ib_isert.c

/*******************************************************************************
 * This file contains iSCSI extentions for RDMA (iSER) Verbs
 *
 * (c) Copyright 2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@linux-iscsi.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 ****************************************************************************/

#include <linux/string.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/iscsi/iscsi_transport.h>
#include <linux/semaphore.h>

#include "isert_proto.h"
#include "ib_isert.h"

#define	ISERT_MAX_CONN		8
#define ISER_MAX_RX_CQ_LEN	(ISERT_QP_MAX_RECV_DTOS * ISERT_MAX_CONN)
#define ISER_MAX_TX_CQ_LEN	(ISERT_QP_MAX_REQ_DTOS  * ISERT_MAX_CONN)
#define ISER_MAX_CQ_LEN		(ISER_MAX_RX_CQ_LEN + ISER_MAX_TX_CQ_LEN + \
				 ISERT_MAX_CONN)

static int isert_debug_level;
module_param_named(debug_level, isert_debug_level, int, 0644);
MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:0)");

static DEFINE_MUTEX(device_list_mutex);
static LIST_HEAD(device_list);
static struct workqueue_struct *isert_comp_wq;
static struct workqueue_struct *isert_release_wq;

static void
isert_unmap_cmd(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn);
static int
isert_map_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
	       struct isert_rdma_wr *wr);
static void
isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn);
static int
isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
	       struct isert_rdma_wr *wr);
static int
isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd);
static int
isert_rdma_post_recvl(struct isert_conn *isert_conn);
static int
isert_rdma_accept(struct isert_conn *isert_conn);
struct rdma_cm_id *isert_setup_id(struct isert_np *isert_np);

static void isert_release_work(struct work_struct *work);

static inline bool
isert_prot_cmd(struct isert_conn *conn, struct se_cmd *cmd)
{
	return (conn->pi_support &&
		cmd->prot_op != TARGET_PROT_NORMAL);
}


static void
isert_qp_event_callback(struct ib_event *e, void *context)
{
	struct isert_conn *isert_conn = context;

	isert_err("%s (%d): conn %p\n",
		  ib_event_msg(e->event), e->event, isert_conn);

	switch (e->event) {
	case IB_EVENT_COMM_EST:
		rdma_notify(isert_conn->cm_id, IB_EVENT_COMM_EST);
		break;
	case IB_EVENT_QP_LAST_WQE_REACHED:
		isert_warn("Reached TX IB_EVENT_QP_LAST_WQE_REACHED\n");
		break;
	default:
		break;
	}
}

static struct isert_comp *
isert_comp_get(struct isert_conn *isert_conn)
{
	struct isert_device *device = isert_conn->device;
	struct isert_comp *comp;
	int i, min = 0;

	mutex_lock(&device_list_mutex);
	for (i = 0; i < device->comps_used; i++)
		if (device->comps[i].active_qps <
		    device->comps[min].active_qps)
			min = i;
	comp = &device->comps[min];
	comp->active_qps++;
	mutex_unlock(&device_list_mutex);

	isert_info("conn %p, using comp %p min_index: %d\n",
		   isert_conn, comp, min);

	return comp;
}

static void
isert_comp_put(struct isert_comp *comp)
{
	mutex_lock(&device_list_mutex);
	comp->active_qps--;
	mutex_unlock(&device_list_mutex);
}

static struct ib_qp *
isert_create_qp(struct isert_conn *isert_conn,
		struct isert_comp *comp,
		struct rdma_cm_id *cma_id)
{
	struct isert_device *device = isert_conn->device;
	struct ib_qp_init_attr attr;
	int ret;

	memset(&attr, 0, sizeof(struct ib_qp_init_attr));
	attr.event_handler = isert_qp_event_callback;
	attr.qp_context = isert_conn;
	attr.send_cq = comp->cq;
	attr.recv_cq = comp->cq;
	attr.cap.max_send_wr = ISERT_QP_MAX_REQ_DTOS;
	attr.cap.max_recv_wr = ISERT_QP_MAX_RECV_DTOS + 1;
	attr.cap.max_send_sge = device->ib_device->attrs.max_sge;
	isert_conn->max_sge = min(device->ib_device->attrs.max_sge,
				  device->ib_device->attrs.max_sge_rd);
	attr.cap.max_recv_sge = 1;
	attr.sq_sig_type = IB_SIGNAL_REQ_WR;
	attr.qp_type = IB_QPT_RC;
	if (device->pi_capable)
		attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;

	ret = rdma_create_qp(cma_id, device->pd, &attr);
	if (ret) {
		isert_err("rdma_create_qp failed for cma_id %d\n", ret);
		return ERR_PTR(ret);
	}

	return cma_id->qp;
}

static int
isert_conn_setup_qp(struct isert_conn *isert_conn, struct rdma_cm_id *cma_id)
{
	struct isert_comp *comp;
	int ret;

	comp = isert_comp_get(isert_conn);
	isert_conn->qp = isert_create_qp(isert_conn, comp, cma_id);
	if (IS_ERR(isert_conn->qp)) {
		ret = PTR_ERR(isert_conn->qp);
		goto err;
	}

	return 0;
err:
	isert_comp_put(comp);
	return ret;
}

static void
isert_cq_event_callback(struct ib_event *e, void *context)
{
	isert_dbg("event: %d\n", e->event);
}

static int
isert_alloc_rx_descriptors(struct isert_conn *isert_conn)
{
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	struct iser_rx_desc *rx_desc;
	struct ib_sge *rx_sg;
	u64 dma_addr;
	int i, j;

	isert_conn->rx_descs = kzalloc(ISERT_QP_MAX_RECV_DTOS *
				sizeof(struct iser_rx_desc), GFP_KERNEL);
	if (!isert_conn->rx_descs)
		goto fail;

	rx_desc = isert_conn->rx_descs;

	for (i = 0; i < ISERT_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
		dma_addr = ib_dma_map_single(ib_dev, (void *)rx_desc,
					ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
		if (ib_dma_mapping_error(ib_dev, dma_addr))
			goto dma_map_fail;

		rx_desc->dma_addr = dma_addr;

		rx_sg = &rx_desc->rx_sg;
		rx_sg->addr = rx_desc->dma_addr;
		rx_sg->length = ISER_RX_PAYLOAD_SIZE;
		rx_sg->lkey = device->pd->local_dma_lkey;
	}

	return 0;

dma_map_fail:
	rx_desc = isert_conn->rx_descs;
	for (j = 0; j < i; j++, rx_desc++) {
		ib_dma_unmap_single(ib_dev, rx_desc->dma_addr,
				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
	}
	kfree(isert_conn->rx_descs);
	isert_conn->rx_descs = NULL;
fail:
	isert_err("conn %p failed to allocate rx descriptors\n", isert_conn);

	return -ENOMEM;
}

static void
isert_free_rx_descriptors(struct isert_conn *isert_conn)
{
	struct ib_device *ib_dev = isert_conn->device->ib_device;
	struct iser_rx_desc *rx_desc;
	int i;

	if (!isert_conn->rx_descs)
		return;

	rx_desc = isert_conn->rx_descs;
	for (i = 0; i < ISERT_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
		ib_dma_unmap_single(ib_dev, rx_desc->dma_addr,
				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
	}

	kfree(isert_conn->rx_descs);
	isert_conn->rx_descs = NULL;
}

static void isert_cq_work(struct work_struct *);
static void isert_cq_callback(struct ib_cq *, void *);

static void
isert_free_comps(struct isert_device *device)
{
	int i;

	for (i = 0; i < device->comps_used; i++) {
		struct isert_comp *comp = &device->comps[i];

		if (comp->cq) {
			cancel_work_sync(&comp->work);
			ib_destroy_cq(comp->cq);
		}
	}
	kfree(device->comps);
}

static int
isert_alloc_comps(struct isert_device *device)
{
	int i, max_cqe, ret = 0;

	device->comps_used = min(ISERT_MAX_CQ, min_t(int, num_online_cpus(),
				 device->ib_device->num_comp_vectors));

	isert_info("Using %d CQs, %s supports %d vectors support "
		   "Fast registration %d pi_capable %d\n",
		   device->comps_used, device->ib_device->name,
		   device->ib_device->num_comp_vectors, device->use_fastreg,
		   device->pi_capable);

	device->comps = kcalloc(device->comps_used, sizeof(struct isert_comp),
				GFP_KERNEL);
	if (!device->comps) {
		isert_err("Unable to allocate completion contexts\n");
		return -ENOMEM;
	}

	max_cqe = min(ISER_MAX_CQ_LEN, device->ib_device->attrs.max_cqe);

	for (i = 0; i < device->comps_used; i++) {
		struct ib_cq_init_attr cq_attr = {};
		struct isert_comp *comp = &device->comps[i];

		comp->device = device;
		INIT_WORK(&comp->work, isert_cq_work);
		cq_attr.cqe = max_cqe;
		cq_attr.comp_vector = i;
		comp->cq = ib_create_cq(device->ib_device,
					isert_cq_callback,
					isert_cq_event_callback,
					(void *)comp,
					&cq_attr);
		if (IS_ERR(comp->cq)) {
			isert_err("Unable to allocate cq\n");
			ret = PTR_ERR(comp->cq);
			comp->cq = NULL;
			goto out_cq;
		}

		ret = ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP);
		if (ret)
			goto out_cq;
	}

	return 0;
out_cq:
	isert_free_comps(device);
	return ret;
}

static int
isert_create_device_ib_res(struct isert_device *device)
{
	struct ib_device *ib_dev = device->ib_device;
	int ret;

	isert_dbg("devattr->max_sge: %d\n", ib_dev->attrs.max_sge);
	isert_dbg("devattr->max_sge_rd: %d\n", ib_dev->attrs.max_sge_rd);

	/* asign function handlers */
	if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS &&
	    ib_dev->attrs.device_cap_flags & IB_DEVICE_SIGNATURE_HANDOVER) {
		device->use_fastreg = 1;
		device->reg_rdma_mem = isert_reg_rdma;
		device->unreg_rdma_mem = isert_unreg_rdma;
	} else {
		device->use_fastreg = 0;
		device->reg_rdma_mem = isert_map_rdma;
		device->unreg_rdma_mem = isert_unmap_cmd;
	}

	ret = isert_alloc_comps(device);
	if (ret)
		return ret;

	device->pd = ib_alloc_pd(ib_dev);
	if (IS_ERR(device->pd)) {
		ret = PTR_ERR(device->pd);
		isert_err("failed to allocate pd, device %p, ret=%d\n",
			  device, ret);
		goto out_cq;
	}

	/* Check signature cap */
	device->pi_capable = ib_dev->attrs.device_cap_flags &
			     IB_DEVICE_SIGNATURE_HANDOVER ? true : false;

	return 0;

out_cq:
	isert_free_comps(device);
	return ret;
}

static void
isert_free_device_ib_res(struct isert_device *device)
{
	isert_info("device %p\n", device);

	ib_dealloc_pd(device->pd);
	isert_free_comps(device);
}

static void
isert_device_put(struct isert_device *device)
{
	mutex_lock(&device_list_mutex);
	device->refcount--;
	isert_info("device %p refcount %d\n", device, device->refcount);
	if (!device->refcount) {
		isert_free_device_ib_res(device);
		list_del(&device->dev_node);
		kfree(device);
	}
	mutex_unlock(&device_list_mutex);
}

static struct isert_device *
isert_device_get(struct rdma_cm_id *cma_id)
{
	struct isert_device *device;
	int ret;

	mutex_lock(&device_list_mutex);
	list_for_each_entry(device, &device_list, dev_node) {
		if (device->ib_device->node_guid == cma_id->device->node_guid) {
			device->refcount++;
			isert_info("Found iser device %p refcount %d\n",
				   device, device->refcount);
			mutex_unlock(&device_list_mutex);
			return device;
		}
	}

	device = kzalloc(sizeof(struct isert_device), GFP_KERNEL);
	if (!device) {
		mutex_unlock(&device_list_mutex);
		return ERR_PTR(-ENOMEM);
	}

	INIT_LIST_HEAD(&device->dev_node);

	device->ib_device = cma_id->device;
	ret = isert_create_device_ib_res(device);
	if (ret) {
		kfree(device);
		mutex_unlock(&device_list_mutex);
		return ERR_PTR(ret);
	}

	device->refcount++;
	list_add_tail(&device->dev_node, &device_list);
	isert_info("Created a new iser device %p refcount %d\n",
		   device, device->refcount);
	mutex_unlock(&device_list_mutex);

	return device;
}

static void
isert_conn_free_fastreg_pool(struct isert_conn *isert_conn)
{
	struct fast_reg_descriptor *fr_desc, *tmp;
	int i = 0;

	if (list_empty(&isert_conn->fr_pool))
		return;

	isert_info("Freeing conn %p fastreg pool", isert_conn);

	list_for_each_entry_safe(fr_desc, tmp,
				 &isert_conn->fr_pool, list) {
		list_del(&fr_desc->list);
		ib_dereg_mr(fr_desc->data_mr);
		if (fr_desc->pi_ctx) {
			ib_dereg_mr(fr_desc->pi_ctx->prot_mr);
			ib_dereg_mr(fr_desc->pi_ctx->sig_mr);
			kfree(fr_desc->pi_ctx);
		}
		kfree(fr_desc);
		++i;
	}

	if (i < isert_conn->fr_pool_size)
		isert_warn("Pool still has %d regions registered\n",
			isert_conn->fr_pool_size - i);
}

static int
isert_create_pi_ctx(struct fast_reg_descriptor *desc,
		    struct ib_device *device,
		    struct ib_pd *pd)
{
	struct pi_context *pi_ctx;
	int ret;

	pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
	if (!pi_ctx) {
		isert_err("Failed to allocate pi context\n");
		return -ENOMEM;
	}

	pi_ctx->prot_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
				      ISCSI_ISER_SG_TABLESIZE);
	if (IS_ERR(pi_ctx->prot_mr)) {
		isert_err("Failed to allocate prot frmr err=%ld\n",
			  PTR_ERR(pi_ctx->prot_mr));
		ret = PTR_ERR(pi_ctx->prot_mr);
		goto err_pi_ctx;
	}
	desc->ind |= ISERT_PROT_KEY_VALID;

	pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
	if (IS_ERR(pi_ctx->sig_mr)) {
		isert_err("Failed to allocate signature enabled mr err=%ld\n",
			  PTR_ERR(pi_ctx->sig_mr));
		ret = PTR_ERR(pi_ctx->sig_mr);
		goto err_prot_mr;
	}

	desc->pi_ctx = pi_ctx;
	desc->ind |= ISERT_SIG_KEY_VALID;
	desc->ind &= ~ISERT_PROTECTED;

	return 0;

err_prot_mr:
	ib_dereg_mr(pi_ctx->prot_mr);
err_pi_ctx:
	kfree(pi_ctx);

	return ret;
}

static int
isert_create_fr_desc(struct ib_device *ib_device, struct ib_pd *pd,
		     struct fast_reg_descriptor *fr_desc)
{
	fr_desc->data_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
				       ISCSI_ISER_SG_TABLESIZE);
	if (IS_ERR(fr_desc->data_mr)) {
		isert_err("Failed to allocate data frmr err=%ld\n",
			  PTR_ERR(fr_desc->data_mr));
		return PTR_ERR(fr_desc->data_mr);
	}
	fr_desc->ind |= ISERT_DATA_KEY_VALID;

	isert_dbg("Created fr_desc %p\n", fr_desc);

	return 0;
}

static int
isert_conn_create_fastreg_pool(struct isert_conn *isert_conn)
{
	struct fast_reg_descriptor *fr_desc;
	struct isert_device *device = isert_conn->device;
	struct se_session *se_sess = isert_conn->conn->sess->se_sess;
	struct se_node_acl *se_nacl = se_sess->se_node_acl;
	int i, ret, tag_num;
	/*
	 * Setup the number of FRMRs based upon the number of tags
	 * available to session in iscsi_target_locate_portal().
	 */
	tag_num = max_t(u32, ISCSIT_MIN_TAGS, se_nacl->queue_depth);
	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;

	isert_conn->fr_pool_size = 0;
	for (i = 0; i < tag_num; i++) {
		fr_desc = kzalloc(sizeof(*fr_desc), GFP_KERNEL);
		if (!fr_desc) {
			isert_err("Failed to allocate fast_reg descriptor\n");
			ret = -ENOMEM;
			goto err;
		}

		ret = isert_create_fr_desc(device->ib_device,
					   device->pd, fr_desc);
		if (ret) {
			isert_err("Failed to create fastreg descriptor err=%d\n",
			       ret);
			kfree(fr_desc);
			goto err;
		}

		list_add_tail(&fr_desc->list, &isert_conn->fr_pool);
		isert_conn->fr_pool_size++;
	}

	isert_dbg("Creating conn %p fastreg pool size=%d",
		 isert_conn, isert_conn->fr_pool_size);

	return 0;

err:
	isert_conn_free_fastreg_pool(isert_conn);
	return ret;
}

static void
isert_init_conn(struct isert_conn *isert_conn)
{
	isert_conn->state = ISER_CONN_INIT;
	INIT_LIST_HEAD(&isert_conn->node);
	init_completion(&isert_conn->login_comp);
	init_completion(&isert_conn->login_req_comp);
	init_completion(&isert_conn->wait);
	kref_init(&isert_conn->kref);
	mutex_init(&isert_conn->mutex);
	spin_lock_init(&isert_conn->pool_lock);
	INIT_LIST_HEAD(&isert_conn->fr_pool);
	INIT_WORK(&isert_conn->release_work, isert_release_work);
}

static void
isert_free_login_buf(struct isert_conn *isert_conn)
{
	struct ib_device *ib_dev = isert_conn->device->ib_device;

	ib_dma_unmap_single(ib_dev, isert_conn->login_rsp_dma,
			    ISER_RX_LOGIN_SIZE, DMA_TO_DEVICE);
	ib_dma_unmap_single(ib_dev, isert_conn->login_req_dma,
			    ISCSI_DEF_MAX_RECV_SEG_LEN,
			    DMA_FROM_DEVICE);
	kfree(isert_conn->login_buf);
}

static int
isert_alloc_login_buf(struct isert_conn *isert_conn,
		      struct ib_device *ib_dev)
{
	int ret;

	isert_conn->login_buf = kzalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
					ISER_RX_LOGIN_SIZE, GFP_KERNEL);
	if (!isert_conn->login_buf) {
		isert_err("Unable to allocate isert_conn->login_buf\n");
		return -ENOMEM;
	}

	isert_conn->login_req_buf = isert_conn->login_buf;
	isert_conn->login_rsp_buf = isert_conn->login_buf +
				    ISCSI_DEF_MAX_RECV_SEG_LEN;

	isert_dbg("Set login_buf: %p login_req_buf: %p login_rsp_buf: %p\n",
		 isert_conn->login_buf, isert_conn->login_req_buf,
		 isert_conn->login_rsp_buf);

	isert_conn->login_req_dma = ib_dma_map_single(ib_dev,
				(void *)isert_conn->login_req_buf,
				ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_FROM_DEVICE);

	ret = ib_dma_mapping_error(ib_dev, isert_conn->login_req_dma);
	if (ret) {
		isert_err("login_req_dma mapping error: %d\n", ret);
		isert_conn->login_req_dma = 0;
		goto out_login_buf;
	}

	isert_conn->login_rsp_dma = ib_dma_map_single(ib_dev,
					(void *)isert_conn->login_rsp_buf,
					ISER_RX_LOGIN_SIZE, DMA_TO_DEVICE);

	ret = ib_dma_mapping_error(ib_dev, isert_conn->login_rsp_dma);
	if (ret) {
		isert_err("login_rsp_dma mapping error: %d\n", ret);
		isert_conn->login_rsp_dma = 0;
		goto out_req_dma_map;
	}

	return 0;

out_req_dma_map:
	ib_dma_unmap_single(ib_dev, isert_conn->login_req_dma,
			    ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_FROM_DEVICE);
out_login_buf:
	kfree(isert_conn->login_buf);
	return ret;
}

static int
isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
{
	struct isert_np *isert_np = cma_id->context;
	struct iscsi_np *np = isert_np->np;
	struct isert_conn *isert_conn;
	struct isert_device *device;
	int ret = 0;

	spin_lock_bh(&np->np_thread_lock);
	if (!np->enabled) {
		spin_unlock_bh(&np->np_thread_lock);
		isert_dbg("iscsi_np is not enabled, reject connect request\n");
		return rdma_reject(cma_id, NULL, 0);
	}
	spin_unlock_bh(&np->np_thread_lock);

	isert_dbg("cma_id: %p, portal: %p\n",
		 cma_id, cma_id->context);

	isert_conn = kzalloc(sizeof(struct isert_conn), GFP_KERNEL);
	if (!isert_conn)
		return -ENOMEM;

	isert_init_conn(isert_conn);
	isert_conn->cm_id = cma_id;

	ret = isert_alloc_login_buf(isert_conn, cma_id->device);
	if (ret)
		goto out;

	device = isert_device_get(cma_id);
	if (IS_ERR(device)) {
		ret = PTR_ERR(device);
		goto out_rsp_dma_map;
	}
	isert_conn->device = device;

	/* Set max inflight RDMA READ requests */
	isert_conn->initiator_depth = min_t(u8,
				event->param.conn.initiator_depth,
				device->ib_device->attrs.max_qp_init_rd_atom);
	isert_dbg("Using initiator_depth: %u\n", isert_conn->initiator_depth);

	ret = isert_conn_setup_qp(isert_conn, cma_id);
	if (ret)
		goto out_conn_dev;

	ret = isert_rdma_post_recvl(isert_conn);
	if (ret)
		goto out_conn_dev;

	ret = isert_rdma_accept(isert_conn);
	if (ret)
		goto out_conn_dev;

	mutex_lock(&isert_np->mutex);
	list_add_tail(&isert_conn->node, &isert_np->accepted);
	mutex_unlock(&isert_np->mutex);

	return 0;

out_conn_dev:
	isert_device_put(device);
out_rsp_dma_map:
	isert_free_login_buf(isert_conn);
out:
	kfree(isert_conn);
	rdma_reject(cma_id, NULL, 0);
	return ret;
}

static void
isert_connect_release(struct isert_conn *isert_conn)
{
	struct isert_device *device = isert_conn->device;

	isert_dbg("conn %p\n", isert_conn);

	BUG_ON(!device);

	if (device->use_fastreg)
		isert_conn_free_fastreg_pool(isert_conn);

	isert_free_rx_descriptors(isert_conn);
	if (isert_conn->cm_id)
		rdma_destroy_id(isert_conn->cm_id);

	if (isert_conn->qp) {
		struct isert_comp *comp = isert_conn->qp->recv_cq->cq_context;

		isert_comp_put(comp);
		ib_destroy_qp(isert_conn->qp);
	}

	if (isert_conn->login_buf)
		isert_free_login_buf(isert_conn);

	isert_device_put(device);

	kfree(isert_conn);
}

static void
isert_connected_handler(struct rdma_cm_id *cma_id)
{
	struct isert_conn *isert_conn = cma_id->qp->qp_context;
	struct isert_np *isert_np = cma_id->context;

	isert_info("conn %p\n", isert_conn);

	mutex_lock(&isert_conn->mutex);
	isert_conn->state = ISER_CONN_UP;
	kref_get(&isert_conn->kref);
	mutex_unlock(&isert_conn->mutex);

	mutex_lock(&isert_np->mutex);
	list_move_tail(&isert_conn->node, &isert_np->pending);
	mutex_unlock(&isert_np->mutex);

	isert_info("np %p: Allow accept_np to continue\n", isert_np);
	up(&isert_np->sem);
}

static void
isert_release_kref(struct kref *kref)
{
	struct isert_conn *isert_conn = container_of(kref,
				struct isert_conn, kref);

	isert_info("conn %p final kref %s/%d\n", isert_conn, current->comm,
		   current->pid);

	isert_connect_release(isert_conn);
}

static void
isert_put_conn(struct isert_conn *isert_conn)
{
	kref_put(&isert_conn->kref, isert_release_kref);
}

/**
 * isert_conn_terminate() - Initiate connection termination
 * @isert_conn: isert connection struct
 *
 * Notes:
 * In case the connection state is FULL_FEATURE, move state
 * to TEMINATING and start teardown sequence (rdma_disconnect).
 * In case the connection state is UP, complete flush as well.
 *
 * This routine must be called with mutex held. Thus it is
 * safe to call multiple times.
 */
static void
isert_conn_terminate(struct isert_conn *isert_conn)
{
	int err;

	switch (isert_conn->state) {
	case ISER_CONN_TERMINATING:
		break;
	case ISER_CONN_UP:
	case ISER_CONN_FULL_FEATURE: /* FALLTHRU */
		isert_info("Terminating conn %p state %d\n",
			   isert_conn, isert_conn->state);
		isert_conn->state = ISER_CONN_TERMINATING;
		err = rdma_disconnect(isert_conn->cm_id);
		if (err)
			isert_warn("Failed rdma_disconnect isert_conn %p\n",
				   isert_conn);
		break;
	default:
		isert_warn("conn %p teminating in state %d\n",
			   isert_conn, isert_conn->state);
	}
}

static int
isert_np_cma_handler(struct isert_np *isert_np,
		     enum rdma_cm_event_type event)
{
	isert_dbg("%s (%d): isert np %p\n",
		  rdma_event_msg(event), event, isert_np);

	switch (event) {
	case RDMA_CM_EVENT_DEVICE_REMOVAL:
		isert_np->cm_id = NULL;
		break;
	case RDMA_CM_EVENT_ADDR_CHANGE:
		isert_np->cm_id = isert_setup_id(isert_np);
		if (IS_ERR(isert_np->cm_id)) {
			isert_err("isert np %p setup id failed: %ld\n",
				  isert_np, PTR_ERR(isert_np->cm_id));
			isert_np->cm_id = NULL;
		}
		break;
	default:
		isert_err("isert np %p Unexpected event %d\n",
			  isert_np, event);
	}

	return -1;
}

static int
isert_disconnected_handler(struct rdma_cm_id *cma_id,
			   enum rdma_cm_event_type event)
{
	struct isert_np *isert_np = cma_id->context;
	struct isert_conn *isert_conn;
	bool terminating = false;

	if (isert_np->cm_id == cma_id)
		return isert_np_cma_handler(cma_id->context, event);

	isert_conn = cma_id->qp->qp_context;

	mutex_lock(&isert_conn->mutex);
	terminating = (isert_conn->state == ISER_CONN_TERMINATING);
	isert_conn_terminate(isert_conn);
	mutex_unlock(&isert_conn->mutex);

	isert_info("conn %p completing wait\n", isert_conn);
	complete(&isert_conn->wait);

	if (terminating)
		goto out;

	mutex_lock(&isert_np->mutex);
	if (!list_empty(&isert_conn->node)) {
		list_del_init(&isert_conn->node);
		isert_put_conn(isert_conn);
		queue_work(isert_release_wq, &isert_conn->release_work);
	}
	mutex_unlock(&isert_np->mutex);

out:
	return 0;
}

static int
isert_connect_error(struct rdma_cm_id *cma_id)
{
	struct isert_conn *isert_conn = cma_id->qp->qp_context;

	list_del_init(&isert_conn->node);
	isert_conn->cm_id = NULL;
	isert_put_conn(isert_conn);

	return -1;
}

static int
isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
{
	int ret = 0;

	isert_info("%s (%d): status %d id %p np %p\n",
		   rdma_event_msg(event->event), event->event,
		   event->status, cma_id, cma_id->context);

	switch (event->event) {
	case RDMA_CM_EVENT_CONNECT_REQUEST:
		ret = isert_connect_request(cma_id, event);
		if (ret)
			isert_err("failed handle connect request %d\n", ret);
		break;
	case RDMA_CM_EVENT_ESTABLISHED:
		isert_connected_handler(cma_id);
		break;
	case RDMA_CM_EVENT_ADDR_CHANGE:    /* FALLTHRU */
	case RDMA_CM_EVENT_DISCONNECTED:   /* FALLTHRU */
	case RDMA_CM_EVENT_DEVICE_REMOVAL: /* FALLTHRU */
	case RDMA_CM_EVENT_TIMEWAIT_EXIT:  /* FALLTHRU */
		ret = isert_disconnected_handler(cma_id, event->event);
		break;
	case RDMA_CM_EVENT_REJECTED:       /* FALLTHRU */
	case RDMA_CM_EVENT_UNREACHABLE:    /* FALLTHRU */
	case RDMA_CM_EVENT_CONNECT_ERROR:
		ret = isert_connect_error(cma_id);
		break;
	default:
		isert_err("Unhandled RDMA CMA event: %d\n", event->event);
		break;
	}

	return ret;
}

static int
isert_post_recvm(struct isert_conn *isert_conn, u32 count)
{
	struct ib_recv_wr *rx_wr, *rx_wr_failed;
	int i, ret;
	struct iser_rx_desc *rx_desc;

	for (rx_wr = isert_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
		rx_desc = &isert_conn->rx_descs[i];
		rx_wr->wr_id = (uintptr_t)rx_desc;
		rx_wr->sg_list = &rx_desc->rx_sg;
		rx_wr->num_sge = 1;
		rx_wr->next = rx_wr + 1;
	}
	rx_wr--;
	rx_wr->next = NULL; /* mark end of work requests list */

	isert_conn->post_recv_buf_count += count;
	ret = ib_post_recv(isert_conn->qp, isert_conn->rx_wr,
			   &rx_wr_failed);
	if (ret) {
		isert_err("ib_post_recv() failed with ret: %d\n", ret);
		isert_conn->post_recv_buf_count -= count;
	}

	return ret;
}

static int
isert_post_recv(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc)
{
	struct ib_recv_wr *rx_wr_failed, rx_wr;
	int ret;

	rx_wr.wr_id = (uintptr_t)rx_desc;
	rx_wr.sg_list = &rx_desc->rx_sg;
	rx_wr.num_sge = 1;
	rx_wr.next = NULL;

	isert_conn->post_recv_buf_count++;
	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_failed);
	if (ret) {
		isert_err("ib_post_recv() failed with ret: %d\n", ret);
		isert_conn->post_recv_buf_count--;
	}

	return ret;
}

static int
isert_post_send(struct isert_conn *isert_conn, struct iser_tx_desc *tx_desc)
{
	struct ib_device *ib_dev = isert_conn->cm_id->device;
	struct ib_send_wr send_wr, *send_wr_failed;
	int ret;

	ib_dma_sync_single_for_device(ib_dev, tx_desc->dma_addr,
				      ISER_HEADERS_LEN, DMA_TO_DEVICE);

	send_wr.next	= NULL;
	send_wr.wr_id	= (uintptr_t)tx_desc;
	send_wr.sg_list	= tx_desc->tx_sg;
	send_wr.num_sge	= tx_desc->num_sge;
	send_wr.opcode	= IB_WR_SEND;
	send_wr.send_flags = IB_SEND_SIGNALED;

	ret = ib_post_send(isert_conn->qp, &send_wr, &send_wr_failed);
	if (ret)
		isert_err("ib_post_send() failed, ret: %d\n", ret);

	return ret;
}

static void
isert_create_send_desc(struct isert_conn *isert_conn,
		       struct isert_cmd *isert_cmd,
		       struct iser_tx_desc *tx_desc)
{
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;

	ib_dma_sync_single_for_cpu(ib_dev, tx_desc->dma_addr,
				   ISER_HEADERS_LEN, DMA_TO_DEVICE);

	memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
	tx_desc->iser_header.flags = ISER_VER;

	tx_desc->num_sge = 1;
	tx_desc->isert_cmd = isert_cmd;

	if (tx_desc->tx_sg[0].lkey != device->pd->local_dma_lkey) {
		tx_desc->tx_sg[0].lkey = device->pd->local_dma_lkey;
		isert_dbg("tx_desc %p lkey mismatch, fixing\n", tx_desc);
	}
}

static int
isert_init_tx_hdrs(struct isert_conn *isert_conn,
		   struct iser_tx_desc *tx_desc)
{
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	u64 dma_addr;

	dma_addr = ib_dma_map_single(ib_dev, (void *)tx_desc,
			ISER_HEADERS_LEN, DMA_TO_DEVICE);
	if (ib_dma_mapping_error(ib_dev, dma_addr)) {
		isert_err("ib_dma_mapping_error() failed\n");
		return -ENOMEM;
	}

	tx_desc->dma_addr = dma_addr;
	tx_desc->tx_sg[0].addr	= tx_desc->dma_addr;
	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
	tx_desc->tx_sg[0].lkey = device->pd->local_dma_lkey;

	isert_dbg("Setup tx_sg[0].addr: 0x%llx length: %u lkey: 0x%x\n",
		  tx_desc->tx_sg[0].addr, tx_desc->tx_sg[0].length,
		  tx_desc->tx_sg[0].lkey);

	return 0;
}

static void
isert_init_send_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
		   struct ib_send_wr *send_wr)
{
	struct iser_tx_desc *tx_desc = &isert_cmd->tx_desc;

	isert_cmd->rdma_wr.iser_ib_op = ISER_IB_SEND;
	send_wr->wr_id = (uintptr_t)&isert_cmd->tx_desc;
	send_wr->opcode = IB_WR_SEND;
	send_wr->sg_list = &tx_desc->tx_sg[0];
	send_wr->num_sge = isert_cmd->tx_desc.num_sge;
	send_wr->send_flags = IB_SEND_SIGNALED;
}

static int
isert_rdma_post_recvl(struct isert_conn *isert_conn)
{
	struct ib_recv_wr rx_wr, *rx_wr_fail;
	struct ib_sge sge;
	int ret;

	memset(&sge, 0, sizeof(struct ib_sge));
	sge.addr = isert_conn->login_req_dma;
	sge.length = ISER_RX_LOGIN_SIZE;
	sge.lkey = isert_conn->device->pd->local_dma_lkey;

	isert_dbg("Setup sge: addr: %llx length: %d 0x%08x\n",
		sge.addr, sge.length, sge.lkey);

	memset(&rx_wr, 0, sizeof(struct ib_recv_wr));
	rx_wr.wr_id = (uintptr_t)isert_conn->login_req_buf;
	rx_wr.sg_list = &sge;
	rx_wr.num_sge = 1;

	isert_conn->post_recv_buf_count++;
	ret = ib_post_recv(isert_conn->qp, &rx_wr, &rx_wr_fail);
	if (ret) {
		isert_err("ib_post_recv() failed: %d\n", ret);
		isert_conn->post_recv_buf_count--;
	}

	return ret;
}

static int
isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
		   u32 length)
{
	struct isert_conn *isert_conn = conn->context;
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	struct iser_tx_desc *tx_desc = &isert_conn->login_tx_desc;
	int ret;

	isert_create_send_desc(isert_conn, NULL, tx_desc);

	memcpy(&tx_desc->iscsi_header, &login->rsp[0],
	       sizeof(struct iscsi_hdr));

	isert_init_tx_hdrs(isert_conn, tx_desc);

	if (length > 0) {
		struct ib_sge *tx_dsg = &tx_desc->tx_sg[1];

		ib_dma_sync_single_for_cpu(ib_dev, isert_conn->login_rsp_dma,
					   length, DMA_TO_DEVICE);

		memcpy(isert_conn->login_rsp_buf, login->rsp_buf, length);

		ib_dma_sync_single_for_device(ib_dev, isert_conn->login_rsp_dma,
					      length, DMA_TO_DEVICE);

		tx_dsg->addr	= isert_conn->login_rsp_dma;
		tx_dsg->length	= length;
		tx_dsg->lkey	= isert_conn->device->pd->local_dma_lkey;
		tx_desc->num_sge = 2;
	}
	if (!login->login_failed) {
		if (login->login_complete) {
			if (!conn->sess->sess_ops->SessionType &&
			    isert_conn->device->use_fastreg) {
				ret = isert_conn_create_fastreg_pool(isert_conn);
				if (ret) {
					isert_err("Conn: %p failed to create"
					       " fastreg pool\n", isert_conn);
					return ret;
				}
			}

			ret = isert_alloc_rx_descriptors(isert_conn);
			if (ret)
				return ret;

			ret = isert_post_recvm(isert_conn,
					       ISERT_QP_MAX_RECV_DTOS);
			if (ret)
				return ret;

			/* Now we are in FULL_FEATURE phase */
			mutex_lock(&isert_conn->mutex);
			isert_conn->state = ISER_CONN_FULL_FEATURE;
			mutex_unlock(&isert_conn->mutex);
			goto post_send;
		}

		ret = isert_rdma_post_recvl(isert_conn);
		if (ret)
			return ret;
	}
post_send:
	ret = isert_post_send(isert_conn, tx_desc);
	if (ret)
		return ret;

	return 0;
}

static void
isert_rx_login_req(struct isert_conn *isert_conn)
{
	struct iser_rx_desc *rx_desc = (void *)isert_conn->login_req_buf;
	int rx_buflen = isert_conn->login_req_len;
	struct iscsi_conn *conn = isert_conn->conn;
	struct iscsi_login *login = conn->conn_login;
	int size;

	isert_info("conn %p\n", isert_conn);

	WARN_ON_ONCE(!login);

	if (login->first_request) {
		struct iscsi_login_req *login_req =
			(struct iscsi_login_req *)&rx_desc->iscsi_header;
		/*
		 * Setup the initial iscsi_login values from the leading
		 * login request PDU.
		 */
		login->leading_connection = (!login_req->tsih) ? 1 : 0;
		login->current_stage =
			(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK)
			 >> 2;
		login->version_min	= login_req->min_version;
		login->version_max	= login_req->max_version;
		memcpy(login->isid, login_req->isid, 6);
		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
		login->init_task_tag	= login_req->itt;
		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
		login->cid		= be16_to_cpu(login_req->cid);
		login->tsih		= be16_to_cpu(login_req->tsih);
	}

	memcpy(&login->req[0], (void *)&rx_desc->iscsi_header, ISCSI_HDR_LEN);

	size = min(rx_buflen, MAX_KEY_VALUE_PAIRS);
	isert_dbg("Using login payload size: %d, rx_buflen: %d "
		  "MAX_KEY_VALUE_PAIRS: %d\n", size, rx_buflen,
		  MAX_KEY_VALUE_PAIRS);
	memcpy(login->req_buf, &rx_desc->data[0], size);

	if (login->first_request) {
		complete(&isert_conn->login_comp);
		return;
	}
	schedule_delayed_work(&conn->login_work, 0);
}

static struct iscsi_cmd
*isert_allocate_cmd(struct iscsi_conn *conn, struct iser_rx_desc *rx_desc)
{
	struct isert_conn *isert_conn = conn->context;
	struct isert_cmd *isert_cmd;
	struct iscsi_cmd *cmd;

	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
	if (!cmd) {
		isert_err("Unable to allocate iscsi_cmd + isert_cmd\n");
		return NULL;
	}
	isert_cmd = iscsit_priv_cmd(cmd);
	isert_cmd->conn = isert_conn;
	isert_cmd->iscsi_cmd = cmd;
	isert_cmd->rx_desc = rx_desc;

	return cmd;
}

static int
isert_handle_scsi_cmd(struct isert_conn *isert_conn,
		      struct isert_cmd *isert_cmd, struct iscsi_cmd *cmd,
		      struct iser_rx_desc *rx_desc, unsigned char *buf)
{
	struct iscsi_conn *conn = isert_conn->conn;
	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
	int imm_data, imm_data_len, unsol_data, sg_nents, rc;
	bool dump_payload = false;
	unsigned int data_len;

	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
	if (rc < 0)
		return rc;

	imm_data = cmd->immediate_data;
	imm_data_len = cmd->first_burst_len;
	unsol_data = cmd->unsolicited_data;
	data_len = cmd->se_cmd.data_length;

	if (imm_data && imm_data_len == data_len)
		cmd->se_cmd.se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
	if (rc < 0) {
		return 0;
	} else if (rc > 0) {
		dump_payload = true;
		goto sequence_cmd;
	}

	if (!imm_data)
		return 0;

	if (imm_data_len != data_len) {
		sg_nents = max(1UL, DIV_ROUND_UP(imm_data_len, PAGE_SIZE));
		sg_copy_from_buffer(cmd->se_cmd.t_data_sg, sg_nents,
				    &rx_desc->data[0], imm_data_len);
		isert_dbg("Copy Immediate sg_nents: %u imm_data_len: %d\n",
			  sg_nents, imm_data_len);
	} else {
		sg_init_table(&isert_cmd->sg, 1);
		cmd->se_cmd.t_data_sg = &isert_cmd->sg;
		cmd->se_cmd.t_data_nents = 1;
		sg_set_buf(&isert_cmd->sg, &rx_desc->data[0], imm_data_len);
		isert_dbg("Transfer Immediate imm_data_len: %d\n",
			  imm_data_len);
	}

	cmd->write_data_done += imm_data_len;

	if (cmd->write_data_done == cmd->se_cmd.data_length) {
		spin_lock_bh(&cmd->istate_lock);
		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
		spin_unlock_bh(&cmd->istate_lock);
	}

sequence_cmd:
	rc = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);

	if (!rc && dump_payload == false && unsol_data)
		iscsit_set_unsoliticed_dataout(cmd);
	else if (dump_payload && imm_data)
		target_put_sess_cmd(&cmd->se_cmd);

	return 0;
}

static int
isert_handle_iscsi_dataout(struct isert_conn *isert_conn,
			   struct iser_rx_desc *rx_desc, unsigned char *buf)
{
	struct scatterlist *sg_start;
	struct iscsi_conn *conn = isert_conn->conn;
	struct iscsi_cmd *cmd = NULL;
	struct iscsi_data *hdr = (struct iscsi_data *)buf;
	u32 unsol_data_len = ntoh24(hdr->dlength);
	int rc, sg_nents, sg_off, page_off;

	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
	if (rc < 0)
		return rc;
	else if (!cmd)
		return 0;
	/*
	 * FIXME: Unexpected unsolicited_data out
	 */
	if (!cmd->unsolicited_data) {
		isert_err("Received unexpected solicited data payload\n");
		dump_stack();
		return -1;
	}

	isert_dbg("Unsolicited DataOut unsol_data_len: %u, "
		  "write_data_done: %u, data_length: %u\n",
		  unsol_data_len,  cmd->write_data_done,
		  cmd->se_cmd.data_length);

	sg_off = cmd->write_data_done / PAGE_SIZE;
	sg_start = &cmd->se_cmd.t_data_sg[sg_off];
	sg_nents = max(1UL, DIV_ROUND_UP(unsol_data_len, PAGE_SIZE));
	page_off = cmd->write_data_done % PAGE_SIZE;
	/*
	 * FIXME: Non page-aligned unsolicited_data out
	 */
	if (page_off) {
		isert_err("unexpected non-page aligned data payload\n");
		dump_stack();
		return -1;
	}
	isert_dbg("Copying DataOut: sg_start: %p, sg_off: %u "
		  "sg_nents: %u from %p %u\n", sg_start, sg_off,
		  sg_nents, &rx_desc->data[0], unsol_data_len);

	sg_copy_from_buffer(sg_start, sg_nents, &rx_desc->data[0],
			    unsol_data_len);

	rc = iscsit_check_dataout_payload(cmd, hdr, false);
	if (rc < 0)
		return rc;

	/*
	 * multiple data-outs on the same command can arrive -
	 * so post the buffer before hand
	 */
	rc = isert_post_recv(isert_conn, rx_desc);
	if (rc) {
		isert_err("ib_post_recv failed with %d\n", rc);
		return rc;
	}
	return 0;
}

static int
isert_handle_nop_out(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
		     struct iscsi_cmd *cmd, struct iser_rx_desc *rx_desc,
		     unsigned char *buf)
{
	struct iscsi_conn *conn = isert_conn->conn;
	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
	int rc;

	rc = iscsit_setup_nop_out(conn, cmd, hdr);
	if (rc < 0)
		return rc;
	/*
	 * FIXME: Add support for NOPOUT payload using unsolicited RDMA payload
	 */

	return iscsit_process_nop_out(conn, cmd, hdr);
}

static int
isert_handle_text_cmd(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
		      struct iscsi_cmd *cmd, struct iser_rx_desc *rx_desc,
		      struct iscsi_text *hdr)
{
	struct iscsi_conn *conn = isert_conn->conn;
	u32 payload_length = ntoh24(hdr->dlength);
	int rc;
	unsigned char *text_in = NULL;

	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
	if (rc < 0)
		return rc;

	if (payload_length) {
		text_in = kzalloc(payload_length, GFP_KERNEL);
		if (!text_in) {
			isert_err("Unable to allocate text_in of payload_length: %u\n",
				  payload_length);
			return -ENOMEM;
		}
	}
	cmd->text_in_ptr = text_in;

	memcpy(cmd->text_in_ptr, &rx_desc->data[0], payload_length);

	return iscsit_process_text_cmd(conn, cmd, hdr);
}

static int
isert_rx_opcode(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc,
		uint32_t read_stag, uint64_t read_va,
		uint32_t write_stag, uint64_t write_va)
{
	struct iscsi_hdr *hdr = &rx_desc->iscsi_header;
	struct iscsi_conn *conn = isert_conn->conn;
	struct iscsi_cmd *cmd;
	struct isert_cmd *isert_cmd;
	int ret = -EINVAL;
	u8 opcode = (hdr->opcode & ISCSI_OPCODE_MASK);

	if (conn->sess->sess_ops->SessionType &&
	   (!(opcode & ISCSI_OP_TEXT) || !(opcode & ISCSI_OP_LOGOUT))) {
		isert_err("Got illegal opcode: 0x%02x in SessionType=Discovery,"
			  " ignoring\n", opcode);
		return 0;
	}

	switch (opcode) {
	case ISCSI_OP_SCSI_CMD:
		cmd = isert_allocate_cmd(conn, rx_desc);
		if (!cmd)
			break;

		isert_cmd = iscsit_priv_cmd(cmd);
		isert_cmd->read_stag = read_stag;
		isert_cmd->read_va = read_va;
		isert_cmd->write_stag = write_stag;
		isert_cmd->write_va = write_va;

		ret = isert_handle_scsi_cmd(isert_conn, isert_cmd, cmd,
					rx_desc, (unsigned char *)hdr);
		break;
	case ISCSI_OP_NOOP_OUT:
		cmd = isert_allocate_cmd(conn, rx_desc);
		if (!cmd)
			break;

		isert_cmd = iscsit_priv_cmd(cmd);
		ret = isert_handle_nop_out(isert_conn, isert_cmd, cmd,
					   rx_desc, (unsigned char *)hdr);
		break;
	case ISCSI_OP_SCSI_DATA_OUT:
		ret = isert_handle_iscsi_dataout(isert_conn, rx_desc,
						(unsigned char *)hdr);
		break;
	case ISCSI_OP_SCSI_TMFUNC:
		cmd = isert_allocate_cmd(conn, rx_desc);
		if (!cmd)
			break;

		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
						(unsigned char *)hdr);
		break;
	case ISCSI_OP_LOGOUT:
		cmd = isert_allocate_cmd(conn, rx_desc);
		if (!cmd)
			break;

		ret = iscsit_handle_logout_cmd(conn, cmd, (unsigned char *)hdr);
		break;
	case ISCSI_OP_TEXT:
		if (be32_to_cpu(hdr->ttt) != 0xFFFFFFFF)
			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
		else
			cmd = isert_allocate_cmd(conn, rx_desc);

		if (!cmd)
			break;

		isert_cmd = iscsit_priv_cmd(cmd);
		ret = isert_handle_text_cmd(isert_conn, isert_cmd, cmd,
					    rx_desc, (struct iscsi_text *)hdr);
		break;
	default:
		isert_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
		dump_stack();
		break;
	}

	return ret;
}

static void
isert_rx_do_work(struct iser_rx_desc *rx_desc, struct isert_conn *isert_conn)
{
	struct iser_hdr *iser_hdr = &rx_desc->iser_header;
	uint64_t read_va = 0, write_va = 0;
	uint32_t read_stag = 0, write_stag = 0;

	switch (iser_hdr->flags & 0xF0) {
	case ISCSI_CTRL:
		if (iser_hdr->flags & ISER_RSV) {
			read_stag = be32_to_cpu(iser_hdr->read_stag);
			read_va = be64_to_cpu(iser_hdr->read_va);
			isert_dbg("ISER_RSV: read_stag: 0x%x read_va: 0x%llx\n",
				  read_stag, (unsigned long long)read_va);
		}
		if (iser_hdr->flags & ISER_WSV) {
			write_stag = be32_to_cpu(iser_hdr->write_stag);
			write_va = be64_to_cpu(iser_hdr->write_va);
			isert_dbg("ISER_WSV: write_stag: 0x%x write_va: 0x%llx\n",
				  write_stag, (unsigned long long)write_va);
		}

		isert_dbg("ISER ISCSI_CTRL PDU\n");
		break;
	case ISER_HELLO:
		isert_err("iSER Hello message\n");
		break;
	default:
		isert_warn("Unknown iSER hdr flags: 0x%02x\n", iser_hdr->flags);
		break;
	}

	isert_rx_opcode(isert_conn, rx_desc,
			read_stag, read_va, write_stag, write_va);
}

static void
isert_rcv_completion(struct iser_rx_desc *desc,
		     struct isert_conn *isert_conn,
		     u32 xfer_len)
{
	struct ib_device *ib_dev = isert_conn->cm_id->device;
	struct iscsi_hdr *hdr;
	u64 rx_dma;
	int rx_buflen;

	if ((char *)desc == isert_conn->login_req_buf) {
		rx_dma = isert_conn->login_req_dma;
		rx_buflen = ISER_RX_LOGIN_SIZE;
		isert_dbg("login_buf: Using rx_dma: 0x%llx, rx_buflen: %d\n",
			 rx_dma, rx_buflen);
	} else {
		rx_dma = desc->dma_addr;
		rx_buflen = ISER_RX_PAYLOAD_SIZE;
		isert_dbg("req_buf: Using rx_dma: 0x%llx, rx_buflen: %d\n",
			 rx_dma, rx_buflen);
	}

	ib_dma_sync_single_for_cpu(ib_dev, rx_dma, rx_buflen, DMA_FROM_DEVICE);

	hdr = &desc->iscsi_header;
	isert_dbg("iSCSI opcode: 0x%02x, ITT: 0x%08x, flags: 0x%02x dlen: %d\n",
		 hdr->opcode, hdr->itt, hdr->flags,
		 (int)(xfer_len - ISER_HEADERS_LEN));

	if ((char *)desc == isert_conn->login_req_buf) {
		isert_conn->login_req_len = xfer_len - ISER_HEADERS_LEN;
		if (isert_conn->conn) {
			struct iscsi_login *login = isert_conn->conn->conn_login;

			if (login && !login->first_request)
				isert_rx_login_req(isert_conn);
		}
		mutex_lock(&isert_conn->mutex);
		complete(&isert_conn->login_req_comp);
		mutex_unlock(&isert_conn->mutex);
	} else {
		isert_rx_do_work(desc, isert_conn);
	}

	ib_dma_sync_single_for_device(ib_dev, rx_dma, rx_buflen,
				      DMA_FROM_DEVICE);

	isert_conn->post_recv_buf_count--;
}

static int
isert_map_data_buf(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
		   struct scatterlist *sg, u32 nents, u32 length, u32 offset,
		   enum iser_ib_op_code op, struct isert_data_buf *data)
{
	struct ib_device *ib_dev = isert_conn->cm_id->device;

	data->dma_dir = op == ISER_IB_RDMA_WRITE ?
			      DMA_TO_DEVICE : DMA_FROM_DEVICE;

	data->len = length - offset;
	data->offset = offset;
	data->sg_off = data->offset / PAGE_SIZE;

	data->sg = &sg[data->sg_off];
	data->nents = min_t(unsigned int, nents - data->sg_off,
					  ISCSI_ISER_SG_TABLESIZE);
	data->len = min_t(unsigned int, data->len, ISCSI_ISER_SG_TABLESIZE *
					PAGE_SIZE);

	data->dma_nents = ib_dma_map_sg(ib_dev, data->sg, data->nents,
					data->dma_dir);
	if (unlikely(!data->dma_nents)) {
		isert_err("Cmd: unable to dma map SGs %p\n", sg);
		return -EINVAL;
	}

	isert_dbg("Mapped cmd: %p count: %u sg: %p sg_nents: %u rdma_len %d\n",
		  isert_cmd, data->dma_nents, data->sg, data->nents, data->len);

	return 0;
}

static void
isert_unmap_data_buf(struct isert_conn *isert_conn, struct isert_data_buf *data)
{
	struct ib_device *ib_dev = isert_conn->cm_id->device;

	ib_dma_unmap_sg(ib_dev, data->sg, data->nents, data->dma_dir);
	memset(data, 0, sizeof(*data));
}



static void
isert_unmap_cmd(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
{
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;

	isert_dbg("Cmd %p\n", isert_cmd);

	if (wr->data.sg) {
		isert_dbg("Cmd %p unmap_sg op\n", isert_cmd);
		isert_unmap_data_buf(isert_conn, &wr->data);
	}

	if (wr->rdma_wr) {
		isert_dbg("Cmd %p free send_wr\n", isert_cmd);
		kfree(wr->rdma_wr);
		wr->rdma_wr = NULL;
	}

	if (wr->ib_sge) {
		isert_dbg("Cmd %p free ib_sge\n", isert_cmd);
		kfree(wr->ib_sge);
		wr->ib_sge = NULL;
	}
}

static void
isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
{
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;

	isert_dbg("Cmd %p\n", isert_cmd);

	if (wr->fr_desc) {
		isert_dbg("Cmd %p free fr_desc %p\n", isert_cmd, wr->fr_desc);
		if (wr->fr_desc->ind & ISERT_PROTECTED) {
			isert_unmap_data_buf(isert_conn, &wr->prot);
			wr->fr_desc->ind &= ~ISERT_PROTECTED;
		}
		spin_lock_bh(&isert_conn->pool_lock);
		list_add_tail(&wr->fr_desc->list, &isert_conn->fr_pool);
		spin_unlock_bh(&isert_conn->pool_lock);
		wr->fr_desc = NULL;
	}

	if (wr->data.sg) {
		isert_dbg("Cmd %p unmap_sg op\n", isert_cmd);
		isert_unmap_data_buf(isert_conn, &wr->data);
	}

	wr->ib_sge = NULL;
	wr->rdma_wr = NULL;
}

static void
isert_put_cmd(struct isert_cmd *isert_cmd, bool comp_err)
{
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
	struct isert_conn *isert_conn = isert_cmd->conn;
	struct iscsi_conn *conn = isert_conn->conn;
	struct isert_device *device = isert_conn->device;
	struct iscsi_text_rsp *hdr;

	isert_dbg("Cmd %p\n", isert_cmd);

	switch (cmd->iscsi_opcode) {
	case ISCSI_OP_SCSI_CMD:
		spin_lock_bh(&conn->cmd_lock);
		if (!list_empty(&cmd->i_conn_node))
			list_del_init(&cmd->i_conn_node);
		spin_unlock_bh(&conn->cmd_lock);

		if (cmd->data_direction == DMA_TO_DEVICE) {
			iscsit_stop_dataout_timer(cmd);
			/*
			 * Check for special case during comp_err where
			 * WRITE_PENDING has been handed off from core,
			 * but requires an extra target_put_sess_cmd()
			 * before transport_generic_free_cmd() below.
			 */
			if (comp_err &&
			    cmd->se_cmd.t_state == TRANSPORT_WRITE_PENDING) {
				struct se_cmd *se_cmd = &cmd->se_cmd;

				target_put_sess_cmd(se_cmd);
			}
		}

		device->unreg_rdma_mem(isert_cmd, isert_conn);
		transport_generic_free_cmd(&cmd->se_cmd, 0);
		break;
	case ISCSI_OP_SCSI_TMFUNC:
		spin_lock_bh(&conn->cmd_lock);
		if (!list_empty(&cmd->i_conn_node))
			list_del_init(&cmd->i_conn_node);
		spin_unlock_bh(&conn->cmd_lock);

		transport_generic_free_cmd(&cmd->se_cmd, 0);
		break;
	case ISCSI_OP_REJECT:
	case ISCSI_OP_NOOP_OUT:
	case ISCSI_OP_TEXT:
		hdr = (struct iscsi_text_rsp *)&isert_cmd->tx_desc.iscsi_header;
		/* If the continue bit is on, keep the command alive */
		if (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)
			break;

		spin_lock_bh(&conn->cmd_lock);
		if (!list_empty(&cmd->i_conn_node))
			list_del_init(&cmd->i_conn_node);
		spin_unlock_bh(&conn->cmd_lock);

		/*
		 * Handle special case for REJECT when iscsi_add_reject*() has
		 * overwritten the original iscsi_opcode assignment, and the
		 * associated cmd->se_cmd needs to be released.
		 */
		if (cmd->se_cmd.se_tfo != NULL) {
			isert_dbg("Calling transport_generic_free_cmd for 0x%02x\n",
				 cmd->iscsi_opcode);
			transport_generic_free_cmd(&cmd->se_cmd, 0);
			break;
		}
		/*
		 * Fall-through
		 */
	default:
		iscsit_release_cmd(cmd);
		break;
	}
}

static void
isert_unmap_tx_desc(struct iser_tx_desc *tx_desc, struct ib_device *ib_dev)
{
	if (tx_desc->dma_addr != 0) {
		isert_dbg("unmap single for tx_desc->dma_addr\n");
		ib_dma_unmap_single(ib_dev, tx_desc->dma_addr,
				    ISER_HEADERS_LEN, DMA_TO_DEVICE);
		tx_desc->dma_addr = 0;
	}
}

static void
isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd,
		     struct ib_device *ib_dev, bool comp_err)
{
	if (isert_cmd->pdu_buf_dma != 0) {
		isert_dbg("unmap single for isert_cmd->pdu_buf_dma\n");
		ib_dma_unmap_single(ib_dev, isert_cmd->pdu_buf_dma,
				    isert_cmd->pdu_buf_len, DMA_TO_DEVICE);
		isert_cmd->pdu_buf_dma = 0;
	}

	isert_unmap_tx_desc(tx_desc, ib_dev);
	isert_put_cmd(isert_cmd, comp_err);
}

static int
isert_check_pi_status(struct se_cmd *se_cmd, struct ib_mr *sig_mr)
{
	struct ib_mr_status mr_status;
	int ret;

	ret = ib_check_mr_status(sig_mr, IB_MR_CHECK_SIG_STATUS, &mr_status);
	if (ret) {
		isert_err("ib_check_mr_status failed, ret %d\n", ret);
		goto fail_mr_status;
	}

	if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
		u64 sec_offset_err;
		u32 block_size = se_cmd->se_dev->dev_attrib.block_size + 8;

		switch (mr_status.sig_err.err_type) {
		case IB_SIG_BAD_GUARD:
			se_cmd->pi_err = TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
			break;
		case IB_SIG_BAD_REFTAG:
			se_cmd->pi_err = TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
			break;
		case IB_SIG_BAD_APPTAG:
			se_cmd->pi_err = TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED;
			break;
		}
		sec_offset_err = mr_status.sig_err.sig_err_offset;
		do_div(sec_offset_err, block_size);
		se_cmd->bad_sector = sec_offset_err + se_cmd->t_task_lba;

		isert_err("PI error found type %d at sector 0x%llx "
			  "expected 0x%x vs actual 0x%x\n",
			  mr_status.sig_err.err_type,
			  (unsigned long long)se_cmd->bad_sector,
			  mr_status.sig_err.expected,
			  mr_status.sig_err.actual);
		ret = 1;
	}

fail_mr_status:
	return ret;
}

static void
isert_completion_rdma_write(struct iser_tx_desc *tx_desc,
			    struct isert_cmd *isert_cmd)
{
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_conn *isert_conn = isert_cmd->conn;
	struct isert_device *device = isert_conn->device;
	int ret = 0;

	if (wr->fr_desc && wr->fr_desc->ind & ISERT_PROTECTED) {
		ret = isert_check_pi_status(se_cmd,
					    wr->fr_desc->pi_ctx->sig_mr);
		wr->fr_desc->ind &= ~ISERT_PROTECTED;
	}

	device->unreg_rdma_mem(isert_cmd, isert_conn);
	wr->rdma_wr_num = 0;
	if (ret)
		transport_send_check_condition_and_sense(se_cmd,
							 se_cmd->pi_err, 0);
	else
		isert_put_response(isert_conn->conn, cmd);
}

static void
isert_completion_rdma_read(struct iser_tx_desc *tx_desc,
			   struct isert_cmd *isert_cmd)
{
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_conn *isert_conn = isert_cmd->conn;
	struct isert_device *device = isert_conn->device;
	int ret = 0;

	if (wr->fr_desc && wr->fr_desc->ind & ISERT_PROTECTED) {
		ret = isert_check_pi_status(se_cmd,
					    wr->fr_desc->pi_ctx->sig_mr);
		wr->fr_desc->ind &= ~ISERT_PROTECTED;
	}

	iscsit_stop_dataout_timer(cmd);
	device->unreg_rdma_mem(isert_cmd, isert_conn);
	cmd->write_data_done = wr->data.len;
	wr->rdma_wr_num = 0;

	isert_dbg("Cmd: %p RDMA_READ comp calling execute_cmd\n", isert_cmd);
	spin_lock_bh(&cmd->istate_lock);
	cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
	cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
	spin_unlock_bh(&cmd->istate_lock);

	if (ret) {
		target_put_sess_cmd(se_cmd);
		transport_send_check_condition_and_sense(se_cmd,
							 se_cmd->pi_err, 0);
	} else {
		target_execute_cmd(se_cmd);
	}
}

static void
isert_do_control_comp(struct work_struct *work)
{
	struct isert_cmd *isert_cmd = container_of(work,
			struct isert_cmd, comp_work);
	struct isert_conn *isert_conn = isert_cmd->conn;
	struct ib_device *ib_dev = isert_conn->cm_id->device;
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;

	isert_dbg("Cmd %p i_state %d\n", isert_cmd, cmd->i_state);

	switch (cmd->i_state) {
	case ISTATE_SEND_TASKMGTRSP:
		iscsit_tmr_post_handler(cmd, cmd->conn);
	case ISTATE_SEND_REJECT:   /* FALLTHRU */
	case ISTATE_SEND_TEXTRSP:  /* FALLTHRU */
		cmd->i_state = ISTATE_SENT_STATUS;
		isert_completion_put(&isert_cmd->tx_desc, isert_cmd,
				     ib_dev, false);
		break;
	case ISTATE_SEND_LOGOUTRSP:
		iscsit_logout_post_handler(cmd, cmd->conn);
		break;
	default:
		isert_err("Unknown i_state %d\n", cmd->i_state);
		dump_stack();
		break;
	}
}

static void
isert_response_completion(struct iser_tx_desc *tx_desc,
			  struct isert_cmd *isert_cmd,
			  struct isert_conn *isert_conn,
			  struct ib_device *ib_dev)
{
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;

	if (cmd->i_state == ISTATE_SEND_TASKMGTRSP ||
	    cmd->i_state == ISTATE_SEND_LOGOUTRSP ||
	    cmd->i_state == ISTATE_SEND_REJECT ||
	    cmd->i_state == ISTATE_SEND_TEXTRSP) {
		isert_unmap_tx_desc(tx_desc, ib_dev);

		INIT_WORK(&isert_cmd->comp_work, isert_do_control_comp);
		queue_work(isert_comp_wq, &isert_cmd->comp_work);
		return;
	}

	cmd->i_state = ISTATE_SENT_STATUS;
	isert_completion_put(tx_desc, isert_cmd, ib_dev, false);
}

static void
isert_snd_completion(struct iser_tx_desc *tx_desc,
		      struct isert_conn *isert_conn)
{
	struct ib_device *ib_dev = isert_conn->cm_id->device;
	struct isert_cmd *isert_cmd = tx_desc->isert_cmd;
	struct isert_rdma_wr *wr;

	if (!isert_cmd) {
		isert_unmap_tx_desc(tx_desc, ib_dev);
		return;
	}
	wr = &isert_cmd->rdma_wr;

	isert_dbg("Cmd %p iser_ib_op %d\n", isert_cmd, wr->iser_ib_op);

	switch (wr->iser_ib_op) {
	case ISER_IB_SEND:
		isert_response_completion(tx_desc, isert_cmd,
					  isert_conn, ib_dev);
		break;
	case ISER_IB_RDMA_WRITE:
		isert_completion_rdma_write(tx_desc, isert_cmd);
		break;
	case ISER_IB_RDMA_READ:
		isert_completion_rdma_read(tx_desc, isert_cmd);
		break;
	default:
		isert_err("Unknown wr->iser_ib_op: 0x%x\n", wr->iser_ib_op);
		dump_stack();
		break;
	}
}

/**
 * is_isert_tx_desc() - Indicate if the completion wr_id
 *     is a TX descriptor or not.
 * @isert_conn: iser connection
 * @wr_id: completion WR identifier
 *
 * Since we cannot rely on wc opcode in FLUSH errors
 * we must work around it by checking if the wr_id address
 * falls in the iser connection rx_descs buffer. If so
 * it is an RX descriptor, otherwize it is a TX.
 */
static inline bool
is_isert_tx_desc(struct isert_conn *isert_conn, void *wr_id)
{
	void *start = isert_conn->rx_descs;
	int len = ISERT_QP_MAX_RECV_DTOS * sizeof(*isert_conn->rx_descs);

	if (wr_id >= start && wr_id < start + len)
		return false;

	return true;
}

static void
isert_cq_comp_err(struct isert_conn *isert_conn, struct ib_wc *wc)
{
	if (wc->wr_id == ISER_BEACON_WRID) {
		isert_info("conn %p completing wait_comp_err\n",
			   isert_conn);
		complete(&isert_conn->wait_comp_err);
	} else if (is_isert_tx_desc(isert_conn, (void *)(uintptr_t)wc->wr_id)) {
		struct ib_device *ib_dev = isert_conn->cm_id->device;
		struct isert_cmd *isert_cmd;
		struct iser_tx_desc *desc;

		desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
		isert_cmd = desc->isert_cmd;
		if (!isert_cmd)
			isert_unmap_tx_desc(desc, ib_dev);
		else
			isert_completion_put(desc, isert_cmd, ib_dev, true);
	} else {
		isert_conn->post_recv_buf_count--;
		if (!isert_conn->post_recv_buf_count)
			iscsit_cause_connection_reinstatement(isert_conn->conn, 0);
	}
}

static void
isert_handle_wc(struct ib_wc *wc)
{
	struct isert_conn *isert_conn;
	struct iser_tx_desc *tx_desc;
	struct iser_rx_desc *rx_desc;

	isert_conn = wc->qp->qp_context;
	if (likely(wc->status == IB_WC_SUCCESS)) {
		if (wc->opcode == IB_WC_RECV) {
			rx_desc = (struct iser_rx_desc *)(uintptr_t)wc->wr_id;
			isert_rcv_completion(rx_desc, isert_conn, wc->byte_len);
		} else {
			tx_desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
			isert_snd_completion(tx_desc, isert_conn);
		}
	} else {
		if (wc->status != IB_WC_WR_FLUSH_ERR)
			isert_err("%s (%d): wr id %llx vend_err %x\n",
				  ib_wc_status_msg(wc->status), wc->status,
				  wc->wr_id, wc->vendor_err);
		else
			isert_dbg("%s (%d): wr id %llx\n",
				  ib_wc_status_msg(wc->status), wc->status,
				  wc->wr_id);

		if (wc->wr_id != ISER_FASTREG_LI_WRID)
			isert_cq_comp_err(isert_conn, wc);
	}
}

static void
isert_cq_work(struct work_struct *work)
{
	enum { isert_poll_budget = 65536 };
	struct isert_comp *comp = container_of(work, struct isert_comp,
					       work);
	struct ib_wc *const wcs = comp->wcs;
	int i, n, completed = 0;

	while ((n = ib_poll_cq(comp->cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
		for (i = 0; i < n; i++)
			isert_handle_wc(&wcs[i]);

		completed += n;
		if (completed >= isert_poll_budget)
			break;
	}

	ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP);
}

static void
isert_cq_callback(struct ib_cq *cq, void *context)
{
	struct isert_comp *comp = context;

	queue_work(isert_comp_wq, &comp->work);
}

static int
isert_post_response(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd)
{
	struct ib_send_wr *wr_failed;
	int ret;

	ret = isert_post_recv(isert_conn, isert_cmd->rx_desc);
	if (ret) {
		isert_err("ib_post_recv failed with %d\n", ret);
		return ret;
	}

	ret = ib_post_send(isert_conn->qp, &isert_cmd->tx_desc.send_wr,
			   &wr_failed);
	if (ret) {
		isert_err("ib_post_send failed with %d\n", ret);
		return ret;
	}
	return ret;
}

static int
isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)
				&isert_cmd->tx_desc.iscsi_header;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	iscsit_build_rsp_pdu(cmd, conn, true, hdr);
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
	/*
	 * Attach SENSE DATA payload to iSCSI Response PDU
	 */
	if (cmd->se_cmd.sense_buffer &&
	    ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
		struct isert_device *device = isert_conn->device;
		struct ib_device *ib_dev = device->ib_device;
		struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
		u32 padding, pdu_len;

		put_unaligned_be16(cmd->se_cmd.scsi_sense_length,
				   cmd->sense_buffer);
		cmd->se_cmd.scsi_sense_length += sizeof(__be16);

		padding = -(cmd->se_cmd.scsi_sense_length) & 3;
		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
		pdu_len = cmd->se_cmd.scsi_sense_length + padding;

		isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
				(void *)cmd->sense_buffer, pdu_len,
				DMA_TO_DEVICE);

		isert_cmd->pdu_buf_len = pdu_len;
		tx_dsg->addr	= isert_cmd->pdu_buf_dma;
		tx_dsg->length	= pdu_len;
		tx_dsg->lkey	= device->pd->local_dma_lkey;
		isert_cmd->tx_desc.num_sge = 2;
	}

	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("Posting SCSI Response\n");

	return isert_post_response(isert_conn, isert_cmd);
}

static void
isert_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct isert_device *device = isert_conn->device;

	spin_lock_bh(&conn->cmd_lock);
	if (!list_empty(&cmd->i_conn_node))
		list_del_init(&cmd->i_conn_node);
	spin_unlock_bh(&conn->cmd_lock);

	if (cmd->data_direction == DMA_TO_DEVICE)
		iscsit_stop_dataout_timer(cmd);

	device->unreg_rdma_mem(isert_cmd, isert_conn);
}

static enum target_prot_op
isert_get_sup_prot_ops(struct iscsi_conn *conn)
{
	struct isert_conn *isert_conn = conn->context;
	struct isert_device *device = isert_conn->device;

	if (conn->tpg->tpg_attrib.t10_pi) {
		if (device->pi_capable) {
			isert_info("conn %p PI offload enabled\n", isert_conn);
			isert_conn->pi_support = true;
			return TARGET_PROT_ALL;
		}
	}

	isert_info("conn %p PI offload disabled\n", isert_conn);
	isert_conn->pi_support = false;

	return TARGET_PROT_NORMAL;
}

static int
isert_put_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
		bool nopout_response)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	iscsit_build_nopin_rsp(cmd, conn, (struct iscsi_nopin *)
			       &isert_cmd->tx_desc.iscsi_header,
			       nopout_response);
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("conn %p Posting NOPIN Response\n", isert_conn);

	return isert_post_response(isert_conn, isert_cmd);
}

static int
isert_put_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	iscsit_build_logout_rsp(cmd, conn, (struct iscsi_logout_rsp *)
				&isert_cmd->tx_desc.iscsi_header);
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("conn %p Posting Logout Response\n", isert_conn);

	return isert_post_response(isert_conn, isert_cmd);
}

static int
isert_put_tm_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	iscsit_build_task_mgt_rsp(cmd, conn, (struct iscsi_tm_rsp *)
				  &isert_cmd->tx_desc.iscsi_header);
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("conn %p Posting Task Management Response\n", isert_conn);

	return isert_post_response(isert_conn, isert_cmd);
}

static int
isert_put_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
	struct iscsi_reject *hdr =
		(struct iscsi_reject *)&isert_cmd->tx_desc.iscsi_header;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	iscsit_build_reject(cmd, conn, hdr);
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);

	hton24(hdr->dlength, ISCSI_HDR_LEN);
	isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
			(void *)cmd->buf_ptr, ISCSI_HDR_LEN,
			DMA_TO_DEVICE);
	isert_cmd->pdu_buf_len = ISCSI_HDR_LEN;
	tx_dsg->addr	= isert_cmd->pdu_buf_dma;
	tx_dsg->length	= ISCSI_HDR_LEN;
	tx_dsg->lkey	= device->pd->local_dma_lkey;
	isert_cmd->tx_desc.num_sge = 2;

	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("conn %p Posting Reject\n", isert_conn);

	return isert_post_response(isert_conn, isert_cmd);
}

static int
isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
	struct iscsi_text_rsp *hdr =
		(struct iscsi_text_rsp *)&isert_cmd->tx_desc.iscsi_header;
	u32 txt_rsp_len;
	int rc;

	isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
	rc = iscsit_build_text_rsp(cmd, conn, hdr, ISCSI_INFINIBAND);
	if (rc < 0)
		return rc;

	txt_rsp_len = rc;
	isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);

	if (txt_rsp_len) {
		struct isert_device *device = isert_conn->device;
		struct ib_device *ib_dev = device->ib_device;
		struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
		void *txt_rsp_buf = cmd->buf_ptr;

		isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
				txt_rsp_buf, txt_rsp_len, DMA_TO_DEVICE);

		isert_cmd->pdu_buf_len = txt_rsp_len;
		tx_dsg->addr	= isert_cmd->pdu_buf_dma;
		tx_dsg->length	= txt_rsp_len;
		tx_dsg->lkey	= device->pd->local_dma_lkey;
		isert_cmd->tx_desc.num_sge = 2;
	}
	isert_init_send_wr(isert_conn, isert_cmd, send_wr);

	isert_dbg("conn %p Text Response\n", isert_conn);

	return isert_post_response(isert_conn, isert_cmd);
}

static int
isert_build_rdma_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
		    struct ib_sge *ib_sge, struct ib_rdma_wr *rdma_wr,
		    u32 data_left, u32 offset)
{
	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
	struct scatterlist *sg_start, *tmp_sg;
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	u32 sg_off, page_off;
	int i = 0, sg_nents;

	sg_off = offset / PAGE_SIZE;
	sg_start = &cmd->se_cmd.t_data_sg[sg_off];
	sg_nents = min(cmd->se_cmd.t_data_nents - sg_off, isert_conn->max_sge);
	page_off = offset % PAGE_SIZE;

	rdma_wr->wr.sg_list = ib_sge;
	rdma_wr->wr.wr_id = (uintptr_t)&isert_cmd->tx_desc;
	/*
	 * Perform mapping of TCM scatterlist memory ib_sge dma_addr.
	 */
	for_each_sg(sg_start, tmp_sg, sg_nents, i) {
		isert_dbg("RDMA from SGL dma_addr: 0x%llx dma_len: %u, "
			  "page_off: %u\n",
			  (unsigned long long)tmp_sg->dma_address,
			  tmp_sg->length, page_off);

		ib_sge->addr = ib_sg_dma_address(ib_dev, tmp_sg) + page_off;
		ib_sge->length = min_t(u32, data_left,
				ib_sg_dma_len(ib_dev, tmp_sg) - page_off);
		ib_sge->lkey = device->pd->local_dma_lkey;

		isert_dbg("RDMA ib_sge: addr: 0x%llx  length: %u lkey: %x\n",
			  ib_sge->addr, ib_sge->length, ib_sge->lkey);
		page_off = 0;
		data_left -= ib_sge->length;
		if (!data_left)
			break;
		ib_sge++;
		isert_dbg("Incrementing ib_sge pointer to %p\n", ib_sge);
	}

	rdma_wr->wr.num_sge = ++i;
	isert_dbg("Set outgoing sg_list: %p num_sg: %u from TCM SGLs\n",
		  rdma_wr->wr.sg_list, rdma_wr->wr.num_sge);

	return rdma_wr->wr.num_sge;
}

static int
isert_map_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
	       struct isert_rdma_wr *wr)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct isert_data_buf *data = &wr->data;
	struct ib_rdma_wr *rdma_wr;
	struct ib_sge *ib_sge;
	u32 offset, data_len, data_left, rdma_write_max, va_offset = 0;
	int ret = 0, i, ib_sge_cnt;

	isert_cmd->tx_desc.isert_cmd = isert_cmd;

	offset = wr->iser_ib_op == ISER_IB_RDMA_READ ? cmd->write_data_done : 0;
	ret = isert_map_data_buf(isert_conn, isert_cmd, se_cmd->t_data_sg,
				 se_cmd->t_data_nents, se_cmd->data_length,
				 offset, wr->iser_ib_op, &wr->data);
	if (ret)
		return ret;

	data_left = data->len;
	offset = data->offset;

	ib_sge = kzalloc(sizeof(struct ib_sge) * data->nents, GFP_KERNEL);
	if (!ib_sge) {
		isert_warn("Unable to allocate ib_sge\n");
		ret = -ENOMEM;
		goto unmap_cmd;
	}
	wr->ib_sge = ib_sge;

	wr->rdma_wr_num = DIV_ROUND_UP(data->nents, isert_conn->max_sge);
	wr->rdma_wr = kzalloc(sizeof(struct ib_rdma_wr) * wr->rdma_wr_num,
				GFP_KERNEL);
	if (!wr->rdma_wr) {
		isert_dbg("Unable to allocate wr->rdma_wr\n");
		ret = -ENOMEM;
		goto unmap_cmd;
	}

	wr->isert_cmd = isert_cmd;
	rdma_write_max = isert_conn->max_sge * PAGE_SIZE;

	for (i = 0; i < wr->rdma_wr_num; i++) {
		rdma_wr = &isert_cmd->rdma_wr.rdma_wr[i];
		data_len = min(data_left, rdma_write_max);

		rdma_wr->wr.send_flags = 0;
		if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
			rdma_wr->wr.opcode = IB_WR_RDMA_WRITE;
			rdma_wr->remote_addr = isert_cmd->read_va + offset;
			rdma_wr->rkey = isert_cmd->read_stag;
			if (i + 1 == wr->rdma_wr_num)
				rdma_wr->wr.next = &isert_cmd->tx_desc.send_wr;
			else
				rdma_wr->wr.next = &wr->rdma_wr[i + 1].wr;
		} else {
			rdma_wr->wr.opcode = IB_WR_RDMA_READ;
			rdma_wr->remote_addr = isert_cmd->write_va + va_offset;
			rdma_wr->rkey = isert_cmd->write_stag;
			if (i + 1 == wr->rdma_wr_num)
				rdma_wr->wr.send_flags = IB_SEND_SIGNALED;
			else
				rdma_wr->wr.next = &wr->rdma_wr[i + 1].wr;
		}

		ib_sge_cnt = isert_build_rdma_wr(isert_conn, isert_cmd, ib_sge,
					rdma_wr, data_len, offset);
		ib_sge += ib_sge_cnt;

		offset += data_len;
		va_offset += data_len;
		data_left -= data_len;
	}

	return 0;
unmap_cmd:
	isert_unmap_data_buf(isert_conn, data);

	return ret;
}

static inline void
isert_inv_rkey(struct ib_send_wr *inv_wr, struct ib_mr *mr)
{
	u32 rkey;

	memset(inv_wr, 0, sizeof(*inv_wr));
	inv_wr->wr_id = ISER_FASTREG_LI_WRID;
	inv_wr->opcode = IB_WR_LOCAL_INV;
	inv_wr->ex.invalidate_rkey = mr->rkey;

	/* Bump the key */
	rkey = ib_inc_rkey(mr->rkey);
	ib_update_fast_reg_key(mr, rkey);
}

static int
isert_fast_reg_mr(struct isert_conn *isert_conn,
		  struct fast_reg_descriptor *fr_desc,
		  struct isert_data_buf *mem,
		  enum isert_indicator ind,
		  struct ib_sge *sge)
{
	struct isert_device *device = isert_conn->device;
	struct ib_device *ib_dev = device->ib_device;
	struct ib_mr *mr;
	struct ib_reg_wr reg_wr;
	struct ib_send_wr inv_wr, *bad_wr, *wr = NULL;
	int ret, n;

	if (mem->dma_nents == 1) {
		sge->lkey = device->pd->local_dma_lkey;
		sge->addr = ib_sg_dma_address(ib_dev, &mem->sg[0]);
		sge->length = ib_sg_dma_len(ib_dev, &mem->sg[0]);
		isert_dbg("sge: addr: 0x%llx  length: %u lkey: %x\n",
			 sge->addr, sge->length, sge->lkey);
		return 0;
	}

	if (ind == ISERT_DATA_KEY_VALID)
		/* Registering data buffer */
		mr = fr_desc->data_mr;
	else
		/* Registering protection buffer */
		mr = fr_desc->pi_ctx->prot_mr;

	if (!(fr_desc->ind & ind)) {
		isert_inv_rkey(&inv_wr, mr);
		wr = &inv_wr;
	}

	n = ib_map_mr_sg(mr, mem->sg, mem->nents, PAGE_SIZE);
	if (unlikely(n != mem->nents)) {
		isert_err("failed to map mr sg (%d/%d)\n",
			 n, mem->nents);
		return n < 0 ? n : -EINVAL;
	}

	isert_dbg("Use fr_desc %p sg_nents %d offset %u\n",
		  fr_desc, mem->nents, mem->offset);

	reg_wr.wr.next = NULL;
	reg_wr.wr.opcode = IB_WR_REG_MR;
	reg_wr.wr.wr_id = ISER_FASTREG_LI_WRID;
	reg_wr.wr.send_flags = 0;
	reg_wr.wr.num_sge = 0;
	reg_wr.mr = mr;
	reg_wr.key = mr->lkey;
	reg_wr.access = IB_ACCESS_LOCAL_WRITE;

	if (!wr)
		wr = &reg_wr.wr;
	else
		wr->next = &reg_wr.wr;

	ret = ib_post_send(isert_conn->qp, wr, &bad_wr);
	if (ret) {
		isert_err("fast registration failed, ret:%d\n", ret);
		return ret;
	}
	fr_desc->ind &= ~ind;

	sge->lkey = mr->lkey;
	sge->addr = mr->iova;
	sge->length = mr->length;

	isert_dbg("sge: addr: 0x%llx  length: %u lkey: %x\n",
		  sge->addr, sge->length, sge->lkey);

	return ret;
}

static inline void
isert_set_dif_domain(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs,
		     struct ib_sig_domain *domain)
{
	domain->sig_type = IB_SIG_TYPE_T10_DIF;
	domain->sig.dif.bg_type = IB_T10DIF_CRC;
	domain->sig.dif.pi_interval = se_cmd->se_dev->dev_attrib.block_size;
	domain->sig.dif.ref_tag = se_cmd->reftag_seed;
	/*
	 * At the moment we hard code those, but if in the future
	 * the target core would like to use it, we will take it
	 * from se_cmd.
	 */
	domain->sig.dif.apptag_check_mask = 0xffff;
	domain->sig.dif.app_escape = true;
	domain->sig.dif.ref_escape = true;
	if (se_cmd->prot_type == TARGET_DIF_TYPE1_PROT ||
	    se_cmd->prot_type == TARGET_DIF_TYPE2_PROT)
		domain->sig.dif.ref_remap = true;
};

static int
isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
{
	switch (se_cmd->prot_op) {
	case TARGET_PROT_DIN_INSERT:
	case TARGET_PROT_DOUT_STRIP:
		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->wire);
		break;
	case TARGET_PROT_DOUT_INSERT:
	case TARGET_PROT_DIN_STRIP:
		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->mem);
		break;
	case TARGET_PROT_DIN_PASS:
	case TARGET_PROT_DOUT_PASS:
		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->wire);
		isert_set_dif_domain(se_cmd, sig_attrs, &sig_attrs->mem);
		break;
	default:
		isert_err("Unsupported PI operation %d\n", se_cmd->prot_op);
		return -EINVAL;
	}

	return 0;
}

static inline u8
isert_set_prot_checks(u8 prot_checks)
{
	return (prot_checks & TARGET_DIF_CHECK_GUARD  ? 0xc0 : 0) |
	       (prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x30 : 0) |
	       (prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x0f : 0);
}

static int
isert_reg_sig_mr(struct isert_conn *isert_conn,
		 struct se_cmd *se_cmd,
		 struct isert_rdma_wr *rdma_wr,
		 struct fast_reg_descriptor *fr_desc)
{
	struct ib_sig_handover_wr sig_wr;
	struct ib_send_wr inv_wr, *bad_wr, *wr = NULL;
	struct pi_context *pi_ctx = fr_desc->pi_ctx;
	struct ib_sig_attrs sig_attrs;
	int ret;

	memset(&sig_attrs, 0, sizeof(sig_attrs));
	ret = isert_set_sig_attrs(se_cmd, &sig_attrs);
	if (ret)
		goto err;

	sig_attrs.check_mask = isert_set_prot_checks(se_cmd->prot_checks);

	if (!(fr_desc->ind & ISERT_SIG_KEY_VALID)) {
		isert_inv_rkey(&inv_wr, pi_ctx->sig_mr);
		wr = &inv_wr;
	}

	memset(&sig_wr, 0, sizeof(sig_wr));
	sig_wr.wr.opcode = IB_WR_REG_SIG_MR;
	sig_wr.wr.wr_id = ISER_FASTREG_LI_WRID;
	sig_wr.wr.sg_list = &rdma_wr->ib_sg[DATA];
	sig_wr.wr.num_sge = 1;
	sig_wr.access_flags = IB_ACCESS_LOCAL_WRITE;
	sig_wr.sig_attrs = &sig_attrs;
	sig_wr.sig_mr = pi_ctx->sig_mr;
	if (se_cmd->t_prot_sg)
		sig_wr.prot = &rdma_wr->ib_sg[PROT];

	if (!wr)
		wr = &sig_wr.wr;
	else
		wr->next = &sig_wr.wr;

	ret = ib_post_send(isert_conn->qp, wr, &bad_wr);
	if (ret) {
		isert_err("fast registration failed, ret:%d\n", ret);
		goto err;
	}
	fr_desc->ind &= ~ISERT_SIG_KEY_VALID;

	rdma_wr->ib_sg[SIG].lkey = pi_ctx->sig_mr->lkey;
	rdma_wr->ib_sg[SIG].addr = 0;
	rdma_wr->ib_sg[SIG].length = se_cmd->data_length;
	if (se_cmd->prot_op != TARGET_PROT_DIN_STRIP &&
	    se_cmd->prot_op != TARGET_PROT_DOUT_INSERT)
		/*
		 * We have protection guards on the wire
		 * so we need to set a larget transfer
		 */
		rdma_wr->ib_sg[SIG].length += se_cmd->prot_length;

	isert_dbg("sig_sge: addr: 0x%llx  length: %u lkey: %x\n",
		  rdma_wr->ib_sg[SIG].addr, rdma_wr->ib_sg[SIG].length,
		  rdma_wr->ib_sg[SIG].lkey);
err:
	return ret;
}

static int
isert_handle_prot_cmd(struct isert_conn *isert_conn,
		      struct isert_cmd *isert_cmd,
		      struct isert_rdma_wr *wr)
{
	struct isert_device *device = isert_conn->device;
	struct se_cmd *se_cmd = &isert_cmd->iscsi_cmd->se_cmd;
	int ret;

	if (!wr->fr_desc->pi_ctx) {
		ret = isert_create_pi_ctx(wr->fr_desc,
					  device->ib_device,
					  device->pd);
		if (ret) {
			isert_err("conn %p failed to allocate pi_ctx\n",
				  isert_conn);
			return ret;
		}
	}

	if (se_cmd->t_prot_sg) {
		ret = isert_map_data_buf(isert_conn, isert_cmd,
					 se_cmd->t_prot_sg,
					 se_cmd->t_prot_nents,
					 se_cmd->prot_length,
					 0, wr->iser_ib_op, &wr->prot);
		if (ret) {
			isert_err("conn %p failed to map protection buffer\n",
				  isert_conn);
			return ret;
		}

		memset(&wr->ib_sg[PROT], 0, sizeof(wr->ib_sg[PROT]));
		ret = isert_fast_reg_mr(isert_conn, wr->fr_desc, &wr->prot,
					ISERT_PROT_KEY_VALID, &wr->ib_sg[PROT]);
		if (ret) {
			isert_err("conn %p failed to fast reg mr\n",
				  isert_conn);
			goto unmap_prot_cmd;
		}
	}

	ret = isert_reg_sig_mr(isert_conn, se_cmd, wr, wr->fr_desc);
	if (ret) {
		isert_err("conn %p failed to fast reg mr\n",
			  isert_conn);
		goto unmap_prot_cmd;
	}
	wr->fr_desc->ind |= ISERT_PROTECTED;

	return 0;

unmap_prot_cmd:
	if (se_cmd->t_prot_sg)
		isert_unmap_data_buf(isert_conn, &wr->prot);

	return ret;
}

static int
isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
	       struct isert_rdma_wr *wr)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_conn *isert_conn = conn->context;
	struct fast_reg_descriptor *fr_desc = NULL;
	struct ib_rdma_wr *rdma_wr;
	struct ib_sge *ib_sg;
	u32 offset;
	int ret = 0;
	unsigned long flags;

	isert_cmd->tx_desc.isert_cmd = isert_cmd;

	offset = wr->iser_ib_op == ISER_IB_RDMA_READ ? cmd->write_data_done : 0;
	ret = isert_map_data_buf(isert_conn, isert_cmd, se_cmd->t_data_sg,
				 se_cmd->t_data_nents, se_cmd->data_length,
				 offset, wr->iser_ib_op, &wr->data);
	if (ret)
		return ret;

	if (wr->data.dma_nents != 1 || isert_prot_cmd(isert_conn, se_cmd)) {
		spin_lock_irqsave(&isert_conn->pool_lock, flags);
		fr_desc = list_first_entry(&isert_conn->fr_pool,
					   struct fast_reg_descriptor, list);
		list_del(&fr_desc->list);
		spin_unlock_irqrestore(&isert_conn->pool_lock, flags);
		wr->fr_desc = fr_desc;
	}

	ret = isert_fast_reg_mr(isert_conn, fr_desc, &wr->data,
				ISERT_DATA_KEY_VALID, &wr->ib_sg[DATA]);
	if (ret)
		goto unmap_cmd;

	if (isert_prot_cmd(isert_conn, se_cmd)) {
		ret = isert_handle_prot_cmd(isert_conn, isert_cmd, wr);
		if (ret)
			goto unmap_cmd;

		ib_sg = &wr->ib_sg[SIG];
	} else {
		ib_sg = &wr->ib_sg[DATA];
	}

	memcpy(&wr->s_ib_sge, ib_sg, sizeof(*ib_sg));
	wr->ib_sge = &wr->s_ib_sge;
	wr->rdma_wr_num = 1;
	memset(&wr->s_rdma_wr, 0, sizeof(wr->s_rdma_wr));
	wr->rdma_wr = &wr->s_rdma_wr;
	wr->isert_cmd = isert_cmd;

	rdma_wr = &isert_cmd->rdma_wr.s_rdma_wr;
	rdma_wr->wr.sg_list = &wr->s_ib_sge;
	rdma_wr->wr.num_sge = 1;
	rdma_wr->wr.wr_id = (uintptr_t)&isert_cmd->tx_desc;
	if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
		rdma_wr->wr.opcode = IB_WR_RDMA_WRITE;
		rdma_wr->remote_addr = isert_cmd->read_va;
		rdma_wr->rkey = isert_cmd->read_stag;
		rdma_wr->wr.send_flags = !isert_prot_cmd(isert_conn, se_cmd) ?
				      0 : IB_SEND_SIGNALED;
	} else {
		rdma_wr->wr.opcode = IB_WR_RDMA_READ;
		rdma_wr->remote_addr = isert_cmd->write_va;
		rdma_wr->rkey = isert_cmd->write_stag;
		rdma_wr->wr.send_flags = IB_SEND_SIGNALED;
	}

	return 0;

unmap_cmd:
	if (fr_desc) {
		spin_lock_irqsave(&isert_conn->pool_lock, flags);
		list_add_tail(&fr_desc->list, &isert_conn->fr_pool);
		spin_unlock_irqrestore(&isert_conn->pool_lock, flags);
	}
	isert_unmap_data_buf(isert_conn, &wr->data);

	return ret;
}

static int
isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;
	struct isert_conn *isert_conn = conn->context;
	struct isert_device *device = isert_conn->device;
	struct ib_send_wr *wr_failed;
	int rc;

	isert_dbg("Cmd: %p RDMA_WRITE data_length: %u\n",
		 isert_cmd, se_cmd->data_length);

	wr->iser_ib_op = ISER_IB_RDMA_WRITE;
	rc = device->reg_rdma_mem(conn, cmd, wr);
	if (rc) {
		isert_err("Cmd: %p failed to prepare RDMA res\n", isert_cmd);
		return rc;
	}

	if (!isert_prot_cmd(isert_conn, se_cmd)) {
		/*
		 * Build isert_conn->tx_desc for iSCSI response PDU and attach
		 */
		isert_create_send_desc(isert_conn, isert_cmd,
				       &isert_cmd->tx_desc);
		iscsit_build_rsp_pdu(cmd, conn, true, (struct iscsi_scsi_rsp *)
				     &isert_cmd->tx_desc.iscsi_header);
		isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
		isert_init_send_wr(isert_conn, isert_cmd,
				   &isert_cmd->tx_desc.send_wr);
		isert_cmd->rdma_wr.s_rdma_wr.wr.next = &isert_cmd->tx_desc.send_wr;
		wr->rdma_wr_num += 1;

		rc = isert_post_recv(isert_conn, isert_cmd->rx_desc);
		if (rc) {
			isert_err("ib_post_recv failed with %d\n", rc);
			return rc;
		}
	}

	rc = ib_post_send(isert_conn->qp, &wr->rdma_wr->wr, &wr_failed);
	if (rc)
		isert_warn("ib_post_send() failed for IB_WR_RDMA_WRITE\n");

	if (!isert_prot_cmd(isert_conn, se_cmd))
		isert_dbg("Cmd: %p posted RDMA_WRITE + Response for iSER Data "
			 "READ\n", isert_cmd);
	else
		isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ\n",
			 isert_cmd);

	return 1;
}

static int
isert_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd, bool recovery)
{
	struct se_cmd *se_cmd = &cmd->se_cmd;
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;
	struct isert_conn *isert_conn = conn->context;
	struct isert_device *device = isert_conn->device;
	struct ib_send_wr *wr_failed;
	int rc;

	isert_dbg("Cmd: %p RDMA_READ data_length: %u write_data_done: %u\n",
		 isert_cmd, se_cmd->data_length, cmd->write_data_done);
	wr->iser_ib_op = ISER_IB_RDMA_READ;
	rc = device->reg_rdma_mem(conn, cmd, wr);
	if (rc) {
		isert_err("Cmd: %p failed to prepare RDMA res\n", isert_cmd);
		return rc;
	}

	rc = ib_post_send(isert_conn->qp, &wr->rdma_wr->wr, &wr_failed);
	if (rc)
		isert_warn("ib_post_send() failed for IB_WR_RDMA_READ\n");

	isert_dbg("Cmd: %p posted RDMA_READ memory for ISER Data WRITE\n",
		 isert_cmd);

	return 0;
}

static int
isert_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
{
	struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
	int ret = 0;

	switch (state) {
	case ISTATE_REMOVE:
		spin_lock_bh(&conn->cmd_lock);
		list_del_init(&cmd->i_conn_node);
		spin_unlock_bh(&conn->cmd_lock);
		isert_put_cmd(isert_cmd, true);
		break;
	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
		ret = isert_put_nopin(cmd, conn, false);
		break;
	default:
		isert_err("Unknown immediate state: 0x%02x\n", state);
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int
isert_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
{
	struct isert_conn *isert_conn = conn->context;
	int ret;

	switch (state) {
	case ISTATE_SEND_LOGOUTRSP:
		ret = isert_put_logout_rsp(cmd, conn);
		if (!ret)
			isert_conn->logout_posted = true;
		break;
	case ISTATE_SEND_NOPIN:
		ret = isert_put_nopin(cmd, conn, true);
		break;
	case ISTATE_SEND_TASKMGTRSP:
		ret = isert_put_tm_rsp(cmd, conn);
		break;
	case ISTATE_SEND_REJECT:
		ret = isert_put_reject(cmd, conn);
		break;
	case ISTATE_SEND_TEXTRSP:
		ret = isert_put_text_rsp(cmd, conn);
		break;
	case ISTATE_SEND_STATUS:
		/*
		 * Special case for sending non GOOD SCSI status from TX thread
		 * context during pre se_cmd excecution failure.
		 */
		ret = isert_put_response(conn, cmd);
		break;
	default:
		isert_err("Unknown response state: 0x%02x\n", state);
		ret = -EINVAL;
		break;
	}

	return ret;
}

struct rdma_cm_id *
isert_setup_id(struct isert_np *isert_np)
{
	struct iscsi_np *np = isert_np->np;
	struct rdma_cm_id *id;
	struct sockaddr *sa;
	int ret;

	sa = (struct sockaddr *)&np->np_sockaddr;
	isert_dbg("ksockaddr: %p, sa: %p\n", &np->np_sockaddr, sa);

	id = rdma_create_id(&init_net, isert_cma_handler, isert_np,
			    RDMA_PS_TCP, IB_QPT_RC);
	if (IS_ERR(id)) {
		isert_err("rdma_create_id() failed: %ld\n", PTR_ERR(id));
		ret = PTR_ERR(id);
		goto out;
	}
	isert_dbg("id %p context %p\n", id, id->context);

	ret = rdma_bind_addr(id, sa);
	if (ret) {
		isert_err("rdma_bind_addr() failed: %d\n", ret);
		goto out_id;
	}

	ret = rdma_listen(id, 0);
	if (ret) {
		isert_err("rdma_listen() failed: %d\n", ret);
		goto out_id;
	}

	return id;
out_id:
	rdma_destroy_id(id);
out:
	return ERR_PTR(ret);
}

static int
isert_setup_np(struct iscsi_np *np,
	       struct sockaddr_storage *ksockaddr)
{
	struct isert_np *isert_np;
	struct rdma_cm_id *isert_lid;
	int ret;

	isert_np = kzalloc(sizeof(struct isert_np), GFP_KERNEL);
	if (!isert_np) {
		isert_err("Unable to allocate struct isert_np\n");
		return -ENOMEM;
	}
	sema_init(&isert_np->sem, 0);
	mutex_init(&isert_np->mutex);
	INIT_LIST_HEAD(&isert_np->accepted);
	INIT_LIST_HEAD(&isert_np->pending);
	isert_np->np = np;

	/*
	 * Setup the np->np_sockaddr from the passed sockaddr setup
	 * in iscsi_target_configfs.c code..
	 */
	memcpy(&np->np_sockaddr, ksockaddr,
	       sizeof(struct sockaddr_storage));

	isert_lid = isert_setup_id(isert_np);
	if (IS_ERR(isert_lid)) {
		ret = PTR_ERR(isert_lid);
		goto out;
	}

	isert_np->cm_id = isert_lid;
	np->np_context = isert_np;

	return 0;

out:
	kfree(isert_np);

	return ret;
}

static int
isert_rdma_accept(struct isert_conn *isert_conn)
{
	struct rdma_cm_id *cm_id = isert_conn->cm_id;
	struct rdma_conn_param cp;
	int ret;

	memset(&cp, 0, sizeof(struct rdma_conn_param));
	cp.initiator_depth = isert_conn->initiator_depth;
	cp.retry_count = 7;
	cp.rnr_retry_count = 7;

	ret = rdma_accept(cm_id, &cp);
	if (ret) {
		isert_err("rdma_accept() failed with: %d\n", ret);
		return ret;
	}

	return 0;
}

static int
isert_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
{
	struct isert_conn *isert_conn = conn->context;
	int ret;

	isert_info("before login_req comp conn: %p\n", isert_conn);
	ret = wait_for_completion_interruptible(&isert_conn->login_req_comp);
	if (ret) {
		isert_err("isert_conn %p interrupted before got login req\n",
			  isert_conn);
		return ret;
	}
	reinit_completion(&isert_conn->login_req_comp);

	/*
	 * For login requests after the first PDU, isert_rx_login_req() will
	 * kick schedule_delayed_work(&conn->login_work) as the packet is
	 * received, which turns this callback from iscsi_target_do_login_rx()
	 * into a NOP.
	 */
	if (!login->first_request)
		return 0;

	isert_rx_login_req(isert_conn);

	isert_info("before login_comp conn: %p\n", conn);
	ret = wait_for_completion_interruptible(&isert_conn->login_comp);
	if (ret)
		return ret;

	isert_info("processing login->req: %p\n", login->req);

	return 0;
}

static void
isert_set_conn_info(struct iscsi_np *np, struct iscsi_conn *conn,
		    struct isert_conn *isert_conn)
{
	struct rdma_cm_id *cm_id = isert_conn->cm_id;
	struct rdma_route *cm_route = &cm_id->route;

	conn->login_family = np->np_sockaddr.ss_family;

	conn->login_sockaddr = cm_route->addr.dst_addr;
	conn->local_sockaddr = cm_route->addr.src_addr;
}

static int
isert_accept_np(struct iscsi_np *np, struct iscsi_conn *conn)
{
	struct isert_np *isert_np = np->np_context;
	struct isert_conn *isert_conn;
	int ret;

accept_wait:
	ret = down_interruptible(&isert_np->sem);
	if (ret)
		return -ENODEV;

	spin_lock_bh(&np->np_thread_lock);
	if (np->np_thread_state >= ISCSI_NP_THREAD_RESET) {
		spin_unlock_bh(&np->np_thread_lock);
		isert_dbg("np_thread_state %d\n",
			 np->np_thread_state);
		/**
		 * No point in stalling here when np_thread
		 * is in state RESET/SHUTDOWN/EXIT - bail
		 **/
		return -ENODEV;
	}
	spin_unlock_bh(&np->np_thread_lock);

	mutex_lock(&isert_np->mutex);
	if (list_empty(&isert_np->pending)) {
		mutex_unlock(&isert_np->mutex);
		goto accept_wait;
	}
	isert_conn = list_first_entry(&isert_np->pending,
			struct isert_conn, node);
	list_del_init(&isert_conn->node);
	mutex_unlock(&isert_np->mutex);

	conn->context = isert_conn;
	isert_conn->conn = conn;

	isert_set_conn_info(np, conn, isert_conn);

	isert_dbg("Processing isert_conn: %p\n", isert_conn);

	return 0;
}

static void
isert_free_np(struct iscsi_np *np)
{
	struct isert_np *isert_np = np->np_context;
	struct isert_conn *isert_conn, *n;

	if (isert_np->cm_id)
		rdma_destroy_id(isert_np->cm_id);

	/*
	 * FIXME: At this point we don't have a good way to insure
	 * that at this point we don't have hanging connections that
	 * completed RDMA establishment but didn't start iscsi login
	 * process. So work-around this by cleaning up what ever piled
	 * up in accepted and pending lists.
	 */
	mutex_lock(&isert_np->mutex);
	if (!list_empty(&isert_np->pending)) {
		isert_info("Still have isert pending connections\n");
		list_for_each_entry_safe(isert_conn, n,
					 &isert_np->pending,
					 node) {
			isert_info("cleaning isert_conn %p state (%d)\n",
				   isert_conn, isert_conn->state);
			isert_connect_release(isert_conn);
		}
	}

	if (!list_empty(&isert_np->accepted)) {
		isert_info("Still have isert accepted connections\n");
		list_for_each_entry_safe(isert_conn, n,
					 &isert_np->accepted,
					 node) {
			isert_info("cleaning isert_conn %p state (%d)\n",
				   isert_conn, isert_conn->state);
			isert_connect_release(isert_conn);
		}
	}
	mutex_unlock(&isert_np->mutex);

	np->np_context = NULL;
	kfree(isert_np);
}

static void isert_release_work(struct work_struct *work)
{
	struct isert_conn *isert_conn = container_of(work,
						     struct isert_conn,
						     release_work);

	isert_info("Starting release conn %p\n", isert_conn);

	wait_for_completion(&isert_conn->wait);

	mutex_lock(&isert_conn->mutex);
	isert_conn->state = ISER_CONN_DOWN;
	mutex_unlock(&isert_conn->mutex);

	isert_info("Destroying conn %p\n", isert_conn);
	isert_put_conn(isert_conn);
}

static void
isert_wait4logout(struct isert_conn *isert_conn)
{
	struct iscsi_conn *conn = isert_conn->conn;

	isert_info("conn %p\n", isert_conn);

	if (isert_conn->logout_posted) {
		isert_info("conn %p wait for conn_logout_comp\n", isert_conn);
		wait_for_completion_timeout(&conn->conn_logout_comp,
					    SECONDS_FOR_LOGOUT_COMP * HZ);
	}
}

static void
isert_wait4cmds(struct iscsi_conn *conn)
{
	isert_info("iscsi_conn %p\n", conn);

	if (conn->sess) {
		target_sess_cmd_list_set_waiting(conn->sess->se_sess);
		target_wait_for_sess_cmds(conn->sess->se_sess);
	}
}

static void
isert_wait4flush(struct isert_conn *isert_conn)
{
	struct ib_recv_wr *bad_wr;

	isert_info("conn %p\n", isert_conn);

	init_completion(&isert_conn->wait_comp_err);
	isert_conn->beacon.wr_id = ISER_BEACON_WRID;
	/* post an indication that all flush errors were consumed */
	if (ib_post_recv(isert_conn->qp, &isert_conn->beacon, &bad_wr)) {
		isert_err("conn %p failed to post beacon", isert_conn);
		return;
	}

	wait_for_completion(&isert_conn->wait_comp_err);
}

/**
 * isert_put_unsol_pending_cmds() - Drop commands waiting for
 *     unsolicitate dataout
 * @conn:    iscsi connection
 *
 * We might still have commands that are waiting for unsolicited
 * dataouts messages. We must put the extra reference on those
 * before blocking on the target_wait_for_session_cmds
 */
static void
isert_put_unsol_pending_cmds(struct iscsi_conn *conn)
{
	struct iscsi_cmd *cmd, *tmp;
	static LIST_HEAD(drop_cmd_list);

	spin_lock_bh(&conn->cmd_lock);
	list_for_each_entry_safe(cmd, tmp, &conn->conn_cmd_list, i_conn_node) {
		if ((cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA) &&
		    (cmd->write_data_done < conn->sess->sess_ops->FirstBurstLength) &&
		    (cmd->write_data_done < cmd->se_cmd.data_length))
			list_move_tail(&cmd->i_conn_node, &drop_cmd_list);
	}
	spin_unlock_bh(&conn->cmd_lock);

	list_for_each_entry_safe(cmd, tmp, &drop_cmd_list, i_conn_node) {
		list_del_init(&cmd->i_conn_node);
		if (cmd->i_state != ISTATE_REMOVE) {
			struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);

			isert_info("conn %p dropping cmd %p\n", conn, cmd);
			isert_put_cmd(isert_cmd, true);
		}
	}
}

static void isert_wait_conn(struct iscsi_conn *conn)
{
	struct isert_conn *isert_conn = conn->context;

	isert_info("Starting conn %p\n", isert_conn);

	mutex_lock(&isert_conn->mutex);
	/*
	 * Only wait for wait_comp_err if the isert_conn made it
	 * into full feature phase..
	 */
	if (isert_conn->state == ISER_CONN_INIT) {
		mutex_unlock(&isert_conn->mutex);
		return;
	}
	isert_conn_terminate(isert_conn);
	mutex_unlock(&isert_conn->mutex);

	isert_wait4flush(isert_conn);
	isert_put_unsol_pending_cmds(conn);
	isert_wait4cmds(conn);
	isert_wait4logout(isert_conn);

	queue_work(isert_release_wq, &isert_conn->release_work);
}

static void isert_free_conn(struct iscsi_conn *conn)
{
	struct isert_conn *isert_conn = conn->context;

	isert_wait4flush(isert_conn);
	isert_put_conn(isert_conn);
}

static struct iscsit_transport iser_target_transport = {
	.name			= "IB/iSER",
	.transport_type		= ISCSI_INFINIBAND,
	.priv_size		= sizeof(struct isert_cmd),
	.owner			= THIS_MODULE,
	.iscsit_setup_np	= isert_setup_np,
	.iscsit_accept_np	= isert_accept_np,
	.iscsit_free_np		= isert_free_np,
	.iscsit_wait_conn	= isert_wait_conn,
	.iscsit_free_conn	= isert_free_conn,
	.iscsit_get_login_rx	= isert_get_login_rx,
	.iscsit_put_login_tx	= isert_put_login_tx,
	.iscsit_immediate_queue	= isert_immediate_queue,
	.iscsit_response_queue	= isert_response_queue,
	.iscsit_get_dataout	= isert_get_dataout,
	.iscsit_queue_data_in	= isert_put_datain,
	.iscsit_queue_status	= isert_put_response,
	.iscsit_aborted_task	= isert_aborted_task,
	.iscsit_get_sup_prot_ops = isert_get_sup_prot_ops,
};

static int __init isert_init(void)
{
	int ret;

	isert_comp_wq = alloc_workqueue("isert_comp_wq",
					WQ_UNBOUND | WQ_HIGHPRI, 0);
	if (!isert_comp_wq) {
		isert_err("Unable to allocate isert_comp_wq\n");
		ret = -ENOMEM;
		return -ENOMEM;
	}

	isert_release_wq = alloc_workqueue("isert_release_wq", WQ_UNBOUND,
					WQ_UNBOUND_MAX_ACTIVE);
	if (!isert_release_wq) {
		isert_err("Unable to allocate isert_release_wq\n");
		ret = -ENOMEM;
		goto destroy_comp_wq;
	}

	iscsit_register_transport(&iser_target_transport);
	isert_info("iSER_TARGET[0] - Loaded iser_target_transport\n");

	return 0;

destroy_comp_wq:
	destroy_workqueue(isert_comp_wq);

	return ret;
}

static void __exit isert_exit(void)
{
	flush_scheduled_work();
	destroy_workqueue(isert_release_wq);
	destroy_workqueue(isert_comp_wq);
	iscsit_unregister_transport(&iser_target_transport);
	isert_info("iSER_TARGET[0] - Released iser_target_transport\n");
}

MODULE_DESCRIPTION("iSER-Target for mainline target infrastructure");
MODULE_VERSION("1.0");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");

module_init(isert_init);
module_exit(isert_exit);