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/memblock.h> 29 #include <linux/proc_fs.h> 30 #include <linux/memory_hotplug.h> 31 #include <linux/initrd.h> 32 #include <linux/cpumask.h> 33 #include <linux/gfp.h> 34 35 #include <asm/asm.h> 36 #include <asm/bios_ebda.h> 37 #include <asm/processor.h> 38 #include <asm/system.h> 39 #include <asm/uaccess.h> 40 #include <asm/pgtable.h> 41 #include <asm/dma.h> 42 #include <asm/fixmap.h> 43 #include <asm/e820.h> 44 #include <asm/apic.h> 45 #include <asm/bugs.h> 46 #include <asm/tlb.h> 47 #include <asm/tlbflush.h> 48 #include <asm/olpc_ofw.h> 49 #include <asm/pgalloc.h> 50 #include <asm/sections.h> 51 #include <asm/paravirt.h> 52 #include <asm/setup.h> 53 #include <asm/cacheflush.h> 54 #include <asm/page_types.h> 55 #include <asm/init.h> 56 57 unsigned long highstart_pfn, highend_pfn; 58 59 static noinline int do_test_wp_bit(void); 60 61 bool __read_mostly __vmalloc_start_set = false; 62 63 static __init void *alloc_low_page(void) 64 { 65 unsigned long pfn = pgt_buf_end++; 66 void *adr; 67 68 if (pfn >= pgt_buf_top) 69 panic("alloc_low_page: ran out of memory"); 70 71 adr = __va(pfn * PAGE_SIZE); 72 clear_page(adr); 73 return adr; 74 } 75 76 /* 77 * Creates a middle page table and puts a pointer to it in the 78 * given global directory entry. This only returns the gd entry 79 * in non-PAE compilation mode, since the middle layer is folded. 80 */ 81 static pmd_t * __init one_md_table_init(pgd_t *pgd) 82 { 83 pud_t *pud; 84 pmd_t *pmd_table; 85 86 #ifdef CONFIG_X86_PAE 87 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 88 if (after_bootmem) 89 pmd_table = (pmd_t *)alloc_bootmem_pages(PAGE_SIZE); 90 else 91 pmd_table = (pmd_t *)alloc_low_page(); 92 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 93 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 94 pud = pud_offset(pgd, 0); 95 BUG_ON(pmd_table != pmd_offset(pud, 0)); 96 97 return pmd_table; 98 } 99 #endif 100 pud = pud_offset(pgd, 0); 101 pmd_table = pmd_offset(pud, 0); 102 103 return pmd_table; 104 } 105 106 /* 107 * Create a page table and place a pointer to it in a middle page 108 * directory entry: 109 */ 110 static pte_t * __init one_page_table_init(pmd_t *pmd) 111 { 112 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 113 pte_t *page_table = NULL; 114 115 if (after_bootmem) { 116 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) 117 page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); 118 #endif 119 if (!page_table) 120 page_table = 121 (pte_t *)alloc_bootmem_pages(PAGE_SIZE); 122 } else 123 page_table = (pte_t *)alloc_low_page(); 124 125 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 126 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 127 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 128 } 129 130 return pte_offset_kernel(pmd, 0); 131 } 132 133 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 134 { 135 int pgd_idx = pgd_index(vaddr); 136 int pmd_idx = pmd_index(vaddr); 137 138 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; 139 } 140 141 pte_t * __init populate_extra_pte(unsigned long vaddr) 142 { 143 int pte_idx = pte_index(vaddr); 144 pmd_t *pmd; 145 146 pmd = populate_extra_pmd(vaddr); 147 return one_page_table_init(pmd) + pte_idx; 148 } 149 150 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 151 unsigned long vaddr, pte_t *lastpte) 152 { 153 #ifdef CONFIG_HIGHMEM 154 /* 155 * Something (early fixmap) may already have put a pte 156 * page here, which causes the page table allocation 157 * to become nonlinear. Attempt to fix it, and if it 158 * is still nonlinear then we have to bug. 159 */ 160 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 161 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 162 163 if (pmd_idx_kmap_begin != pmd_idx_kmap_end 164 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin 165 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end 166 && ((__pa(pte) >> PAGE_SHIFT) < pgt_buf_start 167 || (__pa(pte) >> PAGE_SHIFT) >= pgt_buf_end)) { 168 pte_t *newpte; 169 int i; 170 171 BUG_ON(after_bootmem); 172 newpte = alloc_low_page(); 173 for (i = 0; i < PTRS_PER_PTE; i++) 174 set_pte(newpte + i, pte[i]); 175 176 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); 177 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); 178 BUG_ON(newpte != pte_offset_kernel(pmd, 0)); 179 __flush_tlb_all(); 180 181 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); 182 pte = newpte; 183 } 184 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) 185 && vaddr > fix_to_virt(FIX_KMAP_END) 186 && lastpte && lastpte + PTRS_PER_PTE != pte); 187 #endif 188 return pte; 189 } 190 191 /* 192 * This function initializes a certain range of kernel virtual memory 193 * with new bootmem page tables, everywhere page tables are missing in 194 * the given range. 195 * 196 * NOTE: The pagetables are allocated contiguous on the physical space 197 * so we can cache the place of the first one and move around without 198 * checking the pgd every time. 199 */ 200 static void __init 201 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 202 { 203 int pgd_idx, pmd_idx; 204 unsigned long vaddr; 205 pgd_t *pgd; 206 pmd_t *pmd; 207 pte_t *pte = NULL; 208 209 vaddr = start; 210 pgd_idx = pgd_index(vaddr); 211 pmd_idx = pmd_index(vaddr); 212 pgd = pgd_base + pgd_idx; 213 214 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 215 pmd = one_md_table_init(pgd); 216 pmd = pmd + pmd_index(vaddr); 217 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 218 pmd++, pmd_idx++) { 219 pte = page_table_kmap_check(one_page_table_init(pmd), 220 pmd, vaddr, pte); 221 222 vaddr += PMD_SIZE; 223 } 224 pmd_idx = 0; 225 } 226 } 227 228 static inline int is_kernel_text(unsigned long addr) 229 { 230 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end) 231 return 1; 232 return 0; 233 } 234 235 /* 236 * This maps the physical memory to kernel virtual address space, a total 237 * of max_low_pfn pages, by creating page tables starting from address 238 * PAGE_OFFSET: 239 */ 240 unsigned long __init 241 kernel_physical_mapping_init(unsigned long start, 242 unsigned long end, 243 unsigned long page_size_mask) 244 { 245 int use_pse = page_size_mask == (1<<PG_LEVEL_2M); 246 unsigned long last_map_addr = end; 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 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE; 350 } else 351 set_pte(pte, pfn_pte(pfn, prot)); 352 } 353 } 354 } 355 if (mapping_iter == 1) { 356 /* 357 * update direct mapping page count only in the first 358 * iteration. 359 */ 360 update_page_count(PG_LEVEL_2M, pages_2m); 361 update_page_count(PG_LEVEL_4K, pages_4k); 362 363 /* 364 * local global flush tlb, which will flush the previous 365 * mappings present in both small and large page TLB's. 366 */ 367 __flush_tlb_all(); 368 369 /* 370 * Second iteration will set the actual desired PTE attributes. 371 */ 372 mapping_iter = 2; 373 goto repeat; 374 } 375 return last_map_addr; 376 } 377 378 pte_t *kmap_pte; 379 pgprot_t kmap_prot; 380 381 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 382 { 383 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 384 vaddr), vaddr), vaddr); 385 } 386 387 static void __init kmap_init(void) 388 { 389 unsigned long kmap_vstart; 390 391 /* 392 * Cache the first kmap pte: 393 */ 394 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 395 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 396 397 kmap_prot = PAGE_KERNEL; 398 } 399 400 #ifdef CONFIG_HIGHMEM 401 static void __init permanent_kmaps_init(pgd_t *pgd_base) 402 { 403 unsigned long vaddr; 404 pgd_t *pgd; 405 pud_t *pud; 406 pmd_t *pmd; 407 pte_t *pte; 408 409 vaddr = PKMAP_BASE; 410 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 411 412 pgd = swapper_pg_dir + pgd_index(vaddr); 413 pud = pud_offset(pgd, vaddr); 414 pmd = pmd_offset(pud, vaddr); 415 pte = pte_offset_kernel(pmd, vaddr); 416 pkmap_page_table = pte; 417 } 418 419 static void __init add_one_highpage_init(struct page *page) 420 { 421 ClearPageReserved(page); 422 init_page_count(page); 423 __free_page(page); 424 totalhigh_pages++; 425 } 426 427 void __init add_highpages_with_active_regions(int nid, 428 unsigned long start_pfn, unsigned long end_pfn) 429 { 430 struct range *range; 431 int nr_range; 432 int i; 433 434 nr_range = __get_free_all_memory_range(&range, nid, start_pfn, end_pfn); 435 436 for (i = 0; i < nr_range; i++) { 437 struct page *page; 438 int node_pfn; 439 440 for (node_pfn = range[i].start; node_pfn < range[i].end; 441 node_pfn++) { 442 if (!pfn_valid(node_pfn)) 443 continue; 444 page = pfn_to_page(node_pfn); 445 add_one_highpage_init(page); 446 } 447 } 448 } 449 #else 450 static inline void permanent_kmaps_init(pgd_t *pgd_base) 451 { 452 } 453 #endif /* CONFIG_HIGHMEM */ 454 455 void __init native_pagetable_setup_start(pgd_t *base) 456 { 457 unsigned long pfn, va; 458 pgd_t *pgd; 459 pud_t *pud; 460 pmd_t *pmd; 461 pte_t *pte; 462 463 /* 464 * Remove any mappings which extend past the end of physical 465 * memory from the boot time page table: 466 */ 467 for (pfn = max_low_pfn + 1; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 468 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 469 pgd = base + pgd_index(va); 470 if (!pgd_present(*pgd)) 471 break; 472 473 pud = pud_offset(pgd, va); 474 pmd = pmd_offset(pud, va); 475 if (!pmd_present(*pmd)) 476 break; 477 478 pte = pte_offset_kernel(pmd, va); 479 if (!pte_present(*pte)) 480 break; 481 482 pte_clear(NULL, va, pte); 483 } 484 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 485 } 486 487 void __init native_pagetable_setup_done(pgd_t *base) 488 { 489 } 490 491 /* 492 * Build a proper pagetable for the kernel mappings. Up until this 493 * point, we've been running on some set of pagetables constructed by 494 * the boot process. 495 * 496 * If we're booting on native hardware, this will be a pagetable 497 * constructed in arch/x86/kernel/head_32.S. The root of the 498 * pagetable will be swapper_pg_dir. 499 * 500 * If we're booting paravirtualized under a hypervisor, then there are 501 * more options: we may already be running PAE, and the pagetable may 502 * or may not be based in swapper_pg_dir. In any case, 503 * paravirt_pagetable_setup_start() will set up swapper_pg_dir 504 * appropriately for the rest of the initialization to work. 505 * 506 * In general, pagetable_init() assumes that the pagetable may already 507 * be partially populated, and so it avoids stomping on any existing 508 * mappings. 509 */ 510 void __init early_ioremap_page_table_range_init(void) 511 { 512 pgd_t *pgd_base = swapper_pg_dir; 513 unsigned long vaddr, end; 514 515 /* 516 * Fixed mappings, only the page table structure has to be 517 * created - mappings will be set by set_fixmap(): 518 */ 519 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 520 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 521 page_table_range_init(vaddr, end, pgd_base); 522 early_ioremap_reset(); 523 } 524 525 static void __init pagetable_init(void) 526 { 527 pgd_t *pgd_base = swapper_pg_dir; 528 529 permanent_kmaps_init(pgd_base); 530 } 531 532 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); 533 EXPORT_SYMBOL_GPL(__supported_pte_mask); 534 535 /* user-defined highmem size */ 536 static unsigned int highmem_pages = -1; 537 538 /* 539 * highmem=size forces highmem to be exactly 'size' bytes. 540 * This works even on boxes that have no highmem otherwise. 541 * This also works to reduce highmem size on bigger boxes. 542 */ 543 static int __init parse_highmem(char *arg) 544 { 545 if (!arg) 546 return -EINVAL; 547 548 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 549 return 0; 550 } 551 early_param("highmem", parse_highmem); 552 553 #define MSG_HIGHMEM_TOO_BIG \ 554 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 555 556 #define MSG_LOWMEM_TOO_SMALL \ 557 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 558 /* 559 * All of RAM fits into lowmem - but if user wants highmem 560 * artificially via the highmem=x boot parameter then create 561 * it: 562 */ 563 void __init lowmem_pfn_init(void) 564 { 565 /* max_low_pfn is 0, we already have early_res support */ 566 max_low_pfn = max_pfn; 567 568 if (highmem_pages == -1) 569 highmem_pages = 0; 570 #ifdef CONFIG_HIGHMEM 571 if (highmem_pages >= max_pfn) { 572 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 573 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 574 highmem_pages = 0; 575 } 576 if (highmem_pages) { 577 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 578 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 579 pages_to_mb(highmem_pages)); 580 highmem_pages = 0; 581 } 582 max_low_pfn -= highmem_pages; 583 } 584 #else 585 if (highmem_pages) 586 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 587 #endif 588 } 589 590 #define MSG_HIGHMEM_TOO_SMALL \ 591 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 592 593 #define MSG_HIGHMEM_TRIMMED \ 594 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 595 /* 596 * We have more RAM than fits into lowmem - we try to put it into 597 * highmem, also taking the highmem=x boot parameter into account: 598 */ 599 void __init highmem_pfn_init(void) 600 { 601 max_low_pfn = MAXMEM_PFN; 602 603 if (highmem_pages == -1) 604 highmem_pages = max_pfn - MAXMEM_PFN; 605 606 if (highmem_pages + MAXMEM_PFN < max_pfn) 607 max_pfn = MAXMEM_PFN + highmem_pages; 608 609 if (highmem_pages + MAXMEM_PFN > max_pfn) { 610 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 611 pages_to_mb(max_pfn - MAXMEM_PFN), 612 pages_to_mb(highmem_pages)); 613 highmem_pages = 0; 614 } 615 #ifndef CONFIG_HIGHMEM 616 /* Maximum memory usable is what is directly addressable */ 617 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 618 if (max_pfn > MAX_NONPAE_PFN) 619 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 620 else 621 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 622 max_pfn = MAXMEM_PFN; 623 #else /* !CONFIG_HIGHMEM */ 624 #ifndef CONFIG_HIGHMEM64G 625 if (max_pfn > MAX_NONPAE_PFN) { 626 max_pfn = MAX_NONPAE_PFN; 627 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 628 } 629 #endif /* !CONFIG_HIGHMEM64G */ 630 #endif /* !CONFIG_HIGHMEM */ 631 } 632 633 /* 634 * Determine low and high memory ranges: 635 */ 636 void __init find_low_pfn_range(void) 637 { 638 /* it could update max_pfn */ 639 640 if (max_pfn <= MAXMEM_PFN) 641 lowmem_pfn_init(); 642 else 643 highmem_pfn_init(); 644 } 645 646 #ifndef CONFIG_NEED_MULTIPLE_NODES 647 void __init initmem_init(void) 648 { 649 #ifdef CONFIG_HIGHMEM 650 highstart_pfn = highend_pfn = max_pfn; 651 if (max_pfn > max_low_pfn) 652 highstart_pfn = max_low_pfn; 653 memblock_x86_register_active_regions(0, 0, highend_pfn); 654 sparse_memory_present_with_active_regions(0); 655 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 656 pages_to_mb(highend_pfn - highstart_pfn)); 657 num_physpages = highend_pfn; 658 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 659 #else 660 memblock_x86_register_active_regions(0, 0, max_low_pfn); 661 sparse_memory_present_with_active_regions(0); 662 num_physpages = max_low_pfn; 663 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 664 #endif 665 #ifdef CONFIG_FLATMEM 666 max_mapnr = num_physpages; 667 #endif 668 __vmalloc_start_set = true; 669 670 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 671 pages_to_mb(max_low_pfn)); 672 673 setup_bootmem_allocator(); 674 } 675 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 676 677 static void __init zone_sizes_init(void) 678 { 679 unsigned long max_zone_pfns[MAX_NR_ZONES]; 680 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 681 #ifdef CONFIG_ZONE_DMA 682 max_zone_pfns[ZONE_DMA] = 683 virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 684 #endif 685 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 686 #ifdef CONFIG_HIGHMEM 687 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn; 688 #endif 689 690 free_area_init_nodes(max_zone_pfns); 691 } 692 693 void __init setup_bootmem_allocator(void) 694 { 695 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 696 max_pfn_mapped<<PAGE_SHIFT); 697 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 698 699 after_bootmem = 1; 700 } 701 702 /* 703 * paging_init() sets up the page tables - note that the first 8MB are 704 * already mapped by head.S. 705 * 706 * This routines also unmaps the page at virtual kernel address 0, so 707 * that we can trap those pesky NULL-reference errors in the kernel. 708 */ 709 void __init paging_init(void) 710 { 711 pagetable_init(); 712 713 __flush_tlb_all(); 714 715 kmap_init(); 716 717 /* 718 * NOTE: at this point the bootmem allocator is fully available. 719 */ 720 olpc_dt_build_devicetree(); 721 sparse_memory_present_with_active_regions(MAX_NUMNODES); 722 sparse_init(); 723 zone_sizes_init(); 724 } 725 726 /* 727 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 728 * and also on some strange 486's. All 586+'s are OK. This used to involve 729 * black magic jumps to work around some nasty CPU bugs, but fortunately the 730 * switch to using exceptions got rid of all that. 731 */ 732 static void __init test_wp_bit(void) 733 { 734 printk(KERN_INFO 735 "Checking if this processor honours the WP bit even in supervisor mode..."); 736 737 /* Any page-aligned address will do, the test is non-destructive */ 738 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_READONLY); 739 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 740 clear_fixmap(FIX_WP_TEST); 741 742 if (!boot_cpu_data.wp_works_ok) { 743 printk(KERN_CONT "No.\n"); 744 #ifdef CONFIG_X86_WP_WORKS_OK 745 panic( 746 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 747 #endif 748 } else { 749 printk(KERN_CONT "Ok.\n"); 750 } 751 } 752 753 void __init mem_init(void) 754 { 755 int codesize, reservedpages, datasize, initsize; 756 int tmp; 757 758 pci_iommu_alloc(); 759 760 #ifdef CONFIG_FLATMEM 761 BUG_ON(!mem_map); 762 #endif 763 /* this will put all low memory onto the freelists */ 764 totalram_pages += free_all_bootmem(); 765 766 reservedpages = 0; 767 for (tmp = 0; tmp < max_low_pfn; tmp++) 768 /* 769 * Only count reserved RAM pages: 770 */ 771 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 772 reservedpages++; 773 774 set_highmem_pages_init(); 775 776 codesize = (unsigned long) &_etext - (unsigned long) &_text; 777 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 778 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 779 780 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 781 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 782 nr_free_pages() << (PAGE_SHIFT-10), 783 num_physpages << (PAGE_SHIFT-10), 784 codesize >> 10, 785 reservedpages << (PAGE_SHIFT-10), 786 datasize >> 10, 787 initsize >> 10, 788 totalhigh_pages << (PAGE_SHIFT-10)); 789 790 printk(KERN_INFO "virtual kernel memory layout:\n" 791 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 792 #ifdef CONFIG_HIGHMEM 793 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 794 #endif 795 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 796 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 797 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 798 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 799 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 800 FIXADDR_START, FIXADDR_TOP, 801 (FIXADDR_TOP - FIXADDR_START) >> 10, 802 803 #ifdef CONFIG_HIGHMEM 804 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 805 (LAST_PKMAP*PAGE_SIZE) >> 10, 806 #endif 807 808 VMALLOC_START, VMALLOC_END, 809 (VMALLOC_END - VMALLOC_START) >> 20, 810 811 (unsigned long)__va(0), (unsigned long)high_memory, 812 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 813 814 (unsigned long)&__init_begin, (unsigned long)&__init_end, 815 ((unsigned long)&__init_end - 816 (unsigned long)&__init_begin) >> 10, 817 818 (unsigned long)&_etext, (unsigned long)&_edata, 819 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 820 821 (unsigned long)&_text, (unsigned long)&_etext, 822 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 823 824 /* 825 * Check boundaries twice: Some fundamental inconsistencies can 826 * be detected at build time already. 827 */ 828 #define __FIXADDR_TOP (-PAGE_SIZE) 829 #ifdef CONFIG_HIGHMEM 830 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 831 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 832 #endif 833 #define high_memory (-128UL << 20) 834 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 835 #undef high_memory 836 #undef __FIXADDR_TOP 837 838 #ifdef CONFIG_HIGHMEM 839 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 840 BUG_ON(VMALLOC_END > PKMAP_BASE); 841 #endif 842 BUG_ON(VMALLOC_START >= VMALLOC_END); 843 BUG_ON((unsigned long)high_memory > VMALLOC_START); 844 845 if (boot_cpu_data.wp_works_ok < 0) 846 test_wp_bit(); 847 } 848 849 #ifdef CONFIG_MEMORY_HOTPLUG 850 int arch_add_memory(int nid, u64 start, u64 size) 851 { 852 struct pglist_data *pgdata = NODE_DATA(nid); 853 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 854 unsigned long start_pfn = start >> PAGE_SHIFT; 855 unsigned long nr_pages = size >> PAGE_SHIFT; 856 857 return __add_pages(nid, zone, start_pfn, nr_pages); 858 } 859 #endif 860 861 /* 862 * This function cannot be __init, since exceptions don't work in that 863 * section. Put this after the callers, so that it cannot be inlined. 864 */ 865 static noinline int do_test_wp_bit(void) 866 { 867 char tmp_reg; 868 int flag; 869 870 __asm__ __volatile__( 871 " movb %0, %1 \n" 872 "1: movb %1, %0 \n" 873 " xorl %2, %2 \n" 874 "2: \n" 875 _ASM_EXTABLE(1b,2b) 876 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 877 "=q" (tmp_reg), 878 "=r" (flag) 879 :"2" (1) 880 :"memory"); 881 882 return flag; 883 } 884 885 #ifdef CONFIG_DEBUG_RODATA 886 const int rodata_test_data = 0xC3; 887 EXPORT_SYMBOL_GPL(rodata_test_data); 888 889 int kernel_set_to_readonly __read_mostly; 890 891 void set_kernel_text_rw(void) 892 { 893 unsigned long start = PFN_ALIGN(_text); 894 unsigned long size = PFN_ALIGN(_etext) - start; 895 896 if (!kernel_set_to_readonly) 897 return; 898 899 pr_debug("Set kernel text: %lx - %lx for read write\n", 900 start, start+size); 901 902 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 903 } 904 905 void set_kernel_text_ro(void) 906 { 907 unsigned long start = PFN_ALIGN(_text); 908 unsigned long size = PFN_ALIGN(_etext) - start; 909 910 if (!kernel_set_to_readonly) 911 return; 912 913 pr_debug("Set kernel text: %lx - %lx for read only\n", 914 start, start+size); 915 916 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 917 } 918 919 static void mark_nxdata_nx(void) 920 { 921 /* 922 * When this called, init has already been executed and released, 923 * so everything past _etext should be NX. 924 */ 925 unsigned long start = PFN_ALIGN(_etext); 926 /* 927 * This comes from is_kernel_text upper limit. Also HPAGE where used: 928 */ 929 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; 930 931 if (__supported_pte_mask & _PAGE_NX) 932 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); 933 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT); 934 } 935 936 void mark_rodata_ro(void) 937 { 938 unsigned long start = PFN_ALIGN(_text); 939 unsigned long size = PFN_ALIGN(_etext) - start; 940 941 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 942 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 943 size >> 10); 944 945 kernel_set_to_readonly = 1; 946 947 #ifdef CONFIG_CPA_DEBUG 948 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 949 start, start+size); 950 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 951 952 printk(KERN_INFO "Testing CPA: write protecting again\n"); 953 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 954 #endif 955 956 start += size; 957 size = (unsigned long)__end_rodata - start; 958 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 959 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 960 size >> 10); 961 rodata_test(); 962 963 #ifdef CONFIG_CPA_DEBUG 964 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 965 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 966 967 printk(KERN_INFO "Testing CPA: write protecting again\n"); 968 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 969 #endif 970 mark_nxdata_nx(); 971 } 972 #endif 973 974