android_kernel_motorola_sm6225/kernel/irq/migration.c
Thomas Gleixner 591d2fb02e genirq: Delegate irq affinity setting to the irq thread
irq_set_thread_affinity() calls set_cpus_allowed_ptr() which might
sleep, but irq_set_thread_affinity() is called with desc->lock held
and can be called from hard interrupt context as well. The code has
another bug as it does not hold a ref on the task struct as required
by set_cpus_allowed_ptr().

Just set the IRQTF_AFFINITY bit in action->thread_flags. The next time
the thread runs it migrates itself. Solves all of the above problems
nicely.

Add kerneldoc to irq_set_thread_affinity() while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
2009-07-21 14:35:07 +02:00

68 lines
1.5 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);
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 (!desc->chip->set_affinity)
return;
assert_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 (!desc->chip->set_affinity(irq, desc->pending_mask)) {
cpumask_copy(desc->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);
if (likely(!(desc->status & IRQ_MOVE_PENDING)))
return;
if (unlikely(desc->status & IRQ_DISABLED))
return;
desc->chip->mask(irq);
move_masked_irq(irq);
desc->chip->unmask(irq);
}