TTY: hvcs, add tty install

This has two outcomes:
* we give the TTY layer a tty_port
* we do not find the info structure every time open is called on that
  tty

>From now on, we only increase the reference count in ->install (and
decrease in ->cleanup).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 33 insertions, 19 deletions

diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 6f5c3be0f495..cab5c7adf8e8 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1102,11 +1102,7 @@ static struct hvcs_struct *hvcs_get_by_index(int index)
         return NULL;
 }
 
-/*
- * This is invoked via the tty_open interface when a user app connects to the
- * /dev node.
- */
-static int hvcs_open(struct tty_struct *tty, struct file *filp)
+static int hvcs_install(struct tty_driver *driver, struct tty_struct *tty)
 {
         struct hvcs_struct *hvcsd;
         struct vio_dev *vdev;
@@ -1114,9 +1110,6 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp)
         unsigned int irq;
         int retval;
 
-        if (tty->driver_data)
-                goto fast_open;
-
         /*
          * Is there a vty-server that shares the same index?
          * This function increments the kref index.
@@ -1139,7 +1132,7 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp)
                 }
         }
 
-        hvcsd->port.count = 1;
+        hvcsd->port.count = 0;
         hvcsd->port.tty = tty;
         tty->driver_data = hvcsd;
 
@@ -1166,28 +1159,42 @@ static int hvcs_open(struct tty_struct *tty, struct file *filp)
                 goto err_put;
         }
 
-        goto open_success;
+        retval = tty_port_install(&hvcsd->port, driver, tty);
+        if (retval)
+                goto err_irq;
 
-fast_open:
-        hvcsd = tty->driver_data;
+        return 0;
+err_irq:
+        spin_lock_irqsave(&hvcsd->lock, flags);
+        vio_disable_interrupts(hvcsd->vdev);
+        spin_unlock_irqrestore(&hvcsd->lock, flags);
+        free_irq(irq, hvcsd);
+err_put:
+        tty_port_put(&hvcsd->port);
+
+        return retval;
+}
+
+/*
+ * This is invoked via the tty_open interface when a user app connects to the
+ * /dev node.
+ */
+static int hvcs_open(struct tty_struct *tty, struct file *filp)
+{
+        struct hvcs_struct *hvcsd = tty->driver_data;
+        unsigned long flags;
 
         spin_lock_irqsave(&hvcsd->lock, flags);
-        tty_port_get(&hvcsd->port);
         hvcsd->port.count++;
         hvcsd->todo_mask |= HVCS_SCHED_READ;
         spin_unlock_irqrestore(&hvcsd->lock, flags);
 
-open_success:
         hvcs_kick();
 
         printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n",
                 hvcsd->vdev->unit_address );
 
         return 0;
-err_put:
-        tty_port_put(&hvcsd->port);
-
-        return retval;
 }
 
 static void hvcs_close(struct tty_struct *tty, struct file *filp)
@@ -1238,7 +1245,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
                 tty->driver_data = NULL;
 
                 free_irq(irq, hvcsd);
-                tty_port_put(&hvcsd->port);
                 return;
         } else if (hvcsd->port.count < 0) {
                 printk(KERN_ERR "HVCS: vty-server@%X open_count: %d"
@@ -1247,6 +1253,12 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
         }
 
         spin_unlock_irqrestore(&hvcsd->lock, flags);
+}
+
+static void hvcs_cleanup(struct tty_struct * tty)
+{
+        struct hvcs_struct *hvcsd = tty->driver_data;
+
         tty_port_put(&hvcsd->port);
 }
 
@@ -1433,8 +1445,10 @@ static int hvcs_chars_in_buffer(struct tty_struct *tty)
 }
 
 static const struct tty_operations hvcs_ops = {
+        .install = hvcs_install,
         .open = hvcs_open,
         .close = hvcs_close,
+        .cleanup = hvcs_cleanup,
         .hangup = hvcs_hangup,
         .write = hvcs_write,
         .write_room = hvcs_write_room,