/*!
* \fn int xnintr_detach (xnintr_t *intr)
* \brief Detach an interrupt object.
*
* Detach an interrupt object previously attached by
* xnintr_attach(). After this operation is completed, no more IRQs
* are directed to the object's ISR, but the interrupt object itself
* remains valid. A detached interrupt object can be attached again by
* a subsequent call to xnintr_attach().
*
* @param intr The descriptor address of the interrupt object to
* detach.
*
* @return 0 is returned on success. Otherwise:
*
* - -EINVAL is returned if a low-level error occurred while detaching
* the interrupt, or if the interrupt object was not attached. In both
* cases, no action is performed.
*
* @note The caller <b>must not</b> hold nklock when invoking this service,
* this would cause deadlocks.
*
* Environments:
*
* This service can be called from:
*
* - Kernel module initialization/cleanup code
* - Kernel-based task
*
* Rescheduling: never.
*/
int xnintr_detach(xnintr_t *intr)
{
int ret;
trace_mark(xn_nucleus, irq_detach, "irq %u", intr->irq);
down(&intrlock);
if (!__testbits(intr->flags, XN_ISR_ATTACHED)) {
ret = -EINVAL;
goto out;
}
__clrbits(intr->flags, XN_ISR_ATTACHED);
ret = xnintr_irq_detach(intr);
if (ret)
goto out;
xnintr_stat_counter_dec();
out:
up(&intrlock);
return ret;
}
int xnintr_attach(xnintr_t *intr, void *cookie)
{
int ret;
trace_mark(xn_nucleus, irq_attach, "irq %u name %s",
intr->irq, intr->name);
intr->cookie = cookie;
memset(&intr->stat, 0, sizeof(intr->stat));
#ifdef CONFIG_SMP
xnarch_set_irq_affinity(intr->irq, nkaffinity);
#endif /* CONFIG_SMP */
down(&intrlock);
if (__testbits(intr->flags, XN_ISR_ATTACHED)) {
ret = -EBUSY;
goto out;
}
ret = xnintr_irq_attach(intr);
if (ret)
goto out;
__setbits(intr->flags, XN_ISR_ATTACHED);
xnintr_stat_counter_inc();
out:
up(&intrlock);
return ret;
}
/*!
* \fn int xnintr_detach (xnintr_t *intr)
* \brief Detach an interrupt object.
*
* Detach an interrupt object previously attached by
* xnintr_attach(). After this operation is completed, no more IRQs
* are directed to the object's ISR, but the interrupt object itself
* remains valid. A detached interrupt object can be attached again by
* a subsequent call to xnintr_attach().
*
* @param intr The descriptor address of the interrupt object to
* detach.
*
* @return 0 is returned on success. Otherwise:
*
* - -EINVAL is returned if a low-level error occurred while detaching
* the interrupt, or if the interrupt object was not attached. In both
* cases, no action is performed.
*
* @note The caller <b>must not</b> hold nklock when invoking this service,
* this would cause deadlocks.
*
* Environments:
*
* This service can be called from:
*
* - Kernel module initialization/cleanup code
* - Kernel-based task
*
* Rescheduling: never.
*/
int xnintr_detach(xnintr_t *intr)
{
int ret;
spl_t s;
trace_mark(xn_nucleus, irq_detach, "irq %u", intr->irq);
xnlock_get_irqsave(&intrlock, s);
if (!__testbits(intr->flags, XN_ISR_ATTACHED)) {
ret = -EINVAL;
goto out;
}
__clrbits(intr->flags, XN_ISR_ATTACHED);
ret = xnintr_irq_detach(intr);
if (ret)
goto out;
xnintr_stat_counter_dec();
out:
xnlock_put_irqrestore(&intrlock, s);
return ret;
}
static inline int xnintr_irq_attach(xnintr_t *intr)
{
xnintr_irq_t *shirq = &xnirqs[intr->irq];
xnintr_t *prev, **p = &shirq->handlers;
int err;
if (intr->irq >= RTHAL_NR_IRQS)
return -EINVAL;
if (__testbits(intr->flags, XN_ISR_ATTACHED))
return -EPERM;
if ((prev = *p) != NULL) {
/* Check on whether the shared mode is allowed. */
if (!(prev->flags & intr->flags & XN_ISR_SHARED) ||
(prev->iack != intr->iack)
|| ((prev->flags & XN_ISR_EDGE) !=
(intr->flags & XN_ISR_EDGE)))
return -EBUSY;
/* Get a position at the end of the list to insert the new element. */
while (prev) {
p = &prev->next;
prev = *p;
}
} else {
/* Initialize the corresponding interrupt channel */
void (*handler) (unsigned, void *) = &xnintr_irq_handler;
if (intr->flags & XN_ISR_SHARED) {
if (intr->flags & XN_ISR_EDGE)
handler = &xnintr_edge_shirq_handler;
else
handler = &xnintr_shirq_handler;
}
shirq->unhandled = 0;
err = xnarch_hook_irq(intr->irq, handler, intr->iack, intr);
if (err)
return err;
}
__setbits(intr->flags, XN_ISR_ATTACHED);
intr->next = NULL;
/* Add the given interrupt object. No need to synchronise with the IRQ
handler, we are only extending the chain. */
*p = intr;
return 0;
}
int xnintr_attach(xnintr_t *intr, void *cookie)
{
int ret;
spl_t s;
trace_mark(xn_nucleus, irq_attach, "irq %u name %s",
intr->irq, intr->name);
intr->cookie = cookie;
memset(&intr->stat, 0, sizeof(intr->stat));
#ifdef CONFIG_SMP
xnarch_set_irq_affinity(intr->irq, nkaffinity);
#endif /* CONFIG_SMP */
xnlock_get_irqsave(&intrlock, s);
if (intr->irq >= XNARCH_NR_IRQS) {
ret = -EINVAL;
goto out;
}
if (__testbits(intr->flags, XN_ISR_ATTACHED)) {
ret = -EBUSY;
goto out;
}
ret = xnintr_irq_attach(intr);
if (ret)
goto out;
__setbits(intr->flags, XN_ISR_ATTACHED);
xnintr_stat_counter_inc();
out:
xnlock_put_irqrestore(&intrlock, s);
return ret;
}
static inline int xnintr_irq_detach(xnintr_t *intr)
{
xnintr_irq_t *shirq = &xnirqs[intr->irq];
xnintr_t *e, **p = &shirq->handlers;
int err = 0;
if (intr->irq >= RTHAL_NR_IRQS)
return -EINVAL;
if (!__testbits(intr->flags, XN_ISR_ATTACHED))
return -EPERM;
__clrbits(intr->flags, XN_ISR_ATTACHED);
while ((e = *p) != NULL) {
if (e == intr) {
/* Remove the given interrupt object from the list. */
xnlock_get(&shirq->lock);
*p = e->next;
xnlock_put(&shirq->lock);
/* Release the IRQ line if this was the last user */
if (shirq->handlers == NULL)
err = xnarch_release_irq(intr->irq);
return err;
}
p = &e->next;
}
xnlogerr("attempted to detach a non previously attached interrupt "
"object.\n");
return err;
}