arch/um/drivers/stdio_console.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
   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 "chan.h"
  24 #include <irq_user.h>
  25 #include "mconsole_kern.h"
  26 #include <init.h>
  27
  28 #define MAX_TTYS (16)
  29
  30 static void stdio_announce(char *dev_name, int dev)
  31 {
  32         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
  33                dev_name);
  34 }
  35
  36 /* Almost const, except that xterm_title may be changed in an initcall */
  37 static struct chan_opts opts = {
  38         .announce       = stdio_announce,
  39         .xterm_title    = "Virtual Console #%d",
  40         .raw            = 1,
  41 };
  42
  43 static int con_config(char *str, char **error_out);
  44 static int con_get_config(char *dev, char *str, int size, char **error_out);
  45 static int con_remove(int n, char **con_remove);
  46
  47
  48 /* Const, except for .mc.list */
  49 static struct line_driver driver = {
  50         .name                   = "UML console",
  51         .device_name            = "tty",
  52         .major                  = TTY_MAJOR,
  53         .minor_start            = 0,
  54         .type                   = TTY_DRIVER_TYPE_CONSOLE,
  55         .subtype                = SYSTEM_TYPE_CONSOLE,
  56         .read_irq_name          = "console",
  57         .write_irq_name         = "console-write",
  58         .mc  = {
  59                 .list           = LIST_HEAD_INIT(driver.mc.list),
  60                 .name           = "con",
  61                 .config         = con_config,
  62                 .get_config     = con_get_config,
  63                 .id             = line_id,
  64                 .remove         = con_remove,
  65         },
  66 };
  67
  68 /* The array is initialized by line_init, at initcall time.  The
  69  * elements are locked individually as needed.
  70  */
  71 static char *vt_conf[MAX_TTYS];
  72 static char *def_conf;
  73 static struct line vts[MAX_TTYS];
  74
  75 static int con_config(char *str, char **error_out)
  76 {
  77         return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
  78 }
  79
  80 static int con_get_config(char *dev, char *str, int size, char **error_out)
  81 {
  82         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
  83 }
  84
  85 static int con_remove(int n, char **error_out)
  86 {
  87         return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
  88 }
  89
  90 /* Set in an initcall, checked in an exitcall */
  91 static int con_init_done;
  92
  93 static int con_install(struct tty_driver *driver, struct tty_struct *tty)
  94 {
  95         return line_install(driver, tty, &vts[tty->index]);
  96 }
  97
  98 static const struct tty_operations console_ops = {
  99         .open                   = line_open,
 100         .install                = con_install,
 101         .close                  = line_close,
 102         .write                  = line_write,
 103         .write_room             = line_write_room,
 104         .chars_in_buffer        = line_chars_in_buffer,
 105         .flush_buffer           = line_flush_buffer,
 106         .flush_chars            = line_flush_chars,
 107         .throttle               = line_throttle,
 108         .unthrottle             = line_unthrottle,
 109         .hangup                 = line_hangup,
 110 };
 111
 112 static void uml_console_write(struct console *console, const char *string,
 113                               unsigned len)
 114 {
 115         struct line *line = &vts[console->index];
 116         unsigned long flags;
 117
 118         spin_lock_irqsave(&line->lock, flags);
 119         console_write_chan(line->chan_out, string, len);
 120         spin_unlock_irqrestore(&line->lock, flags);
 121 }
 122
 123 static struct tty_driver *uml_console_device(struct console *c, int *index)
 124 {
 125         *index = c->index;
 126         return driver.driver;
 127 }
 128
 129 static int uml_console_setup(struct console *co, char *options)
 130 {
 131         struct line *line = &vts[co->index];
 132
 133         return console_open_chan(line, co);
 134 }
 135
 136 /* No locking for register_console call - relies on single-threaded initcalls */
 137 static struct console stdiocons = {
 138         .name           = "tty",
 139         .write          = uml_console_write,
 140         .device         = uml_console_device,
 141         .setup          = uml_console_setup,
 142         .flags          = CON_PRINTBUFFER|CON_ANYTIME,
 143         .index          = -1,
 144 };
 145
 146 static int stdio_init(void)
 147 {
 148         char *new_title;
 149         int err;
 150         int i;
 151
 152         err = register_lines(&driver, &console_ops, vts,
 153                                         ARRAY_SIZE(vts));
 154         if (err)
 155                 return err;
 156
 157         printk(KERN_INFO "Initialized stdio console driver\n");
 158
 159         new_title = add_xterm_umid(opts.xterm_title);
 160         if(new_title != NULL)
 161                 opts.xterm_title = new_title;
 162
 163         for (i = 0; i < MAX_TTYS; i++) {
 164                 char *error;
 165                 char *s = vt_conf[i];
 166                 if (!s)
 167                         s = def_conf;
 168                 if (!s)
 169                         s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
 170                 if (setup_one_line(vts, i, s, &opts, &error))
 171                         printk(KERN_ERR "setup_one_line failed for "
 172                                "device %d : %s\n", i, error);
 173         }
 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         if (!strncmp(str, "sole=", 5))  /* console= option specifies tty */
 192                 return 0;
 193
 194         line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
 195         return 1;
 196 }
 197 __setup("con", console_chan_setup);
 198 __channel_help(console_chan_setup, "con");