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
6 * Code to handle x86 style IRQs plus some generic interrupt stuff.
8 * Copyright (C) 1992 Linus Torvalds
9 * Copyright (C) 1994 - 2000 Ralf Baechle
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>
20 #include <linux/random.h>
21 #include <linux/sched.h>
22 #include <linux/seq_file.h>
23 #include <linux/kallsyms.h>
24 #include <linux/kgdb.h>
25 #include <linux/ftrace.h>
27 #include <asm/atomic.h>
28 #include <asm/system.h>
29 #include <asm/uaccess.h>
35 static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
37 int allocate_irqno(void)
42 irq = find_first_zero_bit(irq_map, NR_IRQS);
47 if (test_and_set_bit(irq, irq_map))
54 * Allocate the 16 legacy interrupts for i8259 devices. This happens early
55 * in the kernel initialization so treating allocation failure as BUG() is
58 void __init alloc_legacy_irqno(void)
62 for (i = 0; i <= 16; i++)
63 BUG_ON(test_and_set_bit(i, irq_map));
66 void free_irqno(unsigned int irq)
68 smp_mb__before_clear_bit();
69 clear_bit(irq, irq_map);
70 smp_mb__after_clear_bit();
74 * 'what should we do if we get a hw irq event on an illegal vector'.
75 * each architecture has to answer this themselves.
77 void ack_bad_irq(unsigned int irq)
80 printk("unexpected IRQ # %d\n", irq);
83 atomic_t irq_err_count;
86 * Generic, controller-independent functions:
89 int show_interrupts(struct seq_file *p, void *v)
91 int i = *(loff_t *) v, j;
92 struct irqaction * action;
97 for_each_online_cpu(j)
98 seq_printf(p, "CPU%d ", j);
103 raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
104 action = irq_desc[i].action;
107 seq_printf(p, "%3d: ", i);
109 seq_printf(p, "%10u ", kstat_irqs(i));
111 for_each_online_cpu(j)
112 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
114 seq_printf(p, " %14s", irq_desc[i].chip->name);
115 seq_printf(p, " %s", action->name);
117 for (action=action->next; action; action = action->next)
118 seq_printf(p, ", %s", action->name);
122 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
123 } else if (i == NR_IRQS) {
125 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
130 asmlinkage void spurious_interrupt(void)
132 atomic_inc(&irq_err_count);
135 void __init init_IRQ(void)
140 if (kgdb_early_setup)
144 for (i = 0; i < NR_IRQS; i++)
150 if (!kgdb_early_setup)
151 kgdb_early_setup = 1;
156 * do_IRQ handles all normal device IRQ's (the special
157 * SMP cross-CPU interrupts have their own specific
160 void __irq_entry do_IRQ(unsigned int irq)
163 __DO_IRQ_SMTC_HOOK(irq);
164 generic_handle_irq(irq);
168 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
170 * To avoid inefficient and in some cases pathological re-checking of
171 * IRQ affinity, we have this variant that skips the affinity check.
174 void __irq_entry do_IRQ_no_affinity(unsigned int irq)
177 __NO_AFFINITY_IRQ_SMTC_HOOK(irq);
178 generic_handle_irq(irq);
182 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */