static void krping_free_buffers(struct krping_cb *cb)
{
	DEBUG_LOG(PFX "krping_free_buffers called on cb %p\n", cb);
	
#if 0
	dma_unmap_single(cb->pd->device->dma_device,
			 pci_unmap_addr(cb, recv_mapping),
			 sizeof(cb->recv_buf), DMA_BIDIRECTIONAL);
	dma_unmap_single(cb->pd->device->dma_device,
			 pci_unmap_addr(cb, send_mapping),
			 sizeof(cb->send_buf), DMA_BIDIRECTIONAL);
	dma_unmap_single(cb->pd->device->dma_device,
			 pci_unmap_addr(cb, rdma_mapping),
			 cb->size, DMA_BIDIRECTIONAL);
#endif
	contigfree(cb->rdma_buf, cb->size, M_DEVBUF);
	if (!cb->server || cb->wlat || cb->rlat || cb->bw) {
#if 0
		dma_unmap_single(cb->pd->device->dma_device,
			 pci_unmap_addr(cb, start_mapping),
			 cb->size, DMA_BIDIRECTIONAL);
#endif
		contigfree(cb->start_buf, cb->size, M_DEVBUF);
	}
	if (cb->use_dmamr)
		ib_dereg_mr(cb->dma_mr);
	else {
		ib_dereg_mr(cb->send_mr);
		ib_dereg_mr(cb->recv_mr);
		ib_dereg_mr(cb->rdma_mr);
		if (!cb->server)
			ib_dereg_mr(cb->start_mr);
	}
}

static int
__frwr_reset_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r)
{
	struct rpcrdma_frmr *f = &r->frmr;
	int rc;

	rc = ib_dereg_mr(f->fr_mr);
	if (rc) {
		pr_warn("rpcrdma: ib_dereg_mr status %d, frwr %p orphaned\n",
			rc, r);
		return rc;
	}

	f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG,
			       ia->ri_max_frmr_depth);
	if (IS_ERR(f->fr_mr)) {
		pr_warn("rpcrdma: ib_alloc_mr status %ld, frwr %p orphaned\n",
			PTR_ERR(f->fr_mr), r);
		return PTR_ERR(f->fr_mr);
	}

	dprintk("RPC:       %s: recovered FRMR %p\n", __func__, f);
	f->fr_state = FRMR_IS_INVALID;
	return 0;
}

/*
 * rpcrdma_ep_destroy
 *
 * Disconnect and destroy endpoint. After this, the only
 * valid operations on the ep are to free it (if dynamically
 * allocated) or re-create it.
 */
void
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
	int rc;

	dprintk("RPC:       %s: entering, connected is %d\n",
		__func__, ep->rep_connected);

	cancel_delayed_work_sync(&ep->rep_connect_worker);

	if (ia->ri_id->qp) {
		rpcrdma_ep_disconnect(ep, ia);
		rdma_destroy_qp(ia->ri_id);
		ia->ri_id->qp = NULL;
	}

	ib_free_cq(ep->rep_attr.recv_cq);
	ib_free_cq(ep->rep_attr.send_cq);

	if (ia->ri_dma_mr) {
		rc = ib_dereg_mr(ia->ri_dma_mr);
		dprintk("RPC:       %s: ib_dereg_mr returned %i\n",
			__func__, rc);
	}
}

static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt)
{
	struct ib_mr *mr;
	struct scatterlist *sg;
	struct svc_rdma_fastreg_mr *frmr;
	u32 num_sg;

	frmr = kmalloc(sizeof(*frmr), GFP_KERNEL);
	if (!frmr)
		goto err;

	num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len);
	mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg);
	if (IS_ERR(mr))
		goto err_free_frmr;

	sg = kcalloc(RPCSVC_MAXPAGES, sizeof(*sg), GFP_KERNEL);
	if (!sg)
		goto err_free_mr;

	sg_init_table(sg, RPCSVC_MAXPAGES);

	frmr->mr = mr;
	frmr->sg = sg;
	INIT_LIST_HEAD(&frmr->frmr_list);
	return frmr;

 err_free_mr:
	ib_dereg_mr(mr);
 err_free_frmr:
	kfree(frmr);
 err:
	return ERR_PTR(-ENOMEM);
}

static int
__frwr_mr_reset(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr)
{
	struct rpcrdma_frwr *frwr = &mr->frwr;
	int rc;

	rc = ib_dereg_mr(frwr->fr_mr);
	if (rc) {
		pr_warn("rpcrdma: ib_dereg_mr status %d, frwr %p orphaned\n",
			rc, mr);
		return rc;
	}

	frwr->fr_mr = ib_alloc_mr(ia->ri_pd, ia->ri_mrtype,
				  ia->ri_max_frwr_depth);
	if (IS_ERR(frwr->fr_mr)) {
		pr_warn("rpcrdma: ib_alloc_mr status %ld, frwr %p orphaned\n",
			PTR_ERR(frwr->fr_mr), mr);
		return PTR_ERR(frwr->fr_mr);
	}

	dprintk("RPC:       %s: recovered FRWR %p\n", __func__, frwr);
	frwr->fr_state = FRWR_IS_INVALID;
	return 0;
}

static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt)
{
	struct ib_mr *mr;
	struct ib_fast_reg_page_list *pl;
	struct svc_rdma_fastreg_mr *frmr;

	frmr = kmalloc(sizeof(*frmr), GFP_KERNEL);
	if (!frmr)
		goto err;

	mr = ib_alloc_fast_reg_mr(xprt->sc_pd, RPCSVC_MAXPAGES);
	if (IS_ERR(mr))
		goto err_free_frmr;

	pl = ib_alloc_fast_reg_page_list(xprt->sc_cm_id->device,
					 RPCSVC_MAXPAGES);
	if (IS_ERR(pl))
		goto err_free_mr;

	frmr->mr = mr;
	frmr->page_list = pl;
	INIT_LIST_HEAD(&frmr->frmr_list);
	return frmr;

 err_free_mr:
	ib_dereg_mr(mr);
 err_free_frmr:
	kfree(frmr);
 err:
	return ERR_PTR(-ENOMEM);
}

static int
frwr_op_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r)
{
	unsigned int depth = ia->ri_max_frmr_depth;
	struct rpcrdma_frmr *f = &r->frmr;
	int rc;

	f->fr_mr = ib_alloc_mr(ia->ri_pd, IB_MR_TYPE_MEM_REG, depth);
	if (IS_ERR(f->fr_mr))
		goto out_mr_err;

	r->mw_sg = kcalloc(depth, sizeof(*r->mw_sg), GFP_KERNEL);
	if (!r->mw_sg)
		goto out_list_err;

	sg_init_table(r->mw_sg, depth);
	init_completion(&f->fr_linv_done);
	return 0;

out_mr_err:
	rc = PTR_ERR(f->fr_mr);
	dprintk("RPC:       %s: ib_alloc_mr status %i\n",
		__func__, rc);
	return rc;

out_list_err:
	rc = -ENOMEM;
	dprintk("RPC:       %s: sg allocation failure\n",
		__func__);
	ib_dereg_mr(f->fr_mr);
	return rc;
}

static void ib_sock_mem_fini_common(struct IB_SOCK *sock)
{
	if (sock->is_mem.ism_mr)
		ib_dereg_mr(sock->is_mem.ism_mr);

	if (sock->is_mem.ism_pd)
		ib_dealloc_pd(sock->is_mem.ism_pd);
}

/**
 * iser_create_device_ib_res - creates Protection Domain (PD), Completion
 * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
 * the adapator.
 *
 * returns 0 on success, -1 on failure
 */
static int iser_create_device_ib_res(struct iser_device *device)
{
	device->pd = ib_alloc_pd(device->ib_device);
	if (IS_ERR(device->pd))
		goto pd_err;

	device->rx_cq = ib_create_cq(device->ib_device,
				  iser_cq_callback,
				  iser_cq_event_callback,
				  (void *)device,
				  ISER_MAX_RX_CQ_LEN, 0);
	if (IS_ERR(device->rx_cq))
		goto rx_cq_err;

	device->tx_cq = ib_create_cq(device->ib_device,
				  NULL, iser_cq_event_callback,
				  (void *)device,
				  ISER_MAX_TX_CQ_LEN, 0);

	if (IS_ERR(device->tx_cq))
		goto tx_cq_err;

	if (ib_req_notify_cq(device->rx_cq, IB_CQ_NEXT_COMP))
		goto cq_arm_err;

	tasklet_init(&device->cq_tasklet,
		     iser_cq_tasklet_fn,
		     (unsigned long)device);

	device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
				   IB_ACCESS_REMOTE_WRITE |
				   IB_ACCESS_REMOTE_READ);
	if (IS_ERR(device->mr))
		goto dma_mr_err;

	INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
				iser_event_handler);
	if (ib_register_event_handler(&device->event_handler))
		goto handler_err;

	return 0;

handler_err:
	ib_dereg_mr(device->mr);
dma_mr_err:
	tasklet_kill(&device->cq_tasklet);
cq_arm_err:
	ib_destroy_cq(device->tx_cq);
tx_cq_err:
	ib_destroy_cq(device->rx_cq);
rx_cq_err:
	ib_dealloc_pd(device->pd);
pd_err:
	iser_err("failed to allocate an IB resource\n");
	return -1;
}

void IBMemBlock::close()
{
    if ( _memoryRegion )
    {
       ib_api_status_t status = ib_dereg_mr( _memoryRegion );
       _memoryRegion = 0;
    }
    _localKey = 0;
    _remoteKey = 0;
}

static int fi_ib_mr_close(struct fid *fid)
{
	int			ret;
	struct fi_ib_mem_desc	*md = (struct fi_ib_mem_desc *) fid;

	print_trace("in\n");

	ret = ib_dereg_mr(md->mr);
	if (ret)
		print_err("ib_dereg_mr returned %d\n", ret);

	return ret;
}

static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt)
{
	struct svc_rdma_fastreg_mr *frmr;

	while (!list_empty(&xprt->sc_frmr_q)) {
		frmr = list_entry(xprt->sc_frmr_q.next,
				  struct svc_rdma_fastreg_mr, frmr_list);
		list_del_init(&frmr->frmr_list);
		ib_dereg_mr(frmr->mr);
		ib_free_fast_reg_page_list(frmr->page_list);
		kfree(frmr);
	}
}

static void
frwr_op_release_mr(struct rpcrdma_mw *r)
{
	int rc;

	/* Ensure MW is not on any rl_registered list */
	if (!list_empty(&r->mw_list))
		list_del(&r->mw_list);

	rc = ib_dereg_mr(r->frmr.fr_mr);
	if (rc)
		pr_err("rpcrdma: final ib_dereg_mr for %p returned %i\n",
		       r, rc);
	kfree(r->mw_sg);
	kfree(r);
}

static void isert_device_release(struct isert_device *isert_dev)
{
	int err, i;

	TRACE_ENTRY();

	lockdep_assert_held(&dev_list_mutex);

	isert_dev_list_remove(isert_dev); /* remove from global list */

	for (i = 0; i < isert_dev->num_cqs; ++i) {
		struct isert_cq *cq_desc = &isert_dev->cq_desc[i];

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 22)
		/*
		 * cancel_work_sync() was introduced in 2.6.22. We can
		 * only wait until all scheduled work is done.
		 */
		flush_workqueue(cq_desc->cq_workqueue);
#else
		cancel_work_sync(&cq_desc->cq_comp_work);
#endif

		err = ib_destroy_cq(cq_desc->cq);
		if (unlikely(err))
			pr_err("Failed to destroy cq, err:%d\n", err);

		destroy_workqueue(cq_desc->cq_workqueue);
	}

	err = ib_dereg_mr(isert_dev->mr);
	if (unlikely(err))
		pr_err("Failed to destroy mr, err:%d\n", err);
	err = ib_dealloc_pd(isert_dev->pd);
	if (unlikely(err))
		pr_err("Failed to destroy pd, err:%d\n", err);

	vfree(isert_dev->cq_desc);
	isert_dev->cq_desc = NULL;

	kfree(isert_dev->cq_qps);
	isert_dev->cq_qps = NULL;

	kfree(isert_dev);

	TRACE_EXIT();
}

static void verbs_remove_device (struct ib_device *dev)
{
	printk (KERN_INFO "IB remove device called. Name = %s\n", dev->name);

	if (ah)
		ib_destroy_ah (ah);
	if (qp)
		ib_destroy_qp (qp);
	if (send_cq)
		ib_destroy_cq (send_cq);
	if (recv_cq)
		ib_destroy_cq (recv_cq);
	if (mr)
		ib_dereg_mr (mr);
	if (pd)
		ib_dealloc_pd (pd);
}

/**
 * ib_dealloc_pd - Deallocates a protection domain.
 * @pd: The protection domain to deallocate.
 *
 * It is an error to call this function while any resources in the pd still
 * exist.  The caller is responsible to synchronously destroy them and
 * guarantee no new allocations will happen.
 */
void ib_dealloc_pd(struct ib_pd *pd)
{
	int ret;

	if (pd->local_mr) {
		ret = ib_dereg_mr(pd->local_mr);
		WARN_ON(ret);
		pd->local_mr = NULL;
	}

	/* uverbs manipulates usecnt with proper locking, while the kabi
	   requires the caller to guarantee we can't race here. */
	WARN_ON(atomic_read(&pd->usecnt));

	/* Making delalloc_pd a void return is a WIP, no driver should return
	   an error here. */
	ret = pd->device->dealloc_pd(pd);
	WARN_ONCE(ret, "Infiniband HW driver failed dealloc_pd");
}

/*
 * Clean up/close an IA.
 *   o if event handles and PD have been initialized, free them.
 *   o close the IA
 */
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
    int rc;

    dprintk("RPC:       %s: entering\n", __func__);
    if (ia->ri_bind_mem != NULL) {
        rc = ib_dereg_mr(ia->ri_bind_mem);
        dprintk("RPC:       %s: ib_dereg_mr returned %i\n",
            __func__, rc);
    }
    if (ia->ri_id != NULL && !IS_ERR(ia->ri_id) && ia->ri_id->qp)
        rdma_destroy_qp(ia->ri_id);
    if (ia->ri_pd != NULL && !IS_ERR(ia->ri_pd)) {
        rc = ib_dealloc_pd(ia->ri_pd);
        dprintk("RPC:       %s: ib_dealloc_pd returned %i\n",
            __func__, rc);
    }
    if (ia->ri_id != NULL && !IS_ERR(ia->ri_id))
        rdma_destroy_id(ia->ri_id);
}

static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
{
	if (!rdma)
		return;

	if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
		ib_dereg_mr(rdma->dma_mr);

	if (rdma->qp && !IS_ERR(rdma->qp))
		ib_destroy_qp(rdma->qp);

	if (rdma->pd && !IS_ERR(rdma->pd))
		ib_dealloc_pd(rdma->pd);

	if (rdma->cq && !IS_ERR(rdma->cq))
		ib_destroy_cq(rdma->cq);

	if (rdma->cm_id && !IS_ERR(rdma->cm_id))
		rdma_destroy_id(rdma->cm_id);

	kfree(rdma);
}

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_umem_object    *memobj;
	int                       ret = -EINVAL;

	if (copy_from_user(&cmd, buf, sizeof cmd))
		return -EFAULT;

	mutex_lock(&ib_uverbs_idr_mutex);

	mr = idr_find(&ib_uverbs_mr_idr, cmd.mr_handle);
	if (!mr || mr->uobject->context != file->ucontext)
		goto out;

	memobj = container_of(mr->uobject, struct ib_umem_object, uobject);

	ret = ib_dereg_mr(mr);
	if (ret)
		goto out;

	idr_remove(&ib_uverbs_mr_idr, cmd.mr_handle);

	mutex_lock(&file->mutex);
	list_del(&memobj->uobject.list);
	mutex_unlock(&file->mutex);

	ib_umem_release(file->device->ib_dev, &memobj->umem);
	kfree(memobj);

out:
	mutex_unlock(&ib_uverbs_idr_mutex);

	return ret ? ret : in_len;
}

void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
		       unsigned long *unpinned, unsigned int goal)
{
	struct rds_ib_mr *ibmr, *next;
	struct rds_ib_frmr *frmr;
	int ret = 0;
	unsigned int freed = *nfreed;

	/* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
	list_for_each_entry(ibmr, list, unmap_list) {
		if (ibmr->sg_dma_len)
			ret |= rds_ib_post_inv(ibmr);
	}
	if (ret)
		pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);

	/* Now we can destroy the DMA mapping and unpin any pages */
	list_for_each_entry_safe(ibmr, next, list, unmap_list) {
		*unpinned += ibmr->sg_len;
		frmr = &ibmr->u.frmr;
		__rds_ib_teardown_mr(ibmr);
		if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
			/* Don't de-allocate if the MR is not free yet */
			if (frmr->fr_state == FRMR_IS_INUSE)
				continue;

			if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
				rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
			else
				rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
			list_del(&ibmr->unmap_list);
			if (frmr->mr)
				ib_dereg_mr(frmr->mr);
			kfree(ibmr);
			freed++;
		}
	}