xref: /openbmc/linux/arch/um/drivers/stdio_console.c (revision 615c36f5)
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 
34 static struct tty_driver *console_driver;
35 
36 static 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 */
43 static struct chan_opts opts = {
44 	.announce 	= stdio_announce,
45 	.xterm_title	= "Virtual Console #%d",
46 	.raw		= 1,
47 };
48 
49 static int con_config(char *str, char **error_out);
50 static int con_get_config(char *dev, char *str, int size, char **error_out);
51 static int con_remove(int n, char **con_remove);
52 
53 
54 /* Const, except for .mc.list */
55 static 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  */
79 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
80 				     [ 1 ... MAX_TTYS - 1 ] =
81 				     LINE_INIT(CONFIG_CON_CHAN, &driver) };
82 
83 static int con_config(char *str, char **error_out)
84 {
85 	return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
86 }
87 
88 static 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 
93 static int con_remove(int n, char **error_out)
94 {
95 	return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
96 }
97 
98 static 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 */
109 static int con_init_done = 0;
110 
111 static 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 
126 static 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 
137 static struct tty_driver *uml_console_device(struct console *c, int *index)
138 {
139 	*index = c->index;
140 	return console_driver;
141 }
142 
143 static 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 */
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|CON_ANYTIME,
157 	.index		= -1,
158 };
159 
160 static int stdio_init(void)
161 {
162 	char *new_title;
163 
164 	console_driver = register_lines(&driver, &console_ops, vts,
165 					ARRAY_SIZE(vts));
166 	if (console_driver == NULL)
167 		return -1;
168 	printk(KERN_INFO "Initialized stdio console driver\n");
169 
170 	new_title = add_xterm_umid(opts.xterm_title);
171 	if(new_title != NULL)
172 		opts.xterm_title = new_title;
173 
174 	lines_init(vts, ARRAY_SIZE(vts), &opts);
175 
176 	con_init_done = 1;
177 	register_console(&stdiocons);
178 	return 0;
179 }
180 late_initcall(stdio_init);
181 
182 static void console_exit(void)
183 {
184 	if (!con_init_done)
185 		return;
186 	close_lines(vts, ARRAY_SIZE(vts));
187 }
188 __uml_exitcall(console_exit);
189 
190 static int console_chan_setup(char *str)
191 {
192 	char *error;
193 	int ret;
194 
195 	ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
196 	if(ret < 0)
197 		printk(KERN_ERR "Failed to set up console with "
198 		       "configuration string \"%s\" : %s\n", str, error);
199 
200 	return 1;
201 }
202 __setup("con", console_chan_setup);
203 __channel_help(console_chan_setup, "con");
204