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