1 /* 2 * linux/arch/alpha/kernel/irq.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * 6 * This file contains the code used by various IRQ handling routines: 7 * asking for different IRQ's should be done through these routines 8 * instead of just grabbing them. Thus setups with different IRQ numbers 9 * shouldn't result in any weird surprises, and installing new handlers 10 * should be easier. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/errno.h> 16 #include <linux/kernel_stat.h> 17 #include <linux/signal.h> 18 #include <linux/sched.h> 19 #include <linux/ptrace.h> 20 #include <linux/interrupt.h> 21 #include <linux/random.h> 22 #include <linux/init.h> 23 #include <linux/irq.h> 24 #include <linux/proc_fs.h> 25 #include <linux/seq_file.h> 26 #include <linux/profile.h> 27 #include <linux/bitops.h> 28 29 #include <asm/system.h> 30 #include <asm/io.h> 31 #include <asm/uaccess.h> 32 33 volatile unsigned long irq_err_count; 34 DEFINE_PER_CPU(unsigned long, irq_pmi_count); 35 36 void ack_bad_irq(unsigned int irq) 37 { 38 irq_err_count++; 39 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq); 40 } 41 42 #ifdef CONFIG_SMP 43 static char irq_user_affinity[NR_IRQS]; 44 45 int irq_select_affinity(unsigned int irq) 46 { 47 struct irq_desc *desc = irq_to_desc[irq]; 48 static int last_cpu; 49 int cpu = last_cpu + 1; 50 51 if (!desc || !get_irq_desc_chip(desc)->set_affinity || irq_user_affinity[irq]) 52 return 1; 53 54 while (!cpu_possible(cpu) || 55 !cpumask_test_cpu(cpu, irq_default_affinity)) 56 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0); 57 last_cpu = cpu; 58 59 cpumask_copy(desc->affinity, cpumask_of(cpu)); 60 get_irq_desc_chip(desc)->set_affinity(irq, cpumask_of(cpu)); 61 return 0; 62 } 63 #endif /* CONFIG_SMP */ 64 65 int 66 show_interrupts(struct seq_file *p, void *v) 67 { 68 int j; 69 int irq = *(loff_t *) v; 70 struct irqaction * action; 71 struct irq_desc *desc; 72 unsigned long flags; 73 74 #ifdef CONFIG_SMP 75 if (irq == 0) { 76 seq_puts(p, " "); 77 for_each_online_cpu(j) 78 seq_printf(p, "CPU%d ", j); 79 seq_putc(p, '\n'); 80 } 81 #endif 82 83 if (irq < ACTUAL_NR_IRQS) { 84 desc = irq_to_desc(irq); 85 86 if (!desc) 87 return 0; 88 89 raw_spin_lock_irqsave(&desc->lock, flags); 90 action = desc->action; 91 if (!action) 92 goto unlock; 93 seq_printf(p, "%3d: ", irq); 94 #ifndef CONFIG_SMP 95 seq_printf(p, "%10u ", kstat_irqs(irq)); 96 #else 97 for_each_online_cpu(j) 98 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j)); 99 #endif 100 seq_printf(p, " %14s", get_irq_desc_chip(desc)->name); 101 seq_printf(p, " %c%s", 102 (action->flags & IRQF_DISABLED)?'+':' ', 103 action->name); 104 105 for (action=action->next; action; action = action->next) { 106 seq_printf(p, ", %c%s", 107 (action->flags & IRQF_DISABLED)?'+':' ', 108 action->name); 109 } 110 111 seq_putc(p, '\n'); 112 unlock: 113 raw_spin_unlock_irqrestore(&desc->lock, flags); 114 } else if (irq == ACTUAL_NR_IRQS) { 115 #ifdef CONFIG_SMP 116 seq_puts(p, "IPI: "); 117 for_each_online_cpu(j) 118 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 119 seq_putc(p, '\n'); 120 #endif 121 seq_puts(p, "PMI: "); 122 for_each_online_cpu(j) 123 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j)); 124 seq_puts(p, " Performance Monitoring\n"); 125 seq_printf(p, "ERR: %10lu\n", irq_err_count); 126 } 127 return 0; 128 } 129 130 /* 131 * handle_irq handles all normal device IRQ's (the special 132 * SMP cross-CPU interrupts have their own specific 133 * handlers). 134 */ 135 136 #define MAX_ILLEGAL_IRQS 16 137 138 void 139 handle_irq(int irq) 140 { 141 /* 142 * We ack quickly, we don't want the irq controller 143 * thinking we're snobs just because some other CPU has 144 * disabled global interrupts (we have already done the 145 * INT_ACK cycles, it's too late to try to pretend to the 146 * controller that we aren't taking the interrupt). 147 * 148 * 0 return value means that this irq is already being 149 * handled by some other CPU. (or is disabled) 150 */ 151 static unsigned int illegal_count=0; 152 struct irq_desc *desc = irq_to_desc(irq); 153 154 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS && 155 illegal_count < MAX_ILLEGAL_IRQS)) { 156 irq_err_count++; 157 illegal_count++; 158 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 159 irq); 160 return; 161 } 162 163 /* 164 * From here we must proceed with IPL_MAX. Note that we do not 165 * explicitly enable interrupts afterwards - some MILO PALcode 166 * (namely LX164 one) seems to have severe problems with RTI 167 * at IPL 0. 168 */ 169 local_irq_disable(); 170 irq_enter(); 171 generic_handle_irq_desc(irq, desc); 172 irq_exit(); 173 } 174