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/init.h> 53 54 unsigned long max_low_pfn_mapped; 55 unsigned long max_pfn_mapped; 56 57 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 58 unsigned long highstart_pfn, highend_pfn; 59 60 static noinline int do_test_wp_bit(void); 61 62 bool __read_mostly __vmalloc_start_set = false; 63 64 static __init void *alloc_low_page(void) 65 { 66 unsigned long pfn = e820_table_end++; 67 void *adr; 68 69 if (pfn >= e820_table_top) 70 panic("alloc_low_page: ran out of memory"); 71 72 adr = __va(pfn * PAGE_SIZE); 73 memset(adr, 0, PAGE_SIZE); 74 return adr; 75 } 76 77 /* 78 * Creates a middle page table and puts a pointer to it in the 79 * given global directory entry. This only returns the gd entry 80 * in non-PAE compilation mode, since the middle layer is folded. 81 */ 82 static pmd_t * __init one_md_table_init(pgd_t *pgd) 83 { 84 pud_t *pud; 85 pmd_t *pmd_table; 86 87 #ifdef CONFIG_X86_PAE 88 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 89 if (after_bootmem) 90 pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); 91 else 92 pmd_table = (pmd_t *)alloc_low_page(); 93 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 94 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 95 pud = pud_offset(pgd, 0); 96 BUG_ON(pmd_table != pmd_offset(pud, 0)); 97 98 return pmd_table; 99 } 100 #endif 101 pud = pud_offset(pgd, 0); 102 pmd_table = pmd_offset(pud, 0); 103 104 return pmd_table; 105 } 106 107 /* 108 * Create a page table and place a pointer to it in a middle page 109 * directory entry: 110 */ 111 static pte_t * __init one_page_table_init(pmd_t *pmd) 112 { 113 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 114 pte_t *page_table = NULL; 115 116 if (after_bootmem) { 117 #ifdef CONFIG_DEBUG_PAGEALLOC 118 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); 119 #endif 120 if (!page_table) 121 page_table = 122 (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); 123 } else 124 page_table = (pte_t *)alloc_low_page(); 125 126 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 127 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 128 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 129 } 130 131 return pte_offset_kernel(pmd, 0); 132 } 133 134 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 135 { 136 int pgd_idx = pgd_index(vaddr); 137 int pmd_idx = pmd_index(vaddr); 138 139 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; 140 } 141 142 pte_t * __init populate_extra_pte(unsigned long vaddr) 143 { 144 int pte_idx = pte_index(vaddr); 145 pmd_t *pmd; 146 147 pmd = populate_extra_pmd(vaddr); 148 return one_page_table_init(pmd) + pte_idx; 149 } 150 151 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 152 unsigned long vaddr, pte_t *lastpte) 153 { 154 #ifdef CONFIG_HIGHMEM 155 /* 156 * Something (early fixmap) may already have put a pte 157 * page here, which causes the page table allocation 158 * to become nonlinear. Attempt to fix it, and if it 159 * is still nonlinear then we have to bug. 160 */ 161 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 162 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 163 164 if (pmd_idx_kmap_begin != pmd_idx_kmap_end 165 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin 166 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end 167 && ((__pa(pte) >> PAGE_SHIFT) < e820_table_start 168 || (__pa(pte) >> PAGE_SHIFT) >= e820_table_end)) { 169 pte_t *newpte; 170 int i; 171 172 BUG_ON(after_bootmem); 173 newpte = alloc_low_page(); 174 for (i = 0; i < PTRS_PER_PTE; i++) 175 set_pte(newpte + i, pte[i]); 176 177 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); 178 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); 179 BUG_ON(newpte != pte_offset_kernel(pmd, 0)); 180 __flush_tlb_all(); 181 182 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); 183 pte = newpte; 184 } 185 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) 186 && vaddr > fix_to_virt(FIX_KMAP_END) 187 && lastpte && lastpte + PTRS_PER_PTE != pte); 188 #endif 189 return pte; 190 } 191 192 /* 193 * This function initializes a certain range of kernel virtual memory 194 * with new bootmem page tables, everywhere page tables are missing in 195 * the given range. 196 * 197 * NOTE: The pagetables are allocated contiguous on the physical space 198 * so we can cache the place of the first one and move around without 199 * checking the pgd every time. 200 */ 201 static void __init 202 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 203 { 204 int pgd_idx, pmd_idx; 205 unsigned long vaddr; 206 pgd_t *pgd; 207 pmd_t *pmd; 208 pte_t *pte = NULL; 209 210 vaddr = start; 211 pgd_idx = pgd_index(vaddr); 212 pmd_idx = pmd_index(vaddr); 213 pgd = pgd_base + pgd_idx; 214 215 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 216 pmd = one_md_table_init(pgd); 217 pmd = pmd + pmd_index(vaddr); 218 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 219 pmd++, pmd_idx++) { 220 pte = page_table_kmap_check(one_page_table_init(pmd), 221 pmd, vaddr, pte); 222 223 vaddr += PMD_SIZE; 224 } 225 pmd_idx = 0; 226 } 227 } 228 229 static inline int is_kernel_text(unsigned long addr) 230 { 231 if (addr >= PAGE_OFFSET && addr <= (unsigned long)__init_end) 232 return 1; 233 return 0; 234 } 235 236 /* 237 * This maps the physical memory to kernel virtual address space, a total 238 * of max_low_pfn pages, by creating page tables starting from address 239 * PAGE_OFFSET: 240 */ 241 unsigned long __init 242 kernel_physical_mapping_init(unsigned long start, 243 unsigned long end, 244 unsigned long page_size_mask) 245 { 246 int use_pse = page_size_mask == (1<<PG_LEVEL_2M); 247 unsigned long start_pfn, end_pfn; 248 pgd_t *pgd_base = swapper_pg_dir; 249 int pgd_idx, pmd_idx, pte_ofs; 250 unsigned long pfn; 251 pgd_t *pgd; 252 pmd_t *pmd; 253 pte_t *pte; 254 unsigned pages_2m, pages_4k; 255 int mapping_iter; 256 257 start_pfn = start >> PAGE_SHIFT; 258 end_pfn = end >> PAGE_SHIFT; 259 260 /* 261 * First iteration will setup identity mapping using large/small pages 262 * based on use_pse, with other attributes same as set by 263 * the early code in head_32.S 264 * 265 * Second iteration will setup the appropriate attributes (NX, GLOBAL..) 266 * as desired for the kernel identity mapping. 267 * 268 * This two pass mechanism conforms to the TLB app note which says: 269 * 270 * "Software should not write to a paging-structure entry in a way 271 * that would change, for any linear address, both the page size 272 * and either the page frame or attributes." 273 */ 274 mapping_iter = 1; 275 276 if (!cpu_has_pse) 277 use_pse = 0; 278 279 repeat: 280 pages_2m = pages_4k = 0; 281 pfn = start_pfn; 282 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 283 pgd = pgd_base + pgd_idx; 284 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 285 pmd = one_md_table_init(pgd); 286 287 if (pfn >= end_pfn) 288 continue; 289 #ifdef CONFIG_X86_PAE 290 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 291 pmd += pmd_idx; 292 #else 293 pmd_idx = 0; 294 #endif 295 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 296 pmd++, pmd_idx++) { 297 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 298 299 /* 300 * Map with big pages if possible, otherwise 301 * create normal page tables: 302 */ 303 if (use_pse) { 304 unsigned int addr2; 305 pgprot_t prot = PAGE_KERNEL_LARGE; 306 /* 307 * first pass will use the same initial 308 * identity mapping attribute + _PAGE_PSE. 309 */ 310 pgprot_t init_prot = 311 __pgprot(PTE_IDENT_ATTR | 312 _PAGE_PSE); 313 314 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 315 PAGE_OFFSET + PAGE_SIZE-1; 316 317 if (is_kernel_text(addr) || 318 is_kernel_text(addr2)) 319 prot = PAGE_KERNEL_LARGE_EXEC; 320 321 pages_2m++; 322 if (mapping_iter == 1) 323 set_pmd(pmd, pfn_pmd(pfn, init_prot)); 324 else 325 set_pmd(pmd, pfn_pmd(pfn, prot)); 326 327 pfn += PTRS_PER_PTE; 328 continue; 329 } 330 pte = one_page_table_init(pmd); 331 332 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 333 pte += pte_ofs; 334 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 335 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 336 pgprot_t prot = PAGE_KERNEL; 337 /* 338 * first pass will use the same initial 339 * identity mapping attribute. 340 */ 341 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); 342 343 if (is_kernel_text(addr)) 344 prot = PAGE_KERNEL_EXEC; 345 346 pages_4k++; 347 if (mapping_iter == 1) 348 set_pte(pte, pfn_pte(pfn, init_prot)); 349 else 350 set_pte(pte, pfn_pte(pfn, prot)); 351 } 352 } 353 } 354 if (mapping_iter == 1) { 355 /* 356 * update direct mapping page count only in the first 357 * iteration. 358 */ 359 update_page_count(PG_LEVEL_2M, pages_2m); 360 update_page_count(PG_LEVEL_4K, pages_4k); 361 362 /* 363 * local global flush tlb, which will flush the previous 364 * mappings present in both small and large page TLB's. 365 */ 366 __flush_tlb_all(); 367 368 /* 369 * Second iteration will set the actual desired PTE attributes. 370 */ 371 mapping_iter = 2; 372 goto repeat; 373 } 374 return 0; 375 } 376 377 pte_t *kmap_pte; 378 pgprot_t kmap_prot; 379 380 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 381 { 382 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 383 vaddr), vaddr), vaddr); 384 } 385 386 static void __init kmap_init(void) 387 { 388 unsigned long kmap_vstart; 389 390 /* 391 * Cache the first kmap pte: 392 */ 393 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 394 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 395 396 kmap_prot = PAGE_KERNEL; 397 } 398 399 #ifdef CONFIG_HIGHMEM 400 static void __init permanent_kmaps_init(pgd_t *pgd_base) 401 { 402 unsigned long vaddr; 403 pgd_t *pgd; 404 pud_t *pud; 405 pmd_t *pmd; 406 pte_t *pte; 407 408 vaddr = PKMAP_BASE; 409 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 410 411 pgd = swapper_pg_dir + pgd_index(vaddr); 412 pud = pud_offset(pgd, vaddr); 413 pmd = pmd_offset(pud, vaddr); 414 pte = pte_offset_kernel(pmd, vaddr); 415 pkmap_page_table = pte; 416 } 417 418 static void __init add_one_highpage_init(struct page *page, int pfn) 419 { 420 ClearPageReserved(page); 421 init_page_count(page); 422 __free_page(page); 423 totalhigh_pages++; 424 } 425 426 struct add_highpages_data { 427 unsigned long start_pfn; 428 unsigned long end_pfn; 429 }; 430 431 static int __init add_highpages_work_fn(unsigned long start_pfn, 432 unsigned long end_pfn, void *datax) 433 { 434 int node_pfn; 435 struct page *page; 436 unsigned long final_start_pfn, final_end_pfn; 437 struct add_highpages_data *data; 438 439 data = (struct add_highpages_data *)datax; 440 441 final_start_pfn = max(start_pfn, data->start_pfn); 442 final_end_pfn = min(end_pfn, data->end_pfn); 443 if (final_start_pfn >= final_end_pfn) 444 return 0; 445 446 for (node_pfn = final_start_pfn; node_pfn < final_end_pfn; 447 node_pfn++) { 448 if (!pfn_valid(node_pfn)) 449 continue; 450 page = pfn_to_page(node_pfn); 451 add_one_highpage_init(page, node_pfn); 452 } 453 454 return 0; 455 456 } 457 458 void __init add_highpages_with_active_regions(int nid, unsigned long start_pfn, 459 unsigned long end_pfn) 460 { 461 struct add_highpages_data data; 462 463 data.start_pfn = start_pfn; 464 data.end_pfn = end_pfn; 465 466 work_with_active_regions(nid, add_highpages_work_fn, &data); 467 } 468 469 #else 470 static inline void permanent_kmaps_init(pgd_t *pgd_base) 471 { 472 } 473 #endif /* CONFIG_HIGHMEM */ 474 475 void __init native_pagetable_setup_start(pgd_t *base) 476 { 477 unsigned long pfn, va; 478 pgd_t *pgd; 479 pud_t *pud; 480 pmd_t *pmd; 481 pte_t *pte; 482 483 /* 484 * Remove any mappings which extend past the end of physical 485 * memory from the boot time page table: 486 */ 487 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 488 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 489 pgd = base + pgd_index(va); 490 if (!pgd_present(*pgd)) 491 break; 492 493 pud = pud_offset(pgd, va); 494 pmd = pmd_offset(pud, va); 495 if (!pmd_present(*pmd)) 496 break; 497 498 pte = pte_offset_kernel(pmd, va); 499 if (!pte_present(*pte)) 500 break; 501 502 pte_clear(NULL, va, pte); 503 } 504 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 505 } 506 507 void __init native_pagetable_setup_done(pgd_t *base) 508 { 509 } 510 511 /* 512 * Build a proper pagetable for the kernel mappings. Up until this 513 * point, we've been running on some set of pagetables constructed by 514 * the boot process. 515 * 516 * If we're booting on native hardware, this will be a pagetable 517 * constructed in arch/x86/kernel/head_32.S. The root of the 518 * pagetable will be swapper_pg_dir. 519 * 520 * If we're booting paravirtualized under a hypervisor, then there are 521 * more options: we may already be running PAE, and the pagetable may 522 * or may not be based in swapper_pg_dir. In any case, 523 * paravirt_pagetable_setup_start() will set up swapper_pg_dir 524 * appropriately for the rest of the initialization to work. 525 * 526 * In general, pagetable_init() assumes that the pagetable may already 527 * be partially populated, and so it avoids stomping on any existing 528 * mappings. 529 */ 530 void __init early_ioremap_page_table_range_init(void) 531 { 532 pgd_t *pgd_base = swapper_pg_dir; 533 unsigned long vaddr, end; 534 535 /* 536 * Fixed mappings, only the page table structure has to be 537 * created - mappings will be set by set_fixmap(): 538 */ 539 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 540 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 541 page_table_range_init(vaddr, end, pgd_base); 542 early_ioremap_reset(); 543 } 544 545 static void __init pagetable_init(void) 546 { 547 pgd_t *pgd_base = swapper_pg_dir; 548 549 permanent_kmaps_init(pgd_base); 550 } 551 552 #ifdef CONFIG_ACPI_SLEEP 553 /* 554 * ACPI suspend needs this for resume, because things like the intel-agp 555 * driver might have split up a kernel 4MB mapping. 556 */ 557 char swsusp_pg_dir[PAGE_SIZE] 558 __attribute__ ((aligned(PAGE_SIZE))); 559 560 static inline void save_pg_dir(void) 561 { 562 memcpy(swsusp_pg_dir, swapper_pg_dir, PAGE_SIZE); 563 } 564 #else /* !CONFIG_ACPI_SLEEP */ 565 static inline void save_pg_dir(void) 566 { 567 } 568 #endif /* !CONFIG_ACPI_SLEEP */ 569 570 void zap_low_mappings(void) 571 { 572 int i; 573 574 /* 575 * Zap initial low-memory mappings. 576 * 577 * Note that "pgd_clear()" doesn't do it for 578 * us, because pgd_clear() is a no-op on i386. 579 */ 580 for (i = 0; i < KERNEL_PGD_BOUNDARY; i++) { 581 #ifdef CONFIG_X86_PAE 582 set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page))); 583 #else 584 set_pgd(swapper_pg_dir+i, __pgd(0)); 585 #endif 586 } 587 flush_tlb_all(); 588 } 589 590 int nx_enabled; 591 592 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); 593 EXPORT_SYMBOL_GPL(__supported_pte_mask); 594 595 #ifdef CONFIG_X86_PAE 596 597 static int disable_nx __initdata; 598 599 /* 600 * noexec = on|off 601 * 602 * Control non executable mappings. 603 * 604 * on Enable 605 * off Disable 606 */ 607 static int __init noexec_setup(char *str) 608 { 609 if (!str || !strcmp(str, "on")) { 610 if (cpu_has_nx) { 611 __supported_pte_mask |= _PAGE_NX; 612 disable_nx = 0; 613 } 614 } else { 615 if (!strcmp(str, "off")) { 616 disable_nx = 1; 617 __supported_pte_mask &= ~_PAGE_NX; 618 } else { 619 return -EINVAL; 620 } 621 } 622 623 return 0; 624 } 625 early_param("noexec", noexec_setup); 626 627 void __init set_nx(void) 628 { 629 unsigned int v[4], l, h; 630 631 if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { 632 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); 633 634 if ((v[3] & (1 << 20)) && !disable_nx) { 635 rdmsr(MSR_EFER, l, h); 636 l |= EFER_NX; 637 wrmsr(MSR_EFER, l, h); 638 nx_enabled = 1; 639 __supported_pte_mask |= _PAGE_NX; 640 } 641 } 642 } 643 #endif 644 645 /* user-defined highmem size */ 646 static unsigned int highmem_pages = -1; 647 648 /* 649 * highmem=size forces highmem to be exactly 'size' bytes. 650 * This works even on boxes that have no highmem otherwise. 651 * This also works to reduce highmem size on bigger boxes. 652 */ 653 static int __init parse_highmem(char *arg) 654 { 655 if (!arg) 656 return -EINVAL; 657 658 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 659 return 0; 660 } 661 early_param("highmem", parse_highmem); 662 663 #define MSG_HIGHMEM_TOO_BIG \ 664 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 665 666 #define MSG_LOWMEM_TOO_SMALL \ 667 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 668 /* 669 * All of RAM fits into lowmem - but if user wants highmem 670 * artificially via the highmem=x boot parameter then create 671 * it: 672 */ 673 void __init lowmem_pfn_init(void) 674 { 675 /* max_low_pfn is 0, we already have early_res support */ 676 max_low_pfn = max_pfn; 677 678 if (highmem_pages == -1) 679 highmem_pages = 0; 680 #ifdef CONFIG_HIGHMEM 681 if (highmem_pages >= max_pfn) { 682 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 683 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 684 highmem_pages = 0; 685 } 686 if (highmem_pages) { 687 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 688 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 689 pages_to_mb(highmem_pages)); 690 highmem_pages = 0; 691 } 692 max_low_pfn -= highmem_pages; 693 } 694 #else 695 if (highmem_pages) 696 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 697 #endif 698 } 699 700 #define MSG_HIGHMEM_TOO_SMALL \ 701 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 702 703 #define MSG_HIGHMEM_TRIMMED \ 704 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 705 /* 706 * We have more RAM than fits into lowmem - we try to put it into 707 * highmem, also taking the highmem=x boot parameter into account: 708 */ 709 void __init highmem_pfn_init(void) 710 { 711 max_low_pfn = MAXMEM_PFN; 712 713 if (highmem_pages == -1) 714 highmem_pages = max_pfn - MAXMEM_PFN; 715 716 if (highmem_pages + MAXMEM_PFN < max_pfn) 717 max_pfn = MAXMEM_PFN + highmem_pages; 718 719 if (highmem_pages + MAXMEM_PFN > max_pfn) { 720 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 721 pages_to_mb(max_pfn - MAXMEM_PFN), 722 pages_to_mb(highmem_pages)); 723 highmem_pages = 0; 724 } 725 #ifndef CONFIG_HIGHMEM 726 /* Maximum memory usable is what is directly addressable */ 727 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 728 if (max_pfn > MAX_NONPAE_PFN) 729 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 730 else 731 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 732 max_pfn = MAXMEM_PFN; 733 #else /* !CONFIG_HIGHMEM */ 734 #ifndef CONFIG_HIGHMEM64G 735 if (max_pfn > MAX_NONPAE_PFN) { 736 max_pfn = MAX_NONPAE_PFN; 737 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 738 } 739 #endif /* !CONFIG_HIGHMEM64G */ 740 #endif /* !CONFIG_HIGHMEM */ 741 } 742 743 /* 744 * Determine low and high memory ranges: 745 */ 746 void __init find_low_pfn_range(void) 747 { 748 /* it could update max_pfn */ 749 750 if (max_pfn <= MAXMEM_PFN) 751 lowmem_pfn_init(); 752 else 753 highmem_pfn_init(); 754 } 755 756 #ifndef CONFIG_NEED_MULTIPLE_NODES 757 void __init initmem_init(unsigned long start_pfn, 758 unsigned long end_pfn) 759 { 760 #ifdef CONFIG_HIGHMEM 761 highstart_pfn = highend_pfn = max_pfn; 762 if (max_pfn > max_low_pfn) 763 highstart_pfn = max_low_pfn; 764 memory_present(0, 0, highend_pfn); 765 e820_register_active_regions(0, 0, highend_pfn); 766 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 767 pages_to_mb(highend_pfn - highstart_pfn)); 768 num_physpages = highend_pfn; 769 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 770 #else 771 memory_present(0, 0, max_low_pfn); 772 e820_register_active_regions(0, 0, max_low_pfn); 773 num_physpages = max_low_pfn; 774 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 775 #endif 776 #ifdef CONFIG_FLATMEM 777 max_mapnr = num_physpages; 778 #endif 779 __vmalloc_start_set = true; 780 781 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 782 pages_to_mb(max_low_pfn)); 783 784 setup_bootmem_allocator(); 785 } 786 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 787 788 static void __init zone_sizes_init(void) 789 { 790 unsigned long max_zone_pfns[MAX_NR_ZONES]; 791 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 792 max_zone_pfns[ZONE_DMA] = 793 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 794 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 795 #ifdef CONFIG_HIGHMEM 796 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn; 797 #endif 798 799 free_area_init_nodes(max_zone_pfns); 800 } 801 802 static unsigned long __init setup_node_bootmem(int nodeid, 803 unsigned long start_pfn, 804 unsigned long end_pfn, 805 unsigned long bootmap) 806 { 807 unsigned long bootmap_size; 808 809 /* don't touch min_low_pfn */ 810 bootmap_size = init_bootmem_node(NODE_DATA(nodeid), 811 bootmap >> PAGE_SHIFT, 812 start_pfn, end_pfn); 813 printk(KERN_INFO " node %d low ram: %08lx - %08lx\n", 814 nodeid, start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT); 815 printk(KERN_INFO " node %d bootmap %08lx - %08lx\n", 816 nodeid, bootmap, bootmap + bootmap_size); 817 free_bootmem_with_active_regions(nodeid, end_pfn); 818 early_res_to_bootmem(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT); 819 820 return bootmap + bootmap_size; 821 } 822 823 void __init setup_bootmem_allocator(void) 824 { 825 int nodeid; 826 unsigned long bootmap_size, bootmap; 827 /* 828 * Initialize the boot-time allocator (with low memory only): 829 */ 830 bootmap_size = bootmem_bootmap_pages(max_low_pfn)<<PAGE_SHIFT; 831 bootmap = find_e820_area(0, max_pfn_mapped<<PAGE_SHIFT, bootmap_size, 832 PAGE_SIZE); 833 if (bootmap == -1L) 834 panic("Cannot find bootmem map of size %ld\n", bootmap_size); 835 reserve_early(bootmap, bootmap + bootmap_size, "BOOTMAP"); 836 837 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 838 max_pfn_mapped<<PAGE_SHIFT); 839 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 840 841 for_each_online_node(nodeid) { 842 unsigned long start_pfn, end_pfn; 843 844 #ifdef CONFIG_NEED_MULTIPLE_NODES 845 start_pfn = node_start_pfn[nodeid]; 846 end_pfn = node_end_pfn[nodeid]; 847 if (start_pfn > max_low_pfn) 848 continue; 849 if (end_pfn > max_low_pfn) 850 end_pfn = max_low_pfn; 851 #else 852 start_pfn = 0; 853 end_pfn = max_low_pfn; 854 #endif 855 bootmap = setup_node_bootmem(nodeid, start_pfn, end_pfn, 856 bootmap); 857 } 858 859 after_bootmem = 1; 860 } 861 862 /* 863 * paging_init() sets up the page tables - note that the first 8MB are 864 * already mapped by head.S. 865 * 866 * This routines also unmaps the page at virtual kernel address 0, so 867 * that we can trap those pesky NULL-reference errors in the kernel. 868 */ 869 void __init paging_init(void) 870 { 871 pagetable_init(); 872 873 __flush_tlb_all(); 874 875 kmap_init(); 876 877 /* 878 * NOTE: at this point the bootmem allocator is fully available. 879 */ 880 sparse_init(); 881 zone_sizes_init(); 882 } 883 884 /* 885 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 886 * and also on some strange 486's. All 586+'s are OK. This used to involve 887 * black magic jumps to work around some nasty CPU bugs, but fortunately the 888 * switch to using exceptions got rid of all that. 889 */ 890 static void __init test_wp_bit(void) 891 { 892 printk(KERN_INFO 893 "Checking if this processor honours the WP bit even in supervisor mode..."); 894 895 /* Any page-aligned address will do, the test is non-destructive */ 896 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); 897 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 898 clear_fixmap(FIX_WP_TEST); 899 900 if (!boot_cpu_data.wp_works_ok) { 901 printk(KERN_CONT "No.\n"); 902 #ifdef CONFIG_X86_WP_WORKS_OK 903 panic( 904 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 905 #endif 906 } else { 907 printk(KERN_CONT "Ok.\n"); 908 } 909 } 910 911 static struct kcore_list kcore_mem, kcore_vmalloc; 912 913 void __init mem_init(void) 914 { 915 int codesize, reservedpages, datasize, initsize; 916 int tmp; 917 918 pci_iommu_alloc(); 919 920 #ifdef CONFIG_FLATMEM 921 BUG_ON(!mem_map); 922 #endif 923 /* this will put all low memory onto the freelists */ 924 totalram_pages += free_all_bootmem(); 925 926 reservedpages = 0; 927 for (tmp = 0; tmp < max_low_pfn; tmp++) 928 /* 929 * Only count reserved RAM pages: 930 */ 931 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 932 reservedpages++; 933 934 set_highmem_pages_init(); 935 936 codesize = (unsigned long) &_etext - (unsigned long) &_text; 937 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 938 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 939 940 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 941 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 942 VMALLOC_END-VMALLOC_START); 943 944 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 945 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 946 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 947 num_physpages << (PAGE_SHIFT-10), 948 codesize >> 10, 949 reservedpages << (PAGE_SHIFT-10), 950 datasize >> 10, 951 initsize >> 10, 952 (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) 953 ); 954 955 printk(KERN_INFO "virtual kernel memory layout:\n" 956 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 957 #ifdef CONFIG_HIGHMEM 958 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 959 #endif 960 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 961 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 962 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 963 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 964 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 965 FIXADDR_START, FIXADDR_TOP, 966 (FIXADDR_TOP - FIXADDR_START) >> 10, 967 968 #ifdef CONFIG_HIGHMEM 969 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 970 (LAST_PKMAP*PAGE_SIZE) >> 10, 971 #endif 972 973 VMALLOC_START, VMALLOC_END, 974 (VMALLOC_END - VMALLOC_START) >> 20, 975 976 (unsigned long)__va(0), (unsigned long)high_memory, 977 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 978 979 (unsigned long)&__init_begin, (unsigned long)&__init_end, 980 ((unsigned long)&__init_end - 981 (unsigned long)&__init_begin) >> 10, 982 983 (unsigned long)&_etext, (unsigned long)&_edata, 984 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 985 986 (unsigned long)&_text, (unsigned long)&_etext, 987 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 988 989 /* 990 * Check boundaries twice: Some fundamental inconsistencies can 991 * be detected at build time already. 992 */ 993 #define __FIXADDR_TOP (-PAGE_SIZE) 994 #ifdef CONFIG_HIGHMEM 995 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 996 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 997 #endif 998 #define high_memory (-128UL << 20) 999 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 1000 #undef high_memory 1001 #undef __FIXADDR_TOP 1002 1003 #ifdef CONFIG_HIGHMEM 1004 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 1005 BUG_ON(VMALLOC_END > PKMAP_BASE); 1006 #endif 1007 BUG_ON(VMALLOC_START >= VMALLOC_END); 1008 BUG_ON((unsigned long)high_memory > VMALLOC_START); 1009 1010 if (boot_cpu_data.wp_works_ok < 0) 1011 test_wp_bit(); 1012 1013 save_pg_dir(); 1014 zap_low_mappings(); 1015 } 1016 1017 #ifdef CONFIG_MEMORY_HOTPLUG 1018 int arch_add_memory(int nid, u64 start, u64 size) 1019 { 1020 struct pglist_data *pgdata = NODE_DATA(nid); 1021 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 1022 unsigned long start_pfn = start >> PAGE_SHIFT; 1023 unsigned long nr_pages = size >> PAGE_SHIFT; 1024 1025 return __add_pages(nid, zone, start_pfn, nr_pages); 1026 } 1027 #endif 1028 1029 /* 1030 * This function cannot be __init, since exceptions don't work in that 1031 * section. Put this after the callers, so that it cannot be inlined. 1032 */ 1033 static noinline int do_test_wp_bit(void) 1034 { 1035 char tmp_reg; 1036 int flag; 1037 1038 __asm__ __volatile__( 1039 " movb %0, %1 \n" 1040 "1: movb %1, %0 \n" 1041 " xorl %2, %2 \n" 1042 "2: \n" 1043 _ASM_EXTABLE(1b,2b) 1044 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 1045 "=q" (tmp_reg), 1046 "=r" (flag) 1047 :"2" (1) 1048 :"memory"); 1049 1050 return flag; 1051 } 1052 1053 #ifdef CONFIG_DEBUG_RODATA 1054 const int rodata_test_data = 0xC3; 1055 EXPORT_SYMBOL_GPL(rodata_test_data); 1056 1057 static int kernel_set_to_readonly; 1058 1059 void set_kernel_text_rw(void) 1060 { 1061 unsigned long start = PFN_ALIGN(_text); 1062 unsigned long size = PFN_ALIGN(_etext) - start; 1063 1064 if (!kernel_set_to_readonly) 1065 return; 1066 1067 pr_debug("Set kernel text: %lx - %lx for read write\n", 1068 start, start+size); 1069 1070 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1071 } 1072 1073 void set_kernel_text_ro(void) 1074 { 1075 unsigned long start = PFN_ALIGN(_text); 1076 unsigned long size = PFN_ALIGN(_etext) - start; 1077 1078 if (!kernel_set_to_readonly) 1079 return; 1080 1081 pr_debug("Set kernel text: %lx - %lx for read only\n", 1082 start, start+size); 1083 1084 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1085 } 1086 1087 void mark_rodata_ro(void) 1088 { 1089 unsigned long start = PFN_ALIGN(_text); 1090 unsigned long size = PFN_ALIGN(_etext) - start; 1091 1092 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1093 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 1094 size >> 10); 1095 1096 kernel_set_to_readonly = 1; 1097 1098 #ifdef CONFIG_CPA_DEBUG 1099 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 1100 start, start+size); 1101 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 1102 1103 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1104 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 1105 #endif 1106 1107 start += size; 1108 size = (unsigned long)__end_rodata - start; 1109 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1110 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 1111 size >> 10); 1112 rodata_test(); 1113 1114 #ifdef CONFIG_CPA_DEBUG 1115 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 1116 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 1117 1118 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1119 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1120 #endif 1121 } 1122 #endif 1123 1124 int __init reserve_bootmem_generic(unsigned long phys, unsigned long len, 1125 int flags) 1126 { 1127 return reserve_bootmem(phys, len, flags); 1128 } 1129