xref: /openbmc/linux/kernel/irq/migration.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
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 coming 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 		int ret = chip->irq_set_affinity(&desc->irq_data,
48 						 desc->pending_mask, false);
49 		switch (ret) {
50 		case IRQ_SET_MASK_OK:
51 			cpumask_copy(desc->irq_data.affinity, desc->pending_mask);
52 		case IRQ_SET_MASK_OK_NOCOPY:
53 			irq_set_thread_affinity(desc);
54 		}
55 	}
56 
57 	cpumask_clear(desc->pending_mask);
58 }
59 
60 void irq_move_irq(struct irq_data *idata)
61 {
62 	bool masked;
63 
64 	if (likely(!irqd_is_setaffinity_pending(idata)))
65 		return;
66 
67 	if (unlikely(irqd_irq_disabled(idata)))
68 		return;
69 
70 	/*
71 	 * Be careful vs. already masked interrupts. If this is a
72 	 * threaded interrupt with ONESHOT set, we can end up with an
73 	 * interrupt storm.
74 	 */
75 	masked = irqd_irq_masked(idata);
76 	if (!masked)
77 		idata->chip->irq_mask(idata);
78 	irq_move_masked_irq(idata);
79 	if (!masked)
80 		idata->chip->irq_unmask(idata);
81 }
82