aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/irq_cpu.c
blob: 3b7cfa407e87394f669d9a9cae5bdd62724a2c94 (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
/*
 * 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(int irq_base);
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>

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

static int mips_cpu_irq_base;

static inline void unmask_mips_irq(unsigned int irq)
{
	set_c0_status(0x100 << (irq - mips_cpu_irq_base));
	irq_enable_hazard();
}

static inline void mask_mips_irq(unsigned int irq)
{
	clear_c0_status(0x100 << (irq - mips_cpu_irq_base));
	irq_disable_hazard();
}

static void mips_cpu_irq_end(unsigned int irq)
{
	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
		unmask_mips_irq(irq);
}

static struct irq_chip mips_cpu_irq_controller = {
	.typename	= "MIPS",
	.ack		= mask_mips_irq,
	.mask		= mask_mips_irq,
	.mask_ack	= mask_mips_irq,
	.unmask		= unmask_mips_irq,
	.end		= mips_cpu_irq_end,
};

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

#define unmask_mips_mt_irq	unmask_mips_irq
#define mask_mips_mt_irq	mask_mips_irq

static unsigned int mips_mt_cpu_irq_startup(unsigned int irq)
{
	unsigned int vpflags = dvpe();

	clear_c0_cause(0x100 << (irq - mips_cpu_irq_base));
	evpe(vpflags);
	unmask_mips_mt_irq(irq);

	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(unsigned int irq)
{
	unsigned int vpflags = dvpe();
	clear_c0_cause(0x100 << (irq - mips_cpu_irq_base));
	evpe(vpflags);
	mask_mips_mt_irq(irq);
}

#define mips_mt_cpu_irq_end mips_cpu_irq_end

static struct irq_chip mips_mt_cpu_irq_controller = {
	.typename	= "MIPS",
	.startup	= mips_mt_cpu_irq_startup,
	.ack		= mips_mt_cpu_irq_ack,
	.mask		= mask_mips_mt_irq,
	.mask_ack	= mips_mt_cpu_irq_ack,
	.unmask		= unmask_mips_mt_irq,
	.end		= mips_mt_cpu_irq_end,
};

void __init mips_cpu_irq_init(int irq_base)
{
	int i;

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

	/*
	 * Only MT is using the software interrupts currently, so we just
	 * leave them uninitialized for other processors.
	 */
	if (cpu_has_mipsmt)
		for (i = irq_base; i < irq_base + 2; i++)
			set_irq_chip(i, &mips_mt_cpu_irq_controller);

	for (i = irq_base + 2; i < irq_base + 8; i++)
		set_irq_chip(i, &mips_cpu_irq_controller);

	mips_cpu_irq_base = irq_base;
}