diff options
Diffstat (limited to 'kernel/irq/handle.c')
| -rw-r--r-- | kernel/irq/handle.c | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 470d08c82bb..63548027085 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -41,6 +41,7 @@ irqreturn_t no_action(int cpl, void *dev_id) { return IRQ_NONE; } +EXPORT_SYMBOL_GPL(no_action); static void warn_no_thread(unsigned int irq, struct irqaction *action) { @@ -51,17 +52,21 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action) "but no thread function available.", irq, action->name); } -static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) +void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action) { /* - * Wake up the handler thread for this action. In case the - * thread crashed and was killed we just pretend that we - * handled the interrupt. The hardirq handler has disabled the - * device interrupt, so no irq storm is lurking. If the + * In case the thread crashed and was killed we just pretend that + * we handled the interrupt. The hardirq handler has disabled the + * device interrupt, so no irq storm is lurking. + */ + if (action->thread->flags & PF_EXITING) + return; + + /* + * Wake up the handler thread for this action. If the * RUNTHREAD bit is already set, nothing to do. */ - if (test_bit(IRQTF_DIED, &action->thread_flags) || - test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) + if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) return; /* @@ -110,6 +115,18 @@ static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) * threads_oneshot untouched and runs the thread another time. */ desc->threads_oneshot |= action->thread_mask; + + /* + * We increment the threads_active counter in case we wake up + * the irq thread. The irq thread decrements the counter when + * it returns from the handler or in the exit path and wakes + * up waiters which are stuck in synchronize_irq() when the + * active count becomes zero. synchronize_irq() is serialized + * against this code (hard irq handler) via IRQS_INPROGRESS + * like the finalize_oneshot() code. See comment above. + */ + atomic_inc(&desc->threads_active); + wake_up_process(action->thread); } @@ -117,7 +134,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) { irqreturn_t retval = IRQ_NONE; - unsigned int random = 0, irq = desc->irq_data.irq; + unsigned int flags = 0, irq = desc->irq_data.irq; do { irqreturn_t res; @@ -141,11 +158,11 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) break; } - irq_wake_thread(desc, action); + __irq_wake_thread(desc, action); /* Fall through to add to randomness */ case IRQ_HANDLED: - random |= action->flags; + flags |= action->flags; break; default: @@ -156,8 +173,7 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action) action = action->next; } while (action); - if (random & IRQF_SAMPLE_RANDOM) - add_interrupt_randomness(irq); + add_interrupt_randomness(irq, flags); if (!noirqdebug) note_interrupt(irq, desc, retval); |