tty: Make epca use the port helpers

Now the locking is straight and the port kref usage is straight we can
replace lots of chunks of code with the standard port helpers

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 26 insertions, 149 deletions

diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index 7a69705..71225d1 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -432,58 +432,15 @@ static void pc_close(struct tty_struct *tty, struct file *filp)
 		return;
 	port = &ch->port;
 
-	spin_lock_irqsave(&port->lock, flags);
-	if (tty_hung_up_p(filp)) {
-		spin_unlock_irqrestore(&port->lock, flags);
-		return;
-	}
-	if (port->count-- > 1)  {
-		/* Begin channel is open more than once */
-		/*
-		 * Return without doing anything. Someone might still
-		 * be using the channel.
-		 */
-		spin_unlock_irqrestore(&port->lock, flags);
+	if (tty_port_close_start(port, tty, filp) == 0)
 		return;
-	}
-	/* Port open only once go ahead with shutdown & reset */
-	WARN_ON(port->count < 0);
 
-	/*
-	 * Let the rest of the driver know the channel is being closed.
-	 * This becomes important if an open is attempted before close
-	 * is finished.
-	 */
-	port->flags |= ASYNC_CLOSING;
-	tty->closing = 1;
-
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	if (port->flags & ASYNC_INITIALIZED)  {
-		/* Setup an event to indicate when the
-		   transmit buffer empties */
-		setup_empty_event(tty, ch);
-		/* 30 seconds timeout */
-		tty_wait_until_sent(tty, 3000);
-	}
 	pc_flush_buffer(tty);
-	tty_ldisc_flush(tty);
 	shutdown(ch, tty);
 
-	spin_lock_irqsave(&port->lock, flags);
-	tty->closing = 0;
-	ch->event = 0;
+	tty_port_close_end(port, tty);
+	ch->event = 0;	/* FIXME: review ch->event locking */
 	tty_port_tty_set(port, NULL);
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	if (port->blocked_open) {
-		if (ch->close_delay)
-			msleep_interruptible(jiffies_to_msecs(ch->close_delay));
-		wake_up_interruptible(&port->open_wait);
-	}
-	port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED |
-							ASYNC_CLOSING);
-	wake_up_interruptible(&port->close_wait);
 }
 
 static void shutdown(struct channel *ch, struct tty_struct *tty)
@@ -527,7 +484,6 @@ static void shutdown(struct channel *ch, struct tty_struct *tty)
 static void pc_hangup(struct tty_struct *tty)
 {
 	struct channel *ch;
-	struct tty_port *port;
 
 	/*
 	 * verifyChannel returns the channel from the tty struct if it is
@@ -536,19 +492,13 @@ static void pc_hangup(struct tty_struct *tty)
 	ch = verifyChannel(tty);
 	if (ch != NULL) {
 		unsigned long flags;
-		port = &ch->port;
 
 		pc_flush_buffer(tty);
 		tty_ldisc_flush(tty);
 		shutdown(ch, tty);
 
-		spin_lock_irqsave(&port->lock, flags);
-		port->tty = NULL;
 		ch->event = 0;	/* FIXME: review locking of ch->event */
-		port->count = 0;
-		port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED);
-		spin_unlock_irqrestore(&port->lock, flags);
-		wake_up_interruptible(&port->open_wait);
+		tty_port_hangup(&ch->port);
 	}
 }
 
@@ -792,98 +742,18 @@ static void pc_flush_chars(struct tty_struct *tty)
 	}
 }
 
-static int block_til_ready(struct tty_struct *tty,
-				struct file *filp, struct channel *ch)
+static int epca_carrier_raised(struct tty_port *port)
 {
-	DECLARE_WAITQUEUE(wait, current);
-	int retval, do_clocal = 0;
-	unsigned long flags;
-	struct tty_port *port = &ch->port;
-
-	if (tty_hung_up_p(filp)) {
-		if (port->flags & ASYNC_HUP_NOTIFY)
-			retval = -EAGAIN;
-		else
-			retval = -ERESTARTSYS;
-		return retval;
-	}
-
-	/*
-	 * If the device is in the middle of being closed, then block until
-	 * it's done, and then try again.
-	 */
-	if (port->flags & ASYNC_CLOSING) {
-		interruptible_sleep_on(&port->close_wait);
-
-		if (port->flags & ASYNC_HUP_NOTIFY)
-			return -EAGAIN;
-		else
-			return -ERESTARTSYS;
-	}
-
-	if (filp->f_flags & O_NONBLOCK)  {
-		/*
-		 * If non-blocking mode is set, then make the check up front
-		 * and then exit.
-		 */
-		port->flags |= ASYNC_NORMAL_ACTIVE;
-		return 0;
-	}
-	if (tty->termios->c_cflag & CLOCAL)
-		do_clocal = 1;
-	/* Block waiting for the carrier detect and the line to become free */
-
-	retval = 0;
-	add_wait_queue(&port->open_wait, &wait);
-
-	spin_lock_irqsave(&port->lock, flags);
-	/* We dec count so that pc_close will know when to free things */
-	if (!tty_hung_up_p(filp))
-		port->count--;
-	port->blocked_open++;
-	while (1) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (tty_hung_up_p(filp) ||
-				!(port->flags & ASYNC_INITIALIZED)) {
-			if (port->flags & ASYNC_HUP_NOTIFY)
-				retval = -EAGAIN;
-			else
-				retval = -ERESTARTSYS;
-			break;
-		}
-		if (!(port->flags & ASYNC_CLOSING) &&
-			  (do_clocal || (ch->imodem & ch->dcd)))
-			break;
-		if (signal_pending(current)) {
-			retval = -ERESTARTSYS;
-			break;
-		}
-		spin_unlock_irqrestore(&port->lock, flags);
-		/*
-		 * Allow someone else to be scheduled. We will occasionally go
-		 * through this loop until one of the above conditions change.
-		 * The below schedule call will allow other processes to enter
-		 * and prevent this loop from hogging the cpu.
-		 */
-		schedule();
-		spin_lock_irqsave(&port->lock, flags);
-	}
-
-	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(&port->open_wait, &wait);
-	if (!tty_hung_up_p(filp))
-		port->count++;
-	port->blocked_open--;
-
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	if (retval)
-		return retval;
-
-	port->flags |= ASYNC_NORMAL_ACTIVE;
+	struct channel *ch = container_of(port, struct channel, port);
+	if (ch->imodem & ch->dcd)
+		return 1;
 	return 0;
 }
 
+static void epca_raise_dtr_rts(struct tty_port *port0
+{
+}
+
 static int pc_open(struct tty_struct *tty, struct file *filp)
 {
 	struct channel *ch;
@@ -978,7 +848,7 @@ static int pc_open(struct tty_struct *tty, struct file *filp)
 	port->flags |= ASYNC_INITIALIZED;
 	spin_unlock_irqrestore(&port->lock, flags);
 
-	retval = block_til_ready(tty, filp, ch);
+	retval = tty_port_block_til_ready(port, tty, filp);
 	if (retval)
 		return retval;
 	/*
@@ -1058,6 +928,11 @@ static const struct tty_operations pc_ops = {
 	.break_ctl = pc_send_break
 };
 
+static const struct tty_port_operations epca_port_ops = {
+	.carrier_raised = epca_carrier_raised,
+	.raise_dtr_rts = epca_raise_dtr_rts,
+};
+
 static int info_open(struct tty_struct *tty, struct file *filp)
 {
 	return 0;
@@ -1393,6 +1268,7 @@ static void post_fep_init(unsigned int crd)
 		u16 tseg, rseg;
 
 		tty_port_init(&ch->port);
+		ch->port.ops - &epca_port_ops;
 		ch->brdchan = bc;
 		ch->mailbox = gd;
 		INIT_WORK(&ch->tqueue, do_softint);
@@ -1526,7 +1402,7 @@ static void post_fep_init(unsigned int crd)
 		ch->fepstartca = 0;
 		ch->fepstopca = 0;
 
-		ch->close_delay = 50;
+		ch->port.close_delay = 50;
 
 		spin_unlock_irqrestore(&epca_lock, flags);
 	}
@@ -1647,7 +1523,7 @@ static void doevent(int crd)
 		if (event & MODEMCHG_IND) {
 			/* A modem signal change has been indicated */
 			ch->imodem = mstat;
-			if (ch->port.flags & ASYNC_CHECK_CD) {
+			if (test_bit(ASYNC_CHECK_CD, &ch->port.flags)) {
 				/* We are now receiving dcd */
 				if (mstat & ch->dcd)
 					wake_up_interruptible(&ch->port.open_wait);
@@ -1894,9 +1770,9 @@ static void epcaparam(struct tty_struct *tty, struct channel *ch)
 		 * that the driver will wait on carrier detect.
 		 */
 		if (ts->c_cflag & CLOCAL)
-			ch->port.flags &= ~ASYNC_CHECK_CD;
+			clear_bit(ASYNC_CHECK_CD, &ch->port.flags);
 		else
-			ch->port.flags |= ASYNC_CHECK_CD;
+			set_bit(ASYNC_CHECK_CD, &ch->port.flags);
 		mval = ch->m_dtr | ch->m_rts;
 	} /* End CBAUD not detected */
 	iflag = termios2digi_i(ch, ts->c_iflag);
@@ -2373,7 +2249,7 @@ static void do_softint(struct work_struct *work)
 			if (test_and_clear_bit(EPCA_EVENT_HANGUP, &ch->event)) {
 				tty_hangup(tty);
 				wake_up_interruptible(&ch->port.open_wait);
-				ch->port.flags &= ~ASYNC_NORMAL_ACTIVE;
+				clear_bit(ASYNC_NORMAL_ACTIVE, &ch->port.flags);
 			}
 		}
 		tty_kref_put(tty);
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index b3175f5..b580fcf 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -286,7 +286,8 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f
 	port->flags |= ASYNC_CLOSING;
 	tty->closing = 1;
 	spin_unlock_irqrestore(&port->lock, flags);
-	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+	if (port->flags & ASYNC_INITIALIZED &&
+			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
 		tty_wait_until_sent(tty, port->closing_wait);
 	return 1;
 }