1#include <linux/gfp.h> 2#include <linux/initrd.h> 3#include <linux/ioport.h> 4#include <linux/swap.h> 5#include <linux/memblock.h> 6#include <linux/bootmem.h> /* for max_low_pfn */ 7 8#include <asm/cacheflush.h> 9#include <asm/e820.h> 10#include <asm/init.h> 11#include <asm/page.h> 12#include <asm/page_types.h> 13#include <asm/sections.h> 14#include <asm/setup.h> 15#include <asm/tlbflush.h> 16#include <asm/tlb.h> 17#include <asm/proto.h> 18#include <asm/dma.h> /* for MAX_DMA_PFN */ 19#include <asm/microcode.h> 20 21/* 22 * We need to define the tracepoints somewhere, and tlb.c 23 * is only compied when SMP=y. 24 */ 25#define CREATE_TRACE_POINTS 26#include <trace/events/tlb.h> 27 28#include "mm_internal.h" 29 30/* 31 * Tables translating between page_cache_type_t and pte encoding. 32 * 33 * Minimal supported modes are defined statically, they are modified 34 * during bootup if more supported cache modes are available. 35 * 36 * Index into __cachemode2pte_tbl[] is the cachemode. 37 * 38 * Index into __pte2cachemode_tbl[] are the caching attribute bits of the pte 39 * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2. 40 */ 41uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = { 42 [_PAGE_CACHE_MODE_WB ] = 0 | 0 , 43 [_PAGE_CACHE_MODE_WC ] = _PAGE_PWT | 0 , 44 [_PAGE_CACHE_MODE_UC_MINUS] = 0 | _PAGE_PCD, 45 [_PAGE_CACHE_MODE_UC ] = _PAGE_PWT | _PAGE_PCD, 46 [_PAGE_CACHE_MODE_WT ] = 0 | _PAGE_PCD, 47 [_PAGE_CACHE_MODE_WP ] = 0 | _PAGE_PCD, 48}; 49EXPORT_SYMBOL(__cachemode2pte_tbl); 50 51uint8_t __pte2cachemode_tbl[8] = { 52 [__pte2cm_idx( 0 | 0 | 0 )] = _PAGE_CACHE_MODE_WB, 53 [__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_WC, 54 [__pte2cm_idx( 0 | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC_MINUS, 55 [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC, 56 [__pte2cm_idx( 0 | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WB, 57 [__pte2cm_idx(_PAGE_PWT | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC, 58 [__pte2cm_idx(0 | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, 59 [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, 60}; 61EXPORT_SYMBOL(__pte2cachemode_tbl); 62 63static unsigned long __initdata pgt_buf_start; 64static unsigned long __initdata pgt_buf_end; 65static unsigned long __initdata pgt_buf_top; 66 67static unsigned long min_pfn_mapped; 68 69static bool __initdata can_use_brk_pgt = true; 70 71/* 72 * Pages returned are already directly mapped. 73 * 74 * Changing that is likely to break Xen, see commit: 75 * 76 * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve 77 * 78 * for detailed information. 79 */ 80__ref void *alloc_low_pages(unsigned int num) 81{ 82 unsigned long pfn; 83 int i; 84 85 if (after_bootmem) { 86 unsigned int order; 87 88 order = get_order((unsigned long)num << PAGE_SHIFT); 89 return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK | 90 __GFP_ZERO, order); 91 } 92 93 if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) { 94 unsigned long ret; 95 if (min_pfn_mapped >= max_pfn_mapped) 96 panic("alloc_low_pages: ran out of memory"); 97 ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT, 98 max_pfn_mapped << PAGE_SHIFT, 99 PAGE_SIZE * num , PAGE_SIZE); 100 if (!ret) 101 panic("alloc_low_pages: can not alloc memory"); 102 memblock_reserve(ret, PAGE_SIZE * num); 103 pfn = ret >> PAGE_SHIFT; 104 } else { 105 pfn = pgt_buf_end; 106 pgt_buf_end += num; 107 printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n", 108 pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1); 109 } 110 111 for (i = 0; i < num; i++) { 112 void *adr; 113 114 adr = __va((pfn + i) << PAGE_SHIFT); 115 clear_page(adr); 116 } 117 118 return __va(pfn << PAGE_SHIFT); 119} 120 121/* need 3 4k for initial PMD_SIZE, 3 4k for 0-ISA_END_ADDRESS */ 122#define INIT_PGT_BUF_SIZE (6 * PAGE_SIZE) 123RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE); 124void __init early_alloc_pgt_buf(void) 125{ 126 unsigned long tables = INIT_PGT_BUF_SIZE; 127 phys_addr_t base; 128 129 base = __pa(extend_brk(tables, PAGE_SIZE)); 130 131 pgt_buf_start = base >> PAGE_SHIFT; 132 pgt_buf_end = pgt_buf_start; 133 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); 134} 135 136int after_bootmem; 137 138early_param_on_off("gbpages", "nogbpages", direct_gbpages, CONFIG_X86_DIRECT_GBPAGES); 139 140struct map_range { 141 unsigned long start; 142 unsigned long end; 143 unsigned page_size_mask; 144}; 145 146static int page_size_mask; 147 148static void __init probe_page_size_mask(void) 149{ 150#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK) 151 /* 152 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 153 * This will simplify cpa(), which otherwise needs to support splitting 154 * large pages into small in interrupt context, etc. 155 */ 156 if (cpu_has_pse) 157 page_size_mask |= 1 << PG_LEVEL_2M; 158#endif 159 160 /* Enable PSE if available */ 161 if (cpu_has_pse) 162 cr4_set_bits_and_update_boot(X86_CR4_PSE); 163 164 /* Enable PGE if available */ 165 if (cpu_has_pge) { 166 cr4_set_bits_and_update_boot(X86_CR4_PGE); 167 __supported_pte_mask |= _PAGE_GLOBAL; 168 } else 169 __supported_pte_mask &= ~_PAGE_GLOBAL; 170 171 /* Enable 1 GB linear kernel mappings if available: */ 172 if (direct_gbpages && cpu_has_gbpages) { 173 printk(KERN_INFO "Using GB pages for direct mapping\n"); 174 page_size_mask |= 1 << PG_LEVEL_1G; 175 } else { 176 direct_gbpages = 0; 177 } 178} 179 180#ifdef CONFIG_X86_32 181#define NR_RANGE_MR 3 182#else /* CONFIG_X86_64 */ 183#define NR_RANGE_MR 5 184#endif 185 186static int __meminit save_mr(struct map_range *mr, int nr_range, 187 unsigned long start_pfn, unsigned long end_pfn, 188 unsigned long page_size_mask) 189{ 190 if (start_pfn < end_pfn) { 191 if (nr_range >= NR_RANGE_MR) 192 panic("run out of range for init_memory_mapping\n"); 193 mr[nr_range].start = start_pfn<<PAGE_SHIFT; 194 mr[nr_range].end = end_pfn<<PAGE_SHIFT; 195 mr[nr_range].page_size_mask = page_size_mask; 196 nr_range++; 197 } 198 199 return nr_range; 200} 201 202/* 203 * adjust the page_size_mask for small range to go with 204 * big page size instead small one if nearby are ram too. 205 */ 206static void __init_refok adjust_range_page_size_mask(struct map_range *mr, 207 int nr_range) 208{ 209 int i; 210 211 for (i = 0; i < nr_range; i++) { 212 if ((page_size_mask & (1<<PG_LEVEL_2M)) && 213 !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) { 214 unsigned long start = round_down(mr[i].start, PMD_SIZE); 215 unsigned long end = round_up(mr[i].end, PMD_SIZE); 216 217#ifdef CONFIG_X86_32 218 if ((end >> PAGE_SHIFT) > max_low_pfn) 219 continue; 220#endif 221 222 if (memblock_is_region_memory(start, end - start)) 223 mr[i].page_size_mask |= 1<<PG_LEVEL_2M; 224 } 225 if ((page_size_mask & (1<<PG_LEVEL_1G)) && 226 !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) { 227 unsigned long start = round_down(mr[i].start, PUD_SIZE); 228 unsigned long end = round_up(mr[i].end, PUD_SIZE); 229 230 if (memblock_is_region_memory(start, end - start)) 231 mr[i].page_size_mask |= 1<<PG_LEVEL_1G; 232 } 233 } 234} 235 236static const char *page_size_string(struct map_range *mr) 237{ 238 static const char str_1g[] = "1G"; 239 static const char str_2m[] = "2M"; 240 static const char str_4m[] = "4M"; 241 static const char str_4k[] = "4k"; 242 243 if (mr->page_size_mask & (1<<PG_LEVEL_1G)) 244 return str_1g; 245 /* 246 * 32-bit without PAE has a 4M large page size. 247 * PG_LEVEL_2M is misnamed, but we can at least 248 * print out the right size in the string. 249 */ 250 if (IS_ENABLED(CONFIG_X86_32) && 251 !IS_ENABLED(CONFIG_X86_PAE) && 252 mr->page_size_mask & (1<<PG_LEVEL_2M)) 253 return str_4m; 254 255 if (mr->page_size_mask & (1<<PG_LEVEL_2M)) 256 return str_2m; 257 258 return str_4k; 259} 260 261static int __meminit split_mem_range(struct map_range *mr, int nr_range, 262 unsigned long start, 263 unsigned long end) 264{ 265 unsigned long start_pfn, end_pfn, limit_pfn; 266 unsigned long pfn; 267 int i; 268 269 limit_pfn = PFN_DOWN(end); 270 271 /* head if not big page alignment ? */ 272 pfn = start_pfn = PFN_DOWN(start); 273#ifdef CONFIG_X86_32 274 /* 275 * Don't use a large page for the first 2/4MB of memory 276 * because there are often fixed size MTRRs in there 277 * and overlapping MTRRs into large pages can cause 278 * slowdowns. 279 */ 280 if (pfn == 0) 281 end_pfn = PFN_DOWN(PMD_SIZE); 282 else 283 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 284#else /* CONFIG_X86_64 */ 285 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 286#endif 287 if (end_pfn > limit_pfn) 288 end_pfn = limit_pfn; 289 if (start_pfn < end_pfn) { 290 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 291 pfn = end_pfn; 292 } 293 294 /* big page (2M) range */ 295 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 296#ifdef CONFIG_X86_32 297 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 298#else /* CONFIG_X86_64 */ 299 end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE)); 300 if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE))) 301 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 302#endif 303 304 if (start_pfn < end_pfn) { 305 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 306 page_size_mask & (1<<PG_LEVEL_2M)); 307 pfn = end_pfn; 308 } 309 310#ifdef CONFIG_X86_64 311 /* big page (1G) range */ 312 start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE)); 313 end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE)); 314 if (start_pfn < end_pfn) { 315 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 316 page_size_mask & 317 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); 318 pfn = end_pfn; 319 } 320 321 /* tail is not big page (1G) alignment */ 322 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 323 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 324 if (start_pfn < end_pfn) { 325 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 326 page_size_mask & (1<<PG_LEVEL_2M)); 327 pfn = end_pfn; 328 } 329#endif 330 331 /* tail is not big page (2M) alignment */ 332 start_pfn = pfn; 333 end_pfn = limit_pfn; 334 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 335 336 if (!after_bootmem) 337 adjust_range_page_size_mask(mr, nr_range); 338 339 /* try to merge same page size and continuous */ 340 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) { 341 unsigned long old_start; 342 if (mr[i].end != mr[i+1].start || 343 mr[i].page_size_mask != mr[i+1].page_size_mask) 344 continue; 345 /* move it */ 346 old_start = mr[i].start; 347 memmove(&mr[i], &mr[i+1], 348 (nr_range - 1 - i) * sizeof(struct map_range)); 349 mr[i--].start = old_start; 350 nr_range--; 351 } 352 353 for (i = 0; i < nr_range; i++) 354 printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n", 355 mr[i].start, mr[i].end - 1, 356 page_size_string(&mr[i])); 357 358 return nr_range; 359} 360 361struct range pfn_mapped[E820_X_MAX]; 362int nr_pfn_mapped; 363 364static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn) 365{ 366 nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX, 367 nr_pfn_mapped, start_pfn, end_pfn); 368 nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX); 369 370 max_pfn_mapped = max(max_pfn_mapped, end_pfn); 371 372 if (start_pfn < (1UL<<(32-PAGE_SHIFT))) 373 max_low_pfn_mapped = max(max_low_pfn_mapped, 374 min(end_pfn, 1UL<<(32-PAGE_SHIFT))); 375} 376 377bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn) 378{ 379 int i; 380 381 for (i = 0; i < nr_pfn_mapped; i++) 382 if ((start_pfn >= pfn_mapped[i].start) && 383 (end_pfn <= pfn_mapped[i].end)) 384 return true; 385 386 return false; 387} 388 389/* 390 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 391 * This runs before bootmem is initialized and gets pages directly from 392 * the physical memory. To access them they are temporarily mapped. 393 */ 394unsigned long __init_refok init_memory_mapping(unsigned long start, 395 unsigned long end) 396{ 397 struct map_range mr[NR_RANGE_MR]; 398 unsigned long ret = 0; 399 int nr_range, i; 400 401 pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n", 402 start, end - 1); 403 404 memset(mr, 0, sizeof(mr)); 405 nr_range = split_mem_range(mr, 0, start, end); 406 407 for (i = 0; i < nr_range; i++) 408 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, 409 mr[i].page_size_mask); 410 411 add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT); 412 413 return ret >> PAGE_SHIFT; 414} 415 416/* 417 * We need to iterate through the E820 memory map and create direct mappings 418 * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply 419 * create direct mappings for all pfns from [0 to max_low_pfn) and 420 * [4GB to max_pfn) because of possible memory holes in high addresses 421 * that cannot be marked as UC by fixed/variable range MTRRs. 422 * Depending on the alignment of E820 ranges, this may possibly result 423 * in using smaller size (i.e. 4K instead of 2M or 1G) page tables. 424 * 425 * init_mem_mapping() calls init_range_memory_mapping() with big range. 426 * That range would have hole in the middle or ends, and only ram parts 427 * will be mapped in init_range_memory_mapping(). 428 */ 429static unsigned long __init init_range_memory_mapping( 430 unsigned long r_start, 431 unsigned long r_end) 432{ 433 unsigned long start_pfn, end_pfn; 434 unsigned long mapped_ram_size = 0; 435 int i; 436 437 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) { 438 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end); 439 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end); 440 if (start >= end) 441 continue; 442 443 /* 444 * if it is overlapping with brk pgt, we need to 445 * alloc pgt buf from memblock instead. 446 */ 447 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >= 448 min(end, (u64)pgt_buf_top<<PAGE_SHIFT); 449 init_memory_mapping(start, end); 450 mapped_ram_size += end - start; 451 can_use_brk_pgt = true; 452 } 453 454 return mapped_ram_size; 455} 456 457static unsigned long __init get_new_step_size(unsigned long step_size) 458{ 459 /* 460 * Initial mapped size is PMD_SIZE (2M). 461 * We can not set step_size to be PUD_SIZE (1G) yet. 462 * In worse case, when we cross the 1G boundary, and 463 * PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k) 464 * to map 1G range with PTE. Hence we use one less than the 465 * difference of page table level shifts. 466 * 467 * Don't need to worry about overflow in the top-down case, on 32bit, 468 * when step_size is 0, round_down() returns 0 for start, and that 469 * turns it into 0x100000000ULL. 470 * In the bottom-up case, round_up(x, 0) returns 0 though too, which 471 * needs to be taken into consideration by the code below. 472 */ 473 return step_size << (PMD_SHIFT - PAGE_SHIFT - 1); 474} 475 476/** 477 * memory_map_top_down - Map [map_start, map_end) top down 478 * @map_start: start address of the target memory range 479 * @map_end: end address of the target memory range 480 * 481 * This function will setup direct mapping for memory range 482 * [map_start, map_end) in top-down. That said, the page tables 483 * will be allocated at the end of the memory, and we map the 484 * memory in top-down. 485 */ 486static void __init memory_map_top_down(unsigned long map_start, 487 unsigned long map_end) 488{ 489 unsigned long real_end, start, last_start; 490 unsigned long step_size; 491 unsigned long addr; 492 unsigned long mapped_ram_size = 0; 493 494 /* xen has big range in reserved near end of ram, skip it at first.*/ 495 addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE); 496 real_end = addr + PMD_SIZE; 497 498 /* step_size need to be small so pgt_buf from BRK could cover it */ 499 step_size = PMD_SIZE; 500 max_pfn_mapped = 0; /* will get exact value next */ 501 min_pfn_mapped = real_end >> PAGE_SHIFT; 502 last_start = start = real_end; 503 504 /* 505 * We start from the top (end of memory) and go to the bottom. 506 * The memblock_find_in_range() gets us a block of RAM from the 507 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages 508 * for page table. 509 */ 510 while (last_start > map_start) { 511 if (last_start > step_size) { 512 start = round_down(last_start - 1, step_size); 513 if (start < map_start) 514 start = map_start; 515 } else 516 start = map_start; 517 mapped_ram_size += init_range_memory_mapping(start, 518 last_start); 519 last_start = start; 520 min_pfn_mapped = last_start >> PAGE_SHIFT; 521 if (mapped_ram_size >= step_size) 522 step_size = get_new_step_size(step_size); 523 } 524 525 if (real_end < map_end) 526 init_range_memory_mapping(real_end, map_end); 527} 528 529/** 530 * memory_map_bottom_up - Map [map_start, map_end) bottom up 531 * @map_start: start address of the target memory range 532 * @map_end: end address of the target memory range 533 * 534 * This function will setup direct mapping for memory range 535 * [map_start, map_end) in bottom-up. Since we have limited the 536 * bottom-up allocation above the kernel, the page tables will 537 * be allocated just above the kernel and we map the memory 538 * in [map_start, map_end) in bottom-up. 539 */ 540static void __init memory_map_bottom_up(unsigned long map_start, 541 unsigned long map_end) 542{ 543 unsigned long next, start; 544 unsigned long mapped_ram_size = 0; 545 /* step_size need to be small so pgt_buf from BRK could cover it */ 546 unsigned long step_size = PMD_SIZE; 547 548 start = map_start; 549 min_pfn_mapped = start >> PAGE_SHIFT; 550 551 /* 552 * We start from the bottom (@map_start) and go to the top (@map_end). 553 * The memblock_find_in_range() gets us a block of RAM from the 554 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages 555 * for page table. 556 */ 557 while (start < map_end) { 558 if (step_size && map_end - start > step_size) { 559 next = round_up(start + 1, step_size); 560 if (next > map_end) 561 next = map_end; 562 } else { 563 next = map_end; 564 } 565 566 mapped_ram_size += init_range_memory_mapping(start, next); 567 start = next; 568 569 if (mapped_ram_size >= step_size) 570 step_size = get_new_step_size(step_size); 571 } 572} 573 574void __init init_mem_mapping(void) 575{ 576 unsigned long end; 577 578 probe_page_size_mask(); 579 580#ifdef CONFIG_X86_64 581 end = max_pfn << PAGE_SHIFT; 582#else 583 end = max_low_pfn << PAGE_SHIFT; 584#endif 585 586 /* the ISA range is always mapped regardless of memory holes */ 587 init_memory_mapping(0, ISA_END_ADDRESS); 588 589 /* 590 * If the allocation is in bottom-up direction, we setup direct mapping 591 * in bottom-up, otherwise we setup direct mapping in top-down. 592 */ 593 if (memblock_bottom_up()) { 594 unsigned long kernel_end = __pa_symbol(_end); 595 596 /* 597 * we need two separate calls here. This is because we want to 598 * allocate page tables above the kernel. So we first map 599 * [kernel_end, end) to make memory above the kernel be mapped 600 * as soon as possible. And then use page tables allocated above 601 * the kernel to map [ISA_END_ADDRESS, kernel_end). 602 */ 603 memory_map_bottom_up(kernel_end, end); 604 memory_map_bottom_up(ISA_END_ADDRESS, kernel_end); 605 } else { 606 memory_map_top_down(ISA_END_ADDRESS, end); 607 } 608 609#ifdef CONFIG_X86_64 610 if (max_pfn > max_low_pfn) { 611 /* can we preseve max_low_pfn ?*/ 612 max_low_pfn = max_pfn; 613 } 614#else 615 early_ioremap_page_table_range_init(); 616#endif 617 618 load_cr3(swapper_pg_dir); 619 __flush_tlb_all(); 620 621 early_memtest(0, max_pfn_mapped << PAGE_SHIFT); 622} 623 624/* 625 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 626 * is valid. The argument is a physical page number. 627 * 628 * 629 * On x86, access has to be given to the first megabyte of ram because that area 630 * contains BIOS code and data regions used by X and dosemu and similar apps. 631 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 632 * mmio resources as well as potential bios/acpi data regions. 633 */ 634int devmem_is_allowed(unsigned long pagenr) 635{ 636 if (pagenr < 256) 637 return 1; 638 if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) 639 return 0; 640 if (!page_is_ram(pagenr)) 641 return 1; 642 return 0; 643} 644 645void free_init_pages(char *what, unsigned long begin, unsigned long end) 646{ 647 unsigned long begin_aligned, end_aligned; 648 649 /* Make sure boundaries are page aligned */ 650 begin_aligned = PAGE_ALIGN(begin); 651 end_aligned = end & PAGE_MASK; 652 653 if (WARN_ON(begin_aligned != begin || end_aligned != end)) { 654 begin = begin_aligned; 655 end = end_aligned; 656 } 657 658 if (begin >= end) 659 return; 660 661 /* 662 * If debugging page accesses then do not free this memory but 663 * mark them not present - any buggy init-section access will 664 * create a kernel page fault: 665 */ 666#ifdef CONFIG_DEBUG_PAGEALLOC 667 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n", 668 begin, end - 1); 669 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 670#else 671 /* 672 * We just marked the kernel text read only above, now that 673 * we are going to free part of that, we need to make that 674 * writeable and non-executable first. 675 */ 676 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); 677 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 678 679 free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what); 680#endif 681} 682 683void free_initmem(void) 684{ 685 free_init_pages("unused kernel", 686 (unsigned long)(&__init_begin), 687 (unsigned long)(&__init_end)); 688} 689 690#ifdef CONFIG_BLK_DEV_INITRD 691void __init free_initrd_mem(unsigned long start, unsigned long end) 692{ 693#ifdef CONFIG_MICROCODE_EARLY 694 /* 695 * Remember, initrd memory may contain microcode or other useful things. 696 * Before we lose initrd mem, we need to find a place to hold them 697 * now that normal virtual memory is enabled. 698 */ 699 save_microcode_in_initrd(); 700#endif 701 702 /* 703 * end could be not aligned, and We can not align that, 704 * decompresser could be confused by aligned initrd_end 705 * We already reserve the end partial page before in 706 * - i386_start_kernel() 707 * - x86_64_start_kernel() 708 * - relocate_initrd() 709 * So here We can do PAGE_ALIGN() safely to get partial page to be freed 710 */ 711 free_init_pages("initrd", start, PAGE_ALIGN(end)); 712} 713#endif 714 715void __init zone_sizes_init(void) 716{ 717 unsigned long max_zone_pfns[MAX_NR_ZONES]; 718 719 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 720 721#ifdef CONFIG_ZONE_DMA 722 max_zone_pfns[ZONE_DMA] = min(MAX_DMA_PFN, max_low_pfn); 723#endif 724#ifdef CONFIG_ZONE_DMA32 725 max_zone_pfns[ZONE_DMA32] = min(MAX_DMA32_PFN, max_low_pfn); 726#endif 727 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 728#ifdef CONFIG_HIGHMEM 729 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 730#endif 731 732 free_area_init_nodes(max_zone_pfns); 733} 734 735DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate) = { 736#ifdef CONFIG_SMP 737 .active_mm = &init_mm, 738 .state = 0, 739#endif 740 .cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */ 741}; 742EXPORT_SYMBOL_GPL(cpu_tlbstate); 743 744void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache) 745{ 746 /* entry 0 MUST be WB (hardwired to speed up translations) */ 747 BUG_ON(!entry && cache != _PAGE_CACHE_MODE_WB); 748 749 __cachemode2pte_tbl[cache] = __cm_idx2pte(entry); 750 __pte2cachemode_tbl[entry] = cache; 751} 752