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