arch/um/drivers/stdio_console.c

   1 /*
   2  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   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 "line.h"
  24 #include "chan_kern.h"
  25 #include "user_util.h"
  26 #include "kern_util.h"
  27 #include "irq_user.h"
  28 #include "mconsole_kern.h"
  29 #include "init.h"
  30
  31 #define MAX_TTYS (16)
  32
  33 /* Referenced only by tty_driver below - presumably it's locked correctly
  34  * by the tty driver.
  35  */
  36
  37 static struct tty_driver *console_driver;
  38
  39 void stdio_announce(char *dev_name, int dev)
  40 {
  41         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  42                dev_name);
  43 }
  44
  45 /* Almost const, except that xterm_title may be changed in an initcall */
  46 static struct chan_opts opts = {
  47         .announce       = stdio_announce,
  48         .xterm_title    = "Virtual Console #%d",
  49         .raw            = 1,
  50         .tramp_stack    = 0,
  51         .in_kernel      = 1,
  52 };
  53
  54 static int con_config(char *str, char **error_out);
  55 static int con_get_config(char *dev, char *str, int size, char **error_out);
  56 static int con_remove(int n, char **con_remove);
  57
  58 static struct line_driver driver = {
  59         .name                   = "UML console",
  60         .device_name            = "tty",
  61         .major                  = TTY_MAJOR,
  62         .minor_start            = 0,
  63         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  64         .subtype                = SYSTEM_TYPE_CONSOLE,
  65         .read_irq               = CONSOLE_IRQ,
  66         .read_irq_name          = "console",
  67         .write_irq              = CONSOLE_WRITE_IRQ,
  68         .write_irq_name         = "console-write",
  69         .symlink_from           = "ttys",
  70         .symlink_to             = "vc",
  71         .mc  = {
  72                 .name           = "con",
  73                 .config         = con_config,
  74                 .get_config     = con_get_config,
  75                 .id             = line_id,
  76                 .remove         = con_remove,
  77         },
  78 };
  79
  80 static struct lines console_lines = LINES_INIT(MAX_TTYS);
  81
  82 /* The array is initialized by line_init, which is an initcall.  The
  83  * individual elements are protected by individual semaphores.
  84  */
  85 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  86                                      [ 1 ... MAX_TTYS - 1 ] =
  87                                      LINE_INIT(CONFIG_CON_CHAN, &driver) };
  88
  89 static int con_config(char *str, char **error_out)
  90 {
  91         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  92 }
  93
  94 static int con_get_config(char *dev, char *str, int size, char **error_out)
  95 {
  96         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  97 }
  98
  99 static int con_remove(int n, char **error_out)
 100 {
 101         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
 102 }
 103
 104 static int con_open(struct tty_struct *tty, struct file *filp)
 105 {
 106         return line_open(vts, tty);
 107 }
 108
 109 /* Set in an initcall, checked in an exitcall */
 110 static int con_init_done = 0;
 111
 112 static const struct tty_operations console_ops = {
 113         .open                   = con_open,
 114         .close                  = line_close,
 115         .write                  = line_write,
 116         .put_char               = line_put_char,
 117         .write_room             = line_write_room,
 118         .chars_in_buffer        = line_chars_in_buffer,
 119         .flush_buffer           = line_flush_buffer,
 120         .flush_chars            = line_flush_chars,
 121         .set_termios            = line_set_termios,
 122         .ioctl                  = line_ioctl,
 123         .throttle               = line_throttle,
 124         .unthrottle             = line_unthrottle,
 125 };
 126
 127 static void uml_console_write(struct console *console, const char *string,
 128                               unsigned len)
 129 {
 130         struct line *line = &vts[console->index];
 131         unsigned long flags;
 132
 133         spin_lock_irqsave(&line->lock, flags);
 134         console_write_chan(&line->chan_list, string, len);
 135         spin_unlock_irqrestore(&line->lock, flags);
 136 }
 137
 138 static struct tty_driver *uml_console_device(struct console *c, int *index)
 139 {
 140         *index = c->index;
 141         return console_driver;
 142 }
 143
 144 static int uml_console_setup(struct console *co, char *options)
 145 {
 146         struct line *line = &vts[co->index];
 147
 148         return console_open_chan(line, co);
 149 }
 150
 151 static struct console stdiocons = {
 152         .name           = "tty",
 153         .write          = uml_console_write,
 154         .device         = uml_console_device,
 155         .setup          = uml_console_setup,
 156         .flags          = CON_PRINTBUFFER,
 157         .index          = -1,
 158         .data           = &vts,
 159 };
 160
 161 int stdio_init(void)
 162 {
 163         char *new_title;
 164
 165         console_driver = line_register_devfs(&console_lines, &driver,
 166                                              &console_ops, vts,
 167                                              ARRAY_SIZE(vts));
 168         if (console_driver == NULL)
 169                 return -1;
 170         printk(KERN_INFO "Initialized stdio console driver\n");
 171
 172         lines_init(vts, ARRAY_SIZE(vts), &opts);
 173
 174         new_title = add_xterm_umid(opts.xterm_title);
 175         if(new_title != NULL)
 176                 opts.xterm_title = new_title;
 177
 178         con_init_done = 1;
 179         register_console(&stdiocons);
 180         return 0;
 181 }
 182 late_initcall(stdio_init);
 183
 184 static 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
 192 static int console_chan_setup(char *str)
 193 {
 194         char *error;
 195         int ret;
 196
 197         ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
 198         if(ret < 0)
 199                 printk(KERN_ERR "Failed to set up console with "
 200                        "configuration string \"%s\" : %s\n", str, error);
 201
 202         return 1;
 203 }
 204 __setup("con", console_chan_setup);
 205 __channel_help(console_chan_setup, "con");