2 * linux/arch/arm/kernel/irq.c
4 * Copyright (C) 1992 Linus Torvalds
5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
7 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
8 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
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.
15 * This file contains the code used by various IRQ handling routines:
16 * asking for different IRQ's should be done through these routines
17 * instead of just grabbing them. Thus setups with different IRQ numbers
18 * shouldn't result in any weird surprises, and installing new handlers
21 * IRQ's are in fact implemented a bit like signal handlers for the kernel.
22 * Naturally it's not a 1:1 relation, but there are similarities.
24 #include <linux/kernel_stat.h>
25 #include <linux/signal.h>
26 #include <linux/ioport.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h>
29 #include <linux/irqchip.h>
30 #include <linux/random.h>
31 #include <linux/smp.h>
32 #include <linux/init.h>
33 #include <linux/seq_file.h>
34 #include <linux/ratelimit.h>
35 #include <linux/errno.h>
36 #include <linux/list.h>
37 #include <linux/kallsyms.h>
38 #include <linux/proc_fs.h>
39 #include <linux/export.h>
41 #include <asm/hardware/cache-l2x0.h>
42 #include <asm/outercache.h>
43 #include <asm/exception.h>
44 #include <asm/mach/arch.h>
45 #include <asm/mach/irq.h>
46 #include <asm/mach/time.h>
48 unsigned long irq_err_count;
50 int arch_show_interrupts(struct seq_file *p, int prec)
53 show_fiq_list(p, prec);
56 show_ipi_list(p, prec);
58 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
63 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
64 * not come via this function. Instead, they should provide their
65 * own 'handler'. Used by platform code implementing C-based 1st
68 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
70 __handle_domain_irq(NULL, irq, false, regs);
74 * asm_do_IRQ is the interface to be used from assembly code.
76 asmlinkage void __exception_irq_entry
77 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
79 handle_IRQ(irq, regs);
82 void __init init_IRQ(void)
86 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
89 machine_desc->init_irq();
91 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
92 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
93 if (!outer_cache.write_sec)
94 outer_cache.write_sec = machine_desc->l2c_write_sec;
95 ret = l2x0_of_init(machine_desc->l2c_aux_val,
96 machine_desc->l2c_aux_mask);
98 pr_err("L2C: failed to init: %d\n", ret);
102 #ifdef CONFIG_MULTI_IRQ_HANDLER
103 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
108 handle_arch_irq = handle_irq;
112 #ifdef CONFIG_SPARSE_IRQ
113 int __init arch_probe_nr_irqs(void)
115 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
120 #ifdef CONFIG_HOTPLUG_CPU
121 static bool migrate_one_irq(struct irq_desc *desc)
123 struct irq_data *d = irq_desc_get_irq_data(desc);
124 const struct cpumask *affinity = irq_data_get_affinity_mask(d);
129 * If this is a per-CPU interrupt, or the affinity does not
130 * include this CPU, then we have nothing to do.
132 if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
135 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
136 affinity = cpu_online_mask;
140 c = irq_data_get_irq_chip(d);
141 if (!c->irq_set_affinity)
142 pr_debug("IRQ%u: unable to set affinity\n", d->irq);
143 else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
144 cpumask_copy(irq_data_get_affinity_mask(d), affinity);
150 * The current CPU has been marked offline. Migrate IRQs off this CPU.
151 * If the affinity settings do not allow other CPUs, force them onto any
154 * Note: we must iterate over all IRQs, whether they have an attached
155 * action structure or not, as we need to get chained interrupts too.
157 void migrate_irqs(void)
160 struct irq_desc *desc;
163 local_irq_save(flags);
165 for_each_irq_desc(i, desc) {
166 bool affinity_broken;
168 raw_spin_lock(&desc->lock);
169 affinity_broken = migrate_one_irq(desc);
170 raw_spin_unlock(&desc->lock);
173 pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
174 i, smp_processor_id());
177 local_irq_restore(flags);
179 #endif /* CONFIG_HOTPLUG_CPU */