arch/x86/mm/init_64.c

   1 /*
   2  *  linux/arch/x86_64/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
   6  *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
   7  */
   8
   9 #include <linux/signal.h>
  10 #include <linux/sched.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 #include <linux/smp.h>
  20 #include <linux/init.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/bootmem.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/pci.h>
  25 #include <linux/pfn.h>
  26 #include <linux/poison.h>
  27 #include <linux/dma-mapping.h>
  28 #include <linux/module.h>
  29 #include <linux/memory_hotplug.h>
  30 #include <linux/nmi.h>
  31
  32 #include <asm/processor.h>
  33 #include <asm/system.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/pgalloc.h>
  37 #include <asm/dma.h>
  38 #include <asm/fixmap.h>
  39 #include <asm/e820.h>
  40 #include <asm/apic.h>
  41 #include <asm/tlb.h>
  42 #include <asm/mmu_context.h>
  43 #include <asm/proto.h>
  44 #include <asm/smp.h>
  45 #include <asm/sections.h>
  46 #include <asm/kdebug.h>
  47 #include <asm/numa.h>
  48
  49 #ifndef Dprintk
  50 #define Dprintk(x...)
  51 #endif
  52
  53 const struct dma_mapping_ops* dma_ops;
  54 EXPORT_SYMBOL(dma_ops);
  55
  56 static unsigned long dma_reserve __initdata;
  57
  58 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  59
  60 /*
  61  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  62  * physical space so we can cache the place of the first one and move
  63  * around without checking the pgd every time.
  64  */
  65
  66 void show_mem(void)
  67 {
  68         long i, total = 0, reserved = 0;
  69         long shared = 0, cached = 0;
  70         pg_data_t *pgdat;
  71         struct page *page;
  72
  73         printk(KERN_INFO "Mem-info:\n");
  74         show_free_areas();
  75         printk(KERN_INFO "Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  76
  77         for_each_online_pgdat(pgdat) {
  78                for (i = 0; i < pgdat->node_spanned_pages; ++i) {
  79                         /* this loop can take a while with 256 GB and 4k pages
  80                            so update the NMI watchdog */
  81                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) {
  82                                 touch_nmi_watchdog();
  83                         }
  84                         if (!pfn_valid(pgdat->node_start_pfn + i))
  85                                 continue;
  86                         page = pfn_to_page(pgdat->node_start_pfn + i);
  87                         total++;
  88                         if (PageReserved(page))
  89                                 reserved++;
  90                         else if (PageSwapCache(page))
  91                                 cached++;
  92                         else if (page_count(page))
  93                                 shared += page_count(page) - 1;
  94                }
  95         }
  96         printk(KERN_INFO "%lu pages of RAM\n", total);
  97         printk(KERN_INFO "%lu reserved pages\n",reserved);
  98         printk(KERN_INFO "%lu pages shared\n",shared);
  99         printk(KERN_INFO "%lu pages swap cached\n",cached);
 100 }
 101
 102 int after_bootmem;
 103
 104 static __init void *spp_getpage(void)
 105 {
 106         void *ptr;
 107         if (after_bootmem)
 108                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 109         else
 110                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 111         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK))
 112                 panic("set_pte_phys: cannot allocate page data %s\n", after_bootmem?"after bootmem":"");
 113
 114         Dprintk("spp_getpage %p\n", ptr);
 115         return ptr;
 116 }
 117
 118 static __init void set_pte_phys(unsigned long vaddr,
 119                          unsigned long phys, pgprot_t prot)
 120 {
 121         pgd_t *pgd;
 122         pud_t *pud;
 123         pmd_t *pmd;
 124         pte_t *pte, new_pte;
 125
 126         Dprintk("set_pte_phys %lx to %lx\n", vaddr, phys);
 127
 128         pgd = pgd_offset_k(vaddr);
 129         if (pgd_none(*pgd)) {
 130                 printk("PGD FIXMAP MISSING, it should be setup in head.S!\n");
 131                 return;
 132         }
 133         pud = pud_offset(pgd, vaddr);
 134         if (pud_none(*pud)) {
 135                 pmd = (pmd_t *) spp_getpage();
 136                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
 137                 if (pmd != pmd_offset(pud, 0)) {
 138                         printk("PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud,0));
 139                         return;
 140                 }
 141         }
 142         pmd = pmd_offset(pud, vaddr);
 143         if (pmd_none(*pmd)) {
 144                 pte = (pte_t *) spp_getpage();
 145                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
 146                 if (pte != pte_offset_kernel(pmd, 0)) {
 147                         printk("PAGETABLE BUG #02!\n");
 148                         return;
 149                 }
 150         }
 151         new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
 152
 153         pte = pte_offset_kernel(pmd, vaddr);
 154         if (!pte_none(*pte) &&
 155             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
 156                 pte_ERROR(*pte);
 157         set_pte(pte, new_pte);
 158
 159         /*
 160          * It's enough to flush this one mapping.
 161          * (PGE mappings get flushed as well)
 162          */
 163         __flush_tlb_one(vaddr);
 164 }
 165
 166 /* NOTE: this is meant to be run only at boot */
 167 void __init
 168 __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 169 {
 170         unsigned long address = __fix_to_virt(idx);
 171
 172         if (idx >= __end_of_fixed_addresses) {
 173                 printk("Invalid __set_fixmap\n");
 174                 return;
 175         }
 176         set_pte_phys(address, phys, prot);
 177 }
 178
 179 static unsigned long __initdata table_start;
 180 static unsigned long __meminitdata table_end;
 181
 182 static __meminit void *alloc_low_page(unsigned long *phys)
 183 {
 184         unsigned long pfn = table_end++;
 185         void *adr;
 186
 187         if (after_bootmem) {
 188                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
 189                 *phys = __pa(adr);
 190                 return adr;
 191         }
 192
 193         if (pfn >= end_pfn)
 194                 panic("alloc_low_page: ran out of memory");
 195
 196         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
 197         memset(adr, 0, PAGE_SIZE);
 198         *phys  = pfn * PAGE_SIZE;
 199         return adr;
 200 }
 201
 202 static __meminit void unmap_low_page(void *adr)
 203 {
 204
 205         if (after_bootmem)
 206                 return;
 207
 208         early_iounmap(adr, PAGE_SIZE);
 209 }
 210
 211 /* Must run before zap_low_mappings */
 212 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
 213 {
 214         unsigned long vaddr;
 215         pmd_t *pmd, *last_pmd;
 216         int i, pmds;
 217
 218         pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
 219         vaddr = __START_KERNEL_map;
 220         pmd = level2_kernel_pgt;
 221         last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
 222         for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
 223                 for (i = 0; i < pmds; i++) {
 224                         if (pmd_present(pmd[i]))
 225                                 goto next;
 226                 }
 227                 vaddr += addr & ~PMD_MASK;
 228                 addr &= PMD_MASK;
 229                 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
 230                         set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
 231                 __flush_tlb_all();
 232                 return (void *)vaddr;
 233         next:
 234                 ;
 235         }
 236         printk("early_ioremap(0x%lx, %lu) failed\n", addr, size);
 237         return NULL;
 238 }
 239
 240 /* To avoid virtual aliases later */
 241 __meminit void early_iounmap(void *addr, unsigned long size)
 242 {
 243         unsigned long vaddr;
 244         pmd_t *pmd;
 245         int i, pmds;
 246
 247         vaddr = (unsigned long)addr;
 248         pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
 249         pmd = level2_kernel_pgt + pmd_index(vaddr);
 250         for (i = 0; i < pmds; i++)
 251                 pmd_clear(pmd + i);
 252         __flush_tlb_all();
 253 }
 254
 255 static void __meminit
 256 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
 257 {
 258         int i = pmd_index(address);
 259
 260         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 261                 unsigned long entry;
 262                 pmd_t *pmd = pmd_page + pmd_index(address);
 263
 264                 if (address >= end) {
 265                         if (!after_bootmem)
 266                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 267                                         set_pmd(pmd, __pmd(0));
 268                         break;
 269                 }
 270
 271                 if (pmd_val(*pmd))
 272                         continue;
 273
 274                 entry = __PAGE_KERNEL_LARGE|_PAGE_GLOBAL|address;
 275                 entry &= __supported_pte_mask;
 276                 set_pmd(pmd, __pmd(entry));
 277         }
 278 }
 279
 280 static void __meminit
 281 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
 282 {
 283         pmd_t *pmd = pmd_offset(pud,0);
 284         spin_lock(&init_mm.page_table_lock);
 285         phys_pmd_init(pmd, address, end);
 286         spin_unlock(&init_mm.page_table_lock);
 287         __flush_tlb_all();
 288 }
 289
 290 static void __meminit phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 291 {
 292         int i = pud_index(addr);
 293
 294
 295         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE ) {
 296                 unsigned long pmd_phys;
 297                 pud_t *pud = pud_page + pud_index(addr);
 298                 pmd_t *pmd;
 299
 300                 if (addr >= end)
 301                         break;
 302
 303                 if (!after_bootmem && !e820_any_mapped(addr,addr+PUD_SIZE,0)) {
 304                         set_pud(pud, __pud(0));
 305                         continue;
 306                 }
 307
 308                 if (pud_val(*pud)) {
 309                         phys_pmd_update(pud, addr, end);
 310                         continue;
 311                 }
 312
 313                 pmd = alloc_low_page(&pmd_phys);
 314                 spin_lock(&init_mm.page_table_lock);
 315                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
 316                 phys_pmd_init(pmd, addr, end);
 317                 spin_unlock(&init_mm.page_table_lock);
 318                 unmap_low_page(pmd);
 319         }
 320         __flush_tlb_all();
 321 }
 322
 323 static void __init find_early_table_space(unsigned long end)
 324 {
 325         unsigned long puds, pmds, tables, start;
 326
 327         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 328         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 329         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
 330                  round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
 331
 332         /* RED-PEN putting page tables only on node 0 could
 333            cause a hotspot and fill up ZONE_DMA. The page tables
 334            need roughly 0.5KB per GB. */
 335         start = 0x8000;
 336         table_start = find_e820_area(start, end, tables);
 337         if (table_start == -1UL)
 338                 panic("Cannot find space for the kernel page tables");
 339
 340         table_start >>= PAGE_SHIFT;
 341         table_end = table_start;
 342
 343         early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
 344                 end, table_start << PAGE_SHIFT,
 345                 (table_start << PAGE_SHIFT) + tables);
 346 }
 347
 348 /* Setup the direct mapping of the physical memory at PAGE_OFFSET.
 349    This runs before bootmem is initialized and gets pages directly from the
 350    physical memory. To access them they are temporarily mapped. */
 351 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
 352 {
 353         unsigned long next;
 354
 355         Dprintk("init_memory_mapping\n");
 356
 357         /*
 358          * Find space for the kernel direct mapping tables.
 359          * Later we should allocate these tables in the local node of the memory
 360          * mapped.  Unfortunately this is done currently before the nodes are
 361          * discovered.
 362          */
 363         if (!after_bootmem)
 364                 find_early_table_space(end);
 365
 366         start = (unsigned long)__va(start);
 367         end = (unsigned long)__va(end);
 368
 369         for (; start < end; start = next) {
 370                 unsigned long pud_phys;
 371                 pgd_t *pgd = pgd_offset_k(start);
 372                 pud_t *pud;
 373
 374                 if (after_bootmem)
 375                         pud = pud_offset(pgd, start & PGDIR_MASK);
 376                 else
 377                         pud = alloc_low_page(&pud_phys);
 378
 379                 next = start + PGDIR_SIZE;
 380                 if (next > end)
 381                         next = end;
 382                 phys_pud_init(pud, __pa(start), __pa(next));
 383                 if (!after_bootmem)
 384                         set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
 385                 unmap_low_page(pud);
 386         }
 387
 388         if (!after_bootmem)
 389                 mmu_cr4_features = read_cr4();
 390         __flush_tlb_all();
 391
 392         reserve_early(table_start << PAGE_SHIFT, table_end << PAGE_SHIFT);
 393 }
 394
 395 #ifndef CONFIG_NUMA
 396 void __init paging_init(void)
 397 {
 398         unsigned long max_zone_pfns[MAX_NR_ZONES];
 399         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 400         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 401         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 402         max_zone_pfns[ZONE_NORMAL] = end_pfn;
 403
 404         memory_present(0, 0, end_pfn);
 405         sparse_init();
 406         free_area_init_nodes(max_zone_pfns);
 407 }
 408 #endif
 409
 410 /* Unmap a kernel mapping if it exists. This is useful to avoid prefetches
 411    from the CPU leading to inconsistent cache lines. address and size
 412    must be aligned to 2MB boundaries.
 413    Does nothing when the mapping doesn't exist. */
 414 void __init clear_kernel_mapping(unsigned long address, unsigned long size)
 415 {
 416         unsigned long end = address + size;
 417
 418         BUG_ON(address & ~LARGE_PAGE_MASK);
 419         BUG_ON(size & ~LARGE_PAGE_MASK);
 420
 421         for (; address < end; address += LARGE_PAGE_SIZE) {
 422                 pgd_t *pgd = pgd_offset_k(address);
 423                 pud_t *pud;
 424                 pmd_t *pmd;
 425                 if (pgd_none(*pgd))
 426                         continue;
 427                 pud = pud_offset(pgd, address);
 428                 if (pud_none(*pud))
 429                         continue;
 430                 pmd = pmd_offset(pud, address);
 431                 if (!pmd || pmd_none(*pmd))
 432                         continue;
 433                 if (0 == (pmd_val(*pmd) & _PAGE_PSE)) {
 434                         /* Could handle this, but it should not happen currently. */
 435                         printk(KERN_ERR
 436                "clear_kernel_mapping: mapping has been split. will leak memory\n");
 437                         pmd_ERROR(*pmd);
 438                 }
 439                 set_pmd(pmd, __pmd(0));
 440         }
 441         __flush_tlb_all();
 442 }
 443
 444 /*
 445  * Memory hotplug specific functions
 446  */
 447 void online_page(struct page *page)
 448 {
 449         ClearPageReserved(page);
 450         init_page_count(page);
 451         __free_page(page);
 452         totalram_pages++;
 453         num_physpages++;
 454 }
 455
 456 #ifdef CONFIG_MEMORY_HOTPLUG
 457 /*
 458  * Memory is added always to NORMAL zone. This means you will never get
 459  * additional DMA/DMA32 memory.
 460  */
 461 int arch_add_memory(int nid, u64 start, u64 size)
 462 {
 463         struct pglist_data *pgdat = NODE_DATA(nid);
 464         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 465         unsigned long start_pfn = start >> PAGE_SHIFT;
 466         unsigned long nr_pages = size >> PAGE_SHIFT;
 467         int ret;
 468
 469         init_memory_mapping(start, (start + size -1));
 470
 471         ret = __add_pages(zone, start_pfn, nr_pages);
 472         if (ret)
 473                 goto error;
 474
 475         return ret;
 476 error:
 477         printk("%s: Problem encountered in __add_pages!\n", __func__);
 478         return ret;
 479 }
 480 EXPORT_SYMBOL_GPL(arch_add_memory);
 481
 482 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 483 int memory_add_physaddr_to_nid(u64 start)
 484 {
 485         return 0;
 486 }
 487 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 488 #endif
 489
 490 #endif /* CONFIG_MEMORY_HOTPLUG */
 491
 492 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules,
 493                          kcore_vsyscall;
 494
 495 void __init mem_init(void)
 496 {
 497         long codesize, reservedpages, datasize, initsize;
 498
 499         pci_iommu_alloc();
 500
 501         /* clear_bss() already clear the empty_zero_page */
 502
 503         /* temporary debugging - double check it's true: */
 504         {
 505                 int i;
 506
 507                 for (i = 0; i < 1024; i++)
 508                         WARN_ON_ONCE(empty_zero_page[i]);
 509         }
 510
 511         reservedpages = 0;
 512
 513         /* this will put all low memory onto the freelists */
 514 #ifdef CONFIG_NUMA
 515         totalram_pages = numa_free_all_bootmem();
 516 #else
 517         totalram_pages = free_all_bootmem();
 518 #endif
 519         reservedpages = end_pfn - totalram_pages -
 520                                         absent_pages_in_range(0, end_pfn);
 521
 522         after_bootmem = 1;
 523
 524         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 525         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 526         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 527
 528         /* Register memory areas for /proc/kcore */
 529         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 530         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 531                    VMALLOC_END-VMALLOC_START);
 532         kclist_add(&kcore_kernel, &_stext, _end - _stext);
 533         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
 534         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 535                                  VSYSCALL_END - VSYSCALL_START);
 536
 537         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 538                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 539                 end_pfn << (PAGE_SHIFT-10),
 540                 codesize >> 10,
 541                 reservedpages << (PAGE_SHIFT-10),
 542                 datasize >> 10,
 543                 initsize >> 10);
 544 }
 545
 546 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 547 {
 548         unsigned long addr;
 549
 550         if (begin >= end)
 551                 return;
 552
 553         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 554         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 555                 ClearPageReserved(virt_to_page(addr));
 556                 init_page_count(virt_to_page(addr));
 557                 memset((void *)(addr & ~(PAGE_SIZE-1)),
 558                         POISON_FREE_INITMEM, PAGE_SIZE);
 559                 free_page(addr);
 560                 totalram_pages++;
 561         }
 562 #ifdef CONFIG_DEBUG_RODATA
 563         /*
 564          * This will make the __init pages not present and
 565          * not executable, so that any attempt to use a
 566          * __init function from now on will fault immediately
 567          * rather than supriously later when memory gets reused.
 568          *
 569          * We only do this for DEBUG_RODATA to not break up the
 570          * 2Mb kernel mapping just for this debug feature.
 571          */
 572         if (begin >= __START_KERNEL_map) {
 573                 set_memory_rw(begin, (end - begin)/PAGE_SIZE);
 574                 set_memory_np(begin, (end - begin)/PAGE_SIZE);
 575                 set_memory_nx(begin, (end - begin)/PAGE_SIZE);
 576                 rodata_test();
 577         }
 578 #endif
 579 }
 580
 581 void free_initmem(void)
 582 {
 583         free_init_pages("unused kernel memory",
 584                         (unsigned long)(&__init_begin),
 585                         (unsigned long)(&__init_end));
 586 }
 587
 588 #ifdef CONFIG_DEBUG_RODATA
 589 const int rodata_test_data = 0xC3;
 590 EXPORT_SYMBOL_GPL(rodata_test_data);
 591
 592 void mark_rodata_ro(void)
 593 {
 594         unsigned long start = (unsigned long)_stext, end;
 595
 596 #ifdef CONFIG_HOTPLUG_CPU
 597         /* It must still be possible to apply SMP alternatives. */
 598         if (num_possible_cpus() > 1)
 599                 start = (unsigned long)_etext;
 600 #endif
 601
 602 #ifdef CONFIG_KPROBES
 603         start = (unsigned long)__start_rodata;
 604 #endif
 605
 606         end = (unsigned long)__end_rodata;
 607         start = (start + PAGE_SIZE - 1) & PAGE_MASK;
 608         end &= PAGE_MASK;
 609         if (end <= start)
 610                 return;
 611
 612         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 613
 614         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 615                (end - start) >> 10);
 616
 617 #ifdef CONFIG_CPA_DEBUG
 618         printk("Testing CPA: undo %lx-%lx\n", start, end);
 619         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 620
 621         printk("Testing CPA: again\n");
 622         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 623 #endif
 624 }
 625 #endif
 626
 627 #ifdef CONFIG_BLK_DEV_INITRD
 628 void free_initrd_mem(unsigned long start, unsigned long end)
 629 {
 630         free_init_pages("initrd memory", start, end);
 631 }
 632 #endif
 633
 634 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
 635 {
 636 #ifdef CONFIG_NUMA
 637         int nid = phys_to_nid(phys);
 638 #endif
 639         unsigned long pfn = phys >> PAGE_SHIFT;
 640         if (pfn >= end_pfn) {
 641                 /* This can happen with kdump kernels when accessing firmware
 642                    tables. */
 643                 if (pfn < end_pfn_map)
 644                         return;
 645                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
 646                                 phys, len);
 647                 return;
 648         }
 649
 650         /* Should check here against the e820 map to avoid double free */
 651 #ifdef CONFIG_NUMA
 652         reserve_bootmem_node(NODE_DATA(nid), phys, len);
 653 #else
 654         reserve_bootmem(phys, len);
 655 #endif
 656         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
 657                 dma_reserve += len / PAGE_SIZE;
 658                 set_dma_reserve(dma_reserve);
 659         }
 660 }
 661
 662 int kern_addr_valid(unsigned long addr)
 663 {
 664         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 665        pgd_t *pgd;
 666        pud_t *pud;
 667        pmd_t *pmd;
 668        pte_t *pte;
 669
 670         if (above != 0 && above != -1UL)
 671                 return 0;
 672
 673         pgd = pgd_offset_k(addr);
 674         if (pgd_none(*pgd))
 675                 return 0;
 676
 677         pud = pud_offset(pgd, addr);
 678         if (pud_none(*pud))
 679                 return 0;
 680
 681         pmd = pmd_offset(pud, addr);
 682         if (pmd_none(*pmd))
 683                 return 0;
 684         if (pmd_large(*pmd))
 685                 return pfn_valid(pmd_pfn(*pmd));
 686
 687         pte = pte_offset_kernel(pmd, addr);
 688         if (pte_none(*pte))
 689                 return 0;
 690         return pfn_valid(pte_pfn(*pte));
 691 }
 692
 693 /* A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 694    covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 695    not need special handling anymore. */
 696
 697 static struct vm_area_struct gate_vma = {
 698         .vm_start = VSYSCALL_START,
 699         .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES << PAGE_SHIFT),
 700         .vm_page_prot = PAGE_READONLY_EXEC,
 701         .vm_flags = VM_READ | VM_EXEC
 702 };
 703
 704 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 705 {
 706 #ifdef CONFIG_IA32_EMULATION
 707         if (test_tsk_thread_flag(tsk, TIF_IA32))
 708                 return NULL;
 709 #endif
 710         return &gate_vma;
 711 }
 712
 713 int in_gate_area(struct task_struct *task, unsigned long addr)
 714 {
 715         struct vm_area_struct *vma = get_gate_vma(task);
 716         if (!vma)
 717                 return 0;
 718         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 719 }
 720
 721 /* Use this when you have no reliable task/vma, typically from interrupt
 722  * context.  It is less reliable than using the task's vma and may give
 723  * false positives.
 724  */
 725 int in_gate_area_no_task(unsigned long addr)
 726 {
 727         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 728 }
 729
 730 const char *arch_vma_name(struct vm_area_struct *vma)
 731 {
 732         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 733                 return "[vdso]";
 734         if (vma == &gate_vma)
 735                 return "[vsyscall]";
 736         return NULL;
 737 }
 738
 739 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 740 /*
 741  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 742  */
 743 int __meminit vmemmap_populate(struct page *start_page,
 744                                                 unsigned long size, int node)
 745 {
 746         unsigned long addr = (unsigned long)start_page;
 747         unsigned long end = (unsigned long)(start_page + size);
 748         unsigned long next;
 749         pgd_t *pgd;
 750         pud_t *pud;
 751         pmd_t *pmd;
 752
 753         for (; addr < end; addr = next) {
 754                 next = pmd_addr_end(addr, end);
 755
 756                 pgd = vmemmap_pgd_populate(addr, node);
 757                 if (!pgd)
 758                         return -ENOMEM;
 759                 pud = vmemmap_pud_populate(pgd, addr, node);
 760                 if (!pud)
 761                         return -ENOMEM;
 762
 763                 pmd = pmd_offset(pud, addr);
 764                 if (pmd_none(*pmd)) {
 765                         pte_t entry;
 766                         void *p = vmemmap_alloc_block(PMD_SIZE, node);
 767                         if (!p)
 768                                 return -ENOMEM;
 769
 770                         entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL_LARGE);
 771                         set_pmd(pmd, __pmd(pte_val(entry)));
 772
 773                         printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
 774                                 addr, addr + PMD_SIZE - 1, p, node);
 775                 } else
 776                         vmemmap_verify((pte_t *)pmd, node, addr, next);
 777         }
 778
 779         return 0;
 780 }
 781 #endif