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 show_ipi_list(p, prec); 37 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); 38 return 0; 39 } 40 41 void (*handle_arch_irq)(struct pt_regs *) = NULL; 42 43 void __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 51 void __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 59 static 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 */ 95 void 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