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, sizeof(vts)/sizeof(vts[0]), str));
  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, sizeof(vts)/sizeof(vts[0]), str,
 100                                size, error_out));
 101 }
 102
 103 static int con_remove(int n)
 104 {
 105         return line_remove(vts, sizeof(vts)/sizeof(vts[0]), n);
 106 }
 107
 108 static int con_open(struct tty_struct *tty, struct file *filp)
 109 {
 110         return line_open(vts, tty, &opts);
 111 }
 112
 113 static int con_init_done = 0;
 114
 115 static struct tty_operations console_ops = {
 116         .open                   = con_open,
 117         .close                  = line_close,
 118         .write                  = line_write,
 119         .put_char               = line_put_char,
 120         .write_room             = line_write_room,
 121         .chars_in_buffer        = line_chars_in_buffer,
 122         .flush_buffer           = line_flush_buffer,
 123         .flush_chars            = line_flush_chars,
 124         .set_termios            = line_set_termios,
 125         .ioctl                  = line_ioctl,
 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 (NULL == console_driver)
 170                 return -1;
 171         printk(KERN_INFO "Initialized stdio console driver\n");
 172
 173         lines_init(vts, sizeof(vts)/sizeof(vts[0]));
 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, sizeof(vts)/sizeof(vts[0]));
 190 }
 191 __uml_exitcall(console_exit);
 192
 193 static int console_chan_setup(char *str)
 194 {
 195         return(line_setup(vts, sizeof(vts)/sizeof(vts[0]), str, 1));
 196 }
 197 __setup("con", console_chan_setup);
 198 __channel_help(console_chan_setup, "con");