stdio_console.c revision 038b0a6d8d32db934bba6a24e74e76e4e327a94f 
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
39static struct tty_driver *console_driver;
40
41void 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
47static 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
55static int con_config(char *str);
56static int con_get_config(char *dev, char *str, int size, char **error_out);
57static int con_remove(int n);
58
59static 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
81static 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 */
86struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
87			      [ 1 ... MAX_TTYS - 1 ] =
88			      LINE_INIT(CONFIG_CON_CHAN, &driver) };
89
90static int con_config(char *str)
91{
92	return line_config(vts, ARRAY_SIZE(vts), str, &opts);
93}
94
95static 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
100static int con_remove(int n)
101{
102	return line_remove(vts, ARRAY_SIZE(vts), n);
103}
104
105static 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 */
111static int con_init_done = 0;
112
113static 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
128static 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
139static struct tty_driver *uml_console_device(struct console *c, int *index)
140{
141	*index = c->index;
142	return console_driver;
143}
144
145static 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
152static 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
162int 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}
183late_initcall(stdio_init);
184
185static 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
193static 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