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 #include <asm/cacheflush.h>
  49
  50 const struct dma_mapping_ops *dma_ops;
  51 EXPORT_SYMBOL(dma_ops);
  52
  53 static unsigned long dma_reserve __initdata;
  54
  55 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  56
  57 /*
  58  * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
  59  * physical space so we can cache the place of the first one and move
  60  * around without checking the pgd every time.
  61  */
  62
  63 void show_mem(void)
  64 {
  65         long i, total = 0, reserved = 0;
  66         long shared = 0, cached = 0;
  67         struct page *page;
  68         pg_data_t *pgdat;
  69
  70         printk(KERN_INFO "Mem-info:\n");
  71         show_free_areas();
  72         printk(KERN_INFO "Free swap:       %6ldkB\n",
  73                 nr_swap_pages << (PAGE_SHIFT-10));
  74
  75         for_each_online_pgdat(pgdat) {
  76                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
  77                         /*
  78                          * This loop can take a while with 256 GB and
  79                          * 4k pages so defer the NMI watchdog:
  80                          */
  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
  87                         page = pfn_to_page(pgdat->node_start_pfn + i);
  88                         total++;
  89                         if (PageReserved(page))
  90                                 reserved++;
  91                         else if (PageSwapCache(page))
  92                                 cached++;
  93                         else if (page_count(page))
  94                                 shared += page_count(page) - 1;
  95                 }
  96         }
  97         printk(KERN_INFO "%lu pages of RAM\n",          total);
  98         printk(KERN_INFO "%lu reserved pages\n",        reserved);
  99         printk(KERN_INFO "%lu pages shared\n",          shared);
 100         printk(KERN_INFO "%lu pages swap cached\n",     cached);
 101 }
 102
 103 int after_bootmem;
 104
 105 static __init void *spp_getpage(void)
 106 {
 107         void *ptr;
 108
 109         if (after_bootmem)
 110                 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
 111         else
 112                 ptr = alloc_bootmem_pages(PAGE_SIZE);
 113
 114         if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
 115                 panic("set_pte_phys: cannot allocate page data %s\n",
 116                         after_bootmem ? "after bootmem" : "");
 117         }
 118
 119         pr_debug("spp_getpage %p\n", ptr);
 120
 121         return ptr;
 122 }
 123
 124 static __init void
 125 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
 126 {
 127         pgd_t *pgd;
 128         pud_t *pud;
 129         pmd_t *pmd;
 130         pte_t *pte, new_pte;
 131
 132         pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
 133
 134         pgd = pgd_offset_k(vaddr);
 135         if (pgd_none(*pgd)) {
 136                 printk(KERN_ERR
 137                         "PGD FIXMAP MISSING, it should be setup in head.S!\n");
 138                 return;
 139         }
 140         pud = pud_offset(pgd, vaddr);
 141         if (pud_none(*pud)) {
 142                 pmd = (pmd_t *) spp_getpage();
 143                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
 144                 if (pmd != pmd_offset(pud, 0)) {
 145                         printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
 146                                 pmd, pmd_offset(pud, 0));
 147                         return;
 148                 }
 149         }
 150         pmd = pmd_offset(pud, vaddr);
 151         if (pmd_none(*pmd)) {
 152                 pte = (pte_t *) spp_getpage();
 153                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
 154                 if (pte != pte_offset_kernel(pmd, 0)) {
 155                         printk(KERN_ERR "PAGETABLE BUG #02!\n");
 156                         return;
 157                 }
 158         }
 159         new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
 160
 161         pte = pte_offset_kernel(pmd, vaddr);
 162         if (!pte_none(*pte) &&
 163             pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
 164                 pte_ERROR(*pte);
 165         set_pte(pte, new_pte);
 166
 167         /*
 168          * It's enough to flush this one mapping.
 169          * (PGE mappings get flushed as well)
 170          */
 171         __flush_tlb_one(vaddr);
 172 }
 173
 174 /*
 175  * The head.S code sets up the kernel high mapping from:
 176  * __START_KERNEL_map to __START_KERNEL_map + KERNEL_TEXT_SIZE
 177  *
 178  * phys_addr holds the negative offset to the kernel, which is added
 179  * to the compile time generated pmds. This results in invalid pmds up
 180  * to the point where we hit the physaddr 0 mapping.
 181  *
 182  * We limit the mappings to the region from _text to _end.  _end is
 183  * rounded up to the 2MB boundary. This catches the invalid pmds as
 184  * well, as they are located before _text:
 185  */
 186 void __init cleanup_highmap(void)
 187 {
 188         unsigned long vaddr = __START_KERNEL_map;
 189         unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
 190         pmd_t *pmd = level2_kernel_pgt;
 191         pmd_t *last_pmd = pmd + PTRS_PER_PMD;
 192
 193         for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
 194                 if (!pmd_present(*pmd))
 195                         continue;
 196                 if (vaddr < (unsigned long) _text || vaddr > end)
 197                         set_pmd(pmd, __pmd(0));
 198         }
 199 }
 200
 201 /* NOTE: this is meant to be run only at boot */
 202 void __init
 203 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 204 {
 205         unsigned long address = __fix_to_virt(idx);
 206
 207         if (idx >= __end_of_fixed_addresses) {
 208                 printk(KERN_ERR "Invalid __set_fixmap\n");
 209                 return;
 210         }
 211         set_pte_phys(address, phys, prot);
 212 }
 213
 214 static unsigned long __initdata table_start;
 215 static unsigned long __meminitdata table_end;
 216
 217 static __meminit void *alloc_low_page(unsigned long *phys)
 218 {
 219         unsigned long pfn = table_end++;
 220         void *adr;
 221
 222         if (after_bootmem) {
 223                 adr = (void *)get_zeroed_page(GFP_ATOMIC);
 224                 *phys = __pa(adr);
 225
 226                 return adr;
 227         }
 228
 229         if (pfn >= end_pfn)
 230                 panic("alloc_low_page: ran out of memory");
 231
 232         adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
 233         memset(adr, 0, PAGE_SIZE);
 234         *phys  = pfn * PAGE_SIZE;
 235         return adr;
 236 }
 237
 238 static __meminit void unmap_low_page(void *adr)
 239 {
 240         if (after_bootmem)
 241                 return;
 242
 243         early_iounmap(adr, PAGE_SIZE);
 244 }
 245
 246 /* Must run before zap_low_mappings */
 247 __meminit void *early_ioremap(unsigned long addr, unsigned long size)
 248 {
 249         pmd_t *pmd, *last_pmd;
 250         unsigned long vaddr;
 251         int i, pmds;
 252
 253         pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
 254         vaddr = __START_KERNEL_map;
 255         pmd = level2_kernel_pgt;
 256         last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
 257
 258         for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
 259                 for (i = 0; i < pmds; i++) {
 260                         if (pmd_present(pmd[i]))
 261                                 goto continue_outer_loop;
 262                 }
 263                 vaddr += addr & ~PMD_MASK;
 264                 addr &= PMD_MASK;
 265
 266                 for (i = 0; i < pmds; i++, addr += PMD_SIZE)
 267                         set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
 268                 __flush_tlb_all();
 269
 270                 return (void *)vaddr;
 271 continue_outer_loop:
 272                 ;
 273         }
 274         printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
 275
 276         return NULL;
 277 }
 278
 279 /*
 280  * To avoid virtual aliases later:
 281  */
 282 __meminit void early_iounmap(void *addr, unsigned long size)
 283 {
 284         unsigned long vaddr;
 285         pmd_t *pmd;
 286         int i, pmds;
 287
 288         vaddr = (unsigned long)addr;
 289         pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
 290         pmd = level2_kernel_pgt + pmd_index(vaddr);
 291
 292         for (i = 0; i < pmds; i++)
 293                 pmd_clear(pmd + i);
 294
 295         __flush_tlb_all();
 296 }
 297
 298 static void __meminit
 299 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
 300 {
 301         int i = pmd_index(address);
 302
 303         for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
 304                 pmd_t *pmd = pmd_page + pmd_index(address);
 305
 306                 if (address >= end) {
 307                         if (!after_bootmem) {
 308                                 for (; i < PTRS_PER_PMD; i++, pmd++)
 309                                         set_pmd(pmd, __pmd(0));
 310                         }
 311                         break;
 312                 }
 313
 314                 if (pmd_val(*pmd))
 315                         continue;
 316
 317                 set_pte((pte_t *)pmd,
 318                         pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
 319         }
 320 }
 321
 322 static void __meminit
 323 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
 324 {
 325         pmd_t *pmd = pmd_offset(pud, 0);
 326         spin_lock(&init_mm.page_table_lock);
 327         phys_pmd_init(pmd, address, end);
 328         spin_unlock(&init_mm.page_table_lock);
 329         __flush_tlb_all();
 330 }
 331
 332 static void __meminit
 333 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 334 {
 335         int i = pud_index(addr);
 336
 337         for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
 338                 unsigned long pmd_phys;
 339                 pud_t *pud = pud_page + pud_index(addr);
 340                 pmd_t *pmd;
 341
 342                 if (addr >= end)
 343                         break;
 344
 345                 if (!after_bootmem &&
 346                                 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
 347                         set_pud(pud, __pud(0));
 348                         continue;
 349                 }
 350
 351                 if (pud_val(*pud)) {
 352                         phys_pmd_update(pud, addr, end);
 353                         continue;
 354                 }
 355
 356                 pmd = alloc_low_page(&pmd_phys);
 357
 358                 spin_lock(&init_mm.page_table_lock);
 359                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
 360                 phys_pmd_init(pmd, addr, end);
 361                 spin_unlock(&init_mm.page_table_lock);
 362
 363                 unmap_low_page(pmd);
 364         }
 365         __flush_tlb_all();
 366 }
 367
 368 static void __init find_early_table_space(unsigned long end)
 369 {
 370         unsigned long puds, pmds, tables, start;
 371
 372         puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
 373         pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
 374         tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
 375                  round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
 376
 377         /*
 378          * RED-PEN putting page tables only on node 0 could
 379          * cause a hotspot and fill up ZONE_DMA. The page tables
 380          * need roughly 0.5KB per GB.
 381          */
 382         start = 0x8000;
 383         table_start = find_e820_area(start, end, tables, PAGE_SIZE);
 384         if (table_start == -1UL)
 385                 panic("Cannot find space for the kernel page tables");
 386
 387         table_start >>= PAGE_SHIFT;
 388         table_end = table_start;
 389
 390         early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
 391                 end, table_start << PAGE_SHIFT,
 392                 (table_start << PAGE_SHIFT) + tables);
 393 }
 394
 395 /*
 396  * Setup the direct mapping of the physical memory at PAGE_OFFSET.
 397  * This runs before bootmem is initialized and gets pages directly from
 398  * the physical memory. To access them they are temporarily mapped.
 399  */
 400 void __init_refok init_memory_mapping(unsigned long start, unsigned long end)
 401 {
 402         unsigned long next;
 403
 404         pr_debug("init_memory_mapping\n");
 405
 406         /*
 407          * Find space for the kernel direct mapping tables.
 408          *
 409          * Later we should allocate these tables in the local node of the
 410          * memory mapped. Unfortunately this is done currently before the
 411          * nodes are discovered.
 412          */
 413         if (!after_bootmem)
 414                 find_early_table_space(end);
 415
 416         start = (unsigned long)__va(start);
 417         end = (unsigned long)__va(end);
 418
 419         for (; start < end; start = next) {
 420                 pgd_t *pgd = pgd_offset_k(start);
 421                 unsigned long pud_phys;
 422                 pud_t *pud;
 423
 424                 if (after_bootmem)
 425                         pud = pud_offset(pgd, start & PGDIR_MASK);
 426                 else
 427                         pud = alloc_low_page(&pud_phys);
 428
 429                 next = start + PGDIR_SIZE;
 430                 if (next > end)
 431                         next = end;
 432                 phys_pud_init(pud, __pa(start), __pa(next));
 433                 if (!after_bootmem)
 434                         set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
 435                 unmap_low_page(pud);
 436         }
 437
 438         if (!after_bootmem)
 439                 mmu_cr4_features = read_cr4();
 440         __flush_tlb_all();
 441
 442         if (!after_bootmem)
 443                 reserve_early(table_start << PAGE_SHIFT,
 444                                  table_end << PAGE_SHIFT, "PGTABLE");
 445 }
 446
 447 #ifndef CONFIG_NUMA
 448 void __init paging_init(void)
 449 {
 450         unsigned long max_zone_pfns[MAX_NR_ZONES];
 451
 452         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 453         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 454         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 455         max_zone_pfns[ZONE_NORMAL] = end_pfn;
 456
 457         memory_present(0, 0, end_pfn);
 458         sparse_init();
 459         free_area_init_nodes(max_zone_pfns);
 460 }
 461 #endif
 462
 463 /*
 464  * Memory hotplug specific functions
 465  */
 466 void online_page(struct page *page)
 467 {
 468         ClearPageReserved(page);
 469         init_page_count(page);
 470         __free_page(page);
 471         totalram_pages++;
 472         num_physpages++;
 473 }
 474
 475 #ifdef CONFIG_MEMORY_HOTPLUG
 476 /*
 477  * Memory is added always to NORMAL zone. This means you will never get
 478  * additional DMA/DMA32 memory.
 479  */
 480 int arch_add_memory(int nid, u64 start, u64 size)
 481 {
 482         struct pglist_data *pgdat = NODE_DATA(nid);
 483         struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
 484         unsigned long start_pfn = start >> PAGE_SHIFT;
 485         unsigned long nr_pages = size >> PAGE_SHIFT;
 486         int ret;
 487
 488         init_memory_mapping(start, start + size-1);
 489
 490         ret = __add_pages(zone, start_pfn, nr_pages);
 491         WARN_ON(1);
 492
 493         return ret;
 494 }
 495 EXPORT_SYMBOL_GPL(arch_add_memory);
 496
 497 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
 498 int memory_add_physaddr_to_nid(u64 start)
 499 {
 500         return 0;
 501 }
 502 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 503 #endif
 504
 505 #endif /* CONFIG_MEMORY_HOTPLUG */
 506
 507 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
 508                          kcore_modules, kcore_vsyscall;
 509
 510 void __init mem_init(void)
 511 {
 512         long codesize, reservedpages, datasize, initsize;
 513
 514         pci_iommu_alloc();
 515
 516         /* clear_bss() already clear the empty_zero_page */
 517
 518         /* temporary debugging - double check it's true: */
 519         {
 520                 int i;
 521
 522                 for (i = 0; i < 1024; i++)
 523                         WARN_ON_ONCE(empty_zero_page[i]);
 524         }
 525
 526         reservedpages = 0;
 527
 528         /* this will put all low memory onto the freelists */
 529 #ifdef CONFIG_NUMA
 530         totalram_pages = numa_free_all_bootmem();
 531 #else
 532         totalram_pages = free_all_bootmem();
 533 #endif
 534         reservedpages = end_pfn - totalram_pages -
 535                                         absent_pages_in_range(0, end_pfn);
 536         after_bootmem = 1;
 537
 538         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 539         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 540         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 541
 542         /* Register memory areas for /proc/kcore */
 543         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 544         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 545                    VMALLOC_END-VMALLOC_START);
 546         kclist_add(&kcore_kernel, &_stext, _end - _stext);
 547         kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
 548         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
 549                                  VSYSCALL_END - VSYSCALL_START);
 550
 551         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 552                                 "%ldk reserved, %ldk data, %ldk init)\n",
 553                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 554                 end_pfn << (PAGE_SHIFT-10),
 555                 codesize >> 10,
 556                 reservedpages << (PAGE_SHIFT-10),
 557                 datasize >> 10,
 558                 initsize >> 10);
 559
 560         cpa_init();
 561 }
 562
 563 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 564 {
 565         unsigned long addr = begin;
 566
 567         if (addr >= end)
 568                 return;
 569
 570         /*
 571          * If debugging page accesses then do not free this memory but
 572          * mark them not present - any buggy init-section access will
 573          * create a kernel page fault:
 574          */
 575 #ifdef CONFIG_DEBUG_PAGEALLOC
 576         printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
 577                 begin, PAGE_ALIGN(end));
 578         set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 579 #else
 580         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 581
 582         for (; addr < end; addr += PAGE_SIZE) {
 583                 ClearPageReserved(virt_to_page(addr));
 584                 init_page_count(virt_to_page(addr));
 585                 memset((void *)(addr & ~(PAGE_SIZE-1)),
 586                         POISON_FREE_INITMEM, PAGE_SIZE);
 587                 free_page(addr);
 588                 totalram_pages++;
 589         }
 590 #endif
 591 }
 592
 593 void free_initmem(void)
 594 {
 595         free_init_pages("unused kernel memory",
 596                         (unsigned long)(&__init_begin),
 597                         (unsigned long)(&__init_end));
 598 }
 599
 600 #ifdef CONFIG_DEBUG_RODATA
 601 const int rodata_test_data = 0xC3;
 602 EXPORT_SYMBOL_GPL(rodata_test_data);
 603
 604 void mark_rodata_ro(void)
 605 {
 606         unsigned long start = (unsigned long)_stext, end;
 607
 608 #ifdef CONFIG_HOTPLUG_CPU
 609         /* It must still be possible to apply SMP alternatives. */
 610         if (num_possible_cpus() > 1)
 611                 start = (unsigned long)_etext;
 612 #endif
 613
 614 #ifdef CONFIG_KPROBES
 615         start = (unsigned long)__start_rodata;
 616 #endif
 617
 618         end = (unsigned long)__end_rodata;
 619         start = (start + PAGE_SIZE - 1) & PAGE_MASK;
 620         end &= PAGE_MASK;
 621         if (end <= start)
 622                 return;
 623
 624
 625         printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 626                (end - start) >> 10);
 627         set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 628
 629         /*
 630          * The rodata section (but not the kernel text!) should also be
 631          * not-executable.
 632          */
 633         start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
 634         set_memory_nx(start, (end - start) >> PAGE_SHIFT);
 635
 636         rodata_test();
 637
 638 #ifdef CONFIG_CPA_DEBUG
 639         printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
 640         set_memory_rw(start, (end-start) >> PAGE_SHIFT);
 641
 642         printk(KERN_INFO "Testing CPA: again\n");
 643         set_memory_ro(start, (end-start) >> PAGE_SHIFT);
 644 #endif
 645 }
 646 #endif
 647
 648 #ifdef CONFIG_BLK_DEV_INITRD
 649 void free_initrd_mem(unsigned long start, unsigned long end)
 650 {
 651         free_init_pages("initrd memory", start, end);
 652 }
 653 #endif
 654
 655 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
 656 {
 657 #ifdef CONFIG_NUMA
 658         int nid = phys_to_nid(phys);
 659 #endif
 660         unsigned long pfn = phys >> PAGE_SHIFT;
 661
 662         if (pfn >= end_pfn) {
 663                 /*
 664                  * This can happen with kdump kernels when accessing
 665                  * firmware tables:
 666                  */
 667                 if (pfn < end_pfn_map)
 668                         return;
 669
 670                 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
 671                                 phys, len);
 672                 return;
 673         }
 674
 675         /* Should check here against the e820 map to avoid double free */
 676 #ifdef CONFIG_NUMA
 677         reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
 678 #else
 679         reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
 680 #endif
 681         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
 682                 dma_reserve += len / PAGE_SIZE;
 683                 set_dma_reserve(dma_reserve);
 684         }
 685 }
 686
 687 int kern_addr_valid(unsigned long addr)
 688 {
 689         unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
 690         pgd_t *pgd;
 691         pud_t *pud;
 692         pmd_t *pmd;
 693         pte_t *pte;
 694
 695         if (above != 0 && above != -1UL)
 696                 return 0;
 697
 698         pgd = pgd_offset_k(addr);
 699         if (pgd_none(*pgd))
 700                 return 0;
 701
 702         pud = pud_offset(pgd, addr);
 703         if (pud_none(*pud))
 704                 return 0;
 705
 706         pmd = pmd_offset(pud, addr);
 707         if (pmd_none(*pmd))
 708                 return 0;
 709
 710         if (pmd_large(*pmd))
 711                 return pfn_valid(pmd_pfn(*pmd));
 712
 713         pte = pte_offset_kernel(pmd, addr);
 714         if (pte_none(*pte))
 715                 return 0;
 716
 717         return pfn_valid(pte_pfn(*pte));
 718 }
 719
 720 /*
 721  * A pseudo VMA to allow ptrace access for the vsyscall page.  This only
 722  * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
 723  * not need special handling anymore:
 724  */
 725 static struct vm_area_struct gate_vma = {
 726         .vm_start       = VSYSCALL_START,
 727         .vm_end         = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
 728         .vm_page_prot   = PAGE_READONLY_EXEC,
 729         .vm_flags       = VM_READ | VM_EXEC
 730 };
 731
 732 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 733 {
 734 #ifdef CONFIG_IA32_EMULATION
 735         if (test_tsk_thread_flag(tsk, TIF_IA32))
 736                 return NULL;
 737 #endif
 738         return &gate_vma;
 739 }
 740
 741 int in_gate_area(struct task_struct *task, unsigned long addr)
 742 {
 743         struct vm_area_struct *vma = get_gate_vma(task);
 744
 745         if (!vma)
 746                 return 0;
 747
 748         return (addr >= vma->vm_start) && (addr < vma->vm_end);
 749 }
 750
 751 /*
 752  * Use this when you have no reliable task/vma, typically from interrupt
 753  * context. It is less reliable than using the task's vma and may give
 754  * false positives:
 755  */
 756 int in_gate_area_no_task(unsigned long addr)
 757 {
 758         return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 759 }
 760
 761 const char *arch_vma_name(struct vm_area_struct *vma)
 762 {
 763         if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
 764                 return "[vdso]";
 765         if (vma == &gate_vma)
 766                 return "[vsyscall]";
 767         return NULL;
 768 }
 769
 770 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 771 /*
 772  * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 773  */
 774 int __meminit
 775 vmemmap_populate(struct page *start_page, unsigned long size, int node)
 776 {
 777         unsigned long addr = (unsigned long)start_page;
 778         unsigned long end = (unsigned long)(start_page + size);
 779         unsigned long next;
 780         pgd_t *pgd;
 781         pud_t *pud;
 782         pmd_t *pmd;
 783
 784         for (; addr < end; addr = next) {
 785                 next = pmd_addr_end(addr, end);
 786
 787                 pgd = vmemmap_pgd_populate(addr, node);
 788                 if (!pgd)
 789                         return -ENOMEM;
 790
 791                 pud = vmemmap_pud_populate(pgd, addr, node);
 792                 if (!pud)
 793                         return -ENOMEM;
 794
 795                 pmd = pmd_offset(pud, addr);
 796                 if (pmd_none(*pmd)) {
 797                         pte_t entry;
 798                         void *p;
 799
 800                         p = vmemmap_alloc_block(PMD_SIZE, node);
 801                         if (!p)
 802                                 return -ENOMEM;
 803
 804                         entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
 805                                                         PAGE_KERNEL_LARGE);
 806                         set_pmd(pmd, __pmd(pte_val(entry)));
 807
 808                         printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
 809                                 addr, addr + PMD_SIZE - 1, p, node);
 810                 } else {
 811                         vmemmap_verify((pte_t *)pmd, node, addr, next);
 812                 }
 813         }
 814         return 0;
 815 }
 816 #endif