kernel/irq/migration.c

   1
   2 #include <linux/irq.h>
   3 #include <linux/interrupt.h>
   4
   5 #include "internals.h"
   6
   7 void irq_move_masked_irq(struct irq_data *idata)
   8 {
   9         struct irq_desc *desc = irq_data_to_desc(idata);
  10         struct irq_chip *chip = idata->chip;
  11
  12         if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
  13                 return;
  14
  15         /*
  16          * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
  17          */
  18         if (!irqd_can_balance(&desc->irq_data)) {
  19                 WARN_ON(1);
  20                 return;
  21         }
  22
  23         irqd_clr_move_pending(&desc->irq_data);
  24
  25         if (unlikely(cpumask_empty(desc->pending_mask)))
  26                 return;
  27
  28         if (!chip->irq_set_affinity)
  29                 return;
  30
  31         assert_raw_spin_locked(&desc->lock);
  32
  33         /*
  34          * If there was a valid mask to work with, please
  35          * do the disable, re-program, enable sequence.
  36          * This is *not* particularly important for level triggered
  37          * but in a edge trigger case, we might be setting rte
  38          * when an active trigger is comming in. This could
  39          * cause some ioapics to mal-function.
  40          * Being paranoid i guess!
  41          *
  42          * For correct operation this depends on the caller
  43          * masking the irqs.
  44          */
  45         if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
  46                    < nr_cpu_ids))
  47                 if (!chip->irq_set_affinity(&desc->irq_data,
  48                                             desc->pending_mask, false)) {
  49                         cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
  50                         irq_set_thread_affinity(desc);
  51                 }
  52
  53         cpumask_clear(desc->pending_mask);
  54 }
  55
  56 void irq_move_irq(struct irq_data *idata)
  57 {
  58         bool masked;
  59
  60         if (likely(!irqd_is_setaffinity_pending(idata)))
  61                 return;
  62
  63         if (unlikely(irqd_irq_disabled(idata)))
  64                 return;
  65
  66         /*
  67          * Be careful vs. already masked interrupts. If this is a
  68          * threaded interrupt with ONESHOT set, we can end up with an
  69          * interrupt storm.
  70          */
  71         masked = irqd_irq_masked(idata);
  72         if (!masked)
  73                 idata->chip->irq_mask(idata);
  74         irq_move_masked_irq(idata);
  75         if (!masked)
  76                 idata->chip->irq_unmask(idata);
  77 }