Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 1663 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
new file mode 100644
index 000000000..8f0b598a4
--- /dev/null
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -0,0 +1,1663 @@
+/*
+ * Copyright (c) 2006 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 <rdma/ib_cm.h>
+#include <net/dst.h>
+#include <net/icmp.h>
+#include <linux/icmpv6.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/moduleparam.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+
+#include "ipoib.h"
+
+int ipoib_max_conn_qp = 128;
+
+module_param_named(max_nonsrq_conn_qp, ipoib_max_conn_qp, int, 0444);
+MODULE_PARM_DESC(max_nonsrq_conn_qp,
+		 "Max number of connected-mode QPs per interface "
+		 "(applied only if shared receive queue is not available)");
+
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
+static int data_debug_level;
+
+module_param_named(cm_data_debug_level, data_debug_level, int, 0644);
+MODULE_PARM_DESC(cm_data_debug_level,
+		 "Enable data path debug tracing for connected mode if > 0");
+#endif
+
+#define IPOIB_CM_IETF_ID 0x1000000000000000ULL
+
+#define IPOIB_CM_RX_UPDATE_TIME (256 * HZ)
+#define IPOIB_CM_RX_TIMEOUT     (2 * 256 * HZ)
+#define IPOIB_CM_RX_DELAY       (3 * 256 * HZ)
+#define IPOIB_CM_RX_UPDATE_MASK (0x3)
+
+#define IPOIB_CM_RX_RESERVE     (ALIGN(IPOIB_HARD_LEN, 16) - IPOIB_ENCAP_LEN)
+
+static struct ib_qp_attr ipoib_cm_err_attr = {
+	.qp_state = IB_QPS_ERR
+};
+
+#define IPOIB_CM_RX_DRAIN_WRID 0xffffffff
+
+static struct ib_send_wr ipoib_cm_rx_drain_wr = {
+	.opcode = IB_WR_SEND,
+};
+
+static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
+			       const struct ib_cm_event *event);
+
+static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
+				  u64 mapping[IPOIB_CM_RX_SG])
+{
+	int i;
+
+	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
+
+	for (i = 0; i < frags; ++i)
+		ib_dma_unmap_page(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
+}
+
+static int ipoib_cm_post_receive_srq(struct net_device *dev, int id)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int i, ret;
+
+	priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
+
+	for (i = 0; i < priv->cm.num_frags; ++i)
+		priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
+
+	ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, NULL);
+	if (unlikely(ret)) {
+		ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
+		ipoib_cm_dma_unmap_rx(priv, priv->cm.num_frags - 1,
+				      priv->cm.srq_ring[id].mapping);
+		dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
+		priv->cm.srq_ring[id].skb = NULL;
+	}
+
+	return ret;
+}
+
+static int ipoib_cm_post_receive_nonsrq(struct net_device *dev,
+					struct ipoib_cm_rx *rx,
+					struct ib_recv_wr *wr,
+					struct ib_sge *sge, int id)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int i, ret;
+
+	wr->wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
+
+	for (i = 0; i < IPOIB_CM_RX_SG; ++i)
+		sge[i].addr = rx->rx_ring[id].mapping[i];
+
+	ret = ib_post_recv(rx->qp, wr, NULL);
+	if (unlikely(ret)) {
+		ipoib_warn(priv, "post recv failed for buf %d (%d)\n", id, ret);
+		ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+				      rx->rx_ring[id].mapping);
+		dev_kfree_skb_any(rx->rx_ring[id].skb);
+		rx->rx_ring[id].skb = NULL;
+	}
+
+	return ret;
+}
+
+static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev,
+					     struct ipoib_cm_rx_buf *rx_ring,
+					     int id, int frags,
+					     u64 mapping[IPOIB_CM_RX_SG],
+					     gfp_t gfp)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct sk_buff *skb;
+	int i;
+
+	skb = dev_alloc_skb(ALIGN(IPOIB_CM_HEAD_SIZE + IPOIB_PSEUDO_LEN, 16));
+	if (unlikely(!skb))
+		return NULL;
+
+	/*
+	 * IPoIB adds a IPOIB_ENCAP_LEN byte header, this will align the
+	 * IP header to a multiple of 16.
+	 */
+	skb_reserve(skb, IPOIB_CM_RX_RESERVE);
+
+	mapping[0] = ib_dma_map_single(priv->ca, skb->data, IPOIB_CM_HEAD_SIZE,
+				       DMA_FROM_DEVICE);
+	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+
+	for (i = 0; i < frags; i++) {
+		struct page *page = alloc_page(gfp);
+
+		if (!page)
+			goto partial_error;
+		skb_fill_page_desc(skb, i, page, 0, PAGE_SIZE);
+
+		mapping[i + 1] = ib_dma_map_page(priv->ca, page,
+						 0, PAGE_SIZE, DMA_FROM_DEVICE);
+		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[i + 1])))
+			goto partial_error;
+	}
+
+	rx_ring[id].skb = skb;
+	return skb;
+
+partial_error:
+
+	ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
+
+	for (; i > 0; --i)
+		ib_dma_unmap_page(priv->ca, mapping[i], PAGE_SIZE, DMA_FROM_DEVICE);
+
+	dev_kfree_skb_any(skb);
+	return NULL;
+}
+
+static void ipoib_cm_free_rx_ring(struct net_device *dev,
+				  struct ipoib_cm_rx_buf *rx_ring)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int i;
+
+	for (i = 0; i < ipoib_recvq_size; ++i)
+		if (rx_ring[i].skb) {
+			ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+					      rx_ring[i].mapping);
+			dev_kfree_skb_any(rx_ring[i].skb);
+		}
+
+	vfree(rx_ring);
+}
+
+static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv *priv)
+{
+	struct ipoib_cm_rx *p;
+
+	/* We only reserved 1 extra slot in CQ for drain WRs, so
+	 * make sure we have at most 1 outstanding WR. */
+	if (list_empty(&priv->cm.rx_flush_list) ||
+	    !list_empty(&priv->cm.rx_drain_list))
+		return;
+
+	/*
+	 * QPs on flush list are error state.  This way, a "flush
+	 * error" WC will be immediately generated for each WR we post.
+	 */
+	p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list);
+	ipoib_cm_rx_drain_wr.wr_id = IPOIB_CM_RX_DRAIN_WRID;
+	if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, NULL))
+		ipoib_warn(priv, "failed to post drain wr\n");
+
+	list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list);
+}
+
+static void ipoib_cm_rx_event_handler(struct ib_event *event, void *ctx)
+{
+	struct ipoib_cm_rx *p = ctx;
+	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
+	unsigned long flags;
+
+	if (event->event != IB_EVENT_QP_LAST_WQE_REACHED)
+		return;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_move(&p->list, &priv->cm.rx_flush_list);
+	p->state = IPOIB_CM_RX_FLUSH;
+	ipoib_cm_start_rx_drain(priv);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
+					   struct ipoib_cm_rx *p)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ib_qp_init_attr attr = {
+		.event_handler = ipoib_cm_rx_event_handler,
+		.send_cq = priv->recv_cq, /* For drain WR */
+		.recv_cq = priv->recv_cq,
+		.srq = priv->cm.srq,
+		.cap.max_send_wr = 1, /* For drain WR */
+		.cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */
+		.sq_sig_type = IB_SIGNAL_ALL_WR,
+		.qp_type = IB_QPT_RC,
+		.qp_context = p,
+	};
+
+	if (!ipoib_cm_has_srq(dev)) {
+		attr.cap.max_recv_wr  = ipoib_recvq_size;
+		attr.cap.max_recv_sge = IPOIB_CM_RX_SG;
+	}
+
+	return ib_create_qp(priv->pd, &attr);
+}
+
+static int ipoib_cm_modify_rx_qp(struct net_device *dev,
+				 struct ib_cm_id *cm_id, struct ib_qp *qp,
+				 unsigned int psn)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ib_qp_attr qp_attr;
+	int qp_attr_mask, ret;
+
+	qp_attr.qp_state = IB_QPS_INIT;
+	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to init QP attr for INIT: %d\n", ret);
+		return ret;
+	}
+	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify QP to INIT: %d\n", ret);
+		return ret;
+	}
+	qp_attr.qp_state = IB_QPS_RTR;
+	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
+		return ret;
+	}
+	qp_attr.rq_psn = psn;
+	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Current Mellanox HCA firmware won't generate completions
+	 * with error for drain WRs unless the QP has been moved to
+	 * RTS first. This work-around leaves a window where a QP has
+	 * moved to error asynchronously, but this will eventually get
+	 * fixed in firmware, so let's not error out if modify QP
+	 * fails.
+	 */
+	qp_attr.qp_state = IB_QPS_RTS;
+	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
+		return 0;
+	}
+	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
+		return 0;
+	}
+
+	return 0;
+}
+
+static void ipoib_cm_init_rx_wr(struct net_device *dev,
+				struct ib_recv_wr *wr,
+				struct ib_sge *sge)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int i;
+
+	for (i = 0; i < priv->cm.num_frags; ++i)
+		sge[i].lkey = priv->pd->local_dma_lkey;
+
+	sge[0].length = IPOIB_CM_HEAD_SIZE;
+	for (i = 1; i < priv->cm.num_frags; ++i)
+		sge[i].length = PAGE_SIZE;
+
+	wr->next    = NULL;
+	wr->sg_list = sge;
+	wr->num_sge = priv->cm.num_frags;
+}
+
+static int ipoib_cm_nonsrq_init_rx(struct net_device *dev, struct ib_cm_id *cm_id,
+				   struct ipoib_cm_rx *rx)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct {
+		struct ib_recv_wr wr;
+		struct ib_sge sge[IPOIB_CM_RX_SG];
+	} *t;
+	int ret;
+	int i;
+
+	rx->rx_ring = vzalloc(array_size(ipoib_recvq_size,
+					 sizeof(*rx->rx_ring)));
+	if (!rx->rx_ring)
+		return -ENOMEM;
+
+	t = kmalloc(sizeof(*t), GFP_KERNEL);
+	if (!t) {
+		ret = -ENOMEM;
+		goto err_free_1;
+	}
+
+	ipoib_cm_init_rx_wr(dev, &t->wr, t->sge);
+
+	spin_lock_irq(&priv->lock);
+
+	if (priv->cm.nonsrq_conn_qp >= ipoib_max_conn_qp) {
+		spin_unlock_irq(&priv->lock);
+		ib_send_cm_rej(cm_id, IB_CM_REJ_NO_QP, NULL, 0, NULL, 0);
+		ret = -EINVAL;
+		goto err_free;
+	} else
+		++priv->cm.nonsrq_conn_qp;
+
+	spin_unlock_irq(&priv->lock);
+
+	for (i = 0; i < ipoib_recvq_size; ++i) {
+		if (!ipoib_cm_alloc_rx_skb(dev, rx->rx_ring, i, IPOIB_CM_RX_SG - 1,
+					   rx->rx_ring[i].mapping,
+					   GFP_KERNEL)) {
+			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
+			ret = -ENOMEM;
+			goto err_count;
+		}
+		ret = ipoib_cm_post_receive_nonsrq(dev, rx, &t->wr, t->sge, i);
+		if (ret) {
+			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq "
+				   "failed for buf %d\n", i);
+			ret = -EIO;
+			goto err_count;
+		}
+	}
+
+	rx->recv_count = ipoib_recvq_size;
+
+	kfree(t);
+
+	return 0;
+
+err_count:
+	spin_lock_irq(&priv->lock);
+	--priv->cm.nonsrq_conn_qp;
+	spin_unlock_irq(&priv->lock);
+
+err_free:
+	kfree(t);
+
+err_free_1:
+	ipoib_cm_free_rx_ring(dev, rx->rx_ring);
+
+	return ret;
+}
+
+static int ipoib_cm_send_rep(struct net_device *dev, struct ib_cm_id *cm_id,
+			     struct ib_qp *qp,
+			     const struct ib_cm_req_event_param *req,
+			     unsigned int psn)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_data data = {};
+	struct ib_cm_rep_param rep = {};
+
+	data.qpn = cpu_to_be32(priv->qp->qp_num);
+	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
+
+	rep.private_data = &data;
+	rep.private_data_len = sizeof(data);
+	rep.flow_control = 0;
+	rep.rnr_retry_count = req->rnr_retry_count;
+	rep.srq = ipoib_cm_has_srq(dev);
+	rep.qp_num = qp->qp_num;
+	rep.starting_psn = psn;
+	return ib_send_cm_rep(cm_id, &rep);
+}
+
+static int ipoib_cm_req_handler(struct ib_cm_id *cm_id,
+				const struct ib_cm_event *event)
+{
+	struct net_device *dev = cm_id->context;
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_rx *p;
+	unsigned int psn;
+	int ret;
+
+	ipoib_dbg(priv, "REQ arrived\n");
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+	p->dev = dev;
+	p->id = cm_id;
+	cm_id->context = p;
+	p->state = IPOIB_CM_RX_LIVE;
+	p->jiffies = jiffies;
+	INIT_LIST_HEAD(&p->list);
+
+	p->qp = ipoib_cm_create_rx_qp(dev, p);
+	if (IS_ERR(p->qp)) {
+		ret = PTR_ERR(p->qp);
+		goto err_qp;
+	}
+
+	psn = prandom_u32() & 0xffffff;
+	ret = ipoib_cm_modify_rx_qp(dev, cm_id, p->qp, psn);
+	if (ret)
+		goto err_modify;
+
+	if (!ipoib_cm_has_srq(dev)) {
+		ret = ipoib_cm_nonsrq_init_rx(dev, cm_id, p);
+		if (ret)
+			goto err_modify;
+	}
+
+	spin_lock_irq(&priv->lock);
+	queue_delayed_work(priv->wq,
+			   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
+	/* Add this entry to passive ids list head, but do not re-add it
+	 * if IB_EVENT_QP_LAST_WQE_REACHED has moved it to flush list. */
+	p->jiffies = jiffies;
+	if (p->state == IPOIB_CM_RX_LIVE)
+		list_move(&p->list, &priv->cm.passive_ids);
+	spin_unlock_irq(&priv->lock);
+
+	ret = ipoib_cm_send_rep(dev, cm_id, p->qp, &event->param.req_rcvd, psn);
+	if (ret) {
+		ipoib_warn(priv, "failed to send REP: %d\n", ret);
+		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
+			ipoib_warn(priv, "unable to move qp to error state\n");
+	}
+	return 0;
+
+err_modify:
+	ib_destroy_qp(p->qp);
+err_qp:
+	kfree(p);
+	return ret;
+}
+
+static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
+			       const struct ib_cm_event *event)
+{
+	struct ipoib_cm_rx *p;
+	struct ipoib_dev_priv *priv;
+
+	switch (event->event) {
+	case IB_CM_REQ_RECEIVED:
+		return ipoib_cm_req_handler(cm_id, event);
+	case IB_CM_DREQ_RECEIVED:
+		ib_send_cm_drep(cm_id, NULL, 0);
+		fallthrough;
+	case IB_CM_REJ_RECEIVED:
+		p = cm_id->context;
+		priv = ipoib_priv(p->dev);
+		if (ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE))
+			ipoib_warn(priv, "unable to move qp to error state\n");
+		fallthrough;
+	default:
+		return 0;
+	}
+}
+/* Adjust length of skb with fragments to match received data */
+static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
+			  unsigned int length, struct sk_buff *toskb)
+{
+	int i, num_frags;
+	unsigned int size;
+
+	/* put header into skb */
+	size = min(length, hdr_space);
+	skb->tail += size;
+	skb->len += size;
+	length -= size;
+
+	num_frags = skb_shinfo(skb)->nr_frags;
+	for (i = 0; i < num_frags; i++) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+		if (length == 0) {
+			/* don't need this page */
+			skb_fill_page_desc(toskb, i, skb_frag_page(frag),
+					   0, PAGE_SIZE);
+			--skb_shinfo(skb)->nr_frags;
+		} else {
+			size = min_t(unsigned int, length, PAGE_SIZE);
+
+			skb_frag_size_set(frag, size);
+			skb->data_len += size;
+			skb->truesize += size;
+			skb->len += size;
+			length -= size;
+		}
+	}
+}
+
+void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_rx_buf *rx_ring;
+	unsigned int wr_id = wc->wr_id & ~(IPOIB_OP_CM | IPOIB_OP_RECV);
+	struct sk_buff *skb, *newskb;
+	struct ipoib_cm_rx *p;
+	unsigned long flags;
+	u64 mapping[IPOIB_CM_RX_SG];
+	int frags;
+	int has_srq;
+	struct sk_buff *small_skb;
+
+	ipoib_dbg_data(priv, "cm recv completion: id %d, status: %d\n",
+		       wr_id, wc->status);
+
+	if (unlikely(wr_id >= ipoib_recvq_size)) {
+		if (wr_id == (IPOIB_CM_RX_DRAIN_WRID & ~(IPOIB_OP_CM | IPOIB_OP_RECV))) {
+			spin_lock_irqsave(&priv->lock, flags);
+			list_splice_init(&priv->cm.rx_drain_list, &priv->cm.rx_reap_list);
+			ipoib_cm_start_rx_drain(priv);
+			queue_work(priv->wq, &priv->cm.rx_reap_task);
+			spin_unlock_irqrestore(&priv->lock, flags);
+		} else
+			ipoib_warn(priv, "cm recv completion event with wrid %d (> %d)\n",
+				   wr_id, ipoib_recvq_size);
+		return;
+	}
+
+	p = wc->qp->qp_context;
+
+	has_srq = ipoib_cm_has_srq(dev);
+	rx_ring = has_srq ? priv->cm.srq_ring : p->rx_ring;
+
+	skb = rx_ring[wr_id].skb;
+
+	if (unlikely(wc->status != IB_WC_SUCCESS)) {
+		ipoib_dbg(priv,
+			  "cm recv error (status=%d, wrid=%d vend_err %#x)\n",
+			  wc->status, wr_id, wc->vendor_err);
+		++dev->stats.rx_dropped;
+		if (has_srq)
+			goto repost;
+		else {
+			if (!--p->recv_count) {
+				spin_lock_irqsave(&priv->lock, flags);
+				list_move(&p->list, &priv->cm.rx_reap_list);
+				spin_unlock_irqrestore(&priv->lock, flags);
+				queue_work(priv->wq, &priv->cm.rx_reap_task);
+			}
+			return;
+		}
+	}
+
+	if (unlikely(!(wr_id & IPOIB_CM_RX_UPDATE_MASK))) {
+		if (p && time_after_eq(jiffies, p->jiffies + IPOIB_CM_RX_UPDATE_TIME)) {
+			spin_lock_irqsave(&priv->lock, flags);
+			p->jiffies = jiffies;
+			/* Move this entry to list head, but do not re-add it
+			 * if it has been moved out of list. */
+			if (p->state == IPOIB_CM_RX_LIVE)
+				list_move(&p->list, &priv->cm.passive_ids);
+			spin_unlock_irqrestore(&priv->lock, flags);
+		}
+	}
+
+	if (wc->byte_len < IPOIB_CM_COPYBREAK) {
+		int dlen = wc->byte_len;
+
+		small_skb = dev_alloc_skb(dlen + IPOIB_CM_RX_RESERVE);
+		if (small_skb) {
+			skb_reserve(small_skb, IPOIB_CM_RX_RESERVE);
+			ib_dma_sync_single_for_cpu(priv->ca, rx_ring[wr_id].mapping[0],
+						   dlen, DMA_FROM_DEVICE);
+			skb_copy_from_linear_data(skb, small_skb->data, dlen);
+			ib_dma_sync_single_for_device(priv->ca, rx_ring[wr_id].mapping[0],
+						      dlen, DMA_FROM_DEVICE);
+			skb_put(small_skb, dlen);
+			skb = small_skb;
+			goto copied;
+		}
+	}
+
+	frags = PAGE_ALIGN(wc->byte_len -
+			   min_t(u32, wc->byte_len, IPOIB_CM_HEAD_SIZE)) /
+		PAGE_SIZE;
+
+	newskb = ipoib_cm_alloc_rx_skb(dev, rx_ring, wr_id, frags,
+				       mapping, GFP_ATOMIC);
+	if (unlikely(!newskb)) {
+		/*
+		 * If we can't allocate a new RX buffer, dump
+		 * this packet and reuse the old buffer.
+		 */
+		ipoib_dbg(priv, "failed to allocate receive buffer %d\n", wr_id);
+		++dev->stats.rx_dropped;
+		goto repost;
+	}
+
+	ipoib_cm_dma_unmap_rx(priv, frags, rx_ring[wr_id].mapping);
+	memcpy(rx_ring[wr_id].mapping, mapping, (frags + 1) * sizeof(*mapping));
+
+	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
+		       wc->byte_len, wc->slid);
+
+	skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
+
+copied:
+	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
+	skb_add_pseudo_hdr(skb);
+
+	++dev->stats.rx_packets;
+	dev->stats.rx_bytes += skb->len;
+
+	skb->dev = dev;
+	/* XXX get correct PACKET_ type here */
+	skb->pkt_type = PACKET_HOST;
+	netif_receive_skb(skb);
+
+repost:
+	if (has_srq) {
+		if (unlikely(ipoib_cm_post_receive_srq(dev, wr_id)))
+			ipoib_warn(priv, "ipoib_cm_post_receive_srq failed "
+				   "for buf %d\n", wr_id);
+	} else {
+		if (unlikely(ipoib_cm_post_receive_nonsrq(dev, p,
+							  &priv->cm.rx_wr,
+							  priv->cm.rx_sge,
+							  wr_id))) {
+			--p->recv_count;
+			ipoib_warn(priv, "ipoib_cm_post_receive_nonsrq failed "
+				   "for buf %d\n", wr_id);
+		}
+	}
+}
+
+static inline int post_send(struct ipoib_dev_priv *priv,
+			    struct ipoib_cm_tx *tx,
+			    unsigned int wr_id,
+			    struct ipoib_tx_buf *tx_req)
+{
+	ipoib_build_sge(priv, tx_req);
+
+	priv->tx_wr.wr.wr_id	= wr_id | IPOIB_OP_CM;
+
+	return ib_post_send(tx->qp, &priv->tx_wr.wr, NULL);
+}
+
+void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_tx *tx)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_tx_buf *tx_req;
+	int rc;
+	unsigned int usable_sge = tx->max_send_sge - !!skb_headlen(skb);
+
+	if (unlikely(skb->len > tx->mtu)) {
+		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
+			   skb->len, tx->mtu);
+		++dev->stats.tx_dropped;
+		++dev->stats.tx_errors;
+		ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN);
+		return;
+	}
+	if (skb_shinfo(skb)->nr_frags > usable_sge) {
+		if (skb_linearize(skb) < 0) {
+			ipoib_warn(priv, "skb could not be linearized\n");
+			++dev->stats.tx_dropped;
+			++dev->stats.tx_errors;
+			dev_kfree_skb_any(skb);
+			return;
+		}
+		/* Does skb_linearize return ok without reducing nr_frags? */
+		if (skb_shinfo(skb)->nr_frags > usable_sge) {
+			ipoib_warn(priv, "too many frags after skb linearize\n");
+			++dev->stats.tx_dropped;
+			++dev->stats.tx_errors;
+			dev_kfree_skb_any(skb);
+			return;
+		}
+	}
+	ipoib_dbg_data(priv, "sending packet: head 0x%x length %d connection 0x%x\n",
+		       tx->tx_head, skb->len, tx->qp->qp_num);
+
+	/*
+	 * We put the skb into the tx_ring _before_ we call post_send()
+	 * because it's entirely possible that the completion handler will
+	 * run before we execute anything after the post_send().  That
+	 * means we have to make sure everything is properly recorded and
+	 * our state is consistent before we call post_send().
+	 */
+	tx_req = &tx->tx_ring[tx->tx_head & (ipoib_sendq_size - 1)];
+	tx_req->skb = skb;
+
+	if (unlikely(ipoib_dma_map_tx(priv->ca, tx_req))) {
+		++dev->stats.tx_errors;
+		dev_kfree_skb_any(skb);
+		return;
+	}
+
+	if ((priv->global_tx_head - priv->global_tx_tail) ==
+	    ipoib_sendq_size - 1) {
+		ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net queue\n",
+			  tx->qp->qp_num);
+		netif_stop_queue(dev);
+	}
+
+	skb_orphan(skb);
+	skb_dst_drop(skb);
+
+	if (netif_queue_stopped(dev)) {
+		rc = ib_req_notify_cq(priv->send_cq, IB_CQ_NEXT_COMP |
+				      IB_CQ_REPORT_MISSED_EVENTS);
+		if (unlikely(rc < 0))
+			ipoib_warn(priv, "IPoIB/CM:request notify on send CQ failed\n");
+		else if (rc)
+			napi_schedule(&priv->send_napi);
+	}
+
+	rc = post_send(priv, tx, tx->tx_head & (ipoib_sendq_size - 1), tx_req);
+	if (unlikely(rc)) {
+		ipoib_warn(priv, "IPoIB/CM:post_send failed, error %d\n", rc);
+		++dev->stats.tx_errors;
+		ipoib_dma_unmap_tx(priv, tx_req);
+		dev_kfree_skb_any(skb);
+
+		if (netif_queue_stopped(dev))
+			netif_wake_queue(dev);
+	} else {
+		netif_trans_update(dev);
+		++tx->tx_head;
+		++priv->global_tx_head;
+	}
+}
+
+void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_tx *tx = wc->qp->qp_context;
+	unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
+	struct ipoib_tx_buf *tx_req;
+	unsigned long flags;
+
+	ipoib_dbg_data(priv, "cm send completion: id %d, status: %d\n",
+		       wr_id, wc->status);
+
+	if (unlikely(wr_id >= ipoib_sendq_size)) {
+		ipoib_warn(priv, "cm send completion event with wrid %d (> %d)\n",
+			   wr_id, ipoib_sendq_size);
+		return;
+	}
+
+	tx_req = &tx->tx_ring[wr_id];
+
+	ipoib_dma_unmap_tx(priv, tx_req);
+
+	/* FIXME: is this right? Shouldn't we only increment on success? */
+	++dev->stats.tx_packets;
+	dev->stats.tx_bytes += tx_req->skb->len;
+
+	dev_kfree_skb_any(tx_req->skb);
+
+	netif_tx_lock(dev);
+
+	++tx->tx_tail;
+	++priv->global_tx_tail;
+
+	if (unlikely(netif_queue_stopped(dev) &&
+		     ((priv->global_tx_head - priv->global_tx_tail) <=
+		      ipoib_sendq_size >> 1) &&
+		     test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags)))
+		netif_wake_queue(dev);
+
+	if (wc->status != IB_WC_SUCCESS &&
+	    wc->status != IB_WC_WR_FLUSH_ERR) {
+		struct ipoib_neigh *neigh;
+
+		/* IB_WC[_RNR]_RETRY_EXC_ERR error is part of the life cycle,
+		 * so don't make waves.
+		 */
+		if (wc->status == IB_WC_RNR_RETRY_EXC_ERR ||
+		    wc->status == IB_WC_RETRY_EXC_ERR)
+			ipoib_dbg(priv,
+				  "%s: failed cm send event (status=%d, wrid=%d vend_err %#x)\n",
+				   __func__, wc->status, wr_id, wc->vendor_err);
+		else
+			ipoib_warn(priv,
+				    "%s: failed cm send event (status=%d, wrid=%d vend_err %#x)\n",
+				   __func__, wc->status, wr_id, wc->vendor_err);
+
+		spin_lock_irqsave(&priv->lock, flags);
+		neigh = tx->neigh;
+
+		if (neigh) {
+			neigh->cm = NULL;
+			ipoib_neigh_free(neigh);
+
+			tx->neigh = NULL;
+		}
+
+		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
+			list_move(&tx->list, &priv->cm.reap_list);
+			queue_work(priv->wq, &priv->cm.reap_task);
+		}
+
+		clear_bit(IPOIB_FLAG_OPER_UP, &tx->flags);
+
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	netif_tx_unlock(dev);
+}
+
+int ipoib_cm_dev_open(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int ret;
+
+	if (!IPOIB_CM_SUPPORTED(dev->dev_addr))
+		return 0;
+
+	priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev);
+	if (IS_ERR(priv->cm.id)) {
+		pr_warn("%s: failed to create CM ID\n", priv->ca->name);
+		ret = PTR_ERR(priv->cm.id);
+		goto err_cm;
+	}
+
+	ret = ib_cm_listen(priv->cm.id, cpu_to_be64(IPOIB_CM_IETF_ID | priv->qp->qp_num),
+			   0);
+	if (ret) {
+		pr_warn("%s: failed to listen on ID 0x%llx\n", priv->ca->name,
+			IPOIB_CM_IETF_ID | priv->qp->qp_num);
+		goto err_listen;
+	}
+
+	return 0;
+
+err_listen:
+	ib_destroy_cm_id(priv->cm.id);
+err_cm:
+	priv->cm.id = NULL;
+	return ret;
+}
+
+static void ipoib_cm_free_rx_reap_list(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_rx *rx, *n;
+	LIST_HEAD(list);
+
+	spin_lock_irq(&priv->lock);
+	list_splice_init(&priv->cm.rx_reap_list, &list);
+	spin_unlock_irq(&priv->lock);
+
+	list_for_each_entry_safe(rx, n, &list, list) {
+		ib_destroy_cm_id(rx->id);
+		ib_destroy_qp(rx->qp);
+		if (!ipoib_cm_has_srq(dev)) {
+			ipoib_cm_free_rx_ring(priv->dev, rx->rx_ring);
+			spin_lock_irq(&priv->lock);
+			--priv->cm.nonsrq_conn_qp;
+			spin_unlock_irq(&priv->lock);
+		}
+		kfree(rx);
+	}
+}
+
+void ipoib_cm_dev_stop(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_rx *p;
+	unsigned long begin;
+	int ret;
+
+	if (!IPOIB_CM_SUPPORTED(dev->dev_addr) || !priv->cm.id)
+		return;
+
+	ib_destroy_cm_id(priv->cm.id);
+	priv->cm.id = NULL;
+
+	spin_lock_irq(&priv->lock);
+	while (!list_empty(&priv->cm.passive_ids)) {
+		p = list_entry(priv->cm.passive_ids.next, typeof(*p), list);
+		list_move(&p->list, &priv->cm.rx_error_list);
+		p->state = IPOIB_CM_RX_ERROR;
+		spin_unlock_irq(&priv->lock);
+		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
+		if (ret)
+			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
+		spin_lock_irq(&priv->lock);
+	}
+
+	/* Wait for all RX to be drained */
+	begin = jiffies;
+
+	while (!list_empty(&priv->cm.rx_error_list) ||
+	       !list_empty(&priv->cm.rx_flush_list) ||
+	       !list_empty(&priv->cm.rx_drain_list)) {
+		if (time_after(jiffies, begin + 5 * HZ)) {
+			ipoib_warn(priv, "RX drain timing out\n");
+
+			/*
+			 * assume the HW is wedged and just free up everything.
+			 */
+			list_splice_init(&priv->cm.rx_flush_list,
+					 &priv->cm.rx_reap_list);
+			list_splice_init(&priv->cm.rx_error_list,
+					 &priv->cm.rx_reap_list);
+			list_splice_init(&priv->cm.rx_drain_list,
+					 &priv->cm.rx_reap_list);
+			break;
+		}
+		spin_unlock_irq(&priv->lock);
+		usleep_range(1000, 2000);
+		ipoib_drain_cq(dev);
+		spin_lock_irq(&priv->lock);
+	}
+
+	spin_unlock_irq(&priv->lock);
+
+	ipoib_cm_free_rx_reap_list(dev);
+
+	cancel_delayed_work(&priv->cm.stale_task);
+}
+
+static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id,
+				const struct ib_cm_event *event)
+{
+	struct ipoib_cm_tx *p = cm_id->context;
+	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
+	struct ipoib_cm_data *data = event->private_data;
+	struct sk_buff_head skqueue;
+	struct ib_qp_attr qp_attr;
+	int qp_attr_mask, ret;
+	struct sk_buff *skb;
+
+	p->mtu = be32_to_cpu(data->mtu);
+
+	if (p->mtu <= IPOIB_ENCAP_LEN) {
+		ipoib_warn(priv, "Rejecting connection: mtu %d <= %d\n",
+			   p->mtu, IPOIB_ENCAP_LEN);
+		return -EINVAL;
+	}
+
+	qp_attr.qp_state = IB_QPS_RTR;
+	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to init QP attr for RTR: %d\n", ret);
+		return ret;
+	}
+
+	qp_attr.rq_psn = 0 /* FIXME */;
+	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret);
+		return ret;
+	}
+
+	qp_attr.qp_state = IB_QPS_RTS;
+	ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret);
+		return ret;
+	}
+	ret = ib_modify_qp(p->qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret);
+		return ret;
+	}
+
+	skb_queue_head_init(&skqueue);
+
+	netif_tx_lock_bh(p->dev);
+	spin_lock_irq(&priv->lock);
+	set_bit(IPOIB_FLAG_OPER_UP, &p->flags);
+	if (p->neigh)
+		while ((skb = __skb_dequeue(&p->neigh->queue)))
+			__skb_queue_tail(&skqueue, skb);
+	spin_unlock_irq(&priv->lock);
+	netif_tx_unlock_bh(p->dev);
+
+	while ((skb = __skb_dequeue(&skqueue))) {
+		skb->dev = p->dev;
+		ret = dev_queue_xmit(skb);
+		if (ret)
+			ipoib_warn(priv, "%s:dev_queue_xmit failed to re-queue packet, ret:%d\n",
+				   __func__, ret);
+	}
+
+	ret = ib_send_cm_rtu(cm_id, NULL, 0);
+	if (ret) {
+		ipoib_warn(priv, "failed to send RTU: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct ipoib_cm_tx *tx)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ib_qp_init_attr attr = {
+		.send_cq		= priv->send_cq,
+		.recv_cq		= priv->recv_cq,
+		.srq			= priv->cm.srq,
+		.cap.max_send_wr	= ipoib_sendq_size,
+		.cap.max_send_sge	= 1,
+		.sq_sig_type		= IB_SIGNAL_ALL_WR,
+		.qp_type		= IB_QPT_RC,
+		.qp_context		= tx,
+		.create_flags		= 0
+	};
+	struct ib_qp *tx_qp;
+
+	if (dev->features & NETIF_F_SG)
+		attr.cap.max_send_sge = min_t(u32, priv->ca->attrs.max_send_sge,
+					      MAX_SKB_FRAGS + 1);
+
+	tx_qp = ib_create_qp(priv->pd, &attr);
+	tx->max_send_sge = attr.cap.max_send_sge;
+	return tx_qp;
+}
+
+static int ipoib_cm_send_req(struct net_device *dev,
+			     struct ib_cm_id *id, struct ib_qp *qp,
+			     u32 qpn,
+			     struct sa_path_rec *pathrec)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_data data = {};
+	struct ib_cm_req_param req = {};
+
+	data.qpn = cpu_to_be32(priv->qp->qp_num);
+	data.mtu = cpu_to_be32(IPOIB_CM_BUF_SIZE);
+
+	req.primary_path		= pathrec;
+	req.alternate_path		= NULL;
+	req.service_id			= cpu_to_be64(IPOIB_CM_IETF_ID | qpn);
+	req.qp_num			= qp->qp_num;
+	req.qp_type			= qp->qp_type;
+	req.private_data		= &data;
+	req.private_data_len		= sizeof(data);
+	req.flow_control		= 0;
+
+	req.starting_psn		= 0; /* FIXME */
+
+	/*
+	 * Pick some arbitrary defaults here; we could make these
+	 * module parameters if anyone cared about setting them.
+	 */
+	req.responder_resources		= 4;
+	req.remote_cm_response_timeout	= 20;
+	req.local_cm_response_timeout	= 20;
+	req.retry_count			= 0; /* RFC draft warns against retries */
+	req.rnr_retry_count		= 0; /* RFC draft warns against retries */
+	req.max_cm_retries		= 15;
+	req.srq				= ipoib_cm_has_srq(dev);
+	return ib_send_cm_req(id, &req);
+}
+
+static int ipoib_cm_modify_tx_init(struct net_device *dev,
+				  struct ib_cm_id *cm_id, struct ib_qp *qp)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ib_qp_attr qp_attr;
+	int qp_attr_mask, ret;
+	ret = ib_find_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index);
+	if (ret) {
+		ipoib_warn(priv, "pkey 0x%x not found: %d\n", priv->pkey, ret);
+		return ret;
+	}
+
+	qp_attr.qp_state = IB_QPS_INIT;
+	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE;
+	qp_attr.port_num = priv->port;
+	qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PKEY_INDEX | IB_QP_PORT;
+
+	ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify tx QP to INIT: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
+			    struct sa_path_rec *pathrec)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
+	unsigned int noio_flag;
+	int ret;
+
+	noio_flag = memalloc_noio_save();
+	p->tx_ring = vzalloc(array_size(ipoib_sendq_size, sizeof(*p->tx_ring)));
+	if (!p->tx_ring) {
+		memalloc_noio_restore(noio_flag);
+		ret = -ENOMEM;
+		goto err_tx;
+	}
+
+	p->qp = ipoib_cm_create_tx_qp(p->dev, p);
+	memalloc_noio_restore(noio_flag);
+	if (IS_ERR(p->qp)) {
+		ret = PTR_ERR(p->qp);
+		ipoib_warn(priv, "failed to create tx qp: %d\n", ret);
+		goto err_qp;
+	}
+
+	p->id = ib_create_cm_id(priv->ca, ipoib_cm_tx_handler, p);
+	if (IS_ERR(p->id)) {
+		ret = PTR_ERR(p->id);
+		ipoib_warn(priv, "failed to create tx cm id: %d\n", ret);
+		goto err_id;
+	}
+
+	ret = ipoib_cm_modify_tx_init(p->dev, p->id,  p->qp);
+	if (ret) {
+		ipoib_warn(priv, "failed to modify tx qp to rtr: %d\n", ret);
+		goto err_modify_send;
+	}
+
+	ret = ipoib_cm_send_req(p->dev, p->id, p->qp, qpn, pathrec);
+	if (ret) {
+		ipoib_warn(priv, "failed to send cm req: %d\n", ret);
+		goto err_modify_send;
+	}
+
+	ipoib_dbg(priv, "Request connection 0x%x for gid %pI6 qpn 0x%x\n",
+		  p->qp->qp_num, pathrec->dgid.raw, qpn);
+
+	return 0;
+
+err_modify_send:
+	ib_destroy_cm_id(p->id);
+err_id:
+	p->id = NULL;
+	ib_destroy_qp(p->qp);
+err_qp:
+	p->qp = NULL;
+	vfree(p->tx_ring);
+err_tx:
+	return ret;
+}
+
+static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(p->dev);
+	struct ipoib_tx_buf *tx_req;
+	unsigned long begin;
+
+	ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
+		  p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
+
+	if (p->id)
+		ib_destroy_cm_id(p->id);
+
+	if (p->tx_ring) {
+		/* Wait for all sends to complete */
+		begin = jiffies;
+		while ((int) p->tx_tail - (int) p->tx_head < 0) {
+			if (time_after(jiffies, begin + 5 * HZ)) {
+				ipoib_warn(priv, "timing out; %d sends not completed\n",
+					   p->tx_head - p->tx_tail);
+				goto timeout;
+			}
+
+			usleep_range(1000, 2000);
+		}
+	}
+
+timeout:
+
+	while ((int) p->tx_tail - (int) p->tx_head < 0) {
+		tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size - 1)];
+		ipoib_dma_unmap_tx(priv, tx_req);
+		dev_kfree_skb_any(tx_req->skb);
+		netif_tx_lock_bh(p->dev);
+		++p->tx_tail;
+		++priv->global_tx_tail;
+		if (unlikely((priv->global_tx_head - priv->global_tx_tail) <=
+			     ipoib_sendq_size >> 1) &&
+		    netif_queue_stopped(p->dev) &&
+		    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
+			netif_wake_queue(p->dev);
+		netif_tx_unlock_bh(p->dev);
+	}
+
+	if (p->qp)
+		ib_destroy_qp(p->qp);
+
+	vfree(p->tx_ring);
+	kfree(p);
+}
+
+static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
+			       const struct ib_cm_event *event)
+{
+	struct ipoib_cm_tx *tx = cm_id->context;
+	struct ipoib_dev_priv *priv = ipoib_priv(tx->dev);
+	struct net_device *dev = priv->dev;
+	struct ipoib_neigh *neigh;
+	unsigned long flags;
+	int ret;
+
+	switch (event->event) {
+	case IB_CM_DREQ_RECEIVED:
+		ipoib_dbg(priv, "DREQ received.\n");
+		ib_send_cm_drep(cm_id, NULL, 0);
+		break;
+	case IB_CM_REP_RECEIVED:
+		ipoib_dbg(priv, "REP received.\n");
+		ret = ipoib_cm_rep_handler(cm_id, event);
+		if (ret)
+			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,
+				       NULL, 0, NULL, 0);
+		break;
+	case IB_CM_REQ_ERROR:
+	case IB_CM_REJ_RECEIVED:
+	case IB_CM_TIMEWAIT_EXIT:
+		ipoib_dbg(priv, "CM error %d.\n", event->event);
+		netif_tx_lock_bh(dev);
+		spin_lock_irqsave(&priv->lock, flags);
+		neigh = tx->neigh;
+
+		if (neigh) {
+			neigh->cm = NULL;
+			ipoib_neigh_free(neigh);
+
+			tx->neigh = NULL;
+		}
+
+		if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
+			list_move(&tx->list, &priv->cm.reap_list);
+			queue_work(priv->wq, &priv->cm.reap_task);
+		}
+
+		spin_unlock_irqrestore(&priv->lock, flags);
+		netif_tx_unlock_bh(dev);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path *path,
+				       struct ipoib_neigh *neigh)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ipoib_cm_tx *tx;
+
+	tx = kzalloc(sizeof(*tx), GFP_ATOMIC);
+	if (!tx)
+		return NULL;
+
+	neigh->cm = tx;
+	tx->neigh = neigh;
+	tx->dev = dev;
+	list_add(&tx->list, &priv->cm.start_list);
+	set_bit(IPOIB_FLAG_INITIALIZED, &tx->flags);
+	queue_work(priv->wq, &priv->cm.start_task);
+	return tx;
+}
+
+void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(tx->dev);
+	unsigned long flags;
+	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
+		spin_lock_irqsave(&priv->lock, flags);
+		list_move(&tx->list, &priv->cm.reap_list);
+		queue_work(priv->wq, &priv->cm.reap_task);
+		ipoib_dbg(priv, "Reap connection for gid %pI6\n",
+			  tx->neigh->daddr + 4);
+		tx->neigh = NULL;
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+}
+
+#define QPN_AND_OPTIONS_OFFSET	4
+
+static void ipoib_cm_tx_start(struct work_struct *work)
+{
+	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+						   cm.start_task);
+	struct net_device *dev = priv->dev;
+	struct ipoib_neigh *neigh;
+	struct ipoib_cm_tx *p;
+	unsigned long flags;
+	struct ipoib_path *path;
+	int ret;
+
+	struct sa_path_rec pathrec;
+	u32 qpn;
+
+	netif_tx_lock_bh(dev);
+	spin_lock_irqsave(&priv->lock, flags);
+
+	while (!list_empty(&priv->cm.start_list)) {
+		p = list_entry(priv->cm.start_list.next, typeof(*p), list);
+		list_del_init(&p->list);
+		neigh = p->neigh;
+
+		qpn = IPOIB_QPN(neigh->daddr);
+		/*
+		 * As long as the search is with these 2 locks,
+		 * path existence indicates its validity.
+		 */
+		path = __path_find(dev, neigh->daddr + QPN_AND_OPTIONS_OFFSET);
+		if (!path) {
+			pr_info("%s ignore not valid path %pI6\n",
+				__func__,
+				neigh->daddr + QPN_AND_OPTIONS_OFFSET);
+			goto free_neigh;
+		}
+		memcpy(&pathrec, &path->pathrec, sizeof(pathrec));
+
+		spin_unlock_irqrestore(&priv->lock, flags);
+		netif_tx_unlock_bh(dev);
+
+		ret = ipoib_cm_tx_init(p, qpn, &pathrec);
+
+		netif_tx_lock_bh(dev);
+		spin_lock_irqsave(&priv->lock, flags);
+
+		if (ret) {
+free_neigh:
+			neigh = p->neigh;
+			if (neigh) {
+				neigh->cm = NULL;
+				ipoib_neigh_free(neigh);
+			}
+			list_del(&p->list);
+			kfree(p);
+		}
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	netif_tx_unlock_bh(dev);
+}
+
+static void ipoib_cm_tx_reap(struct work_struct *work)
+{
+	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+						   cm.reap_task);
+	struct net_device *dev = priv->dev;
+	struct ipoib_cm_tx *p;
+	unsigned long flags;
+
+	netif_tx_lock_bh(dev);
+	spin_lock_irqsave(&priv->lock, flags);
+
+	while (!list_empty(&priv->cm.reap_list)) {
+		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
+		list_del_init(&p->list);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		netif_tx_unlock_bh(dev);
+		ipoib_cm_tx_destroy(p);
+		netif_tx_lock_bh(dev);
+		spin_lock_irqsave(&priv->lock, flags);
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	netif_tx_unlock_bh(dev);
+}
+
+static void ipoib_cm_skb_reap(struct work_struct *work)
+{
+	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+						   cm.skb_task);
+	struct net_device *dev = priv->dev;
+	struct sk_buff *skb;
+	unsigned long flags;
+	unsigned int mtu = priv->mcast_mtu;
+
+	netif_tx_lock_bh(dev);
+	spin_lock_irqsave(&priv->lock, flags);
+
+	while ((skb = skb_dequeue(&priv->cm.skb_queue))) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		netif_tx_unlock_bh(dev);
+
+		if (skb->protocol == htons(ETH_P_IP)) {
+			memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		else if (skb->protocol == htons(ETH_P_IPV6)) {
+			memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+		}
+#endif
+		dev_kfree_skb_any(skb);
+
+		netif_tx_lock_bh(dev);
+		spin_lock_irqsave(&priv->lock, flags);
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	netif_tx_unlock_bh(dev);
+}
+
+void ipoib_cm_skb_too_long(struct net_device *dev, struct sk_buff *skb,
+			   unsigned int mtu)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int e = skb_queue_empty(&priv->cm.skb_queue);
+
+	skb_dst_update_pmtu(skb, mtu);
+
+	skb_queue_tail(&priv->cm.skb_queue, skb);
+	if (e)
+		queue_work(priv->wq, &priv->cm.skb_task);
+}
+
+static void ipoib_cm_rx_reap(struct work_struct *work)
+{
+	ipoib_cm_free_rx_reap_list(container_of(work, struct ipoib_dev_priv,
+						cm.rx_reap_task)->dev);
+}
+
+static void ipoib_cm_stale_task(struct work_struct *work)
+{
+	struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv,
+						   cm.stale_task.work);
+	struct ipoib_cm_rx *p;
+	int ret;
+
+	spin_lock_irq(&priv->lock);
+	while (!list_empty(&priv->cm.passive_ids)) {
+		/* List is sorted by LRU, start from tail,
+		 * stop when we see a recently used entry */
+		p = list_entry(priv->cm.passive_ids.prev, typeof(*p), list);
+		if (time_before_eq(jiffies, p->jiffies + IPOIB_CM_RX_TIMEOUT))
+			break;
+		list_move(&p->list, &priv->cm.rx_error_list);
+		p->state = IPOIB_CM_RX_ERROR;
+		spin_unlock_irq(&priv->lock);
+		ret = ib_modify_qp(p->qp, &ipoib_cm_err_attr, IB_QP_STATE);
+		if (ret)
+			ipoib_warn(priv, "unable to move qp to error state: %d\n", ret);
+		spin_lock_irq(&priv->lock);
+	}
+
+	if (!list_empty(&priv->cm.passive_ids))
+		queue_delayed_work(priv->wq,
+				   &priv->cm.stale_task, IPOIB_CM_RX_DELAY);
+	spin_unlock_irq(&priv->lock);
+}
+
+static ssize_t show_mode(struct device *d, struct device_attribute *attr,
+			 char *buf)
+{
+	struct net_device *dev = to_net_dev(d);
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+
+	if (test_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags))
+		return sprintf(buf, "connected\n");
+	else
+		return sprintf(buf, "datagram\n");
+}
+
+static ssize_t set_mode(struct device *d, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct net_device *dev = to_net_dev(d);
+	int ret;
+
+	if (!rtnl_trylock()) {
+		return restart_syscall();
+	}
+
+	if (dev->reg_state != NETREG_REGISTERED) {
+		rtnl_unlock();
+		return -EPERM;
+	}
+
+	ret = ipoib_set_mode(dev, buf);
+
+	/* The assumption is that the function ipoib_set_mode returned
+	 * with the rtnl held by it, if not the value -EBUSY returned,
+	 * then no need to rtnl_unlock
+	 */
+	if (ret != -EBUSY)
+		rtnl_unlock();
+
+	return (!ret || ret == -EBUSY) ? count : ret;
+}
+
+static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, set_mode);
+
+int ipoib_cm_add_mode_attr(struct net_device *dev)
+{
+	return device_create_file(&dev->dev, &dev_attr_mode);
+}
+
+static void ipoib_cm_create_srq(struct net_device *dev, int max_sge)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	struct ib_srq_init_attr srq_init_attr = {
+		.srq_type = IB_SRQT_BASIC,
+		.attr = {
+			.max_wr  = ipoib_recvq_size,
+			.max_sge = max_sge
+		}
+	};
+
+	priv->cm.srq = ib_create_srq(priv->pd, &srq_init_attr);
+	if (IS_ERR(priv->cm.srq)) {
+		if (PTR_ERR(priv->cm.srq) != -EOPNOTSUPP)
+			pr_warn("%s: failed to allocate SRQ, error %ld\n",
+			       priv->ca->name, PTR_ERR(priv->cm.srq));
+		priv->cm.srq = NULL;
+		return;
+	}
+
+	priv->cm.srq_ring = vzalloc(array_size(ipoib_recvq_size,
+					       sizeof(*priv->cm.srq_ring)));
+	if (!priv->cm.srq_ring) {
+		ib_destroy_srq(priv->cm.srq);
+		priv->cm.srq = NULL;
+		return;
+	}
+
+}
+
+int ipoib_cm_dev_init(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+	int max_srq_sge, i;
+
+	INIT_LIST_HEAD(&priv->cm.passive_ids);
+	INIT_LIST_HEAD(&priv->cm.reap_list);
+	INIT_LIST_HEAD(&priv->cm.start_list);
+	INIT_LIST_HEAD(&priv->cm.rx_error_list);
+	INIT_LIST_HEAD(&priv->cm.rx_flush_list);
+	INIT_LIST_HEAD(&priv->cm.rx_drain_list);
+	INIT_LIST_HEAD(&priv->cm.rx_reap_list);
+	INIT_WORK(&priv->cm.start_task, ipoib_cm_tx_start);
+	INIT_WORK(&priv->cm.reap_task, ipoib_cm_tx_reap);
+	INIT_WORK(&priv->cm.skb_task, ipoib_cm_skb_reap);
+	INIT_WORK(&priv->cm.rx_reap_task, ipoib_cm_rx_reap);
+	INIT_DELAYED_WORK(&priv->cm.stale_task, ipoib_cm_stale_task);
+
+	skb_queue_head_init(&priv->cm.skb_queue);
+
+	ipoib_dbg(priv, "max_srq_sge=%d\n", priv->ca->attrs.max_srq_sge);
+
+	max_srq_sge = min_t(int, IPOIB_CM_RX_SG, priv->ca->attrs.max_srq_sge);
+	ipoib_cm_create_srq(dev, max_srq_sge);
+	if (ipoib_cm_has_srq(dev)) {
+		priv->cm.max_cm_mtu = max_srq_sge * PAGE_SIZE - 0x10;
+		priv->cm.num_frags  = max_srq_sge;
+		ipoib_dbg(priv, "max_cm_mtu = 0x%x, num_frags=%d\n",
+			  priv->cm.max_cm_mtu, priv->cm.num_frags);
+	} else {
+		priv->cm.max_cm_mtu = IPOIB_CM_MTU;
+		priv->cm.num_frags  = IPOIB_CM_RX_SG;
+	}
+
+	ipoib_cm_init_rx_wr(dev, &priv->cm.rx_wr, priv->cm.rx_sge);
+
+	if (ipoib_cm_has_srq(dev)) {
+		for (i = 0; i < ipoib_recvq_size; ++i) {
+			if (!ipoib_cm_alloc_rx_skb(dev, priv->cm.srq_ring, i,
+						   priv->cm.num_frags - 1,
+						   priv->cm.srq_ring[i].mapping,
+						   GFP_KERNEL)) {
+				ipoib_warn(priv, "failed to allocate "
+					   "receive buffer %d\n", i);
+				ipoib_cm_dev_cleanup(dev);
+				return -ENOMEM;
+			}
+
+			if (ipoib_cm_post_receive_srq(dev, i)) {
+				ipoib_warn(priv, "ipoib_cm_post_receive_srq "
+					   "failed for buf %d\n", i);
+				ipoib_cm_dev_cleanup(dev);
+				return -EIO;
+			}
+		}
+	}
+
+	priv->dev->dev_addr[0] = IPOIB_FLAGS_RC;
+	return 0;
+}
+
+void ipoib_cm_dev_cleanup(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = ipoib_priv(dev);
+
+	if (!priv->cm.srq)
+		return;
+
+	ipoib_dbg(priv, "Cleanup ipoib connected mode.\n");
+
+	ib_destroy_srq(priv->cm.srq);
+	priv->cm.srq = NULL;
+	if (!priv->cm.srq_ring)
+		return;
+
+	ipoib_cm_free_rx_ring(dev, priv->cm.srq_ring);
+	priv->cm.srq_ring = NULL;
+}