Kernel/arch/armv7/mm_virt.c

   1 /*
   2  * Acess2
   3  *
   4  * ARM7 Virtual Memory Manager
   5  * - arch/arm7/mm_virt.c
   6  */
   7 #define DEBUG   0
   8 #include <acess.h>
   9 #include <mm_virt.h>
  10 #include <hal_proc.h>
  11
  12 #define TRACE_MAPS      0
  13
  14 #define AP_KRW_ONLY     1       // Kernel page
  15 #define AP_KRO_ONLY     5       // Kernel RO page
  16 #define AP_RW_BOTH      3       // Standard RW
  17 #define AP_RO_BOTH      7       // COW Page
  18 #define AP_RO_USER      2       // User RO Page
  19 #define PADDR_MASK_LVL1 0xFFFFFC00
  20
  21 // === IMPORTS ===
  22 extern Uint32   kernel_table0[];
  23
  24 // === TYPES ===
  25 typedef struct
  26 {
  27         tPAddr  PhysAddr;
  28         Uint8   Size;
  29         Uint8   Domain;
  30         BOOL    bExecutable;
  31         BOOL    bGlobal;
  32         BOOL    bShared;
  33          int    AP;
  34 } tMM_PageInfo;
  35
  36 //#define FRACTAL(table1, addr) ((table1)[ (0xFF8/4*1024) + ((addr)>>20)])
  37 #define FRACTAL(table1, addr)   ((table1)[ (0xFF8/4*1024) + ((addr)>>22)])
  38 #define USRFRACTAL(addr)        (*((Uint32*)(0x7FDFF000) + ((addr)>>22)))
  39 #define TLBIALL()       __asm__ __volatile__ ("mcr p15, 0, %0, c8, c7, 0" : : "r" (0))
  40 #define TLBIMVA(addr)   __asm__ __volatile__ ("mcr p15, 0, %0, c8, c7, 1" : : "r" (addr))
  41
  42 // === PROTOTYPES ===
  43 void    MM_int_GetTables(tVAddr VAddr, Uint32 **Table0, Uint32 **Table1);
  44  int    MM_int_AllocateCoarse(tVAddr VAddr, int Domain);
  45  int    MM_int_SetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
  46  int    MM_int_GetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
  47 tVAddr  MM_NewUserStack(void);
  48 tPAddr  MM_AllocateZero(tVAddr VAddr);
  49 tPAddr  MM_AllocateRootTable(void);
  50 void    MM_int_CloneTable(Uint32 *DestEnt, int Table);
  51 tPAddr  MM_Clone(void);
  52 tVAddr  MM_NewKStack(int bGlobal);
  53 void    MM_int_DumpTableEnt(tVAddr Start, size_t Len, tMM_PageInfo *Info);
  54 //void  MM_DumpTables(tVAddr Start, tVAddr End);
  55 void    MM_PageFault(Uint32 PC, Uint32 Addr, Uint32 DFSR, int bPrefetch);
  56
  57 // === GLOBALS ===
  58 tPAddr  giMM_ZeroPage;
  59
  60 // === CODE ===
  61 int MM_InitialiseVirtual(void)
  62 {
  63         return 0;
  64 }
  65
  66 void MM_int_GetTables(tVAddr VAddr, Uint32 **Table0, Uint32 **Table1)
  67 {
  68         if(VAddr & 0x80000000) {
  69                 *Table0 = (void*)&kernel_table0;        // Level 0
  70                 *Table1 = (void*)MM_TABLE1KERN; // Level 1
  71         }
  72         else {
  73                 *Table0 = (void*)MM_TABLE0USER;
  74                 *Table1 = (void*)MM_TABLE1USER;
  75         }
  76 }
  77
  78 int MM_int_AllocateCoarse(tVAddr VAddr, int Domain)
  79 {
  80         Uint32  *table0, *table1;
  81         Uint32  *desc;
  82         tPAddr  paddr;
  83
  84         ENTER("xVAddr iDomain", VAddr, Domain);
  85
  86         MM_int_GetTables(VAddr, &table0, &table1);
  87
  88         VAddr &= ~(0x400000-1); // 4MiB per "block", 1 Page
  89
  90         desc = &table0[ VAddr>>20];
  91         LOG("desc = %p", desc);
  92
  93         // table0: 4 bytes = 1 MiB
  94
  95         LOG("desc[0] = %x", desc[0]);
  96         LOG("desc[1] = %x", desc[1]);
  97         LOG("desc[2] = %x", desc[2]);
  98         LOG("desc[3] = %x", desc[3]);
  99
 100         if( (desc[0] & 3) != 0 || (desc[1] & 3) != 0
 101          || (desc[2] & 3) != 0 || (desc[3] & 3) != 0 )
 102         {
 103                 // Error?
 104                 LEAVE('i', 1);
 105                 return 1;
 106         }
 107
 108         paddr = MM_AllocPhys();
 109         if( !paddr )
 110         {
 111                 // Error
 112                 LEAVE('i', 2);
 113                 return 2;
 114         }
 115
 116         *desc = paddr | (Domain << 5) | 1;
 117         desc[1] = desc[0] + 0x400;
 118         desc[2] = desc[0] + 0x800;
 119         desc[3] = desc[0] + 0xC00;
 120
 121         if( VAddr < 0x80000000 ) {
 122                 USRFRACTAL(VAddr) = paddr | 0x13;
 123         }
 124         else {
 125                 FRACTAL(table1, VAddr) = paddr | 0x13;
 126         }
 127
 128         // TLBIALL
 129         TLBIALL();
 130
 131         memset( (void*)&table1[ (VAddr >> 12) & ~(1024-1) ], 0, 0x1000 );
 132
 133         LEAVE('i', 0);
 134         return 0;
 135 }
 136
 137 int MM_int_SetPageInfo(tVAddr VAddr, tMM_PageInfo *pi)
 138 {
 139         Uint32  *table0, *table1;
 140         Uint32  *desc;
 141
 142         ENTER("pVAddr ppi", VAddr, pi);
 143
 144         MM_int_GetTables(VAddr, &table0, &table1);
 145
 146         desc = &table0[ VAddr >> 20 ];
 147         LOG("desc = %p", desc);
 148
 149         switch(pi->Size)
 150         {
 151         case 12:        // Small Page
 152         case 16:        // Large Page
 153                 LOG("Page");
 154                 if( (*desc & 3) == 0 ) {
 155                         MM_int_AllocateCoarse( VAddr, pi->Domain );
 156                 }
 157                 desc = &table1[ VAddr >> 12 ];
 158                 LOG("desc (2) = %p", desc);
 159                 if( pi->Size == 12 )
 160                 {
 161                         // Small page
 162                         // - Error if overwriting a large page
 163                         if( (*desc & 3) == 1 )  LEAVE_RET('i', 1);
 164                         if( pi->PhysAddr == 0 ) {
 165                                 *desc = 0;
 166                                 TLBIMVA(VAddr & 0xFFFFF000);
 167                                 LEAVE('i', 0);
 168                                 return 0;
 169                         }
 170
 171                         *desc = (pi->PhysAddr & 0xFFFFF000) | 2;
 172                         if(!pi->bExecutable)    *desc |= 1;     // XN
 173                         if(!pi->bGlobal)        *desc |= 1 << 11;       // nG
 174                         if( pi->bShared)        *desc |= 1 << 10;       // S
 175                         *desc |= (pi->AP & 3) << 4;     // AP
 176                         *desc |= ((pi->AP >> 2) & 1) << 9;      // APX
 177                         TLBIMVA(VAddr & 0xFFFFF000);
 178                         LEAVE('i', 0);
 179                         return 0;
 180                 }
 181                 else
 182                 {
 183                         // Large page
 184                         Log_Warning("MMVirt", "TODO: Implement large pages in MM_int_SetPageInfo");
 185                 }
 186                 break;
 187         case 20:        // Section or unmapped
 188                 Log_Warning("MMVirt", "TODO: Implement sections in MM_int_SetPageInfo");
 189                 break;
 190         case 24:        // Supersection
 191                 // Error if not aligned
 192                 if( VAddr & 0xFFFFFF ) {
 193                         LEAVE('i', 1);
 194                         return 1;
 195                 }
 196                 if( (*desc & 3) == 0 || ((*desc & 3) == 2 && (*desc & (1 << 18)))  )
 197                 {
 198                         if( pi->PhysAddr == 0 ) {
 199                                 *desc = 0;
 200                         }
 201                         else {
 202                                 // Apply
 203                                 *desc = pi->PhysAddr & 0xFF000000;
 204 //                              *desc |= ((pi->PhysAddr >> 32) & 0xF) << 20;
 205 //                              *desc |= ((pi->PhysAddr >> 36) & 0x7) << 5;
 206                                 *desc |= 2 | (1 << 18);
 207                         }
 208                         // TODO: Apply to all entries
 209                         Log_Warning("MMVirt", "TODO: Apply changes to all entries of supersections");
 210                         LEAVE('i', 0);
 211                         return 0;
 212                 }
 213                 // TODO: What here?
 214                 Log_Warning("MMVirt", "TODO: 24-bit not on supersection?");
 215                 LEAVE('i', 1);
 216                 return 1;
 217         }
 218
 219         LEAVE('i', 1);
 220         return 1;
 221 }
 222
 223 int MM_int_GetPageInfo(tVAddr VAddr, tMM_PageInfo *pi)
 224 {
 225         Uint32  *table0, *table1;
 226         Uint32  desc;
 227
 228 //      LogF("MM_int_GetPageInfo: VAddr=%p, pi=%p\n", VAddr, pi);
 229
 230         MM_int_GetTables(VAddr, &table0, &table1);
 231
 232         desc = table0[ VAddr >> 20 ];
 233
 234 //      if( VAddr > 0x90000000)
 235 //              LOG("table0 desc(%p) = %x", &table0[ VAddr >> 20 ], desc);
 236
 237         pi->bExecutable = 1;
 238         pi->bGlobal = 0;
 239         pi->bShared = 0;
 240         pi->AP = 0;
 241
 242         switch( (desc & 3) )
 243         {
 244         // 0: Unmapped
 245         case 0:
 246                 pi->PhysAddr = 0;
 247                 pi->Size = 20;
 248                 pi->Domain = 0;
 249                 return 1;
 250
 251         // 1: Coarse page table
 252         case 1:
 253                 // Domain from top level table
 254                 pi->Domain = (desc >> 5) & 7;
 255                 // Get next level
 256                 desc = table1[ VAddr >> 12 ];
 257 //              LOG("table1 desc(%p) = %x", &table1[ VAddr >> 12 ], desc);
 258                 switch( desc & 3 )
 259                 {
 260                 // 0: Unmapped
 261                 case 0:
 262                         pi->Size = 12;
 263                         return 1;
 264                 // 1: Large Page (64KiB)
 265                 case 1:
 266                         pi->Size = 16;
 267                         pi->PhysAddr = desc & 0xFFFF0000;
 268                         pi->AP = ((desc >> 4) & 3) | (((desc >> 9) & 1) << 2);
 269                         pi->bExecutable = !(desc & 0x8000);
 270                         pi->bShared = (desc >> 10) & 1;
 271                         return 0;
 272                 // 2/3: Small page
 273                 case 2:
 274                 case 3:
 275                         pi->Size = 12;
 276                         pi->PhysAddr = desc & 0xFFFFF000;
 277                         pi->bExecutable = !(desc & 1);
 278                         pi->bGlobal = !(desc >> 11);
 279                         pi->bShared = (desc >> 10) & 1;
 280                         pi->AP = ((desc >> 4) & 3) | (((desc >> 9) & 1) << 2);
 281                         return 0;
 282                 }
 283                 return 1;
 284
 285         // 2: Section (or Supersection)
 286         case 2:
 287                 if( desc & (1 << 18) ) {
 288                         // Supersection
 289                         pi->PhysAddr = desc & 0xFF000000;
 290                         pi->PhysAddr |= (Uint64)((desc >> 20) & 0xF) << 32;
 291                         pi->PhysAddr |= (Uint64)((desc >> 5) & 0x7) << 36;
 292                         pi->Size = 24;
 293                         pi->Domain = 0; // Supersections default to zero
 294                         pi->AP = ((desc >> 10) & 3) | (((desc >> 15) & 1) << 2);
 295                         return 0;
 296                 }
 297
 298                 // Section
 299                 pi->PhysAddr = desc & 0xFFF80000;
 300                 pi->Size = 20;
 301                 pi->Domain = (desc >> 5) & 7;
 302                 pi->AP = ((desc >> 10) & 3) | (((desc >> 15) & 1) << 2);
 303                 return 0;
 304
 305         // 3: Reserved (invalid)
 306         case 3:
 307                 pi->PhysAddr = 0;
 308                 pi->Size = 20;
 309                 pi->Domain = 0;
 310                 return 2;
 311         }
 312         return 2;
 313 }
 314
 315 // --- Exports ---
 316 tPAddr MM_GetPhysAddr(tVAddr VAddr)
 317 {
 318         tMM_PageInfo    pi;
 319         if( MM_int_GetPageInfo(VAddr, &pi) )
 320                 return 0;
 321         return pi.PhysAddr | (VAddr & ((1 << pi.Size)-1));
 322 }
 323
 324 Uint MM_GetFlags(tVAddr VAddr)
 325 {
 326         tMM_PageInfo    pi;
 327          int    ret;
 328
 329         if( MM_int_GetPageInfo(VAddr, &pi) )
 330                 return 0;
 331
 332         ret = 0;
 333
 334         switch(pi.AP)
 335         {
 336         case 0:
 337                 break;
 338         case AP_KRW_ONLY:
 339                 ret |= MM_PFLAG_KERNEL;
 340                 break;
 341         case AP_KRO_ONLY:
 342                 ret |= MM_PFLAG_KERNEL|MM_PFLAG_RO;
 343                 break;
 344         case AP_RW_BOTH:
 345                 break;
 346         case AP_RO_BOTH:
 347                 ret |= MM_PFLAG_COW;
 348                 break;
 349         case AP_RO_USER:
 350                 ret |= MM_PFLAG_RO;
 351                 break;
 352         }
 353
 354         if( pi.bExecutable )    ret |= MM_PFLAG_EXEC;
 355         return ret;
 356 }
 357
 358 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 359 {
 360         tMM_PageInfo    pi;
 361         Uint    curFlags;
 362
 363         if( MM_int_GetPageInfo(VAddr, &pi) )
 364                 return ;
 365
 366         curFlags = MM_GetFlags(VAddr);
 367         if( (curFlags & Mask) == Flags )
 368                 return ;
 369         curFlags &= ~Mask;
 370         curFlags |= Flags;
 371
 372         if( curFlags & MM_PFLAG_COW )
 373                 pi.AP = AP_RO_BOTH;
 374         else
 375         {
 376                 switch(curFlags & (MM_PFLAG_KERNEL|MM_PFLAG_RO) )
 377                 {
 378                 case 0:
 379                         pi.AP = AP_RW_BOTH;     break;
 380                 case MM_PFLAG_KERNEL:
 381                         pi.AP = AP_KRW_ONLY;    break;
 382                 case MM_PFLAG_RO:
 383                         pi.AP = AP_RO_USER;     break;
 384                 case MM_PFLAG_KERNEL|MM_PFLAG_RO:
 385                         pi.AP = AP_KRO_ONLY;    break;
 386                 }
 387         }
 388
 389         pi.bExecutable = !!(curFlags & MM_PFLAG_EXEC);
 390
 391         MM_int_SetPageInfo(VAddr, &pi);
 392 }
 393
 394 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 395 {
 396         tMM_PageInfo    pi = {0};
 397         #if TRACE_MAPS
 398         Log("MM_Map %P=>%p", PAddr, VAddr);
 399         #endif
 400
 401         pi.PhysAddr = PAddr;
 402         pi.Size = 12;
 403         if(VAddr < USER_STACK_TOP)
 404                 pi.AP = AP_RW_BOTH;
 405         else
 406                 pi.AP = AP_KRW_ONLY;    // Kernel Read/Write
 407         pi.bExecutable = 1;
 408         if( MM_int_SetPageInfo(VAddr, &pi) ) {
 409 //              MM_DerefPhys(pi.PhysAddr);
 410                 return 0;
 411         }
 412         return pi.PhysAddr;
 413 }
 414
 415 tPAddr MM_Allocate(tVAddr VAddr)
 416 {
 417         tMM_PageInfo    pi = {0};
 418
 419         ENTER("pVAddr", VAddr);
 420
 421         pi.PhysAddr = MM_AllocPhys();
 422         if( pi.PhysAddr == 0 )  LEAVE_RET('i', 0);
 423         pi.Size = 12;
 424         if(VAddr < USER_STACK_TOP)
 425                 pi.AP = AP_RW_BOTH;
 426         else
 427                 pi.AP = AP_KRW_ONLY;
 428         pi.bExecutable = 0;
 429         if( MM_int_SetPageInfo(VAddr, &pi) ) {
 430                 MM_DerefPhys(pi.PhysAddr);
 431                 LEAVE('i', 0);
 432                 return 0;
 433         }
 434         LEAVE('x', pi.PhysAddr);
 435         return pi.PhysAddr;
 436 }
 437
 438 tPAddr MM_AllocateZero(tVAddr VAddr)
 439 {
 440         if( !giMM_ZeroPage ) {
 441                 giMM_ZeroPage = MM_Allocate(VAddr);
 442                 MM_RefPhys(giMM_ZeroPage);
 443                 memset((void*)VAddr, 0, PAGE_SIZE);
 444         }
 445         else {
 446                 MM_RefPhys(giMM_ZeroPage);
 447                 MM_Map(VAddr, giMM_ZeroPage);
 448         }
 449         MM_SetFlags(VAddr, MM_PFLAG_COW, MM_PFLAG_COW);
 450         return giMM_ZeroPage;
 451 }
 452
 453 void MM_Deallocate(tVAddr VAddr)
 454 {
 455         tMM_PageInfo    pi;
 456
 457         if( MM_int_GetPageInfo(VAddr, &pi) )    return ;
 458
 459         if( pi.PhysAddr == 0 )  return;
 460         MM_DerefPhys(pi.PhysAddr);
 461
 462         pi.PhysAddr = 0;
 463         pi.AP = 0;
 464         pi.bExecutable = 0;
 465         MM_int_SetPageInfo(VAddr, &pi);
 466 }
 467
 468 tPAddr MM_AllocateRootTable(void)
 469 {
 470         tPAddr  ret;
 471
 472         ret = MM_AllocPhysRange(2, -1);
 473         if( ret & 0x1000 ) {
 474                 MM_DerefPhys(ret);
 475                 MM_DerefPhys(ret+0x1000);
 476                 ret = MM_AllocPhysRange(3, -1);
 477                 if( ret & 0x1000 ) {
 478                         MM_DerefPhys(ret);
 479                         ret += 0x1000;
 480 //                      Log("MM_AllocateRootTable: Second try not aligned, %P", ret);
 481                 }
 482                 else {
 483                         MM_DerefPhys(ret + 0x2000);
 484 //                      Log("MM_AllocateRootTable: Second try aligned, %P", ret);
 485                 }
 486         }
 487 //      else
 488 //              Log("MM_AllocateRootTable: Got it in one, %P", ret);
 489         return ret;
 490 }
 491
 492 void MM_int_CloneTable(Uint32 *DestEnt, int Table)
 493 {
 494         tPAddr  table;
 495         Uint32  *tmp_map;
 496         Uint32  *cur = (void*)MM_TABLE1USER;
 497 //      Uint32  *cur = &FRACTAL(MM_TABLE1USER,0);
 498          int    i;
 499
 500         table = MM_AllocPhys();
 501         if(!table)      return ;
 502
 503         cur += 256*Table;
 504
 505         tmp_map = (void*)MM_MapTemp(table);
 506
 507         for( i = 0; i < 1024; i ++ )
 508         {
 509 //              Log_Debug("MMVirt", "cur[%i] (%p) = %x", Table*256+i, &cur[Table*256+i], cur[Table*256+i]);
 510                 switch(cur[i] & 3)
 511                 {
 512                 case 0: tmp_map[i] = 0; break;
 513                 case 1:
 514                         tmp_map[i] = 0;
 515                         Log_Error("MMVirt", "TODO: Support large pages in MM_int_CloneTable (%p)", (Table*256+i)*0x1000);
 516                         // Large page?
 517                         break;
 518                 case 2:
 519                 case 3:
 520                         // Small page
 521                         // - If full RW
 522 //                      Debug("%p cur[%i] & 0x230 = 0x%x", Table*256*0x1000, i, cur[i] & 0x230);
 523                         if( (cur[i] & 0x230) == 0x010 )
 524                         {
 525                                 void    *dst, *src;
 526                                 tPAddr  newpage;
 527                                 newpage = MM_AllocPhys();
 528                                 src = (void*)( (Table*256+i)*0x1000 );
 529                                 dst = (void*)MM_MapTemp(newpage);
 530 //                              Debug("Taking a copy of kernel page %p (%P)", src, cur[i] & ~0xFFF);
 531                                 memcpy(dst, src, PAGE_SIZE);
 532                                 MM_FreeTemp( (tVAddr)dst );
 533                                 tmp_map[i] = newpage | (cur[i] & 0xFFF);
 534                         }
 535                         else
 536                         {
 537                                 if( (cur[i] & 0x230) == 0x030 )
 538                                         cur[i] |= 0x200;        // Set to full RO (Full RO=COW, User RO = RO)
 539                                 tmp_map[i] = cur[i];
 540                                 MM_RefPhys( tmp_map[i] & ~0xFFF );
 541                         }
 542                         break;
 543                 }
 544         }
 545         MM_FreeTemp( (tVAddr) tmp_map );
 546
 547         DestEnt[0] = table + 0*0x400 + 1;
 548         DestEnt[1] = table + 1*0x400 + 1;
 549         DestEnt[2] = table + 2*0x400 + 1;
 550         DestEnt[3] = table + 3*0x400 + 1;
 551 }
 552
 553 tPAddr MM_Clone(void)
 554 {
 555         tPAddr  ret;
 556         Uint32  *new_lvl1_1, *new_lvl1_2, *cur;
 557         Uint32  *tmp_map;
 558          int    i;
 559
 560 //      MM_DumpTables(0, KERNEL_BASE);
 561
 562         ret = MM_AllocateRootTable();
 563
 564         cur = (void*)MM_TABLE0USER;
 565         new_lvl1_1 = (void*)MM_MapTemp(ret);
 566         new_lvl1_2 = (void*)MM_MapTemp(ret+0x1000);
 567         tmp_map = new_lvl1_1;
 568         for( i = 0; i < 0x800-4; i ++ )
 569         {
 570                 // HACK! Ignore the original identity mapping
 571                 if( i == 0 && Threads_GetTID() == 0 ) {
 572                         tmp_map[0] = 0;
 573                         continue;
 574                 }
 575                 if( i == 0x400 )
 576                         tmp_map = &new_lvl1_2[-0x400];
 577                 switch( cur[i] & 3 )
 578                 {
 579                 case 0: tmp_map[i] = 0; break;
 580                 case 1:
 581                         MM_int_CloneTable(&tmp_map[i], i);
 582                         i += 3; // Tables are alocated in blocks of 4
 583                         break;
 584                 case 2:
 585                 case 3:
 586                         Log_Error("MMVirt", "TODO: Support Sections/Supersections in MM_Clone (i=%i)", i);
 587                         tmp_map[i] = 0;
 588                         break;
 589                 }
 590         }
 591
 592         // Allocate Fractal table
 593         {
 594                  int    j, num;
 595                 tPAddr  tmp = MM_AllocPhys();
 596                 Uint32  *table = (void*)MM_MapTemp(tmp);
 597                 Uint32  sp;
 598                 register Uint32 __SP asm("sp");
 599
 600                 // Map table to last 4MiB of user space
 601                 new_lvl1_2[0x3FC] = tmp + 0*0x400 + 1;
 602                 new_lvl1_2[0x3FD] = tmp + 1*0x400 + 1;
 603                 new_lvl1_2[0x3FE] = tmp + 2*0x400 + 1;
 604                 new_lvl1_2[0x3FF] = tmp + 3*0x400 + 1;
 605
 606                 tmp_map = new_lvl1_1;
 607                 for( j = 0; j < 512; j ++ )
 608                 {
 609                         if( j == 256 )
 610                                 tmp_map = &new_lvl1_2[-0x400];
 611                         if( (tmp_map[j*4] & 3) == 1 )
 612                         {
 613                                 table[j] = tmp_map[j*4] & PADDR_MASK_LVL1;// 0xFFFFFC00;
 614                                 table[j] |= 0x813;      // nG, Kernel Only, Small page, XN
 615                         }
 616                         else
 617                                 table[j] = 0;
 618                 }
 619                 // Fractal
 620                 table[j++] = (ret + 0x0000) | 0x813;
 621                 table[j++] = (ret + 0x1000) | 0x813;
 622                 // Nuke the rest
 623                 for(      ; j < 1024; j ++ )
 624                         table[j] = 0;
 625
 626                 // Get kernel stack bottom
 627                 sp = __SP & ~(MM_KSTACK_SIZE-1);
 628                 j = (sp / 0x1000) % 1024;
 629                 num = MM_KSTACK_SIZE/0x1000;
 630
 631 //              Log("num = %i, sp = %p, j = %i", num, sp, j);
 632
 633                 // Copy stack pages
 634                 for(; num--; j ++, sp += 0x1000)
 635                 {
 636                         tVAddr  page;
 637                         void    *tmp_page;
 638
 639                         page = MM_AllocPhys();
 640 //                      Log("page = %P", page);
 641                         table[j] = page | 0x813;
 642
 643                         tmp_page = (void*)MM_MapTemp(page);
 644                         memcpy(tmp_page, (void*)sp, 0x1000);
 645                         MM_FreeTemp( (tVAddr) tmp_page );
 646                 }
 647
 648                 MM_FreeTemp( (tVAddr)table );
 649         }
 650
 651         MM_FreeTemp( (tVAddr)new_lvl1_1 );
 652         MM_FreeTemp( (tVAddr)new_lvl1_2 );
 653
 654         return ret;
 655 }
 656
 657 void MM_ClearUser(void)
 658 {
 659          int    i, j;
 660         const int       user_table_count = USER_STACK_TOP / (256*0x1000);
 661         Uint32  *cur = (void*)MM_TABLE0USER;
 662         Uint32  *tab;
 663
 664 //      MM_DumpTables(0, 0x80000000);
 665
 666 //      Log("user_table_count = %i (as opposed to %i)", user_table_count, 0x800-4);
 667
 668         for( i = 0; i < user_table_count; i ++ )
 669         {
 670                 switch( cur[i] & 3 )
 671                 {
 672                 case 0: break;  // Already unmapped
 673                 case 1: // Sub pages
 674                         tab = (void*)(MM_TABLE1USER + i*256*sizeof(Uint32));
 675                         for( j = 0; j < 1024; j ++ )
 676                         {
 677                                 switch( tab[j] & 3 )
 678                                 {
 679                                 case 0: break;  // Unmapped
 680                                 case 1:
 681                                         Log_Error("MMVirt", "TODO: Support large pages in MM_ClearUser");
 682                                         break;
 683                                 case 2:
 684                                 case 3:
 685                                         MM_DerefPhys( tab[j] & ~(PAGE_SIZE-1) );
 686                                         break;
 687                                 }
 688                         }
 689                         MM_DerefPhys( cur[i] & ~(PAGE_SIZE-1) );
 690                         cur[i+0] = 0;
 691                         cur[i+1] = 0;
 692                         cur[i+2] = 0;
 693                         i += 3;
 694                         break;
 695                 case 2:
 696                 case 3:
 697                         Log_Error("MMVirt", "TODO: Implement sections/supersections in MM_ClearUser");
 698                         break;
 699                 }
 700                 cur[i] = 0;
 701         }
 702
 703         // Final block of 4 tables are KStack
 704         i = 0x800 - 4;
 705
 706         // Clear out unused stacks
 707         {
 708                 register Uint32 __SP asm("sp");
 709                  int    cur_stack_base = ((__SP & ~(MM_KSTACK_SIZE-1)) / PAGE_SIZE) % 1024;
 710
 711                 tab = (void*)(MM_TABLE1USER + i*256*sizeof(Uint32));
 712
 713                 // First 512 is the Table1 mapping + 2 for Table0 mapping
 714                 for( j = 512+2; j < 1024; j ++ )
 715                 {
 716                         // Skip current stack
 717                         if( j == cur_stack_base ) {
 718                                 j += (MM_KSTACK_SIZE / PAGE_SIZE) - 1;
 719                                 continue ;
 720                         }
 721                         if( !(tab[j] & 3) )     continue;
 722                         ASSERT( (tab[j] & 3) == 2 );
 723                         MM_DerefPhys( tab[j] & ~(PAGE_SIZE) );
 724                         tab[j] = 0;
 725                 }
 726         }
 727
 728
 729 //      MM_DumpTables(0, 0x80000000);
 730 }
 731
 732 tVAddr MM_MapTemp(tPAddr PAddr)
 733 {
 734         tVAddr  ret;
 735         tMM_PageInfo    pi;
 736
 737         for( ret = MM_TMPMAP_BASE; ret < MM_TMPMAP_END - PAGE_SIZE; ret += PAGE_SIZE )
 738         {
 739                 if( MM_int_GetPageInfo(ret, &pi) == 0 )
 740                         continue;
 741
 742                 Log("MapTemp %P at %p by %p", PAddr, ret, __builtin_return_address(0));
 743                 MM_RefPhys(PAddr);      // Counter the MM_Deallocate in FreeTemp
 744                 MM_Map(ret, PAddr);
 745
 746                 return ret;
 747         }
 748         Log_Warning("MMVirt", "MM_MapTemp: All slots taken");
 749         return 0;
 750 }
 751
 752 void MM_FreeTemp(tVAddr VAddr)
 753 {
 754         if( VAddr < MM_TMPMAP_BASE || VAddr >= MM_TMPMAP_END ) {
 755                 Log_Warning("MMVirt", "MM_FreeTemp: Passed an addr not from MM_MapTemp (%p)", VAddr);
 756                 return ;
 757         }
 758
 759         MM_Deallocate(VAddr);
 760 }
 761
 762 tVAddr MM_MapHWPages(tPAddr PAddr, Uint NPages)
 763 {
 764         tVAddr  ret;
 765          int    i;
 766         tMM_PageInfo    pi;
 767
 768         ENTER("xPAddr iNPages", PAddr, NPages);
 769
 770         // Scan for a location
 771         for( ret = MM_HWMAP_BASE; ret < MM_HWMAP_END - NPages * PAGE_SIZE; ret += PAGE_SIZE )
 772         {
 773 //              LOG("checking %p", ret);
 774                 // Check if there is `NPages` free pages
 775                 for( i = 0; i < NPages; i ++ )
 776                 {
 777                         if( MM_int_GetPageInfo(ret + i*PAGE_SIZE, &pi) == 0 )
 778                                 break;
 779                 }
 780                 // Nope, jump to after the used page found and try again
 781 //              LOG("i = %i, ==? %i", i, NPages);
 782                 if( i != NPages ) {
 783                         ret += i * PAGE_SIZE;
 784                         continue ;
 785                 }
 786
 787                 // Map the pages
 788                 for( i = 0; i < NPages; i ++ )
 789                         MM_Map(ret+i*PAGE_SIZE, PAddr+i*PAGE_SIZE);
 790                 // and return
 791                 LEAVE('p', ret);
 792                 return ret;
 793         }
 794         Log_Warning("MMVirt", "MM_MapHWPages: No space for a %i page block", NPages);
 795         LEAVE('p', 0);
 796         return 0;
 797 }
 798
 799 tVAddr MM_AllocDMA(int Pages, int MaxBits, tPAddr *PAddr)
 800 {
 801         tPAddr  phys;
 802         tVAddr  ret;
 803
 804         phys = MM_AllocPhysRange(Pages, MaxBits);
 805         if(!phys) {
 806                 Log_Warning("MMVirt", "No space left for a %i page block (MM_AllocDMA)", Pages);
 807                 return 0;
 808         }
 809
 810         ret = MM_MapHWPages(phys, Pages);
 811         *PAddr = phys;
 812
 813         return ret;
 814 }
 815
 816 void MM_UnmapHWPages(tVAddr Vaddr, Uint Number)
 817 {
 818         Log_Error("MMVirt", "TODO: Implement MM_UnmapHWPages");
 819 }
 820
 821 tVAddr MM_NewKStack(int bShared)
 822 {
 823         tVAddr  min_addr, max_addr;
 824         tVAddr  addr, ofs;
 825
 826         if( bShared ) {
 827                 min_addr = MM_GLOBALSTACKS;
 828                 max_addr = MM_GLOBALSTACKS_END;
 829         }
 830         else {
 831                 min_addr = MM_KSTACK_BASE;
 832                 max_addr = MM_KSTACK_END;
 833         }
 834
 835         // Locate a free slot
 836         for( addr = min_addr; addr < max_addr; addr += MM_KSTACK_SIZE )
 837         {
 838                 tMM_PageInfo    pi;
 839                 if( MM_int_GetPageInfo(addr+MM_KSTACK_SIZE-PAGE_SIZE, &pi) )    break;
 840         }
 841
 842         // Check for an error
 843         if(addr >= max_addr) {
 844                 return 0;
 845         }
 846
 847         // 1 guard page
 848         for( ofs = PAGE_SIZE; ofs < MM_KSTACK_SIZE; ofs += PAGE_SIZE )
 849         {
 850                 if( MM_Allocate(addr + ofs) == 0 )
 851                 {
 852                         while(ofs)
 853                         {
 854                                 ofs -= PAGE_SIZE;
 855                                 MM_Deallocate(addr + ofs);
 856                         }
 857                         Log_Warning("MMVirt", "MM_NewKStack: Unable to allocate");
 858                         return 0;
 859                 }
 860         }
 861         return addr + ofs;
 862 }
 863
 864 tVAddr MM_NewUserStack(void)
 865 {
 866         tVAddr  addr, ofs;
 867
 868         addr = USER_STACK_TOP - USER_STACK_SIZE;
 869         if( MM_GetPhysAddr(addr + PAGE_SIZE) ) {
 870                 Log_Error("MMVirt", "Unable to create initial user stack, addr %p taken",
 871                         addr + PAGE_SIZE
 872                         );
 873                 return 0;
 874         }
 875
 876         // 1 guard page
 877         for( ofs = PAGE_SIZE; ofs < USER_STACK_SIZE; ofs += PAGE_SIZE )
 878         {
 879                 tPAddr  rv;
 880                 if(ofs >= USER_STACK_SIZE - USER_STACK_COMM)
 881                         rv = MM_Allocate(addr + ofs);
 882                 else
 883                         rv = MM_AllocateZero(addr + ofs);
 884                 if(rv == 0)
 885                 {
 886                         while(ofs)
 887                         {
 888                                 ofs -= PAGE_SIZE;
 889                                 MM_Deallocate(addr + ofs);
 890                         }
 891                         Log_Warning("MMVirt", "MM_NewUserStack: Unable to allocate");
 892                         return 0;
 893                 }
 894                 MM_SetFlags(addr+ofs, 0, MM_PFLAG_KERNEL);
 895         }
 896 //      Log("Return %p", addr + ofs);
 897 //      MM_DumpTables(0, 0x80000000);
 898         return addr + ofs;
 899 }
 900
 901 void MM_int_DumpTableEnt(tVAddr Start, size_t Len, tMM_PageInfo *Info)
 902 {
 903         if( giMM_ZeroPage && Info->PhysAddr == giMM_ZeroPage )
 904         {
 905                 Debug("%p => %8s - 0x%7x %i %x",
 906                         Start, "ZERO", Len,
 907                         Info->Domain, Info->AP
 908                         );
 909         }
 910         else
 911         {
 912                 Debug("%p => %8x - 0x%7x %i %x",
 913                         Start, Info->PhysAddr-Len, Len,
 914                         Info->Domain, Info->AP
 915                         );
 916         }
 917 }
 918
 919 void MM_DumpTables(tVAddr Start, tVAddr End)
 920 {
 921         tVAddr  range_start = 0, addr;
 922         tMM_PageInfo    pi, pi_old;
 923          int    i = 0, inRange=0;
 924
 925         pi_old.Size = 0;
 926
 927         Debug("Page Table Dump (%p to %p):", Start, End);
 928         range_start = Start;
 929         for( addr = Start; i == 0 || (addr && addr < End); i = 1 )
 930         {
 931                  int    rv;
 932 //              Log("addr = %p", addr);
 933                 rv = MM_int_GetPageInfo(addr, &pi);
 934                 if( rv
 935                  || pi.Size != pi_old.Size
 936                  || pi.Domain != pi_old.Domain
 937                  || pi.AP != pi_old.AP
 938                  || pi_old.PhysAddr != pi.PhysAddr )
 939                 {
 940                         if(inRange) {
 941                                 MM_int_DumpTableEnt(range_start, addr - range_start, &pi_old);
 942                         }
 943                         addr &= ~((1 << pi.Size)-1);
 944                         range_start = addr;
 945                 }
 946
 947                 pi_old = pi;
 948                 // Handle the zero page
 949                 if( !giMM_ZeroPage || pi_old.Size != 12 || pi_old.PhysAddr != giMM_ZeroPage )
 950                         pi_old.PhysAddr += 1 << pi_old.Size;
 951                 addr += 1 << pi_old.Size;
 952                 inRange = (rv == 0);
 953         }
 954         if(inRange)
 955                 MM_int_DumpTableEnt(range_start, addr - range_start, &pi);
 956         Debug("Done");
 957 }
 958
 959 // NOTE: Runs in abort context, not much differe, just a smaller stack
 960 void MM_PageFault(Uint32 PC, Uint32 Addr, Uint32 DFSR, int bPrefetch)
 961 {
 962          int    rv;
 963         tMM_PageInfo    pi;
 964
 965         rv = MM_int_GetPageInfo(Addr, &pi);
 966
 967         // Check for COW
 968         if( rv == 0 &&  pi.AP == AP_RO_BOTH )
 969         {
 970                 pi.AP = AP_RW_BOTH;
 971                 if( giMM_ZeroPage && pi.PhysAddr == giMM_ZeroPage )
 972                 {
 973                         tPAddr  newpage;
 974                         newpage = MM_AllocPhys();
 975                         if( !newpage ) {
 976                                 Log_Error("MMVirt", "Unable to allocate new page for COW of ZERO");
 977                                 for(;;);
 978                         }
 979
 980                         Log_Notice("MMVirt", "COW %p caused by %p, ZERO duped to %P (RefCnt(%i)--)", Addr, PC,
 981                                 newpage, MM_GetRefCount(pi.PhysAddr));
 982
 983                         MM_DerefPhys(pi.PhysAddr);
 984                         pi.PhysAddr = newpage;
 985                         pi.AP = AP_RW_BOTH;
 986                         MM_int_SetPageInfo(Addr, &pi);
 987
 988                         memset( (void*)(Addr & ~(PAGE_SIZE-1)), 0, PAGE_SIZE );
 989
 990                         return ;
 991                 }
 992                 else if( MM_GetRefCount(pi.PhysAddr) > 1 )
 993                 {
 994                         // Duplicate the page
 995                         tPAddr  newpage;
 996                         void    *dst, *src;
 997
 998                         newpage = MM_AllocPhys();
 999                         if(!newpage) {
1000                                 Log_Error("MMVirt", "Unable to allocate new page for COW");
1001                                 for(;;);
1002                         }
1003                         dst = (void*)MM_MapTemp(newpage);
1004                         src = (void*)(Addr & ~(PAGE_SIZE-1));
1005                         memcpy( dst, src, PAGE_SIZE );
1006                         MM_FreeTemp( (tVAddr)dst );
1007
1008                         Log_Notice("MMVirt", "COW %p caused by %p, %P duped to %P (RefCnt(%i)--)", Addr, PC,
1009                                 pi.PhysAddr, newpage, MM_GetRefCount(pi.PhysAddr));
1010
1011                         MM_DerefPhys(pi.PhysAddr);
1012                         pi.PhysAddr = newpage;
1013                 }
1014                 else {
1015                         Log_Notice("MMVirt", "COW %p caused by %p, took last reference to %P",
1016                                 Addr, PC, pi.PhysAddr);
1017                 }
1018                 // Unset COW
1019                 pi.AP = AP_RW_BOTH;
1020                 MM_int_SetPageInfo(Addr, &pi);
1021                 return ;
1022         }
1023
1024
1025         Log_Error("MMVirt", "Code at %p accessed %p (DFSR = 0x%x)%s", PC, Addr, DFSR,
1026                 (bPrefetch ? " - Prefetch" : "")
1027                 );
1028         if( Addr < 0x80000000 )
1029                 MM_DumpTables(0, 0x80000000);
1030         else
1031                 MM_DumpTables(0x80000000, -1);
1032         for(;;);
1033 }
1034