1 /*
2  *
3  *	linux/arch/cris/kernel/irq.c
4  *
5  *      Copyright (c) 2000,2007 Axis Communications AB
6  *
7  *      Authors: Bjorn Wesen (bjornw@axis.com)
8  *
9  * This file contains the code used by various IRQ handling routines:
10  * asking for different IRQs should be done through these routines
11  * instead of just grabbing them. Thus setups with different IRQ numbers
12  * shouldn't result in any weird surprises, and installing new handlers
13  * should be easier.
14  *
15  */
16 
17 /*
18  * IRQs are in fact implemented a bit like signal handlers for the kernel.
19  * Naturally it's not a 1:1 relation, but there are similarities.
20  */
21 
22 #include <linux/module.h>
23 #include <linux/ptrace.h>
24 #include <linux/irq.h>
25 
26 #include <linux/kernel_stat.h>
27 #include <linux/signal.h>
28 #include <linux/sched.h>
29 #include <linux/ioport.h>
30 #include <linux/interrupt.h>
31 #include <linux/timex.h>
32 #include <linux/random.h>
33 #include <linux/init.h>
34 #include <linux/seq_file.h>
35 #include <linux/errno.h>
36 #include <linux/spinlock.h>
37 
38 #include <asm/io.h>
39 
40 /* called by the assembler IRQ entry functions defined in irq.h
41  * to dispatch the interrupts to registered handlers
42  * interrupts are disabled upon entry - depending on if the
43  * interrupt was registered with IRQF_DISABLED or not, interrupts
44  * are re-enabled or not.
45  */
46 
do_IRQ(int irq,struct pt_regs * regs)47 asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
48 {
49 	unsigned long sp;
50 	struct pt_regs *old_regs = set_irq_regs(regs);
51 	irq_enter();
52 	sp = rdsp();
53 	if (unlikely((sp & (PAGE_SIZE - 1)) < (PAGE_SIZE/8))) {
54 		printk("do_IRQ: stack overflow: %lX\n", sp);
55 		show_stack(NULL, (unsigned long *)sp);
56 	}
57 	generic_handle_irq(irq);
58 	irq_exit();
59 	set_irq_regs(old_regs);
60 }
61 
weird_irq(void)62 void weird_irq(void)
63 {
64 	local_irq_disable();
65 	printk("weird irq\n");
66 	while(1);
67 }
68 
69