summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/irq.c
blob: 0f08dfd69ebc73ea99b7b7f6d68c4b2f320eb2d1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/*
 * Based on arch/arm/kernel/irq.c
 *
 * Copyright (C) 1992 Linus Torvalds
 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel_stat.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/irqchip.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>

unsigned long irq_err_count;

int arch_show_interrupts(struct seq_file *p, int prec)
{
#ifdef CONFIG_SMP
	show_ipi_list(p, prec);
#endif
	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
	return 0;
}

/*
 * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
 * not come via this function.  Instead, they should provide their
 * own 'handler'.  Used by platform code implementing C-based 1st
 * level decoding.
 */
void handle_IRQ(unsigned int irq, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);

	irq_enter();

	/*
	 * Some hardware gives randomly wrong interrupts.  Rather
	 * than crashing, do something sensible.
	 */
	if (unlikely(irq >= nr_irqs)) {
		pr_warn_ratelimited("Bad IRQ%u\n", irq);
		ack_bad_irq(irq);
	} else {
		generic_handle_irq(irq);
	}

	irq_exit();
	set_irq_regs(old_regs);
}

void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
{
	if (handle_arch_irq)
		return;

	handle_arch_irq = handle_irq;
}

void __init init_IRQ(void)
{
	irqchip_init();
	if (!handle_arch_irq)
		panic("No interrupt controller found.");
}

#ifdef CONFIG_HOTPLUG_CPU
static bool migrate_one_irq(struct irq_desc *desc)
{
	struct irq_data *d = irq_desc_get_irq_data(desc);
	const struct cpumask *affinity = d->affinity;
	struct irq_chip *c;
	bool ret = false;

	/*
	 * If this is a per-CPU interrupt, or the affinity does not
	 * include this CPU, then we have nothing to do.
	 */
	if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
		return false;

	if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids)
		ret = true;

	/*
	 * when using forced irq_set_affinity we must ensure that the cpu
	 * being offlined is not present in the affinity mask, it may be
	 * selected as the target CPU otherwise
	 */
	affinity = cpu_online_mask;
	c = irq_data_get_irq_chip(d);
	if (!c->irq_set_affinity)
		pr_debug("IRQ%u: unable to set affinity\n", d->irq);
	else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret)
		cpumask_copy(d->affinity, affinity);

	return ret;
}

/*
 * The current CPU has been marked offline.  Migrate IRQs off this CPU.
 * If the affinity settings do not allow other CPUs, force them onto any
 * available CPU.
 *
 * Note: we must iterate over all IRQs, whether they have an attached
 * action structure or not, as we need to get chained interrupts too.
 */
void migrate_irqs(void)
{
	unsigned int i;
	struct irq_desc *desc;
	unsigned long flags;

	local_irq_save(flags);

	for_each_irq_desc(i, desc) {
		bool affinity_broken;

		raw_spin_lock(&desc->lock);
		affinity_broken = migrate_one_irq(desc);
		raw_spin_unlock(&desc->lock);

		if (affinity_broken)
			pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
					    i, smp_processor_id());
	}

	local_irq_restore(flags);
}
#endif /* CONFIG_HOTPLUG_CPU */