16 #define DEBUG_TRACE_SWITCH 0
19 #define SWITCH_MAGIC 0x55ECAFFF##FFFACE55 // There is no code in this area
21 #define TIMER_DIVISOR 11931 //~100Hz
25 extern void APStartup(void); // 16-bit AP startup code
26 extern Uint GetRIP(void); // start.asm
27 extern Uint64 gInitialPML4[512]; // start.asm
28 extern void gInitialKernelStack;
29 extern tSpinlock glThreadListLock;
32 extern int giTotalTickets;
33 extern int giNumActiveThreads;
34 extern tThread gThreadZero;
35 extern tThread *gActiveThreads;
36 extern tThread *gSleepingThreads;
37 extern tThread *gDeleteThreads;
38 extern tThread *Threads_GetNextToRun(int CPU);
39 extern void Threads_Dump(void);
40 extern tThread *Threads_CloneTCB(Uint *Err, Uint Flags);
41 extern void Proc_ReturnToUser(void);
42 extern int GetCPUNum(void);
45 void ArchThreads_Init(void);
47 void MP_StartAP(int CPU);
48 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
50 void Proc_Start(void);
51 tThread *Proc_GetCurThread(void);
52 void Proc_ChangeStack(void);
53 int Proc_Clone(Uint *Err, Uint Flags);
54 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
55 void Proc_CallFaultHandler(tThread *Thread);
56 void Proc_Scheduler(int CPU);
59 // --- Multiprocessing ---
61 volatile int giNumInitingCPUs = 0;
62 tMPInfo *gMPFloatPtr = NULL;
63 tAPIC *gpMP_LocalAPIC = NULL;
64 Uint8 gaAPIC_to_CPU[256] = {0};
65 tCPU gaCPUs[MAX_CPUS];
67 tThread *gCurrentThread = NULL;
71 // --- Error Recovery ---
72 Uint32 gaDoubleFaultStack[1024];
76 * \fn void ArchThreads_Init(void)
77 * \brief Starts the process scheduler
79 void ArchThreads_Init(void)
89 // -- Initialise Multiprocessing
90 // Find MP Floating Table
91 // - EBDA/Last 1Kib (640KiB)
92 for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
93 if( *(Uint*)(pos) == MPPTR_IDENT ) {
94 Log("Possible %p", pos);
95 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
96 gMPFloatPtr = (void*)pos;
100 // - Last KiB (512KiB base mem)
102 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
103 if( *(Uint*)(pos) == MPPTR_IDENT ) {
104 Log("Possible %p", pos);
105 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
106 gMPFloatPtr = (void*)pos;
113 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
114 if( *(Uint*)(pos) == MPPTR_IDENT ) {
115 Log("Possible %p", pos);
116 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
117 gMPFloatPtr = (void*)pos;
123 // If the MP Table Exists, parse it
128 Log("gMPFloatPtr = %p", gMPFloatPtr);
129 Log("*gMPFloatPtr = {");
130 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
131 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
132 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
133 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
134 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
135 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
136 gMPFloatPtr->Features[0], gMPFloatPtr->Features[1],
137 gMPFloatPtr->Features[2], gMPFloatPtr->Features[3],
138 gMPFloatPtr->Features[4]
142 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
143 Log("mptable = %p", mptable);
145 Log("\t.Sig = 0x%08x", mptable->Sig);
146 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
147 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
148 Log("\t.Checksum = 0x%02x", mptable->Checksum);
149 Log("\t.OEMID = '%8c'", mptable->OemID);
150 Log("\t.ProductID = '%8c'", mptable->ProductID);
151 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
152 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
153 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
154 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
155 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
156 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
159 gpMP_LocalAPIC = (void*)MM_MapHWPage(mptable->LocalAPICMemMap, 1);
161 ents = mptable->Entries;
164 for( i = 0; i < mptable->EntryCount; i ++ )
171 Log("%i: Processor", i);
172 Log("\t.APICID = %i", ents->Proc.APICID);
173 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
174 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
175 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
176 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
179 if( !(ents->Proc.CPUFlags & 1) ) {
184 // Check if there is too many processors
185 if(giNumCPUs >= MAX_CPUS) {
186 giNumCPUs ++; // If `giNumCPUs` > MAX_CPUS later, it will be clipped
190 // Initialise CPU Info
191 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
192 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
193 gaCPUs[giNumCPUs].State = 0;
197 if( !(ents->Proc.CPUFlags & 2) )
199 MP_StartAP( giNumCPUs-1 );
206 Log("\t.ID = %i", ents->Bus.ID);
207 Log("\t.TypeString = '%6c'", ents->Bus.TypeString);
211 Log("%i: I/O APIC", i);
212 Log("\t.ID = %i", ents->IOAPIC.ID);
213 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
214 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
215 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
217 case 3: // I/O Interrupt Assignment
219 Log("%i: I/O Interrupt Assignment", i);
220 Log("\t.IntType = %i", ents->IOInt.IntType);
221 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
222 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
223 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
224 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
225 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
227 case 4: // Local Interrupt Assignment
229 Log("%i: Local Interrupt Assignment", i);
230 Log("\t.IntType = %i", ents->LocalInt.IntType);
231 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
232 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
233 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
234 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
235 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
238 Log("%i: Unknown (%i)", i, ents->Type);
241 ents = (void*)( (Uint)ents + entSize );
244 if( giNumCPUs > MAX_CPUS ) {
245 Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
246 giNumCPUs = MAX_CPUS;
249 while( giNumInitingCPUs )
250 MM_FinishVirtualInit();
252 Panic("Uh oh... MP Table Parsing is unimplemented\n");
255 Log("No MP Table was found, assuming uniprocessor\n");
262 MM_FinishVirtualInit();
266 // Initialise Normal TSS(s)
267 for(pos=0;pos<giNumCPUs;pos++)
272 gTSSs[pos].RSP0 = 0; // Set properly by scheduler
273 gGDT[7+pos*2].LimitLow = sizeof(tTSS) & 0xFFFF;
274 gGDT[7+pos*2].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
275 gGDT[7+pos*2].BaseMid = ((Uint)(&gTSSs[pos])) >> 16;
276 gGDT[7+pos*2].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
277 gGDT[7+pos*2+1].DWord[0] = ((Uint)(&gTSSs[pos])) >> 32;
280 for(pos=0;pos<giNumCPUs;pos++) {
282 __asm__ __volatile__ ("ltr %%ax"::"a"(0x38+pos*16));
288 gaCPUs[0].Current = &gThreadZero;
290 gCurrentThread = &gThreadZero;
293 gThreadZero.MemState.CR3 = (Uint)gInitialPML4 - KERNEL_BASE;
295 // Set timer frequency
296 outb(0x43, 0x34); // Set Channel 0, Low/High, Rate Generator
297 outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
298 outb(0x40, (TIMER_DIVISOR>>8)&0xFF); // High Byte
300 // Create Per-Process Data Block
301 MM_Allocate(MM_PPD_CFG);
308 void MP_StartAP(int CPU)
310 Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
311 // Set location of AP startup code and mark for a warm restart
312 *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);
313 *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
314 outb(0x70, 0x0F); outb(0x71, 0x0A); // Warm Reset
315 MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);
319 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
321 Uint32 addr = (Uint)gpMP_LocalAPIC + 0x300;
325 val = (Uint)APICID << 24;
326 Log("*%p = 0x%08x", addr+0x10, val);
327 *(Uint32*)(addr+0x10) = val;
329 val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
330 Log("*%p = 0x%08x", addr, val);
331 *(Uint32*)addr = val;
336 * \fn void Proc_Start(void)
337 * \brief Start process scheduler
339 void Proc_Start(void)
341 // Start Interrupts (and hence scheduler)
342 __asm__ __volatile__("sti");
346 * \fn tThread *Proc_GetCurThread(void)
347 * \brief Gets the current thread
349 tThread *Proc_GetCurThread(void)
352 return gaCPUs[ GetCPUNum() ].Current;
354 return gCurrentThread;
359 * \fn void Proc_ChangeStack(void)
360 * \brief Swaps the current stack for a new one (in the proper stack reigon)
362 void Proc_ChangeStack(void)
365 Uint tmp_rbp, old_rsp;
366 Uint curBase, newBase;
368 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
369 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
374 newBase = MM_NewKStack();
377 Panic("What the?? Unable to allocate space for initial kernel stack");
381 curBase = (Uint)&gInitialKernelStack;
383 Log("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
385 // Get ESP as a used size
387 Log("memcpy( %p, %p, 0x%x )", (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
389 memcpy( (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
390 // Get ESP as an offset in the new stack
393 rbp = newBase - (curBase - rbp);
396 // Repair EBPs & Stack Addresses
397 // Catches arguments also, but may trash stack-address-like values
398 for(tmp_rbp = rsp; tmp_rbp < newBase; tmp_rbp += sizeof(Uint))
400 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < curBase)
401 *(Uint*)tmp_rbp += newBase - curBase;
404 Log("Applying Changes");
405 Proc_GetCurThread()->KernelStack = newBase;
406 __asm__ __volatile__ ("mov %0, %%rsp"::"r"(rsp));
407 __asm__ __volatile__ ("mov %0, %%rbp"::"r"(rbp));
411 * \fn int Proc_Clone(Uint *Err, Uint Flags)
412 * \brief Clone the current process
414 int Proc_Clone(Uint *Err, Uint Flags)
417 tThread *cur = Proc_GetCurThread();
420 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
421 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
423 newThread = Threads_CloneTCB(Err, Flags);
424 if(!newThread) return -1;
426 Log("Proc_Clone: newThread = %p", newThread);
428 // Initialise Memory Space (New Addr space or kernel stack)
429 if(Flags & CLONE_VM) {
430 Log("Proc_Clone: Cloning VM");
431 newThread->MemState.CR3 = MM_Clone();
432 newThread->KernelStack = cur->KernelStack;
434 Uint tmp_rbp, old_rsp = rsp;
437 newThread->MemState.CR3 = cur->MemState.CR3;
440 newThread->KernelStack = MM_NewKStack();
441 Log("Proc_Clone: newKStack = %p", newThread->KernelStack);
443 if(newThread->KernelStack == 0) {
448 // Get ESP as a used size
449 rsp = cur->KernelStack - rsp;
452 (void*)(newThread->KernelStack - rsp),
453 (void*)(cur->KernelStack - rsp),
456 // Get ESP as an offset in the new stack
457 rsp = newThread->KernelStack - rsp;
459 rbp = newThread->KernelStack - (cur->KernelStack - rbp);
461 // Repair EBPs & Stack Addresses
462 // Catches arguments also, but may trash stack-address-like values
463 for(tmp_rbp = rsp; tmp_rbp < newThread->KernelStack; tmp_rbp += sizeof(Uint))
465 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < cur->KernelStack)
466 *(Uint*)tmp_rbp += newThread->KernelStack - cur->KernelStack;
470 // Save core machine state
471 newThread->SavedState.RSP = rsp;
472 newThread->SavedState.RBP = rbp;
474 if(rip == SWITCH_MAGIC) {
475 outb(0x20, 0x20); // ACK Timer and return as child
480 newThread->SavedState.RIP = rip;
482 // Lock list and add to active
483 Threads_AddActive(newThread);
485 return newThread->TID;
489 * \fn int Proc_SpawnWorker(void)
490 * \brief Spawns a new worker thread
492 int Proc_SpawnWorker(void)
497 cur = Proc_GetCurThread();
500 new = malloc( sizeof(tThread) );
502 Warning("Proc_SpawnWorker - Out of heap space!\n");
505 memcpy(new, &gThreadZero, sizeof(tThread));
507 new->TID = giNextTID++;
508 // Create a new worker stack (in PID0's address space)
509 // The stack is relocated by this code
510 new->KernelStack = MM_NewWorkerStack();
512 // Get ESP and EBP based in the new stack
513 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
514 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
515 rsp = new->KernelStack - (cur->KernelStack - rsp);
516 rbp = new->KernelStack - (cur->KernelStack - rbp);
518 // Save core machine state
519 new->SavedState.RSP = rsp;
520 new->SavedState.RBP = rbp;
522 if(rip == SWITCH_MAGIC) {
523 outb(0x20, 0x20); // ACK Timer and return as child
528 new->SavedState.RIP = rip;
530 new->Status = THREAD_STAT_ACTIVE;
531 Threads_AddActive( new );
537 * \fn Uint Proc_MakeUserStack(void)
538 * \brief Creates a new user stack
540 Uint Proc_MakeUserStack(void)
543 Uint base = USER_STACK_TOP - USER_STACK_SZ;
545 // Check Prospective Space
546 for( i = USER_STACK_SZ >> 12; i--; )
547 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
550 if(i != -1) return 0;
552 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
553 for( i = 0; i < USER_STACK_SZ/4069; i++ )
554 MM_Allocate( base + (i<<12) );
556 return base + USER_STACK_SZ;
561 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
562 * \brief Starts a user task
564 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
566 Uint *stack = (void*)Proc_MakeUserStack();
571 LOG("stack = 0x%x", stack);
574 stack = (void*)( (Uint)stack - DataSize );
575 memcpy( stack, ArgV, DataSize );
577 // Adjust Arguments and environment
578 delta = (Uint)stack - (Uint)ArgV;
579 ArgV = (char**)stack;
580 for( i = 0; ArgV[i]; i++ ) ArgV[i] += delta;
583 for( i = 0; EnvP[i]; i++ ) EnvP[i] += delta;
585 // User Mode Segments
586 ss = 0x23; cs = 0x1B;
589 *--stack = (Uint)EnvP;
590 *--stack = (Uint)ArgV;
591 *--stack = (Uint)ArgC;
594 *--stack = 0; // Return Address
596 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
599 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
601 Uint *stack = (void*)Stack;
602 *--stack = SS; //Stack Segment
603 *--stack = Stack; //Stack Pointer
604 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
605 *--stack = CS; //Code Segment
608 *--stack = 0xAAAAAAAA; // eax
609 *--stack = 0xCCCCCCCC; // ecx
610 *--stack = 0xDDDDDDDD; // edx
611 *--stack = 0xBBBBBBBB; // ebx
612 *--stack = 0xD1D1D1D1; // edi
613 *--stack = 0x54545454; // rsp - NOT POPED
614 *--stack = 0x51515151; // esi
615 *--stack = 0xB4B4B4B4; // rbp
619 __asm__ __volatile__ (
620 "mov %%rax,%%rsp;\n\t" // Set stack pointer
621 "iret;\n\t" : : "a" (stack));
626 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
627 * \brief Demotes a process to a lower permission level
628 * \param Err Pointer to user's errno
629 * \param Dest New Permission Level
630 * \param Regs Pointer to user's register structure
632 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
634 int cpl = Regs->CS & 3;
636 if(Dest > 3 || Dest < 0) {
647 // Change the Segment Registers
648 Regs->CS = (((Dest+1)<<4) | Dest) - 8;
649 Regs->SS = ((Dest+1)<<4) | Dest;
655 * \brief Calls a signal handler in user mode
656 * \note Used for signals
658 void Proc_CallFaultHandler(tThread *Thread)
660 // Rewinds the stack and calls the user function
662 __asm__ __volatile__ ("mov %0, %%rbp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
667 * \fn void Proc_Scheduler(int CPU)
668 * \brief Swap current thread and clears dead threads
670 void Proc_Scheduler(int CPU)
675 // If the spinlock is set, let it complete
676 if(IS_LOCKED(&glThreadListLock)) return;
678 // Clear Delete Queue
679 while(gDeleteThreads)
681 thread = gDeleteThreads->Next;
682 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
683 gDeleteThreads->Status = THREAD_STAT_NULL;
684 free( gDeleteThreads );
686 gDeleteThreads = thread;
689 // Check if there is any tasks running
690 if(giNumActiveThreads == 0) {
691 Log("No Active threads, sleeping");
692 __asm__ __volatile__ ("hlt");
696 // Get current thread
698 thread = gaCPUs[CPU].Current;
700 thread = gCurrentThread;
703 // Reduce remaining quantum and continue timeslice if non-zero
704 if(thread->Remaining--) return;
705 // Reset quantum for next call
706 thread->Remaining = thread->Quantum;
709 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
710 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
712 if(rip == SWITCH_MAGIC) return; // Check if a switch happened
714 // Save machine state
715 thread->SavedState.RSP = rsp;
716 thread->SavedState.RBP = rbp;
717 thread->SavedState.RIP = rip;
720 thread = Threads_GetNextToRun(CPU);
724 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
728 #if DEBUG_TRACE_SWITCH
729 Log("Switching to task %i, CR3 = 0x%x, RIP = %p",
731 thread->MemState.CR3,
732 thread->SavedState.RIP
736 // Set current thread
738 gaCPUs[CPU].Current = thread;
740 gCurrentThread = thread;
743 // Update Kernel Stack pointer
744 gTSSs[CPU].RSP0 = thread->KernelStack-4;
748 # error "Todo: Implement PAE Address space switching"
750 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
754 if(thread->SavedState.RSP > 0xC0000000
755 && thread->SavedState.RSP < thread->KernelStack-0x2000) {
756 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
761 __asm__ __volatile__ (
762 "mov %1, %%rsp\n\t" // Restore RSP
763 "mov %2, %%rbp\n\t" // and RBP
764 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
765 "a"(SWITCH_MAGIC), "b"(thread->SavedState.RSP),
766 "d"(thread->SavedState.RBP), "c"(thread->SavedState.RIP)
768 for(;;); // Shouldn't reach here
772 EXPORT(Proc_SpawnWorker);