ntoskrnl/ke/powerpc/ctxswitch.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/ke/i386/ctxswitch.S
   5  * PURPOSE:         Thread Context Switching
   6  *
   7  * PROGRAMMERS:     arty
   8                     (i386 implementation by Alex Ionescu)
   9  */
  10
  11 /* INCLUDES ******************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <debug.h>
  16 #include <ppcmmu/mmu.h>
  17
  18 /*++
  19  * KiThreadStartup
  20  *
  21  *     The KiThreadStartup routine is the beginning of any thread.
  22  *
  23  * Params:
  24  *     SystemRoutine - Pointer to the System Startup Routine. Either
  25  *                     PspUserThreadStartup or PspSystemThreadStartup
  26  *
  27  *     StartRoutine - For Kernel Threads only, specifies the starting execution
  28  *                    point of the new thread.
  29  *
  30  *     StartContext - For Kernel Threads only, specifies a pointer to variable
  31  *                    context data to be sent to the StartRoutine above.
  32  *
  33  *     UserThread - Indicates whether or not this is a user thread. This tells
  34  *                  us if the thread has a context or not.
  35  *
  36  *     TrapFrame - Pointer to the KTHREAD to which the caller wishes to
  37  *           switch from.
  38  *
  39  * Returns:
  40  *     Should never return for a system thread. Returns through the System Call
  41  *     Exit Dispatcher for a user thread.
  42  *
  43  * Remarks:
  44  *     If a return from a system thread is detected, a bug check will occur.
  45  *
  46  *--*/
  47
  48 VOID
  49 NTAPI
  50 KiThreadStartup(PKSYSTEM_ROUTINE SystemRoutine,
  51                 PKSTART_ROUTINE StartRoutine,
  52                 PVOID StartContext,
  53                 BOOLEAN UserThread,
  54                 KTRAP_FRAME TrapFrame)
  55 {
  56     KeLowerIrql(APC_LEVEL);
  57     __asm__("mr 0,%0\n\t"
  58             "mr 3,%1\n\t"
  59             "mr 4,%2\n\t"
  60             "mr 5,%3\n\t"
  61             "mr 6,%4\n\t"
  62             "sc" : :
  63             "r" (0xf0000), /* Thread start function */
  64             "r" (SystemRoutine),
  65             "r" (StartRoutine),
  66             "r" (StartContext),
  67             "r" (UserThread));
  68     PspTerminateThreadByPointer(PsGetCurrentThread(), STATUS_THREAD_IS_TERMINATING, TRUE);
  69 }
  70
  71 /* Take a decrementer trap, and prepare the given trap frame, swapping
  72  * process and thread context as appropriate. */
  73 VOID KiDecrementerTrapFinish(PKTRAP_FRAME TrapFrame);
  74
  75 VOID
  76 FASTCALL
  77 KiQueueReadyThread(IN PKTHREAD Thread,
  78                    IN PKPRCB Prcb);
  79
  80 PKTHREAD KiLastThread = NULL;
  81 PKTRAP_FRAME KiLastThreadTrapFrame = NULL;
  82
  83 VOID
  84 NTAPI
  85 KiDecrementerTrap(PKTRAP_FRAME TrapFrame)
  86 {
  87     KIRQL Irql;
  88     PKPRCB Prcb = KeGetPcr()->Prcb;
  89     if (!KiLastThread)
  90         KiLastThread = KeGetCurrentThread();
  91
  92     if (KiLastThread->State == Running)
  93         KiQueueReadyThread(KiLastThread, Prcb);
  94
  95     if (!KiLastThreadTrapFrame)
  96         KiLastThreadTrapFrame = Prcb->IdleThread->TrapFrame;
  97
  98     TrapFrame->OldIrql = KeGetCurrentIrql();
  99     *KiLastThreadTrapFrame = *TrapFrame;
 100
 101     if (Prcb->NextThread)
 102     {
 103         Prcb->CurrentThread = Prcb->NextThread;
 104         Prcb->NextThread = NULL;
 105     }
 106     else
 107         Prcb->CurrentThread = Prcb->IdleThread;
 108
 109     Prcb->CurrentThread->State = Running;
 110
 111     KiLastThreadTrapFrame = Prcb->CurrentThread->TrapFrame;
 112     KiLastThread = Prcb->CurrentThread;
 113
 114     *TrapFrame = *KiLastThreadTrapFrame;
 115     Irql = KeGetCurrentIrql();
 116
 117     if (Irql > TrapFrame->OldIrql)
 118         KfRaiseIrql(Irql);
 119     else if (Irql < TrapFrame->OldIrql)
 120         KfLowerIrql(Irql);
 121
 122     /* When we return, we'll go through rfi and be in new thread land */
 123     __asm__("mtdec %0" : : "r" (0x1000000)); // Reset the trap
 124 }