xref: /linux/kernel/irq/migration.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/irq.h>
4 #include <linux/interrupt.h>
5 
6 #include "internals.h"
7 
8 /**
9  * irq_fixup_move_pending - Cleanup irq move pending from a dying CPU
10  * @desc:		Interrupt descpriptor to clean up
11  * @force_clear:	If set clear the move pending bit unconditionally.
12  *			If not set, clear it only when the dying CPU is the
13  *			last one in the pending mask.
14  *
15  * Returns true if the pending bit was set and the pending mask contains an
16  * online CPU other than the dying CPU.
17  */
18 bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear)
19 {
20 	struct irq_data *data = irq_desc_get_irq_data(desc);
21 
22 	if (!irqd_is_setaffinity_pending(data))
23 		return false;
24 
25 	/*
26 	 * The outgoing CPU might be the last online target in a pending
27 	 * interrupt move. If that's the case clear the pending move bit.
28 	 */
29 	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) >= nr_cpu_ids) {
30 		irqd_clr_move_pending(data);
31 		return false;
32 	}
33 	if (force_clear)
34 		irqd_clr_move_pending(data);
35 	return true;
36 }
37 
38 void irq_move_masked_irq(struct irq_data *idata)
39 {
40 	struct irq_desc *desc = irq_data_to_desc(idata);
41 	struct irq_chip *chip = desc->irq_data.chip;
42 
43 	if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
44 		return;
45 
46 	irqd_clr_move_pending(&desc->irq_data);
47 
48 	/*
49 	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
50 	 */
51 	if (irqd_is_per_cpu(&desc->irq_data)) {
52 		WARN_ON(1);
53 		return;
54 	}
55 
56 	if (unlikely(cpumask_empty(desc->pending_mask)))
57 		return;
58 
59 	if (!chip->irq_set_affinity)
60 		return;
61 
62 	assert_raw_spin_locked(&desc->lock);
63 
64 	/*
65 	 * If there was a valid mask to work with, please
66 	 * do the disable, re-program, enable sequence.
67 	 * This is *not* particularly important for level triggered
68 	 * but in a edge trigger case, we might be setting rte
69 	 * when an active trigger is coming in. This could
70 	 * cause some ioapics to mal-function.
71 	 * Being paranoid i guess!
72 	 *
73 	 * For correct operation this depends on the caller
74 	 * masking the irqs.
75 	 */
76 	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids)
77 		irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);
78 
79 	cpumask_clear(desc->pending_mask);
80 }
81 
82 void irq_move_irq(struct irq_data *idata)
83 {
84 	bool masked;
85 
86 	/*
87 	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
88 	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
89 	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
90 	 */
91 	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
92 
93 	if (likely(!irqd_is_setaffinity_pending(idata)))
94 		return;
95 
96 	if (unlikely(irqd_irq_disabled(idata)))
97 		return;
98 
99 	/*
100 	 * Be careful vs. already masked interrupts. If this is a
101 	 * threaded interrupt with ONESHOT set, we can end up with an
102 	 * interrupt storm.
103 	 */
104 	masked = irqd_irq_masked(idata);
105 	if (!masked)
106 		idata->chip->irq_mask(idata);
107 	irq_move_masked_irq(idata);
108 	if (!masked)
109 		idata->chip->irq_unmask(idata);
110 }
111