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/system.h>
  39 #include <asm/uaccess.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/pgalloc.h>
  42 #include <asm/dma.h>
  43 #include <asm/fixmap.h>
  44 #include <asm/e820.h>
  45 #include <asm/apic.h>
  46 #include <asm/tlb.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/proto.h>
  49 #include <asm/smp.h>
  50 #include <asm/sections.h>
  51 #include <asm/kdebug.h>
  52 #include <asm/numa.h>
  53 #include <asm/cacheflush.h>
  54 #include <asm/init.h>
  55 #include <asm/uv/uv.h>
  56 #include <asm/setup.h>
  57
  58 static int __init parse_direct_gbpages_off(char *arg)
  59 {
  60         direct_gbpages = 0;
  61         return 0;
  62 }
  63 early_param("nogbpages", parse_direct_gbpages_off);
  64
  65 static int __init parse_direct_gbpages_on(char *arg)
  66 {
  67         direct_gbpages = 1;
  68         return 0;
  69 }
  70 early_param("gbpages", parse_direct_gbpages_on);
  71
  72 /*
  73  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  74  * physical space so we can cache the place of the first one and move
  75  * around without checking the pgd every time.
  76  */
  77
  78 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
  79 EXPORT_SYMBOL_GPL(__supported_pte_mask);
  80
  81 int force_personality32;
  82
  83 /*
  84  * noexec32=on|off
  85  * Control non executable heap for 32bit processes.
  86  * To control the stack too use noexec=off
  87  *
  88  * on   PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
  89  * off  PROT_READ implies PROT_EXEC
  90  */
  91 static int __init nonx32_setup(char *str)
  92 {
  93         if (!strcmp(str, "on"))
  94                 force_personality32 &= ~READ_IMPLIES_EXEC;
  95         else if (!strcmp(str, "off"))
  96                 force_personality32 |= READ_IMPLIES_EXEC;
  97         return 1;
  98 }
  99 __setup("noexec32=", nonx32_setup);
 100
 101 /*
 102  * When memory was added/removed make sure all the processes MM have
 103  * suitable PGD entries in the local PGD level page.
 104  */
 105 void sync_global_pgds(unsigned long start, unsigned long end)
 106 {
 107         unsigned long address;
 108
 109         for (address = start; address <= end; address += PGDIR_SIZE) {
 110                 const pgd_t *pgd_ref = pgd_offset_k(address);
 111                 struct page *page;
 112
 113                 if (pgd_none(*pgd_ref))
 114                         continue;
 115
 116                 spin_lock(&pgd_lock);
 117                 list_for_each_entry(page, &pgd_list, lru) {
 118                         pgd_t *pgd;
 119                         spinlock_t *pgt_lock;
 120
 121                         pgd = (pgd_t *)page_address(page) + pgd_index(address);
 122                         /* the pgt_lock only for Xen */
 123                         pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 124                         spin_lock(pgt_lock);
 125
 126                         if (pgd_none(*pgd))
 127                                 set_pgd(pgd, *pgd_ref);
 128                         else
 129                                 BUG_ON(pgd_page_vaddr(*pgd)
 130                                        != pgd_page_vaddr(*pgd_ref));
 131
 132                         spin_unlock(pgt_lock);
 133                 }
 134                 spin_unlock(&pgd_lock);
 135         }
 136 }
 137
 138 /*
 139  * NOTE: This function is marked __ref because it calls __init function
 140  * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
 141  */
 142 static __ref void *spp_getpage(void)
 143 {
 144         void *ptr;
 145
 146         if (after_bootmem)
 147                 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 148         else
 149                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 150
 151         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 152                 panic("set_pte_phys: cannot allocate page data %s\n",
 153                         after_bootmem ? "after bootmem" : "");
 154         }
 155
 156         pr_debug("spp_getpage %p\n", ptr);
 157
 158         return ptr;
 159 }
 160
 161 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
 162 {
 163         if (pgd_none(*pgd)) {
 164                 pud_t *pud = (pud_t *)spp_getpage();
 165                 pgd_populate(&init_mm, pgd, pud);
 166                 if (pud != pud_offset(pgd, 0))
 167                         printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
 168                                pud, pud_offset(pgd, 0));
 169         }
 170         return pud_offset(pgd, vaddr);
 171 }
 172
 173 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
 174 {
 175         if (pud_none(*pud)) {
 176                 pmd_t *pmd = (pmd_t *) spp_getpage();
 177                 pud_populate(&init_mm, pud, pmd);
 178                 if (pmd != pmd_offset(pud, 0))
 179                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 180                                pmd, pmd_offset(pud, 0));
 181         }
 182         return pmd_offset(pud, vaddr);
 183 }
 184
 185 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
 186 {
 187         if (pmd_none(*pmd)) {
 188                 pte_t *pte = (pte_t *) spp_getpage();
 189                 pmd_populate_kernel(&init_mm, pmd, pte);
 190                 if (pte != pte_offset_kernel(pmd, 0))
 191                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 192         }
 193         return pte_offset_kernel(pmd, vaddr);
 194 }
 195
 196 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
 197 {
 198         pud_t *pud;
 199         pmd_t *pmd;
 200         pte_t *pte;
 201
 202         pud = pud_page + pud_index(vaddr);
 203         pmd = fill_pmd(pud, vaddr);
 204         pte = fill_pte(pmd, vaddr);
 205
 206         set_pte(pte, new_pte);
 207
 208         /*
 209          * It's enough to flush this one mapping.
 210          * (PGE mappings get flushed as well)
 211          */
 212         __flush_tlb_one(vaddr);
 213 }
 214
 215 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
 216 {
 217         pgd_t *pgd;
 218         pud_t *pud_page;
 219
 220         pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
 221
 222         pgd = pgd_offset_k(vaddr);
 223         if (pgd_none(*pgd)) {
 224                 printk(KERN_ERR
 225                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 226                 return;
 227         }
 228         pud_page = (pud_t*)pgd_page_vaddr(*pgd);
 229         set_pte_vaddr_pud(pud_page, vaddr, pteval);
 230 }
 231
 232 pmd_t * __init populate_extra_pmd(unsigned long vaddr)
 233 {
 234         pgd_t *pgd;
 235         pud_t *pud;
 236
 237         pgd = pgd_offset_k(vaddr);
 238         pud = fill_pud(pgd, vaddr);
 239         return fill_pmd(pud, vaddr);
 240 }
 241
 242 pte_t * __init populate_extra_pte(unsigned long vaddr)
 243 {
 244         pmd_t *pmd;
 245
 246         pmd = populate_extra_pmd(vaddr);
 247         return fill_pte(pmd, vaddr);
 248 }
 249
 250 /*
 251  * Create large page table mappings for a range of physical addresses.
 252  */
 253 static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
 254                                                 pgprot_t prot)
 255 {
 256         pgd_t *pgd;
 257         pud_t *pud;
 258         pmd_t *pmd;
 259
 260         BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
 261         for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
 262                 pgd = pgd_offset_k((unsigned long)__va(phys));
 263                 if (pgd_none(*pgd)) {
 264                         pud = (pud_t *) spp_getpage();
 265                         set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
 266                                                 _PAGE_USER));
 267                 }
 268                 pud = pud_offset(pgd, (unsigned long)__va(phys));
 269                 if (pud_none(*pud)) {
 270                         pmd = (pmd_t *) spp_getpage();
 271                         set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
 272                                                 _PAGE_USER));
 273                 }
 274                 pmd = pmd_offset(pud, phys);
 275                 BUG_ON(!pmd_none(*pmd));
 276                 set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
 277         }
 278 }
 279
 280 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
 281 {
 282         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE);
 283 }
 284
 285 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
 286 {
 287         __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE);
 288 }
 289
 290 /*
 291  * The head.S code sets up the kernel high mapping:
 292  *
 293  *   from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
 294  *
 295  * phys_addr holds the negative offset to the kernel, which is added
 296  * to the compile time generated pmds. This results in invalid pmds up
 297  * to the point where we hit the physaddr 0 mapping.
 298  *
 299  * We limit the mappings to the region from _text to _brk_end.  _brk_end
 300  * is rounded up to the 2MB boundary. This catches the invalid pmds as
 301  * well, as they are located before _text:
 302  */
 303 void __init cleanup_highmap(void)
 304 {
 305         unsigned long vaddr = __START_KERNEL_map;
 306         unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
 307         unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
 308         pmd_t *pmd = level2_kernel_pgt;
 309
 310         for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
 311                 if (pmd_none(*pmd))
 312                         continue;
 313                 if (vaddr < (unsigned long) _text || vaddr > end)
 314                         set_pmd(pmd, __pmd(0));
 315         }
 316 }
 317
 318 static __ref void *alloc_low_page(unsigned long *phys)
 319 {
 320         unsigned long pfn = pgt_buf_end++;
 321         void *adr;
 322
 323         if (after_bootmem) {
 324                 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
 325                 *phys = __pa(adr);
 326
 327                 return adr;
 328         }
 329
 330         if (pfn >= pgt_buf_top)
 331                 panic("alloc_low_page: ran out of memory");
 332
 333         adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
 334         clear_page(adr);
 335         *phys  = pfn * PAGE_SIZE;
 336         return adr;
 337 }
 338
 339 static __ref void *map_low_page(void *virt)
 340 {
 341         void *adr;
 342         unsigned long phys, left;
 343
 344         if (after_bootmem)
 345                 return virt;
 346
 347         phys = __pa(virt);
 348         left = phys & (PAGE_SIZE - 1);
 349         adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);
 350         adr = (void *)(((unsigned long)adr) | left);
 351
 352         return adr;
 353 }
 354
 355 static __ref void unmap_low_page(void *adr)
 356 {
 357         if (after_bootmem)
 358                 return;
 359
 360         early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
 361 }
 362
 363 static unsigned long __meminit
 364 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 365               pgprot_t prot)
 366 {
 367         unsigned pages = 0;
 368         unsigned long last_map_addr = end;
 369         int i;
 370
 371         pte_t *pte = pte_page + pte_index(addr);
 372
 373         for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
 374
 375                 if (addr >= end) {
 376                         if (!after_bootmem) {
 377                                 for(; i < PTRS_PER_PTE; i++, pte++)
 378                                         set_pte(pte, __pte(0));
 379                         }
 380                         break;
 381                 }
 382
 383                 /*
 384                  * We will re-use the existing mapping.
 385                  * Xen for example has some special requirements, like mapping
 386                  * pagetable pages as RO. So assume someone who pre-setup
 387                  * these mappings are more intelligent.
 388                  */
 389                 if (pte_val(*pte)) {
 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;
 412         unsigned long last_map_addr = end;
 413
 414         int i = pmd_index(address);
 415
 416         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 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                 if (pmd_val(*pmd)) {
 431                         if (!pmd_large(*pmd)) {
 432                                 spin_lock(&init_mm.page_table_lock);
 433                                 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
 434                                 last_map_addr = phys_pte_init(pte, address,
 435                                                                 end, prot);
 436                                 unmap_low_page(pte);
 437                                 spin_unlock(&init_mm.page_table_lock);
 438                                 continue;
 439                         }
 440                         /*
 441                          * If we are ok with PG_LEVEL_2M mapping, then we will
 442                          * use the existing mapping,
 443                          *
 444                          * Otherwise, we will split the large page mapping but
 445                          * use the same existing protection bits except for
 446                          * large page, so that we don't violate Intel's TLB
 447                          * Application note (317080) which says, while changing
 448                          * the page sizes, new and old translations should
 449                          * not differ with respect to page frame and
 450                          * attributes.
 451                          */
 452                         if (page_size_mask & (1 << PG_LEVEL_2M)) {
 453                                 pages++;
 454                                 continue;
 455                         }
 456                         new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
 457                 }
 458
 459                 if (page_size_mask & (1<<PG_LEVEL_2M)) {
 460                         pages++;
 461                         spin_lock(&init_mm.page_table_lock);
 462                         set_pte((pte_t *)pmd,
 463                                 pfn_pte(address >> PAGE_SHIFT,
 464                                         __pgprot(pgprot_val(prot) | _PAGE_PSE)));
 465                         spin_unlock(&init_mm.page_table_lock);
 466                         last_map_addr = (address & PMD_MASK) + PMD_SIZE;
 467                         continue;
 468                 }
 469
 470                 pte = alloc_low_page(&pte_phys);
 471                 last_map_addr = phys_pte_init(pte, address, end, new_prot);
 472                 unmap_low_page(pte);
 473
 474                 spin_lock(&init_mm.page_table_lock);
 475                 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
 476                 spin_unlock(&init_mm.page_table_lock);
 477         }
 478         update_page_count(PG_LEVEL_2M, pages);
 479         return last_map_addr;
 480 }
 481
 482 static unsigned long __meminit
 483 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 484                          unsigned long page_size_mask)
 485 {
 486         unsigned long pages = 0;
 487         unsigned long last_map_addr = end;
 488         int i = pud_index(addr);
 489
 490         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 491                 unsigned long pmd_phys;
 492                 pud_t *pud = pud_page + pud_index(addr);
 493                 pmd_t *pmd;
 494                 pgprot_t prot = PAGE_KERNEL;
 495
 496                 if (addr >= end)
 497                         break;
 498
 499                 if (!after_bootmem &&
 500                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 501                         set_pud(pud, __pud(0));
 502                         continue;
 503                 }
 504
 505                 if (pud_val(*pud)) {
 506                         if (!pud_large(*pud)) {
 507                                 pmd = map_low_page(pmd_offset(pud, 0));
 508                                 last_map_addr = phys_pmd_init(pmd, addr, end,
 509                                                          page_size_mask, prot);
 510                                 unmap_low_page(pmd);
 511                                 __flush_tlb_all();
 512                                 continue;
 513                         }
 514                         /*
 515                          * If we are ok with PG_LEVEL_1G mapping, then we will
 516                          * use the existing mapping.
 517                          *
 518                          * Otherwise, we will split the gbpage mapping but use
 519                          * the same existing protection  bits except for large
 520                          * page, so that we don't violate Intel's TLB
 521                          * Application note (317080) which says, while changing
 522                          * the page sizes, new and old translations should
 523                          * not differ with respect to page frame and
 524                          * attributes.
 525                          */
 526                         if (page_size_mask & (1 << PG_LEVEL_1G)) {
 527                                 pages++;
 528                                 continue;
 529                         }
 530                         prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
 531                 }
 532
 533                 if (page_size_mask & (1<<PG_LEVEL_1G)) {
 534                         pages++;
 535                         spin_lock(&init_mm.page_table_lock);
 536                         set_pte((pte_t *)pud,
 537                                 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 538                         spin_unlock(&init_mm.page_table_lock);
 539                         last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
 540                         continue;
 541                 }
 542
 543                 pmd = alloc_low_page(&pmd_phys);
 544                 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
 545                                               prot);
 546                 unmap_low_page(pmd);
 547
 548                 spin_lock(&init_mm.page_table_lock);
 549                 pud_populate(&init_mm, pud, __va(pmd_phys));
 550                 spin_unlock(&init_mm.page_table_lock);
 551         }
 552         __flush_tlb_all();
 553
 554         update_page_count(PG_LEVEL_1G, pages);
 555
 556         return last_map_addr;
 557 }
 558
 559 unsigned long __meminit
 560 kernel_physical_mapping_init(unsigned long start,
 561                              unsigned long end,
 562                              unsigned long page_size_mask)
 563 {
 564         bool pgd_changed = false;
 565         unsigned long next, last_map_addr = end;
 566         unsigned long addr;
 567
 568         start = (unsigned long)__va(start);
 569         end = (unsigned long)__va(end);
 570         addr = start;
 571
 572         for (; start < end; start = next) {
 573                 pgd_t *pgd = pgd_offset_k(start);
 574                 unsigned long pud_phys;
 575                 pud_t *pud;
 576
 577                 next = (start + PGDIR_SIZE) & PGDIR_MASK;
 578                 if (next > end)
 579                         next = end;
 580
 581                 if (pgd_val(*pgd)) {
 582                         pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
 583                         last_map_addr = phys_pud_init(pud, __pa(start),
 584                                                  __pa(end), page_size_mask);
 585                         unmap_low_page(pud);
 586                         continue;
 587                 }
 588
 589                 pud = alloc_low_page(&pud_phys);
 590                 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
 591                                                  page_size_mask);
 592                 unmap_low_page(pud);
 593
 594                 spin_lock(&init_mm.page_table_lock);
 595                 pgd_populate(&init_mm, pgd, __va(pud_phys));
 596                 spin_unlock(&init_mm.page_table_lock);
 597                 pgd_changed = true;
 598         }
 599
 600         if (pgd_changed)
 601                 sync_global_pgds(addr, end);
 602
 603         __flush_tlb_all();
 604
 605         return last_map_addr;
 606 }
 607
 608 #ifndef CONFIG_NUMA
 609 void __init initmem_init(void)
 610 {
 611         memblock_x86_register_active_regions(0, 0, max_pfn);
 612 }
 613 #endif
 614
 615 void __init paging_init(void)
 616 {
 617         unsigned long max_zone_pfns[MAX_NR_ZONES];
 618
 619         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 620 #ifdef CONFIG_ZONE_DMA
 621         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 622 #endif
 623         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 624         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 625
 626         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 627         sparse_init();
 628
 629         /*
 630          * clear the default setting with node 0
 631          * note: don't use nodes_clear here, that is really clearing when
 632          *       numa support is not compiled in, and later node_set_state
 633          *       will not set it back.
 634          */
 635         node_clear_state(0, N_NORMAL_MEMORY);
 636
 637         free_area_init_nodes(max_zone_pfns);
 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         unsigned long all_end = PFN_ALIGN(&_end);
 782
 783         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 784                (end - start) >> 10);
 785         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 786
 787         kernel_set_to_readonly = 1;
 788
 789         /*
 790          * The rodata/data/bss/brk section (but not the kernel text!)
 791          * should also be not-executable.
 792          */
 793         set_memory_nx(rodata_start, (all_end - rodata_start) >> PAGE_SHIFT);
 794
 795         rodata_test();
 796
 797 #ifdef CONFIG_CPA_DEBUG
 798         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 799         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 800
 801         printk(KERN_INFO "Testing CPA: again\n");
 802         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 803 #endif
 804
 805         free_init_pages("unused kernel memory",
 806                         (unsigned long) page_address(virt_to_page(text_end)),
 807                         (unsigned long)
 808                                  page_address(virt_to_page(rodata_start)));
 809         free_init_pages("unused kernel memory",
 810                         (unsigned long) page_address(virt_to_page(rodata_end)),
 811                         (unsigned long) page_address(virt_to_page(data_start)));
 812 }
 813
 814 #endif
 815
 816 int kern_addr_valid(unsigned long addr)
 817 {
 818         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 819         pgd_t *pgd;
 820         pud_t *pud;
 821         pmd_t *pmd;
 822         pte_t *pte;
 823
 824         if (above != 0 && above != -1UL)
 825                 return 0;
 826
 827         pgd = pgd_offset_k(addr);
 828         if (pgd_none(*pgd))
 829                 return 0;
 830
 831         pud = pud_offset(pgd, addr);
 832         if (pud_none(*pud))
 833                 return 0;
 834
 835         if (pud_large(*pud))
 836                 return pfn_valid(pud_pfn(*pud));
 837
 838         pmd = pmd_offset(pud, addr);
 839         if (pmd_none(*pmd))
 840                 return 0;
 841
 842         if (pmd_large(*pmd))
 843                 return pfn_valid(pmd_pfn(*pmd));
 844
 845         pte = pte_offset_kernel(pmd, addr);
 846         if (pte_none(*pte))
 847                 return 0;
 848
 849         return pfn_valid(pte_pfn(*pte));
 850 }
 851
 852 /*
 853  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 854  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 855  * not need special handling anymore:
 856  */
 857 static struct vm_area_struct gate_vma = {
 858         .vm_start       = VSYSCALL_START,
 859         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 860         .vm_page_prot   = PAGE_READONLY_EXEC,
 861         .vm_flags       = VM_READ | VM_EXEC
 862 };
 863
 864 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 865 {
 866 #ifdef CONFIG_IA32_EMULATION
 867         if (!mm || mm->context.ia32_compat)
 868                 return NULL;
 869 #endif
 870         return &gate_vma;
 871 }
 872
 873 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 874 {
 875         struct vm_area_struct *vma = get_gate_vma(mm);
 876
 877         if (!vma)
 878                 return 0;
 879
 880         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 881 }
 882
 883 /*
 884  * Use this when you have no reliable mm, typically from interrupt
 885  * context. It is less reliable than using a task's mm and may give
 886  * false positives.
 887  */
 888 int in_gate_area_no_mm(unsigned long addr)
 889 {
 890         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 891 }
 892
 893 const char *arch_vma_name(struct vm_area_struct *vma)
 894 {
 895         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 896                 return "[vdso]";
 897         if (vma == &gate_vma)
 898                 return "[vsyscall]";
 899         return NULL;
 900 }
 901
 902 #ifdef CONFIG_X86_UV
 903 unsigned long memory_block_size_bytes(void)
 904 {
 905         if (is_uv_system()) {
 906                 printk(KERN_INFO "UV: memory block size 2GB\n");
 907                 return 2UL * 1024 * 1024 * 1024;
 908         }
 909         return MIN_MEMORY_BLOCK_SIZE;
 910 }
 911 #endif
 912
 913 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 914 /*
 915  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 916  */
 917 static long __meminitdata addr_start, addr_end;
 918 static void __meminitdata *p_start, *p_end;
 919 static int __meminitdata node_start;
 920
 921 int __meminit
 922 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 923 {
 924         unsigned long addr = (unsigned long)start_page;
 925         unsigned long end = (unsigned long)(start_page + size);
 926         unsigned long next;
 927         pgd_t *pgd;
 928         pud_t *pud;
 929         pmd_t *pmd;
 930
 931         for (; addr < end; addr = next) {
 932                 void *p = NULL;
 933
 934                 pgd = vmemmap_pgd_populate(addr, node);
 935                 if (!pgd)
 936                         return -ENOMEM;
 937
 938                 pud = vmemmap_pud_populate(pgd, addr, node);
 939                 if (!pud)
 940                         return -ENOMEM;
 941
 942                 if (!cpu_has_pse) {
 943                         next = (addr + PAGE_SIZE) & PAGE_MASK;
 944                         pmd = vmemmap_pmd_populate(pud, addr, node);
 945
 946                         if (!pmd)
 947                                 return -ENOMEM;
 948
 949                         p = vmemmap_pte_populate(pmd, addr, node);
 950
 951                         if (!p)
 952                                 return -ENOMEM;
 953
 954                         addr_end = addr + PAGE_SIZE;
 955                         p_end = p + PAGE_SIZE;
 956                 } else {
 957                         next = pmd_addr_end(addr, end);
 958
 959                         pmd = pmd_offset(pud, addr);
 960                         if (pmd_none(*pmd)) {
 961                                 pte_t entry;
 962
 963                                 p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 964                                 if (!p)
 965                                         return -ENOMEM;
 966
 967                                 entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 968                                                 PAGE_KERNEL_LARGE);
 969                                 set_pmd(pmd, __pmd(pte_val(entry)));
 970
 971                                 /* check to see if we have contiguous blocks */
 972                                 if (p_end != p || node_start != node) {
 973                                         if (p_start)
 974                                                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 975                                                        addr_start, addr_end-1, p_start, p_end-1, node_start);
 976                                         addr_start = addr;
 977                                         node_start = node;
 978                                         p_start = p;
 979                                 }
 980
 981                                 addr_end = addr + PMD_SIZE;
 982                                 p_end = p + PMD_SIZE;
 983                         } else
 984                                 vmemmap_verify((pte_t *)pmd, node, addr, next);
 985                 }
 986
 987         }
 988         sync_global_pgds((unsigned long)start_page, end);
 989         return 0;
 990 }
 991
 992 void __meminit vmemmap_populate_print_last(void)
 993 {
 994         if (p_start) {
 995                 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
 996                         addr_start, addr_end-1, p_start, p_end-1, node_start);
 997                 p_start = NULL;
 998                 p_end = NULL;
 999                 node_start = 0;
1000         }
1001 }
1002 #endif