stdio_console.c

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/* 
 * Copyright (C) 2000, 2001 Jeff Dike ([email protected])
 * Licensed under the GPL
 */

#include <linux/posix_types.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/types.h>
#include <linux/major.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
#include <asm/current.h>
#include <asm/irq.h>
#include "stdio_console.h"
#include "chan.h"
#include <irq_user.h>
#include "mconsole_kern.h"
#include <init.h>

#define MAX_TTYS (16)

static void stdio_announce(char *dev_name, int dev)
{
    printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
           dev_name);
}

/* Almost const, except that xterm_title may be changed in an initcall */
static struct chan_opts opts = {
    .announce   = stdio_announce,
    .xterm_title    = "Virtual Console #%d",
    .raw        = 1,
};

static int con_config(char *str, char **error_out);
static int con_get_config(char *dev, char *str, int size, char **error_out);
static int con_remove(int n, char **con_remove);


/* Const, except for .mc.list */
static struct line_driver driver = {
    .name           = "UML console",
    .device_name        = "tty",
    .major          = TTY_MAJOR,
    .minor_start        = 0,
    .type           = TTY_DRIVER_TYPE_CONSOLE,
    .subtype        = SYSTEM_TYPE_CONSOLE,
    .read_irq       = CONSOLE_IRQ,
    .read_irq_name      = "console",
    .write_irq      = CONSOLE_WRITE_IRQ,
    .write_irq_name     = "console-write",
    .mc  = {
        .list       = LIST_HEAD_INIT(driver.mc.list),
        .name       = "con",
        .config     = con_config,
        .get_config     = con_get_config,
        .id     = line_id,
        .remove     = con_remove,
    },
};

/* The array is initialized by line_init, at initcall time.  The
 * elements are locked individually as needed.
 */
static char *vt_conf[MAX_TTYS];
static char *def_conf;
static struct line vts[MAX_TTYS];

static int con_config(char *str, char **error_out)
{
    return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
}

static int con_get_config(char *dev, char *str, int size, char **error_out)
{
    return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
}

static int con_remove(int n, char **error_out)
{
    return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
}

/* Set in an initcall, checked in an exitcall */
static int con_init_done = 0;

static int con_install(struct tty_driver *driver, struct tty_struct *tty)
{
    return line_install(driver, tty, &vts[tty->index]);
}

static const struct tty_operations console_ops = {
    .open           = line_open,
    .install        = con_install,
    .close          = line_close,
    .write          = line_write,
    .put_char       = line_put_char,
    .write_room     = line_write_room,
    .chars_in_buffer    = line_chars_in_buffer,
    .flush_buffer       = line_flush_buffer,
    .flush_chars        = line_flush_chars,
    .set_termios        = line_set_termios,
    .throttle       = line_throttle,
    .unthrottle         = line_unthrottle,
    .cleanup        = line_cleanup,
    .hangup         = line_hangup,
};

static void uml_console_write(struct console *console, const char *string,
                  unsigned len)
{
    struct line *line = &vts[console->index];
    unsigned long flags;

    spin_lock_irqsave(&line->lock, flags);
    console_write_chan(line->chan_out, string, len);
    spin_unlock_irqrestore(&line->lock, flags);
}

static struct tty_driver *uml_console_device(struct console *c, int *index)
{
    *index = c->index;
    return driver.driver;
}

static int uml_console_setup(struct console *co, char *options)
{
    struct line *line = &vts[co->index];

    return console_open_chan(line, co);
}

/* No locking for register_console call - relies on single-threaded initcalls */
static struct console stdiocons = {
    .name       = "tty",
    .write      = uml_console_write,
    .device     = uml_console_device,
    .setup      = uml_console_setup,
    .flags      = CON_PRINTBUFFER|CON_ANYTIME,
    .index      = -1,
};

static int stdio_init(void)
{
    char *new_title;
    int err;
    int i;

    err = register_lines(&driver, &console_ops, vts,
                    ARRAY_SIZE(vts));
    if (err)
        return err;

    printk(KERN_INFO "Initialized stdio console driver\n");

    new_title = add_xterm_umid(opts.xterm_title);
    if(new_title != NULL)
        opts.xterm_title = new_title;

    for (i = 0; i < MAX_TTYS; i++) {
        char *error;
        char *s = vt_conf[i];
        if (!s)
            s = def_conf;
        if (!s)
            s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
        if (setup_one_line(vts, i, s, &opts, &error))
            printk(KERN_ERR "setup_one_line failed for "
                   "device %d : %s\n", i, error);
    }

    con_init_done = 1;
    register_console(&stdiocons);
    return 0;
}
late_initcall(stdio_init);

static void console_exit(void)
{
    if (!con_init_done)
        return;
    close_lines(vts, ARRAY_SIZE(vts));
}
__uml_exitcall(console_exit);

static int console_chan_setup(char *str)
{
    line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
    return 1;
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");