99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
#include "types.h"
|
|
#include "defs.h"
|
|
#include "param.h"
|
|
#include "mmu.h"
|
|
#include "proc.h"
|
|
#include "x86.h"
|
|
#include "traps.h"
|
|
#include "spinlock.h"
|
|
|
|
// Interrupt descriptor table (shared by all CPUs).
|
|
struct gatedesc idt[256];
|
|
extern uint vectors[]; // in vectors.S: array of 256 entry pointers
|
|
struct spinlock tickslock;
|
|
int ticks;
|
|
|
|
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], 1, SEG_KCODE<<3, vectors[T_SYSCALL], DPL_USER);
|
|
|
|
initlock(&tickslock, "time");
|
|
}
|
|
|
|
void
|
|
idtinit(void)
|
|
{
|
|
lidt(idt, sizeof(idt));
|
|
}
|
|
|
|
void
|
|
trap(struct trapframe *tf)
|
|
{
|
|
if(tf->trapno == T_SYSCALL){
|
|
if(cp->killed)
|
|
exit();
|
|
cp->tf = tf;
|
|
syscall();
|
|
if(cp->killed)
|
|
exit();
|
|
return;
|
|
}
|
|
|
|
switch(tf->trapno){
|
|
case IRQ_OFFSET + IRQ_TIMER:
|
|
if(cpu() == 0){
|
|
acquire(&tickslock);
|
|
ticks++;
|
|
wakeup(&ticks);
|
|
release(&tickslock);
|
|
}
|
|
lapiceoi();
|
|
break;
|
|
case IRQ_OFFSET + IRQ_IDE:
|
|
ideintr();
|
|
lapiceoi();
|
|
break;
|
|
case IRQ_OFFSET + IRQ_KBD:
|
|
kbdintr();
|
|
lapiceoi();
|
|
break;
|
|
case IRQ_OFFSET + IRQ_SPURIOUS:
|
|
cprintf("cpu%d: spurious interrupt at %x:%x\n",
|
|
cpu(), tf->cs, tf->eip);
|
|
lapiceoi();
|
|
break;
|
|
|
|
default:
|
|
if(cp == 0 || (tf->cs&3) == 0){
|
|
// In kernel, it must be our mistake.
|
|
cprintf("unexpected trap %d from cpu %d eip %x\n",
|
|
tf->trapno, cpu(), tf->eip);
|
|
panic("trap");
|
|
}
|
|
// In user space, assume process misbehaved.
|
|
cprintf("pid %d %s: trap %d err %d on cpu %d eip %x -- kill proc\n",
|
|
cp->pid, cp->name, tf->trapno, tf->err, cpu(), tf->eip);
|
|
cp->killed = 1;
|
|
}
|
|
|
|
// 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(cp && cp->killed && (tf->cs&3) == DPL_USER)
|
|
exit();
|
|
|
|
// Force process to give up CPU on clock tick.
|
|
// If interrupts were on while locks held, would need to check nlock.
|
|
if(cp && cp->state == RUNNING && tf->trapno == IRQ_OFFSET+IRQ_TIMER)
|
|
yield();
|
|
|
|
// Check if the process has been killed since we yielded
|
|
if(cp && cp->killed && (tf->cs&3) == DPL_USER)
|
|
exit();
|
|
}
|