arch/x86/mm/init_64.c

   1 /*
   2  *  linux/arch/x86_64/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *  Copyright (C) 2000  Pavel Machek <pavel@ucw.cz>
   6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7  */
   8
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 #include <linux/smp.h>
  20 #include <linux/init.h>
  21 #include <linux/initrd.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memblock.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/pci.h>
  27 #include <linux/pfn.h>
  28 #include <linux/poison.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/module.h>
  31 #include <linux/memory_hotplug.h>
  32 #include <linux/nmi.h>
  33 #include <linux/gfp.h>
  34
  35 #include <asm/processor.h>
  36 #include <asm/bios_ebda.h>
  37 #include <asm/system.h>
  38 #include <asm/uaccess.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/dma.h>
  42 #include <asm/fixmap.h>
  43 #include <asm/e820.h>
  44 #include <asm/apic.h>
  45 #include <asm/tlb.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/proto.h>
  48 #include <asm/smp.h>
  49 #include <asm/sections.h>
  50 #include <asm/kdebug.h>
  51 #include <asm/numa.h>
  52 #include <asm/cacheflush.h>
  53 #include <asm/init.h>
  54 #include <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                         pages++;
 390                         continue;
 391                 }
 392
 393                 if (0)
 394                         printk("   pte=%p addr=%lx pte=%016lx\n",
 395                                pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
 396                 pages++;
 397                 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
 398                 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
 399         }
 400
 401         update_page_count(PG_LEVEL_4K, pages);
 402
 403         return last_map_addr;
 404 }
 405
 406 static unsigned long __meminit
 407 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 408               unsigned long page_size_mask, pgprot_t prot)
 409 {
 410         unsigned long pages = 0;
 411         unsigned long last_map_addr = end;
 412
 413         int i = pmd_index(address);
 414
 415         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 416                 unsigned long pte_phys;
 417                 pmd_t *pmd = pmd_page + pmd_index(address);
 418                 pte_t *pte;
 419                 pgprot_t new_prot = prot;
 420
 421                 if (address >= end) {
 422                         if (!after_bootmem) {
 423                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 424                                         set_pmd(pmd, __pmd(0));
 425                         }
 426                         break;
 427                 }
 428
 429                 if (pmd_val(*pmd)) {
 430                         if (!pmd_large(*pmd)) {
 431                                 spin_lock(&init_mm.page_table_lock);
 432                                 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
 433                                 last_map_addr = phys_pte_init(pte, address,
 434                                                                 end, prot);
 435                                 unmap_low_page(pte);
 436                                 spin_unlock(&init_mm.page_table_lock);
 437                                 continue;
 438                         }
 439                         /*
 440                          * If we are ok with PG_LEVEL_2M mapping, then we will
 441                          * use the existing mapping,
 442                          *
 443                          * Otherwise, we will split the large page mapping but
 444                          * use the same existing protection bits except for
 445                          * large page, so that we don't violate Intel's TLB
 446                          * Application note (317080) which says, while changing
 447                          * the page sizes, new and old translations should
 448                          * not differ with respect to page frame and
 449                          * attributes.
 450                          */
 451                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 452                                 pages++;
 453                                 continue;
 454                         }
 455                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 456                 }
 457
 458                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 459                         pages++;
 460                         spin_lock(&init_mm.page_table_lock);
 461                         set_pte((pte_t *)pmd,
 462                                 pfn_pte(address >> PAGE_SHIFT,
 463                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 464                         spin_unlock(&init_mm.page_table_lock);
 465                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 466                         continue;
 467                 }
 468
 469                 pte = alloc_low_page(&pte_phys);
 470                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 471                 unmap_low_page(pte);
 472
 473                 spin_lock(&init_mm.page_table_lock);
 474                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 475                 spin_unlock(&init_mm.page_table_lock);
 476         }
 477         update_page_count(PG_LEVEL_2M, pages);
 478         return last_map_addr;
 479 }
 480
 481 static unsigned long __meminit
 482 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 483                          unsigned long page_size_mask)
 484 {
 485         unsigned long pages = 0;
 486         unsigned long last_map_addr = end;
 487         int i = pud_index(addr);
 488
 489         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 490                 unsigned long pmd_phys;
 491                 pud_t *pud = pud_page + pud_index(addr);
 492                 pmd_t *pmd;
 493                 pgprot_t prot = PAGE_KERNEL;
 494
 495                 if (addr >= end)
 496                         break;
 497
 498                 if (!after_bootmem &&
 499                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 500                         set_pud(pud, __pud(0));
 501                         continue;
 502                 }
 503
 504                 if (pud_val(*pud)) {
 505                         if (!pud_large(*pud)) {
 506                                 pmd = map_low_page(pmd_offset(pud, 0));
 507                                 last_map_addr = phys_pmd_init(pmd, addr, end,
 508                                                          page_size_mask, prot);
 509                                 unmap_low_page(pmd);
 510                                 __flush_tlb_all();
 511                                 continue;
 512                         }
 513                         /*
 514                          * If we are ok with PG_LEVEL_1G mapping, then we will
 515                          * use the existing mapping.
 516                          *
 517                          * Otherwise, we will split the gbpage mapping but use
 518                          * the same existing protection  bits except for large
 519                          * page, so that we don't violate Intel's TLB
 520                          * Application note (317080) which says, while changing
 521                          * the page sizes, new and old translations should
 522                          * not differ with respect to page frame and
 523                          * attributes.
 524                          */
 525                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 526                                 pages++;
 527                                 continue;
 528                         }
 529                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 530                 }
 531
 532                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 533                         pages++;
 534                         spin_lock(&init_mm.page_table_lock);
 535                         set_pte((pte_t *)pud,
 536                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 537                         spin_unlock(&init_mm.page_table_lock);
 538                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 539                         continue;
 540                 }
 541
 542                 pmd = alloc_low_page(&pmd_phys);
 543                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 544                                               prot);
 545                 unmap_low_page(pmd);
 546
 547                 spin_lock(&init_mm.page_table_lock);
 548                 pud_populate(&init_mm, pud, __va(pmd_phys));
 549                 spin_unlock(&init_mm.page_table_lock);
 550         }
 551         __flush_tlb_all();
 552
 553         update_page_count(PG_LEVEL_1G, pages);
 554
 555         return last_map_addr;
 556 }
 557
 558 unsigned long __meminit
 559 kernel_physical_mapping_init(unsigned long start,
 560                              unsigned long end,
 561                              unsigned long page_size_mask)
 562 {
 563         bool pgd_changed = false;
 564         unsigned long next, last_map_addr = end;
 565         unsigned long addr;
 566
 567         start = (unsigned long)__va(start);
 568         end = (unsigned long)__va(end);
 569         addr = start;
 570
 571         for (; start < end; start = next) {
 572                 pgd_t *pgd = pgd_offset_k(start);
 573                 unsigned long pud_phys;
 574                 pud_t *pud;
 575
 576                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 577                 if (next > end)
 578                         next = end;
 579
 580                 if (pgd_val(*pgd)) {
 581                         pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
 582                         last_map_addr = phys_pud_init(pud, __pa(start),
 583                                                  __pa(end), page_size_mask);
 584                         unmap_low_page(pud);
 585                         continue;
 586                 }
 587
 588                 pud = alloc_low_page(&pud_phys);
 589                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 590                                                  page_size_mask);
 591                 unmap_low_page(pud);
 592
 593                 spin_lock(&init_mm.page_table_lock);
 594                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 595                 spin_unlock(&init_mm.page_table_lock);
 596                 pgd_changed = true;
 597         }
 598
 599         if (pgd_changed)
 600                 sync_global_pgds(addr, end);
 601
 602         __flush_tlb_all();
 603
 604         return last_map_addr;
 605 }
 606
 607 #ifndef CONFIG_NUMA
 608 void __init initmem_init(void)
 609 {
 610         memblock_x86_register_active_regions(0, 0, max_pfn);
 611 }
 612 #endif
 613
 614 void __init paging_init(void)
 615 {
 616         unsigned long max_zone_pfns[MAX_NR_ZONES];
 617
 618         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 619         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 620         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 621         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 622
 623         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 624         sparse_init();
 625
 626         /*
 627          * clear the default setting with node 0
 628          * note: don't use nodes_clear here, that is really clearing when
 629          *       numa support is not compiled in, and later node_set_state
 630          *       will not set it back.
 631          */
 632         node_clear_state(0, N_NORMAL_MEMORY);
 633
 634         free_area_init_nodes(max_zone_pfns);
 635 }
 636
 637 /*
 638  * Memory hotplug specific functions
 639  */
 640 #ifdef CONFIG_MEMORY_HOTPLUG
 641 /*
 642  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 643  * updating.
 644  */
 645 static void  update_end_of_memory_vars(u64 start, u64 size)
 646 {
 647         unsigned long end_pfn = PFN_UP(start + size);
 648
 649         if (end_pfn > max_pfn) {
 650                 max_pfn = end_pfn;
 651                 max_low_pfn = end_pfn;
 652                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 653         }
 654 }
 655
 656 /*
 657  * Memory is added always to NORMAL zone. This means you will never get
 658  * additional DMA/DMA32 memory.
 659  */
 660 int arch_add_memory(int nid, u64 start, u64 size)
 661 {
 662         struct pglist_data *pgdat = NODE_DATA(nid);
 663         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 664         unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
 665         unsigned long nr_pages = size >> PAGE_SHIFT;
 666         int ret;
 667
 668         last_mapped_pfn = init_memory_mapping(start, start + size);
 669         if (last_mapped_pfn > max_pfn_mapped)
 670                 max_pfn_mapped = last_mapped_pfn;
 671
 672         ret = __add_pages(nid, zone, start_pfn, nr_pages);
 673         WARN_ON_ONCE(ret);
 674
 675         /* update max_pfn, max_low_pfn and high_memory */
 676         update_end_of_memory_vars(start, size);
 677
 678         return ret;
 679 }
 680 EXPORT_SYMBOL_GPL(arch_add_memory);
 681
 682 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 683 int memory_add_physaddr_to_nid(u64 start)
 684 {
 685         return 0;
 686 }
 687 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 688 #endif
 689
 690 #endif /* CONFIG_MEMORY_HOTPLUG */
 691
 692 static struct kcore_list kcore_vsyscall;
 693
 694 void __init mem_init(void)
 695 {
 696         long codesize, reservedpages, datasize, initsize;
 697         unsigned long absent_pages;
 698
 699         pci_iommu_alloc();
 700
 701         /* clear_bss() already clear the empty_zero_page */
 702
 703         reservedpages = 0;
 704
 705         /* this will put all low memory onto the freelists */
 706 #ifdef CONFIG_NUMA
 707         totalram_pages = numa_free_all_bootmem();
 708 #else
 709         totalram_pages = free_all_bootmem();
 710 #endif
 711
 712         absent_pages = absent_pages_in_range(0, max_pfn);
 713         reservedpages = max_pfn - totalram_pages - absent_pages;
 714         after_bootmem = 1;
 715
 716         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 717         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 718         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 719
 720         /* Register memory areas for /proc/kcore */
 721         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 722                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 723
 724         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 725                          "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n",
 726                 nr_free_pages() << (PAGE_SHIFT-10),
 727                 max_pfn << (PAGE_SHIFT-10),
 728                 codesize >> 10,
 729                 absent_pages << (PAGE_SHIFT-10),
 730                 reservedpages << (PAGE_SHIFT-10),
 731                 datasize >> 10,
 732                 initsize >> 10);
 733 }
 734
 735 #ifdef CONFIG_DEBUG_RODATA
 736 const int rodata_test_data = 0xC3;
 737 EXPORT_SYMBOL_GPL(rodata_test_data);
 738
 739 int kernel_set_to_readonly;
 740
 741 void set_kernel_text_rw(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 write\n",
 750                  start, end);
 751
 752         /*
 753          * Make the kernel identity mapping for text RW. Kernel text
 754          * mapping will always be RO. Refer to the comment in
 755          * static_protections() in pageattr.c
 756          */
 757         set_memory_rw(start, (end - start) >> PAGE_SHIFT);
 758 }
 759
 760 void set_kernel_text_ro(void)
 761 {
 762         unsigned long start = PFN_ALIGN(_text);
 763         unsigned long end = PFN_ALIGN(__stop___ex_table);
 764
 765         if (!kernel_set_to_readonly)
 766                 return;
 767
 768         pr_debug("Set kernel text: %lx - %lx for read only\n",
 769                  start, end);
 770
 771         /*
 772          * Set the kernel identity mapping for text RO.
 773          */
 774         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 775 }
 776
 777 void mark_rodata_ro(void)
 778 {
 779         unsigned long start = PFN_ALIGN(_text);
 780         unsigned long rodata_start =
 781                 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 782         unsigned long end = (unsigned long) &__end_rodata_hpage_align;
 783         unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
 784         unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
 785         unsigned long data_start = (unsigned long) &_sdata;
 786
 787         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 788                (end - start) >> 10);
 789         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 790
 791         kernel_set_to_readonly = 1;
 792
 793         /*
 794          * The rodata section (but not the kernel text!) should also be
 795          * not-executable.
 796          */
 797         set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);
 798
 799         rodata_test();
 800
 801 #ifdef CONFIG_CPA_DEBUG
 802         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 803         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 804
 805         printk(KERN_INFO "Testing CPA: again\n");
 806         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 807 #endif
 808
 809         free_init_pages("unused kernel memory",
 810                         (unsigned long) page_address(virt_to_page(text_end)),
 811                         (unsigned long)
 812                                  page_address(virt_to_page(rodata_start)));
 813         free_init_pages("unused kernel memory",
 814                         (unsigned long) page_address(virt_to_page(rodata_end)),
 815                         (unsigned long) page_address(virt_to_page(data_start)));
 816 }
 817
 818 #endif
 819
 820 int kern_addr_valid(unsigned long addr)
 821 {
 822         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 823         pgd_t *pgd;
 824         pud_t *pud;
 825         pmd_t *pmd;
 826         pte_t *pte;
 827
 828         if (above != 0 && above != -1UL)
 829                 return 0;
 830
 831         pgd = pgd_offset_k(addr);
 832         if (pgd_none(*pgd))
 833                 return 0;
 834
 835         pud = pud_offset(pgd, addr);
 836         if (pud_none(*pud))
 837                 return 0;
 838
 839         pmd = pmd_offset(pud, addr);
 840         if (pmd_none(*pmd))
 841                 return 0;
 842
 843         if (pmd_large(*pmd))
 844                 return pfn_valid(pmd_pfn(*pmd));
 845
 846         pte = pte_offset_kernel(pmd, addr);
 847         if (pte_none(*pte))
 848                 return 0;
 849
 850         return pfn_valid(pte_pfn(*pte));
 851 }
 852
 853 /*
 854  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 855  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 856  * not need special handling anymore:
 857  */
 858 static struct vm_area_struct gate_vma = {
 859         .vm_start       = VSYSCALL_START,
 860         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 861         .vm_page_prot   = PAGE_READONLY_EXEC,
 862         .vm_flags       = VM_READ | VM_EXEC
 863 };
 864
 865 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 866 {
 867 #ifdef CONFIG_IA32_EMULATION
 868         if (!mm || mm->context.ia32_compat)
 869                 return NULL;
 870 #endif
 871         return &gate_vma;
 872 }
 873
 874 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 875 {
 876         struct vm_area_struct *vma = get_gate_vma(mm);
 877
 878         if (!vma)
 879                 return 0;
 880
 881         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 882 }
 883
 884 /*
 885  * Use this when you have no reliable mm, typically from interrupt
 886  * context. It is less reliable than using a task's mm and may give
 887  * false positives.
 888  */
 889 int in_gate_area_no_mm(unsigned long addr)
 890 {
 891         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 892 }
 893
 894 const char *arch_vma_name(struct vm_area_struct *vma)
 895 {
 896         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 897                 return "[vdso]";
 898         if (vma == &gate_vma)
 899                 return "[vsyscall]";
 900         return NULL;
 901 }
 902
 903 #ifdef CONFIG_X86_UV
 904 #define MIN_MEMORY_BLOCK_SIZE   (1 << SECTION_SIZE_BITS)
 905
 906 unsigned long memory_block_size_bytes(void)
 907 {
 908         if (is_uv_system()) {
 909                 printk(KERN_INFO "UV: memory block size 2GB\n");
 910                 return 2UL * 1024 * 1024 * 1024;
 911         }
 912         return MIN_MEMORY_BLOCK_SIZE;
 913 }
 914 #endif
 915
 916 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 917 /*
 918  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 919  */
 920 static long __meminitdata addr_start, addr_end;
 921 static void __meminitdata *p_start, *p_end;
 922 static int __meminitdata node_start;
 923
 924 int __meminit
 925 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 926 {
 927         unsigned long addr = (unsigned long)start_page;
 928         unsigned long end = (unsigned long)(start_page + size);
 929         unsigned long next;
 930         pgd_t *pgd;
 931         pud_t *pud;
 932         pmd_t *pmd;
 933
 934         for (; addr < end; addr = next) {
 935                 void *p = NULL;
 936
 937                 pgd = vmemmap_pgd_populate(addr, node);
 938                 if (!pgd)
 939                         return -ENOMEM;
 940
 941                 pud = vmemmap_pud_populate(pgd, addr, node);
 942                 if (!pud)
 943                         return -ENOMEM;
 944
 945                 if (!cpu_has_pse) {
 946                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 947                         pmd = vmemmap_pmd_populate(pud, addr, node);
 948
 949                         if (!pmd)
 950                                 return -ENOMEM;
 951
 952                         p = vmemmap_pte_populate(pmd, addr, node);
 953
 954                         if (!p)
 955                                 return -ENOMEM;
 956
 957                         addr_end = addr + PAGE_SIZE;
 958                         p_end = p + PAGE_SIZE;
 959                 } else {
 960                         next = pmd_addr_end(addr, end);
 961
 962                         pmd = pmd_offset(pud, addr);
 963                         if (pmd_none(*pmd)) {
 964                                 pte_t entry;
 965
 966                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 967                                 if (!p)
 968                                         return -ENOMEM;
 969
 970                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 971                                                 PAGE_KERNEL_LARGE);
 972                                 set_pmd(pmd, __pmd(pte_val(entry)));
 973
 974                                 /* check to see if we have contiguous blocks */
 975                                 if (p_end != p || node_start != node) {
 976                                         if (p_start)
 977                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 978                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 979                                         addr_start = addr;
 980                                         node_start = node;
 981                                         p_start = p;
 982                                 }
 983
 984                                 addr_end = addr + PMD_SIZE;
 985                                 p_end = p + PMD_SIZE;
 986                         } else
 987                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
 988                 }
 989
 990         }
 991         sync_global_pgds((unsigned long)start_page, end);
 992         return 0;
 993 }
 994
 995 void __meminit vmemmap_populate_print_last(void)
 996 {
 997         if (p_start) {
 998                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 999                         addr_start, addr_end-1, p_start, p_end-1, node_start);
1000                 p_start = NULL;
1001                 p_end = NULL;
1002                 node_start = 0;
1003         }
1004 }
1005 #endif