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_init(void) 449 { 450 unsigned long pfn, va; 451 pgd_t *pgd, *base = swapper_pg_dir; 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 paging_init(); 479 } 480 481 /* 482 * Build a proper pagetable for the kernel mappings. Up until this 483 * point, we've been running on some set of pagetables constructed by 484 * the boot process. 485 * 486 * If we're booting on native hardware, this will be a pagetable 487 * constructed in arch/x86/kernel/head_32.S. The root of the 488 * pagetable will be swapper_pg_dir. 489 * 490 * If we're booting paravirtualized under a hypervisor, then there are 491 * more options: we may already be running PAE, and the pagetable may 492 * or may not be based in swapper_pg_dir. In any case, 493 * paravirt_pagetable_init() will set up swapper_pg_dir 494 * appropriately for the rest of the initialization to work. 495 * 496 * In general, pagetable_init() assumes that the pagetable may already 497 * be partially populated, and so it avoids stomping on any existing 498 * mappings. 499 */ 500 void __init early_ioremap_page_table_range_init(void) 501 { 502 pgd_t *pgd_base = swapper_pg_dir; 503 unsigned long vaddr, end; 504 505 /* 506 * Fixed mappings, only the page table structure has to be 507 * created - mappings will be set by set_fixmap(): 508 */ 509 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 510 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 511 page_table_range_init(vaddr, end, pgd_base); 512 early_ioremap_reset(); 513 } 514 515 static void __init pagetable_init(void) 516 { 517 pgd_t *pgd_base = swapper_pg_dir; 518 519 permanent_kmaps_init(pgd_base); 520 } 521 522 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); 523 EXPORT_SYMBOL_GPL(__supported_pte_mask); 524 525 /* user-defined highmem size */ 526 static unsigned int highmem_pages = -1; 527 528 /* 529 * highmem=size forces highmem to be exactly 'size' bytes. 530 * This works even on boxes that have no highmem otherwise. 531 * This also works to reduce highmem size on bigger boxes. 532 */ 533 static int __init parse_highmem(char *arg) 534 { 535 if (!arg) 536 return -EINVAL; 537 538 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 539 return 0; 540 } 541 early_param("highmem", parse_highmem); 542 543 #define MSG_HIGHMEM_TOO_BIG \ 544 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 545 546 #define MSG_LOWMEM_TOO_SMALL \ 547 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 548 /* 549 * All of RAM fits into lowmem - but if user wants highmem 550 * artificially via the highmem=x boot parameter then create 551 * it: 552 */ 553 void __init lowmem_pfn_init(void) 554 { 555 /* max_low_pfn is 0, we already have early_res support */ 556 max_low_pfn = max_pfn; 557 558 if (highmem_pages == -1) 559 highmem_pages = 0; 560 #ifdef CONFIG_HIGHMEM 561 if (highmem_pages >= max_pfn) { 562 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 563 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 564 highmem_pages = 0; 565 } 566 if (highmem_pages) { 567 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 568 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 569 pages_to_mb(highmem_pages)); 570 highmem_pages = 0; 571 } 572 max_low_pfn -= highmem_pages; 573 } 574 #else 575 if (highmem_pages) 576 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 577 #endif 578 } 579 580 #define MSG_HIGHMEM_TOO_SMALL \ 581 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 582 583 #define MSG_HIGHMEM_TRIMMED \ 584 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 585 /* 586 * We have more RAM than fits into lowmem - we try to put it into 587 * highmem, also taking the highmem=x boot parameter into account: 588 */ 589 void __init highmem_pfn_init(void) 590 { 591 max_low_pfn = MAXMEM_PFN; 592 593 if (highmem_pages == -1) 594 highmem_pages = max_pfn - MAXMEM_PFN; 595 596 if (highmem_pages + MAXMEM_PFN < max_pfn) 597 max_pfn = MAXMEM_PFN + highmem_pages; 598 599 if (highmem_pages + MAXMEM_PFN > max_pfn) { 600 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 601 pages_to_mb(max_pfn - MAXMEM_PFN), 602 pages_to_mb(highmem_pages)); 603 highmem_pages = 0; 604 } 605 #ifndef CONFIG_HIGHMEM 606 /* Maximum memory usable is what is directly addressable */ 607 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 608 if (max_pfn > MAX_NONPAE_PFN) 609 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 610 else 611 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 612 max_pfn = MAXMEM_PFN; 613 #else /* !CONFIG_HIGHMEM */ 614 #ifndef CONFIG_HIGHMEM64G 615 if (max_pfn > MAX_NONPAE_PFN) { 616 max_pfn = MAX_NONPAE_PFN; 617 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 618 } 619 #endif /* !CONFIG_HIGHMEM64G */ 620 #endif /* !CONFIG_HIGHMEM */ 621 } 622 623 /* 624 * Determine low and high memory ranges: 625 */ 626 void __init find_low_pfn_range(void) 627 { 628 /* it could update max_pfn */ 629 630 if (max_pfn <= MAXMEM_PFN) 631 lowmem_pfn_init(); 632 else 633 highmem_pfn_init(); 634 } 635 636 #ifndef CONFIG_NEED_MULTIPLE_NODES 637 void __init initmem_init(void) 638 { 639 #ifdef CONFIG_HIGHMEM 640 highstart_pfn = highend_pfn = max_pfn; 641 if (max_pfn > max_low_pfn) 642 highstart_pfn = max_low_pfn; 643 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 644 pages_to_mb(highend_pfn - highstart_pfn)); 645 num_physpages = highend_pfn; 646 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 647 #else 648 num_physpages = max_low_pfn; 649 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 650 #endif 651 652 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0); 653 sparse_memory_present_with_active_regions(0); 654 655 #ifdef CONFIG_FLATMEM 656 max_mapnr = num_physpages; 657 #endif 658 __vmalloc_start_set = true; 659 660 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 661 pages_to_mb(max_low_pfn)); 662 663 setup_bootmem_allocator(); 664 } 665 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 666 667 void __init setup_bootmem_allocator(void) 668 { 669 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 670 max_pfn_mapped<<PAGE_SHIFT); 671 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 672 673 after_bootmem = 1; 674 } 675 676 /* 677 * paging_init() sets up the page tables - note that the first 8MB are 678 * already mapped by head.S. 679 * 680 * This routines also unmaps the page at virtual kernel address 0, so 681 * that we can trap those pesky NULL-reference errors in the kernel. 682 */ 683 void __init paging_init(void) 684 { 685 pagetable_init(); 686 687 __flush_tlb_all(); 688 689 kmap_init(); 690 691 /* 692 * NOTE: at this point the bootmem allocator is fully available. 693 */ 694 olpc_dt_build_devicetree(); 695 sparse_memory_present_with_active_regions(MAX_NUMNODES); 696 sparse_init(); 697 zone_sizes_init(); 698 } 699 700 /* 701 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 702 * and also on some strange 486's. All 586+'s are OK. This used to involve 703 * black magic jumps to work around some nasty CPU bugs, but fortunately the 704 * switch to using exceptions got rid of all that. 705 */ 706 static void __init test_wp_bit(void) 707 { 708 printk(KERN_INFO 709 "Checking if this processor honours the WP bit even in supervisor mode..."); 710 711 /* Any page-aligned address will do, the test is non-destructive */ 712 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_KERNEL_RO); 713 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 714 clear_fixmap(FIX_WP_TEST); 715 716 if (!boot_cpu_data.wp_works_ok) { 717 printk(KERN_CONT "No.\n"); 718 #ifdef CONFIG_X86_WP_WORKS_OK 719 panic( 720 "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!"); 721 #endif 722 } else { 723 printk(KERN_CONT "Ok.\n"); 724 } 725 } 726 727 void __init mem_init(void) 728 { 729 int codesize, reservedpages, datasize, initsize; 730 int tmp; 731 732 pci_iommu_alloc(); 733 734 #ifdef CONFIG_FLATMEM 735 BUG_ON(!mem_map); 736 #endif 737 /* 738 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to 739 * be done before free_all_bootmem(). Memblock use free low memory for 740 * temporary data (see find_range_array()) and for this purpose can use 741 * pages that was already passed to the buddy allocator, hence marked as 742 * not accessible in the page tables when compiled with 743 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not 744 * important here. 745 */ 746 set_highmem_pages_init(); 747 748 /* this will put all low memory onto the freelists */ 749 totalram_pages += free_all_bootmem(); 750 751 reservedpages = 0; 752 for (tmp = 0; tmp < max_low_pfn; tmp++) 753 /* 754 * Only count reserved RAM pages: 755 */ 756 if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) 757 reservedpages++; 758 759 codesize = (unsigned long) &_etext - (unsigned long) &_text; 760 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 761 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 762 763 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 764 "%dk reserved, %dk data, %dk init, %ldk highmem)\n", 765 nr_free_pages() << (PAGE_SHIFT-10), 766 num_physpages << (PAGE_SHIFT-10), 767 codesize >> 10, 768 reservedpages << (PAGE_SHIFT-10), 769 datasize >> 10, 770 initsize >> 10, 771 totalhigh_pages << (PAGE_SHIFT-10)); 772 773 printk(KERN_INFO "virtual kernel memory layout:\n" 774 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 775 #ifdef CONFIG_HIGHMEM 776 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 777 #endif 778 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 779 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 780 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 781 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 782 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 783 FIXADDR_START, FIXADDR_TOP, 784 (FIXADDR_TOP - FIXADDR_START) >> 10, 785 786 #ifdef CONFIG_HIGHMEM 787 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 788 (LAST_PKMAP*PAGE_SIZE) >> 10, 789 #endif 790 791 VMALLOC_START, VMALLOC_END, 792 (VMALLOC_END - VMALLOC_START) >> 20, 793 794 (unsigned long)__va(0), (unsigned long)high_memory, 795 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 796 797 (unsigned long)&__init_begin, (unsigned long)&__init_end, 798 ((unsigned long)&__init_end - 799 (unsigned long)&__init_begin) >> 10, 800 801 (unsigned long)&_etext, (unsigned long)&_edata, 802 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 803 804 (unsigned long)&_text, (unsigned long)&_etext, 805 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 806 807 /* 808 * Check boundaries twice: Some fundamental inconsistencies can 809 * be detected at build time already. 810 */ 811 #define __FIXADDR_TOP (-PAGE_SIZE) 812 #ifdef CONFIG_HIGHMEM 813 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 814 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 815 #endif 816 #define high_memory (-128UL << 20) 817 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 818 #undef high_memory 819 #undef __FIXADDR_TOP 820 821 #ifdef CONFIG_HIGHMEM 822 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 823 BUG_ON(VMALLOC_END > PKMAP_BASE); 824 #endif 825 BUG_ON(VMALLOC_START >= VMALLOC_END); 826 BUG_ON((unsigned long)high_memory > VMALLOC_START); 827 828 if (boot_cpu_data.wp_works_ok < 0) 829 test_wp_bit(); 830 } 831 832 #ifdef CONFIG_MEMORY_HOTPLUG 833 int arch_add_memory(int nid, u64 start, u64 size) 834 { 835 struct pglist_data *pgdata = NODE_DATA(nid); 836 struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; 837 unsigned long start_pfn = start >> PAGE_SHIFT; 838 unsigned long nr_pages = size >> PAGE_SHIFT; 839 840 return __add_pages(nid, zone, start_pfn, nr_pages); 841 } 842 #endif 843 844 /* 845 * This function cannot be __init, since exceptions don't work in that 846 * section. Put this after the callers, so that it cannot be inlined. 847 */ 848 static noinline int do_test_wp_bit(void) 849 { 850 char tmp_reg; 851 int flag; 852 853 __asm__ __volatile__( 854 " movb %0, %1 \n" 855 "1: movb %1, %0 \n" 856 " xorl %2, %2 \n" 857 "2: \n" 858 _ASM_EXTABLE(1b,2b) 859 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 860 "=q" (tmp_reg), 861 "=r" (flag) 862 :"2" (1) 863 :"memory"); 864 865 return flag; 866 } 867 868 #ifdef CONFIG_DEBUG_RODATA 869 const int rodata_test_data = 0xC3; 870 EXPORT_SYMBOL_GPL(rodata_test_data); 871 872 int kernel_set_to_readonly __read_mostly; 873 874 void set_kernel_text_rw(void) 875 { 876 unsigned long start = PFN_ALIGN(_text); 877 unsigned long size = PFN_ALIGN(_etext) - start; 878 879 if (!kernel_set_to_readonly) 880 return; 881 882 pr_debug("Set kernel text: %lx - %lx for read write\n", 883 start, start+size); 884 885 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 886 } 887 888 void set_kernel_text_ro(void) 889 { 890 unsigned long start = PFN_ALIGN(_text); 891 unsigned long size = PFN_ALIGN(_etext) - start; 892 893 if (!kernel_set_to_readonly) 894 return; 895 896 pr_debug("Set kernel text: %lx - %lx for read only\n", 897 start, start+size); 898 899 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 900 } 901 902 static void mark_nxdata_nx(void) 903 { 904 /* 905 * When this called, init has already been executed and released, 906 * so everything past _etext should be NX. 907 */ 908 unsigned long start = PFN_ALIGN(_etext); 909 /* 910 * This comes from is_kernel_text upper limit. Also HPAGE where used: 911 */ 912 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; 913 914 if (__supported_pte_mask & _PAGE_NX) 915 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); 916 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT); 917 } 918 919 void mark_rodata_ro(void) 920 { 921 unsigned long start = PFN_ALIGN(_text); 922 unsigned long size = PFN_ALIGN(_etext) - start; 923 924 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 925 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 926 size >> 10); 927 928 kernel_set_to_readonly = 1; 929 930 #ifdef CONFIG_CPA_DEBUG 931 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 932 start, start+size); 933 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 934 935 printk(KERN_INFO "Testing CPA: write protecting again\n"); 936 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 937 #endif 938 939 start += size; 940 size = (unsigned long)__end_rodata - start; 941 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 942 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 943 size >> 10); 944 rodata_test(); 945 946 #ifdef CONFIG_CPA_DEBUG 947 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 948 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 949 950 printk(KERN_INFO "Testing CPA: write protecting again\n"); 951 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 952 #endif 953 mark_nxdata_nx(); 954 } 955 #endif 956 957