diff options
Diffstat (limited to 'kernel/irq/spurious.c')
-rw-r--r-- | kernel/irq/spurious.c | 163 |
1 files changed, 104 insertions, 59 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 3089d3b..dd586eb 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -21,70 +21,94 @@ static int irqfixup __read_mostly; #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10) static void poll_spurious_irqs(unsigned long dummy); static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0); +static int irq_poll_cpu; +static atomic_t irq_poll_active; + +/* + * We wait here for a poller to finish. + * + * If the poll runs on this CPU, then we yell loudly and return + * false. That will leave the interrupt line disabled in the worst + * case, but it should never happen. + * + * We wait until the poller is done and then recheck disabled and + * action (about to be disabled). Only if it's still active, we return + * true and let the handler run. + */ +bool irq_wait_for_poll(struct irq_desc *desc) +{ + if (WARN_ONCE(irq_poll_cpu == smp_processor_id(), + "irq poll in progress on cpu %d for irq %d\n", + smp_processor_id(), desc->irq_data.irq)) + return false; + +#ifdef CONFIG_SMP + do { + raw_spin_unlock(&desc->lock); + while (desc->istate & IRQS_INPROGRESS) + cpu_relax(); + raw_spin_lock(&desc->lock); + } while (desc->istate & IRQS_INPROGRESS); + /* Might have been disabled in meantime */ + return !(desc->istate & IRQS_DISABLED) && desc->action; +#else + return false; +#endif +} + /* * Recovery handler for misrouted interrupts. */ -static int try_one_irq(int irq, struct irq_desc *desc) +static int try_one_irq(int irq, struct irq_desc *desc, bool force) { + irqreturn_t ret = IRQ_NONE; struct irqaction *action; - int ok = 0, work = 0; raw_spin_lock(&desc->lock); - /* Already running on another processor */ - if (desc->status & IRQ_INPROGRESS) { - /* - * Already running: If it is shared get the other - * CPU to go looking for our mystery interrupt too - */ - if (desc->action && (desc->action->flags & IRQF_SHARED)) - desc->status |= IRQ_PENDING; - raw_spin_unlock(&desc->lock); - return ok; - } - /* Honour the normal IRQ locking */ - desc->status |= IRQ_INPROGRESS; - action = desc->action; - raw_spin_unlock(&desc->lock); - while (action) { - /* Only shared IRQ handlers are safe to call */ - if (action->flags & IRQF_SHARED) { - if (action->handler(irq, action->dev_id) == - IRQ_HANDLED) - ok = 1; - } - action = action->next; - } - local_irq_disable(); - /* Now clean up the flags */ - raw_spin_lock(&desc->lock); - action = desc->action; + /* PER_CPU and nested thread interrupts are never polled */ + if (irq_settings_is_per_cpu(desc) || irq_settings_is_nested_thread(desc)) + goto out; /* - * While we were looking for a fixup someone queued a real - * IRQ clashing with our walk: + * Do not poll disabled interrupts unless the spurious + * disabled poller asks explicitely. */ - while ((desc->status & IRQ_PENDING) && action) { + if ((desc->istate & IRQS_DISABLED) && !force) + goto out; + + /* + * All handlers must agree on IRQF_SHARED, so we test just the + * first. Check for action->next as well. + */ + action = desc->action; + if (!action || !(action->flags & IRQF_SHARED) || + (action->flags & __IRQF_TIMER) || !action->next) + goto out; + + /* Already running on another processor */ + if (desc->istate & IRQS_INPROGRESS) { /* - * Perform real IRQ processing for the IRQ we deferred + * Already running: If it is shared get the other + * CPU to go looking for our mystery interrupt too */ - work = 1; - raw_spin_unlock(&desc->lock); - handle_IRQ_event(irq, action); - raw_spin_lock(&desc->lock); - desc->status &= ~IRQ_PENDING; + irq_compat_set_pending(desc); + desc->istate |= IRQS_PENDING; + goto out; } - desc->status &= ~IRQ_INPROGRESS; - /* - * If we did actual work for the real IRQ line we must let the - * IRQ controller clean up too - */ - if (work) - irq_end(irq, desc); - raw_spin_unlock(&desc->lock); - return ok; + /* Mark it poll in progress */ + desc->istate |= IRQS_POLL_INPROGRESS; + do { + if (handle_irq_event(desc) == IRQ_HANDLED) + ret = IRQ_HANDLED; + action = desc->action; + } while ((desc->istate & IRQS_PENDING) && action); + desc->istate &= ~IRQS_POLL_INPROGRESS; +out: + raw_spin_unlock(&desc->lock); + return ret == IRQ_HANDLED; } static int misrouted_irq(int irq) @@ -92,6 +116,11 @@ static int misrouted_irq(int irq) struct irq_desc *desc; int i, ok = 0; + if (atomic_inc_return(&irq_poll_active) == 1) + goto out; + + irq_poll_cpu = smp_processor_id(); + for_each_irq_desc(i, desc) { if (!i) continue; @@ -99,9 +128,11 @@ static int misrouted_irq(int irq) if (i == irq) /* Already tried */ continue; - if (try_one_irq(i, desc)) + if (try_one_irq(i, desc, false)) ok = 1; } +out: + atomic_dec(&irq_poll_active); /* So the caller can adjust the irq error counts */ return ok; } @@ -111,23 +142,28 @@ static void poll_spurious_irqs(unsigned long dummy) struct irq_desc *desc; int i; + if (atomic_inc_return(&irq_poll_active) != 1) + goto out; + irq_poll_cpu = smp_processor_id(); + for_each_irq_desc(i, desc) { - unsigned int status; + unsigned int state; if (!i) continue; /* Racy but it doesn't matter */ - status = desc->status; + state = desc->istate; barrier(); - if (!(status & IRQ_SPURIOUS_DISABLED)) + if (!(state & IRQS_SPURIOUS_DISABLED)) continue; local_irq_disable(); - try_one_irq(i, desc); + try_one_irq(i, desc, true); local_irq_enable(); } - +out: + atomic_dec(&irq_poll_active); mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); } @@ -139,15 +175,13 @@ static void poll_spurious_irqs(unsigned long dummy) * * (The other 100-of-100,000 interrupts may have been a correctly * functioning device sharing an IRQ with the failing one) - * - * Called under desc->lock */ - static void __report_bad_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) { struct irqaction *action; + unsigned long flags; if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) { printk(KERN_ERR "irq event %d: bogus return value %x\n", @@ -159,6 +193,13 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc, dump_stack(); printk(KERN_ERR "handlers:\n"); + /* + * We need to take desc->lock here. note_interrupt() is called + * w/o desc->lock held, but IRQ_PROGRESS set. We might race + * with something else removing an action. It's ok to take + * desc->lock here. See synchronize_irq(). + */ + raw_spin_lock_irqsave(&desc->lock, flags); action = desc->action; while (action) { printk(KERN_ERR "[<%p>]", action->handler); @@ -167,6 +208,7 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc, printk("\n"); action = action->next; } + raw_spin_unlock_irqrestore(&desc->lock, flags); } static void @@ -218,6 +260,9 @@ try_misrouted_irq(unsigned int irq, struct irq_desc *desc, void note_interrupt(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret) { + if (desc->istate & IRQS_POLL_INPROGRESS) + return; + if (unlikely(action_ret != IRQ_HANDLED)) { /* * If we are seeing only the odd spurious IRQ caused by @@ -254,9 +299,9 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, * Now kill the IRQ */ printk(KERN_EMERG "Disabling IRQ #%d\n", irq); - desc->status |= IRQ_DISABLED | IRQ_SPURIOUS_DISABLED; + desc->istate |= IRQS_SPURIOUS_DISABLED; desc->depth++; - desc->irq_data.chip->irq_disable(&desc->irq_data); + irq_disable(desc); mod_timer(&poll_spurious_irq_timer, jiffies + POLL_SPURIOUS_IRQ_INTERVAL); |