linux/kernel/irq/migration.c
Thomas Gleixner f6d87f4bd2 genirq: keep affinities set from userspace across free/request_irq()
Impact: preserve user-modified affinities on interrupts

Kumar Galak noticed that commit
1840475676 (genirq: Expose default irq
affinity mask (take 3))

overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.

Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-09 22:23:49 +01:00

65 lines
1.3 KiB
C

#include <linux/irq.h>
void move_masked_irq(int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
cpumask_t tmp;
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(cpus_empty(desc->pending_mask)))
return;
if (!desc->chip->set_affinity)
return;
assert_spin_locked(&desc->lock);
cpus_and(tmp, desc->pending_mask, cpu_online_map);
/*
* 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(!cpus_empty(tmp))) {
desc->chip->set_affinity(irq,tmp);
}
cpus_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);
}