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 coming 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                 int ret = chip->irq_set_affinity(&desc->irq_data,
  48                                                  desc->pending_mask, false);
  49                 switch (ret) {
  50                 case IRQ_SET_MASK_OK:
  51                         cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
  52                 case IRQ_SET_MASK_OK_NOCOPY:
  53                         irq_set_thread_affinity(desc);
  54                 }
  55         }
  56
  57         cpumask_clear(desc->pending_mask);
  58 }
  59
  60 void irq_move_irq(struct irq_data *idata)
  61 {
  62         bool masked;
  63
  64         if (likely(!irqd_is_setaffinity_pending(idata)))
  65                 return;
  66
  67         if (unlikely(irqd_irq_disabled(idata)))
  68                 return;
  69
  70         /*
  71          * Be careful vs. already masked interrupts. If this is a
  72          * threaded interrupt with ONESHOT set, we can end up with an
  73          * interrupt storm.
  74          */
  75         masked = irqd_irq_masked(idata);
  76         if (!masked)
  77                 idata->chip->irq_mask(idata);
  78         irq_move_masked_irq(idata);
  79         if (!masked)
  80                 idata->chip->irq_unmask(idata);
  81 }