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/initrd.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/proc_fs.h> 25 #include <linux/pci.h> 26 #include <linux/pfn.h> 27 #include <linux/poison.h> 28 #include <linux/dma-mapping.h> 29 #include <linux/module.h> 30 #include <linux/memory_hotplug.h> 31 #include <linux/nmi.h> 32 33 #include <asm/processor.h> 34 #include <asm/bios_ebda.h> 35 #include <asm/system.h> 36 #include <asm/uaccess.h> 37 #include <asm/pgtable.h> 38 #include <asm/pgalloc.h> 39 #include <asm/dma.h> 40 #include <asm/fixmap.h> 41 #include <asm/e820.h> 42 #include <asm/apic.h> 43 #include <asm/tlb.h> 44 #include <asm/mmu_context.h> 45 #include <asm/proto.h> 46 #include <asm/smp.h> 47 #include <asm/sections.h> 48 #include <asm/kdebug.h> 49 #include <asm/numa.h> 50 #include <asm/cacheflush.h> 51 #include <asm/init.h> 52 53 /* 54 * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries. 55 * The direct mapping extends to max_pfn_mapped, so that we can directly access 56 * apertures, ACPI and other tables without having to play with fixmaps. 57 */ 58 unsigned long max_low_pfn_mapped; 59 unsigned long max_pfn_mapped; 60 61 static unsigned long dma_reserve __initdata; 62 63 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 64 65 static int __init parse_direct_gbpages_off(char *arg) 66 { 67 direct_gbpages = 0; 68 return 0; 69 } 70 early_param("nogbpages", parse_direct_gbpages_off); 71 72 static int __init parse_direct_gbpages_on(char *arg) 73 { 74 direct_gbpages = 1; 75 return 0; 76 } 77 early_param("gbpages", parse_direct_gbpages_on); 78 79 /* 80 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 81 * physical space so we can cache the place of the first one and move 82 * around without checking the pgd every time. 83 */ 84 85 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; 86 EXPORT_SYMBOL_GPL(__supported_pte_mask); 87 88 static int disable_nx __cpuinitdata; 89 90 /* 91 * noexec=on|off 92 * Control non-executable mappings for 64-bit processes. 93 * 94 * on Enable (default) 95 * off Disable 96 */ 97 static int __init nonx_setup(char *str) 98 { 99 if (!str) 100 return -EINVAL; 101 if (!strncmp(str, "on", 2)) { 102 __supported_pte_mask |= _PAGE_NX; 103 disable_nx = 0; 104 } else if (!strncmp(str, "off", 3)) { 105 disable_nx = 1; 106 __supported_pte_mask &= ~_PAGE_NX; 107 } 108 return 0; 109 } 110 early_param("noexec", nonx_setup); 111 112 void __cpuinit check_efer(void) 113 { 114 unsigned long efer; 115 116 rdmsrl(MSR_EFER, efer); 117 if (!(efer & EFER_NX) || disable_nx) 118 __supported_pte_mask &= ~_PAGE_NX; 119 } 120 121 int force_personality32; 122 123 /* 124 * noexec32=on|off 125 * Control non executable heap for 32bit processes. 126 * To control the stack too use noexec=off 127 * 128 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 129 * off PROT_READ implies PROT_EXEC 130 */ 131 static int __init nonx32_setup(char *str) 132 { 133 if (!strcmp(str, "on")) 134 force_personality32 &= ~READ_IMPLIES_EXEC; 135 else if (!strcmp(str, "off")) 136 force_personality32 |= READ_IMPLIES_EXEC; 137 return 1; 138 } 139 __setup("noexec32=", nonx32_setup); 140 141 /* 142 * NOTE: This function is marked __ref because it calls __init function 143 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 144 */ 145 static __ref void *spp_getpage(void) 146 { 147 void *ptr; 148 149 if (after_bootmem) 150 ptr = (void *) get_zeroed_page(GFP_ATOMIC); 151 else 152 ptr = alloc_bootmem_pages(PAGE_SIZE); 153 154 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 155 panic("set_pte_phys: cannot allocate page data %s\n", 156 after_bootmem ? "after bootmem" : ""); 157 } 158 159 pr_debug("spp_getpage %p\n", ptr); 160 161 return ptr; 162 } 163 164 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 165 { 166 if (pgd_none(*pgd)) { 167 pud_t *pud = (pud_t *)spp_getpage(); 168 pgd_populate(&init_mm, pgd, pud); 169 if (pud != pud_offset(pgd, 0)) 170 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 171 pud, pud_offset(pgd, 0)); 172 } 173 return pud_offset(pgd, vaddr); 174 } 175 176 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 177 { 178 if (pud_none(*pud)) { 179 pmd_t *pmd = (pmd_t *) spp_getpage(); 180 pud_populate(&init_mm, pud, pmd); 181 if (pmd != pmd_offset(pud, 0)) 182 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 183 pmd, pmd_offset(pud, 0)); 184 } 185 return pmd_offset(pud, vaddr); 186 } 187 188 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 189 { 190 if (pmd_none(*pmd)) { 191 pte_t *pte = (pte_t *) spp_getpage(); 192 pmd_populate_kernel(&init_mm, pmd, pte); 193 if (pte != pte_offset_kernel(pmd, 0)) 194 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 195 } 196 return pte_offset_kernel(pmd, vaddr); 197 } 198 199 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 200 { 201 pud_t *pud; 202 pmd_t *pmd; 203 pte_t *pte; 204 205 pud = pud_page + pud_index(vaddr); 206 pmd = fill_pmd(pud, vaddr); 207 pte = fill_pte(pmd, vaddr); 208 209 set_pte(pte, new_pte); 210 211 /* 212 * It's enough to flush this one mapping. 213 * (PGE mappings get flushed as well) 214 */ 215 __flush_tlb_one(vaddr); 216 } 217 218 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 219 { 220 pgd_t *pgd; 221 pud_t *pud_page; 222 223 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 224 225 pgd = pgd_offset_k(vaddr); 226 if (pgd_none(*pgd)) { 227 printk(KERN_ERR 228 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 229 return; 230 } 231 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 232 set_pte_vaddr_pud(pud_page, vaddr, pteval); 233 } 234 235 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 236 { 237 pgd_t *pgd; 238 pud_t *pud; 239 240 pgd = pgd_offset_k(vaddr); 241 pud = fill_pud(pgd, vaddr); 242 return fill_pmd(pud, vaddr); 243 } 244 245 pte_t * __init populate_extra_pte(unsigned long vaddr) 246 { 247 pmd_t *pmd; 248 249 pmd = populate_extra_pmd(vaddr); 250 return fill_pte(pmd, vaddr); 251 } 252 253 /* 254 * Create large page table mappings for a range of physical addresses. 255 */ 256 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 257 pgprot_t prot) 258 { 259 pgd_t *pgd; 260 pud_t *pud; 261 pmd_t *pmd; 262 263 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 264 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 265 pgd = pgd_offset_k((unsigned long)__va(phys)); 266 if (pgd_none(*pgd)) { 267 pud = (pud_t *) spp_getpage(); 268 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 269 _PAGE_USER)); 270 } 271 pud = pud_offset(pgd, (unsigned long)__va(phys)); 272 if (pud_none(*pud)) { 273 pmd = (pmd_t *) spp_getpage(); 274 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 275 _PAGE_USER)); 276 } 277 pmd = pmd_offset(pud, phys); 278 BUG_ON(!pmd_none(*pmd)); 279 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 280 } 281 } 282 283 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 284 { 285 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE); 286 } 287 288 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 289 { 290 __init_extra_mapping(phys, size, PAGE_KERNEL_LARGE_NOCACHE); 291 } 292 293 /* 294 * The head.S code sets up the kernel high mapping: 295 * 296 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 297 * 298 * phys_addr holds the negative offset to the kernel, which is added 299 * to the compile time generated pmds. This results in invalid pmds up 300 * to the point where we hit the physaddr 0 mapping. 301 * 302 * We limit the mappings to the region from _text to _end. _end is 303 * rounded up to the 2MB boundary. This catches the invalid pmds as 304 * well, as they are located before _text: 305 */ 306 void __init cleanup_highmap(void) 307 { 308 unsigned long vaddr = __START_KERNEL_map; 309 unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; 310 pmd_t *pmd = level2_kernel_pgt; 311 pmd_t *last_pmd = pmd + PTRS_PER_PMD; 312 313 for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { 314 if (pmd_none(*pmd)) 315 continue; 316 if (vaddr < (unsigned long) _text || vaddr > end) 317 set_pmd(pmd, __pmd(0)); 318 } 319 } 320 321 static __ref void *alloc_low_page(unsigned long *phys) 322 { 323 unsigned long pfn = e820_table_end++; 324 void *adr; 325 326 if (after_bootmem) { 327 adr = (void *)get_zeroed_page(GFP_ATOMIC); 328 *phys = __pa(adr); 329 330 return adr; 331 } 332 333 if (pfn >= e820_table_top) 334 panic("alloc_low_page: ran out of memory"); 335 336 adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); 337 memset(adr, 0, PAGE_SIZE); 338 *phys = pfn * PAGE_SIZE; 339 return adr; 340 } 341 342 static __ref void unmap_low_page(void *adr) 343 { 344 if (after_bootmem) 345 return; 346 347 early_iounmap(adr, PAGE_SIZE); 348 } 349 350 static unsigned long __meminit 351 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 352 pgprot_t prot) 353 { 354 unsigned pages = 0; 355 unsigned long last_map_addr = end; 356 int i; 357 358 pte_t *pte = pte_page + pte_index(addr); 359 360 for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { 361 362 if (addr >= end) { 363 if (!after_bootmem) { 364 for(; i < PTRS_PER_PTE; i++, pte++) 365 set_pte(pte, __pte(0)); 366 } 367 break; 368 } 369 370 /* 371 * We will re-use the existing mapping. 372 * Xen for example has some special requirements, like mapping 373 * pagetable pages as RO. So assume someone who pre-setup 374 * these mappings are more intelligent. 375 */ 376 if (pte_val(*pte)) { 377 pages++; 378 continue; 379 } 380 381 if (0) 382 printk(" pte=%p addr=%lx pte=%016lx\n", 383 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 384 pages++; 385 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 386 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 387 } 388 389 update_page_count(PG_LEVEL_4K, pages); 390 391 return last_map_addr; 392 } 393 394 static unsigned long __meminit 395 phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end, 396 pgprot_t prot) 397 { 398 pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd); 399 400 return phys_pte_init(pte, address, end, prot); 401 } 402 403 static unsigned long __meminit 404 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 405 unsigned long page_size_mask, pgprot_t prot) 406 { 407 unsigned long pages = 0; 408 unsigned long last_map_addr = end; 409 410 int i = pmd_index(address); 411 412 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) { 413 unsigned long pte_phys; 414 pmd_t *pmd = pmd_page + pmd_index(address); 415 pte_t *pte; 416 pgprot_t new_prot = prot; 417 418 if (address >= end) { 419 if (!after_bootmem) { 420 for (; i < PTRS_PER_PMD; i++, pmd++) 421 set_pmd(pmd, __pmd(0)); 422 } 423 break; 424 } 425 426 if (pmd_val(*pmd)) { 427 if (!pmd_large(*pmd)) { 428 spin_lock(&init_mm.page_table_lock); 429 last_map_addr = phys_pte_update(pmd, address, 430 end, prot); 431 spin_unlock(&init_mm.page_table_lock); 432 continue; 433 } 434 /* 435 * If we are ok with PG_LEVEL_2M mapping, then we will 436 * use the existing mapping, 437 * 438 * Otherwise, we will split the large page mapping but 439 * use the same existing protection bits except for 440 * large page, so that we don't violate Intel's TLB 441 * Application note (317080) which says, while changing 442 * the page sizes, new and old translations should 443 * not differ with respect to page frame and 444 * attributes. 445 */ 446 if (page_size_mask & (1 << PG_LEVEL_2M)) { 447 pages++; 448 continue; 449 } 450 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 451 } 452 453 if (page_size_mask & (1<<PG_LEVEL_2M)) { 454 pages++; 455 spin_lock(&init_mm.page_table_lock); 456 set_pte((pte_t *)pmd, 457 pfn_pte(address >> PAGE_SHIFT, 458 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 459 spin_unlock(&init_mm.page_table_lock); 460 last_map_addr = (address & PMD_MASK) + PMD_SIZE; 461 continue; 462 } 463 464 pte = alloc_low_page(&pte_phys); 465 last_map_addr = phys_pte_init(pte, address, end, new_prot); 466 unmap_low_page(pte); 467 468 spin_lock(&init_mm.page_table_lock); 469 pmd_populate_kernel(&init_mm, pmd, __va(pte_phys)); 470 spin_unlock(&init_mm.page_table_lock); 471 } 472 update_page_count(PG_LEVEL_2M, pages); 473 return last_map_addr; 474 } 475 476 static unsigned long __meminit 477 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, 478 unsigned long page_size_mask, pgprot_t prot) 479 { 480 pmd_t *pmd = pmd_offset(pud, 0); 481 unsigned long last_map_addr; 482 483 last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot); 484 __flush_tlb_all(); 485 return last_map_addr; 486 } 487 488 static unsigned long __meminit 489 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 490 unsigned long page_size_mask) 491 { 492 unsigned long pages = 0; 493 unsigned long last_map_addr = end; 494 int i = pud_index(addr); 495 496 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) { 497 unsigned long pmd_phys; 498 pud_t *pud = pud_page + pud_index(addr); 499 pmd_t *pmd; 500 pgprot_t prot = PAGE_KERNEL; 501 502 if (addr >= end) 503 break; 504 505 if (!after_bootmem && 506 !e820_any_mapped(addr, addr+PUD_SIZE, 0)) { 507 set_pud(pud, __pud(0)); 508 continue; 509 } 510 511 if (pud_val(*pud)) { 512 if (!pud_large(*pud)) { 513 last_map_addr = phys_pmd_update(pud, addr, end, 514 page_size_mask, prot); 515 continue; 516 } 517 /* 518 * If we are ok with PG_LEVEL_1G mapping, then we will 519 * use the existing mapping. 520 * 521 * Otherwise, we will split the gbpage mapping but use 522 * the same existing protection bits except for large 523 * page, so that we don't violate Intel's TLB 524 * Application note (317080) which says, while changing 525 * the page sizes, new and old translations should 526 * not differ with respect to page frame and 527 * attributes. 528 */ 529 if (page_size_mask & (1 << PG_LEVEL_1G)) { 530 pages++; 531 continue; 532 } 533 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 534 } 535 536 if (page_size_mask & (1<<PG_LEVEL_1G)) { 537 pages++; 538 spin_lock(&init_mm.page_table_lock); 539 set_pte((pte_t *)pud, 540 pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); 541 spin_unlock(&init_mm.page_table_lock); 542 last_map_addr = (addr & PUD_MASK) + PUD_SIZE; 543 continue; 544 } 545 546 pmd = alloc_low_page(&pmd_phys); 547 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 548 prot); 549 unmap_low_page(pmd); 550 551 spin_lock(&init_mm.page_table_lock); 552 pud_populate(&init_mm, pud, __va(pmd_phys)); 553 spin_unlock(&init_mm.page_table_lock); 554 } 555 __flush_tlb_all(); 556 557 update_page_count(PG_LEVEL_1G, pages); 558 559 return last_map_addr; 560 } 561 562 static unsigned long __meminit 563 phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end, 564 unsigned long page_size_mask) 565 { 566 pud_t *pud; 567 568 pud = (pud_t *)pgd_page_vaddr(*pgd); 569 570 return phys_pud_init(pud, addr, end, page_size_mask); 571 } 572 573 unsigned long __init 574 kernel_physical_mapping_init(unsigned long start, 575 unsigned long end, 576 unsigned long page_size_mask) 577 { 578 579 unsigned long next, last_map_addr = end; 580 581 start = (unsigned long)__va(start); 582 end = (unsigned long)__va(end); 583 584 for (; start < end; start = next) { 585 pgd_t *pgd = pgd_offset_k(start); 586 unsigned long pud_phys; 587 pud_t *pud; 588 589 next = (start + PGDIR_SIZE) & PGDIR_MASK; 590 if (next > end) 591 next = end; 592 593 if (pgd_val(*pgd)) { 594 last_map_addr = phys_pud_update(pgd, __pa(start), 595 __pa(end), page_size_mask); 596 continue; 597 } 598 599 pud = alloc_low_page(&pud_phys); 600 last_map_addr = phys_pud_init(pud, __pa(start), __pa(next), 601 page_size_mask); 602 unmap_low_page(pud); 603 604 spin_lock(&init_mm.page_table_lock); 605 pgd_populate(&init_mm, pgd, __va(pud_phys)); 606 spin_unlock(&init_mm.page_table_lock); 607 } 608 __flush_tlb_all(); 609 610 return last_map_addr; 611 } 612 613 #ifndef CONFIG_NUMA 614 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn) 615 { 616 unsigned long bootmap_size, bootmap; 617 618 bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT; 619 bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size, 620 PAGE_SIZE); 621 if (bootmap == -1L) 622 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 623 /* don't touch min_low_pfn */ 624 bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT, 625 0, end_pfn); 626 e820_register_active_regions(0, start_pfn, end_pfn); 627 free_bootmem_with_active_regions(0, end_pfn); 628 early_res_to_bootmem(0, end_pfn<<PAGE_SHIFT); 629 reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT); 630 } 631 632 void __init paging_init(void) 633 { 634 unsigned long max_zone_pfns[MAX_NR_ZONES]; 635 636 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 637 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; 638 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; 639 max_zone_pfns[ZONE_NORMAL] = max_pfn; 640 641 memory_present(0, 0, max_pfn); 642 sparse_init(); 643 free_area_init_nodes(max_zone_pfns); 644 } 645 #endif 646 647 /* 648 * Memory hotplug specific functions 649 */ 650 #ifdef CONFIG_MEMORY_HOTPLUG 651 /* 652 * Memory is added always to NORMAL zone. This means you will never get 653 * additional DMA/DMA32 memory. 654 */ 655 int arch_add_memory(int nid, u64 start, u64 size) 656 { 657 struct pglist_data *pgdat = NODE_DATA(nid); 658 struct zone *zone = pgdat->node_zones + ZONE_NORMAL; 659 unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT; 660 unsigned long nr_pages = size >> PAGE_SHIFT; 661 int ret; 662 663 last_mapped_pfn = init_memory_mapping(start, start + size); 664 if (last_mapped_pfn > max_pfn_mapped) 665 max_pfn_mapped = last_mapped_pfn; 666 667 ret = __add_pages(nid, zone, start_pfn, nr_pages); 668 WARN_ON_ONCE(ret); 669 670 return ret; 671 } 672 EXPORT_SYMBOL_GPL(arch_add_memory); 673 674 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA) 675 int memory_add_physaddr_to_nid(u64 start) 676 { 677 return 0; 678 } 679 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 680 #endif 681 682 #endif /* CONFIG_MEMORY_HOTPLUG */ 683 684 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, 685 kcore_modules, kcore_vsyscall; 686 687 void __init mem_init(void) 688 { 689 long codesize, reservedpages, datasize, initsize; 690 unsigned long absent_pages; 691 692 pci_iommu_alloc(); 693 694 /* clear_bss() already clear the empty_zero_page */ 695 696 reservedpages = 0; 697 698 /* this will put all low memory onto the freelists */ 699 #ifdef CONFIG_NUMA 700 totalram_pages = numa_free_all_bootmem(); 701 #else 702 totalram_pages = free_all_bootmem(); 703 #endif 704 705 absent_pages = absent_pages_in_range(0, max_pfn); 706 reservedpages = max_pfn - totalram_pages - absent_pages; 707 after_bootmem = 1; 708 709 codesize = (unsigned long) &_etext - (unsigned long) &_text; 710 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 711 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 712 713 /* Register memory areas for /proc/kcore */ 714 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 715 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 716 VMALLOC_END-VMALLOC_START); 717 kclist_add(&kcore_kernel, &_stext, _end - _stext); 718 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN); 719 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 720 VSYSCALL_END - VSYSCALL_START); 721 722 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, " 723 "%ldk absent, %ldk reserved, %ldk data, %ldk init)\n", 724 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 725 max_pfn << (PAGE_SHIFT-10), 726 codesize >> 10, 727 absent_pages << (PAGE_SHIFT-10), 728 reservedpages << (PAGE_SHIFT-10), 729 datasize >> 10, 730 initsize >> 10); 731 } 732 733 #ifdef CONFIG_DEBUG_RODATA 734 const int rodata_test_data = 0xC3; 735 EXPORT_SYMBOL_GPL(rodata_test_data); 736 737 static int kernel_set_to_readonly; 738 739 void set_kernel_text_rw(void) 740 { 741 unsigned long start = PFN_ALIGN(_stext); 742 unsigned long end = PFN_ALIGN(__start_rodata); 743 744 if (!kernel_set_to_readonly) 745 return; 746 747 pr_debug("Set kernel text: %lx - %lx for read write\n", 748 start, end); 749 750 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 751 } 752 753 void set_kernel_text_ro(void) 754 { 755 unsigned long start = PFN_ALIGN(_stext); 756 unsigned long end = PFN_ALIGN(__start_rodata); 757 758 if (!kernel_set_to_readonly) 759 return; 760 761 pr_debug("Set kernel text: %lx - %lx for read only\n", 762 start, end); 763 764 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 765 } 766 767 void mark_rodata_ro(void) 768 { 769 unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata); 770 unsigned long rodata_start = 771 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 772 773 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 774 (end - start) >> 10); 775 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 776 777 kernel_set_to_readonly = 1; 778 779 /* 780 * The rodata section (but not the kernel text!) should also be 781 * not-executable. 782 */ 783 set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); 784 785 rodata_test(); 786 787 #ifdef CONFIG_CPA_DEBUG 788 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 789 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 790 791 printk(KERN_INFO "Testing CPA: again\n"); 792 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 793 #endif 794 } 795 796 #endif 797 798 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 799 int flags) 800 { 801 #ifdef CONFIG_NUMA 802 int nid, next_nid; 803 int ret; 804 #endif 805 unsigned long pfn = phys >> PAGE_SHIFT; 806 807 if (pfn >= max_pfn) { 808 /* 809 * This can happen with kdump kernels when accessing 810 * firmware tables: 811 */ 812 if (pfn < max_pfn_mapped) 813 return -EFAULT; 814 815 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %lu\n", 816 phys, len); 817 return -EFAULT; 818 } 819 820 /* Should check here against the e820 map to avoid double free */ 821 #ifdef CONFIG_NUMA 822 nid = phys_to_nid(phys); 823 next_nid = phys_to_nid(phys + len - 1); 824 if (nid == next_nid) 825 ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags); 826 else 827 ret = reserve_bootmem(phys, len, flags); 828 829 if (ret != 0) 830 return ret; 831 832 #else 833 reserve_bootmem(phys, len, BOOTMEM_DEFAULT); 834 #endif 835 836 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) { 837 dma_reserve += len / PAGE_SIZE; 838 set_dma_reserve(dma_reserve); 839 } 840 841 return 0; 842 } 843 844 int kern_addr_valid(unsigned long addr) 845 { 846 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 847 pgd_t *pgd; 848 pud_t *pud; 849 pmd_t *pmd; 850 pte_t *pte; 851 852 if (above != 0 && above != -1UL) 853 return 0; 854 855 pgd = pgd_offset_k(addr); 856 if (pgd_none(*pgd)) 857 return 0; 858 859 pud = pud_offset(pgd, addr); 860 if (pud_none(*pud)) 861 return 0; 862 863 pmd = pmd_offset(pud, addr); 864 if (pmd_none(*pmd)) 865 return 0; 866 867 if (pmd_large(*pmd)) 868 return pfn_valid(pmd_pfn(*pmd)); 869 870 pte = pte_offset_kernel(pmd, addr); 871 if (pte_none(*pte)) 872 return 0; 873 874 return pfn_valid(pte_pfn(*pte)); 875 } 876 877 /* 878 * A pseudo VMA to allow ptrace access for the vsyscall page. This only 879 * covers the 64bit vsyscall page now. 32bit has a real VMA now and does 880 * not need special handling anymore: 881 */ 882 static struct vm_area_struct gate_vma = { 883 .vm_start = VSYSCALL_START, 884 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE), 885 .vm_page_prot = PAGE_READONLY_EXEC, 886 .vm_flags = VM_READ | VM_EXEC 887 }; 888 889 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 890 { 891 #ifdef CONFIG_IA32_EMULATION 892 if (test_tsk_thread_flag(tsk, TIF_IA32)) 893 return NULL; 894 #endif 895 return &gate_vma; 896 } 897 898 int in_gate_area(struct task_struct *task, unsigned long addr) 899 { 900 struct vm_area_struct *vma = get_gate_vma(task); 901 902 if (!vma) 903 return 0; 904 905 return (addr >= vma->vm_start) && (addr < vma->vm_end); 906 } 907 908 /* 909 * Use this when you have no reliable task/vma, typically from interrupt 910 * context. It is less reliable than using the task's vma and may give 911 * false positives: 912 */ 913 int in_gate_area_no_task(unsigned long addr) 914 { 915 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END); 916 } 917 918 const char *arch_vma_name(struct vm_area_struct *vma) 919 { 920 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) 921 return "[vdso]"; 922 if (vma == &gate_vma) 923 return "[vsyscall]"; 924 return NULL; 925 } 926 927 #ifdef CONFIG_SPARSEMEM_VMEMMAP 928 /* 929 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 930 */ 931 static long __meminitdata addr_start, addr_end; 932 static void __meminitdata *p_start, *p_end; 933 static int __meminitdata node_start; 934 935 int __meminit 936 vmemmap_populate(struct page *start_page, unsigned long size, int node) 937 { 938 unsigned long addr = (unsigned long)start_page; 939 unsigned long end = (unsigned long)(start_page + size); 940 unsigned long next; 941 pgd_t *pgd; 942 pud_t *pud; 943 pmd_t *pmd; 944 945 for (; addr < end; addr = next) { 946 void *p = NULL; 947 948 pgd = vmemmap_pgd_populate(addr, node); 949 if (!pgd) 950 return -ENOMEM; 951 952 pud = vmemmap_pud_populate(pgd, addr, node); 953 if (!pud) 954 return -ENOMEM; 955 956 if (!cpu_has_pse) { 957 next = (addr + PAGE_SIZE) & PAGE_MASK; 958 pmd = vmemmap_pmd_populate(pud, addr, node); 959 960 if (!pmd) 961 return -ENOMEM; 962 963 p = vmemmap_pte_populate(pmd, addr, node); 964 965 if (!p) 966 return -ENOMEM; 967 968 addr_end = addr + PAGE_SIZE; 969 p_end = p + PAGE_SIZE; 970 } else { 971 next = pmd_addr_end(addr, end); 972 973 pmd = pmd_offset(pud, addr); 974 if (pmd_none(*pmd)) { 975 pte_t entry; 976 977 p = vmemmap_alloc_block(PMD_SIZE, node); 978 if (!p) 979 return -ENOMEM; 980 981 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 982 PAGE_KERNEL_LARGE); 983 set_pmd(pmd, __pmd(pte_val(entry))); 984 985 /* check to see if we have contiguous blocks */ 986 if (p_end != p || node_start != node) { 987 if (p_start) 988 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 989 addr_start, addr_end-1, p_start, p_end-1, node_start); 990 addr_start = addr; 991 node_start = node; 992 p_start = p; 993 } 994 995 addr_end = addr + PMD_SIZE; 996 p_end = p + PMD_SIZE; 997 } else 998 vmemmap_verify((pte_t *)pmd, node, addr, next); 999 } 1000 1001 } 1002 return 0; 1003 } 1004 1005 void __meminit vmemmap_populate_print_last(void) 1006 { 1007 if (p_start) { 1008 printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n", 1009 addr_start, addr_end-1, p_start, p_end-1, node_start); 1010 p_start = NULL; 1011 p_end = NULL; 1012 node_start = 0; 1013 } 1014 } 1015 #endif 1016