1 files changed, 40 insertions, 65 deletions

diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 4ba24963685e..f57fd9095f75 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -47,11 +47,12 @@
  * using the 2.6 Linux kernel kref construct.
  *
  * For direction on installation and usage of this driver please reference
- * Documentation/powerpc/hvcs.rst.
+ * Documentation/arch/powerpc/hvcs.rst.
  */
 
 #include <linux/device.h>
 #include <linux/init.h>
+#include <linux/completion.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
@@ -285,6 +286,7 @@ struct hvcs_struct {
 	char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */
 	struct list_head next; /* list management */
 	struct vio_dev *vdev;
+	struct completion *destroyed;
 };
 
 static LIST_HEAD(hvcs_structs);
@@ -432,7 +434,7 @@ static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr
 
 static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL);
 
-static struct attribute *hvcs_attrs[] = {
+static struct attribute *hvcs_dev_attrs[] = {
 	&dev_attr_partner_vtys.attr,
 	&dev_attr_partner_clcs.attr,
 	&dev_attr_current_vty.attr,
@@ -441,9 +443,7 @@ static struct attribute *hvcs_attrs[] = {
 	NULL,
 };
 
-static struct attribute_group hvcs_attr_group = {
-	.attrs = hvcs_attrs,
-};
+ATTRIBUTE_GROUPS(hvcs_dev);
 
 static ssize_t rescan_show(struct device_driver *ddp, char *buf)
 {
@@ -468,6 +468,13 @@ static ssize_t rescan_store(struct device_driver *ddp, const char * buf,
 
 static DRIVER_ATTR_RW(rescan);
 
+static struct attribute *hvcs_attrs[] = {
+	&driver_attr_rescan.attr,
+	NULL,
+};
+
+ATTRIBUTE_GROUPS(hvcs);
+
 static void hvcs_kick(void)
 {
 	hvcs_kicked = 1;
@@ -657,12 +664,13 @@ static void hvcs_return_index(int index)
 static void hvcs_destruct_port(struct tty_port *p)
 {
 	struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port);
-	struct vio_dev *vdev;
+	struct completion *comp;
 	unsigned long flags;
 
 	spin_lock(&hvcs_structs_lock);
 	spin_lock_irqsave(&hvcsd->lock, flags);
 
+	comp = hvcsd->destroyed;
 	/* the list_del poisons the pointers */
 	list_del(&(hvcsd->next));
 
@@ -677,20 +685,20 @@ static void hvcs_destruct_port(struct tty_port *p)
 	printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n",
 			hvcsd->vdev->unit_address);
 
-	vdev = hvcsd->vdev;
 	hvcsd->vdev = NULL;
 
 	hvcsd->p_unit_address = 0;
 	hvcsd->p_partition_ID = 0;
+	hvcsd->destroyed = NULL;
 	hvcs_return_index(hvcsd->index);
 	memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1);
 
 	spin_unlock_irqrestore(&hvcsd->lock, flags);
 	spin_unlock(&hvcs_structs_lock);
 
-	sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group);
-
 	kfree(hvcsd);
+	if (comp)
+		complete(comp);
 }
 
 static const struct tty_port_operations hvcs_port_ops = {
@@ -721,7 +729,6 @@ static int hvcs_probe(
 {
 	struct hvcs_struct *hvcsd;
 	int index, rc;
-	int retval;
 
 	if (!dev || !id) {
 		printk(KERN_ERR "HVCS: probed with invalid parameter.\n");
@@ -778,13 +785,6 @@ static int hvcs_probe(
 	list_add_tail(&(hvcsd->next), &hvcs_structs);
 	spin_unlock(&hvcs_structs_lock);
 
-	retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group);
-	if (retval) {
-		printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n",
-		       hvcsd->vdev->unit_address);
-		return retval;
-	}
-
 	printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address);
 
 	/*
@@ -797,6 +797,7 @@ static int hvcs_probe(
 static void hvcs_remove(struct vio_dev *dev)
 {
 	struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev);
+	DECLARE_COMPLETION_ONSTACK(comp);
 	unsigned long flags;
 	struct tty_struct *tty;
 
@@ -804,24 +805,22 @@ static void hvcs_remove(struct vio_dev *dev)
 
 	spin_lock_irqsave(&hvcsd->lock, flags);
 
-	tty = hvcsd->port.tty;
+	hvcsd->destroyed = &comp;
+	tty = tty_port_tty_get(&hvcsd->port);
 
 	spin_unlock_irqrestore(&hvcsd->lock, flags);
 
 	/*
-	 * Let the last holder of this object cause it to be removed, which
-	 * would probably be tty_hangup below.
-	 */
-	tty_port_put(&hvcsd->port);
-
-	/*
-	 * The hangup is a scheduled function which will auto chain call
-	 * hvcs_hangup.  The tty should always be valid at this time unless a
+	 * The tty should always be valid at this time unless a
 	 * simultaneous tty close already cleaned up the hvcs_struct.
 	 */
-	if (tty)
-		tty_hangup(tty);
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
 
+	tty_port_put(&hvcsd->port);
+	wait_for_completion(&comp);
 	printk(KERN_INFO "HVCS: vty-server@%X removed from the"
 			" vio bus.\n", dev->unit_address);
 };
@@ -831,6 +830,10 @@ static struct vio_driver hvcs_vio_driver = {
 	.probe		= hvcs_probe,
 	.remove		= hvcs_remove,
 	.name		= hvcs_driver_name,
+	.driver = {
+		.groups = hvcs_groups,
+		.dev_groups = hvcs_dev_groups,
+	},
 };
 
 /* Only called from hvcs_get_pi please */
@@ -1171,7 +1174,10 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 	hvcsd = tty->driver_data;
 
 	spin_lock_irqsave(&hvcsd->lock, flags);
-	if (--hvcsd->port.count == 0) {
+	if (hvcsd->port.count == 0) {
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
+		return;
+	} else if (--hvcsd->port.count == 0) {
 
 		vio_disable_interrupts(hvcsd->vdev);
 
@@ -1215,12 +1221,9 @@ static void hvcs_hangup(struct tty_struct * tty)
 {
 	struct hvcs_struct *hvcsd = tty->driver_data;
 	unsigned long flags;
-	int temp_open_count;
 	int irq;
 
 	spin_lock_irqsave(&hvcsd->lock, flags);
-	/* Preserve this so that we know how many kref refs to put */
-	temp_open_count = hvcsd->port.count;
 
 	/*
 	 * Don't kref put inside the spinlock because the destruction
@@ -1230,11 +1233,7 @@ static void hvcs_hangup(struct tty_struct * tty)
 	vio_disable_interrupts(hvcsd->vdev);
 
 	hvcsd->todo_mask = 0;
-
-	/* I don't think the tty needs the hvcs_struct pointer after a hangup */
-	tty->driver_data = NULL;
 	hvcsd->port.tty = NULL;
-
 	hvcsd->port.count = 0;
 
 	/* This will drop any buffered data on the floor which is OK in a hangup
@@ -1247,21 +1246,6 @@ static void hvcs_hangup(struct tty_struct * tty)
 	spin_unlock_irqrestore(&hvcsd->lock, flags);
 
 	free_irq(irq, hvcsd);
-
-	/*
-	 * We need to kref_put() for every open_count we have since the
-	 * tty_hangup() function doesn't invoke a close per open connection on a
-	 * non-console device.
-	 */
-	while(temp_open_count) {
-		--temp_open_count;
-		/*
-		 * The final put will trigger destruction of the hvcs_struct.
-		 * NOTE:  If this hangup was signaled from user space then the
-		 * final put will never happen.
-		 */
-		tty_port_put(&hvcsd->port);
-	}
 }
 
 /*
@@ -1271,15 +1255,14 @@ static void hvcs_hangup(struct tty_struct * tty)
  * tty_hangup will allow hvcs_write time to complete execution before it
  * terminates our device.
  */
-static int hvcs_write(struct tty_struct *tty,
-		const unsigned char *buf, int count)
+static ssize_t hvcs_write(struct tty_struct *tty, const u8 *buf, size_t count)
 {
 	struct hvcs_struct *hvcsd = tty->driver_data;
 	unsigned int unit_address;
 	const unsigned char *charbuf;
 	unsigned long flags;
-	int total_sent = 0;
-	int tosend = 0;
+	size_t total_sent = 0;
+	size_t tosend = 0;
 	int result = 0;
 
 	/*
@@ -1314,7 +1297,8 @@ static int hvcs_write(struct tty_struct *tty,
 	unit_address = hvcsd->vdev->unit_address;
 
 	while (count > 0) {
-		tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer));
+		tosend = min_t(size_t, count,
+			       (HVCS_BUFF_LEN - hvcsd->chars_in_buffer));
 		/*
 		 * No more space, this probably means that the last call to
 		 * hvcs_write() didn't succeed and the buffer was filled up.
@@ -1525,13 +1509,6 @@ static int __init hvcs_module_init(void)
 
 	pr_info("HVCS: Driver registered.\n");
 
-	/* This needs to be done AFTER the vio_register_driver() call or else
-	 * the kobjects won't be initialized properly.
-	 */
-	rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan);
-	if (rc)
-		pr_warn("HVCS: Failed to create rescan file (err %d)\n", rc);
-
 	return 0;
 }
 
@@ -1556,8 +1533,6 @@ static void __exit hvcs_module_exit(void)
 	hvcs_pi_buff = NULL;
 	spin_unlock(&hvcs_pi_lock);
 
-	driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan);
-
 	tty_unregister_driver(hvcs_tty_driver);
 
 	hvcs_free_index_list();