kernel-ark/arch/um/drivers/ssl.c
Jeff Dike e4dcee8099 [PATCH] uml: Add throttling to console driver
This patch adds support for throttling and unthrottling input when the tty
driver can't handle it.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:46 -08:00

222 lines
5.0 KiB
C

/*
* Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/config.h"
#include "linux/fs.h"
#include "linux/tty.h"
#include "linux/tty_driver.h"
#include "linux/major.h"
#include "linux/mm.h"
#include "linux/init.h"
#include "linux/console.h"
#include "asm/termbits.h"
#include "asm/irq.h"
#include "line.h"
#include "ssl.h"
#include "chan_kern.h"
#include "user_util.h"
#include "kern_util.h"
#include "kern.h"
#include "init.h"
#include "irq_user.h"
#include "mconsole_kern.h"
static int ssl_version = 1;
/* Referenced only by tty_driver below - presumably it's locked correctly
* by the tty driver.
*/
static struct tty_driver *ssl_driver;
#define NR_PORTS 64
void ssl_announce(char *dev_name, int dev)
{
printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
dev_name);
}
static struct chan_opts opts = {
.announce = ssl_announce,
.xterm_title = "Serial Line #%d",
.raw = 1,
.tramp_stack = 0,
.in_kernel = 1,
};
static int ssl_config(char *str);
static int ssl_get_config(char *dev, char *str, int size, char **error_out);
static int ssl_remove(int n);
static struct line_driver driver = {
.name = "UML serial line",
.device_name = "ttyS",
.devfs_name = "tts/",
.major = TTY_MAJOR,
.minor_start = 64,
.type = TTY_DRIVER_TYPE_SERIAL,
.subtype = 0,
.read_irq = SSL_IRQ,
.read_irq_name = "ssl",
.write_irq = SSL_WRITE_IRQ,
.write_irq_name = "ssl-write",
.symlink_from = "serial",
.symlink_to = "tts",
.mc = {
.name = "ssl",
.config = ssl_config,
.get_config = ssl_get_config,
.id = line_id,
.remove = ssl_remove,
},
};
/* The array is initialized by line_init, which is an initcall. The
* individual elements are protected by individual semaphores.
*/
static struct line serial_lines[NR_PORTS] =
{ [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
static struct lines lines = LINES_INIT(NR_PORTS);
static int ssl_config(char *str)
{
return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts);
}
static int ssl_get_config(char *dev, char *str, int size, char **error_out)
{
return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
size, error_out);
}
static int ssl_remove(int n)
{
return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n);
}
int ssl_open(struct tty_struct *tty, struct file *filp)
{
return line_open(serial_lines, tty);
}
#if 0
static void ssl_flush_buffer(struct tty_struct *tty)
{
return;
}
static void ssl_stop(struct tty_struct *tty)
{
printk(KERN_ERR "Someone should implement ssl_stop\n");
}
static void ssl_start(struct tty_struct *tty)
{
printk(KERN_ERR "Someone should implement ssl_start\n");
}
void ssl_hangup(struct tty_struct *tty)
{
}
#endif
static struct tty_operations ssl_ops = {
.open = ssl_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,
#if 0
.stop = ssl_stop,
.start = ssl_start,
.hangup = ssl_hangup,
#endif
};
/* Changed by ssl_init and referenced by ssl_exit, which are both serialized
* by being an initcall and exitcall, respectively.
*/
static int ssl_init_done = 0;
static void ssl_console_write(struct console *c, const char *string,
unsigned len)
{
struct line *line = &serial_lines[c->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 *ssl_console_device(struct console *c, int *index)
{
*index = c->index;
return ssl_driver;
}
static int ssl_console_setup(struct console *co, char *options)
{
struct line *line = &serial_lines[co->index];
return console_open_chan(line, co, &opts);
}
static struct console ssl_cons = {
.name = "ttyS",
.write = ssl_console_write,
.device = ssl_console_device,
.setup = ssl_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
int ssl_init(void)
{
char *new_title;
printk(KERN_INFO "Initializing software serial port version %d\n",
ssl_version);
ssl_driver = line_register_devfs(&lines, &driver, &ssl_ops,
serial_lines,
ARRAY_SIZE(serial_lines));
lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
new_title = add_xterm_umid(opts.xterm_title);
if (new_title != NULL)
opts.xterm_title = new_title;
ssl_init_done = 1;
register_console(&ssl_cons);
return 0;
}
late_initcall(ssl_init);
static void ssl_exit(void)
{
if (!ssl_init_done)
return;
close_lines(serial_lines, ARRAY_SIZE(serial_lines));
}
__uml_exitcall(ssl_exit);
static int ssl_chan_setup(char *str)
{
return line_setup(serial_lines, ARRAY_SIZE(serial_lines), str);
}
__setup("ssl", ssl_chan_setup);
__channel_help(ssl_chan_setup, "ssl");