kernel/irq/migration.c

   1
   2 #include <linux/irq.h>
   3
   4 void set_pending_irq(unsigned int irq, cpumask_t mask)
   5 {
   6         struct irq_desc *desc = irq_desc + irq;
   7         unsigned long flags;
   8
   9         spin_lock_irqsave(&desc->lock, flags);
  10         desc->move_irq = 1;
  11         irq_desc[irq].pending_mask = mask;
  12         spin_unlock_irqrestore(&desc->lock, flags);
  13 }
  14
  15 void move_native_irq(int irq)
  16 {
  17         struct irq_desc *desc = irq_desc + irq;
  18         cpumask_t tmp;
  19
  20         if (likely(!desc->move_irq))
  21                 return;
  22
  23         /*
  24          * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
  25          */
  26         if (CHECK_IRQ_PER_CPU(desc->status)) {
  27                 WARN_ON(1);
  28                 return;
  29         }
  30
  31         desc->move_irq = 0;
  32
  33         if (unlikely(cpus_empty(irq_desc[irq].pending_mask)))
  34                 return;
  35
  36         if (!desc->chip->set_affinity)
  37                 return;
  38
  39         assert_spin_locked(&desc->lock);
  40
  41         cpus_and(tmp, irq_desc[irq].pending_mask, cpu_online_map);
  42
  43         /*
  44          * If there was a valid mask to work with, please
  45          * do the disable, re-program, enable sequence.
  46          * This is *not* particularly important for level triggered
  47          * but in a edge trigger case, we might be setting rte
  48          * when an active trigger is comming in. This could
  49          * cause some ioapics to mal-function.
  50          * Being paranoid i guess!
  51          */
  52         if (likely(!cpus_empty(tmp))) {
  53                 if (likely(!(desc->status & IRQ_DISABLED)))
  54                         desc->chip->disable(irq);
  55
  56                 desc->chip->set_affinity(irq,tmp);
  57
  58                 if (likely(!(desc->status & IRQ_DISABLED)))
  59                         desc->chip->enable(irq);
  60         }
  61         cpus_clear(irq_desc[irq].pending_mask);
  62 }