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