tty: Replace ASYNC_INITIALIZED bit and update atomically

Replace ASYNC_INITIALIZED bit in the tty_port::flags field with
TTY_PORT_INITIALIZED bit in the tty_port::iflags field. Introduce helpers
tty_port_set_initialized() and tty_port_initialized() to abstract
atomic bit ops.

Note: the transforms for test_and_set_bit() and test_and_clear_bit()
are unnecessary as the state transitions are already mutually exclusive;
the tty lock prevents concurrent open/close/hangup.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 22 insertions, 24 deletions

diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index b67b54a800bb..bc4bc1ff775e 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -1749,13 +1749,13 @@ static irqreturn_t mgsl_interrupt(int dummy, void *dev_id)
 static int startup(struct mgsl_struct * info)
 {
 	int retval = 0;
-	
+
 	if ( debug_level >= DEBUG_LEVEL_INFO )
 		printk("%s(%d):mgsl_startup(%s)\n",__FILE__,__LINE__,info->device_name);
-		
-	if (info->port.flags & ASYNC_INITIALIZED)
+
+	if (tty_port_initialized(&info->port))
 		return 0;
-	
+
 	if (!info->xmit_buf) {
 		/* allocate a page of memory for a transmit buffer */
 		info->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
@@ -1788,14 +1788,13 @@ static int startup(struct mgsl_struct * info)
 
 	/* program hardware for current parameters */
 	mgsl_change_params(info);
-	
+
 	if (info->port.tty)
 		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
 
-	info->port.flags |= ASYNC_INITIALIZED;
-	
+	tty_port_set_initialized(&info->port, 1);
+
 	return 0;
-	
 }	/* end of startup() */
 
 /* shutdown()
@@ -1808,8 +1807,8 @@ static int startup(struct mgsl_struct * info)
 static void shutdown(struct mgsl_struct * info)
 {
 	unsigned long flags;
-	
-	if (!(info->port.flags & ASYNC_INITIALIZED))
+
+	if (!tty_port_initialized(&info->port))
 		return;
 
 	if (debug_level >= DEBUG_LEVEL_INFO)
@@ -1853,13 +1852,12 @@ static void shutdown(struct mgsl_struct * info)
 
 	spin_unlock_irqrestore(&info->irq_spinlock,flags);
 
-	mgsl_release_resources(info);	
-	
+	mgsl_release_resources(info);
+
 	if (info->port.tty)
 		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
 
-	info->port.flags &= ~ASYNC_INITIALIZED;
-	
+	tty_port_set_initialized(&info->port, 0);
 }	/* end of shutdown() */
 
 static void mgsl_program_hw(struct mgsl_struct *info)
@@ -3084,7 +3082,7 @@ static void mgsl_close(struct tty_struct *tty, struct file * filp)
 		goto cleanup;
 
 	mutex_lock(&info->port.mutex);
- 	if (info->port.flags & ASYNC_INITIALIZED)
+	if (tty_port_initialized(&info->port))
  		mgsl_wait_until_sent(tty, info->timeout);
 	mgsl_flush_buffer(tty);
 	tty_ldisc_flush(tty);
@@ -3122,15 +3120,15 @@ static void mgsl_wait_until_sent(struct tty_struct *tty, int timeout)
 	if (debug_level >= DEBUG_LEVEL_INFO)
 		printk("%s(%d):mgsl_wait_until_sent(%s) entry\n",
 			 __FILE__,__LINE__, info->device_name );
-      
+
 	if (mgsl_paranoia_check(info, tty->name, "mgsl_wait_until_sent"))
 		return;
 
-	if (!(info->port.flags & ASYNC_INITIALIZED))
+	if (!tty_port_initialized(&info->port))
 		goto exit;
-	 
+
 	orig_jiffies = jiffies;
-      
+
 	/* Set check interval to 1/5 of estimated time to
 	 * send a character, and make it at least 1. The check
 	 * interval should also be less than the timeout.
@@ -3290,14 +3288,14 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
 	port->count--;
 	spin_unlock_irqrestore(&info->irq_spinlock, flags);
 	port->blocked_open++;
-	
+
 	while (1) {
-		if (C_BAUD(tty) && test_bit(ASYNCB_INITIALIZED, &port->flags))
+		if (C_BAUD(tty) && tty_port_initialized(port))
 			tty_port_raise_dtr_rts(port);
-		
+
 		set_current_state(TASK_INTERRUPTIBLE);
-		
-		if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)){
+
+		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
 			retval = (port->flags & ASYNC_HUP_NOTIFY) ?
 					-EAGAIN : -ERESTARTSYS;
 			break;