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 void (*handle_arch_irq)(struct pt_regs *) = NULL; 44 45 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) 46 { 47 if (handle_arch_irq) 48 return; 49 50 handle_arch_irq = handle_irq; 51 } 52 53 void __init init_IRQ(void) 54 { 55 irqchip_init(); 56 if (!handle_arch_irq) 57 panic("No interrupt controller found."); 58 } 59 60 #ifdef CONFIG_HOTPLUG_CPU 61 static bool migrate_one_irq(struct irq_desc *desc) 62 { 63 struct irq_data *d = irq_desc_get_irq_data(desc); 64 const struct cpumask *affinity = d->affinity; 65 struct irq_chip *c; 66 bool ret = false; 67 68 /* 69 * If this is a per-CPU interrupt, or the affinity does not 70 * include this CPU, then we have nothing to do. 71 */ 72 if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) 73 return false; 74 75 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { 76 affinity = cpu_online_mask; 77 ret = true; 78 } 79 80 c = irq_data_get_irq_chip(d); 81 if (!c->irq_set_affinity) 82 pr_debug("IRQ%u: unable to set affinity\n", d->irq); 83 else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret) 84 cpumask_copy(d->affinity, affinity); 85 86 return ret; 87 } 88 89 /* 90 * The current CPU has been marked offline. Migrate IRQs off this CPU. 91 * If the affinity settings do not allow other CPUs, force them onto any 92 * available CPU. 93 * 94 * Note: we must iterate over all IRQs, whether they have an attached 95 * action structure or not, as we need to get chained interrupts too. 96 */ 97 void migrate_irqs(void) 98 { 99 unsigned int i; 100 struct irq_desc *desc; 101 unsigned long flags; 102 103 local_irq_save(flags); 104 105 for_each_irq_desc(i, desc) { 106 bool affinity_broken; 107 108 raw_spin_lock(&desc->lock); 109 affinity_broken = migrate_one_irq(desc); 110 raw_spin_unlock(&desc->lock); 111 112 if (affinity_broken) 113 pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", 114 i, smp_processor_id()); 115 } 116 117 local_irq_restore(flags); 118 } 119 #endif /* CONFIG_HOTPLUG_CPU */ 120