Kernel/arch/x86/mm_virt.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * mm_virt.c
   4  *
   5  * Memory Map
   6  * 0xE0 - Kernel Base
   7  * 0xF0 - Kernel Stacks
   8  * 0xFD - Fractals
   9  * 0xFE - Unused
  10  * 0xFF - System Calls / Kernel's User Code
  11  */
  12 #define DEBUG   1
  13 #define SANITY  1
  14 #include <acess.h>
  15 #include <mm_phys.h>
  16 #include <proc.h>
  17
  18 #if USE_PAE
  19 # define TAB    21
  20 # define DIR    30
  21 #else
  22 # define TAB    22
  23 #endif
  24
  25 #define KERNEL_STACKS           0xF0000000
  26 #define KERNEL_STACK_SIZE       0x00008000
  27 #define KERNEL_STACKS_END       0xFC000000
  28 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  29 #define WORKER_STACK_SIZE       KERNEL_STACK_SIZE
  30 #define WORKER_STACKS_END       0xB0000000
  31 #define NUM_WORKER_STACKS       ((WORKER_STACKS_END-WORKER_STACKS)/WORKER_STACK_SIZE)
  32
  33 #define PAE_PAGE_TABLE_ADDR     0xFC000000      // 16 MiB
  34 #define PAE_PAGE_DIR_ADDR       0xFCFC0000      // 16 KiB
  35 #define PAE_PAGE_PDPT_ADDR      0xFCFC3F00      // 32 bytes
  36 #define PAE_TMP_PDPT_ADDR       0xFCFC3F20      // 32 bytes
  37 #define PAE_TMP_DIR_ADDR        0xFCFE0000      // 16 KiB
  38 #define PAE_TMP_TABLE_ADDR      0xFD000000      // 16 MiB
  39
  40 #define PAGE_TABLE_ADDR 0xFC000000
  41 #define PAGE_DIR_ADDR   0xFC3F0000
  42 #define PAGE_CR3_ADDR   0xFC3F0FC0
  43 #define TMP_CR3_ADDR    0xFC3F0FC4      // Part of core instead of temp
  44 #define TMP_DIR_ADDR    0xFC3F1000      // Same
  45 #define TMP_TABLE_ADDR  0xFC400000
  46
  47 #define HW_MAP_ADDR             0xFE000000
  48 #define HW_MAP_MAX              0xFFEF0000
  49 #define NUM_HW_PAGES    ((HW_MAP_MAX-HW_MAP_ADDR)/0x1000)
  50 #define TEMP_MAP_ADDR   0xFFEF0000      // Allows 16 "temp" pages
  51 #define NUM_TEMP_PAGES  16
  52 #define LAST_BLOCK_ADDR 0xFFFF0000      // Free space for kernel provided user code/ *(-1) protection
  53
  54 #define PF_PRESENT      0x1
  55 #define PF_WRITE        0x2
  56 #define PF_USER         0x4
  57 #define PF_COW          0x200
  58 #define PF_PAGED        0x400
  59
  60 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  61
  62 #if USE_PAE
  63 typedef Uint64  tTabEnt;
  64 #else
  65 typedef Uint32  tTabEnt;
  66 #endif
  67
  68 // === IMPORTS ===
  69 extern Uint32   gaInitPageDir[1024];
  70 extern Uint32   gaInitPageTable[1024];
  71 extern void     Threads_SegFault(tVAddr Addr);
  72 extern void     Error_Backtrace(Uint eip, Uint ebp);
  73
  74 // === PROTOTYPES ===
  75 void    MM_PreinitVirtual();
  76 void    MM_InstallVirtual();
  77 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  78 void    MM_DumpTables(tVAddr Start, tVAddr End);
  79 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  80
  81 // === GLOBALS ===
  82 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  83 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  84 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  85 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  86 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  87 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  88
  89 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  90 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  91 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  92 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  93 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  94 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  95  int    gbUsePAE = 0;
  96  int    gilTempMappings = 0;
  97  int    gilTempFractal = 0;
  98 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
  99  int    giLastUsedWorker = 0;
 100
 101 // === CODE ===
 102 /**
 103  * \fn void MM_PreinitVirtual()
 104  * \brief Maps the fractal mappings
 105  */
 106 void MM_PreinitVirtual()
 107 {
 108         #if USE_PAE
 109         gaInitPageDir[ ((PAGE_TABLE_ADDR >> TAB)-3*512+3)*2 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 110         #else
 111         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 112         #endif
 113         INVLPG( PAGE_TABLE_ADDR );
 114 }
 115
 116 /**
 117  * \fn void MM_InstallVirtual()
 118  * \brief Sets up the constant page mappings
 119  */
 120 void MM_InstallVirtual()
 121 {
 122          int    i;
 123
 124         #if USE_PAE
 125         // --- Pre-Allocate kernel tables
 126         for( i = KERNEL_BASE >> TAB; i < 1024*4; i ++ )
 127         {
 128                 if( gaPAE_PageDir[ i ] )        continue;
 129
 130                 // Skip stack tables, they are process unique
 131                 if( i > KERNEL_STACKS >> TAB && i < KERNEL_STACKS_END >> TAB) {
 132                         gaPAE_PageDir[ i ] = 0;
 133                         continue;
 134                 }
 135                 // Preallocate table
 136                 gaPAE_PageDir[ i ] = MM_AllocPhys() | 3;
 137                 INVLPG( &gaPAE_PageTable[i*512] );
 138                 memset( &gaPAE_PageTable[i*512], 0, 0x1000 );
 139         }
 140         #else
 141         // --- Pre-Allocate kernel tables
 142         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 143         {
 144                 if( gaPageDir[ i ] )    continue;
 145                 // Skip stack tables, they are process unique
 146                 if( i > KERNEL_STACKS >> 22 && i < KERNEL_STACKS_END >> 22) {
 147                         gaPageDir[ i ] = 0;
 148                         continue;
 149                 }
 150                 // Preallocate table
 151                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 152                 INVLPG( &gaPageTable[i*1024] );
 153                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 154         }
 155         #endif
 156 }
 157
 158 /**
 159  * \brief Cleans up the SMP required mappings
 160  */
 161 void MM_FinishVirtualInit()
 162 {
 163         #if USE_PAE
 164         gaInitPDPT[ 0 ] = 0;
 165         #else
 166         gaInitPageDir[ 0 ] = 0;
 167         #endif
 168 }
 169
 170 /**
 171  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 172  * \brief Called on a page fault
 173  */
 174 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 175 {
 176         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 177
 178         // -- Check for COW --
 179         if( gaPageDir  [Addr>>22] & PF_PRESENT
 180          && gaPageTable[Addr>>12] & PF_PRESENT
 181          && gaPageTable[Addr>>12] & PF_COW )
 182         {
 183                 tPAddr  paddr;
 184                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 185                 {
 186                         gaPageTable[Addr>>12] &= ~PF_COW;
 187                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 188                 }
 189                 else
 190                 {
 191                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 192                         paddr = MM_DuplicatePage( Addr );
 193                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 194                         gaPageTable[Addr>>12] &= PF_USER;
 195                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 196                 }
 197
 198                 INVLPG( Addr & ~0xFFF );
 199                 //LEAVE('-')
 200                 return;
 201         }
 202
 203         // If it was a user, tell the thread handler
 204         if(ErrorCode & 4) {
 205                 Warning("%s %s %s memory%s",
 206                         (ErrorCode&4?"User":"Kernel"),
 207                         (ErrorCode&2?"write to":"read from"),
 208                         (ErrorCode&1?"bad/locked":"non-present"),
 209                         (ErrorCode&16?" (Instruction Fetch)":"")
 210                         );
 211                 Warning("User Pagefault: Instruction at %p accessed %p", Regs->eip, Addr);
 212                 __asm__ __volatile__ ("sti");   // Restart IRQs
 213                 Threads_SegFault(Addr);
 214                 return ;
 215         }
 216
 217         // -- Check Error Code --
 218         if(ErrorCode & 8)
 219                 Warning("Reserved Bits Trashed!");
 220         else
 221         {
 222                 Warning("%s %s %s memory%s",
 223                         (ErrorCode&4?"User":"Kernel"),
 224                         (ErrorCode&2?"write to":"read from"),
 225                         (ErrorCode&1?"bad/locked":"non-present"),
 226                         (ErrorCode&16?" (Instruction Fetch)":"")
 227                         );
 228         }
 229
 230         Log("Code at %p accessed %p", Regs->eip, Addr);
 231         // Print Stack Backtrace
 232         Error_Backtrace(Regs->eip, Regs->ebp);
 233
 234         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 235         if( gaPageDir[Addr>>22] & PF_PRESENT )
 236                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 237
 238         //MM_DumpTables(0, -1);
 239
 240         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 241 }
 242
 243 /**
 244  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 245  * \brief Dumps the layout of the page tables
 246  */
 247 void MM_DumpTables(tVAddr Start, tVAddr End)
 248 {
 249         tVAddr  rangeStart = 0;
 250         tPAddr  expected = 0;
 251         tVAddr  curPos;
 252         Uint    page;
 253         const tPAddr    MASK = ~0xF98;
 254
 255         Start >>= 12;   End >>= 12;
 256
 257         #if 0
 258         Log("Directory Entries:");
 259         for(page = Start >> 10;
 260                 page < (End >> 10)+1;
 261                 page ++)
 262         {
 263                 if(gaPageDir[page])
 264                 {
 265                         Log(" 0x%08x-0x%08x :: 0x%08x",
 266                                 page<<22, ((page+1)<<22)-1,
 267                                 gaPageDir[page]&~0xFFF
 268                                 );
 269                 }
 270         }
 271         #endif
 272
 273         Log("Table Entries:");
 274         for(page = Start, curPos = Start<<12;
 275                 page < End;
 276                 curPos += 0x1000, page++)
 277         {
 278                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 279                 ||  !(gaPageTable[page] & PF_PRESENT)
 280                 ||  (gaPageTable[page] & MASK) != expected)
 281                 {
 282                         if(expected) {
 283                                 Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 284                                         rangeStart, curPos - 1,
 285                                         gaPageTable[rangeStart>>12] & ~0xFFF,
 286                                         (expected & ~0xFFF) - 1,
 287                                         (expected & PF_PAGED ? "p" : "-"),
 288                                         (expected & PF_COW ? "C" : "-"),
 289                                         (expected & PF_USER ? "U" : "-"),
 290                                         (expected & PF_WRITE ? "W" : "-")
 291                                         );
 292                                 expected = 0;
 293                         }
 294                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 295                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 296
 297                         expected = (gaPageTable[page] & MASK);
 298                         rangeStart = curPos;
 299                 }
 300                 if(expected)    expected += 0x1000;
 301         }
 302
 303         if(expected) {
 304                 Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 305                         rangeStart, curPos - 1,
 306                         gaPageTable[rangeStart>>12] & ~0xFFF,
 307                         (expected & ~0xFFF) - 1,
 308                         (expected & PF_PAGED ? "p" : "-"),
 309                         (expected & PF_COW ? "C" : "-"),
 310                         (expected & PF_USER ? "U" : "-"),
 311                         (expected & PF_WRITE ? "W" : "-")
 312                         );
 313                 expected = 0;
 314         }
 315 }
 316
 317 /**
 318  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 319  */
 320 tPAddr MM_Allocate(tVAddr VAddr)
 321 {
 322         tPAddr  paddr;
 323         //ENTER("xVAddr", VAddr);
 324         //__asm__ __volatile__ ("xchg %bx,%bx");
 325         // Check if the directory is mapped
 326         if( gaPageDir[ VAddr >> 22 ] == 0 )
 327         {
 328                 // Allocate directory
 329                 paddr = MM_AllocPhys();
 330                 //LOG("paddr = 0x%llx (new table)", paddr);
 331                 if( paddr == 0 ) {
 332                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 333                         //LEAVE('i',0);
 334                         return 0;
 335                 }
 336                 // Map
 337                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 338                 // Mark as user
 339                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 340
 341                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 342                 //LOG("Clearing new table");
 343                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 344         }
 345         // Check if the page is already allocated
 346         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 347                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 348                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 349                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 350         }
 351
 352         // Allocate
 353         paddr = MM_AllocPhys();
 354         //LOG("paddr = 0x%llx", paddr);
 355         if( paddr == 0 ) {
 356                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 357                         VAddr, __builtin_return_address(0));
 358                 //LEAVE('i',0);
 359                 return 0;
 360         }
 361         // Map
 362         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 363         // Mark as user
 364         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 365         // Invalidate Cache for address
 366         INVLPG( VAddr & ~0xFFF );
 367
 368         //LEAVE('X', paddr);
 369         return paddr;
 370 }
 371
 372 /**
 373  * \fn void MM_Deallocate(tVAddr VAddr)
 374  */
 375 void MM_Deallocate(tVAddr VAddr)
 376 {
 377         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 378                 Warning("MM_Deallocate - Directory not mapped");
 379                 return;
 380         }
 381
 382         if(gaPageTable[ VAddr >> 12 ] == 0) {
 383                 Warning("MM_Deallocate - Page is not allocated");
 384                 return;
 385         }
 386
 387         // Dereference page
 388         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 389         // Clear page
 390         gaPageTable[ VAddr >> 12 ] = 0;
 391 }
 392
 393 /**
 394  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 395  * \brief Checks if the passed address is accesable
 396  */
 397 tPAddr MM_GetPhysAddr(tVAddr Addr)
 398 {
 399         if( !(gaPageDir[Addr >> 22] & 1) )
 400                 return 0;
 401         if( !(gaPageTable[Addr >> 12] & 1) )
 402                 return 0;
 403         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 404 }
 405
 406
 407 /**
 408  * \fn int MM_IsUser(tVAddr VAddr)
 409  * \brief Checks if a page is user accessable
 410  */
 411 int MM_IsUser(tVAddr VAddr)
 412 {
 413         if( !(gaPageDir[VAddr >> 22] & 1) )
 414                 return 0;
 415         if( !(gaPageTable[VAddr >> 12] & 1) )
 416                 return 0;
 417         if( !(gaPageTable[VAddr >> 12] & PF_USER) )
 418                 return 0;
 419         return 1;
 420 }
 421
 422 /**
 423  * \fn void MM_SetCR3(tPAddr CR3)
 424  * \brief Sets the current process space
 425  */
 426 void MM_SetCR3(tPAddr CR3)
 427 {
 428         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 429 }
 430
 431 /**
 432  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 433  * \brief Map a physical page to a virtual one
 434  */
 435 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 436 {
 437         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 438         // Sanity check
 439         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 440                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 441                 //LEAVE('i', 0);
 442                 return 0;
 443         }
 444
 445         // Align addresses
 446         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 447
 448         // Check if the directory is mapped
 449         if( gaPageDir[ VAddr >> 22 ] == 0 )
 450         {
 451                 gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
 452
 453                 // Mark as user
 454                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 455
 456                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 457                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 458         }
 459         // Check if the page is already allocated
 460         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 461                 Warning("MM_Map - Allocating to used address");
 462                 //LEAVE('i', 0);
 463                 return 0;
 464         }
 465
 466         // Map
 467         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 468         // Mark as user
 469         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 470
 471         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 472         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 473
 474         // Reference
 475         MM_RefPhys( PAddr );
 476
 477         //LOG("INVLPG( 0x%x )", VAddr);
 478         INVLPG( VAddr );
 479
 480         //LEAVE('i', 1);
 481         return 1;
 482 }
 483
 484 /**
 485  * \fn tVAddr MM_ClearUser()
 486  * \brief Clear user's address space
 487  */
 488 tVAddr MM_ClearUser()
 489 {
 490         Uint    i, j;
 491
 492         // Copy Directories
 493         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 494         {
 495                 // Check if directory is not allocated
 496                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 497                         gaPageDir[i] = 0;
 498                         continue;
 499                 }
 500
 501
 502                 for( j = 0; j < 1024; j ++ )
 503                 {
 504                         if( gaPageTable[i*1024+j] & 1 )
 505                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 506                         gaPageTable[i*1024+j] = 0;
 507                 }
 508
 509                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 510                 gaPageDir[i] = 0;
 511                 INVLPG( &gaPageTable[i*1024] );
 512         }
 513         INVLPG( gaPageDir );
 514
 515         return *gpPageCR3;
 516 }
 517
 518 /**
 519  * \fn tPAddr MM_Clone()
 520  * \brief Clone the current address space
 521  */
 522 tPAddr MM_Clone()
 523 {
 524         Uint    i, j;
 525         tVAddr  ret;
 526         Uint    page = 0;
 527         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 528         void    *tmp;
 529
 530         LOCK( &gilTempFractal );
 531
 532         // Create Directory Table
 533         *gpTmpCR3 = MM_AllocPhys() | 3;
 534         INVLPG( gaTmpDir );
 535         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 536         memsetd( gaTmpDir, 0, 1024 );
 537
 538         // Copy Tables
 539         for( i = 0; i < 768; i ++)
 540         {
 541                 // Check if table is allocated
 542                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 543                         gaTmpDir[i] = 0;
 544                         page += 1024;
 545                         continue;
 546                 }
 547
 548                 // Allocate new table
 549                 gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 550                 INVLPG( &gaTmpTable[page] );
 551                 // Fill
 552                 for( j = 0; j < 1024; j ++, page++ )
 553                 {
 554                         if( !(gaPageTable[page] & PF_PRESENT) ) {
 555                                 gaTmpTable[page] = 0;
 556                                 continue;
 557                         }
 558
 559                         // Refrence old page
 560                         MM_RefPhys( gaPageTable[page] & ~0xFFF );
 561                         // Add to new table
 562                         if(gaPageTable[page] & PF_WRITE) {
 563                                 gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 564                                 gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 565                                 INVLPG( page << 12 );
 566                         }
 567                         else
 568                                 gaTmpTable[page] = gaPageTable[page];
 569                 }
 570         }
 571
 572         // Map in kernel tables (and make fractal mapping)
 573         for( i = 768; i < 1024; i ++ )
 574         {
 575                 // Fractal
 576                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 577                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 578                         continue;
 579                 }
 580
 581                 if( gaPageDir[i] == 0 ) {
 582                         gaTmpDir[i] = 0;
 583                         continue;
 584                 }
 585
 586                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 587                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 588                 gaTmpDir[i] = gaPageDir[i];
 589         }
 590
 591         // Allocate kernel stack
 592         for(i = KERNEL_STACKS >> 22;
 593                 i < KERNEL_STACKS_END >> 22;
 594                 i ++ )
 595         {
 596                 // Check if directory is allocated
 597                 if( (gaPageDir[i] & 1) == 0 ) {
 598                         gaTmpDir[i] = 0;
 599                         continue;
 600                 }
 601
 602                 // We don't care about other kernel stacks, just the current one
 603                 if( i != kStackBase >> 22 ) {
 604                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 605                         gaTmpDir[i] = 0;
 606                         continue;
 607                 }
 608
 609                 // Create a copy
 610                 gaTmpDir[i] = MM_AllocPhys() | 3;
 611                 INVLPG( &gaTmpTable[i*1024] );
 612                 for( j = 0; j < 1024; j ++ )
 613                 {
 614                         // Is the page allocated? If not, skip
 615                         if( !(gaPageTable[i*1024+j] & 1) ) {
 616                                 gaTmpTable[i*1024+j] = 0;
 617                                 continue;
 618                         }
 619
 620                         // We don't care about other kernel stacks
 621                         if( ((i*1024+j)*4096 & ~(KERNEL_STACK_SIZE-1)) != kStackBase ) {
 622                                 gaTmpTable[i*1024+j] = 0;
 623                                 continue;
 624                         }
 625
 626                         // Allocate page
 627                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 628
 629                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 630
 631                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 632                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 633                         MM_FreeTemp( (Uint)tmp );
 634                 }
 635         }
 636
 637         ret = *gpTmpCR3 & ~0xFFF;
 638         RELEASE( &gilTempFractal );
 639
 640         //LEAVE('x', ret);
 641         return ret;
 642 }
 643
 644 /**
 645  * \fn tVAddr MM_NewKStack()
 646  * \brief Create a new kernel stack
 647  */
 648 tVAddr MM_NewKStack()
 649 {
 650         tVAddr  base = KERNEL_STACKS;
 651         Uint    i;
 652         for(;base<KERNEL_STACKS_END;base+=KERNEL_STACK_SIZE)
 653         {
 654                 if(MM_GetPhysAddr(base) != 0)   continue;
 655                 for(i=0;i<KERNEL_STACK_SIZE;i+=0x1000) {
 656                         MM_Allocate(base+i);
 657                 }
 658                 return base+KERNEL_STACK_SIZE;
 659         }
 660         Warning("MM_NewKStack - No address space left\n");
 661         return 0;
 662 }
 663
 664 /**
 665  * \fn tVAddr MM_NewWorkerStack()
 666  * \brief Creates a new worker stack
 667  */
 668 tVAddr MM_NewWorkerStack()
 669 {
 670         Uint    esp, ebp;
 671         Uint    oldstack;
 672         Uint    base, addr;
 673          int    i, j;
 674         Uint    *tmpPage;
 675         tPAddr  pages[WORKER_STACK_SIZE>>12];
 676
 677         // Get the old ESP and EBP
 678         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 679         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 680
 681         // Find a free worker stack address
 682         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 683         {
 684                 // Used block
 685                 if( gWorkerStacks[base/32] == -1 ) {
 686                         base += 31;     base &= ~31;
 687                         base --;        // Counteracted by the base++
 688                         continue;
 689                 }
 690                 // Used stack
 691                 if( gWorkerStacks[base/32] & (1 << base) ) {
 692                         continue;
 693                 }
 694                 break;
 695         }
 696         if(base >= NUM_WORKER_STACKS) {
 697                 Warning("Uh-oh! Out of worker stacks");
 698                 return 0;
 699         }
 700
 701         // It's ours now!
 702         gWorkerStacks[base/32] |= (1 << base);
 703         // Make life easier for later calls
 704         giLastUsedWorker = base;
 705         // We have one
 706         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 707         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 708
 709         // Acquire the lock for the temp fractal mappings
 710         LOCK(&gilTempFractal);
 711
 712         // Set the temp fractals to TID0's address space
 713         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 714         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 715         INVLPG( gaTmpDir );
 716
 717
 718         // Check if the directory is mapped (we are assuming that the stacks
 719         // will fit neatly in a directory)
 720         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 721         if(gaTmpDir[ base >> 22 ] == 0) {
 722                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 723                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 724         }
 725
 726         // Mapping Time!
 727         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 728         {
 729                 pages[ addr >> 12 ] = MM_AllocPhys();
 730                 gaTmpTable[ (base + addr) >> 12 ] = pages[addr>>12] | 3;
 731         }
 732         *gpTmpCR3 = 0;
 733         // Release the temp mapping lock
 734         RELEASE(&gilTempFractal);
 735
 736         // Copy the old stack
 737         oldstack = (esp + KERNEL_STACK_SIZE-1) & ~(KERNEL_STACK_SIZE-1);
 738         esp = oldstack - esp;   // ESP as an offset in the stack
 739
 740         // Make `base` be the top of the stack
 741         base += WORKER_STACK_SIZE;
 742
 743         i = (WORKER_STACK_SIZE>>12) - 1;
 744         // Copy the contents of the old stack to the new one, altering the addresses
 745         // `addr` is refering to bytes from the stack base (mem downwards)
 746         for(addr = 0; addr < esp; addr += 0x1000)
 747         {
 748                 Uint    *stack = (Uint*)( oldstack-(addr+0x1000) );
 749                 tmpPage = (void*)MM_MapTemp( pages[i] );
 750                 // Copy old stack
 751                 for(j = 0; j < 1024; j++)
 752                 {
 753                         // Possible Stack address?
 754                         if(oldstack-esp < stack[j] && stack[j] < oldstack)
 755                                 tmpPage[j] = base - (oldstack - stack[j]);
 756                         else    // Seems not, best leave it alone
 757                                 tmpPage[j] = stack[j];
 758                 }
 759                 MM_FreeTemp((tVAddr)tmpPage);
 760                 i --;
 761         }
 762
 763         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 764         return base;
 765 }
 766
 767 /**
 768  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 769  * \brief Sets the flags on a page
 770  */
 771 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 772 {
 773         tTabEnt *ent;
 774         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 775         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 776
 777         ent = &gaPageTable[VAddr >> 12];
 778
 779         // Read-Only
 780         if( Mask & MM_PFLAG_RO )
 781         {
 782                 if( Flags & MM_PFLAG_RO )       *ent &= ~PF_WRITE;
 783                 else    *ent |= PF_WRITE;
 784         }
 785
 786         // Kernel
 787         if( Mask & MM_PFLAG_KERNEL )
 788         {
 789                 if( Flags & MM_PFLAG_KERNEL )   *ent &= ~PF_USER;
 790                 else    *ent |= PF_USER;
 791         }
 792
 793         // Copy-On-Write
 794         if( Mask & MM_PFLAG_COW )
 795         {
 796                 if( Flags & MM_PFLAG_COW ) {
 797                         *ent &= ~PF_WRITE;
 798                         *ent |= PF_COW;
 799                 }
 800                 else {
 801                         *ent &= ~PF_COW;
 802                         *ent |= PF_WRITE;
 803                 }
 804         }
 805 }
 806
 807 /**
 808  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 809  * \brief Duplicates a virtual page to a physical one
 810  */
 811 tPAddr MM_DuplicatePage(tVAddr VAddr)
 812 {
 813         tPAddr  ret;
 814         Uint    temp;
 815          int    wasRO = 0;
 816
 817         //ENTER("xVAddr", VAddr);
 818
 819         // Check if mapped
 820         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 821         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 822
 823         // Page Align
 824         VAddr &= ~0xFFF;
 825
 826         // Allocate new page
 827         ret = MM_AllocPhys();
 828
 829         // Write-lock the page (to keep data constistent), saving its R/W state
 830         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 831         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 832         INVLPG( VAddr );
 833
 834         // Copy Data
 835         temp = MM_MapTemp(ret);
 836         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 837         MM_FreeTemp(temp);
 838
 839         // Restore Writeable status
 840         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 841         INVLPG(VAddr);
 842
 843         //LEAVE('X', ret);
 844         return ret;
 845 }
 846
 847 /**
 848  * \fn Uint MM_MapTemp(tPAddr PAddr)
 849  * \brief Create a temporary memory mapping
 850  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 851  */
 852 tVAddr MM_MapTemp(tPAddr PAddr)
 853 {
 854          int    i;
 855
 856         //ENTER("XPAddr", PAddr);
 857
 858         PAddr &= ~0xFFF;
 859
 860         //LOG("gilTempMappings = %i", gilTempMappings);
 861
 862         for(;;)
 863         {
 864                 LOCK( &gilTempMappings );
 865
 866                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 867                 {
 868                         // Check if page used
 869                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 870                         // Mark as used
 871                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 872                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 873                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 874                         RELEASE( &gilTempMappings );
 875                         return TEMP_MAP_ADDR + (i << 12);
 876                 }
 877                 RELEASE( &gilTempMappings );
 878                 Threads_Yield();
 879         }
 880 }
 881
 882 /**
 883  * \fn void MM_FreeTemp(tVAddr PAddr)
 884  * \brief Free's a temp mapping
 885  */
 886 void MM_FreeTemp(tVAddr VAddr)
 887 {
 888          int    i = VAddr >> 12;
 889         //ENTER("xVAddr", VAddr);
 890
 891         if(i >= (TEMP_MAP_ADDR >> 12))
 892                 gaPageTable[ i ] = 0;
 893
 894         //LEAVE('-');
 895 }
 896
 897 /**
 898  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 899  * \brief Allocates a contigous number of pages
 900  */
 901 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 902 {
 903          int    i, j;
 904
 905         PAddr &= ~0xFFF;
 906
 907         // Scan List
 908         for( i = 0; i < NUM_HW_PAGES; i ++ )
 909         {
 910                 // Check if addr used
 911                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 912                         continue;
 913
 914                 // Check possible region
 915                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 916                 {
 917                         // If there is an allocated page in the region we are testing, break
 918                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 919                 }
 920                 // Is it all free?
 921                 if( j == Number )
 922                 {
 923                         // Allocate
 924                         for( j = 0; j < Number; j++ ) {
 925                                 MM_RefPhys( PAddr + (j<<12) );
 926                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 927                         }
 928                         return HW_MAP_ADDR + (i<<12);
 929                 }
 930         }
 931         // If we don't find any, return NULL
 932         return 0;
 933 }
 934
 935 /**
 936  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 937  * \brief Allocates DMA physical memory
 938  * \param Pages Number of pages required
 939  * \param MaxBits       Maximum number of bits the physical address can have
 940  * \param PhysAddr      Pointer to the location to place the physical address allocated
 941  * \return Virtual address allocate
 942  */
 943 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 944 {
 945         tPAddr  maxCheck = (1 << MaxBits);
 946         tPAddr  phys;
 947         tVAddr  ret;
 948
 949         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
 950
 951         // Sanity Check
 952         if(MaxBits < 12 || !PhysAddr) {
 953                 LEAVE('i', 0);
 954                 return 0;
 955         }
 956
 957         // Bound
 958         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
 959
 960         // Fast Allocate
 961         if(Pages == 1 && MaxBits >= PHYS_BITS)
 962         {
 963                 phys = MM_AllocPhys();
 964                 *PhysAddr = phys;
 965                 ret = MM_MapHWPages(phys, 1);
 966                 if(ret == 0) {
 967                         MM_DerefPhys(phys);
 968                         LEAVE('i', 0);
 969                         return 0;
 970                 }
 971                 LEAVE('x', ret);
 972                 return ret;
 973         }
 974
 975         // Slow Allocate
 976         phys = MM_AllocPhysRange(Pages, MaxBits);
 977         // - Was it allocated?
 978         if(phys == 0) {
 979                 LEAVE('i', 0);
 980                 return 0;
 981         }
 982
 983         // Allocated successfully, now map
 984         ret = MM_MapHWPages(phys, Pages);
 985         if( ret == 0 ) {
 986                 // If it didn't map, free then return 0
 987                 for(;Pages--;phys+=0x1000)
 988                         MM_DerefPhys(phys);
 989                 LEAVE('i', 0);
 990                 return 0;
 991         }
 992
 993         *PhysAddr = phys;
 994         LEAVE('x', ret);
 995         return ret;
 996 }
 997
 998 /**
 999  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1000  * \brief Unmap a hardware page
1001  */
1002 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1003 {
1004          int    i, j;
1005         // Sanity Check
1006         if(VAddr < HW_MAP_ADDR || VAddr-Number*0x1000 > HW_MAP_MAX)     return;
1007
1008         i = VAddr >> 12;
1009
1010         LOCK( &gilTempMappings );       // Temp and HW share a directory, so they share a lock
1011
1012         for( j = 0; j < Number; j++ )
1013         {
1014                 MM_DerefPhys( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] );
1015                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = 0;
1016         }
1017
1018         RELEASE( &gilTempMappings );
1019 }
1020
1021 // --- EXPORTS ---
1022 EXPORT(MM_GetPhysAddr);
1023 EXPORT(MM_Map);
1024 //EXPORT(MM_Unmap);
1025 EXPORT(MM_MapHWPages);
1026 EXPORT(MM_AllocDMA);
1027 EXPORT(MM_UnmapHWPages);