xref: /openbmc/linux/arch/um/drivers/stdio_console.c (revision d79a5809)
1 /*
2  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/posix_types.h"
7 #include "linux/tty.h"
8 #include "linux/tty_flip.h"
9 #include "linux/types.h"
10 #include "linux/major.h"
11 #include "linux/kdev_t.h"
12 #include "linux/console.h"
13 #include "linux/string.h"
14 #include "linux/sched.h"
15 #include "linux/list.h"
16 #include "linux/init.h"
17 #include "linux/interrupt.h"
18 #include "linux/slab.h"
19 #include "linux/hardirq.h"
20 #include "asm/current.h"
21 #include "asm/irq.h"
22 #include "stdio_console.h"
23 #include "line.h"
24 #include "chan_kern.h"
25 #include "user_util.h"
26 #include "kern_util.h"
27 #include "irq_user.h"
28 #include "mconsole_kern.h"
29 #include "init.h"
30 
31 #define MAX_TTYS (16)
32 
33 /* ----------------------------------------------------------------------------- */
34 
35 /* Referenced only by tty_driver below - presumably it's locked correctly
36  * by the tty driver.
37  */
38 
39 static struct tty_driver *console_driver;
40 
41 void stdio_announce(char *dev_name, int dev)
42 {
43 	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
44 	       dev_name);
45 }
46 
47 static struct chan_opts opts = {
48 	.announce 	= stdio_announce,
49 	.xterm_title	= "Virtual Console #%d",
50 	.raw		= 1,
51 	.tramp_stack 	= 0,
52 	.in_kernel 	= 1,
53 };
54 
55 static int con_config(char *str);
56 static int con_get_config(char *dev, char *str, int size, char **error_out);
57 static int con_remove(int n);
58 
59 static struct line_driver driver = {
60 	.name 			= "UML console",
61 	.device_name 		= "tty",
62 	.major 			= TTY_MAJOR,
63 	.minor_start 		= 0,
64 	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
65 	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
66 	.read_irq 		= CONSOLE_IRQ,
67 	.read_irq_name 		= "console",
68 	.write_irq 		= CONSOLE_WRITE_IRQ,
69 	.write_irq_name 	= "console-write",
70 	.symlink_from 		= "ttys",
71 	.symlink_to 		= "vc",
72 	.mc  = {
73 		.name  		= "con",
74 		.config 	= con_config,
75 		.get_config 	= con_get_config,
76 		.id		= line_id,
77 		.remove 	= con_remove,
78 	},
79 };
80 
81 static struct lines console_lines = LINES_INIT(MAX_TTYS);
82 
83 /* The array is initialized by line_init, which is an initcall.  The
84  * individual elements are protected by individual semaphores.
85  */
86 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
87 				     [ 1 ... MAX_TTYS - 1 ] =
88 				     LINE_INIT(CONFIG_CON_CHAN, &driver) };
89 
90 static int con_config(char *str)
91 {
92 	return line_config(vts, ARRAY_SIZE(vts), str, &opts);
93 }
94 
95 static int con_get_config(char *dev, char *str, int size, char **error_out)
96 {
97 	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
98 }
99 
100 static int con_remove(int n)
101 {
102 	return line_remove(vts, ARRAY_SIZE(vts), n);
103 }
104 
105 static int con_open(struct tty_struct *tty, struct file *filp)
106 {
107 	return line_open(vts, tty);
108 }
109 
110 /* Set in an initcall, checked in an exitcall */
111 static int con_init_done = 0;
112 
113 static const struct tty_operations console_ops = {
114 	.open 	 		= con_open,
115 	.close 	 		= line_close,
116 	.write 	 		= line_write,
117 	.put_char 		= line_put_char,
118 	.write_room		= line_write_room,
119 	.chars_in_buffer 	= line_chars_in_buffer,
120 	.flush_buffer 		= line_flush_buffer,
121 	.flush_chars 		= line_flush_chars,
122 	.set_termios 		= line_set_termios,
123 	.ioctl 	 		= line_ioctl,
124 	.throttle 		= line_throttle,
125 	.unthrottle 		= line_unthrottle,
126 };
127 
128 static void uml_console_write(struct console *console, const char *string,
129 			      unsigned len)
130 {
131 	struct line *line = &vts[console->index];
132 	unsigned long flags;
133 
134 	spin_lock_irqsave(&line->lock, flags);
135 	console_write_chan(&line->chan_list, string, len);
136 	spin_unlock_irqrestore(&line->lock, flags);
137 }
138 
139 static struct tty_driver *uml_console_device(struct console *c, int *index)
140 {
141 	*index = c->index;
142 	return console_driver;
143 }
144 
145 static int uml_console_setup(struct console *co, char *options)
146 {
147 	struct line *line = &vts[co->index];
148 
149 	return console_open_chan(line, co, &opts);
150 }
151 
152 static struct console stdiocons = {
153 	.name		= "tty",
154 	.write		= uml_console_write,
155 	.device		= uml_console_device,
156 	.setup		= uml_console_setup,
157 	.flags		= CON_PRINTBUFFER,
158 	.index		= -1,
159 	.data		= &vts,
160 };
161 
162 int stdio_init(void)
163 {
164 	char *new_title;
165 
166 	console_driver = line_register_devfs(&console_lines, &driver,
167 					     &console_ops, vts,
168 					     ARRAY_SIZE(vts));
169 	if (console_driver == NULL)
170 		return -1;
171 	printk(KERN_INFO "Initialized stdio console driver\n");
172 
173 	lines_init(vts, ARRAY_SIZE(vts), &opts);
174 
175 	new_title = add_xterm_umid(opts.xterm_title);
176 	if(new_title != NULL)
177 		opts.xterm_title = new_title;
178 
179 	con_init_done = 1;
180 	register_console(&stdiocons);
181 	return 0;
182 }
183 late_initcall(stdio_init);
184 
185 static void console_exit(void)
186 {
187 	if (!con_init_done)
188 		return;
189 	close_lines(vts, ARRAY_SIZE(vts));
190 }
191 __uml_exitcall(console_exit);
192 
193 static int console_chan_setup(char *str)
194 {
195 	return line_setup(vts, ARRAY_SIZE(vts), str);
196 }
197 __setup("con", console_chan_setup);
198 __channel_help(console_chan_setup, "con");
199