63 lines
1.6 KiB
C
63 lines
1.6 KiB
C
/*
|
|
* Copyright (c) 2026, Chloe M.
|
|
* Provided under the BSD-3 clause.
|
|
*
|
|
* Description: MD context management
|
|
* Author: Chloe M.
|
|
*/
|
|
|
|
#include <hal/context.h>
|
|
#include <hal/kpcr.h>
|
|
#include <hal/thread.h>
|
|
#include <hal/mmu.h>
|
|
#include <ps/process.h>
|
|
#include <string.h>
|
|
|
|
VOID
|
|
HalContextSwitch(TRAP_FRAME *Frame)
|
|
{
|
|
THREAD *ThisThread, *NextThread;
|
|
PROCESS *NextParent;
|
|
TCB *ThisTcb, *NextTcb;
|
|
KPCR *Kpcr;
|
|
|
|
Kpcr = HalKpcrCurrent();
|
|
ThisThread = Kpcr->CurrentThread;
|
|
NextThread = NULL;
|
|
|
|
/* If there is no thread, get one */
|
|
if (ThisThread == NULL) {
|
|
NextThread = KeSchedDequeue(&Kpcr->SchedQueue);
|
|
if (NextThread == NULL) {
|
|
HalPrimeThreadTimer(SCHED_MIN_QUANTUM);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Nothing to do if there is no next thread */
|
|
if (NextThread == NULL) {
|
|
NextThread = KeSchedDequeue(&Kpcr->SchedQueue);
|
|
if (NextThread == NULL) {
|
|
HalPrimeThreadTimer(SCHED_MIN_QUANTUM);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Save the current thread if we have one */
|
|
if (ThisThread != NULL) {
|
|
ThisTcb = &ThisThread->Tcb;
|
|
RtlMemCpy(&ThisTcb->FrameSnapshot, Frame, sizeof(*Frame));
|
|
KeSchedEnqueue(&Kpcr->SchedQueue, ThisThread);
|
|
}
|
|
|
|
/* Switch the address space */
|
|
NextParent = NextThread->Parent;
|
|
HalMmuWriteVas(&NextParent->Vas);
|
|
|
|
/* Context switch here */
|
|
Kpcr->CurrentThread = NextThread;
|
|
NextTcb = &NextThread->Tcb;
|
|
RtlMemCpy(Frame, &NextTcb->FrameSnapshot, sizeof(*Frame));
|
|
HalPrimeThreadTimer(SCHED_MIN_QUANTUM);
|
|
}
|