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/errno.h>
35 #include <linux/list.h>
36 #include <linux/kallsyms.h>
37 #include <linux/proc_fs.h>
38 #include <linux/export.h>
40 #include <asm/hardware/cache-l2x0.h>
41 #include <asm/exception.h>
42 #include <asm/mach/arch.h>
43 #include <asm/mach/irq.h>
44 #include <asm/mach/time.h>
46 unsigned long irq_err_count;
48 int arch_show_interrupts(struct seq_file *p, int prec)
51 show_fiq_list(p, prec);
54 show_ipi_list(p, prec);
56 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
61 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
62 * not come via this function. Instead, they should provide their
63 * own 'handler'. Used by platform code implementing C-based 1st
66 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
68 struct pt_regs *old_regs = set_irq_regs(regs);
73 * Some hardware gives randomly wrong interrupts. Rather
74 * than crashing, do something sensible.
76 if (unlikely(irq >= nr_irqs)) {
77 if (printk_ratelimit())
78 printk(KERN_WARNING "Bad IRQ%u\n", irq);
81 generic_handle_irq(irq);
85 set_irq_regs(old_regs);
89 * asm_do_IRQ is the interface to be used from assembly code.
91 asmlinkage void __exception_irq_entry
92 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
94 handle_IRQ(irq, regs);
97 void set_irq_flags(unsigned int irq, unsigned int iflags)
99 unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
101 if (irq >= nr_irqs) {
102 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
106 if (iflags & IRQF_VALID)
107 clr |= IRQ_NOREQUEST;
108 if (iflags & IRQF_PROBE)
110 if (!(iflags & IRQF_NOAUTOEN))
112 /* Order is clear bits in "clr" then set bits in "set" */
113 irq_modify_status(irq, clr, set & ~clr);
115 EXPORT_SYMBOL_GPL(set_irq_flags);
117 void __init init_IRQ(void)
121 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
124 machine_desc->init_irq();
126 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
127 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
128 outer_cache.write_sec = machine_desc->l2c_write_sec;
129 ret = l2x0_of_init(machine_desc->l2c_aux_val,
130 machine_desc->l2c_aux_mask);
132 pr_err("L2C: failed to init: %d\n", ret);
136 #ifdef CONFIG_MULTI_IRQ_HANDLER
137 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
142 handle_arch_irq = handle_irq;
146 #ifdef CONFIG_SPARSE_IRQ
147 int __init arch_probe_nr_irqs(void)
149 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
154 #ifdef CONFIG_HOTPLUG_CPU
156 static bool migrate_one_irq(struct irq_desc *desc)
158 struct irq_data *d = irq_desc_get_irq_data(desc);
159 const struct cpumask *affinity = d->affinity;
164 * If this is a per-CPU interrupt, or the affinity does not
165 * include this CPU, then we have nothing to do.
167 if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
170 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
171 affinity = cpu_online_mask;
175 c = irq_data_get_irq_chip(d);
176 if (!c->irq_set_affinity)
177 pr_debug("IRQ%u: unable to set affinity\n", d->irq);
178 else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret)
179 cpumask_copy(d->affinity, affinity);
185 * The current CPU has been marked offline. Migrate IRQs off this CPU.
186 * If the affinity settings do not allow other CPUs, force them onto any
189 * Note: we must iterate over all IRQs, whether they have an attached
190 * action structure or not, as we need to get chained interrupts too.
192 void migrate_irqs(void)
195 struct irq_desc *desc;
198 local_irq_save(flags);
200 for_each_irq_desc(i, desc) {
201 bool affinity_broken;
203 raw_spin_lock(&desc->lock);
204 affinity_broken = migrate_one_irq(desc);
205 raw_spin_unlock(&desc->lock);
207 if (affinity_broken && printk_ratelimit())
208 pr_warning("IRQ%u no longer affine to CPU%u\n", i,
212 local_irq_restore(flags);
214 #endif /* CONFIG_HOTPLUG_CPU */