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         .tramp_stack    = 0,
  50         .in_kernel      = 1,
  51 };
  52
  53 static int con_config(char *str, char **error_out);
  54 static int con_get_config(char *dev, char *str, int size, char **error_out);
  55 static int con_remove(int n, char **con_remove);
  56
  57
  58 /* Const, except for .mc.list */
  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         .mc  = {
  71                 .list           = LIST_HEAD_INIT(driver.mc.list),
  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 /* The array is initialized by line_init, at initcall time.  The
  81  * elements are locked individually as needed.
  82  */
  83 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  84                                      [ 1 ... MAX_TTYS - 1 ] =
  85                                      LINE_INIT(CONFIG_CON_CHAN, &driver) };
  86
  87 static int con_config(char *str, char **error_out)
  88 {
  89         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  90 }
  91
  92 static int con_get_config(char *dev, char *str, int size, char **error_out)
  93 {
  94         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  95 }
  96
  97 static int con_remove(int n, char **error_out)
  98 {
  99         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
 100 }
 101
 102 static int con_open(struct tty_struct *tty, struct file *filp)
 103 {
 104         return line_open(vts, tty);
 105 }
 106
 107 /* Set in an initcall, checked in an exitcall */
 108 static int con_init_done = 0;
 109
 110 static const struct tty_operations console_ops = {
 111         .open                   = con_open,
 112         .close                  = line_close,
 113         .write                  = line_write,
 114         .put_char               = line_put_char,
 115         .write_room             = line_write_room,
 116         .chars_in_buffer        = line_chars_in_buffer,
 117         .flush_buffer           = line_flush_buffer,
 118         .flush_chars            = line_flush_chars,
 119         .set_termios            = line_set_termios,
 120         .ioctl                  = line_ioctl,
 121         .throttle               = line_throttle,
 122         .unthrottle             = line_unthrottle,
 123 };
 124
 125 static void uml_console_write(struct console *console, const char *string,
 126                               unsigned len)
 127 {
 128         struct line *line = &vts[console->index];
 129         unsigned long flags;
 130
 131         spin_lock_irqsave(&line->lock, flags);
 132         console_write_chan(&line->chan_list, string, len);
 133         spin_unlock_irqrestore(&line->lock, flags);
 134 }
 135
 136 static struct tty_driver *uml_console_device(struct console *c, int *index)
 137 {
 138         *index = c->index;
 139         return console_driver;
 140 }
 141
 142 static int uml_console_setup(struct console *co, char *options)
 143 {
 144         struct line *line = &vts[co->index];
 145
 146         return console_open_chan(line, co);
 147 }
 148
 149 /* No locking for register_console call - relies on single-threaded initcalls */
 150 static struct console stdiocons = {
 151         .name           = "tty",
 152         .write          = uml_console_write,
 153         .device         = uml_console_device,
 154         .setup          = uml_console_setup,
 155         .flags          = CON_PRINTBUFFER|CON_ANYTIME,
 156         .index          = -1,
 157 };
 158
 159 int stdio_init(void)
 160 {
 161         char *new_title;
 162
 163         console_driver = register_lines(&driver, &console_ops, vts,
 164                                         ARRAY_SIZE(vts));
 165         if (console_driver == NULL)
 166                 return -1;
 167         printk(KERN_INFO "Initialized stdio console driver\n");
 168
 169         new_title = add_xterm_umid(opts.xterm_title);
 170         if(new_title != NULL)
 171                 opts.xterm_title = new_title;
 172
 173         lines_init(vts, ARRAY_SIZE(vts), &opts);
 174
 175         con_init_done = 1;
 176         register_console(&stdiocons);
 177         return 0;
 178 }
 179 late_initcall(stdio_init);
 180
 181 static void console_exit(void)
 182 {
 183         if (!con_init_done)
 184                 return;
 185         close_lines(vts, ARRAY_SIZE(vts));
 186 }
 187 __uml_exitcall(console_exit);
 188
 189 static int console_chan_setup(char *str)
 190 {
 191         char *error;
 192         int ret;
 193
 194         ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
 195         if(ret < 0)
 196                 printk(KERN_ERR "Failed to set up console with "
 197                        "configuration string \"%s\" : %s\n", str, error);
 198
 199         return 1;
 200 }
 201 __setup("con", console_chan_setup);
 202 __channel_help(console_chan_setup, "con");