1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
7 * Copyright (C) 2013 Imagination Technologies Ltd.
8 */
9#include <linux/device.h>
10#include <linux/fs.h>
11#include <linux/err.h>
12#include <linux/wait.h>
13#include <linux/sched.h>
14#include <linux/smp.h>
15
16#include <asm/mips_mt.h>
17#include <asm/vpe.h>
18#include <asm/rtlx.h>
19
20static int major;
21
22static void rtlx_interrupt(void)
23{
24	int i;
25	struct rtlx_info *info;
26	struct rtlx_info **p = vpe_get_shared(aprp_cpu_index());
27
28	if (p == NULL || *p == NULL)
29		return;
30
31	info = *p;
32
33	if (info->ap_int_pending == 1 && smp_processor_id() == 0) {
34		for (i = 0; i < RTLX_CHANNELS; i++) {
35			wake_up(&channel_wqs[i].lx_queue);
36			wake_up(&channel_wqs[i].rt_queue);
37		}
38		info->ap_int_pending = 0;
39	}
40}
41
42void _interrupt_sp(void)
43{
44	smp_send_reschedule(aprp_cpu_index());
45}
46
47int __init rtlx_module_init(void)
48{
49	struct device *dev;
50	int i, err;
51
52	if (!cpu_has_mipsmt) {
53		pr_warn("VPE loader: not a MIPS MT capable processor\n");
54		return -ENODEV;
55	}
56
57	if (num_possible_cpus() - aprp_cpu_index() < 1) {
58		pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
59			"Pass maxcpus=<n> argument as kernel argument\n");
60
61		return -ENODEV;
62	}
63
64	major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
65	if (major < 0) {
66		pr_err("rtlx_module_init: unable to register device\n");
67		return major;
68	}
69
70	/* initialise the wait queues */
71	for (i = 0; i < RTLX_CHANNELS; i++) {
72		init_waitqueue_head(&channel_wqs[i].rt_queue);
73		init_waitqueue_head(&channel_wqs[i].lx_queue);
74		atomic_set(&channel_wqs[i].in_open, 0);
75		mutex_init(&channel_wqs[i].mutex);
76
77		dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
78				    "%s%d", RTLX_MODULE_NAME, i);
79		if (IS_ERR(dev)) {
80			while (i--)
81				device_destroy(mt_class, MKDEV(major, i));
82
83			err = PTR_ERR(dev);
84			goto out_chrdev;
85		}
86	}
87
88	/* set up notifiers */
89	rtlx_notify.start = rtlx_starting;
90	rtlx_notify.stop = rtlx_stopping;
91	vpe_notify(aprp_cpu_index(), &rtlx_notify);
92
93	if (cpu_has_vint) {
94		aprp_hook = rtlx_interrupt;
95	} else {
96		pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
97		err = -ENODEV;
98		goto out_class;
99	}
100
101	return 0;
102
103out_class:
104	for (i = 0; i < RTLX_CHANNELS; i++)
105		device_destroy(mt_class, MKDEV(major, i));
106out_chrdev:
107	unregister_chrdev(major, RTLX_MODULE_NAME);
108
109	return err;
110}
111
112void __exit rtlx_module_exit(void)
113{
114	int i;
115
116	for (i = 0; i < RTLX_CHANNELS; i++)
117		device_destroy(mt_class, MKDEV(major, i));
118
119	unregister_chrdev(major, RTLX_MODULE_NAME);
120
121	aprp_hook = NULL;
122}
123