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_to_desc(irq);
   7         unsigned long flags;
   8
   9         spin_lock_irqsave(&desc->lock, flags);
  10         desc->status |= IRQ_MOVE_PENDING;
  11         desc->pending_mask = mask;
  12         spin_unlock_irqrestore(&desc->lock, flags);
  13 }
  14
  15 void move_masked_irq(int irq)
  16 {
  17         struct irq_desc *desc = irq_to_desc(irq);
  18         cpumask_t tmp;
  19
  20         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
  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->status &= ~IRQ_MOVE_PENDING;
  32
  33         if (unlikely(cpus_empty(desc->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, desc->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          * For correct operation this depends on the caller
  53          * masking the irqs.
  54          */
  55         if (likely(!cpus_empty(tmp))) {
  56                 desc->chip->set_affinity(irq,tmp);
  57         }
  58         cpus_clear(desc->pending_mask);
  59 }
  60
  61 void move_native_irq(int irq)
  62 {
  63         struct irq_desc *desc = irq_to_desc(irq);
  64
  65         if (likely(!(desc->status & IRQ_MOVE_PENDING)))
  66                 return;
  67
  68         if (unlikely(desc->status & IRQ_DISABLED))
  69                 return;
  70
  71         desc->chip->mask(irq);
  72         move_masked_irq(irq);
  73         desc->chip->unmask(irq);
  74 }
  75