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 void 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[ gaAPIC_to_CPU[gpMP_LocalAPIC->ID.Val&0xFF] ].Current;
353 return gaCPUs[ GetCPUNum() ].Current;
355 return gCurrentThread;
360 * \fn void Proc_ChangeStack(void)
361 * \brief Swaps the current stack for a new one (in the proper stack reigon)
363 void Proc_ChangeStack(void)
366 Uint tmp_rbp, old_rsp;
367 Uint curBase, newBase;
369 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
370 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
375 newBase = MM_NewKStack();
378 Panic("What the?? Unable to allocate space for initial kernel stack");
382 curBase = (Uint)&gInitialKernelStack;
384 Log("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
386 // Get ESP as a used size
388 Log("memcpy( %p, %p, 0x%x )", (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
390 memcpy( (void*)(newBase - rsp), (void*)(curBase - rsp), rsp );
391 // Get ESP as an offset in the new stack
394 rbp = newBase - (curBase - rbp);
397 // Repair EBPs & Stack Addresses
398 // Catches arguments also, but may trash stack-address-like values
399 for(tmp_rbp = rsp; tmp_rbp < newBase; tmp_rbp += sizeof(Uint))
401 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < curBase)
402 *(Uint*)tmp_rbp += newBase - curBase;
405 Log("Applying Changes");
406 Proc_GetCurThread()->KernelStack = newBase;
407 __asm__ __volatile__ ("mov %0, %%rsp"::"r"(rsp));
408 __asm__ __volatile__ ("mov %0, %%rbp"::"r"(rbp));
412 * \fn int Proc_Clone(Uint *Err, Uint Flags)
413 * \brief Clone the current process
415 int Proc_Clone(Uint *Err, Uint Flags)
418 tThread *cur = Proc_GetCurThread();
421 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
422 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
424 newThread = Threads_CloneTCB(Err, Flags);
425 if(!newThread) return -1;
427 Log("Proc_Clone: newThread = %p", newThread);
429 // Initialise Memory Space (New Addr space or kernel stack)
430 if(Flags & CLONE_VM) {
431 Log("Proc_Clone: Cloning VM");
432 newThread->MemState.CR3 = MM_Clone();
433 newThread->KernelStack = cur->KernelStack;
435 Uint tmp_rbp, old_rsp = rsp;
438 newThread->MemState.CR3 = cur->MemState.CR3;
441 newThread->KernelStack = MM_NewKStack();
442 Log("Proc_Clone: newKStack = %p", newThread->KernelStack);
444 if(newThread->KernelStack == 0) {
449 // Get ESP as a used size
450 rsp = cur->KernelStack - rsp;
453 (void*)(newThread->KernelStack - rsp),
454 (void*)(cur->KernelStack - rsp),
457 // Get ESP as an offset in the new stack
458 rsp = newThread->KernelStack - rsp;
460 rbp = newThread->KernelStack - (cur->KernelStack - rbp);
462 // Repair EBPs & Stack Addresses
463 // Catches arguments also, but may trash stack-address-like values
464 for(tmp_rbp = rsp; tmp_rbp < newThread->KernelStack; tmp_rbp += sizeof(Uint))
466 if(old_rsp < *(Uint*)tmp_rbp && *(Uint*)tmp_rbp < cur->KernelStack)
467 *(Uint*)tmp_rbp += newThread->KernelStack - cur->KernelStack;
471 // Save core machine state
472 newThread->SavedState.RSP = rsp;
473 newThread->SavedState.RBP = rbp;
475 if(rip == SWITCH_MAGIC) {
476 outb(0x20, 0x20); // ACK Timer and return as child
481 newThread->SavedState.RIP = rip;
483 // Lock list and add to active
484 Threads_AddActive(newThread);
486 return newThread->TID;
490 * \fn int Proc_SpawnWorker(void)
491 * \brief Spawns a new worker thread
493 int Proc_SpawnWorker(void)
498 cur = Proc_GetCurThread();
501 new = malloc( sizeof(tThread) );
503 Warning("Proc_SpawnWorker - Out of heap space!\n");
506 memcpy(new, &gThreadZero, sizeof(tThread));
508 new->TID = giNextTID++;
509 // Create a new worker stack (in PID0's address space)
510 // The stack is relocated by this code
511 new->KernelStack = MM_NewWorkerStack();
513 // Get ESP and EBP based in the new stack
514 __asm__ __volatile__ ("mov %%rsp, %0": "=r"(rsp));
515 __asm__ __volatile__ ("mov %%rbp, %0": "=r"(rbp));
516 rsp = new->KernelStack - (cur->KernelStack - rsp);
517 rbp = new->KernelStack - (cur->KernelStack - rbp);
519 // Save core machine state
520 new->SavedState.RSP = rsp;
521 new->SavedState.RBP = rbp;
523 if(rip == SWITCH_MAGIC) {
524 outb(0x20, 0x20); // ACK Timer and return as child
529 new->SavedState.RIP = rip;
531 new->Status = THREAD_STAT_ACTIVE;
532 Threads_AddActive( new );
538 * \fn Uint Proc_MakeUserStack(void)
539 * \brief Creates a new user stack
541 Uint Proc_MakeUserStack(void)
544 Uint base = USER_STACK_TOP - USER_STACK_SZ;
546 // Check Prospective Space
547 for( i = USER_STACK_SZ >> 12; i--; )
548 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
551 if(i != -1) return 0;
553 // Allocate Stack - Allocate incrementally to clean up MM_Dump output
554 for( i = 0; i < USER_STACK_SZ/4069; i++ )
555 MM_Allocate( base + (i<<12) );
557 return base + USER_STACK_SZ;
562 * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
563 * \brief Starts a user task
565 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
567 Uint *stack = (void*)Proc_MakeUserStack();
572 LOG("stack = 0x%x", stack);
575 stack = (void*)( (Uint)stack - DataSize );
576 memcpy( stack, ArgV, DataSize );
578 // Adjust Arguments and environment
579 delta = (Uint)stack - (Uint)ArgV;
580 ArgV = (char**)stack;
581 for( i = 0; ArgV[i]; i++ ) ArgV[i] += delta;
584 for( i = 0; EnvP[i]; i++ ) EnvP[i] += delta;
586 // User Mode Segments
587 ss = 0x23; cs = 0x1B;
590 *--stack = (Uint)EnvP;
591 *--stack = (Uint)ArgV;
592 *--stack = (Uint)ArgC;
595 *--stack = 0; // Return Address
597 Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
600 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
602 Uint *stack = (void*)Stack;
603 *--stack = SS; //Stack Segment
604 *--stack = Stack; //Stack Pointer
605 *--stack = Flags; //EFLAGS (Resvd (0x2) and IF (0x20))
606 *--stack = CS; //Code Segment
609 *--stack = 0xAAAAAAAA; // eax
610 *--stack = 0xCCCCCCCC; // ecx
611 *--stack = 0xDDDDDDDD; // edx
612 *--stack = 0xBBBBBBBB; // ebx
613 *--stack = 0xD1D1D1D1; // edi
614 *--stack = 0x54545454; // rsp - NOT POPED
615 *--stack = 0x51515151; // esi
616 *--stack = 0xB4B4B4B4; // rbp
620 __asm__ __volatile__ (
621 "mov %%rax,%%rsp;\n\t" // Set stack pointer
622 "iret;\n\t" : : "a" (stack));
627 * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
628 * \brief Demotes a process to a lower permission level
629 * \param Err Pointer to user's errno
630 * \param Dest New Permission Level
631 * \param Regs Pointer to user's register structure
633 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
635 int cpl = Regs->CS & 3;
637 if(Dest > 3 || Dest < 0) {
648 // Change the Segment Registers
649 Regs->CS = (((Dest+1)<<4) | Dest) - 8;
650 Regs->SS = ((Dest+1)<<4) | Dest;
656 * \brief Calls a signal handler in user mode
657 * \note Used for signals
659 void Proc_CallFaultHandler(tThread *Thread)
661 // Rewinds the stack and calls the user function
663 __asm__ __volatile__ ("mov %0, %%rbp;\n\tcall Proc_ReturnToUser" :: "r"(Thread->FaultHandler));
668 * \fn void Proc_Scheduler(int CPU)
669 * \brief Swap current thread and clears dead threads
671 void Proc_Scheduler(int CPU)
676 // If the spinlock is set, let it complete
677 if(IS_LOCKED(&glThreadListLock)) return;
679 // Clear Delete Queue
680 while(gDeleteThreads)
682 thread = gDeleteThreads->Next;
683 if(gDeleteThreads->IsLocked) { // Only free if structure is unused
684 gDeleteThreads->Status = THREAD_STAT_NULL;
685 free( gDeleteThreads );
687 gDeleteThreads = thread;
690 // Check if there is any tasks running
691 if(giNumActiveThreads == 0) {
692 Log("No Active threads, sleeping");
693 __asm__ __volatile__ ("hlt");
697 // Get current thread
699 thread = gaCPUs[CPU].Current;
701 thread = gCurrentThread;
704 // Reduce remaining quantum and continue timeslice if non-zero
705 if(thread->Remaining--) return;
706 // Reset quantum for next call
707 thread->Remaining = thread->Quantum;
710 __asm__ __volatile__ ("mov %%rsp, %0":"=r"(rsp));
711 __asm__ __volatile__ ("mov %%rbp, %0":"=r"(rbp));
713 if(rip == SWITCH_MAGIC) return; // Check if a switch happened
715 // Save machine state
716 thread->SavedState.RSP = rsp;
717 thread->SavedState.RBP = rbp;
718 thread->SavedState.RIP = rip;
721 thread = Threads_GetNextToRun(CPU);
725 Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
729 #if DEBUG_TRACE_SWITCH
730 Log("Switching to task %i, CR3 = 0x%x, RIP = %p",
732 thread->MemState.CR3,
733 thread->SavedState.RIP
737 // Set current thread
739 gaCPUs[CPU].Current = thread;
741 gCurrentThread = thread;
744 // Update Kernel Stack pointer
745 gTSSs[CPU].RSP0 = thread->KernelStack-4;
749 # error "Todo: Implement PAE Address space switching"
751 __asm__ __volatile__ ("mov %0, %%cr3"::"a"(thread->MemState.CR3));
755 if(thread->SavedState.RSP > 0xC0000000
756 && thread->SavedState.RSP < thread->KernelStack-0x2000) {
757 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
762 __asm__ __volatile__ (
763 "mov %1, %%rsp\n\t" // Restore RSP
764 "mov %2, %%rbp\n\t" // and RBP
765 "jmp *%3" : : // And return to where we saved state (Proc_Clone or Proc_Scheduler)
766 "a"(SWITCH_MAGIC), "b"(thread->SavedState.RSP),
767 "d"(thread->SavedState.RBP), "c"(thread->SavedState.RIP)
769 for(;;); // Shouldn't reach here
773 EXPORT(Proc_SpawnWorker);