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 #include <hal_proc.h>
  19
  20 #define TAB     22
  21
  22 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  23 #define WORKER_STACK_SIZE       MM_KERNEL_STACK_SIZE
  24 #define WORKER_STACKS_END       0xB0000000
  25 #define NUM_WORKER_STACKS       ((WORKER_STACKS_END-WORKER_STACKS)/WORKER_STACK_SIZE)
  26
  27 #define PAE_PAGE_TABLE_ADDR     0xFC000000      // 16 MiB
  28 #define PAE_PAGE_DIR_ADDR       0xFCFC0000      // 16 KiB
  29 #define PAE_PAGE_PDPT_ADDR      0xFCFC3F00      // 32 bytes
  30 #define PAE_TMP_PDPT_ADDR       0xFCFC3F20      // 32 bytes
  31 #define PAE_TMP_DIR_ADDR        0xFCFE0000      // 16 KiB
  32 #define PAE_TMP_TABLE_ADDR      0xFD000000      // 16 MiB
  33
  34 #define PAGE_TABLE_ADDR 0xFC000000
  35 #define PAGE_DIR_ADDR   0xFC3F0000
  36 #define PAGE_CR3_ADDR   0xFC3F0FC0
  37 #define TMP_CR3_ADDR    0xFC3F0FC4      // Part of core instead of temp
  38 #define TMP_DIR_ADDR    0xFC3F1000      // Same
  39 #define TMP_TABLE_ADDR  0xFC400000
  40
  41 #define HW_MAP_ADDR             0xFE000000
  42 #define HW_MAP_MAX              0xFFEF0000
  43 #define NUM_HW_PAGES    ((HW_MAP_MAX-HW_MAP_ADDR)/0x1000)
  44 #define TEMP_MAP_ADDR   0xFFEF0000      // Allows 16 "temp" pages
  45 #define NUM_TEMP_PAGES  16
  46 #define LAST_BLOCK_ADDR 0xFFFF0000      // Free space for kernel provided user code/ *(-1) protection
  47
  48 #define PF_PRESENT      0x1
  49 #define PF_WRITE        0x2
  50 #define PF_USER         0x4
  51 #define PF_GLOBAL       0x80
  52 #define PF_COW          0x200
  53 #define PF_NOPAGE       0x400
  54
  55 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  56
  57 typedef Uint32  tTabEnt;
  58
  59 // === IMPORTS ===
  60 extern char     _UsertextEnd[], _UsertextBase[];
  61 extern Uint32   gaInitPageDir[1024];
  62 extern Uint32   gaInitPageTable[1024];
  63 extern void     Threads_SegFault(tVAddr Addr);
  64 extern void     Error_Backtrace(Uint eip, Uint ebp);
  65
  66 // === PROTOTYPES ===
  67 void    MM_PreinitVirtual(void);
  68 void    MM_InstallVirtual(void);
  69 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  70 //void  MM_DumpTables(tVAddr Start, tVAddr End);
  71 //void  MM_ClearUser(void);
  72 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  73
  74 // === GLOBALS ===
  75 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  76 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  77 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  78 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  79 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  80 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  81
  82 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  83 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  84 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  85 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  86 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  87 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  88  int    gbUsePAE = 0;
  89 tMutex  glTempMappings;
  90 tMutex  glTempFractal;
  91 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
  92  int    giLastUsedWorker = 0;
  93 struct sPageInfo {
  94         void    *Node;
  95         tVAddr  Base;
  96         Uint64  Offset;
  97          int    Length;
  98          int    Flags;
  99 }       *gaMappedRegions;       // sizeof = 24 bytes
 100
 101 // === CODE ===
 102 /**
 103  * \fn void MM_PreinitVirtual(void)
 104  * \brief Maps the fractal mappings
 105  */
 106 void MM_PreinitVirtual(void)
 107 {
 108         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 109         INVLPG( PAGE_TABLE_ADDR );
 110 }
 111
 112 /**
 113  * \fn void MM_InstallVirtual(void)
 114  * \brief Sets up the constant page mappings
 115  */
 116 void MM_InstallVirtual(void)
 117 {
 118          int    i;
 119
 120         // --- Pre-Allocate kernel tables
 121         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 122         {
 123                 if( gaPageDir[ i ] )    continue;
 124                 // Skip stack tables, they are process unique
 125                 if( i > MM_KERNEL_STACKS >> 22 && i < MM_KERNEL_STACKS_END >> 22) {
 126                         gaPageDir[ i ] = 0;
 127                         continue;
 128                 }
 129                 // Preallocate table
 130                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 131                 INVLPG( &gaPageTable[i*1024] );
 132                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 133         }
 134
 135         // Unset kernel on the User Text pages
 136         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 137                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 138         }
 139 }
 140
 141 /**
 142  * \brief Cleans up the SMP required mappings
 143  */
 144 void MM_FinishVirtualInit(void)
 145 {
 146         gaInitPageDir[ 0 ] = 0;
 147 }
 148
 149 /**
 150  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 151  * \brief Called on a page fault
 152  */
 153 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 154 {
 155         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 156
 157         // -- Check for COW --
 158         if( gaPageDir  [Addr>>22] & PF_PRESENT  && gaPageTable[Addr>>12] & PF_PRESENT
 159          && gaPageTable[Addr>>12] & PF_COW )
 160         {
 161                 tPAddr  paddr;
 162                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 163                 {
 164                         gaPageTable[Addr>>12] &= ~PF_COW;
 165                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 166                 }
 167                 else
 168                 {
 169                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 170                         paddr = MM_DuplicatePage( Addr );
 171                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 172                         gaPageTable[Addr>>12] &= PF_USER;
 173                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 174                 }
 175
 176 //              Log_Debug("MMVirt", "COW for %p (%P)", Addr, gaPageTable[Addr>>12]);
 177
 178                 INVLPG( Addr & ~0xFFF );
 179                 return;
 180         }
 181
 182         __asm__ __volatile__ ("pushf; andw $0xFEFF, 0(%esp); popf");
 183         Proc_GetCurThread()->bInstrTrace = 0;
 184
 185         // If it was a user, tell the thread handler
 186         if(ErrorCode & 4) {
 187                 Log_Warning("MMVirt", "User %s %s memory%s",
 188                         (ErrorCode&2?"write to":"read from"),
 189                         (ErrorCode&1?"bad/locked":"non-present"),
 190                         (ErrorCode&16?" (Instruction Fetch)":"")
 191                         );
 192                 Log_Warning("MMVirt", "Instruction %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 193                 __asm__ __volatile__ ("sti");   // Restart IRQs
 194                 #if 1
 195                 Error_Backtrace(Regs->eip, Regs->ebp);
 196                 #endif
 197                 Threads_SegFault(Addr);
 198                 return ;
 199         }
 200
 201         Debug_KernelPanic();
 202
 203         // -- Check Error Code --
 204         if(ErrorCode & 8)
 205                 Warning("Reserved Bits Trashed!");
 206         else
 207         {
 208                 Warning("Kernel %s %s memory%s",
 209                         (ErrorCode&2?"write to":"read from"),
 210                         (ErrorCode&1?"bad/locked":"non-present"),
 211                         (ErrorCode&16?" (Instruction Fetch)":"")
 212                         );
 213         }
 214
 215         Log("CPU %i - Code at %p accessed %p", GetCPUNum(), Regs->eip, Addr);
 216         // Print Stack Backtrace
 217         Error_Backtrace(Regs->eip, Regs->ebp);
 218
 219         #if 0
 220         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 221         if( gaPageDir[Addr>>22] & PF_PRESENT )
 222                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 223         #endif
 224         //MM_DumpTables(0, -1);
 225
 226         // Register Dump
 227         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 228         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 229         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 230         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 231         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 232         {
 233                 Uint    dr0, dr1;
 234                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 235                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 236                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 237         }
 238
 239         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 240 }
 241
 242 /**
 243  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 244  * \brief Dumps the layout of the page tables
 245  */
 246 void MM_DumpTables(tVAddr Start, tVAddr End)
 247 {
 248         tVAddr  rangeStart = 0;
 249         tPAddr  expected = 0;
 250         void    *expected_node = NULL, *tmpnode = NULL;
 251         tVAddr  curPos;
 252         Uint    page;
 253         const tPAddr    MASK = ~0xF78;
 254
 255         Start >>= 12;   End >>= 12;
 256
 257         #if 0
 258         Log("Directory Entries:");
 259         for(page = Start >> 10;
 260                 page < (End >> 10)+1;
 261                 page ++)
 262         {
 263                 if(gaPageDir[page])
 264                 {
 265                         Log(" 0x%08x-0x%08x :: 0x%08x",
 266                                 page<<22, ((page+1)<<22)-1,
 267                                 gaPageDir[page]&~0xFFF
 268                                 );
 269                 }
 270         }
 271         #endif
 272
 273         Log("Table Entries:");
 274         for(page = Start, curPos = Start<<12;
 275                 page < End;
 276                 curPos += 0x1000, page++)
 277         {
 278                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 279                 ||  !(gaPageTable[page] & PF_PRESENT)
 280                 ||  (gaPageTable[page] & MASK) != expected
 281                 ||  (tmpnode=NULL,MM_GetPageNode(expected, &tmpnode), tmpnode != expected_node))
 282                 {
 283                         if(expected) {
 284                                 tPAddr  orig = gaPageTable[rangeStart>>12];
 285                                 Log(" 0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 286                                         rangeStart,
 287                                         orig & ~0xFFF,
 288                                         curPos - rangeStart,
 289                                         (orig & PF_NOPAGE ? "P" : "-"),
 290                                         (orig & PF_COW ? "C" : "-"),
 291                                         (orig & PF_GLOBAL ? "G" : "-"),
 292                                         (orig & PF_USER ? "U" : "-"),
 293                                         (orig & PF_WRITE ? "W" : "-"),
 294                                         expected_node
 295                                         );
 296                                 expected = 0;
 297                         }
 298                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 299                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 300
 301                         expected = (gaPageTable[page] & MASK);
 302                         MM_GetPageNode(expected, &expected_node);
 303                         rangeStart = curPos;
 304                 }
 305                 if(expected)    expected += 0x1000;
 306         }
 307
 308         if(expected) {
 309                 tPAddr  orig = gaPageTable[rangeStart>>12];
 310                 Log("0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 311                         rangeStart,
 312                         orig & ~0xFFF,
 313                         curPos - rangeStart,
 314                         (orig & PF_NOPAGE ? "p" : "-"),
 315                         (orig & PF_COW ? "C" : "-"),
 316                         (orig & PF_GLOBAL ? "G" : "-"),
 317                         (orig & PF_USER ? "U" : "-"),
 318                         (orig & PF_WRITE ? "W" : "-"),
 319                         expected_node
 320                         );
 321                 expected = 0;
 322         }
 323 }
 324
 325 /**
 326  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 327  */
 328 tPAddr MM_Allocate(tVAddr VAddr)
 329 {
 330         tPAddr  paddr;
 331         //ENTER("xVAddr", VAddr);
 332         //__asm__ __volatile__ ("xchg %bx,%bx");
 333         // Check if the directory is mapped
 334         if( gaPageDir[ VAddr >> 22 ] == 0 )
 335         {
 336                 // Allocate directory
 337                 paddr = MM_AllocPhys();
 338                 if( paddr == 0 ) {
 339                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 340                         //LEAVE('i',0);
 341                         return 0;
 342                 }
 343                 // Map and mark as user (if needed)
 344                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 345                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 346
 347                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 348                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 349         }
 350         // Check if the page is already allocated
 351         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 352                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 353                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 354                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 355         }
 356
 357         // Allocate
 358         paddr = MM_AllocPhys();
 359         //LOG("paddr = 0x%llx", paddr);
 360         if( paddr == 0 ) {
 361                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 362                         VAddr, __builtin_return_address(0));
 363                 //LEAVE('i',0);
 364                 return 0;
 365         }
 366         // Map
 367         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 368         // Mark as user
 369         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 370         // Invalidate Cache for address
 371         INVLPG( VAddr & ~0xFFF );
 372
 373         //LEAVE('X', paddr);
 374         return paddr;
 375 }
 376
 377 /**
 378  * \fn void MM_Deallocate(tVAddr VAddr)
 379  */
 380 void MM_Deallocate(tVAddr VAddr)
 381 {
 382         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 383                 Warning("MM_Deallocate - Directory not mapped");
 384                 return;
 385         }
 386
 387         if(gaPageTable[ VAddr >> 12 ] == 0) {
 388                 Warning("MM_Deallocate - Page is not allocated");
 389                 return;
 390         }
 391
 392         // Dereference page
 393         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 394         // Clear page
 395         gaPageTable[ VAddr >> 12 ] = 0;
 396 }
 397
 398 /**
 399  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 400  * \brief Checks if the passed address is accesable
 401  */
 402 tPAddr MM_GetPhysAddr(tVAddr Addr)
 403 {
 404         if( !(gaPageDir[Addr >> 22] & 1) )
 405                 return 0;
 406         if( !(gaPageTable[Addr >> 12] & 1) )
 407                 return 0;
 408         return (gaPageTable[Addr >> 12] & ~0xFFF) | (Addr & 0xFFF);
 409 }
 410
 411 /**
 412  * \fn void MM_SetCR3(Uint CR3)
 413  * \brief Sets the current process space
 414  */
 415 void MM_SetCR3(Uint CR3)
 416 {
 417         __asm__ __volatile__ ("mov %0, %%cr3"::"r"(CR3));
 418 }
 419
 420 /**
 421  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 422  * \brief Map a physical page to a virtual one
 423  */
 424 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 425 {
 426         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 427         // Sanity check
 428         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 429                 Warning("MM_Map - Physical or Virtual Addresses are not aligned");
 430                 //LEAVE('i', 0);
 431                 return 0;
 432         }
 433
 434         // Align addresses
 435         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 436
 437         // Check if the directory is mapped
 438         if( gaPageDir[ VAddr >> 22 ] == 0 )
 439         {
 440                 tPAddr  tmp = MM_AllocPhys();
 441                 if( tmp == 0 )
 442                         return 0;
 443                 gaPageDir[ VAddr >> 22 ] = tmp | 3;
 444
 445                 // Mark as user
 446                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 447
 448                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 449                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 450         }
 451         // Check if the page is already allocated
 452         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 453                 Warning("MM_Map - Allocating to used address");
 454                 //LEAVE('i', 0);
 455                 return 0;
 456         }
 457
 458         // Map
 459         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 460         // Mark as user
 461         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 462
 463         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 464         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 465
 466         // Reference
 467         MM_RefPhys( PAddr );
 468
 469         //LOG("INVLPG( 0x%x )", VAddr);
 470         INVLPG( VAddr );
 471
 472         //LEAVE('i', 1);
 473         return 1;
 474 }
 475
 476 /**
 477  * \brief Clear user's address space
 478  */
 479 void MM_ClearUser(void)
 480 {
 481         Uint    i, j;
 482
 483         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 484         {
 485                 // Check if directory is not allocated
 486                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 487                         gaPageDir[i] = 0;
 488                         continue;
 489                 }
 490
 491                 // Deallocate tables
 492                 for( j = 0; j < 1024; j ++ )
 493                 {
 494                         if( gaPageTable[i*1024+j] & 1 )
 495                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 496                         gaPageTable[i*1024+j] = 0;
 497                 }
 498
 499                 // Deallocate directory
 500                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 501                 gaPageDir[i] = 0;
 502                 INVLPG( &gaPageTable[i*1024] );
 503         }
 504         INVLPG( gaPageDir );
 505 }
 506
 507 /**
 508  * \fn tPAddr MM_Clone(void)
 509  * \brief Clone the current address space
 510  */
 511 tPAddr MM_Clone(void)
 512 {
 513         Uint    i, j;
 514         tVAddr  ret;
 515         Uint    page = 0;
 516         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - MM_KERNEL_STACK_SIZE;
 517         void    *tmp;
 518
 519         Mutex_Acquire( &glTempFractal );
 520
 521         // Create Directory Table
 522         *gpTmpCR3 = MM_AllocPhys() | 3;
 523         if( *gpTmpCR3 == 3 ) {
 524                 *gpTmpCR3 = 0;
 525                 return 0;
 526         }
 527         INVLPG( gaTmpDir );
 528         //LOG("Allocated Directory (%x)", *gpTmpCR3);
 529         memsetd( gaTmpDir, 0, 1024 );
 530
 531         if( Threads_GetPID() != 0 )
 532         {
 533                 // Copy Tables
 534                 for( i = 0; i < 768; i ++)
 535                 {
 536                         // Check if table is allocated
 537                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 538                                 gaTmpDir[i] = 0;
 539                                 page += 1024;
 540                                 continue;
 541                         }
 542
 543                         // Allocate new table
 544                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 545                         INVLPG( &gaTmpTable[page] );
 546                         // Fill
 547                         for( j = 0; j < 1024; j ++, page++ )
 548                         {
 549                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 550                                         gaTmpTable[page] = 0;
 551                                         continue;
 552                                 }
 553
 554                                 // Refrence old page
 555                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 556                                 // Add to new table
 557                                 if(gaPageTable[page] & PF_WRITE) {
 558                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 559                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 560                                         INVLPG( page << 12 );
 561                                 }
 562                                 else
 563                                         gaTmpTable[page] = gaPageTable[page];
 564                         }
 565                 }
 566         }
 567
 568         // Map in kernel tables (and make fractal mapping)
 569         for( i = 768; i < 1024; i ++ )
 570         {
 571                 // Fractal
 572                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 573                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 574                         continue;
 575                 }
 576
 577                 if( gaPageDir[i] == 0 ) {
 578                         gaTmpDir[i] = 0;
 579                         continue;
 580                 }
 581
 582                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 583                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 584                 gaTmpDir[i] = gaPageDir[i];
 585         }
 586
 587         // Allocate kernel stack
 588         for(i = MM_KERNEL_STACKS >> 22; i < MM_KERNEL_STACKS_END >> 22; i ++ )
 589         {
 590                 // Check if directory is allocated
 591                 if( (gaPageDir[i] & 1) == 0 ) {
 592                         gaTmpDir[i] = 0;
 593                         continue;
 594                 }
 595
 596                 // We don't care about other kernel stacks, just the current one
 597                 if( i != kStackBase >> 22 ) {
 598                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 599                         gaTmpDir[i] = 0;
 600                         continue;
 601                 }
 602
 603                 // Create a copy
 604                 gaTmpDir[i] = MM_AllocPhys() | 3;
 605                 INVLPG( &gaTmpTable[i*1024] );
 606                 for( j = 0; j < 1024; j ++ )
 607                 {
 608                         // Is the page allocated? If not, skip
 609                         if( !(gaPageTable[i*1024+j] & 1) ) {
 610                                 gaTmpTable[i*1024+j] = 0;
 611                                 continue;
 612                         }
 613
 614                         // We don't care about other kernel stacks
 615                         if( ((i*1024+j)*4096 & ~(MM_KERNEL_STACK_SIZE-1)) != kStackBase ) {
 616                                 gaTmpTable[i*1024+j] = 0;
 617                                 continue;
 618                         }
 619
 620                         // Allocate page
 621                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 622
 623                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 624
 625                         tmp = (void *) MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 626                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 627                         MM_FreeTemp( (Uint)tmp );
 628                 }
 629         }
 630
 631         ret = *gpTmpCR3 & ~0xFFF;
 632         Mutex_Release( &glTempFractal );
 633
 634         //LEAVE('x', ret);
 635         return ret;
 636 }
 637
 638 /**
 639  * \fn tVAddr MM_NewKStack(void)
 640  * \brief Create a new kernel stack
 641  */
 642 tVAddr MM_NewKStack(void)
 643 {
 644         tVAddr  base;
 645         Uint    i;
 646         for(base = MM_KERNEL_STACKS; base < MM_KERNEL_STACKS_END; base += MM_KERNEL_STACK_SIZE)
 647         {
 648                 // Check if space is free
 649                 if(MM_GetPhysAddr(base) != 0)   continue;
 650                 // Allocate
 651                 //for(i = MM_KERNEL_STACK_SIZE; i -= 0x1000 ; )
 652                 for(i = 0; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 653                 {
 654                         if( MM_Allocate(base+i) == 0 )
 655                         {
 656                                 // On error, print a warning and return error
 657                                 Warning("MM_NewKStack - Out of memory");
 658                                 // - Clean up
 659                                 //for( i += 0x1000 ; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 660                                 //      MM_Deallocate(base+i);
 661                                 return 0;
 662                         }
 663                 }
 664                 // Success
 665 //              Log("MM_NewKStack - Allocated %p", base + MM_KERNEL_STACK_SIZE);
 666                 return base+MM_KERNEL_STACK_SIZE;
 667         }
 668         // No stacks left
 669         Log_Warning("MMVirt", "MM_NewKStack - No address space left");
 670         return 0;
 671 }
 672
 673 /**
 674  * \fn tVAddr MM_NewWorkerStack()
 675  * \brief Creates a new worker stack
 676  */
 677 tVAddr MM_NewWorkerStack(Uint *StackContents, size_t ContentsSize)
 678 {
 679         Uint    base, addr;
 680         tVAddr  tmpPage;
 681         tPAddr  page;
 682
 683         // TODO: Thread safety
 684         // Find a free worker stack address
 685         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 686         {
 687                 // Used block
 688                 if( gWorkerStacks[base/32] == -1 ) {
 689                         base += 31;     base &= ~31;
 690                         base --;        // Counteracted by the base++
 691                         continue;
 692                 }
 693                 // Used stack
 694                 if( gWorkerStacks[base/32] & (1 << base) ) {
 695                         continue;
 696                 }
 697                 break;
 698         }
 699         if(base >= NUM_WORKER_STACKS) {
 700                 Warning("Uh-oh! Out of worker stacks");
 701                 return 0;
 702         }
 703
 704         // It's ours now!
 705         gWorkerStacks[base/32] |= (1 << base);
 706         // Make life easier for later calls
 707         giLastUsedWorker = base;
 708         // We have one
 709         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 710         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 711
 712         // Acquire the lock for the temp fractal mappings
 713         Mutex_Acquire(&glTempFractal);
 714
 715         // Set the temp fractals to TID0's address space
 716         *gpTmpCR3 = ((Uint)gaInitPageDir - KERNEL_BASE) | 3;
 717         //Log(" MM_NewWorkerStack: *gpTmpCR3 = 0x%x", *gpTmpCR3);
 718         INVLPG( gaTmpDir );
 719
 720
 721         // Check if the directory is mapped (we are assuming that the stacks
 722         // will fit neatly in a directory)
 723         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 724         if(gaTmpDir[ base >> 22 ] == 0) {
 725                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 726                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 727         }
 728
 729         // Mapping Time!
 730         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 731         {
 732                 page = MM_AllocPhys();
 733                 gaTmpTable[ (base + addr) >> 12 ] = page | 3;
 734         }
 735         *gpTmpCR3 = 0;
 736         // Release the temp mapping lock
 737         Mutex_Release(&glTempFractal);
 738
 739         // NOTE: Max of 1 page
 740         // `page` is the last allocated page from the previious for loop
 741         tmpPage = MM_MapTemp( page );
 742         memcpy( (void*)( tmpPage + (0x1000 - ContentsSize) ), StackContents, ContentsSize);
 743         MM_FreeTemp(tmpPage);
 744
 745         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 746         return base + WORKER_STACK_SIZE;
 747 }
 748
 749 /**
 750  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 751  * \brief Sets the flags on a page
 752  */
 753 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 754 {
 755         tTabEnt *ent;
 756         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 757         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 758
 759         ent = &gaPageTable[VAddr >> 12];
 760
 761         // Read-Only
 762         if( Mask & MM_PFLAG_RO )
 763         {
 764                 if( Flags & MM_PFLAG_RO ) {
 765                         *ent &= ~PF_WRITE;
 766                 }
 767                 else {
 768                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 769                         *ent |= PF_WRITE;
 770                 }
 771         }
 772
 773         // Kernel
 774         if( Mask & MM_PFLAG_KERNEL )
 775         {
 776                 if( Flags & MM_PFLAG_KERNEL ) {
 777                         *ent &= ~PF_USER;
 778                 }
 779                 else {
 780                         gaPageDir[VAddr >> 22] |= PF_USER;
 781                         *ent |= PF_USER;
 782                 }
 783         }
 784
 785         // Copy-On-Write
 786         if( Mask & MM_PFLAG_COW )
 787         {
 788                 if( Flags & MM_PFLAG_COW ) {
 789                         *ent &= ~PF_WRITE;
 790                         *ent |= PF_COW;
 791                 }
 792                 else {
 793                         *ent &= ~PF_COW;
 794                         *ent |= PF_WRITE;
 795                 }
 796         }
 797
 798         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 799         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 800 }
 801
 802 /**
 803  * \brief Get the flags on a page
 804  */
 805 Uint MM_GetFlags(tVAddr VAddr)
 806 {
 807         tTabEnt *ent;
 808         Uint    ret = 0;
 809
 810         // Validity Check
 811         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 812         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 813
 814         ent = &gaPageTable[VAddr >> 12];
 815
 816         // Read-Only
 817         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 818         // Kernel
 819         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 820         // Copy-On-Write
 821         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 822
 823         return ret;
 824 }
 825
 826 /**
 827  * \brief Check if the provided buffer is valid
 828  * \return Boolean valid
 829  */
 830 int MM_IsValidBuffer(tVAddr Addr, size_t Size)
 831 {
 832          int    bIsUser;
 833          int    dir, tab;
 834
 835         Size += Addr & (PAGE_SIZE-1);
 836         Addr &= ~(PAGE_SIZE-1);
 837
 838         dir = Addr >> 22;
 839         tab = Addr >> 12;
 840
 841 //      Debug("Addr = %p, Size = 0x%x, dir = %i, tab = %i", Addr, Size, dir, tab);
 842
 843         if( !(gaPageDir[dir] & 1) )     return 0;
 844         if( !(gaPageTable[tab] & 1) )   return 0;
 845
 846         bIsUser = !!(gaPageTable[tab] & PF_USER);
 847
 848         while( Size >= PAGE_SIZE )
 849         {
 850                 if( (tab & 1023) == 0 )
 851                 {
 852                         dir ++;
 853                         if( !(gaPageDir[dir] & 1) )     return 0;
 854                 }
 855
 856                 if( !(gaPageTable[tab] & 1) )   return 0;
 857                 if( bIsUser && !(gaPageTable[tab] & PF_USER) )  return 0;
 858
 859                 tab ++;
 860                 Size -= PAGE_SIZE;
 861         }
 862         return 1;
 863 }
 864
 865 /**
 866  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 867  * \brief Duplicates a virtual page to a physical one
 868  */
 869 tPAddr MM_DuplicatePage(tVAddr VAddr)
 870 {
 871         tPAddr  ret;
 872         Uint    temp;
 873          int    wasRO = 0;
 874
 875         //ENTER("xVAddr", VAddr);
 876
 877         // Check if mapped
 878         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 879         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 880
 881         // Page Align
 882         VAddr &= ~0xFFF;
 883
 884         // Allocate new page
 885         ret = MM_AllocPhys();
 886         if( !ret ) {
 887                 return 0;
 888         }
 889
 890         // Write-lock the page (to keep data constistent), saving its R/W state
 891         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 892         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 893         INVLPG( VAddr );
 894
 895         // Copy Data
 896         temp = MM_MapTemp(ret);
 897         memcpy( (void*)temp, (void*)VAddr, 0x1000 );
 898         MM_FreeTemp(temp);
 899
 900         // Restore Writeable status
 901         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 902         INVLPG(VAddr);
 903
 904         //LEAVE('X', ret);
 905         return ret;
 906 }
 907
 908 /**
 909  * \fn Uint MM_MapTemp(tPAddr PAddr)
 910  * \brief Create a temporary memory mapping
 911  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 912  */
 913 tVAddr MM_MapTemp(tPAddr PAddr)
 914 {
 915          int    i;
 916
 917         //ENTER("XPAddr", PAddr);
 918
 919         PAddr &= ~0xFFF;
 920
 921         //LOG("glTempMappings = %i", glTempMappings);
 922
 923         for(;;)
 924         {
 925                 Mutex_Acquire( &glTempMappings );
 926
 927                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 928                 {
 929                         // Check if page used
 930                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 931                         // Mark as used
 932                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
 933                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
 934                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
 935                         Mutex_Release( &glTempMappings );
 936                         return TEMP_MAP_ADDR + (i << 12);
 937                 }
 938                 Mutex_Release( &glTempMappings );
 939                 Threads_Yield();        // TODO: Use a sleep queue here instead
 940         }
 941 }
 942
 943 /**
 944  * \fn void MM_FreeTemp(tVAddr PAddr)
 945  * \brief Free's a temp mapping
 946  */
 947 void MM_FreeTemp(tVAddr VAddr)
 948 {
 949          int    i = VAddr >> 12;
 950         //ENTER("xVAddr", VAddr);
 951
 952         if(i >= (TEMP_MAP_ADDR >> 12))
 953                 gaPageTable[ i ] = 0;
 954
 955         //LEAVE('-');
 956 }
 957
 958 /**
 959  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 960  * \brief Allocates a contigous number of pages
 961  */
 962 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
 963 {
 964          int    i, j;
 965
 966         PAddr &= ~0xFFF;
 967
 968         // Scan List
 969         for( i = 0; i < NUM_HW_PAGES; i ++ )
 970         {
 971                 // Check if addr used
 972                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
 973                         continue;
 974
 975                 // Check possible region
 976                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
 977                 {
 978                         // If there is an allocated page in the region we are testing, break
 979                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
 980                 }
 981                 // Is it all free?
 982                 if( j == Number )
 983                 {
 984                         // Allocate
 985                         for( j = 0; j < Number; j++ ) {
 986                                 MM_RefPhys( PAddr + (j<<12) );
 987                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
 988                         }
 989                         return HW_MAP_ADDR + (i<<12);
 990                 }
 991         }
 992         // If we don't find any, return NULL
 993         return 0;
 994 }
 995
 996 /**
 997  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
 998  * \brief Allocates DMA physical memory
 999  * \param Pages Number of pages required
1000  * \param MaxBits       Maximum number of bits the physical address can have
1001  * \param PhysAddr      Pointer to the location to place the physical address allocated
1002  * \return Virtual address allocate
1003  */
1004 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1005 {
1006         tPAddr  maxCheck = (1 << MaxBits);
1007         tPAddr  phys;
1008         tVAddr  ret;
1009
1010         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
1011
1012         // Sanity Check
1013         if(MaxBits < 12 || !PhysAddr) {
1014                 LEAVE('i', 0);
1015                 return 0;
1016         }
1017
1018         // Bound
1019         if(MaxBits >= PHYS_BITS)        maxCheck = -1;
1020
1021         // Fast Allocate
1022         if(Pages == 1 && MaxBits >= PHYS_BITS)
1023         {
1024                 phys = MM_AllocPhys();
1025                 if( !phys ) {
1026                         *PhysAddr = 0;
1027                         LEAVE_RET('i', 0);
1028                 }
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