xref: /openbmc/linux/arch/mips/kernel/irq.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/module.h>
18 #include <linux/proc_fs.h>
19 #include <linux/slab.h>
20 #include <linux/mm.h>
21 #include <linux/random.h>
22 #include <linux/sched.h>
23 #include <linux/seq_file.h>
24 #include <linux/kallsyms.h>
25 
26 #include <asm/atomic.h>
27 #include <asm/system.h>
28 #include <asm/uaccess.h>
29 
30 /*
31  * 'what should we do if we get a hw irq event on an illegal vector'.
32  * each architecture has to answer this themselves.
33  */
34 void ack_bad_irq(unsigned int irq)
35 {
36 	printk("unexpected IRQ # %d\n", irq);
37 }
38 
39 atomic_t irq_err_count;
40 
41 #undef do_IRQ
42 
43 /*
44  * do_IRQ handles all normal device IRQ's (the special
45  * SMP cross-CPU interrupts have their own specific
46  * handlers).
47  */
48 asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs)
49 {
50 	irq_enter();
51 
52 	__do_IRQ(irq, regs);
53 
54 	irq_exit();
55 
56 	return 1;
57 }
58 
59 /*
60  * Generic, controller-independent functions:
61  */
62 
63 int show_interrupts(struct seq_file *p, void *v)
64 {
65 	int i = *(loff_t *) v, j;
66 	struct irqaction * action;
67 	unsigned long flags;
68 
69 	if (i == 0) {
70 		seq_printf(p, "           ");
71 		for (j=0; j<NR_CPUS; j++)
72 			if (cpu_online(j))
73 				seq_printf(p, "CPU%d       ",j);
74 		seq_putc(p, '\n');
75 	}
76 
77 	if (i < NR_IRQS) {
78 		spin_lock_irqsave(&irq_desc[i].lock, flags);
79 		action = irq_desc[i].action;
80 		if (!action)
81 			goto skip;
82 		seq_printf(p, "%3d: ",i);
83 #ifndef CONFIG_SMP
84 		seq_printf(p, "%10u ", kstat_irqs(i));
85 #else
86 		for (j = 0; j < NR_CPUS; j++)
87 			if (cpu_online(j))
88 				seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
89 #endif
90 		seq_printf(p, " %14s", irq_desc[i].handler->typename);
91 		seq_printf(p, "  %s", action->name);
92 
93 		for (action=action->next; action; action = action->next)
94 			seq_printf(p, ", %s", action->name);
95 
96 		seq_putc(p, '\n');
97 skip:
98 		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
99 	} else if (i == NR_IRQS) {
100 		seq_putc(p, '\n');
101 		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
102 	}
103 	return 0;
104 }
105 
106 #ifdef CONFIG_KGDB
107 extern void breakpoint(void);
108 extern void set_debug_traps(void);
109 
110 static int kgdb_flag = 1;
111 static int __init nokgdb(char *str)
112 {
113 	kgdb_flag = 0;
114 	return 1;
115 }
116 __setup("nokgdb", nokgdb);
117 #endif
118 
119 void __init init_IRQ(void)
120 {
121 	int i;
122 
123 	for (i = 0; i < NR_IRQS; i++) {
124 		irq_desc[i].status  = IRQ_DISABLED;
125 		irq_desc[i].action  = NULL;
126 		irq_desc[i].depth   = 1;
127 		irq_desc[i].handler = &no_irq_type;
128 		spin_lock_init(&irq_desc[i].lock);
129 	}
130 
131 	arch_init_irq();
132 
133 #ifdef CONFIG_KGDB
134 	if (kgdb_flag) {
135 		printk("Wait for gdb client connection ...\n");
136 		set_debug_traps();
137 		breakpoint();
138 	}
139 #endif
140 }
141