.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/pci.h>
  27 #include <linux/pfn.h>
  28 #include <linux/poison.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/memory.h>
  31 #include <linux/memory_hotplug.h>
  32 #include <linux/memremap.h>
  33 #include <linux/nmi.h>
  34 #include <linux/gfp.h>
  35 #include <linux/kcore.h>
  36
  37 #include <asm/processor.h>
  38 #include <asm/bios_ebda.h>
  39 #include <asm/uaccess.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/pgalloc.h>
  42 #include <asm/dma.h>
  43 #include <asm/fixmap.h>
  44 #include <asm/e820.h>
  45 #include <asm/apic.h>
  46 #include <asm/tlb.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/proto.h>
  49 #include <asm/smp.h>
  50 #include <asm/sections.h>
  51 #include <asm/kdebug.h>
  52 #include <asm/numa.h>
  53 #include <asm/cacheflush.h>
  54 #include <asm/init.h>
  55 #include <asm/uv/uv.h>
  56 #include <asm/setup.h>
  57
  58 #include "mm_internal.h"
  59
  60 #include "ident_map.c"
  61
  62 /*
  63  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  64  * physical space so we can cache the place of the first one and move
  65  * around without checking the pgd every time.
  66  */
  67
  68 pteval_t __supported_pte_mask __read_mostly = ~0;
  69 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  70
  71 int force_personality32;
  72
  73 /*
  74  * noexec32=on|off
  75  * Control non executable heap for 32bit processes.
  76  * To control the stack too use noexec=off
  77  *
  78  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  79  * off  PROT_READ implies PROT_EXEC
  80  */
  81 static int __init nonx32_setup(char *str)
  82 {
  83         if (!strcmp(str, "on"))
  84                 force_personality32 &= ~READ_IMPLIES_EXEC;
  85         else if (!strcmp(str, "off"))
  86                 force_personality32 |= READ_IMPLIES_EXEC;
  87         return 1;
  88 }
  89 __setup("noexec32=", nonx32_setup);
  90
  91 /*
  92  * When memory was added/removed make sure all the processes MM have
  93  * suitable PGD entries in the local PGD level page.
  94  */
  95 void sync_global_pgds(unsigned long start, unsigned long end, int removed)
  96 {
  97         unsigned long address;
  98
  99         for (address = start; address <= end; address += PGDIR_SIZE) {
 100                 const pgd_t *pgd_ref = pgd_offset_k(address);
 101                 struct page *page;
 102
 103                 /*
 104                  * When it is called after memory hot remove, pgd_none()
 105                  * returns true. In this case (removed == 1), we must clear
 106                  * the PGD entries in the local PGD level page.
 107                  */
 108                 if (pgd_none(*pgd_ref) && !removed)
 109                         continue;
 110
 111                 spin_lock(&pgd_lock);
 112                 list_for_each_entry(page, &pgd_list, lru) {
 113                         pgd_t *pgd;
 114                         spinlock_t *pgt_lock;
 115
 116                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
 117                         /* the pgt_lock only for Xen */
 118                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 119                         spin_lock(pgt_lock);
 120
 121                         if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
 122                                 BUG_ON(pgd_page_vaddr(*pgd)
 123                                        != pgd_page_vaddr(*pgd_ref));
 124
 125                         if (removed) {
 126                                 if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
 127                                         pgd_clear(pgd);
 128                         } else {
 129                                 if (pgd_none(*pgd))
 130                                         set_pgd(pgd, *pgd_ref);
 131                         }
 132
 133                         spin_unlock(pgt_lock);
 134                 }
 135                 spin_unlock(&pgd_lock);
 136         }
 137 }
 138
 139 /*
 140  * NOTE: This function is marked __ref because it calls __init function
 141  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 142  */
 143 static __ref void *spp_getpage(void)
 144 {
 145         void *ptr;
 146
 147         if (after_bootmem)
 148                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 149         else
 150                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 151
 152         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 153                 panic("set_pte_phys: cannot allocate page data %s\n",
 154                         after_bootmem ? "after bootmem" : "");
 155         }
 156
 157         pr_debug("spp_getpage %p\n", ptr);
 158
 159         return ptr;
 160 }
 161
 162 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 163 {
 164         if (pgd_none(*pgd)) {
 165                 pud_t *pud = (pud_t *)spp_getpage();
 166                 pgd_populate(&init_mm, pgd, pud);
 167                 if (pud != pud_offset(pgd, 0))
 168                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 169                                pud, pud_offset(pgd, 0));
 170         }
 171         return pud_offset(pgd, vaddr);
 172 }
 173
 174 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 175 {
 176         if (pud_none(*pud)) {
 177                 pmd_t *pmd = (pmd_t *) spp_getpage();
 178                 pud_populate(&init_mm, pud, pmd);
 179                 if (pmd != pmd_offset(pud, 0))
 180                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 181                                pmd, pmd_offset(pud, 0));
 182         }
 183         return pmd_offset(pud, vaddr);
 184 }
 185
 186 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 187 {
 188         if (pmd_none(*pmd)) {
 189                 pte_t *pte = (pte_t *) spp_getpage();
 190                 pmd_populate_kernel(&init_mm, pmd, pte);
 191                 if (pte != pte_offset_kernel(pmd, 0))
 192                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 193         }
 194         return pte_offset_kernel(pmd, vaddr);
 195 }
 196
 197 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 198 {
 199         pud_t *pud;
 200         pmd_t *pmd;
 201         pte_t *pte;
 202
 203         pud = pud_page + pud_index(vaddr);
 204         pmd = fill_pmd(pud, vaddr);
 205         pte = fill_pte(pmd, vaddr);
 206
 207         set_pte(pte, new_pte);
 208
 209         /*
 210          * It's enough to flush this one mapping.
 211          * (PGE mappings get flushed as well)
 212          */
 213         __flush_tlb_one(vaddr);
 214 }
 215
 216 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 217 {
 218         pgd_t *pgd;
 219         pud_t *pud_page;
 220
 221         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 222
 223         pgd = pgd_offset_k(vaddr);
 224         if (pgd_none(*pgd)) {
 225                 printk(KERN_ERR
 226                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 227                 return;
 228         }
 229         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 230         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 231 }
 232
 233 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 234 {
 235         pgd_t *pgd;
 236         pud_t *pud;
 237
 238         pgd = pgd_offset_k(vaddr);
 239         pud = fill_pud(pgd, vaddr);
 240         return fill_pmd(pud, vaddr);
 241 }
 242
 243 pte_t * __init populate_extra_pte(unsigned long vaddr)
 244 {
 245         pmd_t *pmd;
 246
 247         pmd = populate_extra_pmd(vaddr);
 248         return fill_pte(pmd, vaddr);
 249 }
 250
 251 /*
 252  * Create large page table mappings for a range of physical addresses.
 253  */
 254 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 255                                         enum page_cache_mode cache)
 256 {
 257         pgd_t *pgd;
 258         pud_t *pud;
 259         pmd_t *pmd;
 260         pgprot_t prot;
 261
 262         pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
 263                 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
 264         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 265         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 266                 pgd = pgd_offset_k((unsigned long)__va(phys));
 267                 if (pgd_none(*pgd)) {
 268                         pud = (pud_t *) spp_getpage();
 269                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 270                                                 _PAGE_USER));
 271                 }
 272                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 273                 if (pud_none(*pud)) {
 274                         pmd = (pmd_t *) spp_getpage();
 275                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 276                                                 _PAGE_USER));
 277                 }
 278                 pmd = pmd_offset(pud, phys);
 279                 BUG_ON(!pmd_none(*pmd));
 280                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 281         }
 282 }
 283
 284 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 285 {
 286         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
 287 }
 288
 289 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 290 {
 291         __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
 292 }
 293
 294 /*
 295  * The head.S code sets up the kernel high mapping:
 296  *
 297  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 298  *
 299  * phys_base holds the negative offset to the kernel, which is added
 300  * to the compile time generated pmds. This results in invalid pmds up
 301  * to the point where we hit the physaddr 0 mapping.
 302  *
 303  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 304  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 305  * well, as they are located before _text:
 306  */
 307 void __init cleanup_highmap(void)
 308 {
 309         unsigned long vaddr = __START_KERNEL_map;
 310         unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
 311         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 312         pmd_t *pmd = level2_kernel_pgt;
 313
 314         /*
 315          * Native path, max_pfn_mapped is not set yet.
 316          * Xen has valid max_pfn_mapped set in
 317          *      arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
 318          */
 319         if (max_pfn_mapped)
 320                 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 321
 322         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 323                 if (pmd_none(*pmd))
 324                         continue;
 325                 if (vaddr < (unsigned long) _text || vaddr > end)
 326                         set_pmd(pmd, __pmd(0));
 327         }
 328 }
 329
 330 static unsigned long __meminit
 331 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 332               pgprot_t prot)
 333 {
 334         unsigned long pages = 0, next;
 335         unsigned long last_map_addr = end;
 336         int i;
 337
 338         pte_t *pte = pte_page + pte_index(addr);
 339
 340         for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
 341                 next = (addr & PAGE_MASK) + PAGE_SIZE;
 342                 if (addr >= end) {
 343                         if (!after_bootmem &&
 344                             !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
 345                             !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
 346                                 set_pte(pte, __pte(0));
 347                         continue;
 348                 }
 349
 350                 /*
 351                  * We will re-use the existing mapping.
 352                  * Xen for example has some special requirements, like mapping
 353                  * pagetable pages as RO. So assume someone who pre-setup
 354                  * these mappings are more intelligent.
 355                  */
 356                 if (pte_val(*pte)) {
 357                         if (!after_bootmem)
 358                                 pages++;
 359                         continue;
 360                 }
 361
 362                 if (0)
 363                         printk("   pte=%p addr=%lx pte=%016lx\n",
 364                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 365                 pages++;
 366                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 367                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 368         }
 369
 370         update_page_count(PG_LEVEL_4K, pages);
 371
 372         return last_map_addr;
 373 }
 374
 375 static unsigned long __meminit
 376 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 377               unsigned long page_size_mask, pgprot_t prot)
 378 {
 379         unsigned long pages = 0, next;
 380         unsigned long last_map_addr = end;
 381
 382         int i = pmd_index(address);
 383
 384         for (; i < PTRS_PER_PMD; i++, address = next) {
 385                 pmd_t *pmd = pmd_page + pmd_index(address);
 386                 pte_t *pte;
 387                 pgprot_t new_prot = prot;
 388
 389                 next = (address & PMD_MASK) + PMD_SIZE;
 390                 if (address >= end) {
 391                         if (!after_bootmem &&
 392                             !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
 393                             !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
 394                                 set_pmd(pmd, __pmd(0));
 395                         continue;
 396                 }
 397
 398                 if (pmd_val(*pmd)) {
 399                         if (!pmd_large(*pmd)) {
 400                                 spin_lock(&init_mm.page_table_lock);
 401                                 pte = (pte_t *)pmd_page_vaddr(*pmd);
 402                                 last_map_addr = phys_pte_init(pte, address,
 403                                                                 end, prot);
 404                                 spin_unlock(&init_mm.page_table_lock);
 405                                 continue;
 406                         }
 407                         /*
 408                          * If we are ok with PG_LEVEL_2M mapping, then we will
 409                          * use the existing mapping,
 410                          *
 411                          * Otherwise, we will split the large page mapping but
 412                          * use the same existing protection bits except for
 413                          * large page, so that we don't violate Intel's TLB
 414                          * Application note (317080) which says, while changing
 415                          * the page sizes, new and old translations should
 416                          * not differ with respect to page frame and
 417                          * attributes.
 418                          */
 419                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 420                                 if (!after_bootmem)
 421                                         pages++;
 422                                 last_map_addr = next;
 423                                 continue;
 424                         }
 425                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 426                 }
 427
 428                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 429                         pages++;
 430                         spin_lock(&init_mm.page_table_lock);
 431                         set_pte((pte_t *)pmd,
 432                                 pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
 433                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 434                         spin_unlock(&init_mm.page_table_lock);
 435                         last_map_addr = next;
 436                         continue;
 437                 }
 438
 439                 pte = alloc_low_page();
 440                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 441
 442                 spin_lock(&init_mm.page_table_lock);
 443                 pmd_populate_kernel(&init_mm, pmd, pte);
 444                 spin_unlock(&init_mm.page_table_lock);
 445         }
 446         update_page_count(PG_LEVEL_2M, pages);
 447         return last_map_addr;
 448 }
 449
 450 static unsigned long __meminit
 451 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 452                          unsigned long page_size_mask)
 453 {
 454         unsigned long pages = 0, next;
 455         unsigned long last_map_addr = end;
 456         int i = pud_index(addr);
 457
 458         for (; i < PTRS_PER_PUD; i++, addr = next) {
 459                 pud_t *pud = pud_page + pud_index(addr);
 460                 pmd_t *pmd;
 461                 pgprot_t prot = PAGE_KERNEL;
 462
 463                 next = (addr & PUD_MASK) + PUD_SIZE;
 464                 if (addr >= end) {
 465                         if (!after_bootmem &&
 466                             !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
 467                             !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
 468                                 set_pud(pud, __pud(0));
 469                         continue;
 470                 }
 471
 472                 if (pud_val(*pud)) {
 473                         if (!pud_large(*pud)) {
 474                                 pmd = pmd_offset(pud, 0);
 475                                 last_map_addr = phys_pmd_init(pmd, addr, end,
 476                                                          page_size_mask, prot);
 477                                 __flush_tlb_all();
 478                                 continue;
 479                         }
 480                         /*
 481                          * If we are ok with PG_LEVEL_1G mapping, then we will
 482                          * use the existing mapping.
 483                          *
 484                          * Otherwise, we will split the gbpage mapping but use
 485                          * the same existing protection  bits except for large
 486                          * page, so that we don't violate Intel's TLB
 487                          * Application note (317080) which says, while changing
 488                          * the page sizes, new and old translations should
 489                          * not differ with respect to page frame and
 490                          * attributes.
 491                          */
 492                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 493                                 if (!after_bootmem)
 494                                         pages++;
 495                                 last_map_addr = next;
 496                                 continue;
 497                         }
 498                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 499                 }
 500
 501                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 502                         pages++;
 503                         spin_lock(&init_mm.page_table_lock);
 504                         set_pte((pte_t *)pud,
 505                                 pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
 506                                         PAGE_KERNEL_LARGE));
 507                         spin_unlock(&init_mm.page_table_lock);
 508                         last_map_addr = next;
 509                         continue;
 510                 }
 511
 512                 pmd = alloc_low_page();
 513                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 514                                               prot);
 515
 516                 spin_lock(&init_mm.page_table_lock);
 517                 pud_populate(&init_mm, pud, pmd);
 518                 spin_unlock(&init_mm.page_table_lock);
 519         }
 520         __flush_tlb_all();
 521
 522         update_page_count(PG_LEVEL_1G, pages);
 523
 524         return last_map_addr;
 525 }
 526
 527 unsigned long __meminit
 528 kernel_physical_mapping_init(unsigned long start,
 529                              unsigned long end,
 530                              unsigned long page_size_mask)
 531 {
 532         bool pgd_changed = false;
 533         unsigned long next, last_map_addr = end;
 534         unsigned long addr;
 535
 536         start = (unsigned long)__va(start);
 537         end = (unsigned long)__va(end);
 538         addr = start;
 539
 540         for (; start < end; start = next) {
 541                 pgd_t *pgd = pgd_offset_k(start);
 542                 pud_t *pud;
 543
 544                 next = (start & PGDIR_MASK) + PGDIR_SIZE;
 545
 546                 if (pgd_val(*pgd)) {
 547                         pud = (pud_t *)pgd_page_vaddr(*pgd);
 548                         last_map_addr = phys_pud_init(pud, __pa(start),
 549                                                  __pa(end), page_size_mask);
 550                         continue;
 551                 }
 552
 553                 pud = alloc_low_page();
 554                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
 555                                                  page_size_mask);
 556
 557                 spin_lock(&init_mm.page_table_lock);
 558                 pgd_populate(&init_mm, pgd, pud);
 559                 spin_unlock(&init_mm.page_table_lock);
 560                 pgd_changed = true;
 561         }
 562
 563         if (pgd_changed)
 564                 sync_global_pgds(addr, end - 1, 0);
 565
 566         __flush_tlb_all();
 567
 568         return last_map_addr;
 569 }
 570
 571 #ifndef CONFIG_NUMA
 572 void __init initmem_init(void)
 573 {
 574         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 575 }
 576 #endif
 577
 578 void __init paging_init(void)
 579 {
 580         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 581         sparse_init();
 582
 583         /*
 584          * clear the default setting with node 0
 585          * note: don't use nodes_clear here, that is really clearing when
 586          *       numa support is not compiled in, and later node_set_state
 587          *       will not set it back.
 588          */
 589         node_clear_state(0, N_MEMORY);
 590         if (N_MEMORY != N_NORMAL_MEMORY)
 591                 node_clear_state(0, N_NORMAL_MEMORY);
 592
 593         zone_sizes_init();
 594 }
 595
 596 /*
 597  * Memory hotplug specific functions
 598  */
 599 #ifdef CONFIG_MEMORY_HOTPLUG
 600 /*
 601  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 602  * updating.
 603  */
 604 static void  update_end_of_memory_vars(u64 start, u64 size)
 605 {
 606         unsigned long end_pfn = PFN_UP(start + size);
 607
 608         if (end_pfn > max_pfn) {
 609                 max_pfn = end_pfn;
 610                 max_low_pfn = end_pfn;
 611                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 612         }
 613 }
 614
 615 /*
 616  * Memory is added always to NORMAL zone. This means you will never get
 617  * additional DMA/DMA32 memory.
 618  */
 619 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
 620 {
 621         struct pglist_data *pgdat = NODE_DATA(nid);
 622         struct zone *zone = pgdat->node_zones +
 623                 zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
 624         unsigned long start_pfn = start >> PAGE_SHIFT;
 625         unsigned long nr_pages = size >> PAGE_SHIFT;
 626         int ret;
 627
 628         init_memory_mapping(start, start + size);
 629
 630         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 631         WARN_ON_ONCE(ret);
 632
 633         /* update max_pfn, max_low_pfn and high_memory */
 634         update_end_of_memory_vars(start, size);
 635
 636         return ret;
 637 }
 638 EXPORT_SYMBOL_GPL(arch_add_memory);
 639
 640 #define PAGE_INUSE 0xFD
 641
 642 static void __meminit free_pagetable(struct page *page, int order)
 643 {
 644         unsigned long magic;
 645         unsigned int nr_pages = 1 << order;
 646         struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
 647
 648         if (altmap) {
 649                 vmem_altmap_free(altmap, nr_pages);
 650                 return;
 651         }
 652
 653         /* bootmem page has reserved flag */
 654         if (PageReserved(page)) {
 655                 __ClearPageReserved(page);
 656
 657                 magic = (unsigned long)page->lru.next;
 658                 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
 659                         while (nr_pages--)
 660                                 put_page_bootmem(page++);
 661                 } else
 662                         while (nr_pages--)
 663                                 free_reserved_page(page++);
 664         } else
 665                 free_pages((unsigned long)page_address(page), order);
 666 }
 667
 668 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
 669 {
 670         pte_t *pte;
 671         int i;
 672
 673         for (i = 0; i < PTRS_PER_PTE; i++) {
 674                 pte = pte_start + i;
 675                 if (pte_val(*pte))
 676                         return;
 677         }
 678
 679         /* free a pte talbe */
 680         free_pagetable(pmd_page(*pmd), 0);
 681         spin_lock(&init_mm.page_table_lock);
 682         pmd_clear(pmd);
 683         spin_unlock(&init_mm.page_table_lock);
 684 }
 685
 686 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 687 {
 688         pmd_t *pmd;
 689         int i;
 690
 691         for (i = 0; i < PTRS_PER_PMD; i++) {
 692                 pmd = pmd_start + i;
 693                 if (pmd_val(*pmd))
 694                         return;
 695         }
 696
 697         /* free a pmd talbe */
 698         free_pagetable(pud_page(*pud), 0);
 699         spin_lock(&init_mm.page_table_lock);
 700         pud_clear(pud);
 701         spin_unlock(&init_mm.page_table_lock);
 702 }
 703
 704 /* Return true if pgd is changed, otherwise return false. */
 705 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
 706 {
 707         pud_t *pud;
 708         int i;
 709
 710         for (i = 0; i < PTRS_PER_PUD; i++) {
 711                 pud = pud_start + i;
 712                 if (pud_val(*pud))
 713                         return false;
 714         }
 715
 716         /* free a pud table */
 717         free_pagetable(pgd_page(*pgd), 0);
 718         spin_lock(&init_mm.page_table_lock);
 719         pgd_clear(pgd);
 720         spin_unlock(&init_mm.page_table_lock);
 721
 722         return true;
 723 }
 724
 725 static void __meminit
 726 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 727                  bool direct)
 728 {
 729         unsigned long next, pages = 0;
 730         pte_t *pte;
 731         void *page_addr;
 732         phys_addr_t phys_addr;
 733
 734         pte = pte_start + pte_index(addr);
 735         for (; addr < end; addr = next, pte++) {
 736                 next = (addr + PAGE_SIZE) & PAGE_MASK;
 737                 if (next > end)
 738                         next = end;
 739
 740                 if (!pte_present(*pte))
 741                         continue;
 742
 743                 /*
 744                  * We mapped [0,1G) memory as identity mapping when
 745                  * initializing, in arch/x86/kernel/head_64.S. These
 746                  * pagetables cannot be removed.
 747                  */
 748                 phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
 749                 if (phys_addr < (phys_addr_t)0x40000000)
 750                         return;
 751
 752                 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
 753                         /*
 754                          * Do not free direct mapping pages since they were
 755                          * freed when offlining, or simplely not in use.
 756                          */
 757                         if (!direct)
 758                                 free_pagetable(pte_page(*pte), 0);
 759
 760                         spin_lock(&init_mm.page_table_lock);
 761                         pte_clear(&init_mm, addr, pte);
 762                         spin_unlock(&init_mm.page_table_lock);
 763
 764                         /* For non-direct mapping, pages means nothing. */
 765                         pages++;
 766                 } else {
 767                         /*
 768                          * If we are here, we are freeing vmemmap pages since
 769                          * direct mapped memory ranges to be freed are aligned.
 770                          *
 771                          * If we are not removing the whole page, it means
 772                          * other page structs in this page are being used and
 773                          * we canot remove them. So fill the unused page_structs
 774                          * with 0xFD, and remove the page when it is wholly
 775                          * filled with 0xFD.
 776                          */
 777                         memset((void *)addr, PAGE_INUSE, next - addr);
 778
 779                         page_addr = page_address(pte_page(*pte));
 780                         if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
 781                                 free_pagetable(pte_page(*pte), 0);
 782
 783                                 spin_lock(&init_mm.page_table_lock);
 784                                 pte_clear(&init_mm, addr, pte);
 785                                 spin_unlock(&init_mm.page_table_lock);
 786                         }
 787                 }
 788         }
 789
 790         /* Call free_pte_table() in remove_pmd_table(). */
 791         flush_tlb_all();
 792         if (direct)
 793                 update_page_count(PG_LEVEL_4K, -pages);
 794 }
 795
 796 static void __meminit
 797 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
 798                  bool direct)
 799 {
 800         unsigned long next, pages = 0;
 801         pte_t *pte_base;
 802         pmd_t *pmd;
 803         void *page_addr;
 804
 805         pmd = pmd_start + pmd_index(addr);
 806         for (; addr < end; addr = next, pmd++) {
 807                 next = pmd_addr_end(addr, end);
 808
 809                 if (!pmd_present(*pmd))
 810                         continue;
 811
 812                 if (pmd_large(*pmd)) {
 813                         if (IS_ALIGNED(addr, PMD_SIZE) &&
 814                             IS_ALIGNED(next, PMD_SIZE)) {
 815                                 if (!direct)
 816                                         free_pagetable(pmd_page(*pmd),
 817                                                        get_order(PMD_SIZE));
 818
 819                                 spin_lock(&init_mm.page_table_lock);
 820                                 pmd_clear(pmd);
 821                                 spin_unlock(&init_mm.page_table_lock);
 822                                 pages++;
 823                         } else {
 824                                 /* If here, we are freeing vmemmap pages. */
 825                                 memset((void *)addr, PAGE_INUSE, next - addr);
 826
 827                                 page_addr = page_address(pmd_page(*pmd));
 828                                 if (!memchr_inv(page_addr, PAGE_INUSE,
 829                                                 PMD_SIZE)) {
 830                                         free_pagetable(pmd_page(*pmd),
 831                                                        get_order(PMD_SIZE));
 832
 833                                         spin_lock(&init_mm.page_table_lock);
 834                                         pmd_clear(pmd);
 835                                         spin_unlock(&init_mm.page_table_lock);
 836                                 }
 837                         }
 838
 839                         continue;
 840                 }
 841
 842                 pte_base = (pte_t *)pmd_page_vaddr(*pmd);
 843                 remove_pte_table(pte_base, addr, next, direct);
 844                 free_pte_table(pte_base, pmd);
 845         }
 846
 847         /* Call free_pmd_table() in remove_pud_table(). */
 848         if (direct)
 849                 update_page_count(PG_LEVEL_2M, -pages);
 850 }
 851
 852 static void __meminit
 853 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
 854                  bool direct)
 855 {
 856         unsigned long next, pages = 0;
 857         pmd_t *pmd_base;
 858         pud_t *pud;
 859         void *page_addr;
 860
 861         pud = pud_start + pud_index(addr);
 862         for (; addr < end; addr = next, pud++) {
 863                 next = pud_addr_end(addr, end);
 864
 865                 if (!pud_present(*pud))
 866                         continue;
 867
 868                 if (pud_large(*pud)) {
 869                         if (IS_ALIGNED(addr, PUD_SIZE) &&
 870                             IS_ALIGNED(next, PUD_SIZE)) {
 871                                 if (!direct)
 872                                         free_pagetable(pud_page(*pud),
 873                                                        get_order(PUD_SIZE));
 874
 875                                 spin_lock(&init_mm.page_table_lock);
 876                                 pud_clear(pud);
 877                                 spin_unlock(&init_mm.page_table_lock);
 878                                 pages++;
 879                         } else {
 880                                 /* If here, we are freeing vmemmap pages. */
 881                                 memset((void *)addr, PAGE_INUSE, next - addr);
 882
 883                                 page_addr = page_address(pud_page(*pud));
 884                                 if (!memchr_inv(page_addr, PAGE_INUSE,
 885                                                 PUD_SIZE)) {
 886                                         free_pagetable(pud_page(*pud),
 887                                                        get_order(PUD_SIZE));
 888
 889                                         spin_lock(&init_mm.page_table_lock);
 890                                         pud_clear(pud);
 891                                         spin_unlock(&init_mm.page_table_lock);
 892                                 }
 893                         }
 894
 895                         continue;
 896                 }
 897
 898                 pmd_base = (pmd_t *)pud_page_vaddr(*pud);
 899                 remove_pmd_table(pmd_base, addr, next, direct);
 900                 free_pmd_table(pmd_base, pud);
 901         }
 902
 903         if (direct)
 904                 update_page_count(PG_LEVEL_1G, -pages);
 905 }
 906
 907 /* start and end are both virtual address. */
 908 static void __meminit
 909 remove_pagetable(unsigned long start, unsigned long end, bool direct)
 910 {
 911         unsigned long next;
 912         unsigned long addr;
 913         pgd_t *pgd;
 914         pud_t *pud;
 915         bool pgd_changed = false;
 916
 917         for (addr = start; addr < end; addr = next) {
 918                 next = pgd_addr_end(addr, end);
 919
 920                 pgd = pgd_offset_k(addr);
 921                 if (!pgd_present(*pgd))
 922                         continue;
 923
 924                 pud = (pud_t *)pgd_page_vaddr(*pgd);
 925                 remove_pud_table(pud, addr, next, direct);
 926                 if (free_pud_table(pud, pgd))
 927                         pgd_changed = true;
 928         }
 929
 930         if (pgd_changed)
 931                 sync_global_pgds(start, end - 1, 1);
 932
 933         flush_tlb_all();
 934 }
 935
 936 void __ref vmemmap_free(unsigned long start, unsigned long end)
 937 {
 938         remove_pagetable(start, end, false);
 939 }
 940
 941 #ifdef CONFIG_MEMORY_HOTREMOVE
 942 static void __meminit
 943 kernel_physical_mapping_remove(unsigned long start, unsigned long end)
 944 {
 945         start = (unsigned long)__va(start);
 946         end = (unsigned long)__va(end);
 947
 948         remove_pagetable(start, end, true);
 949 }
 950
 951 int __ref arch_remove_memory(u64 start, u64 size)
 952 {
 953         unsigned long start_pfn = start >> PAGE_SHIFT;
 954         unsigned long nr_pages = size >> PAGE_SHIFT;
 955         struct page *page = pfn_to_page(start_pfn);
 956         struct vmem_altmap *altmap;
 957         struct zone *zone;
 958         int ret;
 959
 960         /* With altmap the first mapped page is offset from @start */
 961         altmap = to_vmem_altmap((unsigned long) page);
 962         if (altmap)
 963                 page += vmem_altmap_offset(altmap);
 964         zone = page_zone(page);
 965         ret = __remove_pages(zone, start_pfn, nr_pages);
 966         WARN_ON_ONCE(ret);
 967         kernel_physical_mapping_remove(start, start + size);
 968
 969         return ret;
 970 }
 971 #endif
 972 #endif /* CONFIG_MEMORY_HOTPLUG */
 973
 974 static struct kcore_list kcore_vsyscall;
 975
 976 static void __init register_page_bootmem_info(void)
 977 {
 978 #ifdef CONFIG_NUMA
 979         int i;
 980
 981         for_each_online_node(i)
 982                 register_page_bootmem_info_node(NODE_DATA(i));
 983 #endif
 984 }
 985
 986 void __init mem_init(void)
 987 {
 988         pci_iommu_alloc();
 989
 990         /* clear_bss() already clear the empty_zero_page */
 991
 992         register_page_bootmem_info();
 993
 994         /* this will put all memory onto the freelists */
 995         free_all_bootmem();
 996         after_bootmem = 1;
 997
 998         /* Register memory areas for /proc/kcore */
 999         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
1000                          PAGE_SIZE, KCORE_OTHER);
1001
1002         mem_init_print_info(NULL);
1003 }
1004
1005 const int rodata_test_data = 0xC3;
1006 EXPORT_SYMBOL_GPL(rodata_test_data);
1007
1008 int kernel_set_to_readonly;
1009
1010 void set_kernel_text_rw(void)
1011 {
1012         unsigned long start = PFN_ALIGN(_text);
1013         unsigned long end = PFN_ALIGN(__stop___ex_table);
1014
1015         if (!kernel_set_to_readonly)
1016                 return;
1017
1018         pr_debug("Set kernel text: %lx - %lx for read write\n",
1019                  start, end);
1020
1021         /*
1022          * Make the kernel identity mapping for text RW. Kernel text
1023          * mapping will always be RO. Refer to the comment in
1024          * static_protections() in pageattr.c
1025          */
1026         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
1027 }
1028
1029 void set_kernel_text_ro(void)
1030 {
1031         unsigned long start = PFN_ALIGN(_text);
1032         unsigned long end = PFN_ALIGN(__stop___ex_table);
1033
1034         if (!kernel_set_to_readonly)
1035                 return;
1036
1037         pr_debug("Set kernel text: %lx - %lx for read only\n",
1038                  start, end);
1039
1040         /*
1041          * Set the kernel identity mapping for text RO.
1042          */
1043         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1044 }
1045
1046 void mark_rodata_ro(void)
1047 {
1048         unsigned long start = PFN_ALIGN(_text);
1049         unsigned long rodata_start = PFN_ALIGN(__start_rodata);
1050         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
1051         unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
1052         unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
1053         unsigned long all_end;
1054
1055         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
1056                (end - start) >> 10);
1057         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
1058
1059         kernel_set_to_readonly = 1;
1060
1061         /*
1062          * The rodata/data/bss/brk section (but not the kernel text!)
1063          * should also be not-executable.
1064          *
1065          * We align all_end to PMD_SIZE because the existing mapping
1066          * is a full PMD. If we would align _brk_end to PAGE_SIZE we
1067          * split the PMD and the reminder between _brk_end and the end
1068          * of the PMD will remain mapped executable.
1069          *
1070          * Any PMD which was setup after the one which covers _brk_end
1071          * has been zapped already via cleanup_highmem().
1072          */
1073         all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
1074         set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
1075
1076         rodata_test();
1077
1078 #ifdef CONFIG_CPA_DEBUG
1079         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
1080         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
1081
1082         printk(KERN_INFO "Testing CPA: again\n");
1083         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
1084 #endif
1085
1086         free_init_pages("unused kernel",
1087                         (unsigned long) __va(__pa_symbol(text_end)),
1088                         (unsigned long) __va(__pa_symbol(rodata_start)));
1089         free_init_pages("unused kernel",
1090                         (unsigned long) __va(__pa_symbol(rodata_end)),
1091                         (unsigned long) __va(__pa_symbol(_sdata)));
1092
1093         debug_checkwx();
1094 }
1095
1096 int kern_addr_valid(unsigned long addr)
1097 {
1098         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1099         pgd_t *pgd;
1100         pud_t *pud;
1101         pmd_t *pmd;
1102         pte_t *pte;
1103
1104         if (above != 0 && above != -1UL)
1105                 return 0;
1106
1107         pgd = pgd_offset_k(addr);
1108         if (pgd_none(*pgd))
1109                 return 0;
1110
1111         pud = pud_offset(pgd, addr);
1112         if (pud_none(*pud))
1113                 return 0;
1114
1115         if (pud_large(*pud))
1116                 return pfn_valid(pud_pfn(*pud));
1117
1118         pmd = pmd_offset(pud, addr);
1119         if (pmd_none(*pmd))
1120                 return 0;
1121
1122         if (pmd_large(*pmd))
1123                 return pfn_valid(pmd_pfn(*pmd));
1124
1125         pte = pte_offset_kernel(pmd, addr);
1126         if (pte_none(*pte))
1127                 return 0;
1128
1129         return pfn_valid(pte_pfn(*pte));
1130 }
1131
1132 static unsigned long probe_memory_block_size(void)
1133 {
1134         unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
1135
1136         /* if system is UV or has 64GB of RAM or more, use large blocks */
1137         if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
1138                 bz = 2UL << 30; /* 2GB */
1139
1140         pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
1141
1142         return bz;
1143 }
1144
1145 static unsigned long memory_block_size_probed;
1146 unsigned long memory_block_size_bytes(void)
1147 {
1148         if (!memory_block_size_probed)
1149                 memory_block_size_probed = probe_memory_block_size();
1150
1151         return memory_block_size_probed;
1152 }
1153
1154 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1155 /*
1156  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1157  */
1158 static long __meminitdata addr_start, addr_end;
1159 static void __meminitdata *p_start, *p_end;
1160 static int __meminitdata node_start;
1161
1162 static int __meminit vmemmap_populate_hugepages(unsigned long start,
1163                 unsigned long end, int node, struct vmem_altmap *altmap)
1164 {
1165         unsigned long addr;
1166         unsigned long next;
1167         pgd_t *pgd;
1168         pud_t *pud;
1169         pmd_t *pmd;
1170
1171         for (addr = start; addr < end; addr = next) {
1172                 next = pmd_addr_end(addr, end);
1173
1174                 pgd = vmemmap_pgd_populate(addr, node);
1175                 if (!pgd)
1176                         return -ENOMEM;
1177
1178                 pud = vmemmap_pud_populate(pgd, addr, node);
1179                 if (!pud)
1180                         return -ENOMEM;
1181
1182                 pmd = pmd_offset(pud, addr);
1183                 if (pmd_none(*pmd)) {
1184                         void *p;
1185
1186                         p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
1187                         if (p) {
1188                                 pte_t entry;
1189
1190                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1191                                                 PAGE_KERNEL_LARGE);
1192                                 set_pmd(pmd, __pmd(pte_val(entry)));
1193
1194                                 /* check to see if we have contiguous blocks */
1195                                 if (p_end != p || node_start != node) {
1196                                         if (p_start)
1197                                                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1198                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1199                                         addr_start = addr;
1200                                         node_start = node;
1201                                         p_start = p;
1202                                 }
1203
1204                                 addr_end = addr + PMD_SIZE;
1205                                 p_end = p + PMD_SIZE;
1206                                 continue;
1207                         } else if (altmap)
1208                                 return -ENOMEM; /* no fallback */
1209                 } else if (pmd_large(*pmd)) {
1210                         vmemmap_verify((pte_t *)pmd, node, addr, next);
1211                         continue;
1212                 }
1213                 pr_warn_once("vmemmap: falling back to regular page backing\n");
1214                 if (vmemmap_populate_basepages(addr, next, node))
1215                         return -ENOMEM;
1216         }
1217         return 0;
1218 }
1219
1220 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
1221 {
1222         struct vmem_altmap *altmap = to_vmem_altmap(start);
1223         int err;
1224
1225         if (boot_cpu_has(X86_FEATURE_PSE))
1226                 err = vmemmap_populate_hugepages(start, end, node, altmap);
1227         else if (altmap) {
1228                 pr_err_once("%s: no cpu support for altmap allocations\n",
1229                                 __func__);
1230                 err = -ENOMEM;
1231         } else
1232                 err = vmemmap_populate_basepages(start, end, node);
1233         if (!err)
1234                 sync_global_pgds(start, end - 1, 0);
1235         return err;
1236 }
1237
1238 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
1239 void register_page_bootmem_memmap(unsigned long section_nr,
1240                                   struct page *start_page, unsigned long size)
1241 {
1242         unsigned long addr = (unsigned long)start_page;
1243         unsigned long end = (unsigned long)(start_page + size);
1244         unsigned long next;
1245         pgd_t *pgd;
1246         pud_t *pud;
1247         pmd_t *pmd;
1248         unsigned int nr_pages;
1249         struct page *page;
1250
1251         for (; addr < end; addr = next) {
1252                 pte_t *pte = NULL;
1253
1254                 pgd = pgd_offset_k(addr);
1255                 if (pgd_none(*pgd)) {
1256                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1257                         continue;
1258                 }
1259                 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
1260
1261                 pud = pud_offset(pgd, addr);
1262                 if (pud_none(*pud)) {
1263                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1264                         continue;
1265                 }
1266                 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
1267
1268                 if (!boot_cpu_has(X86_FEATURE_PSE)) {
1269                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1270                         pmd = pmd_offset(pud, addr);
1271                         if (pmd_none(*pmd))
1272                                 continue;
1273                         get_page_bootmem(section_nr, pmd_page(*pmd),
1274                                          MIX_SECTION_INFO);
1275
1276                         pte = pte_offset_kernel(pmd, addr);
1277                         if (pte_none(*pte))
1278                                 continue;
1279                         get_page_bootmem(section_nr, pte_page(*pte),
1280                                          SECTION_INFO);
1281                 } else {
1282                         next = pmd_addr_end(addr, end);
1283
1284                         pmd = pmd_offset(pud, addr);
1285                         if (pmd_none(*pmd))
1286                                 continue;
1287
1288                         nr_pages = 1 << (get_order(PMD_SIZE));
1289                         page = pmd_page(*pmd);
1290                         while (nr_pages--)
1291                                 get_page_bootmem(section_nr, page++,
1292                                                  SECTION_INFO);
1293                 }
1294         }
1295 }
1296 #endif
1297
1298 void __meminit vmemmap_populate_print_last(void)
1299 {
1300         if (p_start) {
1301                 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1302                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1303                 p_start = NULL;
1304                 p_end = NULL;
1305                 node_start = 0;
1306         }
1307 }
1308 #endif