1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Code to handle x86 style IRQs plus some generic interrupt stuff. 7 * 8 * Copyright (C) 1992 Linus Torvalds 9 * Copyright (C) 1994 - 2000 Ralf Baechle 10 */ 11 #include <linux/kernel.h> 12 #include <linux/delay.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/kernel_stat.h> 16 #include <linux/module.h> 17 #include <linux/proc_fs.h> 18 #include <linux/slab.h> 19 #include <linux/mm.h> 20 #include <linux/random.h> 21 #include <linux/sched.h> 22 #include <linux/seq_file.h> 23 #include <linux/kallsyms.h> 24 25 #include <asm/atomic.h> 26 #include <asm/system.h> 27 #include <asm/uaccess.h> 28 29 static unsigned long irq_map[NR_IRQS / BITS_PER_LONG]; 30 31 int allocate_irqno(void) 32 { 33 int irq; 34 35 again: 36 irq = find_first_zero_bit(irq_map, NR_IRQS); 37 38 if (irq >= NR_IRQS) 39 return -ENOSPC; 40 41 if (test_and_set_bit(irq, irq_map)) 42 goto again; 43 44 return irq; 45 } 46 47 /* 48 * Allocate the 16 legacy interrupts for i8259 devices. This happens early 49 * in the kernel initialization so treating allocation failure as BUG() is 50 * ok. 51 */ 52 void __init alloc_legacy_irqno(void) 53 { 54 int i; 55 56 for (i = 0; i <= 16; i++) 57 BUG_ON(test_and_set_bit(i, irq_map)); 58 } 59 60 void free_irqno(unsigned int irq) 61 { 62 smp_mb__before_clear_bit(); 63 clear_bit(irq, irq_map); 64 smp_mb__after_clear_bit(); 65 } 66 67 /* 68 * 'what should we do if we get a hw irq event on an illegal vector'. 69 * each architecture has to answer this themselves. 70 */ 71 void ack_bad_irq(unsigned int irq) 72 { 73 smtc_im_ack_irq(irq); 74 printk("unexpected IRQ # %d\n", irq); 75 } 76 77 atomic_t irq_err_count; 78 79 /* 80 * Generic, controller-independent functions: 81 */ 82 83 int show_interrupts(struct seq_file *p, void *v) 84 { 85 int i = *(loff_t *) v, j; 86 struct irqaction * action; 87 unsigned long flags; 88 89 if (i == 0) { 90 seq_printf(p, " "); 91 for_each_online_cpu(j) 92 seq_printf(p, "CPU%d ", j); 93 seq_putc(p, '\n'); 94 } 95 96 if (i < NR_IRQS) { 97 spin_lock_irqsave(&irq_desc[i].lock, flags); 98 action = irq_desc[i].action; 99 if (!action) 100 goto skip; 101 seq_printf(p, "%3d: ", i); 102 #ifndef CONFIG_SMP 103 seq_printf(p, "%10u ", kstat_irqs(i)); 104 #else 105 for_each_online_cpu(j) 106 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 107 #endif 108 seq_printf(p, " %14s", irq_desc[i].chip->name); 109 seq_printf(p, " %s", action->name); 110 111 for (action=action->next; action; action = action->next) 112 seq_printf(p, ", %s", action->name); 113 114 seq_putc(p, '\n'); 115 skip: 116 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 117 } else if (i == NR_IRQS) { 118 seq_putc(p, '\n'); 119 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 120 } 121 return 0; 122 } 123 124 asmlinkage void spurious_interrupt(void) 125 { 126 atomic_inc(&irq_err_count); 127 } 128 129 #ifdef CONFIG_KGDB 130 extern void breakpoint(void); 131 extern void set_debug_traps(void); 132 133 static int kgdb_flag = 1; 134 static int __init nokgdb(char *str) 135 { 136 kgdb_flag = 0; 137 return 1; 138 } 139 __setup("nokgdb", nokgdb); 140 #endif 141 142 void __init init_IRQ(void) 143 { 144 int i; 145 146 for (i = 0; i < NR_IRQS; i++) 147 set_irq_noprobe(i); 148 149 arch_init_irq(); 150 151 #ifdef CONFIG_KGDB 152 if (kgdb_flag) { 153 printk("Wait for gdb client connection ...\n"); 154 set_debug_traps(); 155 breakpoint(); 156 } 157 #endif 158 } 159