text: /*******************************************************************************
   * 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("conn %p event: %d\n", isert_conn, e->event);
  	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 int
  isert_query_device(struct ib_device *ib_dev, struct ib_device_attr *devattr)
  {
  	int ret;
  
  	ret = ib_query_device(ib_dev, devattr);
  	if (ret) {
  		isert_err("ib_query_device() failed: %d\n", ret);
  		return ret;
  	}
  	isert_dbg("devattr->max_sge: %d\n", devattr->max_sge);
  	isert_dbg("devattr->max_sge_rd: %d\n", devattr->max_sge_rd);
  
  	return 0;
  }
  
  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;
  	/*
  	 * FIXME: Use devattr.max_sge - 2 for max_send_sge as
  	 * work-around for RDMA_READs with ConnectX-2.
  	 *
  	 * Also, still make sure to have at least two SGEs for
  	 * outgoing control PDU responses.
  	 */
  	attr.cap.max_send_sge = max(2, device->dev_attr.max_sge - 2);
  	isert_conn->max_sge = attr.cap.max_send_sge;
  
  	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->mr->lkey;
  	}
  
  	isert_conn->rx_desc_head = 0;
  
  	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,
  		  struct ib_device_attr *attr)
  {
  	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, attr->max_cqe);
  
  	for (i = 0; i < device->comps_used; i++) {
  		struct isert_comp *comp = &device->comps[i];
  
  		comp->device = device;
  		INIT_WORK(&comp->work, isert_cq_work);
  		comp->cq = ib_create_cq(device->ib_device,
  					isert_cq_callback,
  					isert_cq_event_callback,
  					(void *)comp,
  					max_cqe, i);
  		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_attr *dev_attr;
  	int ret;
  
  	dev_attr = &device->dev_attr;
  	ret = isert_query_device(device->ib_device, dev_attr);
  	if (ret)
  		return ret;
  
  	/* asign function handlers */
  	if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS &&
  	    dev_attr->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, dev_attr);
  	if (ret)
  		return ret;
  
  	device->pd = ib_alloc_pd(device->ib_device);
  	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;
  	}
  
  	device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE);
  	if (IS_ERR(device->mr)) {
  		ret = PTR_ERR(device->mr);
  		isert_err("failed to create dma mr, device %p, ret=%d\n",
  			  device, ret);
  		goto out_mr;
  	}
  
  	/* Check signature cap */
  	device->pi_capable = dev_attr->device_cap_flags &
  			     IB_DEVICE_SIGNATURE_HANDOVER ? true : false;
  
  	return 0;
  
  out_mr:
  	ib_dealloc_pd(device->pd);
  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_dereg_mr(device->mr);
  	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_free_fast_reg_page_list(fr_desc->data_frpl);
  		ib_dereg_mr(fr_desc->data_mr);
  		if (fr_desc->pi_ctx) {
  			ib_free_fast_reg_page_list(fr_desc->pi_ctx->prot_frpl);
  			ib_dereg_mr(fr_desc->pi_ctx->prot_mr);
  			ib_destroy_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 ib_mr_init_attr mr_init_attr;
  	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_frpl = ib_alloc_fast_reg_page_list(device,
  					    ISCSI_ISER_SG_TABLESIZE);
  	if (IS_ERR(pi_ctx->prot_frpl)) {
  		isert_err("Failed to allocate prot frpl err=%ld\n",
  			  PTR_ERR(pi_ctx->prot_frpl));
  		ret = PTR_ERR(pi_ctx->prot_frpl);
  		goto err_pi_ctx;
  	}
  
  	pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd, 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_prot_frpl;
  	}
  	desc->ind |= ISERT_PROT_KEY_VALID;
  
  	memset(&mr_init_attr, 0, sizeof(mr_init_attr));
  	mr_init_attr.max_reg_descriptors = 2;
  	mr_init_attr.flags |= IB_MR_SIGNATURE_EN;
  	pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
  	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_prot_frpl:
  	ib_free_fast_reg_page_list(pi_ctx->prot_frpl);
  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)
  {
  	int ret;
  
  	fr_desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
  							 ISCSI_ISER_SG_TABLESIZE);
  	if (IS_ERR(fr_desc->data_frpl)) {
  		isert_err("Failed to allocate data frpl err=%ld\n",
  			  PTR_ERR(fr_desc->data_frpl));
  		return PTR_ERR(fr_desc->data_frpl);
  	}
  
  	fr_desc->data_mr = ib_alloc_fast_reg_mr(pd, 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));
  		ret = PTR_ERR(fr_desc->data_mr);
  		goto err_data_frpl;
  	}
  	fr_desc->ind |= ISERT_DATA_KEY_VALID;
  
  	isert_dbg("Created fr_desc %p\n", fr_desc);
  
  	return 0;
  
  err_data_frpl:
  	ib_free_fast_reg_page_list(fr_desc->data_frpl);
  
  	return ret;
  }
  
  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->accept_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->dev_attr.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->np_accept_mutex);
  	list_add_tail(&isert_conn->accept_node, &isert_np->np_accept_list);
  	mutex_unlock(&isert_np->np_accept_mutex);
  
  	isert_info("np %p: Allow accept_np to continue\n", np);
  	up(&isert_np->np_sem);
  	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;
  
  	isert_info("conn %p\n", isert_conn);
  
  	if (!kref_get_unless_zero(&isert_conn->kref)) {
  		isert_warn("conn %p connect_release is running\n", isert_conn);
  		return;
  	}
  
  	mutex_lock(&isert_conn->mutex);
  	if (isert_conn->state != ISER_CONN_FULL_FEATURE)
  		isert_conn->state = ISER_CONN_UP;
  	mutex_unlock(&isert_conn->mutex);
  }
  
  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("isert np %p, handling event %d\n", isert_np, event);
  
  	switch (event) {
  	case RDMA_CM_EVENT_DEVICE_REMOVAL:
  		isert_np->np_cm_id = NULL;
  		break;
  	case RDMA_CM_EVENT_ADDR_CHANGE:
  		isert_np->np_cm_id = isert_setup_id(isert_np);
  		if (IS_ERR(isert_np->np_cm_id)) {
  			isert_err("isert np %p setup id failed: %ld\n",
  				  isert_np, PTR_ERR(isert_np->np_cm_id));
  			isert_np->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->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->np_accept_mutex);
  	if (!list_empty(&isert_conn->accept_node)) {
  		list_del_init(&isert_conn->accept_node);
  		isert_put_conn(isert_conn);
  		queue_work(isert_release_wq, &isert_conn->release_work);
  	}
  	mutex_unlock(&isert_np->np_accept_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;
  
  	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("event %d status %d id %p np %p\n", 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_recv(struct isert_conn *isert_conn, u32 count)
  {
  	struct ib_recv_wr *rx_wr, *rx_wr_failed;
  	int i, ret;
  	unsigned int rx_head = isert_conn->rx_desc_head;
  	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[rx_head];
  		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_head = (rx_head + 1) & (ISERT_QP_MAX_RECV_DTOS - 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;
  	} else {
  		isert_dbg("Posted %d RX buffers\n", count);
  		isert_conn->rx_desc_head = rx_head;
  	}
  	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->mr->lkey) {
  		tx_desc->tx_sg[0].lkey = device->mr->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->mr->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->mr->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->mr->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_recv(isert_conn, ISERT_MIN_POSTED_RX);
  			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 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;
  
  	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;
  	struct scatterlist *sg;
  	int imm_data, imm_data_len, unsol_data, sg_nents, rc;
  	bool dump_payload = false;
  
  	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;
  
  	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;
  
  	sg = &cmd->se_cmd.t_data_sg[0];
  	sg_nents = max(1UL, DIV_ROUND_UP(imm_data_len, PAGE_SIZE));
  
  	isert_dbg("Copying Immediate SG: %p sg_nents: %u from %p imm_data_len: %d\n",
  		  sg, sg_nents, &rx_desc->data[0], imm_data_len);
  
  	sg_copy_from_buffer(sg, sg_nents, &rx_desc->data[0], 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;
  
  	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);
  		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);
  		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);
  		if (!cmd)
  			break;
  
  		ret = iscsit_handle_task_mgt_cmd(conn, cmd,
  						(unsigned char *)hdr);
  		break;
  	case ISCSI_OP_LOGOUT:
  		cmd = isert_allocate_cmd(conn);
  		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);
  			if (!cmd)
  				break;
  		} else {
  			cmd = isert_allocate_cmd(conn);
  			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;
  	int rc;
  
  	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;
  	}
  
  	rc = 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, outstanding;
  
  	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--;
  	isert_dbg("Decremented post_recv_buf_count: %d\n",
  		  isert_conn->post_recv_buf_count);
  
  	if ((char *)desc == isert_conn->login_req_buf)
  		return;
  
  	outstanding = isert_conn->post_recv_buf_count;
  	if (outstanding + ISERT_MIN_POSTED_RX <= ISERT_QP_MAX_RECV_DTOS) {
  		int err, count = min(ISERT_QP_MAX_RECV_DTOS - outstanding,
  				ISERT_MIN_POSTED_RX);
  		err = isert_post_recv(isert_conn, count);
  		if (err) {
  			isert_err("isert_post_recv() count: %d failed, %d\n",
  			       count, err);
  		}
  	}
  }
  
  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->send_wr) {
  		isert_dbg("Cmd %p free send_wr\n", isert_cmd);
  		kfree(wr->send_wr);
  		wr->send_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->send_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->send_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->send_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("wr id %llx status %d vend_err %x\n",
  				  wc->wr_id, wc->status, wc->vendor_err);
  		else
  			isert_dbg("flush error: wr id %llx\n", 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 = 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->mr->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->mr->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->mr->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_send_wr *send_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;
  
  	send_wr->sg_list = ib_sge;
  	send_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->mr->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);
  	}
  
  	send_wr->num_sge = ++i;
  	isert_dbg("Set outgoing sg_list: %p num_sg: %u from TCM SGLs\n",
  		  send_wr->sg_list, send_wr->num_sge);
  
  	return send_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_send_wr *send_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->send_wr_num = DIV_ROUND_UP(data->nents, isert_conn->max_sge);
  	wr->send_wr = kzalloc(sizeof(struct ib_send_wr) * wr->send_wr_num,
  				GFP_KERNEL);
  	if (!wr->send_wr) {
  		isert_dbg("Unable to allocate wr->send_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->send_wr_num; i++) {
  		send_wr = &isert_cmd->rdma_wr.send_wr[i];
  		data_len = min(data_left, rdma_write_max);
  
  		send_wr->send_flags = 0;
  		if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
  			send_wr->opcode = IB_WR_RDMA_WRITE;
  			send_wr->wr.rdma.remote_addr = isert_cmd->read_va + offset;
  			send_wr->wr.rdma.rkey = isert_cmd->read_stag;
  			if (i + 1 == wr->send_wr_num)
  				send_wr->next = &isert_cmd->tx_desc.send_wr;
  			else
  				send_wr->next = &wr->send_wr[i + 1];
  		} else {
  			send_wr->opcode = IB_WR_RDMA_READ;
  			send_wr->wr.rdma.remote_addr = isert_cmd->write_va + va_offset;
  			send_wr->wr.rdma.rkey = isert_cmd->write_stag;
  			if (i + 1 == wr->send_wr_num)
  				send_wr->send_flags = IB_SEND_SIGNALED;
  			else
  				send_wr->next = &wr->send_wr[i + 1];
  		}
  
  		ib_sge_cnt = isert_build_rdma_wr(isert_conn, isert_cmd, ib_sge,
  					send_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 int
  isert_map_fr_pagelist(struct ib_device *ib_dev,
  		      struct scatterlist *sg_start, int sg_nents, u64 *fr_pl)
  {
  	u64 start_addr, end_addr, page, chunk_start = 0;
  	struct scatterlist *tmp_sg;
  	int i = 0, new_chunk, last_ent, n_pages;
  
  	n_pages = 0;
  	new_chunk = 1;
  	last_ent = sg_nents - 1;
  	for_each_sg(sg_start, tmp_sg, sg_nents, i) {
  		start_addr = ib_sg_dma_address(ib_dev, tmp_sg);
  		if (new_chunk)
  			chunk_start = start_addr;
  		end_addr = start_addr + ib_sg_dma_len(ib_dev, tmp_sg);
  
  		isert_dbg("SGL[%d] dma_addr: 0x%llx len: %u\n",
  			  i, (unsigned long long)tmp_sg->dma_address,
  			  tmp_sg->length);
  
  		if ((end_addr & ~PAGE_MASK) && i < last_ent) {
  			new_chunk = 0;
  			continue;
  		}
  		new_chunk = 1;
  
  		page = chunk_start & PAGE_MASK;
  		do {
  			fr_pl[n_pages++] = page;
  			isert_dbg("Mapped page_list[%d] page_addr: 0x%llx\n",
  				  n_pages - 1, page);
  			page += PAGE_SIZE;
  		} while (page < end_addr);
  	}
  
  	return n_pages;
  }
  
  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_fast_reg_page_list *frpl;
  	struct ib_send_wr fr_wr, inv_wr;
  	struct ib_send_wr *bad_wr, *wr = NULL;
  	int ret, pagelist_len;
  	u32 page_off;
  
  	if (mem->dma_nents == 1) {
  		sge->lkey = device->mr->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;
  		frpl = fr_desc->data_frpl;
  	} else {
  		/* Registering protection buffer */
  		mr = fr_desc->pi_ctx->prot_mr;
  		frpl = fr_desc->pi_ctx->prot_frpl;
  	}
  
  	page_off = mem->offset % PAGE_SIZE;
  
  	isert_dbg("Use fr_desc %p sg_nents %d offset %u\n",
  		  fr_desc, mem->nents, mem->offset);
  
  	pagelist_len = isert_map_fr_pagelist(ib_dev, mem->sg, mem->nents,
  					     &frpl->page_list[0]);
  
  	if (!(fr_desc->ind & ind)) {
  		isert_inv_rkey(&inv_wr, mr);
  		wr = &inv_wr;
  	}
  
  	/* Prepare FASTREG WR */
  	memset(&fr_wr, 0, sizeof(fr_wr));
  	fr_wr.wr_id = ISER_FASTREG_LI_WRID;
  	fr_wr.opcode = IB_WR_FAST_REG_MR;
  	fr_wr.wr.fast_reg.iova_start = frpl->page_list[0] + page_off;
  	fr_wr.wr.fast_reg.page_list = frpl;
  	fr_wr.wr.fast_reg.page_list_len = pagelist_len;
  	fr_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
  	fr_wr.wr.fast_reg.length = mem->len;
  	fr_wr.wr.fast_reg.rkey = mr->rkey;
  	fr_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE;
  
  	if (!wr)
  		wr = &fr_wr;
  	else
  		wr->next = &fr_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 = frpl->page_list[0] + page_off;
  	sge->length = mem->len;
  
  	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_send_wr sig_wr, inv_wr;
  	struct ib_send_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.opcode = IB_WR_REG_SIG_MR;
  	sig_wr.wr_id = ISER_FASTREG_LI_WRID;
  	sig_wr.sg_list = &rdma_wr->ib_sg[DATA];
  	sig_wr.num_sge = 1;
  	sig_wr.wr.sig_handover.access_flags = IB_ACCESS_LOCAL_WRITE;
  	sig_wr.wr.sig_handover.sig_attrs = &sig_attrs;
  	sig_wr.wr.sig_handover.sig_mr = pi_ctx->sig_mr;
  	if (se_cmd->t_prot_sg)
  		sig_wr.wr.sig_handover.prot = &rdma_wr->ib_sg[PROT];
  
  	if (!wr)
  		wr = &sig_wr;
  	else
  		wr->next = &sig_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_send_wr *send_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->send_wr_num = 1;
  	memset(&wr->s_send_wr, 0, sizeof(*send_wr));
  	wr->send_wr = &wr->s_send_wr;
  	wr->isert_cmd = isert_cmd;
  
  	send_wr = &isert_cmd->rdma_wr.s_send_wr;
  	send_wr->sg_list = &wr->s_ib_sge;
  	send_wr->num_sge = 1;
  	send_wr->wr_id = (uintptr_t)&isert_cmd->tx_desc;
  	if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
  		send_wr->opcode = IB_WR_RDMA_WRITE;
  		send_wr->wr.rdma.remote_addr = isert_cmd->read_va;
  		send_wr->wr.rdma.rkey = isert_cmd->read_stag;
  		send_wr->send_flags = !isert_prot_cmd(isert_conn, se_cmd) ?
  				      0 : IB_SEND_SIGNALED;
  	} else {
  		send_wr->opcode = IB_WR_RDMA_READ;
  		send_wr->wr.rdma.remote_addr = isert_cmd->write_va;
  		send_wr->wr.rdma.rkey = isert_cmd->write_stag;
  		send_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_send_wr.next = &isert_cmd->tx_desc.send_wr;
  		wr->send_wr_num += 1;
  	}
  
  	rc = ib_post_send(isert_conn->qp, wr->send_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->send_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(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 __kernel_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->np_sem, 0);
  	mutex_init(&isert_np->np_accept_mutex);
  	INIT_LIST_HEAD(&isert_np->np_accept_list);
  	init_completion(&isert_np->np_login_comp);
  	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 __kernel_sockaddr_storage));
  
  	isert_lid = isert_setup_id(isert_np);
  	if (IS_ERR(isert_lid)) {
  		ret = PTR_ERR(isert_lid);
  		goto out;
  	}
  
  	isert_np->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;
  	struct sockaddr_in *sock_in;
  	struct sockaddr_in6 *sock_in6;
  
  	conn->login_family = np->np_sockaddr.ss_family;
  
  	if (np->np_sockaddr.ss_family == AF_INET6) {
  		sock_in6 = (struct sockaddr_in6 *)&cm_route->addr.dst_addr;
  		snprintf(conn->login_ip, sizeof(conn->login_ip), "%pI6c",
  			 &sock_in6->sin6_addr.in6_u);
  		conn->login_port = ntohs(sock_in6->sin6_port);
  
  		sock_in6 = (struct sockaddr_in6 *)&cm_route->addr.src_addr;
  		snprintf(conn->local_ip, sizeof(conn->local_ip), "%pI6c",
  			 &sock_in6->sin6_addr.in6_u);
  		conn->local_port = ntohs(sock_in6->sin6_port);
  	} else {
  		sock_in = (struct sockaddr_in *)&cm_route->addr.dst_addr;
  		sprintf(conn->login_ip, "%pI4",
  			&sock_in->sin_addr.s_addr);
  		conn->login_port = ntohs(sock_in->sin_port);
  
  		sock_in = (struct sockaddr_in *)&cm_route->addr.src_addr;
  		sprintf(conn->local_ip, "%pI4",
  			&sock_in->sin_addr.s_addr);
  		conn->local_port = ntohs(sock_in->sin_port);
  	}
  }
  
  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->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->np_accept_mutex);
  	if (list_empty(&isert_np->np_accept_list)) {
  		mutex_unlock(&isert_np->np_accept_mutex);
  		goto accept_wait;
  	}
  	isert_conn = list_first_entry(&isert_np->np_accept_list,
  			struct isert_conn, accept_node);
  	list_del_init(&isert_conn->accept_node);
  	mutex_unlock(&isert_np->np_accept_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->np_cm_id)
  		rdma_destroy_id(isert_np->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 np_accept_list.
  	 */
  	mutex_lock(&isert_np->np_accept_mutex);
  	if (!list_empty(&isert_np->np_accept_list)) {
  		isert_info("Still have isert connections, cleaning up...\n");
  		list_for_each_entry_safe(isert_conn, n,
  					 &isert_np->np_accept_list,
  					 accept_node) {
  			isert_info("cleaning isert_conn %p state (%d)\n",
  				   isert_conn, isert_conn->state);
  			isert_connect_release(isert_conn);
  		}
  	}
  	mutex_unlock(&isert_np->np_accept_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);
  