LXR linux/arch/arm64/kernel/irq.c

   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
  32unsigned long irq_err_count;
  33
  34int arch_show_interrupts(struct seq_file *p, int prec)
  35{
  36        show_ipi_list(p, prec);
  37        seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  38        return 0;
  39}
  40
  41void (*handle_arch_irq)(struct pt_regs *) = NULL;
  42
  43void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
  44{
  45        if (handle_arch_irq)
  46                return;
  47
  48        handle_arch_irq = handle_irq;
  49}
  50
  51void __init init_IRQ(void)
  52{
  53        irqchip_init();
  54        if (!handle_arch_irq)
  55                panic("No interrupt controller found.");
  56}
  57
  58#ifdef CONFIG_HOTPLUG_CPU
  59static bool migrate_one_irq(struct irq_desc *desc)
  60{
  61        struct irq_data *d = irq_desc_get_irq_data(desc);
  62        const struct cpumask *affinity = irq_data_get_affinity_mask(d);
  63        struct irq_chip *c;
  64        bool ret = false;
  65
  66        /*
  67         * If this is a per-CPU interrupt, or the affinity does not
  68         * include this CPU, then we have nothing to do.
  69         */
  70        if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
  71                return false;
  72
  73        if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
  74                affinity = cpu_online_mask;
  75                ret = true;
  76        }
  77
  78        c = irq_data_get_irq_chip(d);
  79        if (!c->irq_set_affinity)
  80                pr_debug("IRQ%u: unable to set affinity\n", d->irq);
  81        else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret)
  82                cpumask_copy(irq_data_get_affinity_mask(d), affinity);
  83
  84        return ret;
  85}
  86
  87/*
  88 * The current CPU has been marked offline.  Migrate IRQs off this CPU.
  89 * If the affinity settings do not allow other CPUs, force them onto any
  90 * available CPU.
  91 *
  92 * Note: we must iterate over all IRQs, whether they have an attached
  93 * action structure or not, as we need to get chained interrupts too.
  94 */
  95void migrate_irqs(void)
  96{
  97        unsigned int i;
  98        struct irq_desc *desc;
  99        unsigned long flags;
 100
 101        local_irq_save(flags);
 102
 103        for_each_irq_desc(i, desc) {
 104                bool affinity_broken;
 105
 106                raw_spin_lock(&desc->lock);
 107                affinity_broken = migrate_one_irq(desc);
 108                raw_spin_unlock(&desc->lock);
 109
 110                if (affinity_broken)
 111                        pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n",
 112                                            i, smp_processor_id());
 113        }
 114
 115        local_irq_restore(flags);
 116}
 117#endif /* CONFIG_HOTPLUG_CPU */
 118