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/bios_ebda.h> 35 #include <asm/processor.h> 36 #include <asm/system.h> 37 #include <asm/uaccess.h> 38 #include <asm/pgtable.h> 39 #include <asm/dma.h> 40 #include <asm/fixmap.h> 41 #include <asm/e820.h> 42 #include <asm/apic.h> 43 #include <asm/bugs.h> 44 #include <asm/tlb.h> 45 #include <asm/tlbflush.h> 46 #include <asm/pgalloc.h> 47 #include <asm/sections.h> 48 #include <asm/paravirt.h> 49 #include <asm/setup.h> 50 #include <asm/cacheflush.h> 51 #include <asm/smp.h> 52 53 unsigned int __VMALLOC_RESERVE = 128 << 20; 54 55 unsigned long max_low_pfn_mapped; 56 unsigned long max_pfn_mapped; 57 58 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 59 unsigned long highstart_pfn, highend_pfn; 60 61 static noinline int do_test_wp_bit(void); 62 63 64 static unsigned long __initdata table_start; 65 static unsigned long __meminitdata table_end; 66 static unsigned long __meminitdata table_top; 67 68 static int __initdata after_init_bootmem; 69 70 static __init void *alloc_low_page(unsigned long *phys) 71 { 72 unsigned long pfn = table_end++; 73 void *adr; 74 75 if (pfn >= table_top) 76 panic("alloc_low_page: ran out of memory"); 77 78 adr = __va(pfn * PAGE_SIZE); 79 memset(adr, 0, PAGE_SIZE); 80 *phys = pfn * PAGE_SIZE; 81 return adr; 82 } 83 84 /* 85 * Creates a middle page table and puts a pointer to it in the 86 * given global directory entry. This only returns the gd entry 87 * in non-PAE compilation mode, since the middle layer is folded. 88 */ 89 static pmd_t * __init one_md_table_init(pgd_t *pgd) 90 { 91 pud_t *pud; 92 pmd_t *pmd_table; 93 94 #ifdef CONFIG_X86_PAE 95 unsigned long phys; 96 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 97 if (after_init_bootmem) 98 pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); 99 else 100 pmd_table = (pmd_t *)alloc_low_page(&phys); 101 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 102 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 103 pud = pud_offset(pgd, 0); 104 BUG_ON(pmd_table != pmd_offset(pud, 0)); 105 } 106 #endif 107 pud = pud_offset(pgd, 0); 108 pmd_table = pmd_offset(pud, 0); 109 110 return pmd_table; 111 } 112 113 /* 114 * Create a page table and place a pointer to it in a middle page 115 * directory entry: 116 */ 117 static pte_t * __init one_page_table_init(pmd_t *pmd) 118 { 119 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 120 pte_t *page_table = NULL; 121 122 if (after_init_bootmem) { 123 #ifdef CONFIG_DEBUG_PAGEALLOC 124 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); 125 #endif 126 if (!page_table) 127 page_table = 128 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); 129 } else { 130 unsigned long phys; 131 page_table = (pte_t *)alloc_low_page(&phys); 132 } 133 134 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 135 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 136 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 137 } 138 139 return pte_offset_kernel(pmd, 0); 140 } 141 142 /* 143 * This function initializes a certain range of kernel virtual memory 144 * with new bootmem page tables, everywhere page tables are missing in 145 * the given range. 146 * 147 * NOTE: The pagetables are allocated contiguous on the physical space 148 * so we can cache the place of the first one and move around without 149 * checking the pgd every time. 150 */ 151 static void __init 152 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 153 { 154 int pgd_idx, pmd_idx; 155 unsigned long vaddr; 156 pgd_t *pgd; 157 pmd_t *pmd; 158 159 vaddr = start; 160 pgd_idx = pgd_index(vaddr); 161 pmd_idx = pmd_index(vaddr); 162 pgd = pgd_base + pgd_idx; 163 164 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 165 pmd = one_md_table_init(pgd); 166 pmd = pmd + pmd_index(vaddr); 167 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 168 pmd++, pmd_idx++) { 169 one_page_table_init(pmd); 170 171 vaddr += PMD_SIZE; 172 } 173 pmd_idx = 0; 174 } 175 } 176 177 static inline int is_kernel_text(unsigned long addr) 178 { 179 if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) 180 return 1; 181 return 0; 182 } 183 184 /* 185 * This maps the physical memory to kernel virtual address space, a total 186 * of max_low_pfn pages, by creating page tables starting from address 187 * PAGE_OFFSET: 188 */ 189 static void __init kernel_physical_mapping_init(pgd_t *pgd_base, 190 unsigned long start_pfn, 191 unsigned long end_pfn, 192 int use_pse) 193 { 194 int pgd_idx, pmd_idx, pte_ofs; 195 unsigned long pfn; 196 pgd_t *pgd; 197 pmd_t *pmd; 198 pte_t *pte; 199 unsigned pages_2m, pages_4k; 200 int mapping_iter; 201 202 /* 203 * First iteration will setup identity mapping using large/small pages 204 * based on use_pse, with other attributes same as set by 205 * the early code in head_32.S 206 * 207 * Second iteration will setup the appropriate attributes (NX, GLOBAL..) 208 * as desired for the kernel identity mapping. 209 * 210 * This two pass mechanism conforms to the TLB app note which says: 211 * 212 * "Software should not write to a paging-structure entry in a way 213 * that would change, for any linear address, both the page size 214 * and either the page frame or attributes." 215 */ 216 mapping_iter = 1; 217 218 if (!cpu_has_pse) 219 use_pse = 0; 220 221 repeat: 222 pages_2m = pages_4k = 0; 223 pfn = start_pfn; 224 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 225 pgd = pgd_base + pgd_idx; 226 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 227 pmd = one_md_table_init(pgd); 228 229 if (pfn >= end_pfn) 230 continue; 231 #ifdef CONFIG_X86_PAE 232 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 233 pmd += pmd_idx; 234 #else 235 pmd_idx = 0; 236 #endif 237 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 238 pmd++, pmd_idx++) { 239 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 240 241 /* 242 * Map with big pages if possible, otherwise 243 * create normal page tables: 244 */ 245 if (use_pse) { 246 unsigned int addr2; 247 pgprot_t prot = PAGE_KERNEL_LARGE; 248 /* 249 * first pass will use the same initial 250 * identity mapping attribute + _PAGE_PSE. 251 */ 252 pgprot_t init_prot = 253 __pgprot(PTE_IDENT_ATTR | 254 _PAGE_PSE); 255 256 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 257 PAGE_OFFSET + PAGE_SIZE-1; 258 259 if (is_kernel_text(addr) || 260 is_kernel_text(addr2)) 261 prot = PAGE_KERNEL_LARGE_EXEC; 262 263 pages_2m++; 264 if (mapping_iter == 1) 265 set_pmd(pmd, pfn_pmd(pfn, init_prot)); 266 else 267 set_pmd(pmd, pfn_pmd(pfn, prot)); 268 269 pfn += PTRS_PER_PTE; 270 continue; 271 } 272 pte = one_page_table_init(pmd); 273 274 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 275 pte += pte_ofs; 276 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 277 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 278 pgprot_t prot = PAGE_KERNEL; 279 /* 280 * first pass will use the same initial 281 * identity mapping attribute. 282 */ 283 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); 284 285 if (is_kernel_text(addr)) 286 prot = PAGE_KERNEL_EXEC; 287 288 pages_4k++; 289 if (mapping_iter == 1) 290 set_pte(pte, pfn_pte(pfn, init_prot)); 291 else 292 set_pte(pte, pfn_pte(pfn, prot)); 293 } 294 } 295 } 296 if (mapping_iter == 1) { 297 /* 298 * update direct mapping page count only in the first 299 * iteration. 300 */ 301 update_page_count(PG_LEVEL_2M, pages_2m); 302 update_page_count(PG_LEVEL_4K, pages_4k); 303 304 /* 305 * local global flush tlb, which will flush the previous 306 * mappings present in both small and large page TLB's. 307 */ 308 __flush_tlb_all(); 309 310 /* 311 * Second iteration will set the actual desired PTE attributes. 312 */ 313 mapping_iter = 2; 314 goto repeat; 315 } 316 } 317 318 /* 319 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 320 * is valid. The argument is a physical page number. 321 * 322 * 323 * On x86, access has to be given to the first megabyte of ram because that area 324 * contains bios code and data regions used by X and dosemu and similar apps. 325 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 326 * mmio resources as well as potential bios/acpi data regions. 327 */ 328 int devmem_is_allowed(unsigned long pagenr) 329 { 330 if (pagenr <= 256) 331 return 1; 332 if (!page_is_ram(pagenr)) 333 return 1; 334 return 0; 335 } 336 337 #ifdef CONFIG_HIGHMEM 338 pte_t *kmap_pte; 339 pgprot_t kmap_prot; 340 341 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 342 { 343 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 344 vaddr), vaddr), vaddr); 345 } 346 347 static void __init kmap_init(void) 348 { 349 unsigned long kmap_vstart; 350 351 /* 352 * Cache the first kmap pte: 353 */ 354 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 355 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 356 357 kmap_prot = PAGE_KERNEL; 358 } 359 360 static void __init permanent_kmaps_init(pgd_t *pgd_base) 361 { 362 unsigned long vaddr; 363 pgd_t *pgd; 364 pud_t *pud; 365 pmd_t *pmd; 366 pte_t *pte; 367 368 vaddr = PKMAP_BASE; 369 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 370 371 pgd = swapper_pg_dir + pgd_index(vaddr); 372 pud = pud_offset(pgd, vaddr); 373 pmd = pmd_offset(pud, vaddr); 374 pte = pte_offset_kernel(pmd, vaddr); 375 pkmap_page_table = pte; 376 } 377 378 static void __init add_one_highpage_init(struct page *page, int pfn) 379 { 380 ClearPageReserved(page); 381 init_page_count(page); 382 __free_page(page); 383 totalhigh_pages++; 384 } 385 386 struct add_highpages_data { 387 unsigned long start_pfn; 388 unsigned long end_pfn; 389 }; 390 391 static int __init add_highpages_work_fn(unsigned long start_pfn, 392 unsigned long end_pfn, void *datax) 393 { 394 int node_pfn; 395 struct page *page; 396 unsigned long final_start_pfn, final_end_pfn; 397 struct add_highpages_data *data; 398 399 data = (struct add_highpages_data *)datax; 400 401 final_start_pfn = max(start_pfn, data->start_pfn); 402 final_end_pfn = min(end_pfn, data->end_pfn); 403 if (final_start_pfn >= final_end_pfn) 404 return 0; 405 406 for (node_pfn = final_start_pfn; node_pfn < final_end_pfn; 407 node_pfn++) { 408 if (!pfn_valid(node_pfn)) 409 continue; 410 page = pfn_to_page(node_pfn); 411 add_one_highpage_init(page, node_pfn); 412 } 413 414 return 0; 415 416 } 417 418 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn, 419 unsigned long end_pfn) 420 { 421 struct add_highpages_data data; 422 423 data.start_pfn = start_pfn; 424 data.end_pfn = end_pfn; 425 426 work_with_active_regions(nid, add_highpages_work_fn, &data); 427 } 428 429 #ifndef CONFIG_NUMA 430 static void __init set_highmem_pages_init(void) 431 { 432 add_highpages_with_active_regions(0, highstart_pfn, highend_pfn); 433 434 totalram_pages += totalhigh_pages; 435 } 436 #endif /* !CONFIG_NUMA */ 437 438 #else 439 # define kmap_init() do { } while (0) 440 # define permanent_kmaps_init(pgd_base) do { } while (0) 441 # define set_highmem_pages_init() do { } while (0) 442 #endif /* CONFIG_HIGHMEM */ 443 444 void __init native_pagetable_setup_start(pgd_t *base) 445 { 446 unsigned long pfn, va; 447 pgd_t *pgd; 448 pud_t *pud; 449 pmd_t *pmd; 450 pte_t *pte; 451 452 /* 453 * Remove any mappings which extend past the end of physical 454 * memory from the boot time page table: 455 */ 456 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 457 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 458 pgd = base + pgd_index(va); 459 if (!pgd_present(*pgd)) 460 break; 461 462 pud = pud_offset(pgd, va); 463 pmd = pmd_offset(pud, va); 464 if (!pmd_present(*pmd)) 465 break; 466 467 pte = pte_offset_kernel(pmd, va); 468 if (!pte_present(*pte)) 469 break; 470 471 pte_clear(NULL, va, pte); 472 } 473 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 474 } 475 476 void __init native_pagetable_setup_done(pgd_t *base) 477 { 478 } 479 480 /* 481 * Build a proper pagetable for the kernel mappings. Up until this 482 * point, we've been running on some set of pagetables constructed by 483 * the boot process. 484 * 485 * If we're booting on native hardware, this will be a pagetable 486 * constructed in arch/x86/kernel/head_32.S. The root of the 487 * pagetable will be swapper_pg_dir. 488 * 489 * If we're booting paravirtualized under a hypervisor, then there are 490 * more options: we may already be running PAE, and the pagetable may 491 * or may not be based in swapper_pg_dir. In any case, 492 * paravirt_pagetable_setup_start() will set up swapper_pg_dir 493 * appropriately for the rest of the initialization to work. 494 * 495 * In general, pagetable_init() assumes that the pagetable may already 496 * be partially populated, and so it avoids stomping on any existing 497 * mappings. 498 */ 499 static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base) 500 { 501 unsigned long vaddr, end; 502 503 /* 504 * Fixed mappings, only the page table structure has to be 505 * created - mappings will be set by set_fixmap(): 506 */ 507 early_ioremap_clear(); 508 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 509 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 510 page_table_range_init(vaddr, end, pgd_base); 511 early_ioremap_reset(); 512 } 513 514 static void __init pagetable_init(void) 515 { 516 pgd_t *pgd_base = swapper_pg_dir; 517 518 permanent_kmaps_init(pgd_base); 519 } 520 521 #ifdef CONFIG_ACPI_SLEEP 522 /* 523 * ACPI suspend needs this for resume, because things like the intel-agp 524 * driver might have split up a kernel 4MB mapping. 525 */ 526 char swsusp_pg_dir[PAGE_SIZE] 527 __attribute__ ((aligned(PAGE_SIZE))); 528 529 static inline void save_pg_dir(void) 530 { 531 memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); 532 } 533 #else /* !CONFIG_ACPI_SLEEP */ 534 static inline void save_pg_dir(void) 535 { 536 } 537 #endif /* !CONFIG_ACPI_SLEEP */ 538 539 void zap_low_mappings(void) 540 { 541 int i; 542 543 /* 544 * Zap initial low-memory mappings. 545 * 546 * Note that "pgd_clear()" doesn't do it for 547 * us, because pgd_clear() is a no-op on i386. 548 */ 549 for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) { 550 #ifdef CONFIG_X86_PAE 551 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); 552 #else 553 set_pgd(swapper_pg_dir+i, __pgd(0)); 554 #endif 555 } 556 flush_tlb_all(); 557 } 558 559 int nx_enabled; 560 561 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); 562 EXPORT_SYMBOL_GPL(__supported_pte_mask); 563 564 #ifdef CONFIG_X86_PAE 565 566 static int disable_nx __initdata; 567 568 /* 569 * noexec = on|off 570 * 571 * Control non executable mappings. 572 * 573 * on Enable 574 * off Disable 575 */ 576 static int __init noexec_setup(char *str) 577 { 578 if (!str || !strcmp(str, "on")) { 579 if (cpu_has_nx) { 580 __supported_pte_mask |= _PAGE_NX; 581 disable_nx = 0; 582 } 583 } else { 584 if (!strcmp(str, "off")) { 585 disable_nx = 1; 586 __supported_pte_mask &= ~_PAGE_NX; 587 } else { 588 return -EINVAL; 589 } 590 } 591 592 return 0; 593 } 594 early_param("noexec", noexec_setup); 595 596 static void __init set_nx(void) 597 { 598 unsigned int v[4], l, h; 599 600 if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { 601 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); 602 603 if ((v[3] & (1 << 20)) && !disable_nx) { 604 rdmsr(MSR_EFER, l, h); 605 l |= EFER_NX; 606 wrmsr(MSR_EFER, l, h); 607 nx_enabled = 1; 608 __supported_pte_mask |= _PAGE_NX; 609 } 610 } 611 } 612 #endif 613 614 /* user-defined highmem size */ 615 static unsigned int highmem_pages = -1; 616 617 /* 618 * highmem=size forces highmem to be exactly 'size' bytes. 619 * This works even on boxes that have no highmem otherwise. 620 * This also works to reduce highmem size on bigger boxes. 621 */ 622 static int __init parse_highmem(char *arg) 623 { 624 if (!arg) 625 return -EINVAL; 626 627 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 628 return 0; 629 } 630 early_param("highmem", parse_highmem); 631 632 /* 633 * Determine low and high memory ranges: 634 */ 635 void __init find_low_pfn_range(void) 636 { 637 /* it could update max_pfn */ 638 639 /* max_low_pfn is 0, we already have early_res support */ 640 641 max_low_pfn = max_pfn; 642 if (max_low_pfn > MAXMEM_PFN) { 643 if (highmem_pages == -1) 644 highmem_pages = max_pfn - MAXMEM_PFN; 645 if (highmem_pages + MAXMEM_PFN < max_pfn) 646 max_pfn = MAXMEM_PFN + highmem_pages; 647 if (highmem_pages + MAXMEM_PFN > max_pfn) { 648 printk(KERN_WARNING "only %luMB highmem pages " 649 "available, ignoring highmem size of %uMB.\n", 650 pages_to_mb(max_pfn - MAXMEM_PFN), 651 pages_to_mb(highmem_pages)); 652 highmem_pages = 0; 653 } 654 max_low_pfn = MAXMEM_PFN; 655 #ifndef CONFIG_HIGHMEM 656 /* Maximum memory usable is what is directly addressable */ 657 printk(KERN_WARNING "Warning only %ldMB will be used.\n", 658 MAXMEM>>20); 659 if (max_pfn > MAX_NONPAE_PFN) 660 printk(KERN_WARNING 661 "Use a HIGHMEM64G enabled kernel.\n"); 662 else 663 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 664 max_pfn = MAXMEM_PFN; 665 #else /* !CONFIG_HIGHMEM */ 666 #ifndef CONFIG_HIGHMEM64G 667 if (max_pfn > MAX_NONPAE_PFN) { 668 max_pfn = MAX_NONPAE_PFN; 669 printk(KERN_WARNING "Warning only 4GB will be used." 670 "Use a HIGHMEM64G enabled kernel.\n"); 671 } 672 #endif /* !CONFIG_HIGHMEM64G */ 673 #endif /* !CONFIG_HIGHMEM */ 674 } else { 675 if (highmem_pages == -1) 676 highmem_pages = 0; 677 #ifdef CONFIG_HIGHMEM 678 if (highmem_pages >= max_pfn) { 679 printk(KERN_ERR "highmem size specified (%uMB) is " 680 "bigger than pages available (%luMB)!.\n", 681 pages_to_mb(highmem_pages), 682 pages_to_mb(max_pfn)); 683 highmem_pages = 0; 684 } 685 if (highmem_pages) { 686 if (max_low_pfn - highmem_pages < 687 64*1024*1024/PAGE_SIZE){ 688 printk(KERN_ERR "highmem size %uMB results in " 689 "smaller than 64MB lowmem, ignoring it.\n" 690 , pages_to_mb(highmem_pages)); 691 highmem_pages = 0; 692 } 693 max_low_pfn -= highmem_pages; 694 } 695 #else 696 if (highmem_pages) 697 printk(KERN_ERR "ignoring highmem size on non-highmem" 698 " kernel!\n"); 699 #endif 700 } 701 } 702 703 #ifndef CONFIG_NEED_MULTIPLE_NODES 704 void __init initmem_init(unsigned long start_pfn, 705 unsigned long end_pfn) 706 { 707 #ifdef CONFIG_HIGHMEM 708 highstart_pfn = highend_pfn = max_pfn; 709 if (max_pfn > max_low_pfn) 710 highstart_pfn = max_low_pfn; 711 memory_present(0, 0, highend_pfn); 712 e820_register_active_regions(0, 0, highend_pfn); 713 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 714 pages_to_mb(highend_pfn - highstart_pfn)); 715 num_physpages = highend_pfn; 716 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 717 #else 718 memory_present(0, 0, max_low_pfn); 719 e820_register_active_regions(0, 0, max_low_pfn); 720 num_physpages = max_low_pfn; 721 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 722 #endif 723 #ifdef CONFIG_FLATMEM 724 max_mapnr = num_physpages; 725 #endif 726 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 727 pages_to_mb(max_low_pfn)); 728 729 setup_bootmem_allocator(); 730 } 731 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 732 733 static void __init zone_sizes_init(void) 734 { 735 unsigned long max_zone_pfns[MAX_NR_ZONES]; 736 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 737 max_zone_pfns[ZONE_DMA] = 738 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 739 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 740 #ifdef CONFIG_HIGHMEM 741 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn; 742 #endif 743 744 free_area_init_nodes(max_zone_pfns); 745 } 746 747 void __init setup_bootmem_allocator(void) 748 { 749 int i; 750 unsigned long bootmap_size, bootmap; 751 /* 752 * Initialize the boot-time allocator (with low memory only): 753 */ 754 bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT; 755 bootmap = find_e820_area(min_low_pfn<<PAGE_SHIFT, 756 max_pfn_mapped<<PAGE_SHIFT, bootmap_size, 757 PAGE_SIZE); 758 if (bootmap == -1L) 759 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 760 reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP"); 761 762 /* don't touch min_low_pfn */ 763 bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap >> PAGE_SHIFT, 764 min_low_pfn, max_low_pfn); 765 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 766 max_pfn_mapped<<PAGE_SHIFT); 767 printk(KERN_INFO " low ram: %08lx - %08lx\n", 768 min_low_pfn<<PAGE_SHIFT, max_low_pfn<<PAGE_SHIFT); 769 printk(KERN_INFO " bootmap %08lx - %08lx\n", 770 bootmap, bootmap + bootmap_size); 771 for_each_online_node(i) 772 free_bootmem_with_active_regions(i, max_low_pfn); 773 early_res_to_bootmem(0, max_low_pfn<<PAGE_SHIFT); 774 775 after_init_bootmem = 1; 776 } 777 778 static void __init find_early_table_space(unsigned long end, int use_pse) 779 { 780 unsigned long puds, pmds, ptes, tables, start; 781 782 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; 783 tables = PAGE_ALIGN(puds * sizeof(pud_t)); 784 785 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; 786 tables += PAGE_ALIGN(pmds * sizeof(pmd_t)); 787 788 if (use_pse) { 789 unsigned long extra; 790 791 extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); 792 extra += PMD_SIZE; 793 ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; 794 } else 795 ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; 796 797 tables += PAGE_ALIGN(ptes * sizeof(pte_t)); 798 799 /* for fixmap */ 800 tables += PAGE_SIZE * 2; 801 802 /* 803 * RED-PEN putting page tables only on node 0 could 804 * cause a hotspot and fill up ZONE_DMA. The page tables 805 * need roughly 0.5KB per GB. 806 */ 807 start = 0x7000; 808 table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT, 809 tables, PAGE_SIZE); 810 if (table_start == -1UL) 811 panic("Cannot find space for the kernel page tables"); 812 813 table_start >>= PAGE_SHIFT; 814 table_end = table_start; 815 table_top = table_start + (tables>>PAGE_SHIFT); 816 817 printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n", 818 end, table_start << PAGE_SHIFT, 819 (table_start << PAGE_SHIFT) + tables); 820 } 821 822 unsigned long __init_refok init_memory_mapping(unsigned long start, 823 unsigned long end) 824 { 825 pgd_t *pgd_base = swapper_pg_dir; 826 unsigned long start_pfn, end_pfn; 827 unsigned long big_page_start; 828 #ifdef CONFIG_DEBUG_PAGEALLOC 829 /* 830 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 831 * This will simplify cpa(), which otherwise needs to support splitting 832 * large pages into small in interrupt context, etc. 833 */ 834 int use_pse = 0; 835 #else 836 int use_pse = cpu_has_pse; 837 #endif 838 839 /* 840 * Find space for the kernel direct mapping tables. 841 */ 842 if (!after_init_bootmem) 843 find_early_table_space(end, use_pse); 844 845 #ifdef CONFIG_X86_PAE 846 set_nx(); 847 if (nx_enabled) 848 printk(KERN_INFO "NX (Execute Disable) protection: active\n"); 849 #endif 850 851 /* Enable PSE if available */ 852 if (cpu_has_pse) 853 set_in_cr4(X86_CR4_PSE); 854 855 /* Enable PGE if available */ 856 if (cpu_has_pge) { 857 set_in_cr4(X86_CR4_PGE); 858 __supported_pte_mask |= _PAGE_GLOBAL; 859 } 860 861 /* 862 * Don't use a large page for the first 2/4MB of memory 863 * because there are often fixed size MTRRs in there 864 * and overlapping MTRRs into large pages can cause 865 * slowdowns. 866 */ 867 big_page_start = PMD_SIZE; 868 869 if (start < big_page_start) { 870 start_pfn = start >> PAGE_SHIFT; 871 end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT); 872 } else { 873 /* head is not big page alignment ? */ 874 start_pfn = start >> PAGE_SHIFT; 875 end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT) 876 << (PMD_SHIFT - PAGE_SHIFT); 877 } 878 if (start_pfn < end_pfn) 879 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0); 880 881 /* big page range */ 882 start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT) 883 << (PMD_SHIFT - PAGE_SHIFT); 884 if (start_pfn < (big_page_start >> PAGE_SHIFT)) 885 start_pfn = big_page_start >> PAGE_SHIFT; 886 end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); 887 if (start_pfn < end_pfn) 888 kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 889 use_pse); 890 891 /* tail is not big page alignment ? */ 892 start_pfn = end_pfn; 893 if (start_pfn > (big_page_start>>PAGE_SHIFT)) { 894 end_pfn = end >> PAGE_SHIFT; 895 if (start_pfn < end_pfn) 896 kernel_physical_mapping_init(pgd_base, start_pfn, 897 end_pfn, 0); 898 } 899 900 early_ioremap_page_table_range_init(pgd_base); 901 902 load_cr3(swapper_pg_dir); 903 904 __flush_tlb_all(); 905 906 if (!after_init_bootmem) 907 reserve_early(table_start << PAGE_SHIFT, 908 table_end << PAGE_SHIFT, "PGTABLE"); 909 910 if (!after_init_bootmem) 911 early_memtest(start, end); 912 913 return end >> PAGE_SHIFT; 914 } 915 916 917 /* 918 * paging_init() sets up the page tables - note that the first 8MB are 919 * already mapped by head.S. 920 * 921 * This routines also unmaps the page at virtual kernel address 0, so 922 * that we can trap those pesky NULL-reference errors in the kernel. 923 */ 924 void __init paging_init(void) 925 { 926 pagetable_init(); 927 928 __flush_tlb_all(); 929 930 kmap_init(); 931 932 /* 933 * NOTE: at this point the bootmem allocator is fully available. 934 */ 935 sparse_init(); 936 zone_sizes_init(); 937 } 938 939 /* 940 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 941 * and also on some strange 486's. All 586+'s are OK. This used to involve 942 * black magic jumps to work around some nasty CPU bugs, but fortunately the 943 * switch to using exceptions got rid of all that. 944 */ 945 static void __init test_wp_bit(void) 946 { 947 printk(KERN_INFO 948 "Checking if this processor honours the WP bit even in supervisor mode..."); 949 950 /* Any page-aligned address will do, the test is non-destructive */ 951 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); 952 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 953 clear_fixmap(FIX_WP_TEST); 954 955 if (!boot_cpu_data.wp_works_ok) { 956 printk(KERN_CONT "No.\n"); 957 #ifdef CONFIG_X86_WP_WORKS_OK 958 panic( 959 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 960 #endif 961 } else { 962 printk(KERN_CONT "Ok.\n"); 963 } 964 } 965 966 static struct kcore_list kcore_mem, kcore_vmalloc; 967 968 void __init mem_init(void) 969 { 970 int codesize, reservedpages, datasize, initsize; 971 int tmp; 972 973 start_periodic_check_for_corruption(); 974 975 #ifdef CONFIG_FLATMEM 976 BUG_ON(!mem_map); 977 #endif 978 /* this will put all low memory onto the freelists */ 979 totalram_pages += free_all_bootmem(); 980 981 reservedpages = 0; 982 for (tmp = 0; tmp < max_low_pfn; tmp++) 983 /* 984 * Only count reserved RAM pages: 985 */ 986 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 987 reservedpages++; 988 989 set_highmem_pages_init(); 990 991 codesize = (unsigned long) &_etext - (unsigned long) &_text; 992 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 993 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 994 995 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 996 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 997 VMALLOC_END-VMALLOC_START); 998 999 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 1000 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 1001 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 1002 num_physpages << (PAGE_SHIFT-10), 1003 codesize >> 10, 1004 reservedpages << (PAGE_SHIFT-10), 1005 datasize >> 10, 1006 initsize >> 10, 1007 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) 1008 ); 1009 1010 printk(KERN_INFO "virtual kernel memory layout:\n" 1011 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 1012 #ifdef CONFIG_HIGHMEM 1013 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 1014 #endif 1015 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 1016 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 1017 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 1018 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 1019 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 1020 FIXADDR_START, FIXADDR_TOP, 1021 (FIXADDR_TOP - FIXADDR_START) >> 10, 1022 1023 #ifdef CONFIG_HIGHMEM 1024 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 1025 (LAST_PKMAP*PAGE_SIZE) >> 10, 1026 #endif 1027 1028 VMALLOC_START, VMALLOC_END, 1029 (VMALLOC_END - VMALLOC_START) >> 20, 1030 1031 (unsigned long)__va(0), (unsigned long)high_memory, 1032 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 1033 1034 (unsigned long)&__init_begin, (unsigned long)&__init_end, 1035 ((unsigned long)&__init_end - 1036 (unsigned long)&__init_begin) >> 10, 1037 1038 (unsigned long)&_etext, (unsigned long)&_edata, 1039 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 1040 1041 (unsigned long)&_text, (unsigned long)&_etext, 1042 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 1043 1044 #ifdef CONFIG_HIGHMEM 1045 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 1046 BUG_ON(VMALLOC_END > PKMAP_BASE); 1047 #endif 1048 BUG_ON(VMALLOC_START > VMALLOC_END); 1049 BUG_ON((unsigned long)high_memory > VMALLOC_START); 1050 1051 if (boot_cpu_data.wp_works_ok < 0) 1052 test_wp_bit(); 1053 1054 save_pg_dir(); 1055 zap_low_mappings(); 1056 } 1057 1058 #ifdef CONFIG_MEMORY_HOTPLUG 1059 int arch_add_memory(int nid, u64 start, u64 size) 1060 { 1061 struct pglist_data *pgdata = NODE_DATA(nid); 1062 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 1063 unsigned long start_pfn = start >> PAGE_SHIFT; 1064 unsigned long nr_pages = size >> PAGE_SHIFT; 1065 1066 return __add_pages(zone, start_pfn, nr_pages); 1067 } 1068 #endif 1069 1070 /* 1071 * This function cannot be __init, since exceptions don't work in that 1072 * section. Put this after the callers, so that it cannot be inlined. 1073 */ 1074 static noinline int do_test_wp_bit(void) 1075 { 1076 char tmp_reg; 1077 int flag; 1078 1079 __asm__ __volatile__( 1080 " movb %0, %1 \n" 1081 "1: movb %1, %0 \n" 1082 " xorl %2, %2 \n" 1083 "2: \n" 1084 _ASM_EXTABLE(1b,2b) 1085 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 1086 "=q" (tmp_reg), 1087 "=r" (flag) 1088 :"2" (1) 1089 :"memory"); 1090 1091 return flag; 1092 } 1093 1094 #ifdef CONFIG_DEBUG_RODATA 1095 const int rodata_test_data = 0xC3; 1096 EXPORT_SYMBOL_GPL(rodata_test_data); 1097 1098 void mark_rodata_ro(void) 1099 { 1100 unsigned long start = PFN_ALIGN(_text); 1101 unsigned long size = PFN_ALIGN(_etext) - start; 1102 1103 #ifndef CONFIG_DYNAMIC_FTRACE 1104 /* Dynamic tracing modifies the kernel text section */ 1105 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1106 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 1107 size >> 10); 1108 1109 #ifdef CONFIG_CPA_DEBUG 1110 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 1111 start, start+size); 1112 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 1113 1114 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1115 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 1116 #endif 1117 #endif /* CONFIG_DYNAMIC_FTRACE */ 1118 1119 start += size; 1120 size = (unsigned long)__end_rodata - start; 1121 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1122 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 1123 size >> 10); 1124 rodata_test(); 1125 1126 #ifdef CONFIG_CPA_DEBUG 1127 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 1128 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1129 1130 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1131 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1132 #endif 1133 } 1134 #endif 1135 1136 void free_init_pages(char *what, unsigned long begin, unsigned long end) 1137 { 1138 #ifdef CONFIG_DEBUG_PAGEALLOC 1139 /* 1140 * If debugging page accesses then do not free this memory but 1141 * mark them not present - any buggy init-section access will 1142 * create a kernel page fault: 1143 */ 1144 printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n", 1145 begin, PAGE_ALIGN(end)); 1146 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 1147 #else 1148 unsigned long addr; 1149 1150 /* 1151 * We just marked the kernel text read only above, now that 1152 * we are going to free part of that, we need to make that 1153 * writeable first. 1154 */ 1155 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 1156 1157 for (addr = begin; addr < end; addr += PAGE_SIZE) { 1158 ClearPageReserved(virt_to_page(addr)); 1159 init_page_count(virt_to_page(addr)); 1160 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 1161 free_page(addr); 1162 totalram_pages++; 1163 } 1164 printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10); 1165 #endif 1166 } 1167 1168 void free_initmem(void) 1169 { 1170 free_init_pages("unused kernel memory", 1171 (unsigned long)(&__init_begin), 1172 (unsigned long)(&__init_end)); 1173 } 1174 1175 #ifdef CONFIG_BLK_DEV_INITRD 1176 void free_initrd_mem(unsigned long start, unsigned long end) 1177 { 1178 free_init_pages("initrd memory", start, end); 1179 } 1180 #endif 1181 1182 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 1183 int flags) 1184 { 1185 return reserve_bootmem(phys, len, flags); 1186 } 1187