[PATCH] uml: mconsole locking
[linux-2.6] / arch / um / drivers / ssl.c
1 /* 
2  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
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 "line.h"
16 #include "ssl.h"
17 #include "chan_kern.h"
18 #include "user_util.h"
19 #include "kern_util.h"
20 #include "kern.h"
21 #include "init.h"
22 #include "irq_user.h"
23 #include "mconsole_kern.h"
24
25 static const int ssl_version = 1;
26
27 /* Referenced only by tty_driver below - presumably it's locked correctly
28  * by the tty driver.
29  */
30
31 static struct tty_driver *ssl_driver;
32
33 #define NR_PORTS 64
34
35 static void ssl_announce(char *dev_name, int dev)
36 {
37         printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
38                dev_name);
39 }
40
41 static struct chan_opts opts = {
42         .announce       = ssl_announce,
43         .xterm_title    = "Serial Line #%d",
44         .raw            = 1,
45         .tramp_stack    = 0,
46         .in_kernel      = 1,
47 };
48
49 static int ssl_config(char *str, char **error_out);
50 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
51 static int ssl_remove(int n, char **error_out);
52
53 static struct line_driver driver = {
54         .name                   = "UML serial line",
55         .device_name            = "ttyS",
56         .major                  = TTY_MAJOR,
57         .minor_start            = 64,
58         .type                   = TTY_DRIVER_TYPE_SERIAL,
59         .subtype                = 0,
60         .read_irq               = SSL_IRQ,
61         .read_irq_name          = "ssl",
62         .write_irq              = SSL_WRITE_IRQ,
63         .write_irq_name         = "ssl-write",
64         .symlink_from           = "serial",
65         .symlink_to             = "tts",
66         .mc  = {
67                 .list           = LIST_HEAD_INIT(driver.mc.list),
68                 .name           = "ssl",
69                 .config         = ssl_config,
70                 .get_config     = ssl_get_config,
71                 .id             = line_id,
72                 .remove         = ssl_remove,
73         },
74 };
75
76 /* The array is initialized by line_init, which is an initcall.  The 
77  * individual elements are protected by individual semaphores.
78  */
79 static struct line serial_lines[NR_PORTS] =
80         { [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
81
82 static struct lines lines = LINES_INIT(NR_PORTS);
83
84 static int ssl_config(char *str, char **error_out)
85 {
86         return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
87                            error_out);
88 }
89
90 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
91 {
92         return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
93                                size, error_out);
94 }
95
96 static int ssl_remove(int n, char **error_out)
97 {
98         return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
99                            error_out);
100 }
101
102 static int ssl_open(struct tty_struct *tty, struct file *filp)
103 {
104         return line_open(serial_lines, tty);
105 }
106
107 #if 0
108 static void ssl_flush_buffer(struct tty_struct *tty)
109 {
110         return;
111 }
112
113 static void ssl_stop(struct tty_struct *tty)
114 {
115         printk(KERN_ERR "Someone should implement ssl_stop\n");
116 }
117
118 static void ssl_start(struct tty_struct *tty)
119 {
120         printk(KERN_ERR "Someone should implement ssl_start\n");
121 }
122
123 void ssl_hangup(struct tty_struct *tty)
124 {
125 }
126 #endif
127
128 static const struct tty_operations ssl_ops = {
129         .open                   = ssl_open,
130         .close                  = line_close,
131         .write                  = line_write,
132         .put_char               = line_put_char,
133         .write_room             = line_write_room,
134         .chars_in_buffer        = line_chars_in_buffer,
135         .flush_buffer           = line_flush_buffer,
136         .flush_chars            = line_flush_chars,
137         .set_termios            = line_set_termios,
138         .ioctl                  = line_ioctl,
139         .throttle               = line_throttle,
140         .unthrottle             = line_unthrottle,
141 #if 0
142         .stop                   = ssl_stop,
143         .start                  = ssl_start,
144         .hangup                 = ssl_hangup,
145 #endif
146 };
147
148 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
149  * by being an initcall and exitcall, respectively.
150  */
151 static int ssl_init_done = 0;
152
153 static void ssl_console_write(struct console *c, const char *string,
154                               unsigned len)
155 {
156         struct line *line = &serial_lines[c->index];
157         unsigned long flags;
158
159         spin_lock_irqsave(&line->lock, flags);
160         console_write_chan(&line->chan_list, string, len);
161         spin_unlock_irqrestore(&line->lock, flags);
162 }
163
164 static struct tty_driver *ssl_console_device(struct console *c, int *index)
165 {
166         *index = c->index;
167         return ssl_driver;
168 }
169
170 static int ssl_console_setup(struct console *co, char *options)
171 {
172         struct line *line = &serial_lines[co->index];
173
174         return console_open_chan(line, co, &opts);
175 }
176
177 static struct console ssl_cons = {
178         .name           = "ttyS",
179         .write          = ssl_console_write,
180         .device         = ssl_console_device,
181         .setup          = ssl_console_setup,
182         .flags          = CON_PRINTBUFFER,
183         .index          = -1,
184 };
185
186 static int ssl_init(void)
187 {
188         char *new_title;
189
190         printk(KERN_INFO "Initializing software serial port version %d\n",
191                ssl_version);
192         ssl_driver = line_register_devfs(&lines, &driver, &ssl_ops,
193                                          serial_lines,
194                                          ARRAY_SIZE(serial_lines));
195
196         lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
197
198         new_title = add_xterm_umid(opts.xterm_title);
199         if (new_title != NULL)
200                 opts.xterm_title = new_title;
201
202         ssl_init_done = 1;
203         register_console(&ssl_cons);
204         return 0;
205 }
206 late_initcall(ssl_init);
207
208 static void ssl_exit(void)
209 {
210         if (!ssl_init_done)
211                 return;
212         close_lines(serial_lines, ARRAY_SIZE(serial_lines));
213 }
214 __uml_exitcall(ssl_exit);
215
216 static int ssl_chan_setup(char *str)
217 {
218         char *error;
219         int ret;
220
221         ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
222         if(ret < 0)
223                 printk(KERN_ERR "Failed to set up serial line with "
224                        "configuration string \"%s\" : %s\n", str, error);
225
226         return 1;
227 }
228
229 __setup("ssl", ssl_chan_setup);
230 __channel_help(ssl_chan_setup, "ssl");