aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/kernel/irq_cpu.c
blob: 72ef2d25cbf21ab5bebb1a93b0c0bf6e4e4fdff7 (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
/*
 * Copyright 2001 MontaVista Software Inc.
 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
 *
 * Copyright (C) 2001 Ralf Baechle
 * Copyright (C) 2005  MIPS Technologies, Inc.	All rights reserved.
 *	Author: Maciej W. Rozycki <macro@mips.com>
 *
 * This file define the irq handler for MIPS CPU interrupts.
 *
 * 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.
 */

/*
 * Almost all MIPS CPUs define 8 interrupt sources.  They are typically
 * level triggered (i.e., cannot be cleared from CPU; must be cleared from
 * device).  The first two are software interrupts which we don't really
 * use or support.  The last one is usually the CPU timer interrupt if
 * counter register is present or, for CPUs with an external FPU, by
 * convention it's the FPU exception interrupt.
 *
 * Don't even think about using this on SMP.  You have been warned.
 *
 * This file exports one global function:
 *	void mips_cpu_irq_init(void);
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>

#include <asm/irq_cpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>

static inline void unmask_mips_irq(struct irq_data *d)
{
	set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
	irq_enable_hazard();
}

static inline void mask_mips_irq(struct irq_data *d)
{
	clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
	irq_disable_hazard();
}

static struct irq_chip mips_cpu_irq_controller = {
	.name		= "MIPS",
	.irq_ack	= mask_mips_irq,
	.irq_mask	= mask_mips_irq,
	.irq_mask_ack	= mask_mips_irq,
	.irq_unmask	= unmask_mips_irq,
	.irq_eoi	= unmask_mips_irq,
};

/*
 * Basically the same as above but taking care of all the MT stuff
 */

static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d)
{
	unsigned int vpflags = dvpe();

	clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
	evpe(vpflags);
	unmask_mips_irq(d);
	return 0;
}

/*
 * While we ack the interrupt interrupts are disabled and thus we don't need
 * to deal with concurrency issues.  Same for mips_cpu_irq_end.
 */
static void mips_mt_cpu_irq_ack(struct irq_data *d)
{
	unsigned int vpflags = dvpe();
	clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
	evpe(vpflags);
	mask_mips_irq(d);
}

static struct irq_chip mips_mt_cpu_irq_controller = {
	.name		= "MIPS",
	.irq_startup	= mips_mt_cpu_irq_startup,
	.irq_ack	= mips_mt_cpu_irq_ack,
	.irq_mask	= mask_mips_irq,
	.irq_mask_ack	= mips_mt_cpu_irq_ack,
	.irq_unmask	= unmask_mips_irq,
	.irq_eoi	= unmask_mips_irq,
};

void __init mips_cpu_irq_init(void)
{
	int irq_base = MIPS_CPU_IRQ_BASE;
	int i;

	/* Mask interrupts. */
	clear_c0_status(ST0_IM);
	clear_c0_cause(CAUSEF_IP);

	/* Software interrupts are used for MT/CMT IPI */
	for (i = irq_base; i < irq_base + 2; i++)
		irq_set_chip_and_handler(i, cpu_has_mipsmt ?
					 &mips_mt_cpu_irq_controller :
					 &mips_cpu_irq_controller,
					 handle_percpu_irq);

	for (i = irq_base + 2; i < irq_base + 8; i++)
		irq_set_chip_and_handler(i, &mips_cpu_irq_controller,
					 handle_percpu_irq);
}

#ifdef CONFIG_IRQ_DOMAIN
static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
			     irq_hw_number_t hw)
{
	static struct irq_chip *chip;

	if (hw < 2 && cpu_has_mipsmt) {
		/* Software interrupts are used for MT/CMT IPI */
		chip = &mips_mt_cpu_irq_controller;
	} else {
		chip = &mips_cpu_irq_controller;
	}

	irq_set_chip_and_handler(irq, chip, handle_percpu_irq);

	return 0;
}

static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = {
	.map = mips_cpu_intc_map,
	.xlate = irq_domain_xlate_onecell,
};

int __init mips_cpu_intc_init(struct device_node *of_node,
			      struct device_node *parent)
{
	struct irq_domain *domain;

	/* Mask interrupts. */
	clear_c0_status(ST0_IM);
	clear_c0_cause(CAUSEF_IP);

	domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0,
				       &mips_cpu_intc_irq_domain_ops, NULL);
	if (!domain)
		panic("Failed to add irqdomain for MIPS CPU\n");

	return 0;
}
#endif /* CONFIG_IRQ_DOMAIN */