1 /* 2 * linux/arch/x86_64/mm/init.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * Copyright (C) 2000 Pavel Machek <pavel@ucw.cz> 6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de> 7 */ 8 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/swap.h> 19 #include <linux/smp.h> 20 #include <linux/init.h> 21 #include <linux/initrd.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/memblock.h> 25 #include <linux/proc_fs.h> 26 #include <linux/pci.h> 27 #include <linux/pfn.h> 28 #include <linux/poison.h> 29 #include <linux/dma-mapping.h> 30 #include <linux/module.h> 31 #include <linux/memory.h> 32 #include <linux/memory_hotplug.h> 33 #include <linux/memremap.h> 34 #include <linux/nmi.h> 35 #include <linux/gfp.h> 36 #include <linux/kcore.h> 37 38 #include <asm/processor.h> 39 #include <asm/bios_ebda.h> 40 #include <asm/uaccess.h> 41 #include <asm/pgtable.h> 42 #include <asm/pgalloc.h> 43 #include <asm/dma.h> 44 #include <asm/fixmap.h> 45 #include <asm/e820.h> 46 #include <asm/apic.h> 47 #include <asm/tlb.h> 48 #include <asm/mmu_context.h> 49 #include <asm/proto.h> 50 #include <asm/smp.h> 51 #include <asm/sections.h> 52 #include <asm/kdebug.h> 53 #include <asm/numa.h> 54 #include <asm/cacheflush.h> 55 #include <asm/init.h> 56 #include <asm/uv/uv.h> 57 #include <asm/setup.h> 58 59 #include "mm_internal.h" 60 61 #include "ident_map.c" 62 63 /* 64 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the 65 * physical space so we can cache the place of the first one and move 66 * around without checking the pgd every time. 67 */ 68 69 pteval_t __supported_pte_mask __read_mostly = ~0; 70 EXPORT_SYMBOL_GPL(__supported_pte_mask); 71 72 int force_personality32; 73 74 /* 75 * noexec32=on|off 76 * Control non executable heap for 32bit processes. 77 * To control the stack too use noexec=off 78 * 79 * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) 80 * off PROT_READ implies PROT_EXEC 81 */ 82 static int __init nonx32_setup(char *str) 83 { 84 if (!strcmp(str, "on")) 85 force_personality32 &= ~READ_IMPLIES_EXEC; 86 else if (!strcmp(str, "off")) 87 force_personality32 |= READ_IMPLIES_EXEC; 88 return 1; 89 } 90 __setup("noexec32=", nonx32_setup); 91 92 /* 93 * When memory was added/removed make sure all the processes MM have 94 * suitable PGD entries in the local PGD level page. 95 */ 96 void sync_global_pgds(unsigned long start, unsigned long end, int removed) 97 { 98 unsigned long address; 99 100 for (address = start; address <= end; address += PGDIR_SIZE) { 101 const pgd_t *pgd_ref = pgd_offset_k(address); 102 struct page *page; 103 104 /* 105 * When it is called after memory hot remove, pgd_none() 106 * returns true. In this case (removed == 1), we must clear 107 * the PGD entries in the local PGD level page. 108 */ 109 if (pgd_none(*pgd_ref) && !removed) 110 continue; 111 112 spin_lock(&pgd_lock); 113 list_for_each_entry(page, &pgd_list, lru) { 114 pgd_t *pgd; 115 spinlock_t *pgt_lock; 116 117 pgd = (pgd_t *)page_address(page) + pgd_index(address); 118 /* the pgt_lock only for Xen */ 119 pgt_lock = &pgd_page_get_mm(page)->page_table_lock; 120 spin_lock(pgt_lock); 121 122 if (!pgd_none(*pgd_ref) && !pgd_none(*pgd)) 123 BUG_ON(pgd_page_vaddr(*pgd) 124 != pgd_page_vaddr(*pgd_ref)); 125 126 if (removed) { 127 if (pgd_none(*pgd_ref) && !pgd_none(*pgd)) 128 pgd_clear(pgd); 129 } else { 130 if (pgd_none(*pgd)) 131 set_pgd(pgd, *pgd_ref); 132 } 133 134 spin_unlock(pgt_lock); 135 } 136 spin_unlock(&pgd_lock); 137 } 138 } 139 140 /* 141 * NOTE: This function is marked __ref because it calls __init function 142 * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. 143 */ 144 static __ref void *spp_getpage(void) 145 { 146 void *ptr; 147 148 if (after_bootmem) 149 ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); 150 else 151 ptr = alloc_bootmem_pages(PAGE_SIZE); 152 153 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) { 154 panic("set_pte_phys: cannot allocate page data %s\n", 155 after_bootmem ? "after bootmem" : ""); 156 } 157 158 pr_debug("spp_getpage %p\n", ptr); 159 160 return ptr; 161 } 162 163 static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr) 164 { 165 if (pgd_none(*pgd)) { 166 pud_t *pud = (pud_t *)spp_getpage(); 167 pgd_populate(&init_mm, pgd, pud); 168 if (pud != pud_offset(pgd, 0)) 169 printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n", 170 pud, pud_offset(pgd, 0)); 171 } 172 return pud_offset(pgd, vaddr); 173 } 174 175 static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr) 176 { 177 if (pud_none(*pud)) { 178 pmd_t *pmd = (pmd_t *) spp_getpage(); 179 pud_populate(&init_mm, pud, pmd); 180 if (pmd != pmd_offset(pud, 0)) 181 printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n", 182 pmd, pmd_offset(pud, 0)); 183 } 184 return pmd_offset(pud, vaddr); 185 } 186 187 static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr) 188 { 189 if (pmd_none(*pmd)) { 190 pte_t *pte = (pte_t *) spp_getpage(); 191 pmd_populate_kernel(&init_mm, pmd, pte); 192 if (pte != pte_offset_kernel(pmd, 0)) 193 printk(KERN_ERR "PAGETABLE BUG #02!\n"); 194 } 195 return pte_offset_kernel(pmd, vaddr); 196 } 197 198 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte) 199 { 200 pud_t *pud; 201 pmd_t *pmd; 202 pte_t *pte; 203 204 pud = pud_page + pud_index(vaddr); 205 pmd = fill_pmd(pud, vaddr); 206 pte = fill_pte(pmd, vaddr); 207 208 set_pte(pte, new_pte); 209 210 /* 211 * It's enough to flush this one mapping. 212 * (PGE mappings get flushed as well) 213 */ 214 __flush_tlb_one(vaddr); 215 } 216 217 void set_pte_vaddr(unsigned long vaddr, pte_t pteval) 218 { 219 pgd_t *pgd; 220 pud_t *pud_page; 221 222 pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval)); 223 224 pgd = pgd_offset_k(vaddr); 225 if (pgd_none(*pgd)) { 226 printk(KERN_ERR 227 "PGD FIXMAP MISSING, it should be setup in head.S!\n"); 228 return; 229 } 230 pud_page = (pud_t*)pgd_page_vaddr(*pgd); 231 set_pte_vaddr_pud(pud_page, vaddr, pteval); 232 } 233 234 pmd_t * __init populate_extra_pmd(unsigned long vaddr) 235 { 236 pgd_t *pgd; 237 pud_t *pud; 238 239 pgd = pgd_offset_k(vaddr); 240 pud = fill_pud(pgd, vaddr); 241 return fill_pmd(pud, vaddr); 242 } 243 244 pte_t * __init populate_extra_pte(unsigned long vaddr) 245 { 246 pmd_t *pmd; 247 248 pmd = populate_extra_pmd(vaddr); 249 return fill_pte(pmd, vaddr); 250 } 251 252 /* 253 * Create large page table mappings for a range of physical addresses. 254 */ 255 static void __init __init_extra_mapping(unsigned long phys, unsigned long size, 256 enum page_cache_mode cache) 257 { 258 pgd_t *pgd; 259 pud_t *pud; 260 pmd_t *pmd; 261 pgprot_t prot; 262 263 pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) | 264 pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache))); 265 BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK)); 266 for (; size; phys += PMD_SIZE, size -= PMD_SIZE) { 267 pgd = pgd_offset_k((unsigned long)__va(phys)); 268 if (pgd_none(*pgd)) { 269 pud = (pud_t *) spp_getpage(); 270 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE | 271 _PAGE_USER)); 272 } 273 pud = pud_offset(pgd, (unsigned long)__va(phys)); 274 if (pud_none(*pud)) { 275 pmd = (pmd_t *) spp_getpage(); 276 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | 277 _PAGE_USER)); 278 } 279 pmd = pmd_offset(pud, phys); 280 BUG_ON(!pmd_none(*pmd)); 281 set_pmd(pmd, __pmd(phys | pgprot_val(prot))); 282 } 283 } 284 285 void __init init_extra_mapping_wb(unsigned long phys, unsigned long size) 286 { 287 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB); 288 } 289 290 void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) 291 { 292 __init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC); 293 } 294 295 /* 296 * The head.S code sets up the kernel high mapping: 297 * 298 * from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text) 299 * 300 * phys_base holds the negative offset to the kernel, which is added 301 * to the compile time generated pmds. This results in invalid pmds up 302 * to the point where we hit the physaddr 0 mapping. 303 * 304 * We limit the mappings to the region from _text to _brk_end. _brk_end 305 * is rounded up to the 2MB boundary. This catches the invalid pmds as 306 * well, as they are located before _text: 307 */ 308 void __init cleanup_highmap(void) 309 { 310 unsigned long vaddr = __START_KERNEL_map; 311 unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE; 312 unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; 313 pmd_t *pmd = level2_kernel_pgt; 314 315 /* 316 * Native path, max_pfn_mapped is not set yet. 317 * Xen has valid max_pfn_mapped set in 318 * arch/x86/xen/mmu.c:xen_setup_kernel_pagetable(). 319 */ 320 if (max_pfn_mapped) 321 vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); 322 323 for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { 324 if (pmd_none(*pmd)) 325 continue; 326 if (vaddr < (unsigned long) _text || vaddr > end) 327 set_pmd(pmd, __pmd(0)); 328 } 329 } 330 331 static unsigned long __meminit 332 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, 333 pgprot_t prot) 334 { 335 unsigned long pages = 0, next; 336 unsigned long last_map_addr = end; 337 int i; 338 339 pte_t *pte = pte_page + pte_index(addr); 340 341 for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { 342 next = (addr & PAGE_MASK) + PAGE_SIZE; 343 if (addr >= end) { 344 if (!after_bootmem && 345 !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) && 346 !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN)) 347 set_pte(pte, __pte(0)); 348 continue; 349 } 350 351 /* 352 * We will re-use the existing mapping. 353 * Xen for example has some special requirements, like mapping 354 * pagetable pages as RO. So assume someone who pre-setup 355 * these mappings are more intelligent. 356 */ 357 if (pte_val(*pte)) { 358 if (!after_bootmem) 359 pages++; 360 continue; 361 } 362 363 if (0) 364 printk(" pte=%p addr=%lx pte=%016lx\n", 365 pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); 366 pages++; 367 set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); 368 last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; 369 } 370 371 update_page_count(PG_LEVEL_4K, pages); 372 373 return last_map_addr; 374 } 375 376 static unsigned long __meminit 377 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, 378 unsigned long page_size_mask, pgprot_t prot) 379 { 380 unsigned long pages = 0, next; 381 unsigned long last_map_addr = end; 382 383 int i = pmd_index(address); 384 385 for (; i < PTRS_PER_PMD; i++, address = next) { 386 pmd_t *pmd = pmd_page + pmd_index(address); 387 pte_t *pte; 388 pgprot_t new_prot = prot; 389 390 next = (address & PMD_MASK) + PMD_SIZE; 391 if (address >= end) { 392 if (!after_bootmem && 393 !e820_any_mapped(address & PMD_MASK, next, E820_RAM) && 394 !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN)) 395 set_pmd(pmd, __pmd(0)); 396 continue; 397 } 398 399 if (pmd_val(*pmd)) { 400 if (!pmd_large(*pmd)) { 401 spin_lock(&init_mm.page_table_lock); 402 pte = (pte_t *)pmd_page_vaddr(*pmd); 403 last_map_addr = phys_pte_init(pte, address, 404 end, prot); 405 spin_unlock(&init_mm.page_table_lock); 406 continue; 407 } 408 /* 409 * If we are ok with PG_LEVEL_2M mapping, then we will 410 * use the existing mapping, 411 * 412 * Otherwise, we will split the large page mapping but 413 * use the same existing protection bits except for 414 * large page, so that we don't violate Intel's TLB 415 * Application note (317080) which says, while changing 416 * the page sizes, new and old translations should 417 * not differ with respect to page frame and 418 * attributes. 419 */ 420 if (page_size_mask & (1 << PG_LEVEL_2M)) { 421 if (!after_bootmem) 422 pages++; 423 last_map_addr = next; 424 continue; 425 } 426 new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); 427 } 428 429 if (page_size_mask & (1<<PG_LEVEL_2M)) { 430 pages++; 431 spin_lock(&init_mm.page_table_lock); 432 set_pte((pte_t *)pmd, 433 pfn_pte((address & PMD_MASK) >> PAGE_SHIFT, 434 __pgprot(pgprot_val(prot) | _PAGE_PSE))); 435 spin_unlock(&init_mm.page_table_lock); 436 last_map_addr = next; 437 continue; 438 } 439 440 pte = alloc_low_page(); 441 last_map_addr = phys_pte_init(pte, address, end, new_prot); 442 443 spin_lock(&init_mm.page_table_lock); 444 pmd_populate_kernel(&init_mm, pmd, pte); 445 spin_unlock(&init_mm.page_table_lock); 446 } 447 update_page_count(PG_LEVEL_2M, pages); 448 return last_map_addr; 449 } 450 451 static unsigned long __meminit 452 phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, 453 unsigned long page_size_mask) 454 { 455 unsigned long pages = 0, next; 456 unsigned long last_map_addr = end; 457 int i = pud_index(addr); 458 459 for (; i < PTRS_PER_PUD; i++, addr = next) { 460 pud_t *pud = pud_page + pud_index(addr); 461 pmd_t *pmd; 462 pgprot_t prot = PAGE_KERNEL; 463 464 next = (addr & PUD_MASK) + PUD_SIZE; 465 if (addr >= end) { 466 if (!after_bootmem && 467 !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) && 468 !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN)) 469 set_pud(pud, __pud(0)); 470 continue; 471 } 472 473 if (pud_val(*pud)) { 474 if (!pud_large(*pud)) { 475 pmd = pmd_offset(pud, 0); 476 last_map_addr = phys_pmd_init(pmd, addr, end, 477 page_size_mask, prot); 478 __flush_tlb_all(); 479 continue; 480 } 481 /* 482 * If we are ok with PG_LEVEL_1G mapping, then we will 483 * use the existing mapping. 484 * 485 * Otherwise, we will split the gbpage mapping but use 486 * the same existing protection bits except for large 487 * page, so that we don't violate Intel's TLB 488 * Application note (317080) which says, while changing 489 * the page sizes, new and old translations should 490 * not differ with respect to page frame and 491 * attributes. 492 */ 493 if (page_size_mask & (1 << PG_LEVEL_1G)) { 494 if (!after_bootmem) 495 pages++; 496 last_map_addr = next; 497 continue; 498 } 499 prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); 500 } 501 502 if (page_size_mask & (1<<PG_LEVEL_1G)) { 503 pages++; 504 spin_lock(&init_mm.page_table_lock); 505 set_pte((pte_t *)pud, 506 pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT, 507 PAGE_KERNEL_LARGE)); 508 spin_unlock(&init_mm.page_table_lock); 509 last_map_addr = next; 510 continue; 511 } 512 513 pmd = alloc_low_page(); 514 last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, 515 prot); 516 517 spin_lock(&init_mm.page_table_lock); 518 pud_populate(&init_mm, pud, pmd); 519 spin_unlock(&init_mm.page_table_lock); 520 } 521 __flush_tlb_all(); 522 523 update_page_count(PG_LEVEL_1G, pages); 524 525 return last_map_addr; 526 } 527 528 unsigned long __meminit 529 kernel_physical_mapping_init(unsigned long start, 530 unsigned long end, 531 unsigned long page_size_mask) 532 { 533 bool pgd_changed = false; 534 unsigned long next, last_map_addr = end; 535 unsigned long addr; 536 537 start = (unsigned long)__va(start); 538 end = (unsigned long)__va(end); 539 addr = start; 540 541 for (; start < end; start = next) { 542 pgd_t *pgd = pgd_offset_k(start); 543 pud_t *pud; 544 545 next = (start & PGDIR_MASK) + PGDIR_SIZE; 546 547 if (pgd_val(*pgd)) { 548 pud = (pud_t *)pgd_page_vaddr(*pgd); 549 last_map_addr = phys_pud_init(pud, __pa(start), 550 __pa(end), page_size_mask); 551 continue; 552 } 553 554 pud = alloc_low_page(); 555 last_map_addr = phys_pud_init(pud, __pa(start), __pa(end), 556 page_size_mask); 557 558 spin_lock(&init_mm.page_table_lock); 559 pgd_populate(&init_mm, pgd, pud); 560 spin_unlock(&init_mm.page_table_lock); 561 pgd_changed = true; 562 } 563 564 if (pgd_changed) 565 sync_global_pgds(addr, end - 1, 0); 566 567 __flush_tlb_all(); 568 569 return last_map_addr; 570 } 571 572 #ifndef CONFIG_NUMA 573 void __init initmem_init(void) 574 { 575 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0); 576 } 577 #endif 578 579 void __init paging_init(void) 580 { 581 sparse_memory_present_with_active_regions(MAX_NUMNODES); 582 sparse_init(); 583 584 /* 585 * clear the default setting with node 0 586 * note: don't use nodes_clear here, that is really clearing when 587 * numa support is not compiled in, and later node_set_state 588 * will not set it back. 589 */ 590 node_clear_state(0, N_MEMORY); 591 if (N_MEMORY != N_NORMAL_MEMORY) 592 node_clear_state(0, N_NORMAL_MEMORY); 593 594 zone_sizes_init(); 595 } 596 597 /* 598 * Memory hotplug specific functions 599 */ 600 #ifdef CONFIG_MEMORY_HOTPLUG 601 /* 602 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need 603 * updating. 604 */ 605 static void update_end_of_memory_vars(u64 start, u64 size) 606 { 607 unsigned long end_pfn = PFN_UP(start + size); 608 609 if (end_pfn > max_pfn) { 610 max_pfn = end_pfn; 611 max_low_pfn = end_pfn; 612 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; 613 } 614 } 615 616 /* 617 * Memory is added always to NORMAL zone. This means you will never get 618 * additional DMA/DMA32 memory. 619 */ 620 int arch_add_memory(int nid, u64 start, u64 size, bool for_device) 621 { 622 struct pglist_data *pgdat = NODE_DATA(nid); 623 struct zone *zone = pgdat->node_zones + 624 zone_for_memory(nid, start, size, ZONE_NORMAL, for_device); 625 unsigned long start_pfn = start >> PAGE_SHIFT; 626 unsigned long nr_pages = size >> PAGE_SHIFT; 627 int ret; 628 629 init_memory_mapping(start, start + size); 630 631 ret = __add_pages(nid, zone, start_pfn, nr_pages); 632 WARN_ON_ONCE(ret); 633 634 /* update max_pfn, max_low_pfn and high_memory */ 635 update_end_of_memory_vars(start, size); 636 637 return ret; 638 } 639 EXPORT_SYMBOL_GPL(arch_add_memory); 640 641 #define PAGE_INUSE 0xFD 642 643 static void __meminit free_pagetable(struct page *page, int order) 644 { 645 unsigned long magic; 646 unsigned int nr_pages = 1 << order; 647 struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page); 648 649 if (altmap) { 650 vmem_altmap_free(altmap, nr_pages); 651 return; 652 } 653 654 /* bootmem page has reserved flag */ 655 if (PageReserved(page)) { 656 __ClearPageReserved(page); 657 658 magic = (unsigned long)page->lru.next; 659 if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) { 660 while (nr_pages--) 661 put_page_bootmem(page++); 662 } else 663 while (nr_pages--) 664 free_reserved_page(page++); 665 } else 666 free_pages((unsigned long)page_address(page), order); 667 } 668 669 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd) 670 { 671 pte_t *pte; 672 int i; 673 674 for (i = 0; i < PTRS_PER_PTE; i++) { 675 pte = pte_start + i; 676 if (pte_val(*pte)) 677 return; 678 } 679 680 /* free a pte talbe */ 681 free_pagetable(pmd_page(*pmd), 0); 682 spin_lock(&init_mm.page_table_lock); 683 pmd_clear(pmd); 684 spin_unlock(&init_mm.page_table_lock); 685 } 686 687 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud) 688 { 689 pmd_t *pmd; 690 int i; 691 692 for (i = 0; i < PTRS_PER_PMD; i++) { 693 pmd = pmd_start + i; 694 if (pmd_val(*pmd)) 695 return; 696 } 697 698 /* free a pmd talbe */ 699 free_pagetable(pud_page(*pud), 0); 700 spin_lock(&init_mm.page_table_lock); 701 pud_clear(pud); 702 spin_unlock(&init_mm.page_table_lock); 703 } 704 705 /* Return true if pgd is changed, otherwise return false. */ 706 static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd) 707 { 708 pud_t *pud; 709 int i; 710 711 for (i = 0; i < PTRS_PER_PUD; i++) { 712 pud = pud_start + i; 713 if (pud_val(*pud)) 714 return false; 715 } 716 717 /* free a pud table */ 718 free_pagetable(pgd_page(*pgd), 0); 719 spin_lock(&init_mm.page_table_lock); 720 pgd_clear(pgd); 721 spin_unlock(&init_mm.page_table_lock); 722 723 return true; 724 } 725 726 static void __meminit 727 remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, 728 bool direct) 729 { 730 unsigned long next, pages = 0; 731 pte_t *pte; 732 void *page_addr; 733 phys_addr_t phys_addr; 734 735 pte = pte_start + pte_index(addr); 736 for (; addr < end; addr = next, pte++) { 737 next = (addr + PAGE_SIZE) & PAGE_MASK; 738 if (next > end) 739 next = end; 740 741 if (!pte_present(*pte)) 742 continue; 743 744 /* 745 * We mapped [0,1G) memory as identity mapping when 746 * initializing, in arch/x86/kernel/head_64.S. These 747 * pagetables cannot be removed. 748 */ 749 phys_addr = pte_val(*pte) + (addr & PAGE_MASK); 750 if (phys_addr < (phys_addr_t)0x40000000) 751 return; 752 753 if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) { 754 /* 755 * Do not free direct mapping pages since they were 756 * freed when offlining, or simplely not in use. 757 */ 758 if (!direct) 759 free_pagetable(pte_page(*pte), 0); 760 761 spin_lock(&init_mm.page_table_lock); 762 pte_clear(&init_mm, addr, pte); 763 spin_unlock(&init_mm.page_table_lock); 764 765 /* For non-direct mapping, pages means nothing. */ 766 pages++; 767 } else { 768 /* 769 * If we are here, we are freeing vmemmap pages since 770 * direct mapped memory ranges to be freed are aligned. 771 * 772 * If we are not removing the whole page, it means 773 * other page structs in this page are being used and 774 * we canot remove them. So fill the unused page_structs 775 * with 0xFD, and remove the page when it is wholly 776 * filled with 0xFD. 777 */ 778 memset((void *)addr, PAGE_INUSE, next - addr); 779 780 page_addr = page_address(pte_page(*pte)); 781 if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) { 782 free_pagetable(pte_page(*pte), 0); 783 784 spin_lock(&init_mm.page_table_lock); 785 pte_clear(&init_mm, addr, pte); 786 spin_unlock(&init_mm.page_table_lock); 787 } 788 } 789 } 790 791 /* Call free_pte_table() in remove_pmd_table(). */ 792 flush_tlb_all(); 793 if (direct) 794 update_page_count(PG_LEVEL_4K, -pages); 795 } 796 797 static void __meminit 798 remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end, 799 bool direct) 800 { 801 unsigned long next, pages = 0; 802 pte_t *pte_base; 803 pmd_t *pmd; 804 void *page_addr; 805 806 pmd = pmd_start + pmd_index(addr); 807 for (; addr < end; addr = next, pmd++) { 808 next = pmd_addr_end(addr, end); 809 810 if (!pmd_present(*pmd)) 811 continue; 812 813 if (pmd_large(*pmd)) { 814 if (IS_ALIGNED(addr, PMD_SIZE) && 815 IS_ALIGNED(next, PMD_SIZE)) { 816 if (!direct) 817 free_pagetable(pmd_page(*pmd), 818 get_order(PMD_SIZE)); 819 820 spin_lock(&init_mm.page_table_lock); 821 pmd_clear(pmd); 822 spin_unlock(&init_mm.page_table_lock); 823 pages++; 824 } else { 825 /* If here, we are freeing vmemmap pages. */ 826 memset((void *)addr, PAGE_INUSE, next - addr); 827 828 page_addr = page_address(pmd_page(*pmd)); 829 if (!memchr_inv(page_addr, PAGE_INUSE, 830 PMD_SIZE)) { 831 free_pagetable(pmd_page(*pmd), 832 get_order(PMD_SIZE)); 833 834 spin_lock(&init_mm.page_table_lock); 835 pmd_clear(pmd); 836 spin_unlock(&init_mm.page_table_lock); 837 } 838 } 839 840 continue; 841 } 842 843 pte_base = (pte_t *)pmd_page_vaddr(*pmd); 844 remove_pte_table(pte_base, addr, next, direct); 845 free_pte_table(pte_base, pmd); 846 } 847 848 /* Call free_pmd_table() in remove_pud_table(). */ 849 if (direct) 850 update_page_count(PG_LEVEL_2M, -pages); 851 } 852 853 static void __meminit 854 remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end, 855 bool direct) 856 { 857 unsigned long next, pages = 0; 858 pmd_t *pmd_base; 859 pud_t *pud; 860 void *page_addr; 861 862 pud = pud_start + pud_index(addr); 863 for (; addr < end; addr = next, pud++) { 864 next = pud_addr_end(addr, end); 865 866 if (!pud_present(*pud)) 867 continue; 868 869 if (pud_large(*pud)) { 870 if (IS_ALIGNED(addr, PUD_SIZE) && 871 IS_ALIGNED(next, PUD_SIZE)) { 872 if (!direct) 873 free_pagetable(pud_page(*pud), 874 get_order(PUD_SIZE)); 875 876 spin_lock(&init_mm.page_table_lock); 877 pud_clear(pud); 878 spin_unlock(&init_mm.page_table_lock); 879 pages++; 880 } else { 881 /* If here, we are freeing vmemmap pages. */ 882 memset((void *)addr, PAGE_INUSE, next - addr); 883 884 page_addr = page_address(pud_page(*pud)); 885 if (!memchr_inv(page_addr, PAGE_INUSE, 886 PUD_SIZE)) { 887 free_pagetable(pud_page(*pud), 888 get_order(PUD_SIZE)); 889 890 spin_lock(&init_mm.page_table_lock); 891 pud_clear(pud); 892 spin_unlock(&init_mm.page_table_lock); 893 } 894 } 895 896 continue; 897 } 898 899 pmd_base = (pmd_t *)pud_page_vaddr(*pud); 900 remove_pmd_table(pmd_base, addr, next, direct); 901 free_pmd_table(pmd_base, pud); 902 } 903 904 if (direct) 905 update_page_count(PG_LEVEL_1G, -pages); 906 } 907 908 /* start and end are both virtual address. */ 909 static void __meminit 910 remove_pagetable(unsigned long start, unsigned long end, bool direct) 911 { 912 unsigned long next; 913 unsigned long addr; 914 pgd_t *pgd; 915 pud_t *pud; 916 bool pgd_changed = false; 917 918 for (addr = start; addr < end; addr = next) { 919 next = pgd_addr_end(addr, end); 920 921 pgd = pgd_offset_k(addr); 922 if (!pgd_present(*pgd)) 923 continue; 924 925 pud = (pud_t *)pgd_page_vaddr(*pgd); 926 remove_pud_table(pud, addr, next, direct); 927 if (free_pud_table(pud, pgd)) 928 pgd_changed = true; 929 } 930 931 if (pgd_changed) 932 sync_global_pgds(start, end - 1, 1); 933 934 flush_tlb_all(); 935 } 936 937 void __ref vmemmap_free(unsigned long start, unsigned long end) 938 { 939 remove_pagetable(start, end, false); 940 } 941 942 #ifdef CONFIG_MEMORY_HOTREMOVE 943 static void __meminit 944 kernel_physical_mapping_remove(unsigned long start, unsigned long end) 945 { 946 start = (unsigned long)__va(start); 947 end = (unsigned long)__va(end); 948 949 remove_pagetable(start, end, true); 950 } 951 952 int __ref arch_remove_memory(u64 start, u64 size) 953 { 954 unsigned long start_pfn = start >> PAGE_SHIFT; 955 unsigned long nr_pages = size >> PAGE_SHIFT; 956 struct page *page = pfn_to_page(start_pfn); 957 struct vmem_altmap *altmap; 958 struct zone *zone; 959 int ret; 960 961 /* With altmap the first mapped page is offset from @start */ 962 altmap = to_vmem_altmap((unsigned long) page); 963 if (altmap) 964 page += vmem_altmap_offset(altmap); 965 zone = page_zone(page); 966 ret = __remove_pages(zone, start_pfn, nr_pages); 967 WARN_ON_ONCE(ret); 968 kernel_physical_mapping_remove(start, start + size); 969 970 return ret; 971 } 972 #endif 973 #endif /* CONFIG_MEMORY_HOTPLUG */ 974 975 static struct kcore_list kcore_vsyscall; 976 977 static void __init register_page_bootmem_info(void) 978 { 979 #ifdef CONFIG_NUMA 980 int i; 981 982 for_each_online_node(i) 983 register_page_bootmem_info_node(NODE_DATA(i)); 984 #endif 985 } 986 987 void __init mem_init(void) 988 { 989 pci_iommu_alloc(); 990 991 /* clear_bss() already clear the empty_zero_page */ 992 993 register_page_bootmem_info(); 994 995 /* this will put all memory onto the freelists */ 996 free_all_bootmem(); 997 after_bootmem = 1; 998 999 /* Register memory areas for /proc/kcore */ 1000 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, 1001 PAGE_SIZE, KCORE_OTHER); 1002 1003 mem_init_print_info(NULL); 1004 } 1005 1006 const int rodata_test_data = 0xC3; 1007 EXPORT_SYMBOL_GPL(rodata_test_data); 1008 1009 int kernel_set_to_readonly; 1010 1011 void set_kernel_text_rw(void) 1012 { 1013 unsigned long start = PFN_ALIGN(_text); 1014 unsigned long end = PFN_ALIGN(__stop___ex_table); 1015 1016 if (!kernel_set_to_readonly) 1017 return; 1018 1019 pr_debug("Set kernel text: %lx - %lx for read write\n", 1020 start, end); 1021 1022 /* 1023 * Make the kernel identity mapping for text RW. Kernel text 1024 * mapping will always be RO. Refer to the comment in 1025 * static_protections() in pageattr.c 1026 */ 1027 set_memory_rw(start, (end - start) >> PAGE_SHIFT); 1028 } 1029 1030 void set_kernel_text_ro(void) 1031 { 1032 unsigned long start = PFN_ALIGN(_text); 1033 unsigned long end = PFN_ALIGN(__stop___ex_table); 1034 1035 if (!kernel_set_to_readonly) 1036 return; 1037 1038 pr_debug("Set kernel text: %lx - %lx for read only\n", 1039 start, end); 1040 1041 /* 1042 * Set the kernel identity mapping for text RO. 1043 */ 1044 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 1045 } 1046 1047 void mark_rodata_ro(void) 1048 { 1049 unsigned long start = PFN_ALIGN(_text); 1050 unsigned long rodata_start = PFN_ALIGN(__start_rodata); 1051 unsigned long end = (unsigned long) &__end_rodata_hpage_align; 1052 unsigned long text_end = PFN_ALIGN(&__stop___ex_table); 1053 unsigned long rodata_end = PFN_ALIGN(&__end_rodata); 1054 unsigned long all_end; 1055 1056 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 1057 (end - start) >> 10); 1058 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 1059 1060 kernel_set_to_readonly = 1; 1061 1062 /* 1063 * The rodata/data/bss/brk section (but not the kernel text!) 1064 * should also be not-executable. 1065 * 1066 * We align all_end to PMD_SIZE because the existing mapping 1067 * is a full PMD. If we would align _brk_end to PAGE_SIZE we 1068 * split the PMD and the reminder between _brk_end and the end 1069 * of the PMD will remain mapped executable. 1070 * 1071 * Any PMD which was setup after the one which covers _brk_end 1072 * has been zapped already via cleanup_highmem(). 1073 */ 1074 all_end = roundup((unsigned long)_brk_end, PMD_SIZE); 1075 set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT); 1076 1077 rodata_test(); 1078 1079 #ifdef CONFIG_CPA_DEBUG 1080 printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end); 1081 set_memory_rw(start, (end-start) >> PAGE_SHIFT); 1082 1083 printk(KERN_INFO "Testing CPA: again\n"); 1084 set_memory_ro(start, (end-start) >> PAGE_SHIFT); 1085 #endif 1086 1087 free_init_pages("unused kernel", 1088 (unsigned long) __va(__pa_symbol(text_end)), 1089 (unsigned long) __va(__pa_symbol(rodata_start))); 1090 free_init_pages("unused kernel", 1091 (unsigned long) __va(__pa_symbol(rodata_end)), 1092 (unsigned long) __va(__pa_symbol(_sdata))); 1093 1094 debug_checkwx(); 1095 } 1096 1097 int kern_addr_valid(unsigned long addr) 1098 { 1099 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; 1100 pgd_t *pgd; 1101 pud_t *pud; 1102 pmd_t *pmd; 1103 pte_t *pte; 1104 1105 if (above != 0 && above != -1UL) 1106 return 0; 1107 1108 pgd = pgd_offset_k(addr); 1109 if (pgd_none(*pgd)) 1110 return 0; 1111 1112 pud = pud_offset(pgd, addr); 1113 if (pud_none(*pud)) 1114 return 0; 1115 1116 if (pud_large(*pud)) 1117 return pfn_valid(pud_pfn(*pud)); 1118 1119 pmd = pmd_offset(pud, addr); 1120 if (pmd_none(*pmd)) 1121 return 0; 1122 1123 if (pmd_large(*pmd)) 1124 return pfn_valid(pmd_pfn(*pmd)); 1125 1126 pte = pte_offset_kernel(pmd, addr); 1127 if (pte_none(*pte)) 1128 return 0; 1129 1130 return pfn_valid(pte_pfn(*pte)); 1131 } 1132 1133 static unsigned long probe_memory_block_size(void) 1134 { 1135 unsigned long bz = MIN_MEMORY_BLOCK_SIZE; 1136 1137 /* if system is UV or has 64GB of RAM or more, use large blocks */ 1138 if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30))) 1139 bz = 2UL << 30; /* 2GB */ 1140 1141 pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20); 1142 1143 return bz; 1144 } 1145 1146 static unsigned long memory_block_size_probed; 1147 unsigned long memory_block_size_bytes(void) 1148 { 1149 if (!memory_block_size_probed) 1150 memory_block_size_probed = probe_memory_block_size(); 1151 1152 return memory_block_size_probed; 1153 } 1154 1155 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1156 /* 1157 * Initialise the sparsemem vmemmap using huge-pages at the PMD level. 1158 */ 1159 static long __meminitdata addr_start, addr_end; 1160 static void __meminitdata *p_start, *p_end; 1161 static int __meminitdata node_start; 1162 1163 static int __meminit vmemmap_populate_hugepages(unsigned long start, 1164 unsigned long end, int node, struct vmem_altmap *altmap) 1165 { 1166 unsigned long addr; 1167 unsigned long next; 1168 pgd_t *pgd; 1169 pud_t *pud; 1170 pmd_t *pmd; 1171 1172 for (addr = start; addr < end; addr = next) { 1173 next = pmd_addr_end(addr, end); 1174 1175 pgd = vmemmap_pgd_populate(addr, node); 1176 if (!pgd) 1177 return -ENOMEM; 1178 1179 pud = vmemmap_pud_populate(pgd, addr, node); 1180 if (!pud) 1181 return -ENOMEM; 1182 1183 pmd = pmd_offset(pud, addr); 1184 if (pmd_none(*pmd)) { 1185 void *p; 1186 1187 p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap); 1188 if (p) { 1189 pte_t entry; 1190 1191 entry = pfn_pte(__pa(p) >> PAGE_SHIFT, 1192 PAGE_KERNEL_LARGE); 1193 set_pmd(pmd, __pmd(pte_val(entry))); 1194 1195 /* check to see if we have contiguous blocks */ 1196 if (p_end != p || node_start != node) { 1197 if (p_start) 1198 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n", 1199 addr_start, addr_end-1, p_start, p_end-1, node_start); 1200 addr_start = addr; 1201 node_start = node; 1202 p_start = p; 1203 } 1204 1205 addr_end = addr + PMD_SIZE; 1206 p_end = p + PMD_SIZE; 1207 continue; 1208 } else if (altmap) 1209 return -ENOMEM; /* no fallback */ 1210 } else if (pmd_large(*pmd)) { 1211 vmemmap_verify((pte_t *)pmd, node, addr, next); 1212 continue; 1213 } 1214 pr_warn_once("vmemmap: falling back to regular page backing\n"); 1215 if (vmemmap_populate_basepages(addr, next, node)) 1216 return -ENOMEM; 1217 } 1218 return 0; 1219 } 1220 1221 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 1222 { 1223 struct vmem_altmap *altmap = to_vmem_altmap(start); 1224 int err; 1225 1226 if (boot_cpu_has(X86_FEATURE_PSE)) 1227 err = vmemmap_populate_hugepages(start, end, node, altmap); 1228 else if (altmap) { 1229 pr_err_once("%s: no cpu support for altmap allocations\n", 1230 __func__); 1231 err = -ENOMEM; 1232 } else 1233 err = vmemmap_populate_basepages(start, end, node); 1234 if (!err) 1235 sync_global_pgds(start, end - 1, 0); 1236 return err; 1237 } 1238 1239 #if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE) 1240 void register_page_bootmem_memmap(unsigned long section_nr, 1241 struct page *start_page, unsigned long size) 1242 { 1243 unsigned long addr = (unsigned long)start_page; 1244 unsigned long end = (unsigned long)(start_page + size); 1245 unsigned long next; 1246 pgd_t *pgd; 1247 pud_t *pud; 1248 pmd_t *pmd; 1249 unsigned int nr_pages; 1250 struct page *page; 1251 1252 for (; addr < end; addr = next) { 1253 pte_t *pte = NULL; 1254 1255 pgd = pgd_offset_k(addr); 1256 if (pgd_none(*pgd)) { 1257 next = (addr + PAGE_SIZE) & PAGE_MASK; 1258 continue; 1259 } 1260 get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO); 1261 1262 pud = pud_offset(pgd, addr); 1263 if (pud_none(*pud)) { 1264 next = (addr + PAGE_SIZE) & PAGE_MASK; 1265 continue; 1266 } 1267 get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO); 1268 1269 if (!boot_cpu_has(X86_FEATURE_PSE)) { 1270 next = (addr + PAGE_SIZE) & PAGE_MASK; 1271 pmd = pmd_offset(pud, addr); 1272 if (pmd_none(*pmd)) 1273 continue; 1274 get_page_bootmem(section_nr, pmd_page(*pmd), 1275 MIX_SECTION_INFO); 1276 1277 pte = pte_offset_kernel(pmd, addr); 1278 if (pte_none(*pte)) 1279 continue; 1280 get_page_bootmem(section_nr, pte_page(*pte), 1281 SECTION_INFO); 1282 } else { 1283 next = pmd_addr_end(addr, end); 1284 1285 pmd = pmd_offset(pud, addr); 1286 if (pmd_none(*pmd)) 1287 continue; 1288 1289 nr_pages = 1 << (get_order(PMD_SIZE)); 1290 page = pmd_page(*pmd); 1291 while (nr_pages--) 1292 get_page_bootmem(section_nr, page++, 1293 SECTION_INFO); 1294 } 1295 } 1296 } 1297 #endif 1298 1299 void __meminit vmemmap_populate_print_last(void) 1300 { 1301 if (p_start) { 1302 pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n", 1303 addr_start, addr_end-1, p_start, p_end-1, node_start); 1304 p_start = NULL; 1305 p_end = NULL; 1306 node_start = 0; 1307 } 1308 } 1309 #endif 1310