summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/rtlx-mt.c
blob: 91d61ba422b4677fdc956b0a5707ddb58740212a (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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
 * Copyright (C) 2013 Imagination Technologies Ltd.
 */
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

#include <asm/mips_mt.h>
#include <asm/vpe.h>
#include <asm/rtlx.h>

static int major;

static void rtlx_dispatch(void)
{
	if (read_c0_cause() & read_c0_status() & C_SW0)
		do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
}

/*
 * Interrupt handler may be called before rtlx_init has otherwise had
 * a chance to run.
 */
static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
{
	unsigned int vpeflags;
	unsigned long flags;
	int i;

	/* Ought not to be strictly necessary for SMTC builds */
	local_irq_save(flags);
	vpeflags = dvpe();
	set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
	irq_enable_hazard();
	evpe(vpeflags);
	local_irq_restore(flags);

	for (i = 0; i < RTLX_CHANNELS; i++) {
		wake_up(&channel_wqs[i].lx_queue);
		wake_up(&channel_wqs[i].rt_queue);
	}

	return IRQ_HANDLED;
}

static struct irqaction rtlx_irq = {
	.handler	= rtlx_interrupt,
	.name		= "RTLX",
};

static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;

void _interrupt_sp(void)
{
	unsigned long flags;

	local_irq_save(flags);
	dvpe();
	settc(1);
	write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
	evpe(EVPE_ENABLE);
	local_irq_restore(flags);
}

int __init rtlx_module_init(void)
{
	struct device *dev;
	int i, err;

	if (!cpu_has_mipsmt) {
		pr_warn("VPE loader: not a MIPS MT capable processor\n");
		return -ENODEV;
	}

	if (aprp_cpu_index() == 0) {
		pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
			"Pass maxtcs=<n> argument as kernel argument\n");

		return -ENODEV;
	}

	major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
	if (major < 0) {
		pr_err("rtlx_module_init: unable to register device\n");
		return major;
	}

	/* initialise the wait queues */
	for (i = 0; i < RTLX_CHANNELS; i++) {
		init_waitqueue_head(&channel_wqs[i].rt_queue);
		init_waitqueue_head(&channel_wqs[i].lx_queue);
		atomic_set(&channel_wqs[i].in_open, 0);
		mutex_init(&channel_wqs[i].mutex);

		dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
				    "%s%d", RTLX_MODULE_NAME, i);
		if (IS_ERR(dev)) {
			err = PTR_ERR(dev);
			goto out_chrdev;
		}
	}

	/* set up notifiers */
	rtlx_notify.start = rtlx_starting;
	rtlx_notify.stop = rtlx_stopping;
	vpe_notify(aprp_cpu_index(), &rtlx_notify);

	if (cpu_has_vint) {
		aprp_hook = rtlx_dispatch;
	} else {
		pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
		err = -ENODEV;
		goto out_class;
	}

	rtlx_irq.dev_id = rtlx;
	err = setup_irq(rtlx_irq_num, &rtlx_irq);
	if (err)
		goto out_class;

	return 0;

out_class:
	for (i = 0; i < RTLX_CHANNELS; i++)
		device_destroy(mt_class, MKDEV(major, i));
out_chrdev:
	unregister_chrdev(major, RTLX_MODULE_NAME);

	return err;
}

void __exit rtlx_module_exit(void)
{
	int i;

	for (i = 0; i < RTLX_CHANNELS; i++)
		device_destroy(mt_class, MKDEV(major, i));
	unregister_chrdev(major, RTLX_MODULE_NAME);
}