1 /* 2 * linux/arch/arm/kernel/irq.c 3 * 4 * Copyright (C) 1992 Linus Torvalds 5 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King. 6 * 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>. 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 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 19 * should be easier. 20 * 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. 23 */ 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/ratelimit.h> 35 #include <linux/errno.h> 36 #include <linux/list.h> 37 #include <linux/kallsyms.h> 38 #include <linux/proc_fs.h> 39 #include <linux/export.h> 40 41 #include <asm/hardware/cache-l2x0.h> 42 #include <asm/outercache.h> 43 #include <asm/exception.h> 44 #include <asm/mach/arch.h> 45 #include <asm/mach/irq.h> 46 #include <asm/mach/time.h> 47 48 unsigned long irq_err_count; 49 50 int arch_show_interrupts(struct seq_file *p, int prec) 51 { 52 #ifdef CONFIG_FIQ 53 show_fiq_list(p, prec); 54 #endif 55 #ifdef CONFIG_SMP 56 show_ipi_list(p, prec); 57 #endif 58 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); 59 return 0; 60 } 61 62 /* 63 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should 64 * not come via this function. Instead, they should provide their 65 * own 'handler'. Used by platform code implementing C-based 1st 66 * level decoding. 67 */ 68 void handle_IRQ(unsigned int irq, struct pt_regs *regs) 69 { 70 __handle_domain_irq(NULL, irq, false, regs); 71 } 72 73 /* 74 * asm_do_IRQ is the interface to be used from assembly code. 75 */ 76 asmlinkage void __exception_irq_entry 77 asm_do_IRQ(unsigned int irq, struct pt_regs *regs) 78 { 79 handle_IRQ(irq, regs); 80 } 81 82 void __init init_IRQ(void) 83 { 84 int ret; 85 86 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq) 87 irqchip_init(); 88 else 89 machine_desc->init_irq(); 90 91 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) && 92 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) { 93 if (!outer_cache.write_sec) 94 outer_cache.write_sec = machine_desc->l2c_write_sec; 95 ret = l2x0_of_init(machine_desc->l2c_aux_val, 96 machine_desc->l2c_aux_mask); 97 if (ret) 98 pr_err("L2C: failed to init: %d\n", ret); 99 } 100 } 101 102 #ifdef CONFIG_MULTI_IRQ_HANDLER 103 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) 104 { 105 if (handle_arch_irq) 106 return; 107 108 handle_arch_irq = handle_irq; 109 } 110 #endif 111 112 #ifdef CONFIG_SPARSE_IRQ 113 int __init arch_probe_nr_irqs(void) 114 { 115 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS; 116 return nr_irqs; 117 } 118 #endif 119 120 #ifdef CONFIG_HOTPLUG_CPU 121 static bool migrate_one_irq(struct irq_desc *desc) 122 { 123 struct irq_data *d = irq_desc_get_irq_data(desc); 124 const struct cpumask *affinity = irq_data_get_affinity_mask(d); 125 struct irq_chip *c; 126 bool ret = false; 127 128 /* 129 * If this is a per-CPU interrupt, or the affinity does not 130 * include this CPU, then we have nothing to do. 131 */ 132 if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) 133 return false; 134 135 if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { 136 affinity = cpu_online_mask; 137 ret = true; 138 } 139 140 c = irq_data_get_irq_chip(d); 141 if (!c->irq_set_affinity) 142 pr_debug("IRQ%u: unable to set affinity\n", d->irq); 143 else if (c->irq_set_affinity(d, affinity, false) == IRQ_SET_MASK_OK && ret) 144 cpumask_copy(irq_data_get_affinity_mask(d), affinity); 145 146 return ret; 147 } 148 149 /* 150 * The current CPU has been marked offline. Migrate IRQs off this CPU. 151 * If the affinity settings do not allow other CPUs, force them onto any 152 * available CPU. 153 * 154 * Note: we must iterate over all IRQs, whether they have an attached 155 * action structure or not, as we need to get chained interrupts too. 156 */ 157 void migrate_irqs(void) 158 { 159 unsigned int i; 160 struct irq_desc *desc; 161 unsigned long flags; 162 163 local_irq_save(flags); 164 165 for_each_irq_desc(i, desc) { 166 bool affinity_broken; 167 168 raw_spin_lock(&desc->lock); 169 affinity_broken = migrate_one_irq(desc); 170 raw_spin_unlock(&desc->lock); 171 172 if (affinity_broken) 173 pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", 174 i, smp_processor_id()); 175 } 176 177 local_irq_restore(flags); 178 } 179 #endif /* CONFIG_HOTPLUG_CPU */ 180