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 printk("unexpected IRQ # %d\n", irq); 78 } 79 80 atomic_t irq_err_count; 81 82 #ifdef CONFIG_MIPS_MT_SMTC 83 /* 84 * SMTC Kernel needs to manipulate low-level CPU interrupt mask 85 * in do_IRQ. These are passed in setup_irq_smtc() and stored 86 * in this table. 87 */ 88 unsigned long irq_hwmask[NR_IRQS]; 89 #endif /* CONFIG_MIPS_MT_SMTC */ 90 91 /* 92 * Generic, controller-independent functions: 93 */ 94 95 int show_interrupts(struct seq_file *p, void *v) 96 { 97 int i = *(loff_t *) v, j; 98 struct irqaction * action; 99 unsigned long flags; 100 101 if (i == 0) { 102 seq_printf(p, " "); 103 for_each_online_cpu(j) 104 seq_printf(p, "CPU%d ",j); 105 seq_putc(p, '\n'); 106 } 107 108 if (i < NR_IRQS) { 109 spin_lock_irqsave(&irq_desc[i].lock, flags); 110 action = irq_desc[i].action; 111 if (!action) 112 goto skip; 113 seq_printf(p, "%3d: ",i); 114 #ifndef CONFIG_SMP 115 seq_printf(p, "%10u ", kstat_irqs(i)); 116 #else 117 for_each_online_cpu(j) 118 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 119 #endif 120 seq_printf(p, " %14s", irq_desc[i].chip->name); 121 seq_printf(p, " %s", action->name); 122 123 for (action=action->next; action; action = action->next) 124 seq_printf(p, ", %s", action->name); 125 126 seq_putc(p, '\n'); 127 skip: 128 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 129 } else if (i == NR_IRQS) { 130 seq_putc(p, '\n'); 131 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 132 } 133 return 0; 134 } 135 136 asmlinkage void spurious_interrupt(void) 137 { 138 atomic_inc(&irq_err_count); 139 } 140 141 #ifdef CONFIG_KGDB 142 extern void breakpoint(void); 143 extern void set_debug_traps(void); 144 145 static int kgdb_flag = 1; 146 static int __init nokgdb(char *str) 147 { 148 kgdb_flag = 0; 149 return 1; 150 } 151 __setup("nokgdb", nokgdb); 152 #endif 153 154 void __init init_IRQ(void) 155 { 156 arch_init_irq(); 157 158 #ifdef CONFIG_KGDB 159 if (kgdb_flag) { 160 printk("Wait for gdb client connection ...\n"); 161 set_debug_traps(); 162 breakpoint(); 163 } 164 #endif 165 } 166