android_kernel_samsung_msm8976/arch/um/drivers/stdio_console.c
Paolo 'Blaisorblade' Giarrusso b53378856f [PATCH] um: mark both consoles as CON_ANYTIME
Since both UML consoles do not use percpu variables, they may be called when
the cpu is still offline, and they may be marked CON_ANYTIME (this is
documented in kernel/printk.c, grep for CON_ANYTIME to find mentions of this).

Works well in testing done with lock debug enabled, should be safe but is not
needed for next release.

This would probably help also stderr_console.c, but this is yet to test.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-08 07:38:21 -08:00

203 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);
}
/* 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,
.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);
/* 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 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);
}
/* 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,
};
int stdio_init(void)
{
char *new_title;
console_driver = register_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");