mirror of
https://github.com/torvalds/linux.git
synced 2024-11-02 18:21:49 +00:00
f1a06390d0
move_native_irq() masks and unmasks the interrupt line unconditionally, but the interrupt line might be masked due to a threaded oneshot handler in progress. Unmasking the line in that case can lead to interrupt storms. Observed on PREEMPT_RT. Originally-from: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
79 lines
1.8 KiB
C
79 lines
1.8 KiB
C
|
|
#include <linux/irq.h>
|
|
#include <linux/interrupt.h>
|
|
|
|
#include "internals.h"
|
|
|
|
void move_masked_irq(int irq)
|
|
{
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
struct irq_chip *chip = desc->irq_data.chip;
|
|
|
|
if (likely(!(desc->status & IRQ_MOVE_PENDING)))
|
|
return;
|
|
|
|
/*
|
|
* Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
|
|
*/
|
|
if (CHECK_IRQ_PER_CPU(desc->status)) {
|
|
WARN_ON(1);
|
|
return;
|
|
}
|
|
|
|
desc->status &= ~IRQ_MOVE_PENDING;
|
|
|
|
if (unlikely(cpumask_empty(desc->pending_mask)))
|
|
return;
|
|
|
|
if (!chip->irq_set_affinity)
|
|
return;
|
|
|
|
assert_raw_spin_locked(&desc->lock);
|
|
|
|
/*
|
|
* If there was a valid mask to work with, please
|
|
* do the disable, re-program, enable sequence.
|
|
* This is *not* particularly important for level triggered
|
|
* but in a edge trigger case, we might be setting rte
|
|
* when an active trigger is comming in. This could
|
|
* cause some ioapics to mal-function.
|
|
* Being paranoid i guess!
|
|
*
|
|
* For correct operation this depends on the caller
|
|
* masking the irqs.
|
|
*/
|
|
if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
|
|
< nr_cpu_ids))
|
|
if (!chip->irq_set_affinity(&desc->irq_data,
|
|
desc->pending_mask, false)) {
|
|
cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
|
|
irq_set_thread_affinity(desc);
|
|
}
|
|
|
|
cpumask_clear(desc->pending_mask);
|
|
}
|
|
|
|
void move_native_irq(int irq)
|
|
{
|
|
struct irq_desc *desc = irq_to_desc(irq);
|
|
bool masked;
|
|
|
|
if (likely(!(desc->status & IRQ_MOVE_PENDING)))
|
|
return;
|
|
|
|
if (unlikely(desc->status & IRQ_DISABLED))
|
|
return;
|
|
|
|
/*
|
|
* Be careful vs. already masked interrupts. If this is a
|
|
* threaded interrupt with ONESHOT set, we can end up with an
|
|
* interrupt storm.
|
|
*/
|
|
masked = desc->status & IRQ_MASKED;
|
|
if (!masked)
|
|
desc->irq_data.chip->irq_mask(&desc->irq_data);
|
|
move_masked_irq(irq);
|
|
if (!masked)
|
|
desc->irq_data.chip->irq_unmask(&desc->irq_data);
|
|
}
|