linux/kernel/irq/migration.c
Jiang Liu f5cb92ac82 genirq: Adjust irq thread affinity on IRQ_SET_MASK_OK_NOCOPY return value
irq_move_masked_irq() checks the return code of
chip->irq_set_affinity() only for 0, but IRQ_SET_MASK_OK_NOCOPY is
also a valid return code, which is there to avoid a redundant copy of
the cpumask. But in case of IRQ_SET_MASK_OK_NOCOPY we not only avoid
the redundant copy, we also fail to adjust the thread affinity of an
eventually threaded interrupt handler.

Handle IRQ_SET_MASK_OK (==0) and IRQ_SET_MASK_OK_NOCOPY(==1) return
values correctly by checking the valid return values seperately.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Keping Chen <chenkeping@huawei.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1333120296-13563-2-git-send-email-jiang.liu@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-03-30 23:13:46 +02:00

82 lines
1.9 KiB
C

#include <linux/irq.h>
#include <linux/interrupt.h>
#include "internals.h"
void irq_move_masked_irq(struct irq_data *idata)
{
struct irq_desc *desc = irq_data_to_desc(idata);
struct irq_chip *chip = idata->chip;
if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
return;
/*
* Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
*/
if (!irqd_can_balance(&desc->irq_data)) {
WARN_ON(1);
return;
}
irqd_clr_move_pending(&desc->irq_data);
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 coming 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)) {
int ret = chip->irq_set_affinity(&desc->irq_data,
desc->pending_mask, false);
switch (ret) {
case IRQ_SET_MASK_OK:
cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
case IRQ_SET_MASK_OK_NOCOPY:
irq_set_thread_affinity(desc);
}
}
cpumask_clear(desc->pending_mask);
}
void irq_move_irq(struct irq_data *idata)
{
bool masked;
if (likely(!irqd_is_setaffinity_pending(idata)))
return;
if (unlikely(irqd_irq_disabled(idata)))
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 = irqd_irq_masked(idata);
if (!masked)
idata->chip->irq_mask(idata);
irq_move_masked_irq(idata);
if (!masked)
idata->chip->irq_unmask(idata);
}