/* Unregister an interrupt handler. */
PUBLIC void rm_irq_handler( const irq_hook_t* hook ) {
const int irq = hook->irq;
const int id = hook->id;
irq_hook_t **line;
if( irq < 0 || irq >= NR_IRQ_VECTORS )
panic("invalid call to rm_irq_handler: %d", irq);
/* remove the hook */
line = &irq_handlers[irq];
while( (*line) != NULL ) {
if((*line)->id == id) {
(*line) = (*line)->next;
if (irq_actids[irq] & id)
irq_actids[irq] &= ~id;
}
else {
line = &(*line)->next;
}
}
/* Disable the irq if there are no other handlers registered.
* If the irq is shared, reenable it if there is no active handler.
*/
if (irq_handlers[irq] == NULL) {
hw_intr_mask(irq);
hw_intr_not_used(irq);
}
else if (irq_actids[irq] == 0) {
hw_intr_unmask(irq);
}
}
/* Unregister an interrupt handler. */
PUBLIC void rm_irq_handler( irq_hook_t* hook ) {
int irq = hook->irq;
int id = hook->id;
irq_hook_t **line;
if( irq < 0 || irq >= NR_IRQ_VECTORS )
minix_panic("invalid call to rm_irq_handler", irq);
/* disable the irq. */
irq_actids[hook->irq] |= hook->id;
hw_intr_mask(hook->irq);
/* remove the hook. */
line = &irq_handlers[irq];
while( (*line) != NULL ) {
if((*line)->id == id) {
(*line) = (*line)->next;
if(!irq_handlers[irq])
irq_use &= ~(1 << irq);
if (irq_actids[irq] & id)
irq_actids[irq] &= ~id;
return;
}
line = &(*line)->next;
}
/* When the handler is not found, normally return here. */
}
/*
* The function first disables interrupt is need be and restores the state at
* the end. Before returning, it unmasks the IRQ if and only if all active ID
* bits are cleared, and restart a process.
*/
PUBLIC void irq_handle(int irq)
{
irq_hook_t * hook;
/* here we need not to get this IRQ until all the handlers had a say */
hw_intr_mask(irq);
hook = irq_handlers[irq];
/* Call list of handlers for an IRQ. */
while( hook != NULL ) {
/* For each handler in the list, mark it active by setting its ID bit,
* call the function, and unmark it if the function returns true.
*/
irq_actids[irq] |= hook->id;
/* Call the hooked function. */
if( (*hook->handler)(hook) )
irq_actids[hook->irq] &= ~hook->id;
/* Next hooked function. */
hook = hook->next;
}
/* reenable the IRQ only if there is no active handler */
if (irq_actids[irq] == 0)
hw_intr_unmask(irq);
}
/* Return true if the interrupt was enabled before call. */
PUBLIC int disable_irq(const irq_hook_t *hook)
{
if(irq_actids[hook->irq] & hook->id) /* already disabled */
return 0;
irq_actids[hook->irq] |= hook->id;
hw_intr_mask(hook->irq);
return TRUE;
}
/*
* The function first disables interrupt is need be and restores the state at
* the end. Before returning, it unmasks the IRQ if and only if all active ID
* bits are cleared, and restart a process.
*/
PUBLIC void irq_handle(int irq)
{
irq_hook_t * hook;
/* here we need not to get this IRQ until all the handlers had a say */
assert(irq >= 0 && irq < NR_IRQ_VECTORS);
hw_intr_mask(irq);
hook = irq_handlers[irq];
/* Check for spurious interrupts. */
if(hook == NULL) {
static int nspurious[NR_IRQ_VECTORS], report_interval = 100;
nspurious[irq]++;
if(nspurious[irq] == 1 || !(nspurious[irq] % report_interval)) {
printf("irq_handle: spurious irq %d (count: %d); keeping masked\n",
irq, nspurious[irq]);
if(report_interval < INT_MAX/2)
report_interval *= 2;
}
return;
}
/* Call list of handlers for an IRQ. */
while( hook != NULL ) {
/* For each handler in the list, mark it active by setting its ID bit,
* call the function, and unmark it if the function returns true.
*/
irq_actids[irq] |= hook->id;
/* Call the hooked function. */
if( (*hook->handler)(hook) )
irq_actids[hook->irq] &= ~hook->id;
/* Next hooked function. */
hook = hook->next;
}
/* reenable the IRQ only if there is no active handler */
if (irq_actids[irq] == 0)
hw_intr_unmask(irq);
hw_intr_ack(irq);
}
