Kernel/x86_64 - Separated task switching from timer interrupt

[tpg/acess2.git] / Kernel / arch / x86_64 / proc.c

diff --git a/Kernel/arch/x86_64/proc.c b/Kernel/arch/x86_64/proc.c
index 8cc1933..4971395 100644 (file)
--- a/Kernel/arch/x86_64/proc.c
+++ b/Kernel/arch/x86_64/proc.c
@@ -37,6 +37,7 @@ extern void   APStartup(void);        // 16-bit AP startup code
 
 extern Uint    GetRIP(void);   // start.asm
 extern Uint    SaveState(Uint *RSP, Uint *Regs);
+extern Uint    Proc_CloneInt(Uint *RSP, Uint *CR3);
 extern void    NewTaskHeader(void);    // Actually takes cdecl args
 
 extern Uint64  gInitialPML4[512];      // start.asm
@@ -49,6 +50,7 @@ extern tThread        gThreadZero;
 extern void    Threads_Dump(void);
 extern void    Proc_ReturnToUser(void);
 extern void    Time_UpdateTimestamp(void);
+extern void    SwitchTasks(Uint NewSP, Uint *OldSP, Uint NewIP, Uint *OldIO, Uint CR3);
 
 // === PROTOTYPES ===
 //void ArchThreads_Init(void);
@@ -68,6 +70,7 @@ void  Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NO
  int   Proc_Demote(Uint *Err, int Dest, tRegs *Regs);
 //void Proc_CallFaultHandler(tThread *Thread);
 //void Proc_DumpThreadCPUState(tThread *Thread);
+//void Proc_Reschedule(void);
 void   Proc_Scheduler(int CPU, Uint RSP, Uint RIP);
 
 // === GLOBALS ===
@@ -467,38 +470,35 @@ int Proc_Clone(Uint Flags)
 {
        tThread *newThread, *cur = Proc_GetCurThread();
        Uint    rip;
-       Uint    _savedregs[16+1];
-       
+
+       // Sanity check 
+       if( !(Flags & CLONE_VM) ) {
+               Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
+               return -1;
+       }
+
+       // Create new TCB
        newThread = Threads_CloneTCB(NULL, Flags);
        if(!newThread)  return -1;
        
        // Save core machine state
-       rip = SaveState(&newThread->SavedState.RSP, &_savedregs[0]);
+       rip = Proc_CloneInt(&newThread->SavedState.RSP, &newThread->MemState.CR3);
        if(rip == 0) {
                outb(0x20, 0x20);       // ACK Timer and return as child
                __asm__ __volatile__ ("sti");
                return 0;
        }
-       
-       // Initialise Memory Space (New Addr space or kernel stack)
-       if(Flags & CLONE_VM) {
-               newThread->MemState.CR3 = MM_Clone();
-               newThread->KernelStack = cur->KernelStack;
-       }
-       else {
-               Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
-               return -1;
-       }
-       
-       Log("New (Clone) %p, rsp = %p", rip, newThread->SavedState.RSP);
+       newThread->KernelStack = cur->KernelStack;
+       newThread->SavedState.RIP = rip;
+
+       // DEBUG        
+       Log("New (Clone) %p, rsp = %p, cr3 = %p", rip, newThread->SavedState.RSP, newThread->MemState.CR3);
        {
                Uint cr3;
                __asm__ __volatile__ ("mov %%cr3, %0" : "=r" (cr3));
-               Log(" CR3 = %x, PADDR(RSP) = %x", cr3, MM_GetPhysAddr(newThread->SavedState.RSP));
+               Log("Current CR3 = 0x%x, PADDR(RSP) = 0x%x", cr3, MM_GetPhysAddr(newThread->SavedState.RSP));
        }
-       
-       // Set EIP as parent
-       newThread->SavedState.RIP = rip;
+       // /DEBUG
        
        // Lock list and add to active
        Threads_AddActive(newThread);
@@ -699,6 +699,45 @@ void Proc_DumpThreadCPUState(tThread *Thread)
        Log("  At %04x:%016llx", Thread->SavedState.UserCS, Thread->SavedState.UserRIP);
 }
 
+void Proc_Reschedule(void)
+{
+       tThread *nextthread, *curthread;
+        int    cpu = GetCPUNum();
+
+       // TODO: Wait for it?
+       if(IS_LOCKED(&glThreadListLock))        return;
+       
+       curthread = gaCPUs[cpu].Current;
+
+       nextthread = Threads_GetNextToRun(cpu, curthread);
+
+       if(nextthread == curthread)     return ;
+       if(!nextthread)
+               nextthread = gaCPUs[cpu].IdleThread;
+       if(!nextthread)
+               return ;
+
+       #if DEBUG_TRACE_SWITCH
+       LogF("\nSwitching to task %i, CR3 = 0x%x, RIP = %p, RSP = %p\n",
+               nextthread->TID,
+               nextthread->MemState.CR3,
+               nextthread->SavedState.RIP,
+               nextthread->SavedState.RSP
+               );
+       #endif
+
+       // Update CPU state
+       gaCPUs[cpu].Current = nextthread;
+       gTSSs[cpu].RSP0 = nextthread->KernelStack-4;
+
+       SwitchTasks(
+               nextthread->SavedState.RSP, &curthread->SavedState.RSP,
+               nextthread->SavedState.RIP, &curthread->SavedState.RIP,
+               nextthread->MemState.CR3
+               );
+       return ;
+}
+
 /**
  * \fn void Proc_Scheduler(int CPU)
  * \brief Swap current thread and clears dead threads
@@ -723,12 +762,6 @@ void Proc_Scheduler(int CPU, Uint RSP, Uint RIP)
                if(thread->Remaining--) return;
                // Reset quantum for next call
                thread->Remaining = thread->Quantum;
-       
-               // Save machine state
-               thread->SavedState.RSP = RSP;
-               thread->SavedState.RIP = RIP;
-               
-//             LogF("\nSaved %i, RIP = %p, rsp = %p\n", thread->TID, thread->SavedState.RIP, thread->SavedState.RSP);
                
                // TODO: Make this more stable somehow
                {
@@ -738,62 +771,9 @@ void Proc_Scheduler(int CPU, Uint RSP, Uint RIP)
                }
        }
 
-       #if BREAK_ON_SWITCH
-       {
-       tThread *oldthread = thread;
-       #endif
+       // ACK Timer here?
 
-       // Get next thread
-       thread = Threads_GetNextToRun(CPU, thread);
-       
-       // Error Check
-       if(thread == NULL) {
-               thread = gaCPUs[CPU].IdleThread;
-               //Warning("Hmm... Threads_GetNextToRun returned NULL, I don't think this should happen.\n");
-//             LogF("Zzzzz.\n");
-               //return;
-       }
-       if(thread == NULL ) {
-               return ;
-       }
-       #if BREAK_ON_SWITCH
-       if( thread != oldthread ) {
-               MAGIC_BREAK();
-       }
-       }
-       #endif
-       
-       #if DEBUG_TRACE_SWITCH
-       LogF("\nSwitching to task %i, CR3 = 0x%x, RIP = %p, RSP = %p\n",
-               thread->TID,
-               thread->MemState.CR3,
-               thread->SavedState.RIP,
-               thread->SavedState.RSP
-               );
-       #endif
-       
-       
-       if(CPU > MAX_CPUS)
-               LogF("CPU = %i", CPU);
-       // Set current thread
-       gaCPUs[CPU].Current = thread;
-       
-       // Update Kernel Stack pointer
-       gTSSs[CPU].RSP0 = thread->KernelStack-4;
-       
-       // Switch threads
-       __asm__ __volatile__ (
-               "mov %2, %%cr3\n\t"
-               "mov %0, %%rsp\n\t"     // Restore RSP
-               "invlpg (%%rsp)\n\t"
-               "invlpg 0x1000(%%rsp)\n\t"
-               "invlpg -0x1000(%%rsp)\n\t"
-               "xor %%eax, %%eax\n\t"
-               "jmp *%1" : :   // And return to where we saved state (Proc_Clone or Proc_Scheduler)
-               "r"(thread->SavedState.RSP), "r"(thread->SavedState.RIP),
-               "r"(thread->MemState.CR3)
-               );
-       for(;;);        // Shouldn't reach here
+       Proc_Reschedule();
 }
 
 // === EXPORTS ===