int
spl0(void)
{
int oldspl = curspl;
curspl = 0;
splon();
return oldspl;
}
void
splx(int s)
{
curspl = s;
if (curspl == 0)
splon();
else
sploff();
}
void
clkstart(void)
{
unsigned char byte;
unsigned long s;
intpri[0] = SPLHI;
form_pic_mask();
s = sploff(); /* disable interrupts */
/* Since we use only timer 0, we program that.
* 8254 Manual specifically says you do not need to program
* timers you do not use
*/
outb(pitctl_port, pit0_mode);
clknumb = CLKNUM/hz;
byte = clknumb;
outb(pitctr0_port, byte);
byte = clknumb>>8;
outb(pitctr0_port, byte);
splon(s); /* restore interrupt state */
}
/*
* Common interrupt handler.
*/
void
interrupt_handler(void)
{
uint32_t bits;
int vector, old_ipl, new_ipl;
/* Get interrupt source */
bits = ICU_IRQSTS;
for (vector = 0; vector < NIRQS; vector++) {
if (bits & (uint32_t)(1 << vector))
break;
}
if (vector == NIRQS)
goto out;
/* Adjust interrupt level */
old_ipl = irq_level;
new_ipl = ipl_table[vector];
if (new_ipl > old_ipl) /* Ignore spurious interrupt */
irq_level = new_ipl;
update_mask();
/* Allow another interrupt that has higher priority */
splon();
/* Dispatch interrupt */
irq_handler(vector);
sploff();
/* Restore interrupt level */
irq_level = old_ipl;
update_mask();
out:
return;
}
