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   0
  13 #define SANITY  1
  14 #include <acess.h>
  15 #include <mm_virt.h>
  16 #include <mm_phys.h>
  17 #include <proc.h>
  18
  19 #if USE_PAE
  20 # define TAB    21
  21 # define DIR    30
  22 #else
  23 # define TAB    22
  24 #endif
  25
  26 #define KERNEL_STACKS           0xF0000000
  27 #define KERNEL_STACK_SIZE       0x00008000
  28 #define KERNEL_STACKS_END       0xFC000000
  29 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  30 #define WORKER_STACK_SIZE       KERNEL_STACK_SIZE
  31 #define WORKER_STACKS_END       0xB0000000
  32 #define NUM_WORKER_STACKS       ((WORKER_STACKS_END-WORKER_STACKS)/WORKER_STACK_SIZE)
  33
  34 #define PAE_PAGE_TABLE_ADDR     0xFC000000      // 16 MiB
  35 #define PAE_PAGE_DIR_ADDR       0xFCFC0000      // 16 KiB
  36 #define PAE_PAGE_PDPT_ADDR      0xFCFC3F00      // 32 bytes
  37 #define PAE_TMP_PDPT_ADDR       0xFCFC3F20      // 32 bytes
  38 #define PAE_TMP_DIR_ADDR        0xFCFE0000      // 16 KiB
  39 #define PAE_TMP_TABLE_ADDR      0xFD000000      // 16 MiB
  40
  41 #define PAGE_TABLE_ADDR 0xFC000000
  42 #define PAGE_DIR_ADDR   0xFC3F0000
  43 #define PAGE_CR3_ADDR   0xFC3F0FC0
  44 #define TMP_CR3_ADDR    0xFC3F0FC4      // Part of core instead of temp
  45 #define TMP_DIR_ADDR    0xFC3F1000      // Same
  46 #define TMP_TABLE_ADDR  0xFC400000
  47
  48 #define HW_MAP_ADDR             0xFE000000
  49 #define HW_MAP_MAX              0xFFEF0000
  50 #define NUM_HW_PAGES    ((HW_MAP_MAX-HW_MAP_ADDR)/0x1000)
  51 #define TEMP_MAP_ADDR   0xFFEF0000      // Allows 16 "temp" pages
  52 #define NUM_TEMP_PAGES  16
  53 #define LAST_BLOCK_ADDR 0xFFFF0000      // Free space for kernel provided user code/ *(-1) protection
  54
  55 #define PF_PRESENT      0x1
  56 #define PF_WRITE        0x2
  57 #define PF_USER         0x4
  58 #define PF_COW          0x200
  59 #define PF_PAGED        0x400
  60
  61 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  62
  63 #if USE_PAE
  64 typedef Uint64  tTabEnt;
  65 #else
  66 typedef Uint32  tTabEnt;
  67 #endif
  68
  69 // === IMPORTS ===
  70 extern void     _UsertextEnd, _UsertextBase;
  71 extern Uint32   gaInitPageDir[1024];
  72 extern Uint32   gaInitPageTable[1024];
  73 extern void     Threads_SegFault(tVAddr Addr);
  74 extern void     Error_Backtrace(Uint eip, Uint ebp);
  75
  76 // === PROTOTYPES ===
  77 void    MM_PreinitVirtual(void);
  78 void    MM_InstallVirtual(void);
  79 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  80 void    MM_DumpTables(tVAddr Start, tVAddr End);
  81 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  82
  83 // === GLOBALS ===
  84 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  85 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  86 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  87 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  88 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  89 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  90
  91 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  92 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  93 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  94 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  95 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  96 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  97  int    gbUsePAE = 0;
  98  int    gilTempMappings = 0;
  99  int    gilTempFractal = 0;
 100 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
 101  int    giLastUsedWorker = 0;
 102
 103 // === CODE ===
 104 /**
 105  * \fn void MM_PreinitVirtual(void)
 106  * \brief Maps the fractal mappings
 107  */
 108 void MM_PreinitVirtual(void)
 109 {
 110         #if USE_PAE
 111         gaInitPageDir[ ((PAGE_TABLE_ADDR >> TAB)-3*512+3)*2 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 112         #else
 113         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 114         #endif
 115         INVLPG( PAGE_TABLE_ADDR );
 116 }
 117
 118 /**
 119  * \fn void MM_InstallVirtual(void)
 120  * \brief Sets up the constant page mappings
 121  */
 122 void MM_InstallVirtual(void)
 123 {
 124          int    i;
 125
 126         #if USE_PAE
 127         // --- Pre-Allocate kernel tables
 128         for( i = KERNEL_BASE >> TAB; i < 1024*4; i ++ )
 129         {
 130                 if( gaPAE_PageDir[ i ] )        continue;
 131
 132                 // Skip stack tables, they are process unique
 133                 if( i > KERNEL_STACKS >> TAB && i < KERNEL_STACKS_END >> TAB) {
 134                         gaPAE_PageDir[ i ] = 0;
 135                         continue;
 136                 }
 137                 // Preallocate table
 138                 gaPAE_PageDir[ i ] = MM_AllocPhys() | 3;
 139                 INVLPG( &gaPAE_PageTable[i*512] );
 140                 memset( &gaPAE_PageTable[i*512], 0, 0x1000 );
 141         }
 142         #else
 143         // --- Pre-Allocate kernel tables
 144         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 145         {
 146                 if( gaPageDir[ i ] )    continue;
 147                 // Skip stack tables, they are process unique
 148                 if( i > KERNEL_STACKS >> 22 && i < KERNEL_STACKS_END >> 22) {
 149                         gaPageDir[ i ] = 0;
 150                         continue;
 151                 }
 152                 // Preallocate table
 153                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 154                 INVLPG( &gaPageTable[i*1024] );
 155                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 156         }
 157         #endif
 158
 159         // Unset kernel on the User Text pages
 160         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 161                 Log("MM_SetFlags( 0x%08x, 0, MM_PFLAG_KERNEL)", (tVAddr)&_UsertextBase + i*4096);
 162                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 163         }
 164 }
 165
 166 /**
 167  * \brief Cleans up the SMP required mappings
 168  */
 169 void MM_FinishVirtualInit(void)
 170 {
 171         #if USE_PAE
 172         gaInitPDPT[ 0 ] = 0;
 173         #else
 174         gaInitPageDir[ 0 ] = 0;
 175         #endif
 176 }
 177
 178 /**
 179  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 180  * \brief Called on a page fault
 181  */
 182 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 183 {
 184         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 185
 186         // -- Check for COW --
 187         if( gaPageDir  [Addr>>22] & PF_PRESENT
 188          && gaPageTable[Addr>>12] & PF_PRESENT
 189          && gaPageTable[Addr>>12] & PF_COW )
 190         {
 191                 tPAddr  paddr;
 192                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 193                 {
 194                         gaPageTable[Addr>>12] &= ~PF_COW;
 195                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 196                 }
 197                 else
 198                 {
 199                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 200                         paddr = MM_DuplicatePage( Addr );
 201                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 202                         gaPageTable[Addr>>12] &= PF_USER;
 203                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 204                 }
 205
 206                 INVLPG( Addr & ~0xFFF );
 207                 //LEAVE('-')
 208                 return;
 209         }
 210
 211         // If it was a user, tell the thread handler
 212         if(ErrorCode & 4) {
 213                 Warning("%s %s %s memory%s",
 214                         (ErrorCode&4?"User":"Kernel"),
 215                         (ErrorCode&2?"write to":"read from"),
 216                         (ErrorCode&1?"bad/locked":"non-present"),
 217                         (ErrorCode&16?" (Instruction Fetch)":"")
 218                         );
 219                 Warning("User Pagefault: Instruction at %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 220                 __asm__ __volatile__ ("sti");   // Restart IRQs
 221                 Threads_SegFault(Addr);
 222                 return ;
 223         }
 224
 225         Debug_KernelPanic();
 226
 227         // -- Check Error Code --
 228         if(ErrorCode & 8)
 229                 Warning("Reserved Bits Trashed!");
 230         else
 231         {
 232                 Warning("%s %s %s memory%s",
 233                         (ErrorCode&4?"User":"Kernel"),
 234                         (ErrorCode&2?"write to":"read from"),
 235                         (ErrorCode&1?"bad/locked":"non-present"),
 236                         (ErrorCode&16?" (Instruction Fetch)":"")
 237                         );
 238         }
 239
 240         Log("Code at %p accessed %p", Regs->eip, Addr);
 241         // Print Stack Backtrace
 242         Error_Backtrace(Regs->eip, Regs->ebp);
 243
 244         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 245         if( gaPageDir[Addr>>22] & PF_PRESENT )
 246                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 247
 248         //MM_DumpTables(0, -1);
 249
 250         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 251 }
 252
 253 /**
 254  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 255  * \brief Dumps the layout of the page tables
 256  */
 257 void MM_DumpTables(tVAddr Start, tVAddr End)
 258 {
 259         tVAddr  rangeStart = 0;
 260         tPAddr  expected = 0;
 261         tVAddr  curPos;
 262         Uint    page;
 263         const tPAddr    MASK = ~0xF98;
 264
 265         Start >>= 12;   End >>= 12;
 266
 267         #if 0
 268         Log("Directory Entries:");
 269         for(page = Start >> 10;
 270                 page < (End >> 10)+1;
 271                 page ++)
 272         {
 273                 if(gaPageDir[page])
 274                 {
 275                         Log(" 0x%08x-0x%08x :: 0x%08x",
 276                                 page<<22, ((page+1)<<22)-1,
 277                                 gaPageDir[page]&~0xFFF
 278                                 );
 279                 }
 280         }
 281         #endif
 282
 283         Log("Table Entries:");
 284         for(page = Start, curPos = Start<<12;
 285                 page < End;
 286                 curPos += 0x1000, page++)
 287         {
 288                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 289                 ||  !(gaPageTable[page] & PF_PRESENT)
 290                 ||  (gaPageTable[page] & MASK) != expected)
 291                 {
 292                         if(expected) {
 293                                 Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 294                                         rangeStart, curPos - 1,
 295                                         gaPageTable[rangeStart>>12] & ~0xFFF,
 296                                         (expected & ~0xFFF) - 1,
 297                                         (expected & PF_PAGED ? "p" : "-"),
 298                                         (expected & PF_COW ? "C" : "-"),
 299                                         (expected & PF_USER ? "U" : "-"),
 300                                         (expected & PF_WRITE ? "W" : "-")
 301                                         );
 302                                 expected = 0;
 303                         }
 304                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 305                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 306
 307                         expected = (gaPageTable[page] & MASK);
 308                         rangeStart = curPos;
 309                 }
 310                 if(expected)    expected += 0x1000;
 311         }
 312
 313         if(expected) {
 314                 Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 315                         rangeStart, curPos - 1,
 316                         gaPageTable[rangeStart>>12] & ~0xFFF,
 317                         (expected & ~0xFFF) - 1,
 318                         (expected & PF_PAGED ? "p" : "-"),
 319                         (expected & PF_COW ? "C" : "-"),
 320                         (expected & PF_USER ? "U" : "-"),
 321                         (expected & PF_WRITE ? "W" : "-")
 322                         );
 323                 expected = 0;
 324         }
 325 }
 326
 327 /**
 328  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 329  */
 330 tPAddr MM_Allocate(tVAddr VAddr)
 331 {
 332         tPAddr  paddr;
 333         //ENTER("xVAddr", VAddr);
 334         //__asm__ __volatile__ ("xchg %bx,%bx");
 335         // Check if the directory is mapped
 336         if( gaPageDir[ VAddr >> 22 ] == 0 )
 337         {
 338                 // Allocate directory
 339                 paddr = MM_AllocPhys();
 340                 //LOG("paddr = 0x%llx (new table)", paddr);
 341                 if( paddr == 0 ) {
 342                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 343                         //LEAVE('i',0);
 344                         return 0;
 345                 }
 346                 // Map
 347                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 348                 // Mark as user
 349                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 350
 351                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 352                 //LOG("Clearing new table");
 353                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 354         }
 355         // Check if the page is already allocated
 356         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 357                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 358                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 359                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 360         }
 361
 362         // Allocate
 363         paddr = MM_AllocPhys();
 364         //LOG("paddr = 0x%llx", paddr);
 365         if( paddr == 0 ) {
 366                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 367                         VAddr, __builtin_return_address(0));
 368                 //LEAVE('i',0);
 369                 return 0;
 370         }
 371         // Map
 372         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 373         // Mark as user
 374         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 375         // Invalidate Cache for address
 376         INVLPG( VAddr & ~0xFFF );
 377
 378         //LEAVE('X', paddr);
 379         return paddr;
 380 }
 381
 382 /**
 383  * \fn void MM_Deallocate(tVAddr VAddr)
 384  */
 385 void MM_Deallocate(tVAddr VAddr)
 386 {
 387         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 388                 Warning("MM_Deallocate - Directory not mapped");
 389                 return;
 390         }
 391
 392         if(gaPageTable[ VAddr >> 12 ] == 0) {
 393                 Warning("MM_Deallocate - Page is not allocated");
 394                 return;
 395         }
 396
 397         // Dereference page
 398         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 399         // Clear page
 400         gaPageTable[ VAddr >> 12 ] = 0;
 401 }
 402
 403 /**
 404  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 405  * \brief Checks if the passed address is accesable
 406  */
 407 tPAddr MM_GetPhysAddr(tVAddr Addr)
 408 {
 409         if( !(gaPageDir[Addr >> 22] & 1) )
 410                 return 0;
 411         if( !(gaPageTable[Addr >> 12] & 1) )
 412                 return 0;
 413         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 414 }
 415
 416 /**
 417  * \fn void MM_SetCR3(Uint CR3)
 418  * \brief Sets the current process space
 419  */
 420 void MM_SetCR3(Uint CR3)
 421 {
 422         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 423 }
 424
 425 /**
 426  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 427  * \brief Map a physical page to a virtual one
 428  */
 429 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 430 {
 431         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 432         // Sanity check
 433         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 434                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 435                 //LEAVE('i', 0);
 436                 return 0;
 437         }
 438
 439         // Align addresses
 440         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 441
 442         // Check if the directory is mapped
 443         if( gaPageDir[ VAddr >> 22 ] == 0 )
 444         {
 445                 gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
 446
 447                 // Mark as user
 448                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 449
 450                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 451                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 452         }
 453         // Check if the page is already allocated
 454         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 455                 Warning("MM_Map - Allocating to used address");
 456                 //LEAVE('i', 0);
 457                 return 0;
 458         }
 459
 460         // Map
 461         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 462         // Mark as user
 463         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 464
 465         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 466         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 467
 468         // Reference
 469         MM_RefPhys( PAddr );
 470
 471         //LOG("INVLPG( 0x%x )", VAddr);
 472         INVLPG( VAddr );
 473
 474         //LEAVE('i', 1);
 475         return 1;
 476 }
 477
 478 /**
 479  * \fn tVAddr MM_ClearUser()
 480  * \brief Clear user's address space
 481  */
 482 tVAddr MM_ClearUser(void)
 483 {
 484         Uint    i, j;
 485
 486         // Copy Directories
 487         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 488         {
 489                 // Check if directory is not allocated
 490                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 491                         gaPageDir[i] = 0;
 492                         continue;
 493                 }
 494
 495
 496                 for( j = 0; j < 1024; j ++ )
 497                 {
 498                         if( gaPageTable[i*1024+j] & 1 )
 499                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 500                         gaPageTable[i*1024+j] = 0;
 501                 }
 502
 503                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 504                 gaPageDir[i] = 0;
 505                 INVLPG( &gaPageTable[i*1024] );
 506         }
 507         INVLPG( gaPageDir );
 508
 509         return *gpPageCR3;
 510 }
 511
 512 /**
 513  * \fn tPAddr MM_Clone(void)
 514  * \brief Clone the current address space
 515  */
 516 tPAddr MM_Clone(void)
 517 {
 518         Uint    i, j;
 519         tVAddr  ret;
 520         Uint    page = 0;
 521         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 522         void    *tmp;
 523
 524         LOCK( &gilTempFractal );
 525
 526         // Create Directory Table
 527         *gpTmpCR3 = MM_AllocPhys() | 3;
 528         INVLPG( gaTmpDir );
 529         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 530         memsetd( gaTmpDir, 0, 1024 );
 531
 532         // Copy Tables
 533         for( i = 0; i < 768; i ++)
 534         {
 535                 // Check if table is allocated
 536                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 537                         gaTmpDir[i] = 0;
 538                         page += 1024;
 539                         continue;
 540                 }
 541
 542                 // Allocate new table
 543                 gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 544                 INVLPG( &gaTmpTable[page] );
 545                 // Fill
 546                 for( j = 0; j < 1024; j ++, page++ )
 547                 {
 548                         if( !(gaPageTable[page] & PF_PRESENT) ) {
 549                                 gaTmpTable[page] = 0;
 550                                 continue;
 551                         }
 552
 553                         // Refrence old page
 554                         MM_RefPhys( gaPageTable[page] & ~0xFFF );
 555                         // Add to new table
 556                         if(gaPageTable[page] & PF_WRITE) {
 557                                 gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 558                                 gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 559                                 INVLPG( page << 12 );
 560                         }
 561                         else
 562                                 gaTmpTable[page] = gaPageTable[page];
 563                 }
 564         }
 565
 566         // Map in kernel tables (and make fractal mapping)
 567         for( i = 768; i < 1024; i ++ )
 568         {
 569                 // Fractal
 570                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 571                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 572                         continue;
 573                 }
 574
 575                 if( gaPageDir[i] == 0 ) {
 576                         gaTmpDir[i] = 0;
 577                         continue;
 578                 }
 579
 580                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 581                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 582                 gaTmpDir[i] = gaPageDir[i];
 583         }
 584
 585         // Allocate kernel stack
 586         for(i = KERNEL_STACKS >> 22;
 587                 i < KERNEL_STACKS_END >> 22;
 588                 i ++ )
 589         {
 590                 // Check if directory is allocated
 591                 if( (gaPageDir[i] & 1) == 0 ) {
 592                         gaTmpDir[i] = 0;
 593                         continue;
 594                 }
 595
 596                 // We don't care about other kernel stacks, just the current one
 597                 if( i != kStackBase >> 22 ) {
 598                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 599                         gaTmpDir[i] = 0;
 600                         continue;
 601                 }
 602
 603                 // Create a copy
 604                 gaTmpDir[i] = MM_AllocPhys() | 3;
 605                 INVLPG( &gaTmpTable[i*1024] );
 606                 for( j = 0; j < 1024; j ++ )
 607                 {
 608                         // Is the page allocated? If not, skip
 609                         if( !(gaPageTable[i*1024+j] & 1) ) {
 610                                 gaTmpTable[i*1024+j] = 0;
 611                                 continue;
 612                         }
 613
 614                         // We don't care about other kernel stacks
 615                         if( ((i*1024+j)*4096 & ~(KERNEL_STACK_SIZE-1)) != kStackBase ) {
 616                                 gaTmpTable[i*1024+j] = 0;
 617                                 continue;
 618                         }
 619
 620                         // Allocate page
 621                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 622
 623                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 624
 625                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 626                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 627                         MM_FreeTemp( (Uint)tmp );
 628                 }
 629         }
 630
 631         ret = *gpTmpCR3 & ~0xFFF;
 632         RELEASE( &gilTempFractal );
 633
 634         //LEAVE('x', ret);
 635         return ret;
 636 }
 637
 638 /**
 639  * \fn tVAddr MM_NewKStack(void)
 640  * \brief Create a new kernel stack
 641  */
 642 tVAddr MM_NewKStack(void)
 643 {
 644         tVAddr  base = KERNEL_STACKS;
 645         Uint    i;
 646         for(;base<KERNEL_STACKS_END;base+=KERNEL_STACK_SIZE)
 647         {
 648                 if(MM_GetPhysAddr(base) != 0)   continue;
 649                 for(i=0;i<KERNEL_STACK_SIZE;i+=0x1000) {
 650                         MM_Allocate(base+i);
 651                 }
 652                 return base+KERNEL_STACK_SIZE;
 653         }
 654         Warning("MM_NewKStack - No address space left\n");
 655         return 0;
 656 }
 657
 658 /**
 659  * \fn tVAddr MM_NewWorkerStack()
 660  * \brief Creates a new worker stack
 661  */
 662 tVAddr MM_NewWorkerStack()
 663 {
 664         Uint    esp, ebp;
 665         Uint    oldstack;
 666         Uint    base, addr;
 667          int    i, j;
 668         Uint    *tmpPage;
 669         tPAddr  pages[WORKER_STACK_SIZE>>12];
 670
 671         // Get the old ESP and EBP
 672         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 673         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 674
 675         // Find a free worker stack address
 676         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 677         {
 678                 // Used block
 679                 if( gWorkerStacks[base/32] == -1 ) {
 680                         base += 31;     base &= ~31;
 681                         base --;        // Counteracted by the base++
 682                         continue;
 683                 }
 684                 // Used stack
 685                 if( gWorkerStacks[base/32] & (1 << base) ) {
 686                         continue;
 687                 }
 688                 break;
 689         }
 690         if(base >= NUM_WORKER_STACKS) {
 691                 Warning("Uh-oh! Out of worker stacks");
 692                 return 0;
 693         }
 694
 695         // It's ours now!
 696         gWorkerStacks[base/32] |= (1 << base);
 697         // Make life easier for later calls
 698         giLastUsedWorker = base;
 699         // We have one
 700         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 701         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 702
 703         // Acquire the lock for the temp fractal mappings
 704         LOCK(&gilTempFractal);
 705
 706         // Set the temp fractals to TID0's address space
 707         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 708         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 709         INVLPG( gaTmpDir );
 710
 711
 712         // Check if the directory is mapped (we are assuming that the stacks
 713         // will fit neatly in a directory)
 714         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 715         if(gaTmpDir[ base >> 22 ] == 0) {
 716                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 717                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 718         }
 719
 720         // Mapping Time!
 721         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 722         {
 723                 pages[ addr >> 12 ] = MM_AllocPhys();
 724                 gaTmpTable[ (base + addr) >> 12 ] = pages[addr>>12] | 3;
 725         }
 726         *gpTmpCR3 = 0;
 727         // Release the temp mapping lock
 728         RELEASE(&gilTempFractal);
 729
 730         // Copy the old stack
 731         oldstack = (esp + KERNEL_STACK_SIZE-1) & ~(KERNEL_STACK_SIZE-1);
 732         esp = oldstack - esp;   // ESP as an offset in the stack
 733
 734         // Make `base` be the top of the stack
 735         base += WORKER_STACK_SIZE;
 736
 737         i = (WORKER_STACK_SIZE>>12) - 1;
 738         // Copy the contents of the old stack to the new one, altering the addresses
 739         // `addr` is refering to bytes from the stack base (mem downwards)
 740         for(addr = 0; addr < esp; addr += 0x1000)
 741         {
 742                 Uint    *stack = (Uint*)( oldstack-(addr+0x1000) );
 743                 tmpPage = (void*)MM_MapTemp( pages[i] );
 744                 // Copy old stack
 745                 for(j = 0; j < 1024; j++)
 746                 {
 747                         // Possible Stack address?
 748                         if(oldstack-esp < stack[j] && stack[j] < oldstack)
 749                                 tmpPage[j] = base - (oldstack - stack[j]);
 750                         else    // Seems not, best leave it alone
 751                                 tmpPage[j] = stack[j];
 752                 }
 753                 MM_FreeTemp((tVAddr)tmpPage);
 754                 i --;
 755         }
 756
 757         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 758         return base;
 759 }
 760
 761 /**
 762  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 763  * \brief Sets the flags on a page
 764  */
 765 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 766 {
 767         tTabEnt *ent;
 768         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 769         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 770
 771         ent = &gaPageTable[VAddr >> 12];
 772
 773         // Read-Only
 774         if( Mask & MM_PFLAG_RO )
 775         {
 776                 if( Flags & MM_PFLAG_RO ) {
 777                         *ent &= ~PF_WRITE;
 778                 }
 779                 else {
 780                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 781                         *ent |= PF_WRITE;
 782                 }
 783         }
 784
 785         // Kernel
 786         if( Mask & MM_PFLAG_KERNEL )
 787         {
 788                 if( Flags & MM_PFLAG_KERNEL ) {
 789                         *ent &= ~PF_USER;
 790                 }
 791                 else {
 792                         gaPageDir[VAddr >> 22] |= PF_USER;
 793                         *ent |= PF_USER;
 794                 }
 795         }
 796
 797         // Copy-On-Write
 798         if( Mask & MM_PFLAG_COW )
 799         {
 800                 if( Flags & MM_PFLAG_COW ) {
 801                         *ent &= ~PF_WRITE;
 802                         *ent |= PF_COW;
 803                 }
 804                 else {
 805                         *ent &= ~PF_COW;
 806                         *ent |= PF_WRITE;
 807                 }
 808         }
 809
 810         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 811         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 812 }
 813
 814 /**
 815  * \brief Get the flags on a page
 816  */
 817 Uint MM_GetFlags(tVAddr VAddr)
 818 {
 819         tTabEnt *ent;
 820         Uint    ret = 0;
 821
 822         // Validity Check
 823         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 824         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 825
 826         ent = &gaPageTable[VAddr >> 12];
 827
 828         // Read-Only
 829         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 830         // Kernel
 831         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 832         // Copy-On-Write
 833         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 834
 835         return ret;
 836 }
 837
 838 /**
 839  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 840  * \brief Duplicates a virtual page to a physical one
 841  */
 842 tPAddr MM_DuplicatePage(tVAddr VAddr)
 843 {
 844         tPAddr  ret;
 845         Uint    temp;
 846          int    wasRO = 0;
 847
 848         //ENTER("xVAddr", VAddr);
 849
 850         // Check if mapped
 851         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 852         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 853
 854         // Page Align
 855         VAddr &= ~0xFFF;
 856
 857         // Allocate new page
 858         ret = MM_AllocPhys();
 859
 860         // Write-lock the page (to keep data constistent), saving its R/W state
 861         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 862         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 863         INVLPG( VAddr );
 864
 865         // Copy Data
 866         temp = MM_MapTemp(ret);
 867         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 868         MM_FreeTemp(temp);
 869
 870         // Restore Writeable status
 871         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 872         INVLPG(VAddr);
 873
 874         //LEAVE('X', ret);
 875         return ret;
 876 }
 877
 878 /**
 879  * \fn Uint MM_MapTemp(tPAddr PAddr)
 880  * \brief Create a temporary memory mapping
 881  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 882  */
 883 tVAddr MM_MapTemp(tPAddr PAddr)
 884 {
 885          int    i;
 886
 887         //ENTER("XPAddr", PAddr);
 888
 889         PAddr &= ~0xFFF;
 890
 891         //LOG("gilTempMappings = %i", gilTempMappings);
 892
 893         for(;;)
 894         {
 895                 LOCK( &gilTempMappings );
 896
 897                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 898                 {
 899                         // Check if page used
 900                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 901                         // Mark as used
 902                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 903                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 904                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 905                         RELEASE( &gilTempMappings );
 906                         return TEMP_MAP_ADDR + (i << 12);
 907                 }
 908                 RELEASE( &gilTempMappings );
 909                 Threads_Yield();
 910         }
 911 }
 912
 913 /**
 914  * \fn void MM_FreeTemp(tVAddr PAddr)
 915  * \brief Free's a temp mapping
 916  */
 917 void MM_FreeTemp(tVAddr VAddr)
 918 {
 919          int    i = VAddr >> 12;
 920         //ENTER("xVAddr", VAddr);
 921
 922         if(i >= (TEMP_MAP_ADDR >> 12))
 923                 gaPageTable[ i ] = 0;
 924
 925         //LEAVE('-');
 926 }
 927
 928 /**
 929  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 930  * \brief Allocates a contigous number of pages
 931  */
 932 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 933 {
 934          int    i, j;
 935
 936         PAddr &= ~0xFFF;
 937
 938         // Scan List
 939         for( i = 0; i < NUM_HW_PAGES; i ++ )
 940         {
 941                 // Check if addr used
 942                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 943                         continue;
 944
 945                 // Check possible region
 946                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 947                 {
 948                         // If there is an allocated page in the region we are testing, break
 949                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 950                 }
 951                 // Is it all free?
 952                 if( j == Number )
 953                 {
 954                         // Allocate
 955                         for( j = 0; j < Number; j++ ) {
 956                                 MM_RefPhys( PAddr + (j<<12) );
 957                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 958                         }
 959                         return HW_MAP_ADDR + (i<<12);
 960                 }
 961         }
 962         // If we don't find any, return NULL
 963         return 0;
 964 }
 965
 966 /**
 967  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 968  * \brief Allocates DMA physical memory
 969  * \param Pages Number of pages required
 970  * \param MaxBits       Maximum number of bits the physical address can have
 971  * \param PhysAddr      Pointer to the location to place the physical address allocated
 972  * \return Virtual address allocate
 973  */
 974 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 975 {
 976         tPAddr  maxCheck = (1 << MaxBits);
 977         tPAddr  phys;
 978         tVAddr  ret;
 979
 980         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
 981
 982         // Sanity Check
 983         if(MaxBits < 12 || !PhysAddr) {
 984                 LEAVE('i', 0);
 985                 return 0;
 986         }
 987
 988         // Bound
 989         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
 990
 991         // Fast Allocate
 992         if(Pages == 1 && MaxBits >= PHYS_BITS)
 993         {
 994                 phys = MM_AllocPhys();
 995                 *PhysAddr = phys;
 996                 ret = MM_MapHWPages(phys, 1);
 997                 if(ret == 0) {
 998                         MM_DerefPhys(phys);
 999                         LEAVE('i', 0);
1000                         return 0;
1001                 }
1002                 LEAVE('x', ret);
1003                 return ret;
1004         }
1005
1006         // Slow Allocate
1007         phys = MM_AllocPhysRange(Pages, MaxBits);
1008         // - Was it allocated?
1009         if(phys == 0) {
1010                 LEAVE('i', 0);
1011                 return 0;
1012         }
1013
1014         // Allocated successfully, now map
1015         ret = MM_MapHWPages(phys, Pages);
1016         if( ret == 0 ) {
1017                 // If it didn't map, free then return 0
1018                 for(;Pages--;phys+=0x1000)
1019                         MM_DerefPhys(phys);
1020                 LEAVE('i', 0);
1021                 return 0;
1022         }
1023
1024         *PhysAddr = phys;
1025         LEAVE('x', ret);
1026         return ret;
1027 }
1028
1029 /**
1030  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1031  * \brief Unmap a hardware page
1032  */
1033 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1034 {
1035          int    i, j;
1036
1037         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1038
1039         // Sanity Check
1040         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1041
1042         i = VAddr >> 12;
1043
1044         LOCK( &gilTempMappings );       // Temp and HW share a directory, so they share a lock
1045
1046
1047         for( j = 0; j < Number; j++ )
1048         {
1049                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1050                 gaPageTable[ i + j ] = 0;
1051         }
1052
1053         RELEASE( &gilTempMappings );
1054 }
1055
1056 // --- EXPORTS ---
1057 EXPORT(MM_GetPhysAddr);
1058 EXPORT(MM_Map);
1059 //EXPORT(MM_Unmap);
1060 EXPORT(MM_MapHWPages);
1061 EXPORT(MM_AllocDMA);
1062 EXPORT(MM_UnmapHWPages);