xref: /openbmc/linux/arch/um/drivers/stdio_console.c (revision 0834cc77)
1 /*
2  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/config.h"
7 #include "linux/posix_types.h"
8 #include "linux/tty.h"
9 #include "linux/tty_flip.h"
10 #include "linux/types.h"
11 #include "linux/major.h"
12 #include "linux/kdev_t.h"
13 #include "linux/console.h"
14 #include "linux/string.h"
15 #include "linux/sched.h"
16 #include "linux/list.h"
17 #include "linux/init.h"
18 #include "linux/interrupt.h"
19 #include "linux/slab.h"
20 #include "linux/hardirq.h"
21 #include "asm/current.h"
22 #include "asm/irq.h"
23 #include "stdio_console.h"
24 #include "line.h"
25 #include "chan_kern.h"
26 #include "user_util.h"
27 #include "kern_util.h"
28 #include "irq_user.h"
29 #include "mconsole_kern.h"
30 #include "init.h"
31 
32 #define MAX_TTYS (16)
33 
34 /* ----------------------------------------------------------------------------- */
35 
36 /* Referenced only by tty_driver below - presumably it's locked correctly
37  * by the tty driver.
38  */
39 
40 static struct tty_driver *console_driver;
41 
42 void stdio_announce(char *dev_name, int dev)
43 {
44 	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
45 	       dev_name);
46 }
47 
48 static struct chan_opts opts = {
49 	.announce 	= stdio_announce,
50 	.xterm_title	= "Virtual Console #%d",
51 	.raw		= 1,
52 	.tramp_stack 	= 0,
53 	.in_kernel 	= 1,
54 };
55 
56 static int con_config(char *str);
57 static int con_get_config(char *dev, char *str, int size, char **error_out);
58 static int con_remove(int n);
59 
60 static struct line_driver driver = {
61 	.name 			= "UML console",
62 	.device_name 		= "tty",
63 	.devfs_name 		= "vc/",
64 	.major 			= TTY_MAJOR,
65 	.minor_start 		= 0,
66 	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
67 	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
68 	.read_irq 		= CONSOLE_IRQ,
69 	.read_irq_name 		= "console",
70 	.write_irq 		= CONSOLE_WRITE_IRQ,
71 	.write_irq_name 	= "console-write",
72 	.symlink_from 		= "ttys",
73 	.symlink_to 		= "vc",
74 	.mc  = {
75 		.name  		= "con",
76 		.config 	= con_config,
77 		.get_config 	= con_get_config,
78 		.id		= line_id,
79 		.remove 	= con_remove,
80 	},
81 };
82 
83 static struct lines console_lines = LINES_INIT(MAX_TTYS);
84 
85 /* The array is initialized by line_init, which is an initcall.  The
86  * individual elements are protected by individual semaphores.
87  */
88 struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
89 			      [ 1 ... MAX_TTYS - 1 ] =
90 			      LINE_INIT(CONFIG_CON_CHAN, &driver) };
91 
92 static int con_config(char *str)
93 {
94 	return line_config(vts, ARRAY_SIZE(vts), str);
95 }
96 
97 static int con_get_config(char *dev, char *str, int size, char **error_out)
98 {
99 	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
100 }
101 
102 static int con_remove(int n)
103 {
104 	return line_remove(vts, ARRAY_SIZE(vts), n);
105 }
106 
107 static int con_open(struct tty_struct *tty, struct file *filp)
108 {
109 	return line_open(vts, tty, &opts);
110 }
111 
112 static int con_init_done = 0;
113 
114 static struct tty_operations console_ops = {
115 	.open 	 		= con_open,
116 	.close 	 		= line_close,
117 	.write 	 		= line_write,
118 	.put_char 		= line_put_char,
119 	.write_room		= line_write_room,
120 	.chars_in_buffer 	= line_chars_in_buffer,
121 	.flush_buffer 		= line_flush_buffer,
122 	.flush_chars 		= line_flush_chars,
123 	.set_termios 		= line_set_termios,
124 	.ioctl 	 		= line_ioctl,
125 };
126 
127 static void uml_console_write(struct console *console, const char *string,
128 			      unsigned len)
129 {
130 	struct line *line = &vts[console->index];
131 	unsigned long flags;
132 
133 	spin_lock_irqsave(&line->lock, flags);
134 	console_write_chan(&line->chan_list, string, len);
135 	spin_unlock_irqrestore(&line->lock, flags);
136 }
137 
138 static struct tty_driver *uml_console_device(struct console *c, int *index)
139 {
140 	*index = c->index;
141 	return console_driver;
142 }
143 
144 static int uml_console_setup(struct console *co, char *options)
145 {
146 	struct line *line = &vts[co->index];
147 
148 	return console_open_chan(line, co, &opts);
149 }
150 
151 static 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,
157 	.index		= -1,
158 	.data		= &vts,
159 };
160 
161 int stdio_init(void)
162 {
163 	char *new_title;
164 
165 	console_driver = line_register_devfs(&console_lines, &driver,
166 					     &console_ops, vts,
167 					     ARRAY_SIZE(vts));
168 	if (console_driver == NULL)
169 		return -1;
170 	printk(KERN_INFO "Initialized stdio console driver\n");
171 
172 	lines_init(vts, ARRAY_SIZE(vts));
173 
174 	new_title = add_xterm_umid(opts.xterm_title);
175 	if(new_title != NULL)
176 		opts.xterm_title = new_title;
177 
178 	con_init_done = 1;
179 	register_console(&stdiocons);
180 	return 0;
181 }
182 late_initcall(stdio_init);
183 
184 static void console_exit(void)
185 {
186 	if (!con_init_done)
187 		return;
188 	close_lines(vts, ARRAY_SIZE(vts));
189 }
190 __uml_exitcall(console_exit);
191 
192 static int console_chan_setup(char *str)
193 {
194 	return line_setup(vts, ARRAY_SIZE(vts), str, 1);
195 }
196 __setup("con", console_chan_setup);
197 __channel_help(console_chan_setup, "con");
198