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 EXPORT_SYMBOL_GPL(allocate_irqno); 48 49 /* 50 * Allocate the 16 legacy interrupts for i8259 devices. This happens early 51 * in the kernel initialization so treating allocation failure as BUG() is 52 * ok. 53 */ 54 void __init alloc_legacy_irqno(void) 55 { 56 int i; 57 58 for (i = 0; i <= 16; i++) 59 BUG_ON(test_and_set_bit(i, irq_map)); 60 } 61 62 void free_irqno(unsigned int irq) 63 { 64 smp_mb__before_clear_bit(); 65 clear_bit(irq, irq_map); 66 smp_mb__after_clear_bit(); 67 } 68 69 EXPORT_SYMBOL_GPL(free_irqno); 70 71 /* 72 * 'what should we do if we get a hw irq event on an illegal vector'. 73 * each architecture has to answer this themselves. 74 */ 75 void ack_bad_irq(unsigned int irq) 76 { 77 smtc_im_ack_irq(irq); 78 printk("unexpected IRQ # %d\n", irq); 79 } 80 81 atomic_t irq_err_count; 82 83 /* 84 * Generic, controller-independent functions: 85 */ 86 87 int show_interrupts(struct seq_file *p, void *v) 88 { 89 int i = *(loff_t *) v, j; 90 struct irqaction * action; 91 unsigned long flags; 92 93 if (i == 0) { 94 seq_printf(p, " "); 95 for_each_online_cpu(j) 96 seq_printf(p, "CPU%d ", j); 97 seq_putc(p, '\n'); 98 } 99 100 if (i < NR_IRQS) { 101 spin_lock_irqsave(&irq_desc[i].lock, flags); 102 action = irq_desc[i].action; 103 if (!action) 104 goto skip; 105 seq_printf(p, "%3d: ", i); 106 #ifndef CONFIG_SMP 107 seq_printf(p, "%10u ", kstat_irqs(i)); 108 #else 109 for_each_online_cpu(j) 110 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 111 #endif 112 seq_printf(p, " %14s", irq_desc[i].chip->name); 113 seq_printf(p, " %s", action->name); 114 115 for (action=action->next; action; action = action->next) 116 seq_printf(p, ", %s", action->name); 117 118 seq_putc(p, '\n'); 119 skip: 120 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 121 } else if (i == NR_IRQS) { 122 seq_putc(p, '\n'); 123 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 124 } 125 return 0; 126 } 127 128 asmlinkage void spurious_interrupt(void) 129 { 130 atomic_inc(&irq_err_count); 131 } 132 133 #ifdef CONFIG_KGDB 134 extern void breakpoint(void); 135 extern void set_debug_traps(void); 136 137 static int kgdb_flag = 1; 138 static int __init nokgdb(char *str) 139 { 140 kgdb_flag = 0; 141 return 1; 142 } 143 __setup("nokgdb", nokgdb); 144 #endif 145 146 void __init init_IRQ(void) 147 { 148 arch_init_irq(); 149 150 #ifdef CONFIG_KGDB 151 if (kgdb_flag) { 152 printk("Wait for gdb client connection ...\n"); 153 set_debug_traps(); 154 breakpoint(); 155 } 156 #endif 157 } 158