gic interrupt 27 on arm64

[Alessandro Pistocchi]

Hi all,
in the kernel I see the code below (file: arm64/dev/ampint.c lines:643-666).

void
ampintc_irq_handler(void *frame)
{
struct ampintc_softc *sc = ampintc;
struct intrhand *ih;
void *arg;
uint32_t iack_val;
int irq, pri, s, handled;

iack_val = ampintc_iack();
#ifdef DEBUG_INTC
if (iack_val != 27)
printf("irq  %d fired\n", iack_val);
else {
static int cnt = 0;
if ((cnt++ % 100) == 0) {
printf("irq  %d fired * _100\n", iack_val);
#ifdef DDB
db_enter();
#endif
}

}
#endif

Does anyone know what interrupt 27 is for? It seems to fire quite often.

Thanks,
A