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
29static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
30
31int allocate_irqno(void)
32{
33	int irq;
34
35again:
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
47EXPORT_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 */
54void __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
62void 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
69EXPORT_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 */
75void ack_bad_irq(unsigned int irq)
76{
77	printk("unexpected IRQ # %d\n", irq);
78}
79
80atomic_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 */
88unsigned long irq_hwmask[NR_IRQS];
89#endif /* CONFIG_MIPS_MT_SMTC */
90
91/*
92 * Generic, controller-independent functions:
93 */
94
95int 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');
127skip:
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
136asmlinkage void spurious_interrupt(void)
137{
138	atomic_inc(&irq_err_count);
139}
140
141#ifdef CONFIG_KGDB
142extern void breakpoint(void);
143extern void set_debug_traps(void);
144
145static int kgdb_flag = 1;
146static int __init nokgdb(char *str)
147{
148	kgdb_flag = 0;
149	return 1;
150}
151__setup("nokgdb", nokgdb);
152#endif
153
154void __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