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 * The default values are defined statically as minimal supported mode; 34 * WC and WT fall back to UC-. pat_init() updates these values to support 35 * more cache modes, WC and WT, when it is safe to do so. See pat_init() 36 * for the details. Note, __early_ioremap() used during early boot-time 37 * takes pgprot_t (pte encoding) and does not use these tables. 38 * 39 * Index into __cachemode2pte_tbl[] is the cachemode. 40 * 41 * Index into __pte2cachemode_tbl[] are the caching attribute bits of the pte 42 * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2. 43 */ 44uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = { 45 [_PAGE_CACHE_MODE_WB ] = 0 | 0 , 46 [_PAGE_CACHE_MODE_WC ] = 0 | _PAGE_PCD, 47 [_PAGE_CACHE_MODE_UC_MINUS] = 0 | _PAGE_PCD, 48 [_PAGE_CACHE_MODE_UC ] = _PAGE_PWT | _PAGE_PCD, 49 [_PAGE_CACHE_MODE_WT ] = 0 | _PAGE_PCD, 50 [_PAGE_CACHE_MODE_WP ] = 0 | _PAGE_PCD, 51}; 52EXPORT_SYMBOL(__cachemode2pte_tbl); 53 54uint8_t __pte2cachemode_tbl[8] = { 55 [__pte2cm_idx( 0 | 0 | 0 )] = _PAGE_CACHE_MODE_WB, 56 [__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_UC_MINUS, 57 [__pte2cm_idx( 0 | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC_MINUS, 58 [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC, 59 [__pte2cm_idx( 0 | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_WB, 60 [__pte2cm_idx(_PAGE_PWT | 0 | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, 61 [__pte2cm_idx(0 | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, 62 [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, 63}; 64EXPORT_SYMBOL(__pte2cachemode_tbl); 65 66static unsigned long __initdata pgt_buf_start; 67static unsigned long __initdata pgt_buf_end; 68static unsigned long __initdata pgt_buf_top; 69 70static unsigned long min_pfn_mapped; 71 72static bool __initdata can_use_brk_pgt = true; 73 74/* 75 * Pages returned are already directly mapped. 76 * 77 * Changing that is likely to break Xen, see commit: 78 * 79 * 279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve 80 * 81 * for detailed information. 82 */ 83__ref void *alloc_low_pages(unsigned int num) 84{ 85 unsigned long pfn; 86 int i; 87 88 if (after_bootmem) { 89 unsigned int order; 90 91 order = get_order((unsigned long)num << PAGE_SHIFT); 92 return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK | 93 __GFP_ZERO, order); 94 } 95 96 if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) { 97 unsigned long ret; 98 if (min_pfn_mapped >= max_pfn_mapped) 99 panic("alloc_low_pages: ran out of memory"); 100 ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT, 101 max_pfn_mapped << PAGE_SHIFT, 102 PAGE_SIZE * num , PAGE_SIZE); 103 if (!ret) 104 panic("alloc_low_pages: can not alloc memory"); 105 memblock_reserve(ret, PAGE_SIZE * num); 106 pfn = ret >> PAGE_SHIFT; 107 } else { 108 pfn = pgt_buf_end; 109 pgt_buf_end += num; 110 printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n", 111 pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1); 112 } 113 114 for (i = 0; i < num; i++) { 115 void *adr; 116 117 adr = __va((pfn + i) << PAGE_SHIFT); 118 clear_page(adr); 119 } 120 121 return __va(pfn << PAGE_SHIFT); 122} 123 124/* need 3 4k for initial PMD_SIZE, 3 4k for 0-ISA_END_ADDRESS */ 125#define INIT_PGT_BUF_SIZE (6 * PAGE_SIZE) 126RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE); 127void __init early_alloc_pgt_buf(void) 128{ 129 unsigned long tables = INIT_PGT_BUF_SIZE; 130 phys_addr_t base; 131 132 base = __pa(extend_brk(tables, PAGE_SIZE)); 133 134 pgt_buf_start = base >> PAGE_SHIFT; 135 pgt_buf_end = pgt_buf_start; 136 pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); 137} 138 139int after_bootmem; 140 141early_param_on_off("gbpages", "nogbpages", direct_gbpages, CONFIG_X86_DIRECT_GBPAGES); 142 143struct map_range { 144 unsigned long start; 145 unsigned long end; 146 unsigned page_size_mask; 147}; 148 149static int page_size_mask; 150 151static void __init probe_page_size_mask(void) 152{ 153#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK) 154 /* 155 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. 156 * This will simplify cpa(), which otherwise needs to support splitting 157 * large pages into small in interrupt context, etc. 158 */ 159 if (cpu_has_pse) 160 page_size_mask |= 1 << PG_LEVEL_2M; 161#endif 162 163 /* Enable PSE if available */ 164 if (cpu_has_pse) 165 cr4_set_bits_and_update_boot(X86_CR4_PSE); 166 167 /* Enable PGE if available */ 168 if (cpu_has_pge) { 169 cr4_set_bits_and_update_boot(X86_CR4_PGE); 170 __supported_pte_mask |= _PAGE_GLOBAL; 171 } else 172 __supported_pte_mask &= ~_PAGE_GLOBAL; 173 174 /* Enable 1 GB linear kernel mappings if available: */ 175 if (direct_gbpages && cpu_has_gbpages) { 176 printk(KERN_INFO "Using GB pages for direct mapping\n"); 177 page_size_mask |= 1 << PG_LEVEL_1G; 178 } else { 179 direct_gbpages = 0; 180 } 181} 182 183#ifdef CONFIG_X86_32 184#define NR_RANGE_MR 3 185#else /* CONFIG_X86_64 */ 186#define NR_RANGE_MR 5 187#endif 188 189static int __meminit save_mr(struct map_range *mr, int nr_range, 190 unsigned long start_pfn, unsigned long end_pfn, 191 unsigned long page_size_mask) 192{ 193 if (start_pfn < end_pfn) { 194 if (nr_range >= NR_RANGE_MR) 195 panic("run out of range for init_memory_mapping\n"); 196 mr[nr_range].start = start_pfn<<PAGE_SHIFT; 197 mr[nr_range].end = end_pfn<<PAGE_SHIFT; 198 mr[nr_range].page_size_mask = page_size_mask; 199 nr_range++; 200 } 201 202 return nr_range; 203} 204 205/* 206 * adjust the page_size_mask for small range to go with 207 * big page size instead small one if nearby are ram too. 208 */ 209static void __init_refok adjust_range_page_size_mask(struct map_range *mr, 210 int nr_range) 211{ 212 int i; 213 214 for (i = 0; i < nr_range; i++) { 215 if ((page_size_mask & (1<<PG_LEVEL_2M)) && 216 !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) { 217 unsigned long start = round_down(mr[i].start, PMD_SIZE); 218 unsigned long end = round_up(mr[i].end, PMD_SIZE); 219 220#ifdef CONFIG_X86_32 221 if ((end >> PAGE_SHIFT) > max_low_pfn) 222 continue; 223#endif 224 225 if (memblock_is_region_memory(start, end - start)) 226 mr[i].page_size_mask |= 1<<PG_LEVEL_2M; 227 } 228 if ((page_size_mask & (1<<PG_LEVEL_1G)) && 229 !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) { 230 unsigned long start = round_down(mr[i].start, PUD_SIZE); 231 unsigned long end = round_up(mr[i].end, PUD_SIZE); 232 233 if (memblock_is_region_memory(start, end - start)) 234 mr[i].page_size_mask |= 1<<PG_LEVEL_1G; 235 } 236 } 237} 238 239static const char *page_size_string(struct map_range *mr) 240{ 241 static const char str_1g[] = "1G"; 242 static const char str_2m[] = "2M"; 243 static const char str_4m[] = "4M"; 244 static const char str_4k[] = "4k"; 245 246 if (mr->page_size_mask & (1<<PG_LEVEL_1G)) 247 return str_1g; 248 /* 249 * 32-bit without PAE has a 4M large page size. 250 * PG_LEVEL_2M is misnamed, but we can at least 251 * print out the right size in the string. 252 */ 253 if (IS_ENABLED(CONFIG_X86_32) && 254 !IS_ENABLED(CONFIG_X86_PAE) && 255 mr->page_size_mask & (1<<PG_LEVEL_2M)) 256 return str_4m; 257 258 if (mr->page_size_mask & (1<<PG_LEVEL_2M)) 259 return str_2m; 260 261 return str_4k; 262} 263 264static int __meminit split_mem_range(struct map_range *mr, int nr_range, 265 unsigned long start, 266 unsigned long end) 267{ 268 unsigned long start_pfn, end_pfn, limit_pfn; 269 unsigned long pfn; 270 int i; 271 272 limit_pfn = PFN_DOWN(end); 273 274 /* head if not big page alignment ? */ 275 pfn = start_pfn = PFN_DOWN(start); 276#ifdef CONFIG_X86_32 277 /* 278 * Don't use a large page for the first 2/4MB of memory 279 * because there are often fixed size MTRRs in there 280 * and overlapping MTRRs into large pages can cause 281 * slowdowns. 282 */ 283 if (pfn == 0) 284 end_pfn = PFN_DOWN(PMD_SIZE); 285 else 286 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 287#else /* CONFIG_X86_64 */ 288 end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 289#endif 290 if (end_pfn > limit_pfn) 291 end_pfn = limit_pfn; 292 if (start_pfn < end_pfn) { 293 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 294 pfn = end_pfn; 295 } 296 297 /* big page (2M) range */ 298 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 299#ifdef CONFIG_X86_32 300 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 301#else /* CONFIG_X86_64 */ 302 end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE)); 303 if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE))) 304 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 305#endif 306 307 if (start_pfn < end_pfn) { 308 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 309 page_size_mask & (1<<PG_LEVEL_2M)); 310 pfn = end_pfn; 311 } 312 313#ifdef CONFIG_X86_64 314 /* big page (1G) range */ 315 start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE)); 316 end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE)); 317 if (start_pfn < end_pfn) { 318 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 319 page_size_mask & 320 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G))); 321 pfn = end_pfn; 322 } 323 324 /* tail is not big page (1G) alignment */ 325 start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE)); 326 end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE)); 327 if (start_pfn < end_pfn) { 328 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 329 page_size_mask & (1<<PG_LEVEL_2M)); 330 pfn = end_pfn; 331 } 332#endif 333 334 /* tail is not big page (2M) alignment */ 335 start_pfn = pfn; 336 end_pfn = limit_pfn; 337 nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); 338 339 if (!after_bootmem) 340 adjust_range_page_size_mask(mr, nr_range); 341 342 /* try to merge same page size and continuous */ 343 for (i = 0; nr_range > 1 && i < nr_range - 1; i++) { 344 unsigned long old_start; 345 if (mr[i].end != mr[i+1].start || 346 mr[i].page_size_mask != mr[i+1].page_size_mask) 347 continue; 348 /* move it */ 349 old_start = mr[i].start; 350 memmove(&mr[i], &mr[i+1], 351 (nr_range - 1 - i) * sizeof(struct map_range)); 352 mr[i--].start = old_start; 353 nr_range--; 354 } 355 356 for (i = 0; i < nr_range; i++) 357 pr_debug(" [mem %#010lx-%#010lx] page %s\n", 358 mr[i].start, mr[i].end - 1, 359 page_size_string(&mr[i])); 360 361 return nr_range; 362} 363 364struct range pfn_mapped[E820_X_MAX]; 365int nr_pfn_mapped; 366 367static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn) 368{ 369 nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX, 370 nr_pfn_mapped, start_pfn, end_pfn); 371 nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX); 372 373 max_pfn_mapped = max(max_pfn_mapped, end_pfn); 374 375 if (start_pfn < (1UL<<(32-PAGE_SHIFT))) 376 max_low_pfn_mapped = max(max_low_pfn_mapped, 377 min(end_pfn, 1UL<<(32-PAGE_SHIFT))); 378} 379 380bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn) 381{ 382 int i; 383 384 for (i = 0; i < nr_pfn_mapped; i++) 385 if ((start_pfn >= pfn_mapped[i].start) && 386 (end_pfn <= pfn_mapped[i].end)) 387 return true; 388 389 return false; 390} 391 392/* 393 * Setup the direct mapping of the physical memory at PAGE_OFFSET. 394 * This runs before bootmem is initialized and gets pages directly from 395 * the physical memory. To access them they are temporarily mapped. 396 */ 397unsigned long __init_refok init_memory_mapping(unsigned long start, 398 unsigned long end) 399{ 400 struct map_range mr[NR_RANGE_MR]; 401 unsigned long ret = 0; 402 int nr_range, i; 403 404 pr_debug("init_memory_mapping: [mem %#010lx-%#010lx]\n", 405 start, end - 1); 406 407 memset(mr, 0, sizeof(mr)); 408 nr_range = split_mem_range(mr, 0, start, end); 409 410 for (i = 0; i < nr_range; i++) 411 ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, 412 mr[i].page_size_mask); 413 414 add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT); 415 416 return ret >> PAGE_SHIFT; 417} 418 419/* 420 * We need to iterate through the E820 memory map and create direct mappings 421 * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply 422 * create direct mappings for all pfns from [0 to max_low_pfn) and 423 * [4GB to max_pfn) because of possible memory holes in high addresses 424 * that cannot be marked as UC by fixed/variable range MTRRs. 425 * Depending on the alignment of E820 ranges, this may possibly result 426 * in using smaller size (i.e. 4K instead of 2M or 1G) page tables. 427 * 428 * init_mem_mapping() calls init_range_memory_mapping() with big range. 429 * That range would have hole in the middle or ends, and only ram parts 430 * will be mapped in init_range_memory_mapping(). 431 */ 432static unsigned long __init init_range_memory_mapping( 433 unsigned long r_start, 434 unsigned long r_end) 435{ 436 unsigned long start_pfn, end_pfn; 437 unsigned long mapped_ram_size = 0; 438 int i; 439 440 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) { 441 u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end); 442 u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end); 443 if (start >= end) 444 continue; 445 446 /* 447 * if it is overlapping with brk pgt, we need to 448 * alloc pgt buf from memblock instead. 449 */ 450 can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >= 451 min(end, (u64)pgt_buf_top<<PAGE_SHIFT); 452 init_memory_mapping(start, end); 453 mapped_ram_size += end - start; 454 can_use_brk_pgt = true; 455 } 456 457 return mapped_ram_size; 458} 459 460static unsigned long __init get_new_step_size(unsigned long step_size) 461{ 462 /* 463 * Initial mapped size is PMD_SIZE (2M). 464 * We can not set step_size to be PUD_SIZE (1G) yet. 465 * In worse case, when we cross the 1G boundary, and 466 * PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k) 467 * to map 1G range with PTE. Hence we use one less than the 468 * difference of page table level shifts. 469 * 470 * Don't need to worry about overflow in the top-down case, on 32bit, 471 * when step_size is 0, round_down() returns 0 for start, and that 472 * turns it into 0x100000000ULL. 473 * In the bottom-up case, round_up(x, 0) returns 0 though too, which 474 * needs to be taken into consideration by the code below. 475 */ 476 return step_size << (PMD_SHIFT - PAGE_SHIFT - 1); 477} 478 479/** 480 * memory_map_top_down - Map [map_start, map_end) top down 481 * @map_start: start address of the target memory range 482 * @map_end: end address of the target memory range 483 * 484 * This function will setup direct mapping for memory range 485 * [map_start, map_end) in top-down. That said, the page tables 486 * will be allocated at the end of the memory, and we map the 487 * memory in top-down. 488 */ 489static void __init memory_map_top_down(unsigned long map_start, 490 unsigned long map_end) 491{ 492 unsigned long real_end, start, last_start; 493 unsigned long step_size; 494 unsigned long addr; 495 unsigned long mapped_ram_size = 0; 496 497 /* xen has big range in reserved near end of ram, skip it at first.*/ 498 addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE); 499 real_end = addr + PMD_SIZE; 500 501 /* step_size need to be small so pgt_buf from BRK could cover it */ 502 step_size = PMD_SIZE; 503 max_pfn_mapped = 0; /* will get exact value next */ 504 min_pfn_mapped = real_end >> PAGE_SHIFT; 505 last_start = start = real_end; 506 507 /* 508 * We start from the top (end of memory) and go to the bottom. 509 * The memblock_find_in_range() gets us a block of RAM from the 510 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages 511 * for page table. 512 */ 513 while (last_start > map_start) { 514 if (last_start > step_size) { 515 start = round_down(last_start - 1, step_size); 516 if (start < map_start) 517 start = map_start; 518 } else 519 start = map_start; 520 mapped_ram_size += init_range_memory_mapping(start, 521 last_start); 522 last_start = start; 523 min_pfn_mapped = last_start >> PAGE_SHIFT; 524 if (mapped_ram_size >= step_size) 525 step_size = get_new_step_size(step_size); 526 } 527 528 if (real_end < map_end) 529 init_range_memory_mapping(real_end, map_end); 530} 531 532/** 533 * memory_map_bottom_up - Map [map_start, map_end) bottom up 534 * @map_start: start address of the target memory range 535 * @map_end: end address of the target memory range 536 * 537 * This function will setup direct mapping for memory range 538 * [map_start, map_end) in bottom-up. Since we have limited the 539 * bottom-up allocation above the kernel, the page tables will 540 * be allocated just above the kernel and we map the memory 541 * in [map_start, map_end) in bottom-up. 542 */ 543static void __init memory_map_bottom_up(unsigned long map_start, 544 unsigned long map_end) 545{ 546 unsigned long next, start; 547 unsigned long mapped_ram_size = 0; 548 /* step_size need to be small so pgt_buf from BRK could cover it */ 549 unsigned long step_size = PMD_SIZE; 550 551 start = map_start; 552 min_pfn_mapped = start >> PAGE_SHIFT; 553 554 /* 555 * We start from the bottom (@map_start) and go to the top (@map_end). 556 * The memblock_find_in_range() gets us a block of RAM from the 557 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages 558 * for page table. 559 */ 560 while (start < map_end) { 561 if (step_size && map_end - start > step_size) { 562 next = round_up(start + 1, step_size); 563 if (next > map_end) 564 next = map_end; 565 } else { 566 next = map_end; 567 } 568 569 mapped_ram_size += init_range_memory_mapping(start, next); 570 start = next; 571 572 if (mapped_ram_size >= step_size) 573 step_size = get_new_step_size(step_size); 574 } 575} 576 577void __init init_mem_mapping(void) 578{ 579 unsigned long end; 580 581 probe_page_size_mask(); 582 583#ifdef CONFIG_X86_64 584 end = max_pfn << PAGE_SHIFT; 585#else 586 end = max_low_pfn << PAGE_SHIFT; 587#endif 588 589 /* the ISA range is always mapped regardless of memory holes */ 590 init_memory_mapping(0, ISA_END_ADDRESS); 591 592 /* 593 * If the allocation is in bottom-up direction, we setup direct mapping 594 * in bottom-up, otherwise we setup direct mapping in top-down. 595 */ 596 if (memblock_bottom_up()) { 597 unsigned long kernel_end = __pa_symbol(_end); 598 599 /* 600 * we need two separate calls here. This is because we want to 601 * allocate page tables above the kernel. So we first map 602 * [kernel_end, end) to make memory above the kernel be mapped 603 * as soon as possible. And then use page tables allocated above 604 * the kernel to map [ISA_END_ADDRESS, kernel_end). 605 */ 606 memory_map_bottom_up(kernel_end, end); 607 memory_map_bottom_up(ISA_END_ADDRESS, kernel_end); 608 } else { 609 memory_map_top_down(ISA_END_ADDRESS, end); 610 } 611 612#ifdef CONFIG_X86_64 613 if (max_pfn > max_low_pfn) { 614 /* can we preseve max_low_pfn ?*/ 615 max_low_pfn = max_pfn; 616 } 617#else 618 early_ioremap_page_table_range_init(); 619#endif 620 621 load_cr3(swapper_pg_dir); 622 __flush_tlb_all(); 623 624 early_memtest(0, max_pfn_mapped << PAGE_SHIFT); 625} 626 627/* 628 * devmem_is_allowed() checks to see if /dev/mem access to a certain address 629 * is valid. The argument is a physical page number. 630 * 631 * 632 * On x86, access has to be given to the first megabyte of ram because that area 633 * contains BIOS code and data regions used by X and dosemu and similar apps. 634 * Access has to be given to non-kernel-ram areas as well, these contain the PCI 635 * mmio resources as well as potential bios/acpi data regions. 636 */ 637int devmem_is_allowed(unsigned long pagenr) 638{ 639 if (pagenr < 256) 640 return 1; 641 if (iomem_is_exclusive(pagenr << PAGE_SHIFT)) 642 return 0; 643 if (!page_is_ram(pagenr)) 644 return 1; 645 return 0; 646} 647 648void free_init_pages(char *what, unsigned long begin, unsigned long end) 649{ 650 unsigned long begin_aligned, end_aligned; 651 652 /* Make sure boundaries are page aligned */ 653 begin_aligned = PAGE_ALIGN(begin); 654 end_aligned = end & PAGE_MASK; 655 656 if (WARN_ON(begin_aligned != begin || end_aligned != end)) { 657 begin = begin_aligned; 658 end = end_aligned; 659 } 660 661 if (begin >= end) 662 return; 663 664 /* 665 * If debugging page accesses then do not free this memory but 666 * mark them not present - any buggy init-section access will 667 * create a kernel page fault: 668 */ 669#ifdef CONFIG_DEBUG_PAGEALLOC 670 printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n", 671 begin, end - 1); 672 set_memory_np(begin, (end - begin) >> PAGE_SHIFT); 673#else 674 /* 675 * We just marked the kernel text read only above, now that 676 * we are going to free part of that, we need to make that 677 * writeable and non-executable first. 678 */ 679 set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); 680 set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); 681 682 free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what); 683#endif 684} 685 686void free_initmem(void) 687{ 688 free_init_pages("unused kernel", 689 (unsigned long)(&__init_begin), 690 (unsigned long)(&__init_end)); 691} 692 693#ifdef CONFIG_BLK_DEV_INITRD 694void __init free_initrd_mem(unsigned long start, unsigned long end) 695{ 696 /* 697 * Remember, initrd memory may contain microcode or other useful things. 698 * Before we lose initrd mem, we need to find a place to hold them 699 * now that normal virtual memory is enabled. 700 */ 701 save_microcode_in_initrd(); 702 703 /* 704 * end could be not aligned, and We can not align that, 705 * decompresser could be confused by aligned initrd_end 706 * We already reserve the end partial page before in 707 * - i386_start_kernel() 708 * - x86_64_start_kernel() 709 * - relocate_initrd() 710 * So here We can do PAGE_ALIGN() safely to get partial page to be freed 711 */ 712 free_init_pages("initrd", start, PAGE_ALIGN(end)); 713} 714#endif 715 716void __init zone_sizes_init(void) 717{ 718 unsigned long max_zone_pfns[MAX_NR_ZONES]; 719 720 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 721 722#ifdef CONFIG_ZONE_DMA 723 max_zone_pfns[ZONE_DMA] = min(MAX_DMA_PFN, max_low_pfn); 724#endif 725#ifdef CONFIG_ZONE_DMA32 726 max_zone_pfns[ZONE_DMA32] = min(MAX_DMA32_PFN, max_low_pfn); 727#endif 728 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 729#ifdef CONFIG_HIGHMEM 730 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 731#endif 732 733 free_area_init_nodes(max_zone_pfns); 734} 735 736DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate) = { 737#ifdef CONFIG_SMP 738 .active_mm = &init_mm, 739 .state = 0, 740#endif 741 .cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */ 742}; 743EXPORT_SYMBOL_GPL(cpu_tlbstate); 744 745void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache) 746{ 747 /* entry 0 MUST be WB (hardwired to speed up translations) */ 748 BUG_ON(!entry && cache != _PAGE_CACHE_MODE_WB); 749 750 __cachemode2pte_tbl[cache] = __cm_idx2pte(entry); 751 __pte2cachemode_tbl[entry] = cache; 752} 753