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@suse.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/proc_fs.h>
  25 #include <linux/pci.h>
  26 #include <linux/pfn.h>
  27 #include <linux/poison.h>
  28 #include <linux/dma-mapping.h>
  29 #include <linux/module.h>
  30 #include <linux/memory_hotplug.h>
  31 #include <linux/nmi.h>
  32
  33 #include <asm/processor.h>
  34 #include <asm/bios_ebda.h>
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/pgalloc.h>
  39 #include <asm/dma.h>
  40 #include <asm/fixmap.h>
  41 #include <asm/e820.h>
  42 #include <asm/apic.h>
  43 #include <asm/tlb.h>
  44 #include <asm/mmu_context.h>
  45 #include <asm/proto.h>
  46 #include <asm/smp.h>
  47 #include <asm/sections.h>
  48 #include <asm/kdebug.h>
  49 #include <asm/numa.h>
  50 #include <asm/cacheflush.h>
  51 #include <asm/init.h>
  52
  53 static unsigned long dma_reserve __initdata;
  54
  55 static int __init parse_direct_gbpages_off(char *arg)
  56 {
  57         direct_gbpages = 0;
  58         return 0;
  59 }
  60 early_param("nogbpages", parse_direct_gbpages_off);
  61
  62 static int __init parse_direct_gbpages_on(char *arg)
  63 {
  64         direct_gbpages = 1;
  65         return 0;
  66 }
  67 early_param("gbpages", parse_direct_gbpages_on);
  68
  69 /*
  70  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  71  * physical space so we can cache the place of the first one and move
  72  * around without checking the pgd every time.
  73  */
  74
  75 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  76 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  77
  78 int force_personality32;
  79
  80 /*
  81  * noexec32=on|off
  82  * Control non executable heap for 32bit processes.
  83  * To control the stack too use noexec=off
  84  *
  85  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  86  * off  PROT_READ implies PROT_EXEC
  87  */
  88 static int __init nonx32_setup(char *str)
  89 {
  90         if (!strcmp(str, "on"))
  91                 force_personality32 &= ~READ_IMPLIES_EXEC;
  92         else if (!strcmp(str, "off"))
  93                 force_personality32 |= READ_IMPLIES_EXEC;
  94         return 1;
  95 }
  96 __setup("noexec32=", nonx32_setup);
  97
  98 /*
  99  * NOTE: This function is marked __ref because it calls __init function
 100  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 101  */
 102 static __ref void *spp_getpage(void)
 103 {
 104         void *ptr;
 105
 106         if (after_bootmem)
 107                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 108         else
 109                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 110
 111         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 112                 panic("set_pte_phys: cannot allocate page data %s\n",
 113                         after_bootmem ? "after bootmem" : "");
 114         }
 115
 116         pr_debug("spp_getpage %p\n", ptr);
 117
 118         return ptr;
 119 }
 120
 121 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 122 {
 123         if (pgd_none(*pgd)) {
 124                 pud_t *pud = (pud_t *)spp_getpage();
 125                 pgd_populate(&init_mm, pgd, pud);
 126                 if (pud != pud_offset(pgd, 0))
 127                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 128                                pud, pud_offset(pgd, 0));
 129         }
 130         return pud_offset(pgd, vaddr);
 131 }
 132
 133 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 134 {
 135         if (pud_none(*pud)) {
 136                 pmd_t *pmd = (pmd_t *) spp_getpage();
 137                 pud_populate(&init_mm, pud, pmd);
 138                 if (pmd != pmd_offset(pud, 0))
 139                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 140                                pmd, pmd_offset(pud, 0));
 141         }
 142         return pmd_offset(pud, vaddr);
 143 }
 144
 145 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 146 {
 147         if (pmd_none(*pmd)) {
 148                 pte_t *pte = (pte_t *) spp_getpage();
 149                 pmd_populate_kernel(&init_mm, pmd, pte);
 150                 if (pte != pte_offset_kernel(pmd, 0))
 151                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 152         }
 153         return pte_offset_kernel(pmd, vaddr);
 154 }
 155
 156 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 157 {
 158         pud_t *pud;
 159         pmd_t *pmd;
 160         pte_t *pte;
 161
 162         pud = pud_page + pud_index(vaddr);
 163         pmd = fill_pmd(pud, vaddr);
 164         pte = fill_pte(pmd, vaddr);
 165
 166         set_pte(pte, new_pte);
 167
 168         /*
 169          * It's enough to flush this one mapping.
 170          * (PGE mappings get flushed as well)
 171          */
 172         __flush_tlb_one(vaddr);
 173 }
 174
 175 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 176 {
 177         pgd_t *pgd;
 178         pud_t *pud_page;
 179
 180         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 181
 182         pgd = pgd_offset_k(vaddr);
 183         if (pgd_none(*pgd)) {
 184                 printk(KERN_ERR
 185                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 186                 return;
 187         }
 188         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 189         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 190 }
 191
 192 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 193 {
 194         pgd_t *pgd;
 195         pud_t *pud;
 196
 197         pgd = pgd_offset_k(vaddr);
 198         pud = fill_pud(pgd, vaddr);
 199         return fill_pmd(pud, vaddr);
 200 }
 201
 202 pte_t * __init populate_extra_pte(unsigned long vaddr)
 203 {
 204         pmd_t *pmd;
 205
 206         pmd = populate_extra_pmd(vaddr);
 207         return fill_pte(pmd, vaddr);
 208 }
 209
 210 /*
 211  * Create large page table mappings for a range of physical addresses.
 212  */
 213 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 214                                                 pgprot_t prot)
 215 {
 216         pgd_t *pgd;
 217         pud_t *pud;
 218         pmd_t *pmd;
 219
 220         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 221         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 222                 pgd = pgd_offset_k((unsigned long)__va(phys));
 223                 if (pgd_none(*pgd)) {
 224                         pud = (pud_t *) spp_getpage();
 225                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 226                                                 _PAGE_USER));
 227                 }
 228                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 229                 if (pud_none(*pud)) {
 230                         pmd = (pmd_t *) spp_getpage();
 231                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 232                                                 _PAGE_USER));
 233                 }
 234                 pmd = pmd_offset(pud, phys);
 235                 BUG_ON(!pmd_none(*pmd));
 236                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 237         }
 238 }
 239
 240 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 241 {
 242         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 243 }
 244
 245 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 246 {
 247         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 248 }
 249
 250 /*
 251  * The head.S code sets up the kernel high mapping:
 252  *
 253  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 254  *
 255  * phys_addr holds the negative offset to the kernel, which is added
 256  * to the compile time generated pmds. This results in invalid pmds up
 257  * to the point where we hit the physaddr 0 mapping.
 258  *
 259  * We limit the mappings to the region from _text to _end.  _end is
 260  * rounded up to the 2MB boundary. This catches the invalid pmds as
 261  * well, as they are located before _text:
 262  */
 263 void __init cleanup_highmap(void)
 264 {
 265         unsigned long vaddr = __START_KERNEL_map;
 266         unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
 267         pmd_t *pmd = level2_kernel_pgt;
 268         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
 269
 270         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
 271                 if (pmd_none(*pmd))
 272                         continue;
 273                 if (vaddr < (unsigned long) _text || vaddr > end)
 274                         set_pmd(pmd, __pmd(0));
 275         }
 276 }
 277
 278 static __ref void *alloc_low_page(unsigned long *phys)
 279 {
 280         unsigned long pfn = e820_table_end++;
 281         void *adr;
 282
 283         if (after_bootmem) {
 284                 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 285                 *phys = __pa(adr);
 286
 287                 return adr;
 288         }
 289
 290         if (pfn >= e820_table_top)
 291                 panic("alloc_low_page: ran out of memory");
 292
 293         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 294         memset(adr, 0, PAGE_SIZE);
 295         *phys  = pfn * PAGE_SIZE;
 296         return adr;
 297 }
 298
 299 static __ref void unmap_low_page(void *adr)
 300 {
 301         if (after_bootmem)
 302                 return;
 303
 304         early_iounmap(adr, PAGE_SIZE);
 305 }
 306
 307 static unsigned long __meminit
 308 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 309               pgprot_t prot)
 310 {
 311         unsigned pages = 0;
 312         unsigned long last_map_addr = end;
 313         int i;
 314
 315         pte_t *pte = pte_page + pte_index(addr);
 316
 317         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 318
 319                 if (addr >= end) {
 320                         if (!after_bootmem) {
 321                                 for(; i < PTRS_PER_PTE; i++, pte++)
 322                                         set_pte(pte, __pte(0));
 323                         }
 324                         break;
 325                 }
 326
 327                 /*
 328                  * We will re-use the existing mapping.
 329                  * Xen for example has some special requirements, like mapping
 330                  * pagetable pages as RO. So assume someone who pre-setup
 331                  * these mappings are more intelligent.
 332                  */
 333                 if (pte_val(*pte)) {
 334                         pages++;
 335                         continue;
 336                 }
 337
 338                 if (0)
 339                         printk("   pte=%p addr=%lx pte=%016lx\n",
 340                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 341                 pages++;
 342                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 343                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 344         }
 345
 346         update_page_count(PG_LEVEL_4K, pages);
 347
 348         return last_map_addr;
 349 }
 350
 351 static unsigned long __meminit
 352 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
 353                 pgprot_t prot)
 354 {
 355         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 356
 357         return phys_pte_init(pte, address, end, prot);
 358 }
 359
 360 static unsigned long __meminit
 361 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 362               unsigned long page_size_mask, pgprot_t prot)
 363 {
 364         unsigned long pages = 0;
 365         unsigned long last_map_addr = end;
 366
 367         int i = pmd_index(address);
 368
 369         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 370                 unsigned long pte_phys;
 371                 pmd_t *pmd = pmd_page + pmd_index(address);
 372                 pte_t *pte;
 373                 pgprot_t new_prot = prot;
 374
 375                 if (address >= end) {
 376                         if (!after_bootmem) {
 377                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 378                                         set_pmd(pmd, __pmd(0));
 379                         }
 380                         break;
 381                 }
 382
 383                 if (pmd_val(*pmd)) {
 384                         if (!pmd_large(*pmd)) {
 385                                 spin_lock(&init_mm.page_table_lock);
 386                                 last_map_addr = phys_pte_update(pmd, address,
 387                                                                 end, prot);
 388                                 spin_unlock(&init_mm.page_table_lock);
 389                                 continue;
 390                         }
 391                         /*
 392                          * If we are ok with PG_LEVEL_2M mapping, then we will
 393                          * use the existing mapping,
 394                          *
 395                          * Otherwise, we will split the large page mapping but
 396                          * use the same existing protection bits except for
 397                          * large page, so that we don't violate Intel's TLB
 398                          * Application note (317080) which says, while changing
 399                          * the page sizes, new and old translations should
 400                          * not differ with respect to page frame and
 401                          * attributes.
 402                          */
 403                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 404                                 pages++;
 405                                 continue;
 406                         }
 407                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 408                 }
 409
 410                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 411                         pages++;
 412                         spin_lock(&init_mm.page_table_lock);
 413                         set_pte((pte_t *)pmd,
 414                                 pfn_pte(address >> PAGE_SHIFT,
 415                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 416                         spin_unlock(&init_mm.page_table_lock);
 417                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 418                         continue;
 419                 }
 420
 421                 pte = alloc_low_page(&pte_phys);
 422                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 423                 unmap_low_page(pte);
 424
 425                 spin_lock(&init_mm.page_table_lock);
 426                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 427                 spin_unlock(&init_mm.page_table_lock);
 428         }
 429         update_page_count(PG_LEVEL_2M, pages);
 430         return last_map_addr;
 431 }
 432
 433 static unsigned long __meminit
 434 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
 435                 unsigned long page_size_mask, pgprot_t prot)
 436 {
 437         pmd_t *pmd = pmd_offset(pud, 0);
 438         unsigned long last_map_addr;
 439
 440         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
 441         __flush_tlb_all();
 442         return last_map_addr;
 443 }
 444
 445 static unsigned long __meminit
 446 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 447                          unsigned long page_size_mask)
 448 {
 449         unsigned long pages = 0;
 450         unsigned long last_map_addr = end;
 451         int i = pud_index(addr);
 452
 453         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 454                 unsigned long pmd_phys;
 455                 pud_t *pud = pud_page + pud_index(addr);
 456                 pmd_t *pmd;
 457                 pgprot_t prot = PAGE_KERNEL;
 458
 459                 if (addr >= end)
 460                         break;
 461
 462                 if (!after_bootmem &&
 463                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 464                         set_pud(pud, __pud(0));
 465                         continue;
 466                 }
 467
 468                 if (pud_val(*pud)) {
 469                         if (!pud_large(*pud)) {
 470                                 last_map_addr = phys_pmd_update(pud, addr, end,
 471                                                          page_size_mask, prot);
 472                                 continue;
 473                         }
 474                         /*
 475                          * If we are ok with PG_LEVEL_1G mapping, then we will
 476                          * use the existing mapping.
 477                          *
 478                          * Otherwise, we will split the gbpage mapping but use
 479                          * the same existing protection  bits except for large
 480                          * page, so that we don't violate Intel's TLB
 481                          * Application note (317080) which says, while changing
 482                          * the page sizes, new and old translations should
 483                          * not differ with respect to page frame and
 484                          * attributes.
 485                          */
 486                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 487                                 pages++;
 488                                 continue;
 489                         }
 490                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 491                 }
 492
 493                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 494                         pages++;
 495                         spin_lock(&init_mm.page_table_lock);
 496                         set_pte((pte_t *)pud,
 497                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 498                         spin_unlock(&init_mm.page_table_lock);
 499                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 500                         continue;
 501                 }
 502
 503                 pmd = alloc_low_page(&pmd_phys);
 504                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 505                                               prot);
 506                 unmap_low_page(pmd);
 507
 508                 spin_lock(&init_mm.page_table_lock);
 509                 pud_populate(&init_mm, pud, __va(pmd_phys));
 510                 spin_unlock(&init_mm.page_table_lock);
 511         }
 512         __flush_tlb_all();
 513
 514         update_page_count(PG_LEVEL_1G, pages);
 515
 516         return last_map_addr;
 517 }
 518
 519 static unsigned long __meminit
 520 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 521                  unsigned long page_size_mask)
 522 {
 523         pud_t *pud;
 524
 525         pud = (pud_t *)pgd_page_vaddr(*pgd);
 526
 527         return phys_pud_init(pud, addr, end, page_size_mask);
 528 }
 529
 530 unsigned long __meminit
 531 kernel_physical_mapping_init(unsigned long start,
 532                              unsigned long end,
 533                              unsigned long page_size_mask)
 534 {
 535
 536         unsigned long next, last_map_addr = end;
 537
 538         start = (unsigned long)__va(start);
 539         end = (unsigned long)__va(end);
 540
 541         for (; start < end; start = next) {
 542                 pgd_t *pgd = pgd_offset_k(start);
 543                 unsigned long pud_phys;
 544                 pud_t *pud;
 545
 546                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 547                 if (next > end)
 548                         next = end;
 549
 550                 if (pgd_val(*pgd)) {
 551                         last_map_addr = phys_pud_update(pgd, __pa(start),
 552                                                  __pa(end), page_size_mask);
 553                         continue;
 554                 }
 555
 556                 pud = alloc_low_page(&pud_phys);
 557                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 558                                                  page_size_mask);
 559                 unmap_low_page(pud);
 560
 561                 spin_lock(&init_mm.page_table_lock);
 562                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 563                 spin_unlock(&init_mm.page_table_lock);
 564         }
 565         __flush_tlb_all();
 566
 567         return last_map_addr;
 568 }
 569
 570 #ifndef CONFIG_NUMA
 571 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 572 {
 573         unsigned long bootmap_size, bootmap;
 574
 575         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
 576         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
 577                                  PAGE_SIZE);
 578         if (bootmap == -1L)
 579                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
 580         /* don't touch min_low_pfn */
 581         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
 582                                          0, end_pfn);
 583         e820_register_active_regions(0, start_pfn, end_pfn);
 584         free_bootmem_with_active_regions(0, end_pfn);
 585         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
 586         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
 587 }
 588 #endif
 589
 590 void __init paging_init(void)
 591 {
 592         unsigned long max_zone_pfns[MAX_NR_ZONES];
 593
 594         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 595         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 596         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 597         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 598
 599         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 600         sparse_init();
 601
 602         /*
 603          * clear the default setting with node 0
 604          * note: don't use nodes_clear here, that is really clearing when
 605          *       numa support is not compiled in, and later node_set_state
 606          *       will not set it back.
 607          */
 608         node_clear_state(0, N_NORMAL_MEMORY);
 609
 610         free_area_init_nodes(max_zone_pfns);
 611 }
 612
 613 /*
 614  * Memory hotplug specific functions
 615  */
 616 #ifdef CONFIG_MEMORY_HOTPLUG
 617 /*
 618  * Memory is added always to NORMAL zone. This means you will never get
 619  * additional DMA/DMA32 memory.
 620  */
 621 int arch_add_memory(int nid, u64 start, u64 size)
 622 {
 623         struct pglist_data *pgdat = NODE_DATA(nid);
 624         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 625         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 626         unsigned long nr_pages = size >> PAGE_SHIFT;
 627         int ret;
 628
 629         last_mapped_pfn = init_memory_mapping(start, start + size);
 630         if (last_mapped_pfn > max_pfn_mapped)
 631                 max_pfn_mapped = last_mapped_pfn;
 632
 633         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 634         WARN_ON_ONCE(ret);
 635
 636         return ret;
 637 }
 638 EXPORT_SYMBOL_GPL(arch_add_memory);
 639
 640 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 641 int memory_add_physaddr_to_nid(u64 start)
 642 {
 643         return 0;
 644 }
 645 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 646 #endif
 647
 648 #endif /* CONFIG_MEMORY_HOTPLUG */
 649
 650 static struct kcore_list kcore_modules, kcore_vsyscall;
 651
 652 void __init mem_init(void)
 653 {
 654         long codesize, reservedpages, datasize, initsize;
 655         unsigned long absent_pages;
 656
 657         pci_iommu_alloc();
 658
 659         /* clear_bss() already clear the empty_zero_page */
 660
 661         reservedpages = 0;
 662
 663         /* this will put all low memory onto the freelists */
 664 #ifdef CONFIG_NUMA
 665         totalram_pages = numa_free_all_bootmem();
 666 #else
 667         totalram_pages = free_all_bootmem();
 668 #endif
 669
 670         absent_pages = absent_pages_in_range(0, max_pfn);
 671         reservedpages = max_pfn - totalram_pages - absent_pages;
 672         after_bootmem = 1;
 673
 674         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 675         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 676         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 677
 678         /* Register memory areas for /proc/kcore */
 679         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN,
 680                         KCORE_OTHER);
 681         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 682                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 683
 684         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 685                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 686                 nr_free_pages() << (PAGE_SHIFT-10),
 687                 max_pfn << (PAGE_SHIFT-10),
 688                 codesize >> 10,
 689                 absent_pages << (PAGE_SHIFT-10),
 690                 reservedpages << (PAGE_SHIFT-10),
 691                 datasize >> 10,
 692                 initsize >> 10);
 693 }
 694
 695 #ifdef CONFIG_DEBUG_RODATA
 696 const int rodata_test_data = 0xC3;
 697 EXPORT_SYMBOL_GPL(rodata_test_data);
 698
 699 static int kernel_set_to_readonly;
 700
 701 void set_kernel_text_rw(void)
 702 {
 703         unsigned long start = PFN_ALIGN(_stext);
 704         unsigned long end = PFN_ALIGN(__start_rodata);
 705
 706         if (!kernel_set_to_readonly)
 707                 return;
 708
 709         pr_debug("Set kernel text: %lx - %lx for read write\n",
 710                  start, end);
 711
 712         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
 713 }
 714
 715 void set_kernel_text_ro(void)
 716 {
 717         unsigned long start = PFN_ALIGN(_stext);
 718         unsigned long end = PFN_ALIGN(__start_rodata);
 719
 720         if (!kernel_set_to_readonly)
 721                 return;
 722
 723         pr_debug("Set kernel text: %lx - %lx for read only\n",
 724                  start, end);
 725
 726         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 727 }
 728
 729 void mark_rodata_ro(void)
 730 {
 731         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
 732         unsigned long rodata_start =
 733                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 734
 735         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 736                (end - start) >> 10);
 737         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 738
 739         kernel_set_to_readonly = 1;
 740
 741         /*
 742          * The rodata section (but not the kernel text!) should also be
 743          * not-executable.
 744          */
 745         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 746
 747         rodata_test();
 748
 749 #ifdef CONFIG_CPA_DEBUG
 750         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 751         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 752
 753         printk(KERN_INFO "Testing CPA: again\n");
 754         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 755 #endif
 756 }
 757
 758 #endif
 759
 760 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
 761                                    int flags)
 762 {
 763 #ifdef CONFIG_NUMA
 764         int nid, next_nid;
 765         int ret;
 766 #endif
 767         unsigned long pfn = phys >> PAGE_SHIFT;
 768
 769         if (pfn >= max_pfn) {
 770                 /*
 771                  * This can happen with kdump kernels when accessing
 772                  * firmware tables:
 773                  */
 774                 if (pfn < max_pfn_mapped)
 775                         return -EFAULT;
 776
 777                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
 778                                 phys, len);
 779                 return -EFAULT;
 780         }
 781
 782         /* Should check here against the e820 map to avoid double free */
 783 #ifdef CONFIG_NUMA
 784         nid = phys_to_nid(phys);
 785         next_nid = phys_to_nid(phys + len - 1);
 786         if (nid == next_nid)
 787                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
 788         else
 789                 ret = reserve_bootmem(phys, len, flags);
 790
 791         if (ret != 0)
 792                 return ret;
 793
 794 #else
 795         reserve_bootmem(phys, len, flags);
 796 #endif
 797
 798         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
 799                 dma_reserve += len / PAGE_SIZE;
 800                 set_dma_reserve(dma_reserve);
 801         }
 802
 803         return 0;
 804 }
 805
 806 int kern_addr_valid(unsigned long addr)
 807 {
 808         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 809         pgd_t *pgd;
 810         pud_t *pud;
 811         pmd_t *pmd;
 812         pte_t *pte;
 813
 814         if (above != 0 && above != -1UL)
 815                 return 0;
 816
 817         pgd = pgd_offset_k(addr);
 818         if (pgd_none(*pgd))
 819                 return 0;
 820
 821         pud = pud_offset(pgd, addr);
 822         if (pud_none(*pud))
 823                 return 0;
 824
 825         pmd = pmd_offset(pud, addr);
 826         if (pmd_none(*pmd))
 827                 return 0;
 828
 829         if (pmd_large(*pmd))
 830                 return pfn_valid(pmd_pfn(*pmd));
 831
 832         pte = pte_offset_kernel(pmd, addr);
 833         if (pte_none(*pte))
 834                 return 0;
 835
 836         return pfn_valid(pte_pfn(*pte));
 837 }
 838
 839 /*
 840  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 841  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 842  * not need special handling anymore:
 843  */
 844 static struct vm_area_struct gate_vma = {
 845         .vm_start       = VSYSCALL_START,
 846         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 847         .vm_page_prot   = PAGE_READONLY_EXEC,
 848         .vm_flags       = VM_READ | VM_EXEC
 849 };
 850
 851 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 852 {
 853 #ifdef CONFIG_IA32_EMULATION
 854         if (test_tsk_thread_flag(tsk, TIF_IA32))
 855                 return NULL;
 856 #endif
 857         return &gate_vma;
 858 }
 859
 860 int in_gate_area(struct task_struct *task, unsigned long addr)
 861 {
 862         struct vm_area_struct *vma = get_gate_vma(task);
 863
 864         if (!vma)
 865                 return 0;
 866
 867         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 868 }
 869
 870 /*
 871  * Use this when you have no reliable task/vma, typically from interrupt
 872  * context. It is less reliable than using the task's vma and may give
 873  * false positives:
 874  */
 875 int in_gate_area_no_task(unsigned long addr)
 876 {
 877         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 878 }
 879
 880 const char *arch_vma_name(struct vm_area_struct *vma)
 881 {
 882         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 883                 return "[vdso]";
 884         if (vma == &gate_vma)
 885                 return "[vsyscall]";
 886         return NULL;
 887 }
 888
 889 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 890 /*
 891  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 892  */
 893 static long __meminitdata addr_start, addr_end;
 894 static void __meminitdata *p_start, *p_end;
 895 static int __meminitdata node_start;
 896
 897 int __meminit
 898 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 899 {
 900         unsigned long addr = (unsigned long)start_page;
 901         unsigned long end = (unsigned long)(start_page + size);
 902         unsigned long next;
 903         pgd_t *pgd;
 904         pud_t *pud;
 905         pmd_t *pmd;
 906
 907         for (; addr < end; addr = next) {
 908                 void *p = NULL;
 909
 910                 pgd = vmemmap_pgd_populate(addr, node);
 911                 if (!pgd)
 912                         return -ENOMEM;
 913
 914                 pud = vmemmap_pud_populate(pgd, addr, node);
 915                 if (!pud)
 916                         return -ENOMEM;
 917
 918                 if (!cpu_has_pse) {
 919                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 920                         pmd = vmemmap_pmd_populate(pud, addr, node);
 921
 922                         if (!pmd)
 923                                 return -ENOMEM;
 924
 925                         p = vmemmap_pte_populate(pmd, addr, node);
 926
 927                         if (!p)
 928                                 return -ENOMEM;
 929
 930                         addr_end = addr + PAGE_SIZE;
 931                         p_end = p + PAGE_SIZE;
 932                 } else {
 933                         next = pmd_addr_end(addr, end);
 934
 935                         pmd = pmd_offset(pud, addr);
 936                         if (pmd_none(*pmd)) {
 937                                 pte_t entry;
 938
 939                                 p = vmemmap_alloc_block(PMD_SIZE, node);
 940                                 if (!p)
 941                                         return -ENOMEM;
 942
 943                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 944                                                 PAGE_KERNEL_LARGE);
 945                                 set_pmd(pmd, __pmd(pte_val(entry)));
 946
 947                                 /* check to see if we have contiguous blocks */
 948                                 if (p_end != p || node_start != node) {
 949                                         if (p_start)
 950                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 951                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 952                                         addr_start = addr;
 953                                         node_start = node;
 954                                         p_start = p;
 955                                 }
 956
 957                                 addr_end = addr + PMD_SIZE;
 958                                 p_end = p + PMD_SIZE;
 959                         } else
 960                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
 961                 }
 962
 963         }
 964         return 0;
 965 }
 966
 967 void __meminit vmemmap_populate_print_last(void)
 968 {
 969         if (p_start) {
 970                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 971                         addr_start, addr_end-1, p_start, p_end-1, node_start);
 972                 p_start = NULL;
 973                 p_end = NULL;
 974                 node_start = 0;
 975         }
 976 }
 977 #endif