xref: /openbmc/linux/arch/um/drivers/stdio_console.c (revision 074a0db8)
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 "irq_user.h"
26 #include "mconsole_kern.h"
27 #include "init.h"
28 
29 #define MAX_TTYS (16)
30 
31 /* Referenced only by tty_driver below - presumably it's locked correctly
32  * by the tty driver.
33  */
34 
35 static struct tty_driver *console_driver;
36 
37 static void stdio_announce(char *dev_name, int dev)
38 {
39 	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
40 	       dev_name);
41 }
42 
43 /* Almost const, except that xterm_title may be changed in an initcall */
44 static struct chan_opts opts = {
45 	.announce 	= stdio_announce,
46 	.xterm_title	= "Virtual Console #%d",
47 	.raw		= 1,
48 };
49 
50 static int con_config(char *str, char **error_out);
51 static int con_get_config(char *dev, char *str, int size, char **error_out);
52 static int con_remove(int n, char **con_remove);
53 
54 
55 /* Const, except for .mc.list */
56 static struct line_driver driver = {
57 	.name 			= "UML console",
58 	.device_name 		= "tty",
59 	.major 			= TTY_MAJOR,
60 	.minor_start 		= 0,
61 	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
62 	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
63 	.read_irq 		= CONSOLE_IRQ,
64 	.read_irq_name 		= "console",
65 	.write_irq 		= CONSOLE_WRITE_IRQ,
66 	.write_irq_name 	= "console-write",
67 	.mc  = {
68 		.list		= LIST_HEAD_INIT(driver.mc.list),
69 		.name  		= "con",
70 		.config 	= con_config,
71 		.get_config 	= con_get_config,
72 		.id		= line_id,
73 		.remove 	= con_remove,
74 	},
75 };
76 
77 /* The array is initialized by line_init, at initcall time.  The
78  * elements are locked individually as needed.
79  */
80 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
81 				     [ 1 ... MAX_TTYS - 1 ] =
82 				     LINE_INIT(CONFIG_CON_CHAN, &driver) };
83 
84 static int con_config(char *str, char **error_out)
85 {
86 	return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
87 }
88 
89 static int con_get_config(char *dev, char *str, int size, char **error_out)
90 {
91 	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
92 }
93 
94 static int con_remove(int n, char **error_out)
95 {
96 	return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
97 }
98 
99 static int con_open(struct tty_struct *tty, struct file *filp)
100 {
101 	int err = line_open(vts, tty);
102 	if (err)
103 		printk(KERN_ERR "Failed to open console %d, err = %d\n",
104 		       tty->index, err);
105 
106 	return err;
107 }
108 
109 /* Set in an initcall, checked in an exitcall */
110 static int con_init_done = 0;
111 
112 static const struct tty_operations console_ops = {
113 	.open 	 		= con_open,
114 	.close 	 		= line_close,
115 	.write 	 		= line_write,
116 	.put_char 		= line_put_char,
117 	.write_room		= line_write_room,
118 	.chars_in_buffer 	= line_chars_in_buffer,
119 	.flush_buffer 		= line_flush_buffer,
120 	.flush_chars 		= line_flush_chars,
121 	.set_termios 		= line_set_termios,
122 	.ioctl 	 		= line_ioctl,
123 	.throttle 		= line_throttle,
124 	.unthrottle 		= line_unthrottle,
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);
149 }
150 
151 /* No locking for register_console call - relies on single-threaded initcalls */
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|CON_ANYTIME,
158 	.index		= -1,
159 };
160 
161 static int stdio_init(void)
162 {
163 	char *new_title;
164 
165 	console_driver = register_lines(&driver, &console_ops, vts,
166 					ARRAY_SIZE(vts));
167 	if (console_driver == NULL)
168 		return -1;
169 	printk(KERN_INFO "Initialized stdio console driver\n");
170 
171 	new_title = add_xterm_umid(opts.xterm_title);
172 	if(new_title != NULL)
173 		opts.xterm_title = new_title;
174 
175 	lines_init(vts, ARRAY_SIZE(vts), &opts);
176 
177 	con_init_done = 1;
178 	register_console(&stdiocons);
179 	return 0;
180 }
181 late_initcall(stdio_init);
182 
183 static void console_exit(void)
184 {
185 	if (!con_init_done)
186 		return;
187 	close_lines(vts, ARRAY_SIZE(vts));
188 }
189 __uml_exitcall(console_exit);
190 
191 static int console_chan_setup(char *str)
192 {
193 	char *error;
194 	int ret;
195 
196 	ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
197 	if(ret < 0)
198 		printk(KERN_ERR "Failed to set up console with "
199 		       "configuration string \"%s\" : %s\n", str, error);
200 
201 	return 1;
202 }
203 __setup("con", console_chan_setup);
204 __channel_help(console_chan_setup, "con");
205