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