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
  52 /*
  53  * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
  54  * The direct mapping extends to max_pfn_mapped, so that we can directly access
  55  * apertures, ACPI and other tables without having to play with fixmaps.
  56  */
  57 unsigned long max_low_pfn_mapped;
  58 unsigned long max_pfn_mapped;
  59
  60 static unsigned long dma_reserve __initdata;
  61
  62 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  63
  64 int direct_gbpages
  65 #ifdef CONFIG_DIRECT_GBPAGES
  66                                 = 1
  67 #endif
  68 ;
  69
  70 static int __init parse_direct_gbpages_off(char *arg)
  71 {
  72         direct_gbpages = 0;
  73         return 0;
  74 }
  75 early_param("nogbpages", parse_direct_gbpages_off);
  76
  77 static int __init parse_direct_gbpages_on(char *arg)
  78 {
  79         direct_gbpages = 1;
  80         return 0;
  81 }
  82 early_param("gbpages", parse_direct_gbpages_on);
  83
  84 /*
  85  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  86  * physical space so we can cache the place of the first one and move
  87  * around without checking the pgd every time.
  88  */
  89
  90 int after_bootmem;
  91
  92 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  93 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  94
  95 static int do_not_nx __cpuinitdata;
  96
  97 /*
  98  * noexec=on|off
  99  * Control non-executable mappings for 64-bit processes.
 100  *
 101  * on   Enable (default)
 102  * off  Disable
 103  */
 104 static int __init nonx_setup(char *str)
 105 {
 106         if (!str)
 107                 return -EINVAL;
 108         if (!strncmp(str, "on", 2)) {
 109                 __supported_pte_mask |= _PAGE_NX;
 110                 do_not_nx = 0;
 111         } else if (!strncmp(str, "off", 3)) {
 112                 do_not_nx = 1;
 113                 __supported_pte_mask &= ~_PAGE_NX;
 114         }
 115         return 0;
 116 }
 117 early_param("noexec", nonx_setup);
 118
 119 void __cpuinit check_efer(void)
 120 {
 121         unsigned long efer;
 122
 123         rdmsrl(MSR_EFER, efer);
 124         if (!(efer & EFER_NX) || do_not_nx)
 125                 __supported_pte_mask &= ~_PAGE_NX;
 126 }
 127
 128 int force_personality32;
 129
 130 /*
 131  * noexec32=on|off
 132  * Control non executable heap for 32bit processes.
 133  * To control the stack too use noexec=off
 134  *
 135  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
 136  * off  PROT_READ implies PROT_EXEC
 137  */
 138 static int __init nonx32_setup(char *str)
 139 {
 140         if (!strcmp(str, "on"))
 141                 force_personality32 &= ~READ_IMPLIES_EXEC;
 142         else if (!strcmp(str, "off"))
 143                 force_personality32 |= READ_IMPLIES_EXEC;
 144         return 1;
 145 }
 146 __setup("noexec32=", nonx32_setup);
 147
 148 /*
 149  * NOTE: This function is marked __ref because it calls __init function
 150  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 151  */
 152 static __ref void *spp_getpage(void)
 153 {
 154         void *ptr;
 155
 156         if (after_bootmem)
 157                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 158         else
 159                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 160
 161         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 162                 panic("set_pte_phys: cannot allocate page data %s\n",
 163                         after_bootmem ? "after bootmem" : "");
 164         }
 165
 166         pr_debug("spp_getpage %p\n", ptr);
 167
 168         return ptr;
 169 }
 170
 171 void
 172 set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 173 {
 174         pud_t *pud;
 175         pmd_t *pmd;
 176         pte_t *pte;
 177
 178         pud = pud_page + pud_index(vaddr);
 179         if (pud_none(*pud)) {
 180                 pmd = (pmd_t *) spp_getpage();
 181                 pud_populate(&init_mm, pud, pmd);
 182                 if (pmd != pmd_offset(pud, 0)) {
 183                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 184                                 pmd, pmd_offset(pud, 0));
 185                         return;
 186                 }
 187         }
 188         pmd = pmd_offset(pud, vaddr);
 189         if (pmd_none(*pmd)) {
 190                 pte = (pte_t *) spp_getpage();
 191                 pmd_populate_kernel(&init_mm, pmd, pte);
 192                 if (pte != pte_offset_kernel(pmd, 0)) {
 193                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 194                         return;
 195                 }
 196         }
 197
 198         pte = pte_offset_kernel(pmd, vaddr);
 199         set_pte(pte, new_pte);
 200
 201         /*
 202          * It's enough to flush this one mapping.
 203          * (PGE mappings get flushed as well)
 204          */
 205         __flush_tlb_one(vaddr);
 206 }
 207
 208 void
 209 set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 210 {
 211         pgd_t *pgd;
 212         pud_t *pud_page;
 213
 214         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 215
 216         pgd = pgd_offset_k(vaddr);
 217         if (pgd_none(*pgd)) {
 218                 printk(KERN_ERR
 219                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 220                 return;
 221         }
 222         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 223         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 224 }
 225
 226 /*
 227  * Create large page table mappings for a range of physical addresses.
 228  */
 229 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 230                                                 pgprot_t prot)
 231 {
 232         pgd_t *pgd;
 233         pud_t *pud;
 234         pmd_t *pmd;
 235
 236         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 237         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 238                 pgd = pgd_offset_k((unsigned long)__va(phys));
 239                 if (pgd_none(*pgd)) {
 240                         pud = (pud_t *) spp_getpage();
 241                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 242                                                 _PAGE_USER));
 243                 }
 244                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 245                 if (pud_none(*pud)) {
 246                         pmd = (pmd_t *) spp_getpage();
 247                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 248                                                 _PAGE_USER));
 249                 }
 250                 pmd = pmd_offset(pud, phys);
 251                 BUG_ON(!pmd_none(*pmd));
 252                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 253         }
 254 }
 255
 256 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 257 {
 258         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 259 }
 260
 261 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 262 {
 263         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 264 }
 265
 266 /*
 267  * The head.S code sets up the kernel high mapping:
 268  *
 269  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 270  *
 271  * phys_addr holds the negative offset to the kernel, which is added
 272  * to the compile time generated pmds. This results in invalid pmds up
 273  * to the point where we hit the physaddr 0 mapping.
 274  *
 275  * We limit the mappings to the region from _text to _end.  _end is
 276  * rounded up to the 2MB boundary. This catches the invalid pmds as
 277  * well, as they are located before _text:
 278  */
 279 void __init cleanup_highmap(void)
 280 {
 281         unsigned long vaddr = __START_KERNEL_map;
 282         unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1;
 283         pmd_t *pmd = level2_kernel_pgt;
 284         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
 285
 286         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
 287                 if (pmd_none(*pmd))
 288                         continue;
 289                 if (vaddr < (unsigned long) _text || vaddr > end)
 290                         set_pmd(pmd, __pmd(0));
 291         }
 292 }
 293
 294 static unsigned long __initdata table_start;
 295 static unsigned long __meminitdata table_end;
 296 static unsigned long __meminitdata table_top;
 297
 298 static __ref void *alloc_low_page(unsigned long *phys)
 299 {
 300         unsigned long pfn = table_end++;
 301         void *adr;
 302
 303         if (after_bootmem) {
 304                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
 305                 *phys = __pa(adr);
 306
 307                 return adr;
 308         }
 309
 310         if (pfn >= table_top)
 311                 panic("alloc_low_page: ran out of memory");
 312
 313         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 314         memset(adr, 0, PAGE_SIZE);
 315         *phys  = pfn * PAGE_SIZE;
 316         return adr;
 317 }
 318
 319 static __ref void unmap_low_page(void *adr)
 320 {
 321         if (after_bootmem)
 322                 return;
 323
 324         early_iounmap(adr, PAGE_SIZE);
 325 }
 326
 327 static unsigned long __meminit
 328 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 329               pgprot_t prot)
 330 {
 331         unsigned pages = 0;
 332         unsigned long last_map_addr = end;
 333         int i;
 334
 335         pte_t *pte = pte_page + pte_index(addr);
 336
 337         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 338
 339                 if (addr >= end) {
 340                         if (!after_bootmem) {
 341                                 for(; i < PTRS_PER_PTE; i++, pte++)
 342                                         set_pte(pte, __pte(0));
 343                         }
 344                         break;
 345                 }
 346
 347                 /*
 348                  * We will re-use the existing mapping.
 349                  * Xen for example has some special requirements, like mapping
 350                  * pagetable pages as RO. So assume someone who pre-setup
 351                  * these mappings are more intelligent.
 352                  */
 353                 if (pte_val(*pte))
 354                         continue;
 355
 356                 if (0)
 357                         printk("   pte=%p addr=%lx pte=%016lx\n",
 358                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 359                 pages++;
 360                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 361                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 362         }
 363
 364         update_page_count(PG_LEVEL_4K, pages);
 365
 366         return last_map_addr;
 367 }
 368
 369 static unsigned long __meminit
 370 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
 371                 pgprot_t prot)
 372 {
 373         pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
 374
 375         return phys_pte_init(pte, address, end, prot);
 376 }
 377
 378 static unsigned long __meminit
 379 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 380               unsigned long page_size_mask, pgprot_t prot)
 381 {
 382         unsigned long pages = 0;
 383         unsigned long last_map_addr = end;
 384
 385         int i = pmd_index(address);
 386
 387         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 388                 unsigned long pte_phys;
 389                 pmd_t *pmd = pmd_page + pmd_index(address);
 390                 pte_t *pte;
 391                 pgprot_t new_prot = prot;
 392
 393                 if (address >= end) {
 394                         if (!after_bootmem) {
 395                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 396                                         set_pmd(pmd, __pmd(0));
 397                         }
 398                         break;
 399                 }
 400
 401                 if (pmd_val(*pmd)) {
 402                         if (!pmd_large(*pmd)) {
 403                                 spin_lock(&init_mm.page_table_lock);
 404                                 last_map_addr = phys_pte_update(pmd, address,
 405                                                                 end, prot);
 406                                 spin_unlock(&init_mm.page_table_lock);
 407                                 continue;
 408                         }
 409                         /*
 410                          * If we are ok with PG_LEVEL_2M mapping, then we will
 411                          * use the existing mapping,
 412                          *
 413                          * Otherwise, we will split the large page mapping but
 414                          * use the same existing protection bits except for
 415                          * large page, so that we don't violate Intel's TLB
 416                          * Application note (317080) which says, while changing
 417                          * the page sizes, new and old translations should
 418                          * not differ with respect to page frame and
 419                          * attributes.
 420                          */
 421                         if (page_size_mask & (1 << PG_LEVEL_2M))
 422                                 continue;
 423                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 424                 }
 425
 426                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 427                         pages++;
 428                         spin_lock(&init_mm.page_table_lock);
 429                         set_pte((pte_t *)pmd,
 430                                 pfn_pte(address >> PAGE_SHIFT,
 431                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 432                         spin_unlock(&init_mm.page_table_lock);
 433                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 434                         continue;
 435                 }
 436
 437                 pte = alloc_low_page(&pte_phys);
 438                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 439                 unmap_low_page(pte);
 440
 441                 spin_lock(&init_mm.page_table_lock);
 442                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 443                 spin_unlock(&init_mm.page_table_lock);
 444         }
 445         update_page_count(PG_LEVEL_2M, pages);
 446         return last_map_addr;
 447 }
 448
 449 static unsigned long __meminit
 450 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
 451                 unsigned long page_size_mask, pgprot_t prot)
 452 {
 453         pmd_t *pmd = pmd_offset(pud, 0);
 454         unsigned long last_map_addr;
 455
 456         last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
 457         __flush_tlb_all();
 458         return last_map_addr;
 459 }
 460
 461 static unsigned long __meminit
 462 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 463                          unsigned long page_size_mask)
 464 {
 465         unsigned long pages = 0;
 466         unsigned long last_map_addr = end;
 467         int i = pud_index(addr);
 468
 469         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 470                 unsigned long pmd_phys;
 471                 pud_t *pud = pud_page + pud_index(addr);
 472                 pmd_t *pmd;
 473                 pgprot_t prot = PAGE_KERNEL;
 474
 475                 if (addr >= end)
 476                         break;
 477
 478                 if (!after_bootmem &&
 479                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 480                         set_pud(pud, __pud(0));
 481                         continue;
 482                 }
 483
 484                 if (pud_val(*pud)) {
 485                         if (!pud_large(*pud)) {
 486                                 last_map_addr = phys_pmd_update(pud, addr, end,
 487                                                          page_size_mask, prot);
 488                                 continue;
 489                         }
 490                         /*
 491                          * If we are ok with PG_LEVEL_1G mapping, then we will
 492                          * use the existing mapping.
 493                          *
 494                          * Otherwise, we will split the gbpage mapping but use
 495                          * the same existing protection  bits except for large
 496                          * page, so that we don't violate Intel's TLB
 497                          * Application note (317080) which says, while changing
 498                          * the page sizes, new and old translations should
 499                          * not differ with respect to page frame and
 500                          * attributes.
 501                          */
 502                         if (page_size_mask & (1 << PG_LEVEL_1G))
 503                                 continue;
 504                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 505                 }
 506
 507                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 508                         pages++;
 509                         spin_lock(&init_mm.page_table_lock);
 510                         set_pte((pte_t *)pud,
 511                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 512                         spin_unlock(&init_mm.page_table_lock);
 513                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 514                         continue;
 515                 }
 516
 517                 pmd = alloc_low_page(&pmd_phys);
 518                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 519                                               prot);
 520                 unmap_low_page(pmd);
 521
 522                 spin_lock(&init_mm.page_table_lock);
 523                 pud_populate(&init_mm, pud, __va(pmd_phys));
 524                 spin_unlock(&init_mm.page_table_lock);
 525         }
 526         __flush_tlb_all();
 527
 528         update_page_count(PG_LEVEL_1G, pages);
 529
 530         return last_map_addr;
 531 }
 532
 533 static unsigned long __meminit
 534 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
 535                  unsigned long page_size_mask)
 536 {
 537         pud_t *pud;
 538
 539         pud = (pud_t *)pgd_page_vaddr(*pgd);
 540
 541         return phys_pud_init(pud, addr, end, page_size_mask);
 542 }
 543
 544 static void __init find_early_table_space(unsigned long end, int use_pse,
 545                                           int use_gbpages)
 546 {
 547         unsigned long puds, pmds, ptes, tables, start;
 548
 549         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 550         tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
 551         if (use_gbpages) {
 552                 unsigned long extra;
 553                 extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
 554                 pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
 555         } else
 556                 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 557         tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
 558
 559         if (use_pse) {
 560                 unsigned long extra;
 561                 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
 562                 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
 563         } else
 564                 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
 565         tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
 566
 567         /*
 568          * RED-PEN putting page tables only on node 0 could
 569          * cause a hotspot and fill up ZONE_DMA. The page tables
 570          * need roughly 0.5KB per GB.
 571          */
 572         start = 0x8000;
 573         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
 574         if (table_start == -1UL)
 575                 panic("Cannot find space for the kernel page tables");
 576
 577         table_start >>= PAGE_SHIFT;
 578         table_end = table_start;
 579         table_top = table_start + (tables >> PAGE_SHIFT);
 580
 581         printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
 582                 end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
 583 }
 584
 585 static void __init init_gbpages(void)
 586 {
 587         if (direct_gbpages && cpu_has_gbpages)
 588                 printk(KERN_INFO "Using GB pages for direct mapping\n");
 589         else
 590                 direct_gbpages = 0;
 591 }
 592
 593 static unsigned long __init kernel_physical_mapping_init(unsigned long start,
 594                                                 unsigned long end,
 595                                                 unsigned long page_size_mask)
 596 {
 597
 598         unsigned long next, last_map_addr = end;
 599
 600         start = (unsigned long)__va(start);
 601         end = (unsigned long)__va(end);
 602
 603         for (; start < end; start = next) {
 604                 pgd_t *pgd = pgd_offset_k(start);
 605                 unsigned long pud_phys;
 606                 pud_t *pud;
 607
 608                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 609                 if (next > end)
 610                         next = end;
 611
 612                 if (pgd_val(*pgd)) {
 613                         last_map_addr = phys_pud_update(pgd, __pa(start),
 614                                                  __pa(end), page_size_mask);
 615                         continue;
 616                 }
 617
 618                 pud = alloc_low_page(&pud_phys);
 619                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 620                                                  page_size_mask);
 621                 unmap_low_page(pud);
 622
 623                 spin_lock(&init_mm.page_table_lock);
 624                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 625                 spin_unlock(&init_mm.page_table_lock);
 626         }
 627         __flush_tlb_all();
 628
 629         return last_map_addr;
 630 }
 631
 632 struct map_range {
 633         unsigned long start;
 634         unsigned long end;
 635         unsigned page_size_mask;
 636 };
 637
 638 #define NR_RANGE_MR 5
 639
 640 static int save_mr(struct map_range *mr, int nr_range,
 641                    unsigned long start_pfn, unsigned long end_pfn,
 642                    unsigned long page_size_mask)
 643 {
 644
 645         if (start_pfn < end_pfn) {
 646                 if (nr_range >= NR_RANGE_MR)
 647                         panic("run out of range for init_memory_mapping\n");
 648                 mr[nr_range].start = start_pfn<<PAGE_SHIFT;
 649                 mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
 650                 mr[nr_range].page_size_mask = page_size_mask;
 651                 nr_range++;
 652         }
 653
 654         return nr_range;
 655 }
 656
 657 /*
 658  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
 659  * This runs before bootmem is initialized and gets pages directly from
 660  * the physical memory. To access them they are temporarily mapped.
 661  */
 662 unsigned long __init_refok init_memory_mapping(unsigned long start,
 663                                                unsigned long end)
 664 {
 665         unsigned long last_map_addr = 0;
 666         unsigned long page_size_mask = 0;
 667         unsigned long start_pfn, end_pfn;
 668
 669         struct map_range mr[NR_RANGE_MR];
 670         int nr_range, i;
 671         int use_pse, use_gbpages;
 672
 673         printk(KERN_INFO "init_memory_mapping\n");
 674
 675         /*
 676          * Find space for the kernel direct mapping tables.
 677          *
 678          * Later we should allocate these tables in the local node of the
 679          * memory mapped. Unfortunately this is done currently before the
 680          * nodes are discovered.
 681          */
 682         if (!after_bootmem)
 683                 init_gbpages();
 684
 685 #ifdef CONFIG_DEBUG_PAGEALLOC
 686         /*
 687          * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
 688          * This will simplify cpa(), which otherwise needs to support splitting
 689          * large pages into small in interrupt context, etc.
 690          */
 691         use_pse = use_gbpages = 0;
 692 #else
 693         use_pse = cpu_has_pse;
 694         use_gbpages = direct_gbpages;
 695 #endif
 696
 697         if (use_gbpages)
 698                 page_size_mask |= 1 << PG_LEVEL_1G;
 699         if (use_pse)
 700                 page_size_mask |= 1 << PG_LEVEL_2M;
 701
 702         memset(mr, 0, sizeof(mr));
 703         nr_range = 0;
 704
 705         /* head if not big page alignment ?*/
 706         start_pfn = start >> PAGE_SHIFT;
 707         end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
 708                         << (PMD_SHIFT - PAGE_SHIFT);
 709         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 710
 711         /* big page (2M) range*/
 712         start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
 713                          << (PMD_SHIFT - PAGE_SHIFT);
 714         end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
 715                          << (PUD_SHIFT - PAGE_SHIFT);
 716         if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
 717                 end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
 718         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 719                         page_size_mask & (1<<PG_LEVEL_2M));
 720
 721         /* big page (1G) range */
 722         start_pfn = end_pfn;
 723         end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
 724         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 725                                 page_size_mask &
 726                                  ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
 727
 728         /* tail is not big page (1G) alignment */
 729         start_pfn = end_pfn;
 730         end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
 731         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 732                         page_size_mask & (1<<PG_LEVEL_2M));
 733
 734         /* tail is not big page (2M) alignment */
 735         start_pfn = end_pfn;
 736         end_pfn = end>>PAGE_SHIFT;
 737         nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 738
 739         /* try to merge same page size and continuous */
 740         for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
 741                 unsigned long old_start;
 742                 if (mr[i].end != mr[i+1].start ||
 743                     mr[i].page_size_mask != mr[i+1].page_size_mask)
 744                         continue;
 745                 /* move it */
 746                 old_start = mr[i].start;
 747                 memmove(&mr[i], &mr[i+1],
 748                          (nr_range - 1 - i) * sizeof (struct map_range));
 749                 mr[i].start = old_start;
 750                 nr_range--;
 751         }
 752
 753         for (i = 0; i < nr_range; i++)
 754                 printk(KERN_DEBUG " %010lx - %010lx page %s\n",
 755                                 mr[i].start, mr[i].end,
 756                         (mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
 757                          (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
 758
 759         if (!after_bootmem)
 760                 find_early_table_space(end, use_pse, use_gbpages);
 761
 762         for (i = 0; i < nr_range; i++)
 763                 last_map_addr = kernel_physical_mapping_init(
 764                                         mr[i].start, mr[i].end,
 765                                         mr[i].page_size_mask);
 766
 767         if (!after_bootmem)
 768                 mmu_cr4_features = read_cr4();
 769         __flush_tlb_all();
 770
 771         if (!after_bootmem && table_end > table_start)
 772                 reserve_early(table_start << PAGE_SHIFT,
 773                                  table_end << PAGE_SHIFT, "PGTABLE");
 774
 775         printk(KERN_INFO "last_map_addr: %lx end: %lx\n",
 776                          last_map_addr, end);
 777
 778         if (!after_bootmem)
 779                 early_memtest(start, end);
 780
 781         return last_map_addr >> PAGE_SHIFT;
 782 }
 783
 784 #ifndef CONFIG_NUMA
 785 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn)
 786 {
 787         unsigned long bootmap_size, bootmap;
 788
 789         bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
 790         bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size,
 791                                  PAGE_SIZE);
 792         if (bootmap == -1L)
 793                 panic("Cannot find bootmem map of size %ld\n", bootmap_size);
 794         /* don't touch min_low_pfn */
 795         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT,
 796                                          0, end_pfn);
 797         e820_register_active_regions(0, start_pfn, end_pfn);
 798         free_bootmem_with_active_regions(0, end_pfn);
 799         early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT);
 800         reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
 801 }
 802
 803 void __init paging_init(void)
 804 {
 805         unsigned long max_zone_pfns[MAX_NR_ZONES];
 806
 807         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 808         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 809         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 810         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 811
 812         memory_present(0, 0, max_pfn);
 813         sparse_init();
 814         free_area_init_nodes(max_zone_pfns);
 815 }
 816 #endif
 817
 818 /*
 819  * Memory hotplug specific functions
 820  */
 821 #ifdef CONFIG_MEMORY_HOTPLUG
 822 /*
 823  * Memory is added always to NORMAL zone. This means you will never get
 824  * additional DMA/DMA32 memory.
 825  */
 826 int arch_add_memory(int nid, u64 start, u64 size)
 827 {
 828         struct pglist_data *pgdat = NODE_DATA(nid);
 829         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 830         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 831         unsigned long nr_pages = size >> PAGE_SHIFT;
 832         int ret;
 833
 834         last_mapped_pfn = init_memory_mapping(start, start + size-1);
 835         if (last_mapped_pfn > max_pfn_mapped)
 836                 max_pfn_mapped = last_mapped_pfn;
 837
 838         ret = __add_pages(zone, start_pfn, nr_pages);
 839         WARN_ON(1);
 840
 841         return ret;
 842 }
 843 EXPORT_SYMBOL_GPL(arch_add_memory);
 844
 845 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 846 int memory_add_physaddr_to_nid(u64 start)
 847 {
 848         return 0;
 849 }
 850 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 851 #endif
 852
 853 #endif /* CONFIG_MEMORY_HOTPLUG */
 854
 855 /*
 856  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
 857  * is valid. The argument is a physical page number.
 858  *
 859  *
 860  * On x86, access has to be given to the first megabyte of ram because that area
 861  * contains bios code and data regions used by X and dosemu and similar apps.
 862  * Access has to be given to non-kernel-ram areas as well, these contain the PCI
 863  * mmio resources as well as potential bios/acpi data regions.
 864  */
 865 int devmem_is_allowed(unsigned long pagenr)
 866 {
 867         if (pagenr <= 256)
 868                 return 1;
 869         if (!page_is_ram(pagenr))
 870                 return 1;
 871         return 0;
 872 }
 873
 874
 875 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
 876                          kcore_modules, kcore_vsyscall;
 877
 878 void __init mem_init(void)
 879 {
 880         long codesize, reservedpages, datasize, initsize;
 881
 882         start_periodic_check_for_corruption();
 883
 884         pci_iommu_alloc();
 885
 886         /* clear_bss() already clear the empty_zero_page */
 887
 888         reservedpages = 0;
 889
 890         /* this will put all low memory onto the freelists */
 891 #ifdef CONFIG_NUMA
 892         totalram_pages = numa_free_all_bootmem();
 893 #else
 894         totalram_pages = free_all_bootmem();
 895 #endif
 896         reservedpages = max_pfn - totalram_pages -
 897                                         absent_pages_in_range(0, max_pfn);
 898         after_bootmem = 1;
 899
 900         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 901         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 902         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 903
 904         /* Register memory areas for /proc/kcore */
 905         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 906         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 907                    VMALLOC_END-VMALLOC_START);
 908         kclist_add(&kcore_kernel, &_stext, _end - _stext);
 909         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
 910         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 911                                  VSYSCALL_END - VSYSCALL_START);
 912
 913         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 914                                 "%ldk reserved, %ldk data, %ldk init)\n",
 915                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 916                 max_pfn << (PAGE_SHIFT-10),
 917                 codesize >> 10,
 918                 reservedpages << (PAGE_SHIFT-10),
 919                 datasize >> 10,
 920                 initsize >> 10);
 921 }
 922
 923 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 924 {
 925         unsigned long addr = begin;
 926
 927         if (addr >= end)
 928                 return;
 929
 930         /*
 931          * If debugging page accesses then do not free this memory but
 932          * mark them not present - any buggy init-section access will
 933          * create a kernel page fault:
 934          */
 935 #ifdef CONFIG_DEBUG_PAGEALLOC
 936         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
 937                 begin, PAGE_ALIGN(end));
 938         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 939 #else
 940         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 941
 942         for (; addr < end; addr += PAGE_SIZE) {
 943                 ClearPageReserved(virt_to_page(addr));
 944                 init_page_count(virt_to_page(addr));
 945                 memset((void *)(addr & ~(PAGE_SIZE-1)),
 946                         POISON_FREE_INITMEM, PAGE_SIZE);
 947                 free_page(addr);
 948                 totalram_pages++;
 949         }
 950 #endif
 951 }
 952
 953 void free_initmem(void)
 954 {
 955         free_init_pages("unused kernel memory",
 956                         (unsigned long)(&__init_begin),
 957                         (unsigned long)(&__init_end));
 958 }
 959
 960 #ifdef CONFIG_DEBUG_RODATA
 961 const int rodata_test_data = 0xC3;
 962 EXPORT_SYMBOL_GPL(rodata_test_data);
 963
 964 void mark_rodata_ro(void)
 965 {
 966         unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
 967         unsigned long rodata_start =
 968                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 969
 970 #ifdef CONFIG_DYNAMIC_FTRACE
 971         /* Dynamic tracing modifies the kernel text section */
 972         start = rodata_start;
 973 #endif
 974
 975         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 976                (end - start) >> 10);
 977         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 978
 979         /*
 980          * The rodata section (but not the kernel text!) should also be
 981          * not-executable.
 982          */
 983         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 984
 985         rodata_test();
 986
 987 #ifdef CONFIG_CPA_DEBUG
 988         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 989         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 990
 991         printk(KERN_INFO "Testing CPA: again\n");
 992         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 993 #endif
 994 }
 995
 996 #endif
 997
 998 #ifdef CONFIG_BLK_DEV_INITRD
 999 void free_initrd_mem(unsigned long start, unsigned long end)
1000 {
1001         free_init_pages("initrd memory", start, end);
1002 }
1003 #endif
1004
1005 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
1006                                    int flags)
1007 {
1008 #ifdef CONFIG_NUMA
1009         int nid, next_nid;
1010         int ret;
1011 #endif
1012         unsigned long pfn = phys >> PAGE_SHIFT;
1013
1014         if (pfn >= max_pfn) {
1015                 /*
1016                  * This can happen with kdump kernels when accessing
1017                  * firmware tables:
1018                  */
1019                 if (pfn < max_pfn_mapped)
1020                         return -EFAULT;
1021
1022                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n",
1023                                 phys, len);
1024                 return -EFAULT;
1025         }
1026
1027         /* Should check here against the e820 map to avoid double free */
1028 #ifdef CONFIG_NUMA
1029         nid = phys_to_nid(phys);
1030         next_nid = phys_to_nid(phys + len - 1);
1031         if (nid == next_nid)
1032                 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags);
1033         else
1034                 ret = reserve_bootmem(phys, len, flags);
1035
1036         if (ret != 0)
1037                 return ret;
1038
1039 #else
1040         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
1041 #endif
1042
1043         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
1044                 dma_reserve += len / PAGE_SIZE;
1045                 set_dma_reserve(dma_reserve);
1046         }
1047
1048         return 0;
1049 }
1050
1051 int kern_addr_valid(unsigned long addr)
1052 {
1053         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
1054         pgd_t *pgd;
1055         pud_t *pud;
1056         pmd_t *pmd;
1057         pte_t *pte;
1058
1059         if (above != 0 && above != -1UL)
1060                 return 0;
1061
1062         pgd = pgd_offset_k(addr);
1063         if (pgd_none(*pgd))
1064                 return 0;
1065
1066         pud = pud_offset(pgd, addr);
1067         if (pud_none(*pud))
1068                 return 0;
1069
1070         pmd = pmd_offset(pud, addr);
1071         if (pmd_none(*pmd))
1072                 return 0;
1073
1074         if (pmd_large(*pmd))
1075                 return pfn_valid(pmd_pfn(*pmd));
1076
1077         pte = pte_offset_kernel(pmd, addr);
1078         if (pte_none(*pte))
1079                 return 0;
1080
1081         return pfn_valid(pte_pfn(*pte));
1082 }
1083
1084 /*
1085  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
1086  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
1087  * not need special handling anymore:
1088  */
1089 static struct vm_area_struct gate_vma = {
1090         .vm_start       = VSYSCALL_START,
1091         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
1092         .vm_page_prot   = PAGE_READONLY_EXEC,
1093         .vm_flags       = VM_READ | VM_EXEC
1094 };
1095
1096 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
1097 {
1098 #ifdef CONFIG_IA32_EMULATION
1099         if (test_tsk_thread_flag(tsk, TIF_IA32))
1100                 return NULL;
1101 #endif
1102         return &gate_vma;
1103 }
1104
1105 int in_gate_area(struct task_struct *task, unsigned long addr)
1106 {
1107         struct vm_area_struct *vma = get_gate_vma(task);
1108
1109         if (!vma)
1110                 return 0;
1111
1112         return (addr >= vma->vm_start) && (addr < vma->vm_end);
1113 }
1114
1115 /*
1116  * Use this when you have no reliable task/vma, typically from interrupt
1117  * context. It is less reliable than using the task's vma and may give
1118  * false positives:
1119  */
1120 int in_gate_area_no_task(unsigned long addr)
1121 {
1122         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
1123 }
1124
1125 const char *arch_vma_name(struct vm_area_struct *vma)
1126 {
1127         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
1128                 return "[vdso]";
1129         if (vma == &gate_vma)
1130                 return "[vsyscall]";
1131         return NULL;
1132 }
1133
1134 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1135 /*
1136  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
1137  */
1138 static long __meminitdata addr_start, addr_end;
1139 static void __meminitdata *p_start, *p_end;
1140 static int __meminitdata node_start;
1141
1142 int __meminit
1143 vmemmap_populate(struct page *start_page, unsigned long size, int node)
1144 {
1145         unsigned long addr = (unsigned long)start_page;
1146         unsigned long end = (unsigned long)(start_page + size);
1147         unsigned long next;
1148         pgd_t *pgd;
1149         pud_t *pud;
1150         pmd_t *pmd;
1151
1152         for (; addr < end; addr = next) {
1153                 void *p = NULL;
1154
1155                 pgd = vmemmap_pgd_populate(addr, node);
1156                 if (!pgd)
1157                         return -ENOMEM;
1158
1159                 pud = vmemmap_pud_populate(pgd, addr, node);
1160                 if (!pud)
1161                         return -ENOMEM;
1162
1163                 if (!cpu_has_pse) {
1164                         next = (addr + PAGE_SIZE) & PAGE_MASK;
1165                         pmd = vmemmap_pmd_populate(pud, addr, node);
1166
1167                         if (!pmd)
1168                                 return -ENOMEM;
1169
1170                         p = vmemmap_pte_populate(pmd, addr, node);
1171
1172                         if (!p)
1173                                 return -ENOMEM;
1174
1175                         addr_end = addr + PAGE_SIZE;
1176                         p_end = p + PAGE_SIZE;
1177                 } else {
1178                         next = pmd_addr_end(addr, end);
1179
1180                         pmd = pmd_offset(pud, addr);
1181                         if (pmd_none(*pmd)) {
1182                                 pte_t entry;
1183
1184                                 p = vmemmap_alloc_block(PMD_SIZE, node);
1185                                 if (!p)
1186                                         return -ENOMEM;
1187
1188                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
1189                                                 PAGE_KERNEL_LARGE);
1190                                 set_pmd(pmd, __pmd(pte_val(entry)));
1191
1192                                 /* check to see if we have contiguous blocks */
1193                                 if (p_end != p || node_start != node) {
1194                                         if (p_start)
1195                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1196                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
1197                                         addr_start = addr;
1198                                         node_start = node;
1199                                         p_start = p;
1200                                 }
1201
1202                                 addr_end = addr + PMD_SIZE;
1203                                 p_end = p + PMD_SIZE;
1204                         } else
1205                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
1206                 }
1207
1208         }
1209         return 0;
1210 }
1211
1212 void __meminit vmemmap_populate_print_last(void)
1213 {
1214         if (p_start) {
1215                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
1216                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1217                 p_start = NULL;
1218                 p_end = NULL;
1219                 node_start = 0;
1220         }
1221 }
1222 #endif