95 lines
2 KiB
C
95 lines
2 KiB
C
#include "types.h"
|
|
#include "param.h"
|
|
#include "mmu.h"
|
|
#include "proc.h"
|
|
#include "defs.h"
|
|
#include "x86.h"
|
|
#include "traps.h"
|
|
#include "syscall.h"
|
|
|
|
// Interrupt descriptor table (shared by all CPUs).
|
|
struct gatedesc idt[256];
|
|
extern uint vectors[]; // in vectors.S: array of 256 entry pointers
|
|
|
|
void
|
|
tvinit(void)
|
|
{
|
|
int i;
|
|
|
|
for(i = 0; i < 256; i++)
|
|
SETGATE(idt[i], 0, SEG_KCODE << 3, vectors[i], 0);
|
|
SETGATE(idt[T_SYSCALL], 0, SEG_KCODE << 3, vectors[T_SYSCALL], 3);
|
|
}
|
|
|
|
void
|
|
idtinit(void)
|
|
{
|
|
lidt(idt, sizeof idt);
|
|
}
|
|
|
|
void
|
|
trap(struct trapframe *tf)
|
|
{
|
|
int v = tf->trapno;
|
|
struct proc *cp = curproc[cpu()];
|
|
|
|
if(v == T_SYSCALL){
|
|
if(cp->killed)
|
|
proc_exit();
|
|
cp->tf = tf;
|
|
syscall();
|
|
if(cp->killed)
|
|
proc_exit();
|
|
return;
|
|
}
|
|
|
|
// Increment nlock to make sure interrupts stay off
|
|
// during interrupt handler. Decrement before returning.
|
|
cpus[cpu()].nlock++;
|
|
|
|
switch(v){
|
|
case IRQ_OFFSET + IRQ_TIMER:
|
|
lapic_timerintr();
|
|
cpus[cpu()].nlock--;
|
|
if(cp){
|
|
// Force process exit if it has been killed and is in user space.
|
|
// (If it is still executing in the kernel, let it keep running
|
|
// until it gets to the regular system call return.)
|
|
if((tf->cs&3) == 3 && cp->killed)
|
|
proc_exit();
|
|
|
|
// Force process to give up CPU and let others run.
|
|
if(cp->state == RUNNING)
|
|
yield();
|
|
}
|
|
return;
|
|
|
|
case IRQ_OFFSET + IRQ_IDE:
|
|
ide_intr();
|
|
lapic_eoi();
|
|
break;
|
|
|
|
case IRQ_OFFSET + IRQ_KBD:
|
|
kbd_intr();
|
|
lapic_eoi();
|
|
break;
|
|
|
|
case IRQ_OFFSET + IRQ_SPURIOUS:
|
|
cprintf("spurious interrupt from cpu %d eip %x\n", cpu(), tf->eip);
|
|
break;
|
|
|
|
default:
|
|
if(curproc[cpu()]) {
|
|
// Assume process divided by zero or dereferenced null, etc.
|
|
cprintf("pid %d: unhandled trap %d on cpu %d eip %x -- kill proc\n",
|
|
curproc[cpu()]->pid, v, cpu(), tf->eip);
|
|
proc_exit();
|
|
}
|
|
|
|
// Otherwise it's our mistake.
|
|
cprintf("unexpected trap %d from cpu %d eip %x\n", v, cpu(), tf->eip);
|
|
panic("trap");
|
|
}
|
|
|
|
cpus[cpu()].nlock--;
|
|
}
|