stdio_console.c revision d8c215adbf3901aa7d00a0f17f08d77be689f838 
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 "chan.h"
24#include "irq_user.h"
25#include "mconsole_kern.h"
26#include "init.h"
27
28#define MAX_TTYS (16)
29
30/* Referenced only by tty_driver below - presumably it's locked correctly
31 * by the tty driver.
32 */
33
34static struct tty_driver *console_driver;
35
36static void stdio_announce(char *dev_name, int dev)
37{
38	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
39	       dev_name);
40}
41
42/* Almost const, except that xterm_title may be changed in an initcall */
43static struct chan_opts opts = {
44	.announce 	= stdio_announce,
45	.xterm_title	= "Virtual Console #%d",
46	.raw		= 1,
47};
48
49static int con_config(char *str, char **error_out);
50static int con_get_config(char *dev, char *str, int size, char **error_out);
51static int con_remove(int n, char **con_remove);
52
53
54/* Const, except for .mc.list */
55static struct line_driver driver = {
56	.name 			= "UML console",
57	.device_name 		= "tty",
58	.major 			= TTY_MAJOR,
59	.minor_start 		= 0,
60	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
61	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
62	.read_irq 		= CONSOLE_IRQ,
63	.read_irq_name 		= "console",
64	.write_irq 		= CONSOLE_WRITE_IRQ,
65	.write_irq_name 	= "console-write",
66	.mc  = {
67		.list		= LIST_HEAD_INIT(driver.mc.list),
68		.name  		= "con",
69		.config 	= con_config,
70		.get_config 	= con_get_config,
71		.id		= line_id,
72		.remove 	= con_remove,
73	},
74};
75
76/* The array is initialized by line_init, at initcall time.  The
77 * elements are locked individually as needed.
78 */
79static char *vt_conf[MAX_TTYS];
80static char *def_conf;
81static struct line vts[MAX_TTYS];
82
83static int con_config(char *str, char **error_out)
84{
85	return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
86}
87
88static int con_get_config(char *dev, char *str, int size, char **error_out)
89{
90	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
91}
92
93static int con_remove(int n, char **error_out)
94{
95	return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
96}
97
98static int con_open(struct tty_struct *tty, struct file *filp)
99{
100	int err = line_open(vts, tty);
101	if (err)
102		printk(KERN_ERR "Failed to open console %d, err = %d\n",
103		       tty->index, err);
104
105	return err;
106}
107
108/* Set in an initcall, checked in an exitcall */
109static int con_init_done = 0;
110
111static const struct tty_operations console_ops = {
112	.open 	 		= con_open,
113	.close 	 		= line_close,
114	.write 	 		= line_write,
115	.put_char 		= line_put_char,
116	.write_room		= line_write_room,
117	.chars_in_buffer 	= line_chars_in_buffer,
118	.flush_buffer 		= line_flush_buffer,
119	.flush_chars 		= line_flush_chars,
120	.set_termios 		= line_set_termios,
121	.ioctl 	 		= line_ioctl,
122	.throttle 		= line_throttle,
123	.unthrottle 		= line_unthrottle,
124};
125
126static void uml_console_write(struct console *console, const char *string,
127			      unsigned len)
128{
129	struct line *line = &vts[console->index];
130	unsigned long flags;
131
132	spin_lock_irqsave(&line->lock, flags);
133	console_write_chan(&line->chan_list, string, len);
134	spin_unlock_irqrestore(&line->lock, flags);
135}
136
137static struct tty_driver *uml_console_device(struct console *c, int *index)
138{
139	*index = c->index;
140	return console_driver;
141}
142
143static int uml_console_setup(struct console *co, char *options)
144{
145	struct line *line = &vts[co->index];
146
147	return console_open_chan(line, co);
148}
149
150/* No locking for register_console call - relies on single-threaded initcalls */
151static struct console stdiocons = {
152	.name		= "tty",
153	.write		= uml_console_write,
154	.device		= uml_console_device,
155	.setup		= uml_console_setup,
156	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
157	.index		= -1,
158};
159
160static int stdio_init(void)
161{
162	char *new_title;
163	int i;
164
165	for (i = 0; i < MAX_TTYS; i++) {
166		char *s = vt_conf[i];
167		if (!s)
168			s = def_conf;
169		if (!s)
170			s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
171		if (s && strcmp(s, "none") != 0) {
172			vts[i].init_str = s;
173			vts[i].valid = 1;
174		}
175		spin_lock_init(&vts[i].lock);
176		mutex_init(&vts[i].count_lock);
177		vts[i].driver = &driver;
178	}
179	console_driver = register_lines(&driver, &console_ops, vts,
180					ARRAY_SIZE(vts));
181	if (console_driver == NULL)
182		return -1;
183	printk(KERN_INFO "Initialized stdio console driver\n");
184
185	new_title = add_xterm_umid(opts.xterm_title);
186	if(new_title != NULL)
187		opts.xterm_title = new_title;
188
189	lines_init(vts, ARRAY_SIZE(vts), &opts);
190
191	con_init_done = 1;
192	register_console(&stdiocons);
193	return 0;
194}
195late_initcall(stdio_init);
196
197static void console_exit(void)
198{
199	if (!con_init_done)
200		return;
201	close_lines(vts, ARRAY_SIZE(vts));
202}
203__uml_exitcall(console_exit);
204
205static int console_chan_setup(char *str)
206{
207	line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
208	return 1;
209}
210__setup("con", console_chan_setup);
211__channel_help(console_chan_setup, "con");
212