1 /* 2 * 3 * Copyright (C) 1995 Linus Torvalds 4 * 5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 6 */ 7 8 #include <linux/module.h> 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/hugetlb.h> 19 #include <linux/swap.h> 20 #include <linux/smp.h> 21 #include <linux/init.h> 22 #include <linux/highmem.h> 23 #include <linux/pagemap.h> 24 #include <linux/pfn.h> 25 #include <linux/poison.h> 26 #include <linux/bootmem.h> 27 #include <linux/slab.h> 28 #include <linux/proc_fs.h> 29 #include <linux/memory_hotplug.h> 30 #include <linux/initrd.h> 31 #include <linux/cpumask.h> 32 33 #include <asm/asm.h> 34 #include <asm/processor.h> 35 #include <asm/system.h> 36 #include <asm/uaccess.h> 37 #include <asm/pgtable.h> 38 #include <asm/dma.h> 39 #include <asm/fixmap.h> 40 #include <asm/e820.h> 41 #include <asm/apic.h> 42 #include <asm/bugs.h> 43 #include <asm/tlb.h> 44 #include <asm/tlbflush.h> 45 #include <asm/pgalloc.h> 46 #include <asm/sections.h> 47 #include <asm/paravirt.h> 48 #include <asm/setup.h> 49 #include <asm/cacheflush.h> 50 51 unsigned int __VMALLOC_RESERVE = 128 << 20; 52 53 unsigned long max_low_pfn_mapped; 54 unsigned long max_pfn_mapped; 55 56 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 57 unsigned long highstart_pfn, highend_pfn; 58 59 static noinline int do_test_wp_bit(void); 60 61 62 static unsigned long __initdata table_start; 63 static unsigned long __meminitdata table_end; 64 static unsigned long __meminitdata table_top; 65 66 static int __initdata after_init_bootmem; 67 68 static __init void *alloc_low_page(unsigned long *phys) 69 { 70 unsigned long pfn = table_end++; 71 void *adr; 72 73 if (pfn >= table_top) 74 panic("alloc_low_page: ran out of memory"); 75 76 adr = __va(pfn * PAGE_SIZE); 77 memset(adr, 0, PAGE_SIZE); 78 *phys = pfn * PAGE_SIZE; 79 return adr; 80 } 81 82 /* 83 * Creates a middle page table and puts a pointer to it in the 84 * given global directory entry. This only returns the gd entry 85 * in non-PAE compilation mode, since the middle layer is folded. 86 */ 87 static pmd_t * __init one_md_table_init(pgd_t *pgd) 88 { 89 pud_t *pud; 90 pmd_t *pmd_table; 91 92 #ifdef CONFIG_X86_PAE 93 unsigned long phys; 94 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 95 if (after_init_bootmem) 96 pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); 97 else 98 pmd_table = (pmd_t *)alloc_low_page(&phys); 99 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 100 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 101 pud = pud_offset(pgd, 0); 102 BUG_ON(pmd_table != pmd_offset(pud, 0)); 103 } 104 #endif 105 pud = pud_offset(pgd, 0); 106 pmd_table = pmd_offset(pud, 0); 107 108 return pmd_table; 109 } 110 111 /* 112 * Create a page table and place a pointer to it in a middle page 113 * directory entry: 114 */ 115 static pte_t * __init one_page_table_init(pmd_t *pmd) 116 { 117 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 118 pte_t *page_table = NULL; 119 120 if (after_init_bootmem) { 121 #ifdef CONFIG_DEBUG_PAGEALLOC 122 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); 123 #endif 124 if (!page_table) 125 page_table = 126 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); 127 } else { 128 unsigned long phys; 129 page_table = (pte_t *)alloc_low_page(&phys); 130 } 131 132 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 133 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 134 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 135 } 136 137 return pte_offset_kernel(pmd, 0); 138 } 139 140 /* 141 * This function initializes a certain range of kernel virtual memory 142 * with new bootmem page tables, everywhere page tables are missing in 143 * the given range. 144 * 145 * NOTE: The pagetables are allocated contiguous on the physical space 146 * so we can cache the place of the first one and move around without 147 * checking the pgd every time. 148 */ 149 static void __init 150 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 151 { 152 int pgd_idx, pmd_idx; 153 unsigned long vaddr; 154 pgd_t *pgd; 155 pmd_t *pmd; 156 157 vaddr = start; 158 pgd_idx = pgd_index(vaddr); 159 pmd_idx = pmd_index(vaddr); 160 pgd = pgd_base + pgd_idx; 161 162 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 163 pmd = one_md_table_init(pgd); 164 pmd = pmd + pmd_index(vaddr); 165 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 166 pmd++, pmd_idx++) { 167 one_page_table_init(pmd); 168 169 vaddr += PMD_SIZE; 170 } 171 pmd_idx = 0; 172 } 173 } 174 175 static inline int is_kernel_text(unsigned long addr) 176 { 177 if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) 178 return 1; 179 return 0; 180 } 181 182 /* 183 * This maps the physical memory to kernel virtual address space, a total 184 * of max_low_pfn pages, by creating page tables starting from address 185 * PAGE_OFFSET: 186 */ 187 static void __init kernel_physical_mapping_init(pgd_t *pgd_base, 188 unsigned long start_pfn, 189 unsigned long end_pfn, 190 int use_pse) 191 { 192 int pgd_idx, pmd_idx, pte_ofs; 193 unsigned long pfn; 194 pgd_t *pgd; 195 pmd_t *pmd; 196 pte_t *pte; 197 unsigned pages_2m = 0, pages_4k = 0; 198 199 if (!cpu_has_pse) 200 use_pse = 0; 201 202 pfn = start_pfn; 203 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 204 pgd = pgd_base + pgd_idx; 205 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 206 pmd = one_md_table_init(pgd); 207 208 if (pfn >= end_pfn) 209 continue; 210 #ifdef CONFIG_X86_PAE 211 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 212 pmd += pmd_idx; 213 #else 214 pmd_idx = 0; 215 #endif 216 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 217 pmd++, pmd_idx++) { 218 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 219 220 /* 221 * Map with big pages if possible, otherwise 222 * create normal page tables: 223 */ 224 if (use_pse) { 225 unsigned int addr2; 226 pgprot_t prot = PAGE_KERNEL_LARGE; 227 228 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 229 PAGE_OFFSET + PAGE_SIZE-1; 230 231 if (is_kernel_text(addr) || 232 is_kernel_text(addr2)) 233 prot = PAGE_KERNEL_LARGE_EXEC; 234 235 pages_2m++; 236 set_pmd(pmd, pfn_pmd(pfn, prot)); 237 238 pfn += PTRS_PER_PTE; 239 continue; 240 } 241 pte = one_page_table_init(pmd); 242 243 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 244 pte += pte_ofs; 245 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 246 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 247 pgprot_t prot = PAGE_KERNEL; 248 249 if (is_kernel_text(addr)) 250 prot = PAGE_KERNEL_EXEC; 251 252 pages_4k++; 253 set_pte(pte, pfn_pte(pfn, prot)); 254 } 255 } 256 } 257 update_page_count(PG_LEVEL_2M, pages_2m); 258 update_page_count(PG_LEVEL_4K, pages_4k); 259 } 260 261 /* 262 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 263 * is valid. The argument is a physical page number. 264 * 265 * 266 * On x86, access has to be given to the first megabyte of ram because that area 267 * contains bios code and data regions used by X and dosemu and similar apps. 268 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 269 * mmio resources as well as potential bios/acpi data regions. 270 */ 271 int devmem_is_allowed(unsigned long pagenr) 272 { 273 if (pagenr <= 256) 274 return 1; 275 if (!page_is_ram(pagenr)) 276 return 1; 277 return 0; 278 } 279 280 #ifdef CONFIG_HIGHMEM 281 pte_t *kmap_pte; 282 pgprot_t kmap_prot; 283 284 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 285 { 286 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 287 vaddr), vaddr), vaddr); 288 } 289 290 static void __init kmap_init(void) 291 { 292 unsigned long kmap_vstart; 293 294 /* 295 * Cache the first kmap pte: 296 */ 297 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 298 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 299 300 kmap_prot = PAGE_KERNEL; 301 } 302 303 static void __init permanent_kmaps_init(pgd_t *pgd_base) 304 { 305 unsigned long vaddr; 306 pgd_t *pgd; 307 pud_t *pud; 308 pmd_t *pmd; 309 pte_t *pte; 310 311 vaddr = PKMAP_BASE; 312 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 313 314 pgd = swapper_pg_dir + pgd_index(vaddr); 315 pud = pud_offset(pgd, vaddr); 316 pmd = pmd_offset(pud, vaddr); 317 pte = pte_offset_kernel(pmd, vaddr); 318 pkmap_page_table = pte; 319 } 320 321 static void __init add_one_highpage_init(struct page *page, int pfn) 322 { 323 ClearPageReserved(page); 324 init_page_count(page); 325 __free_page(page); 326 totalhigh_pages++; 327 } 328 329 struct add_highpages_data { 330 unsigned long start_pfn; 331 unsigned long end_pfn; 332 }; 333 334 static int __init add_highpages_work_fn(unsigned long start_pfn, 335 unsigned long end_pfn, void *datax) 336 { 337 int node_pfn; 338 struct page *page; 339 unsigned long final_start_pfn, final_end_pfn; 340 struct add_highpages_data *data; 341 342 data = (struct add_highpages_data *)datax; 343 344 final_start_pfn = max(start_pfn, data->start_pfn); 345 final_end_pfn = min(end_pfn, data->end_pfn); 346 if (final_start_pfn >= final_end_pfn) 347 return 0; 348 349 for (node_pfn = final_start_pfn; node_pfn < final_end_pfn; 350 node_pfn++) { 351 if (!pfn_valid(node_pfn)) 352 continue; 353 page = pfn_to_page(node_pfn); 354 add_one_highpage_init(page, node_pfn); 355 } 356 357 return 0; 358 359 } 360 361 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn, 362 unsigned long end_pfn) 363 { 364 struct add_highpages_data data; 365 366 data.start_pfn = start_pfn; 367 data.end_pfn = end_pfn; 368 369 work_with_active_regions(nid, add_highpages_work_fn, &data); 370 } 371 372 #ifndef CONFIG_NUMA 373 static void __init set_highmem_pages_init(void) 374 { 375 add_highpages_with_active_regions(0, highstart_pfn, highend_pfn); 376 377 totalram_pages += totalhigh_pages; 378 } 379 #endif /* !CONFIG_NUMA */ 380 381 #else 382 # define kmap_init() do { } while (0) 383 # define permanent_kmaps_init(pgd_base) do { } while (0) 384 # define set_highmem_pages_init() do { } while (0) 385 #endif /* CONFIG_HIGHMEM */ 386 387 void __init native_pagetable_setup_start(pgd_t *base) 388 { 389 unsigned long pfn, va; 390 pgd_t *pgd; 391 pud_t *pud; 392 pmd_t *pmd; 393 pte_t *pte; 394 395 /* 396 * Remove any mappings which extend past the end of physical 397 * memory from the boot time page table: 398 */ 399 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 400 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 401 pgd = base + pgd_index(va); 402 if (!pgd_present(*pgd)) 403 break; 404 405 pud = pud_offset(pgd, va); 406 pmd = pmd_offset(pud, va); 407 if (!pmd_present(*pmd)) 408 break; 409 410 pte = pte_offset_kernel(pmd, va); 411 if (!pte_present(*pte)) 412 break; 413 414 pte_clear(NULL, va, pte); 415 } 416 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 417 } 418 419 void __init native_pagetable_setup_done(pgd_t *base) 420 { 421 } 422 423 /* 424 * Build a proper pagetable for the kernel mappings. Up until this 425 * point, we've been running on some set of pagetables constructed by 426 * the boot process. 427 * 428 * If we're booting on native hardware, this will be a pagetable 429 * constructed in arch/x86/kernel/head_32.S. The root of the 430 * pagetable will be swapper_pg_dir. 431 * 432 * If we're booting paravirtualized under a hypervisor, then there are 433 * more options: we may already be running PAE, and the pagetable may 434 * or may not be based in swapper_pg_dir. In any case, 435 * paravirt_pagetable_setup_start() will set up swapper_pg_dir 436 * appropriately for the rest of the initialization to work. 437 * 438 * In general, pagetable_init() assumes that the pagetable may already 439 * be partially populated, and so it avoids stomping on any existing 440 * mappings. 441 */ 442 static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base) 443 { 444 unsigned long vaddr, end; 445 446 /* 447 * Fixed mappings, only the page table structure has to be 448 * created - mappings will be set by set_fixmap(): 449 */ 450 early_ioremap_clear(); 451 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 452 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 453 page_table_range_init(vaddr, end, pgd_base); 454 early_ioremap_reset(); 455 } 456 457 static void __init pagetable_init(void) 458 { 459 pgd_t *pgd_base = swapper_pg_dir; 460 461 permanent_kmaps_init(pgd_base); 462 } 463 464 #ifdef CONFIG_ACPI_SLEEP 465 /* 466 * ACPI suspend needs this for resume, because things like the intel-agp 467 * driver might have split up a kernel 4MB mapping. 468 */ 469 char swsusp_pg_dir[PAGE_SIZE] 470 __attribute__ ((aligned(PAGE_SIZE))); 471 472 static inline void save_pg_dir(void) 473 { 474 memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); 475 } 476 #else /* !CONFIG_ACPI_SLEEP */ 477 static inline void save_pg_dir(void) 478 { 479 } 480 #endif /* !CONFIG_ACPI_SLEEP */ 481 482 void zap_low_mappings(void) 483 { 484 int i; 485 486 /* 487 * Zap initial low-memory mappings. 488 * 489 * Note that "pgd_clear()" doesn't do it for 490 * us, because pgd_clear() is a no-op on i386. 491 */ 492 for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) { 493 #ifdef CONFIG_X86_PAE 494 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); 495 #else 496 set_pgd(swapper_pg_dir+i, __pgd(0)); 497 #endif 498 } 499 flush_tlb_all(); 500 } 501 502 int nx_enabled; 503 504 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); 505 EXPORT_SYMBOL_GPL(__supported_pte_mask); 506 507 #ifdef CONFIG_X86_PAE 508 509 static int disable_nx __initdata; 510 511 /* 512 * noexec = on|off 513 * 514 * Control non executable mappings. 515 * 516 * on Enable 517 * off Disable 518 */ 519 static int __init noexec_setup(char *str) 520 { 521 if (!str || !strcmp(str, "on")) { 522 if (cpu_has_nx) { 523 __supported_pte_mask |= _PAGE_NX; 524 disable_nx = 0; 525 } 526 } else { 527 if (!strcmp(str, "off")) { 528 disable_nx = 1; 529 __supported_pte_mask &= ~_PAGE_NX; 530 } else { 531 return -EINVAL; 532 } 533 } 534 535 return 0; 536 } 537 early_param("noexec", noexec_setup); 538 539 static void __init set_nx(void) 540 { 541 unsigned int v[4], l, h; 542 543 if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { 544 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); 545 546 if ((v[3] & (1 << 20)) && !disable_nx) { 547 rdmsr(MSR_EFER, l, h); 548 l |= EFER_NX; 549 wrmsr(MSR_EFER, l, h); 550 nx_enabled = 1; 551 __supported_pte_mask |= _PAGE_NX; 552 } 553 } 554 } 555 #endif 556 557 /* user-defined highmem size */ 558 static unsigned int highmem_pages = -1; 559 560 /* 561 * highmem=size forces highmem to be exactly 'size' bytes. 562 * This works even on boxes that have no highmem otherwise. 563 * This also works to reduce highmem size on bigger boxes. 564 */ 565 static int __init parse_highmem(char *arg) 566 { 567 if (!arg) 568 return -EINVAL; 569 570 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 571 return 0; 572 } 573 early_param("highmem", parse_highmem); 574 575 /* 576 * Determine low and high memory ranges: 577 */ 578 void __init find_low_pfn_range(void) 579 { 580 /* it could update max_pfn */ 581 582 /* max_low_pfn is 0, we already have early_res support */ 583 584 max_low_pfn = max_pfn; 585 if (max_low_pfn > MAXMEM_PFN) { 586 if (highmem_pages == -1) 587 highmem_pages = max_pfn - MAXMEM_PFN; 588 if (highmem_pages + MAXMEM_PFN < max_pfn) 589 max_pfn = MAXMEM_PFN + highmem_pages; 590 if (highmem_pages + MAXMEM_PFN > max_pfn) { 591 printk(KERN_WARNING "only %luMB highmem pages " 592 "available, ignoring highmem size of %uMB.\n", 593 pages_to_mb(max_pfn - MAXMEM_PFN), 594 pages_to_mb(highmem_pages)); 595 highmem_pages = 0; 596 } 597 max_low_pfn = MAXMEM_PFN; 598 #ifndef CONFIG_HIGHMEM 599 /* Maximum memory usable is what is directly addressable */ 600 printk(KERN_WARNING "Warning only %ldMB will be used.\n", 601 MAXMEM>>20); 602 if (max_pfn > MAX_NONPAE_PFN) 603 printk(KERN_WARNING 604 "Use a HIGHMEM64G enabled kernel.\n"); 605 else 606 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 607 max_pfn = MAXMEM_PFN; 608 #else /* !CONFIG_HIGHMEM */ 609 #ifndef CONFIG_HIGHMEM64G 610 if (max_pfn > MAX_NONPAE_PFN) { 611 max_pfn = MAX_NONPAE_PFN; 612 printk(KERN_WARNING "Warning only 4GB will be used." 613 "Use a HIGHMEM64G enabled kernel.\n"); 614 } 615 #endif /* !CONFIG_HIGHMEM64G */ 616 #endif /* !CONFIG_HIGHMEM */ 617 } else { 618 if (highmem_pages == -1) 619 highmem_pages = 0; 620 #ifdef CONFIG_HIGHMEM 621 if (highmem_pages >= max_pfn) { 622 printk(KERN_ERR "highmem size specified (%uMB) is " 623 "bigger than pages available (%luMB)!.\n", 624 pages_to_mb(highmem_pages), 625 pages_to_mb(max_pfn)); 626 highmem_pages = 0; 627 } 628 if (highmem_pages) { 629 if (max_low_pfn - highmem_pages < 630 64*1024*1024/PAGE_SIZE){ 631 printk(KERN_ERR "highmem size %uMB results in " 632 "smaller than 64MB lowmem, ignoring it.\n" 633 , pages_to_mb(highmem_pages)); 634 highmem_pages = 0; 635 } 636 max_low_pfn -= highmem_pages; 637 } 638 #else 639 if (highmem_pages) 640 printk(KERN_ERR "ignoring highmem size on non-highmem" 641 " kernel!\n"); 642 #endif 643 } 644 } 645 646 #ifndef CONFIG_NEED_MULTIPLE_NODES 647 void __init initmem_init(unsigned long start_pfn, 648 unsigned long end_pfn) 649 { 650 #ifdef CONFIG_HIGHMEM 651 highstart_pfn = highend_pfn = max_pfn; 652 if (max_pfn > max_low_pfn) 653 highstart_pfn = max_low_pfn; 654 memory_present(0, 0, highend_pfn); 655 e820_register_active_regions(0, 0, highend_pfn); 656 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 657 pages_to_mb(highend_pfn - highstart_pfn)); 658 num_physpages = highend_pfn; 659 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 660 #else 661 memory_present(0, 0, max_low_pfn); 662 e820_register_active_regions(0, 0, max_low_pfn); 663 num_physpages = max_low_pfn; 664 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 665 #endif 666 #ifdef CONFIG_FLATMEM 667 max_mapnr = num_physpages; 668 #endif 669 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 670 pages_to_mb(max_low_pfn)); 671 672 setup_bootmem_allocator(); 673 } 674 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 675 676 static void __init zone_sizes_init(void) 677 { 678 unsigned long max_zone_pfns[MAX_NR_ZONES]; 679 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 680 max_zone_pfns[ZONE_DMA] = 681 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 682 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 683 #ifdef CONFIG_HIGHMEM 684 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn; 685 #endif 686 687 free_area_init_nodes(max_zone_pfns); 688 } 689 690 void __init setup_bootmem_allocator(void) 691 { 692 int i; 693 unsigned long bootmap_size, bootmap; 694 /* 695 * Initialize the boot-time allocator (with low memory only): 696 */ 697 bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT; 698 bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT, 699 max_pfn_mapped<<PAGE_SHIFT, bootmap_size, 700 PAGE_SIZE); 701 if (bootmap == -1L) 702 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 703 reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP"); 704 705 /* don't touch min_low_pfn */ 706 bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT, 707 min_low_pfn, max_low_pfn); 708 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 709 max_pfn_mapped<<PAGE_SHIFT); 710 printk(KERN_INFO " low ram: %08lx - %08lx\n", 711 min_low_pfn<<PAGE_SHIFT, max_low_pfn<<PAGE_SHIFT); 712 printk(KERN_INFO " bootmap %08lx - %08lx\n", 713 bootmap, bootmap + bootmap_size); 714 for_each_online_node(i) 715 free_bootmem_with_active_regions(i, max_low_pfn); 716 early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT); 717 718 after_init_bootmem = 1; 719 } 720 721 static void __init find_early_table_space(unsigned long end) 722 { 723 unsigned long puds, pmds, ptes, tables, start; 724 725 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; 726 tables = PAGE_ALIGN(puds * sizeof(pud_t)); 727 728 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; 729 tables += PAGE_ALIGN(pmds * sizeof(pmd_t)); 730 731 if (cpu_has_pse) { 732 unsigned long extra; 733 734 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); 735 extra += PMD_SIZE; 736 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; 737 } else 738 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; 739 740 tables += PAGE_ALIGN(ptes * sizeof(pte_t)); 741 742 /* for fixmap */ 743 tables += PAGE_SIZE * 2; 744 745 /* 746 * RED-PEN putting page tables only on node 0 could 747 * cause a hotspot and fill up ZONE_DMA. The page tables 748 * need roughly 0.5KB per GB. 749 */ 750 start = 0x7000; 751 table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT, 752 tables, PAGE_SIZE); 753 if (table_start == -1UL) 754 panic("Cannot find space for the kernel page tables"); 755 756 table_start >>= PAGE_SHIFT; 757 table_end = table_start; 758 table_top = table_start + (tables>>PAGE_SHIFT); 759 760 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", 761 end, table_start << PAGE_SHIFT, 762 (table_start << PAGE_SHIFT) + tables); 763 } 764 765 unsigned long __init_refok init_memory_mapping(unsigned long start, 766 unsigned long end) 767 { 768 pgd_t *pgd_base = swapper_pg_dir; 769 unsigned long start_pfn, end_pfn; 770 unsigned long big_page_start; 771 772 /* 773 * Find space for the kernel direct mapping tables. 774 */ 775 if (!after_init_bootmem) 776 find_early_table_space(end); 777 778 #ifdef CONFIG_X86_PAE 779 set_nx(); 780 if (nx_enabled) 781 printk(KERN_INFO "NX (Execute Disable) protection: active\n"); 782 #endif 783 784 /* Enable PSE if available */ 785 if (cpu_has_pse) 786 set_in_cr4(X86_CR4_PSE); 787 788 /* Enable PGE if available */ 789 if (cpu_has_pge) { 790 set_in_cr4(X86_CR4_PGE); 791 __supported_pte_mask |= _PAGE_GLOBAL; 792 } 793 794 /* 795 * Don't use a large page for the first 2/4MB of memory 796 * because there are often fixed size MTRRs in there 797 * and overlapping MTRRs into large pages can cause 798 * slowdowns. 799 */ 800 big_page_start = PMD_SIZE; 801 802 if (start < big_page_start) { 803 start_pfn = start >> PAGE_SHIFT; 804 end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT); 805 } else { 806 /* head is not big page alignment ? */ 807 start_pfn = start >> PAGE_SHIFT; 808 end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT) 809 << (PMD_SHIFT - PAGE_SHIFT); 810 } 811 if (start_pfn < end_pfn) 812 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0); 813 814 /* big page range */ 815 start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT) 816 << (PMD_SHIFT - PAGE_SHIFT); 817 if (start_pfn < (big_page_start >> PAGE_SHIFT)) 818 start_pfn = big_page_start >> PAGE_SHIFT; 819 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 820 if (start_pfn < end_pfn) 821 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 822 cpu_has_pse); 823 824 /* tail is not big page alignment ? */ 825 start_pfn = end_pfn; 826 if (start_pfn > (big_page_start>>PAGE_SHIFT)) { 827 end_pfn = end >> PAGE_SHIFT; 828 if (start_pfn < end_pfn) 829 kernel_physical_mapping_init(pgd_base, start_pfn, 830 end_pfn, 0); 831 } 832 833 early_ioremap_page_table_range_init(pgd_base); 834 835 load_cr3(swapper_pg_dir); 836 837 __flush_tlb_all(); 838 839 if (!after_init_bootmem) 840 reserve_early(table_start << PAGE_SHIFT, 841 table_end << PAGE_SHIFT, "PGTABLE"); 842 843 if (!after_init_bootmem) 844 early_memtest(start, end); 845 846 return end >> PAGE_SHIFT; 847 } 848 849 850 /* 851 * paging_init() sets up the page tables - note that the first 8MB are 852 * already mapped by head.S. 853 * 854 * This routines also unmaps the page at virtual kernel address 0, so 855 * that we can trap those pesky NULL-reference errors in the kernel. 856 */ 857 void __init paging_init(void) 858 { 859 pagetable_init(); 860 861 __flush_tlb_all(); 862 863 kmap_init(); 864 865 /* 866 * NOTE: at this point the bootmem allocator is fully available. 867 */ 868 sparse_init(); 869 zone_sizes_init(); 870 } 871 872 /* 873 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 874 * and also on some strange 486's. All 586+'s are OK. This used to involve 875 * black magic jumps to work around some nasty CPU bugs, but fortunately the 876 * switch to using exceptions got rid of all that. 877 */ 878 static void __init test_wp_bit(void) 879 { 880 printk(KERN_INFO 881 "Checking if this processor honours the WP bit even in supervisor mode..."); 882 883 /* Any page-aligned address will do, the test is non-destructive */ 884 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); 885 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 886 clear_fixmap(FIX_WP_TEST); 887 888 if (!boot_cpu_data.wp_works_ok) { 889 printk(KERN_CONT "No.\n"); 890 #ifdef CONFIG_X86_WP_WORKS_OK 891 panic( 892 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 893 #endif 894 } else { 895 printk(KERN_CONT "Ok.\n"); 896 } 897 } 898 899 static struct kcore_list kcore_mem, kcore_vmalloc; 900 901 void __init mem_init(void) 902 { 903 int codesize, reservedpages, datasize, initsize; 904 int tmp; 905 906 #ifdef CONFIG_FLATMEM 907 BUG_ON(!mem_map); 908 #endif 909 /* this will put all low memory onto the freelists */ 910 totalram_pages += free_all_bootmem(); 911 912 reservedpages = 0; 913 for (tmp = 0; tmp < max_low_pfn; tmp++) 914 /* 915 * Only count reserved RAM pages: 916 */ 917 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 918 reservedpages++; 919 920 set_highmem_pages_init(); 921 922 codesize = (unsigned long) &_etext - (unsigned long) &_text; 923 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 924 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 925 926 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 927 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 928 VMALLOC_END-VMALLOC_START); 929 930 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 931 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 932 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 933 num_physpages << (PAGE_SHIFT-10), 934 codesize >> 10, 935 reservedpages << (PAGE_SHIFT-10), 936 datasize >> 10, 937 initsize >> 10, 938 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) 939 ); 940 941 printk(KERN_INFO "virtual kernel memory layout:\n" 942 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 943 #ifdef CONFIG_HIGHMEM 944 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 945 #endif 946 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 947 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 948 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 949 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 950 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 951 FIXADDR_START, FIXADDR_TOP, 952 (FIXADDR_TOP - FIXADDR_START) >> 10, 953 954 #ifdef CONFIG_HIGHMEM 955 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 956 (LAST_PKMAP*PAGE_SIZE) >> 10, 957 #endif 958 959 VMALLOC_START, VMALLOC_END, 960 (VMALLOC_END - VMALLOC_START) >> 20, 961 962 (unsigned long)__va(0), (unsigned long)high_memory, 963 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 964 965 (unsigned long)&__init_begin, (unsigned long)&__init_end, 966 ((unsigned long)&__init_end - 967 (unsigned long)&__init_begin) >> 10, 968 969 (unsigned long)&_etext, (unsigned long)&_edata, 970 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 971 972 (unsigned long)&_text, (unsigned long)&_etext, 973 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 974 975 #ifdef CONFIG_HIGHMEM 976 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 977 BUG_ON(VMALLOC_END > PKMAP_BASE); 978 #endif 979 BUG_ON(VMALLOC_START > VMALLOC_END); 980 BUG_ON((unsigned long)high_memory > VMALLOC_START); 981 982 if (boot_cpu_data.wp_works_ok < 0) 983 test_wp_bit(); 984 985 cpa_init(); 986 save_pg_dir(); 987 zap_low_mappings(); 988 } 989 990 #ifdef CONFIG_MEMORY_HOTPLUG 991 int arch_add_memory(int nid, u64 start, u64 size) 992 { 993 struct pglist_data *pgdata = NODE_DATA(nid); 994 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 995 unsigned long start_pfn = start >> PAGE_SHIFT; 996 unsigned long nr_pages = size >> PAGE_SHIFT; 997 998 return __add_pages(zone, start_pfn, nr_pages); 999 } 1000 #endif 1001 1002 /* 1003 * This function cannot be __init, since exceptions don't work in that 1004 * section. Put this after the callers, so that it cannot be inlined. 1005 */ 1006 static noinline int do_test_wp_bit(void) 1007 { 1008 char tmp_reg; 1009 int flag; 1010 1011 __asm__ __volatile__( 1012 " movb %0, %1 \n" 1013 "1: movb %1, %0 \n" 1014 " xorl %2, %2 \n" 1015 "2: \n" 1016 _ASM_EXTABLE(1b,2b) 1017 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 1018 "=q" (tmp_reg), 1019 "=r" (flag) 1020 :"2" (1) 1021 :"memory"); 1022 1023 return flag; 1024 } 1025 1026 #ifdef CONFIG_DEBUG_RODATA 1027 const int rodata_test_data = 0xC3; 1028 EXPORT_SYMBOL_GPL(rodata_test_data); 1029 1030 void mark_rodata_ro(void) 1031 { 1032 unsigned long start = PFN_ALIGN(_text); 1033 unsigned long size = PFN_ALIGN(_etext) - start; 1034 1035 #ifndef CONFIG_DYNAMIC_FTRACE 1036 /* Dynamic tracing modifies the kernel text section */ 1037 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1038 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 1039 size >> 10); 1040 1041 #ifdef CONFIG_CPA_DEBUG 1042 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 1043 start, start+size); 1044 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 1045 1046 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1047 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 1048 #endif 1049 #endif /* CONFIG_DYNAMIC_FTRACE */ 1050 1051 start += size; 1052 size = (unsigned long)__end_rodata - start; 1053 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1054 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 1055 size >> 10); 1056 rodata_test(); 1057 1058 #ifdef CONFIG_CPA_DEBUG 1059 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 1060 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1061 1062 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1063 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1064 #endif 1065 } 1066 #endif 1067 1068 void free_init_pages(char *what, unsigned long begin, unsigned long end) 1069 { 1070 #ifdef CONFIG_DEBUG_PAGEALLOC 1071 /* 1072 * If debugging page accesses then do not free this memory but 1073 * mark them not present - any buggy init-section access will 1074 * create a kernel page fault: 1075 */ 1076 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", 1077 begin, PAGE_ALIGN(end)); 1078 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 1079 #else 1080 unsigned long addr; 1081 1082 /* 1083 * We just marked the kernel text read only above, now that 1084 * we are going to free part of that, we need to make that 1085 * writeable first. 1086 */ 1087 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 1088 1089 for (addr = begin; addr < end; addr += PAGE_SIZE) { 1090 ClearPageReserved(virt_to_page(addr)); 1091 init_page_count(virt_to_page(addr)); 1092 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 1093 free_page(addr); 1094 totalram_pages++; 1095 } 1096 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 1097 #endif 1098 } 1099 1100 void free_initmem(void) 1101 { 1102 free_init_pages("unused kernel memory", 1103 (unsigned long)(&__init_begin), 1104 (unsigned long)(&__init_end)); 1105 } 1106 1107 #ifdef CONFIG_BLK_DEV_INITRD 1108 void free_initrd_mem(unsigned long start, unsigned long end) 1109 { 1110 free_init_pages("initrd memory", start, end); 1111 } 1112 #endif 1113 1114 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 1115 int flags) 1116 { 1117 return reserve_bootmem(phys, len, flags); 1118 } 1119