1 /* 2 * Copyright 2008-2010, Ingo Weinhold, ingo_weinhold@gmx.de. 3 * Copyright 2002-2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved. 4 * Distributed under the terms of the MIT License. 5 * 6 * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved. 7 * Distributed under the terms of the NewOS License. 8 */ 9 10 11 #include "paging/32bit/X86PagingMethod32Bit.h" 12 13 #include <stdlib.h> 14 #include <string.h> 15 16 #include <AutoDeleter.h> 17 18 #include <arch/smp.h> 19 #include <arch_system_info.h> 20 #include <boot/kernel_args.h> 21 #include <int.h> 22 #include <thread.h> 23 #include <vm/vm.h> 24 #include <vm/VMAddressSpace.h> 25 26 #include "paging/32bit/X86PagingStructures32Bit.h" 27 #include "paging/32bit/X86VMTranslationMap32Bit.h" 28 #include "paging/x86_physical_page_mapper.h" 29 #include "paging/x86_physical_page_mapper_large_memory.h" 30 31 32 //#define TRACE_X86_PAGING_METHOD_32_BIT 33 #ifdef TRACE_X86_PAGING_METHOD_32_BIT 34 # define TRACE(x...) dprintf(x) 35 #else 36 # define TRACE(x...) ; 37 #endif 38 39 40 #define MAX_INITIAL_POOLS \ 41 (ROUNDUP(SMP_MAX_CPUS * TOTAL_SLOTS_PER_CPU + EXTRA_SLOTS, 1024) / 1024) 42 43 44 using X86LargePhysicalPageMapper::PhysicalPageSlot; 45 46 47 // #pragma mark - X86PagingMethod32Bit::PhysicalPageSlotPool 48 49 50 struct X86PagingMethod32Bit::PhysicalPageSlotPool final 51 : X86LargePhysicalPageMapper::PhysicalPageSlotPool { 52 public: 53 virtual ~PhysicalPageSlotPool(); 54 55 status_t InitInitial(kernel_args* args); 56 status_t InitInitialPostArea(kernel_args* args); 57 58 void Init(area_id dataArea, void* data, 59 area_id virtualArea, addr_t virtualBase); 60 61 virtual status_t AllocatePool( 62 X86LargePhysicalPageMapper 63 ::PhysicalPageSlotPool*& _pool); 64 virtual void Map(phys_addr_t physicalAddress, 65 addr_t virtualAddress); 66 67 public: 68 static PhysicalPageSlotPool sInitialPhysicalPagePool[MAX_INITIAL_POOLS]; 69 70 private: 71 area_id fDataArea; 72 area_id fVirtualArea; 73 addr_t fVirtualBase; 74 page_table_entry* fPageTable; 75 }; 76 77 78 X86PagingMethod32Bit::PhysicalPageSlotPool 79 X86PagingMethod32Bit::PhysicalPageSlotPool::sInitialPhysicalPagePool[ 80 MAX_INITIAL_POOLS]; 81 82 83 X86PagingMethod32Bit::PhysicalPageSlotPool::~PhysicalPageSlotPool() 84 { 85 } 86 87 88 status_t 89 X86PagingMethod32Bit::PhysicalPageSlotPool::InitInitial(kernel_args* args) 90 { 91 // allocate a virtual address range for the pages to be mapped into 92 addr_t virtualBase = vm_allocate_early(args, 1024 * B_PAGE_SIZE, 0, 0, 93 kPageTableAlignment); 94 if (virtualBase == 0) { 95 panic("LargeMemoryPhysicalPageMapper::Init(): Failed to reserve " 96 "physical page pool space in virtual address space!"); 97 return B_ERROR; 98 } 99 100 // allocate memory for the page table and data 101 size_t areaSize = B_PAGE_SIZE + sizeof(PhysicalPageSlot[1024]); 102 page_table_entry* pageTable = (page_table_entry*)vm_allocate_early(args, 103 areaSize, ~0L, B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA, 0); 104 if (pageTable == 0) { 105 panic("X86PagingMethod32Bit::PhysicalPageSlotPool::InitInitial(): " 106 "Failed to allocate memory for page table!"); 107 return B_ERROR; 108 } 109 110 // prepare the page table 111 _EarlyPreparePageTables(pageTable, virtualBase, 1024 * B_PAGE_SIZE); 112 113 // init the pool structure and add the initial pool 114 Init(-1, pageTable, -1, (addr_t)virtualBase); 115 116 return B_OK; 117 } 118 119 120 status_t 121 X86PagingMethod32Bit::PhysicalPageSlotPool::InitInitialPostArea( 122 kernel_args* args) 123 { 124 // create an area for the (already allocated) data 125 size_t areaSize = B_PAGE_SIZE + sizeof(PhysicalPageSlot[1024]); 126 void* temp = fPageTable; 127 area_id area = create_area("physical page pool", &temp, 128 B_EXACT_ADDRESS, areaSize, B_ALREADY_WIRED, 129 B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA); 130 if (area < B_OK) { 131 panic("LargeMemoryPhysicalPageMapper::InitPostArea(): Failed to " 132 "create area for physical page pool."); 133 return area; 134 } 135 fDataArea = area; 136 137 // create an area for the virtual address space 138 temp = (void*)fVirtualBase; 139 area = vm_create_null_area(VMAddressSpace::KernelID(), 140 "physical page pool space", &temp, B_EXACT_ADDRESS, 141 1024 * B_PAGE_SIZE, 0); 142 if (area < B_OK) { 143 panic("LargeMemoryPhysicalPageMapper::InitPostArea(): Failed to " 144 "create area for physical page pool space."); 145 return area; 146 } 147 fVirtualArea = area; 148 149 return B_OK; 150 } 151 152 153 void 154 X86PagingMethod32Bit::PhysicalPageSlotPool::Init(area_id dataArea, void* data, 155 area_id virtualArea, addr_t virtualBase) 156 { 157 fDataArea = dataArea; 158 fVirtualArea = virtualArea; 159 fVirtualBase = virtualBase; 160 fPageTable = (page_table_entry*)data; 161 162 // init slot list 163 fSlots = (PhysicalPageSlot*)(fPageTable + 1024); 164 addr_t slotAddress = virtualBase; 165 for (int32 i = 0; i < 1024; i++, slotAddress += B_PAGE_SIZE) { 166 PhysicalPageSlot* slot = &fSlots[i]; 167 slot->next = slot + 1; 168 slot->pool = this; 169 slot->address = slotAddress; 170 } 171 172 fSlots[1023].next = NULL; 173 // terminate list 174 } 175 176 177 void 178 X86PagingMethod32Bit::PhysicalPageSlotPool::Map(phys_addr_t physicalAddress, 179 addr_t virtualAddress) 180 { 181 page_table_entry& pte = fPageTable[ 182 (virtualAddress - fVirtualBase) / B_PAGE_SIZE]; 183 pte = (physicalAddress & X86_PTE_ADDRESS_MASK) 184 | X86_PTE_WRITABLE | X86_PTE_GLOBAL | X86_PTE_PRESENT; 185 186 invalidate_TLB(virtualAddress); 187 } 188 189 190 status_t 191 X86PagingMethod32Bit::PhysicalPageSlotPool::AllocatePool( 192 X86LargePhysicalPageMapper::PhysicalPageSlotPool*& _pool) 193 { 194 // create the pool structure 195 PhysicalPageSlotPool* pool = new(std::nothrow) PhysicalPageSlotPool; 196 if (pool == NULL) 197 return B_NO_MEMORY; 198 ObjectDeleter<PhysicalPageSlotPool> poolDeleter(pool); 199 200 // create an area that can contain the page table and the slot 201 // structures 202 size_t areaSize = B_PAGE_SIZE + sizeof(PhysicalPageSlot[1024]); 203 void* data; 204 virtual_address_restrictions virtualRestrictions = {}; 205 virtualRestrictions.address_specification = B_ANY_KERNEL_ADDRESS; 206 physical_address_restrictions physicalRestrictions = {}; 207 area_id dataArea = create_area_etc(B_SYSTEM_TEAM, "physical page pool", 208 PAGE_ALIGN(areaSize), B_FULL_LOCK, 209 B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA, CREATE_AREA_DONT_WAIT, 0, 210 &virtualRestrictions, &physicalRestrictions, &data); 211 if (dataArea < 0) 212 return dataArea; 213 214 // create the null area for the virtual address space 215 void* virtualBase; 216 area_id virtualArea = vm_create_null_area( 217 VMAddressSpace::KernelID(), "physical page pool space", 218 &virtualBase, B_ANY_KERNEL_BLOCK_ADDRESS, 1024 * B_PAGE_SIZE, 219 CREATE_AREA_PRIORITY_VIP); 220 if (virtualArea < 0) { 221 delete_area(dataArea); 222 return virtualArea; 223 } 224 225 // prepare the page table 226 memset(data, 0, B_PAGE_SIZE); 227 228 // get the page table's physical address 229 phys_addr_t physicalTable; 230 X86VMTranslationMap32Bit* map = static_cast<X86VMTranslationMap32Bit*>( 231 VMAddressSpace::Kernel()->TranslationMap()); 232 uint32 dummyFlags; 233 cpu_status state = disable_interrupts(); 234 map->QueryInterrupt((addr_t)data, &physicalTable, &dummyFlags); 235 restore_interrupts(state); 236 237 // put the page table into the page directory 238 int32 index = (addr_t)virtualBase / (B_PAGE_SIZE * 1024); 239 page_directory_entry* entry 240 = &map->PagingStructures32Bit()->pgdir_virt[index]; 241 PutPageTableInPageDir(entry, physicalTable, 242 B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA); 243 X86PagingStructures32Bit::UpdateAllPageDirs(index, *entry); 244 245 // init the pool structure 246 pool->Init(dataArea, data, virtualArea, (addr_t)virtualBase); 247 poolDeleter.Detach(); 248 _pool = pool; 249 return B_OK; 250 } 251 252 253 // #pragma mark - X86PagingMethod32Bit 254 255 256 X86PagingMethod32Bit::X86PagingMethod32Bit() 257 : 258 fPageHole(NULL), 259 fPageHolePageDir(NULL), 260 fKernelPhysicalPageDirectory(0), 261 fKernelVirtualPageDirectory(NULL), 262 fPhysicalPageMapper(NULL), 263 fKernelPhysicalPageMapper(NULL) 264 { 265 } 266 267 268 X86PagingMethod32Bit::~X86PagingMethod32Bit() 269 { 270 } 271 272 273 status_t 274 X86PagingMethod32Bit::Init(kernel_args* args, 275 VMPhysicalPageMapper** _physicalPageMapper) 276 { 277 TRACE("X86PagingMethod32Bit::Init(): entry\n"); 278 279 // page hole set up in stage2 280 fPageHole = (page_table_entry*)(addr_t)args->arch_args.page_hole; 281 // calculate where the pgdir would be 282 fPageHolePageDir = (page_directory_entry*) 283 (((addr_t)args->arch_args.page_hole) 284 + (B_PAGE_SIZE * 1024 - B_PAGE_SIZE)); 285 // clear out the bottom 2 GB, unmap everything 286 memset(fPageHolePageDir + FIRST_USER_PGDIR_ENT, 0, 287 sizeof(page_directory_entry) * NUM_USER_PGDIR_ENTS); 288 289 fKernelPhysicalPageDirectory = args->arch_args.phys_pgdir; 290 fKernelVirtualPageDirectory = (page_directory_entry*)(addr_t) 291 args->arch_args.vir_pgdir; 292 293 #ifdef TRACE_X86_PAGING_METHOD_32_BIT 294 TRACE("page hole: %p, page dir: %p\n", fPageHole, fPageHolePageDir); 295 TRACE("page dir: %p (physical: %#" B_PRIx32 ")\n", 296 fKernelVirtualPageDirectory, fKernelPhysicalPageDirectory); 297 #endif 298 299 X86PagingStructures32Bit::StaticInit(); 300 301 // create the initial pools for the physical page mapper 302 int32 poolCount = _GetInitialPoolCount(); 303 PhysicalPageSlotPool* pool = PhysicalPageSlotPool::sInitialPhysicalPagePool; 304 305 for (int32 i = 0; i < poolCount; i++) { 306 new(&pool[i]) PhysicalPageSlotPool; 307 status_t error = pool[i].InitInitial(args); 308 if (error != B_OK) { 309 panic("X86PagingMethod32Bit::Init(): Failed to create initial pool " 310 "for physical page mapper!"); 311 return error; 312 } 313 } 314 315 // create physical page mapper 316 large_memory_physical_page_ops_init(args, pool, poolCount, sizeof(*pool), 317 fPhysicalPageMapper, fKernelPhysicalPageMapper); 318 // TODO: Select the best page mapper! 319 320 // enable global page feature if available 321 if (x86_check_feature(IA32_FEATURE_PGE, FEATURE_COMMON)) { 322 // this prevents kernel pages from being flushed from TLB on 323 // context-switch 324 x86_write_cr4(x86_read_cr4() | IA32_CR4_GLOBAL_PAGES); 325 } 326 327 TRACE("X86PagingMethod32Bit::Init(): done\n"); 328 329 *_physicalPageMapper = fPhysicalPageMapper; 330 return B_OK; 331 } 332 333 334 status_t 335 X86PagingMethod32Bit::InitPostArea(kernel_args* args) 336 { 337 // now that the vm is initialized, create an area that represents 338 // the page hole 339 void *temp; 340 area_id area; 341 342 // unmap the page hole hack we were using before 343 fKernelVirtualPageDirectory[1023] = 0; 344 fPageHolePageDir = NULL; 345 fPageHole = NULL; 346 347 temp = (void*)fKernelVirtualPageDirectory; 348 area = create_area("kernel_pgdir", &temp, B_EXACT_ADDRESS, B_PAGE_SIZE, 349 B_ALREADY_WIRED, B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA); 350 if (area < B_OK) 351 return area; 352 353 int32 poolCount = _GetInitialPoolCount(); 354 for (int32 i = 0; i < poolCount; i++) { 355 status_t error = PhysicalPageSlotPool::sInitialPhysicalPagePool[i] 356 .InitInitialPostArea(args); 357 if (error != B_OK) 358 return error; 359 } 360 361 return B_OK; 362 } 363 364 365 status_t 366 X86PagingMethod32Bit::CreateTranslationMap(bool kernel, VMTranslationMap** _map) 367 { 368 X86VMTranslationMap32Bit* map = new(std::nothrow) X86VMTranslationMap32Bit; 369 if (map == NULL) 370 return B_NO_MEMORY; 371 372 status_t error = map->Init(kernel); 373 if (error != B_OK) { 374 delete map; 375 return error; 376 } 377 378 *_map = map; 379 return B_OK; 380 } 381 382 383 status_t 384 X86PagingMethod32Bit::MapEarly(kernel_args* args, addr_t virtualAddress, 385 phys_addr_t physicalAddress, uint8 attributes, 386 page_num_t (*get_free_page)(kernel_args*)) 387 { 388 // XXX horrible back door to map a page quickly regardless of translation 389 // map object, etc. used only during VM setup. 390 // uses a 'page hole' set up in the stage 2 bootloader. The page hole is 391 // created by pointing one of the pgdir entries back at itself, effectively 392 // mapping the contents of all of the 4MB of pagetables into a 4 MB region. 393 // It's only used here, and is later unmapped. 394 395 // check to see if a page table exists for this range 396 int index = VADDR_TO_PDENT(virtualAddress); 397 if ((fPageHolePageDir[index] & X86_PDE_PRESENT) == 0) { 398 phys_addr_t pgtable; 399 page_directory_entry *e; 400 // we need to allocate a pgtable 401 pgtable = get_free_page(args); 402 // pgtable is in pages, convert to physical address 403 pgtable *= B_PAGE_SIZE; 404 405 TRACE("X86PagingMethod32Bit::MapEarly(): asked for free page for " 406 "pgtable. %#" B_PRIxPHYSADDR "\n", pgtable); 407 408 // put it in the pgdir 409 e = &fPageHolePageDir[index]; 410 PutPageTableInPageDir(e, pgtable, attributes); 411 412 // zero it out in it's new mapping 413 memset((unsigned int*)((addr_t)fPageHole 414 + (virtualAddress / B_PAGE_SIZE / 1024) * B_PAGE_SIZE), 415 0, B_PAGE_SIZE); 416 } 417 418 ASSERT_PRINT( 419 (fPageHole[virtualAddress / B_PAGE_SIZE] & X86_PTE_PRESENT) == 0, 420 "virtual address: %#" B_PRIxADDR ", pde: %#" B_PRIx32 421 ", existing pte: %#" B_PRIx32, virtualAddress, fPageHolePageDir[index], 422 fPageHole[virtualAddress / B_PAGE_SIZE]); 423 424 // now, fill in the pentry 425 PutPageTableEntryInTable(fPageHole + virtualAddress / B_PAGE_SIZE, 426 physicalAddress, attributes, 0, IS_KERNEL_ADDRESS(virtualAddress)); 427 428 return B_OK; 429 } 430 431 432 bool 433 X86PagingMethod32Bit::IsKernelPageAccessible(addr_t virtualAddress, 434 uint32 protection) 435 { 436 // We only trust the kernel team's page directory. So switch to it first. 437 // Always set it to make sure the TLBs don't contain obsolete data. 438 uint32 physicalPageDirectory = x86_read_cr3(); 439 x86_write_cr3(fKernelPhysicalPageDirectory); 440 441 // get the page directory entry for the address 442 page_directory_entry pageDirectoryEntry; 443 uint32 index = VADDR_TO_PDENT(virtualAddress); 444 445 if (physicalPageDirectory == fKernelPhysicalPageDirectory) { 446 pageDirectoryEntry = fKernelVirtualPageDirectory[index]; 447 } else if (fPhysicalPageMapper != NULL) { 448 // map the original page directory and get the entry 449 void* handle; 450 addr_t virtualPageDirectory; 451 status_t error = fPhysicalPageMapper->GetPageDebug( 452 physicalPageDirectory, &virtualPageDirectory, &handle); 453 if (error == B_OK) { 454 pageDirectoryEntry 455 = ((page_directory_entry*)virtualPageDirectory)[index]; 456 fPhysicalPageMapper->PutPageDebug(virtualPageDirectory, handle); 457 } else 458 pageDirectoryEntry = 0; 459 } else 460 pageDirectoryEntry = 0; 461 462 // map the page table and get the entry 463 page_table_entry pageTableEntry; 464 index = VADDR_TO_PTENT(virtualAddress); 465 466 if ((pageDirectoryEntry & X86_PDE_PRESENT) != 0 467 && fPhysicalPageMapper != NULL) { 468 void* handle; 469 addr_t virtualPageTable; 470 status_t error = fPhysicalPageMapper->GetPageDebug( 471 pageDirectoryEntry & X86_PDE_ADDRESS_MASK, &virtualPageTable, 472 &handle); 473 if (error == B_OK) { 474 pageTableEntry = ((page_table_entry*)virtualPageTable)[index]; 475 fPhysicalPageMapper->PutPageDebug(virtualPageTable, handle); 476 } else 477 pageTableEntry = 0; 478 } else 479 pageTableEntry = 0; 480 481 // switch back to the original page directory 482 if (physicalPageDirectory != fKernelPhysicalPageDirectory) 483 x86_write_cr3(physicalPageDirectory); 484 485 if ((pageTableEntry & X86_PTE_PRESENT) == 0) 486 return false; 487 488 // present means kernel-readable, so check for writable 489 return (protection & B_KERNEL_WRITE_AREA) == 0 490 || (pageTableEntry & X86_PTE_WRITABLE) != 0; 491 } 492 493 494 /*static*/ void 495 X86PagingMethod32Bit::PutPageTableInPageDir(page_directory_entry* entry, 496 phys_addr_t pgtablePhysical, uint32 attributes) 497 { 498 *entry = (pgtablePhysical & X86_PDE_ADDRESS_MASK) 499 | X86_PDE_PRESENT 500 | X86_PDE_WRITABLE 501 | X86_PDE_USER; 502 // TODO: we ignore the attributes of the page table - for compatibility 503 // with BeOS we allow having user accessible areas in the kernel address 504 // space. This is currently being used by some drivers, mainly for the 505 // frame buffer. Our current real time data implementation makes use of 506 // this fact, too. 507 // We might want to get rid of this possibility one day, especially if 508 // we intend to port it to a platform that does not support this. 509 } 510 511 512 /*static*/ void 513 X86PagingMethod32Bit::PutPageTableEntryInTable(page_table_entry* entry, 514 phys_addr_t physicalAddress, uint32 attributes, uint32 memoryType, 515 bool globalPage) 516 { 517 page_table_entry page = (physicalAddress & X86_PTE_ADDRESS_MASK) 518 | X86_PTE_PRESENT | (globalPage ? X86_PTE_GLOBAL : 0) 519 | MemoryTypeToPageTableEntryFlags(memoryType); 520 521 // if the page is user accessible, it's automatically 522 // accessible in kernel space, too (but with the same 523 // protection) 524 if ((attributes & B_USER_PROTECTION) != 0) { 525 page |= X86_PTE_USER; 526 if ((attributes & B_WRITE_AREA) != 0) 527 page |= X86_PTE_WRITABLE; 528 } else if ((attributes & B_KERNEL_WRITE_AREA) != 0) 529 page |= X86_PTE_WRITABLE; 530 531 // put it in the page table 532 *(volatile page_table_entry*)entry = page; 533 } 534 535 536 inline int32 537 X86PagingMethod32Bit::_GetInitialPoolCount() 538 { 539 int32 requiredSlots = smp_get_num_cpus() * TOTAL_SLOTS_PER_CPU 540 + EXTRA_SLOTS; 541 return (requiredSlots + 1023) / 1024; 542 } 543 544 545 /*static*/ void 546 X86PagingMethod32Bit::_EarlyPreparePageTables(page_table_entry* pageTables, 547 addr_t address, size_t size) 548 { 549 memset(pageTables, 0, B_PAGE_SIZE * (size / (B_PAGE_SIZE * 1024))); 550 551 // put the array of pgtables directly into the kernel pagedir 552 // these will be wired and kept mapped into virtual space to be easy to get 553 // to 554 { 555 addr_t virtualTable = (addr_t)pageTables; 556 557 page_directory_entry* pageHolePageDir 558 = X86PagingMethod32Bit::Method()->PageHolePageDir(); 559 560 for (size_t i = 0; i < (size / (B_PAGE_SIZE * 1024)); 561 i++, virtualTable += B_PAGE_SIZE) { 562 phys_addr_t physicalTable = 0; 563 _EarlyQuery(virtualTable, &physicalTable); 564 page_directory_entry* entry = &pageHolePageDir[ 565 (address / (B_PAGE_SIZE * 1024)) + i]; 566 PutPageTableInPageDir(entry, physicalTable, 567 B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA); 568 } 569 } 570 } 571 572 573 //! TODO: currently assumes this translation map is active 574 /*static*/ status_t 575 X86PagingMethod32Bit::_EarlyQuery(addr_t virtualAddress, 576 phys_addr_t *_physicalAddress) 577 { 578 X86PagingMethod32Bit* method = X86PagingMethod32Bit::Method(); 579 int index = VADDR_TO_PDENT(virtualAddress); 580 if ((method->PageHolePageDir()[index] & X86_PDE_PRESENT) == 0) { 581 // no pagetable here 582 return B_ERROR; 583 } 584 585 page_table_entry* entry = method->PageHole() + virtualAddress / B_PAGE_SIZE; 586 if ((*entry & X86_PTE_PRESENT) == 0) { 587 // page mapping not valid 588 return B_ERROR; 589 } 590 591 *_physicalAddress = *entry & X86_PTE_ADDRESS_MASK; 592 return B_OK; 593 } 594