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fb9bd7d6 MZ |
1 | /* |
2 | * Based on arch/arm/kernel/irq.c | |
3 | * | |
4 | * Copyright (C) 1992 Linus Torvalds | |
5 | * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. | |
6 | * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation. | |
7 | * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and | |
8 | * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>. | |
9 | * Copyright (C) 2012 ARM Ltd. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
22 | */ | |
23 | ||
24 | #include <linux/kernel_stat.h> | |
25 | #include <linux/irq.h> | |
26 | #include <linux/smp.h> | |
27 | #include <linux/init.h> | |
e851b58c | 28 | #include <linux/irqchip.h> |
fb9bd7d6 MZ |
29 | #include <linux/seq_file.h> |
30 | #include <linux/ratelimit.h> | |
31 | ||
32 | unsigned long irq_err_count; | |
33 | ||
34 | int arch_show_interrupts(struct seq_file *p, int prec) | |
35 | { | |
36 | #ifdef CONFIG_SMP | |
37 | show_ipi_list(p, prec); | |
38 | #endif | |
39 | seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); | |
40 | return 0; | |
41 | } | |
42 | ||
43 | /* | |
44 | * handle_IRQ handles all hardware IRQ's. Decoded IRQs should | |
45 | * not come via this function. Instead, they should provide their | |
46 | * own 'handler'. Used by platform code implementing C-based 1st | |
47 | * level decoding. | |
48 | */ | |
49 | void handle_IRQ(unsigned int irq, struct pt_regs *regs) | |
50 | { | |
51 | struct pt_regs *old_regs = set_irq_regs(regs); | |
52 | ||
53 | irq_enter(); | |
54 | ||
55 | /* | |
56 | * Some hardware gives randomly wrong interrupts. Rather | |
57 | * than crashing, do something sensible. | |
58 | */ | |
59 | if (unlikely(irq >= nr_irqs)) { | |
60 | pr_warn_ratelimited("Bad IRQ%u\n", irq); | |
61 | ack_bad_irq(irq); | |
62 | } else { | |
63 | generic_handle_irq(irq); | |
64 | } | |
65 | ||
66 | irq_exit(); | |
67 | set_irq_regs(old_regs); | |
68 | } | |
69 | ||
e851b58c CM |
70 | void __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) |
71 | { | |
72 | if (handle_arch_irq) | |
73 | return; | |
74 | ||
75 | handle_arch_irq = handle_irq; | |
76 | } | |
fb9bd7d6 MZ |
77 | |
78 | void __init init_IRQ(void) | |
79 | { | |
e851b58c | 80 | irqchip_init(); |
fb9bd7d6 MZ |
81 | if (!handle_arch_irq) |
82 | panic("No interrupt controller found."); | |
83 | } | |
9327e2c6 MR |
84 | |
85 | #ifdef CONFIG_HOTPLUG_CPU | |
86 | static bool migrate_one_irq(struct irq_desc *desc) | |
87 | { | |
88 | struct irq_data *d = irq_desc_get_irq_data(desc); | |
89 | const struct cpumask *affinity = d->affinity; | |
90 | struct irq_chip *c; | |
91 | bool ret = false; | |
92 | ||
93 | /* | |
94 | * If this is a per-CPU interrupt, or the affinity does not | |
95 | * include this CPU, then we have nothing to do. | |
96 | */ | |
97 | if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) | |
98 | return false; | |
99 | ||
601c9421 | 100 | if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) |
9327e2c6 | 101 | ret = true; |
9327e2c6 | 102 | |
601c9421 SH |
103 | /* |
104 | * when using forced irq_set_affinity we must ensure that the cpu | |
105 | * being offlined is not present in the affinity mask, it may be | |
106 | * selected as the target CPU otherwise | |
107 | */ | |
108 | affinity = cpu_online_mask; | |
9327e2c6 MR |
109 | c = irq_data_get_irq_chip(d); |
110 | if (!c->irq_set_affinity) | |
111 | pr_debug("IRQ%u: unable to set affinity\n", d->irq); | |
112 | else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret) | |
113 | cpumask_copy(d->affinity, affinity); | |
114 | ||
115 | return ret; | |
116 | } | |
117 | ||
118 | /* | |
119 | * The current CPU has been marked offline. Migrate IRQs off this CPU. | |
120 | * If the affinity settings do not allow other CPUs, force them onto any | |
121 | * available CPU. | |
122 | * | |
123 | * Note: we must iterate over all IRQs, whether they have an attached | |
124 | * action structure or not, as we need to get chained interrupts too. | |
125 | */ | |
126 | void migrate_irqs(void) | |
127 | { | |
128 | unsigned int i; | |
129 | struct irq_desc *desc; | |
130 | unsigned long flags; | |
131 | ||
132 | local_irq_save(flags); | |
133 | ||
134 | for_each_irq_desc(i, desc) { | |
135 | bool affinity_broken; | |
136 | ||
137 | raw_spin_lock(&desc->lock); | |
138 | affinity_broken = migrate_one_irq(desc); | |
139 | raw_spin_unlock(&desc->lock); | |
140 | ||
141 | if (affinity_broken) | |
142 | pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", | |
143 | i, smp_processor_id()); | |
144 | } | |
145 | ||
146 | local_irq_restore(flags); | |
147 | } | |
148 | #endif /* CONFIG_HOTPLUG_CPU */ |