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>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 3d2acc2265f7..851d7c29132b 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1274,7 +1274,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
         struct uart_port *uport;
         unsigned long flags;
 
-        BUG_ON(!kernel_locked());
+        BUG_ON(!tty_locked());
 
         if (!state)
                 return;
@@ -1382,7 +1382,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
                 return;
 
-        lock_kernel();
+        tty_lock_nested(); /* already locked when coming from close */
 
         /*
          * Set the check interval to be 1/5 of the estimated time to
@@ -1429,7 +1429,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
                         break;
         }
         set_current_state(TASK_RUNNING); /* might not be needed */
-        unlock_kernel();
+        tty_unlock();
 }
 
 /*
@@ -1444,7 +1444,7 @@ static void uart_hangup(struct tty_struct *tty)
         struct tty_port *port = &state->port;
         unsigned long flags;
 
-        BUG_ON(!kernel_locked());
+        BUG_ON(!tty_locked());
         pr_debug("uart_hangup(%d)\n", state->uart_port->line);
 
         mutex_lock(&port->mutex);
@@ -1578,7 +1578,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
         struct tty_port *port;
         int retval, line = tty->index;
 
-        BUG_ON(!kernel_locked());
+        BUG_ON(!tty_locked());
         pr_debug("uart_open(%d) called\n", line);
 
         /*