kernel/irq/migration.c

   1
   2 #include <linux/irq.h>
   3
   4 void move_masked_irq(int irq)
   5 {
   6         struct irq_desc *desc = irq_to_desc(irq);
   7
   8         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
   9                 return;
  10
  11         /*
  12          * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
  13          */
  14         if (CHECK_IRQ_PER_CPU(desc->status)) {
  15                 WARN_ON(1);
  16                 return;
  17         }
  18
  19         desc->status &= ~IRQ_MOVE_PENDING;
  20
  21         if (unlikely(cpumask_empty(desc->pending_mask)))
  22                 return;
  23
  24         if (!desc->chip->set_affinity)
  25                 return;
  26
  27         assert_spin_locked(&desc->lock);
  28
  29         /*
  30          * If there was a valid mask to work with, please
  31          * do the disable, re-program, enable sequence.
  32          * This is *not* particularly important for level triggered
  33          * but in a edge trigger case, we might be setting rte
  34          * when an active trigger is comming in. This could
  35          * cause some ioapics to mal-function.
  36          * Being paranoid i guess!
  37          *
  38          * For correct operation this depends on the caller
  39          * masking the irqs.
  40          */
  41         if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
  42                    < nr_cpu_ids)) {
  43                 cpumask_and(desc->affinity,
  44                             desc->pending_mask, cpu_online_mask);
  45                 desc->chip->set_affinity(irq, desc->affinity);
  46         }
  47         cpumask_clear(desc->pending_mask);
  48 }
  49
  50 void move_native_irq(int irq)
  51 {
  52         struct irq_desc *desc = irq_to_desc(irq);
  53         int mask = 1;
  54
  55         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
  56                 return;
  57
  58         if (unlikely(desc->status & IRQ_DISABLED))
  59                 return;
  60
  61         /*
  62          * If the irq is already in progress, it should be masked.
  63          * If we unmask it, we might cause an interrupt storm on RT.
  64          */
  65         if (unlikely(desc->status & IRQ_INPROGRESS))
  66                 mask = 0;
  67
  68         if (mask)
  69                 desc->chip->mask(irq);
  70         move_masked_irq(irq);
  71         if (mask)
  72                 desc->chip->unmask(irq);
  73 }
  74