Commit | Line | Data |
---|---|---|
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 | ||
415fcf1a TG |
17 | /* For !GENERIC_IRQ_EFFECTIVE_AFF_MASK this looks at general affinity mask */ |
18 | static inline bool irq_needs_fixup(struct irq_data *d) | |
19 | { | |
20 | const struct cpumask *m = irq_data_get_effective_affinity_mask(d); | |
21 | ||
22 | return cpumask_test_cpu(smp_processor_id(), m); | |
23 | } | |
24 | ||
f1e0bb0a YY |
25 | static bool migrate_one_irq(struct irq_desc *desc) |
26 | { | |
27 | struct irq_data *d = irq_desc_get_irq_data(desc); | |
e8a70350 | 28 | struct irq_chip *chip = irq_data_get_irq_chip(d); |
47a06d3a | 29 | bool maskchip = !irq_can_move_pcntxt(d) && !irqd_irq_masked(d); |
f0383c24 | 30 | const struct cpumask *affinity; |
e8a70350 TG |
31 | bool brokeaff = false; |
32 | int err; | |
33 | ||
34 | /* | |
35 | * IRQ chip might be already torn down, but the irq descriptor is | |
36 | * still in the radix tree. Also if the chip has no affinity setter, | |
37 | * nothing can be done here. | |
38 | */ | |
39 | if (!chip || !chip->irq_set_affinity) { | |
40 | pr_debug("IRQ %u: Unable to migrate away\n", d->irq); | |
41 | return false; | |
42 | } | |
f1e0bb0a YY |
43 | |
44 | /* | |
91f26cb4 TG |
45 | * No move required, if: |
46 | * - Interrupt is per cpu | |
47 | * - Interrupt is not started | |
48 | * - Affinity mask does not include this CPU. | |
49 | * | |
50 | * Note: Do not check desc->action as this might be a chained | |
51 | * interrupt. | |
f1e0bb0a | 52 | */ |
415fcf1a | 53 | if (irqd_is_per_cpu(d) || !irqd_is_started(d) || !irq_needs_fixup(d)) { |
f0383c24 TG |
54 | /* |
55 | * If an irq move is pending, abort it if the dying CPU is | |
56 | * the sole target. | |
57 | */ | |
58 | irq_fixup_move_pending(desc, false); | |
f1e0bb0a | 59 | return false; |
f0383c24 TG |
60 | } |
61 | ||
62 | /* | |
63 | * Complete an eventually pending irq move cleanup. If this | |
64 | * interrupt was moved in hard irq context, then the vectors need | |
65 | * to be cleaned up. It can't wait until this interrupt actually | |
66 | * happens and this CPU was involved. | |
67 | */ | |
68 | irq_force_complete_move(desc); | |
69 | ||
70 | /* | |
71 | * If there is a setaffinity pending, then try to reuse the pending | |
72 | * mask, so the last change of the affinity does not get lost. If | |
73 | * there is no move pending or the pending mask does not contain | |
74 | * any online CPU, use the current affinity mask. | |
75 | */ | |
76 | if (irq_fixup_move_pending(desc, true)) | |
77 | affinity = irq_desc_get_pending_mask(desc); | |
415fcf1a TG |
78 | else |
79 | affinity = irq_data_get_affinity_mask(d); | |
f1e0bb0a | 80 | |
47a06d3a TG |
81 | /* Mask the chip for interrupts which cannot move in process context */ |
82 | if (maskchip && chip->irq_mask) | |
83 | chip->irq_mask(d); | |
84 | ||
f1e0bb0a | 85 | if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { |
c5cb83bb TG |
86 | /* |
87 | * If the interrupt is managed, then shut it down and leave | |
88 | * the affinity untouched. | |
89 | */ | |
90 | if (irqd_affinity_is_managed(d)) { | |
91 | irqd_set_managed_shutdown(d); | |
92 | irq_shutdown(desc); | |
93 | return false; | |
94 | } | |
f1e0bb0a | 95 | affinity = cpu_online_mask; |
e8a70350 | 96 | brokeaff = true; |
f1e0bb0a | 97 | } |
83979133 TG |
98 | /* |
99 | * Do not set the force argument of irq_do_set_affinity() as this | |
100 | * disables the masking of offline CPUs from the supplied affinity | |
101 | * mask and therefore might keep/reassign the irq to the outgoing | |
102 | * CPU. | |
103 | */ | |
104 | err = irq_do_set_affinity(d, affinity, false); | |
e8a70350 TG |
105 | if (err) { |
106 | pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", | |
107 | d->irq, err); | |
47a06d3a | 108 | brokeaff = false; |
f1e0bb0a | 109 | } |
47a06d3a TG |
110 | |
111 | if (maskchip && chip->irq_unmask) | |
112 | chip->irq_unmask(d); | |
113 | ||
e8a70350 | 114 | return brokeaff; |
f1e0bb0a YY |
115 | } |
116 | ||
117 | /** | |
118 | * irq_migrate_all_off_this_cpu - Migrate irqs away from offline cpu | |
119 | * | |
120 | * The current CPU has been marked offline. Migrate IRQs off this CPU. | |
121 | * If the affinity settings do not allow other CPUs, force them onto any | |
122 | * available CPU. | |
123 | * | |
124 | * Note: we must iterate over all IRQs, whether they have an attached | |
125 | * action structure or not, as we need to get chained interrupts too. | |
126 | */ | |
127 | void irq_migrate_all_off_this_cpu(void) | |
128 | { | |
f1e0bb0a | 129 | struct irq_desc *desc; |
0dd945ff | 130 | unsigned int irq; |
f1e0bb0a YY |
131 | |
132 | for_each_active_irq(irq) { | |
133 | bool affinity_broken; | |
134 | ||
135 | desc = irq_to_desc(irq); | |
136 | raw_spin_lock(&desc->lock); | |
137 | affinity_broken = migrate_one_irq(desc); | |
138 | raw_spin_unlock(&desc->lock); | |
139 | ||
0dd945ff TG |
140 | if (affinity_broken) { |
141 | pr_warn_ratelimited("IRQ %u: no longer affine to CPU%u\n", | |
f1e0bb0a | 142 | irq, smp_processor_id()); |
0dd945ff | 143 | } |
f1e0bb0a | 144 | } |
f1e0bb0a | 145 | } |
c5cb83bb TG |
146 | |
147 | static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu) | |
148 | { | |
149 | struct irq_data *data = irq_desc_get_irq_data(desc); | |
150 | const struct cpumask *affinity = irq_data_get_affinity_mask(data); | |
151 | ||
152 | if (!irqd_affinity_is_managed(data) || !desc->action || | |
153 | !irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity)) | |
154 | return; | |
155 | ||
8f31a984 | 156 | if (irqd_is_managed_and_shutdown(data)) { |
c5cb83bb | 157 | irq_startup(desc, IRQ_RESEND, IRQ_START_COND); |
8f31a984 TG |
158 | return; |
159 | } | |
160 | ||
161 | /* | |
162 | * If the interrupt can only be directed to a single target | |
163 | * CPU then it is already assigned to a CPU in the affinity | |
164 | * mask. No point in trying to move it around. | |
165 | */ | |
166 | if (!irqd_is_single_target(data)) | |
c5cb83bb TG |
167 | irq_set_affinity_locked(data, affinity, false); |
168 | } | |
169 | ||
170 | /** | |
171 | * irq_affinity_online_cpu - Restore affinity for managed interrupts | |
172 | * @cpu: Upcoming CPU for which interrupts should be restored | |
173 | */ | |
174 | int irq_affinity_online_cpu(unsigned int cpu) | |
175 | { | |
176 | struct irq_desc *desc; | |
177 | unsigned int irq; | |
178 | ||
179 | irq_lock_sparse(); | |
180 | for_each_active_irq(irq) { | |
181 | desc = irq_to_desc(irq); | |
182 | raw_spin_lock_irq(&desc->lock); | |
183 | irq_restore_affinity_of_irq(desc, cpu); | |
184 | raw_spin_unlock_irq(&desc->lock); | |
185 | } | |
186 | irq_unlock_sparse(); | |
187 | ||
188 | return 0; | |
189 | } |