android_kernel_samsung_univ.../arch/um/drivers/stdio_console.c
Jeff Dike f28169d200 [PATCH] uml: return hotplug errors to host
I noticed that errors happening while hotplugging devices from the host were
never returned back to the mconsole client.  In some cases, success was
returned instead of even an information-free error.

This patch cleans that up by having the low-level configuration code pass back
an error string along with an error code.  At the top level, which knows
whether it is early boot time or responding to an mconsole request, the string
is printk'd or returned to the mconsole client.

There are also whitespace and trivial code cleanups in the surrounding code.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:21 -08:00

207 lines
4.9 KiB
C

/*
* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
* 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 "line.h"
#include "chan_kern.h"
#include "user_util.h"
#include "kern_util.h"
#include "irq_user.h"
#include "mconsole_kern.h"
#include "init.h"
#define MAX_TTYS (16)
/* ----------------------------------------------------------------------------- */
/* Referenced only by tty_driver below - presumably it's locked correctly
* by the tty driver.
*/
static struct tty_driver *console_driver;
void stdio_announce(char *dev_name, int dev)
{
printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
dev_name);
}
static struct chan_opts opts = {
.announce = stdio_announce,
.xterm_title = "Virtual Console #%d",
.raw = 1,
.tramp_stack = 0,
.in_kernel = 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);
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",
.symlink_from = "ttys",
.symlink_to = "vc",
.mc = {
.name = "con",
.config = con_config,
.get_config = con_get_config,
.id = line_id,
.remove = con_remove,
},
};
static struct lines console_lines = LINES_INIT(MAX_TTYS);
/* The array is initialized by line_init, which is an initcall. The
* individual elements are protected by individual semaphores.
*/
static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
[ 1 ... MAX_TTYS - 1 ] =
LINE_INIT(CONFIG_CON_CHAN, &driver) };
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);
}
static int con_open(struct tty_struct *tty, struct file *filp)
{
return line_open(vts, tty);
}
/* Set in an initcall, checked in an exitcall */
static int con_init_done = 0;
static const struct tty_operations console_ops = {
.open = con_open,
.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,
.ioctl = line_ioctl,
.throttle = line_throttle,
.unthrottle = line_unthrottle,
};
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_list, string, len);
spin_unlock_irqrestore(&line->lock, flags);
}
static struct tty_driver *uml_console_device(struct console *c, int *index)
{
*index = c->index;
return console_driver;
}
static int uml_console_setup(struct console *co, char *options)
{
struct line *line = &vts[co->index];
return console_open_chan(line, co, &opts);
}
static struct console stdiocons = {
.name = "tty",
.write = uml_console_write,
.device = uml_console_device,
.setup = uml_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &vts,
};
int stdio_init(void)
{
char *new_title;
console_driver = line_register_devfs(&console_lines, &driver,
&console_ops, vts,
ARRAY_SIZE(vts));
if (console_driver == NULL)
return -1;
printk(KERN_INFO "Initialized stdio console driver\n");
lines_init(vts, ARRAY_SIZE(vts), &opts);
new_title = add_xterm_umid(opts.xterm_title);
if(new_title != NULL)
opts.xterm_title = new_title;
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)
{
char *error;
int ret;
ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
if(ret < 0)
printk(KERN_ERR "Failed to set up console with "
"configuration string \"%s\" : %s\n", str, error);
return 1;
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");