Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1497 insertions, 0 deletions

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
new file mode 100644
index 000000000..d96c78e43
--- /dev/null
+++ b/drivers/infiniband/core/user_mad.c
@@ -0,0 +1,1497 @@
+/*
+ * Copyright (c) 2004 Topspin Communications.  All rights reserved.
+ * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
+ * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
+ * Copyright (c) 2008 Cisco. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#define pr_fmt(fmt) "user_mad: " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/kref.h>
+#include <linux/compat.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+#include <linux/slab.h>
+#include <linux/nospec.h>
+
+#include <linux/uaccess.h>
+
+#include <rdma/ib_mad.h>
+#include <rdma/ib_user_mad.h>
+#include <rdma/rdma_netlink.h>
+
+#include "core_priv.h"
+
+MODULE_AUTHOR("Roland Dreier");
+MODULE_DESCRIPTION("InfiniBand userspace MAD packet access");
+MODULE_LICENSE("Dual BSD/GPL");
+
+enum {
+	IB_UMAD_MAX_PORTS  = RDMA_MAX_PORTS,
+	IB_UMAD_MAX_AGENTS = 32,
+
+	IB_UMAD_MAJOR      = 231,
+	IB_UMAD_MINOR_BASE = 0,
+	IB_UMAD_NUM_FIXED_MINOR = 64,
+	IB_UMAD_NUM_DYNAMIC_MINOR = IB_UMAD_MAX_PORTS - IB_UMAD_NUM_FIXED_MINOR,
+	IB_ISSM_MINOR_BASE        = IB_UMAD_NUM_FIXED_MINOR,
+};
+
+/*
+ * Our lifetime rules for these structs are the following:
+ * device special file is opened, we take a reference on the
+ * ib_umad_port's struct ib_umad_device. 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 drop the module's reference.
+ */
+
+struct ib_umad_port {
+	struct cdev           cdev;
+	struct device	      dev;
+	struct cdev           sm_cdev;
+	struct device	      sm_dev;
+	struct semaphore       sm_sem;
+
+	struct mutex	       file_mutex;
+	struct list_head       file_list;
+
+	struct ib_device      *ib_dev;
+	struct ib_umad_device *umad_dev;
+	int                    dev_num;
+	u32                     port_num;
+};
+
+struct ib_umad_device {
+	struct kref kref;
+	struct ib_umad_port ports[];
+};
+
+struct ib_umad_file {
+	struct mutex		mutex;
+	struct ib_umad_port    *port;
+	struct list_head	recv_list;
+	struct list_head	send_list;
+	struct list_head	port_list;
+	spinlock_t		send_lock;
+	wait_queue_head_t	recv_wait;
+	struct ib_mad_agent    *agent[IB_UMAD_MAX_AGENTS];
+	int			agents_dead;
+	u8			use_pkey_index;
+	u8			already_used;
+};
+
+struct ib_umad_packet {
+	struct ib_mad_send_buf *msg;
+	struct ib_mad_recv_wc  *recv_wc;
+	struct list_head   list;
+	int		   length;
+	struct ib_user_mad mad;
+};
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/ib_umad.h>
+
+static const dev_t base_umad_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
+static const dev_t base_issm_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE) +
+				   IB_UMAD_NUM_FIXED_MINOR;
+static dev_t dynamic_umad_dev;
+static dev_t dynamic_issm_dev;
+
+static DEFINE_IDA(umad_ida);
+
+static int ib_umad_add_one(struct ib_device *device);
+static void ib_umad_remove_one(struct ib_device *device, void *client_data);
+
+static void ib_umad_dev_free(struct kref *kref)
+{
+	struct ib_umad_device *dev =
+		container_of(kref, struct ib_umad_device, kref);
+
+	kfree(dev);
+}
+
+static void ib_umad_dev_get(struct ib_umad_device *dev)
+{
+	kref_get(&dev->kref);
+}
+
+static void ib_umad_dev_put(struct ib_umad_device *dev)
+{
+	kref_put(&dev->kref, ib_umad_dev_free);
+}
+
+static int hdr_size(struct ib_umad_file *file)
+{
+	return file->use_pkey_index ? sizeof(struct ib_user_mad_hdr) :
+				      sizeof(struct ib_user_mad_hdr_old);
+}
+
+/* caller must hold file->mutex */
+static struct ib_mad_agent *__get_agent(struct ib_umad_file *file, int id)
+{
+	return file->agents_dead ? NULL : file->agent[id];
+}
+
+static int queue_packet(struct ib_umad_file *file,
+			struct ib_mad_agent *agent,
+			struct ib_umad_packet *packet)
+{
+	int ret = 1;
+
+	mutex_lock(&file->mutex);
+
+	for (packet->mad.hdr.id = 0;
+	     packet->mad.hdr.id < IB_UMAD_MAX_AGENTS;
+	     packet->mad.hdr.id++)
+		if (agent == __get_agent(file, packet->mad.hdr.id)) {
+			list_add_tail(&packet->list, &file->recv_list);
+			wake_up_interruptible(&file->recv_wait);
+			ret = 0;
+			break;
+		}
+
+	mutex_unlock(&file->mutex);
+
+	return ret;
+}
+
+static void dequeue_send(struct ib_umad_file *file,
+			 struct ib_umad_packet *packet)
+{
+	spin_lock_irq(&file->send_lock);
+	list_del(&packet->list);
+	spin_unlock_irq(&file->send_lock);
+}
+
+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 *packet = send_wc->send_buf->context[0];
+
+	dequeue_send(file, packet);
+	rdma_destroy_ah(packet->msg->ah, RDMA_DESTROY_AH_SLEEPABLE);
+	ib_free_send_mad(packet->msg);
+
+	if (send_wc->status == IB_WC_RESP_TIMEOUT_ERR) {
+		packet->length = IB_MGMT_MAD_HDR;
+		packet->mad.hdr.status = ETIMEDOUT;
+		if (!queue_packet(file, agent, packet))
+			return;
+	}
+	kfree(packet);
+}
+
+static void recv_handler(struct ib_mad_agent *agent,
+			 struct ib_mad_send_buf *send_buf,
+			 struct ib_mad_recv_wc *mad_recv_wc)
+{
+	struct ib_umad_file *file = agent->context;
+	struct ib_umad_packet *packet;
+
+	if (mad_recv_wc->wc->status != IB_WC_SUCCESS)
+		goto err1;
+
+	packet = kzalloc(sizeof *packet, GFP_KERNEL);
+	if (!packet)
+		goto err1;
+
+	packet->length = mad_recv_wc->mad_len;
+	packet->recv_wc = mad_recv_wc;
+
+	packet->mad.hdr.status	   = 0;
+	packet->mad.hdr.length	   = hdr_size(file) + mad_recv_wc->mad_len;
+	packet->mad.hdr.qpn	   = cpu_to_be32(mad_recv_wc->wc->src_qp);
+	/*
+	 * On OPA devices it is okay to lose the upper 16 bits of LID as this
+	 * information is obtained elsewhere. Mask off the upper 16 bits.
+	 */
+	if (rdma_cap_opa_mad(agent->device, agent->port_num))
+		packet->mad.hdr.lid = ib_lid_be16(0xFFFF &
+						  mad_recv_wc->wc->slid);
+	else
+		packet->mad.hdr.lid = ib_lid_be16(mad_recv_wc->wc->slid);
+	packet->mad.hdr.sl	   = mad_recv_wc->wc->sl;
+	packet->mad.hdr.path_bits  = mad_recv_wc->wc->dlid_path_bits;
+	packet->mad.hdr.pkey_index = mad_recv_wc->wc->pkey_index;
+	packet->mad.hdr.grh_present = !!(mad_recv_wc->wc->wc_flags & IB_WC_GRH);
+	if (packet->mad.hdr.grh_present) {
+		struct rdma_ah_attr ah_attr;
+		const struct ib_global_route *grh;
+		int ret;
+
+		ret = ib_init_ah_attr_from_wc(agent->device, agent->port_num,
+					      mad_recv_wc->wc,
+					      mad_recv_wc->recv_buf.grh,
+					      &ah_attr);
+		if (ret)
+			goto err2;
+
+		grh = rdma_ah_read_grh(&ah_attr);
+		packet->mad.hdr.gid_index = grh->sgid_index;
+		packet->mad.hdr.hop_limit = grh->hop_limit;
+		packet->mad.hdr.traffic_class = grh->traffic_class;
+		memcpy(packet->mad.hdr.gid, &grh->dgid, 16);
+		packet->mad.hdr.flow_label = cpu_to_be32(grh->flow_label);
+		rdma_destroy_ah_attr(&ah_attr);
+	}
+
+	if (queue_packet(file, agent, packet))
+		goto err2;
+	return;
+
+err2:
+	kfree(packet);
+err1:
+	ib_free_recv_mad(mad_recv_wc);
+}
+
+static ssize_t copy_recv_mad(struct ib_umad_file *file, char __user *buf,
+			     struct ib_umad_packet *packet, size_t count)
+{
+	struct ib_mad_recv_buf *recv_buf;
+	int left, seg_payload, offset, max_seg_payload;
+	size_t seg_size;
+
+	recv_buf = &packet->recv_wc->recv_buf;
+	seg_size = packet->recv_wc->mad_seg_size;
+
+	/* We need enough room to copy the first (or only) MAD segment. */
+	if ((packet->length <= seg_size &&
+	     count < hdr_size(file) + packet->length) ||
+	    (packet->length > seg_size &&
+	     count < hdr_size(file) + seg_size))
+		return -EINVAL;
+
+	if (copy_to_user(buf, &packet->mad, hdr_size(file)))
+		return -EFAULT;
+
+	buf += hdr_size(file);
+	seg_payload = min_t(int, packet->length, seg_size);
+	if (copy_to_user(buf, recv_buf->mad, seg_payload))
+		return -EFAULT;
+
+	if (seg_payload < packet->length) {
+		/*
+		 * Multipacket RMPP MAD message. Copy remainder of message.
+		 * Note that last segment may have a shorter payload.
+		 */
+		if (count < hdr_size(file) + packet->length) {
+			/*
+			 * The buffer is too small, return the first RMPP segment,
+			 * which includes the RMPP message length.
+			 */
+			return -ENOSPC;
+		}
+		offset = ib_get_mad_data_offset(recv_buf->mad->mad_hdr.mgmt_class);
+		max_seg_payload = seg_size - offset;
+
+		for (left = packet->length - seg_payload, buf += seg_payload;
+		     left; left -= seg_payload, buf += seg_payload) {
+			recv_buf = container_of(recv_buf->list.next,
+						struct ib_mad_recv_buf, list);
+			seg_payload = min(left, max_seg_payload);
+			if (copy_to_user(buf, ((void *) recv_buf->mad) + offset,
+					 seg_payload))
+				return -EFAULT;
+		}
+	}
+
+	trace_ib_umad_read_recv(file, &packet->mad.hdr, &recv_buf->mad->mad_hdr);
+
+	return hdr_size(file) + packet->length;
+}
+
+static ssize_t copy_send_mad(struct ib_umad_file *file, char __user *buf,
+			     struct ib_umad_packet *packet, size_t count)
+{
+	ssize_t size = hdr_size(file) + packet->length;
+
+	if (count < size)
+		return -EINVAL;
+
+	if (copy_to_user(buf, &packet->mad, hdr_size(file)))
+		return -EFAULT;
+
+	buf += hdr_size(file);
+
+	if (copy_to_user(buf, packet->mad.data, packet->length))
+		return -EFAULT;
+
+	trace_ib_umad_read_send(file, &packet->mad.hdr,
+				(struct ib_mad_hdr *)&packet->mad.data);
+
+	return size;
+}
+
+static ssize_t ib_umad_read(struct file *filp, char __user *buf,
+			    size_t count, loff_t *pos)
+{
+	struct ib_umad_file *file = filp->private_data;
+	struct ib_umad_packet *packet;
+	ssize_t ret;
+
+	if (count < hdr_size(file))
+		return -EINVAL;
+
+	mutex_lock(&file->mutex);
+
+	if (file->agents_dead) {
+		mutex_unlock(&file->mutex);
+		return -EIO;
+	}
+
+	while (list_empty(&file->recv_list)) {
+		mutex_unlock(&file->mutex);
+
+		if (filp->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+
+		if (wait_event_interruptible(file->recv_wait,
+					     !list_empty(&file->recv_list)))
+			return -ERESTARTSYS;
+
+		mutex_lock(&file->mutex);
+	}
+
+	if (file->agents_dead) {
+		mutex_unlock(&file->mutex);
+		return -EIO;
+	}
+
+	packet = list_entry(file->recv_list.next, struct ib_umad_packet, list);
+	list_del(&packet->list);
+
+	mutex_unlock(&file->mutex);
+
+	if (packet->recv_wc)
+		ret = copy_recv_mad(file, buf, packet, count);
+	else
+		ret = copy_send_mad(file, buf, packet, count);
+
+	if (ret < 0) {
+		/* Requeue packet */
+		mutex_lock(&file->mutex);
+		list_add(&packet->list, &file->recv_list);
+		mutex_unlock(&file->mutex);
+	} else {
+		if (packet->recv_wc)
+			ib_free_recv_mad(packet->recv_wc);
+		kfree(packet);
+	}
+	return ret;
+}
+
+static int copy_rmpp_mad(struct ib_mad_send_buf *msg, const char __user *buf)
+{
+	int left, seg;
+
+	/* Copy class specific header */
+	if ((msg->hdr_len > IB_MGMT_RMPP_HDR) &&
+	    copy_from_user(msg->mad + IB_MGMT_RMPP_HDR, buf + IB_MGMT_RMPP_HDR,
+			   msg->hdr_len - IB_MGMT_RMPP_HDR))
+		return -EFAULT;
+
+	/* All headers are in place.  Copy data segments. */
+	for (seg = 1, left = msg->data_len, buf += msg->hdr_len; left > 0;
+	     seg++, left -= msg->seg_size, buf += msg->seg_size) {
+		if (copy_from_user(ib_get_rmpp_segment(msg, seg), buf,
+				   min(left, msg->seg_size)))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+static int same_destination(struct ib_user_mad_hdr *hdr1,
+			    struct ib_user_mad_hdr *hdr2)
+{
+	if (!hdr1->grh_present && !hdr2->grh_present)
+	   return (hdr1->lid == hdr2->lid);
+
+	if (hdr1->grh_present && hdr2->grh_present)
+	   return !memcmp(hdr1->gid, hdr2->gid, 16);
+
+	return 0;
+}
+
+static int is_duplicate(struct ib_umad_file *file,
+			struct ib_umad_packet *packet)
+{
+	struct ib_umad_packet *sent_packet;
+	struct ib_mad_hdr *sent_hdr, *hdr;
+
+	hdr = (struct ib_mad_hdr *) packet->mad.data;
+	list_for_each_entry(sent_packet, &file->send_list, list) {
+		sent_hdr = (struct ib_mad_hdr *) sent_packet->mad.data;
+
+		if ((hdr->tid != sent_hdr->tid) ||
+		    (hdr->mgmt_class != sent_hdr->mgmt_class))
+			continue;
+
+		/*
+		 * No need to be overly clever here.  If two new operations have
+		 * the same TID, reject the second as a duplicate.  This is more
+		 * restrictive than required by the spec.
+		 */
+		if (!ib_response_mad(hdr)) {
+			if (!ib_response_mad(sent_hdr))
+				return 1;
+			continue;
+		} else if (!ib_response_mad(sent_hdr))
+			continue;
+
+		if (same_destination(&packet->mad.hdr, &sent_packet->mad.hdr))
+			return 1;
+	}
+
+	return 0;
+}
+
+static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
+			     size_t count, loff_t *pos)
+{
+	struct ib_umad_file *file = filp->private_data;
+	struct ib_umad_packet *packet;
+	struct ib_mad_agent *agent;
+	struct rdma_ah_attr ah_attr;
+	struct ib_ah *ah;
+	struct ib_rmpp_mad *rmpp_mad;
+	__be64 *tid;
+	int ret, data_len, hdr_len, copy_offset, rmpp_active;
+	u8 base_version;
+
+	if (count < hdr_size(file) + IB_MGMT_RMPP_HDR)
+		return -EINVAL;
+
+	packet = kzalloc(sizeof *packet + IB_MGMT_RMPP_HDR, GFP_KERNEL);
+	if (!packet)
+		return -ENOMEM;
+
+	if (copy_from_user(&packet->mad, buf, hdr_size(file))) {
+		ret = -EFAULT;
+		goto err;
+	}
+
+	if (packet->mad.hdr.id >= IB_UMAD_MAX_AGENTS) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	buf += hdr_size(file);
+
+	if (copy_from_user(packet->mad.data, buf, IB_MGMT_RMPP_HDR)) {
+		ret = -EFAULT;
+		goto err;
+	}
+
+	mutex_lock(&file->mutex);
+
+	trace_ib_umad_write(file, &packet->mad.hdr,
+			    (struct ib_mad_hdr *)&packet->mad.data);
+
+	agent = __get_agent(file, packet->mad.hdr.id);
+	if (!agent) {
+		ret = -EIO;
+		goto err_up;
+	}
+
+	memset(&ah_attr, 0, sizeof ah_attr);
+	ah_attr.type = rdma_ah_find_type(agent->device,
+					 file->port->port_num);
+	rdma_ah_set_dlid(&ah_attr, be16_to_cpu(packet->mad.hdr.lid));
+	rdma_ah_set_sl(&ah_attr, packet->mad.hdr.sl);
+	rdma_ah_set_path_bits(&ah_attr, packet->mad.hdr.path_bits);
+	rdma_ah_set_port_num(&ah_attr, file->port->port_num);
+	if (packet->mad.hdr.grh_present) {
+		rdma_ah_set_grh(&ah_attr, NULL,
+				be32_to_cpu(packet->mad.hdr.flow_label),
+				packet->mad.hdr.gid_index,
+				packet->mad.hdr.hop_limit,
+				packet->mad.hdr.traffic_class);
+		rdma_ah_set_dgid_raw(&ah_attr, packet->mad.hdr.gid);
+	}
+
+	ah = rdma_create_user_ah(agent->qp->pd, &ah_attr, NULL);
+	if (IS_ERR(ah)) {
+		ret = PTR_ERR(ah);
+		goto err_up;
+	}
+
+	rmpp_mad = (struct ib_rmpp_mad *) packet->mad.data;
+	hdr_len = ib_get_mad_data_offset(rmpp_mad->mad_hdr.mgmt_class);
+
+	if (ib_is_mad_class_rmpp(rmpp_mad->mad_hdr.mgmt_class)
+	    && ib_mad_kernel_rmpp_agent(agent)) {
+		copy_offset = IB_MGMT_RMPP_HDR;
+		rmpp_active = ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) &
+						IB_MGMT_RMPP_FLAG_ACTIVE;
+	} else {
+		copy_offset = IB_MGMT_MAD_HDR;
+		rmpp_active = 0;
+	}
+
+	base_version = ((struct ib_mad_hdr *)&packet->mad.data)->base_version;
+	data_len = count - hdr_size(file) - hdr_len;
+	packet->msg = ib_create_send_mad(agent,
+					 be32_to_cpu(packet->mad.hdr.qpn),
+					 packet->mad.hdr.pkey_index, rmpp_active,
+					 hdr_len, data_len, GFP_KERNEL,
+					 base_version);
+	if (IS_ERR(packet->msg)) {
+		ret = PTR_ERR(packet->msg);
+		goto err_ah;
+	}
+
+	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;
+
+	/* Copy MAD header.  Any RMPP header is already in place. */
+	memcpy(packet->msg->mad, packet->mad.data, IB_MGMT_MAD_HDR);
+
+	if (!rmpp_active) {
+		if (copy_from_user(packet->msg->mad + copy_offset,
+				   buf + copy_offset,
+				   hdr_len + data_len - copy_offset)) {
+			ret = -EFAULT;
+			goto err_msg;
+		}
+	} else {
+		ret = copy_rmpp_mad(packet->msg, buf);
+		if (ret)
+			goto err_msg;
+	}
+
+	/*
+	 * Set the high-order part of the transaction ID to make MADs from
+	 * different agents unique, and allow routing responses back to the
+	 * original requestor.
+	 */
+	if (!ib_response_mad(packet->msg->mad)) {
+		tid = &((struct ib_mad_hdr *) packet->msg->mad)->tid;
+		*tid = cpu_to_be64(((u64) agent->hi_tid) << 32 |
+				   (be64_to_cpup(tid) & 0xffffffff));
+		rmpp_mad->mad_hdr.tid = *tid;
+	}
+
+	if (!ib_mad_kernel_rmpp_agent(agent)
+	   && ib_is_mad_class_rmpp(rmpp_mad->mad_hdr.mgmt_class)
+	   && (ib_get_rmpp_flags(&rmpp_mad->rmpp_hdr) & IB_MGMT_RMPP_FLAG_ACTIVE)) {
+		spin_lock_irq(&file->send_lock);
+		list_add_tail(&packet->list, &file->send_list);
+		spin_unlock_irq(&file->send_lock);
+	} else {
+		spin_lock_irq(&file->send_lock);
+		ret = is_duplicate(file, packet);
+		if (!ret)
+			list_add_tail(&packet->list, &file->send_list);
+		spin_unlock_irq(&file->send_lock);
+		if (ret) {
+			ret = -EINVAL;
+			goto err_msg;
+		}
+	}
+
+	ret = ib_post_send_mad(packet->msg, NULL);
+	if (ret)
+		goto err_send;
+
+	mutex_unlock(&file->mutex);
+	return count;
+
+err_send:
+	dequeue_send(file, packet);
+err_msg:
+	ib_free_send_mad(packet->msg);
+err_ah:
+	rdma_destroy_ah(ah, RDMA_DESTROY_AH_SLEEPABLE);
+err_up:
+	mutex_unlock(&file->mutex);
+err:
+	kfree(packet);
+	return ret;
+}
+
+static __poll_t ib_umad_poll(struct file *filp, struct poll_table_struct *wait)
+{
+	struct ib_umad_file *file = filp->private_data;
+
+	/* we will always be able to post a MAD send */
+	__poll_t mask = EPOLLOUT | EPOLLWRNORM;
+
+	mutex_lock(&file->mutex);
+	poll_wait(filp, &file->recv_wait, wait);
+
+	if (!list_empty(&file->recv_list))
+		mask |= EPOLLIN | EPOLLRDNORM;
+	if (file->agents_dead)
+		mask = EPOLLERR;
+	mutex_unlock(&file->mutex);
+
+	return mask;
+}
+
+static int ib_umad_reg_agent(struct ib_umad_file *file, void __user *arg,
+			     int compat_method_mask)
+{
+	struct ib_user_mad_reg_req ureq;
+	struct ib_mad_reg_req req;
+	struct ib_mad_agent *agent = NULL;
+	int agent_id;
+	int ret;
+
+	mutex_lock(&file->port->file_mutex);
+	mutex_lock(&file->mutex);
+
+	if (!file->port->ib_dev) {
+		dev_notice(&file->port->dev, "%s: invalid device\n", __func__);
+		ret = -EPIPE;
+		goto out;
+	}
+
+	if (copy_from_user(&ureq, arg, sizeof ureq)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (ureq.qpn != 0 && ureq.qpn != 1) {
+		dev_notice(&file->port->dev,
+			   "%s: invalid QPN %u specified\n", __func__,
+			   ureq.qpn);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (agent_id = 0; agent_id < IB_UMAD_MAX_AGENTS; ++agent_id)
+		if (!__get_agent(file, agent_id))
+			goto found;
+
+	dev_notice(&file->port->dev, "%s: Max Agents (%u) reached\n", __func__,
+		   IB_UMAD_MAX_AGENTS);
+
+	ret = -ENOMEM;
+	goto out;
+
+found:
+	if (ureq.mgmt_class) {
+		memset(&req, 0, sizeof(req));
+		req.mgmt_class         = ureq.mgmt_class;
+		req.mgmt_class_version = ureq.mgmt_class_version;
+		memcpy(req.oui, ureq.oui, sizeof req.oui);
+
+		if (compat_method_mask) {
+			u32 *umm = (u32 *) ureq.method_mask;
+			int i;
+
+			for (i = 0; i < BITS_TO_LONGS(IB_MGMT_MAX_METHODS); ++i)
+				req.method_mask[i] =
+					umm[i * 2] | ((u64) umm[i * 2 + 1] << 32);
+		} else
+			memcpy(req.method_mask, ureq.method_mask,
+			       sizeof req.method_mask);
+	}
+
+	agent = ib_register_mad_agent(file->port->ib_dev, file->port->port_num,
+				      ureq.qpn ? IB_QPT_GSI : IB_QPT_SMI,
+				      ureq.mgmt_class ? &req : NULL,
+				      ureq.rmpp_version,
+				      send_handler, recv_handler, file, 0);
+	if (IS_ERR(agent)) {
+		ret = PTR_ERR(agent);
+		agent = NULL;
+		goto out;
+	}
+
+	if (put_user(agent_id,
+		     (u32 __user *) (arg + offsetof(struct ib_user_mad_reg_req, id)))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (!file->already_used) {
+		file->already_used = 1;
+		if (!file->use_pkey_index) {
+			dev_warn(&file->port->dev,
+				"process %s did not enable P_Key index support.\n",
+				current->comm);
+			dev_warn(&file->port->dev,
+				"   Documentation/infiniband/user_mad.rst has info on the new ABI.\n");
+		}
+	}
+
+	file->agent[agent_id] = agent;
+	ret = 0;
+
+out:
+	mutex_unlock(&file->mutex);
+
+	if (ret && agent)
+		ib_unregister_mad_agent(agent);
+
+	mutex_unlock(&file->port->file_mutex);
+
+	return ret;
+}
+
+static int ib_umad_reg_agent2(struct ib_umad_file *file, void __user *arg)
+{
+	struct ib_user_mad_reg_req2 ureq;
+	struct ib_mad_reg_req req;
+	struct ib_mad_agent *agent = NULL;
+	int agent_id;
+	int ret;
+
+	mutex_lock(&file->port->file_mutex);
+	mutex_lock(&file->mutex);
+
+	if (!file->port->ib_dev) {
+		dev_notice(&file->port->dev, "%s: invalid device\n", __func__);
+		ret = -EPIPE;
+		goto out;
+	}
+
+	if (copy_from_user(&ureq, arg, sizeof(ureq))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (ureq.qpn != 0 && ureq.qpn != 1) {
+		dev_notice(&file->port->dev, "%s: invalid QPN %u specified\n",
+			   __func__, ureq.qpn);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (ureq.flags & ~IB_USER_MAD_REG_FLAGS_CAP) {
+		dev_notice(&file->port->dev,
+			   "%s failed: invalid registration flags specified 0x%x; supported 0x%x\n",
+			   __func__, ureq.flags, IB_USER_MAD_REG_FLAGS_CAP);
+		ret = -EINVAL;
+
+		if (put_user((u32)IB_USER_MAD_REG_FLAGS_CAP,
+				(u32 __user *) (arg + offsetof(struct
+				ib_user_mad_reg_req2, flags))))
+			ret = -EFAULT;
+
+		goto out;
+	}
+
+	for (agent_id = 0; agent_id < IB_UMAD_MAX_AGENTS; ++agent_id)
+		if (!__get_agent(file, agent_id))
+			goto found;
+
+	dev_notice(&file->port->dev, "%s: Max Agents (%u) reached\n", __func__,
+		   IB_UMAD_MAX_AGENTS);
+	ret = -ENOMEM;
+	goto out;
+
+found:
+	if (ureq.mgmt_class) {
+		memset(&req, 0, sizeof(req));
+		req.mgmt_class         = ureq.mgmt_class;
+		req.mgmt_class_version = ureq.mgmt_class_version;
+		if (ureq.oui & 0xff000000) {
+			dev_notice(&file->port->dev,
+				   "%s failed: oui invalid 0x%08x\n", __func__,
+				   ureq.oui);
+			ret = -EINVAL;
+			goto out;
+		}
+		req.oui[2] =  ureq.oui & 0x0000ff;
+		req.oui[1] = (ureq.oui & 0x00ff00) >> 8;
+		req.oui[0] = (ureq.oui & 0xff0000) >> 16;
+		memcpy(req.method_mask, ureq.method_mask,
+			sizeof(req.method_mask));
+	}
+
+	agent = ib_register_mad_agent(file->port->ib_dev, file->port->port_num,
+				      ureq.qpn ? IB_QPT_GSI : IB_QPT_SMI,
+				      ureq.mgmt_class ? &req : NULL,
+				      ureq.rmpp_version,
+				      send_handler, recv_handler, file,
+				      ureq.flags);
+	if (IS_ERR(agent)) {
+		ret = PTR_ERR(agent);
+		agent = NULL;
+		goto out;
+	}
+
+	if (put_user(agent_id,
+		     (u32 __user *)(arg +
+				offsetof(struct ib_user_mad_reg_req2, id)))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (!file->already_used) {
+		file->already_used = 1;
+		file->use_pkey_index = 1;
+	}
+
+	file->agent[agent_id] = agent;
+	ret = 0;
+
+out:
+	mutex_unlock(&file->mutex);
+
+	if (ret && agent)
+		ib_unregister_mad_agent(agent);
+
+	mutex_unlock(&file->port->file_mutex);
+
+	return ret;
+}
+
+
+static int ib_umad_unreg_agent(struct ib_umad_file *file, u32 __user *arg)
+{
+	struct ib_mad_agent *agent = NULL;
+	u32 id;
+	int ret = 0;
+
+	if (get_user(id, arg))
+		return -EFAULT;
+	if (id >= IB_UMAD_MAX_AGENTS)
+		return -EINVAL;
+
+	mutex_lock(&file->port->file_mutex);
+	mutex_lock(&file->mutex);
+
+	id = array_index_nospec(id, IB_UMAD_MAX_AGENTS);
+	if (!__get_agent(file, id)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	agent = file->agent[id];
+	file->agent[id] = NULL;
+
+out:
+	mutex_unlock(&file->mutex);
+
+	if (agent)
+		ib_unregister_mad_agent(agent);
+
+	mutex_unlock(&file->port->file_mutex);
+
+	return ret;
+}
+
+static long ib_umad_enable_pkey(struct ib_umad_file *file)
+{
+	int ret = 0;
+
+	mutex_lock(&file->mutex);
+	if (file->already_used)
+		ret = -EINVAL;
+	else
+		file->use_pkey_index = 1;
+	mutex_unlock(&file->mutex);
+
+	return ret;
+}
+
+static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
+			  unsigned long arg)
+{
+	switch (cmd) {
+	case IB_USER_MAD_REGISTER_AGENT:
+		return ib_umad_reg_agent(filp->private_data, (void __user *) arg, 0);
+	case IB_USER_MAD_UNREGISTER_AGENT:
+		return ib_umad_unreg_agent(filp->private_data, (__u32 __user *) arg);
+	case IB_USER_MAD_ENABLE_PKEY:
+		return ib_umad_enable_pkey(filp->private_data);
+	case IB_USER_MAD_REGISTER_AGENT2:
+		return ib_umad_reg_agent2(filp->private_data, (void __user *) arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd,
+				 unsigned long arg)
+{
+	switch (cmd) {
+	case IB_USER_MAD_REGISTER_AGENT:
+		return ib_umad_reg_agent(filp->private_data, compat_ptr(arg), 1);
+	case IB_USER_MAD_UNREGISTER_AGENT:
+		return ib_umad_unreg_agent(filp->private_data, compat_ptr(arg));
+	case IB_USER_MAD_ENABLE_PKEY:
+		return ib_umad_enable_pkey(filp->private_data);
+	case IB_USER_MAD_REGISTER_AGENT2:
+		return ib_umad_reg_agent2(filp->private_data, compat_ptr(arg));
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+#endif
+
+/*
+ * ib_umad_open() does not need the BKL:
+ *
+ *  - the ib_umad_port structures are properly reference counted, and
+ *    everything else is purely local to the file being created, so
+ *    races against other open calls are not a problem;
+ *  - the ioctl method does not affect any global state outside of the
+ *    file structure being operated on;
+ */
+static int ib_umad_open(struct inode *inode, struct file *filp)
+{
+	struct ib_umad_port *port;
+	struct ib_umad_file *file;
+	int ret = 0;
+
+	port = container_of(inode->i_cdev, struct ib_umad_port, cdev);
+
+	mutex_lock(&port->file_mutex);
+
+	if (!port->ib_dev) {
+		ret = -ENXIO;
+		goto out;
+	}
+
+	if (!rdma_dev_access_netns(port->ib_dev, current->nsproxy->net_ns)) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	file = kzalloc(sizeof(*file), GFP_KERNEL);
+	if (!file) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	mutex_init(&file->mutex);
+	spin_lock_init(&file->send_lock);
+	INIT_LIST_HEAD(&file->recv_list);
+	INIT_LIST_HEAD(&file->send_list);
+	init_waitqueue_head(&file->recv_wait);
+
+	file->port = port;
+	filp->private_data = file;
+
+	list_add_tail(&file->port_list, &port->file_list);
+
+	stream_open(inode, filp);
+out:
+	mutex_unlock(&port->file_mutex);
+	return ret;
+}
+
+static int ib_umad_close(struct inode *inode, struct file *filp)
+{
+	struct ib_umad_file *file = filp->private_data;
+	struct ib_umad_packet *packet, *tmp;
+	int already_dead;
+	int i;
+
+	mutex_lock(&file->port->file_mutex);
+	mutex_lock(&file->mutex);
+
+	already_dead = file->agents_dead;
+	file->agents_dead = 1;
+
+	list_for_each_entry_safe(packet, tmp, &file->recv_list, list) {
+		if (packet->recv_wc)
+			ib_free_recv_mad(packet->recv_wc);
+		kfree(packet);
+	}
+
+	list_del(&file->port_list);
+
+	mutex_unlock(&file->mutex);
+
+	if (!already_dead)
+		for (i = 0; i < IB_UMAD_MAX_AGENTS; ++i)
+			if (file->agent[i])
+				ib_unregister_mad_agent(file->agent[i]);
+
+	mutex_unlock(&file->port->file_mutex);
+	mutex_destroy(&file->mutex);
+	kfree(file);
+	return 0;
+}
+
+static const struct file_operations umad_fops = {
+	.owner		= THIS_MODULE,
+	.read		= ib_umad_read,
+	.write		= ib_umad_write,
+	.poll		= ib_umad_poll,
+	.unlocked_ioctl = ib_umad_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ib_umad_compat_ioctl,
+#endif
+	.open		= ib_umad_open,
+	.release	= ib_umad_close,
+	.llseek		= no_llseek,
+};
+
+static int ib_umad_sm_open(struct inode *inode, struct file *filp)
+{
+	struct ib_umad_port *port;
+	struct ib_port_modify props = {
+		.set_port_cap_mask = IB_PORT_SM
+	};
+	int ret;
+
+	port = container_of(inode->i_cdev, struct ib_umad_port, sm_cdev);
+
+	if (filp->f_flags & O_NONBLOCK) {
+		if (down_trylock(&port->sm_sem)) {
+			ret = -EAGAIN;
+			goto fail;
+		}
+	} else {
+		if (down_interruptible(&port->sm_sem)) {
+			ret = -ERESTARTSYS;
+			goto fail;
+		}
+	}
+
+	if (!rdma_dev_access_netns(port->ib_dev, current->nsproxy->net_ns)) {
+		ret = -EPERM;
+		goto err_up_sem;
+	}
+
+	ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
+	if (ret)
+		goto err_up_sem;
+
+	filp->private_data = port;
+
+	nonseekable_open(inode, filp);
+	return 0;
+
+err_up_sem:
+	up(&port->sm_sem);
+
+fail:
+	return ret;
+}
+
+static int ib_umad_sm_close(struct inode *inode, struct file *filp)
+{
+	struct ib_umad_port *port = filp->private_data;
+	struct ib_port_modify props = {
+		.clr_port_cap_mask = IB_PORT_SM
+	};
+	int ret = 0;
+
+	mutex_lock(&port->file_mutex);
+	if (port->ib_dev)
+		ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
+	mutex_unlock(&port->file_mutex);
+
+	up(&port->sm_sem);
+
+	return ret;
+}
+
+static const struct file_operations umad_sm_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = ib_umad_sm_open,
+	.release = ib_umad_sm_close,
+	.llseek	 = no_llseek,
+};
+
+static struct ib_umad_port *get_port(struct ib_device *ibdev,
+				     struct ib_umad_device *umad_dev,
+				     u32 port)
+{
+	if (!umad_dev)
+		return ERR_PTR(-EOPNOTSUPP);
+	if (!rdma_is_port_valid(ibdev, port))
+		return ERR_PTR(-EINVAL);
+	if (!rdma_cap_ib_mad(ibdev, port))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	return &umad_dev->ports[port - rdma_start_port(ibdev)];
+}
+
+static int ib_umad_get_nl_info(struct ib_device *ibdev, void *client_data,
+			       struct ib_client_nl_info *res)
+{
+	struct ib_umad_port *port = get_port(ibdev, client_data, res->port);
+
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	res->abi = IB_USER_MAD_ABI_VERSION;
+	res->cdev = &port->dev;
+	return 0;
+}
+
+static struct ib_client umad_client = {
+	.name   = "umad",
+	.add    = ib_umad_add_one,
+	.remove = ib_umad_remove_one,
+	.get_nl_info = ib_umad_get_nl_info,
+};
+MODULE_ALIAS_RDMA_CLIENT("umad");
+
+static int ib_issm_get_nl_info(struct ib_device *ibdev, void *client_data,
+			       struct ib_client_nl_info *res)
+{
+	struct ib_umad_port *port = get_port(ibdev, client_data, res->port);
+
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	res->abi = IB_USER_MAD_ABI_VERSION;
+	res->cdev = &port->sm_dev;
+	return 0;
+}
+
+static struct ib_client issm_client = {
+	.name = "issm",
+	.get_nl_info = ib_issm_get_nl_info,
+};
+MODULE_ALIAS_RDMA_CLIENT("issm");
+
+static ssize_t ibdev_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct ib_umad_port *port = dev_get_drvdata(dev);
+
+	if (!port)
+		return -ENODEV;
+
+	return sysfs_emit(buf, "%s\n", dev_name(&port->ib_dev->dev));
+}
+static DEVICE_ATTR_RO(ibdev);
+
+static ssize_t port_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct ib_umad_port *port = dev_get_drvdata(dev);
+
+	if (!port)
+		return -ENODEV;
+
+	return sysfs_emit(buf, "%d\n", port->port_num);
+}
+static DEVICE_ATTR_RO(port);
+
+static struct attribute *umad_class_dev_attrs[] = {
+	&dev_attr_ibdev.attr,
+	&dev_attr_port.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(umad_class_dev);
+
+static char *umad_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
+}
+
+static ssize_t abi_version_show(struct class *class,
+				struct class_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", IB_USER_MAD_ABI_VERSION);
+}
+static CLASS_ATTR_RO(abi_version);
+
+static struct attribute *umad_class_attrs[] = {
+	&class_attr_abi_version.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(umad_class);
+
+static struct class umad_class = {
+	.name		= "infiniband_mad",
+	.devnode	= umad_devnode,
+	.class_groups	= umad_class_groups,
+	.dev_groups	= umad_class_dev_groups,
+};
+
+static void ib_umad_release_port(struct device *device)
+{
+	struct ib_umad_port *port = dev_get_drvdata(device);
+	struct ib_umad_device *umad_dev = port->umad_dev;
+
+	ib_umad_dev_put(umad_dev);
+}
+
+static void ib_umad_init_port_dev(struct device *dev,
+				  struct ib_umad_port *port,
+				  const struct ib_device *device)
+{
+	device_initialize(dev);
+	ib_umad_dev_get(port->umad_dev);
+	dev->class = &umad_class;
+	dev->parent = device->dev.parent;
+	dev_set_drvdata(dev, port);
+	dev->release = ib_umad_release_port;
+}
+
+static int ib_umad_init_port(struct ib_device *device, int port_num,
+			     struct ib_umad_device *umad_dev,
+			     struct ib_umad_port *port)
+{
+	int devnum;
+	dev_t base_umad;
+	dev_t base_issm;
+	int ret;
+
+	devnum = ida_alloc_max(&umad_ida, IB_UMAD_MAX_PORTS - 1, GFP_KERNEL);
+	if (devnum < 0)
+		return -1;
+	port->dev_num = devnum;
+	if (devnum >= IB_UMAD_NUM_FIXED_MINOR) {
+		base_umad = dynamic_umad_dev + devnum - IB_UMAD_NUM_FIXED_MINOR;
+		base_issm = dynamic_issm_dev + devnum - IB_UMAD_NUM_FIXED_MINOR;
+	} else {
+		base_umad = devnum + base_umad_dev;
+		base_issm = devnum + base_issm_dev;
+	}
+
+	port->ib_dev   = device;
+	port->umad_dev = umad_dev;
+	port->port_num = port_num;
+	sema_init(&port->sm_sem, 1);
+	mutex_init(&port->file_mutex);
+	INIT_LIST_HEAD(&port->file_list);
+
+	ib_umad_init_port_dev(&port->dev, port, device);
+	port->dev.devt = base_umad;
+	dev_set_name(&port->dev, "umad%d", port->dev_num);
+	cdev_init(&port->cdev, &umad_fops);
+	port->cdev.owner = THIS_MODULE;
+
+	ret = cdev_device_add(&port->cdev, &port->dev);
+	if (ret)
+		goto err_cdev;
+
+	ib_umad_init_port_dev(&port->sm_dev, port, device);
+	port->sm_dev.devt = base_issm;
+	dev_set_name(&port->sm_dev, "issm%d", port->dev_num);
+	cdev_init(&port->sm_cdev, &umad_sm_fops);
+	port->sm_cdev.owner = THIS_MODULE;
+
+	ret = cdev_device_add(&port->sm_cdev, &port->sm_dev);
+	if (ret)
+		goto err_dev;
+
+	return 0;
+
+err_dev:
+	put_device(&port->sm_dev);
+	cdev_device_del(&port->cdev, &port->dev);
+err_cdev:
+	put_device(&port->dev);
+	ida_free(&umad_ida, devnum);
+	return ret;
+}
+
+static void ib_umad_kill_port(struct ib_umad_port *port)
+{
+	struct ib_umad_file *file;
+	int id;
+
+	cdev_device_del(&port->sm_cdev, &port->sm_dev);
+	cdev_device_del(&port->cdev, &port->dev);
+
+	mutex_lock(&port->file_mutex);
+
+	/* Mark ib_dev NULL and block ioctl or other file ops to progress
+	 * further.
+	 */
+	port->ib_dev = NULL;
+
+	list_for_each_entry(file, &port->file_list, port_list) {
+		mutex_lock(&file->mutex);
+		file->agents_dead = 1;
+		wake_up_interruptible(&file->recv_wait);
+		mutex_unlock(&file->mutex);
+
+		for (id = 0; id < IB_UMAD_MAX_AGENTS; ++id)
+			if (file->agent[id])
+				ib_unregister_mad_agent(file->agent[id]);
+	}
+
+	mutex_unlock(&port->file_mutex);
+
+	ida_free(&umad_ida, port->dev_num);
+
+	/* balances device_initialize() */
+	put_device(&port->sm_dev);
+	put_device(&port->dev);
+}
+
+static int ib_umad_add_one(struct ib_device *device)
+{
+	struct ib_umad_device *umad_dev;
+	int s, e, i;
+	int count = 0;
+	int ret;
+
+	s = rdma_start_port(device);
+	e = rdma_end_port(device);
+
+	umad_dev = kzalloc(struct_size(umad_dev, ports,
+				       size_add(size_sub(e, s), 1)),
+			   GFP_KERNEL);
+	if (!umad_dev)
+		return -ENOMEM;
+
+	kref_init(&umad_dev->kref);
+	for (i = s; i <= e; ++i) {
+		if (!rdma_cap_ib_mad(device, i))
+			continue;
+
+		ret = ib_umad_init_port(device, i, umad_dev,
+					&umad_dev->ports[i - s]);
+		if (ret)
+			goto err;
+
+		count++;
+	}
+
+	if (!count) {
+		ret = -EOPNOTSUPP;
+		goto free;
+	}
+
+	ib_set_client_data(device, &umad_client, umad_dev);
+
+	return 0;
+
+err:
+	while (--i >= s) {
+		if (!rdma_cap_ib_mad(device, i))
+			continue;
+
+		ib_umad_kill_port(&umad_dev->ports[i - s]);
+	}
+free:
+	/* balances kref_init */
+	ib_umad_dev_put(umad_dev);
+	return ret;
+}
+
+static void ib_umad_remove_one(struct ib_device *device, void *client_data)
+{
+	struct ib_umad_device *umad_dev = client_data;
+	unsigned int i;
+
+	rdma_for_each_port (device, i) {
+		if (rdma_cap_ib_mad(device, i))
+			ib_umad_kill_port(
+				&umad_dev->ports[i - rdma_start_port(device)]);
+	}
+	/* balances kref_init() */
+	ib_umad_dev_put(umad_dev);
+}
+
+static int __init ib_umad_init(void)
+{
+	int ret;
+
+	ret = register_chrdev_region(base_umad_dev,
+				     IB_UMAD_NUM_FIXED_MINOR * 2,
+				     umad_class.name);
+	if (ret) {
+		pr_err("couldn't register device number\n");
+		goto out;
+	}
+
+	ret = alloc_chrdev_region(&dynamic_umad_dev, 0,
+				  IB_UMAD_NUM_DYNAMIC_MINOR * 2,
+				  umad_class.name);
+	if (ret) {
+		pr_err("couldn't register dynamic device number\n");
+		goto out_alloc;
+	}
+	dynamic_issm_dev = dynamic_umad_dev + IB_UMAD_NUM_DYNAMIC_MINOR;
+
+	ret = class_register(&umad_class);
+	if (ret) {
+		pr_err("couldn't create class infiniband_mad\n");
+		goto out_chrdev;
+	}
+
+	ret = ib_register_client(&umad_client);
+	if (ret)
+		goto out_class;
+
+	ret = ib_register_client(&issm_client);
+	if (ret)
+		goto out_client;
+
+	return 0;
+
+out_client:
+	ib_unregister_client(&umad_client);
+out_class:
+	class_unregister(&umad_class);
+
+out_chrdev:
+	unregister_chrdev_region(dynamic_umad_dev,
+				 IB_UMAD_NUM_DYNAMIC_MINOR * 2);
+
+out_alloc:
+	unregister_chrdev_region(base_umad_dev,
+				 IB_UMAD_NUM_FIXED_MINOR * 2);
+
+out:
+	return ret;
+}
+
+static void __exit ib_umad_cleanup(void)
+{
+	ib_unregister_client(&issm_client);
+	ib_unregister_client(&umad_client);
+	class_unregister(&umad_class);
+	unregister_chrdev_region(base_umad_dev,
+				 IB_UMAD_NUM_FIXED_MINOR * 2);
+	unregister_chrdev_region(dynamic_umad_dev,
+				 IB_UMAD_NUM_DYNAMIC_MINOR * 2);
+}
+
+module_init(ib_umad_init);
+module_exit(ib_umad_cleanup);