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);
+}