1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
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
30static void stdio_announce(char *dev_name, int dev)
31{
32	printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
33	       dev_name);
34}
35
36/* Almost const, except that xterm_title may be changed in an initcall */
37static struct chan_opts opts = {
38	.announce 	= stdio_announce,
39	.xterm_title	= "Virtual Console #%d",
40	.raw		= 1,
41};
42
43static int con_config(char *str, char **error_out);
44static int con_get_config(char *dev, char *str, int size, char **error_out);
45static int con_remove(int n, char **con_remove);
46
47
48/* Const, except for .mc.list */
49static struct line_driver driver = {
50	.name 			= "UML console",
51	.device_name 		= "tty",
52	.major 			= TTY_MAJOR,
53	.minor_start 		= 0,
54	.type 		 	= TTY_DRIVER_TYPE_CONSOLE,
55	.subtype 	 	= SYSTEM_TYPE_CONSOLE,
56	.read_irq 		= CONSOLE_IRQ,
57	.read_irq_name 		= "console",
58	.write_irq 		= CONSOLE_WRITE_IRQ,
59	.write_irq_name 	= "console-write",
60	.mc  = {
61		.list		= LIST_HEAD_INIT(driver.mc.list),
62		.name  		= "con",
63		.config 	= con_config,
64		.get_config 	= con_get_config,
65		.id		= line_id,
66		.remove 	= con_remove,
67	},
68};
69
70/* The array is initialized by line_init, at initcall time.  The
71 * elements are locked individually as needed.
72 */
73static char *vt_conf[MAX_TTYS];
74static char *def_conf;
75static struct line vts[MAX_TTYS];
76
77static int con_config(char *str, char **error_out)
78{
79	return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
80}
81
82static int con_get_config(char *dev, char *str, int size, char **error_out)
83{
84	return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
85}
86
87static int con_remove(int n, char **error_out)
88{
89	return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
90}
91
92/* Set in an initcall, checked in an exitcall */
93static int con_init_done = 0;
94
95static int con_install(struct tty_driver *driver, struct tty_struct *tty)
96{
97	return line_install(driver, tty, &vts[tty->index]);
98}
99
100static const struct tty_operations console_ops = {
101	.open 	 		= line_open,
102	.install		= con_install,
103	.close 	 		= line_close,
104	.write 	 		= line_write,
105	.write_room		= line_write_room,
106	.chars_in_buffer 	= line_chars_in_buffer,
107	.flush_buffer 		= line_flush_buffer,
108	.flush_chars 		= line_flush_chars,
109	.set_termios 		= line_set_termios,
110	.throttle 		= line_throttle,
111	.unthrottle 		= line_unthrottle,
112	.hangup			= line_hangup,
113};
114
115static void uml_console_write(struct console *console, const char *string,
116			      unsigned len)
117{
118	struct line *line = &vts[console->index];
119	unsigned long flags;
120
121	spin_lock_irqsave(&line->lock, flags);
122	console_write_chan(line->chan_out, string, len);
123	spin_unlock_irqrestore(&line->lock, flags);
124}
125
126static struct tty_driver *uml_console_device(struct console *c, int *index)
127{
128	*index = c->index;
129	return driver.driver;
130}
131
132static int uml_console_setup(struct console *co, char *options)
133{
134	struct line *line = &vts[co->index];
135
136	return console_open_chan(line, co);
137}
138
139/* No locking for register_console call - relies on single-threaded initcalls */
140static struct console stdiocons = {
141	.name		= "tty",
142	.write		= uml_console_write,
143	.device		= uml_console_device,
144	.setup		= uml_console_setup,
145	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
146	.index		= -1,
147};
148
149static int stdio_init(void)
150{
151	char *new_title;
152	int err;
153	int i;
154
155	err = register_lines(&driver, &console_ops, vts,
156					ARRAY_SIZE(vts));
157	if (err)
158		return err;
159
160	printk(KERN_INFO "Initialized stdio console driver\n");
161
162	new_title = add_xterm_umid(opts.xterm_title);
163	if(new_title != NULL)
164		opts.xterm_title = new_title;
165
166	for (i = 0; i < MAX_TTYS; i++) {
167		char *error;
168		char *s = vt_conf[i];
169		if (!s)
170			s = def_conf;
171		if (!s)
172			s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
173		if (setup_one_line(vts, i, s, &opts, &error))
174			printk(KERN_ERR "setup_one_line failed for "
175			       "device %d : %s\n", i, error);
176	}
177
178	con_init_done = 1;
179	register_console(&stdiocons);
180	return 0;
181}
182late_initcall(stdio_init);
183
184static 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
192static int console_chan_setup(char *str)
193{
194	if (!strncmp(str, "sole=", 5))	/* console= option specifies tty */
195		return 0;
196
197	line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
198	return 1;
199}
200__setup("con", console_chan_setup);
201__channel_help(console_chan_setup, "con");
202