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 /* 44 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should 45 * not come via this function. Instead, they should provide their 46 * own 'handler'. Used by platform code implementing C-based 1st 47 * level decoding. 48 */ 49 void handle_IRQ(unsigned int irq, struct pt_regs *regs) 50 { 51 __handle_domain_irq(NULL, irq, false, regs); 52 } 53 54 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) 55 { 56 if (handle_arch_irq) 57 return; 58 59 handle_arch_irq = handle_irq; 60 } 61 62 void __init init_IRQ(void) 63 { 64 irqchip_init(); 65 if (!handle_arch_irq) 66 panic("No interrupt controller found."); 67 } 68 69 #ifdef CONFIG_HOTPLUG_CPU 70 static bool migrate_one_irq(struct irq_desc *desc) 71 { 72 struct irq_data *d = irq_desc_get_irq_data(desc); 73 const struct cpumask *affinity = d->affinity; 74 struct irq_chip *c; 75 bool ret = false; 76 77 /* 78 * If this is a per-CPU interrupt, or the affinity does not 79 * include this CPU, then we have nothing to do. 80 */ 81 if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) 82 return false; 83 84 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) 85 ret = true; 86 87 /* 88 * when using forced irq_set_affinity we must ensure that the cpu 89 * being offlined is not present in the affinity mask, it may be 90 * selected as the target CPU otherwise 91 */ 92 affinity = cpu_online_mask; 93 c = irq_data_get_irq_chip(d); 94 if (!c->irq_set_affinity) 95 pr_debug("IRQ%u: unable to set affinity\n", d->irq); 96 else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret) 97 cpumask_copy(d->affinity, affinity); 98 99 return ret; 100 } 101 102 /* 103 * The current CPU has been marked offline. Migrate IRQs off this CPU. 104 * If the affinity settings do not allow other CPUs, force them onto any 105 * available CPU. 106 * 107 * Note: we must iterate over all IRQs, whether they have an attached 108 * action structure or not, as we need to get chained interrupts too. 109 */ 110 void migrate_irqs(void) 111 { 112 unsigned int i; 113 struct irq_desc *desc; 114 unsigned long flags; 115 116 local_irq_save(flags); 117 118 for_each_irq_desc(i, desc) { 119 bool affinity_broken; 120 121 raw_spin_lock(&desc->lock); 122 affinity_broken = migrate_one_irq(desc); 123 raw_spin_unlock(&desc->lock); 124 125 if (affinity_broken) 126 pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", 127 i, smp_processor_id()); 128 } 129 130 local_irq_restore(flags); 131 } 132 #endif /* CONFIG_HOTPLUG_CPU */ 133