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_hotplug.h>
  32 #include <linux/nmi.h>
  33 #include <linux/gfp.h>
  34
  35 #include <asm/processor.h>
  36 #include <asm/bios_ebda.h>
  37 #include <asm/system.h>
  38 #include <asm/uaccess.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/dma.h>
  42 #include <asm/fixmap.h>
  43 #include <asm/e820.h>
  44 #include <asm/apic.h>
  45 #include <asm/tlb.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/proto.h>
  48 #include <asm/smp.h>
  49 #include <asm/sections.h>
  50 #include <asm/kdebug.h>
  51 #include <asm/numa.h>
  52 #include <asm/cacheflush.h>
  53 #include <asm/init.h>
  54 #include <linux/bootmem.h>
  55
  56 static int __init parse_direct_gbpages_off(char *arg)
  57 {
  58         direct_gbpages = 0;
  59         return 0;
  60 }
  61 early_param("nogbpages", parse_direct_gbpages_off);
  62
  63 static int __init parse_direct_gbpages_on(char *arg)
  64 {
  65         direct_gbpages = 1;
  66         return 0;
  67 }
  68 early_param("gbpages", parse_direct_gbpages_on);
  69
  70 /*
  71  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  72  * physical space so we can cache the place of the first one and move
  73  * around without checking the pgd every time.
  74  */
  75
  76 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  77 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  78
  79 int force_personality32;
  80
  81 /*
  82  * noexec32=on|off
  83  * Control non executable heap for 32bit processes.
  84  * To control the stack too use noexec=off
  85  *
  86  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  87  * off  PROT_READ implies PROT_EXEC
  88  */
  89 static int __init nonx32_setup(char *str)
  90 {
  91         if (!strcmp(str, "on"))
  92                 force_personality32 &= ~READ_IMPLIES_EXEC;
  93         else if (!strcmp(str, "off"))
  94                 force_personality32 |= READ_IMPLIES_EXEC;
  95         return 1;
  96 }
  97 __setup("noexec32=", nonx32_setup);
  98
  99 /*
 100  * NOTE: This function is marked __ref because it calls __init function
 101  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 102  */
 103 static __ref void *spp_getpage(void)
 104 {
 105         void *ptr;
 106
 107         if (after_bootmem)
 108                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 109         else
 110                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 111
 112         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 113                 panic("set_pte_phys: cannot allocate page data %s\n",
 114                         after_bootmem ? "after bootmem" : "");
 115         }
 116
 117         pr_debug("spp_getpage %p\n", ptr);
 118
 119         return ptr;
 120 }
 121
 122 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 123 {
 124         if (pgd_none(*pgd)) {
 125                 pud_t *pud = (pud_t *)spp_getpage();
 126                 pgd_populate(&init_mm, pgd, pud);
 127                 if (pud != pud_offset(pgd, 0))
 128                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 129                                pud, pud_offset(pgd, 0));
 130         }
 131         return pud_offset(pgd, vaddr);
 132 }
 133
 134 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 135 {
 136         if (pud_none(*pud)) {
 137                 pmd_t *pmd = (pmd_t *) spp_getpage();
 138                 pud_populate(&init_mm, pud, pmd);
 139                 if (pmd != pmd_offset(pud, 0))
 140                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 141                                pmd, pmd_offset(pud, 0));
 142         }
 143         return pmd_offset(pud, vaddr);
 144 }
 145
 146 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 147 {
 148         if (pmd_none(*pmd)) {
 149                 pte_t *pte = (pte_t *) spp_getpage();
 150                 pmd_populate_kernel(&init_mm, pmd, pte);
 151                 if (pte != pte_offset_kernel(pmd, 0))
 152                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 153         }
 154         return pte_offset_kernel(pmd, vaddr);
 155 }
 156
 157 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 158 {
 159         pud_t *pud;
 160         pmd_t *pmd;
 161         pte_t *pte;
 162
 163         pud = pud_page + pud_index(vaddr);
 164         pmd = fill_pmd(pud, vaddr);
 165         pte = fill_pte(pmd, vaddr);
 166
 167         set_pte(pte, new_pte);
 168
 169         /*
 170          * It's enough to flush this one mapping.
 171          * (PGE mappings get flushed as well)
 172          */
 173         __flush_tlb_one(vaddr);
 174 }
 175
 176 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 177 {
 178         pgd_t *pgd;
 179         pud_t *pud_page;
 180
 181         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 182
 183         pgd = pgd_offset_k(vaddr);
 184         if (pgd_none(*pgd)) {
 185                 printk(KERN_ERR
 186                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 187                 return;
 188         }
 189         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 190         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 191 }
 192
 193 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 194 {
 195         pgd_t *pgd;
 196         pud_t *pud;
 197
 198         pgd = pgd_offset_k(vaddr);
 199         pud = fill_pud(pgd, vaddr);
 200         return fill_pmd(pud, vaddr);
 201 }
 202
 203 pte_t * __init populate_extra_pte(unsigned long vaddr)
 204 {
 205         pmd_t *pmd;
 206
 207         pmd = populate_extra_pmd(vaddr);
 208         return fill_pte(pmd, vaddr);
 209 }
 210
 211 /*
 212  * Create large page table mappings for a range of physical addresses.
 213  */
 214 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 215                                                 pgprot_t prot)
 216 {
 217         pgd_t *pgd;
 218         pud_t *pud;
 219         pmd_t *pmd;
 220
 221         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 222         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 223                 pgd = pgd_offset_k((unsigned long)__va(phys));
 224                 if (pgd_none(*pgd)) {
 225                         pud = (pud_t *) spp_getpage();
 226                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 227                                                 _PAGE_USER));
 228                 }
 229                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 230                 if (pud_none(*pud)) {
 231                         pmd = (pmd_t *) spp_getpage();
 232                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 233                                                 _PAGE_USER));
 234                 }
 235                 pmd = pmd_offset(pud, phys);
 236                 BUG_ON(!pmd_none(*pmd));
 237                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 238         }
 239 }
 240
 241 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 242 {
 243         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 244 }
 245
 246 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 247 {
 248         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 249 }
 250
 251 /*
 252  * The head.S code sets up the kernel high mapping:
 253  *
 254  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 255  *
 256  * phys_addr holds the negative offset to the kernel, which is added
 257  * to the compile time generated pmds. This results in invalid pmds up
 258  * to the point where we hit the physaddr 0 mapping.
 259  *
 260  * We limit the mappings to the region from _text to _end.  _end is
 261  * rounded up to the 2MB boundary. This catches the invalid pmds as
 262  * well, as they are located before _text:
 263  */
 264 void __init cleanup_highmap(void)
 265 {
 266         unsigned long vaddr = __START_KERNEL_map;
 267         unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
 268         pmd_t *pmd = level2_kernel_pgt;
 269         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
 270
 271         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
 272                 if (pmd_none(*pmd))
 273                         continue;
 274                 if (vaddr < (unsigned long) _text || vaddr > end)
 275                         set_pmd(pmd, __pmd(0));
 276         }
 277 }
 278
 279 static __ref void *alloc_low_page(unsigned long *phys)
 280 {
 281         unsigned long pfn = e820_table_end++;
 282         void *adr;
 283
 284         if (after_bootmem) {
 285                 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 286                 *phys = __pa(adr);
 287
 288                 return adr;
 289         }
 290
 291         if (pfn >= e820_table_top)
 292                 panic("alloc_low_page: ran out of memory");
 293
 294         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 295         memset(adr, 0, PAGE_SIZE);
 296         *phys  = pfn * PAGE_SIZE;
 297         return adr;
 298 }
 299
 300 static __ref void unmap_low_page(void *adr)
 301 {
 302         if (after_bootmem)
 303                 return;
 304
 305         early_iounmap(adr, PAGE_SIZE);
 306 }
 307
 308 static unsigned long __meminit
 309 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 310               pgprot_t prot)
 311 {
 312         unsigned pages = 0;
 313         unsigned long last_map_addr = end;
 314         int i;
 315
 316         pte_t *pte = pte_page + pte_index(addr);
 317
 318         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 319
 320                 if (addr >= end) {
 321                         if (!after_bootmem) {
 322                                 for(; i < PTRS_PER_PTE; i++, pte++)
 323                                         set_pte(pte, __pte(0));
 324                         }
 325                         break;
 326                 }
 327
 328                 /*
 329                  * We will re-use the existing mapping.
 330                  * Xen for example has some special requirements, like mapping
 331                  * pagetable pages as RO. So assume someone who pre-setup
 332                  * these mappings are more intelligent.
 333                  */
 334                 if (pte_val(*pte)) {
 335                         pages++;
 336                         continue;
 337                 }
 338
 339                 if (0)
 340                         printk("   pte=%p addr=%lx pte=%016lx\n",
 341                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 342                 pages++;
 343                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 344                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 345         }
 346
 347         update_page_count(PG_LEVEL_4K, pages);
 348
 349         return last_map_addr;
 350 }
 351
 352 static unsigned long __meminit
 353 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
 354                 pgprot_t prot)
 355 {
 356         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 357
 358         return phys_pte_init(pte, address, end, prot);
 359 }
 360
 361 static unsigned long __meminit
 362 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 363               unsigned long page_size_mask, pgprot_t prot)
 364 {
 365         unsigned long pages = 0;
 366         unsigned long last_map_addr = end;
 367
 368         int i = pmd_index(address);
 369
 370         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 371                 unsigned long pte_phys;
 372                 pmd_t *pmd = pmd_page + pmd_index(address);
 373                 pte_t *pte;
 374                 pgprot_t new_prot = prot;
 375
 376                 if (address >= end) {
 377                         if (!after_bootmem) {
 378                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 379                                         set_pmd(pmd, __pmd(0));
 380                         }
 381                         break;
 382                 }
 383
 384                 if (pmd_val(*pmd)) {
 385                         if (!pmd_large(*pmd)) {
 386                                 spin_lock(&init_mm.page_table_lock);
 387                                 last_map_addr = phys_pte_update(pmd, address,
 388                                                                 end, prot);
 389                                 spin_unlock(&init_mm.page_table_lock);
 390                                 continue;
 391                         }
 392                         /*
 393                          * If we are ok with PG_LEVEL_2M mapping, then we will
 394                          * use the existing mapping,
 395                          *
 396                          * Otherwise, we will split the large page mapping but
 397                          * use the same existing protection bits except for
 398                          * large page, so that we don't violate Intel's TLB
 399                          * Application note (317080) which says, while changing
 400                          * the page sizes, new and old translations should
 401                          * not differ with respect to page frame and
 402                          * attributes.
 403                          */
 404                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 405                                 pages++;
 406                                 continue;
 407                         }
 408                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 409                 }
 410
 411                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 412                         pages++;
 413                         spin_lock(&init_mm.page_table_lock);
 414                         set_pte((pte_t *)pmd,
 415                                 pfn_pte(address >> PAGE_SHIFT,
 416                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 417                         spin_unlock(&init_mm.page_table_lock);
 418                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 419                         continue;
 420                 }
 421
 422                 pte = alloc_low_page(&pte_phys);
 423                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 424                 unmap_low_page(pte);
 425
 426                 spin_lock(&init_mm.page_table_lock);
 427                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 428                 spin_unlock(&init_mm.page_table_lock);
 429         }
 430         update_page_count(PG_LEVEL_2M, pages);
 431         return last_map_addr;
 432 }
 433
 434 static unsigned long __meminit
 435 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
 436                 unsigned long page_size_mask, pgprot_t prot)
 437 {
 438         pmd_t *pmd = pmd_offset(pud, 0);
 439         unsigned long last_map_addr;
 440
 441         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
 442         __flush_tlb_all();
 443         return last_map_addr;
 444 }
 445
 446 static unsigned long __meminit
 447 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 448                          unsigned long page_size_mask)
 449 {
 450         unsigned long pages = 0;
 451         unsigned long last_map_addr = end;
 452         int i = pud_index(addr);
 453
 454         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 455                 unsigned long pmd_phys;
 456                 pud_t *pud = pud_page + pud_index(addr);
 457                 pmd_t *pmd;
 458                 pgprot_t prot = PAGE_KERNEL;
 459
 460                 if (addr >= end)
 461                         break;
 462
 463                 if (!after_bootmem &&
 464                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 465                         set_pud(pud, __pud(0));
 466                         continue;
 467                 }
 468
 469                 if (pud_val(*pud)) {
 470                         if (!pud_large(*pud)) {
 471                                 last_map_addr = phys_pmd_update(pud, addr, end,
 472                                                          page_size_mask, prot);
 473                                 continue;
 474                         }
 475                         /*
 476                          * If we are ok with PG_LEVEL_1G mapping, then we will
 477                          * use the existing mapping.
 478                          *
 479                          * Otherwise, we will split the gbpage mapping but use
 480                          * the same existing protection  bits except for large
 481                          * page, so that we don't violate Intel's TLB
 482                          * Application note (317080) which says, while changing
 483                          * the page sizes, new and old translations should
 484                          * not differ with respect to page frame and
 485                          * attributes.
 486                          */
 487                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 488                                 pages++;
 489                                 continue;
 490                         }
 491                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 492                 }
 493
 494                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 495                         pages++;
 496                         spin_lock(&init_mm.page_table_lock);
 497                         set_pte((pte_t *)pud,
 498                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 499                         spin_unlock(&init_mm.page_table_lock);
 500                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 501                         continue;
 502                 }
 503
 504                 pmd = alloc_low_page(&pmd_phys);
 505                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 506                                               prot);
 507                 unmap_low_page(pmd);
 508
 509                 spin_lock(&init_mm.page_table_lock);
 510                 pud_populate(&init_mm, pud, __va(pmd_phys));
 511                 spin_unlock(&init_mm.page_table_lock);
 512         }
 513         __flush_tlb_all();
 514
 515         update_page_count(PG_LEVEL_1G, pages);
 516
 517         return last_map_addr;
 518 }
 519
 520 static unsigned long __meminit
 521 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 522                  unsigned long page_size_mask)
 523 {
 524         pud_t *pud;
 525
 526         pud = (pud_t *)pgd_page_vaddr(*pgd);
 527
 528         return phys_pud_init(pud, addr, end, page_size_mask);
 529 }
 530
 531 unsigned long __meminit
 532 kernel_physical_mapping_init(unsigned long start,
 533                              unsigned long end,
 534                              unsigned long page_size_mask)
 535 {
 536
 537         unsigned long next, last_map_addr = end;
 538
 539         start = (unsigned long)__va(start);
 540         end = (unsigned long)__va(end);
 541
 542         for (; start < end; start = next) {
 543                 pgd_t *pgd = pgd_offset_k(start);
 544                 unsigned long pud_phys;
 545                 pud_t *pud;
 546
 547                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 548                 if (next > end)
 549                         next = end;
 550
 551                 if (pgd_val(*pgd)) {
 552                         last_map_addr = phys_pud_update(pgd, __pa(start),
 553                                                  __pa(end), page_size_mask);
 554                         continue;
 555                 }
 556
 557                 pud = alloc_low_page(&pud_phys);
 558                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 559                                                  page_size_mask);
 560                 unmap_low_page(pud);
 561
 562                 spin_lock(&init_mm.page_table_lock);
 563                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 564                 spin_unlock(&init_mm.page_table_lock);
 565         }
 566         __flush_tlb_all();
 567
 568         return last_map_addr;
 569 }
 570
 571 #ifndef CONFIG_NUMA
 572 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn,
 573                                 int acpi, int k8)
 574 {
 575         memblock_x86_register_active_regions(0, start_pfn, end_pfn);
 576 }
 577 #endif
 578
 579 void __init paging_init(void)
 580 {
 581         unsigned long max_zone_pfns[MAX_NR_ZONES];
 582
 583         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 584         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 585         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 586         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 587
 588         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 589         sparse_init();
 590
 591         /*
 592          * clear the default setting with node 0
 593          * note: don't use nodes_clear here, that is really clearing when
 594          *       numa support is not compiled in, and later node_set_state
 595          *       will not set it back.
 596          */
 597         node_clear_state(0, N_NORMAL_MEMORY);
 598
 599         free_area_init_nodes(max_zone_pfns);
 600 }
 601
 602 /*
 603  * Memory hotplug specific functions
 604  */
 605 #ifdef CONFIG_MEMORY_HOTPLUG
 606 /*
 607  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 608  * updating.
 609  */
 610 static void  update_end_of_memory_vars(u64 start, u64 size)
 611 {
 612         unsigned long end_pfn = PFN_UP(start + size);
 613
 614         if (end_pfn > max_pfn) {
 615                 max_pfn = end_pfn;
 616                 max_low_pfn = end_pfn;
 617                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 618         }
 619 }
 620
 621 /*
 622  * Memory is added always to NORMAL zone. This means you will never get
 623  * additional DMA/DMA32 memory.
 624  */
 625 int arch_add_memory(int nid, u64 start, u64 size)
 626 {
 627         struct pglist_data *pgdat = NODE_DATA(nid);
 628         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 629         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 630         unsigned long nr_pages = size >> PAGE_SHIFT;
 631         int ret;
 632
 633         last_mapped_pfn = init_memory_mapping(start, start + size);
 634         if (last_mapped_pfn > max_pfn_mapped)
 635                 max_pfn_mapped = last_mapped_pfn;
 636
 637         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 638         WARN_ON_ONCE(ret);
 639
 640         /* update max_pfn, max_low_pfn and high_memory */
 641         update_end_of_memory_vars(start, size);
 642
 643         return ret;
 644 }
 645 EXPORT_SYMBOL_GPL(arch_add_memory);
 646
 647 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 648 int memory_add_physaddr_to_nid(u64 start)
 649 {
 650         return 0;
 651 }
 652 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 653 #endif
 654
 655 #endif /* CONFIG_MEMORY_HOTPLUG */
 656
 657 static struct kcore_list kcore_vsyscall;
 658
 659 void __init mem_init(void)
 660 {
 661         long codesize, reservedpages, datasize, initsize;
 662         unsigned long absent_pages;
 663
 664         pci_iommu_alloc();
 665
 666         /* clear_bss() already clear the empty_zero_page */
 667
 668         reservedpages = 0;
 669
 670         /* this will put all low memory onto the freelists */
 671 #ifdef CONFIG_NUMA
 672         totalram_pages = numa_free_all_bootmem();
 673 #else
 674         totalram_pages = free_all_bootmem();
 675 #endif
 676
 677         absent_pages = absent_pages_in_range(0, max_pfn);
 678         reservedpages = max_pfn - totalram_pages - absent_pages;
 679         after_bootmem = 1;
 680
 681         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 682         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 683         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 684
 685         /* Register memory areas for /proc/kcore */
 686         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 687                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 688
 689         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 690                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 691                 nr_free_pages() << (PAGE_SHIFT-10),
 692                 max_pfn << (PAGE_SHIFT-10),
 693                 codesize >> 10,
 694                 absent_pages << (PAGE_SHIFT-10),
 695                 reservedpages << (PAGE_SHIFT-10),
 696                 datasize >> 10,
 697                 initsize >> 10);
 698 }
 699
 700 #ifdef CONFIG_DEBUG_RODATA
 701 const int rodata_test_data = 0xC3;
 702 EXPORT_SYMBOL_GPL(rodata_test_data);
 703
 704 int kernel_set_to_readonly;
 705
 706 void set_kernel_text_rw(void)
 707 {
 708         unsigned long start = PFN_ALIGN(_text);
 709         unsigned long end = PFN_ALIGN(__stop___ex_table);
 710
 711         if (!kernel_set_to_readonly)
 712                 return;
 713
 714         pr_debug("Set kernel text: %lx - %lx for read write\n",
 715                  start, end);
 716
 717         /*
 718          * Make the kernel identity mapping for text RW. Kernel text
 719          * mapping will always be RO. Refer to the comment in
 720          * static_protections() in pageattr.c
 721          */
 722         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
 723 }
 724
 725 void set_kernel_text_ro(void)
 726 {
 727         unsigned long start = PFN_ALIGN(_text);
 728         unsigned long end = PFN_ALIGN(__stop___ex_table);
 729
 730         if (!kernel_set_to_readonly)
 731                 return;
 732
 733         pr_debug("Set kernel text: %lx - %lx for read only\n",
 734                  start, end);
 735
 736         /*
 737          * Set the kernel identity mapping for text RO.
 738          */
 739         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 740 }
 741
 742 void mark_rodata_ro(void)
 743 {
 744         unsigned long start = PFN_ALIGN(_text);
 745         unsigned long rodata_start =
 746                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 747         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
 748         unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
 749         unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
 750         unsigned long data_start = (unsigned long) &_sdata;
 751
 752         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 753                (end - start) >> 10);
 754         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 755
 756         kernel_set_to_readonly = 1;
 757
 758         /*
 759          * The rodata section (but not the kernel text!) should also be
 760          * not-executable.
 761          */
 762         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 763
 764         rodata_test();
 765
 766 #ifdef CONFIG_CPA_DEBUG
 767         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 768         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 769
 770         printk(KERN_INFO "Testing CPA: again\n");
 771         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 772 #endif
 773
 774         free_init_pages("unused kernel memory",
 775                         (unsigned long) page_address(virt_to_page(text_end)),
 776                         (unsigned long)
 777                                  page_address(virt_to_page(rodata_start)));
 778         free_init_pages("unused kernel memory",
 779                         (unsigned long) page_address(virt_to_page(rodata_end)),
 780                         (unsigned long) page_address(virt_to_page(data_start)));
 781 }
 782
 783 #endif
 784
 785 int kern_addr_valid(unsigned long addr)
 786 {
 787         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 788         pgd_t *pgd;
 789         pud_t *pud;
 790         pmd_t *pmd;
 791         pte_t *pte;
 792
 793         if (above != 0 && above != -1UL)
 794                 return 0;
 795
 796         pgd = pgd_offset_k(addr);
 797         if (pgd_none(*pgd))
 798                 return 0;
 799
 800         pud = pud_offset(pgd, addr);
 801         if (pud_none(*pud))
 802                 return 0;
 803
 804         pmd = pmd_offset(pud, addr);
 805         if (pmd_none(*pmd))
 806                 return 0;
 807
 808         if (pmd_large(*pmd))
 809                 return pfn_valid(pmd_pfn(*pmd));
 810
 811         pte = pte_offset_kernel(pmd, addr);
 812         if (pte_none(*pte))
 813                 return 0;
 814
 815         return pfn_valid(pte_pfn(*pte));
 816 }
 817
 818 /*
 819  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 820  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 821  * not need special handling anymore:
 822  */
 823 static struct vm_area_struct gate_vma = {
 824         .vm_start       = VSYSCALL_START,
 825         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 826         .vm_page_prot   = PAGE_READONLY_EXEC,
 827         .vm_flags       = VM_READ | VM_EXEC
 828 };
 829
 830 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 831 {
 832 #ifdef CONFIG_IA32_EMULATION
 833         if (test_tsk_thread_flag(tsk, TIF_IA32))
 834                 return NULL;
 835 #endif
 836         return &gate_vma;
 837 }
 838
 839 int in_gate_area(struct task_struct *task, unsigned long addr)
 840 {
 841         struct vm_area_struct *vma = get_gate_vma(task);
 842
 843         if (!vma)
 844                 return 0;
 845
 846         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 847 }
 848
 849 /*
 850  * Use this when you have no reliable task/vma, typically from interrupt
 851  * context. It is less reliable than using the task's vma and may give
 852  * false positives:
 853  */
 854 int in_gate_area_no_task(unsigned long addr)
 855 {
 856         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 857 }
 858
 859 const char *arch_vma_name(struct vm_area_struct *vma)
 860 {
 861         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 862                 return "[vdso]";
 863         if (vma == &gate_vma)
 864                 return "[vsyscall]";
 865         return NULL;
 866 }
 867
 868 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 869 /*
 870  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 871  */
 872 static long __meminitdata addr_start, addr_end;
 873 static void __meminitdata *p_start, *p_end;
 874 static int __meminitdata node_start;
 875
 876 int __meminit
 877 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 878 {
 879         unsigned long addr = (unsigned long)start_page;
 880         unsigned long end = (unsigned long)(start_page + size);
 881         unsigned long next;
 882         pgd_t *pgd;
 883         pud_t *pud;
 884         pmd_t *pmd;
 885
 886         for (; addr < end; addr = next) {
 887                 void *p = NULL;
 888
 889                 pgd = vmemmap_pgd_populate(addr, node);
 890                 if (!pgd)
 891                         return -ENOMEM;
 892
 893                 pud = vmemmap_pud_populate(pgd, addr, node);
 894                 if (!pud)
 895                         return -ENOMEM;
 896
 897                 if (!cpu_has_pse) {
 898                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 899                         pmd = vmemmap_pmd_populate(pud, addr, node);
 900
 901                         if (!pmd)
 902                                 return -ENOMEM;
 903
 904                         p = vmemmap_pte_populate(pmd, addr, node);
 905
 906                         if (!p)
 907                                 return -ENOMEM;
 908
 909                         addr_end = addr + PAGE_SIZE;
 910                         p_end = p + PAGE_SIZE;
 911                 } else {
 912                         next = pmd_addr_end(addr, end);
 913
 914                         pmd = pmd_offset(pud, addr);
 915                         if (pmd_none(*pmd)) {
 916                                 pte_t entry;
 917
 918                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 919                                 if (!p)
 920                                         return -ENOMEM;
 921
 922                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 923                                                 PAGE_KERNEL_LARGE);
 924                                 set_pmd(pmd, __pmd(pte_val(entry)));
 925
 926                                 /* check to see if we have contiguous blocks */
 927                                 if (p_end != p || node_start != node) {
 928                                         if (p_start)
 929                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 930                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 931                                         addr_start = addr;
 932                                         node_start = node;
 933                                         p_start = p;
 934                                 }
 935
 936                                 addr_end = addr + PMD_SIZE;
 937                                 p_end = p + PMD_SIZE;
 938                         } else
 939                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
 940                 }
 941
 942         }
 943         return 0;
 944 }
 945
 946 void __meminit vmemmap_populate_print_last(void)
 947 {
 948         if (p_start) {
 949                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 950                         addr_start, addr_end-1, p_start, p_end-1, node_start);
 951                 p_start = NULL;
 952                 p_end = NULL;
 953                 node_start = 0;
 954         }
 955 }
 956 #endif