kernel/irq/migration.c

   1
   2 #include <linux/irq.h>
   3 #include <linux/interrupt.h>
   4
   5 #include "internals.h"
   6
   7 void move_masked_irq(int irq)
   8 {
   9         struct irq_desc *desc = irq_to_desc(irq);
  10         struct irq_chip *chip = desc->irq_data.chip;
  11
  12         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
  13                 return;
  14
  15         /*
  16          * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
  17          */
  18         if (CHECK_IRQ_PER_CPU(desc->status)) {
  19                 WARN_ON(1);
  20                 return;
  21         }
  22
  23         desc->status &= ~IRQ_MOVE_PENDING;
  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 move_native_irq(int irq)
  57 {
  58         struct irq_desc *desc = irq_to_desc(irq);
  59         bool masked;
  60
  61         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
  62                 return;
  63
  64         if (unlikely(desc->status & IRQ_DISABLED))
  65                 return;
  66
  67         /*
  68          * Be careful vs. already masked interrupts. If this is a
  69          * threaded interrupt with ONESHOT set, we can end up with an
  70          * interrupt storm.
  71          */
  72         masked = desc->status & IRQ_MASKED;
  73         if (!masked)
  74                 desc->irq_data.chip->irq_mask(&desc->irq_data);
  75         move_masked_irq(irq);
  76         if (!masked)
  77                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
  78 }