android_kernel_xiaomi_sm8350/arch/um/drivers/stdio_console.c
Paolo 'Blaisorblade' Giarrusso b97b77cca6 [PATCH] uml: redo console locking
Fix some console locking problems (including scheduling in atomic) and various
reorderings and cleanup in that code.  Not yet ready for 2.6.12 probably.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:56 -07:00

199 lines
4.7 KiB
C

/*
* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/config.h"
#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"
#include "2_5compat.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);
static int con_get_config(char *dev, char *str, int size, char **error_out);
static int con_remove(char *str);
static struct line_driver driver = {
.name = "UML console",
.device_name = "tty",
.devfs_name = "vc/",
.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,
.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.
*/
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)
{
return(line_config(vts, sizeof(vts)/sizeof(vts[0]), str));
}
static int con_get_config(char *dev, char *str, int size, char **error_out)
{
return(line_get_config(dev, vts, sizeof(vts)/sizeof(vts[0]), str,
size, error_out));
}
static int con_remove(char *str)
{
return(line_remove(vts, sizeof(vts)/sizeof(vts[0]), str));
}
static int con_open(struct tty_struct *tty, struct file *filp)
{
return line_open(vts, tty, &opts);
}
static int con_init_done = 0;
static 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,
};
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 (NULL == console_driver)
return -1;
printk(KERN_INFO "Initialized stdio console driver\n");
lines_init(vts, sizeof(vts)/sizeof(vts[0]));
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, sizeof(vts)/sizeof(vts[0]));
}
__uml_exitcall(console_exit);
static int console_chan_setup(char *str)
{
return(line_setup(vts, sizeof(vts)/sizeof(vts[0]), str, 1));
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");