1 files changed, 643 insertions, 0 deletions

diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
new file mode 100644
index 000000000..f1ffbd414
--- /dev/null
+++ b/net/smc/smc_ib.c
@@ -0,0 +1,643 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  IB infrastructure:
+ *  Establish SMC-R as an Infiniband Client to be notified about added and
+ *  removed IB devices of type RDMA.
+ *  Determine device and port characteristics for these IB devices.
+ *
+ *  Copyright IBM Corp. 2016
+ *
+ *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
+ */
+
+#include <linux/random.h>
+#include <linux/workqueue.h>
+#include <linux/scatterlist.h>
+#include <linux/wait.h>
+#include <linux/mutex.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_cache.h>
+
+#include "smc_pnet.h"
+#include "smc_ib.h"
+#include "smc_core.h"
+#include "smc_wr.h"
+#include "smc.h"
+
+#define SMC_MAX_CQE 32766	/* max. # of completion queue elements */
+
+#define SMC_QP_MIN_RNR_TIMER		5
+#define SMC_QP_TIMEOUT			15 /* 4096 * 2 ** timeout usec */
+#define SMC_QP_RETRY_CNT			7 /* 7: infinite */
+#define SMC_QP_RNR_RETRY			7 /* 7: infinite */
+
+struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
+	.mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
+	.list = LIST_HEAD_INIT(smc_ib_devices.list),
+};
+
+u8 local_systemid[SMC_SYSTEMID_LEN];		/* unique system identifier */
+
+static int smc_ib_modify_qp_init(struct smc_link *lnk)
+{
+	struct ib_qp_attr qp_attr;
+
+	memset(&qp_attr, 0, sizeof(qp_attr));
+	qp_attr.qp_state = IB_QPS_INIT;
+	qp_attr.pkey_index = 0;
+	qp_attr.port_num = lnk->ibport;
+	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
+				| IB_ACCESS_REMOTE_WRITE;
+	return ib_modify_qp(lnk->roce_qp, &qp_attr,
+			    IB_QP_STATE | IB_QP_PKEY_INDEX |
+			    IB_QP_ACCESS_FLAGS | IB_QP_PORT);
+}
+
+static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
+{
+	enum ib_qp_attr_mask qp_attr_mask =
+		IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
+		IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
+	struct ib_qp_attr qp_attr;
+
+	memset(&qp_attr, 0, sizeof(qp_attr));
+	qp_attr.qp_state = IB_QPS_RTR;
+	qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
+	qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
+	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
+	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
+	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
+	memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
+	       sizeof(lnk->peer_mac));
+	qp_attr.dest_qp_num = lnk->peer_qpn;
+	qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
+	qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
+					 * requests
+					 */
+	qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
+
+	return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
+}
+
+int smc_ib_modify_qp_rts(struct smc_link *lnk)
+{
+	struct ib_qp_attr qp_attr;
+
+	memset(&qp_attr, 0, sizeof(qp_attr));
+	qp_attr.qp_state = IB_QPS_RTS;
+	qp_attr.timeout = SMC_QP_TIMEOUT;	/* local ack timeout */
+	qp_attr.retry_cnt = SMC_QP_RETRY_CNT;	/* retry count */
+	qp_attr.rnr_retry = SMC_QP_RNR_RETRY;	/* RNR retries, 7=infinite */
+	qp_attr.sq_psn = lnk->psn_initial;	/* starting send packet seq # */
+	qp_attr.max_rd_atomic = 1;	/* # of outstanding RDMA reads and
+					 * atomic ops allowed
+					 */
+	return ib_modify_qp(lnk->roce_qp, &qp_attr,
+			    IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
+			    IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
+			    IB_QP_MAX_QP_RD_ATOMIC);
+}
+
+int smc_ib_modify_qp_error(struct smc_link *lnk)
+{
+	struct ib_qp_attr qp_attr;
+
+	memset(&qp_attr, 0, sizeof(qp_attr));
+	qp_attr.qp_state = IB_QPS_ERR;
+	return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
+}
+
+int smc_ib_ready_link(struct smc_link *lnk)
+{
+	struct smc_link_group *lgr = smc_get_lgr(lnk);
+	int rc = 0;
+
+	rc = smc_ib_modify_qp_init(lnk);
+	if (rc)
+		goto out;
+
+	rc = smc_ib_modify_qp_rtr(lnk);
+	if (rc)
+		goto out;
+	smc_wr_remember_qp_attr(lnk);
+	rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
+			      IB_CQ_SOLICITED_MASK);
+	if (rc)
+		goto out;
+	rc = smc_wr_rx_post_init(lnk);
+	if (rc)
+		goto out;
+	smc_wr_remember_qp_attr(lnk);
+
+	if (lgr->role == SMC_SERV) {
+		rc = smc_ib_modify_qp_rts(lnk);
+		if (rc)
+			goto out;
+		smc_wr_remember_qp_attr(lnk);
+	}
+out:
+	return rc;
+}
+
+static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
+{
+	const struct ib_gid_attr *attr;
+	int rc;
+
+	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
+	if (IS_ERR(attr))
+		return -ENODEV;
+
+	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
+	rdma_put_gid_attr(attr);
+	return rc;
+}
+
+/* Create an identifier unique for this instance of SMC-R.
+ * The MAC-address of the first active registered IB device
+ * plus a random 2-byte number is used to create this identifier.
+ * This name is delivered to the peer during connection initialization.
+ */
+static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
+						u8 ibport)
+{
+	memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
+	       sizeof(smcibdev->mac[ibport - 1]));
+}
+
+bool smc_ib_is_valid_local_systemid(void)
+{
+	return !is_zero_ether_addr(&local_systemid[2]);
+}
+
+static void smc_ib_init_local_systemid(void)
+{
+	get_random_bytes(&local_systemid[0], 2);
+}
+
+bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
+{
+	return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
+}
+
+/* determine the gid for an ib-device port and vlan id */
+int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
+			 unsigned short vlan_id, u8 gid[], u8 *sgid_index)
+{
+	const struct ib_gid_attr *attr;
+	const struct net_device *ndev;
+	int i;
+
+	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
+		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
+		if (IS_ERR(attr))
+			continue;
+
+		rcu_read_lock();
+		ndev = rdma_read_gid_attr_ndev_rcu(attr);
+		if (!IS_ERR(ndev) &&
+		    ((!vlan_id && !is_vlan_dev(ndev)) ||
+		     (vlan_id && is_vlan_dev(ndev) &&
+		      vlan_dev_vlan_id(ndev) == vlan_id)) &&
+		    attr->gid_type == IB_GID_TYPE_ROCE) {
+			rcu_read_unlock();
+			if (gid)
+				memcpy(gid, &attr->gid, SMC_GID_SIZE);
+			if (sgid_index)
+				*sgid_index = attr->index;
+			rdma_put_gid_attr(attr);
+			return 0;
+		}
+		rcu_read_unlock();
+		rdma_put_gid_attr(attr);
+	}
+	return -ENODEV;
+}
+
+static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
+{
+	int rc;
+
+	memset(&smcibdev->pattr[ibport - 1], 0,
+	       sizeof(smcibdev->pattr[ibport - 1]));
+	rc = ib_query_port(smcibdev->ibdev, ibport,
+			   &smcibdev->pattr[ibport - 1]);
+	if (rc)
+		goto out;
+	/* the SMC protocol requires specification of the RoCE MAC address */
+	rc = smc_ib_fill_mac(smcibdev, ibport);
+	if (rc)
+		goto out;
+	if (!smc_ib_is_valid_local_systemid() &&
+	    smc_ib_port_active(smcibdev, ibport))
+		/* create unique system identifier */
+		smc_ib_define_local_systemid(smcibdev, ibport);
+out:
+	return rc;
+}
+
+/* process context wrapper for might_sleep smc_ib_remember_port_attr */
+static void smc_ib_port_event_work(struct work_struct *work)
+{
+	struct smc_ib_device *smcibdev = container_of(
+		work, struct smc_ib_device, port_event_work);
+	u8 port_idx;
+
+	for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
+		smc_ib_remember_port_attr(smcibdev, port_idx + 1);
+		clear_bit(port_idx, &smcibdev->port_event_mask);
+		if (!smc_ib_port_active(smcibdev, port_idx + 1)) {
+			set_bit(port_idx, smcibdev->ports_going_away);
+			smcr_port_err(smcibdev, port_idx + 1);
+		} else {
+			clear_bit(port_idx, smcibdev->ports_going_away);
+			smcr_port_add(smcibdev, port_idx + 1);
+		}
+	}
+}
+
+/* can be called in IRQ context */
+static void smc_ib_global_event_handler(struct ib_event_handler *handler,
+					struct ib_event *ibevent)
+{
+	struct smc_ib_device *smcibdev;
+	bool schedule = false;
+	u8 port_idx;
+
+	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
+
+	switch (ibevent->event) {
+	case IB_EVENT_DEVICE_FATAL:
+		/* terminate all ports on device */
+		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
+			set_bit(port_idx, &smcibdev->port_event_mask);
+			if (!test_and_set_bit(port_idx,
+					      smcibdev->ports_going_away))
+				schedule = true;
+		}
+		if (schedule)
+			schedule_work(&smcibdev->port_event_work);
+		break;
+	case IB_EVENT_PORT_ACTIVE:
+		port_idx = ibevent->element.port_num - 1;
+		if (port_idx >= SMC_MAX_PORTS)
+			break;
+		set_bit(port_idx, &smcibdev->port_event_mask);
+		if (test_and_clear_bit(port_idx, smcibdev->ports_going_away))
+			schedule_work(&smcibdev->port_event_work);
+		break;
+	case IB_EVENT_PORT_ERR:
+		port_idx = ibevent->element.port_num - 1;
+		if (port_idx >= SMC_MAX_PORTS)
+			break;
+		set_bit(port_idx, &smcibdev->port_event_mask);
+		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
+			schedule_work(&smcibdev->port_event_work);
+		break;
+	case IB_EVENT_GID_CHANGE:
+		port_idx = ibevent->element.port_num - 1;
+		if (port_idx >= SMC_MAX_PORTS)
+			break;
+		set_bit(port_idx, &smcibdev->port_event_mask);
+		schedule_work(&smcibdev->port_event_work);
+		break;
+	default:
+		break;
+	}
+}
+
+void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
+{
+	if (lnk->roce_pd)
+		ib_dealloc_pd(lnk->roce_pd);
+	lnk->roce_pd = NULL;
+}
+
+int smc_ib_create_protection_domain(struct smc_link *lnk)
+{
+	int rc;
+
+	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
+	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
+	if (IS_ERR(lnk->roce_pd))
+		lnk->roce_pd = NULL;
+	return rc;
+}
+
+static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
+{
+	struct smc_link *lnk = (struct smc_link *)priv;
+	struct smc_ib_device *smcibdev = lnk->smcibdev;
+	u8 port_idx;
+
+	switch (ibevent->event) {
+	case IB_EVENT_QP_FATAL:
+	case IB_EVENT_QP_ACCESS_ERR:
+		port_idx = ibevent->element.qp->port - 1;
+		if (port_idx >= SMC_MAX_PORTS)
+			break;
+		set_bit(port_idx, &smcibdev->port_event_mask);
+		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
+			schedule_work(&smcibdev->port_event_work);
+		break;
+	default:
+		break;
+	}
+}
+
+void smc_ib_destroy_queue_pair(struct smc_link *lnk)
+{
+	if (lnk->roce_qp)
+		ib_destroy_qp(lnk->roce_qp);
+	lnk->roce_qp = NULL;
+}
+
+/* create a queue pair within the protection domain for a link */
+int smc_ib_create_queue_pair(struct smc_link *lnk)
+{
+	struct ib_qp_init_attr qp_attr = {
+		.event_handler = smc_ib_qp_event_handler,
+		.qp_context = lnk,
+		.send_cq = lnk->smcibdev->roce_cq_send,
+		.recv_cq = lnk->smcibdev->roce_cq_recv,
+		.srq = NULL,
+		.cap = {
+				/* include unsolicited rdma_writes as well,
+				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
+				 */
+			.max_send_wr = SMC_WR_BUF_CNT * 3,
+			.max_recv_wr = SMC_WR_BUF_CNT * 3,
+			.max_send_sge = SMC_IB_MAX_SEND_SGE,
+			.max_recv_sge = 1,
+		},
+		.sq_sig_type = IB_SIGNAL_REQ_WR,
+		.qp_type = IB_QPT_RC,
+	};
+	int rc;
+
+	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
+	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
+	if (IS_ERR(lnk->roce_qp))
+		lnk->roce_qp = NULL;
+	else
+		smc_wr_remember_qp_attr(lnk);
+	return rc;
+}
+
+void smc_ib_put_memory_region(struct ib_mr *mr)
+{
+	ib_dereg_mr(mr);
+}
+
+static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot, u8 link_idx)
+{
+	unsigned int offset = 0;
+	int sg_num;
+
+	/* map the largest prefix of a dma mapped SG list */
+	sg_num = ib_map_mr_sg(buf_slot->mr_rx[link_idx],
+			      buf_slot->sgt[link_idx].sgl,
+			      buf_slot->sgt[link_idx].orig_nents,
+			      &offset, PAGE_SIZE);
+
+	return sg_num;
+}
+
+/* Allocate a memory region and map the dma mapped SG list of buf_slot */
+int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
+			     struct smc_buf_desc *buf_slot, u8 link_idx)
+{
+	if (buf_slot->mr_rx[link_idx])
+		return 0; /* already done */
+
+	buf_slot->mr_rx[link_idx] =
+		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
+	if (IS_ERR(buf_slot->mr_rx[link_idx])) {
+		int rc;
+
+		rc = PTR_ERR(buf_slot->mr_rx[link_idx]);
+		buf_slot->mr_rx[link_idx] = NULL;
+		return rc;
+	}
+
+	if (smc_ib_map_mr_sg(buf_slot, link_idx) != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* synchronize buffer usage for cpu access */
+void smc_ib_sync_sg_for_cpu(struct smc_link *lnk,
+			    struct smc_buf_desc *buf_slot,
+			    enum dma_data_direction data_direction)
+{
+	struct scatterlist *sg;
+	unsigned int i;
+
+	/* for now there is just one DMA address */
+	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
+		    buf_slot->sgt[lnk->link_idx].nents, i) {
+		if (!sg_dma_len(sg))
+			break;
+		ib_dma_sync_single_for_cpu(lnk->smcibdev->ibdev,
+					   sg_dma_address(sg),
+					   sg_dma_len(sg),
+					   data_direction);
+	}
+}
+
+/* synchronize buffer usage for device access */
+void smc_ib_sync_sg_for_device(struct smc_link *lnk,
+			       struct smc_buf_desc *buf_slot,
+			       enum dma_data_direction data_direction)
+{
+	struct scatterlist *sg;
+	unsigned int i;
+
+	/* for now there is just one DMA address */
+	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
+		    buf_slot->sgt[lnk->link_idx].nents, i) {
+		if (!sg_dma_len(sg))
+			break;
+		ib_dma_sync_single_for_device(lnk->smcibdev->ibdev,
+					      sg_dma_address(sg),
+					      sg_dma_len(sg),
+					      data_direction);
+	}
+}
+
+/* Map a new TX or RX buffer SG-table to DMA */
+int smc_ib_buf_map_sg(struct smc_link *lnk,
+		      struct smc_buf_desc *buf_slot,
+		      enum dma_data_direction data_direction)
+{
+	int mapped_nents;
+
+	mapped_nents = ib_dma_map_sg(lnk->smcibdev->ibdev,
+				     buf_slot->sgt[lnk->link_idx].sgl,
+				     buf_slot->sgt[lnk->link_idx].orig_nents,
+				     data_direction);
+	if (!mapped_nents)
+		return -ENOMEM;
+
+	return mapped_nents;
+}
+
+void smc_ib_buf_unmap_sg(struct smc_link *lnk,
+			 struct smc_buf_desc *buf_slot,
+			 enum dma_data_direction data_direction)
+{
+	if (!buf_slot->sgt[lnk->link_idx].sgl->dma_address)
+		return; /* already unmapped */
+
+	ib_dma_unmap_sg(lnk->smcibdev->ibdev,
+			buf_slot->sgt[lnk->link_idx].sgl,
+			buf_slot->sgt[lnk->link_idx].orig_nents,
+			data_direction);
+	buf_slot->sgt[lnk->link_idx].sgl->dma_address = 0;
+}
+
+long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
+{
+	struct ib_cq_init_attr cqattr =	{
+		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
+	int cqe_size_order, smc_order;
+	long rc;
+
+	mutex_lock(&smcibdev->mutex);
+	rc = 0;
+	if (smcibdev->initialized)
+		goto out;
+	/* the calculated number of cq entries fits to mlx5 cq allocation */
+	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
+	smc_order = MAX_ORDER - cqe_size_order - 1;
+	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
+		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
+	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
+					      smc_wr_tx_cq_handler, NULL,
+					      smcibdev, &cqattr);
+	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
+	if (IS_ERR(smcibdev->roce_cq_send)) {
+		smcibdev->roce_cq_send = NULL;
+		goto out;
+	}
+	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
+					      smc_wr_rx_cq_handler, NULL,
+					      smcibdev, &cqattr);
+	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
+	if (IS_ERR(smcibdev->roce_cq_recv)) {
+		smcibdev->roce_cq_recv = NULL;
+		goto err;
+	}
+	smc_wr_add_dev(smcibdev);
+	smcibdev->initialized = 1;
+	goto out;
+
+err:
+	ib_destroy_cq(smcibdev->roce_cq_send);
+out:
+	mutex_unlock(&smcibdev->mutex);
+	return rc;
+}
+
+static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
+{
+	mutex_lock(&smcibdev->mutex);
+	if (!smcibdev->initialized)
+		goto out;
+	smcibdev->initialized = 0;
+	ib_destroy_cq(smcibdev->roce_cq_recv);
+	ib_destroy_cq(smcibdev->roce_cq_send);
+	smc_wr_remove_dev(smcibdev);
+out:
+	mutex_unlock(&smcibdev->mutex);
+}
+
+static struct ib_client smc_ib_client;
+
+/* callback function for ib_register_client() */
+static int smc_ib_add_dev(struct ib_device *ibdev)
+{
+	struct smc_ib_device *smcibdev;
+	u8 port_cnt;
+	int i;
+
+	if (ibdev->node_type != RDMA_NODE_IB_CA)
+		return -EOPNOTSUPP;
+
+	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
+	if (!smcibdev)
+		return -ENOMEM;
+
+	smcibdev->ibdev = ibdev;
+	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
+	atomic_set(&smcibdev->lnk_cnt, 0);
+	init_waitqueue_head(&smcibdev->lnks_deleted);
+	mutex_init(&smcibdev->mutex);
+	mutex_lock(&smc_ib_devices.mutex);
+	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
+	mutex_unlock(&smc_ib_devices.mutex);
+	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
+	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
+			      smc_ib_global_event_handler);
+	ib_register_event_handler(&smcibdev->event_handler);
+
+	/* trigger reading of the port attributes */
+	port_cnt = smcibdev->ibdev->phys_port_cnt;
+	pr_warn_ratelimited("smc: adding ib device %s with port count %d\n",
+			    smcibdev->ibdev->name, port_cnt);
+	for (i = 0;
+	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
+	     i++) {
+		set_bit(i, &smcibdev->port_event_mask);
+		/* determine pnetids of the port */
+		if (smc_pnetid_by_dev_port(ibdev->dev.parent, i,
+					   smcibdev->pnetid[i]))
+			smc_pnetid_by_table_ib(smcibdev, i + 1);
+		pr_warn_ratelimited("smc:    ib device %s port %d has pnetid "
+				    "%.16s%s\n",
+				    smcibdev->ibdev->name, i + 1,
+				    smcibdev->pnetid[i],
+				    smcibdev->pnetid_by_user[i] ?
+				     " (user defined)" :
+				     "");
+	}
+	schedule_work(&smcibdev->port_event_work);
+	return 0;
+}
+
+/* callback function for ib_unregister_client() */
+static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
+{
+	struct smc_ib_device *smcibdev = client_data;
+
+	mutex_lock(&smc_ib_devices.mutex);
+	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
+	mutex_unlock(&smc_ib_devices.mutex);
+	pr_warn_ratelimited("smc: removing ib device %s\n",
+			    smcibdev->ibdev->name);
+	smc_smcr_terminate_all(smcibdev);
+	smc_ib_cleanup_per_ibdev(smcibdev);
+	ib_unregister_event_handler(&smcibdev->event_handler);
+	cancel_work_sync(&smcibdev->port_event_work);
+	kfree(smcibdev);
+}
+
+static struct ib_client smc_ib_client = {
+	.name	= "smc_ib",
+	.add	= smc_ib_add_dev,
+	.remove = smc_ib_remove_dev,
+};
+
+int __init smc_ib_register_client(void)
+{
+	smc_ib_init_local_systemid();
+	return ib_register_client(&smc_ib_client);
+}
+
+void smc_ib_unregister_client(void)
+{
+	ib_unregister_client(&smc_ib_client);
+}