[13/13] IB/isert: RW API WIP

Commit Message

Christoph Hellwig Feb. 27, 2016, 6:10 p.m. UTC

The SIG code still lives in ib_isert for now, although it operates
on the RW API data structures and could probably be moved to the
core without too much work once fully debugged.

Ignores the issue that more than a single MR might be required for
a command (guess that doesn't happen with mlx5 as the old code
didn't handle it either).
---
 drivers/infiniband/ulp/isert/ib_isert.c | 855 ++++++--------------------------
 drivers/infiniband/ulp/isert/ib_isert.h |  70 +--
 2 files changed, 161 insertions(+), 764 deletions(-)

Comments

Sagi Grimberg Feb. 28, 2016, 1:57 p.m. UTC | #1

>   drivers/infiniband/ulp/isert/ib_isert.c | 855 ++++++--------------------------
>   drivers/infiniband/ulp/isert/ib_isert.h |  70 +--
>   2 files changed, 161 insertions(+), 764 deletions(-)

Ha! 603 LOC deletion!

I plan to incorporate the signature stuff into the rdma_rw API
and then we can reduce it even further! It'll take me some time
though...
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Christoph Hellwig Feb. 28, 2016, 4:04 p.m. UTC | #2

On Sun, Feb 28, 2016 at 03:57:15PM +0200, Sagi Grimberg wrote:
>
>>   drivers/infiniband/ulp/isert/ib_isert.c | 855 ++++++--------------------------
>>   drivers/infiniband/ulp/isert/ib_isert.h |  70 +--
>>   2 files changed, 161 insertions(+), 764 deletions(-)
>
> Ha! 603 LOC deletion!
>
> I plan to incorporate the signature stuff into the rdma_rw API
> and then we can reduce it even further! It'll take me some time
> though...

The whole series including the CQ API actually removes more code
than it adds even with a single consumer.
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Patch

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index e1a553f..900533c 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -33,7 +33,8 @@ 
 
 #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_TX_CQ_LEN \
+	((ISERT_QP_MAX_REQ_DTOS + ISERT_QP_MAX_RDMA_OPS) * ISERT_MAX_CONN)
 #define ISER_MAX_CQ_LEN		(ISER_MAX_RX_CQ_LEN + ISER_MAX_TX_CQ_LEN + \
 				 ISERT_MAX_CONN)
 
@@ -46,14 +47,6 @@  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 isert_cmd *isert_cmd, struct iscsi_conn *conn);
-static void
-isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn);
-static int
-isert_reg_rdma(struct isert_cmd *isert_cmd, struct iscsi_conn *conn);
 static int
 isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd);
 static int
@@ -142,6 +135,7 @@  isert_create_qp(struct isert_conn *isert_conn,
 	attr.recv_cq = comp->cq;
 	attr.cap.max_send_wr = ISERT_QP_MAX_REQ_DTOS;
 	attr.cap.max_recv_wr = ISERT_QP_MAX_RECV_DTOS + 1;
+	attr.cap.max_rdma_ctxs = ISERT_QP_MAX_RDMA_OPS;
 	attr.cap.max_send_sge = device->ib_device->attrs.max_sge;
 	isert_conn->max_sge = min(device->ib_device->attrs.max_sge,
 				  device->ib_device->attrs.max_sge_rd);
@@ -269,9 +263,9 @@  isert_alloc_comps(struct isert_device *device)
 				 device->ib_device->num_comp_vectors));
 
 	isert_info("Using %d CQs, %s supports %d vectors support "
-		   "Fast registration %d pi_capable %d\n",
+		   "pi_capable %d\n",
 		   device->comps_used, device->ib_device->name,
-		   device->ib_device->num_comp_vectors, device->use_fastreg,
+		   device->ib_device->num_comp_vectors,
 		   device->pi_capable);
 
 	device->comps = kcalloc(device->comps_used, sizeof(struct isert_comp),
@@ -312,18 +306,6 @@  isert_create_device_ib_res(struct isert_device *device)
 	isert_dbg("devattr->max_sge: %d\n", ib_dev->attrs.max_sge);
 	isert_dbg("devattr->max_sge_rd: %d\n", ib_dev->attrs.max_sge_rd);
 
-	/* asign function handlers */
-	if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS &&
-	    ib_dev->attrs.device_cap_flags & IB_DEVICE_SIGNATURE_HANDOVER) {
-		device->use_fastreg = 1;
-		device->reg_rdma_mem = isert_reg_rdma;
-		device->unreg_rdma_mem = isert_unreg_rdma;
-	} else {
-		device->use_fastreg = 0;
-		device->reg_rdma_mem = isert_map_rdma;
-		device->unreg_rdma_mem = isert_unmap_cmd;
-	}
-
 	ret = isert_alloc_comps(device);
 	if (ret)
 		goto out;
@@ -416,146 +398,6 @@  isert_device_get(struct rdma_cm_id *cma_id)
 }
 
 static void
-isert_conn_free_fastreg_pool(struct isert_conn *isert_conn)
-{
-	struct fast_reg_descriptor *fr_desc, *tmp;
-	int i = 0;
-
-	if (list_empty(&isert_conn->fr_pool))
-		return;
-
-	isert_info("Freeing conn %p fastreg pool", isert_conn);
-
-	list_for_each_entry_safe(fr_desc, tmp,
-				 &isert_conn->fr_pool, list) {
-		list_del(&fr_desc->list);
-		ib_dereg_mr(fr_desc->data_mr);
-		if (fr_desc->pi_ctx) {
-			ib_dereg_mr(fr_desc->pi_ctx->prot_mr);
-			ib_dereg_mr(fr_desc->pi_ctx->sig_mr);
-			kfree(fr_desc->pi_ctx);
-		}
-		kfree(fr_desc);
-		++i;
-	}
-
-	if (i < isert_conn->fr_pool_size)
-		isert_warn("Pool still has %d regions registered\n",
-			isert_conn->fr_pool_size - i);
-}
-
-static int
-isert_create_pi_ctx(struct fast_reg_descriptor *desc,
-		    struct ib_device *device,
-		    struct ib_pd *pd)
-{
-	struct pi_context *pi_ctx;
-	int ret;
-
-	pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
-	if (!pi_ctx) {
-		isert_err("Failed to allocate pi context\n");
-		return -ENOMEM;
-	}
-
-	pi_ctx->prot_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
-				      ISCSI_ISER_SG_TABLESIZE);
-	if (IS_ERR(pi_ctx->prot_mr)) {
-		isert_err("Failed to allocate prot frmr err=%ld\n",
-			  PTR_ERR(pi_ctx->prot_mr));
-		ret = PTR_ERR(pi_ctx->prot_mr);
-		goto err_pi_ctx;
-	}
-	desc->ind |= ISERT_PROT_KEY_VALID;
-
-	pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
-	if (IS_ERR(pi_ctx->sig_mr)) {
-		isert_err("Failed to allocate signature enabled mr err=%ld\n",
-			  PTR_ERR(pi_ctx->sig_mr));
-		ret = PTR_ERR(pi_ctx->sig_mr);
-		goto err_prot_mr;
-	}
-
-	desc->pi_ctx = pi_ctx;
-	desc->ind |= ISERT_SIG_KEY_VALID;
-	desc->ind &= ~ISERT_PROTECTED;
-
-	return 0;
-
-err_prot_mr:
-	ib_dereg_mr(pi_ctx->prot_mr);
-err_pi_ctx:
-	kfree(pi_ctx);
-
-	return ret;
-}
-
-static int
-isert_create_fr_desc(struct ib_device *ib_device, struct ib_pd *pd,
-		     struct fast_reg_descriptor *fr_desc)
-{
-	fr_desc->data_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
-				       ISCSI_ISER_SG_TABLESIZE);
-	if (IS_ERR(fr_desc->data_mr)) {
-		isert_err("Failed to allocate data frmr err=%ld\n",
-			  PTR_ERR(fr_desc->data_mr));
-		return PTR_ERR(fr_desc->data_mr);
-	}
-	fr_desc->ind |= ISERT_DATA_KEY_VALID;
-
-	isert_dbg("Created fr_desc %p\n", fr_desc);
-
-	return 0;
-}
-
-static int
-isert_conn_create_fastreg_pool(struct isert_conn *isert_conn)
-{
-	struct fast_reg_descriptor *fr_desc;
-	struct isert_device *device = isert_conn->device;
-	struct se_session *se_sess = isert_conn->conn->sess->se_sess;
-	struct se_node_acl *se_nacl = se_sess->se_node_acl;
-	int i, ret, tag_num;
-	/*
-	 * Setup the number of FRMRs based upon the number of tags
-	 * available to session in iscsi_target_locate_portal().
-	 */
-	tag_num = max_t(u32, ISCSIT_MIN_TAGS, se_nacl->queue_depth);
-	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
-
-	isert_conn->fr_pool_size = 0;
-	for (i = 0; i < tag_num; i++) {
-		fr_desc = kzalloc(sizeof(*fr_desc), GFP_KERNEL);
-		if (!fr_desc) {
-			isert_err("Failed to allocate fast_reg descriptor\n");
-			ret = -ENOMEM;
-			goto err;
-		}
-
-		ret = isert_create_fr_desc(device->ib_device,
-					   device->pd, fr_desc);
-		if (ret) {
-			isert_err("Failed to create fastreg descriptor err=%d\n",
-			       ret);
-			kfree(fr_desc);
-			goto err;
-		}
-
-		list_add_tail(&fr_desc->list, &isert_conn->fr_pool);
-		isert_conn->fr_pool_size++;
-	}
-
-	isert_dbg("Creating conn %p fastreg pool size=%d",
-		 isert_conn, isert_conn->fr_pool_size);
-
-	return 0;
-
-err:
-	isert_conn_free_fastreg_pool(isert_conn);
-	return ret;
-}
-
-static void
 isert_init_conn(struct isert_conn *isert_conn)
 {
 	isert_conn->state = ISER_CONN_INIT;
@@ -565,8 +407,6 @@  isert_init_conn(struct isert_conn *isert_conn)
 	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);
 }
 
@@ -739,9 +579,6 @@  isert_connect_release(struct isert_conn *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);
@@ -1083,7 +920,6 @@  isert_init_send_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
 {
 	struct iser_tx_desc *tx_desc = &isert_cmd->tx_desc;
 
-	isert_cmd->iser_ib_op = ISER_IB_SEND;
 	tx_desc->tx_cqe.done = isert_send_done;
 	send_wr->wr_cqe = &tx_desc->tx_cqe;
 
@@ -1166,16 +1002,6 @@  isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
 	}
 	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;
@@ -1647,97 +1473,29 @@  isert_login_recv_done(struct ib_cq *cq, struct ib_wc *wc)
 	isert_conn->post_recv_buf_count--;
 }
 
-static int
-isert_map_data_buf(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
-		   struct scatterlist *sg, u32 nents, u32 length, u32 offset,
-		   enum iser_ib_op_code op, struct isert_data_buf *data)
-{
-	struct ib_device *ib_dev = isert_conn->cm_id->device;
-
-	data->dma_dir = op == ISER_IB_RDMA_WRITE ?
-			      DMA_TO_DEVICE : DMA_FROM_DEVICE;
-
-	data->len = length - offset;
-	data->offset = offset;
-	data->sg_off = data->offset / PAGE_SIZE;
-
-	data->sg = &sg[data->sg_off];
-	data->nents = min_t(unsigned int, nents - data->sg_off,
-					  ISCSI_ISER_SG_TABLESIZE);
-	data->len = min_t(unsigned int, data->len, ISCSI_ISER_SG_TABLESIZE *
-					PAGE_SIZE);
-
-	data->dma_nents = ib_dma_map_sg(ib_dev, data->sg, data->nents,
-					data->dma_dir);
-	if (unlikely(!data->dma_nents)) {
-		isert_err("Cmd: unable to dma map SGs %p\n", sg);
-		return -EINVAL;
-	}
-
-	isert_dbg("Mapped cmd: %p count: %u sg: %p sg_nents: %u rdma_len %d\n",
-		  isert_cmd, data->dma_nents, data->sg, data->nents, data->len);
-
-	return 0;
-}
-
-static void
-isert_unmap_data_buf(struct isert_conn *isert_conn, struct isert_data_buf *data)
-{
-	struct ib_device *ib_dev = isert_conn->cm_id->device;
-
-	ib_dma_unmap_sg(ib_dev, data->sg, data->nents, data->dma_dir);
-	memset(data, 0, sizeof(*data));
-}
-
-
-
 static void
-isert_unmap_cmd(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
+isert_unreg_rdma_mem(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
 {
 	isert_dbg("Cmd %p\n", isert_cmd);
-
-	if (isert_cmd->data.sg) {
-		isert_dbg("Cmd %p unmap_sg op\n", isert_cmd);
-		isert_unmap_data_buf(isert_conn, &isert_cmd->data);
-	}
-
-	if (isert_cmd->rdma_wr) {
-		isert_dbg("Cmd %p free send_wr\n", isert_cmd);
-		kfree(isert_cmd->rdma_wr);
-		isert_cmd->rdma_wr = NULL;
-	}
-
-	if (isert_cmd->ib_sge) {
-		isert_dbg("Cmd %p free ib_sge\n", isert_cmd);
-		kfree(isert_cmd->ib_sge);
-		isert_cmd->ib_sge = NULL;
-	}
-}
-
-static void
-isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
-{
-	isert_dbg("Cmd %p\n", isert_cmd);
-
-	if (isert_cmd->fr_desc) {
-		isert_dbg("Cmd %p free fr_desc %p\n", isert_cmd, isert_cmd->fr_desc);
-		if (isert_cmd->fr_desc->ind & ISERT_PROTECTED) {
-			isert_unmap_data_buf(isert_conn, &isert_cmd->prot);
-			isert_cmd->fr_desc->ind &= ~ISERT_PROTECTED;
+		
+	if (isert_cmd->sig_mr) {
+		if (isert_cmd->prot.sg) {
+			rdma_rw_ctx_destroy(&isert_cmd->prot, isert_conn->qp,
+					isert_conn->cm_id->port_num);
+			isert_cmd->prot.sg = NULL;
 		}
-		spin_lock_bh(&isert_conn->pool_lock);
-		list_add_tail(&isert_cmd->fr_desc->list, &isert_conn->fr_pool);
-		spin_unlock_bh(&isert_conn->pool_lock);
-		isert_cmd->fr_desc = NULL;
+
+		ib_mr_pool_put(isert_conn->qp, &isert_conn->qp->sig_mrs,
+			isert_cmd->sig_mr);
+		isert_cmd->sig_mr = NULL;
 	}
 
 	if (isert_cmd->data.sg) {
 		isert_dbg("Cmd %p unmap_sg op\n", isert_cmd);
-		isert_unmap_data_buf(isert_conn, &isert_cmd->data);
+		rdma_rw_ctx_destroy(&isert_cmd->data, isert_conn->qp,
+				isert_conn->cm_id->port_num);
+		isert_cmd->data.sg = NULL;
 	}
-
-	isert_cmd->ib_sge = NULL;
-	isert_cmd->rdma_wr = NULL;
 }
 
 static void
@@ -1746,7 +1504,6 @@  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);
@@ -1774,7 +1531,7 @@  isert_put_cmd(struct isert_cmd *isert_cmd, bool comp_err)
 			}
 		}
 
-		device->unreg_rdma_mem(isert_cmd, isert_conn);
+		isert_unreg_rdma_mem(isert_cmd, isert_conn);
 		transport_generic_free_cmd(&cmd->se_cmd, 0);
 		break;
 	case ISCSI_OP_SCSI_TMFUNC:
@@ -1908,14 +1665,10 @@  isert_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc)
 
 	isert_dbg("Cmd %p\n", isert_cmd);
 
-	if (isert_cmd->fr_desc && isert_cmd->fr_desc->ind & ISERT_PROTECTED) {
-		ret = isert_check_pi_status(cmd,
-				isert_cmd->fr_desc->pi_ctx->sig_mr);
-		isert_cmd->fr_desc->ind &= ~ISERT_PROTECTED;
-	}
+	if (isert_cmd->sig_mr)
+		ret = isert_check_pi_status(cmd, isert_cmd->sig_mr);
 
-	device->unreg_rdma_mem(isert_cmd, isert_conn);
-	isert_cmd->rdma_wr_num = 0;
+	isert_unreg_rdma_mem(isert_cmd, isert_conn);
 	if (ret)
 		transport_send_check_condition_and_sense(cmd, cmd->pi_err, 0);
 	else
@@ -1943,16 +1696,13 @@  isert_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
 
 	isert_dbg("Cmd %p\n", isert_cmd);
 
-	if (isert_cmd->fr_desc && isert_cmd->fr_desc->ind & ISERT_PROTECTED) {
-		ret = isert_check_pi_status(se_cmd,
-					    isert_cmd->fr_desc->pi_ctx->sig_mr);
-		isert_cmd->fr_desc->ind &= ~ISERT_PROTECTED;
-	}
+	if (isert_cmd->sig_mr)
+		ret = isert_check_pi_status(se_cmd, isert_cmd->sig_mr);
 
 	iscsit_stop_dataout_timer(cmd);
-	device->unreg_rdma_mem(isert_cmd, isert_conn);
-	cmd->write_data_done = isert_cmd->data.len;
-	isert_cmd->rdma_wr_num = 0;
+	isert_unreg_rdma_mem(isert_cmd, isert_conn);
+
+	cmd->write_data_done = 0;
 
 	isert_dbg("Cmd: %p RDMA_READ comp calling execute_cmd\n", isert_cmd);
 	spin_lock_bh(&cmd->istate_lock);
@@ -2123,7 +1873,6 @@  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))
@@ -2133,7 +1882,7 @@  isert_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 	if (cmd->data_direction == DMA_TO_DEVICE)
 		iscsit_stop_dataout_timer(cmd);
 
-	device->unreg_rdma_mem(isert_cmd, isert_conn);
+	isert_unreg_rdma_mem(isert_cmd, isert_conn);
 }
 
 static enum target_prot_op
@@ -2286,234 +2035,6 @@  isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
 	return isert_post_response(isert_conn, isert_cmd);
 }
 
-static int
-isert_build_rdma_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
-		    struct ib_sge *ib_sge, struct ib_rdma_wr *rdma_wr,
-		    u32 data_left, u32 offset)
-{
-	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
-	struct scatterlist *sg_start, *tmp_sg;
-	struct isert_device *device = isert_conn->device;
-	struct ib_device *ib_dev = device->ib_device;
-	u32 sg_off, page_off;
-	int i = 0, sg_nents;
-
-	sg_off = offset / PAGE_SIZE;
-	sg_start = &cmd->se_cmd.t_data_sg[sg_off];
-	sg_nents = min(cmd->se_cmd.t_data_nents - sg_off, isert_conn->max_sge);
-	page_off = offset % PAGE_SIZE;
-
-	rdma_wr->wr.sg_list = ib_sge;
-	rdma_wr->wr.wr_cqe = &isert_cmd->tx_desc.tx_cqe;
-
-	/*
-	 * Perform mapping of TCM scatterlist memory ib_sge dma_addr.
-	 */
-	for_each_sg(sg_start, tmp_sg, sg_nents, i) {
-		isert_dbg("RDMA from SGL dma_addr: 0x%llx dma_len: %u, "
-			  "page_off: %u\n",
-			  (unsigned long long)tmp_sg->dma_address,
-			  tmp_sg->length, page_off);
-
-		ib_sge->addr = ib_sg_dma_address(ib_dev, tmp_sg) + page_off;
-		ib_sge->length = min_t(u32, data_left,
-				ib_sg_dma_len(ib_dev, tmp_sg) - page_off);
-		ib_sge->lkey = device->pd->local_dma_lkey;
-
-		isert_dbg("RDMA ib_sge: addr: 0x%llx  length: %u lkey: %x\n",
-			  ib_sge->addr, ib_sge->length, ib_sge->lkey);
-		page_off = 0;
-		data_left -= ib_sge->length;
-		if (!data_left)
-			break;
-		ib_sge++;
-		isert_dbg("Incrementing ib_sge pointer to %p\n", ib_sge);
-	}
-
-	rdma_wr->wr.num_sge = ++i;
-	isert_dbg("Set outgoing sg_list: %p num_sg: %u from TCM SGLs\n",
-		  rdma_wr->wr.sg_list, rdma_wr->wr.num_sge);
-
-	return rdma_wr->wr.num_sge;
-}
-
-static int
-isert_map_rdma(struct isert_cmd *isert_cmd, struct iscsi_conn *conn)
-{
-	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
-	struct se_cmd *se_cmd = &cmd->se_cmd;
-	struct isert_conn *isert_conn = conn->context;
-	struct isert_data_buf *data = &isert_cmd->data;
-	struct ib_rdma_wr *rdma_wr;
-	struct ib_sge *ib_sge;
-	u32 offset, data_len, data_left, rdma_write_max, va_offset = 0;
-	int ret = 0, i, ib_sge_cnt;
-
-	offset = isert_cmd->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, isert_cmd->iser_ib_op,
-				 &isert_cmd->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;
-	}
-	isert_cmd->ib_sge = ib_sge;
-
-	isert_cmd->rdma_wr_num = DIV_ROUND_UP(data->nents, isert_conn->max_sge);
-	isert_cmd->rdma_wr = kzalloc(sizeof(struct ib_rdma_wr) *
-			isert_cmd->rdma_wr_num, GFP_KERNEL);
-	if (!isert_cmd->rdma_wr) {
-		isert_dbg("Unable to allocate isert_cmd->rdma_wr\n");
-		ret = -ENOMEM;
-		goto unmap_cmd;
-	}
-
-	rdma_write_max = isert_conn->max_sge * PAGE_SIZE;
-
-	for (i = 0; i < isert_cmd->rdma_wr_num; i++) {
-		rdma_wr = &isert_cmd->rdma_wr[i];
-		data_len = min(data_left, rdma_write_max);
-
-		rdma_wr->wr.send_flags = 0;
-		if (isert_cmd->iser_ib_op == ISER_IB_RDMA_WRITE) {
-			isert_cmd->tx_desc.tx_cqe.done = isert_rdma_write_done;
-
-			rdma_wr->wr.opcode = IB_WR_RDMA_WRITE;
-			rdma_wr->remote_addr = isert_cmd->read_va + offset;
-			rdma_wr->rkey = isert_cmd->read_stag;
-			if (i + 1 == isert_cmd->rdma_wr_num)
-				rdma_wr->wr.next = &isert_cmd->tx_desc.send_wr;
-			else
-				rdma_wr->wr.next = &isert_cmd->rdma_wr[i + 1].wr;
-		} else {
-			isert_cmd->tx_desc.tx_cqe.done = isert_rdma_read_done;
-
-			rdma_wr->wr.opcode = IB_WR_RDMA_READ;
-			rdma_wr->remote_addr = isert_cmd->write_va + va_offset;
-			rdma_wr->rkey = isert_cmd->write_stag;
-			if (i + 1 == isert_cmd->rdma_wr_num)
-				rdma_wr->wr.send_flags = IB_SEND_SIGNALED;
-			else
-				rdma_wr->wr.next = &isert_cmd->rdma_wr[i + 1].wr;
-		}
-
-		ib_sge_cnt = isert_build_rdma_wr(isert_conn, isert_cmd, ib_sge,
-					rdma_wr, data_len, offset);
-		ib_sge += ib_sge_cnt;
-
-		offset += data_len;
-		va_offset += data_len;
-		data_left -= data_len;
-	}
-
-	return 0;
-unmap_cmd:
-	isert_unmap_data_buf(isert_conn, data);
-
-	return ret;
-}
-
-static inline void
-isert_inv_rkey(struct ib_send_wr *inv_wr, struct ib_mr *mr)
-{
-	u32 rkey;
-
-	memset(inv_wr, 0, sizeof(*inv_wr));
-	inv_wr->wr_cqe = NULL;
-	inv_wr->opcode = IB_WR_LOCAL_INV;
-	inv_wr->ex.invalidate_rkey = mr->rkey;
-
-	/* Bump the key */
-	rkey = ib_inc_rkey(mr->rkey);
-	ib_update_fast_reg_key(mr, rkey);
-}
-
-static int
-isert_fast_reg_mr(struct isert_conn *isert_conn,
-		  struct fast_reg_descriptor *fr_desc,
-		  struct isert_data_buf *mem,
-		  enum isert_indicator ind,
-		  struct ib_sge *sge)
-{
-	struct isert_device *device = isert_conn->device;
-	struct ib_device *ib_dev = device->ib_device;
-	struct ib_mr *mr;
-	struct ib_reg_wr reg_wr;
-	struct ib_send_wr inv_wr, *bad_wr, *wr = NULL;
-	int ret, n;
-
-	if (mem->dma_nents == 1) {
-		sge->lkey = device->pd->local_dma_lkey;
-		sge->addr = ib_sg_dma_address(ib_dev, &mem->sg[0]);
-		sge->length = ib_sg_dma_len(ib_dev, &mem->sg[0]);
-		isert_dbg("sge: addr: 0x%llx  length: %u lkey: %x\n",
-			 sge->addr, sge->length, sge->lkey);
-		return 0;
-	}
-
-	if (ind == ISERT_DATA_KEY_VALID)
-		/* Registering data buffer */
-		mr = fr_desc->data_mr;
-	else
-		/* Registering protection buffer */
-		mr = fr_desc->pi_ctx->prot_mr;
-
-	if (!(fr_desc->ind & ind)) {
-		isert_inv_rkey(&inv_wr, mr);
-		wr = &inv_wr;
-	}
-
-	n = ib_map_mr_sg(mr, mem->sg, mem->nents, 0, PAGE_SIZE);
-	if (unlikely(n != mem->nents)) {
-		isert_err("failed to map mr sg (%d/%d)\n",
-			 n, mem->nents);
-		return n < 0 ? n : -EINVAL;
-	}
-
-	isert_dbg("Use fr_desc %p sg_nents %d offset %u\n",
-		  fr_desc, mem->nents, mem->offset);
-
-	reg_wr.wr.next = NULL;
-	reg_wr.wr.opcode = IB_WR_REG_MR;
-	reg_wr.wr.wr_cqe = NULL;
-	reg_wr.wr.send_flags = 0;
-	reg_wr.wr.num_sge = 0;
-	reg_wr.mr = mr;
-	reg_wr.key = mr->lkey;
-	reg_wr.access = IB_ACCESS_LOCAL_WRITE;
-
-	if (!wr)
-		wr = &reg_wr.wr;
-	else
-		wr->next = &reg_wr.wr;
-
-	ret = ib_post_send(isert_conn->qp, wr, &bad_wr);
-	if (ret) {
-		isert_err("fast registration failed, ret:%d\n", ret);
-		return ret;
-	}
-	fr_desc->ind &= ~ind;
-
-	sge->lkey = mr->lkey;
-	sge->addr = mr->iova;
-	sge->length = mr->length;
-
-	isert_dbg("sge: addr: 0x%llx  length: %u lkey: %x\n",
-		  sge->addr, sge->length, sge->lkey);
-
-	return ret;
-}
-
 static inline void
 isert_set_dif_domain(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs,
 		     struct ib_sig_domain *domain)
@@ -2538,6 +2059,8 @@  isert_set_dif_domain(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs,
 static int
 isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
 {
+	memset(sig_attrs, 0, sizeof(*sig_attrs));
+
 	switch (se_cmd->prot_op) {
 	case TARGET_PROT_DIN_INSERT:
 	case TARGET_PROT_DOUT_STRIP:
@@ -2559,229 +2082,152 @@  isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
 		return -EINVAL;
 	}
 
+	sig_attrs->check_mask =
+	       (se_cmd->prot_checks & TARGET_DIF_CHECK_GUARD  ? 0xc0 : 0) |
+	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x30 : 0) |
+	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x0f : 0);
 	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,
+isert_reg_sig_mr(struct ib_qp *qp,
 		 struct isert_cmd *isert_cmd,
-		 struct fast_reg_descriptor *fr_desc)
+		 struct ib_sig_attrs *sig_attrs)
 {
 	struct se_cmd *se_cmd = &isert_cmd->iscsi_cmd->se_cmd;
 	struct ib_sig_handover_wr sig_wr;
 	struct ib_send_wr inv_wr, *bad_wr, *wr = NULL;
-	struct pi_context *pi_ctx = fr_desc->pi_ctx;
-	struct ib_sig_attrs sig_attrs;
+	struct ib_rdma_wr rdma_wr;
+	struct ib_sge sge;
 	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);
+	isert_cmd->sig_mr = ib_mr_pool_get(qp, &qp->sig_mrs);
+	if (!isert_cmd->sig_mr)
+		return -EAGAIN;
 
-	if (!(fr_desc->ind & ISERT_SIG_KEY_VALID)) {
-		isert_inv_rkey(&inv_wr, pi_ctx->sig_mr);
+	if (1 /* add need_inval flag to the MR */) {
+		memset(&inv_wr, 0, sizeof(inv_wr));
+		inv_wr.opcode = IB_WR_LOCAL_INV;
+		inv_wr.ex.invalidate_rkey = isert_cmd->sig_mr->rkey;
+		ib_update_fast_reg_key(isert_cmd->sig_mr,
+			ib_inc_rkey(isert_cmd->sig_mr->rkey));
 		wr = &inv_wr;
 	}
 
 	memset(&sig_wr, 0, sizeof(sig_wr));
 	sig_wr.wr.opcode = IB_WR_REG_SIG_MR;
 	sig_wr.wr.wr_cqe = NULL;
-	sig_wr.wr.sg_list = &isert_cmd->ib_sg[DATA];
+	sig_wr.wr.sg_list = &isert_cmd->data.reg->sge;
 	sig_wr.wr.num_sge = 1;
 	sig_wr.access_flags = IB_ACCESS_LOCAL_WRITE;
-	sig_wr.sig_attrs = &sig_attrs;
-	sig_wr.sig_mr = pi_ctx->sig_mr;
+	sig_wr.sig_attrs = sig_attrs;
+	sig_wr.sig_mr = isert_cmd->sig_mr;
 	if (se_cmd->t_prot_sg)
-		sig_wr.prot = &isert_cmd->ib_sg[PROT];
+		sig_wr.prot = &isert_cmd->prot.reg->sge;
 
 	if (!wr)
 		wr = &sig_wr.wr;
 	else
 		wr->next = &sig_wr.wr;
 
-	ret = ib_post_send(isert_conn->qp, wr, &bad_wr);
-	if (ret) {
-		isert_err("fast registration failed, ret:%d\n", ret);
-		goto err;
-	}
-	fr_desc->ind &= ~ISERT_SIG_KEY_VALID;
-
-	isert_cmd->ib_sg[SIG].lkey = pi_ctx->sig_mr->lkey;
-	isert_cmd->ib_sg[SIG].addr = 0;
-	isert_cmd->ib_sg[SIG].length = se_cmd->data_length;
+	sge.lkey = isert_cmd->sig_mr->lkey;
+	sge.addr = 0;
+	sge.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
 		 */
-		isert_cmd->ib_sg[SIG].length += se_cmd->prot_length;
+		sge.length += se_cmd->prot_length;
 
 	isert_dbg("sig_sge: addr: 0x%llx  length: %u lkey: %x\n",
-		  isert_cmd->ib_sg[SIG].addr, isert_cmd->ib_sg[SIG].length,
-		  isert_cmd->ib_sg[SIG].lkey);
-err:
-	return ret;
-}
+		  sge.addr, sge.length, sge.lkey);
 
-static int
-isert_handle_prot_cmd(struct isert_conn *isert_conn,
-		      struct isert_cmd *isert_cmd)
-{
-	struct isert_device *device = isert_conn->device;
-	struct se_cmd *se_cmd = &isert_cmd->iscsi_cmd->se_cmd;
-	int ret;
+	rdma_wr.wr.sg_list = &sge;
+	rdma_wr.wr.num_sge = 1;
+	rdma_wr.wr.wr_cqe = &isert_cmd->tx_desc.tx_cqe;
+	rdma_wr.wr.send_flags = IB_SEND_SIGNALED;
 
-	if (!isert_cmd->fr_desc->pi_ctx) {
-		ret = isert_create_pi_ctx(isert_cmd->fr_desc,
-					  device->ib_device,
-					  device->pd);
-		if (ret) {
-			isert_err("conn %p failed to allocate pi_ctx\n",
-				  isert_conn);
-			return ret;
-		}
+	if (isert_cmd->data.dma_dir == DMA_TO_DEVICE) {
+		rdma_wr.wr.opcode = IB_WR_RDMA_WRITE;
+		rdma_wr.remote_addr = isert_cmd->read_va;
+		rdma_wr.rkey = isert_cmd->read_stag;
+	} else {
+		rdma_wr.wr.opcode = IB_WR_RDMA_READ;
+		rdma_wr.remote_addr = isert_cmd->write_va;
+		rdma_wr.rkey = isert_cmd->write_stag;
 	}
 
-	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,
-					 isert_cmd->iser_ib_op,
-					 &isert_cmd->prot);
-		if (ret) {
-			isert_err("conn %p failed to map protection buffer\n",
-				  isert_conn);
-			return ret;
-		}
+	sig_wr.wr.next = &rdma_wr.wr;
 
-		memset(&isert_cmd->ib_sg[PROT], 0, sizeof(isert_cmd->ib_sg[PROT]));
-		ret = isert_fast_reg_mr(isert_conn, isert_cmd->fr_desc,
-					&isert_cmd->prot,
-					ISERT_PROT_KEY_VALID,
-					&isert_cmd->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, isert_cmd, isert_cmd->fr_desc);
+	ret = ib_post_send(qp, wr, &bad_wr);
 	if (ret) {
-		isert_err("conn %p failed to fast reg mr\n",
-			  isert_conn);
-		goto unmap_prot_cmd;
+		isert_err("sig registration failed, ret:%d\n", ret);
+		goto err;
 	}
-	isert_cmd->fr_desc->ind |= ISERT_PROTECTED;
-
-	return 0;
-
-unmap_prot_cmd:
-	if (se_cmd->t_prot_sg)
-		isert_unmap_data_buf(isert_conn, &isert_cmd->prot);
 
+err:
 	return ret;
 }
 
-static int
-isert_reg_rdma(struct isert_cmd *isert_cmd, struct iscsi_conn *conn)
+static void
+isert_handle_prot_cmd(struct isert_conn *isert_conn,
+		      struct isert_cmd *isert_cmd)
 {
-	struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
-	struct se_cmd *se_cmd = &cmd->se_cmd;
-	struct isert_conn *isert_conn = conn->context;
-	struct fast_reg_descriptor *fr_desc = NULL;
-	struct ib_rdma_wr *rdma_wr;
-	struct ib_sge *ib_sg;
-	u32 offset;
-	int ret = 0;
-	unsigned long flags;
-
-	offset = isert_cmd->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, isert_cmd->iser_ib_op,
-				 &isert_cmd->data);
-	if (ret)
-		return ret;
-
-	if (isert_cmd->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);
-		isert_cmd->fr_desc = fr_desc;
-	}
-
-	ret = isert_fast_reg_mr(isert_conn, fr_desc, &isert_cmd->data,
-				ISERT_DATA_KEY_VALID, &isert_cmd->ib_sg[DATA]);
-	if (ret)
-		goto unmap_cmd;
+	struct se_cmd *se_cmd = &isert_cmd->iscsi_cmd->se_cmd;
+	struct ib_sig_attrs sig_attrs;
+	struct ib_send_wr *first_wr, *bad_wr;
+	int ret;
 
-	if (isert_prot_cmd(isert_conn, se_cmd)) {
-		ret = isert_handle_prot_cmd(isert_conn, isert_cmd);
-		if (ret)
-			goto unmap_cmd;
+	/*
+	 * Nasty layering violation by poking deep into RW API internals in
+	 * terms of WR chaining.  Hopefully we can move this to the core
+	 * and/or clean it up.
+	 */
+	BUG_ON(isert_cmd->data.nr_ops > 1);
 
-		ib_sg = &isert_cmd->ib_sg[SIG];
-	} else {
-		ib_sg = &isert_cmd->ib_sg[DATA];
+	if (se_cmd->t_prot_sg) {
+		ret = rdma_rw_ctx_init(&isert_cmd->prot, isert_conn->qp,
+				isert_conn->cm_id->port_num, se_cmd->t_prot_sg,
+				se_cmd->t_prot_nents, se_cmd->prot_length,
+				0, 0, /* va and stag are unused */
+				DMA_TO_DEVICE, 0);
+		if (ret < 0)
+			return;
+
+		BUG_ON(isert_cmd->prot.nr_ops > 1);
+
+		isert_cmd->data.reg->reg_wr.wr.next = &isert_cmd->prot.reg->reg_wr.wr;
+		if (1 /* need_inval in MR */) {
+			isert_cmd->data.reg->inv_wr.next = &isert_cmd->prot.reg->inv_wr;
+			isert_cmd->prot.reg->inv_wr.next = &isert_cmd->data.reg->reg_wr.wr;
+		}
 	}
 
-	memcpy(&isert_cmd->s_ib_sge, ib_sg, sizeof(*ib_sg));
-	isert_cmd->ib_sge = &isert_cmd->s_ib_sge;
-	isert_cmd->rdma_wr_num = 1;
-	memset(&isert_cmd->s_rdma_wr, 0, sizeof(isert_cmd->s_rdma_wr));
-	isert_cmd->rdma_wr = &isert_cmd->s_rdma_wr;
-
-	rdma_wr = &isert_cmd->s_rdma_wr;
-	rdma_wr->wr.sg_list = &isert_cmd->s_ib_sge;
-	rdma_wr->wr.num_sge = 1;
-	rdma_wr->wr.wr_cqe = &isert_cmd->tx_desc.tx_cqe;
-	if (isert_cmd->iser_ib_op == ISER_IB_RDMA_WRITE) {
-		isert_cmd->tx_desc.tx_cqe.done = isert_rdma_write_done;
+	isert_cmd->data.reg->reg_wr.wr.next = NULL;
 
-		rdma_wr->wr.opcode = IB_WR_RDMA_WRITE;
-		rdma_wr->remote_addr = isert_cmd->read_va;
-		rdma_wr->rkey = isert_cmd->read_stag;
-		rdma_wr->wr.send_flags = !isert_prot_cmd(isert_conn, se_cmd) ?
-				      0 : IB_SEND_SIGNALED;
-	} else {
-		isert_cmd->tx_desc.tx_cqe.done = isert_rdma_read_done;
+	if (1 /* need_inval in MR */)
+		first_wr = &isert_cmd->data.reg->inv_wr;
+	else
+		first_wr = &isert_cmd->data.reg->reg_wr.wr;
 
-		rdma_wr->wr.opcode = IB_WR_RDMA_READ;
-		rdma_wr->remote_addr = isert_cmd->write_va;
-		rdma_wr->rkey = isert_cmd->write_stag;
-		rdma_wr->wr.send_flags = IB_SEND_SIGNALED;
+	ret = ib_post_send(isert_conn->qp, first_wr, &bad_wr);
+	if (ret) {
+		isert_err("mem registration failed, ret:%d\n", ret);
+		return;
 	}
 
-	return 0;
+	ret = isert_set_sig_attrs(se_cmd, &sig_attrs);
+	if (ret)
+		return;
 
-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);
+	ret = isert_reg_sig_mr(isert_conn->qp, isert_cmd, &sig_attrs);
+	if (ret) {
+		isert_err("conn %p failed to fast reg mr\n",
+			  isert_conn);
+		return;
 	}
-	isert_unmap_data_buf(isert_conn, &isert_cmd->data);
-
-	return ret;
 }
 
 static int
@@ -2790,21 +2236,25 @@  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_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);
 
-	isert_cmd->iser_ib_op = ISER_IB_RDMA_WRITE;
-	rc = device->reg_rdma_mem(isert_cmd, conn);
-	if (rc) {
+	rc = rdma_rw_ctx_init(&isert_cmd->data, isert_conn->qp,
+			isert_conn->cm_id->port_num, se_cmd->t_data_sg,
+			se_cmd->t_data_nents, se_cmd->data_length,
+			isert_cmd->read_va, isert_cmd->read_stag,
+			DMA_TO_DEVICE, 0);
+	if (rc < 0) {
 		isert_err("Cmd: %p failed to prepare RDMA res\n", isert_cmd);
 		return rc;
 	}
 
-	if (!isert_prot_cmd(isert_conn, se_cmd)) {
+	if (isert_prot_cmd(isert_conn, se_cmd)) {
+		isert_cmd->tx_desc.tx_cqe.done = isert_rdma_write_done;
+		isert_handle_prot_cmd(isert_conn, isert_cmd);
+	} else {
 		/*
 		 * Build isert_conn->tx_desc for iSCSI response PDU and attach
 		 */
@@ -2815,27 +2265,21 @@  isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
 		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->s_rdma_wr.wr.next = &isert_cmd->tx_desc.send_wr;
-		isert_cmd->rdma_wr_num += 1;
 
 		rc = isert_post_recv(isert_conn, isert_cmd->rx_desc);
 		if (rc) {
 			isert_err("ib_post_recv failed with %d\n", rc);
 			return rc;
 		}
+	
+		rc = rdma_rw_ctx_post(&isert_cmd->data, isert_conn->qp,
+				isert_conn->cm_id->port_num,
+				NULL, &isert_cmd->tx_desc.send_wr);
+		if (rc)
+			isert_warn("posting RDMA WRITE failed\n");
 	}
 
-	rc = ib_post_send(isert_conn->qp, &isert_cmd->rdma_wr->wr, &wr_failed);
-	if (rc)
-		isert_warn("ib_post_send() failed for IB_WR_RDMA_WRITE\n");
-
-	if (!isert_prot_cmd(isert_conn, se_cmd))
-		isert_dbg("Cmd: %p posted RDMA_WRITE + Response for iSER Data "
-			 "READ\n", isert_cmd);
-	else
-		isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ\n",
-			 isert_cmd);
-
+	isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ\n", isert_cmd);
 	return 1;
 }
 
@@ -2845,22 +2289,31 @@  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_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);
-	isert_cmd->iser_ib_op = ISER_IB_RDMA_READ;
-	rc = device->reg_rdma_mem(isert_cmd, conn);
-	if (rc) {
+
+	rc = rdma_rw_ctx_init(&isert_cmd->data, isert_conn->qp,
+			isert_conn->cm_id->port_num, se_cmd->t_data_sg,
+			se_cmd->t_data_nents, se_cmd->data_length,
+			isert_cmd->write_va, isert_cmd->write_stag,
+			DMA_FROM_DEVICE, cmd->write_data_done);
+	if (rc < 0) {
 		isert_err("Cmd: %p failed to prepare RDMA res\n", isert_cmd);
 		return rc;
 	}
 
-	rc = ib_post_send(isert_conn->qp, &isert_cmd->rdma_wr->wr, &wr_failed);
-	if (rc)
-		isert_warn("ib_post_send() failed for IB_WR_RDMA_READ\n");
+	isert_cmd->tx_desc.tx_cqe.done = isert_rdma_read_done;
+	if (isert_prot_cmd(isert_conn, se_cmd)) {
+		isert_handle_prot_cmd(isert_conn, isert_cmd);
+	} else {
+		rc = rdma_rw_ctx_post(&isert_cmd->data, isert_conn->qp,
+				isert_conn->cm_id->port_num,
+				&isert_cmd->tx_desc.tx_cqe, NULL);
+		if (rc)
+			isert_warn("posting RDMA READ failed\n");
+	}
 
 	isert_dbg("Cmd: %p posted RDMA_READ memory for ISER Data WRITE\n",
 		 isert_cmd);
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index 2614403..4e6af12 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -3,6 +3,7 @@ 
 #include <linux/in6.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
+#include <rdma/rw.h>
 #include <scsi/iser.h>
 
 
@@ -57,11 +58,12 @@ 
 
 #define ISERT_INFLIGHT_DATAOUTS	8
 
-#define ISERT_QP_MAX_REQ_DTOS	(ISCSI_DEF_XMIT_CMDS_MAX *    \
-				(1 + ISERT_INFLIGHT_DATAOUTS) + \
+#define ISERT_QP_MAX_REQ_DTOS	(ISCSI_DEF_XMIT_CMDS_MAX +    \
 				ISERT_MAX_TX_MISC_PDUS	+ \
 				ISERT_MAX_RX_MISC_PDUS)
 
+#define ISERT_QP_MAX_RDMA_OPS	(ISCSI_DEF_XMIT_CMDS_MAX * ISERT_INFLIGHT_DATAOUTS)
+
 #define ISER_RX_PAD_SIZE	(ISER_RECV_DATA_SEG_LEN + 4096 - \
 		(ISER_RX_PAYLOAD_SIZE + sizeof(u64) + sizeof(struct ib_sge) + \
 		 sizeof(struct ib_cqe)))
@@ -73,13 +75,6 @@  enum isert_desc_type {
 	ISCSI_TX_DATAIN
 };
 
-enum iser_ib_op_code {
-	ISER_IB_RECV,
-	ISER_IB_SEND,
-	ISER_IB_RDMA_WRITE,
-	ISER_IB_RDMA_READ,
-};
-
 enum iser_conn_state {
 	ISER_CONN_INIT,
 	ISER_CONN_UP,
@@ -109,41 +104,6 @@  struct iser_tx_desc {
 	struct ib_send_wr send_wr;
 } __packed;
 
-enum isert_indicator {
-	ISERT_PROTECTED		= 1 << 0,
-	ISERT_DATA_KEY_VALID	= 1 << 1,
-	ISERT_PROT_KEY_VALID	= 1 << 2,
-	ISERT_SIG_KEY_VALID	= 1 << 3,
-};
-
-struct pi_context {
-	struct ib_mr		       *prot_mr;
-	struct ib_mr		       *sig_mr;
-};
-
-struct fast_reg_descriptor {
-	struct list_head		list;
-	struct ib_mr		       *data_mr;
-	u8				ind;
-	struct pi_context	       *pi_ctx;
-};
-
-struct isert_data_buf {
-	struct scatterlist     *sg;
-	int			nents;
-	u32			sg_off;
-	u32			len; /* cur_rdma_length */
-	u32			offset;
-	unsigned int		dma_nents;
-	enum dma_data_direction dma_dir;
-};
-
-enum {
-	DATA = 0,
-	PROT = 1,
-	SIG = 2,
-};
-
 struct isert_cmd {
 	uint32_t		read_stag;
 	uint32_t		write_stag;
@@ -156,16 +116,9 @@  struct isert_cmd {
 	struct iscsi_cmd	*iscsi_cmd;
 	struct iser_tx_desc	tx_desc;
 	struct iser_rx_desc	*rx_desc;
-	enum iser_ib_op_code	iser_ib_op;
-	struct ib_sge		*ib_sge;
-	struct ib_sge		s_ib_sge;
-	int			rdma_wr_num;
-	struct ib_rdma_wr	*rdma_wr;
-	struct ib_rdma_wr	s_rdma_wr;
-	struct ib_sge		ib_sg[3];
-	struct isert_data_buf	data;
-	struct isert_data_buf	prot;
-	struct fast_reg_descriptor *fr_desc;
+	struct rdma_rw_ctx	data;
+	struct rdma_rw_ctx	prot;
+	struct ib_mr		*sig_mr;
 	struct work_struct	comp_work;
 	struct scatterlist	sg;
 };
@@ -198,10 +151,6 @@  struct isert_conn {
 	struct completion	wait;
 	struct completion	wait_comp_err;
 	struct kref		kref;
-	struct list_head	fr_pool;
-	int			fr_pool_size;
-	/* lock to protect fastreg pool */
-	spinlock_t		pool_lock;
 	struct work_struct	release_work;
 	struct ib_recv_wr       beacon;
 	bool                    logout_posted;
@@ -225,7 +174,6 @@  struct isert_comp {
 };
 
 struct isert_device {
-	int			use_fastreg;
 	bool			pi_capable;
 	int			refcount;
 	struct ib_device	*ib_device;
@@ -233,10 +181,6 @@  struct isert_device {
 	struct isert_comp	*comps;
 	int                     comps_used;
 	struct list_head	dev_node;
-	int			(*reg_rdma_mem)(struct isert_cmd *isert_cmd,
-						struct iscsi_conn *conn);
-	void			(*unreg_rdma_mem)(struct isert_cmd *isert_cmd,
-						  struct isert_conn *isert_conn);
 };
 
 struct isert_np {