aboutsummaryrefslogtreecommitdiff
path: root/arch/blackfin/kernel/irqchip.c
blob: 1fc001c7abdac10b22be68d12b89c6be3638a69f (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
/*
 * File:         arch/blackfin/kernel/irqchip.c
 * Based on:
 * Author:
 *
 * Created:
 * Description:  This file contains the simple DMA Implementation for Blackfin
 *
 * Modified:
 *               Copyright 2004-2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

static unsigned long irq_err_count;
static spinlock_t irq_controller_lock;

/*
 * Dummy mask/unmask handler
 */
void dummy_mask_unmask_irq(unsigned int irq)
{
}

void ack_bad_irq(unsigned int irq)
{
	irq_err_count += 1;
	printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
}
EXPORT_SYMBOL(ack_bad_irq);

static struct irq_chip bad_chip = {
	.ack = dummy_mask_unmask_irq,
	.mask = dummy_mask_unmask_irq,
	.unmask = dummy_mask_unmask_irq,
};

static struct irq_desc bad_irq_desc = {
	.chip = &bad_chip,
	.handle_irq = handle_bad_irq,
	.depth = 1,
};

int show_interrupts(struct seq_file *p, void *v)
{
	int i = *(loff_t *) v;
	struct irqaction *action;
	unsigned long flags;

	if (i < NR_IRQS) {
		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto unlock;

		seq_printf(p, "%3d: %10u ", i, kstat_irqs(i));
		seq_printf(p, "  %s", action->name);
		for (action = action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
 unlock:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	} else if (i == NR_IRQS) {
		seq_printf(p, "Err: %10lu\n", irq_err_count);
	}
	return 0;
}

/*
 * do_IRQ handles all hardware IRQs.  Decoded IRQs should not
 * come via this function.  Instead, they should provide their
 * own 'handler'
 */

#ifdef CONFIG_DO_IRQ_L1
asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)__attribute__((l1_text));
#endif

asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
{
	struct pt_regs *old_regs;
	struct irq_desc *desc = irq_desc + irq;
	unsigned short pending, other_ints;

	old_regs = set_irq_regs(regs);

	/*
	 * Some hardware gives randomly wrong interrupts.  Rather
	 * than crashing, do something sensible.
	 */
	if (irq >= NR_IRQS)
		desc = &bad_irq_desc;

	irq_enter();

	generic_handle_irq(irq);

	/* If we're the only interrupt running (ignoring IRQ15 which is for
	   syscalls), lower our priority to IRQ14 so that softirqs run at
	   that level.  If there's another, lower-level interrupt, irq_exit
	   will defer softirqs to that.  */
	CSYNC();
	pending = bfin_read_IPEND() & ~0x8000;
	other_ints = pending & (pending - 1);
	if (other_ints == 0)
		lower_to_irq14();
	irq_exit();

	set_irq_regs(old_regs);
}

void __init init_IRQ(void)
{
	struct irq_desc *desc;
	int irq;

	spin_lock_init(&irq_controller_lock);
	for (irq = 0, desc = irq_desc; irq < NR_IRQS; irq++, desc++) {
		*desc = bad_irq_desc;
	}

	init_arch_irq();
}