//drivers/net/gianfar.c
static int register_grp_irqs(struct gfar_priv_grp *grp)
{
struct gfar_private *priv = grp->priv;
struct net_device *dev = priv->ndev;
int err;
#ifdef CONFIG_GFAR_SW_PKT_STEERING
int i, j;
int cpus = num_online_cpus();
struct cpumask cpumask_msg_intrs;
#endif
/* If the device has multiple interrupts, register for
* them. Otherwise, only register for the one */
if (priv->device_flags & FSL_GIANFAR_DEV_HAS_MULTI_INTR) {
/* Install our interrupt handlers for Error,
* Transmit, and Receive */
if ((err = request_irq(grp->interruptError, gfar_error, 0,
grp->int_name_er,grp)) < 0) {
if (netif_msg_intr(priv))
printk(KERN_ERR "%s: Can't get IRQ %d\n",
dev->name, grp->interruptError);
goto err_irq_fail;
}
#ifndef CONFIG_RX_TX_BD_XNGE
if ((err = request_irq(grp->interruptTransmit, gfar_transmit,//安装发送中断
0, grp->int_name_tx, grp)) < 0) {
if (netif_msg_intr(priv))
printk(KERN_ERR "%s: Can't get IRQ %d\n",
dev->name, grp->interruptTransmit);
goto tx_irq_fail;
}
#endif
if ((err = request_irq(grp->interruptReceive, gfar_receive, 0,
grp->int_name_rx, grp)) < 0) {
if (netif_msg_intr(priv))
printk(KERN_ERR "%s: Can't get IRQ %d\n",
dev->name, grp->interruptReceive);
goto rx_irq_fail;
}
} else {
if ((err = request_irq(grp->interruptTransmit, gfar_interrupt, 0,
grp->int_name_tx, grp)) < 0) {
if (netif_msg_intr(priv))
printk(KERN_ERR "%s: Can't get IRQ %d\n",
dev->name, grp->interruptTransmit);
goto err_irq_fail;
}
}
#ifdef CONFIG_GFAR_SW_PKT_STEERING
if (priv->sps) {
for (i = 0; i < cpus; i++) {
sprintf(grp->int_name_vtx[i], "%s_g%d_vtx%d",
priv->ndev->name, grp->grp_id, i);
err = request_irq(grp->msg_virtual_tx[i]->irq,
gfar_virtual_transmit, 0,
grp->int_name_vtx[i], grp);
if (err < 0) {
priv->sps = 0;
printk(KERN_WARNING
"%s: Can't request msg IRQ %d for dev %s\n",
__func__,
grp->msg_virtual_tx[i]->irq, dev->name);
for (j = 0; j < i; j++) {
free_irq(grp->msg_virtual_tx[j]->irq,
grp);
clrbits32(grp->msg_virtual_tx[j]->mer,
1 << grp->msg_virtual_tx[j]->msg_num);
}
goto vtx_irq_fail;
}
cpumask_clear(&cpumask_msg_intrs);
cpumask_set_cpu(i, &cpumask_msg_intrs);
irq_set_affinity(grp->msg_virtual_tx[i]->irq,
&cpumask_msg_intrs);
fsl_enable_msg(grp->msg_virtual_tx[i]);
}
}
#endif
return 0;
#ifdef CONFIG_GFAR_SW_PKT_STEERING
vtx_irq_fail:
free_irq(grp->interruptReceive, grp);
#endif
rx_irq_fail:
#ifndef CONFIG_RX_TX_BD_XNGE
free_irq(grp->interruptTransmit, grp);
#endif
tx_irq_fail:
free_irq(grp->interruptError, grp);
err_irq_fail:
return err;
}
static inline int __must_check
request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
const char *name, void *dev)
{
return request_threaded_irq(irq, handler, NULL, flags, name, dev);
}
//kernel/irq/manage.c
int request_threaded_irq(unsigned int irq, irq_handler_t handler,
irq_handler_t thread_fn, unsigned long irqflags,
const char *devname, void *dev_id)
{
struct irqaction *action;
struct irq_desc *desc;
int retval;
/*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
* which interrupt is which (messes up the interrupt freeing
* logic etc).
*/
if ((irqflags & IRQF_SHARED) && !dev_id)
return -EINVAL;
desc = irq_to_desc(irq);
if (!desc)
return -EINVAL;
if (desc->status & IRQ_NOREQUEST)
return -EINVAL;
if (!handler) {
if (!thread_fn)
return -EINVAL;
handler = irq_default_primary_handler;
}
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);//分配action结构
if (!action)
return -ENOMEM;
action->handler = handler;
action->thread_fn = thread_fn;
action->flags = irqflags;
action->name = devname;
action->dev_id = dev_id;
chip_bus_lock(irq, desc);
retval = __setup_irq(irq, desc, action);
chip_bus_sync_unlock(irq, desc);
if (retval)
kfree(action);
#ifdef CONFIG_DEBUG_SHIRQ
if (!retval && (irqflags & IRQF_SHARED)) {
/*
* It's a shared IRQ -- the driver ought to be prepared for it
* to happen immediately, so let's make sure....
* We disable the irq to make sure that a 'real' IRQ doesn't
* run in parallel with our fake.
*/
unsigned long flags;
disable_irq(irq);
local_irq_save(flags);
handler(irq, dev_id);
local_irq_restore(flags);
enable_irq(irq);
}
#endif
return retval;
}
static int
__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
{
struct irqaction *old, **old_ptr;
const char *old_name = NULL;
unsigned long flags;
int nested, shared = 0;
int ret;
if (!desc)
return -EINVAL;
if (desc->chip == &no_irq_chip)
return -ENOSYS;
/*
* Some drivers like serial.c use request_irq() heavily,
* so we have to be careful not to interfere with a
* running system.
*/
if (new->flags & IRQF_SAMPLE_RANDOM) {
/*
* This function might sleep, we want to call it first,
* outside of the atomic block.
* Yes, this might clear the entropy pool if the wrong
* driver is attempted to be loaded, without actually
* installing a new handler, but is this really a problem,
* only the sysadmin is able to do this.
*/
rand_initialize_irq(irq);
}
/* Oneshot interrupts are not allowed with shared */
if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
return -EINVAL;
/*
* Check whether the interrupt nests into another interrupt
* thread.
*/
nested = desc->status & IRQ_NESTED_THREAD;
if (nested) {
if (!new->thread_fn)
return -EINVAL;
/*
* Replace the primary handler which was provided from
* the driver for non nested interrupt handling by the
* dummy function which warns when called.
*/
new->handler = irq_nested_primary_handler;
}
/*
* Create a handler thread when a thread function is supplied
* and the interrupt does not nest into another interrupt
* thread.
*/
if (new->thread_fn && !nested) {
struct task_struct *t;
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
new->name);
if (IS_ERR(t))
return PTR_ERR(t);
/*
* We keep the reference to the task struct even if
* the thread dies to avoid that the interrupt code
* references an already freed task_struct.
*/
get_task_struct(t);
new->thread = t;
}
/*
* The following block of code has to be executed atomically
*/
raw_spin_lock_irqsave(&desc->lock, flags);
old_ptr = &desc->action;
old = *old_ptr;
if (old) {
/*
* Can't share interrupts unless both agree to and are
* the same type (level, edge, polarity). So both flag
* fields must have IRQF_SHARED set and the bits which
* set the trigger type must match.
*/
if (!((old->flags & new->flags) & IRQF_SHARED) ||
((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) {
old_name = old->name;
goto mismatch;
}
#if defined(CONFIG_IRQ_PER_CPU)
/* All handlers must agree on per-cpuness */
if ((old->flags & IRQF_PERCPU) !=
(new->flags & IRQF_PERCPU))
goto mismatch;
#endif
/* add new interrupt at end of irq queue */
do {
old_ptr = &old->next;
old = *old_ptr;
} while (old);
shared = 1;
}
if (!shared) {
irq_chip_set_defaults(desc->chip);
init_waitqueue_head(&desc->wait_for_threads);
/* Setup the type (level, edge polarity) if configured: */
if (new->flags & IRQF_TRIGGER_MASK) {
ret = __irq_set_trigger(desc, irq,
new->flags & IRQF_TRIGGER_MASK);
if (ret)
goto out_thread;
} else
compat_irq_chip_set_default_handler(desc);
#if defined(CONFIG_IRQ_PER_CPU)
if (new->flags & IRQF_PERCPU)
desc->status |= IRQ_PER_CPU;
#endif
desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT |
IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
if (new->flags & IRQF_ONESHOT)
desc->status |= IRQ_ONESHOT;
if (!(desc->status & IRQ_NOAUTOEN)) {
desc->depth = 0;
desc->status &= ~IRQ_DISABLED;
desc->chip->startup(irq);//调用chip的startup函数，其实就是default_startup，在default_startup中调用enable，在enable调用具体芯片的mpic_unmask_irq，这样不屏蔽该中断
} else
/* Undo nested disables: */
desc->depth = 1;
/* Exclude IRQ from balancing if requested */
if (new->flags & IRQF_NOBALANCING)
desc->status |= IRQ_NO_BALANCING;
/* Set default affinity mask once everything is setup */
setup_affinity(irq, desc);
} else if ((new->flags & IRQF_TRIGGER_MASK)
&& (new->flags & IRQF_TRIGGER_MASK)
!= (desc->status & IRQ_TYPE_SENSE_MASK)) {
/* hope the handler works with the actual trigger mode... */
pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK),
(int)(new->flags & IRQF_TRIGGER_MASK));
}
new->irq = irq;
*old_ptr = new;
/* Reset broken irq detection when installing new handler */
desc->irq_count = 0;
desc->irqs_unhandled = 0;
/*
* Check whether we disabled the irq via the spurious handler
* before. Reenable it and give it another chance.
*/
if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
desc->status &= ~IRQ_SPURIOUS_DISABLED;
__enable_irq(desc, irq, false);
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
/*
* Strictly no need to wake it up, but hung_task complains
* when no hard interrupt wakes the thread up.
*/
if (new->thread)
wake_up_process(new->thread);
register_irq_proc(irq, desc);
new->dir = NULL;
register_handler_proc(irq, new);
return 0;
mismatch:
#ifdef CONFIG_DEBUG_SHIRQ
if (!(new->flags & IRQF_PROBE_SHARED)) {
printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
if (old_name)
printk(KERN_ERR "current handler: %s\n", old_name);
dump_stack();
}
#endif
ret = -EBUSY;
out_thread:
raw_spin_unlock_irqrestore(&desc->lock, flags);
if (new->thread) {
struct task_struct *t = new->thread;
new->thread = NULL;
if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
kthread_stop(t);
put_task_struct(t);
}
return ret;
}
//arch/powerpc/sysdev/mpic.c
void mpic_unmask_irq(unsigned int irq)
{
unsigned int loops = 100000;
struct mpic *mpic = mpic_from_irq(irq);
unsigned int src = mpic_irq_to_hw(irq);
DBG("%p: %s: enable_irq: %d (src %d)\n", mpic, mpic->name, irq, src);
mpic_irq_write(src, MPIC_INFO(IRQ_VECTOR_PRI),
mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) &
~MPIC_VECPRI_MASK);
/* make sure mask gets to controller before we return to user */
do {
if (!loops--) {
printk(KERN_ERR "mpic_enable_irq timeout\n");
break;
}
} while(mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) & MPIC_VECPRI_MASK);
}
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