xref: /linux/arch/mips/kernel/irq.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 #ifdef CONFIG_MIPS_MT_SMTC
42 /*
43  * SMTC Kernel needs to manipulate low-level CPU interrupt mask
44  * in do_IRQ. These are passed in setup_irq_smtc() and stored
45  * in this table.
46  */
47 unsigned long irq_hwmask[NR_IRQS];
48 #endif /* CONFIG_MIPS_MT_SMTC */
49 
50 #undef do_IRQ
51 
52 /*
53  * do_IRQ handles all normal device IRQ's (the special
54  * SMP cross-CPU interrupts have their own specific
55  * handlers).
56  */
57 asmlinkage unsigned int do_IRQ(unsigned int irq, struct pt_regs *regs)
58 {
59 	irq_enter();
60 
61 	__DO_IRQ_SMTC_HOOK();
62 	__do_IRQ(irq, regs);
63 
64 	irq_exit();
65 
66 	return 1;
67 }
68 
69 /*
70  * Generic, controller-independent functions:
71  */
72 
73 int show_interrupts(struct seq_file *p, void *v)
74 {
75 	int i = *(loff_t *) v, j;
76 	struct irqaction * action;
77 	unsigned long flags;
78 
79 	if (i == 0) {
80 		seq_printf(p, "           ");
81 		for_each_online_cpu(j)
82 			seq_printf(p, "CPU%d       ",j);
83 		seq_putc(p, '\n');
84 	}
85 
86 	if (i < NR_IRQS) {
87 		spin_lock_irqsave(&irq_desc[i].lock, flags);
88 		action = irq_desc[i].action;
89 		if (!action)
90 			goto skip;
91 		seq_printf(p, "%3d: ",i);
92 #ifndef CONFIG_SMP
93 		seq_printf(p, "%10u ", kstat_irqs(i));
94 #else
95 		for_each_online_cpu(j)
96 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
97 #endif
98 		seq_printf(p, " %14s", irq_desc[i].handler->typename);
99 		seq_printf(p, "  %s", action->name);
100 
101 		for (action=action->next; action; action = action->next)
102 			seq_printf(p, ", %s", action->name);
103 
104 		seq_putc(p, '\n');
105 skip:
106 		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
107 	} else if (i == NR_IRQS) {
108 		seq_putc(p, '\n');
109 		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
110 	}
111 	return 0;
112 }
113 
114 asmlinkage void spurious_interrupt(struct pt_regs *regs)
115 {
116 	atomic_inc(&irq_err_count);
117 }
118 
119 #ifdef CONFIG_KGDB
120 extern void breakpoint(void);
121 extern void set_debug_traps(void);
122 
123 static int kgdb_flag = 1;
124 static int __init nokgdb(char *str)
125 {
126 	kgdb_flag = 0;
127 	return 1;
128 }
129 __setup("nokgdb", nokgdb);
130 #endif
131 
132 void __init init_IRQ(void)
133 {
134 	int i;
135 
136 	for (i = 0; i < NR_IRQS; i++) {
137 		irq_desc[i].status  = IRQ_DISABLED;
138 		irq_desc[i].action  = NULL;
139 		irq_desc[i].depth   = 1;
140 		irq_desc[i].handler = &no_irq_type;
141 		spin_lock_init(&irq_desc[i].lock);
142 #ifdef CONFIG_MIPS_MT_SMTC
143 		irq_hwmask[i] = 0;
144 #endif /* CONFIG_MIPS_MT_SMTC */
145 	}
146 
147 	arch_init_irq();
148 
149 #ifdef CONFIG_KGDB
150 	if (kgdb_flag) {
151 		printk("Wait for gdb client connection ...\n");
152 		set_debug_traps();
153 		breakpoint();
154 	}
155 #endif
156 }
157