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/config.h"
   7 #include "linux/posix_types.h"
   8 #include "linux/tty.h"
   9 #include "linux/tty_flip.h"
  10 #include "linux/types.h"
  11 #include "linux/major.h"
  12 #include "linux/kdev_t.h"
  13 #include "linux/console.h"
  14 #include "linux/string.h"
  15 #include "linux/sched.h"
  16 #include "linux/list.h"
  17 #include "linux/init.h"
  18 #include "linux/interrupt.h"
  19 #include "linux/slab.h"
  20 #include "linux/hardirq.h"
  21 #include "asm/current.h"
  22 #include "asm/irq.h"
  23 #include "stdio_console.h"
  24 #include "line.h"
  25 #include "chan_kern.h"
  26 #include "user_util.h"
  27 #include "kern_util.h"
  28 #include "irq_user.h"
  29 #include "mconsole_kern.h"
  30 #include "init.h"
  31
  32 #define MAX_TTYS (16)
  33
  34 /* ----------------------------------------------------------------------------- */
  35
  36 /* Referenced only by tty_driver below - presumably it's locked correctly
  37  * by the tty driver.
  38  */
  39
  40 static struct tty_driver *console_driver;
  41
  42 void stdio_announce(char *dev_name, int dev)
  43 {
  44         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  45                dev_name);
  46 }
  47
  48 static struct chan_opts opts = {
  49         .announce       = stdio_announce,
  50         .xterm_title    = "Virtual Console #%d",
  51         .raw            = 1,
  52         .tramp_stack    = 0,
  53         .in_kernel      = 1,
  54 };
  55
  56 static int con_config(char *str);
  57 static int con_get_config(char *dev, char *str, int size, char **error_out);
  58 static int con_remove(int n);
  59
  60 static struct line_driver driver = {
  61         .name                   = "UML console",
  62         .device_name            = "tty",
  63         .devfs_name             = "vc/",
  64         .major                  = TTY_MAJOR,
  65         .minor_start            = 0,
  66         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  67         .subtype                = SYSTEM_TYPE_CONSOLE,
  68         .read_irq               = CONSOLE_IRQ,
  69         .read_irq_name          = "console",
  70         .write_irq              = CONSOLE_WRITE_IRQ,
  71         .write_irq_name         = "console-write",
  72         .symlink_from           = "ttys",
  73         .symlink_to             = "vc",
  74         .mc  = {
  75                 .name           = "con",
  76                 .config         = con_config,
  77                 .get_config     = con_get_config,
  78                 .id             = line_id,
  79                 .remove         = con_remove,
  80         },
  81 };
  82
  83 static struct lines console_lines = LINES_INIT(MAX_TTYS);
  84
  85 /* The array is initialized by line_init, which is an initcall.  The
  86  * individual elements are protected by individual semaphores.
  87  */
  88 struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  89                               [ 1 ... MAX_TTYS - 1 ] =
  90                               LINE_INIT(CONFIG_CON_CHAN, &driver) };
  91
  92 static int con_config(char *str)
  93 {
  94         return line_config(vts, ARRAY_SIZE(vts), str, &opts);
  95 }
  96
  97 static int con_get_config(char *dev, char *str, int size, char **error_out)
  98 {
  99         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
 100 }
 101
 102 static int con_remove(int n)
 103 {
 104         return line_remove(vts, ARRAY_SIZE(vts), n);
 105 }
 106
 107 static int con_open(struct tty_struct *tty, struct file *filp)
 108 {
 109         return line_open(vts, tty);
 110 }
 111
 112 static int con_init_done = 0;
 113
 114 static struct tty_operations console_ops = {
 115         .open                   = con_open,
 116         .close                  = line_close,
 117         .write                  = line_write,
 118         .put_char               = line_put_char,
 119         .write_room             = line_write_room,
 120         .chars_in_buffer        = line_chars_in_buffer,
 121         .flush_buffer           = line_flush_buffer,
 122         .flush_chars            = line_flush_chars,
 123         .set_termios            = line_set_termios,
 124         .ioctl                  = line_ioctl,
 125         .throttle               = line_throttle,
 126         .unthrottle             = line_unthrottle,
 127 };
 128
 129 static void uml_console_write(struct console *console, const char *string,
 130                               unsigned len)
 131 {
 132         struct line *line = &vts[console->index];
 133         unsigned long flags;
 134
 135         spin_lock_irqsave(&line->lock, flags);
 136         console_write_chan(&line->chan_list, string, len);
 137         spin_unlock_irqrestore(&line->lock, flags);
 138 }
 139
 140 static struct tty_driver *uml_console_device(struct console *c, int *index)
 141 {
 142         *index = c->index;
 143         return console_driver;
 144 }
 145
 146 static int uml_console_setup(struct console *co, char *options)
 147 {
 148         struct line *line = &vts[co->index];
 149
 150         return console_open_chan(line, co, &opts);
 151 }
 152
 153 static struct console stdiocons = {
 154         .name           = "tty",
 155         .write          = uml_console_write,
 156         .device         = uml_console_device,
 157         .setup          = uml_console_setup,
 158         .flags          = CON_PRINTBUFFER,
 159         .index          = -1,
 160         .data           = &vts,
 161 };
 162
 163 int stdio_init(void)
 164 {
 165         char *new_title;
 166
 167         console_driver = line_register_devfs(&console_lines, &driver,
 168                                              &console_ops, vts,
 169                                              ARRAY_SIZE(vts));
 170         if (console_driver == NULL)
 171                 return -1;
 172         printk(KERN_INFO "Initialized stdio console driver\n");
 173
 174         lines_init(vts, ARRAY_SIZE(vts), &opts);
 175
 176         new_title = add_xterm_umid(opts.xterm_title);
 177         if(new_title != NULL)
 178                 opts.xterm_title = new_title;
 179
 180         con_init_done = 1;
 181         register_console(&stdiocons);
 182         return 0;
 183 }
 184 late_initcall(stdio_init);
 185
 186 static void console_exit(void)
 187 {
 188         if (!con_init_done)
 189                 return;
 190         close_lines(vts, ARRAY_SIZE(vts));
 191 }
 192 __uml_exitcall(console_exit);
 193
 194 static int console_chan_setup(char *str)
 195 {
 196         return line_setup(vts, ARRAY_SIZE(vts), str);
 197 }
 198 __setup("con", console_chan_setup);
 199 __channel_help(console_chan_setup, "con");