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