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_NOPAGE       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 tVAddr  MM_ClearUser(void);
  82 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  83
  84 // === GLOBALS ===
  85 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  86 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  87 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  88 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  89 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  90 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  91
  92 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  93 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  94 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  95 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  96 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  97 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  98  int    gbUsePAE = 0;
  99 tMutex  glTempMappings;
 100 tMutex  glTempFractal;
 101 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
 102  int    giLastUsedWorker = 0;
 103
 104 // === CODE ===
 105 /**
 106  * \fn void MM_PreinitVirtual(void)
 107  * \brief Maps the fractal mappings
 108  */
 109 void MM_PreinitVirtual(void)
 110 {
 111         #if USE_PAE
 112         gaInitPageDir[ ((PAGE_TABLE_ADDR >> TAB)-3*512+3)*2 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 113         #else
 114         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 115         #endif
 116         INVLPG( PAGE_TABLE_ADDR );
 117 }
 118
 119 /**
 120  * \fn void MM_InstallVirtual(void)
 121  * \brief Sets up the constant page mappings
 122  */
 123 void MM_InstallVirtual(void)
 124 {
 125          int    i;
 126
 127         #if USE_PAE
 128         // --- Pre-Allocate kernel tables
 129         for( i = KERNEL_BASE >> TAB; i < 1024*4; i ++ )
 130         {
 131                 if( gaPAE_PageDir[ i ] )        continue;
 132
 133                 // Skip stack tables, they are process unique
 134                 if( i > KERNEL_STACKS >> TAB && i < KERNEL_STACKS_END >> TAB) {
 135                         gaPAE_PageDir[ i ] = 0;
 136                         continue;
 137                 }
 138                 // Preallocate table
 139                 gaPAE_PageDir[ i ] = MM_AllocPhys() | 3;
 140                 INVLPG( &gaPAE_PageTable[i*512] );
 141                 memset( &gaPAE_PageTable[i*512], 0, 0x1000 );
 142         }
 143         #else
 144         // --- Pre-Allocate kernel tables
 145         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 146         {
 147                 if( gaPageDir[ i ] )    continue;
 148                 // Skip stack tables, they are process unique
 149                 if( i > KERNEL_STACKS >> 22 && i < KERNEL_STACKS_END >> 22) {
 150                         gaPageDir[ i ] = 0;
 151                         continue;
 152                 }
 153                 // Preallocate table
 154                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 155                 INVLPG( &gaPageTable[i*1024] );
 156                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 157         }
 158         #endif
 159
 160         // Unset kernel on the User Text pages
 161         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 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         // Register Dump
 251         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 252         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 253         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 254         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 255         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 256         {
 257                 Uint    dr0, dr1;
 258                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 259                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 260                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 261         }
 262
 263         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 264 }
 265
 266 /**
 267  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 268  * \brief Dumps the layout of the page tables
 269  */
 270 void MM_DumpTables(tVAddr Start, tVAddr End)
 271 {
 272         tVAddr  rangeStart = 0;
 273         tPAddr  expected = 0;
 274         tVAddr  curPos;
 275         Uint    page;
 276         const tPAddr    MASK = ~0xF98;
 277
 278         Start >>= 12;   End >>= 12;
 279
 280         #if 0
 281         Log("Directory Entries:");
 282         for(page = Start >> 10;
 283                 page < (End >> 10)+1;
 284                 page ++)
 285         {
 286                 if(gaPageDir[page])
 287                 {
 288                         Log(" 0x%08x-0x%08x :: 0x%08x",
 289                                 page<<22, ((page+1)<<22)-1,
 290                                 gaPageDir[page]&~0xFFF
 291                                 );
 292                 }
 293         }
 294         #endif
 295
 296         Log("Table Entries:");
 297         for(page = Start, curPos = Start<<12;
 298                 page < End;
 299                 curPos += 0x1000, page++)
 300         {
 301                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 302                 ||  !(gaPageTable[page] & PF_PRESENT)
 303                 ||  (gaPageTable[page] & MASK) != expected)
 304                 {
 305                         if(expected) {
 306                                 Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 307                                         rangeStart, curPos - 1,
 308                                         gaPageTable[rangeStart>>12] & ~0xFFF,
 309                                         (expected & ~0xFFF) - 1,
 310                                         (expected & PF_NOPAGE ? "P" : "-"),
 311                                         (expected & PF_COW ? "C" : "-"),
 312                                         (expected & PF_USER ? "U" : "-"),
 313                                         (expected & PF_WRITE ? "W" : "-")
 314                                         );
 315                                 expected = 0;
 316                         }
 317                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 318                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 319
 320                         expected = (gaPageTable[page] & MASK);
 321                         rangeStart = curPos;
 322                 }
 323                 if(expected)    expected += 0x1000;
 324         }
 325
 326         if(expected) {
 327                 Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
 328                         rangeStart, curPos - 1,
 329                         gaPageTable[rangeStart>>12] & ~0xFFF,
 330                         (expected & ~0xFFF) - 1,
 331                         (expected & PF_NOPAGE ? "p" : "-"),
 332                         (expected & PF_COW ? "C" : "-"),
 333                         (expected & PF_USER ? "U" : "-"),
 334                         (expected & PF_WRITE ? "W" : "-")
 335                         );
 336                 expected = 0;
 337         }
 338 }
 339
 340 /**
 341  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 342  */
 343 tPAddr MM_Allocate(tVAddr VAddr)
 344 {
 345         tPAddr  paddr;
 346         //ENTER("xVAddr", VAddr);
 347         //__asm__ __volatile__ ("xchg %bx,%bx");
 348         // Check if the directory is mapped
 349         if( gaPageDir[ VAddr >> 22 ] == 0 )
 350         {
 351                 // Allocate directory
 352                 paddr = MM_AllocPhys();
 353                 //LOG("paddr = 0x%llx (new table)", paddr);
 354                 if( paddr == 0 ) {
 355                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 356                         //LEAVE('i',0);
 357                         return 0;
 358                 }
 359                 // Map
 360                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 361                 // Mark as user
 362                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 363
 364                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 365                 //LOG("Clearing new table");
 366                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 367         }
 368         // Check if the page is already allocated
 369         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 370                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 371                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 372                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 373         }
 374
 375         // Allocate
 376         paddr = MM_AllocPhys();
 377         //LOG("paddr = 0x%llx", paddr);
 378         if( paddr == 0 ) {
 379                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 380                         VAddr, __builtin_return_address(0));
 381                 //LEAVE('i',0);
 382                 return 0;
 383         }
 384         // Map
 385         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 386         // Mark as user
 387         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 388         // Invalidate Cache for address
 389         INVLPG( VAddr & ~0xFFF );
 390
 391         //LEAVE('X', paddr);
 392         return paddr;
 393 }
 394
 395 /**
 396  * \fn void MM_Deallocate(tVAddr VAddr)
 397  */
 398 void MM_Deallocate(tVAddr VAddr)
 399 {
 400         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 401                 Warning("MM_Deallocate - Directory not mapped");
 402                 return;
 403         }
 404
 405         if(gaPageTable[ VAddr >> 12 ] == 0) {
 406                 Warning("MM_Deallocate - Page is not allocated");
 407                 return;
 408         }
 409
 410         // Dereference page
 411         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 412         // Clear page
 413         gaPageTable[ VAddr >> 12 ] = 0;
 414 }
 415
 416 /**
 417  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 418  * \brief Checks if the passed address is accesable
 419  */
 420 tPAddr MM_GetPhysAddr(tVAddr Addr)
 421 {
 422         if( !(gaPageDir[Addr >> 22] & 1) )
 423                 return 0;
 424         if( !(gaPageTable[Addr >> 12] & 1) )
 425                 return 0;
 426         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 427 }
 428
 429 /**
 430  * \fn void MM_SetCR3(Uint CR3)
 431  * \brief Sets the current process space
 432  */
 433 void MM_SetCR3(Uint CR3)
 434 {
 435         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 436 }
 437
 438 /**
 439  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 440  * \brief Map a physical page to a virtual one
 441  */
 442 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 443 {
 444         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 445         // Sanity check
 446         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 447                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 448                 //LEAVE('i', 0);
 449                 return 0;
 450         }
 451
 452         // Align addresses
 453         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 454
 455         // Check if the directory is mapped
 456         if( gaPageDir[ VAddr >> 22 ] == 0 )
 457         {
 458                 gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
 459
 460                 // Mark as user
 461                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 462
 463                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 464                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 465         }
 466         // Check if the page is already allocated
 467         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 468                 Warning("MM_Map - Allocating to used address");
 469                 //LEAVE('i', 0);
 470                 return 0;
 471         }
 472
 473         // Map
 474         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 475         // Mark as user
 476         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 477
 478         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 479         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 480
 481         // Reference
 482         MM_RefPhys( PAddr );
 483
 484         //LOG("INVLPG( 0x%x )", VAddr);
 485         INVLPG( VAddr );
 486
 487         //LEAVE('i', 1);
 488         return 1;
 489 }
 490
 491 /**
 492  * \fn tVAddr MM_ClearUser()
 493  * \brief Clear user's address space
 494  */
 495 tVAddr MM_ClearUser(void)
 496 {
 497         Uint    i, j;
 498
 499         // Copy Directories
 500         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 501         {
 502                 // Check if directory is not allocated
 503                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 504                         gaPageDir[i] = 0;
 505                         continue;
 506                 }
 507
 508
 509                 for( j = 0; j < 1024; j ++ )
 510                 {
 511                         if( gaPageTable[i*1024+j] & 1 )
 512                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 513                         gaPageTable[i*1024+j] = 0;
 514                 }
 515
 516                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 517                 gaPageDir[i] = 0;
 518                 INVLPG( &gaPageTable[i*1024] );
 519         }
 520         INVLPG( gaPageDir );
 521
 522         return *gpPageCR3;
 523 }
 524
 525 /**
 526  * \fn tPAddr MM_Clone(void)
 527  * \brief Clone the current address space
 528  */
 529 tPAddr MM_Clone(void)
 530 {
 531         Uint    i, j;
 532         tVAddr  ret;
 533         Uint    page = 0;
 534         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 535         void    *tmp;
 536
 537         Mutex_Acquire( &glTempFractal );
 538
 539         // Create Directory Table
 540         *gpTmpCR3 = MM_AllocPhys() | 3;
 541         INVLPG( gaTmpDir );
 542         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 543         memsetd( gaTmpDir, 0, 1024 );
 544
 545         if( Threads_GetPID() != 0 )
 546         {
 547                 // Copy Tables
 548                 for( i = 0; i < 768; i ++)
 549                 {
 550                         // Check if table is allocated
 551                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 552                                 gaTmpDir[i] = 0;
 553                                 page += 1024;
 554                                 continue;
 555                         }
 556
 557                         // Allocate new table
 558                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 559                         INVLPG( &gaTmpTable[page] );
 560                         // Fill
 561                         for( j = 0; j < 1024; j ++, page++ )
 562                         {
 563                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 564                                         gaTmpTable[page] = 0;
 565                                         continue;
 566                                 }
 567
 568                                 // Refrence old page
 569                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 570                                 // Add to new table
 571                                 if(gaPageTable[page] & PF_WRITE) {
 572                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 573                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 574                                         INVLPG( page << 12 );
 575                                 }
 576                                 else
 577                                         gaTmpTable[page] = gaPageTable[page];
 578                         }
 579                 }
 580         }
 581
 582         // Map in kernel tables (and make fractal mapping)
 583         for( i = 768; i < 1024; i ++ )
 584         {
 585                 // Fractal
 586                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 587                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 588                         continue;
 589                 }
 590
 591                 if( gaPageDir[i] == 0 ) {
 592                         gaTmpDir[i] = 0;
 593                         continue;
 594                 }
 595
 596                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 597                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 598                 gaTmpDir[i] = gaPageDir[i];
 599         }
 600
 601         // Allocate kernel stack
 602         for(i = KERNEL_STACKS >> 22;
 603                 i < KERNEL_STACKS_END >> 22;
 604                 i ++ )
 605         {
 606                 // Check if directory is allocated
 607                 if( (gaPageDir[i] & 1) == 0 ) {
 608                         gaTmpDir[i] = 0;
 609                         continue;
 610                 }
 611
 612                 // We don't care about other kernel stacks, just the current one
 613                 if( i != kStackBase >> 22 ) {
 614                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 615                         gaTmpDir[i] = 0;
 616                         continue;
 617                 }
 618
 619                 // Create a copy
 620                 gaTmpDir[i] = MM_AllocPhys() | 3;
 621                 INVLPG( &gaTmpTable[i*1024] );
 622                 for( j = 0; j < 1024; j ++ )
 623                 {
 624                         // Is the page allocated? If not, skip
 625                         if( !(gaPageTable[i*1024+j] & 1) ) {
 626                                 gaTmpTable[i*1024+j] = 0;
 627                                 continue;
 628                         }
 629
 630                         // We don't care about other kernel stacks
 631                         if( ((i*1024+j)*4096 & ~(KERNEL_STACK_SIZE-1)) != kStackBase ) {
 632                                 gaTmpTable[i*1024+j] = 0;
 633                                 continue;
 634                         }
 635
 636                         // Allocate page
 637                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 638
 639                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 640
 641                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 642                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 643                         MM_FreeTemp( (Uint)tmp );
 644                 }
 645         }
 646
 647         ret = *gpTmpCR3 & ~0xFFF;
 648         Mutex_Release( &glTempFractal );
 649
 650         //LEAVE('x', ret);
 651         return ret;
 652 }
 653
 654 /**
 655  * \fn tVAddr MM_NewKStack(void)
 656  * \brief Create a new kernel stack
 657  */
 658 tVAddr MM_NewKStack(void)
 659 {
 660         tVAddr  base;
 661         Uint    i;
 662         for(base = KERNEL_STACKS; base < KERNEL_STACKS_END; base += KERNEL_STACK_SIZE)
 663         {
 664                 // Check if space is free
 665                 if(MM_GetPhysAddr(base) != 0)   continue;
 666                 // Allocate
 667                 //for(i = KERNEL_STACK_SIZE; i -= 0x1000 ; )
 668                 for(i = 0; i < KERNEL_STACK_SIZE; i += 0x1000 )
 669                 {
 670                         if( MM_Allocate(base+i) == 0 )
 671                         {
 672                                 // On error, print a warning and return error
 673                                 Warning("MM_NewKStack - Out of memory");
 674                                 // - Clean up
 675                                 //for( i += 0x1000 ; i < KERNEL_STACK_SIZE; i += 0x1000 )
 676                                 //      MM_Deallocate(base+i);
 677                                 return 0;
 678                         }
 679                 }
 680                 // Success
 681                 Log("MM_NewKStack - Allocated %p", base + KERNEL_STACK_SIZE);
 682                 return base+KERNEL_STACK_SIZE;
 683         }
 684         // No stacks left
 685         Warning("MM_NewKStack - No address space left");
 686         return 0;
 687 }
 688
 689 /**
 690  * \fn tVAddr MM_NewWorkerStack()
 691  * \brief Creates a new worker stack
 692  */
 693 tVAddr MM_NewWorkerStack()
 694 {
 695         Uint    esp, ebp;
 696         Uint    oldstack;
 697         Uint    base, addr;
 698          int    i, j;
 699         Uint    *tmpPage;
 700         tPAddr  pages[WORKER_STACK_SIZE>>12];
 701
 702         // Get the old ESP and EBP
 703         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 704         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 705
 706         // TODO: Thread safety
 707         // Find a free worker stack address
 708         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 709         {
 710                 // Used block
 711                 if( gWorkerStacks[base/32] == -1 ) {
 712                         base += 31;     base &= ~31;
 713                         base --;        // Counteracted by the base++
 714                         continue;
 715                 }
 716                 // Used stack
 717                 if( gWorkerStacks[base/32] & (1 << base) ) {
 718                         continue;
 719                 }
 720                 break;
 721         }
 722         if(base >= NUM_WORKER_STACKS) {
 723                 Warning("Uh-oh! Out of worker stacks");
 724                 return 0;
 725         }
 726
 727         // It's ours now!
 728         gWorkerStacks[base/32] |= (1 << base);
 729         // Make life easier for later calls
 730         giLastUsedWorker = base;
 731         // We have one
 732         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 733         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 734
 735         // Acquire the lock for the temp fractal mappings
 736         Mutex_Acquire(&glTempFractal);
 737
 738         // Set the temp fractals to TID0's address space
 739         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 740         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 741         INVLPG( gaTmpDir );
 742
 743
 744         // Check if the directory is mapped (we are assuming that the stacks
 745         // will fit neatly in a directory)
 746         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 747         if(gaTmpDir[ base >> 22 ] == 0) {
 748                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 749                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 750         }
 751
 752         // Mapping Time!
 753         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 754         //for( addr = WORKER_STACK_SIZE; addr; addr -= 0x1000 )
 755         {
 756                 pages[ addr >> 12 ] = MM_AllocPhys();
 757                 gaTmpTable[ (base + addr) >> 12 ] = pages[addr>>12] | 3;
 758         }
 759         *gpTmpCR3 = 0;
 760         // Release the temp mapping lock
 761         Mutex_Release(&glTempFractal);
 762
 763         // Copy the old stack
 764         oldstack = (esp + KERNEL_STACK_SIZE-1) & ~(KERNEL_STACK_SIZE-1);
 765         esp = oldstack - esp;   // ESP as an offset in the stack
 766
 767         // Make `base` be the top of the stack
 768         base += WORKER_STACK_SIZE;
 769
 770         i = (WORKER_STACK_SIZE>>12) - 1;
 771         // Copy the contents of the old stack to the new one, altering the addresses
 772         // `addr` is refering to bytes from the stack base (mem downwards)
 773         for(addr = 0; addr < esp; addr += 0x1000)
 774         {
 775                 Uint    *stack = (Uint*)( oldstack-(addr+0x1000) );
 776                 tmpPage = (void*)MM_MapTemp( pages[i] );
 777                 // Copy old stack
 778                 for(j = 0; j < 1024; j++)
 779                 {
 780                         // Possible Stack address?
 781                         if(oldstack-esp < stack[j] && stack[j] < oldstack)
 782                                 tmpPage[j] = base - (oldstack - stack[j]);
 783                         else    // Seems not, best leave it alone
 784                                 tmpPage[j] = stack[j];
 785                 }
 786                 MM_FreeTemp((tVAddr)tmpPage);
 787                 i --;
 788         }
 789
 790         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 791         return base;
 792 }
 793
 794 /**
 795  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 796  * \brief Sets the flags on a page
 797  */
 798 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 799 {
 800         tTabEnt *ent;
 801         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 802         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 803
 804         ent = &gaPageTable[VAddr >> 12];
 805
 806         // Read-Only
 807         if( Mask & MM_PFLAG_RO )
 808         {
 809                 if( Flags & MM_PFLAG_RO ) {
 810                         *ent &= ~PF_WRITE;
 811                 }
 812                 else {
 813                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 814                         *ent |= PF_WRITE;
 815                 }
 816         }
 817
 818         // Kernel
 819         if( Mask & MM_PFLAG_KERNEL )
 820         {
 821                 if( Flags & MM_PFLAG_KERNEL ) {
 822                         *ent &= ~PF_USER;
 823                 }
 824                 else {
 825                         gaPageDir[VAddr >> 22] |= PF_USER;
 826                         *ent |= PF_USER;
 827                 }
 828         }
 829
 830         // Copy-On-Write
 831         if( Mask & MM_PFLAG_COW )
 832         {
 833                 if( Flags & MM_PFLAG_COW ) {
 834                         *ent &= ~PF_WRITE;
 835                         *ent |= PF_COW;
 836                 }
 837                 else {
 838                         *ent &= ~PF_COW;
 839                         *ent |= PF_WRITE;
 840                 }
 841         }
 842
 843         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 844         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 845 }
 846
 847 /**
 848  * \brief Get the flags on a page
 849  */
 850 Uint MM_GetFlags(tVAddr VAddr)
 851 {
 852         tTabEnt *ent;
 853         Uint    ret = 0;
 854
 855         // Validity Check
 856         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 857         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 858
 859         ent = &gaPageTable[VAddr >> 12];
 860
 861         // Read-Only
 862         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 863         // Kernel
 864         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 865         // Copy-On-Write
 866         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 867
 868         return ret;
 869 }
 870
 871 /**
 872  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 873  * \brief Duplicates a virtual page to a physical one
 874  */
 875 tPAddr MM_DuplicatePage(tVAddr VAddr)
 876 {
 877         tPAddr  ret;
 878         Uint    temp;
 879          int    wasRO = 0;
 880
 881         //ENTER("xVAddr", VAddr);
 882
 883         // Check if mapped
 884         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 885         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 886
 887         // Page Align
 888         VAddr &= ~0xFFF;
 889
 890         // Allocate new page
 891         ret = MM_AllocPhys();
 892
 893         // Write-lock the page (to keep data constistent), saving its R/W state
 894         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 895         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 896         INVLPG( VAddr );
 897
 898         // Copy Data
 899         temp = MM_MapTemp(ret);
 900         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 901         MM_FreeTemp(temp);
 902
 903         // Restore Writeable status
 904         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 905         INVLPG(VAddr);
 906
 907         //LEAVE('X', ret);
 908         return ret;
 909 }
 910
 911 /**
 912  * \fn Uint MM_MapTemp(tPAddr PAddr)
 913  * \brief Create a temporary memory mapping
 914  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 915  */
 916 tVAddr MM_MapTemp(tPAddr PAddr)
 917 {
 918          int    i;
 919
 920         //ENTER("XPAddr", PAddr);
 921
 922         PAddr &= ~0xFFF;
 923
 924         //LOG("glTempMappings = %i", glTempMappings);
 925
 926         for(;;)
 927         {
 928                 Mutex_Acquire( &glTempMappings );
 929
 930                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 931                 {
 932                         // Check if page used
 933                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 934                         // Mark as used
 935                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 936                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 937                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 938                         Mutex_Release( &glTempMappings );
 939                         return TEMP_MAP_ADDR + (i << 12);
 940                 }
 941                 Mutex_Release( &glTempMappings );
 942                 Threads_Yield();        // TODO: Use a sleep queue here instead
 943         }
 944 }
 945
 946 /**
 947  * \fn void MM_FreeTemp(tVAddr PAddr)
 948  * \brief Free's a temp mapping
 949  */
 950 void MM_FreeTemp(tVAddr VAddr)
 951 {
 952          int    i = VAddr >> 12;
 953         //ENTER("xVAddr", VAddr);
 954
 955         if(i >= (TEMP_MAP_ADDR >> 12))
 956                 gaPageTable[ i ] = 0;
 957
 958         //LEAVE('-');
 959 }
 960
 961 /**
 962  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 963  * \brief Allocates a contigous number of pages
 964  */
 965 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 966 {
 967          int    i, j;
 968
 969         PAddr &= ~0xFFF;
 970
 971         // Scan List
 972         for( i = 0; i < NUM_HW_PAGES; i ++ )
 973         {
 974                 // Check if addr used
 975                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 976                         continue;
 977
 978                 // Check possible region
 979                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 980                 {
 981                         // If there is an allocated page in the region we are testing, break
 982                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 983                 }
 984                 // Is it all free?
 985                 if( j == Number )
 986                 {
 987                         // Allocate
 988                         for( j = 0; j < Number; j++ ) {
 989                                 MM_RefPhys( PAddr + (j<<12) );
 990                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 991                         }
 992                         return HW_MAP_ADDR + (i<<12);
 993                 }
 994         }
 995         // If we don't find any, return NULL
 996         return 0;
 997 }
 998
 999 /**
1000  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1001  * \brief Allocates DMA physical memory
1002  * \param Pages Number of pages required
1003  * \param MaxBits       Maximum number of bits the physical address can have
1004  * \param PhysAddr      Pointer to the location to place the physical address allocated
1005  * \return Virtual address allocate
1006  */
1007 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1008 {
1009         tPAddr  maxCheck = (1 << MaxBits);
1010         tPAddr  phys;
1011         tVAddr  ret;
1012
1013         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
1014
1015         // Sanity Check
1016         if(MaxBits < 12 || !PhysAddr) {
1017                 LEAVE('i', 0);
1018                 return 0;
1019         }
1020
1021         // Bound
1022         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
1023
1024         // Fast Allocate
1025         if(Pages == 1 && MaxBits >= PHYS_BITS)
1026         {
1027                 phys = MM_AllocPhys();
1028                 *PhysAddr = phys;
1029                 ret = MM_MapHWPages(phys, 1);
1030                 if(ret == 0) {
1031                         MM_DerefPhys(phys);
1032                         LEAVE('i', 0);
1033                         return 0;
1034                 }
1035                 LEAVE('x', ret);
1036                 return ret;
1037         }
1038
1039         // Slow Allocate
1040         phys = MM_AllocPhysRange(Pages, MaxBits);
1041         // - Was it allocated?
1042         if(phys == 0) {
1043                 LEAVE('i', 0);
1044                 return 0;
1045         }
1046
1047         // Allocated successfully, now map
1048         ret = MM_MapHWPages(phys, Pages);
1049         if( ret == 0 ) {
1050                 // If it didn't map, free then return 0
1051                 for(;Pages--;phys+=0x1000)
1052                         MM_DerefPhys(phys);
1053                 LEAVE('i', 0);
1054                 return 0;
1055         }
1056
1057         *PhysAddr = phys;
1058         LEAVE('x', ret);
1059         return ret;
1060 }
1061
1062 /**
1063  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1064  * \brief Unmap a hardware page
1065  */
1066 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1067 {
1068          int    i, j;
1069
1070         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1071
1072         // Sanity Check
1073         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1074
1075         i = VAddr >> 12;
1076
1077         Mutex_Acquire( &glTempMappings );       // Temp and HW share a directory, so they share a lock
1078
1079         for( j = 0; j < Number; j++ )
1080         {
1081                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1082                 gaPageTable[ i + j ] = 0;
1083         }
1084
1085         Mutex_Release( &glTempMappings );
1086 }
1087
1088 // --- EXPORTS ---
1089 EXPORT(MM_GetPhysAddr);
1090 EXPORT(MM_Map);
1091 //EXPORT(MM_Unmap);
1092 EXPORT(MM_MapHWPages);
1093 EXPORT(MM_AllocDMA);
1094 EXPORT(MM_UnmapHWPages);