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/slab.h> 22 #include <linux/random.h> 23 #include <linux/init.h> 24 #include <linux/irq.h> 25 #include <linux/proc_fs.h> 26 #include <linux/seq_file.h> 27 #include <linux/profile.h> 28 #include <linux/bitops.h> 29 30 #include <asm/system.h> 31 #include <asm/io.h> 32 #include <asm/uaccess.h> 33 34 volatile unsigned long irq_err_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) || !cpu_isset(cpu, irq_default_affinity)) 54 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0); 55 last_cpu = cpu; 56 57 irq_desc[irq].affinity = cpumask_of_cpu(cpu); 58 irq_desc[irq].chip->set_affinity(irq, cpumask_of_cpu(cpu)); 59 return 0; 60 } 61 #endif /* CONFIG_SMP */ 62 63 int 64 show_interrupts(struct seq_file *p, void *v) 65 { 66 #ifdef CONFIG_SMP 67 int j; 68 #endif 69 int irq = *(loff_t *) v; 70 struct irqaction * action; 71 unsigned long flags; 72 73 #ifdef CONFIG_SMP 74 if (irq == 0) { 75 seq_puts(p, " "); 76 for_each_online_cpu(j) 77 seq_printf(p, "CPU%d ", j); 78 seq_putc(p, '\n'); 79 } 80 #endif 81 82 if (irq < ACTUAL_NR_IRQS) { 83 spin_lock_irqsave(&irq_desc[irq].lock, flags); 84 action = irq_desc[irq].action; 85 if (!action) 86 goto unlock; 87 seq_printf(p, "%3d: ", irq); 88 #ifndef CONFIG_SMP 89 seq_printf(p, "%10u ", kstat_irqs(irq)); 90 #else 91 for_each_online_cpu(j) 92 seq_printf(p, "%10u ", kstat_cpu(j).irqs[irq]); 93 #endif 94 seq_printf(p, " %14s", irq_desc[irq].chip->typename); 95 seq_printf(p, " %c%s", 96 (action->flags & IRQF_DISABLED)?'+':' ', 97 action->name); 98 99 for (action=action->next; action; action = action->next) { 100 seq_printf(p, ", %c%s", 101 (action->flags & IRQF_DISABLED)?'+':' ', 102 action->name); 103 } 104 105 seq_putc(p, '\n'); 106 unlock: 107 spin_unlock_irqrestore(&irq_desc[irq].lock, flags); 108 } else if (irq == ACTUAL_NR_IRQS) { 109 #ifdef CONFIG_SMP 110 seq_puts(p, "IPI: "); 111 for_each_online_cpu(j) 112 seq_printf(p, "%10lu ", cpu_data[j].ipi_count); 113 seq_putc(p, '\n'); 114 #endif 115 seq_printf(p, "ERR: %10lu\n", irq_err_count); 116 } 117 return 0; 118 } 119 120 /* 121 * handle_irq handles all normal device IRQ's (the special 122 * SMP cross-CPU interrupts have their own specific 123 * handlers). 124 */ 125 126 #define MAX_ILLEGAL_IRQS 16 127 128 void 129 handle_irq(int irq) 130 { 131 /* 132 * We ack quickly, we don't want the irq controller 133 * thinking we're snobs just because some other CPU has 134 * disabled global interrupts (we have already done the 135 * INT_ACK cycles, it's too late to try to pretend to the 136 * controller that we aren't taking the interrupt). 137 * 138 * 0 return value means that this irq is already being 139 * handled by some other CPU. (or is disabled) 140 */ 141 static unsigned int illegal_count=0; 142 143 if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) { 144 irq_err_count++; 145 illegal_count++; 146 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n", 147 irq); 148 return; 149 } 150 151 irq_enter(); 152 /* 153 * __do_IRQ() must be called with IPL_MAX. Note that we do not 154 * explicitly enable interrupts afterwards - some MILO PALcode 155 * (namely LX164 one) seems to have severe problems with RTI 156 * at IPL 0. 157 */ 158 local_irq_disable(); 159 __do_IRQ(irq); 160 irq_exit(); 161 } 162