tty: replace BKL with a new tty_lock

As a preparation for replacing the big kernel lock
in the TTY layer, wrap all the callers in new
macros tty_lock, tty_lock_nested and tty_unlock.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index 4f8d60c..1b21a7a 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -1072,7 +1072,7 @@
 	if (!retinfo)
 		return -EFAULT;
 	memset(&tmp, 0, sizeof(tmp));
-	lock_kernel();
+	tty_lock();
 	tmp.type = state->type;
 	tmp.line = state->line;
 	tmp.port = state->port;
@@ -1083,7 +1083,7 @@
 	tmp.close_delay = state->close_delay;
 	tmp.closing_wait = state->closing_wait;
 	tmp.custom_divisor = state->custom_divisor;
-	unlock_kernel();
+	tty_unlock();
 	if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
 		return -EFAULT;
 	return 0;
@@ -1100,14 +1100,14 @@
 	if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
 		return -EFAULT;
 
-	lock_kernel();
+	tty_lock();
 	state = info->state;
 	old_state = *state;
   
 	change_irq = new_serial.irq != state->irq;
 	change_port = (new_serial.port != state->port);
 	if(change_irq || change_port || (new_serial.xmit_fifo_size != state->xmit_fifo_size)) {
-	  unlock_kernel();
+	  tty_unlock();
 	  return -EINVAL;
 	}
   
@@ -1127,7 +1127,7 @@
 	}
 
 	if (new_serial.baud_base < 9600) {
-		unlock_kernel();
+		tty_unlock();
 		return -EINVAL;
 	}
 
@@ -1163,7 +1163,7 @@
 		}
 	} else
 		retval = startup(info);
-	unlock_kernel();
+	tty_unlock();
 	return retval;
 }
 
@@ -1538,7 +1538,7 @@
 
 	orig_jiffies = jiffies;
 
-	lock_kernel();
+	tty_lock_nested(); /* tty_wait_until_sent is called from lots of places */
 	/*
 	 * Set the check interval to be 1/5 of the estimated time to
 	 * send a single character, and make it at least 1.  The check
@@ -1579,7 +1579,7 @@
 			break;
 	}
 	__set_current_state(TASK_RUNNING);
-	unlock_kernel();
+	tty_unlock();
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
 	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif