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 #include <linux/bootmem.h>
  53
  54 static unsigned long dma_reserve __initdata;
  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 #ifndef CONFIG_NO_BOOTMEM
 576         unsigned long bootmap_size, bootmap;
 577
 578         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
 579         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
 580                                  PAGE_SIZE);
 581         if (bootmap == -1L)
 582                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
 583         reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP");
 584         /* don't touch min_low_pfn */
 585         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
 586                                          0, end_pfn);
 587         e820_register_active_regions(0, start_pfn, end_pfn);
 588         free_bootmem_with_active_regions(0, end_pfn);
 589 #else
 590         e820_register_active_regions(0, start_pfn, end_pfn);
 591 #endif
 592 }
 593 #endif
 594
 595 void __init paging_init(void)
 596 {
 597         unsigned long max_zone_pfns[MAX_NR_ZONES];
 598
 599         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 600         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 601         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 602         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 603
 604         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 605         sparse_init();
 606
 607         /*
 608          * clear the default setting with node 0
 609          * note: don't use nodes_clear here, that is really clearing when
 610          *       numa support is not compiled in, and later node_set_state
 611          *       will not set it back.
 612          */
 613         node_clear_state(0, N_NORMAL_MEMORY);
 614
 615         free_area_init_nodes(max_zone_pfns);
 616 }
 617
 618 /*
 619  * Memory hotplug specific functions
 620  */
 621 #ifdef CONFIG_MEMORY_HOTPLUG
 622 /*
 623  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 624  * updating.
 625  */
 626 static void  update_end_of_memory_vars(u64 start, u64 size)
 627 {
 628         unsigned long end_pfn = PFN_UP(start + size);
 629
 630         if (end_pfn > max_pfn) {
 631                 max_pfn = end_pfn;
 632                 max_low_pfn = end_pfn;
 633                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 634         }
 635 }
 636
 637 /*
 638  * Memory is added always to NORMAL zone. This means you will never get
 639  * additional DMA/DMA32 memory.
 640  */
 641 int arch_add_memory(int nid, u64 start, u64 size)
 642 {
 643         struct pglist_data *pgdat = NODE_DATA(nid);
 644         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 645         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 646         unsigned long nr_pages = size >> PAGE_SHIFT;
 647         int ret;
 648
 649         last_mapped_pfn = init_memory_mapping(start, start + size);
 650         if (last_mapped_pfn > max_pfn_mapped)
 651                 max_pfn_mapped = last_mapped_pfn;
 652
 653         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 654         WARN_ON_ONCE(ret);
 655
 656         /* update max_pfn, max_low_pfn and high_memory */
 657         update_end_of_memory_vars(start, size);
 658
 659         return ret;
 660 }
 661 EXPORT_SYMBOL_GPL(arch_add_memory);
 662
 663 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 664 int memory_add_physaddr_to_nid(u64 start)
 665 {
 666         return 0;
 667 }
 668 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 669 #endif
 670
 671 #endif /* CONFIG_MEMORY_HOTPLUG */
 672
 673 static struct kcore_list kcore_vsyscall;
 674
 675 void __init mem_init(void)
 676 {
 677         long codesize, reservedpages, datasize, initsize;
 678         unsigned long absent_pages;
 679
 680         pci_iommu_alloc();
 681
 682         /* clear_bss() already clear the empty_zero_page */
 683
 684         reservedpages = 0;
 685
 686         /* this will put all low memory onto the freelists */
 687 #ifdef CONFIG_NUMA
 688         totalram_pages = numa_free_all_bootmem();
 689 #else
 690         totalram_pages = free_all_bootmem();
 691 #endif
 692
 693         absent_pages = absent_pages_in_range(0, max_pfn);
 694         reservedpages = max_pfn - totalram_pages - absent_pages;
 695         after_bootmem = 1;
 696
 697         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 698         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 699         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 700
 701         /* Register memory areas for /proc/kcore */
 702         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 703                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 704
 705         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 706                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 707                 nr_free_pages() << (PAGE_SHIFT-10),
 708                 max_pfn << (PAGE_SHIFT-10),
 709                 codesize >> 10,
 710                 absent_pages << (PAGE_SHIFT-10),
 711                 reservedpages << (PAGE_SHIFT-10),
 712                 datasize >> 10,
 713                 initsize >> 10);
 714 }
 715
 716 #ifdef CONFIG_DEBUG_RODATA
 717 const int rodata_test_data = 0xC3;
 718 EXPORT_SYMBOL_GPL(rodata_test_data);
 719
 720 int kernel_set_to_readonly;
 721
 722 void set_kernel_text_rw(void)
 723 {
 724         unsigned long start = PFN_ALIGN(_text);
 725         unsigned long end = PFN_ALIGN(__stop___ex_table);
 726
 727         if (!kernel_set_to_readonly)
 728                 return;
 729
 730         pr_debug("Set kernel text: %lx - %lx for read write\n",
 731                  start, end);
 732
 733         /*
 734          * Make the kernel identity mapping for text RW. Kernel text
 735          * mapping will always be RO. Refer to the comment in
 736          * static_protections() in pageattr.c
 737          */
 738         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
 739 }
 740
 741 void set_kernel_text_ro(void)
 742 {
 743         unsigned long start = PFN_ALIGN(_text);
 744         unsigned long end = PFN_ALIGN(__stop___ex_table);
 745
 746         if (!kernel_set_to_readonly)
 747                 return;
 748
 749         pr_debug("Set kernel text: %lx - %lx for read only\n",
 750                  start, end);
 751
 752         /*
 753          * Set the kernel identity mapping for text RO.
 754          */
 755         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 756 }
 757
 758 void mark_rodata_ro(void)
 759 {
 760         unsigned long start = PFN_ALIGN(_text);
 761         unsigned long rodata_start =
 762                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 763         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
 764         unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
 765         unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
 766         unsigned long data_start = (unsigned long) &_sdata;
 767
 768         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 769                (end - start) >> 10);
 770         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 771
 772         kernel_set_to_readonly = 1;
 773
 774         /*
 775          * The rodata section (but not the kernel text!) should also be
 776          * not-executable.
 777          */
 778         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 779
 780         rodata_test();
 781
 782 #ifdef CONFIG_CPA_DEBUG
 783         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 784         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 785
 786         printk(KERN_INFO "Testing CPA: again\n");
 787         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 788 #endif
 789
 790         free_init_pages("unused kernel memory",
 791                         (unsigned long) page_address(virt_to_page(text_end)),
 792                         (unsigned long)
 793                                  page_address(virt_to_page(rodata_start)));
 794         free_init_pages("unused kernel memory",
 795                         (unsigned long) page_address(virt_to_page(rodata_end)),
 796                         (unsigned long) page_address(virt_to_page(data_start)));
 797 }
 798
 799 #endif
 800
 801 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
 802                                    int flags)
 803 {
 804 #ifdef CONFIG_NUMA
 805         int nid, next_nid;
 806         int ret;
 807 #endif
 808         unsigned long pfn = phys >> PAGE_SHIFT;
 809
 810         if (pfn >= max_pfn) {
 811                 /*
 812                  * This can happen with kdump kernels when accessing
 813                  * firmware tables:
 814                  */
 815                 if (pfn < max_pfn_mapped)
 816                         return -EFAULT;
 817
 818                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
 819                                 phys, len);
 820                 return -EFAULT;
 821         }
 822
 823         /* Should check here against the e820 map to avoid double free */
 824 #ifdef CONFIG_NUMA
 825         nid = phys_to_nid(phys);
 826         next_nid = phys_to_nid(phys + len - 1);
 827         if (nid == next_nid)
 828                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
 829         else
 830                 ret = reserve_bootmem(phys, len, flags);
 831
 832         if (ret != 0)
 833                 return ret;
 834
 835 #else
 836         reserve_bootmem(phys, len, flags);
 837 #endif
 838
 839         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
 840                 dma_reserve += len / PAGE_SIZE;
 841                 set_dma_reserve(dma_reserve);
 842         }
 843
 844         return 0;
 845 }
 846
 847 int kern_addr_valid(unsigned long addr)
 848 {
 849         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 850         pgd_t *pgd;
 851         pud_t *pud;
 852         pmd_t *pmd;
 853         pte_t *pte;
 854
 855         if (above != 0 && above != -1UL)
 856                 return 0;
 857
 858         pgd = pgd_offset_k(addr);
 859         if (pgd_none(*pgd))
 860                 return 0;
 861
 862         pud = pud_offset(pgd, addr);
 863         if (pud_none(*pud))
 864                 return 0;
 865
 866         pmd = pmd_offset(pud, addr);
 867         if (pmd_none(*pmd))
 868                 return 0;
 869
 870         if (pmd_large(*pmd))
 871                 return pfn_valid(pmd_pfn(*pmd));
 872
 873         pte = pte_offset_kernel(pmd, addr);
 874         if (pte_none(*pte))
 875                 return 0;
 876
 877         return pfn_valid(pte_pfn(*pte));
 878 }
 879
 880 /*
 881  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 882  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 883  * not need special handling anymore:
 884  */
 885 static struct vm_area_struct gate_vma = {
 886         .vm_start       = VSYSCALL_START,
 887         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 888         .vm_page_prot   = PAGE_READONLY_EXEC,
 889         .vm_flags       = VM_READ | VM_EXEC
 890 };
 891
 892 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 893 {
 894 #ifdef CONFIG_IA32_EMULATION
 895         if (test_tsk_thread_flag(tsk, TIF_IA32))
 896                 return NULL;
 897 #endif
 898         return &gate_vma;
 899 }
 900
 901 int in_gate_area(struct task_struct *task, unsigned long addr)
 902 {
 903         struct vm_area_struct *vma = get_gate_vma(task);
 904
 905         if (!vma)
 906                 return 0;
 907
 908         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 909 }
 910
 911 /*
 912  * Use this when you have no reliable task/vma, typically from interrupt
 913  * context. It is less reliable than using the task's vma and may give
 914  * false positives:
 915  */
 916 int in_gate_area_no_task(unsigned long addr)
 917 {
 918         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 919 }
 920
 921 const char *arch_vma_name(struct vm_area_struct *vma)
 922 {
 923         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 924                 return "[vdso]";
 925         if (vma == &gate_vma)
 926                 return "[vsyscall]";
 927         return NULL;
 928 }
 929
 930 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 931 /*
 932  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 933  */
 934 static long __meminitdata addr_start, addr_end;
 935 static void __meminitdata *p_start, *p_end;
 936 static int __meminitdata node_start;
 937
 938 int __meminit
 939 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 940 {
 941         unsigned long addr = (unsigned long)start_page;
 942         unsigned long end = (unsigned long)(start_page + size);
 943         unsigned long next;
 944         pgd_t *pgd;
 945         pud_t *pud;
 946         pmd_t *pmd;
 947
 948         for (; addr < end; addr = next) {
 949                 void *p = NULL;
 950
 951                 pgd = vmemmap_pgd_populate(addr, node);
 952                 if (!pgd)
 953                         return -ENOMEM;
 954
 955                 pud = vmemmap_pud_populate(pgd, addr, node);
 956                 if (!pud)
 957                         return -ENOMEM;
 958
 959                 if (!cpu_has_pse) {
 960                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 961                         pmd = vmemmap_pmd_populate(pud, addr, node);
 962
 963                         if (!pmd)
 964                                 return -ENOMEM;
 965
 966                         p = vmemmap_pte_populate(pmd, addr, node);
 967
 968                         if (!p)
 969                                 return -ENOMEM;
 970
 971                         addr_end = addr + PAGE_SIZE;
 972                         p_end = p + PAGE_SIZE;
 973                 } else {
 974                         next = pmd_addr_end(addr, end);
 975
 976                         pmd = pmd_offset(pud, addr);
 977                         if (pmd_none(*pmd)) {
 978                                 pte_t entry;
 979
 980                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 981                                 if (!p)
 982                                         return -ENOMEM;
 983
 984                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 985                                                 PAGE_KERNEL_LARGE);
 986                                 set_pmd(pmd, __pmd(pte_val(entry)));
 987
 988                                 /* check to see if we have contiguous blocks */
 989                                 if (p_end != p || node_start != node) {
 990                                         if (p_start)
 991                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 992                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 993                                         addr_start = addr;
 994                                         node_start = node;
 995                                         p_start = p;
 996                                 }
 997
 998                                 addr_end = addr + PMD_SIZE;
 999                                 p_end = p + PMD_SIZE;
1000                         } else
1001                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1002                 }
1003
1004         }
1005         return 0;
1006 }
1007
1008 void __meminit vmemmap_populate_print_last(void)
1009 {
1010         if (p_start) {
1011                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1012                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1013                 p_start = NULL;
1014                 p_end = NULL;
1015                 node_start = 0;
1016         }
1017 }
1018 #endif