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 #define TAB     22
  20
  21 #define KERNEL_STACKS           0xF0000000
  22 #define KERNEL_STACK_SIZE       0x00008000
  23 #define KERNEL_STACKS_END       0xFC000000
  24 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  25 #define WORKER_STACK_SIZE       KERNEL_STACK_SIZE
  26 #define WORKER_STACKS_END       0xB0000000
  27 #define NUM_WORKER_STACKS       ((WORKER_STACKS_END-WORKER_STACKS)/WORKER_STACK_SIZE)
  28
  29 #define PAE_PAGE_TABLE_ADDR     0xFC000000      // 16 MiB
  30 #define PAE_PAGE_DIR_ADDR       0xFCFC0000      // 16 KiB
  31 #define PAE_PAGE_PDPT_ADDR      0xFCFC3F00      // 32 bytes
  32 #define PAE_TMP_PDPT_ADDR       0xFCFC3F20      // 32 bytes
  33 #define PAE_TMP_DIR_ADDR        0xFCFE0000      // 16 KiB
  34 #define PAE_TMP_TABLE_ADDR      0xFD000000      // 16 MiB
  35
  36 #define PAGE_TABLE_ADDR 0xFC000000
  37 #define PAGE_DIR_ADDR   0xFC3F0000
  38 #define PAGE_CR3_ADDR   0xFC3F0FC0
  39 #define TMP_CR3_ADDR    0xFC3F0FC4      // Part of core instead of temp
  40 #define TMP_DIR_ADDR    0xFC3F1000      // Same
  41 #define TMP_TABLE_ADDR  0xFC400000
  42
  43 #define HW_MAP_ADDR             0xFE000000
  44 #define HW_MAP_MAX              0xFFEF0000
  45 #define NUM_HW_PAGES    ((HW_MAP_MAX-HW_MAP_ADDR)/0x1000)
  46 #define TEMP_MAP_ADDR   0xFFEF0000      // Allows 16 "temp" pages
  47 #define NUM_TEMP_PAGES  16
  48 #define LAST_BLOCK_ADDR 0xFFFF0000      // Free space for kernel provided user code/ *(-1) protection
  49
  50 #define PF_PRESENT      0x1
  51 #define PF_WRITE        0x2
  52 #define PF_USER         0x4
  53 #define PF_GLOBAL       0x80
  54 #define PF_COW          0x200
  55 #define PF_NOPAGE       0x400
  56
  57 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  58
  59 typedef Uint32  tTabEnt;
  60
  61 // === IMPORTS ===
  62 extern void     _UsertextEnd, _UsertextBase;
  63 extern Uint32   gaInitPageDir[1024];
  64 extern Uint32   gaInitPageTable[1024];
  65 extern void     Threads_SegFault(tVAddr Addr);
  66 extern void     Error_Backtrace(Uint eip, Uint ebp);
  67
  68 // === PROTOTYPES ===
  69 void    MM_PreinitVirtual(void);
  70 void    MM_InstallVirtual(void);
  71 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  72 void    MM_DumpTables(tVAddr Start, tVAddr End);
  73 tVAddr  MM_ClearUser(void);
  74 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  75
  76 // === GLOBALS ===
  77 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  78 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  79 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  80 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  81 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  82 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  83
  84 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  85 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  86 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  87 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  88 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  89 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  90  int    gbUsePAE = 0;
  91 tMutex  glTempMappings;
  92 tMutex  glTempFractal;
  93 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
  94  int    giLastUsedWorker = 0;
  95 struct sPageInfo {
  96         void    *Node;
  97         tVAddr  Base;
  98         Uint64  Offset;
  99          int    Length;
 100          int    Flags;
 101 }       *gaMappedRegions;       // sizeof = 24 bytes
 102
 103 // === CODE ===
 104 /**
 105  * \fn void MM_PreinitVirtual(void)
 106  * \brief Maps the fractal mappings
 107  */
 108 void MM_PreinitVirtual(void)
 109 {
 110         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 111         INVLPG( PAGE_TABLE_ADDR );
 112 }
 113
 114 /**
 115  * \fn void MM_InstallVirtual(void)
 116  * \brief Sets up the constant page mappings
 117  */
 118 void MM_InstallVirtual(void)
 119 {
 120          int    i;
 121
 122         // --- Pre-Allocate kernel tables
 123         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 124         {
 125                 if( gaPageDir[ i ] )    continue;
 126                 // Skip stack tables, they are process unique
 127                 if( i > KERNEL_STACKS >> 22 && i < KERNEL_STACKS_END >> 22) {
 128                         gaPageDir[ i ] = 0;
 129                         continue;
 130                 }
 131                 // Preallocate table
 132                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 133                 INVLPG( &gaPageTable[i*1024] );
 134                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 135         }
 136
 137         // Unset kernel on the User Text pages
 138         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 139                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 140         }
 141 }
 142
 143 /**
 144  * \brief Cleans up the SMP required mappings
 145  */
 146 void MM_FinishVirtualInit(void)
 147 {
 148         gaInitPageDir[ 0 ] = 0;
 149 }
 150
 151 /**
 152  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 153  * \brief Called on a page fault
 154  */
 155 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 156 {
 157         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 158
 159         // -- Check for COW --
 160         if( gaPageDir  [Addr>>22] & PF_PRESENT  && gaPageTable[Addr>>12] & PF_PRESENT
 161          && gaPageTable[Addr>>12] & PF_COW )
 162         {
 163                 tPAddr  paddr;
 164                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 165                 {
 166                         gaPageTable[Addr>>12] &= ~PF_COW;
 167                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 168                 }
 169                 else
 170                 {
 171                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 172                         paddr = MM_DuplicatePage( Addr );
 173                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 174                         gaPageTable[Addr>>12] &= PF_USER;
 175                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 176                 }
 177
 178                 INVLPG( Addr & ~0xFFF );
 179                 return;
 180         }
 181
 182         // If it was a user, tell the thread handler
 183         if(ErrorCode & 4) {
 184                 Warning("%s %s %s memory%s",
 185                         (ErrorCode&4?"User":"Kernel"),
 186                         (ErrorCode&2?"write to":"read from"),
 187                         (ErrorCode&1?"bad/locked":"non-present"),
 188                         (ErrorCode&16?" (Instruction Fetch)":"")
 189                         );
 190                 Warning("User Pagefault: Instruction at %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 191                 __asm__ __volatile__ ("sti");   // Restart IRQs
 192                 #if 1
 193                 Error_Backtrace(Regs->eip, Regs->ebp);
 194                 #endif
 195                 Threads_SegFault(Addr);
 196                 return ;
 197         }
 198
 199         Debug_KernelPanic();
 200
 201         // -- Check Error Code --
 202         if(ErrorCode & 8)
 203                 Warning("Reserved Bits Trashed!");
 204         else
 205         {
 206                 Warning("%s %s %s memory%s",
 207                         (ErrorCode&4?"User":"Kernel"),
 208                         (ErrorCode&2?"write to":"read from"),
 209                         (ErrorCode&1?"bad/locked":"non-present"),
 210                         (ErrorCode&16?" (Instruction Fetch)":"")
 211                         );
 212         }
 213
 214         Log("Code at %p accessed %p", Regs->eip, Addr);
 215         // Print Stack Backtrace
 216         Error_Backtrace(Regs->eip, Regs->ebp);
 217
 218         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 219         if( gaPageDir[Addr>>22] & PF_PRESENT )
 220                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 221
 222         //MM_DumpTables(0, -1);
 223
 224         // Register Dump
 225         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 226         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 227         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 228         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 229         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 230         {
 231                 Uint    dr0, dr1;
 232                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 233                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 234                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 235         }
 236
 237         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 238 }
 239
 240 /**
 241  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 242  * \brief Dumps the layout of the page tables
 243  */
 244 void MM_DumpTables(tVAddr Start, tVAddr End)
 245 {
 246         tVAddr  rangeStart = 0;
 247         tPAddr  expected = 0;
 248         tVAddr  curPos;
 249         Uint    page;
 250         const tPAddr    MASK = ~0xF78;
 251
 252         Start >>= 12;   End >>= 12;
 253
 254         #if 0
 255         Log("Directory Entries:");
 256         for(page = Start >> 10;
 257                 page < (End >> 10)+1;
 258                 page ++)
 259         {
 260                 if(gaPageDir[page])
 261                 {
 262                         Log(" 0x%08x-0x%08x :: 0x%08x",
 263                                 page<<22, ((page+1)<<22)-1,
 264                                 gaPageDir[page]&~0xFFF
 265                                 );
 266                 }
 267         }
 268         #endif
 269
 270         Log("Table Entries:");
 271         for(page = Start, curPos = Start<<12;
 272                 page < End;
 273                 curPos += 0x1000, page++)
 274         {
 275                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 276                 ||  !(gaPageTable[page] & PF_PRESENT)
 277                 ||  (gaPageTable[page] & MASK) != expected)
 278                 {
 279                         if(expected) {
 280                                 Log(" 0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s)",
 281                                         rangeStart,
 282                                         gaPageTable[rangeStart>>12] & ~0xFFF,
 283                                         curPos - rangeStart,
 284                                         (expected & PF_NOPAGE ? "P" : "-"),
 285                                         (expected & PF_COW ? "C" : "-"),
 286                                         (expected & PF_GLOBAL ? "G" : "-"),
 287                                         (expected & PF_USER ? "U" : "-"),
 288                                         (expected & PF_WRITE ? "W" : "-")
 289                                         );
 290                                 expected = 0;
 291                         }
 292                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 293                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 294
 295                         expected = (gaPageTable[page] & MASK);
 296                         rangeStart = curPos;
 297                 }
 298                 if(expected)    expected += 0x1000;
 299         }
 300
 301         if(expected) {
 302                 Log("0x%08x => 0x%08x - 0x%08x (%s%s%s%s)",
 303                         rangeStart,
 304                         gaPageTable[rangeStart>>12] & ~0xFFF,
 305                         curPos - rangeStart,
 306                         (expected & PF_NOPAGE ? "p" : "-"),
 307                         (expected & PF_COW ? "C" : "-"),
 308                         (expected & PF_USER ? "U" : "-"),
 309                         (expected & PF_WRITE ? "W" : "-")
 310                         );
 311                 expected = 0;
 312         }
 313 }
 314
 315 /**
 316  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 317  */
 318 tPAddr MM_Allocate(tVAddr VAddr)
 319 {
 320         tPAddr  paddr;
 321         //ENTER("xVAddr", VAddr);
 322         //__asm__ __volatile__ ("xchg %bx,%bx");
 323         // Check if the directory is mapped
 324         if( gaPageDir[ VAddr >> 22 ] == 0 )
 325         {
 326                 // Allocate directory
 327                 paddr = MM_AllocPhys();
 328                 if( paddr == 0 ) {
 329                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 330                         //LEAVE('i',0);
 331                         return 0;
 332                 }
 333                 // Map and mark as user (if needed)
 334                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 335                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 336
 337                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 338                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 339         }
 340         // Check if the page is already allocated
 341         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 342                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 343                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 344                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 345         }
 346
 347         // Allocate
 348         paddr = MM_AllocPhys();
 349         //LOG("paddr = 0x%llx", paddr);
 350         if( paddr == 0 ) {
 351                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 352                         VAddr, __builtin_return_address(0));
 353                 //LEAVE('i',0);
 354                 return 0;
 355         }
 356         // Map
 357         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 358         // Mark as user
 359         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 360         // Invalidate Cache for address
 361         INVLPG( VAddr & ~0xFFF );
 362
 363         //LEAVE('X', paddr);
 364         return paddr;
 365 }
 366
 367 /**
 368  * \fn void MM_Deallocate(tVAddr VAddr)
 369  */
 370 void MM_Deallocate(tVAddr VAddr)
 371 {
 372         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 373                 Warning("MM_Deallocate - Directory not mapped");
 374                 return;
 375         }
 376
 377         if(gaPageTable[ VAddr >> 12 ] == 0) {
 378                 Warning("MM_Deallocate - Page is not allocated");
 379                 return;
 380         }
 381
 382         // Dereference page
 383         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 384         // Clear page
 385         gaPageTable[ VAddr >> 12 ] = 0;
 386 }
 387
 388 /**
 389  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 390  * \brief Checks if the passed address is accesable
 391  */
 392 tPAddr MM_GetPhysAddr(tVAddr Addr)
 393 {
 394         if( !(gaPageDir[Addr >> 22] & 1) )
 395                 return 0;
 396         if( !(gaPageTable[Addr >> 12] & 1) )
 397                 return 0;
 398         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 399 }
 400
 401 /**
 402  * \fn void MM_SetCR3(Uint CR3)
 403  * \brief Sets the current process space
 404  */
 405 void MM_SetCR3(Uint CR3)
 406 {
 407         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 408 }
 409
 410 /**
 411  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 412  * \brief Map a physical page to a virtual one
 413  */
 414 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 415 {
 416         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 417         // Sanity check
 418         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 419                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 420                 //LEAVE('i', 0);
 421                 return 0;
 422         }
 423
 424         // Align addresses
 425         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 426
 427         // Check if the directory is mapped
 428         if( gaPageDir[ VAddr >> 22 ] == 0 )
 429         {
 430                 gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
 431
 432                 // Mark as user
 433                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 434
 435                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 436                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 437         }
 438         // Check if the page is already allocated
 439         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 440                 Warning("MM_Map - Allocating to used address");
 441                 //LEAVE('i', 0);
 442                 return 0;
 443         }
 444
 445         // Map
 446         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 447         // Mark as user
 448         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 449
 450         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 451         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 452
 453         // Reference
 454         MM_RefPhys( PAddr );
 455
 456         //LOG("INVLPG( 0x%x )", VAddr);
 457         INVLPG( VAddr );
 458
 459         //LEAVE('i', 1);
 460         return 1;
 461 }
 462
 463 /**
 464  * \fn tVAddr MM_ClearUser()
 465  * \brief Clear user's address space
 466  */
 467 tVAddr MM_ClearUser(void)
 468 {
 469         Uint    i, j;
 470
 471         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 472         {
 473                 // Check if directory is not allocated
 474                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 475                         gaPageDir[i] = 0;
 476                         continue;
 477                 }
 478
 479                 // Deallocate tables
 480                 for( j = 0; j < 1024; j ++ )
 481                 {
 482                         if( gaPageTable[i*1024+j] & 1 )
 483                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 484                         gaPageTable[i*1024+j] = 0;
 485                 }
 486
 487                 // Deallocate directory
 488                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 489                 gaPageDir[i] = 0;
 490                 INVLPG( &gaPageTable[i*1024] );
 491         }
 492         INVLPG( gaPageDir );
 493
 494         return *gpPageCR3;
 495 }
 496
 497 /**
 498  * \fn tPAddr MM_Clone(void)
 499  * \brief Clone the current address space
 500  */
 501 tPAddr MM_Clone(void)
 502 {
 503         Uint    i, j;
 504         tVAddr  ret;
 505         Uint    page = 0;
 506         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE;
 507         void    *tmp;
 508
 509         Mutex_Acquire( &glTempFractal );
 510
 511         // Create Directory Table
 512         *gpTmpCR3 = MM_AllocPhys() | 3;
 513         INVLPG( gaTmpDir );
 514         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 515         memsetd( gaTmpDir, 0, 1024 );
 516
 517         if( Threads_GetPID() != 0 )
 518         {
 519                 // Copy Tables
 520                 for( i = 0; i < 768; i ++)
 521                 {
 522                         // Check if table is allocated
 523                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 524                                 gaTmpDir[i] = 0;
 525                                 page += 1024;
 526                                 continue;
 527                         }
 528
 529                         // Allocate new table
 530                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 531                         INVLPG( &gaTmpTable[page] );
 532                         // Fill
 533                         for( j = 0; j < 1024; j ++, page++ )
 534                         {
 535                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 536                                         gaTmpTable[page] = 0;
 537                                         continue;
 538                                 }
 539
 540                                 // Refrence old page
 541                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 542                                 // Add to new table
 543                                 if(gaPageTable[page] & PF_WRITE) {
 544                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 545                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 546                                         INVLPG( page << 12 );
 547                                 }
 548                                 else
 549                                         gaTmpTable[page] = gaPageTable[page];
 550                         }
 551                 }
 552         }
 553
 554         // Map in kernel tables (and make fractal mapping)
 555         for( i = 768; i < 1024; i ++ )
 556         {
 557                 // Fractal
 558                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 559                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 560                         continue;
 561                 }
 562
 563                 if( gaPageDir[i] == 0 ) {
 564                         gaTmpDir[i] = 0;
 565                         continue;
 566                 }
 567
 568                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 569                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 570                 gaTmpDir[i] = gaPageDir[i];
 571         }
 572
 573         // Allocate kernel stack
 574         for(i = KERNEL_STACKS >> 22;
 575                 i < KERNEL_STACKS_END >> 22;
 576                 i ++ )
 577         {
 578                 // Check if directory is allocated
 579                 if( (gaPageDir[i] & 1) == 0 ) {
 580                         gaTmpDir[i] = 0;
 581                         continue;
 582                 }
 583
 584                 // We don't care about other kernel stacks, just the current one
 585                 if( i != kStackBase >> 22 ) {
 586                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 587                         gaTmpDir[i] = 0;
 588                         continue;
 589                 }
 590
 591                 // Create a copy
 592                 gaTmpDir[i] = MM_AllocPhys() | 3;
 593                 INVLPG( &gaTmpTable[i*1024] );
 594                 for( j = 0; j < 1024; j ++ )
 595                 {
 596                         // Is the page allocated? If not, skip
 597                         if( !(gaPageTable[i*1024+j] & 1) ) {
 598                                 gaTmpTable[i*1024+j] = 0;
 599                                 continue;
 600                         }
 601
 602                         // We don't care about other kernel stacks
 603                         if( ((i*1024+j)*4096 & ~(KERNEL_STACK_SIZE-1)) != kStackBase ) {
 604                                 gaTmpTable[i*1024+j] = 0;
 605                                 continue;
 606                         }
 607
 608                         // Allocate page
 609                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 610
 611                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 612
 613                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 614                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 615                         MM_FreeTemp( (Uint)tmp );
 616                 }
 617         }
 618
 619         ret = *gpTmpCR3 & ~0xFFF;
 620         Mutex_Release( &glTempFractal );
 621
 622         //LEAVE('x', ret);
 623         return ret;
 624 }
 625
 626 /**
 627  * \fn tVAddr MM_NewKStack(void)
 628  * \brief Create a new kernel stack
 629  */
 630 tVAddr MM_NewKStack(void)
 631 {
 632         tVAddr  base;
 633         Uint    i;
 634         for(base = KERNEL_STACKS; base < KERNEL_STACKS_END; base += KERNEL_STACK_SIZE)
 635         {
 636                 // Check if space is free
 637                 if(MM_GetPhysAddr(base) != 0)   continue;
 638                 // Allocate
 639                 //for(i = KERNEL_STACK_SIZE; i -= 0x1000 ; )
 640                 for(i = 0; i < KERNEL_STACK_SIZE; i += 0x1000 )
 641                 {
 642                         if( MM_Allocate(base+i) == 0 )
 643                         {
 644                                 // On error, print a warning and return error
 645                                 Warning("MM_NewKStack - Out of memory");
 646                                 // - Clean up
 647                                 //for( i += 0x1000 ; i < KERNEL_STACK_SIZE; i += 0x1000 )
 648                                 //      MM_Deallocate(base+i);
 649                                 return 0;
 650                         }
 651                 }
 652                 // Success
 653                 Log("MM_NewKStack - Allocated %p", base + KERNEL_STACK_SIZE);
 654                 return base+KERNEL_STACK_SIZE;
 655         }
 656         // No stacks left
 657         Warning("MM_NewKStack - No address space left");
 658         return 0;
 659 }
 660
 661 /**
 662  * \fn tVAddr MM_NewWorkerStack()
 663  * \brief Creates a new worker stack
 664  */
 665 tVAddr MM_NewWorkerStack()
 666 {
 667         Uint    esp, ebp;
 668         Uint    oldstack;
 669         Uint    base, addr;
 670          int    i, j;
 671         Uint    *tmpPage;
 672         tPAddr  pages[WORKER_STACK_SIZE>>12];
 673
 674         // Get the old ESP and EBP
 675         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 676         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 677
 678         // TODO: Thread safety
 679         // Find a free worker stack address
 680         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 681         {
 682                 // Used block
 683                 if( gWorkerStacks[base/32] == -1 ) {
 684                         base += 31;     base &= ~31;
 685                         base --;        // Counteracted by the base++
 686                         continue;
 687                 }
 688                 // Used stack
 689                 if( gWorkerStacks[base/32] & (1 << base) ) {
 690                         continue;
 691                 }
 692                 break;
 693         }
 694         if(base >= NUM_WORKER_STACKS) {
 695                 Warning("Uh-oh! Out of worker stacks");
 696                 return 0;
 697         }
 698
 699         // It's ours now!
 700         gWorkerStacks[base/32] |= (1 << base);
 701         // Make life easier for later calls
 702         giLastUsedWorker = base;
 703         // We have one
 704         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 705         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 706
 707         // Acquire the lock for the temp fractal mappings
 708         Mutex_Acquire(&glTempFractal);
 709
 710         // Set the temp fractals to TID0's address space
 711         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 712         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 713         INVLPG( gaTmpDir );
 714
 715
 716         // Check if the directory is mapped (we are assuming that the stacks
 717         // will fit neatly in a directory)
 718         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 719         if(gaTmpDir[ base >> 22 ] == 0) {
 720                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 721                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 722         }
 723
 724         // Mapping Time!
 725         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 726         //for( addr = WORKER_STACK_SIZE; addr; addr -= 0x1000 )
 727         {
 728                 pages[ addr >> 12 ] = MM_AllocPhys();
 729                 gaTmpTable[ (base + addr) >> 12 ] = pages[addr>>12] | 3;
 730         }
 731         *gpTmpCR3 = 0;
 732         // Release the temp mapping lock
 733         Mutex_Release(&glTempFractal);
 734
 735         // Copy the old stack
 736         oldstack = (esp + KERNEL_STACK_SIZE-1) & ~(KERNEL_STACK_SIZE-1);
 737         esp = oldstack - esp;   // ESP as an offset in the stack
 738
 739         // Make `base` be the top of the stack
 740         base += WORKER_STACK_SIZE;
 741
 742         i = (WORKER_STACK_SIZE>>12) - 1;
 743         // Copy the contents of the old stack to the new one, altering the addresses
 744         // `addr` is refering to bytes from the stack base (mem downwards)
 745         for(addr = 0; addr < esp; addr += 0x1000)
 746         {
 747                 Uint    *stack = (Uint*)( oldstack-(addr+0x1000) );
 748                 tmpPage = (void*)MM_MapTemp( pages[i] );
 749                 // Copy old stack
 750                 for(j = 0; j < 1024; j++)
 751                 {
 752                         // Possible Stack address?
 753                         if(oldstack-esp < stack[j] && stack[j] < oldstack)
 754                                 tmpPage[j] = base - (oldstack - stack[j]);
 755                         else    // Seems not, best leave it alone
 756                                 tmpPage[j] = stack[j];
 757                 }
 758                 MM_FreeTemp((tVAddr)tmpPage);
 759                 i --;
 760         }
 761
 762         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 763         return base;
 764 }
 765
 766 /**
 767  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 768  * \brief Sets the flags on a page
 769  */
 770 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 771 {
 772         tTabEnt *ent;
 773         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 774         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 775
 776         ent = &gaPageTable[VAddr >> 12];
 777
 778         // Read-Only
 779         if( Mask & MM_PFLAG_RO )
 780         {
 781                 if( Flags & MM_PFLAG_RO ) {
 782                         *ent &= ~PF_WRITE;
 783                 }
 784                 else {
 785                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 786                         *ent |= PF_WRITE;
 787                 }
 788         }
 789
 790         // Kernel
 791         if( Mask & MM_PFLAG_KERNEL )
 792         {
 793                 if( Flags & MM_PFLAG_KERNEL ) {
 794                         *ent &= ~PF_USER;
 795                 }
 796                 else {
 797                         gaPageDir[VAddr >> 22] |= PF_USER;
 798                         *ent |= PF_USER;
 799                 }
 800         }
 801
 802         // Copy-On-Write
 803         if( Mask & MM_PFLAG_COW )
 804         {
 805                 if( Flags & MM_PFLAG_COW ) {
 806                         *ent &= ~PF_WRITE;
 807                         *ent |= PF_COW;
 808                 }
 809                 else {
 810                         *ent &= ~PF_COW;
 811                         *ent |= PF_WRITE;
 812                 }
 813         }
 814
 815         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 816         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 817 }
 818
 819 /**
 820  * \brief Get the flags on a page
 821  */
 822 Uint MM_GetFlags(tVAddr VAddr)
 823 {
 824         tTabEnt *ent;
 825         Uint    ret = 0;
 826
 827         // Validity Check
 828         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 829         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 830
 831         ent = &gaPageTable[VAddr >> 12];
 832
 833         // Read-Only
 834         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 835         // Kernel
 836         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 837         // Copy-On-Write
 838         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 839
 840         return ret;
 841 }
 842
 843 /**
 844  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 845  * \brief Duplicates a virtual page to a physical one
 846  */
 847 tPAddr MM_DuplicatePage(tVAddr VAddr)
 848 {
 849         tPAddr  ret;
 850         Uint    temp;
 851          int    wasRO = 0;
 852
 853         //ENTER("xVAddr", VAddr);
 854
 855         // Check if mapped
 856         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 857         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 858
 859         // Page Align
 860         VAddr &= ~0xFFF;
 861
 862         // Allocate new page
 863         ret = MM_AllocPhys();
 864
 865         // Write-lock the page (to keep data constistent), saving its R/W state
 866         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 867         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 868         INVLPG( VAddr );
 869
 870         // Copy Data
 871         temp = MM_MapTemp(ret);
 872         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 873         MM_FreeTemp(temp);
 874
 875         // Restore Writeable status
 876         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 877         INVLPG(VAddr);
 878
 879         //LEAVE('X', ret);
 880         return ret;
 881 }
 882
 883 /**
 884  * \fn Uint MM_MapTemp(tPAddr PAddr)
 885  * \brief Create a temporary memory mapping
 886  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 887  */
 888 tVAddr MM_MapTemp(tPAddr PAddr)
 889 {
 890          int    i;
 891
 892         //ENTER("XPAddr", PAddr);
 893
 894         PAddr &= ~0xFFF;
 895
 896         //LOG("glTempMappings = %i", glTempMappings);
 897
 898         for(;;)
 899         {
 900                 Mutex_Acquire( &glTempMappings );
 901
 902                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 903                 {
 904                         // Check if page used
 905                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 906                         // Mark as used
 907                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 908                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 909                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 910                         Mutex_Release( &glTempMappings );
 911                         return TEMP_MAP_ADDR + (i << 12);
 912                 }
 913                 Mutex_Release( &glTempMappings );
 914                 Threads_Yield();        // TODO: Use a sleep queue here instead
 915         }
 916 }
 917
 918 /**
 919  * \fn void MM_FreeTemp(tVAddr PAddr)
 920  * \brief Free's a temp mapping
 921  */
 922 void MM_FreeTemp(tVAddr VAddr)
 923 {
 924          int    i = VAddr >> 12;
 925         //ENTER("xVAddr", VAddr);
 926
 927         if(i >= (TEMP_MAP_ADDR >> 12))
 928                 gaPageTable[ i ] = 0;
 929
 930         //LEAVE('-');
 931 }
 932
 933 /**
 934  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 935  * \brief Allocates a contigous number of pages
 936  */
 937 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 938 {
 939          int    i, j;
 940
 941         PAddr &= ~0xFFF;
 942
 943         // Scan List
 944         for( i = 0; i < NUM_HW_PAGES; i ++ )
 945         {
 946                 // Check if addr used
 947                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 948                         continue;
 949
 950                 // Check possible region
 951                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 952                 {
 953                         // If there is an allocated page in the region we are testing, break
 954                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 955                 }
 956                 // Is it all free?
 957                 if( j == Number )
 958                 {
 959                         // Allocate
 960                         for( j = 0; j < Number; j++ ) {
 961                                 MM_RefPhys( PAddr + (j<<12) );
 962                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 963                         }
 964                         return HW_MAP_ADDR + (i<<12);
 965                 }
 966         }
 967         // If we don't find any, return NULL
 968         return 0;
 969 }
 970
 971 /**
 972  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 973  * \brief Allocates DMA physical memory
 974  * \param Pages Number of pages required
 975  * \param MaxBits       Maximum number of bits the physical address can have
 976  * \param PhysAddr      Pointer to the location to place the physical address allocated
 977  * \return Virtual address allocate
 978  */
 979 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 980 {
 981         tPAddr  maxCheck = (1 << MaxBits);
 982         tPAddr  phys;
 983         tVAddr  ret;
 984
 985         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
 986
 987         // Sanity Check
 988         if(MaxBits < 12 || !PhysAddr) {
 989                 LEAVE('i', 0);
 990                 return 0;
 991         }
 992
 993         // Bound
 994         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
 995
 996         // Fast Allocate
 997         if(Pages == 1 && MaxBits >= PHYS_BITS)
 998         {
 999                 phys = MM_AllocPhys();
1000                 *PhysAddr = phys;
1001                 ret = MM_MapHWPages(phys, 1);
1002                 if(ret == 0) {
1003                         MM_DerefPhys(phys);
1004                         LEAVE('i', 0);
1005                         return 0;
1006                 }
1007                 LEAVE('x', ret);
1008                 return ret;
1009         }
1010
1011         // Slow Allocate
1012         phys = MM_AllocPhysRange(Pages, MaxBits);
1013         // - Was it allocated?
1014         if(phys == 0) {
1015                 LEAVE('i', 0);
1016                 return 0;
1017         }
1018
1019         // Allocated successfully, now map
1020         ret = MM_MapHWPages(phys, Pages);
1021         if( ret == 0 ) {
1022                 // If it didn't map, free then return 0
1023                 for(;Pages--;phys+=0x1000)
1024                         MM_DerefPhys(phys);
1025                 LEAVE('i', 0);
1026                 return 0;
1027         }
1028
1029         *PhysAddr = phys;
1030         LEAVE('x', ret);
1031         return ret;
1032 }
1033
1034 /**
1035  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1036  * \brief Unmap a hardware page
1037  */
1038 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1039 {
1040          int    i, j;
1041
1042         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1043
1044         // Sanity Check
1045         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1046
1047         i = VAddr >> 12;
1048
1049         Mutex_Acquire( &glTempMappings );       // Temp and HW share a directory, so they share a lock
1050
1051         for( j = 0; j < Number; j++ )
1052         {
1053                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1054                 gaPageTable[ i + j ] = 0;
1055         }
1056
1057         Mutex_Release( &glTempMappings );
1058 }
1059