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
rtlx_dispatch(void)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 */
rtlx_interrupt(int irq,void * dev_id)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 struct irqaction rtlx_irq = {
55 .handler = rtlx_interrupt,
56 .name = "RTLX",
57 };
58
59 static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
60
_interrupt_sp(void)61 void _interrupt_sp(void)
62 {
63 unsigned long flags;
64
65 local_irq_save(flags);
66 dvpe();
67 settc(1);
68 write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
69 evpe(EVPE_ENABLE);
70 local_irq_restore(flags);
71 }
72
rtlx_module_init(void)73 int __init rtlx_module_init(void)
74 {
75 struct device *dev;
76 int i, err;
77
78 if (!cpu_has_mipsmt) {
79 pr_warn("VPE loader: not a MIPS MT capable processor\n");
80 return -ENODEV;
81 }
82
83 if (aprp_cpu_index() == 0) {
84 pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
85 "Pass maxtcs=<n> argument as kernel argument\n");
86
87 return -ENODEV;
88 }
89
90 major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
91 if (major < 0) {
92 pr_err("rtlx_module_init: unable to register device\n");
93 return major;
94 }
95
96 /* initialise the wait queues */
97 for (i = 0; i < RTLX_CHANNELS; i++) {
98 init_waitqueue_head(&channel_wqs[i].rt_queue);
99 init_waitqueue_head(&channel_wqs[i].lx_queue);
100 atomic_set(&channel_wqs[i].in_open, 0);
101 mutex_init(&channel_wqs[i].mutex);
102
103 dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
104 "%s%d", RTLX_MODULE_NAME, i);
105 if (IS_ERR(dev)) {
106 while (i--)
107 device_destroy(mt_class, MKDEV(major, i));
108
109 err = PTR_ERR(dev);
110 goto out_chrdev;
111 }
112 }
113
114 /* set up notifiers */
115 rtlx_notify.start = rtlx_starting;
116 rtlx_notify.stop = rtlx_stopping;
117 vpe_notify(aprp_cpu_index(), &rtlx_notify);
118
119 if (cpu_has_vint) {
120 aprp_hook = rtlx_dispatch;
121 } else {
122 pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
123 err = -ENODEV;
124 goto out_class;
125 }
126
127 rtlx_irq.dev_id = rtlx;
128 err = setup_irq(rtlx_irq_num, &rtlx_irq);
129 if (err)
130 goto out_class;
131
132 return 0;
133
134 out_class:
135 for (i = 0; i < RTLX_CHANNELS; i++)
136 device_destroy(mt_class, MKDEV(major, i));
137 out_chrdev:
138 unregister_chrdev(major, RTLX_MODULE_NAME);
139
140 return err;
141 }
142
rtlx_module_exit(void)143 void __exit rtlx_module_exit(void)
144 {
145 int i;
146
147 for (i = 0; i < RTLX_CHANNELS; i++)
148 device_destroy(mt_class, MKDEV(major, i));
149
150 unregister_chrdev(major, RTLX_MODULE_NAME);
151
152 aprp_hook = NULL;
153 }
154