text: /*
   * Copyright (c) 2005 Topspin Communications.  All rights reserved.
   * Copyright (c) 2005, 2006, 2007 Cisco Systems.  All rights reserved.
   * Copyright (c) 2005 PathScale, Inc.  All rights reserved.
   * Copyright (c) 2006 Mellanox Technologies.  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.
   */
  
  #include <linux/file.h>
  #include <linux/fs.h>
  #include <linux/slab.h>
  
  #include <asm/uaccess.h>
  
  #include "uverbs.h"
  
  struct uverbs_lock_class {
  	struct lock_class_key	key;
  	char			name[16];
  };
  
  static struct uverbs_lock_class pd_lock_class	= { .name = "PD-uobj" };
  static struct uverbs_lock_class mr_lock_class	= { .name = "MR-uobj" };
  static struct uverbs_lock_class mw_lock_class	= { .name = "MW-uobj" };
  static struct uverbs_lock_class cq_lock_class	= { .name = "CQ-uobj" };
  static struct uverbs_lock_class qp_lock_class	= { .name = "QP-uobj" };
  static struct uverbs_lock_class ah_lock_class	= { .name = "AH-uobj" };
  static struct uverbs_lock_class srq_lock_class	= { .name = "SRQ-uobj" };
  static struct uverbs_lock_class xrcd_lock_class = { .name = "XRCD-uobj" };
  
  #define INIT_UDATA(udata, ibuf, obuf, ilen, olen)			\
  	do {								\
  		(udata)->inbuf  = (void __user *) (ibuf);		\
  		(udata)->outbuf = (void __user *) (obuf);		\
  		(udata)->inlen  = (ilen);				\
  		(udata)->outlen = (olen);				\
  	} while (0)
  
  /*
   * The ib_uobject locking scheme is as follows:
   *
   * - ib_uverbs_idr_lock protects the uverbs idrs themselves, so it
   *   needs to be held during all idr operations.  When an object is
   *   looked up, a reference must be taken on the object's kref before
   *   dropping this lock.
   *
   * - Each object also has an rwsem.  This rwsem must be held for
   *   reading while an operation that uses the object is performed.
   *   For example, while registering an MR, the associated PD's
   *   uobject.mutex must be held for reading.  The rwsem must be held
   *   for writing while initializing or destroying an object.
   *
   * - In addition, each object has a "live" flag.  If this flag is not
   *   set, then lookups of the object will fail even if it is found in
   *   the idr.  This handles a reader that blocks and does not acquire
   *   the rwsem until after the object is destroyed.  The destroy
   *   operation will set the live flag to 0 and then drop the rwsem;
   *   this will allow the reader to acquire the rwsem, see that the
   *   live flag is 0, and then drop the rwsem and its reference to
   *   object.  The underlying storage will not be freed until the last
   *   reference to the object is dropped.
   */
  
  static void init_uobj(struct ib_uobject *uobj, u64 user_handle,
  		      struct ib_ucontext *context, struct uverbs_lock_class *c)
  {
  	uobj->user_handle = user_handle;
  	uobj->context     = context;
  	kref_init(&uobj->ref);
  	init_rwsem(&uobj->mutex);
  	lockdep_set_class_and_name(&uobj->mutex, &c->key, c->name);
  	uobj->live        = 0;
  }
  
  static void release_uobj(struct kref *kref)
  {
  	kfree(container_of(kref, struct ib_uobject, ref));
  }
  
  static void put_uobj(struct ib_uobject *uobj)
  {
  	kref_put(&uobj->ref, release_uobj);
  }
  
  static void put_uobj_read(struct ib_uobject *uobj)
  {
  	up_read(&uobj->mutex);
  	put_uobj(uobj);
  }
  
  static void put_uobj_write(struct ib_uobject *uobj)
  {
  	up_write(&uobj->mutex);
  	put_uobj(uobj);
  }
  
  static int idr_add_uobj(struct idr *idr, struct ib_uobject *uobj)
  {
  	int ret;
  
  	idr_preload(GFP_KERNEL);
  	spin_lock(&ib_uverbs_idr_lock);
  
  	ret = idr_alloc(idr, uobj, 0, 0, GFP_NOWAIT);
  	if (ret >= 0)
  		uobj->id = ret;
  
  	spin_unlock(&ib_uverbs_idr_lock);
  	idr_preload_end();
  
  	return ret < 0 ? ret : 0;
  }
  
  void idr_remove_uobj(struct idr *idr, struct ib_uobject *uobj)
  {
  	spin_lock(&ib_uverbs_idr_lock);
  	idr_remove(idr, uobj->id);
  	spin_unlock(&ib_uverbs_idr_lock);
  }
  
  static struct ib_uobject *__idr_get_uobj(struct idr *idr, int id,
  					 struct ib_ucontext *context)
  {
  	struct ib_uobject *uobj;
  
  	spin_lock(&ib_uverbs_idr_lock);
  	uobj = idr_find(idr, id);
  	if (uobj) {
  		if (uobj->context == context)
  			kref_get(&uobj->ref);
  		else
  			uobj = NULL;
  	}
  	spin_unlock(&ib_uverbs_idr_lock);
  
  	return uobj;
  }
  
  static struct ib_uobject *idr_read_uobj(struct idr *idr, int id,
  					struct ib_ucontext *context, int nested)
  {
  	struct ib_uobject *uobj;
  
  	uobj = __idr_get_uobj(idr, id, context);
  	if (!uobj)
  		return NULL;
  
  	if (nested)
  		down_read_nested(&uobj->mutex, SINGLE_DEPTH_NESTING);
  	else
  		down_read(&uobj->mutex);
  	if (!uobj->live) {
  		put_uobj_read(uobj);
  		return NULL;
  	}
  
  	return uobj;
  }
  
  static struct ib_uobject *idr_write_uobj(struct idr *idr, int id,
  					 struct ib_ucontext *context)
  {
  	struct ib_uobject *uobj;
  
  	uobj = __idr_get_uobj(idr, id, context);
  	if (!uobj)
  		return NULL;
  
  	down_write(&uobj->mutex);
  	if (!uobj->live) {
  		put_uobj_write(uobj);
  		return NULL;
  	}
  
  	return uobj;
  }
  
  static void *idr_read_obj(struct idr *idr, int id, struct ib_ucontext *context,
  			  int nested)
  {
  	struct ib_uobject *uobj;
  
  	uobj = idr_read_uobj(idr, id, context, nested);
  	return uobj ? uobj->object : NULL;
  }
  
  static struct ib_pd *idr_read_pd(int pd_handle, struct ib_ucontext *context)
  {
  	return idr_read_obj(&ib_uverbs_pd_idr, pd_handle, context, 0);
  }
  
  static void put_pd_read(struct ib_pd *pd)
  {
  	put_uobj_read(pd->uobject);
  }
  
  static struct ib_cq *idr_read_cq(int cq_handle, struct ib_ucontext *context, int nested)
  {
  	return idr_read_obj(&ib_uverbs_cq_idr, cq_handle, context, nested);
  }
  
  static void put_cq_read(struct ib_cq *cq)
  {
  	put_uobj_read(cq->uobject);
  }
  
  static struct ib_ah *idr_read_ah(int ah_handle, struct ib_ucontext *context)
  {
  	return idr_read_obj(&ib_uverbs_ah_idr, ah_handle, context, 0);
  }
  
  static void put_ah_read(struct ib_ah *ah)
  {
  	put_uobj_read(ah->uobject);
  }
  
  static struct ib_qp *idr_read_qp(int qp_handle, struct ib_ucontext *context)
  {
  	return idr_read_obj(&ib_uverbs_qp_idr, qp_handle, context, 0);
  }
  
  static struct ib_qp *idr_write_qp(int qp_handle, struct ib_ucontext *context)
  {
  	struct ib_uobject *uobj;
  
  	uobj = idr_write_uobj(&ib_uverbs_qp_idr, qp_handle, context);
  	return uobj ? uobj->object : NULL;
  }
  
  static void put_qp_read(struct ib_qp *qp)
  {
  	put_uobj_read(qp->uobject);
  }
  
  static void put_qp_write(struct ib_qp *qp)
  {
  	put_uobj_write(qp->uobject);
  }
  
  static struct ib_srq *idr_read_srq(int srq_handle, struct ib_ucontext *context)
  {
  	return idr_read_obj(&ib_uverbs_srq_idr, srq_handle, context, 0);
  }
  
  static void put_srq_read(struct ib_srq *srq)
  {
  	put_uobj_read(srq->uobject);
  }
  
  static struct ib_xrcd *idr_read_xrcd(int xrcd_handle, struct ib_ucontext *context,
  				     struct ib_uobject **uobj)
  {
  	*uobj = idr_read_uobj(&ib_uverbs_xrcd_idr, xrcd_handle, context, 0);
  	return *uobj ? (*uobj)->object : NULL;
  }
  
  static void put_xrcd_read(struct ib_uobject *uobj)
  {
  	put_uobj_read(uobj);
  }
  
  ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
  			      const char __user *buf,
  			      int in_len, int out_len)
  {
  	struct ib_uverbs_get_context      cmd;
  	struct ib_uverbs_get_context_resp resp;
  	struct ib_udata                   udata;
  	struct ib_device                 *ibdev = file->device->ib_dev;
  	struct ib_ucontext		 *ucontext;
  	struct file			 *filp;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	mutex_lock(&file->mutex);
  
  	if (file->ucontext) {
  		ret = -EINVAL;
  		goto err;
  	}
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	ucontext = ibdev->alloc_ucontext(ibdev, &udata);
  	if (IS_ERR(ucontext)) {
  		ret = PTR_ERR(ucontext);
  		goto err;
  	}
  
  	ucontext->device = ibdev;
  	INIT_LIST_HEAD(&ucontext->pd_list);
  	INIT_LIST_HEAD(&ucontext->mr_list);
  	INIT_LIST_HEAD(&ucontext->mw_list);
  	INIT_LIST_HEAD(&ucontext->cq_list);
  	INIT_LIST_HEAD(&ucontext->qp_list);
  	INIT_LIST_HEAD(&ucontext->srq_list);
  	INIT_LIST_HEAD(&ucontext->ah_list);
  	INIT_LIST_HEAD(&ucontext->xrcd_list);
  	ucontext->closing = 0;
  
  	resp.num_comp_vectors = file->device->num_comp_vectors;
  
  	ret = get_unused_fd();
  	if (ret < 0)
  		goto err_free;
  	resp.async_fd = ret;
  
  	filp = ib_uverbs_alloc_event_file(file, 1);
  	if (IS_ERR(filp)) {
  		ret = PTR_ERR(filp);
  		goto err_fd;
  	}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_file;
  	}
  
  	file->async_file = filp->private_data;
  
  	INIT_IB_EVENT_HANDLER(&file->event_handler, file->device->ib_dev,
  			      ib_uverbs_event_handler);
  	ret = ib_register_event_handler(&file->event_handler);
  	if (ret)
  		goto err_file;
  
  	kref_get(&file->async_file->ref);
  	kref_get(&file->ref);
  	file->ucontext = ucontext;
  
  	fd_install(resp.async_fd, filp);
  
  	mutex_unlock(&file->mutex);
  
  	return in_len;
  
  err_file:
  	fput(filp);
  
  err_fd:
  	put_unused_fd(resp.async_fd);
  
  err_free:
  	ibdev->dealloc_ucontext(ucontext);
  
  err:
  	mutex_unlock(&file->mutex);
  	return ret;
  }
  
  ssize_t ib_uverbs_query_device(struct ib_uverbs_file *file,
  			       const char __user *buf,
  			       int in_len, int out_len)
  {
  	struct ib_uverbs_query_device      cmd;
  	struct ib_uverbs_query_device_resp resp;
  	struct ib_device_attr              attr;
  	int                                ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	ret = ib_query_device(file->device->ib_dev, &attr);
  	if (ret)
  		return ret;
  
  	memset(&resp, 0, sizeof resp);
  
  	resp.fw_ver 		       = attr.fw_ver;
  	resp.node_guid 		       = file->device->ib_dev->node_guid;
  	resp.sys_image_guid 	       = attr.sys_image_guid;
  	resp.max_mr_size 	       = attr.max_mr_size;
  	resp.page_size_cap 	       = attr.page_size_cap;
  	resp.vendor_id 		       = attr.vendor_id;
  	resp.vendor_part_id 	       = attr.vendor_part_id;
  	resp.hw_ver 		       = attr.hw_ver;
  	resp.max_qp 		       = attr.max_qp;
  	resp.max_qp_wr 		       = attr.max_qp_wr;
  	resp.device_cap_flags 	       = attr.device_cap_flags;
  	resp.max_sge 		       = attr.max_sge;
  	resp.max_sge_rd 	       = attr.max_sge_rd;
  	resp.max_cq 		       = attr.max_cq;
  	resp.max_cqe 		       = attr.max_cqe;
  	resp.max_mr 		       = attr.max_mr;
  	resp.max_pd 		       = attr.max_pd;
  	resp.max_qp_rd_atom 	       = attr.max_qp_rd_atom;
  	resp.max_ee_rd_atom 	       = attr.max_ee_rd_atom;
  	resp.max_res_rd_atom 	       = attr.max_res_rd_atom;
  	resp.max_qp_init_rd_atom       = attr.max_qp_init_rd_atom;
  	resp.max_ee_init_rd_atom       = attr.max_ee_init_rd_atom;
  	resp.atomic_cap 	       = attr.atomic_cap;
  	resp.max_ee 		       = attr.max_ee;
  	resp.max_rdd 		       = attr.max_rdd;
  	resp.max_mw 		       = attr.max_mw;
  	resp.max_raw_ipv6_qp 	       = attr.max_raw_ipv6_qp;
  	resp.max_raw_ethy_qp 	       = attr.max_raw_ethy_qp;
  	resp.max_mcast_grp 	       = attr.max_mcast_grp;
  	resp.max_mcast_qp_attach       = attr.max_mcast_qp_attach;
  	resp.max_total_mcast_qp_attach = attr.max_total_mcast_qp_attach;
  	resp.max_ah 		       = attr.max_ah;
  	resp.max_fmr 		       = attr.max_fmr;
  	resp.max_map_per_fmr 	       = attr.max_map_per_fmr;
  	resp.max_srq 		       = attr.max_srq;
  	resp.max_srq_wr 	       = attr.max_srq_wr;
  	resp.max_srq_sge 	       = attr.max_srq_sge;
  	resp.max_pkeys 		       = attr.max_pkeys;
  	resp.local_ca_ack_delay        = attr.local_ca_ack_delay;
  	resp.phys_port_cnt	       = file->device->ib_dev->phys_port_cnt;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		return -EFAULT;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_query_port(struct ib_uverbs_file *file,
  			     const char __user *buf,
  			     int in_len, int out_len)
  {
  	struct ib_uverbs_query_port      cmd;
  	struct ib_uverbs_query_port_resp resp;
  	struct ib_port_attr              attr;
  	int                              ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	ret = ib_query_port(file->device->ib_dev, cmd.port_num, &attr);
  	if (ret)
  		return ret;
  
  	memset(&resp, 0, sizeof resp);
  
  	resp.state 	     = attr.state;
  	resp.max_mtu 	     = attr.max_mtu;
  	resp.active_mtu      = attr.active_mtu;
  	resp.gid_tbl_len     = attr.gid_tbl_len;
  	resp.port_cap_flags  = attr.port_cap_flags;
  	resp.max_msg_sz      = attr.max_msg_sz;
  	resp.bad_pkey_cntr   = attr.bad_pkey_cntr;
  	resp.qkey_viol_cntr  = attr.qkey_viol_cntr;
  	resp.pkey_tbl_len    = attr.pkey_tbl_len;
  	resp.lid 	     = attr.lid;
  	resp.sm_lid 	     = attr.sm_lid;
  	resp.lmc 	     = attr.lmc;
  	resp.max_vl_num      = attr.max_vl_num;
  	resp.sm_sl 	     = attr.sm_sl;
  	resp.subnet_timeout  = attr.subnet_timeout;
  	resp.init_type_reply = attr.init_type_reply;
  	resp.active_width    = attr.active_width;
  	resp.active_speed    = attr.active_speed;
  	resp.phys_state      = attr.phys_state;
  	resp.link_layer      = rdma_port_get_link_layer(file->device->ib_dev,
  							cmd.port_num);
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		return -EFAULT;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_alloc_pd(struct ib_uverbs_file *file,
  			   const char __user *buf,
  			   int in_len, int out_len)
  {
  	struct ib_uverbs_alloc_pd      cmd;
  	struct ib_uverbs_alloc_pd_resp resp;
  	struct ib_udata                udata;
  	struct ib_uobject             *uobj;
  	struct ib_pd                  *pd;
  	int                            ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	uobj = kmalloc(sizeof *uobj, GFP_KERNEL);
  	if (!uobj)
  		return -ENOMEM;
  
  	init_uobj(uobj, 0, file->ucontext, &pd_lock_class);
  	down_write(&uobj->mutex);
  
  	pd = file->device->ib_dev->alloc_pd(file->device->ib_dev,
  					    file->ucontext, &udata);
  	if (IS_ERR(pd)) {
  		ret = PTR_ERR(pd);
  		goto err;
  	}
  
  	pd->device  = file->device->ib_dev;
  	pd->uobject = uobj;
  	atomic_set(&pd->usecnt, 0);
  
  	uobj->object = pd;
  	ret = idr_add_uobj(&ib_uverbs_pd_idr, uobj);
  	if (ret)
  		goto err_idr;
  
  	memset(&resp, 0, sizeof resp);
  	resp.pd_handle = uobj->id;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&uobj->list, &file->ucontext->pd_list);
  	mutex_unlock(&file->mutex);
  
  	uobj->live = 1;
  
  	up_write(&uobj->mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
  
  err_idr:
  	ib_dealloc_pd(pd);
  
  err:
  	put_uobj_write(uobj);
  	return ret;
  }
  
  ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file,
  			     const char __user *buf,
  			     int in_len, int out_len)
  {
  	struct ib_uverbs_dealloc_pd cmd;
  	struct ib_uobject          *uobj;
  	int                         ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_pd_idr, cmd.pd_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  
  	ret = ib_dealloc_pd(uobj->object);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	put_uobj(uobj);
  
  	return in_len;
  }
  
  struct xrcd_table_entry {
  	struct rb_node  node;
  	struct ib_xrcd *xrcd;
  	struct inode   *inode;
  };
  
  static int xrcd_table_insert(struct ib_uverbs_device *dev,
  			    struct inode *inode,
  			    struct ib_xrcd *xrcd)
  {
  	struct xrcd_table_entry *entry, *scan;
  	struct rb_node **p = &dev->xrcd_tree.rb_node;
  	struct rb_node *parent = NULL;
  
  	entry = kmalloc(sizeof *entry, GFP_KERNEL);
  	if (!entry)
  		return -ENOMEM;
  
  	entry->xrcd  = xrcd;
  	entry->inode = inode;
  
  	while (*p) {
  		parent = *p;
  		scan = rb_entry(parent, struct xrcd_table_entry, node);
  
  		if (inode < scan->inode) {
  			p = &(*p)->rb_left;
  		} else if (inode > scan->inode) {
  			p = &(*p)->rb_right;
  		} else {
  			kfree(entry);
  			return -EEXIST;
  		}
  	}
  
  	rb_link_node(&entry->node, parent, p);
  	rb_insert_color(&entry->node, &dev->xrcd_tree);
  	igrab(inode);
  	return 0;
  }
  
  static struct xrcd_table_entry *xrcd_table_search(struct ib_uverbs_device *dev,
  						  struct inode *inode)
  {
  	struct xrcd_table_entry *entry;
  	struct rb_node *p = dev->xrcd_tree.rb_node;
  
  	while (p) {
  		entry = rb_entry(p, struct xrcd_table_entry, node);
  
  		if (inode < entry->inode)
  			p = p->rb_left;
  		else if (inode > entry->inode)
  			p = p->rb_right;
  		else
  			return entry;
  	}
  
  	return NULL;
  }
  
  static struct ib_xrcd *find_xrcd(struct ib_uverbs_device *dev, struct inode *inode)
  {
  	struct xrcd_table_entry *entry;
  
  	entry = xrcd_table_search(dev, inode);
  	if (!entry)
  		return NULL;
  
  	return entry->xrcd;
  }
  
  static void xrcd_table_delete(struct ib_uverbs_device *dev,
  			      struct inode *inode)
  {
  	struct xrcd_table_entry *entry;
  
  	entry = xrcd_table_search(dev, inode);
  	if (entry) {
  		iput(inode);
  		rb_erase(&entry->node, &dev->xrcd_tree);
  		kfree(entry);
  	}
  }
  
  ssize_t ib_uverbs_open_xrcd(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_open_xrcd	cmd;
  	struct ib_uverbs_open_xrcd_resp	resp;
  	struct ib_udata			udata;
  	struct ib_uxrcd_object         *obj;
  	struct ib_xrcd                 *xrcd = NULL;
  	struct fd			f = {NULL, 0};
  	struct inode                   *inode = NULL;
  	int				ret = 0;
  	int				new_xrcd = 0;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof  resp);
  
  	mutex_lock(&file->device->xrcd_tree_mutex);
  
  	if (cmd.fd != -1) {
  		/* search for file descriptor */
  		f = fdget(cmd.fd);
  		if (!f.file) {
  			ret = -EBADF;
  			goto err_tree_mutex_unlock;
  		}
  
  		inode = file_inode(f.file);
  		xrcd = find_xrcd(file->device, inode);
  		if (!xrcd && !(cmd.oflags & O_CREAT)) {
  			/* no file descriptor. Need CREATE flag */
  			ret = -EAGAIN;
  			goto err_tree_mutex_unlock;
  		}
  
  		if (xrcd && cmd.oflags & O_EXCL) {
  			ret = -EINVAL;
  			goto err_tree_mutex_unlock;
  		}
  	}
  
  	obj = kmalloc(sizeof *obj, GFP_KERNEL);
  	if (!obj) {
  		ret = -ENOMEM;
  		goto err_tree_mutex_unlock;
  	}
  
  	init_uobj(&obj->uobject, 0, file->ucontext, &xrcd_lock_class);
  
  	down_write(&obj->uobject.mutex);
  
  	if (!xrcd) {
  		xrcd = file->device->ib_dev->alloc_xrcd(file->device->ib_dev,
  							file->ucontext, &udata);
  		if (IS_ERR(xrcd)) {
  			ret = PTR_ERR(xrcd);
  			goto err;
  		}
  
  		xrcd->inode   = inode;
  		xrcd->device  = file->device->ib_dev;
  		atomic_set(&xrcd->usecnt, 0);
  		mutex_init(&xrcd->tgt_qp_mutex);
  		INIT_LIST_HEAD(&xrcd->tgt_qp_list);
  		new_xrcd = 1;
  	}
  
  	atomic_set(&obj->refcnt, 0);
  	obj->uobject.object = xrcd;
  	ret = idr_add_uobj(&ib_uverbs_xrcd_idr, &obj->uobject);
  	if (ret)
  		goto err_idr;
  
  	memset(&resp, 0, sizeof resp);
  	resp.xrcd_handle = obj->uobject.id;
  
  	if (inode) {
  		if (new_xrcd) {
  			/* create new inode/xrcd table entry */
  			ret = xrcd_table_insert(file->device, inode, xrcd);
  			if (ret)
  				goto err_insert_xrcd;
  		}
  		atomic_inc(&xrcd->usecnt);
  	}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	if (f.file)
  		fdput(f);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&obj->uobject.list, &file->ucontext->xrcd_list);
  	mutex_unlock(&file->mutex);
  
  	obj->uobject.live = 1;
  	up_write(&obj->uobject.mutex);
  
  	mutex_unlock(&file->device->xrcd_tree_mutex);
  	return in_len;
  
  err_copy:
  	if (inode) {
  		if (new_xrcd)
  			xrcd_table_delete(file->device, inode);
  		atomic_dec(&xrcd->usecnt);
  	}
  
  err_insert_xrcd:
  	idr_remove_uobj(&ib_uverbs_xrcd_idr, &obj->uobject);
  
  err_idr:
  	ib_dealloc_xrcd(xrcd);
  
  err:
  	put_uobj_write(&obj->uobject);
  
  err_tree_mutex_unlock:
  	if (f.file)
  		fdput(f);
  
  	mutex_unlock(&file->device->xrcd_tree_mutex);
  
  	return ret;
  }
  
  ssize_t ib_uverbs_close_xrcd(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len,
  			     int out_len)
  {
  	struct ib_uverbs_close_xrcd cmd;
  	struct ib_uobject           *uobj;
  	struct ib_xrcd              *xrcd = NULL;
  	struct inode                *inode = NULL;
  	struct ib_uxrcd_object      *obj;
  	int                         live;
  	int                         ret = 0;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	mutex_lock(&file->device->xrcd_tree_mutex);
  	uobj = idr_write_uobj(&ib_uverbs_xrcd_idr, cmd.xrcd_handle, file->ucontext);
  	if (!uobj) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	xrcd  = uobj->object;
  	inode = xrcd->inode;
  	obj   = container_of(uobj, struct ib_uxrcd_object, uobject);
  	if (atomic_read(&obj->refcnt)) {
  		put_uobj_write(uobj);
  		ret = -EBUSY;
  		goto out;
  	}
  
  	if (!inode || atomic_dec_and_test(&xrcd->usecnt)) {
  		ret = ib_dealloc_xrcd(uobj->object);
  		if (!ret)
  			uobj->live = 0;
  	}
  
  	live = uobj->live;
  	if (inode && ret)
  		atomic_inc(&xrcd->usecnt);
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		goto out;
  
  	if (inode && !live)
  		xrcd_table_delete(file->device, inode);
  
  	idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	put_uobj(uobj);
  	ret = in_len;
  
  out:
  	mutex_unlock(&file->device->xrcd_tree_mutex);
  	return ret;
  }
  
  void ib_uverbs_dealloc_xrcd(struct ib_uverbs_device *dev,
  			    struct ib_xrcd *xrcd)
  {
  	struct inode *inode;
  
  	inode = xrcd->inode;
  	if (inode && !atomic_dec_and_test(&xrcd->usecnt))
  		return;
  
  	ib_dealloc_xrcd(xrcd);
  
  	if (inode)
  		xrcd_table_delete(dev, inode);
  }
  
  ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
  			 const char __user *buf, int in_len,
  			 int out_len)
  {
  	struct ib_uverbs_reg_mr      cmd;
  	struct ib_uverbs_reg_mr_resp resp;
  	struct ib_udata              udata;
  	struct ib_uobject           *uobj;
  	struct ib_pd                *pd;
  	struct ib_mr                *mr;
  	int                          ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	if ((cmd.start & ~PAGE_MASK) != (cmd.hca_va & ~PAGE_MASK))
  		return -EINVAL;
  
  	/*
  	 * Local write permission is required if remote write or
  	 * remote atomic permission is also requested.
  	 */
  	if (cmd.access_flags & (IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_REMOTE_WRITE) &&
  	    !(cmd.access_flags & IB_ACCESS_LOCAL_WRITE))
  		return -EINVAL;
  
  	uobj = kmalloc(sizeof *uobj, GFP_KERNEL);
  	if (!uobj)
  		return -ENOMEM;
  
  	init_uobj(uobj, 0, file->ucontext, &mr_lock_class);
  	down_write(&uobj->mutex);
  
  	pd = idr_read_pd(cmd.pd_handle, file->ucontext);
  	if (!pd) {
  		ret = -EINVAL;
  		goto err_free;
  	}
  
  	mr = pd->device->reg_user_mr(pd, cmd.start, cmd.length, cmd.hca_va,
  				     cmd.access_flags, &udata);
  	if (IS_ERR(mr)) {
  		ret = PTR_ERR(mr);
  		goto err_put;
  	}
  
  	mr->device  = pd->device;
  	mr->pd      = pd;
  	mr->uobject = uobj;
  	atomic_inc(&pd->usecnt);
  	atomic_set(&mr->usecnt, 0);
  
  	uobj->object = mr;
  	ret = idr_add_uobj(&ib_uverbs_mr_idr, uobj);
  	if (ret)
  		goto err_unreg;
  
  	memset(&resp, 0, sizeof resp);
  	resp.lkey      = mr->lkey;
  	resp.rkey      = mr->rkey;
  	resp.mr_handle = uobj->id;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	put_pd_read(pd);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&uobj->list, &file->ucontext->mr_list);
  	mutex_unlock(&file->mutex);
  
  	uobj->live = 1;
  
  	up_write(&uobj->mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
  
  err_unreg:
  	ib_dereg_mr(mr);
  
  err_put:
  	put_pd_read(pd);
  
  err_free:
  	put_uobj_write(uobj);
  	return ret;
  }
  
  ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
  			   const char __user *buf, int in_len,
  			   int out_len)
  {
  	struct ib_uverbs_dereg_mr cmd;
  	struct ib_mr             *mr;
  	struct ib_uobject	 *uobj;
  	int                       ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_mr_idr, cmd.mr_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  
  	mr = uobj->object;
  
  	ret = ib_dereg_mr(mr);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	put_uobj(uobj);
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_alloc_mw(struct ib_uverbs_file *file,
  			 const char __user *buf, int in_len,
  			 int out_len)
  {
  	struct ib_uverbs_alloc_mw      cmd;
  	struct ib_uverbs_alloc_mw_resp resp;
  	struct ib_uobject             *uobj;
  	struct ib_pd                  *pd;
  	struct ib_mw                  *mw;
  	int                            ret;
  
  	if (out_len < sizeof(resp))
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof(cmd)))
  		return -EFAULT;
  
  	uobj = kmalloc(sizeof(*uobj), GFP_KERNEL);
  	if (!uobj)
  		return -ENOMEM;
  
  	init_uobj(uobj, 0, file->ucontext, &mw_lock_class);
  	down_write(&uobj->mutex);
  
  	pd = idr_read_pd(cmd.pd_handle, file->ucontext);
  	if (!pd) {
  		ret = -EINVAL;
  		goto err_free;
  	}
  
  	mw = pd->device->alloc_mw(pd, cmd.mw_type);
  	if (IS_ERR(mw)) {
  		ret = PTR_ERR(mw);
  		goto err_put;
  	}
  
  	mw->device  = pd->device;
  	mw->pd      = pd;
  	mw->uobject = uobj;
  	atomic_inc(&pd->usecnt);
  
  	uobj->object = mw;
  	ret = idr_add_uobj(&ib_uverbs_mw_idr, uobj);
  	if (ret)
  		goto err_unalloc;
  
  	memset(&resp, 0, sizeof(resp));
  	resp.rkey      = mw->rkey;
  	resp.mw_handle = uobj->id;
  
  	if (copy_to_user((void __user *)(unsigned long)cmd.response,
  			 &resp, sizeof(resp))) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	put_pd_read(pd);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&uobj->list, &file->ucontext->mw_list);
  	mutex_unlock(&file->mutex);
  
  	uobj->live = 1;
  
  	up_write(&uobj->mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
  
  err_unalloc:
  	ib_dealloc_mw(mw);
  
  err_put:
  	put_pd_read(pd);
  
  err_free:
  	put_uobj_write(uobj);
  	return ret;
  }
  
  ssize_t ib_uverbs_dealloc_mw(struct ib_uverbs_file *file,
  			   const char __user *buf, int in_len,
  			   int out_len)
  {
  	struct ib_uverbs_dealloc_mw cmd;
  	struct ib_mw               *mw;
  	struct ib_uobject	   *uobj;
  	int                         ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof(cmd)))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_mw_idr, cmd.mw_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  
  	mw = uobj->object;
  
  	ret = ib_dealloc_mw(mw);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	put_uobj(uobj);
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_create_comp_channel(struct ib_uverbs_file *file,
  				      const char __user *buf, int in_len,
  				      int out_len)
  {
  	struct ib_uverbs_create_comp_channel	   cmd;
  	struct ib_uverbs_create_comp_channel_resp  resp;
  	struct file				  *filp;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	ret = get_unused_fd();
  	if (ret < 0)
  		return ret;
  	resp.fd = ret;
  
  	filp = ib_uverbs_alloc_event_file(file, 0);
  	if (IS_ERR(filp)) {
  		put_unused_fd(resp.fd);
  		return PTR_ERR(filp);
  	}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		put_unused_fd(resp.fd);
  		fput(filp);
  		return -EFAULT;
  	}
  
  	fd_install(resp.fd, filp);
  	return in_len;
  }
  
  ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_create_cq      cmd;
  	struct ib_uverbs_create_cq_resp resp;
  	struct ib_udata                 udata;
  	struct ib_ucq_object           *obj;
  	struct ib_uverbs_event_file    *ev_file = NULL;
  	struct ib_cq                   *cq;
  	int                             ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	if (cmd.comp_vector >= file->device->num_comp_vectors)
  		return -EINVAL;
  
  	obj = kmalloc(sizeof *obj, GFP_KERNEL);
  	if (!obj)
  		return -ENOMEM;
  
  	init_uobj(&obj->uobject, cmd.user_handle, file->ucontext, &cq_lock_class);
  	down_write(&obj->uobject.mutex);
  
  	if (cmd.comp_channel >= 0) {
  		ev_file = ib_uverbs_lookup_comp_file(cmd.comp_channel);
  		if (!ev_file) {
  			ret = -EINVAL;
  			goto err;
  		}
  	}
  
  	obj->uverbs_file	   = file;
  	obj->comp_events_reported  = 0;
  	obj->async_events_reported = 0;
  	INIT_LIST_HEAD(&obj->comp_list);
  	INIT_LIST_HEAD(&obj->async_list);
  
  	cq = file->device->ib_dev->create_cq(file->device->ib_dev, cmd.cqe,
  					     cmd.comp_vector,
  					     file->ucontext, &udata);
  	if (IS_ERR(cq)) {
  		ret = PTR_ERR(cq);
  		goto err_file;
  	}
  
  	cq->device        = file->device->ib_dev;
  	cq->uobject       = &obj->uobject;
  	cq->comp_handler  = ib_uverbs_comp_handler;
  	cq->event_handler = ib_uverbs_cq_event_handler;
  	cq->cq_context    = ev_file;
  	atomic_set(&cq->usecnt, 0);
  
  	obj->uobject.object = cq;
  	ret = idr_add_uobj(&ib_uverbs_cq_idr, &obj->uobject);
  	if (ret)
  		goto err_free;
  
  	memset(&resp, 0, sizeof resp);
  	resp.cq_handle = obj->uobject.id;
  	resp.cqe       = cq->cqe;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&obj->uobject.list, &file->ucontext->cq_list);
  	mutex_unlock(&file->mutex);
  
  	obj->uobject.live = 1;
  
  	up_write(&obj->uobject.mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_cq_idr, &obj->uobject);
  
  err_free:
  	ib_destroy_cq(cq);
  
  err_file:
  	if (ev_file)
  		ib_uverbs_release_ucq(file, ev_file, obj);
  
  err:
  	put_uobj_write(&obj->uobject);
  	return ret;
  }
  
  ssize_t ib_uverbs_resize_cq(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_resize_cq	cmd;
  	struct ib_uverbs_resize_cq_resp	resp;
  	struct ib_udata                 udata;
  	struct ib_cq			*cq;
  	int				ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	cq = idr_read_cq(cmd.cq_handle, file->ucontext, 0);
  	if (!cq)
  		return -EINVAL;
  
  	ret = cq->device->resize_cq(cq, cmd.cqe, &udata);
  	if (ret)
  		goto out;
  
  	resp.cqe = cq->cqe;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp.cqe))
  		ret = -EFAULT;
  
  out:
  	put_cq_read(cq);
  
  	return ret ? ret : in_len;
  }
  
  static int copy_wc_to_user(void __user *dest, struct ib_wc *wc)
  {
  	struct ib_uverbs_wc tmp;
  
  	tmp.wr_id		= wc->wr_id;
  	tmp.status		= wc->status;
  	tmp.opcode		= wc->opcode;
  	tmp.vendor_err		= wc->vendor_err;
  	tmp.byte_len		= wc->byte_len;
  	tmp.ex.imm_data		= (__u32 __force) wc->ex.imm_data;
  	tmp.qp_num		= wc->qp->qp_num;
  	tmp.src_qp		= wc->src_qp;
  	tmp.wc_flags		= wc->wc_flags;
  	tmp.pkey_index		= wc->pkey_index;
  	tmp.slid		= wc->slid;
  	tmp.sl			= wc->sl;
  	tmp.dlid_path_bits	= wc->dlid_path_bits;
  	tmp.port_num		= wc->port_num;
  	tmp.reserved		= 0;
  
  	if (copy_to_user(dest, &tmp, sizeof tmp))
  		return -EFAULT;
  
  	return 0;
  }
  
  ssize_t ib_uverbs_poll_cq(struct ib_uverbs_file *file,
  			  const char __user *buf, int in_len,
  			  int out_len)
  {
  	struct ib_uverbs_poll_cq       cmd;
  	struct ib_uverbs_poll_cq_resp  resp;
  	u8 __user                     *header_ptr;
  	u8 __user                     *data_ptr;
  	struct ib_cq                  *cq;
  	struct ib_wc                   wc;
  	int                            ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	cq = idr_read_cq(cmd.cq_handle, file->ucontext, 0);
  	if (!cq)
  		return -EINVAL;
  
  	/* we copy a struct ib_uverbs_poll_cq_resp to user space */
  	header_ptr = (void __user *)(unsigned long) cmd.response;
  	data_ptr = header_ptr + sizeof resp;
  
  	memset(&resp, 0, sizeof resp);
  	while (resp.count < cmd.ne) {
  		ret = ib_poll_cq(cq, 1, &wc);
  		if (ret < 0)
  			goto out_put;
  		if (!ret)
  			break;
  
  		ret = copy_wc_to_user(data_ptr, &wc);
  		if (ret)
  			goto out_put;
  
  		data_ptr += sizeof(struct ib_uverbs_wc);
  		++resp.count;
  	}
  
  	if (copy_to_user(header_ptr, &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto out_put;
  	}
  
  	ret = in_len;
  
  out_put:
  	put_cq_read(cq);
  	return ret;
  }
  
  ssize_t ib_uverbs_req_notify_cq(struct ib_uverbs_file *file,
  				const char __user *buf, int in_len,
  				int out_len)
  {
  	struct ib_uverbs_req_notify_cq cmd;
  	struct ib_cq                  *cq;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	cq = idr_read_cq(cmd.cq_handle, file->ucontext, 0);
  	if (!cq)
  		return -EINVAL;
  
  	ib_req_notify_cq(cq, cmd.solicited_only ?
  			 IB_CQ_SOLICITED : IB_CQ_NEXT_COMP);
  
  	put_cq_read(cq);
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len,
  			     int out_len)
  {
  	struct ib_uverbs_destroy_cq      cmd;
  	struct ib_uverbs_destroy_cq_resp resp;
  	struct ib_uobject		*uobj;
  	struct ib_cq               	*cq;
  	struct ib_ucq_object        	*obj;
  	struct ib_uverbs_event_file	*ev_file;
  	int                        	 ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_cq_idr, cmd.cq_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  	cq      = uobj->object;
  	ev_file = cq->cq_context;
  	obj     = container_of(cq->uobject, struct ib_ucq_object, uobject);
  
  	ret = ib_destroy_cq(cq);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	ib_uverbs_release_ucq(file, ev_file, obj);
  
  	memset(&resp, 0, sizeof resp);
  	resp.comp_events_reported  = obj->comp_events_reported;
  	resp.async_events_reported = obj->async_events_reported;
  
  	put_uobj(uobj);
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		return -EFAULT;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_create_qp      cmd;
  	struct ib_uverbs_create_qp_resp resp;
  	struct ib_udata                 udata;
  	struct ib_uqp_object           *obj;
  	struct ib_device	       *device;
  	struct ib_pd                   *pd = NULL;
  	struct ib_xrcd		       *xrcd = NULL;
  	struct ib_uobject	       *uninitialized_var(xrcd_uobj);
  	struct ib_cq                   *scq = NULL, *rcq = NULL;
  	struct ib_srq                  *srq = NULL;
  	struct ib_qp                   *qp;
  	struct ib_qp_init_attr          attr;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	if (cmd.qp_type == IB_QPT_RAW_PACKET && !capable(CAP_NET_RAW))
  		return -EPERM;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	obj = kmalloc(sizeof *obj, GFP_KERNEL);
  	if (!obj)
  		return -ENOMEM;
  
  	init_uobj(&obj->uevent.uobject, cmd.user_handle, file->ucontext, &qp_lock_class);
  	down_write(&obj->uevent.uobject.mutex);
  
  	if (cmd.qp_type == IB_QPT_XRC_TGT) {
  		xrcd = idr_read_xrcd(cmd.pd_handle, file->ucontext, &xrcd_uobj);
  		if (!xrcd) {
  			ret = -EINVAL;
  			goto err_put;
  		}
  		device = xrcd->device;
  	} else {
  		if (cmd.qp_type == IB_QPT_XRC_INI) {
  			cmd.max_recv_wr = cmd.max_recv_sge = 0;
  		} else {
  			if (cmd.is_srq) {
  				srq = idr_read_srq(cmd.srq_handle, file->ucontext);
  				if (!srq || srq->srq_type != IB_SRQT_BASIC) {
  					ret = -EINVAL;
  					goto err_put;
  				}
  			}
  
  			if (cmd.recv_cq_handle != cmd.send_cq_handle) {
  				rcq = idr_read_cq(cmd.recv_cq_handle, file->ucontext, 0);
  				if (!rcq) {
  					ret = -EINVAL;
  					goto err_put;
  				}
  			}
  		}
  
  		scq = idr_read_cq(cmd.send_cq_handle, file->ucontext, !!rcq);
  		rcq = rcq ?: scq;
  		pd  = idr_read_pd(cmd.pd_handle, file->ucontext);
  		if (!pd || !scq) {
  			ret = -EINVAL;
  			goto err_put;
  		}
  
  		device = pd->device;
  	}
  
  	attr.event_handler = ib_uverbs_qp_event_handler;
  	attr.qp_context    = file;
  	attr.send_cq       = scq;
  	attr.recv_cq       = rcq;
  	attr.srq           = srq;
  	attr.xrcd	   = xrcd;
  	attr.sq_sig_type   = cmd.sq_sig_all ? IB_SIGNAL_ALL_WR : IB_SIGNAL_REQ_WR;
  	attr.qp_type       = cmd.qp_type;
  	attr.create_flags  = 0;
  
  	attr.cap.max_send_wr     = cmd.max_send_wr;
  	attr.cap.max_recv_wr     = cmd.max_recv_wr;
  	attr.cap.max_send_sge    = cmd.max_send_sge;
  	attr.cap.max_recv_sge    = cmd.max_recv_sge;
  	attr.cap.max_inline_data = cmd.max_inline_data;
  
  	obj->uevent.events_reported     = 0;
  	INIT_LIST_HEAD(&obj->uevent.event_list);
  	INIT_LIST_HEAD(&obj->mcast_list);
  
  	if (cmd.qp_type == IB_QPT_XRC_TGT)
  		qp = ib_create_qp(pd, &attr);
  	else
  		qp = device->create_qp(pd, &attr, &udata);
  
  	if (IS_ERR(qp)) {
  		ret = PTR_ERR(qp);
  		goto err_put;
  	}
  
  	if (cmd.qp_type != IB_QPT_XRC_TGT) {
  		qp->real_qp	  = qp;
  		qp->device	  = device;
  		qp->pd		  = pd;
  		qp->send_cq	  = attr.send_cq;
  		qp->recv_cq	  = attr.recv_cq;
  		qp->srq		  = attr.srq;
  		qp->event_handler = attr.event_handler;
  		qp->qp_context	  = attr.qp_context;
  		qp->qp_type	  = attr.qp_type;
  		atomic_set(&qp->usecnt, 0);
  		atomic_inc(&pd->usecnt);
  		atomic_inc(&attr.send_cq->usecnt);
  		if (attr.recv_cq)
  			atomic_inc(&attr.recv_cq->usecnt);
  		if (attr.srq)
  			atomic_inc(&attr.srq->usecnt);
  	}
  	qp->uobject = &obj->uevent.uobject;
  
  	obj->uevent.uobject.object = qp;
  	ret = idr_add_uobj(&ib_uverbs_qp_idr, &obj->uevent.uobject);
  	if (ret)
  		goto err_destroy;
  
  	memset(&resp, 0, sizeof resp);
  	resp.qpn             = qp->qp_num;
  	resp.qp_handle       = obj->uevent.uobject.id;
  	resp.max_recv_sge    = attr.cap.max_recv_sge;
  	resp.max_send_sge    = attr.cap.max_send_sge;
  	resp.max_recv_wr     = attr.cap.max_recv_wr;
  	resp.max_send_wr     = attr.cap.max_send_wr;
  	resp.max_inline_data = attr.cap.max_inline_data;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	if (xrcd)
  		put_xrcd_read(xrcd_uobj);
  	if (pd)
  		put_pd_read(pd);
  	if (scq)
  		put_cq_read(scq);
  	if (rcq && rcq != scq)
  		put_cq_read(rcq);
  	if (srq)
  		put_srq_read(srq);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&obj->uevent.uobject.list, &file->ucontext->qp_list);
  	mutex_unlock(&file->mutex);
  
  	obj->uevent.uobject.live = 1;
  
  	up_write(&obj->uevent.uobject.mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_qp_idr, &obj->uevent.uobject);
  
  err_destroy:
  	ib_destroy_qp(qp);
  
  err_put:
  	if (xrcd)
  		put_xrcd_read(xrcd_uobj);
  	if (pd)
  		put_pd_read(pd);
  	if (scq)
  		put_cq_read(scq);
  	if (rcq && rcq != scq)
  		put_cq_read(rcq);
  	if (srq)
  		put_srq_read(srq);
  
  	put_uobj_write(&obj->uevent.uobject);
  	return ret;
  }
  
  ssize_t ib_uverbs_open_qp(struct ib_uverbs_file *file,
  			  const char __user *buf, int in_len, int out_len)
  {
  	struct ib_uverbs_open_qp        cmd;
  	struct ib_uverbs_create_qp_resp resp;
  	struct ib_udata                 udata;
  	struct ib_uqp_object           *obj;
  	struct ib_xrcd		       *xrcd;
  	struct ib_uobject	       *uninitialized_var(xrcd_uobj);
  	struct ib_qp                   *qp;
  	struct ib_qp_open_attr          attr;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	obj = kmalloc(sizeof *obj, GFP_KERNEL);
  	if (!obj)
  		return -ENOMEM;
  
  	init_uobj(&obj->uevent.uobject, cmd.user_handle, file->ucontext, &qp_lock_class);
  	down_write(&obj->uevent.uobject.mutex);
  
  	xrcd = idr_read_xrcd(cmd.pd_handle, file->ucontext, &xrcd_uobj);
  	if (!xrcd) {
  		ret = -EINVAL;
  		goto err_put;
  	}
  
  	attr.event_handler = ib_uverbs_qp_event_handler;
  	attr.qp_context    = file;
  	attr.qp_num        = cmd.qpn;
  	attr.qp_type       = cmd.qp_type;
  
  	obj->uevent.events_reported = 0;
  	INIT_LIST_HEAD(&obj->uevent.event_list);
  	INIT_LIST_HEAD(&obj->mcast_list);
  
  	qp = ib_open_qp(xrcd, &attr);
  	if (IS_ERR(qp)) {
  		ret = PTR_ERR(qp);
  		goto err_put;
  	}
  
  	qp->uobject = &obj->uevent.uobject;
  
  	obj->uevent.uobject.object = qp;
  	ret = idr_add_uobj(&ib_uverbs_qp_idr, &obj->uevent.uobject);
  	if (ret)
  		goto err_destroy;
  
  	memset(&resp, 0, sizeof resp);
  	resp.qpn       = qp->qp_num;
  	resp.qp_handle = obj->uevent.uobject.id;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_remove;
  	}
  
  	put_xrcd_read(xrcd_uobj);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&obj->uevent.uobject.list, &file->ucontext->qp_list);
  	mutex_unlock(&file->mutex);
  
  	obj->uevent.uobject.live = 1;
  
  	up_write(&obj->uevent.uobject.mutex);
  
  	return in_len;
  
  err_remove:
  	idr_remove_uobj(&ib_uverbs_qp_idr, &obj->uevent.uobject);
  
  err_destroy:
  	ib_destroy_qp(qp);
  
  err_put:
  	put_xrcd_read(xrcd_uobj);
  	put_uobj_write(&obj->uevent.uobject);
  	return ret;
  }
  
  ssize_t ib_uverbs_query_qp(struct ib_uverbs_file *file,
  			   const char __user *buf, int in_len,
  			   int out_len)
  {
  	struct ib_uverbs_query_qp      cmd;
  	struct ib_uverbs_query_qp_resp resp;
  	struct ib_qp                   *qp;
  	struct ib_qp_attr              *attr;
  	struct ib_qp_init_attr         *init_attr;
  	int                            ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	attr      = kmalloc(sizeof *attr, GFP_KERNEL);
  	init_attr = kmalloc(sizeof *init_attr, GFP_KERNEL);
  	if (!attr || !init_attr) {
  		ret = -ENOMEM;
  		goto out;
  	}
  
  	qp = idr_read_qp(cmd.qp_handle, file->ucontext);
  	if (!qp) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ret = ib_query_qp(qp, attr, cmd.attr_mask, init_attr);
  
  	put_qp_read(qp);
  
  	if (ret)
  		goto out;
  
  	memset(&resp, 0, sizeof resp);
  
  	resp.qp_state               = attr->qp_state;
  	resp.cur_qp_state           = attr->cur_qp_state;
  	resp.path_mtu               = attr->path_mtu;
  	resp.path_mig_state         = attr->path_mig_state;
  	resp.qkey                   = attr->qkey;
  	resp.rq_psn                 = attr->rq_psn;
  	resp.sq_psn                 = attr->sq_psn;
  	resp.dest_qp_num            = attr->dest_qp_num;
  	resp.qp_access_flags        = attr->qp_access_flags;
  	resp.pkey_index             = attr->pkey_index;
  	resp.alt_pkey_index         = attr->alt_pkey_index;
  	resp.sq_draining            = attr->sq_draining;
  	resp.max_rd_atomic          = attr->max_rd_atomic;
  	resp.max_dest_rd_atomic     = attr->max_dest_rd_atomic;
  	resp.min_rnr_timer          = attr->min_rnr_timer;
  	resp.port_num               = attr->port_num;
  	resp.timeout                = attr->timeout;
  	resp.retry_cnt              = attr->retry_cnt;
  	resp.rnr_retry              = attr->rnr_retry;
  	resp.alt_port_num           = attr->alt_port_num;
  	resp.alt_timeout            = attr->alt_timeout;
  
  	memcpy(resp.dest.dgid, attr->ah_attr.grh.dgid.raw, 16);
  	resp.dest.flow_label        = attr->ah_attr.grh.flow_label;
  	resp.dest.sgid_index        = attr->ah_attr.grh.sgid_index;
  	resp.dest.hop_limit         = attr->ah_attr.grh.hop_limit;
  	resp.dest.traffic_class     = attr->ah_attr.grh.traffic_class;
  	resp.dest.dlid              = attr->ah_attr.dlid;
  	resp.dest.sl                = attr->ah_attr.sl;
  	resp.dest.src_path_bits     = attr->ah_attr.src_path_bits;
  	resp.dest.static_rate       = attr->ah_attr.static_rate;
  	resp.dest.is_global         = !!(attr->ah_attr.ah_flags & IB_AH_GRH);
  	resp.dest.port_num          = attr->ah_attr.port_num;
  
  	memcpy(resp.alt_dest.dgid, attr->alt_ah_attr.grh.dgid.raw, 16);
  	resp.alt_dest.flow_label    = attr->alt_ah_attr.grh.flow_label;
  	resp.alt_dest.sgid_index    = attr->alt_ah_attr.grh.sgid_index;
  	resp.alt_dest.hop_limit     = attr->alt_ah_attr.grh.hop_limit;
  	resp.alt_dest.traffic_class = attr->alt_ah_attr.grh.traffic_class;
  	resp.alt_dest.dlid          = attr->alt_ah_attr.dlid;
  	resp.alt_dest.sl            = attr->alt_ah_attr.sl;
  	resp.alt_dest.src_path_bits = attr->alt_ah_attr.src_path_bits;
  	resp.alt_dest.static_rate   = attr->alt_ah_attr.static_rate;
  	resp.alt_dest.is_global     = !!(attr->alt_ah_attr.ah_flags & IB_AH_GRH);
  	resp.alt_dest.port_num      = attr->alt_ah_attr.port_num;
  
  	resp.max_send_wr            = init_attr->cap.max_send_wr;
  	resp.max_recv_wr            = init_attr->cap.max_recv_wr;
  	resp.max_send_sge           = init_attr->cap.max_send_sge;
  	resp.max_recv_sge           = init_attr->cap.max_recv_sge;
  	resp.max_inline_data        = init_attr->cap.max_inline_data;
  	resp.sq_sig_all             = init_attr->sq_sig_type == IB_SIGNAL_ALL_WR;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		ret = -EFAULT;
  
  out:
  	kfree(attr);
  	kfree(init_attr);
  
  	return ret ? ret : in_len;
  }
  
  /* Remove ignored fields set in the attribute mask */
  static int modify_qp_mask(enum ib_qp_type qp_type, int mask)
  {
  	switch (qp_type) {
  	case IB_QPT_XRC_INI:
  		return mask & ~(IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER);
  	case IB_QPT_XRC_TGT:
  		return mask & ~(IB_QP_MAX_QP_RD_ATOMIC | IB_QP_RETRY_CNT |
  				IB_QP_RNR_RETRY);
  	default:
  		return mask;
  	}
  }
  
  ssize_t ib_uverbs_modify_qp(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_modify_qp cmd;
  	struct ib_udata            udata;
  	struct ib_qp              *qp;
  	struct ib_qp_attr         *attr;
  	int                        ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd, NULL, in_len - sizeof cmd,
  		   out_len);
  
  	attr = kmalloc(sizeof *attr, GFP_KERNEL);
  	if (!attr)
  		return -ENOMEM;
  
  	qp = idr_read_qp(cmd.qp_handle, file->ucontext);
  	if (!qp) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	attr->qp_state 		  = cmd.qp_state;
  	attr->cur_qp_state 	  = cmd.cur_qp_state;
  	attr->path_mtu 		  = cmd.path_mtu;
  	attr->path_mig_state 	  = cmd.path_mig_state;
  	attr->qkey 		  = cmd.qkey;
  	attr->rq_psn 		  = cmd.rq_psn;
  	attr->sq_psn 		  = cmd.sq_psn;
  	attr->dest_qp_num 	  = cmd.dest_qp_num;
  	attr->qp_access_flags 	  = cmd.qp_access_flags;
  	attr->pkey_index 	  = cmd.pkey_index;
  	attr->alt_pkey_index 	  = cmd.alt_pkey_index;
  	attr->en_sqd_async_notify = cmd.en_sqd_async_notify;
  	attr->max_rd_atomic 	  = cmd.max_rd_atomic;
  	attr->max_dest_rd_atomic  = cmd.max_dest_rd_atomic;
  	attr->min_rnr_timer 	  = cmd.min_rnr_timer;
  	attr->port_num 		  = cmd.port_num;
  	attr->timeout 		  = cmd.timeout;
  	attr->retry_cnt 	  = cmd.retry_cnt;
  	attr->rnr_retry 	  = cmd.rnr_retry;
  	attr->alt_port_num 	  = cmd.alt_port_num;
  	attr->alt_timeout 	  = cmd.alt_timeout;
  
  	memcpy(attr->ah_attr.grh.dgid.raw, cmd.dest.dgid, 16);
  	attr->ah_attr.grh.flow_label        = cmd.dest.flow_label;
  	attr->ah_attr.grh.sgid_index        = cmd.dest.sgid_index;
  	attr->ah_attr.grh.hop_limit         = cmd.dest.hop_limit;
  	attr->ah_attr.grh.traffic_class     = cmd.dest.traffic_class;
  	attr->ah_attr.dlid 	    	    = cmd.dest.dlid;
  	attr->ah_attr.sl   	    	    = cmd.dest.sl;
  	attr->ah_attr.src_path_bits 	    = cmd.dest.src_path_bits;
  	attr->ah_attr.static_rate   	    = cmd.dest.static_rate;
  	attr->ah_attr.ah_flags 	    	    = cmd.dest.is_global ? IB_AH_GRH : 0;
  	attr->ah_attr.port_num 	    	    = cmd.dest.port_num;
  
  	memcpy(attr->alt_ah_attr.grh.dgid.raw, cmd.alt_dest.dgid, 16);
  	attr->alt_ah_attr.grh.flow_label    = cmd.alt_dest.flow_label;
  	attr->alt_ah_attr.grh.sgid_index    = cmd.alt_dest.sgid_index;
  	attr->alt_ah_attr.grh.hop_limit     = cmd.alt_dest.hop_limit;
  	attr->alt_ah_attr.grh.traffic_class = cmd.alt_dest.traffic_class;
  	attr->alt_ah_attr.dlid 	    	    = cmd.alt_dest.dlid;
  	attr->alt_ah_attr.sl   	    	    = cmd.alt_dest.sl;
  	attr->alt_ah_attr.src_path_bits     = cmd.alt_dest.src_path_bits;
  	attr->alt_ah_attr.static_rate       = cmd.alt_dest.static_rate;
  	attr->alt_ah_attr.ah_flags 	    = cmd.alt_dest.is_global ? IB_AH_GRH : 0;
  	attr->alt_ah_attr.port_num 	    = cmd.alt_dest.port_num;
  
  	if (qp->real_qp == qp) {
  		ret = qp->device->modify_qp(qp, attr,
  			modify_qp_mask(qp->qp_type, cmd.attr_mask), &udata);
  	} else {
  		ret = ib_modify_qp(qp, attr, modify_qp_mask(qp->qp_type, cmd.attr_mask));
  	}
  
  	put_qp_read(qp);
  
  	if (ret)
  		goto out;
  
  	ret = in_len;
  
  out:
  	kfree(attr);
  
  	return ret;
  }
  
  ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len,
  			     int out_len)
  {
  	struct ib_uverbs_destroy_qp      cmd;
  	struct ib_uverbs_destroy_qp_resp resp;
  	struct ib_uobject		*uobj;
  	struct ib_qp               	*qp;
  	struct ib_uqp_object        	*obj;
  	int                        	 ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	memset(&resp, 0, sizeof resp);
  
  	uobj = idr_write_uobj(&ib_uverbs_qp_idr, cmd.qp_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  	qp  = uobj->object;
  	obj = container_of(uobj, struct ib_uqp_object, uevent.uobject);
  
  	if (!list_empty(&obj->mcast_list)) {
  		put_uobj_write(uobj);
  		return -EBUSY;
  	}
  
  	ret = ib_destroy_qp(qp);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	ib_uverbs_release_uevent(file, &obj->uevent);
  
  	resp.events_reported = obj->uevent.events_reported;
  
  	put_uobj(uobj);
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		return -EFAULT;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_post_send      cmd;
  	struct ib_uverbs_post_send_resp resp;
  	struct ib_uverbs_send_wr       *user_wr;
  	struct ib_send_wr              *wr = NULL, *last, *next, *bad_wr;
  	struct ib_qp                   *qp;
  	int                             i, sg_ind;
  	int				is_ud;
  	ssize_t                         ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	if (in_len < sizeof cmd + cmd.wqe_size * cmd.wr_count +
  	    cmd.sge_count * sizeof (struct ib_uverbs_sge))
  		return -EINVAL;
  
  	if (cmd.wqe_size < sizeof (struct ib_uverbs_send_wr))
  		return -EINVAL;
  
  	user_wr = kmalloc(cmd.wqe_size, GFP_KERNEL);
  	if (!user_wr)
  		return -ENOMEM;
  
  	qp = idr_read_qp(cmd.qp_handle, file->ucontext);
  	if (!qp)
  		goto out;
  
  	is_ud = qp->qp_type == IB_QPT_UD;
  	sg_ind = 0;
  	last = NULL;
  	for (i = 0; i < cmd.wr_count; ++i) {
  		if (copy_from_user(user_wr,
  				   buf + sizeof cmd + i * cmd.wqe_size,
  				   cmd.wqe_size)) {
  			ret = -EFAULT;
  			goto out_put;
  		}
  
  		if (user_wr->num_sge + sg_ind > cmd.sge_count) {
  			ret = -EINVAL;
  			goto out_put;
  		}
  
  		next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) +
  			       user_wr->num_sge * sizeof (struct ib_sge),
  			       GFP_KERNEL);
  		if (!next) {
  			ret = -ENOMEM;
  			goto out_put;
  		}
  
  		if (!last)
  			wr = next;
  		else
  			last->next = next;
  		last = next;
  
  		next->next       = NULL;
  		next->wr_id      = user_wr->wr_id;
  		next->num_sge    = user_wr->num_sge;
  		next->opcode     = user_wr->opcode;
  		next->send_flags = user_wr->send_flags;
  
  		if (is_ud) {
  			if (next->opcode != IB_WR_SEND &&
  			    next->opcode != IB_WR_SEND_WITH_IMM) {
  				ret = -EINVAL;
  				goto out_put;
  			}
  
  			next->wr.ud.ah = idr_read_ah(user_wr->wr.ud.ah,
  						     file->ucontext);
  			if (!next->wr.ud.ah) {
  				ret = -EINVAL;
  				goto out_put;
  			}
  			next->wr.ud.remote_qpn  = user_wr->wr.ud.remote_qpn;
  			next->wr.ud.remote_qkey = user_wr->wr.ud.remote_qkey;
  		} else {
  			switch (next->opcode) {
  			case IB_WR_RDMA_WRITE_WITH_IMM:
  				next->ex.imm_data =
  					(__be32 __force) user_wr->ex.imm_data;
  			case IB_WR_RDMA_WRITE:
  			case IB_WR_RDMA_READ:
  				next->wr.rdma.remote_addr =
  					user_wr->wr.rdma.remote_addr;
  				next->wr.rdma.rkey        =
  					user_wr->wr.rdma.rkey;
  				break;
  			case IB_WR_SEND_WITH_IMM:
  				next->ex.imm_data =
  					(__be32 __force) user_wr->ex.imm_data;
  				break;
  			case IB_WR_SEND_WITH_INV:
  				next->ex.invalidate_rkey =
  					user_wr->ex.invalidate_rkey;
  				break;
  			case IB_WR_ATOMIC_CMP_AND_SWP:
  			case IB_WR_ATOMIC_FETCH_AND_ADD:
  				next->wr.atomic.remote_addr =
  					user_wr->wr.atomic.remote_addr;
  				next->wr.atomic.compare_add =
  					user_wr->wr.atomic.compare_add;
  				next->wr.atomic.swap = user_wr->wr.atomic.swap;
  				next->wr.atomic.rkey = user_wr->wr.atomic.rkey;
  			case IB_WR_SEND:
  				break;
  			default:
  				ret = -EINVAL;
  				goto out_put;
  			}
  		}
  
  		if (next->num_sge) {
  			next->sg_list = (void *) next +
  				ALIGN(sizeof *next, sizeof (struct ib_sge));
  			if (copy_from_user(next->sg_list,
  					   buf + sizeof cmd +
  					   cmd.wr_count * cmd.wqe_size +
  					   sg_ind * sizeof (struct ib_sge),
  					   next->num_sge * sizeof (struct ib_sge))) {
  				ret = -EFAULT;
  				goto out_put;
  			}
  			sg_ind += next->num_sge;
  		} else
  			next->sg_list = NULL;
  	}
  
  	resp.bad_wr = 0;
  	ret = qp->device->post_send(qp->real_qp, wr, &bad_wr);
  	if (ret)
  		for (next = wr; next; next = next->next) {
  			++resp.bad_wr;
  			if (next == bad_wr)
  				break;
  		}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		ret = -EFAULT;
  
  out_put:
  	put_qp_read(qp);
  
  	while (wr) {
  		if (is_ud && wr->wr.ud.ah)
  			put_ah_read(wr->wr.ud.ah);
  		next = wr->next;
  		kfree(wr);
  		wr = next;
  	}
  
  out:
  	kfree(user_wr);
  
  	return ret ? ret : in_len;
  }
  
  static struct ib_recv_wr *ib_uverbs_unmarshall_recv(const char __user *buf,
  						    int in_len,
  						    u32 wr_count,
  						    u32 sge_count,
  						    u32 wqe_size)
  {
  	struct ib_uverbs_recv_wr *user_wr;
  	struct ib_recv_wr        *wr = NULL, *last, *next;
  	int                       sg_ind;
  	int                       i;
  	int                       ret;
  
  	if (in_len < wqe_size * wr_count +
  	    sge_count * sizeof (struct ib_uverbs_sge))
  		return ERR_PTR(-EINVAL);
  
  	if (wqe_size < sizeof (struct ib_uverbs_recv_wr))
  		return ERR_PTR(-EINVAL);
  
  	user_wr = kmalloc(wqe_size, GFP_KERNEL);
  	if (!user_wr)
  		return ERR_PTR(-ENOMEM);
  
  	sg_ind = 0;
  	last = NULL;
  	for (i = 0; i < wr_count; ++i) {
  		if (copy_from_user(user_wr, buf + i * wqe_size,
  				   wqe_size)) {
  			ret = -EFAULT;
  			goto err;
  		}
  
  		if (user_wr->num_sge + sg_ind > sge_count) {
  			ret = -EINVAL;
  			goto err;
  		}
  
  		next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) +
  			       user_wr->num_sge * sizeof (struct ib_sge),
  			       GFP_KERNEL);
  		if (!next) {
  			ret = -ENOMEM;
  			goto err;
  		}
  
  		if (!last)
  			wr = next;
  		else
  			last->next = next;
  		last = next;
  
  		next->next       = NULL;
  		next->wr_id      = user_wr->wr_id;
  		next->num_sge    = user_wr->num_sge;
  
  		if (next->num_sge) {
  			next->sg_list = (void *) next +
  				ALIGN(sizeof *next, sizeof (struct ib_sge));
  			if (copy_from_user(next->sg_list,
  					   buf + wr_count * wqe_size +
  					   sg_ind * sizeof (struct ib_sge),
  					   next->num_sge * sizeof (struct ib_sge))) {
  				ret = -EFAULT;
  				goto err;
  			}
  			sg_ind += next->num_sge;
  		} else
  			next->sg_list = NULL;
  	}
  
  	kfree(user_wr);
  	return wr;
  
  err:
  	kfree(user_wr);
  
  	while (wr) {
  		next = wr->next;
  		kfree(wr);
  		wr = next;
  	}
  
  	return ERR_PTR(ret);
  }
  
  ssize_t ib_uverbs_post_recv(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_post_recv      cmd;
  	struct ib_uverbs_post_recv_resp resp;
  	struct ib_recv_wr              *wr, *next, *bad_wr;
  	struct ib_qp                   *qp;
  	ssize_t                         ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	wr = ib_uverbs_unmarshall_recv(buf + sizeof cmd,
  				       in_len - sizeof cmd, cmd.wr_count,
  				       cmd.sge_count, cmd.wqe_size);
  	if (IS_ERR(wr))
  		return PTR_ERR(wr);
  
  	qp = idr_read_qp(cmd.qp_handle, file->ucontext);
  	if (!qp)
  		goto out;
  
  	resp.bad_wr = 0;
  	ret = qp->device->post_recv(qp->real_qp, wr, &bad_wr);
  
  	put_qp_read(qp);
  
  	if (ret)
  		for (next = wr; next; next = next->next) {
  			++resp.bad_wr;
  			if (next == bad_wr)
  				break;
  		}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		ret = -EFAULT;
  
  out:
  	while (wr) {
  		next = wr->next;
  		kfree(wr);
  		wr = next;
  	}
  
  	return ret ? ret : in_len;
  }
  
  ssize_t ib_uverbs_post_srq_recv(struct ib_uverbs_file *file,
  				const char __user *buf, int in_len,
  				int out_len)
  {
  	struct ib_uverbs_post_srq_recv      cmd;
  	struct ib_uverbs_post_srq_recv_resp resp;
  	struct ib_recv_wr                  *wr, *next, *bad_wr;
  	struct ib_srq                      *srq;
  	ssize_t                             ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	wr = ib_uverbs_unmarshall_recv(buf + sizeof cmd,
  				       in_len - sizeof cmd, cmd.wr_count,
  				       cmd.sge_count, cmd.wqe_size);
  	if (IS_ERR(wr))
  		return PTR_ERR(wr);
  
  	srq = idr_read_srq(cmd.srq_handle, file->ucontext);
  	if (!srq)
  		goto out;
  
  	resp.bad_wr = 0;
  	ret = srq->device->post_srq_recv(srq, wr, &bad_wr);
  
  	put_srq_read(srq);
  
  	if (ret)
  		for (next = wr; next; next = next->next) {
  			++resp.bad_wr;
  			if (next == bad_wr)
  				break;
  		}
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		ret = -EFAULT;
  
  out:
  	while (wr) {
  		next = wr->next;
  		kfree(wr);
  		wr = next;
  	}
  
  	return ret ? ret : in_len;
  }
  
  ssize_t ib_uverbs_create_ah(struct ib_uverbs_file *file,
  			    const char __user *buf, int in_len,
  			    int out_len)
  {
  	struct ib_uverbs_create_ah	 cmd;
  	struct ib_uverbs_create_ah_resp	 resp;
  	struct ib_uobject		*uobj;
  	struct ib_pd			*pd;
  	struct ib_ah			*ah;
  	struct ib_ah_attr		attr;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = kmalloc(sizeof *uobj, GFP_KERNEL);
  	if (!uobj)
  		return -ENOMEM;
  
  	init_uobj(uobj, cmd.user_handle, file->ucontext, &ah_lock_class);
  	down_write(&uobj->mutex);
  
  	pd = idr_read_pd(cmd.pd_handle, file->ucontext);
  	if (!pd) {
  		ret = -EINVAL;
  		goto err;
  	}
  
  	attr.dlid 	       = cmd.attr.dlid;
  	attr.sl 	       = cmd.attr.sl;
  	attr.src_path_bits     = cmd.attr.src_path_bits;
  	attr.static_rate       = cmd.attr.static_rate;
  	attr.ah_flags          = cmd.attr.is_global ? IB_AH_GRH : 0;
  	attr.port_num 	       = cmd.attr.port_num;
  	attr.grh.flow_label    = cmd.attr.grh.flow_label;
  	attr.grh.sgid_index    = cmd.attr.grh.sgid_index;
  	attr.grh.hop_limit     = cmd.attr.grh.hop_limit;
  	attr.grh.traffic_class = cmd.attr.grh.traffic_class;
  	memcpy(attr.grh.dgid.raw, cmd.attr.grh.dgid, 16);
  
  	ah = ib_create_ah(pd, &attr);
  	if (IS_ERR(ah)) {
  		ret = PTR_ERR(ah);
  		goto err_put;
  	}
  
  	ah->uobject  = uobj;
  	uobj->object = ah;
  
  	ret = idr_add_uobj(&ib_uverbs_ah_idr, uobj);
  	if (ret)
  		goto err_destroy;
  
  	resp.ah_handle = uobj->id;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	put_pd_read(pd);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&uobj->list, &file->ucontext->ah_list);
  	mutex_unlock(&file->mutex);
  
  	uobj->live = 1;
  
  	up_write(&uobj->mutex);
  
  	return in_len;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
  
  err_destroy:
  	ib_destroy_ah(ah);
  
  err_put:
  	put_pd_read(pd);
  
  err:
  	put_uobj_write(uobj);
  	return ret;
  }
  
  ssize_t ib_uverbs_destroy_ah(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len, int out_len)
  {
  	struct ib_uverbs_destroy_ah cmd;
  	struct ib_ah		   *ah;
  	struct ib_uobject	   *uobj;
  	int			    ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_ah_idr, cmd.ah_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  	ah = uobj->object;
  
  	ret = ib_destroy_ah(ah);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	put_uobj(uobj);
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_attach_mcast(struct ib_uverbs_file *file,
  			       const char __user *buf, int in_len,
  			       int out_len)
  {
  	struct ib_uverbs_attach_mcast cmd;
  	struct ib_qp                 *qp;
  	struct ib_uqp_object         *obj;
  	struct ib_uverbs_mcast_entry *mcast;
  	int                           ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	qp = idr_write_qp(cmd.qp_handle, file->ucontext);
  	if (!qp)
  		return -EINVAL;
  
  	obj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
  
  	list_for_each_entry(mcast, &obj->mcast_list, list)
  		if (cmd.mlid == mcast->lid &&
  		    !memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
  			ret = 0;
  			goto out_put;
  		}
  
  	mcast = kmalloc(sizeof *mcast, GFP_KERNEL);
  	if (!mcast) {
  		ret = -ENOMEM;
  		goto out_put;
  	}
  
  	mcast->lid = cmd.mlid;
  	memcpy(mcast->gid.raw, cmd.gid, sizeof mcast->gid.raw);
  
  	ret = ib_attach_mcast(qp, &mcast->gid, cmd.mlid);
  	if (!ret)
  		list_add_tail(&mcast->list, &obj->mcast_list);
  	else
  		kfree(mcast);
  
  out_put:
  	put_qp_write(qp);
  
  	return ret ? ret : in_len;
  }
  
  ssize_t ib_uverbs_detach_mcast(struct ib_uverbs_file *file,
  			       const char __user *buf, int in_len,
  			       int out_len)
  {
  	struct ib_uverbs_detach_mcast cmd;
  	struct ib_uqp_object         *obj;
  	struct ib_qp                 *qp;
  	struct ib_uverbs_mcast_entry *mcast;
  	int                           ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	qp = idr_write_qp(cmd.qp_handle, file->ucontext);
  	if (!qp)
  		return -EINVAL;
  
  	ret = ib_detach_mcast(qp, (union ib_gid *) cmd.gid, cmd.mlid);
  	if (ret)
  		goto out_put;
  
  	obj = container_of(qp->uobject, struct ib_uqp_object, uevent.uobject);
  
  	list_for_each_entry(mcast, &obj->mcast_list, list)
  		if (cmd.mlid == mcast->lid &&
  		    !memcmp(cmd.gid, mcast->gid.raw, sizeof mcast->gid.raw)) {
  			list_del(&mcast->list);
  			kfree(mcast);
  			break;
  		}
  
  out_put:
  	put_qp_write(qp);
  
  	return ret ? ret : in_len;
  }
  
  static int __uverbs_create_xsrq(struct ib_uverbs_file *file,
  				struct ib_uverbs_create_xsrq *cmd,
  				struct ib_udata *udata)
  {
  	struct ib_uverbs_create_srq_resp resp;
  	struct ib_usrq_object           *obj;
  	struct ib_pd                    *pd;
  	struct ib_srq                   *srq;
  	struct ib_uobject               *uninitialized_var(xrcd_uobj);
  	struct ib_srq_init_attr          attr;
  	int ret;
  
  	obj = kmalloc(sizeof *obj, GFP_KERNEL);
  	if (!obj)
  		return -ENOMEM;
  
  	init_uobj(&obj->uevent.uobject, cmd->user_handle, file->ucontext, &srq_lock_class);
  	down_write(&obj->uevent.uobject.mutex);
  
  	if (cmd->srq_type == IB_SRQT_XRC) {
  		attr.ext.xrc.xrcd  = idr_read_xrcd(cmd->xrcd_handle, file->ucontext, &xrcd_uobj);
  		if (!attr.ext.xrc.xrcd) {
  			ret = -EINVAL;
  			goto err;
  		}
  
  		obj->uxrcd = container_of(xrcd_uobj, struct ib_uxrcd_object, uobject);
  		atomic_inc(&obj->uxrcd->refcnt);
  
  		attr.ext.xrc.cq  = idr_read_cq(cmd->cq_handle, file->ucontext, 0);
  		if (!attr.ext.xrc.cq) {
  			ret = -EINVAL;
  			goto err_put_xrcd;
  		}
  	}
  
  	pd  = idr_read_pd(cmd->pd_handle, file->ucontext);
  	if (!pd) {
  		ret = -EINVAL;
  		goto err_put_cq;
  	}
  
  	attr.event_handler  = ib_uverbs_srq_event_handler;
  	attr.srq_context    = file;
  	attr.srq_type       = cmd->srq_type;
  	attr.attr.max_wr    = cmd->max_wr;
  	attr.attr.max_sge   = cmd->max_sge;
  	attr.attr.srq_limit = cmd->srq_limit;
  
  	obj->uevent.events_reported = 0;
  	INIT_LIST_HEAD(&obj->uevent.event_list);
  
  	srq = pd->device->create_srq(pd, &attr, udata);
  	if (IS_ERR(srq)) {
  		ret = PTR_ERR(srq);
  		goto err_put;
  	}
  
  	srq->device        = pd->device;
  	srq->pd            = pd;
  	srq->srq_type	   = cmd->srq_type;
  	srq->uobject       = &obj->uevent.uobject;
  	srq->event_handler = attr.event_handler;
  	srq->srq_context   = attr.srq_context;
  
  	if (cmd->srq_type == IB_SRQT_XRC) {
  		srq->ext.xrc.cq   = attr.ext.xrc.cq;
  		srq->ext.xrc.xrcd = attr.ext.xrc.xrcd;
  		atomic_inc(&attr.ext.xrc.cq->usecnt);
  		atomic_inc(&attr.ext.xrc.xrcd->usecnt);
  	}
  
  	atomic_inc(&pd->usecnt);
  	atomic_set(&srq->usecnt, 0);
  
  	obj->uevent.uobject.object = srq;
  	ret = idr_add_uobj(&ib_uverbs_srq_idr, &obj->uevent.uobject);
  	if (ret)
  		goto err_destroy;
  
  	memset(&resp, 0, sizeof resp);
  	resp.srq_handle = obj->uevent.uobject.id;
  	resp.max_wr     = attr.attr.max_wr;
  	resp.max_sge    = attr.attr.max_sge;
  	if (cmd->srq_type == IB_SRQT_XRC)
  		resp.srqn = srq->ext.xrc.srq_num;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd->response,
  			 &resp, sizeof resp)) {
  		ret = -EFAULT;
  		goto err_copy;
  	}
  
  	if (cmd->srq_type == IB_SRQT_XRC) {
  		put_uobj_read(xrcd_uobj);
  		put_cq_read(attr.ext.xrc.cq);
  	}
  	put_pd_read(pd);
  
  	mutex_lock(&file->mutex);
  	list_add_tail(&obj->uevent.uobject.list, &file->ucontext->srq_list);
  	mutex_unlock(&file->mutex);
  
  	obj->uevent.uobject.live = 1;
  
  	up_write(&obj->uevent.uobject.mutex);
  
  	return 0;
  
  err_copy:
  	idr_remove_uobj(&ib_uverbs_srq_idr, &obj->uevent.uobject);
  
  err_destroy:
  	ib_destroy_srq(srq);
  
  err_put:
  	put_pd_read(pd);
  
  err_put_cq:
  	if (cmd->srq_type == IB_SRQT_XRC)
  		put_cq_read(attr.ext.xrc.cq);
  
  err_put_xrcd:
  	if (cmd->srq_type == IB_SRQT_XRC) {
  		atomic_dec(&obj->uxrcd->refcnt);
  		put_uobj_read(xrcd_uobj);
  	}
  
  err:
  	put_uobj_write(&obj->uevent.uobject);
  	return ret;
  }
  
  ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len,
  			     int out_len)
  {
  	struct ib_uverbs_create_srq      cmd;
  	struct ib_uverbs_create_xsrq     xcmd;
  	struct ib_uverbs_create_srq_resp resp;
  	struct ib_udata                  udata;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	xcmd.response	 = cmd.response;
  	xcmd.user_handle = cmd.user_handle;
  	xcmd.srq_type	 = IB_SRQT_BASIC;
  	xcmd.pd_handle	 = cmd.pd_handle;
  	xcmd.max_wr	 = cmd.max_wr;
  	xcmd.max_sge	 = cmd.max_sge;
  	xcmd.srq_limit	 = cmd.srq_limit;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	ret = __uverbs_create_xsrq(file, &xcmd, &udata);
  	if (ret)
  		return ret;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_create_xsrq(struct ib_uverbs_file *file,
  			      const char __user *buf, int in_len, int out_len)
  {
  	struct ib_uverbs_create_xsrq     cmd;
  	struct ib_uverbs_create_srq_resp resp;
  	struct ib_udata                  udata;
  	int ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd,
  		   (unsigned long) cmd.response + sizeof resp,
  		   in_len - sizeof cmd, out_len - sizeof resp);
  
  	ret = __uverbs_create_xsrq(file, &cmd, &udata);
  	if (ret)
  		return ret;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_modify_srq(struct ib_uverbs_file *file,
  			     const char __user *buf, int in_len,
  			     int out_len)
  {
  	struct ib_uverbs_modify_srq cmd;
  	struct ib_udata             udata;
  	struct ib_srq              *srq;
  	struct ib_srq_attr          attr;
  	int                         ret;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	INIT_UDATA(&udata, buf + sizeof cmd, NULL, in_len - sizeof cmd,
  		   out_len);
  
  	srq = idr_read_srq(cmd.srq_handle, file->ucontext);
  	if (!srq)
  		return -EINVAL;
  
  	attr.max_wr    = cmd.max_wr;
  	attr.srq_limit = cmd.srq_limit;
  
  	ret = srq->device->modify_srq(srq, &attr, cmd.attr_mask, &udata);
  
  	put_srq_read(srq);
  
  	return ret ? ret : in_len;
  }
  
  ssize_t ib_uverbs_query_srq(struct ib_uverbs_file *file,
  			    const char __user *buf,
  			    int in_len, int out_len)
  {
  	struct ib_uverbs_query_srq      cmd;
  	struct ib_uverbs_query_srq_resp resp;
  	struct ib_srq_attr              attr;
  	struct ib_srq                   *srq;
  	int                             ret;
  
  	if (out_len < sizeof resp)
  		return -ENOSPC;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	srq = idr_read_srq(cmd.srq_handle, file->ucontext);
  	if (!srq)
  		return -EINVAL;
  
  	ret = ib_query_srq(srq, &attr);
  
  	put_srq_read(srq);
  
  	if (ret)
  		return ret;
  
  	memset(&resp, 0, sizeof resp);
  
  	resp.max_wr    = attr.max_wr;
  	resp.max_sge   = attr.max_sge;
  	resp.srq_limit = attr.srq_limit;
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		return -EFAULT;
  
  	return in_len;
  }
  
  ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file,
  			      const char __user *buf, int in_len,
  			      int out_len)
  {
  	struct ib_uverbs_destroy_srq      cmd;
  	struct ib_uverbs_destroy_srq_resp resp;
  	struct ib_uobject		 *uobj;
  	struct ib_srq               	 *srq;
  	struct ib_uevent_object        	 *obj;
  	int                         	  ret = -EINVAL;
  
  	if (copy_from_user(&cmd, buf, sizeof cmd))
  		return -EFAULT;
  
  	uobj = idr_write_uobj(&ib_uverbs_srq_idr, cmd.srq_handle, file->ucontext);
  	if (!uobj)
  		return -EINVAL;
  	srq = uobj->object;
  	obj = container_of(uobj, struct ib_uevent_object, uobject);
  
  	ret = ib_destroy_srq(srq);
  	if (!ret)
  		uobj->live = 0;
  
  	put_uobj_write(uobj);
  
  	if (ret)
  		return ret;
  
  	idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
  
  	mutex_lock(&file->mutex);
  	list_del(&uobj->list);
  	mutex_unlock(&file->mutex);
  
  	ib_uverbs_release_uevent(file, obj);
  
  	memset(&resp, 0, sizeof resp);
  	resp.events_reported = obj->events_reported;
  
  	put_uobj(uobj);
  
  	if (copy_to_user((void __user *) (unsigned long) cmd.response,
  			 &resp, sizeof resp))
  		ret = -EFAULT;
  
  	return ret ? ret : in_len;
  }
  