release/src-rt-6.x.4708/linux/linux-2.6.36/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 "irq_user.h"
  26 #include "mconsole_kern.h"
  27 #include "init.h"
  28
  29 #define MAX_TTYS (16)
  30
  31 /* Referenced only by tty_driver below - presumably it's locked correctly
  32  * by the tty driver.
  33  */
  34
  35 static struct tty_driver *console_driver;
  36
  37 static void stdio_announce(char *dev_name, int dev)
  38 {
  39         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  40                dev_name);
  41 }
  42
  43 /* Almost const, except that xterm_title may be changed in an initcall */
  44 static struct chan_opts opts = {
  45         .announce       = stdio_announce,
  46         .xterm_title    = "Virtual Console #%d",
  47         .raw            = 1,
  48 };
  49
  50 static int con_config(char *str, char **error_out);
  51 static int con_get_config(char *dev, char *str, int size, char **error_out);
  52 static int con_remove(int n, char **con_remove);
  53
  54
  55 /* Const, except for .mc.list */
  56 static struct line_driver driver = {
  57         .name                   = "UML console",
  58         .device_name            = "tty",
  59         .major                  = TTY_MAJOR,
  60         .minor_start            = 0,
  61         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  62         .subtype                = SYSTEM_TYPE_CONSOLE,
  63         .read_irq               = CONSOLE_IRQ,
  64         .read_irq_name          = "console",
  65         .write_irq              = CONSOLE_WRITE_IRQ,
  66         .write_irq_name         = "console-write",
  67         .mc  = {
  68                 .list           = LIST_HEAD_INIT(driver.mc.list),
  69                 .name           = "con",
  70                 .config         = con_config,
  71                 .get_config     = con_get_config,
  72                 .id             = line_id,
  73                 .remove         = con_remove,
  74         },
  75 };
  76
  77 /* The array is initialized by line_init, at initcall time.  The
  78  * elements are locked individually as needed.
  79  */
  80 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  81                                      [ 1 ... MAX_TTYS - 1 ] =
  82                                      LINE_INIT(CONFIG_CON_CHAN, &driver) };
  83
  84 static int con_config(char *str, char **error_out)
  85 {
  86         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  87 }
  88
  89 static int con_get_config(char *dev, char *str, int size, char **error_out)
  90 {
  91         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  92 }
  93
  94 static int con_remove(int n, char **error_out)
  95 {
  96         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
  97 }
  98
  99 static int con_open(struct tty_struct *tty, struct file *filp)
 100 {
 101         int err = line_open(vts, tty);
 102         if (err)
 103                 printk(KERN_ERR "Failed to open console %d, err = %d\n",
 104                        tty->index, err);
 105
 106         return err;
 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 /* No locking for register_console call - relies on single-threaded initcalls */
 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|CON_ANYTIME,
 158         .index          = -1,
 159 };
 160
 161 static int stdio_init(void)
 162 {
 163         char *new_title;
 164
 165         console_driver = register_lines(&driver, &console_ops, vts,
 166                                         ARRAY_SIZE(vts));
 167         if (console_driver == NULL)
 168                 return -1;
 169         printk(KERN_INFO "Initialized stdio console driver\n");
 170
 171         new_title = add_xterm_umid(opts.xterm_title);
 172         if(new_title != NULL)
 173                 opts.xterm_title = new_title;
 174
 175         lines_init(vts, ARRAY_SIZE(vts), &opts);
 176
 177         con_init_done = 1;
 178         register_console(&stdiocons);
 179         return 0;
 180 }
 181 late_initcall(stdio_init);
 182
 183 static void console_exit(void)
 184 {
 185         if (!con_init_done)
 186                 return;
 187         close_lines(vts, ARRAY_SIZE(vts));
 188 }
 189 __uml_exitcall(console_exit);
 190
 191 static int console_chan_setup(char *str)
 192 {
 193         char *error;
 194         int ret;
 195
 196         ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
 197         if(ret < 0)
 198                 printk(KERN_ERR "Failed to set up console with "
 199                        "configuration string \"%s\" : %s\n", str, error);
 200
 201         return 1;
 202 }
 203 __setup("con", console_chan_setup);
 204 __channel_help(console_chan_setup, "con");