Kernel/arch/x86_64/proc.c

   1 /*
   2  * Acess2 x86_64 port
   3  * proc.c
   4  */
   5 #include <acess.h>
   6 #include <proc.h>
   7 #include <threads.h>
   8 #include <threads_int.h>
   9 #include <desctab.h>
  10 #include <mm_virt.h>
  11 #include <errno.h>
  12 #if USE_MP
  13 # include <mp.h>
  14 #endif
  15 #include <arch_config.h>
  16 #include <hal_proc.h>
  17
  18 // === FLAGS ===
  19 #define DEBUG_TRACE_SWITCH      0
  20 #define BREAK_ON_SWITCH         0       // Break into bochs debugger on a task switch
  21
  22 // === CONSTANTS ===
  23
  24 // === TYPES ===
  25 typedef struct sCPU
  26 {
  27         Uint8   APICID;
  28         Uint8   State;  // 0: Unavaliable, 1: Idle, 2: Active
  29         Uint16  Resvd;
  30         tThread *Current;
  31         tThread *IdleThread;
  32 }       tCPU;
  33
  34 // === IMPORTS ===
  35 extern tGDT     gGDT[];
  36 extern void     APStartup(void);        // 16-bit AP startup code
  37
  38 extern Uint     GetRIP(void);   // start.asm
  39 extern Uint     SaveState(Uint *RSP, Uint *Regs);
  40 extern Uint     Proc_CloneInt(Uint *RSP, Uint *CR3);
  41 extern void     NewTaskHeader(void);    // Actually takes cdecl args
  42 extern void     Proc_InitialiseSSE(void);
  43 extern void     Proc_SaveSSE(Uint DestPtr);
  44 extern void     Proc_DisableSSE(void);
  45
  46 extern Uint64   gInitialPML4[512];      // start.asm
  47 extern int      giNumCPUs;
  48 extern int      giNextTID;
  49 extern int      giTotalTickets;
  50 extern int      giNumActiveThreads;
  51 extern tThread  gThreadZero;
  52 extern void     Threads_Dump(void);
  53 extern void     Proc_ReturnToUser(tVAddr Handler, tVAddr KStackTop, int Argument);
  54 extern void     Time_UpdateTimestamp(void);
  55 extern void     SwitchTasks(Uint NewSP, Uint *OldSP, Uint NewIP, Uint *OldIO, Uint CR3);
  56
  57 // === PROTOTYPES ===
  58 //void  ArchThreads_Init(void);
  59 #if USE_MP
  60 void    MP_StartAP(int CPU);
  61 void    MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
  62 #endif
  63 void    Proc_IdleTask(void *unused);
  64 //void  Proc_Start(void);
  65 //tThread       *Proc_GetCurThread(void);
  66 // int  Proc_NewKThread(void (*Fcn)(void*), void *Data);
  67 // int  Proc_Clone(Uint *Err, Uint Flags);
  68 // int  Proc_SpawnWorker(void);
  69 Uint    Proc_MakeUserStack(void);
  70 //void  Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize);
  71 void    Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NORETURN;
  72  int    Proc_Demote(Uint *Err, int Dest, tRegs *Regs);
  73 //void  Proc_CallFaultHandler(tThread *Thread);
  74 //void  Proc_DumpThreadCPUState(tThread *Thread);
  75 //void  Proc_Reschedule(void);
  76 void    Proc_Scheduler(int CPU, Uint RSP, Uint RIP);
  77
  78 // === GLOBALS ===
  79 //!\brief Used by desctab.asm in SyscallStub
  80 const int ci_offsetof_tThread_KernelStack = offsetof(tThread, KernelStack);
  81 // --- Multiprocessing ---
  82 #if USE_MP
  83 volatile int    giNumInitingCPUs = 0;
  84 tMPInfo *gMPFloatPtr = NULL;
  85 tAPIC   *gpMP_LocalAPIC = NULL;
  86 Uint8   gaAPIC_to_CPU[256] = {0};
  87 #endif
  88 tCPU    gaCPUs[MAX_CPUS];
  89 tTSS    *gTSSs = NULL;
  90 tTSS    gTSS0 = {0};
  91 // --- Error Recovery ---
  92 Uint32  gaDoubleFaultStack[1024];
  93
  94 // === CODE ===
  95 /**
  96  * \fn void ArchThreads_Init(void)
  97  * \brief Starts the process scheduler
  98  */
  99 void ArchThreads_Init(void)
 100 {
 101         Uint    pos = 0;
 102
 103         #if USE_MP
 104         tMPTable        *mptable;
 105
 106         // Mark BSP as active
 107         gaCPUs[0].State = 2;
 108
 109         // -- Initialise Multiprocessing
 110         // Find MP Floating Table
 111         // - EBDA/Last 1Kib (640KiB)
 112         for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
 113                 if( *(Uint*)(pos) == MPPTR_IDENT ) {
 114                         Log("Possible %p", pos);
 115                         if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 116                         gMPFloatPtr = (void*)pos;
 117                         break;
 118                 }
 119         }
 120         // - Last KiB (512KiB base mem)
 121         if(!gMPFloatPtr) {
 122                 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
 123                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 124                                 Log("Possible %p", pos);
 125                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 126                                 gMPFloatPtr = (void*)pos;
 127                                 break;
 128                         }
 129                 }
 130         }
 131         // - BIOS ROM
 132         if(!gMPFloatPtr) {
 133                 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
 134                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 135                                 Log("Possible %p", pos);
 136                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 137                                 gMPFloatPtr = (void*)pos;
 138                                 break;
 139                         }
 140                 }
 141         }
 142
 143         // If the MP Table Exists, parse it
 144         if(gMPFloatPtr)
 145         {
 146                  int    i;
 147                 tMPTable_Ent    *ents;
 148                 Log("gMPFloatPtr = %p", gMPFloatPtr);
 149                 Log("*gMPFloatPtr = {");
 150                 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
 151                 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
 152                 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
 153                 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
 154                 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
 155                 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
 156                         gMPFloatPtr->Features[0],       gMPFloatPtr->Features[1],
 157                         gMPFloatPtr->Features[2],       gMPFloatPtr->Features[3],
 158                         gMPFloatPtr->Features[4]
 159                         );
 160                 Log("}");
 161
 162                 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
 163                 Log("mptable = %p", mptable);
 164                 Log("*mptable = {");
 165                 Log("\t.Sig = 0x%08x", mptable->Sig);
 166                 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
 167                 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
 168                 Log("\t.Checksum = 0x%02x", mptable->Checksum);
 169                 Log("\t.OEMID = '%8c'", mptable->OemID);
 170                 Log("\t.ProductID = '%8c'", mptable->ProductID);
 171                 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
 172                 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
 173                 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
 174                 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
 175                 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
 176                 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
 177                 Log("}");
 178
 179                 gpMP_LocalAPIC = (void*)MM_MapHWPage(mptable->LocalAPICMemMap, 1);
 180
 181                 ents = mptable->Entries;
 182                 giNumCPUs = 0;
 183
 184                 for( i = 0; i < mptable->EntryCount; i ++ )
 185                 {
 186                          int    entSize = 0;
 187                         switch( ents->Type )
 188                         {
 189                         case 0: // Processor
 190                                 entSize = 20;
 191                                 Log("%i: Processor", i);
 192                                 Log("\t.APICID = %i", ents->Proc.APICID);
 193                                 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
 194                                 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
 195                                 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
 196                                 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
 197
 198
 199                                 if( !(ents->Proc.CPUFlags & 1) ) {
 200                                         Log("DISABLED");
 201                                         break;
 202                                 }
 203
 204                                 // Check if there is too many processors
 205                                 if(giNumCPUs >= MAX_CPUS) {
 206                                         giNumCPUs ++;   // If `giNumCPUs` > MAX_CPUS later, it will be clipped
 207                                         break;
 208                                 }
 209
 210                                 // Initialise CPU Info
 211                                 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
 212                                 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
 213                                 gaCPUs[giNumCPUs].State = 0;
 214                                 giNumCPUs ++;
 215
 216                                 // Send IPI
 217                                 if( !(ents->Proc.CPUFlags & 2) )
 218                                 {
 219                                         MP_StartAP( giNumCPUs-1 );
 220                                 }
 221
 222                                 break;
 223                         case 1: // Bus
 224                                 entSize = 8;
 225                                 Log("%i: Bus", i);
 226                                 Log("\t.ID = %i", ents->Bus.ID);
 227                                 Log("\t.TypeString = '%6c'", ents->Bus.TypeString);
 228                                 break;
 229                         case 2: // I/O APIC
 230                                 entSize = 8;
 231                                 Log("%i: I/O APIC", i);
 232                                 Log("\t.ID = %i", ents->IOAPIC.ID);
 233                                 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
 234                                 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
 235                                 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
 236                                 break;
 237                         case 3: // I/O Interrupt Assignment
 238                                 entSize = 8;
 239                                 Log("%i: I/O Interrupt Assignment", i);
 240                                 Log("\t.IntType = %i", ents->IOInt.IntType);
 241                                 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
 242                                 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
 243                                 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
 244                                 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
 245                                 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
 246                                 break;
 247                         case 4: // Local Interrupt Assignment
 248                                 entSize = 8;
 249                                 Log("%i: Local Interrupt Assignment", i);
 250                                 Log("\t.IntType = %i", ents->LocalInt.IntType);
 251                                 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
 252                                 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
 253                                 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
 254                                 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
 255                                 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
 256                                 break;
 257                         default:
 258                                 Log("%i: Unknown (%i)", i, ents->Type);
 259                                 break;
 260                         }
 261                         ents = (void*)( (Uint)ents + entSize );
 262                 }
 263
 264                 if( giNumCPUs > MAX_CPUS ) {
 265                         Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
 266                         giNumCPUs = MAX_CPUS;
 267                 }
 268
 269                 while( giNumInitingCPUs )
 270                         MM_FinishVirtualInit();
 271
 272                 Panic("Uh oh... MP Table Parsing is unimplemented\n");
 273         }
 274         else {
 275                 Log("No MP Table was found, assuming uniprocessor\n");
 276                 giNumCPUs = 1;
 277                 gTSSs = &gTSS0;
 278         }
 279         #else
 280         giNumCPUs = 1;
 281         gTSSs = &gTSS0;
 282         MM_FinishVirtualInit();
 283         #endif
 284
 285         #if USE_MP
 286         // Initialise Normal TSS(s)
 287         for(pos=0;pos<giNumCPUs;pos++)
 288         {
 289         #else
 290         pos = 0;
 291         #endif
 292                 gTSSs[pos].RSP0 = 0;    // Set properly by scheduler
 293                 gGDT[7+pos*2].LimitLow = sizeof(tTSS) & 0xFFFF;
 294                 gGDT[7+pos*2].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
 295                 gGDT[7+pos*2].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
 296                 gGDT[7+pos*2].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
 297                 gGDT[7+pos*2+1].DWord[0] = ((Uint)(&gTSSs[pos])) >> 32;
 298         #if USE_MP
 299         }
 300         for(pos=0;pos<giNumCPUs;pos++) {
 301                 __asm__ __volatile__ ("ltr %%ax"::"a"(0x38+pos*16));
 302         }
 303         #else
 304         __asm__ __volatile__ ("ltr %%ax"::"a"(0x38));
 305         #endif
 306
 307         // Set Debug registers
 308         __asm__ __volatile__ ("mov %0, %%db0" : : "r"(&gThreadZero));
 309         __asm__ __volatile__ ("mov %%rax, %%db1" : : "a"(0));
 310
 311         gaCPUs[0].Current = &gThreadZero;
 312
 313         gThreadZero.MemState.CR3 = (Uint)gInitialPML4 - KERNEL_BASE;
 314         gThreadZero.CurCPU = 0;
 315         gThreadZero.KernelStack = 0xFFFFA00000000000 + KERNEL_STACK_SIZE;
 316
 317         // Set timer frequency
 318         outb(0x43, 0x34);       // Set Channel 0, Low/High, Rate Generator
 319         outb(0x40, PIT_TIMER_DIVISOR&0xFF);     // Low Byte of Divisor
 320         outb(0x40, (PIT_TIMER_DIVISOR>>8)&0xFF);        // High Byte
 321
 322         // Create Per-Process Data Block
 323         if( !MM_Allocate(MM_PPD_CFG) )
 324         {
 325                 Warning("Oh, hell, Unable to allocate PPD for Thread#0");
 326         }
 327
 328         Proc_InitialiseSSE();
 329
 330         Log_Log("Proc", "Multithreading initialised");
 331 }
 332
 333 #if USE_MP
 334 void MP_StartAP(int CPU)
 335 {
 336         Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
 337         // Set location of AP startup code and mark for a warm restart
 338         *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);
 339         *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
 340         outb(0x70, 0x0F);       outb(0x71, 0x0A);       // Warm Reset
 341         MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);
 342         giNumInitingCPUs ++;
 343 }
 344
 345 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 346 {
 347         Uint32  addr = (Uint)gpMP_LocalAPIC + 0x300;
 348         Uint32  val;
 349
 350         // High
 351         val = (Uint)APICID << 24;
 352         Log("*%p = 0x%08x", addr+0x10, val);
 353         *(Uint32*)(addr+0x10) = val;
 354         // Low (and send)
 355         val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
 356         Log("*%p = 0x%08x", addr, val);
 357         *(Uint32*)addr = val;
 358 }
 359 #endif
 360
 361 /**
 362  * \brief Idle task
 363  */
 364 void Proc_IdleTask(void *ptr)
 365 {
 366         tCPU    *cpu = ptr;
 367         cpu->IdleThread = Proc_GetCurThread();
 368         cpu->IdleThread->ThreadName = (char*)"Idle Thread";
 369         Threads_SetPriority( cpu->IdleThread, -1 );     // Never called randomly
 370         cpu->IdleThread->Quantum = 1;   // 1 slice quantum
 371         for(;;) {
 372                 HALT(); // Just yeilds
 373                 Threads_Yield();
 374         }
 375 }
 376
 377 /**
 378  * \fn void Proc_Start(void)
 379  * \brief Start process scheduler
 380  */
 381 void Proc_Start(void)
 382 {
 383         #if USE_MP
 384          int    i;
 385         #endif
 386
 387         #if USE_MP
 388         // Start APs
 389         for( i = 0; i < giNumCPUs; i ++ )
 390         {
 391                  int    tid;
 392                 if(i)   gaCPUs[i].Current = NULL;
 393
 394                 Proc_NewKThread(Proc_IdleTask, &gaCPUs[i]);
 395
 396                 // Create Idle Task
 397                 gaCPUs[i].IdleThread = Threads_GetThread(tid);
 398
 399
 400                 // Start the AP
 401                 if( i != giProc_BootProcessorID ) {
 402                         MP_StartAP( i );
 403                 }
 404         }
 405
 406         // BSP still should run the current task
 407         gaCPUs[0].Current = &gThreadZero;
 408
 409         // Start interrupts and wait for APs to come up
 410         Log("Waiting for APs to come up\n");
 411         __asm__ __volatile__ ("sti");
 412         while( giNumInitingCPUs )       __asm__ __volatile__ ("hlt");
 413         #else
 414         Proc_NewKThread(Proc_IdleTask, &gaCPUs[0]);
 415
 416         // Start Interrupts (and hence scheduler)
 417         __asm__ __volatile__("sti");
 418         #endif
 419         MM_FinishVirtualInit();
 420         Log_Log("Proc", "Multithreading started");
 421 }
 422
 423 /**
 424  * \fn tThread *Proc_GetCurThread(void)
 425  * \brief Gets the current thread
 426  */
 427 tThread *Proc_GetCurThread(void)
 428 {
 429         #if USE_MP
 430         return gaCPUs[ GetCPUNum() ].Current;
 431         #else
 432         return gaCPUs[ 0 ].Current;
 433         #endif
 434 }
 435
 436 /*
 437  *
 438  */
 439 void Proc_ClearThread(tThread *Thread)
 440 {
 441         Log_Warning("Proc", "TODO: Nuke address space etc");
 442 }
 443
 444 /**
 445  * \brief Create a new kernel thread
 446  */
 447 int Proc_NewKThread(void (*Fcn)(void*), void *Data)
 448 {
 449         Uint    rsp;
 450         tThread *newThread, *cur;
 451
 452         cur = Proc_GetCurThread();
 453         newThread = Threads_CloneTCB(0);
 454         if(!newThread)  return -1;
 455
 456         // Set CR3
 457         newThread->MemState.CR3 = cur->MemState.CR3;
 458
 459         // Create new KStack
 460         newThread->KernelStack = MM_NewKStack();
 461         // Check for errors
 462         if(newThread->KernelStack == 0) {
 463                 free(newThread);
 464                 return -1;
 465         }
 466
 467         rsp = newThread->KernelStack;
 468         *(Uint*)(rsp-=8) = (Uint)Data;  // Data (shadowed)
 469         *(Uint*)(rsp-=8) = 1;   // Number of params
 470         *(Uint*)(rsp-=8) = (Uint)Fcn;   // Function to call
 471         *(Uint*)(rsp-=8) = (Uint)newThread;     // Thread ID
 472
 473         newThread->SavedState.RSP = rsp;
 474         newThread->SavedState.RIP = (Uint)&NewTaskHeader;
 475         newThread->SavedState.SSE = NULL;
 476 //      Log("New (KThread) %p, rsp = %p\n", newThread->SavedState.RIP, newThread->SavedState.RSP);
 477
 478 //      MAGIC_BREAK();
 479         Threads_AddActive(newThread);
 480
 481         return newThread->TID;
 482 }
 483
 484 /**
 485  * \fn int Proc_Clone(Uint Flags)
 486  * \brief Clone the current process
 487  */
 488 int Proc_Clone(Uint Flags)
 489 {
 490         tThread *newThread, *cur = Proc_GetCurThread();
 491         Uint    rip;
 492
 493         // Sanity check
 494         if( !(Flags & CLONE_VM) ) {
 495                 Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
 496                 return -1;
 497         }
 498
 499         // Create new TCB
 500         newThread = Threads_CloneTCB(Flags);
 501         if(!newThread)  return -1;
 502
 503         // Save core machine state
 504         rip = Proc_CloneInt(&newThread->SavedState.RSP, &newThread->MemState.CR3);
 505         if(rip == 0)    return 0;       // Child
 506         newThread->KernelStack = cur->KernelStack;
 507         newThread->SavedState.RIP = rip;
 508         newThread->SavedState.SSE = NULL;
 509
 510         // DEBUG
 511         #if 0
 512         Log("New (Clone) %p, rsp = %p, cr3 = %p", rip, newThread->SavedState.RSP, newThread->MemState.CR3);
 513         {
 514                 Uint cr3;
 515                 __asm__ __volatile__ ("mov %%cr3, %0" : "=r" (cr3));
 516                 Log("Current CR3 = 0x%x, PADDR(RSP) = 0x%x", cr3, MM_GetPhysAddr(newThread->SavedState.RSP));
 517         }
 518         #endif
 519         // /DEBUG
 520
 521         // Lock list and add to active
 522         Threads_AddActive(newThread);
 523
 524         return newThread->TID;
 525 }
 526
 527 /**
 528  * \fn int Proc_SpawnWorker(void)
 529  * \brief Spawns a new worker thread
 530  */
 531 int Proc_SpawnWorker(void (*Fcn)(void*), void *Data)
 532 {
 533         tThread *new, *cur;
 534         Uint    stack_contents[4];
 535
 536         cur = Proc_GetCurThread();
 537
 538         // Create new thread
 539         new = malloc( sizeof(tThread) );
 540         if(!new) {
 541                 Warning("Proc_SpawnWorker - Out of heap space!\n");
 542                 return -1;
 543         }
 544         memcpy(new, &gThreadZero, sizeof(tThread));
 545         // Set Thread ID
 546         new->TID = giNextTID++;
 547
 548         // Create the stack contents
 549         stack_contents[3] = (Uint)Data;
 550         stack_contents[2] = 1;
 551         stack_contents[1] = (Uint)Fcn;
 552         stack_contents[0] = (Uint)new;
 553
 554         // Create a new worker stack (in PID0's address space)
 555         // The stack is relocated by this code
 556         new->KernelStack = MM_NewWorkerStack(stack_contents, sizeof(stack_contents));
 557
 558         new->SavedState.RSP = new->KernelStack - sizeof(stack_contents);
 559         new->SavedState.RIP = (Uint)&NewTaskHeader;
 560         new->SavedState.SSE = NULL;
 561
 562 //      Log("New (Worker) %p, rsp = %p\n", new->SavedState.RIP, new->SavedState.RSP);
 563
 564         // Mark as active
 565         new->Status = THREAD_STAT_PREINIT;
 566         Threads_AddActive( new );
 567
 568         return new->TID;
 569 }
 570
 571 /**
 572  * \brief Creates a new user stack
 573  */
 574 Uint Proc_MakeUserStack(void)
 575 {
 576          int    i;
 577         Uint    base = USER_STACK_TOP - USER_STACK_SZ;
 578
 579         // Check Prospective Space
 580         for( i = USER_STACK_SZ >> 12; i--; )
 581         {
 582                 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
 583                         break;
 584         }
 585
 586         if(i != -1)     return 0;
 587
 588         // Allocate Stack - Allocate incrementally to clean up MM_Dump output
 589         for( i = 0; i < (USER_STACK_SZ-USER_STACK_PREALLOC)/0x1000; i++ )
 590         {
 591                 MM_AllocateZero( base + (i<<12) );
 592         }
 593         for( ; i < USER_STACK_SZ/0x1000; i++ )
 594         {
 595                 tPAddr  alloc = MM_Allocate( base + (i<<12) );
 596                 if( !alloc )
 597                 {
 598                         // Error
 599                         Log_Error("Proc", "Unable to allocate user stack (%i pages requested)", USER_STACK_SZ/0x1000);
 600                         while( i -- )
 601                                 MM_Deallocate( base + (i<<12) );
 602                         return 0;
 603                 }
 604         }
 605
 606         return base + USER_STACK_SZ;
 607 }
 608
 609 void Proc_StartUser(Uint Entrypoint, Uint Base, int ArgC, char **ArgV, int DataSize)
 610 {
 611         Uint    *stack;
 612          int    i;
 613         char    **envp = NULL;
 614         Uint16  ss, cs;
 615
 616
 617         // Copy Arguments
 618         stack = (void*)Proc_MakeUserStack();
 619         if(!stack) {
 620                 Log_Error("Proc", "Unable to create user stack!");
 621                 Threads_Exit(0, -1);
 622         }
 623         stack -= (DataSize+7)/8;
 624         memcpy( stack, ArgV, DataSize );
 625         free(ArgV);
 626
 627         // Adjust Arguments and environment
 628         if(DataSize)
 629         {
 630                 Uint    delta = (Uint)stack - (Uint)ArgV;
 631                 ArgV = (char**)stack;
 632                 for( i = 0; ArgV[i]; i++ )      ArgV[i] += delta;
 633                 envp = &ArgV[i+1];
 634                 for( i = 0; envp[i]; i++ )      envp[i] += delta;
 635         }
 636
 637         // User Mode Segments
 638         // 0x2B = 64-bit
 639         ss = 0x23;      cs = 0x2B;
 640
 641         // Arguments
 642         *--stack = (Uint)envp;
 643         *--stack = (Uint)ArgV;
 644         *--stack = (Uint)ArgC;
 645         *--stack = Base;
 646
 647         Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 648 }
 649
 650 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
 651 {
 652         if( !(CS == 0x1B || CS == 0x2B) || SS != 0x23 ) {
 653                 Log_Error("Proc", "Proc_StartProcess: CS / SS are not valid (%x, %x)",
 654                         CS, SS);
 655                 Threads_Exit(0, -1);
 656         }
 657 //      Log("Proc_StartProcess: (SS=%x, Stack=%p, Flags=%x, CS=%x, IP=%p)", SS, Stack, Flags, CS, IP);
 658 //      MM_DumpTables(0, USER_MAX);
 659         if(CS == 0x1B)
 660         {
 661                 // 32-bit return
 662                 __asm__ __volatile__ (
 663                         "mov %0, %%rsp;\n\t"    // Set stack pointer
 664                         "mov %2, %%r11;\n\t"    // Set RFLAGS
 665                         "sysret;\n\t"
 666                         : : "r" (Stack), "c" (IP), "r" (Flags)
 667                         );
 668         }
 669         else
 670         {
 671                 // 64-bit return
 672                 __asm__ __volatile__ (
 673                         "mov %0, %%rsp;\n\t"    // Set stack pointer
 674                         "mov %2, %%r11;\n\t"    // Set RFLAGS
 675                         "sysretq;\n\t"
 676                         : : "r" (Stack), "c" (IP), "r" (Flags)
 677                         );
 678         }
 679         for(;;);
 680 }
 681
 682 /**
 683  * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 684  * \brief Demotes a process to a lower permission level
 685  * \param Err   Pointer to user's errno
 686  * \param Dest  New Permission Level
 687  * \param Regs  Pointer to user's register structure
 688  */
 689 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 690 {
 691          int    cpl = Regs->CS & 3;
 692         // Sanity Check
 693         if(Dest > 3 || Dest < 0) {
 694                 *Err = -EINVAL;
 695                 return -1;
 696         }
 697
 698         // Permission Check
 699         if(cpl > Dest) {
 700                 *Err = -EACCES;
 701                 return -1;
 702         }
 703
 704         // Change the Segment Registers
 705         Regs->CS = (((Dest+1)<<4) | Dest) - 8;
 706         Regs->SS = ((Dest+1)<<4) | Dest;
 707
 708         return 0;
 709 }
 710
 711 /**
 712  * \brief Calls a signal handler in user mode
 713  * \note Used for signals
 714  */
 715 void Proc_CallFaultHandler(tThread *Thread)
 716 {
 717         // Never returns
 718         Proc_ReturnToUser(Thread->FaultHandler, Thread->KernelStack, Thread->CurFaultNum);
 719         for(;;);
 720 }
 721
 722 void Proc_DumpThreadCPUState(tThread *Thread)
 723 {
 724         Log("  At %04x:%016llx", Thread->SavedState.UserCS, Thread->SavedState.UserRIP);
 725 }
 726
 727 void Proc_Reschedule(void)
 728 {
 729         tThread *nextthread, *curthread;
 730          int    cpu = GetCPUNum();
 731
 732         // TODO: Wait for it?
 733         if(IS_LOCKED(&glThreadListLock))        return;
 734
 735         curthread = gaCPUs[cpu].Current;
 736
 737         nextthread = Threads_GetNextToRun(cpu, curthread);
 738
 739         if(nextthread == curthread)     return ;
 740         if(!nextthread)
 741                 nextthread = gaCPUs[cpu].IdleThread;
 742         if(!nextthread)
 743                 return ;
 744
 745         #if DEBUG_TRACE_SWITCH
 746         LogF("\nSwitching to task CR3 = 0x%x, RIP = %p, RSP = %p - %i (%s)\n",
 747                 nextthread->MemState.CR3,
 748                 nextthread->SavedState.RIP,
 749                 nextthread->SavedState.RSP,
 750                 nextthread->TID,
 751                 nextthread->ThreadName
 752                 );
 753         #endif
 754
 755         // Update CPU state
 756         gaCPUs[cpu].Current = nextthread;
 757         gTSSs[cpu].RSP0 = nextthread->KernelStack-4;
 758         __asm__ __volatile__ ("mov %0, %%db0" : : "r" (nextthread));
 759
 760         // Save FPU/MMX/XMM/SSE state
 761         if( curthread->SavedState.SSE )
 762         {
 763                 Proc_SaveSSE( ((Uint)curthread->SavedState.SSE + 0xF) & ~0xF );
 764                 curthread->SavedState.bSSEModified = 0;
 765                 Proc_DisableSSE();
 766         }
 767
 768         SwitchTasks(
 769                 nextthread->SavedState.RSP, &curthread->SavedState.RSP,
 770                 nextthread->SavedState.RIP, &curthread->SavedState.RIP,
 771                 nextthread->MemState.CR3
 772                 );
 773         return ;
 774 }
 775
 776 /**
 777  * \fn void Proc_Scheduler(int CPU)
 778  * \brief Swap current thread and clears dead threads
 779  */
 780 void Proc_Scheduler(int CPU, Uint RSP, Uint RIP)
 781 {
 782 #if 0
 783         {
 784         tThread *thread;
 785
 786         // If the spinlock is set, let it complete
 787         if(IS_LOCKED(&glThreadListLock))        return;
 788
 789         // Get current thread
 790         thread = gaCPUs[CPU].Current;
 791
 792         if( thread )
 793         {
 794                 tRegs   *regs;
 795                 // Reduce remaining quantum and continue timeslice if non-zero
 796                 if(thread->Remaining--) return;
 797                 // Reset quantum for next call
 798                 thread->Remaining = thread->Quantum;
 799
 800                 // TODO: Make this more stable somehow
 801                 {
 802                         regs = (tRegs*)(RSP+(1)*8);     // CurThread
 803                         thread->SavedState.UserCS = regs->CS;
 804                         thread->SavedState.UserRIP = regs->RIP;
 805                 }
 806         }
 807
 808         // ACK Timer here?
 809
 810         Proc_Reschedule();
 811         }
 812 #endif
 813 }
 814
 815 // === EXPORTS ===
 816 EXPORT(Proc_SpawnWorker);