xref: /openbmc/linux/arch/arm64/kernel/irq.c (revision e851b58c)
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>
28 #include <linux/irqchip.h>
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 
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 }
77 
78 void __init init_IRQ(void)
79 {
80 	irqchip_init();
81 	if (!handle_arch_irq)
82 		panic("No interrupt controller found.");
83 }
84