arch/x86/mm/init_64.c

   1 /*
   2  *  linux/arch/x86_64/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7  */
   8
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 #include <linux/smp.h>
  20 #include <linux/init.h>
  21 #include <linux/initrd.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memblock.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/pci.h>
  27 #include <linux/pfn.h>
  28 #include <linux/poison.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/module.h>
  31 #include <linux/memory.h>
  32 #include <linux/memory_hotplug.h>
  33 #include <linux/nmi.h>
  34 #include <linux/gfp.h>
  35
  36 #include <asm/processor.h>
  37 #include <asm/bios_ebda.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 <asm/uv/uv.h>
  55 #include <asm/setup.h>
  56
  57 static int __init parse_direct_gbpages_off(char *arg)
  58 {
  59         direct_gbpages = 0;
  60         return 0;
  61 }
  62 early_param("nogbpages", parse_direct_gbpages_off);
  63
  64 static int __init parse_direct_gbpages_on(char *arg)
  65 {
  66         direct_gbpages = 1;
  67         return 0;
  68 }
  69 early_param("gbpages", parse_direct_gbpages_on);
  70
  71 /*
  72  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  73  * physical space so we can cache the place of the first one and move
  74  * around without checking the pgd every time.
  75  */
  76
  77 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  78 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  79
  80 int force_personality32;
  81
  82 /*
  83  * noexec32=on|off
  84  * Control non executable heap for 32bit processes.
  85  * To control the stack too use noexec=off
  86  *
  87  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  88  * off  PROT_READ implies PROT_EXEC
  89  */
  90 static int __init nonx32_setup(char *str)
  91 {
  92         if (!strcmp(str, "on"))
  93                 force_personality32 &= ~READ_IMPLIES_EXEC;
  94         else if (!strcmp(str, "off"))
  95                 force_personality32 |= READ_IMPLIES_EXEC;
  96         return 1;
  97 }
  98 __setup("noexec32=", nonx32_setup);
  99
 100 /*
 101  * When memory was added/removed make sure all the processes MM have
 102  * suitable PGD entries in the local PGD level page.
 103  */
 104 void sync_global_pgds(unsigned long start, unsigned long end)
 105 {
 106         unsigned long address;
 107
 108         for (address = start; address <= end; address += PGDIR_SIZE) {
 109                 const pgd_t *pgd_ref = pgd_offset_k(address);
 110                 struct page *page;
 111
 112                 if (pgd_none(*pgd_ref))
 113                         continue;
 114
 115                 spin_lock(&pgd_lock);
 116                 list_for_each_entry(page, &pgd_list, lru) {
 117                         pgd_t *pgd;
 118                         spinlock_t *pgt_lock;
 119
 120                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
 121                         /* the pgt_lock only for Xen */
 122                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 123                         spin_lock(pgt_lock);
 124
 125                         if (pgd_none(*pgd))
 126                                 set_pgd(pgd, *pgd_ref);
 127                         else
 128                                 BUG_ON(pgd_page_vaddr(*pgd)
 129                                        != pgd_page_vaddr(*pgd_ref));
 130
 131                         spin_unlock(pgt_lock);
 132                 }
 133                 spin_unlock(&pgd_lock);
 134         }
 135 }
 136
 137 /*
 138  * NOTE: This function is marked __ref because it calls __init function
 139  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 140  */
 141 static __ref void *spp_getpage(void)
 142 {
 143         void *ptr;
 144
 145         if (after_bootmem)
 146                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 147         else
 148                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 149
 150         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 151                 panic("set_pte_phys: cannot allocate page data %s\n",
 152                         after_bootmem ? "after bootmem" : "");
 153         }
 154
 155         pr_debug("spp_getpage %p\n", ptr);
 156
 157         return ptr;
 158 }
 159
 160 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 161 {
 162         if (pgd_none(*pgd)) {
 163                 pud_t *pud = (pud_t *)spp_getpage();
 164                 pgd_populate(&init_mm, pgd, pud);
 165                 if (pud != pud_offset(pgd, 0))
 166                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 167                                pud, pud_offset(pgd, 0));
 168         }
 169         return pud_offset(pgd, vaddr);
 170 }
 171
 172 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 173 {
 174         if (pud_none(*pud)) {
 175                 pmd_t *pmd = (pmd_t *) spp_getpage();
 176                 pud_populate(&init_mm, pud, pmd);
 177                 if (pmd != pmd_offset(pud, 0))
 178                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 179                                pmd, pmd_offset(pud, 0));
 180         }
 181         return pmd_offset(pud, vaddr);
 182 }
 183
 184 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 185 {
 186         if (pmd_none(*pmd)) {
 187                 pte_t *pte = (pte_t *) spp_getpage();
 188                 pmd_populate_kernel(&init_mm, pmd, pte);
 189                 if (pte != pte_offset_kernel(pmd, 0))
 190                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 191         }
 192         return pte_offset_kernel(pmd, vaddr);
 193 }
 194
 195 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 196 {
 197         pud_t *pud;
 198         pmd_t *pmd;
 199         pte_t *pte;
 200
 201         pud = pud_page + pud_index(vaddr);
 202         pmd = fill_pmd(pud, vaddr);
 203         pte = fill_pte(pmd, vaddr);
 204
 205         set_pte(pte, new_pte);
 206
 207         /*
 208          * It's enough to flush this one mapping.
 209          * (PGE mappings get flushed as well)
 210          */
 211         __flush_tlb_one(vaddr);
 212 }
 213
 214 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 215 {
 216         pgd_t *pgd;
 217         pud_t *pud_page;
 218
 219         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 220
 221         pgd = pgd_offset_k(vaddr);
 222         if (pgd_none(*pgd)) {
 223                 printk(KERN_ERR
 224                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 225                 return;
 226         }
 227         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 228         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 229 }
 230
 231 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 232 {
 233         pgd_t *pgd;
 234         pud_t *pud;
 235
 236         pgd = pgd_offset_k(vaddr);
 237         pud = fill_pud(pgd, vaddr);
 238         return fill_pmd(pud, vaddr);
 239 }
 240
 241 pte_t * __init populate_extra_pte(unsigned long vaddr)
 242 {
 243         pmd_t *pmd;
 244
 245         pmd = populate_extra_pmd(vaddr);
 246         return fill_pte(pmd, vaddr);
 247 }
 248
 249 /*
 250  * Create large page table mappings for a range of physical addresses.
 251  */
 252 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 253                                                 pgprot_t prot)
 254 {
 255         pgd_t *pgd;
 256         pud_t *pud;
 257         pmd_t *pmd;
 258
 259         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 260         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 261                 pgd = pgd_offset_k((unsigned long)__va(phys));
 262                 if (pgd_none(*pgd)) {
 263                         pud = (pud_t *) spp_getpage();
 264                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 265                                                 _PAGE_USER));
 266                 }
 267                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 268                 if (pud_none(*pud)) {
 269                         pmd = (pmd_t *) spp_getpage();
 270                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 271                                                 _PAGE_USER));
 272                 }
 273                 pmd = pmd_offset(pud, phys);
 274                 BUG_ON(!pmd_none(*pmd));
 275                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 276         }
 277 }
 278
 279 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 280 {
 281         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 282 }
 283
 284 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 285 {
 286         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 287 }
 288
 289 /*
 290  * The head.S code sets up the kernel high mapping:
 291  *
 292  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 293  *
 294  * phys_addr holds the negative offset to the kernel, which is added
 295  * to the compile time generated pmds. This results in invalid pmds up
 296  * to the point where we hit the physaddr 0 mapping.
 297  *
 298  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 299  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 300  * well, as they are located before _text:
 301  */
 302 void __init cleanup_highmap(void)
 303 {
 304         unsigned long vaddr = __START_KERNEL_map;
 305         unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 306         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 307         pmd_t *pmd = level2_kernel_pgt;
 308
 309         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 310                 if (pmd_none(*pmd))
 311                         continue;
 312                 if (vaddr < (unsigned long) _text || vaddr > end)
 313                         set_pmd(pmd, __pmd(0));
 314         }
 315 }
 316
 317 static __ref void *alloc_low_page(unsigned long *phys)
 318 {
 319         unsigned long pfn = pgt_buf_end++;
 320         void *adr;
 321
 322         if (after_bootmem) {
 323                 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 324                 *phys = __pa(adr);
 325
 326                 return adr;
 327         }
 328
 329         if (pfn >= pgt_buf_top)
 330                 panic("alloc_low_page: ran out of memory");
 331
 332         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 333         clear_page(adr);
 334         *phys  = pfn * PAGE_SIZE;
 335         return adr;
 336 }
 337
 338 static __ref void *map_low_page(void *virt)
 339 {
 340         void *adr;
 341         unsigned long phys, left;
 342
 343         if (after_bootmem)
 344                 return virt;
 345
 346         phys = __pa(virt);
 347         left = phys & (PAGE_SIZE - 1);
 348         adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);
 349         adr = (void *)(((unsigned long)adr) | left);
 350
 351         return adr;
 352 }
 353
 354 static __ref void unmap_low_page(void *adr)
 355 {
 356         if (after_bootmem)
 357                 return;
 358
 359         early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
 360 }
 361
 362 static unsigned long __meminit
 363 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 364               pgprot_t prot)
 365 {
 366         unsigned pages = 0;
 367         unsigned long last_map_addr = end;
 368         int i;
 369
 370         pte_t *pte = pte_page + pte_index(addr);
 371
 372         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 373
 374                 if (addr >= end) {
 375                         if (!after_bootmem) {
 376                                 for(; i < PTRS_PER_PTE; i++, pte++)
 377                                         set_pte(pte, __pte(0));
 378                         }
 379                         break;
 380                 }
 381
 382                 /*
 383                  * We will re-use the existing mapping.
 384                  * Xen for example has some special requirements, like mapping
 385                  * pagetable pages as RO. So assume someone who pre-setup
 386                  * these mappings are more intelligent.
 387                  */
 388                 if (pte_val(*pte)) {
 389                         if (!after_bootmem)
 390                                 pages++;
 391                         continue;
 392                 }
 393
 394                 if (0)
 395                         printk("   pte=%p addr=%lx pte=%016lx\n",
 396                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 397                 pages++;
 398                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 399                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 400         }
 401
 402         update_page_count(PG_LEVEL_4K, pages);
 403
 404         return last_map_addr;
 405 }
 406
 407 static unsigned long __meminit
 408 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 409               unsigned long page_size_mask, pgprot_t prot)
 410 {
 411         unsigned long pages = 0, next;
 412         unsigned long last_map_addr = end;
 413
 414         int i = pmd_index(address);
 415
 416         for (; i < PTRS_PER_PMD; i++, address = next) {
 417                 unsigned long pte_phys;
 418                 pmd_t *pmd = pmd_page + pmd_index(address);
 419                 pte_t *pte;
 420                 pgprot_t new_prot = prot;
 421
 422                 if (address >= end) {
 423                         if (!after_bootmem) {
 424                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 425                                         set_pmd(pmd, __pmd(0));
 426                         }
 427                         break;
 428                 }
 429
 430                 next = (address & PMD_MASK) + PMD_SIZE;
 431
 432                 if (pmd_val(*pmd)) {
 433                         if (!pmd_large(*pmd)) {
 434                                 spin_lock(&init_mm.page_table_lock);
 435                                 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
 436                                 last_map_addr = phys_pte_init(pte, address,
 437                                                                 end, prot);
 438                                 unmap_low_page(pte);
 439                                 spin_unlock(&init_mm.page_table_lock);
 440                                 continue;
 441                         }
 442                         /*
 443                          * If we are ok with PG_LEVEL_2M mapping, then we will
 444                          * use the existing mapping,
 445                          *
 446                          * Otherwise, we will split the large page mapping but
 447                          * use the same existing protection bits except for
 448                          * large page, so that we don't violate Intel's TLB
 449                          * Application note (317080) which says, while changing
 450                          * the page sizes, new and old translations should
 451                          * not differ with respect to page frame and
 452                          * attributes.
 453                          */
 454                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 455                                 if (!after_bootmem)
 456                                         pages++;
 457                                 last_map_addr = next;
 458                                 continue;
 459                         }
 460                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 461                 }
 462
 463                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 464                         pages++;
 465                         spin_lock(&init_mm.page_table_lock);
 466                         set_pte((pte_t *)pmd,
 467                                 pfn_pte(address >> PAGE_SHIFT,
 468                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 469                         spin_unlock(&init_mm.page_table_lock);
 470                         last_map_addr = next;
 471                         continue;
 472                 }
 473
 474                 pte = alloc_low_page(&pte_phys);
 475                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 476                 unmap_low_page(pte);
 477
 478                 spin_lock(&init_mm.page_table_lock);
 479                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 480                 spin_unlock(&init_mm.page_table_lock);
 481         }
 482         update_page_count(PG_LEVEL_2M, pages);
 483         return last_map_addr;
 484 }
 485
 486 static unsigned long __meminit
 487 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 488                          unsigned long page_size_mask)
 489 {
 490         unsigned long pages = 0, next;
 491         unsigned long last_map_addr = end;
 492         int i = pud_index(addr);
 493
 494         for (; i < PTRS_PER_PUD; i++, addr = next) {
 495                 unsigned long pmd_phys;
 496                 pud_t *pud = pud_page + pud_index(addr);
 497                 pmd_t *pmd;
 498                 pgprot_t prot = PAGE_KERNEL;
 499
 500                 if (addr >= end)
 501                         break;
 502
 503                 next = (addr & PUD_MASK) + PUD_SIZE;
 504
 505                 if (!after_bootmem && !e820_any_mapped(addr, next, 0)) {
 506                         set_pud(pud, __pud(0));
 507                         continue;
 508                 }
 509
 510                 if (pud_val(*pud)) {
 511                         if (!pud_large(*pud)) {
 512                                 pmd = map_low_page(pmd_offset(pud, 0));
 513                                 last_map_addr = phys_pmd_init(pmd, addr, end,
 514                                                          page_size_mask, prot);
 515                                 unmap_low_page(pmd);
 516                                 __flush_tlb_all();
 517                                 continue;
 518                         }
 519                         /*
 520                          * If we are ok with PG_LEVEL_1G mapping, then we will
 521                          * use the existing mapping.
 522                          *
 523                          * Otherwise, we will split the gbpage mapping but use
 524                          * the same existing protection  bits except for large
 525                          * page, so that we don't violate Intel's TLB
 526                          * Application note (317080) which says, while changing
 527                          * the page sizes, new and old translations should
 528                          * not differ with respect to page frame and
 529                          * attributes.
 530                          */
 531                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 532                                 if (!after_bootmem)
 533                                         pages++;
 534                                 last_map_addr = next;
 535                                 continue;
 536                         }
 537                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 538                 }
 539
 540                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 541                         pages++;
 542                         spin_lock(&init_mm.page_table_lock);
 543                         set_pte((pte_t *)pud,
 544                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 545                         spin_unlock(&init_mm.page_table_lock);
 546                         last_map_addr = next;
 547                         continue;
 548                 }
 549
 550                 pmd = alloc_low_page(&pmd_phys);
 551                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 552                                               prot);
 553                 unmap_low_page(pmd);
 554
 555                 spin_lock(&init_mm.page_table_lock);
 556                 pud_populate(&init_mm, pud, __va(pmd_phys));
 557                 spin_unlock(&init_mm.page_table_lock);
 558         }
 559         __flush_tlb_all();
 560
 561         update_page_count(PG_LEVEL_1G, pages);
 562
 563         return last_map_addr;
 564 }
 565
 566 unsigned long __meminit
 567 kernel_physical_mapping_init(unsigned long start,
 568                              unsigned long end,
 569                              unsigned long page_size_mask)
 570 {
 571         bool pgd_changed = false;
 572         unsigned long next, last_map_addr = end;
 573         unsigned long addr;
 574
 575         start = (unsigned long)__va(start);
 576         end = (unsigned long)__va(end);
 577         addr = start;
 578
 579         for (; start < end; start = next) {
 580                 pgd_t *pgd = pgd_offset_k(start);
 581                 unsigned long pud_phys;
 582                 pud_t *pud;
 583
 584                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 585                 if (next > end)
 586                         next = end;
 587
 588                 if (pgd_val(*pgd)) {
 589                         pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
 590                         last_map_addr = phys_pud_init(pud, __pa(start),
 591                                                  __pa(end), page_size_mask);
 592                         unmap_low_page(pud);
 593                         continue;
 594                 }
 595
 596                 pud = alloc_low_page(&pud_phys);
 597                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 598                                                  page_size_mask);
 599                 unmap_low_page(pud);
 600
 601                 spin_lock(&init_mm.page_table_lock);
 602                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 603                 spin_unlock(&init_mm.page_table_lock);
 604                 pgd_changed = true;
 605         }
 606
 607         if (pgd_changed)
 608                 sync_global_pgds(addr, end - 1);
 609
 610         __flush_tlb_all();
 611
 612         return last_map_addr;
 613 }
 614
 615 #ifndef CONFIG_NUMA
 616 void __init initmem_init(void)
 617 {
 618         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
 619 }
 620 #endif
 621
 622 void __init paging_init(void)
 623 {
 624         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 625         sparse_init();
 626
 627         /*
 628          * clear the default setting with node 0
 629          * note: don't use nodes_clear here, that is really clearing when
 630          *       numa support is not compiled in, and later node_set_state
 631          *       will not set it back.
 632          */
 633         node_clear_state(0, N_MEMORY);
 634         if (N_MEMORY != N_NORMAL_MEMORY)
 635                 node_clear_state(0, N_NORMAL_MEMORY);
 636
 637         zone_sizes_init();
 638 }
 639
 640 /*
 641  * Memory hotplug specific functions
 642  */
 643 #ifdef CONFIG_MEMORY_HOTPLUG
 644 /*
 645  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 646  * updating.
 647  */
 648 static void  update_end_of_memory_vars(u64 start, u64 size)
 649 {
 650         unsigned long end_pfn = PFN_UP(start + size);
 651
 652         if (end_pfn > max_pfn) {
 653                 max_pfn = end_pfn;
 654                 max_low_pfn = end_pfn;
 655                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 656         }
 657 }
 658
 659 /*
 660  * Memory is added always to NORMAL zone. This means you will never get
 661  * additional DMA/DMA32 memory.
 662  */
 663 int arch_add_memory(int nid, u64 start, u64 size)
 664 {
 665         struct pglist_data *pgdat = NODE_DATA(nid);
 666         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 667         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 668         unsigned long nr_pages = size >> PAGE_SHIFT;
 669         int ret;
 670
 671         last_mapped_pfn = init_memory_mapping(start, start + size);
 672         if (last_mapped_pfn > max_pfn_mapped)
 673                 max_pfn_mapped = last_mapped_pfn;
 674
 675         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 676         WARN_ON_ONCE(ret);
 677
 678         /* update max_pfn, max_low_pfn and high_memory */
 679         update_end_of_memory_vars(start, size);
 680
 681         return ret;
 682 }
 683 EXPORT_SYMBOL_GPL(arch_add_memory);
 684
 685 #endif /* CONFIG_MEMORY_HOTPLUG */
 686
 687 static struct kcore_list kcore_vsyscall;
 688
 689 void __init mem_init(void)
 690 {
 691         long codesize, reservedpages, datasize, initsize;
 692         unsigned long absent_pages;
 693
 694         pci_iommu_alloc();
 695
 696         /* clear_bss() already clear the empty_zero_page */
 697
 698         reservedpages = 0;
 699
 700         /* this will put all low memory onto the freelists */
 701 #ifdef CONFIG_NUMA
 702         totalram_pages = numa_free_all_bootmem();
 703 #else
 704         totalram_pages = free_all_bootmem();
 705 #endif
 706
 707         absent_pages = absent_pages_in_range(0, max_pfn);
 708         reservedpages = max_pfn - totalram_pages - absent_pages;
 709         after_bootmem = 1;
 710
 711         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 712         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 713         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 714
 715         /* Register memory areas for /proc/kcore */
 716         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 717                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 718
 719         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 720                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 721                 nr_free_pages() << (PAGE_SHIFT-10),
 722                 max_pfn << (PAGE_SHIFT-10),
 723                 codesize >> 10,
 724                 absent_pages << (PAGE_SHIFT-10),
 725                 reservedpages << (PAGE_SHIFT-10),
 726                 datasize >> 10,
 727                 initsize >> 10);
 728 }
 729
 730 #ifdef CONFIG_DEBUG_RODATA
 731 const int rodata_test_data = 0xC3;
 732 EXPORT_SYMBOL_GPL(rodata_test_data);
 733
 734 int kernel_set_to_readonly;
 735
 736 void set_kernel_text_rw(void)
 737 {
 738         unsigned long start = PFN_ALIGN(_text);
 739         unsigned long end = PFN_ALIGN(__stop___ex_table);
 740
 741         if (!kernel_set_to_readonly)
 742                 return;
 743
 744         pr_debug("Set kernel text: %lx - %lx for read write\n",
 745                  start, end);
 746
 747         /*
 748          * Make the kernel identity mapping for text RW. Kernel text
 749          * mapping will always be RO. Refer to the comment in
 750          * static_protections() in pageattr.c
 751          */
 752         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
 753 }
 754
 755 void set_kernel_text_ro(void)
 756 {
 757         unsigned long start = PFN_ALIGN(_text);
 758         unsigned long end = PFN_ALIGN(__stop___ex_table);
 759
 760         if (!kernel_set_to_readonly)
 761                 return;
 762
 763         pr_debug("Set kernel text: %lx - %lx for read only\n",
 764                  start, end);
 765
 766         /*
 767          * Set the kernel identity mapping for text RO.
 768          */
 769         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 770 }
 771
 772 void mark_rodata_ro(void)
 773 {
 774         unsigned long start = PFN_ALIGN(_text);
 775         unsigned long rodata_start =
 776                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 777         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
 778         unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
 779         unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
 780         unsigned long data_start = (unsigned long) &_sdata;
 781
 782         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 783                (end - start) >> 10);
 784         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 785
 786         kernel_set_to_readonly = 1;
 787
 788         /*
 789          * The rodata section (but not the kernel text!) should also be
 790          * not-executable.
 791          */
 792         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 793
 794         rodata_test();
 795
 796 #ifdef CONFIG_CPA_DEBUG
 797         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 798         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 799
 800         printk(KERN_INFO "Testing CPA: again\n");
 801         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 802 #endif
 803
 804         free_init_pages("unused kernel memory",
 805                         (unsigned long) page_address(virt_to_page(text_end)),
 806                         (unsigned long)
 807                                  page_address(virt_to_page(rodata_start)));
 808         free_init_pages("unused kernel memory",
 809                         (unsigned long) page_address(virt_to_page(rodata_end)),
 810                         (unsigned long) page_address(virt_to_page(data_start)));
 811 }
 812
 813 #endif
 814
 815 int kern_addr_valid(unsigned long addr)
 816 {
 817         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 818         pgd_t *pgd;
 819         pud_t *pud;
 820         pmd_t *pmd;
 821         pte_t *pte;
 822
 823         if (above != 0 && above != -1UL)
 824                 return 0;
 825
 826         pgd = pgd_offset_k(addr);
 827         if (pgd_none(*pgd))
 828                 return 0;
 829
 830         pud = pud_offset(pgd, addr);
 831         if (pud_none(*pud))
 832                 return 0;
 833
 834         if (pud_large(*pud))
 835                 return pfn_valid(pud_pfn(*pud));
 836
 837         pmd = pmd_offset(pud, addr);
 838         if (pmd_none(*pmd))
 839                 return 0;
 840
 841         if (pmd_large(*pmd))
 842                 return pfn_valid(pmd_pfn(*pmd));
 843
 844         pte = pte_offset_kernel(pmd, addr);
 845         if (pte_none(*pte))
 846                 return 0;
 847
 848         return pfn_valid(pte_pfn(*pte));
 849 }
 850
 851 /*
 852  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 853  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 854  * not need special handling anymore:
 855  */
 856 static struct vm_area_struct gate_vma = {
 857         .vm_start       = VSYSCALL_START,
 858         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 859         .vm_page_prot   = PAGE_READONLY_EXEC,
 860         .vm_flags       = VM_READ | VM_EXEC
 861 };
 862
 863 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 864 {
 865 #ifdef CONFIG_IA32_EMULATION
 866         if (!mm || mm->context.ia32_compat)
 867                 return NULL;
 868 #endif
 869         return &gate_vma;
 870 }
 871
 872 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 873 {
 874         struct vm_area_struct *vma = get_gate_vma(mm);
 875
 876         if (!vma)
 877                 return 0;
 878
 879         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 880 }
 881
 882 /*
 883  * Use this when you have no reliable mm, typically from interrupt
 884  * context. It is less reliable than using a task's mm and may give
 885  * false positives.
 886  */
 887 int in_gate_area_no_mm(unsigned long addr)
 888 {
 889         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 890 }
 891
 892 const char *arch_vma_name(struct vm_area_struct *vma)
 893 {
 894         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 895                 return "[vdso]";
 896         if (vma == &gate_vma)
 897                 return "[vsyscall]";
 898         return NULL;
 899 }
 900
 901 #ifdef CONFIG_X86_UV
 902 unsigned long memory_block_size_bytes(void)
 903 {
 904         if (is_uv_system()) {
 905                 printk(KERN_INFO "UV: memory block size 2GB\n");
 906                 return 2UL * 1024 * 1024 * 1024;
 907         }
 908         return MIN_MEMORY_BLOCK_SIZE;
 909 }
 910 #endif
 911
 912 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 913 /*
 914  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 915  */
 916 static long __meminitdata addr_start, addr_end;
 917 static void __meminitdata *p_start, *p_end;
 918 static int __meminitdata node_start;
 919
 920 int __meminit
 921 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 922 {
 923         unsigned long addr = (unsigned long)start_page;
 924         unsigned long end = (unsigned long)(start_page + size);
 925         unsigned long next;
 926         pgd_t *pgd;
 927         pud_t *pud;
 928         pmd_t *pmd;
 929
 930         for (; addr < end; addr = next) {
 931                 void *p = NULL;
 932
 933                 pgd = vmemmap_pgd_populate(addr, node);
 934                 if (!pgd)
 935                         return -ENOMEM;
 936
 937                 pud = vmemmap_pud_populate(pgd, addr, node);
 938                 if (!pud)
 939                         return -ENOMEM;
 940
 941                 if (!cpu_has_pse) {
 942                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 943                         pmd = vmemmap_pmd_populate(pud, addr, node);
 944
 945                         if (!pmd)
 946                                 return -ENOMEM;
 947
 948                         p = vmemmap_pte_populate(pmd, addr, node);
 949
 950                         if (!p)
 951                                 return -ENOMEM;
 952
 953                         addr_end = addr + PAGE_SIZE;
 954                         p_end = p + PAGE_SIZE;
 955                 } else {
 956                         next = pmd_addr_end(addr, end);
 957
 958                         pmd = pmd_offset(pud, addr);
 959                         if (pmd_none(*pmd)) {
 960                                 pte_t entry;
 961
 962                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 963                                 if (!p)
 964                                         return -ENOMEM;
 965
 966                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 967                                                 PAGE_KERNEL_LARGE);
 968                                 set_pmd(pmd, __pmd(pte_val(entry)));
 969
 970                                 /* check to see if we have contiguous blocks */
 971                                 if (p_end != p || node_start != node) {
 972                                         if (p_start)
 973                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 974                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 975                                         addr_start = addr;
 976                                         node_start = node;
 977                                         p_start = p;
 978                                 }
 979
 980                                 addr_end = addr + PMD_SIZE;
 981                                 p_end = p + PMD_SIZE;
 982                         } else
 983                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
 984                 }
 985
 986         }
 987         sync_global_pgds((unsigned long)start_page, end - 1);
 988         return 0;
 989 }
 990
 991 void __meminit vmemmap_populate_print_last(void)
 992 {
 993         if (p_start) {
 994                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 995                         addr_start, addr_end-1, p_start, p_end-1, node_start);
 996                 p_start = NULL;
 997                 p_end = NULL;
 998                 node_start = 0;
 999         }
1000 }
1001 #endif