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