aboutsummaryrefslogtreecommitdiff
path: root/arch/alpha/kernel/irq.c
blob: 5f2cf23c4648f9d7173fe047448459fc8ff6d752 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/*
 *	linux/arch/alpha/kernel/irq.c
 *
 *	Copyright (C) 1995 Linus Torvalds
 *
 * This file contains the code used by various IRQ handling routines:
 * asking for different IRQ's should be done through these routines
 * instead of just grabbing them. Thus setups with different IRQ numbers
 * shouldn't result in any weird surprises, and installing new handlers
 * should be easier.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/profile.h>
#include <linux/bitops.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>

volatile unsigned long irq_err_count;

void ack_bad_irq(unsigned int irq)
{
	irq_err_count++;
	printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
}

#ifdef CONFIG_SMP 
static char irq_user_affinity[NR_IRQS];

int irq_select_affinity(unsigned int irq)
{
	static int last_cpu;
	int cpu = last_cpu + 1;

	if (!irq_desc[irq].chip->set_affinity || irq_user_affinity[irq])
		return 1;

	while (!cpu_possible(cpu) ||
	       !cpumask_test_cpu(cpu, irq_default_affinity))
		cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
	last_cpu = cpu;

	cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu));
	irq_desc[irq].chip->set_affinity(irq, cpumask_of(cpu));
	return 0;
}
#endif /* CONFIG_SMP */

int
show_interrupts(struct seq_file *p, void *v)
{
#ifdef CONFIG_SMP
	int j;
#endif
	int irq = *(loff_t *) v;
	struct irqaction * action;
	unsigned long flags;

#ifdef CONFIG_SMP
	if (irq == 0) {
		seq_puts(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ", j);
		seq_putc(p, '\n');
	}
#endif

	if (irq < ACTUAL_NR_IRQS) {
		raw_spin_lock_irqsave(&irq_desc[irq].lock, flags);
		action = irq_desc[irq].action;
		if (!action) 
			goto unlock;
		seq_printf(p, "%3d: ", irq);
#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(irq));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_irqs_cpu(irq, j));
#endif
		seq_printf(p, " %14s", irq_desc[irq].chip->name);
		seq_printf(p, "  %c%s",
			(action->flags & IRQF_DISABLED)?'+':' ',
			action->name);

		for (action=action->next; action; action = action->next) {
			seq_printf(p, ", %c%s",
				  (action->flags & IRQF_DISABLED)?'+':' ',
				   action->name);
		}

		seq_putc(p, '\n');
unlock:
		raw_spin_unlock_irqrestore(&irq_desc[irq].lock, flags);
	} else if (irq == ACTUAL_NR_IRQS) {
#ifdef CONFIG_SMP
		seq_puts(p, "IPI: ");
		for_each_online_cpu(j)
			seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
		seq_putc(p, '\n');
#endif
		seq_printf(p, "ERR: %10lu\n", irq_err_count);
	}
	return 0;
}

/*
 * handle_irq handles all normal device IRQ's (the special
 * SMP cross-CPU interrupts have their own specific
 * handlers).
 */

#define MAX_ILLEGAL_IRQS 16

void
handle_irq(int irq)
{	
	/* 
	 * We ack quickly, we don't want the irq controller
	 * thinking we're snobs just because some other CPU has
	 * disabled global interrupts (we have already done the
	 * INT_ACK cycles, it's too late to try to pretend to the
	 * controller that we aren't taking the interrupt).
	 *
	 * 0 return value means that this irq is already being
	 * handled by some other CPU. (or is disabled)
	 */
	static unsigned int illegal_count=0;
	
	if ((unsigned) irq > ACTUAL_NR_IRQS && illegal_count < MAX_ILLEGAL_IRQS ) {
		irq_err_count++;
		illegal_count++;
		printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
		       irq);
		return;
	}

	irq_enter();
	/*
	 * __do_IRQ() must be called with IPL_MAX. Note that we do not
	 * explicitly enable interrupts afterwards - some MILO PALcode
	 * (namely LX164 one) seems to have severe problems with RTI
	 * at IPL 0.
	 */
	local_irq_disable();
	__do_IRQ(irq);
	irq_exit();
}