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 static int last_cpu; 48 int cpu = last_cpu + 1; 49 50 if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq]) 51 return 1; 52 53 while (!cpu_possible(cpu) || 54 !cpumask_test_cpu(cpu, irq_default_affinity)) 55 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0); 56 last_cpu = cpu; 57 58 cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu)); 59 irq_desc[irq].chip->set_affinity(irq, cpumask_of(cpu)); 60 return 0; 61 } 62 #endif /* CONFIG_SMP */ 63 64 int 65 show_interrupts(struct seq_file *p, void *v) 66 { 67 int j; 68 int irq = *(loff_t *) v; 69 struct irqaction * action; 70 unsigned long flags; 71 72 #ifdef CONFIG_SMP 73 if (irq == 0) { 74 seq_puts(p, " "); 75 for_each_online_cpu(j) 76 seq_printf(p, "CPU%d ", j); 77 seq_putc(p, '\n'); 78 } 79 #endif 80 81 if (irq < ACTUAL_NR_IRQS) { 82 raw_spin_lock_irqsave(&irq_desc[irq].lock, flags); 83 action = irq_desc[irq].action; 84 if (!action) 85 goto unlock; 86 seq_printf(p, "%3d: ", irq); 87 #ifndef CONFIG_SMP 88 seq_printf(p, "%10u ", kstat_irqs(irq)); 89 #else 90 for_each_online_cpu(j) 91 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j)); 92 #endif 93 seq_printf(p, " %14s", irq_desc[irq].chip->name); 94 seq_printf(p, " %c%s", 95 (action->flags & IRQF_DISABLED)?'+':' ', 96 action->name); 97 98 for (action=action->next; action; action = action->next) { 99 seq_printf(p, ", %c%s", 100 (action->flags & IRQF_DISABLED)?'+':' ', 101 action->name); 102 } 103 104 seq_putc(p, '\n'); 105 unlock: 106 raw_spin_unlock_irqrestore(&irq_desc[irq].lock, flags); 107 } else if (irq == ACTUAL_NR_IRQS) { 108 #ifdef CONFIG_SMP 109 seq_puts(p, "IPI: "); 110 for_each_online_cpu(j) 111 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 112 seq_putc(p, '\n'); 113 #endif 114 seq_puts(p, "PMI: "); 115 for_each_online_cpu(j) 116 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j)); 117 seq_puts(p, " Performance Monitoring\n"); 118 seq_printf(p, "ERR: %10lu\n", irq_err_count); 119 } 120 return 0; 121 } 122 123 /* 124 * handle_irq handles all normal device IRQ's (the special 125 * SMP cross-CPU interrupts have their own specific 126 * handlers). 127 */ 128 129 #define MAX_ILLEGAL_IRQS 16 130 131 void 132 handle_irq(int irq) 133 { 134 /* 135 * We ack quickly, we don't want the irq controller 136 * thinking we're snobs just because some other CPU has 137 * disabled global interrupts (we have already done the 138 * INT_ACK cycles, it's too late to try to pretend to the 139 * controller that we aren't taking the interrupt). 140 * 141 * 0 return value means that this irq is already being 142 * handled by some other CPU. (or is disabled) 143 */ 144 static unsigned int illegal_count=0; 145 146 if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) { 147 irq_err_count++; 148 illegal_count++; 149 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 150 irq); 151 return; 152 } 153 154 irq_enter(); 155 /* 156 * __do_IRQ() must be called with IPL_MAX. Note that we do not 157 * explicitly enable interrupts afterwards - some MILO PALcode 158 * (namely LX164 one) seems to have severe problems with RTI 159 * at IPL 0. 160 */ 161 local_irq_disable(); 162 __do_IRQ(irq); 163 irq_exit(); 164 } 165