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 /* Referenced only by tty_driver below - presumably it's locked correctly
  34  * by the tty driver.
  35  */
  36
  37 static struct tty_driver *console_driver;
  38
  39 void stdio_announce(char *dev_name, int dev)
  40 {
  41         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  42                dev_name);
  43 }
  44
  45 /* Almost const, except that xterm_title may be changed in an initcall */
  46 static struct chan_opts opts = {
  47         .announce       = stdio_announce,
  48         .xterm_title    = "Virtual Console #%d",
  49         .raw            = 1,
  50         .tramp_stack    = 0,
  51         .in_kernel      = 1,
  52 };
  53
  54 static int con_config(char *str, char **error_out);
  55 static int con_get_config(char *dev, char *str, int size, char **error_out);
  56 static int con_remove(int n, char **con_remove);
  57
  58
  59 /* Const, except for .mc.list */
  60 static struct line_driver driver = {
  61         .name                   = "UML console",
  62         .device_name            = "tty",
  63         .major                  = TTY_MAJOR,
  64         .minor_start            = 0,
  65         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  66         .subtype                = SYSTEM_TYPE_CONSOLE,
  67         .read_irq               = CONSOLE_IRQ,
  68         .read_irq_name          = "console",
  69         .write_irq              = CONSOLE_WRITE_IRQ,
  70         .write_irq_name         = "console-write",
  71         .mc  = {
  72                 .list           = LIST_HEAD_INIT(driver.mc.list),
  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 /* The array is initialized by line_init, at initcall time.  The
  82  * elements are locked individually as needed.
  83  */
  84 static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
  85                                      [ 1 ... MAX_TTYS - 1 ] =
  86                                      LINE_INIT(CONFIG_CON_CHAN, &driver) };
  87
  88 static int con_config(char *str, char **error_out)
  89 {
  90         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  91 }
  92
  93 static int con_get_config(char *dev, char *str, int size, char **error_out)
  94 {
  95         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  96 }
  97
  98 static int con_remove(int n, char **error_out)
  99 {
 100         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
 101 }
 102
 103 static int con_open(struct tty_struct *tty, struct file *filp)
 104 {
 105         return line_open(vts, tty);
 106 }
 107
 108 /* Set in an initcall, checked in an exitcall */
 109 static int con_init_done = 0;
 110
 111 static const struct tty_operations console_ops = {
 112         .open                   = con_open,
 113         .close                  = line_close,
 114         .write                  = line_write,
 115         .put_char               = line_put_char,
 116         .write_room             = line_write_room,
 117         .chars_in_buffer        = line_chars_in_buffer,
 118         .flush_buffer           = line_flush_buffer,
 119         .flush_chars            = line_flush_chars,
 120         .set_termios            = line_set_termios,
 121         .ioctl                  = line_ioctl,
 122         .throttle               = line_throttle,
 123         .unthrottle             = line_unthrottle,
 124 };
 125
 126 static void uml_console_write(struct console *console, const char *string,
 127                               unsigned len)
 128 {
 129         struct line *line = &vts[console->index];
 130         unsigned long flags;
 131
 132         spin_lock_irqsave(&line->lock, flags);
 133         console_write_chan(&line->chan_list, string, len);
 134         spin_unlock_irqrestore(&line->lock, flags);
 135 }
 136
 137 static struct tty_driver *uml_console_device(struct console *c, int *index)
 138 {
 139         *index = c->index;
 140         return console_driver;
 141 }
 142
 143 static int uml_console_setup(struct console *co, char *options)
 144 {
 145         struct line *line = &vts[co->index];
 146
 147         return console_open_chan(line, co);
 148 }
 149
 150 /* No locking for register_console call - relies on single-threaded initcalls */
 151 static struct console stdiocons = {
 152         .name           = "tty",
 153         .write          = uml_console_write,
 154         .device         = uml_console_device,
 155         .setup          = uml_console_setup,
 156         .flags          = CON_PRINTBUFFER,
 157         .index          = -1,
 158 };
 159
 160 int stdio_init(void)
 161 {
 162         char *new_title;
 163
 164         console_driver = register_lines(&driver, &console_ops, vts,
 165                                         ARRAY_SIZE(vts));
 166         if (console_driver == NULL)
 167                 return -1;
 168         printk(KERN_INFO "Initialized stdio console driver\n");
 169
 170         lines_init(vts, ARRAY_SIZE(vts), &opts);
 171
 172         new_title = add_xterm_umid(opts.xterm_title);
 173         if(new_title != NULL)
 174                 opts.xterm_title = new_title;
 175
 176         con_init_done = 1;
 177         register_console(&stdiocons);
 178         return 0;
 179 }
 180 late_initcall(stdio_init);
 181
 182 static void console_exit(void)
 183 {
 184         if (!con_init_done)
 185                 return;
 186         close_lines(vts, ARRAY_SIZE(vts));
 187 }
 188 __uml_exitcall(console_exit);
 189
 190 static int console_chan_setup(char *str)
 191 {
 192         char *error;
 193         int ret;
 194
 195         ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
 196         if(ret < 0)
 197                 printk(KERN_ERR "Failed to set up console with "
 198                        "configuration string \"%s\" : %s\n", str, error);
 199
 200         return 1;
 201 }
 202 __setup("con", console_chan_setup);
 203 __channel_help(console_chan_setup, "con");