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f1e0bb0a YY |
1 | /* |
2 | * Generic cpu hotunplug interrupt migration code copied from the | |
3 | * arch/arm implementation | |
4 | * | |
5 | * Copyright (C) Russell King | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/interrupt.h> | |
12 | #include <linux/ratelimit.h> | |
13 | #include <linux/irq.h> | |
14 | ||
15 | #include "internals.h" | |
16 | ||
17 | static bool migrate_one_irq(struct irq_desc *desc) | |
18 | { | |
19 | struct irq_data *d = irq_desc_get_irq_data(desc); | |
e8a70350 | 20 | struct irq_chip *chip = irq_data_get_irq_chip(d); |
f0383c24 | 21 | const struct cpumask *affinity; |
e8a70350 TG |
22 | bool brokeaff = false; |
23 | int err; | |
24 | ||
25 | /* | |
26 | * IRQ chip might be already torn down, but the irq descriptor is | |
27 | * still in the radix tree. Also if the chip has no affinity setter, | |
28 | * nothing can be done here. | |
29 | */ | |
30 | if (!chip || !chip->irq_set_affinity) { | |
31 | pr_debug("IRQ %u: Unable to migrate away\n", d->irq); | |
32 | return false; | |
33 | } | |
f1e0bb0a YY |
34 | |
35 | /* | |
91f26cb4 TG |
36 | * No move required, if: |
37 | * - Interrupt is per cpu | |
38 | * - Interrupt is not started | |
39 | * - Affinity mask does not include this CPU. | |
40 | * | |
41 | * Note: Do not check desc->action as this might be a chained | |
42 | * interrupt. | |
f1e0bb0a | 43 | */ |
f0383c24 | 44 | affinity = irq_data_get_affinity_mask(d); |
91f26cb4 | 45 | if (irqd_is_per_cpu(d) || !irqd_is_started(d) || |
f0383c24 TG |
46 | !cpumask_test_cpu(smp_processor_id(), affinity)) { |
47 | /* | |
48 | * If an irq move is pending, abort it if the dying CPU is | |
49 | * the sole target. | |
50 | */ | |
51 | irq_fixup_move_pending(desc, false); | |
f1e0bb0a | 52 | return false; |
f0383c24 TG |
53 | } |
54 | ||
55 | /* | |
56 | * Complete an eventually pending irq move cleanup. If this | |
57 | * interrupt was moved in hard irq context, then the vectors need | |
58 | * to be cleaned up. It can't wait until this interrupt actually | |
59 | * happens and this CPU was involved. | |
60 | */ | |
61 | irq_force_complete_move(desc); | |
62 | ||
63 | /* | |
64 | * If there is a setaffinity pending, then try to reuse the pending | |
65 | * mask, so the last change of the affinity does not get lost. If | |
66 | * there is no move pending or the pending mask does not contain | |
67 | * any online CPU, use the current affinity mask. | |
68 | */ | |
69 | if (irq_fixup_move_pending(desc, true)) | |
70 | affinity = irq_desc_get_pending_mask(desc); | |
f1e0bb0a YY |
71 | |
72 | if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { | |
73 | affinity = cpu_online_mask; | |
e8a70350 | 74 | brokeaff = true; |
f1e0bb0a YY |
75 | } |
76 | ||
e8a70350 TG |
77 | err = irq_do_set_affinity(d, affinity, false); |
78 | if (err) { | |
79 | pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", | |
80 | d->irq, err); | |
81 | return false; | |
f1e0bb0a | 82 | } |
e8a70350 | 83 | return brokeaff; |
f1e0bb0a YY |
84 | } |
85 | ||
86 | /** | |
87 | * irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu | |
88 | * | |
89 | * The current CPU has been marked offline. Migrate IRQs off this CPU. | |
90 | * If the affinity settings do not allow other CPUs, force them onto any | |
91 | * available CPU. | |
92 | * | |
93 | * Note: we must iterate over all IRQs, whether they have an attached | |
94 | * action structure or not, as we need to get chained interrupts too. | |
95 | */ | |
96 | void irq_migrate_all_off_this_cpu(void) | |
97 | { | |
f1e0bb0a | 98 | struct irq_desc *desc; |
0dd945ff | 99 | unsigned int irq; |
f1e0bb0a YY |
100 | |
101 | for_each_active_irq(irq) { | |
102 | bool affinity_broken; | |
103 | ||
104 | desc = irq_to_desc(irq); | |
105 | raw_spin_lock(&desc->lock); | |
106 | affinity_broken = migrate_one_irq(desc); | |
107 | raw_spin_unlock(&desc->lock); | |
108 | ||
0dd945ff TG |
109 | if (affinity_broken) { |
110 | pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n", | |
f1e0bb0a | 111 | irq, smp_processor_id()); |
0dd945ff | 112 | } |
f1e0bb0a | 113 | } |
f1e0bb0a | 114 | } |