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/interrupt.h>
15 #include <linux/irq.h>
16
17 #include <asm/mips_mt.h>
18 #include <asm/vpe.h>
19 #include <asm/rtlx.h>
20
21 static int major;
22
23 static void rtlx_dispatch(void)
24 {
25 if (read_c0_cause() & read_c0_status() & C_SW0)
26 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
27 }
28
29 /*
30 * Interrupt handler may be called before rtlx_init has otherwise had
31 * a chance to run.
32 */
33 static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
34 {
35 unsigned int vpeflags;
36 unsigned long flags;
37 int i;
38
39 local_irq_save(flags);
40 vpeflags = dvpe();
41 set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
42 irq_enable_hazard();
43 evpe(vpeflags);
44 local_irq_restore(flags);
45
46 for (i = 0; i < RTLX_CHANNELS; i++) {
47 wake_up(&channel_wqs[i].lx_queue);
48 wake_up(&channel_wqs[i].rt_queue);
49 }
50
51 return IRQ_HANDLED;
52 }
53
54 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
55
56 void _interrupt_sp(void)
57 {
58 unsigned long flags;
59
60 local_irq_save(flags);
61 dvpe();
62 settc(1);
63 write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
64 evpe(EVPE_ENABLE);
65 local_irq_restore(flags);
66 }
67
68 int __init rtlx_module_init(void)
69 {
70 struct device *dev;
71 int i, err;
72
73 if (!cpu_has_mipsmt) {
74 pr_warn("VPE loader: not a MIPS MT capable processor\n");
75 return -ENODEV;
76 }
77
78 if (aprp_cpu_index() == 0) {
79 pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
80 "Pass maxtcs=<n> argument as kernel argument\n");
81
82 return -ENODEV;
83 }
84
85 major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
86 if (major < 0) {
87 pr_err("rtlx_module_init: unable to register device\n");
88 return major;
89 }
90
91 /* initialise the wait queues */
92 for (i = 0; i < RTLX_CHANNELS; i++) {
93 init_waitqueue_head(&channel_wqs[i].rt_queue);
94 init_waitqueue_head(&channel_wqs[i].lx_queue);
95 atomic_set(&channel_wqs[i].in_open, 0);
96 mutex_init(&channel_wqs[i].mutex);
97
98 dev = device_create(&mt_class, NULL, MKDEV(major, i), NULL,
99 "%s%d", RTLX_MODULE_NAME, i);
100 if (IS_ERR(dev)) {
101 while (i--)
102 device_destroy(&mt_class, MKDEV(major, i));
103
104 err = PTR_ERR(dev);
105 goto out_chrdev;
106 }
107 }
108
109 /* set up notifiers */
110 rtlx_notify.start = rtlx_starting;
111 rtlx_notify.stop = rtlx_stopping;
112 vpe_notify(aprp_cpu_index(), &rtlx_notify);
113
114 if (cpu_has_vint) {
115 aprp_hook = rtlx_dispatch;
116 } else {
117 pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
118 err = -ENODEV;
119 goto out_class;
120 }
121
122 err = request_irq(rtlx_irq_num, rtlx_interrupt, 0, "RTLX", rtlx);
123 if (err)
124 goto out_class;
125
126 return 0;
127
128 out_class:
129 for (i = 0; i < RTLX_CHANNELS; i++)
130 device_destroy(&mt_class, MKDEV(major, i));
131 out_chrdev:
132 unregister_chrdev(major, RTLX_MODULE_NAME);
133
134 return err;
135 }
136
137 void __exit rtlx_module_exit(void)
138 {
139 int i;
140
141 for (i = 0; i < RTLX_CHANNELS; i++)
142 device_destroy(&mt_class, MKDEV(major, i));
143
144 unregister_chrdev(major, RTLX_MODULE_NAME);
145
146 aprp_hook = NULL;
147 }
148
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