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