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