Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 1174 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
new file mode 100644
index 000000000..bee8c0b1d
--- /dev/null
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -0,0 +1,1174 @@
+/*
+ * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
+ * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+#include "iscsi_iser.h"
+
+#define ISCSI_ISER_MAX_CONN	8
+#define ISER_MAX_RX_LEN		(ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
+#define ISER_MAX_TX_LEN		(ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
+#define ISER_MAX_CQ_LEN		(ISER_MAX_RX_LEN + ISER_MAX_TX_LEN + \
+				 ISCSI_ISER_MAX_CONN)
+
+static void iser_qp_event_callback(struct ib_event *cause, void *context)
+{
+	iser_err("qp event %s (%d)\n",
+		 ib_event_msg(cause->event), cause->event);
+}
+
+static void iser_event_handler(struct ib_event_handler *handler,
+				struct ib_event *event)
+{
+	iser_err("async event %s (%d) on device %s port %d\n",
+		 ib_event_msg(event->event), event->event,
+		 event->device->name, event->element.port_num);
+}
+
+/**
+ * iser_create_device_ib_res - creates Protection Domain (PD), Completion
+ * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
+ * the adapator.
+ *
+ * returns 0 on success, -1 on failure
+ */
+static int iser_create_device_ib_res(struct iser_device *device)
+{
+	struct ib_device *ib_dev = device->ib_device;
+	int ret, i, max_cqe;
+
+	ret = iser_assign_reg_ops(device);
+	if (ret)
+		return ret;
+
+	device->comps_used = min_t(int, num_online_cpus(),
+				 ib_dev->num_comp_vectors);
+
+	device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
+				GFP_KERNEL);
+	if (!device->comps)
+		goto comps_err;
+
+	max_cqe = min(ISER_MAX_CQ_LEN, ib_dev->attrs.max_cqe);
+
+	iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
+		  device->comps_used, ib_dev->name,
+		  ib_dev->num_comp_vectors, max_cqe);
+
+	device->pd = ib_alloc_pd(ib_dev,
+		iser_always_reg ? 0 : IB_PD_UNSAFE_GLOBAL_RKEY);
+	if (IS_ERR(device->pd))
+		goto pd_err;
+
+	for (i = 0; i < device->comps_used; i++) {
+		struct iser_comp *comp = &device->comps[i];
+
+		comp->cq = ib_alloc_cq(ib_dev, comp, max_cqe, i,
+				       IB_POLL_SOFTIRQ);
+		if (IS_ERR(comp->cq)) {
+			comp->cq = NULL;
+			goto cq_err;
+		}
+	}
+
+	INIT_IB_EVENT_HANDLER(&device->event_handler, ib_dev,
+			      iser_event_handler);
+	ib_register_event_handler(&device->event_handler);
+	return 0;
+
+cq_err:
+	for (i = 0; i < device->comps_used; i++) {
+		struct iser_comp *comp = &device->comps[i];
+
+		if (comp->cq)
+			ib_free_cq(comp->cq);
+	}
+	ib_dealloc_pd(device->pd);
+pd_err:
+	kfree(device->comps);
+comps_err:
+	iser_err("failed to allocate an IB resource\n");
+	return -1;
+}
+
+/**
+ * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
+ * CQ and PD created with the device associated with the adapator.
+ */
+static void iser_free_device_ib_res(struct iser_device *device)
+{
+	int i;
+
+	for (i = 0; i < device->comps_used; i++) {
+		struct iser_comp *comp = &device->comps[i];
+
+		ib_free_cq(comp->cq);
+		comp->cq = NULL;
+	}
+
+	ib_unregister_event_handler(&device->event_handler);
+	ib_dealloc_pd(device->pd);
+
+	kfree(device->comps);
+	device->comps = NULL;
+	device->pd = NULL;
+}
+
+/**
+ * iser_alloc_fmr_pool - Creates FMR pool and page_vector
+ *
+ * returns 0 on success, or errno code on failure
+ */
+int iser_alloc_fmr_pool(struct ib_conn *ib_conn,
+			unsigned cmds_max,
+			unsigned int size)
+{
+	struct iser_device *device = ib_conn->device;
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	struct iser_page_vec *page_vec;
+	struct iser_fr_desc *desc;
+	struct ib_fmr_pool *fmr_pool;
+	struct ib_fmr_pool_param params;
+	int ret;
+
+	INIT_LIST_HEAD(&fr_pool->list);
+	spin_lock_init(&fr_pool->lock);
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	page_vec = kmalloc(sizeof(*page_vec) + (sizeof(u64) * size),
+			   GFP_KERNEL);
+	if (!page_vec) {
+		ret = -ENOMEM;
+		goto err_frpl;
+	}
+
+	page_vec->pages = (u64 *)(page_vec + 1);
+
+	params.page_shift        = SHIFT_4K;
+	params.max_pages_per_fmr = size;
+	/* make the pool size twice the max number of SCSI commands *
+	 * the ML is expected to queue, watermark for unmap at 50%  */
+	params.pool_size	 = cmds_max * 2;
+	params.dirty_watermark	 = cmds_max;
+	params.cache		 = 0;
+	params.flush_function	 = NULL;
+	params.access		 = (IB_ACCESS_LOCAL_WRITE  |
+				    IB_ACCESS_REMOTE_WRITE |
+				    IB_ACCESS_REMOTE_READ);
+
+	fmr_pool = ib_create_fmr_pool(device->pd, &params);
+	if (IS_ERR(fmr_pool)) {
+		ret = PTR_ERR(fmr_pool);
+		iser_err("FMR allocation failed, err %d\n", ret);
+		goto err_fmr;
+	}
+
+	desc->rsc.page_vec = page_vec;
+	desc->rsc.fmr_pool = fmr_pool;
+	list_add(&desc->list, &fr_pool->list);
+
+	return 0;
+
+err_fmr:
+	kfree(page_vec);
+err_frpl:
+	kfree(desc);
+
+	return ret;
+}
+
+/**
+ * iser_free_fmr_pool - releases the FMR pool and page vec
+ */
+void iser_free_fmr_pool(struct ib_conn *ib_conn)
+{
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	struct iser_fr_desc *desc;
+
+	desc = list_first_entry(&fr_pool->list,
+				struct iser_fr_desc, list);
+	list_del(&desc->list);
+
+	iser_info("freeing conn %p fmr pool %p\n",
+		  ib_conn, desc->rsc.fmr_pool);
+
+	ib_destroy_fmr_pool(desc->rsc.fmr_pool);
+	kfree(desc->rsc.page_vec);
+	kfree(desc);
+}
+
+static int
+iser_alloc_reg_res(struct iser_device *device,
+		   struct ib_pd *pd,
+		   struct iser_reg_resources *res,
+		   unsigned int size)
+{
+	struct ib_device *ib_dev = device->ib_device;
+	enum ib_mr_type mr_type;
+	int ret;
+
+	if (ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
+		mr_type = IB_MR_TYPE_SG_GAPS;
+	else
+		mr_type = IB_MR_TYPE_MEM_REG;
+
+	res->mr = ib_alloc_mr(pd, mr_type, size);
+	if (IS_ERR(res->mr)) {
+		ret = PTR_ERR(res->mr);
+		iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
+		return ret;
+	}
+	res->mr_valid = 0;
+
+	return 0;
+}
+
+static void
+iser_free_reg_res(struct iser_reg_resources *rsc)
+{
+	ib_dereg_mr(rsc->mr);
+}
+
+static int
+iser_alloc_pi_ctx(struct iser_device *device,
+		  struct ib_pd *pd,
+		  struct iser_fr_desc *desc,
+		  unsigned int size)
+{
+	struct iser_pi_context *pi_ctx = NULL;
+	int ret;
+
+	desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
+	if (!desc->pi_ctx)
+		return -ENOMEM;
+
+	pi_ctx = desc->pi_ctx;
+
+	ret = iser_alloc_reg_res(device, pd, &pi_ctx->rsc, size);
+	if (ret) {
+		iser_err("failed to allocate reg_resources\n");
+		goto alloc_reg_res_err;
+	}
+
+	pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
+	if (IS_ERR(pi_ctx->sig_mr)) {
+		ret = PTR_ERR(pi_ctx->sig_mr);
+		goto sig_mr_failure;
+	}
+	pi_ctx->sig_mr_valid = 0;
+	desc->pi_ctx->sig_protected = 0;
+
+	return 0;
+
+sig_mr_failure:
+	iser_free_reg_res(&pi_ctx->rsc);
+alloc_reg_res_err:
+	kfree(desc->pi_ctx);
+
+	return ret;
+}
+
+static void
+iser_free_pi_ctx(struct iser_pi_context *pi_ctx)
+{
+	iser_free_reg_res(&pi_ctx->rsc);
+	ib_dereg_mr(pi_ctx->sig_mr);
+	kfree(pi_ctx);
+}
+
+static struct iser_fr_desc *
+iser_create_fastreg_desc(struct iser_device *device,
+			 struct ib_pd *pd,
+			 bool pi_enable,
+			 unsigned int size)
+{
+	struct iser_fr_desc *desc;
+	int ret;
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	if (!desc)
+		return ERR_PTR(-ENOMEM);
+
+	ret = iser_alloc_reg_res(device, pd, &desc->rsc, size);
+	if (ret)
+		goto reg_res_alloc_failure;
+
+	if (pi_enable) {
+		ret = iser_alloc_pi_ctx(device, pd, desc, size);
+		if (ret)
+			goto pi_ctx_alloc_failure;
+	}
+
+	return desc;
+
+pi_ctx_alloc_failure:
+	iser_free_reg_res(&desc->rsc);
+reg_res_alloc_failure:
+	kfree(desc);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
+ * for fast registration work requests.
+ * returns 0 on success, or errno code on failure
+ */
+int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
+			    unsigned cmds_max,
+			    unsigned int size)
+{
+	struct iser_device *device = ib_conn->device;
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	struct iser_fr_desc *desc;
+	int i, ret;
+
+	INIT_LIST_HEAD(&fr_pool->list);
+	INIT_LIST_HEAD(&fr_pool->all_list);
+	spin_lock_init(&fr_pool->lock);
+	fr_pool->size = 0;
+	for (i = 0; i < cmds_max; i++) {
+		desc = iser_create_fastreg_desc(device, device->pd,
+						ib_conn->pi_support, size);
+		if (IS_ERR(desc)) {
+			ret = PTR_ERR(desc);
+			goto err;
+		}
+
+		list_add_tail(&desc->list, &fr_pool->list);
+		list_add_tail(&desc->all_list, &fr_pool->all_list);
+		fr_pool->size++;
+	}
+
+	return 0;
+
+err:
+	iser_free_fastreg_pool(ib_conn);
+	return ret;
+}
+
+/**
+ * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
+ */
+void iser_free_fastreg_pool(struct ib_conn *ib_conn)
+{
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	struct iser_fr_desc *desc, *tmp;
+	int i = 0;
+
+	if (list_empty(&fr_pool->all_list))
+		return;
+
+	iser_info("freeing conn %p fr pool\n", ib_conn);
+
+	list_for_each_entry_safe(desc, tmp, &fr_pool->all_list, all_list) {
+		list_del(&desc->all_list);
+		iser_free_reg_res(&desc->rsc);
+		if (desc->pi_ctx)
+			iser_free_pi_ctx(desc->pi_ctx);
+		kfree(desc);
+		++i;
+	}
+
+	if (i < fr_pool->size)
+		iser_warn("pool still has %d regions registered\n",
+			  fr_pool->size - i);
+}
+
+/**
+ * iser_create_ib_conn_res - Queue-Pair (QP)
+ *
+ * returns 0 on success, -1 on failure
+ */
+static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
+{
+	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
+	struct iser_device	*device;
+	struct ib_device	*ib_dev;
+	struct ib_qp_init_attr	init_attr;
+	int			ret = -ENOMEM;
+	int index, min_index = 0;
+
+	BUG_ON(ib_conn->device == NULL);
+
+	device = ib_conn->device;
+	ib_dev = device->ib_device;
+
+	memset(&init_attr, 0, sizeof init_attr);
+
+	mutex_lock(&ig.connlist_mutex);
+	/* select the CQ with the minimal number of usages */
+	for (index = 0; index < device->comps_used; index++) {
+		if (device->comps[index].active_qps <
+		    device->comps[min_index].active_qps)
+			min_index = index;
+	}
+	ib_conn->comp = &device->comps[min_index];
+	ib_conn->comp->active_qps++;
+	mutex_unlock(&ig.connlist_mutex);
+	iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
+
+	init_attr.event_handler = iser_qp_event_callback;
+	init_attr.qp_context	= (void *)ib_conn;
+	init_attr.send_cq	= ib_conn->comp->cq;
+	init_attr.recv_cq	= ib_conn->comp->cq;
+	init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
+	init_attr.cap.max_send_sge = 2;
+	init_attr.cap.max_recv_sge = 1;
+	init_attr.sq_sig_type	= IB_SIGNAL_REQ_WR;
+	init_attr.qp_type	= IB_QPT_RC;
+	if (ib_conn->pi_support) {
+		init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
+		init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
+		iser_conn->max_cmds =
+			ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
+	} else {
+		if (ib_dev->attrs.max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
+			init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
+			iser_conn->max_cmds =
+				ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
+		} else {
+			init_attr.cap.max_send_wr = ib_dev->attrs.max_qp_wr;
+			iser_conn->max_cmds =
+				ISER_GET_MAX_XMIT_CMDS(ib_dev->attrs.max_qp_wr);
+			iser_dbg("device %s supports max_send_wr %d\n",
+				 device->ib_device->name, ib_dev->attrs.max_qp_wr);
+		}
+	}
+
+	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
+	if (ret)
+		goto out_err;
+
+	ib_conn->qp = ib_conn->cma_id->qp;
+	iser_info("setting conn %p cma_id %p qp %p\n",
+		  ib_conn, ib_conn->cma_id,
+		  ib_conn->cma_id->qp);
+	return ret;
+
+out_err:
+	mutex_lock(&ig.connlist_mutex);
+	ib_conn->comp->active_qps--;
+	mutex_unlock(&ig.connlist_mutex);
+	iser_err("unable to alloc mem or create resource, err %d\n", ret);
+
+	return ret;
+}
+
+/**
+ * based on the resolved device node GUID see if there already allocated
+ * device for this device. If there's no such, create one.
+ */
+static
+struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
+{
+	struct iser_device *device;
+
+	mutex_lock(&ig.device_list_mutex);
+
+	list_for_each_entry(device, &ig.device_list, ig_list)
+		/* find if there's a match using the node GUID */
+		if (device->ib_device->node_guid == cma_id->device->node_guid)
+			goto inc_refcnt;
+
+	device = kzalloc(sizeof *device, GFP_KERNEL);
+	if (device == NULL)
+		goto out;
+
+	/* assign this device to the device */
+	device->ib_device = cma_id->device;
+	/* init the device and link it into ig device list */
+	if (iser_create_device_ib_res(device)) {
+		kfree(device);
+		device = NULL;
+		goto out;
+	}
+	list_add(&device->ig_list, &ig.device_list);
+
+inc_refcnt:
+	device->refcount++;
+out:
+	mutex_unlock(&ig.device_list_mutex);
+	return device;
+}
+
+/* if there's no demand for this device, release it */
+static void iser_device_try_release(struct iser_device *device)
+{
+	mutex_lock(&ig.device_list_mutex);
+	device->refcount--;
+	iser_info("device %p refcount %d\n", device, device->refcount);
+	if (!device->refcount) {
+		iser_free_device_ib_res(device);
+		list_del(&device->ig_list);
+		kfree(device);
+	}
+	mutex_unlock(&ig.device_list_mutex);
+}
+
+/**
+ * Called with state mutex held
+ **/
+static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
+				     enum iser_conn_state comp,
+				     enum iser_conn_state exch)
+{
+	int ret;
+
+	ret = (iser_conn->state == comp);
+	if (ret)
+		iser_conn->state = exch;
+
+	return ret;
+}
+
+void iser_release_work(struct work_struct *work)
+{
+	struct iser_conn *iser_conn;
+
+	iser_conn = container_of(work, struct iser_conn, release_work);
+
+	/* Wait for conn_stop to complete */
+	wait_for_completion(&iser_conn->stop_completion);
+	/* Wait for IB resouces cleanup to complete */
+	wait_for_completion(&iser_conn->ib_completion);
+
+	mutex_lock(&iser_conn->state_mutex);
+	iser_conn->state = ISER_CONN_DOWN;
+	mutex_unlock(&iser_conn->state_mutex);
+
+	iser_conn_release(iser_conn);
+}
+
+/**
+ * iser_free_ib_conn_res - release IB related resources
+ * @iser_conn: iser connection struct
+ * @destroy: indicator if we need to try to release the
+ *     iser device and memory regoins pool (only iscsi
+ *     shutdown and DEVICE_REMOVAL will use this).
+ *
+ * This routine is called with the iser state mutex held
+ * so the cm_id removal is out of here. It is Safe to
+ * be invoked multiple times.
+ */
+static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
+				  bool destroy)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	struct iser_device *device = ib_conn->device;
+
+	iser_info("freeing conn %p cma_id %p qp %p\n",
+		  iser_conn, ib_conn->cma_id, ib_conn->qp);
+
+	if (ib_conn->qp != NULL) {
+		mutex_lock(&ig.connlist_mutex);
+		ib_conn->comp->active_qps--;
+		mutex_unlock(&ig.connlist_mutex);
+		rdma_destroy_qp(ib_conn->cma_id);
+		ib_conn->qp = NULL;
+	}
+
+	if (destroy) {
+		if (iser_conn->rx_descs)
+			iser_free_rx_descriptors(iser_conn);
+
+		if (device != NULL) {
+			iser_device_try_release(device);
+			ib_conn->device = NULL;
+		}
+	}
+}
+
+/**
+ * Frees all conn objects and deallocs conn descriptor
+ */
+void iser_conn_release(struct iser_conn *iser_conn)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+
+	mutex_lock(&ig.connlist_mutex);
+	list_del(&iser_conn->conn_list);
+	mutex_unlock(&ig.connlist_mutex);
+
+	mutex_lock(&iser_conn->state_mutex);
+	/* In case we endup here without ep_disconnect being invoked. */
+	if (iser_conn->state != ISER_CONN_DOWN) {
+		iser_warn("iser conn %p state %d, expected state down.\n",
+			  iser_conn, iser_conn->state);
+		iscsi_destroy_endpoint(iser_conn->ep);
+		iser_conn->state = ISER_CONN_DOWN;
+	}
+	/*
+	 * In case we never got to bind stage, we still need to
+	 * release IB resources (which is safe to call more than once).
+	 */
+	iser_free_ib_conn_res(iser_conn, true);
+	mutex_unlock(&iser_conn->state_mutex);
+
+	if (ib_conn->cma_id != NULL) {
+		rdma_destroy_id(ib_conn->cma_id);
+		ib_conn->cma_id = NULL;
+	}
+
+	kfree(iser_conn);
+}
+
+/**
+ * triggers start of the disconnect procedures and wait for them to be done
+ * Called with state mutex held
+ */
+int iser_conn_terminate(struct iser_conn *iser_conn)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	int err = 0;
+
+	/* terminate the iser conn only if the conn state is UP */
+	if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
+				       ISER_CONN_TERMINATING))
+		return 0;
+
+	iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
+
+	/* suspend queuing of new iscsi commands */
+	if (iser_conn->iscsi_conn)
+		iscsi_suspend_queue(iser_conn->iscsi_conn);
+
+	/*
+	 * In case we didn't already clean up the cma_id (peer initiated
+	 * a disconnection), we need to Cause the CMA to change the QP
+	 * state to ERROR.
+	 */
+	if (ib_conn->cma_id) {
+		err = rdma_disconnect(ib_conn->cma_id);
+		if (err)
+			iser_err("Failed to disconnect, conn: 0x%p err %d\n",
+				 iser_conn, err);
+
+		/* block until all flush errors are consumed */
+		ib_drain_sq(ib_conn->qp);
+	}
+
+	return 1;
+}
+
+/**
+ * Called with state mutex held
+ **/
+static void iser_connect_error(struct rdma_cm_id *cma_id)
+{
+	struct iser_conn *iser_conn;
+
+	iser_conn = (struct iser_conn *)cma_id->context;
+	iser_conn->state = ISER_CONN_TERMINATING;
+}
+
+static void
+iser_calc_scsi_params(struct iser_conn *iser_conn,
+		      unsigned int max_sectors)
+{
+	struct iser_device *device = iser_conn->ib_conn.device;
+	struct ib_device_attr *attr = &device->ib_device->attrs;
+	unsigned short sg_tablesize, sup_sg_tablesize;
+	unsigned short reserved_mr_pages;
+
+	/*
+	 * FRs without SG_GAPS or FMRs can only map up to a (device) page per
+	 * entry, but if the first entry is misaligned we'll end up using two
+	 * entries (head and tail) for a single page worth data, so one
+	 * additional entry is required.
+	 */
+	if ((attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) &&
+	    (attr->device_cap_flags & IB_DEVICE_SG_GAPS_REG))
+		reserved_mr_pages = 0;
+	else
+		reserved_mr_pages = 1;
+
+	sg_tablesize = DIV_ROUND_UP(max_sectors * 512, SIZE_4K);
+	if (attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)
+		sup_sg_tablesize =
+			min_t(
+			 uint, ISCSI_ISER_MAX_SG_TABLESIZE,
+			 attr->max_fast_reg_page_list_len - reserved_mr_pages);
+	else
+		sup_sg_tablesize = ISCSI_ISER_MAX_SG_TABLESIZE;
+
+	iser_conn->scsi_sg_tablesize = min(sg_tablesize, sup_sg_tablesize);
+	iser_conn->pages_per_mr =
+		iser_conn->scsi_sg_tablesize + reserved_mr_pages;
+}
+
+/**
+ * Called with state mutex held
+ **/
+static void iser_addr_handler(struct rdma_cm_id *cma_id)
+{
+	struct iser_device *device;
+	struct iser_conn   *iser_conn;
+	struct ib_conn   *ib_conn;
+	int    ret;
+
+	iser_conn = (struct iser_conn *)cma_id->context;
+	if (iser_conn->state != ISER_CONN_PENDING)
+		/* bailout */
+		return;
+
+	ib_conn = &iser_conn->ib_conn;
+	device = iser_device_find_by_ib_device(cma_id);
+	if (!device) {
+		iser_err("device lookup/creation failed\n");
+		iser_connect_error(cma_id);
+		return;
+	}
+
+	ib_conn->device = device;
+
+	/* connection T10-PI support */
+	if (iser_pi_enable) {
+		if (!(device->ib_device->attrs.device_cap_flags &
+		      IB_DEVICE_SIGNATURE_HANDOVER)) {
+			iser_warn("T10-PI requested but not supported on %s, "
+				  "continue without T10-PI\n",
+				  ib_conn->device->ib_device->name);
+			ib_conn->pi_support = false;
+		} else {
+			ib_conn->pi_support = true;
+		}
+	}
+
+	iser_calc_scsi_params(iser_conn, iser_max_sectors);
+
+	ret = rdma_resolve_route(cma_id, 1000);
+	if (ret) {
+		iser_err("resolve route failed: %d\n", ret);
+		iser_connect_error(cma_id);
+		return;
+	}
+}
+
+/**
+ * Called with state mutex held
+ **/
+static void iser_route_handler(struct rdma_cm_id *cma_id)
+{
+	struct rdma_conn_param conn_param;
+	int    ret;
+	struct iser_cm_hdr req_hdr;
+	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	struct iser_device *device = ib_conn->device;
+
+	if (iser_conn->state != ISER_CONN_PENDING)
+		/* bailout */
+		return;
+
+	ret = iser_create_ib_conn_res(ib_conn);
+	if (ret)
+		goto failure;
+
+	memset(&conn_param, 0, sizeof conn_param);
+	conn_param.responder_resources = device->ib_device->attrs.max_qp_rd_atom;
+	conn_param.initiator_depth     = 1;
+	conn_param.retry_count	       = 7;
+	conn_param.rnr_retry_count     = 6;
+
+	memset(&req_hdr, 0, sizeof(req_hdr));
+	req_hdr.flags = ISER_ZBVA_NOT_SUP;
+	if (!device->remote_inv_sup)
+		req_hdr.flags |= ISER_SEND_W_INV_NOT_SUP;
+	conn_param.private_data	= (void *)&req_hdr;
+	conn_param.private_data_len = sizeof(struct iser_cm_hdr);
+
+	ret = rdma_connect(cma_id, &conn_param);
+	if (ret) {
+		iser_err("failure connecting: %d\n", ret);
+		goto failure;
+	}
+
+	return;
+failure:
+	iser_connect_error(cma_id);
+}
+
+static void iser_connected_handler(struct rdma_cm_id *cma_id,
+				   const void *private_data)
+{
+	struct iser_conn *iser_conn;
+	struct ib_qp_attr attr;
+	struct ib_qp_init_attr init_attr;
+
+	iser_conn = (struct iser_conn *)cma_id->context;
+	if (iser_conn->state != ISER_CONN_PENDING)
+		/* bailout */
+		return;
+
+	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
+	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
+
+	if (private_data) {
+		u8 flags = *(u8 *)private_data;
+
+		iser_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP);
+	}
+
+	iser_info("conn %p: negotiated %s invalidation\n",
+		  iser_conn, iser_conn->snd_w_inv ? "remote" : "local");
+
+	iser_conn->state = ISER_CONN_UP;
+	complete(&iser_conn->up_completion);
+}
+
+static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
+{
+	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
+
+	if (iser_conn_terminate(iser_conn)) {
+		if (iser_conn->iscsi_conn)
+			iscsi_conn_failure(iser_conn->iscsi_conn,
+					   ISCSI_ERR_CONN_FAILED);
+		else
+			iser_err("iscsi_iser connection isn't bound\n");
+	}
+}
+
+static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
+				 bool destroy)
+{
+	struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
+
+	/*
+	 * We are not guaranteed that we visited disconnected_handler
+	 * by now, call it here to be safe that we handle CM drep
+	 * and flush errors.
+	 */
+	iser_disconnected_handler(cma_id);
+	iser_free_ib_conn_res(iser_conn, destroy);
+	complete(&iser_conn->ib_completion);
+};
+
+static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
+{
+	struct iser_conn *iser_conn;
+	int ret = 0;
+
+	iser_conn = (struct iser_conn *)cma_id->context;
+	iser_info("%s (%d): status %d conn %p id %p\n",
+		  rdma_event_msg(event->event), event->event,
+		  event->status, cma_id->context, cma_id);
+
+	mutex_lock(&iser_conn->state_mutex);
+	switch (event->event) {
+	case RDMA_CM_EVENT_ADDR_RESOLVED:
+		iser_addr_handler(cma_id);
+		break;
+	case RDMA_CM_EVENT_ROUTE_RESOLVED:
+		iser_route_handler(cma_id);
+		break;
+	case RDMA_CM_EVENT_ESTABLISHED:
+		iser_connected_handler(cma_id, event->param.conn.private_data);
+		break;
+	case RDMA_CM_EVENT_REJECTED:
+		iser_info("Connection rejected: %s\n",
+			 rdma_reject_msg(cma_id, event->status));
+		/* FALLTHROUGH */
+	case RDMA_CM_EVENT_ADDR_ERROR:
+	case RDMA_CM_EVENT_ROUTE_ERROR:
+	case RDMA_CM_EVENT_CONNECT_ERROR:
+	case RDMA_CM_EVENT_UNREACHABLE:
+		iser_connect_error(cma_id);
+		break;
+	case RDMA_CM_EVENT_DISCONNECTED:
+	case RDMA_CM_EVENT_ADDR_CHANGE:
+	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
+		iser_cleanup_handler(cma_id, false);
+		break;
+	case RDMA_CM_EVENT_DEVICE_REMOVAL:
+		/*
+		 * we *must* destroy the device as we cannot rely
+		 * on iscsid to be around to initiate error handling.
+		 * also if we are not in state DOWN implicitly destroy
+		 * the cma_id.
+		 */
+		iser_cleanup_handler(cma_id, true);
+		if (iser_conn->state != ISER_CONN_DOWN) {
+			iser_conn->ib_conn.cma_id = NULL;
+			ret = 1;
+		}
+		break;
+	default:
+		iser_err("Unexpected RDMA CM event: %s (%d)\n",
+			 rdma_event_msg(event->event), event->event);
+		break;
+	}
+	mutex_unlock(&iser_conn->state_mutex);
+
+	return ret;
+}
+
+void iser_conn_init(struct iser_conn *iser_conn)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+
+	iser_conn->state = ISER_CONN_INIT;
+	init_completion(&iser_conn->stop_completion);
+	init_completion(&iser_conn->ib_completion);
+	init_completion(&iser_conn->up_completion);
+	INIT_LIST_HEAD(&iser_conn->conn_list);
+	mutex_init(&iser_conn->state_mutex);
+
+	ib_conn->post_recv_buf_count = 0;
+	ib_conn->reg_cqe.done = iser_reg_comp;
+}
+
+ /**
+ * starts the process of connecting to the target
+ * sleeps until the connection is established or rejected
+ */
+int iser_connect(struct iser_conn   *iser_conn,
+		 struct sockaddr    *src_addr,
+		 struct sockaddr    *dst_addr,
+		 int                 non_blocking)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	int err = 0;
+
+	mutex_lock(&iser_conn->state_mutex);
+
+	sprintf(iser_conn->name, "%pISp", dst_addr);
+
+	iser_info("connecting to: %s\n", iser_conn->name);
+
+	/* the device is known only --after-- address resolution */
+	ib_conn->device = NULL;
+
+	iser_conn->state = ISER_CONN_PENDING;
+
+	ib_conn->cma_id = rdma_create_id(&init_net, iser_cma_handler,
+					 (void *)iser_conn,
+					 RDMA_PS_TCP, IB_QPT_RC);
+	if (IS_ERR(ib_conn->cma_id)) {
+		err = PTR_ERR(ib_conn->cma_id);
+		iser_err("rdma_create_id failed: %d\n", err);
+		goto id_failure;
+	}
+
+	err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
+	if (err) {
+		iser_err("rdma_resolve_addr failed: %d\n", err);
+		goto addr_failure;
+	}
+
+	if (!non_blocking) {
+		wait_for_completion_interruptible(&iser_conn->up_completion);
+
+		if (iser_conn->state != ISER_CONN_UP) {
+			err =  -EIO;
+			goto connect_failure;
+		}
+	}
+	mutex_unlock(&iser_conn->state_mutex);
+
+	mutex_lock(&ig.connlist_mutex);
+	list_add(&iser_conn->conn_list, &ig.connlist);
+	mutex_unlock(&ig.connlist_mutex);
+	return 0;
+
+id_failure:
+	ib_conn->cma_id = NULL;
+addr_failure:
+	iser_conn->state = ISER_CONN_DOWN;
+connect_failure:
+	mutex_unlock(&iser_conn->state_mutex);
+	iser_conn_release(iser_conn);
+	return err;
+}
+
+int iser_post_recvl(struct iser_conn *iser_conn)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	struct iser_login_desc *desc = &iser_conn->login_desc;
+	struct ib_recv_wr wr;
+	int ib_ret;
+
+	desc->sge.addr = desc->rsp_dma;
+	desc->sge.length = ISER_RX_LOGIN_SIZE;
+	desc->sge.lkey = ib_conn->device->pd->local_dma_lkey;
+
+	desc->cqe.done = iser_login_rsp;
+	wr.wr_cqe = &desc->cqe;
+	wr.sg_list = &desc->sge;
+	wr.num_sge = 1;
+	wr.next = NULL;
+
+	ib_conn->post_recv_buf_count++;
+	ib_ret = ib_post_recv(ib_conn->qp, &wr, NULL);
+	if (ib_ret) {
+		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
+		ib_conn->post_recv_buf_count--;
+	}
+
+	return ib_ret;
+}
+
+int iser_post_recvm(struct iser_conn *iser_conn, int count)
+{
+	struct ib_conn *ib_conn = &iser_conn->ib_conn;
+	unsigned int my_rx_head = iser_conn->rx_desc_head;
+	struct iser_rx_desc *rx_desc;
+	struct ib_recv_wr *wr;
+	int i, ib_ret;
+
+	for (wr = ib_conn->rx_wr, i = 0; i < count; i++, wr++) {
+		rx_desc = &iser_conn->rx_descs[my_rx_head];
+		rx_desc->cqe.done = iser_task_rsp;
+		wr->wr_cqe = &rx_desc->cqe;
+		wr->sg_list = &rx_desc->rx_sg;
+		wr->num_sge = 1;
+		wr->next = wr + 1;
+		my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
+	}
+
+	wr--;
+	wr->next = NULL; /* mark end of work requests list */
+
+	ib_conn->post_recv_buf_count += count;
+	ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, NULL);
+	if (ib_ret) {
+		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
+		ib_conn->post_recv_buf_count -= count;
+	} else
+		iser_conn->rx_desc_head = my_rx_head;
+
+	return ib_ret;
+}
+
+
+/**
+ * iser_start_send - Initiate a Send DTO operation
+ *
+ * returns 0 on success, -1 on failure
+ */
+int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
+		   bool signal)
+{
+	struct ib_send_wr *wr = iser_tx_next_wr(tx_desc);
+	int ib_ret;
+
+	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
+				      tx_desc->dma_addr, ISER_HEADERS_LEN,
+				      DMA_TO_DEVICE);
+
+	wr->next = NULL;
+	wr->wr_cqe = &tx_desc->cqe;
+	wr->sg_list = tx_desc->tx_sg;
+	wr->num_sge = tx_desc->num_sge;
+	wr->opcode = IB_WR_SEND;
+	wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
+
+	ib_ret = ib_post_send(ib_conn->qp, &tx_desc->wrs[0].send, NULL);
+	if (ib_ret)
+		iser_err("ib_post_send failed, ret:%d opcode:%d\n",
+			 ib_ret, wr->opcode);
+
+	return ib_ret;
+}
+
+u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
+			     enum iser_data_dir cmd_dir, sector_t *sector)
+{
+	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
+	struct iser_fr_desc *desc = reg->mem_h;
+	unsigned long sector_size = iser_task->sc->device->sector_size;
+	struct ib_mr_status mr_status;
+	int ret;
+
+	if (desc && desc->pi_ctx->sig_protected) {
+		desc->pi_ctx->sig_protected = 0;
+		ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
+					 IB_MR_CHECK_SIG_STATUS, &mr_status);
+		if (ret) {
+			pr_err("ib_check_mr_status failed, ret %d\n", ret);
+			/* Not a lot we can do, return ambiguous guard error */
+			*sector = 0;
+			return 0x1;
+		}
+
+		if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
+			sector_t sector_off = mr_status.sig_err.sig_err_offset;
+
+			sector_div(sector_off, sector_size + 8);
+			*sector = scsi_get_lba(iser_task->sc) + sector_off;
+
+			pr_err("PI error found type %d at sector %llx "
+			       "expected %x vs actual %x\n",
+			       mr_status.sig_err.err_type,
+			       (unsigned long long)*sector,
+			       mr_status.sig_err.expected,
+			       mr_status.sig_err.actual);
+
+			switch (mr_status.sig_err.err_type) {
+			case IB_SIG_BAD_GUARD:
+				return 0x1;
+			case IB_SIG_BAD_REFTAG:
+				return 0x3;
+			case IB_SIG_BAD_APPTAG:
+				return 0x2;
+			}
+		}
+	}
+
+	return 0;
+}
+
+void iser_err_comp(struct ib_wc *wc, const char *type)
+{
+	if (wc->status != IB_WC_WR_FLUSH_ERR) {
+		struct iser_conn *iser_conn = to_iser_conn(wc->qp->qp_context);
+
+		iser_err("%s failure: %s (%d) vend_err %#x\n", type,
+			 ib_wc_status_msg(wc->status), wc->status,
+			 wc->vendor_err);
+
+		if (iser_conn->iscsi_conn)
+			iscsi_conn_failure(iser_conn->iscsi_conn,
+					   ISCSI_ERR_CONN_FAILED);
+	} else {
+		iser_dbg("%s failure: %s (%d)\n", type,
+			 ib_wc_status_msg(wc->status), wc->status);
+	}
+}