text: /*
   * 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 <asm/uaccess.h>
  
  #include <rdma/ib_mad.h>
  #include <rdma/ib_user_mad.h>
  
  MODULE_AUTHOR("Roland Dreier");
  MODULE_DESCRIPTION("InfiniBand userspace MAD packet access");
  MODULE_LICENSE("Dual BSD/GPL");
  
  enum {
  	IB_UMAD_MAX_PORTS  = 64,
  	IB_UMAD_MAX_AGENTS = 32,
  
  	IB_UMAD_MAJOR      = 231,
  	IB_UMAD_MINOR_BASE = 0
  };
  
  /*
   * 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;
  	u8                     port_num;
  };
  
  struct ib_umad_device {
  	struct kobject       kobj;
  	struct ib_umad_port  port[0];
  };
  
  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;
  };
  
  static struct class *umad_class;
  
  static const dev_t base_dev = MKDEV(IB_UMAD_MAJOR, IB_UMAD_MINOR_BASE);
  
  static DEFINE_SPINLOCK(port_lock);
  static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS);
  
  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 kobject *kobj)
  {
  	struct ib_umad_device *dev =
  		container_of(kobj, struct ib_umad_device, kobj);
  
  	kfree(dev);
  }
  
  static struct kobj_type ib_umad_dev_ktype = {
  	.release = ib_umad_release_dev,
  };
  
  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);
  	ib_destroy_ah(packet->msg->ah);
  	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_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);
  	packet->mad.hdr.lid	   = cpu_to_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 ib_ah_attr ah_attr;
  
  		ib_init_ah_from_wc(agent->device, agent->port_num,
  				   mad_recv_wc->wc, mad_recv_wc->recv_buf.grh,
  				   &ah_attr);
  
  		packet->mad.hdr.gid_index = ah_attr.grh.sgid_index;
  		packet->mad.hdr.hop_limit = ah_attr.grh.hop_limit;
  		packet->mad.hdr.traffic_class = ah_attr.grh.traffic_class;
  		memcpy(packet->mad.hdr.gid, &ah_attr.grh.dgid, 16);
  		packet->mad.hdr.flow_label = cpu_to_be32(ah_attr.grh.flow_label);
  	}
  
  	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;
  		}
  	}
  	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;
  
  	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);
  
  	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);
  	}
  
  	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 ib_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);
  
  	agent = __get_agent(file, packet->mad.hdr.id);
  	if (!agent) {
  		ret = -EINVAL;
  		goto err_up;
  	}
  
  	memset(&ah_attr, 0, sizeof ah_attr);
  	ah_attr.dlid          = be16_to_cpu(packet->mad.hdr.lid);
  	ah_attr.sl            = packet->mad.hdr.sl;
  	ah_attr.src_path_bits = packet->mad.hdr.path_bits;
  	ah_attr.port_num      = file->port->port_num;
  	if (packet->mad.hdr.grh_present) {
  		ah_attr.ah_flags = IB_AH_GRH;
  		memcpy(ah_attr.grh.dgid.raw, packet->mad.hdr.gid, 16);
  		ah_attr.grh.sgid_index	   = packet->mad.hdr.gid_index;
  		ah_attr.grh.flow_label	   = be32_to_cpu(packet->mad.hdr.flow_label);
  		ah_attr.grh.hop_limit	   = packet->mad.hdr.hop_limit;
  		ah_attr.grh.traffic_class  = packet->mad.hdr.traffic_class;
  	}
  
  	ah = ib_create_ah(agent->qp->pd, &ah_attr);
  	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:
  	ib_destroy_ah(ah);
  err_up:
  	mutex_unlock(&file->mutex);
  err:
  	kfree(packet);
  	return ret;
  }
  
  static unsigned int 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 */
  	unsigned int mask = POLLOUT | POLLWRNORM;
  
  	poll_wait(filp, &file->recv_wait, wait);
  
  	if (!list_empty(&file->recv_list))
  		mask |= POLLIN | POLLRDNORM;
  
  	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,
  			   "ib_umad_reg_agent: invalid device\n");
  		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,
  			   "ib_umad_reg_agent: invalid QPN %d specified\n",
  			   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,
  		   "ib_umad_reg_agent: Max Agents (%u) reached\n",
  		   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.txt 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,
  			   "ib_umad_reg_agent2: invalid device\n");
  		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,
  			   "ib_umad_reg_agent2: invalid QPN %d specified\n",
  			   ureq.qpn);
  		ret = -EINVAL;
  		goto out;
  	}
  
  	if (ureq.flags & ~IB_USER_MAD_REG_FLAGS_CAP) {
  		dev_notice(file->port->dev,
  			   "ib_umad_reg_agent2 failed: invalid registration flags specified 0x%x; supported 0x%x\n",
  			   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,
  		   "ib_umad_reg_agent2: Max Agents (%u) reached\n",
  		   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,
  				   "ib_umad_reg_agent2 failed: oui invalid 0x%08x\n",
  				   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;
  
  	mutex_lock(&file->port->file_mutex);
  	mutex_lock(&file->mutex);
  
  	if (id >= IB_UMAD_MAX_AGENTS || !__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 = -ENXIO;
  
  	port = container_of(inode->i_cdev, struct ib_umad_port, cdev);
  
  	mutex_lock(&port->file_mutex);
  
  	if (!port->ib_dev)
  		goto out;
  
  	ret = -ENOMEM;
  	file = kzalloc(sizeof *file, GFP_KERNEL);
  	if (!file)
  		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);
  
  	ret = nonseekable_open(inode, filp);
  	if (ret) {
  		list_del(&file->port_list);
  		kfree(file);
  		goto out;
  	}
  
  	kobject_get(&port->umad_dev->kobj);
  
  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_device *dev = file->port->umad_dev;
  	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);
  
  	kfree(file);
  	kobject_put(&dev->kobj);
  
  	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;
  		}
  	}
  
  	ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
  	if (ret)
  		goto err_up_sem;
  
  	filp->private_data = port;
  
  	ret = nonseekable_open(inode, filp);
  	if (ret)
  		goto err_clr_sm_cap;
  
  	kobject_get(&port->umad_dev->kobj);
  
  	return 0;
  
  err_clr_sm_cap:
  	swap(props.set_port_cap_mask, props.clr_port_cap_mask);
  	ib_modify_port(port->ib_dev, port->port_num, 0, &props);
  
  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);
  
  	kobject_put(&port->umad_dev->kobj);
  
  	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_client umad_client = {
  	.name   = "umad",
  	.add    = ib_umad_add_one,
  	.remove = ib_umad_remove_one
  };
  
  static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct ib_umad_port *port = dev_get_drvdata(dev);
  
  	if (!port)
  		return -ENODEV;
  
  	return sprintf(buf, "%s\n", port->ib_dev->name);
  }
  static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
  
  static ssize_t show_port(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct ib_umad_port *port = dev_get_drvdata(dev);
  
  	if (!port)
  		return -ENODEV;
  
  	return sprintf(buf, "%d\n", port->port_num);
  }
  static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
  
  static CLASS_ATTR_STRING(abi_version, S_IRUGO,
  			 __stringify(IB_USER_MAD_ABI_VERSION));
  
  static dev_t overflow_maj;
  static DECLARE_BITMAP(overflow_map, IB_UMAD_MAX_PORTS);
  static int find_overflow_devnum(struct ib_device *device)
  {
  	int ret;
  
  	if (!overflow_maj) {
  		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UMAD_MAX_PORTS * 2,
  					  "infiniband_mad");
  		if (ret) {
  			dev_err(&device->dev,
  				"couldn't register dynamic device number\n");
  			return ret;
  		}
  	}
  
  	ret = find_first_zero_bit(overflow_map, IB_UMAD_MAX_PORTS);
  	if (ret >= IB_UMAD_MAX_PORTS)
  		return -1;
  
  	return ret;
  }
  
  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;
  
  	spin_lock(&port_lock);
  	devnum = find_first_zero_bit(dev_map, IB_UMAD_MAX_PORTS);
  	if (devnum >= IB_UMAD_MAX_PORTS) {
  		spin_unlock(&port_lock);
  		devnum = find_overflow_devnum(device);
  		if (devnum < 0)
  			return -1;
  
  		spin_lock(&port_lock);
  		port->dev_num = devnum + IB_UMAD_MAX_PORTS;
  		base = devnum + overflow_maj;
  		set_bit(devnum, overflow_map);
  	} else {
  		port->dev_num = devnum;
  		base = devnum + base_dev;
  		set_bit(devnum, dev_map);
  	}
  	spin_unlock(&port_lock);
  
  	port->ib_dev   = device;
  	port->port_num = port_num;
  	sema_init(&port->sm_sem, 1);
  	mutex_init(&port->file_mutex);
  	INIT_LIST_HEAD(&port->file_list);
  
  	cdev_init(&port->cdev, &umad_fops);
  	port->cdev.owner = THIS_MODULE;
  	port->cdev.kobj.parent = &umad_dev->kobj;
  	kobject_set_name(&port->cdev.kobj, "umad%d", port->dev_num);
  	if (cdev_add(&port->cdev, base, 1))
  		goto err_cdev;
  
  	port->dev = device_create(umad_class, device->dma_device,
  				  port->cdev.dev, port,
  				  "umad%d", port->dev_num);
  	if (IS_ERR(port->dev))
  		goto err_cdev;
  
  	if (device_create_file(port->dev, &dev_attr_ibdev))
  		goto err_dev;
  	if (device_create_file(port->dev, &dev_attr_port))
  		goto err_dev;
  
  	base += IB_UMAD_MAX_PORTS;
  	cdev_init(&port->sm_cdev, &umad_sm_fops);
  	port->sm_cdev.owner = THIS_MODULE;
  	port->sm_cdev.kobj.parent = &umad_dev->kobj;
  	kobject_set_name(&port->sm_cdev.kobj, "issm%d", port->dev_num);
  	if (cdev_add(&port->sm_cdev, base, 1))
  		goto err_sm_cdev;
  
  	port->sm_dev = device_create(umad_class, device->dma_device,
  				     port->sm_cdev.dev, port,
  				     "issm%d", port->dev_num);
  	if (IS_ERR(port->sm_dev))
  		goto err_sm_cdev;
  
  	if (device_create_file(port->sm_dev, &dev_attr_ibdev))
  		goto err_sm_dev;
  	if (device_create_file(port->sm_dev, &dev_attr_port))
  		goto err_sm_dev;
  
  	return 0;
  
  err_sm_dev:
  	device_destroy(umad_class, port->sm_cdev.dev);
  
  err_sm_cdev:
  	cdev_del(&port->sm_cdev);
  
  err_dev:
  	device_destroy(umad_class, port->cdev.dev);
  
  err_cdev:
  	cdev_del(&port->cdev);
  	if (port->dev_num < IB_UMAD_MAX_PORTS)
  		clear_bit(devnum, dev_map);
  	else
  		clear_bit(devnum, overflow_map);
  
  	return -1;
  }
  
  static void ib_umad_kill_port(struct ib_umad_port *port)
  {
  	struct ib_umad_file *file;
  	int id;
  
  	dev_set_drvdata(port->dev,    NULL);
  	dev_set_drvdata(port->sm_dev, NULL);
  
  	device_destroy(umad_class, port->cdev.dev);
  	device_destroy(umad_class, port->sm_cdev.dev);
  
  	cdev_del(&port->cdev);
  	cdev_del(&port->sm_cdev);
  
  	mutex_lock(&port->file_mutex);
  
  	port->ib_dev = NULL;
  
  	list_for_each_entry(file, &port->file_list, port_list) {
  		mutex_lock(&file->mutex);
  		file->agents_dead = 1;
  		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);
  
  	if (port->dev_num < IB_UMAD_MAX_PORTS)
  		clear_bit(port->dev_num, dev_map);
  	else
  		clear_bit(port->dev_num - IB_UMAD_MAX_PORTS, overflow_map);
  }
  
  static void ib_umad_add_one(struct ib_device *device)
  {
  	struct ib_umad_device *umad_dev;
  	int s, e, i;
  	int count = 0;
  
  	s = rdma_start_port(device);
  	e = rdma_end_port(device);
  
  	umad_dev = kzalloc(sizeof *umad_dev +
  			   (e - s + 1) * sizeof (struct ib_umad_port),
  			   GFP_KERNEL);
  	if (!umad_dev)
  		return;
  
  	kobject_init(&umad_dev->kobj, &ib_umad_dev_ktype);
  
  	for (i = s; i <= e; ++i) {
  		if (!rdma_cap_ib_mad(device, i))
  			continue;
  
  		umad_dev->port[i - s].umad_dev = umad_dev;
  
  		if (ib_umad_init_port(device, i, umad_dev,
  				      &umad_dev->port[i - s]))
  			goto err;
  
  		count++;
  	}
  
  	if (!count)
  		goto free;
  
  	ib_set_client_data(device, &umad_client, umad_dev);
  
  	return;
  
  err:
  	while (--i >= s) {
  		if (!rdma_cap_ib_mad(device, i))
  			continue;
  
  		ib_umad_kill_port(&umad_dev->port[i - s]);
  	}
  free:
  	kobject_put(&umad_dev->kobj);
  }
  
  static void ib_umad_remove_one(struct ib_device *device)
  {
  	struct ib_umad_device *umad_dev = ib_get_client_data(device, &umad_client);
  	int i;
  
  	if (!umad_dev)
  		return;
  
  	for (i = 0; i <= rdma_end_port(device) - rdma_start_port(device); ++i) {
  		if (rdma_cap_ib_mad(device, i + rdma_start_port(device)))
  			ib_umad_kill_port(&umad_dev->port[i]);
  	}
  
  	kobject_put(&umad_dev->kobj);
  }
  
  static char *umad_devnode(struct device *dev, umode_t *mode)
  {
  	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
  }
  
  static int __init ib_umad_init(void)
  {
  	int ret;
  
  	ret = register_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2,
  				     "infiniband_mad");
  	if (ret) {
  		pr_err("couldn't register device number\n");
  		goto out;
  	}
  
  	umad_class = class_create(THIS_MODULE, "infiniband_mad");
  	if (IS_ERR(umad_class)) {
  		ret = PTR_ERR(umad_class);
  		pr_err("couldn't create class infiniband_mad\n");
  		goto out_chrdev;
  	}
  
  	umad_class->devnode = umad_devnode;
  
  	ret = class_create_file(umad_class, &class_attr_abi_version.attr);
  	if (ret) {
  		pr_err("couldn't create abi_version attribute\n");
  		goto out_class;
  	}
  
  	ret = ib_register_client(&umad_client);
  	if (ret) {
  		pr_err("couldn't register ib_umad client\n");
  		goto out_class;
  	}
  
  	return 0;
  
  out_class:
  	class_destroy(umad_class);
  
  out_chrdev:
  	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
  
  out:
  	return ret;
  }
  
  static void __exit ib_umad_cleanup(void)
  {
  	ib_unregister_client(&umad_client);
  	class_destroy(umad_class);
  	unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
  	if (overflow_maj)
  		unregister_chrdev_region(overflow_maj, IB_UMAD_MAX_PORTS * 2);
  }
  
  module_init(ib_umad_init);
  module_exit(ib_umad_cleanup);
  