genirq: Provide forced interrupt threading
[linux-2.6.git] / 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 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_masked_irq(int irq)
57 {
58         irq_move_masked_irq(irq_get_irq_data(irq));
59 }
60
61 void irq_move_irq(struct irq_data *idata)
62 {
63         struct irq_desc *desc = irq_data_to_desc(idata);
64         bool masked;
65
66         if (likely(!irqd_is_setaffinity_pending(idata)))
67                 return;
68
69         if (unlikely(desc->istate & IRQS_DISABLED))
70                 return;
71
72         /*
73          * Be careful vs. already masked interrupts. If this is a
74          * threaded interrupt with ONESHOT set, we can end up with an
75          * interrupt storm.
76          */
77         masked = desc->istate & IRQS_MASKED;
78         if (!masked)
79                 idata->chip->irq_mask(idata);
80         irq_move_masked_irq(idata);
81         if (!masked)
82                 idata->chip->irq_unmask(idata);
83 }
84
85 void move_native_irq(int irq)
86 {
87         irq_move_irq(irq_get_irq_data(irq));
88 }