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 descriptor 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 */
18bool 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(d: 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_intersects(src1p: desc->pending_mask, cpu_online_mask)) {
30 irqd_clr_move_pending(d: data);
31 return false;
32 }
33 if (force_clear)
34 irqd_clr_move_pending(d: data);
35 return true;
36}
37
38void irq_force_complete_move(struct irq_desc *desc)
39{
40 for (struct irq_data *d = irq_desc_get_irq_data(desc); d; d = irqd_get_parent_data(irqd: d)) {
41 if (d->chip && d->chip->irq_force_complete_move) {
42 d->chip->irq_force_complete_move(d);
43 return;
44 }
45 }
46}
47
48void irq_move_masked_irq(struct irq_data *idata)
49{
50 struct irq_desc *desc = irq_data_to_desc(data: idata);
51 struct irq_data *data = &desc->irq_data;
52 struct irq_chip *chip = data->chip;
53
54 if (likely(!irqd_is_setaffinity_pending(data)))
55 return;
56
57 irqd_clr_move_pending(d: data);
58
59 /*
60 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
61 */
62 if (irqd_is_per_cpu(d: data)) {
63 WARN_ON(1);
64 return;
65 }
66
67 if (unlikely(cpumask_empty(desc->pending_mask)))
68 return;
69
70 if (!chip->irq_set_affinity)
71 return;
72
73 assert_raw_spin_locked(&desc->lock);
74
75 /*
76 * If there was a valid mask to work with, please
77 * do the disable, re-program, enable sequence.
78 * This is *not* particularly important for level triggered
79 * but in a edge trigger case, we might be setting rte
80 * when an active trigger is coming in. This could
81 * cause some ioapics to mal-function.
82 * Being paranoid i guess!
83 *
84 * For correct operation this depends on the caller
85 * masking the irqs.
86 */
87 if (cpumask_intersects(src1p: desc->pending_mask, cpu_online_mask)) {
88 int ret;
89
90 ret = irq_do_set_affinity(data, dest: desc->pending_mask, force: false);
91 /*
92 * If the there is a cleanup pending in the underlying
93 * vector management, reschedule the move for the next
94 * interrupt. Leave desc->pending_mask intact.
95 */
96 if (ret == -EBUSY) {
97 irqd_set_move_pending(d: data);
98 return;
99 }
100 }
101 cpumask_clear(dstp: desc->pending_mask);
102}
103
104void __irq_move_irq(struct irq_data *idata)
105{
106 bool masked;
107
108 /*
109 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
110 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
111 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
112 */
113 idata = irq_desc_get_irq_data(desc: irq_data_to_desc(data: idata));
114
115 if (unlikely(irqd_irq_disabled(idata)))
116 return;
117
118 /*
119 * Be careful vs. already masked interrupts. If this is a
120 * threaded interrupt with ONESHOT set, we can end up with an
121 * interrupt storm.
122 */
123 masked = irqd_irq_masked(d: idata);
124 if (!masked)
125 idata->chip->irq_mask(idata);
126 irq_move_masked_irq(idata);
127 if (!masked)
128 idata->chip->irq_unmask(idata);
129}
130
131bool irq_can_move_in_process_context(struct irq_data *data)
132{
133 /*
134 * Get the top level irq_data in the hierarchy, which is optimized
135 * away when CONFIG_IRQ_DOMAIN_HIERARCHY is disabled.
136 */
137 data = irq_desc_get_irq_data(desc: irq_data_to_desc(data));
138 return irq_can_move_pcntxt(data);
139}
140

source code of linux/kernel/irq/migration.c