[PATCH] tty_driver refcounting

arch/mips/baget/vacserial.c converted to dynamic allocation

arch/mips/baget/vacserial.c

@@ -29,7 +29,7 @@
   
 #if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
 #define DBG_CNT(s) baget_printk("(%s):[%x] refc=%d, serc=%d, ttyc=%d-> %s\n", \
-  tty->name,(info->flags),serial_driver.refcount,info->count,tty->count,s)
+  tty->name,(info->flags),serial_driver->refcount,info->count,tty->count,s)
 #else
 #define DBG_CNT(s)
 #endif
@@ -95,7 +95,7 @@ static char *serial_version = "4.26";
 
 static DECLARE_TASK_QUEUE(tq_serial);
 
-static struct tty_driver serial_driver;
+static struct tty_driver *serial_driver;
 
 /* number of characters left in xmit buffer before we ask for more */
 #define WAKEUP_CHARS 256
@@ -2251,6 +2251,28 @@ static void rs_timer(unsigned long dummy)
                 mod_timer(&vacs_timer, jiffies + IRQ_timeout[0] - 2);
         }
 }
+
+static struct tty_operations rs_ops = {
+	.open = rs_open,
+	.close = rs_close,
+	.write = rs_write,
+	.put_char = rs_put_char,
+	.flush_chars = rs_flush_chars,
+	.write_room = rs_write_room,
+	.chars_in_buffer = rs_chars_in_buffer,
+	.flush_buffer = rs_flush_buffer,
+	.ioctl = rs_ioctl,
+	.throttle = rs_throttle,
+	.unthrottle = rs_unthrottle,
+	.send_xchar = rs_send_xchar,
+	.set_termios = rs_set_termios,
+	.stop = rs_stop,
+	.start = rs_start,
+	.hangup = rs_hangup,
+	.break_ctl = rs_break,
+	.wait_until_sent = rs_wait_until_sent,
+	.read_proc = rs_read_proc,
+};
  
 /*
  * The serial driver boot-time initialization code!
@@ -2300,45 +2322,27 @@ int __init rs_init(void)
 #endif
 
 #endif
+	serial_driver = alloc_tty_driver(NR_PORTS);
+	if (!serial_driver)
+		return -ENOMEM;
+
 	show_serial_version();
 
 	/* Initialize the tty_driver structure */
 	
-	memset(&serial_driver, 0, sizeof(struct tty_driver));
-	serial_driver.magic = TTY_DRIVER_MAGIC;
-	serial_driver.driver_name = "serial";
-	serial_driver.name = "ttyS";
-	serial_driver.major = TTY_MAJOR;
-	serial_driver.minor_start = 64;
-	serial_driver.num = NR_PORTS;
-	serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
-	serial_driver.subtype = SERIAL_TYPE_NORMAL;
-	serial_driver.init_termios = tty_std_termios;
-	serial_driver.init_termios.c_cflag =
+	serial_driver->driver_name = "serial";
+	serial_driver->name = "ttyS";
+	serial_driver->major = TTY_MAJOR;
+	serial_driver->minor_start = 64;
+	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	serial_driver->subtype = SERIAL_TYPE_NORMAL;
+	serial_driver->init_termios = tty_std_termios;
+	serial_driver->init_termios.c_cflag =
 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
-	serial_driver.flags = TTY_DRIVER_REAL_RAW;
-
-	serial_driver.open = rs_open;
-	serial_driver.close = rs_close;
-	serial_driver.write = rs_write;
-	serial_driver.put_char = rs_put_char;
-	serial_driver.flush_chars = rs_flush_chars;
-	serial_driver.write_room = rs_write_room;
-	serial_driver.chars_in_buffer = rs_chars_in_buffer;
-	serial_driver.flush_buffer = rs_flush_buffer;
-	serial_driver.ioctl = rs_ioctl;
-	serial_driver.throttle = rs_throttle;
-	serial_driver.unthrottle = rs_unthrottle;
-	serial_driver.send_xchar = rs_send_xchar;
-	serial_driver.set_termios = rs_set_termios;
-	serial_driver.stop = rs_stop;
-	serial_driver.start = rs_start;
-	serial_driver.hangup = rs_hangup;
-	serial_driver.break_ctl = rs_break;
-	serial_driver.wait_until_sent = rs_wait_until_sent;
-	serial_driver.read_proc = rs_read_proc;
+	serial_driver->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(serial_driver, &rs_ops);
 	
-	if (tty_register_driver(&serial_driver))
+	if (tty_register_driver(serial_driver))
 		panic("Couldn't register serial driver\n");
 	
 	for (i = 0, state = rs_table; i < NR_PORTS; i++,state++) {
@@ -2460,10 +2464,11 @@ void cleanup_module(void)
 	del_timer_sync(&vacs_timer);
         remove_bh(SERIAL_BH);
 
-	if ((e1 = tty_unregister_driver(&serial_driver)))
+	if ((e1 = tty_unregister_driver(serial_driver)))
 		printk("SERIAL: failed to unregister serial driver (%d)\n",
 		       e1);
 	restore_flags(flags);
+	put_tty_driver(serial_driver);
 
 	for (i = 0; i < NR_PORTS; i++) {
 		if (rs_table[i].type != PORT_UNKNOWN)
@@ -2551,7 +2556,7 @@ static void serial_console_write(struct console *co, const char *s,
 static struct tty_driver *serial_console_device(struct console *c, int *index)
 {
 	*index = c->index;
-	return &serial_driver;
+	return serial_driver;
 }
 
 /*