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/module.h> 26 #include <linux/signal.h> 27 #include <linux/ioport.h> 28 #include <linux/interrupt.h> 29 #include <linux/irq.h> 30 #include <linux/slab.h> 31 #include <linux/random.h> 32 #include <linux/smp.h> 33 #include <linux/init.h> 34 #include <linux/seq_file.h> 35 #include <linux/errno.h> 36 #include <linux/list.h> 37 #include <linux/kallsyms.h> 38 #include <linux/proc_fs.h> 39 40 #include <asm/system.h> 41 #include <asm/mach/irq.h> 42 #include <asm/mach/time.h> 43 44 /* 45 * No architecture-specific irq_finish function defined in arm/arch/irqs.h. 46 */ 47 #ifndef irq_finish 48 #define irq_finish(irq) do { } while (0) 49 #endif 50 51 void (*init_arch_irq)(void) __initdata = NULL; 52 unsigned long irq_err_count; 53 54 int show_interrupts(struct seq_file *p, void *v) 55 { 56 int i = *(loff_t *) v, cpu; 57 struct irqaction * action; 58 unsigned long flags; 59 60 if (i == 0) { 61 char cpuname[12]; 62 63 seq_printf(p, " "); 64 for_each_present_cpu(cpu) { 65 sprintf(cpuname, "CPU%d", cpu); 66 seq_printf(p, " %10s", cpuname); 67 } 68 seq_putc(p, '\n'); 69 } 70 71 if (i < NR_IRQS) { 72 raw_spin_lock_irqsave(&irq_desc[i].lock, flags); 73 action = irq_desc[i].action; 74 if (!action) 75 goto unlock; 76 77 seq_printf(p, "%3d: ", i); 78 for_each_present_cpu(cpu) 79 seq_printf(p, "%10u ", kstat_irqs_cpu(i, cpu)); 80 seq_printf(p, " %10s", irq_desc[i].chip->name ? : "-"); 81 seq_printf(p, " %s", action->name); 82 for (action = action->next; action; action = action->next) 83 seq_printf(p, ", %s", action->name); 84 85 seq_putc(p, '\n'); 86 unlock: 87 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags); 88 } else if (i == NR_IRQS) { 89 #ifdef CONFIG_FIQ 90 show_fiq_list(p, v); 91 #endif 92 #ifdef CONFIG_SMP 93 show_ipi_list(p); 94 show_local_irqs(p); 95 #endif 96 seq_printf(p, "Err: %10lu\n", irq_err_count); 97 } 98 return 0; 99 } 100 101 /* 102 * do_IRQ handles all hardware IRQ's. Decoded IRQs should not 103 * come via this function. Instead, they should provide their 104 * own 'handler' 105 */ 106 asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs) 107 { 108 struct pt_regs *old_regs = set_irq_regs(regs); 109 110 irq_enter(); 111 112 /* 113 * Some hardware gives randomly wrong interrupts. Rather 114 * than crashing, do something sensible. 115 */ 116 if (unlikely(irq >= NR_IRQS)) { 117 if (printk_ratelimit()) 118 printk(KERN_WARNING "Bad IRQ%u\n", irq); 119 ack_bad_irq(irq); 120 } else { 121 generic_handle_irq(irq); 122 } 123 124 /* AT91 specific workaround */ 125 irq_finish(irq); 126 127 irq_exit(); 128 set_irq_regs(old_regs); 129 } 130 131 void set_irq_flags(unsigned int irq, unsigned int iflags) 132 { 133 struct irq_desc *desc; 134 unsigned long flags; 135 136 if (irq >= NR_IRQS) { 137 printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq); 138 return; 139 } 140 141 desc = irq_desc + irq; 142 raw_spin_lock_irqsave(&desc->lock, flags); 143 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; 144 if (iflags & IRQF_VALID) 145 desc->status &= ~IRQ_NOREQUEST; 146 if (iflags & IRQF_PROBE) 147 desc->status &= ~IRQ_NOPROBE; 148 if (!(iflags & IRQF_NOAUTOEN)) 149 desc->status &= ~IRQ_NOAUTOEN; 150 raw_spin_unlock_irqrestore(&desc->lock, flags); 151 } 152 153 void __init init_IRQ(void) 154 { 155 int irq; 156 157 for (irq = 0; irq < NR_IRQS; irq++) 158 irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_NOPROBE; 159 160 init_arch_irq(); 161 } 162 163 #ifdef CONFIG_HOTPLUG_CPU 164 165 static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu) 166 { 167 pr_debug("IRQ%u: moving from cpu%u to cpu%u\n", irq, desc->node, cpu); 168 169 raw_spin_lock_irq(&desc->lock); 170 desc->chip->set_affinity(irq, cpumask_of(cpu)); 171 raw_spin_unlock_irq(&desc->lock); 172 } 173 174 /* 175 * The CPU has been marked offline. Migrate IRQs off this CPU. If 176 * the affinity settings do not allow other CPUs, force them onto any 177 * available CPU. 178 */ 179 void migrate_irqs(void) 180 { 181 unsigned int i, cpu = smp_processor_id(); 182 183 for (i = 0; i < NR_IRQS; i++) { 184 struct irq_desc *desc = irq_desc + i; 185 186 if (desc->node == cpu) { 187 unsigned int newcpu = cpumask_any_and(desc->affinity, 188 cpu_online_mask); 189 if (newcpu >= nr_cpu_ids) { 190 if (printk_ratelimit()) 191 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", 192 i, cpu); 193 194 cpumask_setall(desc->affinity); 195 newcpu = cpumask_any_and(desc->affinity, 196 cpu_online_mask); 197 } 198 199 route_irq(desc, i, newcpu); 200 } 201 } 202 } 203 #endif /* CONFIG_HOTPLUG_CPU */ 204