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/signal.h> 9 #include <linux/sched.h> 10 #include <linux/kernel.h> 11 #include <linux/errno.h> 12 #include <linux/string.h> 13 #include <linux/types.h> 14 #include <linux/ptrace.h> 15 #include <linux/mman.h> 16 #include <linux/mm.h> 17 #include <linux/hugetlb.h> 18 #include <linux/swap.h> 19 #include <linux/smp.h> 20 #include <linux/init.h> 21 #include <linux/highmem.h> 22 #include <linux/pagemap.h> 23 #include <linux/pci.h> 24 #include <linux/pfn.h> 25 #include <linux/poison.h> 26 #include <linux/bootmem.h> 27 #include <linux/memblock.h> 28 #include <linux/proc_fs.h> 29 #include <linux/memory_hotplug.h> 30 #include <linux/initrd.h> 31 #include <linux/cpumask.h> 32 #include <linux/gfp.h> 33 34 #include <asm/asm.h> 35 #include <asm/bios_ebda.h> 36 #include <asm/processor.h> 37 #include <linux/uaccess.h> 38 #include <asm/pgtable.h> 39 #include <asm/dma.h> 40 #include <asm/fixmap.h> 41 #include <asm/e820.h> 42 #include <asm/apic.h> 43 #include <asm/bugs.h> 44 #include <asm/tlb.h> 45 #include <asm/tlbflush.h> 46 #include <asm/olpc_ofw.h> 47 #include <asm/pgalloc.h> 48 #include <asm/sections.h> 49 #include <asm/paravirt.h> 50 #include <asm/setup.h> 51 #include <asm/cacheflush.h> 52 #include <asm/page_types.h> 53 #include <asm/init.h> 54 55 #include "mm_internal.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 /* 64 * Creates a middle page table and puts a pointer to it in the 65 * given global directory entry. This only returns the gd entry 66 * in non-PAE compilation mode, since the middle layer is folded. 67 */ 68 static pmd_t * __init one_md_table_init(pgd_t *pgd) 69 { 70 pud_t *pud; 71 pmd_t *pmd_table; 72 73 #ifdef CONFIG_X86_PAE 74 if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { 75 pmd_table = (pmd_t *)alloc_low_page(); 76 paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); 77 set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); 78 pud = pud_offset(pgd, 0); 79 BUG_ON(pmd_table != pmd_offset(pud, 0)); 80 81 return pmd_table; 82 } 83 #endif 84 pud = pud_offset(pgd, 0); 85 pmd_table = pmd_offset(pud, 0); 86 87 return pmd_table; 88 } 89 90 /* 91 * Create a page table and place a pointer to it in a middle page 92 * directory entry: 93 */ 94 static pte_t * __init one_page_table_init(pmd_t *pmd) 95 { 96 if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { 97 pte_t *page_table = (pte_t *)alloc_low_page(); 98 99 paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); 100 set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); 101 BUG_ON(page_table != pte_offset_kernel(pmd, 0)); 102 } 103 104 return pte_offset_kernel(pmd, 0); 105 } 106 107 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 108 { 109 int pgd_idx = pgd_index(vaddr); 110 int pmd_idx = pmd_index(vaddr); 111 112 return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; 113 } 114 115 pte_t * __init populate_extra_pte(unsigned long vaddr) 116 { 117 int pte_idx = pte_index(vaddr); 118 pmd_t *pmd; 119 120 pmd = populate_extra_pmd(vaddr); 121 return one_page_table_init(pmd) + pte_idx; 122 } 123 124 static unsigned long __init 125 page_table_range_init_count(unsigned long start, unsigned long end) 126 { 127 unsigned long count = 0; 128 #ifdef CONFIG_HIGHMEM 129 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 130 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 131 int pgd_idx, pmd_idx; 132 unsigned long vaddr; 133 134 if (pmd_idx_kmap_begin == pmd_idx_kmap_end) 135 return 0; 136 137 vaddr = start; 138 pgd_idx = pgd_index(vaddr); 139 pmd_idx = pmd_index(vaddr); 140 141 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) { 142 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 143 pmd_idx++) { 144 if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin && 145 (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) 146 count++; 147 vaddr += PMD_SIZE; 148 } 149 pmd_idx = 0; 150 } 151 #endif 152 return count; 153 } 154 155 static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, 156 unsigned long vaddr, pte_t *lastpte, 157 void **adr) 158 { 159 #ifdef CONFIG_HIGHMEM 160 /* 161 * Something (early fixmap) may already have put a pte 162 * page here, which causes the page table allocation 163 * to become nonlinear. Attempt to fix it, and if it 164 * is still nonlinear then we have to bug. 165 */ 166 int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; 167 int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; 168 169 if (pmd_idx_kmap_begin != pmd_idx_kmap_end 170 && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin 171 && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) { 172 pte_t *newpte; 173 int i; 174 175 BUG_ON(after_bootmem); 176 newpte = *adr; 177 for (i = 0; i < PTRS_PER_PTE; i++) 178 set_pte(newpte + i, pte[i]); 179 *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE); 180 181 paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); 182 set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); 183 BUG_ON(newpte != pte_offset_kernel(pmd, 0)); 184 __flush_tlb_all(); 185 186 paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); 187 pte = newpte; 188 } 189 BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) 190 && vaddr > fix_to_virt(FIX_KMAP_END) 191 && lastpte && lastpte + PTRS_PER_PTE != pte); 192 #endif 193 return pte; 194 } 195 196 /* 197 * This function initializes a certain range of kernel virtual memory 198 * with new bootmem page tables, everywhere page tables are missing in 199 * the given range. 200 * 201 * NOTE: The pagetables are allocated contiguous on the physical space 202 * so we can cache the place of the first one and move around without 203 * checking the pgd every time. 204 */ 205 static void __init 206 page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) 207 { 208 int pgd_idx, pmd_idx; 209 unsigned long vaddr; 210 pgd_t *pgd; 211 pmd_t *pmd; 212 pte_t *pte = NULL; 213 unsigned long count = page_table_range_init_count(start, end); 214 void *adr = NULL; 215 216 if (count) 217 adr = alloc_low_pages(count); 218 219 vaddr = start; 220 pgd_idx = pgd_index(vaddr); 221 pmd_idx = pmd_index(vaddr); 222 pgd = pgd_base + pgd_idx; 223 224 for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { 225 pmd = one_md_table_init(pgd); 226 pmd = pmd + pmd_index(vaddr); 227 for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); 228 pmd++, pmd_idx++) { 229 pte = page_table_kmap_check(one_page_table_init(pmd), 230 pmd, vaddr, pte, &adr); 231 232 vaddr += PMD_SIZE; 233 } 234 pmd_idx = 0; 235 } 236 } 237 238 static inline int is_kernel_text(unsigned long addr) 239 { 240 if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end) 241 return 1; 242 return 0; 243 } 244 245 /* 246 * This maps the physical memory to kernel virtual address space, a total 247 * of max_low_pfn pages, by creating page tables starting from address 248 * PAGE_OFFSET: 249 */ 250 unsigned long __init 251 kernel_physical_mapping_init(unsigned long start, 252 unsigned long end, 253 unsigned long page_size_mask) 254 { 255 int use_pse = page_size_mask == (1<<PG_LEVEL_2M); 256 unsigned long last_map_addr = end; 257 unsigned long start_pfn, end_pfn; 258 pgd_t *pgd_base = swapper_pg_dir; 259 int pgd_idx, pmd_idx, pte_ofs; 260 unsigned long pfn; 261 pgd_t *pgd; 262 pmd_t *pmd; 263 pte_t *pte; 264 unsigned pages_2m, pages_4k; 265 int mapping_iter; 266 267 start_pfn = start >> PAGE_SHIFT; 268 end_pfn = end >> PAGE_SHIFT; 269 270 /* 271 * First iteration will setup identity mapping using large/small pages 272 * based on use_pse, with other attributes same as set by 273 * the early code in head_32.S 274 * 275 * Second iteration will setup the appropriate attributes (NX, GLOBAL..) 276 * as desired for the kernel identity mapping. 277 * 278 * This two pass mechanism conforms to the TLB app note which says: 279 * 280 * "Software should not write to a paging-structure entry in a way 281 * that would change, for any linear address, both the page size 282 * and either the page frame or attributes." 283 */ 284 mapping_iter = 1; 285 286 if (!boot_cpu_has(X86_FEATURE_PSE)) 287 use_pse = 0; 288 289 repeat: 290 pages_2m = pages_4k = 0; 291 pfn = start_pfn; 292 pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 293 pgd = pgd_base + pgd_idx; 294 for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { 295 pmd = one_md_table_init(pgd); 296 297 if (pfn >= end_pfn) 298 continue; 299 #ifdef CONFIG_X86_PAE 300 pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 301 pmd += pmd_idx; 302 #else 303 pmd_idx = 0; 304 #endif 305 for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; 306 pmd++, pmd_idx++) { 307 unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; 308 309 /* 310 * Map with big pages if possible, otherwise 311 * create normal page tables: 312 */ 313 if (use_pse) { 314 unsigned int addr2; 315 pgprot_t prot = PAGE_KERNEL_LARGE; 316 /* 317 * first pass will use the same initial 318 * identity mapping attribute + _PAGE_PSE. 319 */ 320 pgprot_t init_prot = 321 __pgprot(PTE_IDENT_ATTR | 322 _PAGE_PSE); 323 324 pfn &= PMD_MASK >> PAGE_SHIFT; 325 addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + 326 PAGE_OFFSET + PAGE_SIZE-1; 327 328 if (is_kernel_text(addr) || 329 is_kernel_text(addr2)) 330 prot = PAGE_KERNEL_LARGE_EXEC; 331 332 pages_2m++; 333 if (mapping_iter == 1) 334 set_pmd(pmd, pfn_pmd(pfn, init_prot)); 335 else 336 set_pmd(pmd, pfn_pmd(pfn, prot)); 337 338 pfn += PTRS_PER_PTE; 339 continue; 340 } 341 pte = one_page_table_init(pmd); 342 343 pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); 344 pte += pte_ofs; 345 for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; 346 pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { 347 pgprot_t prot = PAGE_KERNEL; 348 /* 349 * first pass will use the same initial 350 * identity mapping attribute. 351 */ 352 pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); 353 354 if (is_kernel_text(addr)) 355 prot = PAGE_KERNEL_EXEC; 356 357 pages_4k++; 358 if (mapping_iter == 1) { 359 set_pte(pte, pfn_pte(pfn, init_prot)); 360 last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE; 361 } else 362 set_pte(pte, pfn_pte(pfn, prot)); 363 } 364 } 365 } 366 if (mapping_iter == 1) { 367 /* 368 * update direct mapping page count only in the first 369 * iteration. 370 */ 371 update_page_count(PG_LEVEL_2M, pages_2m); 372 update_page_count(PG_LEVEL_4K, pages_4k); 373 374 /* 375 * local global flush tlb, which will flush the previous 376 * mappings present in both small and large page TLB's. 377 */ 378 __flush_tlb_all(); 379 380 /* 381 * Second iteration will set the actual desired PTE attributes. 382 */ 383 mapping_iter = 2; 384 goto repeat; 385 } 386 return last_map_addr; 387 } 388 389 pte_t *kmap_pte; 390 391 static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) 392 { 393 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 394 vaddr), vaddr), vaddr); 395 } 396 397 static void __init kmap_init(void) 398 { 399 unsigned long kmap_vstart; 400 401 /* 402 * Cache the first kmap pte: 403 */ 404 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); 405 kmap_pte = kmap_get_fixmap_pte(kmap_vstart); 406 } 407 408 #ifdef CONFIG_HIGHMEM 409 static void __init permanent_kmaps_init(pgd_t *pgd_base) 410 { 411 unsigned long vaddr; 412 pgd_t *pgd; 413 pud_t *pud; 414 pmd_t *pmd; 415 pte_t *pte; 416 417 vaddr = PKMAP_BASE; 418 page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); 419 420 pgd = swapper_pg_dir + pgd_index(vaddr); 421 pud = pud_offset(pgd, vaddr); 422 pmd = pmd_offset(pud, vaddr); 423 pte = pte_offset_kernel(pmd, vaddr); 424 pkmap_page_table = pte; 425 } 426 427 void __init add_highpages_with_active_regions(int nid, 428 unsigned long start_pfn, unsigned long end_pfn) 429 { 430 phys_addr_t start, end; 431 u64 i; 432 433 for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) { 434 unsigned long pfn = clamp_t(unsigned long, PFN_UP(start), 435 start_pfn, end_pfn); 436 unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end), 437 start_pfn, end_pfn); 438 for ( ; pfn < e_pfn; pfn++) 439 if (pfn_valid(pfn)) 440 free_highmem_page(pfn_to_page(pfn)); 441 } 442 } 443 #else 444 static inline void permanent_kmaps_init(pgd_t *pgd_base) 445 { 446 } 447 #endif /* CONFIG_HIGHMEM */ 448 449 void __init native_pagetable_init(void) 450 { 451 unsigned long pfn, va; 452 pgd_t *pgd, *base = swapper_pg_dir; 453 pud_t *pud; 454 pmd_t *pmd; 455 pte_t *pte; 456 457 /* 458 * Remove any mappings which extend past the end of physical 459 * memory from the boot time page table. 460 * In virtual address space, we should have at least two pages 461 * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END 462 * definition. And max_low_pfn is set to VMALLOC_END physical 463 * address. If initial memory mapping is doing right job, we 464 * should have pte used near max_low_pfn or one pmd is not present. 465 */ 466 for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) { 467 va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); 468 pgd = base + pgd_index(va); 469 if (!pgd_present(*pgd)) 470 break; 471 472 pud = pud_offset(pgd, va); 473 pmd = pmd_offset(pud, va); 474 if (!pmd_present(*pmd)) 475 break; 476 477 /* should not be large page here */ 478 if (pmd_large(*pmd)) { 479 pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n", 480 pfn, pmd, __pa(pmd)); 481 BUG_ON(1); 482 } 483 484 pte = pte_offset_kernel(pmd, va); 485 if (!pte_present(*pte)) 486 break; 487 488 printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n", 489 pfn, pmd, __pa(pmd), pte, __pa(pte)); 490 pte_clear(NULL, va, pte); 491 } 492 paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); 493 paging_init(); 494 } 495 496 /* 497 * Build a proper pagetable for the kernel mappings. Up until this 498 * point, we've been running on some set of pagetables constructed by 499 * the boot process. 500 * 501 * If we're booting on native hardware, this will be a pagetable 502 * constructed in arch/x86/kernel/head_32.S. The root of the 503 * pagetable will be swapper_pg_dir. 504 * 505 * If we're booting paravirtualized under a hypervisor, then there are 506 * more options: we may already be running PAE, and the pagetable may 507 * or may not be based in swapper_pg_dir. In any case, 508 * paravirt_pagetable_init() will set up swapper_pg_dir 509 * appropriately for the rest of the initialization to work. 510 * 511 * In general, pagetable_init() assumes that the pagetable may already 512 * be partially populated, and so it avoids stomping on any existing 513 * mappings. 514 */ 515 void __init early_ioremap_page_table_range_init(void) 516 { 517 pgd_t *pgd_base = swapper_pg_dir; 518 unsigned long vaddr, end; 519 520 /* 521 * Fixed mappings, only the page table structure has to be 522 * created - mappings will be set by set_fixmap(): 523 */ 524 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 525 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 526 page_table_range_init(vaddr, end, pgd_base); 527 early_ioremap_reset(); 528 } 529 530 static void __init pagetable_init(void) 531 { 532 pgd_t *pgd_base = swapper_pg_dir; 533 534 permanent_kmaps_init(pgd_base); 535 } 536 537 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); 538 EXPORT_SYMBOL_GPL(__supported_pte_mask); 539 540 /* user-defined highmem size */ 541 static unsigned int highmem_pages = -1; 542 543 /* 544 * highmem=size forces highmem to be exactly 'size' bytes. 545 * This works even on boxes that have no highmem otherwise. 546 * This also works to reduce highmem size on bigger boxes. 547 */ 548 static int __init parse_highmem(char *arg) 549 { 550 if (!arg) 551 return -EINVAL; 552 553 highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; 554 return 0; 555 } 556 early_param("highmem", parse_highmem); 557 558 #define MSG_HIGHMEM_TOO_BIG \ 559 "highmem size (%luMB) is bigger than pages available (%luMB)!\n" 560 561 #define MSG_LOWMEM_TOO_SMALL \ 562 "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" 563 /* 564 * All of RAM fits into lowmem - but if user wants highmem 565 * artificially via the highmem=x boot parameter then create 566 * it: 567 */ 568 static void __init lowmem_pfn_init(void) 569 { 570 /* max_low_pfn is 0, we already have early_res support */ 571 max_low_pfn = max_pfn; 572 573 if (highmem_pages == -1) 574 highmem_pages = 0; 575 #ifdef CONFIG_HIGHMEM 576 if (highmem_pages >= max_pfn) { 577 printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, 578 pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); 579 highmem_pages = 0; 580 } 581 if (highmem_pages) { 582 if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { 583 printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, 584 pages_to_mb(highmem_pages)); 585 highmem_pages = 0; 586 } 587 max_low_pfn -= highmem_pages; 588 } 589 #else 590 if (highmem_pages) 591 printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); 592 #endif 593 } 594 595 #define MSG_HIGHMEM_TOO_SMALL \ 596 "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" 597 598 #define MSG_HIGHMEM_TRIMMED \ 599 "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" 600 /* 601 * We have more RAM than fits into lowmem - we try to put it into 602 * highmem, also taking the highmem=x boot parameter into account: 603 */ 604 static void __init highmem_pfn_init(void) 605 { 606 max_low_pfn = MAXMEM_PFN; 607 608 if (highmem_pages == -1) 609 highmem_pages = max_pfn - MAXMEM_PFN; 610 611 if (highmem_pages + MAXMEM_PFN < max_pfn) 612 max_pfn = MAXMEM_PFN + highmem_pages; 613 614 if (highmem_pages + MAXMEM_PFN > max_pfn) { 615 printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, 616 pages_to_mb(max_pfn - MAXMEM_PFN), 617 pages_to_mb(highmem_pages)); 618 highmem_pages = 0; 619 } 620 #ifndef CONFIG_HIGHMEM 621 /* Maximum memory usable is what is directly addressable */ 622 printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); 623 if (max_pfn > MAX_NONPAE_PFN) 624 printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); 625 else 626 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); 627 max_pfn = MAXMEM_PFN; 628 #else /* !CONFIG_HIGHMEM */ 629 #ifndef CONFIG_HIGHMEM64G 630 if (max_pfn > MAX_NONPAE_PFN) { 631 max_pfn = MAX_NONPAE_PFN; 632 printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); 633 } 634 #endif /* !CONFIG_HIGHMEM64G */ 635 #endif /* !CONFIG_HIGHMEM */ 636 } 637 638 /* 639 * Determine low and high memory ranges: 640 */ 641 void __init find_low_pfn_range(void) 642 { 643 /* it could update max_pfn */ 644 645 if (max_pfn <= MAXMEM_PFN) 646 lowmem_pfn_init(); 647 else 648 highmem_pfn_init(); 649 } 650 651 #ifndef CONFIG_NEED_MULTIPLE_NODES 652 void __init initmem_init(void) 653 { 654 #ifdef CONFIG_HIGHMEM 655 highstart_pfn = highend_pfn = max_pfn; 656 if (max_pfn > max_low_pfn) 657 highstart_pfn = max_low_pfn; 658 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", 659 pages_to_mb(highend_pfn - highstart_pfn)); 660 high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; 661 #else 662 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; 663 #endif 664 665 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0); 666 sparse_memory_present_with_active_regions(0); 667 668 #ifdef CONFIG_FLATMEM 669 max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn; 670 #endif 671 __vmalloc_start_set = true; 672 673 printk(KERN_NOTICE "%ldMB LOWMEM available.\n", 674 pages_to_mb(max_low_pfn)); 675 676 setup_bootmem_allocator(); 677 } 678 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 679 680 void __init setup_bootmem_allocator(void) 681 { 682 printk(KERN_INFO " mapped low ram: 0 - %08lx\n", 683 max_pfn_mapped<<PAGE_SHIFT); 684 printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); 685 } 686 687 /* 688 * paging_init() sets up the page tables - note that the first 8MB are 689 * already mapped by head.S. 690 * 691 * This routines also unmaps the page at virtual kernel address 0, so 692 * that we can trap those pesky NULL-reference errors in the kernel. 693 */ 694 void __init paging_init(void) 695 { 696 pagetable_init(); 697 698 __flush_tlb_all(); 699 700 kmap_init(); 701 702 /* 703 * NOTE: at this point the bootmem allocator is fully available. 704 */ 705 olpc_dt_build_devicetree(); 706 sparse_memory_present_with_active_regions(MAX_NUMNODES); 707 sparse_init(); 708 zone_sizes_init(); 709 } 710 711 /* 712 * Test if the WP bit works in supervisor mode. It isn't supported on 386's 713 * and also on some strange 486's. All 586+'s are OK. This used to involve 714 * black magic jumps to work around some nasty CPU bugs, but fortunately the 715 * switch to using exceptions got rid of all that. 716 */ 717 static void __init test_wp_bit(void) 718 { 719 printk(KERN_INFO 720 "Checking if this processor honours the WP bit even in supervisor mode..."); 721 722 /* Any page-aligned address will do, the test is non-destructive */ 723 __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_KERNEL_RO); 724 boot_cpu_data.wp_works_ok = do_test_wp_bit(); 725 clear_fixmap(FIX_WP_TEST); 726 727 if (!boot_cpu_data.wp_works_ok) { 728 printk(KERN_CONT "No.\n"); 729 panic("Linux doesn't support CPUs with broken WP."); 730 } else { 731 printk(KERN_CONT "Ok.\n"); 732 } 733 } 734 735 void __init mem_init(void) 736 { 737 pci_iommu_alloc(); 738 739 #ifdef CONFIG_FLATMEM 740 BUG_ON(!mem_map); 741 #endif 742 /* 743 * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to 744 * be done before free_all_bootmem(). Memblock use free low memory for 745 * temporary data (see find_range_array()) and for this purpose can use 746 * pages that was already passed to the buddy allocator, hence marked as 747 * not accessible in the page tables when compiled with 748 * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not 749 * important here. 750 */ 751 set_highmem_pages_init(); 752 753 /* this will put all low memory onto the freelists */ 754 free_all_bootmem(); 755 756 after_bootmem = 1; 757 758 mem_init_print_info(NULL); 759 printk(KERN_INFO "virtual kernel memory layout:\n" 760 " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 761 #ifdef CONFIG_HIGHMEM 762 " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" 763 #endif 764 " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" 765 " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" 766 " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" 767 " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" 768 " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", 769 FIXADDR_START, FIXADDR_TOP, 770 (FIXADDR_TOP - FIXADDR_START) >> 10, 771 772 #ifdef CONFIG_HIGHMEM 773 PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, 774 (LAST_PKMAP*PAGE_SIZE) >> 10, 775 #endif 776 777 VMALLOC_START, VMALLOC_END, 778 (VMALLOC_END - VMALLOC_START) >> 20, 779 780 (unsigned long)__va(0), (unsigned long)high_memory, 781 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 782 783 (unsigned long)&__init_begin, (unsigned long)&__init_end, 784 ((unsigned long)&__init_end - 785 (unsigned long)&__init_begin) >> 10, 786 787 (unsigned long)&_etext, (unsigned long)&_edata, 788 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, 789 790 (unsigned long)&_text, (unsigned long)&_etext, 791 ((unsigned long)&_etext - (unsigned long)&_text) >> 10); 792 793 /* 794 * Check boundaries twice: Some fundamental inconsistencies can 795 * be detected at build time already. 796 */ 797 #define __FIXADDR_TOP (-PAGE_SIZE) 798 #ifdef CONFIG_HIGHMEM 799 BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 800 BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); 801 #endif 802 #define high_memory (-128UL << 20) 803 BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); 804 #undef high_memory 805 #undef __FIXADDR_TOP 806 807 #ifdef CONFIG_HIGHMEM 808 BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); 809 BUG_ON(VMALLOC_END > PKMAP_BASE); 810 #endif 811 BUG_ON(VMALLOC_START >= VMALLOC_END); 812 BUG_ON((unsigned long)high_memory > VMALLOC_START); 813 814 if (boot_cpu_data.wp_works_ok < 0) 815 test_wp_bit(); 816 } 817 818 #ifdef CONFIG_MEMORY_HOTPLUG 819 int arch_add_memory(int nid, u64 start, u64 size, bool for_device) 820 { 821 struct pglist_data *pgdata = NODE_DATA(nid); 822 struct zone *zone = pgdata->node_zones + 823 zone_for_memory(nid, start, size, ZONE_HIGHMEM, for_device); 824 unsigned long start_pfn = start >> PAGE_SHIFT; 825 unsigned long nr_pages = size >> PAGE_SHIFT; 826 827 return __add_pages(nid, zone, start_pfn, nr_pages); 828 } 829 830 #ifdef CONFIG_MEMORY_HOTREMOVE 831 int arch_remove_memory(u64 start, u64 size) 832 { 833 unsigned long start_pfn = start >> PAGE_SHIFT; 834 unsigned long nr_pages = size >> PAGE_SHIFT; 835 struct zone *zone; 836 837 zone = page_zone(pfn_to_page(start_pfn)); 838 return __remove_pages(zone, start_pfn, nr_pages); 839 } 840 #endif 841 #endif 842 843 /* 844 * This function cannot be __init, since exceptions don't work in that 845 * section. Put this after the callers, so that it cannot be inlined. 846 */ 847 static noinline int do_test_wp_bit(void) 848 { 849 char tmp_reg; 850 int flag; 851 852 __asm__ __volatile__( 853 " movb %0, %1 \n" 854 "1: movb %1, %0 \n" 855 " xorl %2, %2 \n" 856 "2: \n" 857 _ASM_EXTABLE(1b,2b) 858 :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), 859 "=q" (tmp_reg), 860 "=r" (flag) 861 :"2" (1) 862 :"memory"); 863 864 return flag; 865 } 866 867 int kernel_set_to_readonly __read_mostly; 868 869 void set_kernel_text_rw(void) 870 { 871 unsigned long start = PFN_ALIGN(_text); 872 unsigned long size = PFN_ALIGN(_etext) - start; 873 874 if (!kernel_set_to_readonly) 875 return; 876 877 pr_debug("Set kernel text: %lx - %lx for read write\n", 878 start, start+size); 879 880 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 881 } 882 883 void set_kernel_text_ro(void) 884 { 885 unsigned long start = PFN_ALIGN(_text); 886 unsigned long size = PFN_ALIGN(_etext) - start; 887 888 if (!kernel_set_to_readonly) 889 return; 890 891 pr_debug("Set kernel text: %lx - %lx for read only\n", 892 start, start+size); 893 894 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 895 } 896 897 static void mark_nxdata_nx(void) 898 { 899 /* 900 * When this called, init has already been executed and released, 901 * so everything past _etext should be NX. 902 */ 903 unsigned long start = PFN_ALIGN(_etext); 904 /* 905 * This comes from is_kernel_text upper limit. Also HPAGE where used: 906 */ 907 unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; 908 909 if (__supported_pte_mask & _PAGE_NX) 910 printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); 911 set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT); 912 } 913 914 void mark_rodata_ro(void) 915 { 916 unsigned long start = PFN_ALIGN(_text); 917 unsigned long size = PFN_ALIGN(_etext) - start; 918 919 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 920 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 921 size >> 10); 922 923 kernel_set_to_readonly = 1; 924 925 #ifdef CONFIG_CPA_DEBUG 926 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 927 start, start+size); 928 set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); 929 930 printk(KERN_INFO "Testing CPA: write protecting again\n"); 931 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 932 #endif 933 934 start += size; 935 size = (unsigned long)__end_rodata - start; 936 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 937 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 938 size >> 10); 939 940 #ifdef CONFIG_CPA_DEBUG 941 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); 942 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); 943 944 printk(KERN_INFO "Testing CPA: write protecting again\n"); 945 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 946 #endif 947 mark_nxdata_nx(); 948 if (__supported_pte_mask & _PAGE_NX) 949 debug_checkwx(); 950 } 951