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_GLOBAL       0x80
  59 #define PF_COW          0x200
  60 #define PF_NOPAGE       0x400
  61
  62 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  63
  64 #if USE_PAE
  65 typedef Uint64  tTabEnt;
  66 #else
  67 typedef Uint32  tTabEnt;
  68 #endif
  69
  70 // === IMPORTS ===
  71 extern void     _UsertextEnd, _UsertextBase;
  72 extern Uint32   gaInitPageDir[1024];
  73 extern Uint32   gaInitPageTable[1024];
  74 extern void     Threads_SegFault(tVAddr Addr);
  75 extern void     Error_Backtrace(Uint eip, Uint ebp);
  76
  77 // === PROTOTYPES ===
  78 void    MM_PreinitVirtual(void);
  79 void    MM_InstallVirtual(void);
  80 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  81 void    MM_DumpTables(tVAddr Start, tVAddr End);
  82 tVAddr  MM_ClearUser(void);
  83 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  84
  85 // === GLOBALS ===
  86 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  87 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  88 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  89 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  90 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  91 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  92
  93 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  94 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  95 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  96 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  97 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  98 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  99  int    gbUsePAE = 0;
 100 tMutex  glTempMappings;
 101 tMutex  glTempFractal;
 102 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
 103  int    giLastUsedWorker = 0;
 104
 105 // === CODE ===
 106 /**
 107  * \fn void MM_PreinitVirtual(void)
 108  * \brief Maps the fractal mappings
 109  */
 110 void MM_PreinitVirtual(void)
 111 {
 112         #if USE_PAE
 113         gaInitPageDir[ ((PAGE_TABLE_ADDR >> TAB)-3*512+3)*2 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 114         #else
 115         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 116         #endif
 117         INVLPG( PAGE_TABLE_ADDR );
 118 }
 119
 120 /**
 121  * \fn void MM_InstallVirtual(void)
 122  * \brief Sets up the constant page mappings
 123  */
 124 void MM_InstallVirtual(void)
 125 {
 126          int    i;
 127
 128         #if USE_PAE
 129         // --- Pre-Allocate kernel tables
 130         for( i = KERNEL_BASE >> TAB; i < 1024*4; i ++ )
 131         {
 132                 if( gaPAE_PageDir[ i ] )        continue;
 133
 134                 // Skip stack tables, they are process unique
 135                 if( i > KERNEL_STACKS >> TAB && i < KERNEL_STACKS_END >> TAB) {
 136                         gaPAE_PageDir[ i ] = 0;
 137                         continue;
 138                 }
 139                 // Preallocate table
 140                 gaPAE_PageDir[ i ] = MM_AllocPhys() | 3;
 141                 INVLPG( &gaPAE_PageTable[i*512] );
 142                 memset( &gaPAE_PageTable[i*512], 0, 0x1000 );
 143         }
 144         #else
 145         // --- Pre-Allocate kernel tables
 146         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 147         {
 148                 if( gaPageDir[ i ] )    continue;
 149                 // Skip stack tables, they are process unique
 150                 if( i > KERNEL_STACKS >> 22 && i < KERNEL_STACKS_END >> 22) {
 151                         gaPageDir[ i ] = 0;
 152                         continue;
 153                 }
 154                 // Preallocate table
 155                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 156                 INVLPG( &gaPageTable[i*1024] );
 157                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 158         }
 159         #endif
 160
 161         // Unset kernel on the User Text pages
 162         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 163                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 164         }
 165 }
 166
 167 /**
 168  * \brief Cleans up the SMP required mappings
 169  */
 170 void MM_FinishVirtualInit(void)
 171 {
 172         #if USE_PAE
 173         gaInitPDPT[ 0 ] = 0;
 174         #else
 175         gaInitPageDir[ 0 ] = 0;
 176         #endif
 177 }
 178
 179 /**
 180  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 181  * \brief Called on a page fault
 182  */
 183 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 184 {
 185         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 186
 187         // -- Check for COW --
 188         if( gaPageDir  [Addr>>22] & PF_PRESENT  && 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                 return;
 208         }
 209
 210         // If it was a user, tell the thread handler
 211         if(ErrorCode & 4) {
 212                 Warning("%s %s %s memory%s",
 213                         (ErrorCode&4?"User":"Kernel"),
 214                         (ErrorCode&2?"write to":"read from"),
 215                         (ErrorCode&1?"bad/locked":"non-present"),
 216                         (ErrorCode&16?" (Instruction Fetch)":"")
 217                         );
 218                 Warning("User Pagefault: Instruction at %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 219                 __asm__ __volatile__ ("sti");   // Restart IRQs
 220                 #if 1
 221                 Error_Backtrace(Regs->eip, Regs->ebp);
 222                 #endif
 223                 Threads_SegFault(Addr);
 224                 return ;
 225         }
 226
 227         Debug_KernelPanic();
 228
 229         // -- Check Error Code --
 230         if(ErrorCode & 8)
 231                 Warning("Reserved Bits Trashed!");
 232         else
 233         {
 234                 Warning("%s %s %s memory%s",
 235                         (ErrorCode&4?"User":"Kernel"),
 236                         (ErrorCode&2?"write to":"read from"),
 237                         (ErrorCode&1?"bad/locked":"non-present"),
 238                         (ErrorCode&16?" (Instruction Fetch)":"")
 239                         );
 240         }
 241
 242         Log("Code at %p accessed %p", Regs->eip, Addr);
 243         // Print Stack Backtrace
 244         Error_Backtrace(Regs->eip, Regs->ebp);
 245
 246         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 247         if( gaPageDir[Addr>>22] & PF_PRESENT )
 248                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 249
 250         //MM_DumpTables(0, -1);
 251
 252         // Register Dump
 253         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 254         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 255         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 256         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 257         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 258         {
 259                 Uint    dr0, dr1;
 260                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 261                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 262                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 263         }
 264
 265         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 266 }
 267
 268 /**
 269  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 270  * \brief Dumps the layout of the page tables
 271  */
 272 void MM_DumpTables(tVAddr Start, tVAddr End)
 273 {
 274         tVAddr  rangeStart = 0;
 275         tPAddr  expected = 0;
 276         tVAddr  curPos;
 277         Uint    page;
 278         const tPAddr    MASK = ~0xF78;
 279
 280         Start >>= 12;   End >>= 12;
 281
 282         #if 0
 283         Log("Directory Entries:");
 284         for(page = Start >> 10;
 285                 page < (End >> 10)+1;
 286                 page ++)
 287         {
 288                 if(gaPageDir[page])
 289                 {
 290                         Log(" 0x%08x-0x%08x :: 0x%08x",
 291                                 page<<22, ((page+1)<<22)-1,
 292                                 gaPageDir[page]&~0xFFF
 293                                 );
 294                 }
 295         }
 296         #endif
 297
 298         Log("Table Entries:");
 299         for(page = Start, curPos = Start<<12;
 300                 page < End;
 301                 curPos += 0x1000, page++)
 302         {
 303                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 304                 ||  !(gaPageTable[page] & PF_PRESENT)
 305                 ||  (gaPageTable[page] & MASK) != expected)
 306                 {
 307                         if(expected) {
 308                                 Log(" 0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s)",
 309                                         rangeStart,
 310                                         gaPageTable[rangeStart>>12] & ~0xFFF,
 311                                         curPos - rangeStart,
 312                                         (expected & PF_NOPAGE ? "P" : "-"),
 313                                         (expected & PF_COW ? "C" : "-"),
 314                                         (expected & PF_GLOBAL ? "G" : "-"),
 315                                         (expected & PF_USER ? "U" : "-"),
 316                                         (expected & PF_WRITE ? "W" : "-"),
 317                                         gaPageTable[page] & MASK, expected
 318                                         );
 319                                 expected = 0;
 320                         }
 321                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 322                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 323
 324                         expected = (gaPageTable[page] & MASK);
 325                         rangeStart = curPos;
 326                 }
 327                 if(expected)    expected += 0x1000;
 328         }
 329
 330         if(expected) {
 331                 Log("0x%08x => 0x%08x - 0x%08x (%s%s%s%s)",
 332                         rangeStart,
 333                         gaPageTable[rangeStart>>12] & ~0xFFF,
 334                         curPos - rangeStart,
 335                         (expected & PF_NOPAGE ? "p" : "-"),
 336                         (expected & PF_COW ? "C" : "-"),
 337                         (expected & PF_USER ? "U" : "-"),
 338                         (expected & PF_WRITE ? "W" : "-")
 339                         );
 340                 expected = 0;
 341         }
 342 }
 343
 344 /**
 345  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 346  */
 347 tPAddr MM_Allocate(tVAddr VAddr)
 348 {
 349         tPAddr  paddr;
 350         //ENTER("xVAddr", VAddr);
 351         //__asm__ __volatile__ ("xchg %bx,%bx");
 352         // Check if the directory is mapped
 353         if( gaPageDir[ VAddr >> 22 ] == 0 )
 354         {
 355                 // Allocate directory
 356                 paddr = MM_AllocPhys();
 357                 if( paddr == 0 ) {
 358                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 359                         //LEAVE('i',0);
 360                         return 0;
 361                 }
 362                 // Map and mark as user (if needed)
 363                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 364                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 365
 366                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 367                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 368         }
 369         // Check if the page is already allocated
 370         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 371                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 372                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 373                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 374         }
 375
 376         // Allocate
 377         paddr = MM_AllocPhys();
 378         //LOG("paddr = 0x%llx", paddr);
 379         if( paddr == 0 ) {
 380                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 381                         VAddr, __builtin_return_address(0));
 382                 //LEAVE('i',0);
 383                 return 0;
 384         }
 385         // Map
 386         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 387         // Mark as user
 388         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 389         // Invalidate Cache for address
 390         INVLPG( VAddr & ~0xFFF );
 391
 392         //LEAVE('X', paddr);
 393         return paddr;
 394 }
 395
 396 /**
 397  * \fn void MM_Deallocate(tVAddr VAddr)
 398  */
 399 void MM_Deallocate(tVAddr VAddr)
 400 {
 401         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 402                 Warning("MM_Deallocate - Directory not mapped");
 403                 return;
 404         }
 405
 406         if(gaPageTable[ VAddr >> 12 ] == 0) {
 407                 Warning("MM_Deallocate - Page is not allocated");
 408                 return;
 409         }
 410
 411         // Dereference page
 412         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 413         // Clear page
 414         gaPageTable[ VAddr >> 12 ] = 0;
 415 }
 416
 417 /**
 418  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 419  * \brief Checks if the passed address is accesable
 420  */
 421 tPAddr MM_GetPhysAddr(tVAddr Addr)
 422 {
 423         if( !(gaPageDir[Addr >> 22] & 1) )
 424                 return 0;
 425         if( !(gaPageTable[Addr >> 12] & 1) )
 426                 return 0;
 427         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 428 }
 429
 430 /**
 431  * \fn void MM_SetCR3(Uint CR3)
 432  * \brief Sets the current process space
 433  */
 434 void MM_SetCR3(Uint CR3)
 435 {
 436         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 437 }
 438
 439 /**
 440  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 441  * \brief Map a physical page to a virtual one
 442  */
 443 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 444 {
 445         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 446         // Sanity check
 447         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 448                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 449                 //LEAVE('i', 0);
 450                 return 0;
 451         }
 452
 453         // Align addresses
 454         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 455
 456         // Check if the directory is mapped
 457         if( gaPageDir[ VAddr >> 22 ] == 0 )
 458         {
 459                 gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
 460
 461                 // Mark as user
 462                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 463
 464                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 465                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 466         }
 467         // Check if the page is already allocated
 468         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 469                 Warning("MM_Map - Allocating to used address");
 470                 //LEAVE('i', 0);
 471                 return 0;
 472         }
 473
 474         // Map
 475         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 476         // Mark as user
 477         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 478
 479         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 480         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 481
 482         // Reference
 483         MM_RefPhys( PAddr );
 484
 485         //LOG("INVLPG( 0x%x )", VAddr);
 486         INVLPG( VAddr );
 487
 488         //LEAVE('i', 1);
 489         return 1;
 490 }
 491
 492 /**
 493  * \fn tVAddr MM_ClearUser()
 494  * \brief Clear user's address space
 495  */
 496 tVAddr MM_ClearUser(void)
 497 {
 498         Uint    i, j;
 499
 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                 // Deallocate tables
 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                 // Deallocate directory
 517                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 518                 gaPageDir[i] = 0;
 519                 INVLPG( &gaPageTable[i*1024] );
 520         }
 521         INVLPG( gaPageDir );
 522
 523         return *gpPageCR3;
 524 }
 525
 526 /**
 527  * \fn tPAddr MM_Clone(void)
 528  * \brief Clone the current address space
 529  */
 530 tPAddr MM_Clone(void)
 531 {
 532         Uint    i, j;
 533         tVAddr  ret;
 534         Uint    page = 0;
 535         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 536         void    *tmp;
 537
 538         Mutex_Acquire( &glTempFractal );
 539
 540         // Create Directory Table
 541         *gpTmpCR3 = MM_AllocPhys() | 3;
 542         INVLPG( gaTmpDir );
 543         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 544         memsetd( gaTmpDir, 0, 1024 );
 545
 546         if( Threads_GetPID() != 0 )
 547         {
 548                 // Copy Tables
 549                 for( i = 0; i < 768; i ++)
 550                 {
 551                         // Check if table is allocated
 552                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 553                                 gaTmpDir[i] = 0;
 554                                 page += 1024;
 555                                 continue;
 556                         }
 557
 558                         // Allocate new table
 559                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 560                         INVLPG( &gaTmpTable[page] );
 561                         // Fill
 562                         for( j = 0; j < 1024; j ++, page++ )
 563                         {
 564                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 565                                         gaTmpTable[page] = 0;
 566                                         continue;
 567                                 }
 568
 569                                 // Refrence old page
 570                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 571                                 // Add to new table
 572                                 if(gaPageTable[page] & PF_WRITE) {
 573                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 574                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 575                                         INVLPG( page << 12 );
 576                                 }
 577                                 else
 578                                         gaTmpTable[page] = gaPageTable[page];
 579                         }
 580                 }
 581         }
 582
 583         // Map in kernel tables (and make fractal mapping)
 584         for( i = 768; i < 1024; i ++ )
 585         {
 586                 // Fractal
 587                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 588                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 589                         continue;
 590                 }
 591
 592                 if( gaPageDir[i] == 0 ) {
 593                         gaTmpDir[i] = 0;
 594                         continue;
 595                 }
 596
 597                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 598                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 599                 gaTmpDir[i] = gaPageDir[i];
 600         }
 601
 602         // Allocate kernel stack
 603         for(i = KERNEL_STACKS >> 22;
 604                 i < KERNEL_STACKS_END >> 22;
 605                 i ++ )
 606         {
 607                 // Check if directory is allocated
 608                 if( (gaPageDir[i] & 1) == 0 ) {
 609                         gaTmpDir[i] = 0;
 610                         continue;
 611                 }
 612
 613                 // We don't care about other kernel stacks, just the current one
 614                 if( i != kStackBase >> 22 ) {
 615                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 616                         gaTmpDir[i] = 0;
 617                         continue;
 618                 }
 619
 620                 // Create a copy
 621                 gaTmpDir[i] = MM_AllocPhys() | 3;
 622                 INVLPG( &gaTmpTable[i*1024] );
 623                 for( j = 0; j < 1024; j ++ )
 624                 {
 625                         // Is the page allocated? If not, skip
 626                         if( !(gaPageTable[i*1024+j] & 1) ) {
 627                                 gaTmpTable[i*1024+j] = 0;
 628                                 continue;
 629                         }
 630
 631                         // We don't care about other kernel stacks
 632                         if( ((i*1024+j)*4096 & ~(KERNEL_STACK_SIZE-1)) != kStackBase ) {
 633                                 gaTmpTable[i*1024+j] = 0;
 634                                 continue;
 635                         }
 636
 637                         // Allocate page
 638                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 639
 640                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 641
 642                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 643                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 644                         MM_FreeTemp( (Uint)tmp );
 645                 }
 646         }
 647
 648         ret = *gpTmpCR3 & ~0xFFF;
 649         Mutex_Release( &glTempFractal );
 650
 651         //LEAVE('x', ret);
 652         return ret;
 653 }
 654
 655 /**
 656  * \fn tVAddr MM_NewKStack(void)
 657  * \brief Create a new kernel stack
 658  */
 659 tVAddr MM_NewKStack(void)
 660 {
 661         tVAddr  base;
 662         Uint    i;
 663         for(base = KERNEL_STACKS; base < KERNEL_STACKS_END; base += KERNEL_STACK_SIZE)
 664         {
 665                 // Check if space is free
 666                 if(MM_GetPhysAddr(base) != 0)   continue;
 667                 // Allocate
 668                 //for(i = KERNEL_STACK_SIZE; i -= 0x1000 ; )
 669                 for(i = 0; i < KERNEL_STACK_SIZE; i += 0x1000 )
 670                 {
 671                         if( MM_Allocate(base+i) == 0 )
 672                         {
 673                                 // On error, print a warning and return error
 674                                 Warning("MM_NewKStack - Out of memory");
 675                                 // - Clean up
 676                                 //for( i += 0x1000 ; i < KERNEL_STACK_SIZE; i += 0x1000 )
 677                                 //      MM_Deallocate(base+i);
 678                                 return 0;
 679                         }
 680                 }
 681                 // Success
 682                 Log("MM_NewKStack - Allocated %p", base + KERNEL_STACK_SIZE);
 683                 return base+KERNEL_STACK_SIZE;
 684         }
 685         // No stacks left
 686         Warning("MM_NewKStack - No address space left");
 687         return 0;
 688 }
 689
 690 /**
 691  * \fn tVAddr MM_NewWorkerStack()
 692  * \brief Creates a new worker stack
 693  */
 694 tVAddr MM_NewWorkerStack()
 695 {
 696         Uint    esp, ebp;
 697         Uint    oldstack;
 698         Uint    base, addr;
 699          int    i, j;
 700         Uint    *tmpPage;
 701         tPAddr  pages[WORKER_STACK_SIZE>>12];
 702
 703         // Get the old ESP and EBP
 704         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 705         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 706
 707         // TODO: Thread safety
 708         // Find a free worker stack address
 709         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 710         {
 711                 // Used block
 712                 if( gWorkerStacks[base/32] == -1 ) {
 713                         base += 31;     base &= ~31;
 714                         base --;        // Counteracted by the base++
 715                         continue;
 716                 }
 717                 // Used stack
 718                 if( gWorkerStacks[base/32] & (1 << base) ) {
 719                         continue;
 720                 }
 721                 break;
 722         }
 723         if(base >= NUM_WORKER_STACKS) {
 724                 Warning("Uh-oh! Out of worker stacks");
 725                 return 0;
 726         }
 727
 728         // It's ours now!
 729         gWorkerStacks[base/32] |= (1 << base);
 730         // Make life easier for later calls
 731         giLastUsedWorker = base;
 732         // We have one
 733         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 734         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 735
 736         // Acquire the lock for the temp fractal mappings
 737         Mutex_Acquire(&glTempFractal);
 738
 739         // Set the temp fractals to TID0's address space
 740         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 741         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 742         INVLPG( gaTmpDir );
 743
 744
 745         // Check if the directory is mapped (we are assuming that the stacks
 746         // will fit neatly in a directory)
 747         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 748         if(gaTmpDir[ base >> 22 ] == 0) {
 749                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 750                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 751         }
 752
 753         // Mapping Time!
 754         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 755         //for( addr = WORKER_STACK_SIZE; addr; addr -= 0x1000 )
 756         {
 757                 pages[ addr >> 12 ] = MM_AllocPhys();
 758                 gaTmpTable[ (base + addr) >> 12 ] = pages[addr>>12] | 3;
 759         }
 760         *gpTmpCR3 = 0;
 761         // Release the temp mapping lock
 762         Mutex_Release(&glTempFractal);
 763
 764         // Copy the old stack
 765         oldstack = (esp + KERNEL_STACK_SIZE-1) & ~(KERNEL_STACK_SIZE-1);
 766         esp = oldstack - esp;   // ESP as an offset in the stack
 767
 768         // Make `base` be the top of the stack
 769         base += WORKER_STACK_SIZE;
 770
 771         i = (WORKER_STACK_SIZE>>12) - 1;
 772         // Copy the contents of the old stack to the new one, altering the addresses
 773         // `addr` is refering to bytes from the stack base (mem downwards)
 774         for(addr = 0; addr < esp; addr += 0x1000)
 775         {
 776                 Uint    *stack = (Uint*)( oldstack-(addr+0x1000) );
 777                 tmpPage = (void*)MM_MapTemp( pages[i] );
 778                 // Copy old stack
 779                 for(j = 0; j < 1024; j++)
 780                 {
 781                         // Possible Stack address?
 782                         if(oldstack-esp < stack[j] && stack[j] < oldstack)
 783                                 tmpPage[j] = base - (oldstack - stack[j]);
 784                         else    // Seems not, best leave it alone
 785                                 tmpPage[j] = stack[j];
 786                 }
 787                 MM_FreeTemp((tVAddr)tmpPage);
 788                 i --;
 789         }
 790
 791         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 792         return base;
 793 }
 794
 795 /**
 796  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 797  * \brief Sets the flags on a page
 798  */
 799 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 800 {
 801         tTabEnt *ent;
 802         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 803         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 804
 805         ent = &gaPageTable[VAddr >> 12];
 806
 807         // Read-Only
 808         if( Mask & MM_PFLAG_RO )
 809         {
 810                 if( Flags & MM_PFLAG_RO ) {
 811                         *ent &= ~PF_WRITE;
 812                 }
 813                 else {
 814                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 815                         *ent |= PF_WRITE;
 816                 }
 817         }
 818
 819         // Kernel
 820         if( Mask & MM_PFLAG_KERNEL )
 821         {
 822                 if( Flags & MM_PFLAG_KERNEL ) {
 823                         *ent &= ~PF_USER;
 824                 }
 825                 else {
 826                         gaPageDir[VAddr >> 22] |= PF_USER;
 827                         *ent |= PF_USER;
 828                 }
 829         }
 830
 831         // Copy-On-Write
 832         if( Mask & MM_PFLAG_COW )
 833         {
 834                 if( Flags & MM_PFLAG_COW ) {
 835                         *ent &= ~PF_WRITE;
 836                         *ent |= PF_COW;
 837                 }
 838                 else {
 839                         *ent &= ~PF_COW;
 840                         *ent |= PF_WRITE;
 841                 }
 842         }
 843
 844         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 845         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 846 }
 847
 848 /**
 849  * \brief Get the flags on a page
 850  */
 851 Uint MM_GetFlags(tVAddr VAddr)
 852 {
 853         tTabEnt *ent;
 854         Uint    ret = 0;
 855
 856         // Validity Check
 857         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 858         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 859
 860         ent = &gaPageTable[VAddr >> 12];
 861
 862         // Read-Only
 863         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 864         // Kernel
 865         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 866         // Copy-On-Write
 867         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 868
 869         return ret;
 870 }
 871
 872 /**
 873  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 874  * \brief Duplicates a virtual page to a physical one
 875  */
 876 tPAddr MM_DuplicatePage(tVAddr VAddr)
 877 {
 878         tPAddr  ret;
 879         Uint    temp;
 880          int    wasRO = 0;
 881
 882         //ENTER("xVAddr", VAddr);
 883
 884         // Check if mapped
 885         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 886         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 887
 888         // Page Align
 889         VAddr &= ~0xFFF;
 890
 891         // Allocate new page
 892         ret = MM_AllocPhys();
 893
 894         // Write-lock the page (to keep data constistent), saving its R/W state
 895         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 896         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 897         INVLPG( VAddr );
 898
 899         // Copy Data
 900         temp = MM_MapTemp(ret);
 901         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 902         MM_FreeTemp(temp);
 903
 904         // Restore Writeable status
 905         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 906         INVLPG(VAddr);
 907
 908         //LEAVE('X', ret);
 909         return ret;
 910 }
 911
 912 /**
 913  * \fn Uint MM_MapTemp(tPAddr PAddr)
 914  * \brief Create a temporary memory mapping
 915  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 916  */
 917 tVAddr MM_MapTemp(tPAddr PAddr)
 918 {
 919          int    i;
 920
 921         //ENTER("XPAddr", PAddr);
 922
 923         PAddr &= ~0xFFF;
 924
 925         //LOG("glTempMappings = %i", glTempMappings);
 926
 927         for(;;)
 928         {
 929                 Mutex_Acquire( &glTempMappings );
 930
 931                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 932                 {
 933                         // Check if page used
 934                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 935                         // Mark as used
 936                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 937                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 938                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 939                         Mutex_Release( &glTempMappings );
 940                         return TEMP_MAP_ADDR + (i << 12);
 941                 }
 942                 Mutex_Release( &glTempMappings );
 943                 Threads_Yield();        // TODO: Use a sleep queue here instead
 944         }
 945 }
 946
 947 /**
 948  * \fn void MM_FreeTemp(tVAddr PAddr)
 949  * \brief Free's a temp mapping
 950  */
 951 void MM_FreeTemp(tVAddr VAddr)
 952 {
 953          int    i = VAddr >> 12;
 954         //ENTER("xVAddr", VAddr);
 955
 956         if(i >= (TEMP_MAP_ADDR >> 12))
 957                 gaPageTable[ i ] = 0;
 958
 959         //LEAVE('-');
 960 }
 961
 962 /**
 963  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 964  * \brief Allocates a contigous number of pages
 965  */
 966 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 967 {
 968          int    i, j;
 969
 970         PAddr &= ~0xFFF;
 971
 972         // Scan List
 973         for( i = 0; i < NUM_HW_PAGES; i ++ )
 974         {
 975                 // Check if addr used
 976                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 977                         continue;
 978
 979                 // Check possible region
 980                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 981                 {
 982                         // If there is an allocated page in the region we are testing, break
 983                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 984                 }
 985                 // Is it all free?
 986                 if( j == Number )
 987                 {
 988                         // Allocate
 989                         for( j = 0; j < Number; j++ ) {
 990                                 MM_RefPhys( PAddr + (j<<12) );
 991                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 992                         }
 993                         return HW_MAP_ADDR + (i<<12);
 994                 }
 995         }
 996         // If we don't find any, return NULL
 997         return 0;
 998 }
 999
1000 /**
1001  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1002  * \brief Allocates DMA physical memory
1003  * \param Pages Number of pages required
1004  * \param MaxBits       Maximum number of bits the physical address can have
1005  * \param PhysAddr      Pointer to the location to place the physical address allocated
1006  * \return Virtual address allocate
1007  */
1008 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1009 {
1010         tPAddr  maxCheck = (1 << MaxBits);
1011         tPAddr  phys;
1012         tVAddr  ret;
1013
1014         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
1015
1016         // Sanity Check
1017         if(MaxBits < 12 || !PhysAddr) {
1018                 LEAVE('i', 0);
1019                 return 0;
1020         }
1021
1022         // Bound
1023         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
1024
1025         // Fast Allocate
1026         if(Pages == 1 && MaxBits >= PHYS_BITS)
1027         {
1028                 phys = MM_AllocPhys();
1029                 *PhysAddr = phys;
1030                 ret = MM_MapHWPages(phys, 1);
1031                 if(ret == 0) {
1032                         MM_DerefPhys(phys);
1033                         LEAVE('i', 0);
1034                         return 0;
1035                 }
1036                 LEAVE('x', ret);
1037                 return ret;
1038         }
1039
1040         // Slow Allocate
1041         phys = MM_AllocPhysRange(Pages, MaxBits);
1042         // - Was it allocated?
1043         if(phys == 0) {
1044                 LEAVE('i', 0);
1045                 return 0;
1046         }
1047
1048         // Allocated successfully, now map
1049         ret = MM_MapHWPages(phys, Pages);
1050         if( ret == 0 ) {
1051                 // If it didn't map, free then return 0
1052                 for(;Pages--;phys+=0x1000)
1053                         MM_DerefPhys(phys);
1054                 LEAVE('i', 0);
1055                 return 0;
1056         }
1057
1058         *PhysAddr = phys;
1059         LEAVE('x', ret);
1060         return ret;
1061 }
1062
1063 /**
1064  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1065  * \brief Unmap a hardware page
1066  */
1067 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1068 {
1069          int    i, j;
1070
1071         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1072
1073         // Sanity Check
1074         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1075
1076         i = VAddr >> 12;
1077
1078         Mutex_Acquire( &glTempMappings );       // Temp and HW share a directory, so they share a lock
1079
1080         for( j = 0; j < Number; j++ )
1081         {
1082                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1083                 gaPageTable[ i + j ] = 0;
1084         }
1085
1086         Mutex_Release( &glTempMappings );
1087 }
1088
1089 // --- EXPORTS ---
1090 EXPORT(MM_GetPhysAddr);
1091 EXPORT(MM_Map);
1092 //EXPORT(MM_Unmap);
1093 EXPORT(MM_MapHWPages);
1094 EXPORT(MM_AllocDMA);
1095 EXPORT(MM_UnmapHWPages);