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-rw-r--r--kernel/irq/spurious.c163
1 files changed, 104 insertions, 59 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 3089d3b9..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);
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