KernelLand/Kernel/arch/x86/proc.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * proc.c
   4  */
   5 #include <acess.h>
   6 #include <threads.h>
   7 #include <proc.h>
   8 #include <desctab.h>
   9 #include <mm_virt.h>
  10 #include <errno.h>
  11 #if USE_MP
  12 # include <mp.h>
  13 #endif
  14 #include <hal_proc.h>
  15 #include <arch_int.h>
  16
  17 // === FLAGS ===
  18 #define DEBUG_TRACE_SWITCH      0
  19 #define DEBUG_DISABLE_DOUBLEFAULT       1
  20 #define DEBUG_VERY_SLOW_PERIOD  0
  21
  22 // === CONSTANTS ===
  23 // Base is 1193182
  24 #define TIMER_BASE      1193182
  25 #if DEBUG_VERY_SLOW_PERIOD
  26 # define TIMER_DIVISOR  1193    //~10Hz switch, with 10 quantum = 1s per thread
  27 #else
  28 # define TIMER_DIVISOR  11932   //~100Hz
  29 #endif
  30
  31 // === TYPES ===
  32 typedef struct sCPU
  33 {
  34         Uint8   APICID;
  35         Uint8   State;  // 0: Unavaliable, 1: Idle, 2: Active
  36         Uint16  Resvd;
  37         tThread *Current;
  38         tThread *LastTimerThread;       // Used to do preeemption
  39 }       tCPU;
  40
  41 // === IMPORTS ===
  42 extern tGDT     gGDT[];
  43 extern tIDT     gIDT[];
  44 extern void     APWait(void);   // 16-bit AP pause code
  45 extern void     APStartup(void);        // 16-bit AP startup code
  46 extern Uint     GetEIP(void);   // start.asm
  47 extern Uint     GetEIP_Sched(void);     // proc.asm
  48 extern void     NewTaskHeader(tThread *Thread, void *Fcn, int nArgs, ...);      // Actually takes cdecl args
  49 extern Uint     Proc_CloneInt(Uint *ESP, Uint32 *CR3, int bNoUserClone);
  50 extern Uint32   gaInitPageDir[1024];    // start.asm
  51 extern char     Kernel_Stack_Top[];
  52 extern int      giNumCPUs;
  53 extern int      giNextTID;
  54 extern tThread  gThreadZero;
  55 extern tProcess gProcessZero;
  56 extern void     Isr8(void);     // Double Fault
  57 extern void     Proc_ReturnToUser(tVAddr Handler, Uint Argument, tVAddr KernelStack);
  58 extern char     scheduler_return[];     // Return address in SchedulerBase
  59 extern char     IRQCommon[];    // Common IRQ handler code
  60 extern char     IRQCommon_handled[];    // IRQCommon call return location
  61 extern char     GetEIP_Sched_ret[];     // GetEIP call return location
  62 extern void     SwitchTasks(Uint NewSP, Uint *OldSP, Uint NewIP, Uint *OldIO, Uint CR3);
  63 extern void     Proc_InitialiseSSE(void);
  64 extern void     Proc_SaveSSE(Uint DestPtr);
  65 extern void     Proc_DisableSSE(void);
  66
  67 // === PROTOTYPES ===
  68 //void  ArchThreads_Init(void);
  69 #if USE_MP
  70 void    MP_StartAP(int CPU);
  71 void    MP_SendIPIVector(int CPU, Uint8 Vector);
  72 void    MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
  73 #endif
  74 void    Proc_IdleThread(void *Ptr);
  75 //void  Proc_Start(void);
  76 //tThread       *Proc_GetCurThread(void);
  77 void    Proc_ChangeStack(void);
  78 // int  Proc_NewKThread(void (*Fcn)(void*), void *Data);
  79 // int  Proc_Clone(Uint *Err, Uint Flags);
  80 Uint    Proc_MakeUserStack(void);
  81 //void  Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize);
  82 void    Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NORETURN;
  83  int    Proc_Demote(Uint *Err, int Dest, tRegs *Regs);
  84 //void  Proc_CallFaultHandler(tThread *Thread);
  85 //void  Proc_DumpThreadCPUState(tThread *Thread);
  86 void    Proc_Scheduler(int CPU);
  87
  88 // === GLOBALS ===
  89 // --- Multiprocessing ---
  90 #if USE_MP
  91 volatile int    giNumInitingCPUs = 0;
  92 tMPInfo *gMPFloatPtr = NULL;
  93 volatile Uint32 giMP_TimerCount;        // Start Count for Local APIC Timer
  94 tAPIC   *gpMP_LocalAPIC = NULL;
  95 Uint8   gaAPIC_to_CPU[256] = {0};
  96  int    giProc_BootProcessorID = 0;
  97 tTSS    gaTSSs[MAX_CPUS];       // TSS Array
  98 #endif
  99 tCPU    gaCPUs[MAX_CPUS] = {
 100         {.Current = &gThreadZero}
 101         };
 102 tTSS    *gTSSs = NULL;  // Pointer to TSS array
 103 tTSS    gTSS0 = {0};
 104 // --- Error Recovery ---
 105 char    gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
 106 tTSS    gDoubleFault_TSS = {
 107         .ESP0 = (Uint)&gaDoubleFaultStack[1024],
 108         .SS0 = 0x10,
 109         .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
 110         .EIP = (Uint)Isr8,
 111         .ESP = (Uint)&gaDoubleFaultStack[1024],
 112         .CS = 0x08,     .SS = 0x10,
 113         .DS = 0x10,     .ES = 0x10,
 114         .FS = 0x10,     .GS = 0x10,
 115 };
 116
 117 // === CODE ===
 118 /**
 119  * \fn void ArchThreads_Init(void)
 120  * \brief Starts the process scheduler
 121  */
 122 void ArchThreads_Init(void)
 123 {
 124         Uint    pos = 0;
 125
 126         #if USE_MP
 127         tMPTable        *mptable;
 128
 129         // Mark BSP as active
 130         gaCPUs[0].State = 2;
 131
 132         // -- Initialise Multiprocessing
 133         // Find MP Floating Table
 134         // - EBDA/Last 1Kib (640KiB)
 135         for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
 136                 if( *(Uint*)(pos) == MPPTR_IDENT ) {
 137                         Log("Possible %p", pos);
 138                         if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 139                         gMPFloatPtr = (void*)pos;
 140                         break;
 141                 }
 142         }
 143         // - Last KiB (512KiB base mem)
 144         if(!gMPFloatPtr) {
 145                 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
 146                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 147                                 Log("Possible %p", pos);
 148                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 149                                 gMPFloatPtr = (void*)pos;
 150                                 break;
 151                         }
 152                 }
 153         }
 154         // - BIOS ROM
 155         if(!gMPFloatPtr) {
 156                 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
 157                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 158                                 Log("Possible %p", pos);
 159                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 160                                 gMPFloatPtr = (void*)pos;
 161                                 break;
 162                         }
 163                 }
 164         }
 165
 166         // If the MP Table Exists, parse it
 167         if(gMPFloatPtr)
 168         {
 169                  int    i;
 170                 tMPTable_Ent    *ents;
 171                 #if DUMP_MP_TABLE
 172                 Log("gMPFloatPtr = %p", gMPFloatPtr);
 173                 Log("*gMPFloatPtr = {");
 174                 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
 175                 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
 176                 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
 177                 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
 178                 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
 179                 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
 180                         gMPFloatPtr->Features[0],       gMPFloatPtr->Features[1],
 181                         gMPFloatPtr->Features[2],       gMPFloatPtr->Features[3],
 182                         gMPFloatPtr->Features[4]
 183                         );
 184                 Log("}");
 185                 #endif
 186
 187                 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
 188                 #if DUMP_MP_TABLE
 189                 Log("mptable = %p", mptable);
 190                 Log("*mptable = {");
 191                 Log("\t.Sig = 0x%08x", mptable->Sig);
 192                 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
 193                 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
 194                 Log("\t.Checksum = 0x%02x", mptable->Checksum);
 195                 Log("\t.OEMID = '%8c'", mptable->OemID);
 196                 Log("\t.ProductID = '%8c'", mptable->ProductID);
 197                 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
 198                 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
 199                 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
 200                 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
 201                 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
 202                 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
 203                 Log("}");
 204                 #endif
 205
 206                 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
 207
 208                 ents = mptable->Entries;
 209                 giNumCPUs = 0;
 210
 211                 for( i = 0; i < mptable->EntryCount; i ++ )
 212                 {
 213                          int    entSize = 0;
 214                         switch( ents->Type )
 215                         {
 216                         case 0: // Processor
 217                                 entSize = 20;
 218                                 #if DUMP_MP_TABLE
 219                                 Log("%i: Processor", i);
 220                                 Log("\t.APICID = %i", ents->Proc.APICID);
 221                                 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
 222                                 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
 223                                 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
 224                                 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
 225                                 #endif
 226
 227                                 if( !(ents->Proc.CPUFlags & 1) ) {
 228                                         Log("DISABLED");
 229                                         break;
 230                                 }
 231
 232                                 // Check if there is too many processors
 233                                 if(giNumCPUs >= MAX_CPUS) {
 234                                         giNumCPUs ++;   // If `giNumCPUs` > MAX_CPUS later, it will be clipped
 235                                         break;
 236                                 }
 237
 238                                 // Initialise CPU Info
 239                                 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
 240                                 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
 241                                 gaCPUs[giNumCPUs].State = 0;
 242                                 giNumCPUs ++;
 243
 244                                 // Set BSP Variable
 245                                 if( ents->Proc.CPUFlags & 2 ) {
 246                                         giProc_BootProcessorID = giNumCPUs-1;
 247                                 }
 248
 249                                 break;
 250
 251                         #if DUMP_MP_TABLE >= 2
 252                         case 1: // Bus
 253                                 entSize = 8;
 254                                 Log("%i: Bus", i);
 255                                 Log("\t.ID = %i", ents->Bus.ID);
 256                                 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
 257                                 break;
 258                         case 2: // I/O APIC
 259                                 entSize = 8;
 260                                 Log("%i: I/O APIC", i);
 261                                 Log("\t.ID = %i", ents->IOAPIC.ID);
 262                                 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
 263                                 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
 264                                 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
 265                                 break;
 266                         case 3: // I/O Interrupt Assignment
 267                                 entSize = 8;
 268                                 Log("%i: I/O Interrupt Assignment", i);
 269                                 Log("\t.IntType = %i", ents->IOInt.IntType);
 270                                 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
 271                                 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
 272                                 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
 273                                 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
 274                                 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
 275                                 break;
 276                         case 4: // Local Interrupt Assignment
 277                                 entSize = 8;
 278                                 Log("%i: Local Interrupt Assignment", i);
 279                                 Log("\t.IntType = %i", ents->LocalInt.IntType);
 280                                 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
 281                                 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
 282                                 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
 283                                 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
 284                                 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
 285                                 break;
 286                         default:
 287                                 Log("%i: Unknown (%i)", i, ents->Type);
 288                                 break;
 289                         #endif
 290                         }
 291                         ents = (void*)( (Uint)ents + entSize );
 292                 }
 293
 294                 if( giNumCPUs > MAX_CPUS ) {
 295                         Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
 296                         giNumCPUs = MAX_CPUS;
 297                 }
 298                 gTSSs = gaTSSs;
 299         }
 300         else {
 301                 Log("No MP Table was found, assuming uniprocessor\n");
 302                 giNumCPUs = 1;
 303                 gTSSs = &gTSS0;
 304         }
 305         #else
 306         giNumCPUs = 1;
 307         gTSSs = &gTSS0;
 308         #endif
 309
 310         #if !DEBUG_DISABLE_DOUBLEFAULT
 311         // Initialise Double Fault TSS
 312         gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
 313         gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
 314         gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
 315
 316         // Set double fault IDT to use the new TSS
 317         gIDT[8].OffsetLo = 0;
 318         gIDT[8].CS = 5<<3;
 319         gIDT[8].Flags = 0x8500;
 320         gIDT[8].OffsetHi = 0;
 321         #endif
 322
 323         // Set timer frequency
 324         outb(0x43, 0x34);       // Set Channel 0, Low/High, Rate Generator
 325         outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
 326         outb(0x40, (TIMER_DIVISOR>>8)&0xFF);    // High Byte
 327
 328         Log_Debug("Proc", "PIT Frequency %i.%03i Hz",
 329                 TIMER_BASE/TIMER_DIVISOR,
 330                 ((Uint64)TIMER_BASE*1000/TIMER_DIVISOR)%1000
 331                 );
 332
 333         #if USE_MP
 334         // Get the count setting for APIC timer
 335         Log("Determining APIC Count");
 336         __asm__ __volatile__ ("sti");
 337         while( giMP_TimerCount == 0 )   __asm__ __volatile__ ("hlt");
 338         __asm__ __volatile__ ("cli");
 339         Log("APIC Count %i", giMP_TimerCount);
 340         {
 341                 Uint64  freq = giMP_TimerCount;
 342                 freq *= TIMER_BASE;
 343                 freq /= TIMER_DIVISOR;
 344                 if( (freq /= 1000) < 2*1000)
 345                         Log("Bus Frequency %i KHz", freq);
 346                 else if( (freq /= 1000) < 2*1000)
 347                         Log("Bus Frequency %i MHz", freq);
 348                 else if( (freq /= 1000) < 2*1000)
 349                         Log("Bus Frequency %i GHz", freq);
 350                 else
 351                         Log("Bus Frequency %i THz", freq);
 352         }
 353
 354         // Initialise Normal TSS(s)
 355         for(pos=0;pos<giNumCPUs;pos++)
 356         {
 357         #else
 358         pos = 0;
 359         #endif
 360                 gTSSs[pos].SS0 = 0x10;
 361                 gTSSs[pos].ESP0 = 0;    // Set properly by scheduler
 362                 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
 363                 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos]) >> 16) & 0xFFFF;
 364                 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
 365         #if USE_MP
 366         }
 367         #endif
 368
 369         // Load the BSP's TSS
 370         __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
 371         // Set Current Thread and CPU Number in DR0 and DR1
 372         __asm__ __volatile__ ("mov %0, %%db0"::"r"(&gThreadZero));
 373         __asm__ __volatile__ ("mov %0, %%db1"::"r"(0));
 374
 375         gaCPUs[0].Current = &gThreadZero;
 376         gThreadZero.CurCPU = 0;
 377
 378         gProcessZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
 379
 380         // Create Per-Process Data Block
 381         if( !MM_Allocate(MM_PPD_CFG) )
 382         {
 383                 Panic("OOM - No space for initial Per-Process Config");
 384         }
 385
 386         // Initialise SSE support
 387         Proc_InitialiseSSE();
 388
 389         // Change Stacks
 390         Proc_ChangeStack();
 391 }
 392
 393 #if USE_MP
 394 /**
 395  * \brief Start an AP
 396  */
 397 void MP_StartAP(int CPU)
 398 {
 399         Log_Log("Proc", "Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
 400
 401         // Set location of AP startup code and mark for a warm restart
 402         *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
 403         *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
 404         outb(0x70, 0x0F);       outb(0x71, 0x0A);       // Set warm reset flag
 405         MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);   // Init IPI
 406
 407         // Delay
 408         inb(0x80); inb(0x80); inb(0x80); inb(0x80);
 409
 410         // TODO: Use a better address, preferably registered with the MM
 411         // - MM_AllocDMA mabye?
 412         // Create a far jump
 413         *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA;  // Far JMP
 414         *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);     // IP
 415         *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF;       // CS
 416         // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
 417         // just filled)
 418         MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6);        // StartupIPI
 419
 420         giNumInitingCPUs ++;
 421 }
 422
 423 void MP_SendIPIVector(int CPU, Uint8 Vector)
 424 {
 425         MP_SendIPI(gaCPUs[CPU].APICID, Vector, 0);
 426 }
 427
 428 /**
 429  * \brief Send an Inter-Processor Interrupt
 430  * \param APICID        Processor's Local APIC ID
 431  * \param Vector        Argument of some kind
 432  * \param DeliveryMode  Type of signal
 433  * \note 3A 10.5 "APIC/Handling Local Interrupts"
 434  */
 435 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 436 {
 437         Uint32  val;
 438
 439         // Hi
 440         val = (Uint)APICID << 24;
 441 //      Log("%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
 442         gpMP_LocalAPIC->ICR[1].Val = val;
 443         // Low (and send)
 444         val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
 445 //      Log("%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
 446         gpMP_LocalAPIC->ICR[0].Val = val;
 447 }
 448 #endif
 449
 450 void Proc_IdleThread(void *Ptr)
 451 {
 452         tCPU    *cpu = &gaCPUs[GetCPUNum()];
 453         cpu->Current->ThreadName = strdup("Idle Thread");
 454         Threads_SetPriority( cpu->Current, -1 );        // Never called randomly
 455         cpu->Current->Quantum = 1;      // 1 slice quantum
 456         for(;;) {
 457                 __asm__ __volatile__ ("sti");   // Make sure interrupts are enabled
 458                 __asm__ __volatile__ ("hlt");   // Make sure interrupts are enabled
 459                 Proc_Reschedule();
 460         }
 461 }
 462
 463 /**
 464  * \fn void Proc_Start(void)
 465  * \brief Start process scheduler
 466  */
 467 void Proc_Start(void)
 468 {
 469          int    tid;
 470         #if USE_MP
 471          int    i;
 472         #endif
 473
 474         #if USE_MP
 475         // Start APs
 476         for( i = 0; i < giNumCPUs; i ++ )
 477         {
 478                 if(i)   gaCPUs[i].Current = NULL;
 479
 480                 // Create Idle Task
 481                 tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[i]);
 482
 483                 // Start the AP
 484                 if( i != giProc_BootProcessorID ) {
 485                         MP_StartAP( i );
 486                 }
 487         }
 488
 489         // BSP still should run the current task
 490         gaCPUs[0].Current = &gThreadZero;
 491
 492         // Start interrupts and wait for APs to come up
 493         Log_Debug("Proc", "Waiting for APs to come up");
 494         __asm__ __volatile__ ("sti");
 495         while( giNumInitingCPUs )       __asm__ __volatile__ ("hlt");
 496         #else
 497         // Create Idle Task
 498         tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[0]);
 499 //      gaCPUs[0].IdleThread = Threads_GetThread(tid);
 500
 501         // Set current task
 502         gaCPUs[0].Current = &gThreadZero;
 503
 504         // Start Interrupts (and hence scheduler)
 505         __asm__ __volatile__("sti");
 506         #endif
 507         MM_FinishVirtualInit();
 508 }
 509
 510 /**
 511  * \fn tThread *Proc_GetCurThread(void)
 512  * \brief Gets the current thread
 513  */
 514 tThread *Proc_GetCurThread(void)
 515 {
 516         #if USE_MP
 517         return gaCPUs[ GetCPUNum() ].Current;
 518         #else
 519         return gaCPUs[ 0 ].Current;
 520         #endif
 521 }
 522
 523 /**
 524  * \fn void Proc_ChangeStack(void)
 525  * \brief Swaps the current stack for a new one (in the proper stack reigon)
 526  */
 527 void Proc_ChangeStack(void)
 528 {
 529         Uint    esp, ebp;
 530         Uint    tmpEbp, oldEsp;
 531         Uint    curBase, newBase;
 532
 533         __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
 534         __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
 535
 536         oldEsp = esp;
 537
 538         // Create new KStack
 539         newBase = MM_NewKStack();
 540         // Check for errors
 541         if(newBase == 0) {
 542                 Panic("What the?? Unable to allocate space for initial kernel stack");
 543                 return;
 544         }
 545
 546         curBase = (Uint)&Kernel_Stack_Top;
 547
 548         LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
 549
 550         // Get ESP as a used size
 551         esp = curBase - esp;
 552         LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
 553         // Copy used stack
 554         memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
 555         // Get ESP as an offset in the new stack
 556         esp = newBase - esp;
 557         // Adjust EBP
 558         ebp = newBase - (curBase - ebp);
 559
 560         // Repair EBPs & Stack Addresses
 561         // Catches arguments also, but may trash stack-address-like values
 562         for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
 563         {
 564                 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
 565                         *(Uint*)tmpEbp += newBase - curBase;
 566         }
 567
 568         Proc_GetCurThread()->KernelStack = newBase;
 569
 570         __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
 571         __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
 572 }
 573
 574 void Proc_ClearProcess(tProcess *Process)
 575 {
 576         MM_ClearSpace(Process->MemState.CR3);
 577 }
 578
 579 void Proc_ClearThread(tThread *Thread)
 580 {
 581         if(Thread->SavedState.SSE) {
 582                 free(Thread->SavedState.SSE);
 583                 Thread->SavedState.SSE = NULL;
 584         }
 585 }
 586
 587 tTID Proc_NewKThread(void (*Fcn)(void*), void *Data)
 588 {
 589         Uint    esp;
 590         tThread *newThread, *cur;
 591
 592         cur = Proc_GetCurThread();
 593         newThread = Threads_CloneTCB(0);
 594         if(!newThread)  return -1;
 595
 596         // Create new KStack
 597         newThread->KernelStack = MM_NewKStack();
 598         // Check for errors
 599         if(newThread->KernelStack == 0) {
 600                 free(newThread);
 601                 return -1;
 602         }
 603
 604         esp = newThread->KernelStack;
 605         *(Uint*)(esp-=4) = (Uint)Data;  // Data (shadowed)
 606         *(Uint*)(esp-=4) = 1;   // Number of params
 607         *(Uint*)(esp-=4) = (Uint)Fcn;   // Function to call
 608         *(Uint*)(esp-=4) = (Uint)newThread;     // Thread ID
 609
 610         newThread->SavedState.ESP = esp;
 611         newThread->SavedState.EIP = (Uint)&NewTaskHeader;
 612         newThread->SavedState.SSE = NULL;
 613 //      Log("New (KThread) %p, esp = %p", newThread->SavedState.EIP, newThread->SavedState.ESP);
 614
 615 //      MAGIC_BREAK();
 616         Threads_AddActive(newThread);
 617
 618         return newThread->TID;
 619 }
 620
 621 /**
 622  * \fn int Proc_Clone(Uint *Err, Uint Flags)
 623  * \brief Clone the current process
 624  */
 625 tPID Proc_Clone(Uint Flags)
 626 {
 627         tThread *newThread;
 628         tThread *cur = Proc_GetCurThread();
 629         Uint    eip;
 630
 631         // Sanity, please
 632         if( !(Flags & CLONE_VM) ) {
 633                 Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
 634                 return -1;
 635         }
 636
 637         // New thread
 638         newThread = Threads_CloneTCB(Flags);
 639         if(!newThread)  return -1;
 640
 641         newThread->KernelStack = cur->KernelStack;
 642
 643         // Clone state
 644         eip = Proc_CloneInt(&newThread->SavedState.ESP, &newThread->Process->MemState.CR3, Flags & CLONE_NOUSER);
 645         if( eip == 0 ) {
 646                 return 0;
 647         }
 648         newThread->SavedState.EIP = eip;
 649         newThread->SavedState.SSE = NULL;
 650         newThread->SavedState.bSSEModified = 0;
 651
 652         // Check for errors
 653         if( newThread->Process->MemState.CR3 == 0 ) {
 654                 Log_Error("Proc", "Proc_Clone: MM_Clone failed");
 655                 Threads_Delete(newThread);
 656                 return -1;
 657         }
 658
 659         // Add the new thread to the run queue
 660         Threads_AddActive(newThread);
 661         return newThread->TID;
 662 }
 663
 664 /**
 665  * \fn int Proc_SpawnWorker(void)
 666  * \brief Spawns a new worker thread
 667  */
 668 int Proc_SpawnWorker(void (*Fcn)(void*), void *Data)
 669 {
 670         tThread *new;
 671         Uint    stack_contents[4];
 672
 673         // Create new thread
 674         new = Threads_CloneThreadZero();
 675         if(!new) {
 676                 Warning("Proc_SpawnWorker - Out of heap space!\n");
 677                 return -1;
 678         }
 679
 680         // Create the stack contents
 681         stack_contents[3] = (Uint)Data;
 682         stack_contents[2] = 1;
 683         stack_contents[1] = (Uint)Fcn;
 684         stack_contents[0] = (Uint)new;
 685
 686         // Create a new worker stack (in PID0's address space)
 687         new->KernelStack = MM_NewWorkerStack(stack_contents, sizeof(stack_contents));
 688
 689         // Save core machine state
 690         new->SavedState.ESP = new->KernelStack - sizeof(stack_contents);
 691         new->SavedState.EIP = (Uint)NewTaskHeader;
 692         new->SavedState.SSE = NULL;
 693         new->SavedState.bSSEModified = 0;
 694
 695         // Mark as active
 696         new->Status = THREAD_STAT_PREINIT;
 697         Threads_AddActive( new );
 698
 699         return new->TID;
 700 }
 701
 702 /**
 703  * \fn Uint Proc_MakeUserStack(void)
 704  * \brief Creates a new user stack
 705  */
 706 Uint Proc_MakeUserStack(void)
 707 {
 708          int    i;
 709         Uint    base = USER_STACK_TOP - USER_STACK_SZ;
 710
 711         // Check Prospective Space
 712         for( i = USER_STACK_SZ >> 12; i--; )
 713                 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
 714                         break;
 715
 716         if(i != -1)     return 0;
 717
 718         // Allocate Stack - Allocate incrementally to clean up MM_Dump output
 719         for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
 720         {
 721                 if( !MM_Allocate( base + (i<<12) ) )
 722                 {
 723                         Warning("OOM: Proc_MakeUserStack");
 724                         return 0;
 725                 }
 726         }
 727
 728         return base + USER_STACK_SZ;
 729 }
 730
 731 void Proc_StartUser(Uint Entrypoint, Uint Base, int ArgC, const char **ArgV, int DataSize)
 732 {
 733         Uint    *stack;
 734          int    i;
 735         const char      **envp = NULL;
 736         Uint16  ss, cs;
 737
 738         // Copy data to the user stack and free original buffer
 739         stack = (void*)Proc_MakeUserStack();
 740         stack -= (DataSize+sizeof(*stack)-1)/sizeof(*stack);
 741         memcpy( stack, ArgV, DataSize );
 742         free(ArgV);
 743
 744         // Adjust Arguments and environment
 745         if( DataSize )
 746         {
 747                 Uint delta = (Uint)stack - (Uint)ArgV;
 748                 ArgV = (const char**)stack;
 749                 for( i = 0; ArgV[i]; i++ )      ArgV[i] += delta;
 750                 envp = &ArgV[i+1];
 751                 for( i = 0; envp[i]; i++ )      envp[i] += delta;
 752         }
 753
 754         // User Mode Segments
 755         ss = 0x23;      cs = 0x1B;
 756
 757         // Arguments
 758         *--stack = (Uint)envp;
 759         *--stack = (Uint)ArgV;
 760         *--stack = (Uint)ArgC;
 761         *--stack = Base;
 762
 763         Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 764 }
 765
 766 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
 767 {
 768         Uint    *stack = (void*)Stack;
 769         *--stack = SS;          //Stack Segment
 770         *--stack = Stack;       //Stack Pointer
 771         *--stack = Flags;       //EFLAGS (Resvd (0x2) and IF (0x20))
 772         *--stack = CS;          //Code Segment
 773         *--stack = IP;  //EIP
 774         //PUSHAD
 775         *--stack = 0xAAAAAAAA;  // eax
 776         *--stack = 0xCCCCCCCC;  // ecx
 777         *--stack = 0xDDDDDDDD;  // edx
 778         *--stack = 0xBBBBBBBB;  // ebx
 779         *--stack = 0xD1D1D1D1;  // edi
 780         *--stack = 0x54545454;  // esp - NOT POPED
 781         *--stack = 0x51515151;  // esi
 782         *--stack = 0xB4B4B4B4;  // ebp
 783         //Individual PUSHs
 784         *--stack = SS;  // ds
 785         *--stack = SS;  // es
 786         *--stack = SS;  // fs
 787         *--stack = SS;  // gs
 788
 789         __asm__ __volatile__ (
 790         "mov %%eax,%%esp;\n\t"  // Set stack pointer
 791         "pop %%gs;\n\t"
 792         "pop %%fs;\n\t"
 793         "pop %%es;\n\t"
 794         "pop %%ds;\n\t"
 795         "popa;\n\t"
 796         "iret;\n\t" : : "a" (stack));
 797         for(;;);
 798 }
 799
 800 /**
 801  * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 802  * \brief Demotes a process to a lower permission level
 803  * \param Err   Pointer to user's errno
 804  * \param Dest  New Permission Level
 805  * \param Regs  Pointer to user's register structure
 806  */
 807 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 808 {
 809          int    cpl = Regs->cs & 3;
 810         // Sanity Check
 811         if(Dest > 3 || Dest < 0) {
 812                 *Err = -EINVAL;
 813                 return -1;
 814         }
 815
 816         // Permission Check
 817         if(cpl > Dest) {
 818                 *Err = -EACCES;
 819                 return -1;
 820         }
 821
 822         // Change the Segment Registers
 823         Regs->cs = (((Dest+1)<<4) | Dest) - 8;
 824         Regs->ss = ((Dest+1)<<4) | Dest;
 825         // Check if the GP Segs are GDT, then change them
 826         if(!(Regs->ds & 4))     Regs->ds = ((Dest+1)<<4) | Dest;
 827         if(!(Regs->es & 4))     Regs->es = ((Dest+1)<<4) | Dest;
 828         if(!(Regs->fs & 4))     Regs->fs = ((Dest+1)<<4) | Dest;
 829         if(!(Regs->gs & 4))     Regs->gs = ((Dest+1)<<4) | Dest;
 830
 831         return 0;
 832 }
 833
 834 /**
 835  * \brief Calls a signal handler in user mode
 836  * \note Used for signals
 837  */
 838 void Proc_CallFaultHandler(tThread *Thread)
 839 {
 840         // Rewinds the stack and calls the user function
 841         // Never returns
 842         Proc_ReturnToUser( Thread->FaultHandler, Thread->CurFaultNum, Thread->KernelStack );
 843         for(;;);
 844 }
 845
 846 void Proc_DumpThreadCPUState(tThread *Thread)
 847 {
 848         if( Thread->CurCPU > -1 )
 849         {
 850                  int    maxBacktraceDistance = 6;
 851                 tRegs   *regs = NULL;
 852                 Uint32  *stack;
 853
 854                 if( Thread->CurCPU != GetCPUNum() ) {
 855                         Log("  Currently running");
 856                         return ;
 857                 }
 858
 859                 // Backtrace to find the IRQ entrypoint
 860                 // - This will usually only be called by an IRQ, so this should
 861                 //   work
 862                 __asm__ __volatile__ ("mov %%ebp, %0" : "=r" (stack));
 863                 while( maxBacktraceDistance -- )
 864                 {
 865                         // [ebp] = oldEbp
 866                         // [ebp+4] = retaddr
 867
 868                         if( stack[1] == (tVAddr)&IRQCommon_handled ) {
 869                                 regs = (void*)stack[2];
 870                                 break;
 871                         }
 872
 873                         stack = (void*)stack[0];
 874                 }
 875
 876                 if( !regs ) {
 877                         Log("  Unable to find IRQ Entry");
 878                         return ;
 879                 }
 880
 881                 Log("  at %04x:%08x", regs->cs, regs->eip);
 882                 return ;
 883         }
 884
 885         tVAddr  diffFromScheduler = Thread->SavedState.EIP - (tVAddr)SwitchTasks;
 886         tVAddr  diffFromClone = Thread->SavedState.EIP - (tVAddr)Proc_CloneInt;
 887         tVAddr  diffFromSpawn = Thread->SavedState.EIP - (tVAddr)NewTaskHeader;
 888
 889         if( diffFromClone > 0 && diffFromClone < 40 )   // When I last checked, .newTask was at .+27
 890         {
 891                 Log("  Creating process");
 892                 return ;
 893         }
 894
 895         if( diffFromSpawn == 0 )
 896         {
 897                 Log("  Creating thread");
 898                 return ;
 899         }
 900
 901         if( diffFromScheduler > 0 && diffFromScheduler < 128 )  // When I last checked, GetEIP was at .+0x30
 902         {
 903                 // Scheduled out
 904                 Log("  At %04x:%08x", Thread->SavedState.UserCS, Thread->SavedState.UserEIP);
 905                 return ;
 906         }
 907
 908         Log("  Just created (unknown %p)", Thread->SavedState.EIP);
 909 }
 910
 911 void Proc_Reschedule(void)
 912 {
 913         tThread *nextthread, *curthread;
 914          int    cpu = GetCPUNum();
 915
 916         // TODO: Wait for the lock?
 917         if(IS_LOCKED(&glThreadListLock))        return;
 918
 919         curthread = Proc_GetCurThread();
 920
 921         nextthread = Threads_GetNextToRun(cpu, curthread);
 922
 923         if(!nextthread || nextthread == curthread)
 924                 return ;
 925
 926         #if DEBUG_TRACE_SWITCH
 927         // HACK: Ignores switches to the idle threads
 928         if( nextthread->TID == 0 || nextthread->TID > giNumCPUs )
 929         {
 930                 LogF("\nSwitching CPU %i to %p (%i %s) - CR3 = 0x%x, EIP = %p, ESP = %p\n",
 931                         GetCPUNum(),
 932                         nextthread, nextthread->TID, nextthread->ThreadName,
 933                         nextthread->Process->MemState.CR3,
 934                         nextthread->SavedState.EIP,
 935                         nextthread->SavedState.ESP
 936                         );
 937                 LogF("OldCR3 = %P\n", curthread->Process->MemState.CR3);
 938         }
 939         #endif
 940
 941         // Update CPU state
 942         gaCPUs[cpu].Current = nextthread;
 943         gaCPUs[cpu].LastTimerThread = NULL;
 944         gTSSs[cpu].ESP0 = nextthread->KernelStack-4;
 945         __asm__ __volatile__("mov %0, %%db0\n\t" : : "r"(nextthread) );
 946
 947         // Save FPU/MMX/XMM/SSE state
 948         if( curthread && curthread->SavedState.SSE )
 949         {
 950                 Proc_SaveSSE( ((Uint)curthread->SavedState.SSE + 0xF) & ~0xF );
 951                 curthread->SavedState.bSSEModified = 0;
 952                 Proc_DisableSSE();
 953         }
 954
 955         if( curthread )
 956         {
 957                 SwitchTasks(
 958                         nextthread->SavedState.ESP, &curthread->SavedState.ESP,
 959                         nextthread->SavedState.EIP, &curthread->SavedState.EIP,
 960                         nextthread->Process->MemState.CR3
 961                         );
 962         }
 963         else
 964         {
 965                 SwitchTasks(
 966                         nextthread->SavedState.ESP, 0,
 967                         nextthread->SavedState.EIP, 0,
 968                         nextthread->Process->MemState.CR3
 969                         );
 970         }
 971
 972         return ;
 973 }
 974
 975 /**
 976  * \fn void Proc_Scheduler(int CPU)
 977  * \brief Swap current thread and clears dead threads
 978  */
 979 void Proc_Scheduler(int CPU)
 980 {
 981         #if USE_MP
 982         if( GetCPUNum() )
 983                 gpMP_LocalAPIC->EOI.Val = 0;
 984         else
 985         #endif
 986                 outb(0x20, 0x20);
 987         __asm__ __volatile__ ("sti");
 988
 989         gaCPUs[CPU].LastTimerThread = gaCPUs[CPU].Current;
 990         // Call the timer update code
 991         Timer_CallTimers();
 992
 993         // If two ticks happen within the same task, and it's not an idle task, swap
 994         if( gaCPUs[CPU].Current->TID > giNumCPUs && gaCPUs[CPU].Current == gaCPUs[CPU].LastTimerThread )
 995         {
 996                 Proc_Reschedule();
 997         }
 998 }
 999
1000 // === EXPORTS ===
1001 EXPORT(Proc_SpawnWorker);