KernelLand/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 #include <arch_int.h>
  20
  21 #define TAB     22
  22
  23 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  24 #define WORKER_STACK_SIZE       MM_KERNEL_STACK_SIZE
  25 #define WORKER_STACKS_END       0xB0000000
  26 #define NUM_WORKER_STACKS       ((WORKER_STACKS_END-WORKER_STACKS)/WORKER_STACK_SIZE)
  27
  28 #define PAE_PAGE_TABLE_ADDR     0xFC000000      // 16 MiB
  29 #define PAE_PAGE_DIR_ADDR       0xFCFC0000      // 16 KiB
  30 #define PAE_PAGE_PDPT_ADDR      0xFCFC3F00      // 32 bytes
  31 #define PAE_TMP_PDPT_ADDR       0xFCFC3F20      // 32 bytes
  32 #define PAE_TMP_DIR_ADDR        0xFCFE0000      // 16 KiB
  33 #define PAE_TMP_TABLE_ADDR      0xFD000000      // 16 MiB
  34
  35 #define PAGE_TABLE_ADDR 0xFC000000
  36 #define PAGE_DIR_ADDR   0xFC3F0000
  37 #define PAGE_CR3_ADDR   0xFC3F0FC0
  38 #define TMP_CR3_ADDR    0xFC3F0FC4      // Part of core instead of temp
  39 #define TMP_DIR_ADDR    0xFC3F1000      // Same
  40 #define TMP_TABLE_ADDR  0xFC400000
  41
  42 #define HW_MAP_ADDR             0xFE000000
  43 #define HW_MAP_MAX              0xFFEF0000
  44 #define NUM_HW_PAGES    ((HW_MAP_MAX-HW_MAP_ADDR)/0x1000)
  45 #define TEMP_MAP_ADDR   0xFFEF0000      // Allows 16 "temp" pages
  46 #define NUM_TEMP_PAGES  16
  47 #define LAST_BLOCK_ADDR 0xFFFF0000      // Free space for kernel provided user code/ *(-1) protection
  48
  49 #define PF_PRESENT      0x1
  50 #define PF_WRITE        0x2
  51 #define PF_USER         0x4
  52 #define PF_GLOBAL       0x80
  53 #define PF_COW          0x200
  54 #define PF_NOPAGE       0x400
  55
  56 #define INVLPG(addr)    __asm__ __volatile__ ("invlpg (%0)"::"r"(addr))
  57
  58 #define GET_TEMP_MAPPING(cr3) do { \
  59         __ASM__("cli"); \
  60         __AtomicTestSetLoop( (Uint *)gpTmpCR3, cr3 | 3 ); \
  61 } while(0)
  62 #define REL_TEMP_MAPPING() do { \
  63         *gpTmpCR3 = 0; \
  64         __ASM__("sti"); \
  65 } while(0)
  66
  67 typedef Uint32  tTabEnt;
  68
  69 // === IMPORTS ===
  70 extern char     _UsertextEnd[], _UsertextBase[];
  71 extern Uint32   gaInitPageDir[1024];
  72 extern Uint32   gaInitPageTable[1024];
  73 extern void     Threads_SegFault(tVAddr Addr);
  74 extern void     Error_Backtrace(Uint eip, Uint ebp);
  75
  76 // === PROTOTYPES ===
  77 void    MM_PreinitVirtual(void);
  78 void    MM_InstallVirtual(void);
  79 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  80 //void  MM_DumpTables(tVAddr Start, tVAddr End);
  81 //void  MM_ClearUser(void);
  82 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  83
  84 // === GLOBALS ===
  85 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  86 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  87 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  88 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  89 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  90 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  91
  92 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  93 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  94 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  95 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  96 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  97 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  98  int    gbUsePAE = 0;
  99 tMutex  glTempMappings;
 100 tMutex  glTempFractal;
 101 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
 102  int    giLastUsedWorker = 0;
 103 struct sPageInfo {
 104         void    *Node;
 105         tVAddr  Base;
 106         Uint64  Offset;
 107          int    Length;
 108          int    Flags;
 109 }       *gaMappedRegions;       // sizeof = 24 bytes
 110
 111 // === CODE ===
 112 /**
 113  * \fn void MM_PreinitVirtual(void)
 114  * \brief Maps the fractal mappings
 115  */
 116 void MM_PreinitVirtual(void)
 117 {
 118         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 119         INVLPG( PAGE_TABLE_ADDR );
 120 }
 121
 122 /**
 123  * \fn void MM_InstallVirtual(void)
 124  * \brief Sets up the constant page mappings
 125  */
 126 void MM_InstallVirtual(void)
 127 {
 128          int    i;
 129
 130         // --- Pre-Allocate kernel tables
 131         for( i = KERNEL_BASE>>22; i < 1024; i ++ )
 132         {
 133                 if( gaPageDir[ i ] )    continue;
 134                 // Skip stack tables, they are process unique
 135                 if( i > MM_KERNEL_STACKS >> 22 && i < MM_KERNEL_STACKS_END >> 22) {
 136                         gaPageDir[ i ] = 0;
 137                         continue;
 138                 }
 139                 // Preallocate table
 140                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 141                 INVLPG( &gaPageTable[i*1024] );
 142                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 143         }
 144
 145         // Unset kernel on the User Text pages
 146         for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 147                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 148         }
 149
 150         *gpTmpCR3 = 0;
 151 }
 152
 153 /**
 154  * \brief Cleans up the SMP required mappings
 155  */
 156 void MM_FinishVirtualInit(void)
 157 {
 158         gaInitPageDir[ 0 ] = 0;
 159 }
 160
 161 /**
 162  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 163  * \brief Called on a page fault
 164  */
 165 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 166 {
 167         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 168
 169         // -- Check for COW --
 170         if( gaPageDir  [Addr>>22] & PF_PRESENT  && gaPageTable[Addr>>12] & PF_PRESENT
 171          && gaPageTable[Addr>>12] & PF_COW )
 172         {
 173                 tPAddr  paddr;
 174                 __asm__ __volatile__ ("sti");
 175                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 176                 {
 177                         gaPageTable[Addr>>12] &= ~PF_COW;
 178                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 179                 }
 180                 else
 181                 {
 182                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 183                         paddr = MM_DuplicatePage( Addr );
 184                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 185                         gaPageTable[Addr>>12] &= PF_USER;
 186                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 187                 }
 188
 189 //              Log_Debug("MMVirt", "COW for %p (%P)", Addr, gaPageTable[Addr>>12]);
 190
 191                 INVLPG( Addr & ~0xFFF );
 192                 return;
 193         }
 194
 195         // Disable instruction tracing
 196         __ASM__("pushf; andw $0xFEFF, 0(%esp); popf");
 197         Proc_GetCurThread()->bInstrTrace = 0;
 198
 199         // If it was a user, tell the thread handler
 200         if(ErrorCode & 4) {
 201                 __asm__ __volatile__ ("sti");
 202                 Log_Warning("MMVirt", "User %s %s memory%s",
 203                         (ErrorCode&2?"write to":"read from"),
 204                         (ErrorCode&1?"bad/locked":"non-present"),
 205                         (ErrorCode&16?" (Instruction Fetch)":"")
 206                         );
 207                 Log_Warning("MMVirt", "Instruction %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 208                 __ASM__("sti"); // Restart IRQs
 209                 #if 1
 210                 Error_Backtrace(Regs->eip, Regs->ebp);
 211                 #endif
 212                 Threads_SegFault(Addr);
 213                 return ;
 214         }
 215
 216         Debug_KernelPanic();
 217
 218         // -- Check Error Code --
 219         if(ErrorCode & 8)
 220                 Warning("Reserved Bits Trashed!");
 221         else
 222         {
 223                 Warning("Kernel %s %s memory%s",
 224                         (ErrorCode&2?"write to":"read from"),
 225                         (ErrorCode&1?"bad/locked":"non-present"),
 226                         (ErrorCode&16?" (Instruction Fetch)":"")
 227                         );
 228         }
 229
 230         Log("CPU %i - Code at %p accessed %p", GetCPUNum(), Regs->eip, Addr);
 231         // Print Stack Backtrace
 232         Error_Backtrace(Regs->eip, Regs->ebp);
 233
 234         #if 0
 235         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 236         if( gaPageDir[Addr>>22] & PF_PRESENT )
 237                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 238         #endif
 239         //MM_DumpTables(0, -1);
 240
 241         // Register Dump
 242         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 243         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 244         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 245         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 246         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 247         {
 248                 Uint    dr0, dr1;
 249                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 250                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 251                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 252         }
 253
 254         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 255 }
 256
 257 /**
 258  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 259  * \brief Dumps the layout of the page tables
 260  */
 261 void MM_DumpTables(tVAddr Start, tVAddr End)
 262 {
 263         tVAddr  rangeStart = 0;
 264         tPAddr  expected = 0;
 265         void    *expected_node = NULL, *tmpnode = NULL;
 266         tVAddr  curPos;
 267         Uint    page;
 268         const tPAddr    MASK = ~0xF78;
 269
 270         Start >>= 12;   End >>= 12;
 271
 272         #if 0
 273         Log("Directory Entries:");
 274         for(page = Start >> 10;
 275                 page < (End >> 10)+1;
 276                 page ++)
 277         {
 278                 if(gaPageDir[page])
 279                 {
 280                         Log(" 0x%08x-0x%08x :: 0x%08x",
 281                                 page<<22, ((page+1)<<22)-1,
 282                                 gaPageDir[page]&~0xFFF
 283                                 );
 284                 }
 285         }
 286         #endif
 287
 288         Log("Table Entries:");
 289         for(page = Start, curPos = Start<<12;
 290                 page < End;
 291                 curPos += 0x1000, page++)
 292         {
 293                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 294                 ||  !(gaPageTable[page] & PF_PRESENT)
 295                 ||  (gaPageTable[page] & MASK) != expected
 296                 ||  (tmpnode=NULL,MM_GetPageNode(expected, &tmpnode), tmpnode != expected_node))
 297                 {
 298                         if(expected) {
 299                                 tPAddr  orig = gaPageTable[rangeStart>>12];
 300                                 Log(" 0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 301                                         rangeStart,
 302                                         orig & ~0xFFF,
 303                                         curPos - rangeStart,
 304                                         (orig & PF_NOPAGE ? "P" : "-"),
 305                                         (orig & PF_COW ? "C" : "-"),
 306                                         (orig & PF_GLOBAL ? "G" : "-"),
 307                                         (orig & PF_USER ? "U" : "-"),
 308                                         (orig & PF_WRITE ? "W" : "-"),
 309                                         expected_node
 310                                         );
 311                                 expected = 0;
 312                         }
 313                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 314                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 315
 316                         expected = (gaPageTable[page] & MASK);
 317                         MM_GetPageNode(expected, &expected_node);
 318                         rangeStart = curPos;
 319                 }
 320                 if(expected)    expected += 0x1000;
 321         }
 322
 323         if(expected) {
 324                 tPAddr  orig = gaPageTable[rangeStart>>12];
 325                 Log("0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 326                         rangeStart,
 327                         orig & ~0xFFF,
 328                         curPos - rangeStart,
 329                         (orig & PF_NOPAGE ? "p" : "-"),
 330                         (orig & PF_COW ? "C" : "-"),
 331                         (orig & PF_GLOBAL ? "G" : "-"),
 332                         (orig & PF_USER ? "U" : "-"),
 333                         (orig & PF_WRITE ? "W" : "-"),
 334                         expected_node
 335                         );
 336                 expected = 0;
 337         }
 338 }
 339
 340 /**
 341  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 342  */
 343 tPAddr MM_Allocate(tVAddr VAddr)
 344 {
 345         tPAddr  paddr;
 346         //ENTER("xVAddr", VAddr);
 347         //__ASM__("xchg %bx,%bx");
 348         // Check if the directory is mapped
 349         if( gaPageDir[ VAddr >> 22 ] == 0 )
 350         {
 351                 // Allocate directory
 352                 paddr = MM_AllocPhys();
 353                 if( paddr == 0 ) {
 354                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 355                         //LEAVE('i',0);
 356                         return 0;
 357                 }
 358                 // Map and mark as user (if needed)
 359                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 360                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 361
 362                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 363                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 364         }
 365         // Check if the page is already allocated
 366         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 367                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 368                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 369                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 370         }
 371
 372         // Allocate
 373         paddr = MM_AllocPhys();
 374         //LOG("paddr = 0x%llx", paddr);
 375         if( paddr == 0 ) {
 376                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 377                         VAddr, __builtin_return_address(0));
 378                 //LEAVE('i',0);
 379                 return 0;
 380         }
 381         // Map
 382         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 383         // Mark as user
 384         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 385         // Invalidate Cache for address
 386         INVLPG( VAddr & ~0xFFF );
 387
 388         //LEAVE('X', paddr);
 389         return paddr;
 390 }
 391
 392 /**
 393  * \fn void MM_Deallocate(tVAddr VAddr)
 394  */
 395 void MM_Deallocate(tVAddr VAddr)
 396 {
 397         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 398                 Warning("MM_Deallocate - Directory not mapped");
 399                 return;
 400         }
 401
 402         if(gaPageTable[ VAddr >> 12 ] == 0) {
 403                 Warning("MM_Deallocate - Page is not allocated");
 404                 return;
 405         }
 406
 407         // Dereference page
 408         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 409         // Clear page
 410         gaPageTable[ VAddr >> 12 ] = 0;
 411 }
 412
 413 /**
 414  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 415  * \brief Checks if the passed address is accesable
 416  */
 417 tPAddr MM_GetPhysAddr(const void *Addr)
 418 {
 419         tVAddr  addr = (tVAddr)Addr;
 420         if( !(gaPageDir[addr >> 22] & 1) )
 421                 return 0;
 422         if( !(gaPageTable[addr >> 12] & 1) )
 423                 return 0;
 424         return (gaPageTable[addr >> 12] & ~0xFFF) | (addr & 0xFFF);
 425 }
 426
 427 /**
 428  * \fn void MM_SetCR3(Uint CR3)
 429  * \brief Sets the current process space
 430  */
 431 void MM_SetCR3(Uint CR3)
 432 {
 433         __ASM__("mov %0, %%cr3"::"r"(CR3));
 434 }
 435
 436 /**
 437  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 438  * \brief Map a physical page to a virtual one
 439  */
 440 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 441 {
 442         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 443         // Sanity check
 444         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 445                 Log_Warning("MM_Virt", "MM_Map - Physical or Virtual Addresses are not aligned (0x%P and %p)",
 446                         PAddr, VAddr);
 447                 //LEAVE('i', 0);
 448                 return 0;
 449         }
 450
 451         // Align addresses
 452         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 453
 454         // Check if the directory is mapped
 455         if( gaPageDir[ VAddr >> 22 ] == 0 )
 456         {
 457                 tPAddr  tmp = MM_AllocPhys();
 458                 if( tmp == 0 )
 459                         return 0;
 460                 gaPageDir[ VAddr >> 22 ] = tmp | 3;
 461
 462                 // Mark as user
 463                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 464
 465                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 466                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 467         }
 468         // Check if the page is already allocated
 469         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 470                 Warning("MM_Map - Allocating to used address");
 471                 //LEAVE('i', 0);
 472                 return 0;
 473         }
 474
 475         // Map
 476         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 477         // Mark as user
 478         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 479
 480         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 481         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 482
 483         // Reference
 484         MM_RefPhys( PAddr );
 485
 486         //LOG("INVLPG( 0x%x )", VAddr);
 487         INVLPG( VAddr );
 488
 489         //LEAVE('i', 1);
 490         return 1;
 491 }
 492
 493 /**
 494  * \brief Clear user's address space
 495  */
 496 void 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
 524 /**
 525  * \brief Deallocate an address space
 526  */
 527 void MM_ClearSpace(Uint32 CR3)
 528 {
 529          int    i, j;
 530
 531         if(CR3 == (*gpPageCR3 & ~0xFFF)) {
 532                 Log_Error("MMVirt", "Can't clear current address space");
 533                 return ;
 534         }
 535
 536         if( MM_GetRefCount(CR3) > 1 ) {
 537                 MM_DerefPhys(CR3);
 538                 Log_Log("MMVirt", "CR3 %P is still referenced, not cleaning (but dereferenced)", CR3);
 539                 return ;
 540         }
 541
 542         Log_Debug("MMVirt", "Clearing out address space 0x%x from 0x%x", CR3, *gpPageCR3);
 543
 544         GET_TEMP_MAPPING(CR3);
 545         INVLPG( gaTmpDir );
 546
 547         for( i = 0; i < 1024; i ++ )
 548         {
 549                 Uint32  *table = &gaTmpTable[i*1024];
 550                 if( !(gaTmpDir[i] & PF_PRESENT) )
 551                         continue ;
 552
 553                 INVLPG( table );
 554
 555                 if( i < 768 || (i > MM_KERNEL_STACKS >> 22 && i < MM_KERNEL_STACKS_END >> 22) )
 556                 {
 557                         for( j = 0; j < 1024; j ++ )
 558                         {
 559                                 if( !(table[j] & 1) )
 560                                         continue;
 561                                 MM_DerefPhys( table[j] & ~0xFFF );
 562                         }
 563                 }
 564
 565                 if( i != (PAGE_TABLE_ADDR >> 22) )
 566                 {
 567                         MM_DerefPhys( gaTmpDir[i] & ~0xFFF );
 568                 }
 569         }
 570
 571
 572         MM_DerefPhys( CR3 );
 573
 574         REL_TEMP_MAPPING();
 575 }
 576
 577 /**
 578  * \fn tPAddr MM_Clone(void)
 579  * \brief Clone the current address space
 580  */
 581 tPAddr MM_Clone(int bNoUserCopy)
 582 {
 583         Uint    i, j;
 584         tPAddr  ret;
 585         Uint    page = 0;
 586         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - MM_KERNEL_STACK_SIZE;
 587         void    *tmp;
 588
 589         // Create Directory Table
 590         ret = MM_AllocPhys();
 591         if( ret == 0 ) {
 592                 return 0;
 593         }
 594
 595         // Map
 596         GET_TEMP_MAPPING( ret );
 597         INVLPG( gaTmpDir );
 598         memsetd( gaTmpDir, 0, 1024 );
 599
 600         if( Threads_GetPID() != 0 && !bNoUserCopy )
 601         {
 602                 // Copy Tables
 603                 for( i = 0; i < 768; i ++)
 604                 {
 605                         // Check if table is allocated
 606                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 607                                 gaTmpDir[i] = 0;
 608                                 page += 1024;
 609                                 continue;
 610                         }
 611
 612                         // Allocate new table
 613                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 614                         INVLPG( &gaTmpTable[page] );
 615                         // Fill
 616                         for( j = 0; j < 1024; j ++, page++ )
 617                         {
 618                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 619                                         gaTmpTable[page] = 0;
 620                                         continue;
 621                                 }
 622
 623                                 // Refrence old page
 624                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 625                                 // Add to new table
 626                                 if(gaPageTable[page] & PF_WRITE) {
 627                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 628                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 629                                         INVLPG( page << 12 );
 630                                 }
 631                                 else
 632                                         gaTmpTable[page] = gaPageTable[page];
 633                         }
 634                 }
 635         }
 636
 637         // Map in kernel tables (and make fractal mapping)
 638         for( i = 768; i < 1024; i ++ )
 639         {
 640                 // Fractal
 641                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 642                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 643                         continue;
 644                 }
 645                 if( i == (TMP_TABLE_ADDR >> 22) ) {
 646                         gaTmpDir[ TMP_TABLE_ADDR >> 22 ] = 0;
 647                         continue ;
 648                 }
 649
 650                 if( gaPageDir[i] == 0 ) {
 651                         gaTmpDir[i] = 0;
 652                         continue;
 653                 }
 654
 655                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 656                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 657                 gaTmpDir[i] = gaPageDir[i];
 658         }
 659
 660         // Allocate kernel stack
 661         for(i = MM_KERNEL_STACKS >> 22; i < MM_KERNEL_STACKS_END >> 22; i ++ )
 662         {
 663                 // Check if directory is allocated
 664                 if( (gaPageDir[i] & 1) == 0 ) {
 665                         gaTmpDir[i] = 0;
 666                         continue;
 667                 }
 668
 669                 // We don't care about other kernel stacks, just the current one
 670                 if( i != kStackBase >> 22 ) {
 671                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 672                         gaTmpDir[i] = 0;
 673                         continue;
 674                 }
 675
 676                 // Create a copy
 677                 gaTmpDir[i] = MM_AllocPhys() | 3;
 678                 INVLPG( &gaTmpTable[i*1024] );
 679                 for( j = 0; j < 1024; j ++ )
 680                 {
 681                         // Is the page allocated? If not, skip
 682                         if( !(gaPageTable[i*1024+j] & 1) ) {
 683                                 gaTmpTable[i*1024+j] = 0;
 684                                 continue;
 685                         }
 686
 687                         // We don't care about other kernel stacks
 688                         if( ((i*1024+j)*4096 & ~(MM_KERNEL_STACK_SIZE-1)) != kStackBase ) {
 689                                 gaTmpTable[i*1024+j] = 0;
 690                                 continue;
 691                         }
 692
 693                         // Allocate page
 694                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 695
 696                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 697
 698                         tmp = MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 699                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 700                         MM_FreeTemp( tmp );
 701                 }
 702         }
 703
 704         REL_TEMP_MAPPING();
 705
 706         //LEAVE('x', ret);
 707         return ret;
 708 }
 709
 710 /**
 711  * \fn tVAddr MM_NewKStack(void)
 712  * \brief Create a new kernel stack
 713  */
 714 tVAddr MM_NewKStack(void)
 715 {
 716         tVAddr  base;
 717         Uint    i;
 718         for(base = MM_KERNEL_STACKS; base < MM_KERNEL_STACKS_END; base += MM_KERNEL_STACK_SIZE)
 719         {
 720                 // Check if space is free
 721                 if(MM_GetPhysAddr( (void*) base) != 0)
 722                         continue;
 723                 // Allocate
 724                 //for(i = MM_KERNEL_STACK_SIZE; i -= 0x1000 ; )
 725                 for(i = 0; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 726                 {
 727                         if( MM_Allocate(base+i) == 0 )
 728                         {
 729                                 // On error, print a warning and return error
 730                                 Warning("MM_NewKStack - Out of memory");
 731                                 // - Clean up
 732                                 //for( i += 0x1000 ; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 733                                 //      MM_Deallocate(base+i);
 734                                 return 0;
 735                         }
 736                 }
 737                 // Success
 738 //              Log("MM_NewKStack - Allocated %p", base + MM_KERNEL_STACK_SIZE);
 739                 return base+MM_KERNEL_STACK_SIZE;
 740         }
 741         // No stacks left
 742         Log_Warning("MMVirt", "MM_NewKStack - No address space left");
 743         return 0;
 744 }
 745
 746 /**
 747  * \fn tVAddr MM_NewWorkerStack()
 748  * \brief Creates a new worker stack
 749  */
 750 tVAddr MM_NewWorkerStack(Uint *StackContents, size_t ContentsSize)
 751 {
 752         Uint    base, addr;
 753         tVAddr  tmpPage;
 754         tPAddr  page;
 755
 756         // TODO: Thread safety
 757         // Find a free worker stack address
 758         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 759         {
 760                 // Used block
 761                 if( gWorkerStacks[base/32] == -1 ) {
 762                         base += 31;     base &= ~31;
 763                         base --;        // Counteracted by the base++
 764                         continue;
 765                 }
 766                 // Used stack
 767                 if( gWorkerStacks[base/32] & (1 << base) ) {
 768                         continue;
 769                 }
 770                 break;
 771         }
 772         if(base >= NUM_WORKER_STACKS) {
 773                 Warning("Uh-oh! Out of worker stacks");
 774                 return 0;
 775         }
 776
 777         // It's ours now!
 778         gWorkerStacks[base/32] |= (1 << base);
 779         // Make life easier for later calls
 780         giLastUsedWorker = base;
 781         // We have one
 782         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 783         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 784
 785         // Set the temp fractals to TID0's address space
 786         GET_TEMP_MAPPING( ((Uint)gaInitPageDir - KERNEL_BASE) );
 787         INVLPG( gaTmpDir );
 788
 789         // Check if the directory is mapped (we are assuming that the stacks
 790         // will fit neatly in a directory)
 791         //Log(" MM_NewWorkerStack: gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 792         if(gaTmpDir[ base >> 22 ] == 0) {
 793                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 794                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 795         }
 796
 797         // Mapping Time!
 798         for( addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 799         {
 800                 page = MM_AllocPhys();
 801                 gaTmpTable[ (base + addr) >> 12 ] = page | 3;
 802         }
 803
 804         // Release temporary fractal
 805         REL_TEMP_MAPPING();
 806
 807         // NOTE: Max of 1 page
 808         // `page` is the last allocated page from the previious for loop
 809         tmpPage = (tVAddr)MM_MapTemp( page );
 810         memcpy( (void*)( tmpPage + (0x1000 - ContentsSize) ), StackContents, ContentsSize);
 811         MM_FreeTemp( (void*)tmpPage );
 812
 813         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 814         return base + WORKER_STACK_SIZE;
 815 }
 816
 817 /**
 818  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 819  * \brief Sets the flags on a page
 820  */
 821 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 822 {
 823         tTabEnt *ent;
 824         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 825         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 826
 827         ent = &gaPageTable[VAddr >> 12];
 828
 829         // Read-Only
 830         if( Mask & MM_PFLAG_RO )
 831         {
 832                 if( Flags & MM_PFLAG_RO ) {
 833                         *ent &= ~PF_WRITE;
 834                 }
 835                 else {
 836                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 837                         *ent |= PF_WRITE;
 838                 }
 839         }
 840
 841         // Kernel
 842         if( Mask & MM_PFLAG_KERNEL )
 843         {
 844                 if( Flags & MM_PFLAG_KERNEL ) {
 845                         *ent &= ~PF_USER;
 846                 }
 847                 else {
 848                         gaPageDir[VAddr >> 22] |= PF_USER;
 849                         *ent |= PF_USER;
 850                 }
 851         }
 852
 853         // Copy-On-Write
 854         if( Mask & MM_PFLAG_COW )
 855         {
 856                 if( Flags & MM_PFLAG_COW ) {
 857                         *ent &= ~PF_WRITE;
 858                         *ent |= PF_COW;
 859                 }
 860                 else {
 861                         *ent &= ~PF_COW;
 862                         *ent |= PF_WRITE;
 863                 }
 864         }
 865
 866         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 867         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 868 }
 869
 870 /**
 871  * \brief Get the flags on a page
 872  */
 873 Uint MM_GetFlags(tVAddr VAddr)
 874 {
 875         tTabEnt *ent;
 876         Uint    ret = 0;
 877
 878         // Validity Check
 879         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 880         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 881
 882         ent = &gaPageTable[VAddr >> 12];
 883
 884         // Read-Only
 885         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 886         // Kernel
 887         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 888         // Copy-On-Write
 889         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 890
 891         return ret;
 892 }
 893
 894 /**
 895  * \brief Check if the provided buffer is valid
 896  * \return Boolean valid
 897  */
 898 int MM_IsValidBuffer(tVAddr Addr, size_t Size)
 899 {
 900          int    bIsUser;
 901          int    dir, tab;
 902
 903         Size += Addr & (PAGE_SIZE-1);
 904         Addr &= ~(PAGE_SIZE-1);
 905
 906         dir = Addr >> 22;
 907         tab = Addr >> 12;
 908
 909 //      Debug("Addr = %p, Size = 0x%x, dir = %i, tab = %i", Addr, Size, dir, tab);
 910
 911         if( !(gaPageDir[dir] & 1) )     return 0;
 912         if( !(gaPageTable[tab] & 1) )   return 0;
 913
 914         bIsUser = !!(gaPageTable[tab] & PF_USER);
 915
 916         while( Size >= PAGE_SIZE )
 917         {
 918                 if( (tab & 1023) == 0 )
 919                 {
 920                         dir ++;
 921                         if( !(gaPageDir[dir] & 1) )     return 0;
 922                 }
 923
 924                 if( !(gaPageTable[tab] & 1) )   return 0;
 925                 if( bIsUser && !(gaPageTable[tab] & PF_USER) )  return 0;
 926
 927                 tab ++;
 928                 Size -= PAGE_SIZE;
 929         }
 930         return 1;
 931 }
 932
 933 /**
 934  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 935  * \brief Duplicates a virtual page to a physical one
 936  */
 937 tPAddr MM_DuplicatePage(tVAddr VAddr)
 938 {
 939         tPAddr  ret;
 940         void    *temp;
 941          int    wasRO = 0;
 942
 943         //ENTER("xVAddr", VAddr);
 944
 945         // Check if mapped
 946         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 947         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 948
 949         // Page Align
 950         VAddr &= ~0xFFF;
 951
 952         // Allocate new page
 953         ret = MM_AllocPhys();
 954         if( !ret ) {
 955                 return 0;
 956         }
 957
 958         // Write-lock the page (to keep data constistent), saving its R/W state
 959         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 960         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 961         INVLPG( VAddr );
 962
 963         // Copy Data
 964         temp = MM_MapTemp(ret);
 965         memcpy( temp, (void*)VAddr, 0x1000 );
 966         MM_FreeTemp(temp);
 967
 968         // Restore Writeable status
 969         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 970         INVLPG(VAddr);
 971
 972         //LEAVE('X', ret);
 973         return ret;
 974 }
 975
 976 /**
 977  * \fn Uint MM_MapTemp(tPAddr PAddr)
 978  * \brief Create a temporary memory mapping
 979  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 980  */
 981 void * MM_MapTemp(tPAddr PAddr)
 982 {
 983          int    i;
 984
 985         //ENTER("XPAddr", PAddr);
 986
 987         PAddr &= ~0xFFF;
 988
 989         //LOG("glTempMappings = %i", glTempMappings);
 990
 991         for(;;)
 992         {
 993                 Mutex_Acquire( &glTempMappings );
 994
 995                 for( i = 0; i < NUM_TEMP_PAGES; i ++ )
 996                 {
 997                         // Check if page used
 998                         if(gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] & 1)        continue;
 999                         // Mark as used
1000                         gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ] = PAddr | 3;
1001                         INVLPG( TEMP_MAP_ADDR + (i << 12) );
1002                         //LEAVE('p', TEMP_MAP_ADDR + (i << 12));
1003                         Mutex_Release( &glTempMappings );
1004                         return (void*)( TEMP_MAP_ADDR + (i << 12) );
1005                 }
1006                 Mutex_Release( &glTempMappings );
1007                 Threads_Yield();        // TODO: Use a sleep queue here instead
1008         }
1009 }
1010
1011 /**
1012  * \fn void MM_FreeTemp(tVAddr PAddr)
1013  * \brief Free's a temp mapping
1014  */
1015 void MM_FreeTemp(void *VAddr)
1016 {
1017          int    i = (tVAddr)VAddr >> 12;
1018         //ENTER("xVAddr", VAddr);
1019
1020         if(i >= (TEMP_MAP_ADDR >> 12))
1021                 gaPageTable[ i ] = 0;
1022
1023         //LEAVE('-');
1024 }
1025
1026 /**
1027  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
1028  * \brief Allocates a contigous number of pages
1029  */
1030 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
1031 {
1032          int    i, j;
1033
1034         PAddr &= ~0xFFF;
1035
1036         // Scan List
1037         for( i = 0; i < NUM_HW_PAGES; i ++ )
1038         {
1039                 // Check if addr used
1040                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
1041                         continue;
1042
1043                 // Check possible region
1044                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
1045                 {
1046                         // If there is an allocated page in the region we are testing, break
1047                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
1048                 }
1049                 // Is it all free?
1050                 if( j == Number )
1051                 {
1052                         // Allocate
1053                         for( j = 0; j < Number; j++ ) {
1054                                 MM_RefPhys( PAddr + (j<<12) );
1055                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
1056                         }
1057                         return HW_MAP_ADDR + (i<<12);
1058                 }
1059         }
1060         // If we don't find any, return NULL
1061         return 0;
1062 }
1063
1064 /**
1065  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1066  * \brief Allocates DMA physical memory
1067  * \param Pages Number of pages required
1068  * \param MaxBits       Maximum number of bits the physical address can have
1069  * \param PhysAddr      Pointer to the location to place the physical address allocated
1070  * \return Virtual address allocate
1071  */
1072 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1073 {
1074         tPAddr  phys;
1075         tVAddr  ret;
1076
1077         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
1078
1079         if(MaxBits == -1)
1080                 MaxBits = PHYS_BITS;
1081
1082         // Sanity Check
1083         if(MaxBits < 12) {
1084                 LEAVE('i', 0);
1085                 return 0;
1086         }
1087
1088         // Fast Allocate
1089         if(Pages == 1 && MaxBits >= PHYS_BITS)
1090         {
1091                 phys = MM_AllocPhys();
1092                 if( PhysAddr )
1093                         *PhysAddr = phys;
1094                 if( !phys ) {
1095                         LEAVE_RET('i', 0);
1096                 }
1097                 ret = MM_MapHWPages(phys, 1);
1098                 if(ret == 0) {
1099                         MM_DerefPhys(phys);
1100                         LEAVE('i', 0);
1101                         return 0;
1102                 }
1103                 LEAVE('x', ret);
1104                 return ret;
1105         }
1106
1107         // Slow Allocate
1108         phys = MM_AllocPhysRange(Pages, MaxBits);
1109         // - Was it allocated?
1110         if(phys == 0) {
1111                 LEAVE('i', 0);
1112                 return 0;
1113         }
1114
1115         // Allocated successfully, now map
1116         ret = MM_MapHWPages(phys, Pages);
1117         if( ret == 0 ) {
1118                 // If it didn't map, free then return 0
1119                 for(;Pages--;phys+=0x1000)
1120                         MM_DerefPhys(phys);
1121                 LEAVE('i', 0);
1122                 return 0;
1123         }
1124
1125         if( PhysAddr )
1126                 *PhysAddr = phys;
1127         LEAVE('x', ret);
1128         return ret;
1129 }
1130
1131 /**
1132  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1133  * \brief Unmap a hardware page
1134  */
1135 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1136 {
1137          int    i, j;
1138
1139         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1140
1141         // Sanity Check
1142         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1143
1144         i = VAddr >> 12;
1145
1146         Mutex_Acquire( &glTempMappings );       // Temp and HW share a directory, so they share a lock
1147
1148         for( j = 0; j < Number; j++ )
1149         {
1150                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1151                 gaPageTable[ i + j ] = 0;
1152                 INVLPG( (tVAddr)(i+j) << 12 );
1153         }
1154
1155         Mutex_Release( &glTempMappings );
1156 }
1157