aboutsummaryrefslogtreecommitdiff
path: root/arch/xtensa/kernel/irq.c
blob: 51f9bed455fab0c0576933a7702efb0d51cb84f4 (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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
 * linux/arch/xtensa/kernel/irq.c
 *
 * Xtensa built-in interrupt controller and some generic functions copied
 * from i386.
 *
 * Copyright (C) 2002 - 2005 Tensilica, Inc.
 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
 *
 *
 * Chris Zankel <chris@zankel.net>
 * Kevin Chea
 *
 */

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

#include <asm/uaccess.h>
#include <asm/platform.h>

static void enable_xtensa_irq(unsigned int irq);
static void disable_xtensa_irq(unsigned int irq);
static void mask_and_ack_xtensa(unsigned int irq);
static void end_xtensa_irq(unsigned int irq);

static unsigned int cached_irq_mask;

atomic_t irq_err_count;

/*
 * 'what should we do if we get a hw irq event on an illegal vector'.
 * each architecture has to answer this themselves.
 */
void ack_bad_irq(unsigned int irq)
{
          printk("unexpected IRQ trap at vector %02x\n", irq);
}

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

unsigned int  do_IRQ(int irq, struct pt_regs *regs)
{
	irq_enter();

#ifdef CONFIG_DEBUG_STACKOVERFLOW
	/* Debugging check for stack overflow: is there less than 1KB free? */
	{
		unsigned long sp;

		__asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
		sp &= THREAD_SIZE - 1;

		if (unlikely(sp < (sizeof(thread_info) + 1024)))
			printk("Stack overflow in do_IRQ: %ld\n",
			       sp - sizeof(struct thread_info));
	}
#endif

	__do_IRQ(irq, regs);

	irq_exit();

	return 1;
}

/*
 * Generic, controller-independent functions:
 */

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

	if (i == 0) {
		seq_printf(p, "           ");
		for_each_online_cpu(j)
			seq_printf(p, "CPU%d       ",j);
		seq_putc(p, '\n');
	}

	if (i < NR_IRQS) {
		spin_lock_irqsave(&irq_desc[i].lock, flags);
		action = irq_desc[i].action;
		if (!action)
			goto skip;
		seq_printf(p, "%3d: ",i);
#ifndef CONFIG_SMP
		seq_printf(p, "%10u ", kstat_irqs(i));
#else
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
		seq_printf(p, " %14s", irq_desc[i].handler->typename);
		seq_printf(p, "  %s", action->name);

		for (action=action->next; action; action = action->next)
			seq_printf(p, ", %s", action->name);

		seq_putc(p, '\n');
skip:
		spin_unlock_irqrestore(&irq_desc[i].lock, flags);
	} else if (i == NR_IRQS) {
		seq_printf(p, "NMI: ");
		for_each_online_cpu(j)
			seq_printf(p, "%10u ", nmi_count(j));
		seq_putc(p, '\n');
		seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
	}
	return 0;
}
/* shutdown is same as "disable" */
#define shutdown_xtensa_irq disable_xtensa_irq

static unsigned int startup_xtensa_irq(unsigned int irq)
{
	enable_xtensa_irq(irq);
	return 0;               /* never anything pending */
}

static struct hw_interrupt_type xtensa_irq_type = {
	"Xtensa-IRQ",
	startup_xtensa_irq,
	shutdown_xtensa_irq,
	enable_xtensa_irq,
	disable_xtensa_irq,
	mask_and_ack_xtensa,
	end_xtensa_irq
};

static inline void mask_irq(unsigned int irq)
{
	cached_irq_mask &= ~(1 << irq);
	set_sr (cached_irq_mask, INTENABLE);
}

static inline void unmask_irq(unsigned int irq)
{
	cached_irq_mask |= 1 << irq;
	set_sr (cached_irq_mask, INTENABLE);
}

static void disable_xtensa_irq(unsigned int irq)
{
	unsigned long flags;
	local_save_flags(flags);
	mask_irq(irq);
	local_irq_restore(flags);
}

static void enable_xtensa_irq(unsigned int irq)
{
	unsigned long flags;
	local_save_flags(flags);
	unmask_irq(irq);
	local_irq_restore(flags);
}

static void mask_and_ack_xtensa(unsigned int irq)
{
        disable_xtensa_irq(irq);
}

static void end_xtensa_irq(unsigned int irq)
{
        enable_xtensa_irq(irq);
}


void __init init_IRQ(void)
{
	int i;

	for (i=0; i < XTENSA_NR_IRQS; i++)
		irq_desc[i].handler = &xtensa_irq_type;

	cached_irq_mask = 0;

	platform_init_irq();
}