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 #include <semaphore.h>
  21
  22 #define TAB     22
  23
  24 #define WORKER_STACKS           0x00100000      // Thread0 Only!
  25 #define WORKER_STACK_SIZE       MM_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 #define GET_TEMP_MAPPING(cr3) do { \
  60         __ASM__("cli"); \
  61         __AtomicTestSetLoop( (Uint *)gpTmpCR3, cr3 | 3 ); \
  62 } while(0)
  63 #define REL_TEMP_MAPPING() do { \
  64         *gpTmpCR3 = 0; \
  65         __ASM__("sti"); \
  66 } while(0)
  67
  68 typedef Uint32  tTabEnt;
  69
  70 // === IMPORTS ===
  71 extern char     _UsertextEnd[], _UsertextBase[];
  72 extern Uint32   gaInitPageDir[1024];
  73 extern Uint32   gaInitPageTable[1024];
  74 extern void     Threads_SegFault(tVAddr Addr);
  75 extern void     Error_Backtrace(Uint eip, Uint ebp);
  76
  77 // === PROTOTYPES ===
  78 void    MM_PreinitVirtual(void);
  79 void    MM_InstallVirtual(void);
  80 void    MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
  81 //void  MM_DumpTables(tVAddr Start, tVAddr End);
  82 //void  MM_ClearUser(void);
  83 tPAddr  MM_DuplicatePage(tVAddr VAddr);
  84
  85 // === GLOBALS ===
  86 #define gaPageTable     ((tTabEnt*)PAGE_TABLE_ADDR)
  87 #define gaPageDir       ((tTabEnt*)PAGE_DIR_ADDR)
  88 #define gaTmpTable      ((tTabEnt*)TMP_TABLE_ADDR)
  89 #define gaTmpDir        ((tTabEnt*)TMP_DIR_ADDR)
  90 #define gpPageCR3       ((tTabEnt*)PAGE_CR3_ADDR)
  91 #define gpTmpCR3        ((tTabEnt*)TMP_CR3_ADDR)
  92
  93 #define gaPAE_PageTable ((tTabEnt*)PAE_PAGE_TABLE_ADDR)
  94 #define gaPAE_PageDir   ((tTabEnt*)PAE_PAGE_DIR_ADDR)
  95 #define gaPAE_MainPDPT  ((tTabEnt*)PAE_PAGE_PDPT_ADDR)
  96 #define gaPAE_TmpTable  ((tTabEnt*)PAE_TMP_DIR_ADDR)
  97 #define gaPAE_TmpDir    ((tTabEnt*)PAE_TMP_DIR_ADDR)
  98 #define gaPAE_TmpPDPT   ((tTabEnt*)PAE_TMP_PDPT_ADDR)
  99  int    gbUsePAE = 0;
 100 tMutex  glTempMappings;
 101 tSemaphore      gTempMappingsSem;
 102 tMutex  glTempFractal;
 103 Uint32  gWorkerStacks[(NUM_WORKER_STACKS+31)/32];
 104  int    giLastUsedWorker = 0;
 105 struct sPageInfo {
 106         void    *Node;
 107         tVAddr  Base;
 108         Uint64  Offset;
 109          int    Length;
 110          int    Flags;
 111 }       *gaMappedRegions;       // sizeof = 24 bytes
 112
 113 // === CODE ===
 114 /**
 115  * \fn void MM_PreinitVirtual(void)
 116  * \brief Maps the fractal mappings
 117  */
 118 void MM_PreinitVirtual(void)
 119 {
 120         gaInitPageDir[ PAGE_TABLE_ADDR >> 22 ] = ((tTabEnt)&gaInitPageDir - KERNEL_BASE) | 3;
 121         INVLPG( PAGE_TABLE_ADDR );
 122
 123         Semaphore_Init(&gTempMappingsSem, NUM_TEMP_PAGES, NUM_TEMP_PAGES, "MMVirt", "Temp Mappings");
 124 }
 125
 126 /**
 127  * \fn void MM_InstallVirtual(void)
 128  * \brief Sets up the constant page mappings
 129  */
 130 void MM_InstallVirtual(void)
 131 {
 132         // --- Pre-Allocate kernel tables
 133         for( int i = KERNEL_BASE>>22; i < 1024; i ++ )
 134         {
 135                 if( gaPageDir[ i ] )    continue;
 136                 // Skip stack tables, they are process unique
 137                 if( i > MM_KERNEL_STACKS >> 22 && i < MM_KERNEL_STACKS_END >> 22) {
 138                         gaPageDir[ i ] = 0;
 139                         continue;
 140                 }
 141                 // Preallocate table
 142                 gaPageDir[ i ] = MM_AllocPhys() | 3;
 143                 INVLPG( &gaPageTable[i*1024] );
 144                 memset( &gaPageTable[i*1024], 0, 0x1000 );
 145         }
 146
 147         // Unset kernel on the User Text pages
 148         for( int i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
 149                 MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
 150         }
 151
 152         *gpTmpCR3 = 0;
 153 }
 154
 155 /**
 156  * \brief Cleans up the SMP required mappings
 157  */
 158 void MM_FinishVirtualInit(void)
 159 {
 160         gaInitPageDir[ 0 ] = 0;
 161 }
 162
 163 /**
 164  * \fn void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 165  * \brief Called on a page fault
 166  */
 167 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 168 {
 169         //ENTER("xAddr bErrorCode", Addr, ErrorCode);
 170
 171         // -- Check for COW --
 172         if( gaPageDir  [Addr>>22] & PF_PRESENT  && gaPageTable[Addr>>12] & PF_PRESENT
 173          && gaPageTable[Addr>>12] & PF_COW )
 174         {
 175                 tPAddr  paddr;
 176                 __asm__ __volatile__ ("sti");
 177                 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
 178                 {
 179                         gaPageTable[Addr>>12] &= ~PF_COW;
 180                         gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
 181                 }
 182                 else
 183                 {
 184                         //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
 185                         paddr = MM_DuplicatePage( Addr );
 186                         MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
 187                         gaPageTable[Addr>>12] &= PF_USER;
 188                         gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
 189                 }
 190
 191 //              Log_Debug("MMVirt", "COW for %p (%P)", Addr, gaPageTable[Addr>>12]);
 192
 193                 INVLPG( Addr & ~0xFFF );
 194                 return;
 195         }
 196
 197         // Disable instruction tracing
 198         __ASM__("pushf; andw $0xFEFF, 0(%esp); popf");
 199         Proc_GetCurThread()->bInstrTrace = 0;
 200
 201         // If it was a user, tell the thread handler
 202         if(ErrorCode & 4) {
 203                 __asm__ __volatile__ ("sti");
 204                 Log_Warning("MMVirt", "User %s %s memory%s",
 205                         (ErrorCode&2?"write to":"read from"),
 206                         (ErrorCode&1?"bad/locked":"non-present"),
 207                         (ErrorCode&16?" (Instruction Fetch)":"")
 208                         );
 209                 Log_Warning("MMVirt", "Instruction %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
 210                 __ASM__("sti"); // Restart IRQs
 211                 #if 1
 212                 Error_Backtrace(Regs->eip, Regs->ebp);
 213                 #endif
 214                 Threads_SegFault(Addr);
 215                 return ;
 216         }
 217
 218         Debug_KernelPanic();
 219
 220         // -- Check Error Code --
 221         if(ErrorCode & 8)
 222                 Warning("Reserved Bits Trashed!");
 223         else
 224         {
 225                 Warning("Kernel %s %s memory%s",
 226                         (ErrorCode&2?"write to":"read from"),
 227                         (ErrorCode&1?"bad/locked":"non-present"),
 228                         (ErrorCode&16?" (Instruction Fetch)":"")
 229                         );
 230         }
 231
 232         Log("CPU %i - Code at %p accessed %p", GetCPUNum(), Regs->eip, Addr);
 233         // Print Stack Backtrace
 234         Error_Backtrace(Regs->eip, Regs->ebp);
 235
 236         #if 0
 237         Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]);
 238         if( gaPageDir[Addr>>22] & PF_PRESENT )
 239                 Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]);
 240         #endif
 241         //MM_DumpTables(0, -1);
 242
 243         // Register Dump
 244         Log("EAX %08x ECX %08x EDX %08x EBX %08x", Regs->eax, Regs->ecx, Regs->edx, Regs->ebx);
 245         Log("ESP %08x EBP %08x ESI %08x EDI %08x", Regs->esp, Regs->ebp, Regs->esi, Regs->edi);
 246         //Log("SS:ESP %04x:%08x", Regs->ss, Regs->esp);
 247         Log("CS:EIP %04x:%08x", Regs->cs, Regs->eip);
 248         Log("DS %04x ES %04x FS %04x GS %04x", Regs->ds, Regs->es, Regs->fs, Regs->gs);
 249         {
 250                 Uint    dr0, dr1;
 251                 __ASM__ ("mov %%dr0, %0":"=r"(dr0):);
 252                 __ASM__ ("mov %%dr1, %0":"=r"(dr1):);
 253                 Log("DR0 %08x DR1 %08x", dr0, dr1);
 254         }
 255
 256         Panic("Page Fault at 0x%x (Accessed 0x%x)", Regs->eip, Addr);
 257 }
 258
 259 /**
 260  * \fn void MM_DumpTables(tVAddr Start, tVAddr End)
 261  * \brief Dumps the layout of the page tables
 262  */
 263 void MM_DumpTables(tVAddr Start, tVAddr End)
 264 {
 265         tVAddr  rangeStart = 0;
 266         tPAddr  expected = 0;
 267         void    *expected_node = NULL, *tmpnode = NULL;
 268         tVAddr  curPos;
 269         Uint    page;
 270         const tPAddr    MASK = ~0xF78;
 271
 272         Start >>= 12;   End >>= 12;
 273
 274         #if 0
 275         Log("Directory Entries:");
 276         for(page = Start >> 10;
 277                 page < (End >> 10)+1;
 278                 page ++)
 279         {
 280                 if(gaPageDir[page])
 281                 {
 282                         Log(" 0x%08x-0x%08x :: 0x%08x",
 283                                 page<<22, ((page+1)<<22)-1,
 284                                 gaPageDir[page]&~0xFFF
 285                                 );
 286                 }
 287         }
 288         #endif
 289
 290         Log("Table Entries:");
 291         for(page = Start, curPos = Start<<12;
 292                 page < End;
 293                 curPos += 0x1000, page++)
 294         {
 295                 if( !(gaPageDir[curPos>>22] & PF_PRESENT)
 296                 ||  !(gaPageTable[page] & PF_PRESENT)
 297                 ||  (gaPageTable[page] & MASK) != expected
 298                 ||  (tmpnode=NULL,MM_GetPageNode(expected, &tmpnode), tmpnode != expected_node))
 299                 {
 300                         if(expected) {
 301                                 tPAddr  orig = gaPageTable[rangeStart>>12];
 302                                 Log(" 0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 303                                         rangeStart,
 304                                         orig & ~0xFFF,
 305                                         curPos - rangeStart,
 306                                         (orig & PF_NOPAGE ? "P" : "-"),
 307                                         (orig & PF_COW ? "C" : "-"),
 308                                         (orig & PF_GLOBAL ? "G" : "-"),
 309                                         (orig & PF_USER ? "U" : "-"),
 310                                         (orig & PF_WRITE ? "W" : "-"),
 311                                         expected_node
 312                                         );
 313                                 expected = 0;
 314                         }
 315                         if( !(gaPageDir[curPos>>22] & PF_PRESENT) )     continue;
 316                         if( !(gaPageTable[curPos>>12] & PF_PRESENT) )   continue;
 317
 318                         expected = (gaPageTable[page] & MASK);
 319                         MM_GetPageNode(expected, &expected_node);
 320                         rangeStart = curPos;
 321                 }
 322                 if(expected)    expected += 0x1000;
 323         }
 324
 325         if(expected) {
 326                 tPAddr  orig = gaPageTable[rangeStart>>12];
 327                 Log("0x%08x => 0x%08x - 0x%08x (%s%s%s%s%s) %p",
 328                         rangeStart,
 329                         orig & ~0xFFF,
 330                         curPos - rangeStart,
 331                         (orig & PF_NOPAGE ? "p" : "-"),
 332                         (orig & PF_COW ? "C" : "-"),
 333                         (orig & PF_GLOBAL ? "G" : "-"),
 334                         (orig & PF_USER ? "U" : "-"),
 335                         (orig & PF_WRITE ? "W" : "-"),
 336                         expected_node
 337                         );
 338                 expected = 0;
 339         }
 340 }
 341
 342 /**
 343  * \fn tPAddr MM_Allocate(tVAddr VAddr)
 344  */
 345 tPAddr MM_Allocate(tVAddr VAddr)
 346 {
 347         tPAddr  paddr;
 348         //ENTER("xVAddr", VAddr);
 349         //__ASM__("xchg %bx,%bx");
 350         // Check if the directory is mapped
 351         if( gaPageDir[ VAddr >> 22 ] == 0 )
 352         {
 353                 // Allocate directory
 354                 paddr = MM_AllocPhys();
 355                 if( paddr == 0 ) {
 356                         Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
 357                         //LEAVE('i',0);
 358                         return 0;
 359                 }
 360                 // Map and mark as user (if needed)
 361                 gaPageDir[ VAddr >> 22 ] = paddr | 3;
 362                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 363
 364                 INVLPG( &gaPageDir[ VAddr >> 22 ] );
 365                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 366         }
 367         // Check if the page is already allocated
 368         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 369                 Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
 370                 //LEAVE('X', gaPageTable[ VAddr >> 12 ] & ~0xFFF);
 371                 return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
 372         }
 373
 374         // Allocate
 375         paddr = MM_AllocPhys();
 376         //LOG("paddr = 0x%llx", paddr);
 377         if( paddr == 0 ) {
 378                 Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
 379                         VAddr, __builtin_return_address(0));
 380                 //LEAVE('i',0);
 381                 return 0;
 382         }
 383         // Map
 384         gaPageTable[ VAddr >> 12 ] = paddr | 3;
 385         // Mark as user
 386         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 387         // Invalidate Cache for address
 388         INVLPG( VAddr & ~0xFFF );
 389
 390         //LEAVE('X', paddr);
 391         return paddr;
 392 }
 393
 394 /**
 395  * \fn void MM_Deallocate(tVAddr VAddr)
 396  */
 397 void MM_Deallocate(tVAddr VAddr)
 398 {
 399         if( gaPageDir[ VAddr >> 22 ] == 0 ) {
 400                 Warning("MM_Deallocate - Directory not mapped");
 401                 return;
 402         }
 403
 404         if(gaPageTable[ VAddr >> 12 ] == 0) {
 405                 Warning("MM_Deallocate - Page is not allocated");
 406                 return;
 407         }
 408
 409         // Dereference page
 410         MM_DerefPhys( gaPageTable[ VAddr >> 12 ] & ~0xFFF );
 411         // Clear page
 412         gaPageTable[ VAddr >> 12 ] = 0;
 413 }
 414
 415 /**
 416  * \fn tPAddr MM_GetPhysAddr(tVAddr Addr)
 417  * \brief Checks if the passed address is accesable
 418  */
 419 tPAddr MM_GetPhysAddr(volatile const void *Addr)
 420 {
 421         tVAddr  addr = (tVAddr)Addr;
 422         if( !(gaPageDir[addr >> 22] & 1) )
 423                 return 0;
 424         if( !(gaPageTable[addr >> 12] & 1) )
 425                 return 0;
 426         return (gaPageTable[addr >> 12] & ~0xFFF) | (addr & 0xFFF);
 427 }
 428
 429 /**
 430  * \fn void MM_SetCR3(Uint CR3)
 431  * \brief Sets the current process space
 432  */
 433 void MM_SetCR3(Uint CR3)
 434 {
 435         __ASM__("mov %0, %%cr3"::"r"(CR3));
 436 }
 437
 438 /**
 439  * \fn int MM_Map(tVAddr VAddr, tPAddr PAddr)
 440  * \brief Map a physical page to a virtual one
 441  */
 442 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 443 {
 444         //ENTER("xVAddr xPAddr", VAddr, PAddr);
 445         // Sanity check
 446         if( PAddr & 0xFFF || VAddr & 0xFFF ) {
 447                 Log_Warning("MM_Virt", "MM_Map - Physical or Virtual Addresses are not aligned (0x%P and %p)",
 448                         PAddr, VAddr);
 449                 //LEAVE('i', 0);
 450                 return 0;
 451         }
 452
 453         // Align addresses
 454         PAddr &= ~0xFFF;        VAddr &= ~0xFFF;
 455
 456         // Check if the directory is mapped
 457         if( gaPageDir[ VAddr >> 22 ] == 0 )
 458         {
 459                 tPAddr  tmp = MM_AllocPhys();
 460                 if( tmp == 0 )
 461                         return 0;
 462                 gaPageDir[ VAddr >> 22 ] = tmp | 3;
 463
 464                 // Mark as user
 465                 if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER;
 466
 467                 INVLPG( &gaPageTable[ (VAddr >> 12) & ~0x3FF ] );
 468                 memsetd( &gaPageTable[ (VAddr >> 12) & ~0x3FF ], 0, 1024 );
 469         }
 470         // Check if the page is already allocated
 471         else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
 472                 Warning("MM_Map - Allocating to used address");
 473                 //LEAVE('i', 0);
 474                 return 0;
 475         }
 476
 477         // Map
 478         gaPageTable[ VAddr >> 12 ] = PAddr | 3;
 479         // Mark as user
 480         if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER;
 481
 482         //LOG("gaPageTable[ 0x%x ] = (Uint)%p = 0x%x",
 483         //      VAddr >> 12, &gaPageTable[ VAddr >> 12 ], gaPageTable[ VAddr >> 12 ]);
 484
 485         // Reference
 486         MM_RefPhys( PAddr );
 487
 488         //LOG("INVLPG( 0x%x )", VAddr);
 489         INVLPG( VAddr );
 490
 491         //LEAVE('i', 1);
 492         return 1;
 493 }
 494
 495 /**
 496  * \brief Clear user's address space
 497  */
 498 void MM_ClearUser(void)
 499 {
 500         Uint    i, j;
 501
 502         for( i = 0; i < (MM_USER_MAX>>22); i ++ )
 503         {
 504                 // Check if directory is not allocated
 505                 if( !(gaPageDir[i] & PF_PRESENT) ) {
 506                         gaPageDir[i] = 0;
 507                         continue;
 508                 }
 509
 510                 // Deallocate tables
 511                 for( j = 0; j < 1024; j ++ )
 512                 {
 513                         if( gaPageTable[i*1024+j] & 1 )
 514                                 MM_DerefPhys( gaPageTable[i*1024+j] & ~0xFFF );
 515                         gaPageTable[i*1024+j] = 0;
 516                 }
 517
 518                 // Deallocate directory
 519                 MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 520                 gaPageDir[i] = 0;
 521                 INVLPG( &gaPageTable[i*1024] );
 522         }
 523         INVLPG( gaPageDir );
 524 }
 525
 526 /**
 527  * \brief Deallocate an address space
 528  */
 529 void MM_ClearSpace(Uint32 CR3)
 530 {
 531          int    i, j;
 532
 533         if(CR3 == (*gpPageCR3 & ~0xFFF)) {
 534                 Log_Error("MMVirt", "Can't clear current address space");
 535                 return ;
 536         }
 537
 538         if( MM_GetRefCount(CR3) > 1 ) {
 539                 MM_DerefPhys(CR3);
 540                 Log_Log("MMVirt", "CR3 %P is still referenced, not cleaning (but dereferenced)", CR3);
 541                 return ;
 542         }
 543
 544         Log_Debug("MMVirt", "Clearing out address space 0x%x from 0x%x", CR3, *gpPageCR3);
 545
 546         GET_TEMP_MAPPING(CR3);
 547         INVLPG( gaTmpDir );
 548
 549         for( i = 0; i < 1024; i ++ )
 550         {
 551                 Uint32  *table = &gaTmpTable[i*1024];
 552                 if( !(gaTmpDir[i] & PF_PRESENT) )
 553                         continue ;
 554
 555                 INVLPG( table );
 556
 557                 if( i < 768 || (i > MM_KERNEL_STACKS >> 22 && i < MM_KERNEL_STACKS_END >> 22) )
 558                 {
 559                         for( j = 0; j < 1024; j ++ )
 560                         {
 561                                 if( !(table[j] & 1) )
 562                                         continue;
 563                                 MM_DerefPhys( table[j] & ~0xFFF );
 564                         }
 565                 }
 566
 567                 if( i != (PAGE_TABLE_ADDR >> 22) )
 568                 {
 569                         MM_DerefPhys( gaTmpDir[i] & ~0xFFF );
 570                 }
 571         }
 572
 573
 574         MM_DerefPhys( CR3 );
 575
 576         REL_TEMP_MAPPING();
 577 }
 578
 579 /**
 580  * \fn tPAddr MM_Clone(void)
 581  * \brief Clone the current address space
 582  */
 583 tPAddr MM_Clone(int bNoUserCopy)
 584 {
 585         Uint    i, j;
 586         tPAddr  ret;
 587         Uint    page = 0;
 588         tVAddr  kStackBase = Proc_GetCurThread()->KernelStack - MM_KERNEL_STACK_SIZE;
 589         void    *tmp;
 590
 591         // Create Directory Table
 592         ret = MM_AllocPhys();
 593         if( ret == 0 ) {
 594                 return 0;
 595         }
 596
 597         // Map
 598         GET_TEMP_MAPPING( ret );
 599         INVLPG( gaTmpDir );
 600         memsetd( gaTmpDir, 0, 1024 );
 601
 602         if( Threads_GetPID() != 0 && !bNoUserCopy )
 603         {
 604                 // Copy Tables
 605                 for( i = 0; i < 768; i ++)
 606                 {
 607                         // Check if table is allocated
 608                         if( !(gaPageDir[i] & PF_PRESENT) ) {
 609                                 gaTmpDir[i] = 0;
 610                                 page += 1024;
 611                                 continue;
 612                         }
 613
 614                         // Allocate new table
 615                         gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7);
 616                         INVLPG( &gaTmpTable[page] );
 617                         // Fill
 618                         for( j = 0; j < 1024; j ++, page++ )
 619                         {
 620                                 if( !(gaPageTable[page] & PF_PRESENT) ) {
 621                                         gaTmpTable[page] = 0;
 622                                         continue;
 623                                 }
 624
 625                                 // Refrence old page
 626                                 MM_RefPhys( gaPageTable[page] & ~0xFFF );
 627                                 // Add to new table
 628                                 if(gaPageTable[page] & PF_WRITE) {
 629                                         gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 630                                         gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW;
 631                                         INVLPG( page << 12 );
 632                                 }
 633                                 else
 634                                         gaTmpTable[page] = gaPageTable[page];
 635                         }
 636                 }
 637         }
 638
 639         // Map in kernel tables (and make fractal mapping)
 640         for( i = 768; i < 1024; i ++ )
 641         {
 642                 // Fractal
 643                 if( i == (PAGE_TABLE_ADDR >> 22) ) {
 644                         gaTmpDir[ PAGE_TABLE_ADDR >> 22 ] = *gpTmpCR3;
 645                         continue;
 646                 }
 647                 if( i == (TMP_TABLE_ADDR >> 22) ) {
 648                         gaTmpDir[ TMP_TABLE_ADDR >> 22 ] = 0;
 649                         continue ;
 650                 }
 651
 652                 if( gaPageDir[i] == 0 ) {
 653                         gaTmpDir[i] = 0;
 654                         continue;
 655                 }
 656
 657                 //LOG("gaPageDir[%x/4] = 0x%x", i*4, gaPageDir[i]);
 658                 MM_RefPhys( gaPageDir[i] & ~0xFFF );
 659                 gaTmpDir[i] = gaPageDir[i];
 660         }
 661
 662         // Allocate kernel stack
 663         for(i = MM_KERNEL_STACKS >> 22; i < MM_KERNEL_STACKS_END >> 22; i ++ )
 664         {
 665                 // Check if directory is allocated
 666                 if( (gaPageDir[i] & 1) == 0 ) {
 667                         gaTmpDir[i] = 0;
 668                         continue;
 669                 }
 670
 671                 // We don't care about other kernel stacks, just the current one
 672                 if( i != kStackBase >> 22 ) {
 673                         MM_DerefPhys( gaPageDir[i] & ~0xFFF );
 674                         gaTmpDir[i] = 0;
 675                         continue;
 676                 }
 677
 678                 // Create a copy
 679                 gaTmpDir[i] = MM_AllocPhys() | 3;
 680                 INVLPG( &gaTmpTable[i*1024] );
 681                 for( j = 0; j < 1024; j ++ )
 682                 {
 683                         // Is the page allocated? If not, skip
 684                         if( !(gaPageTable[i*1024+j] & 1) ) {
 685                                 gaTmpTable[i*1024+j] = 0;
 686                                 continue;
 687                         }
 688
 689                         // We don't care about other kernel stacks
 690                         if( ((i*1024+j)*4096 & ~(MM_KERNEL_STACK_SIZE-1)) != kStackBase ) {
 691                                 gaTmpTable[i*1024+j] = 0;
 692                                 continue;
 693                         }
 694
 695                         // Allocate page
 696                         gaTmpTable[i*1024+j] = MM_AllocPhys() | 3;
 697
 698                         MM_RefPhys( gaTmpTable[i*1024+j] & ~0xFFF );
 699
 700                         tmp = MM_MapTemp( gaTmpTable[i*1024+j] & ~0xFFF );
 701                         memcpy( tmp, (void *)( (i*1024+j)*0x1000 ), 0x1000 );
 702                         MM_FreeTemp( tmp );
 703                 }
 704         }
 705
 706         REL_TEMP_MAPPING();
 707
 708         //LEAVE('x', ret);
 709         return ret;
 710 }
 711
 712 /**
 713  * \fn tVAddr MM_NewKStack(void)
 714  * \brief Create a new kernel stack
 715  */
 716 tVAddr MM_NewKStack(void)
 717 {
 718         tVAddr  base;
 719         Uint    i;
 720         for(base = MM_KERNEL_STACKS; base < MM_KERNEL_STACKS_END; base += MM_KERNEL_STACK_SIZE)
 721         {
 722                 // Check if space is free
 723                 if(MM_GetPhysAddr( (void*) base) != 0)
 724                         continue;
 725                 // Allocate
 726                 //for(i = MM_KERNEL_STACK_SIZE; i -= 0x1000 ; )
 727                 for(i = 0; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 728                 {
 729                         if( MM_Allocate(base+i) == 0 )
 730                         {
 731                                 // On error, print a warning and return error
 732                                 Warning("MM_NewKStack - Out of memory");
 733                                 // - Clean up
 734                                 //for( i += 0x1000 ; i < MM_KERNEL_STACK_SIZE; i += 0x1000 )
 735                                 //      MM_Deallocate(base+i);
 736                                 return 0;
 737                         }
 738                 }
 739                 // Success
 740 //              Log("MM_NewKStack - Allocated %p", base + MM_KERNEL_STACK_SIZE);
 741                 return base+MM_KERNEL_STACK_SIZE;
 742         }
 743         // No stacks left
 744         Log_Warning("MMVirt", "MM_NewKStack - No address space left");
 745         return 0;
 746 }
 747
 748 /**
 749  * \fn tVAddr MM_NewWorkerStack()
 750  * \brief Creates a new worker stack
 751  */
 752 tVAddr MM_NewWorkerStack(Uint *StackContents, size_t ContentsSize)
 753 {
 754         Uint    base;
 755         tPAddr  page;
 756
 757         LOG("(StackContents=%p,ContentsSize=%i)", StackContents, ContentsSize);
 758         // TODO: Thread safety
 759         // Find a free worker stack address
 760         for(base = giLastUsedWorker; base < NUM_WORKER_STACKS; base++)
 761         {
 762                 // Used block
 763                 if( gWorkerStacks[base/32] == -1 ) {
 764                         base += 31;     base &= ~31;
 765                         base --;        // Counteracted by the base++
 766                         continue;
 767                 }
 768                 // Used stack
 769                 if( gWorkerStacks[base/32] & (1 << base) ) {
 770                         continue;
 771                 }
 772                 break;
 773         }
 774         if(base >= NUM_WORKER_STACKS) {
 775                 Log_Error("MMVirt", "Uh-oh! Out of worker stacks");
 776                 return 0;
 777         }
 778         LOG("base=0x%x", base);
 779
 780         // It's ours now!
 781         gWorkerStacks[base/32] |= (1 << base);
 782         // Make life easier for later calls
 783         giLastUsedWorker = base;
 784         // We have one
 785         base = WORKER_STACKS + base * WORKER_STACK_SIZE;
 786         //Log(" MM_NewWorkerStack: base = 0x%x", base);
 787         LOG("base=%p (top)", base);
 788
 789         // Set the temp fractals to TID0's address space
 790         GET_TEMP_MAPPING( ((Uint)gaInitPageDir - KERNEL_BASE) );
 791         INVLPG( gaTmpDir );
 792
 793         // Check if the directory is mapped (we are assuming that the stacks
 794         // will fit neatly in a directory)
 795         LOG("gaTmpDir[ 0x%x ] = 0x%x", base>>22, gaTmpDir[ base >> 22 ]);
 796         if(gaTmpDir[ base >> 22 ] == 0) {
 797                 gaTmpDir[ base >> 22 ] = MM_AllocPhys() | 3;
 798                 INVLPG( &gaTmpTable[ (base>>12) & ~0x3FF ] );
 799         }
 800
 801         // Mapping Time!
 802         for( Uint addr = 0; addr < WORKER_STACK_SIZE; addr += 0x1000 )
 803         {
 804                 page = MM_AllocPhys();
 805                 gaTmpTable[ (base + addr) >> 12 ] = page | 3;
 806         }
 807         LOG("mapped");
 808
 809         // Release temporary fractal
 810         REL_TEMP_MAPPING();
 811
 812         // NOTE: Max of 1 page
 813         // `page` is the last allocated page from the previious for loop
 814         LOG("Mapping first page");
 815         char    *tmpPage = MM_MapTemp( page );
 816         LOG("tmpPage=%p", tmpPage);
 817         memcpy( tmpPage + (0x1000 - ContentsSize), StackContents, ContentsSize);
 818         MM_FreeTemp( tmpPage );
 819
 820         //Log("MM_NewWorkerStack: RETURN 0x%x", base);
 821         LOG("return %p", base+WORKER_STACK_SIZE);
 822         return base + WORKER_STACK_SIZE;
 823 }
 824
 825 /**
 826  * \fn void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 827  * \brief Sets the flags on a page
 828  */
 829 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 830 {
 831         tTabEnt *ent;
 832         if( !(gaPageDir[VAddr >> 22] & 1) )     return ;
 833         if( !(gaPageTable[VAddr >> 12] & 1) )   return ;
 834
 835         ent = &gaPageTable[VAddr >> 12];
 836
 837         // Read-Only
 838         if( Mask & MM_PFLAG_RO )
 839         {
 840                 if( Flags & MM_PFLAG_RO ) {
 841                         *ent &= ~PF_WRITE;
 842                 }
 843                 else {
 844                         gaPageDir[VAddr >> 22] |= PF_WRITE;
 845                         *ent |= PF_WRITE;
 846                 }
 847         }
 848
 849         // Kernel
 850         if( Mask & MM_PFLAG_KERNEL )
 851         {
 852                 if( Flags & MM_PFLAG_KERNEL ) {
 853                         *ent &= ~PF_USER;
 854                 }
 855                 else {
 856                         gaPageDir[VAddr >> 22] |= PF_USER;
 857                         *ent |= PF_USER;
 858                 }
 859         }
 860
 861         // Copy-On-Write
 862         if( Mask & MM_PFLAG_COW )
 863         {
 864                 if( Flags & MM_PFLAG_COW ) {
 865                         *ent &= ~PF_WRITE;
 866                         *ent |= PF_COW;
 867                 }
 868                 else {
 869                         *ent &= ~PF_COW;
 870                         *ent |= PF_WRITE;
 871                 }
 872         }
 873
 874         //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
 875         //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 876 }
 877
 878 /**
 879  * \brief Get the flags on a page
 880  */
 881 Uint MM_GetFlags(tVAddr VAddr)
 882 {
 883         tTabEnt *ent;
 884         Uint    ret = 0;
 885
 886         // Validity Check
 887         if( !(gaPageDir[VAddr >> 22] & 1) )     return 0;
 888         if( !(gaPageTable[VAddr >> 12] & 1) )   return 0;
 889
 890         ent = &gaPageTable[VAddr >> 12];
 891
 892         // Read-Only
 893         if( !(*ent & PF_WRITE) )        ret |= MM_PFLAG_RO;
 894         // Kernel
 895         if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
 896         // Copy-On-Write
 897         if( *ent & PF_COW )     ret |= MM_PFLAG_COW;
 898
 899         return ret;
 900 }
 901
 902 /**
 903  * \brief Check if the provided buffer is valid
 904  * \return Boolean valid
 905  */
 906 int MM_IsValidBuffer(tVAddr Addr, size_t Size)
 907 {
 908          int    bIsUser;
 909          int    dir, tab;
 910
 911         Size += Addr & (PAGE_SIZE-1);
 912         Addr &= ~(PAGE_SIZE-1);
 913
 914         dir = Addr >> 22;
 915         tab = Addr >> 12;
 916
 917 //      Debug("Addr = %p, Size = 0x%x, dir = %i, tab = %i", Addr, Size, dir, tab);
 918
 919         if( !(gaPageDir[dir] & 1) )     return 0;
 920         if( !(gaPageTable[tab] & 1) )   return 0;
 921
 922         bIsUser = !!(gaPageTable[tab] & PF_USER);
 923
 924         while( Size >= PAGE_SIZE )
 925         {
 926                 if( (tab & 1023) == 0 )
 927                 {
 928                         dir ++;
 929                         if( !(gaPageDir[dir] & 1) )     return 0;
 930                 }
 931
 932                 if( !(gaPageTable[tab] & 1) )   return 0;
 933                 if( bIsUser && !(gaPageTable[tab] & PF_USER) )  return 0;
 934
 935                 tab ++;
 936                 Size -= PAGE_SIZE;
 937         }
 938         return 1;
 939 }
 940
 941 /**
 942  * \fn tPAddr MM_DuplicatePage(tVAddr VAddr)
 943  * \brief Duplicates a virtual page to a physical one
 944  */
 945 tPAddr MM_DuplicatePage(tVAddr VAddr)
 946 {
 947         tPAddr  ret;
 948         void    *temp;
 949          int    wasRO = 0;
 950
 951         //ENTER("xVAddr", VAddr);
 952
 953         // Check if mapped
 954         if( !(gaPageDir  [VAddr >> 22] & PF_PRESENT) )  return 0;
 955         if( !(gaPageTable[VAddr >> 12] & PF_PRESENT) )  return 0;
 956
 957         // Page Align
 958         VAddr &= ~0xFFF;
 959
 960         // Allocate new page
 961         ret = MM_AllocPhys();
 962         if( !ret ) {
 963                 return 0;
 964         }
 965
 966         // Write-lock the page (to keep data constistent), saving its R/W state
 967         wasRO = (gaPageTable[VAddr >> 12] & PF_WRITE ? 0 : 1);
 968         gaPageTable[VAddr >> 12] &= ~PF_WRITE;
 969         INVLPG( VAddr );
 970
 971         // Copy Data
 972         temp = MM_MapTemp(ret);
 973         memcpy( temp, (void*)VAddr, 0x1000 );
 974         MM_FreeTemp(temp);
 975
 976         // Restore Writeable status
 977         if(!wasRO)      gaPageTable[VAddr >> 12] |= PF_WRITE;
 978         INVLPG(VAddr);
 979
 980         //LEAVE('X', ret);
 981         return ret;
 982 }
 983
 984 /**
 985  * \fn Uint MM_MapTemp(tPAddr PAddr)
 986  * \brief Create a temporary memory mapping
 987  * \todo Show Luigi Barone (C Lecturer) and see what he thinks
 988  */
 989 void *MM_MapTemp(tPAddr PAddr)
 990 {
 991         ENTER("PPAddr", PAddr);
 992
 993         PAddr &= ~0xFFF;
 994
 995         if( Semaphore_Wait(&gTempMappingsSem, 1) != 1 )
 996                 return NULL;
 997         LOG("Semaphore good");
 998         Mutex_Acquire( &glTempMappings );
 999         for( int i = 0; i < NUM_TEMP_PAGES; i ++ )
1000         {
1001                 Uint32  *pte = &gaPageTable[ (TEMP_MAP_ADDR >> 12) + i ];
1002                 LOG("%i: %x", i, *pte);
1003                 // Check if page used
1004                 if(*pte & 1)    continue;
1005                 // Mark as used
1006                 *pte = PAddr | 3;
1007                 INVLPG( TEMP_MAP_ADDR + (i << 12) );
1008                 LEAVE('p', TEMP_MAP_ADDR + (i << 12));
1009                 Mutex_Release( &glTempMappings );
1010                 return (void*)( TEMP_MAP_ADDR + (i << 12) );
1011         }
1012         Mutex_Release( &glTempMappings );
1013         Log_KernelPanic("MMVirt", "Semaphore suplied a mapping, but none are avaliable");
1014         return NULL;
1015 }
1016
1017 /**
1018  * \fn void MM_FreeTemp(tVAddr PAddr)
1019  * \brief Free's a temp mapping
1020  */
1021 void MM_FreeTemp(void *VAddr)
1022 {
1023          int    i = (tVAddr)VAddr >> 12;
1024         //ENTER("xVAddr", VAddr);
1025
1026         if(i >= (TEMP_MAP_ADDR >> 12)) {
1027                 gaPageTable[ i ] = 0;
1028                 Semaphore_Signal(&gTempMappingsSem, 1);
1029         }
1030
1031         //LEAVE('-');
1032 }
1033
1034 /**
1035  * \fn tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
1036  * \brief Allocates a contigous number of pages
1037  */
1038 void *MM_MapHWPages(tPAddr PAddr, Uint Number)
1039 {
1040          int    j;
1041
1042         PAddr &= ~0xFFF;
1043
1044         if( PAddr < 1024*1024 && (1024*1024-PAddr) >= Number * PAGE_SIZE )
1045         {
1046                 return (void*)(KERNEL_BASE + PAddr);
1047         }
1048
1049         // Scan List
1050         for( int i = 0; i < NUM_HW_PAGES; i ++ )
1051         {
1052                 // Check if addr used
1053                 if( gaPageTable[ (HW_MAP_ADDR >> 12) + i ] & 1 )
1054                         continue;
1055
1056                 // Check possible region
1057                 for( j = 0; j < Number && i + j < NUM_HW_PAGES; j ++ )
1058                 {
1059                         // If there is an allocated page in the region we are testing, break
1060                         if( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & 1 )    break;
1061                 }
1062                 // Is it all free?
1063                 if( j == Number )
1064                 {
1065                         // Allocate
1066                         for( j = 0; j < Number; j++ ) {
1067                                 MM_RefPhys( PAddr + (j<<12) );
1068                                 gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = (PAddr + (j<<12)) | 3;
1069                         }
1070                         return (void*)(HW_MAP_ADDR + (i<<12));
1071                 }
1072         }
1073         // If we don't find any, return NULL
1074         return 0;
1075 }
1076
1077 /**
1078  * \fn tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1079  * \brief Allocates DMA physical memory
1080  * \param Pages Number of pages required
1081  * \param MaxBits       Maximum number of bits the physical address can have
1082  * \param PhysAddr      Pointer to the location to place the physical address allocated
1083  * \return Virtual address allocate
1084  */
1085 void *MM_AllocDMA(int Pages, int MaxBits, tPAddr *PhysAddr)
1086 {
1087         tPAddr  phys;
1088         void    *ret;
1089
1090         ENTER("iPages iMaxBits pPhysAddr", Pages, MaxBits, PhysAddr);
1091
1092         if(MaxBits == -1)
1093                 MaxBits = PHYS_BITS;
1094
1095         // Sanity Check
1096         if(MaxBits < 12) {
1097                 LEAVE('i', 0);
1098                 return 0;
1099         }
1100
1101         // Fast Allocate
1102         if(Pages == 1 && MaxBits >= PHYS_BITS)
1103         {
1104                 phys = MM_AllocPhys();
1105                 if( PhysAddr )
1106                         *PhysAddr = phys;
1107                 if( !phys ) {
1108                         LEAVE_RET('i', 0);
1109                 }
1110                 ret = MM_MapHWPages(phys, 1);
1111                 if(ret == 0) {
1112                         MM_DerefPhys(phys);
1113                         LEAVE('i', 0);
1114                         return 0;
1115                 }
1116                 LEAVE('x', ret);
1117                 return (void*)ret;
1118         }
1119
1120         // Slow Allocate
1121         phys = MM_AllocPhysRange(Pages, MaxBits);
1122         // - Was it allocated?
1123         if(phys == 0) {
1124                 LEAVE('i', 0);
1125                 return 0;
1126         }
1127
1128         // Allocated successfully, now map
1129         ret = MM_MapHWPages(phys, Pages);
1130         if( ret == 0 ) {
1131                 // If it didn't map, free then return 0
1132                 for(;Pages--;phys+=0x1000)
1133                         MM_DerefPhys(phys);
1134                 LEAVE('i', 0);
1135                 return 0;
1136         }
1137
1138         if( PhysAddr )
1139                 *PhysAddr = phys;
1140         LEAVE('x', ret);
1141         return (void*)ret;
1142 }
1143
1144 /**
1145  * \fn void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1146  * \brief Unmap a hardware page
1147  */
1148 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
1149 {
1150          int    i, j;
1151
1152         //Log_Debug("VirtMem", "MM_UnmapHWPages: (VAddr=0x%08x, Number=%i)", VAddr, Number);
1153
1154         //
1155         if( KERNEL_BASE <= VAddr && VAddr < KERNEL_BASE + 1024*1024 )
1156                 return ;
1157
1158         // Sanity Check
1159         if(VAddr < HW_MAP_ADDR || VAddr+Number*0x1000 > HW_MAP_MAX)     return;
1160
1161         i = VAddr >> 12;
1162
1163         Mutex_Acquire( &glTempMappings );       // Temp and HW share a directory, so they share a lock
1164
1165         for( j = 0; j < Number; j++ )
1166         {
1167                 MM_DerefPhys( gaPageTable[ i + j ] & ~0xFFF );
1168                 gaPageTable[ i + j ] = 0;
1169                 INVLPG( (tVAddr)(i+j) << 12 );
1170         }
1171
1172         Mutex_Release( &glTempMappings );
1173 }
1174