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_name = "console",
57 .write_irq_name = "console-write",
58 .mc = {
59 .list = LIST_HEAD_INIT(driver.mc.list),
60 .name = "con",
61 .config = con_config,
62 .get_config = con_get_config,
63 .id = line_id,
64 .remove = con_remove,
65 },
66};
67
68/* The array is initialized by line_init, at initcall time. The
69 * elements are locked individually as needed.
70 */
71static char *vt_conf[MAX_TTYS];
72static char *def_conf;
73static struct line vts[MAX_TTYS];
74
75static int con_config(char *str, char **error_out)
76{
77 return line_config(lines: vts, ARRAY_SIZE(vts), str, opts: &opts, error_out);
78}
79
80static int con_get_config(char *dev, char *str, int size, char **error_out)
81{
82 return line_get_config(dev, lines: vts, ARRAY_SIZE(vts), str, size, error_out);
83}
84
85static int con_remove(int n, char **error_out)
86{
87 return line_remove(lines: vts, ARRAY_SIZE(vts), n, error_out);
88}
89
90/* Set in an initcall, checked in an exitcall */
91static int con_init_done;
92
93static int con_install(struct tty_driver *driver, struct tty_struct *tty)
94{
95 return line_install(driver, tty, line: &vts[tty->index]);
96}
97
98static const struct tty_operations console_ops = {
99 .open = line_open,
100 .install = con_install,
101 .close = line_close,
102 .write = line_write,
103 .write_room = line_write_room,
104 .chars_in_buffer = line_chars_in_buffer,
105 .flush_buffer = line_flush_buffer,
106 .flush_chars = line_flush_chars,
107 .throttle = line_throttle,
108 .unthrottle = line_unthrottle,
109 .hangup = line_hangup,
110};
111
112static void uml_console_write(struct console *console, const char *string,
113 unsigned len)
114{
115 struct line *line = &vts[console->index];
116 unsigned long flags;
117
118 spin_lock_irqsave(&line->lock, flags);
119 console_write_chan(chan: line->chan_out, buf: string, len);
120 spin_unlock_irqrestore(lock: &line->lock, flags);
121}
122
123static struct tty_driver *uml_console_device(struct console *c, int *index)
124{
125 *index = c->index;
126 return driver.driver;
127}
128
129static int uml_console_setup(struct console *co, char *options)
130{
131 struct line *line = &vts[co->index];
132
133 return console_open_chan(line, co);
134}
135
136/* No locking for register_console call - relies on single-threaded initcalls */
137static struct console stdiocons = {
138 .name = "tty",
139 .write = uml_console_write,
140 .device = uml_console_device,
141 .setup = uml_console_setup,
142 .flags = CON_PRINTBUFFER|CON_ANYTIME,
143 .index = -1,
144};
145
146static int stdio_init(void)
147{
148 char *new_title;
149 int err;
150 int i;
151
152 err = register_lines(line_driver: &driver, driver: &console_ops, lines: vts,
153 ARRAY_SIZE(vts));
154 if (err)
155 return err;
156
157 printk(KERN_INFO "Initialized stdio console driver\n");
158
159 new_title = add_xterm_umid(base: opts.xterm_title);
160 if(new_title != NULL)
161 opts.xterm_title = new_title;
162
163 for (i = 0; i < MAX_TTYS; i++) {
164 char *error;
165 char *s = vt_conf[i];
166 if (!s)
167 s = def_conf;
168 if (!s)
169 s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
170 if (setup_one_line(lines: vts, n: i, init: s, opts: &opts, error_out: &error))
171 printk(KERN_ERR "setup_one_line failed for "
172 "device %d : %s\n", i, error);
173 }
174
175 con_init_done = 1;
176 register_console(&stdiocons);
177 return 0;
178}
179late_initcall(stdio_init);
180
181static void console_exit(void)
182{
183 if (!con_init_done)
184 return;
185 close_lines(lines: vts, ARRAY_SIZE(vts));
186}
187__uml_exitcall(console_exit);
188
189static int console_chan_setup(char *str)
190{
191 if (!strncmp(str, "sole=", 5)) /* console= option specifies tty */
192 return 0;
193
194 line_setup(conf: vt_conf, MAX_TTYS, def: &def_conf, init: str, name: "console");
195 return 1;
196}
197__setup("con", console_chan_setup);
198__channel_help(console_chan_setup, "con");
199

source code of linux/arch/um/drivers/stdio_console.c