1 /* 2 * linux/arch/x86_64/mm/init.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * Copyright (C) 2000 Pavel Machek <pavel@ucw.cz> 6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de> 7 */ 8 9 #include <linux/signal.h> 10 #include <linux/sched.h> 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/string.h> 14 #include <linux/types.h> 15 #include <linux/ptrace.h> 16 #include <linux/mman.h> 17 #include <linux/mm.h> 18 #include <linux/swap.h> 19 #include <linux/smp.h> 20 #include <linux/init.h> 21 #include <linux/initrd.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/memblock.h> 25 #include <linux/proc_fs.h> 26 #include <linux/pci.h> 27 #include <linux/pfn.h> 28 #include <linux/poison.h> 29 #include <linux/dma-mapping.h> 30 #include <linux/module.h> 31 #include <linux/memory_hotplug.h> 32 #include <linux/nmi.h> 33 #include <linux/gfp.h> 34 35 #include <asm/processor.h> 36 #include <asm/bios_ebda.h> 37 #include <asm/system.h> 38 #include <asm/uaccess.h> 39 #include <asm/pgtable.h> 40 #include <asm/pgalloc.h> 41 #include <asm/dma.h> 42 #include <asm/fixmap.h> 43 #include <asm/e820.h> 44 #include <asm/apic.h> 45 #include <asm/tlb.h> 46 #include <asm/mmu_context.h> 47 #include <asm/proto.h> 48 #include <asm/smp.h> 49 #include <asm/sections.h> 50 #include <asm/kdebug.h> 51 #include <asm/numa.h> 52 #include <asm/cacheflush.h> 53 #include <asm/init.h> 54 #include <asm/uv/uv.h> 55 #include <asm/setup.h> 56 57 static int __init parse_direct_gbpages_off(char *arg) 58 { 59 direct_gbpages = 0; 60 return 0; 61 } 62 early_param("nogbpages", parse_direct_gbpages_off); 63 64 static int __init parse_direct_gbpages_on(char *arg) 65 { 66 direct_gbpages = 1; 67 return 0; 68 } 69 early_param("gbpages", parse_direct_gbpages_on); 70 71 /* 72 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 73 * physical space so we can cache the place of the first one and move 74 * around without checking the pgd every time. 75 */ 76 77 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 78 EXPORT_SYMBOL_GPL(__supported_pte_mask); 79 80 int force_personality32; 81 82 /* 83 * noexec32=on|off 84 * Control non executable heap for 32bit processes. 85 * To control the stack too use noexec=off 86 * 87 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 88 * off PROT_READ implies PROT_EXEC 89 */ 90 static int __init nonx32_setup(char *str) 91 { 92 if (!strcmp(str, "on")) 93 force_personality32 &= ~READ_IMPLIES_EXEC; 94 else if (!strcmp(str, "off")) 95 force_personality32 |= READ_IMPLIES_EXEC; 96 return 1; 97 } 98 __setup("noexec32=", nonx32_setup); 99 100 /* 101 * When memory was added/removed make sure all the processes MM have 102 * suitable PGD entries in the local PGD level page. 103 */ 104 void sync_global_pgds(unsigned long start, unsigned long end) 105 { 106 unsigned long address; 107 108 for (address = start; address <= end; address += PGDIR_SIZE) { 109 const pgd_t *pgd_ref = pgd_offset_k(address); 110 struct page *page; 111 112 if (pgd_none(*pgd_ref)) 113 continue; 114 115 spin_lock(&pgd_lock); 116 list_for_each_entry(page, &pgd_list, lru) { 117 pgd_t *pgd; 118 spinlock_t *pgt_lock; 119 120 pgd = (pgd_t *)page_address(page) + pgd_index(address); 121 /* the pgt_lock only for Xen */ 122 pgt_lock = &pgd_page_get_mm(page)->page_table_lock; 123 spin_lock(pgt_lock); 124 125 if (pgd_none(*pgd)) 126 set_pgd(pgd, *pgd_ref); 127 else 128 BUG_ON(pgd_page_vaddr(*pgd) 129 != pgd_page_vaddr(*pgd_ref)); 130 131 spin_unlock(pgt_lock); 132 } 133 spin_unlock(&pgd_lock); 134 } 135 } 136 137 /* 138 * NOTE: This function is marked __ref because it calls __init function 139 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 140 */ 141 static __ref void *spp_getpage(void) 142 { 143 void *ptr; 144 145 if (after_bootmem) 146 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 147 else 148 ptr = alloc_bootmem_pages(PAGE_SIZE); 149 150 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 151 panic("set_pte_phys: cannot allocate page data %s\n", 152 after_bootmem ? "after bootmem" : ""); 153 } 154 155 pr_debug("spp_getpage %p\n", ptr); 156 157 return ptr; 158 } 159 160 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 161 { 162 if (pgd_none(*pgd)) { 163 pud_t *pud = (pud_t *)spp_getpage(); 164 pgd_populate(&init_mm, pgd, pud); 165 if (pud != pud_offset(pgd, 0)) 166 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 167 pud, pud_offset(pgd, 0)); 168 } 169 return pud_offset(pgd, vaddr); 170 } 171 172 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 173 { 174 if (pud_none(*pud)) { 175 pmd_t *pmd = (pmd_t *) spp_getpage(); 176 pud_populate(&init_mm, pud, pmd); 177 if (pmd != pmd_offset(pud, 0)) 178 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 179 pmd, pmd_offset(pud, 0)); 180 } 181 return pmd_offset(pud, vaddr); 182 } 183 184 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 185 { 186 if (pmd_none(*pmd)) { 187 pte_t *pte = (pte_t *) spp_getpage(); 188 pmd_populate_kernel(&init_mm, pmd, pte); 189 if (pte != pte_offset_kernel(pmd, 0)) 190 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 191 } 192 return pte_offset_kernel(pmd, vaddr); 193 } 194 195 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 196 { 197 pud_t *pud; 198 pmd_t *pmd; 199 pte_t *pte; 200 201 pud = pud_page + pud_index(vaddr); 202 pmd = fill_pmd(pud, vaddr); 203 pte = fill_pte(pmd, vaddr); 204 205 set_pte(pte, new_pte); 206 207 /* 208 * It's enough to flush this one mapping. 209 * (PGE mappings get flushed as well) 210 */ 211 __flush_tlb_one(vaddr); 212 } 213 214 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 215 { 216 pgd_t *pgd; 217 pud_t *pud_page; 218 219 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 220 221 pgd = pgd_offset_k(vaddr); 222 if (pgd_none(*pgd)) { 223 printk(KERN_ERR 224 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 225 return; 226 } 227 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 228 set_pte_vaddr_pud(pud_page, vaddr, pteval); 229 } 230 231 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 232 { 233 pgd_t *pgd; 234 pud_t *pud; 235 236 pgd = pgd_offset_k(vaddr); 237 pud = fill_pud(pgd, vaddr); 238 return fill_pmd(pud, vaddr); 239 } 240 241 pte_t * __init populate_extra_pte(unsigned long vaddr) 242 { 243 pmd_t *pmd; 244 245 pmd = populate_extra_pmd(vaddr); 246 return fill_pte(pmd, vaddr); 247 } 248 249 /* 250 * Create large page table mappings for a range of physical addresses. 251 */ 252 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 253 pgprot_t prot) 254 { 255 pgd_t *pgd; 256 pud_t *pud; 257 pmd_t *pmd; 258 259 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 260 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 261 pgd = pgd_offset_k((unsigned long)__va(phys)); 262 if (pgd_none(*pgd)) { 263 pud = (pud_t *) spp_getpage(); 264 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 265 _PAGE_USER)); 266 } 267 pud = pud_offset(pgd, (unsigned long)__va(phys)); 268 if (pud_none(*pud)) { 269 pmd = (pmd_t *) spp_getpage(); 270 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 271 _PAGE_USER)); 272 } 273 pmd = pmd_offset(pud, phys); 274 BUG_ON(!pmd_none(*pmd)); 275 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 276 } 277 } 278 279 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 280 { 281 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 282 } 283 284 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 285 { 286 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 287 } 288 289 /* 290 * The head.S code sets up the kernel high mapping: 291 * 292 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 293 * 294 * phys_addr holds the negative offset to the kernel, which is added 295 * to the compile time generated pmds. This results in invalid pmds up 296 * to the point where we hit the physaddr 0 mapping. 297 * 298 * We limit the mappings to the region from _text to _brk_end. _brk_end 299 * is rounded up to the 2MB boundary. This catches the invalid pmds as 300 * well, as they are located before _text: 301 */ 302 void __init cleanup_highmap(void) 303 { 304 unsigned long vaddr = __START_KERNEL_map; 305 unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); 306 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; 307 pmd_t *pmd = level2_kernel_pgt; 308 309 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { 310 if (pmd_none(*pmd)) 311 continue; 312 if (vaddr < (unsigned long) _text || vaddr > end) 313 set_pmd(pmd, __pmd(0)); 314 } 315 } 316 317 static __ref void *alloc_low_page(unsigned long *phys) 318 { 319 unsigned long pfn = pgt_buf_end++; 320 void *adr; 321 322 if (after_bootmem) { 323 adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 324 *phys = __pa(adr); 325 326 return adr; 327 } 328 329 if (pfn >= pgt_buf_top) 330 panic("alloc_low_page: ran out of memory"); 331 332 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 333 clear_page(adr); 334 *phys = pfn * PAGE_SIZE; 335 return adr; 336 } 337 338 static __ref void *map_low_page(void *virt) 339 { 340 void *adr; 341 unsigned long phys, left; 342 343 if (after_bootmem) 344 return virt; 345 346 phys = __pa(virt); 347 left = phys & (PAGE_SIZE - 1); 348 adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE); 349 adr = (void *)(((unsigned long)adr) | left); 350 351 return adr; 352 } 353 354 static __ref void unmap_low_page(void *adr) 355 { 356 if (after_bootmem) 357 return; 358 359 early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE); 360 } 361 362 static unsigned long __meminit 363 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 364 pgprot_t prot) 365 { 366 unsigned pages = 0; 367 unsigned long last_map_addr = end; 368 int i; 369 370 pte_t *pte = pte_page + pte_index(addr); 371 372 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 373 374 if (addr >= end) { 375 if (!after_bootmem) { 376 for(; i < PTRS_PER_PTE; i++, pte++) 377 set_pte(pte, __pte(0)); 378 } 379 break; 380 } 381 382 /* 383 * We will re-use the existing mapping. 384 * Xen for example has some special requirements, like mapping 385 * pagetable pages as RO. So assume someone who pre-setup 386 * these mappings are more intelligent. 387 */ 388 if (pte_val(*pte)) { 389 pages++; 390 continue; 391 } 392 393 if (0) 394 printk(" pte=%p addr=%lx pte=%016lx\n", 395 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 396 pages++; 397 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 398 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 399 } 400 401 update_page_count(PG_LEVEL_4K, pages); 402 403 return last_map_addr; 404 } 405 406 static unsigned long __meminit 407 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 408 unsigned long page_size_mask, pgprot_t prot) 409 { 410 unsigned long pages = 0; 411 unsigned long last_map_addr = end; 412 413 int i = pmd_index(address); 414 415 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 416 unsigned long pte_phys; 417 pmd_t *pmd = pmd_page + pmd_index(address); 418 pte_t *pte; 419 pgprot_t new_prot = prot; 420 421 if (address >= end) { 422 if (!after_bootmem) { 423 for (; i < PTRS_PER_PMD; i++, pmd++) 424 set_pmd(pmd, __pmd(0)); 425 } 426 break; 427 } 428 429 if (pmd_val(*pmd)) { 430 if (!pmd_large(*pmd)) { 431 spin_lock(&init_mm.page_table_lock); 432 pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd)); 433 last_map_addr = phys_pte_init(pte, address, 434 end, prot); 435 unmap_low_page(pte); 436 spin_unlock(&init_mm.page_table_lock); 437 continue; 438 } 439 /* 440 * If we are ok with PG_LEVEL_2M mapping, then we will 441 * use the existing mapping, 442 * 443 * Otherwise, we will split the large page mapping but 444 * use the same existing protection bits except for 445 * large page, so that we don't violate Intel's TLB 446 * Application note (317080) which says, while changing 447 * the page sizes, new and old translations should 448 * not differ with respect to page frame and 449 * attributes. 450 */ 451 if (page_size_mask & (1 << PG_LEVEL_2M)) { 452 pages++; 453 continue; 454 } 455 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 456 } 457 458 if (page_size_mask & (1<<PG_LEVEL_2M)) { 459 pages++; 460 spin_lock(&init_mm.page_table_lock); 461 set_pte((pte_t *)pmd, 462 pfn_pte(address >> PAGE_SHIFT, 463 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 464 spin_unlock(&init_mm.page_table_lock); 465 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 466 continue; 467 } 468 469 pte = alloc_low_page(&pte_phys); 470 last_map_addr = phys_pte_init(pte, address, end, new_prot); 471 unmap_low_page(pte); 472 473 spin_lock(&init_mm.page_table_lock); 474 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 475 spin_unlock(&init_mm.page_table_lock); 476 } 477 update_page_count(PG_LEVEL_2M, pages); 478 return last_map_addr; 479 } 480 481 static unsigned long __meminit 482 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 483 unsigned long page_size_mask) 484 { 485 unsigned long pages = 0; 486 unsigned long last_map_addr = end; 487 int i = pud_index(addr); 488 489 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 490 unsigned long pmd_phys; 491 pud_t *pud = pud_page + pud_index(addr); 492 pmd_t *pmd; 493 pgprot_t prot = PAGE_KERNEL; 494 495 if (addr >= end) 496 break; 497 498 if (!after_bootmem && 499 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 500 set_pud(pud, __pud(0)); 501 continue; 502 } 503 504 if (pud_val(*pud)) { 505 if (!pud_large(*pud)) { 506 pmd = map_low_page(pmd_offset(pud, 0)); 507 last_map_addr = phys_pmd_init(pmd, addr, end, 508 page_size_mask, prot); 509 unmap_low_page(pmd); 510 __flush_tlb_all(); 511 continue; 512 } 513 /* 514 * If we are ok with PG_LEVEL_1G mapping, then we will 515 * use the existing mapping. 516 * 517 * Otherwise, we will split the gbpage mapping but use 518 * the same existing protection bits except for large 519 * page, so that we don't violate Intel's TLB 520 * Application note (317080) which says, while changing 521 * the page sizes, new and old translations should 522 * not differ with respect to page frame and 523 * attributes. 524 */ 525 if (page_size_mask & (1 << PG_LEVEL_1G)) { 526 pages++; 527 continue; 528 } 529 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 530 } 531 532 if (page_size_mask & (1<<PG_LEVEL_1G)) { 533 pages++; 534 spin_lock(&init_mm.page_table_lock); 535 set_pte((pte_t *)pud, 536 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 537 spin_unlock(&init_mm.page_table_lock); 538 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 539 continue; 540 } 541 542 pmd = alloc_low_page(&pmd_phys); 543 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 544 prot); 545 unmap_low_page(pmd); 546 547 spin_lock(&init_mm.page_table_lock); 548 pud_populate(&init_mm, pud, __va(pmd_phys)); 549 spin_unlock(&init_mm.page_table_lock); 550 } 551 __flush_tlb_all(); 552 553 update_page_count(PG_LEVEL_1G, pages); 554 555 return last_map_addr; 556 } 557 558 unsigned long __meminit 559 kernel_physical_mapping_init(unsigned long start, 560 unsigned long end, 561 unsigned long page_size_mask) 562 { 563 bool pgd_changed = false; 564 unsigned long next, last_map_addr = end; 565 unsigned long addr; 566 567 start = (unsigned long)__va(start); 568 end = (unsigned long)__va(end); 569 addr = start; 570 571 for (; start < end; start = next) { 572 pgd_t *pgd = pgd_offset_k(start); 573 unsigned long pud_phys; 574 pud_t *pud; 575 576 next = (start + PGDIR_SIZE) & PGDIR_MASK; 577 if (next > end) 578 next = end; 579 580 if (pgd_val(*pgd)) { 581 pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd)); 582 last_map_addr = phys_pud_init(pud, __pa(start), 583 __pa(end), page_size_mask); 584 unmap_low_page(pud); 585 continue; 586 } 587 588 pud = alloc_low_page(&pud_phys); 589 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 590 page_size_mask); 591 unmap_low_page(pud); 592 593 spin_lock(&init_mm.page_table_lock); 594 pgd_populate(&init_mm, pgd, __va(pud_phys)); 595 spin_unlock(&init_mm.page_table_lock); 596 pgd_changed = true; 597 } 598 599 if (pgd_changed) 600 sync_global_pgds(addr, end); 601 602 __flush_tlb_all(); 603 604 return last_map_addr; 605 } 606 607 #ifndef CONFIG_NUMA 608 void __init initmem_init(void) 609 { 610 memblock_x86_register_active_regions(0, 0, max_pfn); 611 } 612 #endif 613 614 void __init paging_init(void) 615 { 616 unsigned long max_zone_pfns[MAX_NR_ZONES]; 617 618 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 619 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 620 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 621 max_zone_pfns[ZONE_NORMAL] = max_pfn; 622 623 sparse_memory_present_with_active_regions(MAX_NUMNODES); 624 sparse_init(); 625 626 /* 627 * clear the default setting with node 0 628 * note: don't use nodes_clear here, that is really clearing when 629 * numa support is not compiled in, and later node_set_state 630 * will not set it back. 631 */ 632 node_clear_state(0, N_NORMAL_MEMORY); 633 634 free_area_init_nodes(max_zone_pfns); 635 } 636 637 /* 638 * Memory hotplug specific functions 639 */ 640 #ifdef CONFIG_MEMORY_HOTPLUG 641 /* 642 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 643 * updating. 644 */ 645 static void update_end_of_memory_vars(u64 start, u64 size) 646 { 647 unsigned long end_pfn = PFN_UP(start + size); 648 649 if (end_pfn > max_pfn) { 650 max_pfn = end_pfn; 651 max_low_pfn = end_pfn; 652 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 653 } 654 } 655 656 /* 657 * Memory is added always to NORMAL zone. This means you will never get 658 * additional DMA/DMA32 memory. 659 */ 660 int arch_add_memory(int nid, u64 start, u64 size) 661 { 662 struct pglist_data *pgdat = NODE_DATA(nid); 663 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 664 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 665 unsigned long nr_pages = size >> PAGE_SHIFT; 666 int ret; 667 668 last_mapped_pfn = init_memory_mapping(start, start + size); 669 if (last_mapped_pfn > max_pfn_mapped) 670 max_pfn_mapped = last_mapped_pfn; 671 672 ret = __add_pages(nid, zone, start_pfn, nr_pages); 673 WARN_ON_ONCE(ret); 674 675 /* update max_pfn, max_low_pfn and high_memory */ 676 update_end_of_memory_vars(start, size); 677 678 return ret; 679 } 680 EXPORT_SYMBOL_GPL(arch_add_memory); 681 682 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 683 int memory_add_physaddr_to_nid(u64 start) 684 { 685 return 0; 686 } 687 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 688 #endif 689 690 #endif /* CONFIG_MEMORY_HOTPLUG */ 691 692 static struct kcore_list kcore_vsyscall; 693 694 void __init mem_init(void) 695 { 696 long codesize, reservedpages, datasize, initsize; 697 unsigned long absent_pages; 698 699 pci_iommu_alloc(); 700 701 /* clear_bss() already clear the empty_zero_page */ 702 703 reservedpages = 0; 704 705 /* this will put all low memory onto the freelists */ 706 #ifdef CONFIG_NUMA 707 totalram_pages = numa_free_all_bootmem(); 708 #else 709 totalram_pages = free_all_bootmem(); 710 #endif 711 712 absent_pages = absent_pages_in_range(0, max_pfn); 713 reservedpages = max_pfn - totalram_pages - absent_pages; 714 after_bootmem = 1; 715 716 codesize = (unsigned long) &_etext - (unsigned long) &_text; 717 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 718 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 719 720 /* Register memory areas for /proc/kcore */ 721 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 722 VSYSCALL_END - VSYSCALL_START, KCORE_OTHER); 723 724 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 725 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 726 nr_free_pages() << (PAGE_SHIFT-10), 727 max_pfn << (PAGE_SHIFT-10), 728 codesize >> 10, 729 absent_pages << (PAGE_SHIFT-10), 730 reservedpages << (PAGE_SHIFT-10), 731 datasize >> 10, 732 initsize >> 10); 733 } 734 735 #ifdef CONFIG_DEBUG_RODATA 736 const int rodata_test_data = 0xC3; 737 EXPORT_SYMBOL_GPL(rodata_test_data); 738 739 int kernel_set_to_readonly; 740 741 void set_kernel_text_rw(void) 742 { 743 unsigned long start = PFN_ALIGN(_text); 744 unsigned long end = PFN_ALIGN(__stop___ex_table); 745 746 if (!kernel_set_to_readonly) 747 return; 748 749 pr_debug("Set kernel text: %lx - %lx for read write\n", 750 start, end); 751 752 /* 753 * Make the kernel identity mapping for text RW. Kernel text 754 * mapping will always be RO. Refer to the comment in 755 * static_protections() in pageattr.c 756 */ 757 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 758 } 759 760 void set_kernel_text_ro(void) 761 { 762 unsigned long start = PFN_ALIGN(_text); 763 unsigned long end = PFN_ALIGN(__stop___ex_table); 764 765 if (!kernel_set_to_readonly) 766 return; 767 768 pr_debug("Set kernel text: %lx - %lx for read only\n", 769 start, end); 770 771 /* 772 * Set the kernel identity mapping for text RO. 773 */ 774 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 775 } 776 777 void mark_rodata_ro(void) 778 { 779 unsigned long start = PFN_ALIGN(_text); 780 unsigned long rodata_start = 781 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 782 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 783 unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table); 784 unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata); 785 unsigned long data_start = (unsigned long) &_sdata; 786 787 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 788 (end - start) >> 10); 789 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 790 791 kernel_set_to_readonly = 1; 792 793 /* 794 * The rodata section (but not the kernel text!) should also be 795 * not-executable. 796 */ 797 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 798 799 rodata_test(); 800 801 #ifdef CONFIG_CPA_DEBUG 802 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 803 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 804 805 printk(KERN_INFO "Testing CPA: again\n"); 806 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 807 #endif 808 809 free_init_pages("unused kernel memory", 810 (unsigned long) page_address(virt_to_page(text_end)), 811 (unsigned long) 812 page_address(virt_to_page(rodata_start))); 813 free_init_pages("unused kernel memory", 814 (unsigned long) page_address(virt_to_page(rodata_end)), 815 (unsigned long) page_address(virt_to_page(data_start))); 816 } 817 818 #endif 819 820 int kern_addr_valid(unsigned long addr) 821 { 822 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 823 pgd_t *pgd; 824 pud_t *pud; 825 pmd_t *pmd; 826 pte_t *pte; 827 828 if (above != 0 && above != -1UL) 829 return 0; 830 831 pgd = pgd_offset_k(addr); 832 if (pgd_none(*pgd)) 833 return 0; 834 835 pud = pud_offset(pgd, addr); 836 if (pud_none(*pud)) 837 return 0; 838 839 pmd = pmd_offset(pud, addr); 840 if (pmd_none(*pmd)) 841 return 0; 842 843 if (pmd_large(*pmd)) 844 return pfn_valid(pmd_pfn(*pmd)); 845 846 pte = pte_offset_kernel(pmd, addr); 847 if (pte_none(*pte)) 848 return 0; 849 850 return pfn_valid(pte_pfn(*pte)); 851 } 852 853 /* 854 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 855 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 856 * not need special handling anymore: 857 */ 858 static struct vm_area_struct gate_vma = { 859 .vm_start = VSYSCALL_START, 860 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 861 .vm_page_prot = PAGE_READONLY_EXEC, 862 .vm_flags = VM_READ | VM_EXEC 863 }; 864 865 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 866 { 867 #ifdef CONFIG_IA32_EMULATION 868 if (test_tsk_thread_flag(tsk, TIF_IA32)) 869 return NULL; 870 #endif 871 return &gate_vma; 872 } 873 874 int in_gate_area(struct task_struct *task, unsigned long addr) 875 { 876 struct vm_area_struct *vma = get_gate_vma(task); 877 878 if (!vma) 879 return 0; 880 881 return (addr >= vma->vm_start) && (addr < vma->vm_end); 882 } 883 884 /* 885 * Use this when you have no reliable task/vma, typically from interrupt 886 * context. It is less reliable than using the task's vma and may give 887 * false positives: 888 */ 889 int in_gate_area_no_task(unsigned long addr) 890 { 891 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 892 } 893 894 const char *arch_vma_name(struct vm_area_struct *vma) 895 { 896 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 897 return "[vdso]"; 898 if (vma == &gate_vma) 899 return "[vsyscall]"; 900 return NULL; 901 } 902 903 #ifdef CONFIG_X86_UV 904 #define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) 905 906 unsigned long memory_block_size_bytes(void) 907 { 908 if (is_uv_system()) { 909 printk(KERN_INFO "UV: memory block size 2GB\n"); 910 return 2UL * 1024 * 1024 * 1024; 911 } 912 return MIN_MEMORY_BLOCK_SIZE; 913 } 914 #endif 915 916 #ifdef CONFIG_SPARSEMEM_VMEMMAP 917 /* 918 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 919 */ 920 static long __meminitdata addr_start, addr_end; 921 static void __meminitdata *p_start, *p_end; 922 static int __meminitdata node_start; 923 924 int __meminit 925 vmemmap_populate(struct page *start_page, unsigned long size, int node) 926 { 927 unsigned long addr = (unsigned long)start_page; 928 unsigned long end = (unsigned long)(start_page + size); 929 unsigned long next; 930 pgd_t *pgd; 931 pud_t *pud; 932 pmd_t *pmd; 933 934 for (; addr < end; addr = next) { 935 void *p = NULL; 936 937 pgd = vmemmap_pgd_populate(addr, node); 938 if (!pgd) 939 return -ENOMEM; 940 941 pud = vmemmap_pud_populate(pgd, addr, node); 942 if (!pud) 943 return -ENOMEM; 944 945 if (!cpu_has_pse) { 946 next = (addr + PAGE_SIZE) & PAGE_MASK; 947 pmd = vmemmap_pmd_populate(pud, addr, node); 948 949 if (!pmd) 950 return -ENOMEM; 951 952 p = vmemmap_pte_populate(pmd, addr, node); 953 954 if (!p) 955 return -ENOMEM; 956 957 addr_end = addr + PAGE_SIZE; 958 p_end = p + PAGE_SIZE; 959 } else { 960 next = pmd_addr_end(addr, end); 961 962 pmd = pmd_offset(pud, addr); 963 if (pmd_none(*pmd)) { 964 pte_t entry; 965 966 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 967 if (!p) 968 return -ENOMEM; 969 970 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 971 PAGE_KERNEL_LARGE); 972 set_pmd(pmd, __pmd(pte_val(entry))); 973 974 /* check to see if we have contiguous blocks */ 975 if (p_end != p || node_start != node) { 976 if (p_start) 977 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 978 addr_start, addr_end-1, p_start, p_end-1, node_start); 979 addr_start = addr; 980 node_start = node; 981 p_start = p; 982 } 983 984 addr_end = addr + PMD_SIZE; 985 p_end = p + PMD_SIZE; 986 } else 987 vmemmap_verify((pte_t *)pmd, node, addr, next); 988 } 989 990 } 991 sync_global_pgds((unsigned long)start_page, end); 992 return 0; 993 } 994 995 void __meminit vmemmap_populate_print_last(void) 996 { 997 if (p_start) { 998 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 999 addr_start, addr_end-1, p_start, p_end-1, node_start); 1000 p_start = NULL; 1001 p_end = NULL; 1002 node_start = 0; 1003 } 1004 } 1005 #endif 1006