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 const struct dma_mapping_ops *dma_ops; 50 EXPORT_SYMBOL(dma_ops); 51 52 static unsigned long dma_reserve __initdata; 53 54 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 55 56 /* 57 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 58 * physical space so we can cache the place of the first one and move 59 * around without checking the pgd every time. 60 */ 61 62 void show_mem(void) 63 { 64 long i, total = 0, reserved = 0; 65 long shared = 0, cached = 0; 66 struct page *page; 67 pg_data_t *pgdat; 68 69 printk(KERN_INFO "Mem-info:\n"); 70 show_free_areas(); 71 printk(KERN_INFO "Free swap: %6ldkB\n", 72 nr_swap_pages << (PAGE_SHIFT-10)); 73 74 for_each_online_pgdat(pgdat) { 75 for (i = 0; i < pgdat->node_spanned_pages; ++i) { 76 /* 77 * This loop can take a while with 256 GB and 78 * 4k pages so defer the NMI watchdog: 79 */ 80 if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) 81 touch_nmi_watchdog(); 82 83 if (!pfn_valid(pgdat->node_start_pfn + i)) 84 continue; 85 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; 107 108 if (after_bootmem) 109 ptr = (void *) get_zeroed_page(GFP_ATOMIC); 110 else 111 ptr = alloc_bootmem_pages(PAGE_SIZE); 112 113 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 114 panic("set_pte_phys: cannot allocate page data %s\n", 115 after_bootmem ? "after bootmem" : ""); 116 } 117 118 pr_debug("spp_getpage %p\n", ptr); 119 120 return ptr; 121 } 122 123 static __init void 124 set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot) 125 { 126 pgd_t *pgd; 127 pud_t *pud; 128 pmd_t *pmd; 129 pte_t *pte, new_pte; 130 131 pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys); 132 133 pgd = pgd_offset_k(vaddr); 134 if (pgd_none(*pgd)) { 135 printk(KERN_ERR 136 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 137 return; 138 } 139 pud = pud_offset(pgd, vaddr); 140 if (pud_none(*pud)) { 141 pmd = (pmd_t *) spp_getpage(); 142 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER)); 143 if (pmd != pmd_offset(pud, 0)) { 144 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 145 pmd, pmd_offset(pud, 0)); 146 return; 147 } 148 } 149 pmd = pmd_offset(pud, vaddr); 150 if (pmd_none(*pmd)) { 151 pte = (pte_t *) spp_getpage(); 152 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); 153 if (pte != pte_offset_kernel(pmd, 0)) { 154 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 155 return; 156 } 157 } 158 new_pte = pfn_pte(phys >> PAGE_SHIFT, prot); 159 160 pte = pte_offset_kernel(pmd, vaddr); 161 if (!pte_none(*pte) && 162 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask)) 163 pte_ERROR(*pte); 164 set_pte(pte, new_pte); 165 166 /* 167 * It's enough to flush this one mapping. 168 * (PGE mappings get flushed as well) 169 */ 170 __flush_tlb_one(vaddr); 171 } 172 173 /* NOTE: this is meant to be run only at boot */ 174 void __init 175 __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 176 { 177 unsigned long address = __fix_to_virt(idx); 178 179 if (idx >= __end_of_fixed_addresses) { 180 printk(KERN_ERR "Invalid __set_fixmap\n"); 181 return; 182 } 183 set_pte_phys(address, phys, prot); 184 } 185 186 static unsigned long __initdata table_start; 187 static unsigned long __meminitdata table_end; 188 189 static __meminit void *alloc_low_page(unsigned long *phys) 190 { 191 unsigned long pfn = table_end++; 192 void *adr; 193 194 if (after_bootmem) { 195 adr = (void *)get_zeroed_page(GFP_ATOMIC); 196 *phys = __pa(adr); 197 198 return adr; 199 } 200 201 if (pfn >= end_pfn) 202 panic("alloc_low_page: ran out of memory"); 203 204 adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE); 205 memset(adr, 0, PAGE_SIZE); 206 *phys = pfn * PAGE_SIZE; 207 return adr; 208 } 209 210 static __meminit void unmap_low_page(void *adr) 211 { 212 if (after_bootmem) 213 return; 214 215 early_iounmap(adr, PAGE_SIZE); 216 } 217 218 /* Must run before zap_low_mappings */ 219 __meminit void *early_ioremap(unsigned long addr, unsigned long size) 220 { 221 pmd_t *pmd, *last_pmd; 222 unsigned long vaddr; 223 int i, pmds; 224 225 pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE; 226 vaddr = __START_KERNEL_map; 227 pmd = level2_kernel_pgt; 228 last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1; 229 230 for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) { 231 for (i = 0; i < pmds; i++) { 232 if (pmd_present(pmd[i])) 233 goto continue_outer_loop; 234 } 235 vaddr += addr & ~PMD_MASK; 236 addr &= PMD_MASK; 237 238 for (i = 0; i < pmds; i++, addr += PMD_SIZE) 239 set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); 240 __flush_tlb_all(); 241 242 return (void *)vaddr; 243 continue_outer_loop: 244 ; 245 } 246 printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size); 247 248 return NULL; 249 } 250 251 /* 252 * To avoid virtual aliases later: 253 */ 254 __meminit void early_iounmap(void *addr, unsigned long size) 255 { 256 unsigned long vaddr; 257 pmd_t *pmd; 258 int i, pmds; 259 260 vaddr = (unsigned long)addr; 261 pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE; 262 pmd = level2_kernel_pgt + pmd_index(vaddr); 263 264 for (i = 0; i < pmds; i++) 265 pmd_clear(pmd + i); 266 267 __flush_tlb_all(); 268 } 269 270 static void __meminit 271 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end) 272 { 273 int i = pmd_index(address); 274 275 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 276 unsigned long entry; 277 pmd_t *pmd = pmd_page + pmd_index(address); 278 279 if (address >= end) { 280 if (!after_bootmem) { 281 for (; i < PTRS_PER_PMD; i++, pmd++) 282 set_pmd(pmd, __pmd(0)); 283 } 284 break; 285 } 286 287 if (pmd_val(*pmd)) 288 continue; 289 290 entry = __PAGE_KERNEL_LARGE|_PAGE_GLOBAL|address; 291 entry &= __supported_pte_mask; 292 set_pmd(pmd, __pmd(entry)); 293 } 294 } 295 296 static void __meminit 297 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end) 298 { 299 pmd_t *pmd = pmd_offset(pud, 0); 300 spin_lock(&init_mm.page_table_lock); 301 phys_pmd_init(pmd, address, end); 302 spin_unlock(&init_mm.page_table_lock); 303 __flush_tlb_all(); 304 } 305 306 static void __meminit 307 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end) 308 { 309 int i = pud_index(addr); 310 311 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 312 unsigned long pmd_phys; 313 pud_t *pud = pud_page + pud_index(addr); 314 pmd_t *pmd; 315 316 if (addr >= end) 317 break; 318 319 if (!after_bootmem && 320 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 321 set_pud(pud, __pud(0)); 322 continue; 323 } 324 325 if (pud_val(*pud)) { 326 phys_pmd_update(pud, addr, end); 327 continue; 328 } 329 330 pmd = alloc_low_page(&pmd_phys); 331 332 spin_lock(&init_mm.page_table_lock); 333 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE)); 334 phys_pmd_init(pmd, addr, end); 335 spin_unlock(&init_mm.page_table_lock); 336 337 unmap_low_page(pmd); 338 } 339 __flush_tlb_all(); 340 } 341 342 static void __init find_early_table_space(unsigned long end) 343 { 344 unsigned long puds, pmds, tables, start; 345 346 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; 347 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; 348 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) + 349 round_up(pmds * sizeof(pmd_t), PAGE_SIZE); 350 351 /* 352 * RED-PEN putting page tables only on node 0 could 353 * cause a hotspot and fill up ZONE_DMA. The page tables 354 * need roughly 0.5KB per GB. 355 */ 356 start = 0x8000; 357 table_start = find_e820_area(start, end, tables, PAGE_SIZE); 358 if (table_start == -1UL) 359 panic("Cannot find space for the kernel page tables"); 360 361 table_start >>= PAGE_SHIFT; 362 table_end = table_start; 363 364 early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n", 365 end, table_start << PAGE_SHIFT, 366 (table_start << PAGE_SHIFT) + tables); 367 } 368 369 /* 370 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 371 * This runs before bootmem is initialized and gets pages directly from 372 * the physical memory. To access them they are temporarily mapped. 373 */ 374 void __init_refok init_memory_mapping(unsigned long start, unsigned long end) 375 { 376 unsigned long next; 377 378 pr_debug("init_memory_mapping\n"); 379 380 /* 381 * Find space for the kernel direct mapping tables. 382 * 383 * Later we should allocate these tables in the local node of the 384 * memory mapped. Unfortunately this is done currently before the 385 * nodes are discovered. 386 */ 387 if (!after_bootmem) 388 find_early_table_space(end); 389 390 start = (unsigned long)__va(start); 391 end = (unsigned long)__va(end); 392 393 for (; start < end; start = next) { 394 pgd_t *pgd = pgd_offset_k(start); 395 unsigned long pud_phys; 396 pud_t *pud; 397 398 if (after_bootmem) 399 pud = pud_offset(pgd, start & PGDIR_MASK); 400 else 401 pud = alloc_low_page(&pud_phys); 402 403 next = start + PGDIR_SIZE; 404 if (next > end) 405 next = end; 406 phys_pud_init(pud, __pa(start), __pa(next)); 407 if (!after_bootmem) 408 set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys)); 409 unmap_low_page(pud); 410 } 411 412 if (!after_bootmem) 413 mmu_cr4_features = read_cr4(); 414 __flush_tlb_all(); 415 416 if (!after_bootmem) 417 reserve_early(table_start << PAGE_SHIFT, 418 table_end << PAGE_SHIFT, "PGTABLE"); 419 } 420 421 #ifndef CONFIG_NUMA 422 void __init paging_init(void) 423 { 424 unsigned long max_zone_pfns[MAX_NR_ZONES]; 425 426 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 427 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 428 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 429 max_zone_pfns[ZONE_NORMAL] = end_pfn; 430 431 memory_present(0, 0, end_pfn); 432 sparse_init(); 433 free_area_init_nodes(max_zone_pfns); 434 } 435 #endif 436 437 /* 438 * Unmap a kernel mapping if it exists. This is useful to avoid 439 * prefetches from the CPU leading to inconsistent cache lines. 440 * address and size must be aligned to 2MB boundaries. 441 * Does nothing when the mapping doesn't exist. 442 */ 443 void __init clear_kernel_mapping(unsigned long address, unsigned long size) 444 { 445 unsigned long end = address + size; 446 447 BUG_ON(address & ~LARGE_PAGE_MASK); 448 BUG_ON(size & ~LARGE_PAGE_MASK); 449 450 for (; address < end; address += LARGE_PAGE_SIZE) { 451 pgd_t *pgd = pgd_offset_k(address); 452 pud_t *pud; 453 pmd_t *pmd; 454 455 if (pgd_none(*pgd)) 456 continue; 457 458 pud = pud_offset(pgd, address); 459 if (pud_none(*pud)) 460 continue; 461 462 pmd = pmd_offset(pud, address); 463 if (!pmd || pmd_none(*pmd)) 464 continue; 465 466 if (!(pmd_val(*pmd) & _PAGE_PSE)) { 467 /* 468 * Could handle this, but it should not happen 469 * currently: 470 */ 471 printk(KERN_ERR "clear_kernel_mapping: " 472 "mapping has been split. will leak memory\n"); 473 pmd_ERROR(*pmd); 474 } 475 set_pmd(pmd, __pmd(0)); 476 } 477 __flush_tlb_all(); 478 } 479 480 /* 481 * Memory hotplug specific functions 482 */ 483 void online_page(struct page *page) 484 { 485 ClearPageReserved(page); 486 init_page_count(page); 487 __free_page(page); 488 totalram_pages++; 489 num_physpages++; 490 } 491 492 #ifdef CONFIG_MEMORY_HOTPLUG 493 /* 494 * Memory is added always to NORMAL zone. This means you will never get 495 * additional DMA/DMA32 memory. 496 */ 497 int arch_add_memory(int nid, u64 start, u64 size) 498 { 499 struct pglist_data *pgdat = NODE_DATA(nid); 500 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 501 unsigned long start_pfn = start >> PAGE_SHIFT; 502 unsigned long nr_pages = size >> PAGE_SHIFT; 503 int ret; 504 505 init_memory_mapping(start, start + size-1); 506 507 ret = __add_pages(zone, start_pfn, nr_pages); 508 WARN_ON(1); 509 510 return ret; 511 } 512 EXPORT_SYMBOL_GPL(arch_add_memory); 513 514 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 515 int memory_add_physaddr_to_nid(u64 start) 516 { 517 return 0; 518 } 519 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 520 #endif 521 522 #endif /* CONFIG_MEMORY_HOTPLUG */ 523 524 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, 525 kcore_modules, kcore_vsyscall; 526 527 void __init mem_init(void) 528 { 529 long codesize, reservedpages, datasize, initsize; 530 531 pci_iommu_alloc(); 532 533 /* clear_bss() already clear the empty_zero_page */ 534 535 /* temporary debugging - double check it's true: */ 536 { 537 int i; 538 539 for (i = 0; i < 1024; i++) 540 WARN_ON_ONCE(empty_zero_page[i]); 541 } 542 543 reservedpages = 0; 544 545 /* this will put all low memory onto the freelists */ 546 #ifdef CONFIG_NUMA 547 totalram_pages = numa_free_all_bootmem(); 548 #else 549 totalram_pages = free_all_bootmem(); 550 #endif 551 reservedpages = end_pfn - totalram_pages - 552 absent_pages_in_range(0, end_pfn); 553 after_bootmem = 1; 554 555 codesize = (unsigned long) &_etext - (unsigned long) &_text; 556 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 557 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 558 559 /* Register memory areas for /proc/kcore */ 560 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 561 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 562 VMALLOC_END-VMALLOC_START); 563 kclist_add(&kcore_kernel, &_stext, _end - _stext); 564 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN); 565 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 566 VSYSCALL_END - VSYSCALL_START); 567 568 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 569 "%ldk reserved, %ldk data, %ldk init)\n", 570 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 571 end_pfn << (PAGE_SHIFT-10), 572 codesize >> 10, 573 reservedpages << (PAGE_SHIFT-10), 574 datasize >> 10, 575 initsize >> 10); 576 } 577 578 void free_init_pages(char *what, unsigned long begin, unsigned long end) 579 { 580 unsigned long addr; 581 582 if (begin >= end) 583 return; 584 585 /* 586 * If debugging page accesses then do not free this memory but 587 * mark them not present - any buggy init-section access will 588 * create a kernel page fault: 589 */ 590 #ifdef CONFIG_DEBUG_PAGEALLOC 591 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", 592 begin, PAGE_ALIGN(end)); 593 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 594 #else 595 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 596 597 for (addr = begin; addr < end; addr += PAGE_SIZE) { 598 ClearPageReserved(virt_to_page(addr)); 599 init_page_count(virt_to_page(addr)); 600 memset((void *)(addr & ~(PAGE_SIZE-1)), 601 POISON_FREE_INITMEM, PAGE_SIZE); 602 free_page(addr); 603 totalram_pages++; 604 } 605 #endif 606 } 607 608 void free_initmem(void) 609 { 610 free_init_pages("unused kernel memory", 611 (unsigned long)(&__init_begin), 612 (unsigned long)(&__init_end)); 613 } 614 615 #ifdef CONFIG_DEBUG_RODATA 616 const int rodata_test_data = 0xC3; 617 EXPORT_SYMBOL_GPL(rodata_test_data); 618 619 void mark_rodata_ro(void) 620 { 621 unsigned long start = (unsigned long)_stext, end; 622 623 #ifdef CONFIG_HOTPLUG_CPU 624 /* It must still be possible to apply SMP alternatives. */ 625 if (num_possible_cpus() > 1) 626 start = (unsigned long)_etext; 627 #endif 628 629 #ifdef CONFIG_KPROBES 630 start = (unsigned long)__start_rodata; 631 #endif 632 633 end = (unsigned long)__end_rodata; 634 start = (start + PAGE_SIZE - 1) & PAGE_MASK; 635 end &= PAGE_MASK; 636 if (end <= start) 637 return; 638 639 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 640 641 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 642 (end - start) >> 10); 643 644 rodata_test(); 645 646 #ifdef CONFIG_CPA_DEBUG 647 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 648 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 649 650 printk(KERN_INFO "Testing CPA: again\n"); 651 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 652 #endif 653 } 654 #endif 655 656 #ifdef CONFIG_BLK_DEV_INITRD 657 void free_initrd_mem(unsigned long start, unsigned long end) 658 { 659 free_init_pages("initrd memory", start, end); 660 } 661 #endif 662 663 void __init reserve_bootmem_generic(unsigned long phys, unsigned len) 664 { 665 #ifdef CONFIG_NUMA 666 int nid = phys_to_nid(phys); 667 #endif 668 unsigned long pfn = phys >> PAGE_SHIFT; 669 670 if (pfn >= end_pfn) { 671 /* 672 * This can happen with kdump kernels when accessing 673 * firmware tables: 674 */ 675 if (pfn < end_pfn_map) 676 return; 677 678 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n", 679 phys, len); 680 return; 681 } 682 683 /* Should check here against the e820 map to avoid double free */ 684 #ifdef CONFIG_NUMA 685 reserve_bootmem_node(NODE_DATA(nid), phys, len); 686 #else 687 reserve_bootmem(phys, len); 688 #endif 689 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) { 690 dma_reserve += len / PAGE_SIZE; 691 set_dma_reserve(dma_reserve); 692 } 693 } 694 695 int kern_addr_valid(unsigned long addr) 696 { 697 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 698 pgd_t *pgd; 699 pud_t *pud; 700 pmd_t *pmd; 701 pte_t *pte; 702 703 if (above != 0 && above != -1UL) 704 return 0; 705 706 pgd = pgd_offset_k(addr); 707 if (pgd_none(*pgd)) 708 return 0; 709 710 pud = pud_offset(pgd, addr); 711 if (pud_none(*pud)) 712 return 0; 713 714 pmd = pmd_offset(pud, addr); 715 if (pmd_none(*pmd)) 716 return 0; 717 718 if (pmd_large(*pmd)) 719 return pfn_valid(pmd_pfn(*pmd)); 720 721 pte = pte_offset_kernel(pmd, addr); 722 if (pte_none(*pte)) 723 return 0; 724 725 return pfn_valid(pte_pfn(*pte)); 726 } 727 728 /* 729 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 730 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 731 * not need special handling anymore: 732 */ 733 static struct vm_area_struct gate_vma = { 734 .vm_start = VSYSCALL_START, 735 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 736 .vm_page_prot = PAGE_READONLY_EXEC, 737 .vm_flags = VM_READ | VM_EXEC 738 }; 739 740 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 741 { 742 #ifdef CONFIG_IA32_EMULATION 743 if (test_tsk_thread_flag(tsk, TIF_IA32)) 744 return NULL; 745 #endif 746 return &gate_vma; 747 } 748 749 int in_gate_area(struct task_struct *task, unsigned long addr) 750 { 751 struct vm_area_struct *vma = get_gate_vma(task); 752 753 if (!vma) 754 return 0; 755 756 return (addr >= vma->vm_start) && (addr < vma->vm_end); 757 } 758 759 /* 760 * Use this when you have no reliable task/vma, typically from interrupt 761 * context. It is less reliable than using the task's vma and may give 762 * false positives: 763 */ 764 int in_gate_area_no_task(unsigned long addr) 765 { 766 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 767 } 768 769 const char *arch_vma_name(struct vm_area_struct *vma) 770 { 771 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 772 return "[vdso]"; 773 if (vma == &gate_vma) 774 return "[vsyscall]"; 775 return NULL; 776 } 777 778 #ifdef CONFIG_SPARSEMEM_VMEMMAP 779 /* 780 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 781 */ 782 int __meminit 783 vmemmap_populate(struct page *start_page, unsigned long size, int node) 784 { 785 unsigned long addr = (unsigned long)start_page; 786 unsigned long end = (unsigned long)(start_page + size); 787 unsigned long next; 788 pgd_t *pgd; 789 pud_t *pud; 790 pmd_t *pmd; 791 792 for (; addr < end; addr = next) { 793 next = pmd_addr_end(addr, end); 794 795 pgd = vmemmap_pgd_populate(addr, node); 796 if (!pgd) 797 return -ENOMEM; 798 799 pud = vmemmap_pud_populate(pgd, addr, node); 800 if (!pud) 801 return -ENOMEM; 802 803 pmd = pmd_offset(pud, addr); 804 if (pmd_none(*pmd)) { 805 pte_t entry; 806 void *p; 807 808 p = vmemmap_alloc_block(PMD_SIZE, node); 809 if (!p) 810 return -ENOMEM; 811 812 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 813 PAGE_KERNEL_LARGE); 814 set_pmd(pmd, __pmd(pte_val(entry))); 815 816 printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n", 817 addr, addr + PMD_SIZE - 1, p, node); 818 } else { 819 vmemmap_verify((pte_t *)pmd, node, addr, next); 820 } 821 } 822 return 0; 823 } 824 #endif 825