arch/um/drivers/ssl.c

   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
  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               = SSL_IRQ,
  51         .read_irq_name          = "ssl",
  52         .write_irq              = SSL_WRITE_IRQ,
  53         .write_irq_name         = "ssl-write",
  54         .mc  = {
  55                 .list           = LIST_HEAD_INIT(driver.mc.list),
  56                 .name           = "ssl",
  57                 .config         = ssl_config,
  58                 .get_config     = ssl_get_config,
  59                 .id             = line_id,
  60                 .remove         = ssl_remove,
  61         },
  62 };
  63
  64 /* The array is initialized by line_init, at initcall time.  The
  65  * elements are locked individually as needed.
  66  */
  67 static char *conf[NR_PORTS];
  68 static char *def_conf = CONFIG_SSL_CHAN;
  69 static struct line serial_lines[NR_PORTS];
  70
  71 static int ssl_config(char *str, char **error_out)
  72 {
  73         return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
  74                            error_out);
  75 }
  76
  77 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
  78 {
  79         return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
  80                                size, error_out);
  81 }
  82
  83 static int ssl_remove(int n, char **error_out)
  84 {
  85         return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
  86                            error_out);
  87 }
  88
  89 static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
  90 {
  91         return line_install(driver, tty, &serial_lines[tty->index]);
  92 }
  93
  94 static const struct tty_operations ssl_ops = {
  95         .open                   = line_open,
  96         .close                  = line_close,
  97         .write                  = line_write,
  98         .put_char               = line_put_char,
  99         .write_room             = line_write_room,
 100         .chars_in_buffer        = line_chars_in_buffer,
 101         .flush_buffer           = line_flush_buffer,
 102         .flush_chars            = line_flush_chars,
 103         .set_termios            = line_set_termios,
 104         .throttle               = line_throttle,
 105         .unthrottle             = line_unthrottle,
 106         .install                = ssl_install,
 107         .hangup                 = line_hangup,
 108 };
 109
 110 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
 111  * by being an initcall and exitcall, respectively.
 112  */
 113 static int ssl_init_done = 0;
 114
 115 static void ssl_console_write(struct console *c, const char *string,
 116                               unsigned len)
 117 {
 118         struct line *line = &serial_lines[c->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
 126 static struct tty_driver *ssl_console_device(struct console *c, int *index)
 127 {
 128         *index = c->index;
 129         return driver.driver;
 130 }
 131
 132 static int ssl_console_setup(struct console *co, char *options)
 133 {
 134         struct line *line = &serial_lines[co->index];
 135
 136         return console_open_chan(line, co);
 137 }
 138
 139 /* No locking for register_console call - relies on single-threaded initcalls */
 140 static struct console ssl_cons = {
 141         .name           = "ttyS",
 142         .write          = ssl_console_write,
 143         .device         = ssl_console_device,
 144         .setup          = ssl_console_setup,
 145         .flags          = CON_PRINTBUFFER|CON_ANYTIME,
 146         .index          = -1,
 147 };
 148
 149 static int ssl_init(void)
 150 {
 151         char *new_title;
 152         int err;
 153         int i;
 154
 155         printk(KERN_INFO "Initializing software serial port version %d\n",
 156                ssl_version);
 157
 158         err = register_lines(&driver, &ssl_ops, serial_lines,
 159                                     ARRAY_SIZE(serial_lines));
 160         if (err)
 161                 return err;
 162
 163         new_title = add_xterm_umid(opts.xterm_title);
 164         if (new_title != NULL)
 165                 opts.xterm_title = new_title;
 166
 167         for (i = 0; i < NR_PORTS; i++) {
 168                 char *error;
 169                 char *s = conf[i];
 170                 if (!s)
 171                         s = def_conf;
 172                 if (setup_one_line(serial_lines, i, s, &opts, &error))
 173                         printk(KERN_ERR "setup_one_line failed for "
 174                                "device %d : %s\n", i, error);
 175         }
 176
 177         ssl_init_done = 1;
 178         register_console(&ssl_cons);
 179         return 0;
 180 }
 181 late_initcall(ssl_init);
 182
 183 static void ssl_exit(void)
 184 {
 185         if (!ssl_init_done)
 186                 return;
 187         close_lines(serial_lines, ARRAY_SIZE(serial_lines));
 188 }
 189 __uml_exitcall(ssl_exit);
 190
 191 static int ssl_chan_setup(char *str)
 192 {
 193         line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
 194         return 1;
 195 }
 196
 197 __setup("ssl", ssl_chan_setup);
 198 __channel_help(ssl_chan_setup, "ssl");
 199
 200 static int ssl_non_raw_setup(char *str)
 201 {
 202         opts.raw = 0;
 203         return 1;
 204 }
 205 __setup("ssl-non-raw", ssl_non_raw_setup);
 206 __channel_help(ssl_non_raw_setup, "set serial lines to non-raw mode");