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 "kern_util.h"
  26 #include "irq_user.h"
  27 #include "mconsole_kern.h"
  28 #include "init.h"
  29
  30 #define MAX_TTYS (16)
  31
  32 /* Referenced only by tty_driver below - presumably it's locked correctly
  33  * by the tty driver.
  34  */
  35
  36 static struct tty_driver *console_driver;
  37
  38 void stdio_announce(char *dev_name, int dev)
  39 {
  40         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  41                dev_name);
  42 }
  43
  44 /* Almost const, except that xterm_title may be changed in an initcall */
  45 static struct chan_opts opts = {
  46         .announce       = stdio_announce,
  47         .xterm_title    = "Virtual Console #%d",
  48         .raw            = 1,
  49 };
  50
  51 static int con_config(char *str, char **error_out);
  52 static int con_get_config(char *dev, char *str, int size, char **error_out);
  53 static int con_remove(int n, char **con_remove);
  54
  55
  56 /* Const, except for .mc.list */
  57 static struct line_driver driver = {
  58         .name                   = "UML console",
  59         .device_name            = "tty",
  60         .major                  = TTY_MAJOR,
  61         .minor_start            = 0,
  62         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  63         .subtype                = SYSTEM_TYPE_CONSOLE,
  64         .read_irq               = CONSOLE_IRQ,
  65         .read_irq_name          = "console",
  66         .write_irq              = CONSOLE_WRITE_IRQ,
  67         .write_irq_name         = "console-write",
  68         .mc  = {
  69                 .list           = LIST_HEAD_INIT(driver.mc.list),
  70                 .name           = "con",
  71                 .config         = con_config,
  72                 .get_config     = con_get_config,
  73                 .id             = line_id,
  74                 .remove         = con_remove,
  75         },
  76 };
  77
  78 /* The array is initialized by line_init, at initcall time.  The
  79  * elements are locked individually as needed.
  80  */
  81 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  82                                      [ 1 ... MAX_TTYS - 1 ] =
  83                                      LINE_INIT(CONFIG_CON_CHAN, &driver) };
  84
  85 static int con_config(char *str, char **error_out)
  86 {
  87         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  88 }
  89
  90 static int con_get_config(char *dev, char *str, int size, char **error_out)
  91 {
  92         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  93 }
  94
  95 static int con_remove(int n, char **error_out)
  96 {
  97         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
  98 }
  99
 100 static int con_open(struct tty_struct *tty, struct file *filp)
 101 {
 102         int err = line_open(vts, tty);
 103         if (err)
 104                 printk(KERN_ERR "Failed to open console %d, err = %d\n",
 105                        tty->index, err);
 106
 107         return err;
 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);
 150 }
 151
 152 /* No locking for register_console call - relies on single-threaded initcalls */
 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|CON_ANYTIME,
 159         .index          = -1,
 160 };
 161
 162 int stdio_init(void)
 163 {
 164         char *new_title;
 165
 166         console_driver = register_lines(&driver, &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         new_title = add_xterm_umid(opts.xterm_title);
 173         if(new_title != NULL)
 174                 opts.xterm_title = new_title;
 175
 176         lines_init(vts, ARRAY_SIZE(vts), &opts);
 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");