Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1087 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
new file mode 100644
index 000000000..620ae5b2d
--- /dev/null
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -0,0 +1,1087 @@
+/*
+ * iSCSI Initiator over iSER Data-Path
+ *
+ * Copyright (C) 2004 Dmitry Yusupov
+ * Copyright (C) 2004 Alex Aizman
+ * Copyright (C) 2005 Mike Christie
+ * Copyright (c) 2005, 2006 Voltaire, Inc. All rights reserved.
+ * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
+ * maintained by openib-general@openib.org
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *	- Redistributions of source code must retain the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer.
+ *
+ *	- Redistributions in binary form must reproduce the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer in the documentation and/or other materials
+ *	  provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Credits:
+ *	Christoph Hellwig
+ *	FUJITA Tomonori
+ *	Arne Redlich
+ *	Zhenyu Wang
+ * Modified by:
+ *      Erez Zilber
+ */
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/hardirq.h>
+#include <linux/kfifo.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/cdev.h>
+#include <linux/in.h>
+#include <linux/net.h>
+#include <linux/scatterlist.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <net/sock.h>
+
+#include <linux/uaccess.h>
+
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_transport_iscsi.h>
+
+#include "iscsi_iser.h"
+
+MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
+
+static struct scsi_host_template iscsi_iser_sht;
+static struct iscsi_transport iscsi_iser_transport;
+static struct scsi_transport_template *iscsi_iser_scsi_transport;
+static struct workqueue_struct *release_wq;
+static DEFINE_MUTEX(unbind_iser_conn_mutex);
+struct iser_global ig;
+
+int iser_debug_level = 0;
+module_param_named(debug_level, iser_debug_level, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
+
+static int iscsi_iser_set(const char *val, const struct kernel_param *kp);
+static const struct kernel_param_ops iscsi_iser_size_ops = {
+	.set = iscsi_iser_set,
+	.get = param_get_uint,
+};
+
+static unsigned int iscsi_max_lun = 512;
+module_param_cb(max_lun, &iscsi_iser_size_ops, &iscsi_max_lun, S_IRUGO);
+MODULE_PARM_DESC(max_lun, "Max LUNs to allow per session, should > 0 (default:512)");
+
+unsigned int iser_max_sectors = ISER_DEF_MAX_SECTORS;
+module_param_cb(max_sectors, &iscsi_iser_size_ops, &iser_max_sectors,
+		S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(max_sectors, "Max number of sectors in a single scsi command, should > 0 (default:1024)");
+
+bool iser_always_reg = true;
+module_param_named(always_register, iser_always_reg, bool, S_IRUGO);
+MODULE_PARM_DESC(always_register,
+		 "Always register memory, even for continuous memory regions (default:true)");
+
+bool iser_pi_enable = false;
+module_param_named(pi_enable, iser_pi_enable, bool, S_IRUGO);
+MODULE_PARM_DESC(pi_enable, "Enable T10-PI offload support (default:disabled)");
+
+static int iscsi_iser_set(const char *val, const struct kernel_param *kp)
+{
+	int ret;
+	unsigned int n = 0;
+
+	ret = kstrtouint(val, 10, &n);
+	if (ret != 0 || n == 0)
+		return -EINVAL;
+
+	return param_set_uint(val, kp);
+}
+
+/*
+ * iscsi_iser_recv() - Process a successful recv completion
+ * @conn:         iscsi connection
+ * @hdr:          iscsi header
+ * @rx_data:      buffer containing receive data payload
+ * @rx_data_len:  length of rx_data
+ *
+ * Notes: In case of data length errors or iscsi PDU completion failures
+ *        this routine will signal iscsi layer of connection failure.
+ */
+void iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+		     char *rx_data, int rx_data_len)
+{
+	int rc = 0;
+	int datalen;
+
+	/* verify PDU length */
+	datalen = ntoh24(hdr->dlength);
+	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {
+		iser_err("wrong datalen %d (hdr), %d (IB)\n",
+			datalen, rx_data_len);
+		rc = ISCSI_ERR_DATALEN;
+		goto error;
+	}
+
+	if (datalen != rx_data_len)
+		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",
+			datalen, rx_data_len);
+
+	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
+	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
+		goto error;
+
+	return;
+error:
+	iscsi_conn_failure(conn, rc);
+}
+
+/**
+ * iscsi_iser_pdu_alloc() - allocate an iscsi-iser PDU
+ * @task:     iscsi task
+ * @opcode:   iscsi command opcode
+ *
+ * Netes: This routine can't fail, just assign iscsi task
+ *        hdr and max hdr size.
+ */
+static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)
+{
+	struct iscsi_iser_task *iser_task = task->dd_data;
+
+	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;
+	task->hdr_max = sizeof(iser_task->desc.iscsi_header);
+
+	return 0;
+}
+
+/**
+ * iser_initialize_task_headers() - Initialize task headers
+ * @task:       iscsi task
+ * @tx_desc:    iser tx descriptor
+ *
+ * Notes:
+ * This routine may race with iser teardown flow for scsi
+ * error handling TMFs. So for TMF we should acquire the
+ * state mutex to avoid dereferencing the IB device which
+ * may have already been terminated.
+ */
+int iser_initialize_task_headers(struct iscsi_task *task,
+				 struct iser_tx_desc *tx_desc)
+{
+	struct iser_conn *iser_conn = task->conn->dd_data;
+	struct iser_device *device = iser_conn->ib_conn.device;
+	struct iscsi_iser_task *iser_task = task->dd_data;
+	u64 dma_addr;
+
+	if (unlikely(iser_conn->state != ISER_CONN_UP))
+		return -ENODEV;
+
+	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,
+				ISER_HEADERS_LEN, DMA_TO_DEVICE);
+	if (ib_dma_mapping_error(device->ib_device, dma_addr))
+		return -ENOMEM;
+
+	tx_desc->inv_wr.next = NULL;
+	tx_desc->reg_wr.wr.next = NULL;
+	tx_desc->mapped = true;
+	tx_desc->dma_addr = dma_addr;
+	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;
+	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
+	tx_desc->tx_sg[0].lkey   = device->pd->local_dma_lkey;
+
+	iser_task->iser_conn = iser_conn;
+
+	return 0;
+}
+
+/**
+ * iscsi_iser_task_init() - Initialize iscsi-iser task
+ * @task: iscsi task
+ *
+ * Initialize the task for the scsi command or mgmt command.
+ *
+ * Return: Returns zero on success or -ENOMEM when failing
+ *         to init task headers (dma mapping error).
+ */
+static int iscsi_iser_task_init(struct iscsi_task *task)
+{
+	struct iscsi_iser_task *iser_task = task->dd_data;
+	int ret;
+
+	ret = iser_initialize_task_headers(task, &iser_task->desc);
+	if (ret) {
+		iser_err("Failed to init task %p, err = %d\n",
+			 iser_task, ret);
+		return ret;
+	}
+
+	/* mgmt task */
+	if (!task->sc)
+		return 0;
+
+	iser_task->command_sent = 0;
+	iser_task_rdma_init(iser_task);
+	iser_task->sc = task->sc;
+
+	return 0;
+}
+
+/**
+ * iscsi_iser_mtask_xmit() - xmit management (immediate) task
+ * @conn: iscsi connection
+ * @task: task management task
+ *
+ * Notes:
+ *	The function can return -EAGAIN in which case caller must
+ *	call it again later, or recover. '0' return code means successful
+ *	xmit.
+ *
+ **/
+static int iscsi_iser_mtask_xmit(struct iscsi_conn *conn,
+				 struct iscsi_task *task)
+{
+	int error = 0;
+
+	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
+
+	error = iser_send_control(conn, task);
+
+	/* since iser xmits control with zero copy, tasks can not be recycled
+	 * right after sending them.
+	 * The recycling scheme is based on whether a response is expected
+	 * - if yes, the task is recycled at iscsi_complete_pdu
+	 * - if no,  the task is recycled at iser_snd_completion
+	 */
+	return error;
+}
+
+static int iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,
+					   struct iscsi_task *task)
+{
+	struct iscsi_r2t_info *r2t = &task->unsol_r2t;
+	struct iscsi_data hdr;
+	int error = 0;
+
+	/* Send data-out PDUs while there's still unsolicited data to send */
+	while (iscsi_task_has_unsol_data(task)) {
+		iscsi_prep_data_out_pdu(task, r2t, &hdr);
+		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",
+			   hdr.itt, r2t->data_count);
+
+		/* the buffer description has been passed with the command */
+		/* Send the command */
+		error = iser_send_data_out(conn, task, &hdr);
+		if (error) {
+			r2t->datasn--;
+			goto iscsi_iser_task_xmit_unsol_data_exit;
+		}
+		r2t->sent += r2t->data_count;
+		iser_dbg("Need to send %d more as data-out PDUs\n",
+			   r2t->data_length - r2t->sent);
+	}
+
+iscsi_iser_task_xmit_unsol_data_exit:
+	return error;
+}
+
+/**
+ * iscsi_iser_task_xmit() - xmit iscsi-iser task
+ * @task: iscsi task
+ *
+ * Return: zero on success or escalates $error on failure.
+ */
+static int iscsi_iser_task_xmit(struct iscsi_task *task)
+{
+	struct iscsi_conn *conn = task->conn;
+	struct iscsi_iser_task *iser_task = task->dd_data;
+	int error = 0;
+
+	if (!task->sc)
+		return iscsi_iser_mtask_xmit(conn, task);
+
+	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {
+		BUG_ON(scsi_bufflen(task->sc) == 0);
+
+		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",
+			   task->itt, scsi_bufflen(task->sc),
+			   task->imm_count, task->unsol_r2t.data_length);
+	}
+
+	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
+		   conn->id, task->itt);
+
+	/* Send the cmd PDU */
+	if (!iser_task->command_sent) {
+		error = iser_send_command(conn, task);
+		if (error)
+			goto iscsi_iser_task_xmit_exit;
+		iser_task->command_sent = 1;
+	}
+
+	/* Send unsolicited data-out PDU(s) if necessary */
+	if (iscsi_task_has_unsol_data(task))
+		error = iscsi_iser_task_xmit_unsol_data(conn, task);
+
+ iscsi_iser_task_xmit_exit:
+	return error;
+}
+
+/**
+ * iscsi_iser_cleanup_task() - cleanup an iscsi-iser task
+ * @task: iscsi task
+ *
+ * Notes: In case the RDMA device is already NULL (might have
+ *        been removed in DEVICE_REMOVAL CM event it will bail-out
+ *        without doing dma unmapping.
+ */
+static void iscsi_iser_cleanup_task(struct iscsi_task *task)
+{
+	struct iscsi_iser_task *iser_task = task->dd_data;
+	struct iser_tx_desc *tx_desc = &iser_task->desc;
+	struct iser_conn *iser_conn = task->conn->dd_data;
+	struct iser_device *device = iser_conn->ib_conn.device;
+
+	/* DEVICE_REMOVAL event might have already released the device */
+	if (!device)
+		return;
+
+	if (likely(tx_desc->mapped)) {
+		ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
+				    ISER_HEADERS_LEN, DMA_TO_DEVICE);
+		tx_desc->mapped = false;
+	}
+
+	/* mgmt tasks do not need special cleanup */
+	if (!task->sc)
+		return;
+
+	if (iser_task->status == ISER_TASK_STATUS_STARTED) {
+		iser_task->status = ISER_TASK_STATUS_COMPLETED;
+		iser_task_rdma_finalize(iser_task);
+	}
+}
+
+/**
+ * iscsi_iser_check_protection() - check protection information status of task.
+ * @task:     iscsi task
+ * @sector:   error sector if exsists (output)
+ *
+ * Return: zero if no data-integrity errors have occured
+ *         0x1: data-integrity error occured in the guard-block
+ *         0x2: data-integrity error occured in the reference tag
+ *         0x3: data-integrity error occured in the application tag
+ *
+ *         In addition the error sector is marked.
+ */
+static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)
+{
+	struct iscsi_iser_task *iser_task = task->dd_data;
+	enum iser_data_dir dir = iser_task->dir[ISER_DIR_IN] ?
+					ISER_DIR_IN : ISER_DIR_OUT;
+
+	return iser_check_task_pi_status(iser_task, dir, sector);
+}
+
+/**
+ * iscsi_iser_conn_create() - create a new iscsi-iser connection
+ * @cls_session: iscsi class connection
+ * @conn_idx:    connection index within the session (for MCS)
+ *
+ * Return: iscsi_cls_conn when iscsi_conn_setup succeeds or NULL
+ *         otherwise.
+ */
+static struct iscsi_cls_conn *
+iscsi_iser_conn_create(struct iscsi_cls_session *cls_session,
+		       uint32_t conn_idx)
+{
+	struct iscsi_conn *conn;
+	struct iscsi_cls_conn *cls_conn;
+
+	cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);
+	if (!cls_conn)
+		return NULL;
+	conn = cls_conn->dd_data;
+
+	/*
+	 * due to issues with the login code re iser sematics
+	 * this not set in iscsi_conn_setup - FIXME
+	 */
+	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;
+
+	return cls_conn;
+}
+
+/**
+ * iscsi_iser_conn_bind() - bind iscsi and iser connection structures
+ * @cls_session:     iscsi class session
+ * @cls_conn:        iscsi class connection
+ * @transport_eph:   transport end-point handle
+ * @is_leading:      indicate if this is the session leading connection (MCS)
+ *
+ * Return: zero on success, $error if iscsi_conn_bind fails and
+ *         -EINVAL in case end-point doesn't exsits anymore or iser connection
+ *         state is not UP (teardown already started).
+ */
+static int iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
+				struct iscsi_cls_conn *cls_conn,
+				uint64_t transport_eph, int is_leading)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iser_conn *iser_conn;
+	struct iscsi_endpoint *ep;
+	int error;
+
+	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
+	if (error)
+		return error;
+
+	/* the transport ep handle comes from user space so it must be
+	 * verified against the global ib connections list */
+	ep = iscsi_lookup_endpoint(transport_eph);
+	if (!ep) {
+		iser_err("can't bind eph %llx\n",
+			 (unsigned long long)transport_eph);
+		return -EINVAL;
+	}
+	iser_conn = ep->dd_data;
+
+	mutex_lock(&iser_conn->state_mutex);
+	if (iser_conn->state != ISER_CONN_UP) {
+		error = -EINVAL;
+		iser_err("iser_conn %p state is %d, teardown started\n",
+			 iser_conn, iser_conn->state);
+		goto out;
+	}
+
+	error = iser_alloc_rx_descriptors(iser_conn, conn->session);
+	if (error)
+		goto out;
+
+	/* binds the iSER connection retrieved from the previously
+	 * connected ep_handle to the iSCSI layer connection. exchanges
+	 * connection pointers */
+	iser_info("binding iscsi conn %p to iser_conn %p\n", conn, iser_conn);
+
+	conn->dd_data = iser_conn;
+	iser_conn->iscsi_conn = conn;
+
+out:
+	iscsi_put_endpoint(ep);
+	mutex_unlock(&iser_conn->state_mutex);
+	return error;
+}
+
+/**
+ * iscsi_iser_conn_start() - start iscsi-iser connection
+ * @cls_conn: iscsi class connection
+ *
+ * Notes: Here iser intialize (or re-initialize) stop_completion as
+ *        from this point iscsi must call conn_stop in session/connection
+ *        teardown so iser transport must wait for it.
+ */
+static int iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
+{
+	struct iscsi_conn *iscsi_conn;
+	struct iser_conn *iser_conn;
+
+	iscsi_conn = cls_conn->dd_data;
+	iser_conn = iscsi_conn->dd_data;
+	reinit_completion(&iser_conn->stop_completion);
+
+	return iscsi_conn_start(cls_conn);
+}
+
+/**
+ * iscsi_iser_conn_stop() - stop iscsi-iser connection
+ * @cls_conn:  iscsi class connection
+ * @flag:      indicate if recover or terminate (passed as is)
+ *
+ * Notes: Calling iscsi_conn_stop might theoretically race with
+ *        DEVICE_REMOVAL event and dereference a previously freed RDMA device
+ *        handle, so we call it under iser the state lock to protect against
+ *        this kind of race.
+ */
+static void iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iser_conn *iser_conn = conn->dd_data;
+
+	iser_info("stopping iscsi_conn: %p, iser_conn: %p\n", conn, iser_conn);
+
+	/*
+	 * Userspace may have goofed up and not bound the connection or
+	 * might have only partially setup the connection.
+	 */
+	if (iser_conn) {
+		mutex_lock(&iser_conn->state_mutex);
+		mutex_lock(&unbind_iser_conn_mutex);
+		iser_conn_terminate(iser_conn);
+		iscsi_conn_stop(cls_conn, flag);
+
+		/* unbind */
+		iser_conn->iscsi_conn = NULL;
+		conn->dd_data = NULL;
+		mutex_unlock(&unbind_iser_conn_mutex);
+
+		complete(&iser_conn->stop_completion);
+		mutex_unlock(&iser_conn->state_mutex);
+	} else {
+		iscsi_conn_stop(cls_conn, flag);
+	}
+}
+
+/**
+ * iscsi_iser_session_destroy() - destroy iscsi-iser session
+ * @cls_session: iscsi class session
+ *
+ * Removes and free iscsi host.
+ */
+static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
+{
+	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
+
+	iscsi_session_teardown(cls_session);
+	iscsi_host_remove(shost, false);
+	iscsi_host_free(shost);
+}
+
+static inline unsigned int iser_dif_prot_caps(int prot_caps)
+{
+	int ret = 0;
+
+	if (prot_caps & IB_PROT_T10DIF_TYPE_1)
+		ret |= SHOST_DIF_TYPE1_PROTECTION |
+		       SHOST_DIX_TYPE0_PROTECTION |
+		       SHOST_DIX_TYPE1_PROTECTION;
+	if (prot_caps & IB_PROT_T10DIF_TYPE_2)
+		ret |= SHOST_DIF_TYPE2_PROTECTION |
+		       SHOST_DIX_TYPE2_PROTECTION;
+	if (prot_caps & IB_PROT_T10DIF_TYPE_3)
+		ret |= SHOST_DIF_TYPE3_PROTECTION |
+		       SHOST_DIX_TYPE3_PROTECTION;
+
+	return ret;
+}
+
+/**
+ * iscsi_iser_session_create() - create an iscsi-iser session
+ * @ep:             iscsi end-point handle
+ * @cmds_max:       maximum commands in this session
+ * @qdepth:         session command queue depth
+ * @initial_cmdsn:  initiator command sequnce number
+ *
+ * Allocates and adds a scsi host, expose DIF supprot if
+ * exists, and sets up an iscsi session.
+ */
+static struct iscsi_cls_session *
+iscsi_iser_session_create(struct iscsi_endpoint *ep,
+			  uint16_t cmds_max, uint16_t qdepth,
+			  uint32_t initial_cmdsn)
+{
+	struct iscsi_cls_session *cls_session;
+	struct Scsi_Host *shost;
+	struct iser_conn *iser_conn = NULL;
+	struct ib_conn *ib_conn;
+	struct ib_device *ib_dev;
+	u32 max_fr_sectors;
+
+	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
+	if (!shost)
+		return NULL;
+	shost->transportt = iscsi_iser_scsi_transport;
+	shost->cmd_per_lun = qdepth;
+	shost->max_lun = iscsi_max_lun;
+	shost->max_id = 0;
+	shost->max_channel = 0;
+	shost->max_cmd_len = 16;
+
+	/*
+	 * older userspace tools (before 2.0-870) did not pass us
+	 * the leading conn's ep so this will be NULL;
+	 */
+	if (ep) {
+		iser_conn = ep->dd_data;
+		shost->sg_tablesize = iser_conn->scsi_sg_tablesize;
+		shost->can_queue = min_t(u16, cmds_max, iser_conn->max_cmds);
+
+		mutex_lock(&iser_conn->state_mutex);
+		if (iser_conn->state != ISER_CONN_UP) {
+			iser_err("iser conn %p already started teardown\n",
+				 iser_conn);
+			mutex_unlock(&iser_conn->state_mutex);
+			goto free_host;
+		}
+
+		ib_conn = &iser_conn->ib_conn;
+		ib_dev = ib_conn->device->ib_device;
+		if (ib_conn->pi_support) {
+			u32 sig_caps = ib_dev->attrs.sig_prot_cap;
+
+			shost->sg_prot_tablesize = shost->sg_tablesize;
+			scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));
+			scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP |
+						   SHOST_DIX_GUARD_CRC);
+		}
+
+		if (!(ib_dev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG))
+			shost->virt_boundary_mask = SZ_4K - 1;
+
+		if (iscsi_host_add(shost, ib_dev->dev.parent)) {
+			mutex_unlock(&iser_conn->state_mutex);
+			goto free_host;
+		}
+		mutex_unlock(&iser_conn->state_mutex);
+	} else {
+		shost->can_queue = min_t(u16, cmds_max, ISER_DEF_XMIT_CMDS_MAX);
+		if (iscsi_host_add(shost, NULL))
+			goto free_host;
+	}
+
+	max_fr_sectors = (shost->sg_tablesize * PAGE_SIZE) >> 9;
+	shost->max_sectors = min(iser_max_sectors, max_fr_sectors);
+
+	iser_dbg("iser_conn %p, sg_tablesize %u, max_sectors %u\n",
+		 iser_conn, shost->sg_tablesize,
+		 shost->max_sectors);
+
+	if (shost->max_sectors < iser_max_sectors)
+		iser_warn("max_sectors was reduced from %u to %u\n",
+			  iser_max_sectors, shost->max_sectors);
+
+	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
+					  shost->can_queue, 0,
+					  sizeof(struct iscsi_iser_task),
+					  initial_cmdsn, 0);
+	if (!cls_session)
+		goto remove_host;
+
+	return cls_session;
+
+remove_host:
+	iscsi_host_remove(shost, false);
+free_host:
+	iscsi_host_free(shost);
+	return NULL;
+}
+
+static int iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
+				enum iscsi_param param, char *buf, int buflen)
+{
+	int value;
+
+	switch (param) {
+	case ISCSI_PARAM_MAX_RECV_DLENGTH:
+		/* TBD */
+		break;
+	case ISCSI_PARAM_HDRDGST_EN:
+		sscanf(buf, "%d", &value);
+		if (value) {
+			iser_err("DataDigest wasn't negotiated to None\n");
+			return -EPROTO;
+		}
+		break;
+	case ISCSI_PARAM_DATADGST_EN:
+		sscanf(buf, "%d", &value);
+		if (value) {
+			iser_err("DataDigest wasn't negotiated to None\n");
+			return -EPROTO;
+		}
+		break;
+	case ISCSI_PARAM_IFMARKER_EN:
+		sscanf(buf, "%d", &value);
+		if (value) {
+			iser_err("IFMarker wasn't negotiated to No\n");
+			return -EPROTO;
+		}
+		break;
+	case ISCSI_PARAM_OFMARKER_EN:
+		sscanf(buf, "%d", &value);
+		if (value) {
+			iser_err("OFMarker wasn't negotiated to No\n");
+			return -EPROTO;
+		}
+		break;
+	default:
+		return iscsi_set_param(cls_conn, param, buf, buflen);
+	}
+
+	return 0;
+}
+
+/**
+ * iscsi_iser_conn_get_stats() - get iscsi connection statistics
+ * @cls_conn:    iscsi class connection
+ * @stats:       iscsi stats to output
+ *
+ * Output connection statistics.
+ */
+static void iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn,
+				      struct iscsi_stats *stats)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+
+	stats->txdata_octets = conn->txdata_octets;
+	stats->rxdata_octets = conn->rxdata_octets;
+	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
+	stats->dataout_pdus = conn->dataout_pdus_cnt;
+	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
+	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
+	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
+	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
+	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
+	stats->custom_length = 0;
+}
+
+static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,
+				   enum iscsi_param param, char *buf)
+{
+	struct iser_conn *iser_conn = ep->dd_data;
+
+	switch (param) {
+	case ISCSI_PARAM_CONN_PORT:
+	case ISCSI_PARAM_CONN_ADDRESS:
+		if (!iser_conn || !iser_conn->ib_conn.cma_id)
+			return -ENOTCONN;
+
+		return iscsi_conn_get_addr_param((struct sockaddr_storage *)
+				&iser_conn->ib_conn.cma_id->route.addr.dst_addr,
+				param, buf);
+	default:
+		break;
+	}
+	return -ENOSYS;
+}
+
+/**
+ * iscsi_iser_ep_connect() - Initiate iSER connection establishment
+ * @shost:          scsi_host
+ * @dst_addr:       destination address
+ * @non_blocking:   indicate if routine can block
+ *
+ * Allocate an iscsi endpoint, an iser_conn structure and bind them.
+ * After that start RDMA connection establishment via rdma_cm. We
+ * don't allocate iser_conn embedded in iscsi_endpoint since in teardown
+ * the endpoint will be destroyed at ep_disconnect while iser_conn will
+ * cleanup its resources asynchronuously.
+ *
+ * Return: iscsi_endpoint created by iscsi layer or ERR_PTR(error)
+ *         if fails.
+ */
+static struct iscsi_endpoint *iscsi_iser_ep_connect(struct Scsi_Host *shost,
+						    struct sockaddr *dst_addr,
+						    int non_blocking)
+{
+	int err;
+	struct iser_conn *iser_conn;
+	struct iscsi_endpoint *ep;
+
+	ep = iscsi_create_endpoint(0);
+	if (!ep)
+		return ERR_PTR(-ENOMEM);
+
+	iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
+	if (!iser_conn) {
+		err = -ENOMEM;
+		goto failure;
+	}
+
+	ep->dd_data = iser_conn;
+	iser_conn->ep = ep;
+	iser_conn_init(iser_conn);
+
+	err = iser_connect(iser_conn, NULL, dst_addr, non_blocking);
+	if (err)
+		goto failure;
+
+	return ep;
+failure:
+	iscsi_destroy_endpoint(ep);
+	return ERR_PTR(err);
+}
+
+/**
+ * iscsi_iser_ep_poll() - poll for iser connection establishment to complete
+ * @ep:            iscsi endpoint (created at ep_connect)
+ * @timeout_ms:    polling timeout allowed in ms.
+ *
+ * This routine boils down to waiting for up_completion signaling
+ * that cma_id got CONNECTED event.
+ *
+ * Return: 1 if succeeded in connection establishment, 0 if timeout expired
+ *         (libiscsi will retry will kick in) or -1 if interrupted by signal
+ *         or more likely iser connection state transitioned to TEMINATING or
+ *         DOWN during the wait period.
+ */
+static int iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
+{
+	struct iser_conn *iser_conn = ep->dd_data;
+	int rc;
+
+	rc = wait_for_completion_interruptible_timeout(&iser_conn->up_completion,
+						       msecs_to_jiffies(timeout_ms));
+	/* if conn establishment failed, return error code to iscsi */
+	if (rc == 0) {
+		mutex_lock(&iser_conn->state_mutex);
+		if (iser_conn->state == ISER_CONN_TERMINATING ||
+		    iser_conn->state == ISER_CONN_DOWN)
+			rc = -1;
+		mutex_unlock(&iser_conn->state_mutex);
+	}
+
+	iser_info("iser conn %p rc = %d\n", iser_conn, rc);
+
+	if (rc > 0)
+		return 1; /* success, this is the equivalent of EPOLLOUT */
+	else if (!rc)
+		return 0; /* timeout */
+	else
+		return rc; /* signal */
+}
+
+/**
+ * iscsi_iser_ep_disconnect() - Initiate connection teardown process
+ * @ep:    iscsi endpoint handle
+ *
+ * This routine is not blocked by iser and RDMA termination process
+ * completion as we queue a deffered work for iser/RDMA destruction
+ * and cleanup or actually call it immediately in case we didn't pass
+ * iscsi conn bind/start stage, thus it is safe.
+ */
+static void iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)
+{
+	struct iser_conn *iser_conn = ep->dd_data;
+
+	iser_info("ep %p iser conn %p\n", ep, iser_conn);
+
+	mutex_lock(&iser_conn->state_mutex);
+	iser_conn_terminate(iser_conn);
+
+	/*
+	 * if iser_conn and iscsi_conn are bound, we must wait for
+	 * iscsi_conn_stop and flush errors completion before freeing
+	 * the iser resources. Otherwise we are safe to free resources
+	 * immediately.
+	 */
+	if (iser_conn->iscsi_conn) {
+		INIT_WORK(&iser_conn->release_work, iser_release_work);
+		queue_work(release_wq, &iser_conn->release_work);
+		mutex_unlock(&iser_conn->state_mutex);
+	} else {
+		iser_conn->state = ISER_CONN_DOWN;
+		mutex_unlock(&iser_conn->state_mutex);
+		iser_conn_release(iser_conn);
+	}
+
+	iscsi_destroy_endpoint(ep);
+}
+
+static umode_t iser_attr_is_visible(int param_type, int param)
+{
+	switch (param_type) {
+	case ISCSI_HOST_PARAM:
+		switch (param) {
+		case ISCSI_HOST_PARAM_NETDEV_NAME:
+		case ISCSI_HOST_PARAM_HWADDRESS:
+		case ISCSI_HOST_PARAM_INITIATOR_NAME:
+			return S_IRUGO;
+		default:
+			return 0;
+		}
+	case ISCSI_PARAM:
+		switch (param) {
+		case ISCSI_PARAM_MAX_RECV_DLENGTH:
+		case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+		case ISCSI_PARAM_HDRDGST_EN:
+		case ISCSI_PARAM_DATADGST_EN:
+		case ISCSI_PARAM_CONN_ADDRESS:
+		case ISCSI_PARAM_CONN_PORT:
+		case ISCSI_PARAM_EXP_STATSN:
+		case ISCSI_PARAM_PERSISTENT_ADDRESS:
+		case ISCSI_PARAM_PERSISTENT_PORT:
+		case ISCSI_PARAM_PING_TMO:
+		case ISCSI_PARAM_RECV_TMO:
+		case ISCSI_PARAM_INITIAL_R2T_EN:
+		case ISCSI_PARAM_MAX_R2T:
+		case ISCSI_PARAM_IMM_DATA_EN:
+		case ISCSI_PARAM_FIRST_BURST:
+		case ISCSI_PARAM_MAX_BURST:
+		case ISCSI_PARAM_PDU_INORDER_EN:
+		case ISCSI_PARAM_DATASEQ_INORDER_EN:
+		case ISCSI_PARAM_TARGET_NAME:
+		case ISCSI_PARAM_TPGT:
+		case ISCSI_PARAM_USERNAME:
+		case ISCSI_PARAM_PASSWORD:
+		case ISCSI_PARAM_USERNAME_IN:
+		case ISCSI_PARAM_PASSWORD_IN:
+		case ISCSI_PARAM_FAST_ABORT:
+		case ISCSI_PARAM_ABORT_TMO:
+		case ISCSI_PARAM_LU_RESET_TMO:
+		case ISCSI_PARAM_TGT_RESET_TMO:
+		case ISCSI_PARAM_IFACE_NAME:
+		case ISCSI_PARAM_INITIATOR_NAME:
+		case ISCSI_PARAM_DISCOVERY_SESS:
+			return S_IRUGO;
+		default:
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+static struct scsi_host_template iscsi_iser_sht = {
+	.module                 = THIS_MODULE,
+	.name                   = "iSCSI Initiator over iSER",
+	.queuecommand           = iscsi_queuecommand,
+	.change_queue_depth	= scsi_change_queue_depth,
+	.sg_tablesize           = ISCSI_ISER_DEF_SG_TABLESIZE,
+	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,
+	.eh_timed_out		= iscsi_eh_cmd_timed_out,
+	.eh_abort_handler       = iscsi_eh_abort,
+	.eh_device_reset_handler= iscsi_eh_device_reset,
+	.eh_target_reset_handler = iscsi_eh_recover_target,
+	.target_alloc		= iscsi_target_alloc,
+	.proc_name              = "iscsi_iser",
+	.this_id                = -1,
+	.track_queue_depth	= 1,
+	.cmd_size		= sizeof(struct iscsi_cmd),
+};
+
+static struct iscsi_transport iscsi_iser_transport = {
+	.owner                  = THIS_MODULE,
+	.name                   = "iser",
+	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,
+	/* session management */
+	.create_session         = iscsi_iser_session_create,
+	.destroy_session        = iscsi_iser_session_destroy,
+	/* connection management */
+	.create_conn            = iscsi_iser_conn_create,
+	.bind_conn              = iscsi_iser_conn_bind,
+	.unbind_conn		= iscsi_conn_unbind,
+	.destroy_conn           = iscsi_conn_teardown,
+	.attr_is_visible	= iser_attr_is_visible,
+	.set_param              = iscsi_iser_set_param,
+	.get_conn_param		= iscsi_conn_get_param,
+	.get_ep_param		= iscsi_iser_get_ep_param,
+	.get_session_param	= iscsi_session_get_param,
+	.start_conn             = iscsi_iser_conn_start,
+	.stop_conn              = iscsi_iser_conn_stop,
+	/* iscsi host params */
+	.get_host_param		= iscsi_host_get_param,
+	.set_host_param		= iscsi_host_set_param,
+	/* IO */
+	.send_pdu		= iscsi_conn_send_pdu,
+	.get_stats		= iscsi_iser_conn_get_stats,
+	.init_task		= iscsi_iser_task_init,
+	.xmit_task		= iscsi_iser_task_xmit,
+	.cleanup_task		= iscsi_iser_cleanup_task,
+	.alloc_pdu		= iscsi_iser_pdu_alloc,
+	.check_protection	= iscsi_iser_check_protection,
+	/* recovery */
+	.session_recovery_timedout = iscsi_session_recovery_timedout,
+
+	.ep_connect             = iscsi_iser_ep_connect,
+	.ep_poll                = iscsi_iser_ep_poll,
+	.ep_disconnect          = iscsi_iser_ep_disconnect
+};
+
+static int __init iser_init(void)
+{
+	int err;
+
+	iser_dbg("Starting iSER datamover...\n");
+
+	memset(&ig, 0, sizeof(struct iser_global));
+
+	ig.desc_cache = kmem_cache_create("iser_descriptors",
+					  sizeof(struct iser_tx_desc),
+					  0, SLAB_HWCACHE_ALIGN,
+					  NULL);
+	if (ig.desc_cache == NULL)
+		return -ENOMEM;
+
+	/* device init is called only after the first addr resolution */
+	mutex_init(&ig.device_list_mutex);
+	INIT_LIST_HEAD(&ig.device_list);
+	mutex_init(&ig.connlist_mutex);
+	INIT_LIST_HEAD(&ig.connlist);
+
+	release_wq = alloc_workqueue("release workqueue", 0, 0);
+	if (!release_wq) {
+		iser_err("failed to allocate release workqueue\n");
+		err = -ENOMEM;
+		goto err_alloc_wq;
+	}
+
+	iscsi_iser_scsi_transport = iscsi_register_transport(
+							&iscsi_iser_transport);
+	if (!iscsi_iser_scsi_transport) {
+		iser_err("iscsi_register_transport failed\n");
+		err = -EINVAL;
+		goto err_reg;
+	}
+
+	return 0;
+
+err_reg:
+	destroy_workqueue(release_wq);
+err_alloc_wq:
+	kmem_cache_destroy(ig.desc_cache);
+
+	return err;
+}
+
+static void __exit iser_exit(void)
+{
+	struct iser_conn *iser_conn, *n;
+	int connlist_empty;
+
+	iser_dbg("Removing iSER datamover...\n");
+	destroy_workqueue(release_wq);
+
+	mutex_lock(&ig.connlist_mutex);
+	connlist_empty = list_empty(&ig.connlist);
+	mutex_unlock(&ig.connlist_mutex);
+
+	if (!connlist_empty) {
+		iser_err("Error cleanup stage completed but we still have iser "
+			 "connections, destroying them anyway\n");
+		list_for_each_entry_safe(iser_conn, n, &ig.connlist,
+					 conn_list) {
+			iser_conn_release(iser_conn);
+		}
+	}
+
+	iscsi_unregister_transport(&iscsi_iser_transport);
+	kmem_cache_destroy(ig.desc_cache);
+}
+
+module_init(iser_init);
+module_exit(iser_exit);