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/pci.h> 25 #include <linux/pfn.h> 26 #include <linux/poison.h> 27 #include <linux/bootmem.h> 28 #include <linux/slab.h> 29 #include <linux/proc_fs.h> 30 #include <linux/memory_hotplug.h> 31 #include <linux/initrd.h> 32 #include <linux/cpumask.h> 33 34 #include <asm/asm.h> 35 #include <asm/bios_ebda.h> 36 #include <asm/processor.h> 37 #include <asm/system.h> 38 #include <asm/uaccess.h> 39 #include <asm/pgtable.h> 40 #include <asm/dma.h> 41 #include <asm/fixmap.h> 42 #include <asm/e820.h> 43 #include <asm/apic.h> 44 #include <asm/bugs.h> 45 #include <asm/tlb.h> 46 #include <asm/tlbflush.h> 47 #include <asm/pgalloc.h> 48 #include <asm/sections.h> 49 #include <asm/paravirt.h> 50 #include <asm/setup.h> 51 #include <asm/cacheflush.h> 52 #include <asm/page_types.h> 53 #include <asm/init.h> 54 55 unsigned long highstart_pfn, highend_pfn; 56 57 static noinline int do_test_wp_bit(void); 58 59 bool __read_mostly __vmalloc_start_set = false; 60 61 static __init void *alloc_low_page(void) 62 { 63 unsigned long pfn = e820_table_end++; 64 void *adr; 65 66 if (pfn >= e820_table_top) 67 panic("alloc_low_page: ran out of memory"); 68 69 adr = __va(pfn * PAGE_SIZE); 70 memset(adr, 0, PAGE_SIZE); 71 return adr; 72 } 73 74 /* 75 * Creates a middle page table and puts a pointer to it in the 76 * given global directory entry. This only returns the gd entry 77 * in non-PAE compilation mode, since the middle layer is folded. 78 */ 79 static pmd_t * __init one_md_table_init(pgd_t *pgd) 80 { 81 pud_t *pud; 82 pmd_t *pmd_table; 83 84 #ifdef CONFIG_X86_PAE 85 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 86 if (after_bootmem) 87 pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE); 88 else 89 pmd_table = (pmd_t *)alloc_low_page(); 90 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 91 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 92 pud = pud_offset(pgd, 0); 93 BUG_ON(pmd_table != pmd_offset(pud, 0)); 94 95 return pmd_table; 96 } 97 #endif 98 pud = pud_offset(pgd, 0); 99 pmd_table = pmd_offset(pud, 0); 100 101 return pmd_table; 102 } 103 104 /* 105 * Create a page table and place a pointer to it in a middle page 106 * directory entry: 107 */ 108 static pte_t * __init one_page_table_init(pmd_t *pmd) 109 { 110 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 111 pte_t *page_table = NULL; 112 113 if (after_bootmem) { 114 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) 115 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); 116 #endif 117 if (!page_table) 118 page_table = 119 (pte_t *)alloc_bootmem_pages(PAGE_SIZE); 120 } else 121 page_table = (pte_t *)alloc_low_page(); 122 123 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 124 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 125 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 126 } 127 128 return pte_offset_kernel(pmd, 0); 129 } 130 131 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 132 { 133 int pgd_idx = pgd_index(vaddr); 134 int pmd_idx = pmd_index(vaddr); 135 136 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; 137 } 138 139 pte_t * __init populate_extra_pte(unsigned long vaddr) 140 { 141 int pte_idx = pte_index(vaddr); 142 pmd_t *pmd; 143 144 pmd = populate_extra_pmd(vaddr); 145 return one_page_table_init(pmd) + pte_idx; 146 } 147 148 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 149 unsigned long vaddr, pte_t *lastpte) 150 { 151 #ifdef CONFIG_HIGHMEM 152 /* 153 * Something (early fixmap) may already have put a pte 154 * page here, which causes the page table allocation 155 * to become nonlinear. Attempt to fix it, and if it 156 * is still nonlinear then we have to bug. 157 */ 158 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 159 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 160 161 if (pmd_idx_kmap_begin != pmd_idx_kmap_end 162 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin 163 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end 164 && ((__pa(pte) >> PAGE_SHIFT) < e820_table_start 165 || (__pa(pte) >> PAGE_SHIFT) >= e820_table_end)) { 166 pte_t *newpte; 167 int i; 168 169 BUG_ON(after_bootmem); 170 newpte = alloc_low_page(); 171 for (i = 0; i < PTRS_PER_PTE; i++) 172 set_pte(newpte + i, pte[i]); 173 174 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); 175 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); 176 BUG_ON(newpte != pte_offset_kernel(pmd, 0)); 177 __flush_tlb_all(); 178 179 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); 180 pte = newpte; 181 } 182 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) 183 && vaddr > fix_to_virt(FIX_KMAP_END) 184 && lastpte && lastpte + PTRS_PER_PTE != pte); 185 #endif 186 return pte; 187 } 188 189 /* 190 * This function initializes a certain range of kernel virtual memory 191 * with new bootmem page tables, everywhere page tables are missing in 192 * the given range. 193 * 194 * NOTE: The pagetables are allocated contiguous on the physical space 195 * so we can cache the place of the first one and move around without 196 * checking the pgd every time. 197 */ 198 static void __init 199 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 200 { 201 int pgd_idx, pmd_idx; 202 unsigned long vaddr; 203 pgd_t *pgd; 204 pmd_t *pmd; 205 pte_t *pte = NULL; 206 207 vaddr = start; 208 pgd_idx = pgd_index(vaddr); 209 pmd_idx = pmd_index(vaddr); 210 pgd = pgd_base + pgd_idx; 211 212 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 213 pmd = one_md_table_init(pgd); 214 pmd = pmd + pmd_index(vaddr); 215 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 216 pmd++, pmd_idx++) { 217 pte = page_table_kmap_check(one_page_table_init(pmd), 218 pmd, vaddr, pte); 219 220 vaddr += PMD_SIZE; 221 } 222 pmd_idx = 0; 223 } 224 } 225 226 static inline int is_kernel_text(unsigned long addr) 227 { 228 if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) 229 return 1; 230 return 0; 231 } 232 233 /* 234 * This maps the physical memory to kernel virtual address space, a total 235 * of max_low_pfn pages, by creating page tables starting from address 236 * PAGE_OFFSET: 237 */ 238 unsigned long __init 239 kernel_physical_mapping_init(unsigned long start, 240 unsigned long end, 241 unsigned long page_size_mask) 242 { 243 int use_pse = page_size_mask == (1<<PG_LEVEL_2M); 244 unsigned long start_pfn, end_pfn; 245 pgd_t *pgd_base = swapper_pg_dir; 246 int pgd_idx, pmd_idx, pte_ofs; 247 unsigned long pfn; 248 pgd_t *pgd; 249 pmd_t *pmd; 250 pte_t *pte; 251 unsigned pages_2m, pages_4k; 252 int mapping_iter; 253 254 start_pfn = start >> PAGE_SHIFT; 255 end_pfn = end >> PAGE_SHIFT; 256 257 /* 258 * First iteration will setup identity mapping using large/small pages 259 * based on use_pse, with other attributes same as set by 260 * the early code in head_32.S 261 * 262 * Second iteration will setup the appropriate attributes (NX, GLOBAL..) 263 * as desired for the kernel identity mapping. 264 * 265 * This two pass mechanism conforms to the TLB app note which says: 266 * 267 * "Software should not write to a paging-structure entry in a way 268 * that would change, for any linear address, both the page size 269 * and either the page frame or attributes." 270 */ 271 mapping_iter = 1; 272 273 if (!cpu_has_pse) 274 use_pse = 0; 275 276 repeat: 277 pages_2m = pages_4k = 0; 278 pfn = start_pfn; 279 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 280 pgd = pgd_base + pgd_idx; 281 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 282 pmd = one_md_table_init(pgd); 283 284 if (pfn >= end_pfn) 285 continue; 286 #ifdef CONFIG_X86_PAE 287 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 288 pmd += pmd_idx; 289 #else 290 pmd_idx = 0; 291 #endif 292 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 293 pmd++, pmd_idx++) { 294 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 295 296 /* 297 * Map with big pages if possible, otherwise 298 * create normal page tables: 299 */ 300 if (use_pse) { 301 unsigned int addr2; 302 pgprot_t prot = PAGE_KERNEL_LARGE; 303 /* 304 * first pass will use the same initial 305 * identity mapping attribute + _PAGE_PSE. 306 */ 307 pgprot_t init_prot = 308 __pgprot(PTE_IDENT_ATTR | 309 _PAGE_PSE); 310 311 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 312 PAGE_OFFSET + PAGE_SIZE-1; 313 314 if (is_kernel_text(addr) || 315 is_kernel_text(addr2)) 316 prot = PAGE_KERNEL_LARGE_EXEC; 317 318 pages_2m++; 319 if (mapping_iter == 1) 320 set_pmd(pmd, pfn_pmd(pfn, init_prot)); 321 else 322 set_pmd(pmd, pfn_pmd(pfn, prot)); 323 324 pfn += PTRS_PER_PTE; 325 continue; 326 } 327 pte = one_page_table_init(pmd); 328 329 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 330 pte += pte_ofs; 331 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 332 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 333 pgprot_t prot = PAGE_KERNEL; 334 /* 335 * first pass will use the same initial 336 * identity mapping attribute. 337 */ 338 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); 339 340 if (is_kernel_text(addr)) 341 prot = PAGE_KERNEL_EXEC; 342 343 pages_4k++; 344 if (mapping_iter == 1) 345 set_pte(pte, pfn_pte(pfn, init_prot)); 346 else 347 set_pte(pte, pfn_pte(pfn, prot)); 348 } 349 } 350 } 351 if (mapping_iter == 1) { 352 /* 353 * update direct mapping page count only in the first 354 * iteration. 355 */ 356 update_page_count(PG_LEVEL_2M, pages_2m); 357 update_page_count(PG_LEVEL_4K, pages_4k); 358 359 /* 360 * local global flush tlb, which will flush the previous 361 * mappings present in both small and large page TLB's. 362 */ 363 __flush_tlb_all(); 364 365 /* 366 * Second iteration will set the actual desired PTE attributes. 367 */ 368 mapping_iter = 2; 369 goto repeat; 370 } 371 return 0; 372 } 373 374 pte_t *kmap_pte; 375 pgprot_t kmap_prot; 376 377 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 378 { 379 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 380 vaddr), vaddr), vaddr); 381 } 382 383 static void __init kmap_init(void) 384 { 385 unsigned long kmap_vstart; 386 387 /* 388 * Cache the first kmap pte: 389 */ 390 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 391 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 392 393 kmap_prot = PAGE_KERNEL; 394 } 395 396 #ifdef CONFIG_HIGHMEM 397 static void __init permanent_kmaps_init(pgd_t *pgd_base) 398 { 399 unsigned long vaddr; 400 pgd_t *pgd; 401 pud_t *pud; 402 pmd_t *pmd; 403 pte_t *pte; 404 405 vaddr = PKMAP_BASE; 406 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 407 408 pgd = swapper_pg_dir + pgd_index(vaddr); 409 pud = pud_offset(pgd, vaddr); 410 pmd = pmd_offset(pud, vaddr); 411 pte = pte_offset_kernel(pmd, vaddr); 412 pkmap_page_table = pte; 413 } 414 415 static void __init add_one_highpage_init(struct page *page) 416 { 417 ClearPageReserved(page); 418 init_page_count(page); 419 __free_page(page); 420 totalhigh_pages++; 421 } 422 423 struct add_highpages_data { 424 unsigned long start_pfn; 425 unsigned long end_pfn; 426 }; 427 428 static int __init add_highpages_work_fn(unsigned long start_pfn, 429 unsigned long end_pfn, void *datax) 430 { 431 int node_pfn; 432 struct page *page; 433 unsigned long final_start_pfn, final_end_pfn; 434 struct add_highpages_data *data; 435 436 data = (struct add_highpages_data *)datax; 437 438 final_start_pfn = max(start_pfn, data->start_pfn); 439 final_end_pfn = min(end_pfn, data->end_pfn); 440 if (final_start_pfn >= final_end_pfn) 441 return 0; 442 443 for (node_pfn = final_start_pfn; node_pfn < final_end_pfn; 444 node_pfn++) { 445 if (!pfn_valid(node_pfn)) 446 continue; 447 page = pfn_to_page(node_pfn); 448 add_one_highpage_init(page); 449 } 450 451 return 0; 452 453 } 454 455 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn, 456 unsigned long end_pfn) 457 { 458 struct add_highpages_data data; 459 460 data.start_pfn = start_pfn; 461 data.end_pfn = end_pfn; 462 463 work_with_active_regions(nid, add_highpages_work_fn, &data); 464 } 465 466 #else 467 static inline void permanent_kmaps_init(pgd_t *pgd_base) 468 { 469 } 470 #endif /* CONFIG_HIGHMEM */ 471 472 void __init native_pagetable_setup_start(pgd_t *base) 473 { 474 unsigned long pfn, va; 475 pgd_t *pgd; 476 pud_t *pud; 477 pmd_t *pmd; 478 pte_t *pte; 479 480 /* 481 * Remove any mappings which extend past the end of physical 482 * memory from the boot time page table: 483 */ 484 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 485 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 486 pgd = base + pgd_index(va); 487 if (!pgd_present(*pgd)) 488 break; 489 490 pud = pud_offset(pgd, va); 491 pmd = pmd_offset(pud, va); 492 if (!pmd_present(*pmd)) 493 break; 494 495 pte = pte_offset_kernel(pmd, va); 496 if (!pte_present(*pte)) 497 break; 498 499 pte_clear(NULL, va, pte); 500 } 501 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 502 } 503 504 void __init native_pagetable_setup_done(pgd_t *base) 505 { 506 } 507 508 /* 509 * Build a proper pagetable for the kernel mappings. Up until this 510 * point, we've been running on some set of pagetables constructed by 511 * the boot process. 512 * 513 * If we're booting on native hardware, this will be a pagetable 514 * constructed in arch/x86/kernel/head_32.S. The root of the 515 * pagetable will be swapper_pg_dir. 516 * 517 * If we're booting paravirtualized under a hypervisor, then there are 518 * more options: we may already be running PAE, and the pagetable may 519 * or may not be based in swapper_pg_dir. In any case, 520 * paravirt_pagetable_setup_start() will set up swapper_pg_dir 521 * appropriately for the rest of the initialization to work. 522 * 523 * In general, pagetable_init() assumes that the pagetable may already 524 * be partially populated, and so it avoids stomping on any existing 525 * mappings. 526 */ 527 void __init early_ioremap_page_table_range_init(void) 528 { 529 pgd_t *pgd_base = swapper_pg_dir; 530 unsigned long vaddr, end; 531 532 /* 533 * Fixed mappings, only the page table structure has to be 534 * created - mappings will be set by set_fixmap(): 535 */ 536 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 537 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 538 page_table_range_init(vaddr, end, pgd_base); 539 early_ioremap_reset(); 540 } 541 542 static void __init pagetable_init(void) 543 { 544 pgd_t *pgd_base = swapper_pg_dir; 545 546 permanent_kmaps_init(pgd_base); 547 } 548 549 #ifdef CONFIG_ACPI_SLEEP 550 /* 551 * ACPI suspend needs this for resume, because things like the intel-agp 552 * driver might have split up a kernel 4MB mapping. 553 */ 554 char swsusp_pg_dir[PAGE_SIZE] 555 __attribute__ ((aligned(PAGE_SIZE))); 556 557 static inline void save_pg_dir(void) 558 { 559 memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); 560 } 561 #else /* !CONFIG_ACPI_SLEEP */ 562 static inline void save_pg_dir(void) 563 { 564 } 565 #endif /* !CONFIG_ACPI_SLEEP */ 566 567 void zap_low_mappings(bool early) 568 { 569 int i; 570 571 /* 572 * Zap initial low-memory mappings. 573 * 574 * Note that "pgd_clear()" doesn't do it for 575 * us, because pgd_clear() is a no-op on i386. 576 */ 577 for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) { 578 #ifdef CONFIG_X86_PAE 579 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); 580 #else 581 set_pgd(swapper_pg_dir+i, __pgd(0)); 582 #endif 583 } 584 585 if (early) 586 __flush_tlb(); 587 else 588 flush_tlb_all(); 589 } 590 591 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); 592 EXPORT_SYMBOL_GPL(__supported_pte_mask); 593 594 /* user-defined highmem size */ 595 static unsigned int highmem_pages = -1; 596 597 /* 598 * highmem=size forces highmem to be exactly 'size' bytes. 599 * This works even on boxes that have no highmem otherwise. 600 * This also works to reduce highmem size on bigger boxes. 601 */ 602 static int __init parse_highmem(char *arg) 603 { 604 if (!arg) 605 return -EINVAL; 606 607 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 608 return 0; 609 } 610 early_param("highmem", parse_highmem); 611 612 #define MSG_HIGHMEM_TOO_BIG \ 613 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 614 615 #define MSG_LOWMEM_TOO_SMALL \ 616 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 617 /* 618 * All of RAM fits into lowmem - but if user wants highmem 619 * artificially via the highmem=x boot parameter then create 620 * it: 621 */ 622 void __init lowmem_pfn_init(void) 623 { 624 /* max_low_pfn is 0, we already have early_res support */ 625 max_low_pfn = max_pfn; 626 627 if (highmem_pages == -1) 628 highmem_pages = 0; 629 #ifdef CONFIG_HIGHMEM 630 if (highmem_pages >= max_pfn) { 631 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 632 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 633 highmem_pages = 0; 634 } 635 if (highmem_pages) { 636 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 637 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 638 pages_to_mb(highmem_pages)); 639 highmem_pages = 0; 640 } 641 max_low_pfn -= highmem_pages; 642 } 643 #else 644 if (highmem_pages) 645 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 646 #endif 647 } 648 649 #define MSG_HIGHMEM_TOO_SMALL \ 650 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 651 652 #define MSG_HIGHMEM_TRIMMED \ 653 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 654 /* 655 * We have more RAM than fits into lowmem - we try to put it into 656 * highmem, also taking the highmem=x boot parameter into account: 657 */ 658 void __init highmem_pfn_init(void) 659 { 660 max_low_pfn = MAXMEM_PFN; 661 662 if (highmem_pages == -1) 663 highmem_pages = max_pfn - MAXMEM_PFN; 664 665 if (highmem_pages + MAXMEM_PFN < max_pfn) 666 max_pfn = MAXMEM_PFN + highmem_pages; 667 668 if (highmem_pages + MAXMEM_PFN > max_pfn) { 669 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 670 pages_to_mb(max_pfn - MAXMEM_PFN), 671 pages_to_mb(highmem_pages)); 672 highmem_pages = 0; 673 } 674 #ifndef CONFIG_HIGHMEM 675 /* Maximum memory usable is what is directly addressable */ 676 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 677 if (max_pfn > MAX_NONPAE_PFN) 678 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 679 else 680 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 681 max_pfn = MAXMEM_PFN; 682 #else /* !CONFIG_HIGHMEM */ 683 #ifndef CONFIG_HIGHMEM64G 684 if (max_pfn > MAX_NONPAE_PFN) { 685 max_pfn = MAX_NONPAE_PFN; 686 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 687 } 688 #endif /* !CONFIG_HIGHMEM64G */ 689 #endif /* !CONFIG_HIGHMEM */ 690 } 691 692 /* 693 * Determine low and high memory ranges: 694 */ 695 void __init find_low_pfn_range(void) 696 { 697 /* it could update max_pfn */ 698 699 if (max_pfn <= MAXMEM_PFN) 700 lowmem_pfn_init(); 701 else 702 highmem_pfn_init(); 703 } 704 705 #ifndef CONFIG_NEED_MULTIPLE_NODES 706 void __init initmem_init(unsigned long start_pfn, unsigned long end_pfn, 707 int acpi, int k8) 708 { 709 #ifdef CONFIG_HIGHMEM 710 highstart_pfn = highend_pfn = max_pfn; 711 if (max_pfn > max_low_pfn) 712 highstart_pfn = max_low_pfn; 713 e820_register_active_regions(0, 0, highend_pfn); 714 sparse_memory_present_with_active_regions(0); 715 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 716 pages_to_mb(highend_pfn - highstart_pfn)); 717 num_physpages = highend_pfn; 718 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 719 #else 720 e820_register_active_regions(0, 0, max_low_pfn); 721 sparse_memory_present_with_active_regions(0); 722 num_physpages = max_low_pfn; 723 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 724 #endif 725 #ifdef CONFIG_FLATMEM 726 max_mapnr = num_physpages; 727 #endif 728 __vmalloc_start_set = true; 729 730 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 731 pages_to_mb(max_low_pfn)); 732 733 setup_bootmem_allocator(); 734 } 735 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 736 737 static void __init zone_sizes_init(void) 738 { 739 unsigned long max_zone_pfns[MAX_NR_ZONES]; 740 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 741 max_zone_pfns[ZONE_DMA] = 742 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 743 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 744 #ifdef CONFIG_HIGHMEM 745 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn; 746 #endif 747 748 free_area_init_nodes(max_zone_pfns); 749 } 750 751 static unsigned long __init setup_node_bootmem(int nodeid, 752 unsigned long start_pfn, 753 unsigned long end_pfn, 754 unsigned long bootmap) 755 { 756 unsigned long bootmap_size; 757 758 /* don't touch min_low_pfn */ 759 bootmap_size = init_bootmem_node(NODE_DATA(nodeid), 760 bootmap >> PAGE_SHIFT, 761 start_pfn, end_pfn); 762 printk(KERN_INFO " node %d low ram: %08lx - %08lx\n", 763 nodeid, start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT); 764 printk(KERN_INFO " node %d bootmap %08lx - %08lx\n", 765 nodeid, bootmap, bootmap + bootmap_size); 766 free_bootmem_with_active_regions(nodeid, end_pfn); 767 early_res_to_bootmem(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT); 768 769 return bootmap + bootmap_size; 770 } 771 772 void __init setup_bootmem_allocator(void) 773 { 774 int nodeid; 775 unsigned long bootmap_size, bootmap; 776 /* 777 * Initialize the boot-time allocator (with low memory only): 778 */ 779 bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT; 780 bootmap = find_e820_area(0, max_pfn_mapped<<PAGE_SHIFT, bootmap_size, 781 PAGE_SIZE); 782 if (bootmap == -1L) 783 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 784 reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP"); 785 786 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 787 max_pfn_mapped<<PAGE_SHIFT); 788 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 789 790 for_each_online_node(nodeid) { 791 unsigned long start_pfn, end_pfn; 792 793 #ifdef CONFIG_NEED_MULTIPLE_NODES 794 start_pfn = node_start_pfn[nodeid]; 795 end_pfn = node_end_pfn[nodeid]; 796 if (start_pfn > max_low_pfn) 797 continue; 798 if (end_pfn > max_low_pfn) 799 end_pfn = max_low_pfn; 800 #else 801 start_pfn = 0; 802 end_pfn = max_low_pfn; 803 #endif 804 bootmap = setup_node_bootmem(nodeid, start_pfn, end_pfn, 805 bootmap); 806 } 807 808 after_bootmem = 1; 809 } 810 811 /* 812 * paging_init() sets up the page tables - note that the first 8MB are 813 * already mapped by head.S. 814 * 815 * This routines also unmaps the page at virtual kernel address 0, so 816 * that we can trap those pesky NULL-reference errors in the kernel. 817 */ 818 void __init paging_init(void) 819 { 820 pagetable_init(); 821 822 __flush_tlb_all(); 823 824 kmap_init(); 825 826 /* 827 * NOTE: at this point the bootmem allocator is fully available. 828 */ 829 sparse_init(); 830 zone_sizes_init(); 831 } 832 833 /* 834 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 835 * and also on some strange 486's. All 586+'s are OK. This used to involve 836 * black magic jumps to work around some nasty CPU bugs, but fortunately the 837 * switch to using exceptions got rid of all that. 838 */ 839 static void __init test_wp_bit(void) 840 { 841 printk(KERN_INFO 842 "Checking if this processor honours the WP bit even in supervisor mode..."); 843 844 /* Any page-aligned address will do, the test is non-destructive */ 845 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); 846 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 847 clear_fixmap(FIX_WP_TEST); 848 849 if (!boot_cpu_data.wp_works_ok) { 850 printk(KERN_CONT "No.\n"); 851 #ifdef CONFIG_X86_WP_WORKS_OK 852 panic( 853 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 854 #endif 855 } else { 856 printk(KERN_CONT "Ok.\n"); 857 } 858 } 859 860 void __init mem_init(void) 861 { 862 int codesize, reservedpages, datasize, initsize; 863 int tmp; 864 865 pci_iommu_alloc(); 866 867 #ifdef CONFIG_FLATMEM 868 BUG_ON(!mem_map); 869 #endif 870 /* this will put all low memory onto the freelists */ 871 totalram_pages += free_all_bootmem(); 872 873 reservedpages = 0; 874 for (tmp = 0; tmp < max_low_pfn; tmp++) 875 /* 876 * Only count reserved RAM pages: 877 */ 878 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 879 reservedpages++; 880 881 set_highmem_pages_init(); 882 883 codesize = (unsigned long) &_etext - (unsigned long) &_text; 884 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 885 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 886 887 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 888 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 889 nr_free_pages() << (PAGE_SHIFT-10), 890 num_physpages << (PAGE_SHIFT-10), 891 codesize >> 10, 892 reservedpages << (PAGE_SHIFT-10), 893 datasize >> 10, 894 initsize >> 10, 895 totalhigh_pages << (PAGE_SHIFT-10)); 896 897 printk(KERN_INFO "virtual kernel memory layout:\n" 898 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 899 #ifdef CONFIG_HIGHMEM 900 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 901 #endif 902 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 903 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 904 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 905 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 906 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 907 FIXADDR_START, FIXADDR_TOP, 908 (FIXADDR_TOP - FIXADDR_START) >> 10, 909 910 #ifdef CONFIG_HIGHMEM 911 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 912 (LAST_PKMAP*PAGE_SIZE) >> 10, 913 #endif 914 915 VMALLOC_START, VMALLOC_END, 916 (VMALLOC_END - VMALLOC_START) >> 20, 917 918 (unsigned long)__va(0), (unsigned long)high_memory, 919 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 920 921 (unsigned long)&__init_begin, (unsigned long)&__init_end, 922 ((unsigned long)&__init_end - 923 (unsigned long)&__init_begin) >> 10, 924 925 (unsigned long)&_etext, (unsigned long)&_edata, 926 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 927 928 (unsigned long)&_text, (unsigned long)&_etext, 929 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 930 931 /* 932 * Check boundaries twice: Some fundamental inconsistencies can 933 * be detected at build time already. 934 */ 935 #define __FIXADDR_TOP (-PAGE_SIZE) 936 #ifdef CONFIG_HIGHMEM 937 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 938 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 939 #endif 940 #define high_memory (-128UL << 20) 941 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 942 #undef high_memory 943 #undef __FIXADDR_TOP 944 945 #ifdef CONFIG_HIGHMEM 946 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 947 BUG_ON(VMALLOC_END > PKMAP_BASE); 948 #endif 949 BUG_ON(VMALLOC_START >= VMALLOC_END); 950 BUG_ON((unsigned long)high_memory > VMALLOC_START); 951 952 if (boot_cpu_data.wp_works_ok < 0) 953 test_wp_bit(); 954 955 save_pg_dir(); 956 zap_low_mappings(true); 957 } 958 959 #ifdef CONFIG_MEMORY_HOTPLUG 960 int arch_add_memory(int nid, u64 start, u64 size) 961 { 962 struct pglist_data *pgdata = NODE_DATA(nid); 963 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 964 unsigned long start_pfn = start >> PAGE_SHIFT; 965 unsigned long nr_pages = size >> PAGE_SHIFT; 966 967 return __add_pages(nid, zone, start_pfn, nr_pages); 968 } 969 #endif 970 971 /* 972 * This function cannot be __init, since exceptions don't work in that 973 * section. Put this after the callers, so that it cannot be inlined. 974 */ 975 static noinline int do_test_wp_bit(void) 976 { 977 char tmp_reg; 978 int flag; 979 980 __asm__ __volatile__( 981 " movb %0, %1 \n" 982 "1: movb %1, %0 \n" 983 " xorl %2, %2 \n" 984 "2: \n" 985 _ASM_EXTABLE(1b,2b) 986 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 987 "=q" (tmp_reg), 988 "=r" (flag) 989 :"2" (1) 990 :"memory"); 991 992 return flag; 993 } 994 995 #ifdef CONFIG_DEBUG_RODATA 996 const int rodata_test_data = 0xC3; 997 EXPORT_SYMBOL_GPL(rodata_test_data); 998 999 int kernel_set_to_readonly __read_mostly; 1000 1001 void set_kernel_text_rw(void) 1002 { 1003 unsigned long start = PFN_ALIGN(_text); 1004 unsigned long size = PFN_ALIGN(_etext) - start; 1005 1006 if (!kernel_set_to_readonly) 1007 return; 1008 1009 pr_debug("Set kernel text: %lx - %lx for read write\n", 1010 start, start+size); 1011 1012 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1013 } 1014 1015 void set_kernel_text_ro(void) 1016 { 1017 unsigned long start = PFN_ALIGN(_text); 1018 unsigned long size = PFN_ALIGN(_etext) - start; 1019 1020 if (!kernel_set_to_readonly) 1021 return; 1022 1023 pr_debug("Set kernel text: %lx - %lx for read only\n", 1024 start, start+size); 1025 1026 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1027 } 1028 1029 void mark_rodata_ro(void) 1030 { 1031 unsigned long start = PFN_ALIGN(_text); 1032 unsigned long size = PFN_ALIGN(_etext) - start; 1033 1034 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1035 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 1036 size >> 10); 1037 1038 kernel_set_to_readonly = 1; 1039 1040 #ifdef CONFIG_CPA_DEBUG 1041 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 1042 start, start+size); 1043 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 1044 1045 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1046 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 1047 #endif 1048 1049 start += size; 1050 size = (unsigned long)__end_rodata - start; 1051 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1052 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 1053 size >> 10); 1054 rodata_test(); 1055 1056 #ifdef CONFIG_CPA_DEBUG 1057 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 1058 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1059 1060 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1061 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1062 #endif 1063 } 1064 #endif 1065 1066 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 1067 int flags) 1068 { 1069 return reserve_bootmem(phys, len, flags); 1070 } 1071