1 files changed, 200 insertions, 199 deletions

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index a64d6b4dcc1..97128e25f78 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -64,18 +64,39 @@ enum {
 	IB_UMAD_MINOR_BASE = 0
 };
 
+/*
+ * Our lifetime rules for these structs are the following: each time a
+ * device special file is opened, we look up the corresponding struct
+ * ib_umad_port by minor in the umad_port[] table while holding the
+ * port_lock.  If this lookup succeeds, we take a reference on the
+ * ib_umad_port's struct ib_umad_device while still holding the
+ * port_lock; if the lookup fails, we fail the open().  We drop these
+ * references in the corresponding close().
+ *
+ * In addition to references coming from open character devices, there
+ * is one more reference to each ib_umad_device representing the
+ * module's reference taken when allocating the ib_umad_device in
+ * ib_umad_add_one().
+ *
+ * When destroying an ib_umad_device, we clear all of its
+ * ib_umad_ports from umad_port[] while holding port_lock before
+ * dropping the module's reference to the ib_umad_device.  This is
+ * always safe because any open() calls will either succeed and obtain
+ * a reference before we clear the umad_port[] entries, or fail after
+ * we clear the umad_port[] entries.
+ */
+
 struct ib_umad_port {
-	int                    devnum;
-	struct cdev            dev;
-	struct class_device    class_dev;
+	struct cdev           *dev;
+	struct class_device   *class_dev;
 
-	int                    sm_devnum;
-	struct cdev            sm_dev;
-	struct class_device    sm_class_dev;
+	struct cdev           *sm_dev;
+	struct class_device   *sm_class_dev;
 	struct semaphore       sm_sem;
 
 	struct ib_device      *ib_dev;
 	struct ib_umad_device *umad_dev;
+	int                    dev_num;
 	u8                     port_num;
 };
 
@@ -96,21 +117,31 @@ struct ib_umad_file {
 };
 
 struct ib_umad_packet {
-	struct ib_ah      *ah;
 	struct ib_mad_send_buf *msg;
 	struct list_head   list;
 	int		   length;
-	DECLARE_PCI_UNMAP_ADDR(mapping)
 	struct ib_user_mad mad;
 };
 
+static struct class *umad_class;
+
 static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
-static spinlock_t map_lock;
+
+static DEFINE_SPINLOCK(port_lock);
+static struct ib_umad_port *umad_port[IB_UMAD_MAX_PORTS];
 static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS * 2);
 
 static void ib_umad_add_one(struct ib_device *device);
 static void ib_umad_remove_one(struct ib_device *device);
 
+static void ib_umad_release_dev(struct kref *ref)
+{
+	struct ib_umad_device *dev =
+		container_of(ref, struct ib_umad_device, ref);
+
+	kfree(dev);
+}
+
 static int queue_packet(struct ib_umad_file *file,
 			struct ib_mad_agent *agent,
 			struct ib_umad_packet *packet)
@@ -139,22 +170,19 @@ static void send_handler(struct ib_mad_agent *agent,
 			 struct ib_mad_send_wc *send_wc)
 {
 	struct ib_umad_file *file = agent->context;
-	struct ib_umad_packet *timeout, *packet =
-		(void *) (unsigned long) send_wc->wr_id;
+	struct ib_umad_packet *timeout;
+	struct ib_umad_packet *packet = send_wc->send_buf->context[0];
 
-	ib_destroy_ah(packet->msg->send_wr.wr.ud.ah);
+	ib_destroy_ah(packet->msg->ah);
 	ib_free_send_mad(packet->msg);
 
 	if (send_wc->status == IB_WC_RESP_TIMEOUT_ERR) {
-		timeout = kmalloc(sizeof *timeout + sizeof (struct ib_mad_hdr),
-				  GFP_KERNEL);
+		timeout = kzalloc(sizeof *timeout + IB_MGMT_MAD_HDR, GFP_KERNEL);
 		if (!timeout)
 			goto out;
 
-		memset(timeout, 0, sizeof *timeout + sizeof (struct ib_mad_hdr));
-
-		timeout->length = sizeof (struct ib_mad_hdr);
-		timeout->mad.hdr.id = packet->mad.hdr.id;
+		timeout->length 	= IB_MGMT_MAD_HDR;
+		timeout->mad.hdr.id 	= packet->mad.hdr.id;
 		timeout->mad.hdr.status = ETIMEDOUT;
 		memcpy(timeout->mad.data, packet->mad.data,
 		       sizeof (struct ib_mad_hdr));
@@ -177,11 +205,10 @@ static void recv_handler(struct ib_mad_agent *agent,
 		goto out;
 
 	length = mad_recv_wc->mad_len;
-	packet = kmalloc(sizeof *packet + length, GFP_KERNEL);
+	packet = kzalloc(sizeof *packet + length, GFP_KERNEL);
 	if (!packet)
 		goto out;
 
-	memset(packet, 0, sizeof *packet + length);
 	packet->length = length;
 
 	ib_coalesce_recv_mad(mad_recv_wc, packet->mad.data);
@@ -247,7 +274,7 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
 		else
 			ret = -ENOSPC;
 	} else if (copy_to_user(buf, &packet->mad,
-			      packet->length + sizeof (struct ib_user_mad)))
+				packet->length + sizeof (struct ib_user_mad)))
 		ret = -EFAULT;
 	else
 		ret = packet->length + sizeof (struct ib_user_mad);
@@ -268,26 +295,23 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 	struct ib_umad_packet *packet;
 	struct ib_mad_agent *agent;
 	struct ib_ah_attr ah_attr;
-	struct ib_send_wr *bad_wr;
+	struct ib_ah *ah;
 	struct ib_rmpp_mad *rmpp_mad;
 	u8 method;
 	__be64 *tid;
-	int ret, length, hdr_len, data_len, rmpp_hdr_size;
+	int ret, length, hdr_len, copy_offset;
 	int rmpp_active = 0;
 
 	if (count < sizeof (struct ib_user_mad))
 		return -EINVAL;
 
 	length = count - sizeof (struct ib_user_mad);
-	packet = kmalloc(sizeof *packet + sizeof(struct ib_mad_hdr) +
-			 sizeof(struct ib_rmpp_hdr), GFP_KERNEL);
+	packet = kmalloc(sizeof *packet + IB_MGMT_RMPP_HDR, GFP_KERNEL);
 	if (!packet)
 		return -ENOMEM;
 
 	if (copy_from_user(&packet->mad, buf,
-			    sizeof (struct ib_user_mad) +
-			    sizeof(struct ib_mad_hdr) +
-			    sizeof(struct ib_rmpp_hdr))) {
+			    sizeof (struct ib_user_mad) + IB_MGMT_RMPP_HDR)) {
 		ret = -EFAULT;
 		goto err;
 	}
@@ -298,8 +322,6 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 		goto err;
 	}
 
-	packet->length = length;
-
 	down_read(&file->agent_mutex);
 
 	agent = file->agent[packet->mad.hdr.id];
@@ -321,9 +343,9 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 		ah_attr.grh.traffic_class  = packet->mad.hdr.traffic_class;
 	}
 
-	packet->ah = ib_create_ah(agent->qp->pd, &ah_attr);
-	if (IS_ERR(packet->ah)) {
-		ret = PTR_ERR(packet->ah);
+	ah = ib_create_ah(agent->qp->pd, &ah_attr);
+	if (IS_ERR(ah)) {
+		ret = PTR_ERR(ah);
 		goto err_up;
 	}
 
@@ -337,64 +359,44 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 
 		/* Validate that the management class can support RMPP */
 		if (rmpp_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_ADM) {
-			hdr_len = offsetof(struct ib_sa_mad, data);
-			data_len = length - hdr_len;
+			hdr_len = IB_MGMT_SA_HDR;
 		} else if ((rmpp_mad->mad_hdr.mgmt_class >= IB_MGMT_CLASS_VENDOR_RANGE2_START) &&
 			    (rmpp_mad->mad_hdr.mgmt_class <= IB_MGMT_CLASS_VENDOR_RANGE2_END)) {
-				hdr_len = offsetof(struct ib_vendor_mad, data);
-				data_len = length - hdr_len;
+				hdr_len = IB_MGMT_VENDOR_HDR;
 		} else {
 			ret = -EINVAL;
 			goto err_ah;
 		}
 		rmpp_active = 1;
+		copy_offset = IB_MGMT_RMPP_HDR;
 	} else {
-		if (length > sizeof(struct ib_mad)) {
-			ret = -EINVAL;
-			goto err_ah;
-		}
-		hdr_len = offsetof(struct ib_mad, data);
-		data_len = length - hdr_len;
+		hdr_len = IB_MGMT_MAD_HDR;
+		copy_offset = IB_MGMT_MAD_HDR;
 	}
 
 	packet->msg = ib_create_send_mad(agent,
 					 be32_to_cpu(packet->mad.hdr.qpn),
-					 0, packet->ah, rmpp_active,
-					 hdr_len, data_len,
+					 0, rmpp_active,
+					 hdr_len, length - hdr_len,
 					 GFP_KERNEL);
 	if (IS_ERR(packet->msg)) {
 		ret = PTR_ERR(packet->msg);
 		goto err_ah;
 	}
 
-	packet->msg->send_wr.wr.ud.timeout_ms  = packet->mad.hdr.timeout_ms;
-	packet->msg->send_wr.wr.ud.retries = packet->mad.hdr.retries;
-
-	/* Override send WR WRID initialized in ib_create_send_mad */
-	packet->msg->send_wr.wr_id = (unsigned long) packet;
-
-	if (!rmpp_active) {
-		/* Copy message from user into send buffer */
-		if (copy_from_user(packet->msg->mad,
-				   buf + sizeof(struct ib_user_mad), length)) {
-			ret = -EFAULT;
-			goto err_msg;
-		}
-	} else {
-		rmpp_hdr_size = sizeof(struct ib_mad_hdr) +
-				sizeof(struct ib_rmpp_hdr);
+	packet->msg->ah 	= ah;
+	packet->msg->timeout_ms = packet->mad.hdr.timeout_ms;
+	packet->msg->retries 	= packet->mad.hdr.retries;
+	packet->msg->context[0] = packet;
 
-		/* Only copy MAD headers (RMPP header in place) */
-		memcpy(packet->msg->mad, packet->mad.data,
-		       sizeof(struct ib_mad_hdr));
-
-		/* Now, copy rest of message from user into send buffer */
-		if (copy_from_user(((struct ib_rmpp_mad *) packet->msg->mad)->data,
-				   buf + sizeof (struct ib_user_mad) + rmpp_hdr_size,
-				   length - rmpp_hdr_size)) {
-			ret = -EFAULT;
-			goto err_msg;
-		}
+	/* Copy MAD headers (RMPP header in place) */
+	memcpy(packet->msg->mad, packet->mad.data, IB_MGMT_MAD_HDR);
+	/* Now, copy rest of message from user into send buffer */
+	if (copy_from_user(packet->msg->mad + copy_offset,
+			   buf + sizeof (struct ib_user_mad) + copy_offset,
+			   length - copy_offset)) {
+		ret = -EFAULT;
+		goto err_msg;
 	}
 
 	/*
@@ -403,29 +405,29 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
 	 * transaction ID matches the agent being used to send the
 	 * MAD.
 	 */
-	method = packet->msg->mad->mad_hdr.method;
+	method = ((struct ib_mad_hdr *) packet->msg->mad)->method;
 
 	if (!(method & IB_MGMT_METHOD_RESP)       &&
 	    method != IB_MGMT_METHOD_TRAP_REPRESS &&
 	    method != IB_MGMT_METHOD_SEND) {
-		tid = &packet->msg->mad->mad_hdr.tid;
+		tid = &((struct ib_mad_hdr *) packet->msg->mad)->tid;
 		*tid = cpu_to_be64(((u64) agent->hi_tid) << 32 |
 				   (be64_to_cpup(tid) & 0xffffffff));
 	}
 
-	ret = ib_post_send_mad(agent, &packet->msg->send_wr, &bad_wr);
+	ret = ib_post_send_mad(packet->msg, NULL);
 	if (ret)
 		goto err_msg;
 
 	up_read(&file->agent_mutex);
 
-	return sizeof (struct ib_user_mad_hdr) + packet->length;
+	return count;
 
 err_msg:
 	ib_free_send_mad(packet->msg);
 
 err_ah:
-	ib_destroy_ah(packet->ah);
+	ib_destroy_ah(ah);
 
 err_up:
 	up_read(&file->agent_mutex);
@@ -565,15 +567,23 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
 
 static int ib_umad_open(struct inode *inode, struct file *filp)
 {
-	struct ib_umad_port *port =
-		container_of(inode->i_cdev, struct ib_umad_port, dev);
+	struct ib_umad_port *port;
 	struct ib_umad_file *file;
 
-	file = kmalloc(sizeof *file, GFP_KERNEL);
-	if (!file)
-		return -ENOMEM;
+	spin_lock(&port_lock);
+	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
+	if (port)
+		kref_get(&port->umad_dev->ref);
+	spin_unlock(&port_lock);
 
-	memset(file, 0, sizeof *file);
+	if (!port)
+		return -ENXIO;
+
+	file = kzalloc(sizeof *file, GFP_KERNEL);
+	if (!file) {
+		kref_put(&port->umad_dev->ref, ib_umad_release_dev);
+		return -ENOMEM;
+	}
 
 	spin_lock_init(&file->recv_lock);
 	init_rwsem(&file->agent_mutex);
@@ -589,6 +599,7 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
 static int ib_umad_close(struct inode *inode, struct file *filp)
 {
 	struct ib_umad_file *file = filp->private_data;
+	struct ib_umad_device *dev = file->port->umad_dev;
 	struct ib_umad_packet *packet, *tmp;
 	int i;
 
@@ -603,6 +614,8 @@ static int ib_umad_close(struct inode *inode, struct file *filp)
 
 	kfree(file);
 
+	kref_put(&dev->ref, ib_umad_release_dev);
+
 	return 0;
 }
 
@@ -619,30 +632,46 @@ static struct file_operations umad_fops = {
 
 static int ib_umad_sm_open(struct inode *inode, struct file *filp)
 {
-	struct ib_umad_port *port =
-		container_of(inode->i_cdev, struct ib_umad_port, sm_dev);
+	struct ib_umad_port *port;
 	struct ib_port_modify props = {
 		.set_port_cap_mask = IB_PORT_SM
 	};
 	int ret;
 
+	spin_lock(&port_lock);
+	port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE - IB_UMAD_MAX_PORTS];
+	if (port)
+		kref_get(&port->umad_dev->ref);
+	spin_unlock(&port_lock);
+
+	if (!port)
+		return -ENXIO;
+
 	if (filp->f_flags & O_NONBLOCK) {
-		if (down_trylock(&port->sm_sem))
-			return -EAGAIN;
+		if (down_trylock(&port->sm_sem)) {
+			ret = -EAGAIN;
+			goto fail;
+		}
 	} else {
-		if (down_interruptible(&port->sm_sem))
-			return -ERESTARTSYS;
+		if (down_interruptible(&port->sm_sem)) {
+			ret = -ERESTARTSYS;
+			goto fail;
+		}
 	}
 
 	ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
 	if (ret) {
 		up(&port->sm_sem);
-		return ret;
+		goto fail;
 	}
 
 	filp->private_data = port;
 
 	return 0;
+
+fail:
+	kref_put(&port->umad_dev->ref, ib_umad_release_dev);
+	return ret;
 }
 
 static int ib_umad_sm_close(struct inode *inode, struct file *filp)
@@ -656,6 +685,8 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
 	ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
 	up(&port->sm_sem);
 
+	kref_put(&port->umad_dev->ref, ib_umad_release_dev);
+
 	return ret;
 }
 
@@ -671,21 +702,13 @@ static struct ib_client umad_client = {
 	.remove = ib_umad_remove_one
 };
 
-static ssize_t show_dev(struct class_device *class_dev, char *buf)
-{
-	struct ib_umad_port *port = class_get_devdata(class_dev);
-
-	if (class_dev == &port->class_dev)
-		return print_dev_t(buf, port->dev.dev);
-	else
-		return print_dev_t(buf, port->sm_dev.dev);
-}
-static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
-
 static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
 {
 	struct ib_umad_port *port = class_get_devdata(class_dev);
 
+	if (!port)
+		return -ENODEV;
+
 	return sprintf(buf, "%s\n", port->ib_dev->name);
 }
 static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
@@ -694,38 +717,13 @@ static ssize_t show_port(struct class_device *class_dev, char *buf)
 {
 	struct ib_umad_port *port = class_get_devdata(class_dev);
 
+	if (!port)
+		return -ENODEV;
+
 	return sprintf(buf, "%d\n", port->port_num);
 }
 static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
 
-static void ib_umad_release_dev(struct kref *ref)
-{
-	struct ib_umad_device *dev =
-		container_of(ref, struct ib_umad_device, ref);
-
-	kfree(dev);
-}
-
-static void ib_umad_release_port(struct class_device *class_dev)
-{
-	struct ib_umad_port *port = class_get_devdata(class_dev);
-
-	if (class_dev == &port->class_dev) {
-		cdev_del(&port->dev);
-		clear_bit(port->devnum, dev_map);
-	} else {
-		cdev_del(&port->sm_dev);
-		clear_bit(port->sm_devnum, dev_map);
-	}
-
-	kref_put(&port->umad_dev->ref, ib_umad_release_dev);
-}
-
-static struct class umad_class = {
-	.name    = "infiniband_mad",
-	.release = ib_umad_release_port
-};
-
 static ssize_t show_abi_version(struct class *class, char *buf)
 {
 	return sprintf(buf, "%d\n", IB_USER_MAD_ABI_VERSION);
@@ -735,91 +733,102 @@ static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
 static int ib_umad_init_port(struct ib_device *device, int port_num,
 			     struct ib_umad_port *port)
 {
-	spin_lock(&map_lock);
-	port->devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
-	if (port->devnum >= IB_UMAD_MAX_PORTS) {
-		spin_unlock(&map_lock);
+	spin_lock(&port_lock);
+	port->dev_num = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
+	if (port->dev_num >= IB_UMAD_MAX_PORTS) {
+		spin_unlock(&port_lock);
 		return -1;
 	}
-	port->sm_devnum = find_next_zero_bit(dev_map, IB_UMAD_MAX_PORTS * 2, IB_UMAD_MAX_PORTS);
-	if (port->sm_devnum >= IB_UMAD_MAX_PORTS * 2) {
-		spin_unlock(&map_lock);
-		return -1;
-	}
-	set_bit(port->devnum, dev_map);
-	set_bit(port->sm_devnum, dev_map);
-	spin_unlock(&map_lock);
+	set_bit(port->dev_num, dev_map);
+	spin_unlock(&port_lock);
 
 	port->ib_dev   = device;
 	port->port_num = port_num;
 	init_MUTEX(&port->sm_sem);
 
-	cdev_init(&port->dev, &umad_fops);
-	port->dev.owner = THIS_MODULE;
-	kobject_set_name(&port->dev.kobj, "umad%d", port->devnum);
-	if (cdev_add(&port->dev, base_dev + port->devnum, 1))
+	port->dev = cdev_alloc();
+	if (!port->dev)
 		return -1;
-
-	port->class_dev.class = &umad_class;
-	port->class_dev.dev   = device->dma_device;
-
-	snprintf(port->class_dev.class_id, BUS_ID_SIZE, "umad%d", port->devnum);
-
-	if (class_device_register(&port->class_dev))
+	port->dev->owner = THIS_MODULE;
+	port->dev->ops   = &umad_fops;
+	kobject_set_name(&port->dev->kobj, "umad%d", port->dev_num);
+	if (cdev_add(port->dev, base_dev + port->dev_num, 1))
 		goto err_cdev;
 
-	class_set_devdata(&port->class_dev, port);
-	kref_get(&port->umad_dev->ref);
+	port->class_dev = class_device_create(umad_class, NULL, port->dev->dev,
+					      device->dma_device,
+					      "umad%d", port->dev_num);
+	if (IS_ERR(port->class_dev))
+		goto err_cdev;
 
-	if (class_device_create_file(&port->class_dev, &class_device_attr_dev))
-		goto err_class;
-	if (class_device_create_file(&port->class_dev, &class_device_attr_ibdev))
+	if (class_device_create_file(port->class_dev, &class_device_attr_ibdev))
 		goto err_class;
-	if (class_device_create_file(&port->class_dev, &class_device_attr_port))
+	if (class_device_create_file(port->class_dev, &class_device_attr_port))
 		goto err_class;
 
-	cdev_init(&port->sm_dev, &umad_sm_fops);
-	port->sm_dev.owner = THIS_MODULE;
-	kobject_set_name(&port->dev.kobj, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
-	if (cdev_add(&port->sm_dev, base_dev + port->sm_devnum, 1))
-		return -1;
-
-	port->sm_class_dev.class = &umad_class;
-	port->sm_class_dev.dev   = device->dma_device;
-
-	snprintf(port->sm_class_dev.class_id, BUS_ID_SIZE, "issm%d", port->sm_devnum - IB_UMAD_MAX_PORTS);
+	port->sm_dev = cdev_alloc();
+	if (!port->sm_dev)
+		goto err_class;
+	port->sm_dev->owner = THIS_MODULE;
+	port->sm_dev->ops   = &umad_sm_fops;
+	kobject_set_name(&port->dev->kobj, "issm%d", port->dev_num);
+	if (cdev_add(port->sm_dev, base_dev + port->dev_num + IB_UMAD_MAX_PORTS, 1))
+		goto err_sm_cdev;
 
-	if (class_device_register(&port->sm_class_dev))
+	port->sm_class_dev = class_device_create(umad_class, NULL, port->sm_dev->dev,
+						 device->dma_device,
+						 "issm%d", port->dev_num);
+	if (IS_ERR(port->sm_class_dev))
 		goto err_sm_cdev;
 
-	class_set_devdata(&port->sm_class_dev, port);
-	kref_get(&port->umad_dev->ref);
+	class_set_devdata(port->class_dev,    port);
+	class_set_devdata(port->sm_class_dev, port);
 
-	if (class_device_create_file(&port->sm_class_dev, &class_device_attr_dev))
-		goto err_sm_class;
-	if (class_device_create_file(&port->sm_class_dev, &class_device_attr_ibdev))
+	if (class_device_create_file(port->sm_class_dev, &class_device_attr_ibdev))
 		goto err_sm_class;
-	if (class_device_create_file(&port->sm_class_dev, &class_device_attr_port))
+	if (class_device_create_file(port->sm_class_dev, &class_device_attr_port))
 		goto err_sm_class;
 
+	spin_lock(&port_lock);
+	umad_port[port->dev_num] = port;
+	spin_unlock(&port_lock);
+
 	return 0;
 
 err_sm_class:
-	class_device_unregister(&port->sm_class_dev);
+	class_device_destroy(umad_class, port->sm_dev->dev);
 
 err_sm_cdev:
-	cdev_del(&port->sm_dev);
+	cdev_del(port->sm_dev);
 
 err_class:
-	class_device_unregister(&port->class_dev);
+	class_device_destroy(umad_class, port->dev->dev);
 
 err_cdev:
-	cdev_del(&port->dev);
-	clear_bit(port->devnum, dev_map);
+	cdev_del(port->dev);
+	clear_bit(port->dev_num, dev_map);
 
 	return -1;
 }
 
+static void ib_umad_kill_port(struct ib_umad_port *port)
+{
+	class_set_devdata(port->class_dev,    NULL);
+	class_set_devdata(port->sm_class_dev, NULL);
+
+	class_device_destroy(umad_class, port->dev->dev);
+	class_device_destroy(umad_class, port->sm_dev->dev);
+
+	cdev_del(port->dev);
+	cdev_del(port->sm_dev);
+
+	spin_lock(&port_lock);
+	umad_port[port->dev_num] = NULL;
+	spin_unlock(&port_lock);
+
+	clear_bit(port->dev_num, dev_map);
+}
+
 static void ib_umad_add_one(struct ib_device *device)
 {
 	struct ib_umad_device *umad_dev;
@@ -832,15 +841,12 @@ static void ib_umad_add_one(struct ib_device *device)
 		e = device->phys_port_cnt;
 	}
 
-	umad_dev = kmalloc(sizeof *umad_dev +
+	umad_dev = kzalloc(sizeof *umad_dev +
 			   (e - s + 1) * sizeof (struct ib_umad_port),
 			   GFP_KERNEL);
 	if (!umad_dev)
 		return;
 
-	memset(umad_dev, 0, sizeof *umad_dev +
-	       (e - s + 1) * sizeof (struct ib_umad_port));
-
 	kref_init(&umad_dev->ref);
 
 	umad_dev->start_port = s;
@@ -858,10 +864,8 @@ static void ib_umad_add_one(struct ib_device *device)
 	return;
 
 err:
-	while (--i >= s) {
-		class_device_unregister(&umad_dev->port[i - s].class_dev);
-		class_device_unregister(&umad_dev->port[i - s].sm_class_dev);
-	}
+	while (--i >= s)
+		ib_umad_kill_port(&umad_dev->port[i]);
 
 	kref_put(&umad_dev->ref, ib_umad_release_dev);
 }
@@ -874,10 +878,8 @@ static void ib_umad_remove_one(struct ib_device *device)
 	if (!umad_dev)
 		return;
 
-	for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i) {
-		class_device_unregister(&umad_dev->port[i].class_dev);
-		class_device_unregister(&umad_dev->port[i].sm_class_dev);
-	}
+	for (i = 0; i <= umad_dev->end_port - umad_dev->start_port; ++i)
+		ib_umad_kill_port(&umad_dev->port[i]);
 
 	kref_put(&umad_dev->ref, ib_umad_release_dev);
 }
@@ -886,8 +888,6 @@ static int __init ib_umad_init(void)
 {
 	int ret;
 
-	spin_lock_init(&map_lock);
-
 	ret = register_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2,
 				     "infiniband_mad");
 	if (ret) {
@@ -895,13 +895,14 @@ static int __init ib_umad_init(void)
 		goto out;
 	}
 
-	ret = class_register(&umad_class);
-	if (ret) {
+	umad_class = class_create(THIS_MODULE, "infiniband_mad");
+	if (IS_ERR(umad_class)) {
+		ret = PTR_ERR(umad_class);
 		printk(KERN_ERR "user_mad: couldn't create class infiniband_mad\n");
 		goto out_chrdev;
 	}
 
-	ret = class_create_file(&umad_class, &class_attr_abi_version);
+	ret = class_create_file(umad_class, &class_attr_abi_version);
 	if (ret) {
 		printk(KERN_ERR "user_mad: couldn't create abi_version attribute\n");
 		goto out_class;
@@ -916,7 +917,7 @@ static int __init ib_umad_init(void)
 	return 0;
 
 out_class:
-	class_unregister(&umad_class);
+	class_destroy(umad_class);
 
 out_chrdev:
 	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
@@ -928,7 +929,7 @@ out:
 static void __exit ib_umad_cleanup(void)
 {
 	ib_unregister_client(&umad_client);
-	class_unregister(&umad_class);
+	class_destroy(umad_class);
 	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
 }