xref: /openbmc/linux/arch/um/drivers/ssl.c (revision 4dc5a328)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
4  */
5 
6 #include <linux/fs.h>
7 #include <linux/tty.h>
8 #include <linux/tty_driver.h>
9 #include <linux/major.h>
10 #include <linux/mm.h>
11 #include <linux/init.h>
12 #include <linux/console.h>
13 #include <asm/termbits.h>
14 #include <asm/irq.h>
15 #include "chan.h"
16 #include <init.h>
17 #include <irq_user.h>
18 #include "mconsole_kern.h"
19 
20 static const int ssl_version = 1;
21 
22 #define NR_PORTS 64
23 
ssl_announce(char * dev_name,int dev)24 static void ssl_announce(char *dev_name, int dev)
25 {
26 	printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
27 	       dev_name);
28 }
29 
30 /* Almost const, except that xterm_title may be changed in an initcall */
31 static struct chan_opts opts = {
32 	.announce 	= ssl_announce,
33 	.xterm_title	= "Serial Line #%d",
34 	.raw		= 1,
35 };
36 
37 static int ssl_config(char *str, char **error_out);
38 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
39 static int ssl_remove(int n, char **error_out);
40 
41 
42 /* Const, except for .mc.list */
43 static struct line_driver driver = {
44 	.name 			= "UML serial line",
45 	.device_name 		= "ttyS",
46 	.major 			= TTY_MAJOR,
47 	.minor_start 		= 64,
48 	.type 		 	= TTY_DRIVER_TYPE_SERIAL,
49 	.subtype 	 	= 0,
50 	.read_irq_name 		= "ssl",
51 	.write_irq_name 	= "ssl-write",
52 	.mc  = {
53 		.list		= LIST_HEAD_INIT(driver.mc.list),
54 		.name  		= "ssl",
55 		.config 	= ssl_config,
56 		.get_config 	= ssl_get_config,
57 		.id		= line_id,
58 		.remove 	= ssl_remove,
59 	},
60 };
61 
62 /* The array is initialized by line_init, at initcall time.  The
63  * elements are locked individually as needed.
64  */
65 static char *conf[NR_PORTS];
66 static char *def_conf = CONFIG_SSL_CHAN;
67 static struct line serial_lines[NR_PORTS];
68 
ssl_config(char * str,char ** error_out)69 static int ssl_config(char *str, char **error_out)
70 {
71 	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
72 			   error_out);
73 }
74 
ssl_get_config(char * dev,char * str,int size,char ** error_out)75 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
76 {
77 	return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
78 			       size, error_out);
79 }
80 
ssl_remove(int n,char ** error_out)81 static int ssl_remove(int n, char **error_out)
82 {
83 	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
84 			   error_out);
85 }
86 
ssl_install(struct tty_driver * driver,struct tty_struct * tty)87 static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
88 {
89 	return line_install(driver, tty, &serial_lines[tty->index]);
90 }
91 
92 static const struct tty_operations ssl_ops = {
93 	.open 	 		= line_open,
94 	.close 	 		= line_close,
95 	.write 	 		= line_write,
96 	.write_room		= line_write_room,
97 	.chars_in_buffer 	= line_chars_in_buffer,
98 	.flush_buffer 		= line_flush_buffer,
99 	.flush_chars 		= line_flush_chars,
100 	.throttle 		= line_throttle,
101 	.unthrottle 		= line_unthrottle,
102 	.install		= ssl_install,
103 	.hangup			= line_hangup,
104 };
105 
106 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
107  * by being an initcall and exitcall, respectively.
108  */
109 static int ssl_init_done;
110 
ssl_console_write(struct console * c,const char * string,unsigned len)111 static void ssl_console_write(struct console *c, const char *string,
112 			      unsigned len)
113 {
114 	struct line *line = &serial_lines[c->index];
115 	unsigned long flags;
116 
117 	spin_lock_irqsave(&line->lock, flags);
118 	console_write_chan(line->chan_out, string, len);
119 	spin_unlock_irqrestore(&line->lock, flags);
120 }
121 
ssl_console_device(struct console * c,int * index)122 static struct tty_driver *ssl_console_device(struct console *c, int *index)
123 {
124 	*index = c->index;
125 	return driver.driver;
126 }
127 
ssl_console_setup(struct console * co,char * options)128 static int ssl_console_setup(struct console *co, char *options)
129 {
130 	struct line *line = &serial_lines[co->index];
131 
132 	return console_open_chan(line, co);
133 }
134 
135 /* No locking for register_console call - relies on single-threaded initcalls */
136 static struct console ssl_cons = {
137 	.name		= "ttyS",
138 	.write		= ssl_console_write,
139 	.device		= ssl_console_device,
140 	.setup		= ssl_console_setup,
141 	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
142 	.index		= -1,
143 };
144 
ssl_init(void)145 static int ssl_init(void)
146 {
147 	char *new_title;
148 	int err;
149 	int i;
150 
151 	printk(KERN_INFO "Initializing software serial port version %d\n",
152 	       ssl_version);
153 
154 	err = register_lines(&driver, &ssl_ops, serial_lines,
155 				    ARRAY_SIZE(serial_lines));
156 	if (err)
157 		return err;
158 
159 	new_title = add_xterm_umid(opts.xterm_title);
160 	if (new_title != NULL)
161 		opts.xterm_title = new_title;
162 
163 	for (i = 0; i < NR_PORTS; i++) {
164 		char *error;
165 		char *s = conf[i];
166 		if (!s)
167 			s = def_conf;
168 		if (setup_one_line(serial_lines, i, s, &opts, &error))
169 			printk(KERN_ERR "setup_one_line failed for "
170 			       "device %d : %s\n", i, error);
171 	}
172 
173 	ssl_init_done = 1;
174 	register_console(&ssl_cons);
175 	return 0;
176 }
177 late_initcall(ssl_init);
178 
ssl_exit(void)179 static void ssl_exit(void)
180 {
181 	if (!ssl_init_done)
182 		return;
183 	close_lines(serial_lines, ARRAY_SIZE(serial_lines));
184 }
185 __uml_exitcall(ssl_exit);
186 
ssl_chan_setup(char * str)187 static int ssl_chan_setup(char *str)
188 {
189 	line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
190 	return 1;
191 }
192 
193 __setup("ssl", ssl_chan_setup);
194 __channel_help(ssl_chan_setup, "ssl");
195 
ssl_non_raw_setup(char * str)196 static int ssl_non_raw_setup(char *str)
197 {
198 	opts.raw = 0;
199 	return 1;
200 }
201 __setup("ssl-non-raw", ssl_non_raw_setup);
202 __channel_help(ssl_non_raw_setup, "set serial lines to non-raw mode");
203