migration.c

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#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 (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids)
        irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);

    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);
}