xref: /openbmc/linux/kernel/irq/migration.c (revision 4800cd83)
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 }
79