unsigned sched_reset_on_fork:1;
unsigned sched_contributes_to_load:1;
+#ifdef CONFIG_GENERIC_HARDIRQS
+ /* IRQ handler threads */
+ unsigned irq_thread:1;
+#endif
+
pid_t pid;
pid_t tgid;
* mempolicy */
spinlock_t alloc_lock;
-#ifdef CONFIG_GENERIC_HARDIRQS
- /* IRQ handler threads */
- struct irqaction *irqaction;
-#endif
-
/* Protection of the PI data structures: */
raw_spinlock_t pi_lock;
/*
* Per process flags
*/
- #define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
* Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
* pins the final release of task.io_context. Also protects ->cpuset and
- * ->cgroup.subsys[].
+ * ->cgroup.subsys[]. And ->vfork_done.
*
* Nests both inside and outside of read_lock(&tasklist_lock).
* It must not be nested with write_lock_irq(&tasklist_lock),
return -EINVAL;
type &= IRQ_TYPE_SENSE_MASK;
- if (type != IRQ_TYPE_NONE)
- ret = __irq_set_trigger(desc, irq, type);
+ ret = __irq_set_trigger(desc, irq, type);
irq_put_desc_busunlock(desc, flags);
return ret;
}
irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
}
- int irq_startup(struct irq_desc *desc)
+ int irq_startup(struct irq_desc *desc, bool resend)
{
+ int ret = 0;
+
irq_state_clr_disabled(desc);
desc->depth = 0;
if (desc->irq_data.chip->irq_startup) {
- int ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
+ ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
irq_state_clr_masked(desc);
- return ret;
+ } else {
+ irq_enable(desc);
}
-
- irq_enable(desc);
- return 0;
+ if (resend)
+ check_irq_resend(desc, desc->irq_data.irq);
+ return ret;
}
void irq_shutdown(struct irq_desc *desc)
}
EXPORT_SYMBOL_GPL(handle_simple_irq);
+ /*
+ * Called unconditionally from handle_level_irq() and only for oneshot
+ * interrupts from handle_fasteoi_irq()
+ */
+ static void cond_unmask_irq(struct irq_desc *desc)
+ {
+ /*
+ * We need to unmask in the following cases:
+ * - Standard level irq (IRQF_ONESHOT is not set)
+ * - Oneshot irq which did not wake the thread (caused by a
+ * spurious interrupt or a primary handler handling it
+ * completely).
+ */
+ if (!irqd_irq_disabled(&desc->irq_data) &&
+ irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
+ unmask_irq(desc);
+ }
+
/**
* handle_level_irq - Level type irq handler
* @irq: the interrupt number
handle_irq_event(desc);
- if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT))
- unmask_irq(desc);
+ cond_unmask_irq(desc);
+
out_unlock:
raw_spin_unlock(&desc->lock);
}
preflow_handler(desc);
handle_irq_event(desc);
+ if (desc->istate & IRQS_ONESHOT)
+ cond_unmask_irq(desc);
+
out_eoi:
desc->irq_data.chip->irq_eoi(&desc->irq_data);
out_unlock:
irq_settings_set_noprobe(desc);
irq_settings_set_norequest(desc);
irq_settings_set_nothread(desc);
- irq_startup(desc);
+ irq_startup(desc, true);
}
out:
irq_put_desc_busunlock(desc, flags);
struct irqaction *action);
int wake;
- if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD,
+ if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
&action->thread_flags))
handler_fn = irq_forced_thread_fn;
else
handler_fn = irq_thread_fn;
sched_setscheduler(current, SCHED_FIFO, ¶m);
- current->irqaction = action;
+ current->irq_thread = 1;
while (!irq_wait_for_interrupt(action)) {
irq_finalize_oneshot(desc, action, true);
/*
- * Clear irqaction. Otherwise exit_irq_thread() would make
+ * Clear irq_thread. Otherwise exit_irq_thread() would make
* fuzz about an active irq thread going into nirvana.
*/
- current->irqaction = NULL;
+ current->irq_thread = 0;
return 0;
}
{
struct task_struct *tsk = current;
struct irq_desc *desc;
+ struct irqaction *action;
- if (!tsk->irqaction)
+ if (!tsk->irq_thread)
return;
+ action = kthread_data(tsk);
+
printk(KERN_ERR
"exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
- tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
-
- desc = irq_to_desc(tsk->irqaction->irq);
+ tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
- /*
- * Prevent a stale desc->threads_oneshot. Must be called
- * before setting the IRQTF_DIED flag.
- */
- irq_finalize_oneshot(desc, tsk->irqaction, true);
+ desc = irq_to_desc(action->irq);
- /*
- * Set the THREAD DIED flag to prevent further wakeups of the
- * soon to be gone threaded handler.
- */
- set_bit(IRQTF_DIED, &tsk->irqaction->flags);
+ /* Prevent a stale desc->threads_oneshot */
+ irq_finalize_oneshot(desc, action, true);
}
static void irq_setup_forced_threading(struct irqaction *new)
/* add new interrupt at end of irq queue */
do {
+ /*
+ * Or all existing action->thread_mask bits,
+ * so we can find the next zero bit for this
+ * new action.
+ */
thread_mask |= old->thread_mask;
old_ptr = &old->next;
old = *old_ptr;
}
/*
- * Setup the thread mask for this irqaction. Unlikely to have
- * 32 resp 64 irqs sharing one line, but who knows.
+ * Setup the thread mask for this irqaction for ONESHOT. For
+ * !ONESHOT irqs the thread mask is 0 so we can avoid a
+ * conditional in irq_wake_thread().
*/
- if (new->flags & IRQF_ONESHOT && thread_mask == ~0UL) {
- ret = -EBUSY;
- goto out_mask;
+ if (new->flags & IRQF_ONESHOT) {
+ /*
+ * Unlikely to have 32 resp 64 irqs sharing one line,
+ * but who knows.
+ */
+ if (thread_mask == ~0UL) {
+ ret = -EBUSY;
+ goto out_mask;
+ }
+ /*
+ * The thread_mask for the action is or'ed to
+ * desc->thread_active to indicate that the
+ * IRQF_ONESHOT thread handler has been woken, but not
+ * yet finished. The bit is cleared when a thread
+ * completes. When all threads of a shared interrupt
+ * line have completed desc->threads_active becomes
+ * zero and the interrupt line is unmasked. See
+ * handle.c:irq_wake_thread() for further information.
+ *
+ * If no thread is woken by primary (hard irq context)
+ * interrupt handlers, then desc->threads_active is
+ * also checked for zero to unmask the irq line in the
+ * affected hard irq flow handlers
+ * (handle_[fasteoi|level]_irq).
+ *
+ * The new action gets the first zero bit of
+ * thread_mask assigned. See the loop above which or's
+ * all existing action->thread_mask bits.
+ */
+ new->thread_mask = 1 << ffz(thread_mask);
}
- new->thread_mask = 1 << ffz(thread_mask);
if (!shared) {
init_waitqueue_head(&desc->wait_for_threads);
desc->istate |= IRQS_ONESHOT;
if (irq_settings_can_autoenable(desc))
- irq_startup(desc);
+ irq_startup(desc, true);
else
/* Undo nested disables: */
desc->depth = 1;
struct task_struct *t = new->thread;
new->thread = NULL;
- if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
- kthread_stop(t);
+ kthread_stop(t);
put_task_struct(t);
}
out_mput:
#endif
if (action->thread) {
- if (!test_bit(IRQTF_DIED, &action->thread_flags))
- kthread_stop(action->thread);
+ kthread_stop(action->thread);
put_task_struct(action->thread);
}