linux/net/rds/ib_cm.c
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   1/*
   2 * Copyright (c) 2006 Oracle.  All rights reserved.
   3 *
   4 * This software is available to you under a choice of one of two
   5 * licenses.  You may choose to be licensed under the terms of the GNU
   6 * General Public License (GPL) Version 2, available from the file
   7 * COPYING in the main directory of this source tree, or the
   8 * OpenIB.org BSD license below:
   9 *
  10 *     Redistribution and use in source and binary forms, with or
  11 *     without modification, are permitted provided that the following
  12 *     conditions are met:
  13 *
  14 *      - Redistributions of source code must retain the above
  15 *        copyright notice, this list of conditions and the following
  16 *        disclaimer.
  17 *
  18 *      - Redistributions in binary form must reproduce the above
  19 *        copyright notice, this list of conditions and the following
  20 *        disclaimer in the documentation and/or other materials
  21 *        provided with the distribution.
  22 *
  23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30 * SOFTWARE.
  31 *
  32 */
  33#include <linux/kernel.h>
  34#include <linux/in.h>
  35#include <linux/slab.h>
  36#include <linux/vmalloc.h>
  37#include <linux/ratelimit.h>
  38
  39#include "rds.h"
  40#include "ib.h"
  41
  42static char *rds_ib_event_type_strings[] = {
  43#define RDS_IB_EVENT_STRING(foo) \
  44                [IB_EVENT_##foo] = __stringify(IB_EVENT_##foo)
  45        RDS_IB_EVENT_STRING(CQ_ERR),
  46        RDS_IB_EVENT_STRING(QP_FATAL),
  47        RDS_IB_EVENT_STRING(QP_REQ_ERR),
  48        RDS_IB_EVENT_STRING(QP_ACCESS_ERR),
  49        RDS_IB_EVENT_STRING(COMM_EST),
  50        RDS_IB_EVENT_STRING(SQ_DRAINED),
  51        RDS_IB_EVENT_STRING(PATH_MIG),
  52        RDS_IB_EVENT_STRING(PATH_MIG_ERR),
  53        RDS_IB_EVENT_STRING(DEVICE_FATAL),
  54        RDS_IB_EVENT_STRING(PORT_ACTIVE),
  55        RDS_IB_EVENT_STRING(PORT_ERR),
  56        RDS_IB_EVENT_STRING(LID_CHANGE),
  57        RDS_IB_EVENT_STRING(PKEY_CHANGE),
  58        RDS_IB_EVENT_STRING(SM_CHANGE),
  59        RDS_IB_EVENT_STRING(SRQ_ERR),
  60        RDS_IB_EVENT_STRING(SRQ_LIMIT_REACHED),
  61        RDS_IB_EVENT_STRING(QP_LAST_WQE_REACHED),
  62        RDS_IB_EVENT_STRING(CLIENT_REREGISTER),
  63#undef RDS_IB_EVENT_STRING
  64};
  65
  66static char *rds_ib_event_str(enum ib_event_type type)
  67{
  68        return rds_str_array(rds_ib_event_type_strings,
  69                             ARRAY_SIZE(rds_ib_event_type_strings), type);
  70};
  71
  72/*
  73 * Set the selected protocol version
  74 */
  75static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
  76{
  77        conn->c_version = version;
  78}
  79
  80/*
  81 * Set up flow control
  82 */
  83static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
  84{
  85        struct rds_ib_connection *ic = conn->c_transport_data;
  86
  87        if (rds_ib_sysctl_flow_control && credits != 0) {
  88                /* We're doing flow control */
  89                ic->i_flowctl = 1;
  90                rds_ib_send_add_credits(conn, credits);
  91        } else {
  92                ic->i_flowctl = 0;
  93        }
  94}
  95
  96/*
  97 * Tune RNR behavior. Without flow control, we use a rather
  98 * low timeout, but not the absolute minimum - this should
  99 * be tunable.
 100 *
 101 * We already set the RNR retry count to 7 (which is the
 102 * smallest infinite number :-) above.
 103 * If flow control is off, we want to change this back to 0
 104 * so that we learn quickly when our credit accounting is
 105 * buggy.
 106 *
 107 * Caller passes in a qp_attr pointer - don't waste stack spacv
 108 * by allocation this twice.
 109 */
 110static void
 111rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
 112{
 113        int ret;
 114
 115        attr->min_rnr_timer = IB_RNR_TIMER_000_32;
 116        ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
 117        if (ret)
 118                printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
 119}
 120
 121/*
 122 * Connection established.
 123 * We get here for both outgoing and incoming connection.
 124 */
 125void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
 126{
 127        const struct rds_ib_connect_private *dp = NULL;
 128        struct rds_ib_connection *ic = conn->c_transport_data;
 129        struct ib_qp_attr qp_attr;
 130        int err;
 131
 132        if (event->param.conn.private_data_len >= sizeof(*dp)) {
 133                dp = event->param.conn.private_data;
 134
 135                /* make sure it isn't empty data */
 136                if (dp->dp_protocol_major) {
 137                        rds_ib_set_protocol(conn,
 138                                RDS_PROTOCOL(dp->dp_protocol_major,
 139                                dp->dp_protocol_minor));
 140                        rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 141                }
 142        }
 143
 144        if (conn->c_version < RDS_PROTOCOL(3,1)) {
 145                printk(KERN_NOTICE "RDS/IB: Connection to %pI4 version %u.%u failed,"
 146                       " no longer supported\n",
 147                       &conn->c_faddr,
 148                       RDS_PROTOCOL_MAJOR(conn->c_version),
 149                       RDS_PROTOCOL_MINOR(conn->c_version));
 150                rds_conn_destroy(conn);
 151                return;
 152        } else {
 153                printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
 154                       &conn->c_faddr,
 155                       RDS_PROTOCOL_MAJOR(conn->c_version),
 156                       RDS_PROTOCOL_MINOR(conn->c_version),
 157                       ic->i_flowctl ? ", flow control" : "");
 158        }
 159
 160        /*
 161         * Init rings and fill recv. this needs to wait until protocol negotiation
 162         * is complete, since ring layout is different from 3.0 to 3.1.
 163         */
 164        rds_ib_send_init_ring(ic);
 165        rds_ib_recv_init_ring(ic);
 166        /* Post receive buffers - as a side effect, this will update
 167         * the posted credit count. */
 168        rds_ib_recv_refill(conn, 1);
 169
 170        /* Tune RNR behavior */
 171        rds_ib_tune_rnr(ic, &qp_attr);
 172
 173        qp_attr.qp_state = IB_QPS_RTS;
 174        err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 175        if (err)
 176                printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
 177
 178        /* update ib_device with this local ipaddr */
 179        err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
 180        if (err)
 181                printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
 182                        err);
 183
 184        /* If the peer gave us the last packet it saw, process this as if
 185         * we had received a regular ACK. */
 186        if (dp && dp->dp_ack_seq)
 187                rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 188
 189        rds_connect_complete(conn);
 190}
 191
 192static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
 193                        struct rdma_conn_param *conn_param,
 194                        struct rds_ib_connect_private *dp,
 195                        u32 protocol_version,
 196                        u32 max_responder_resources,
 197                        u32 max_initiator_depth)
 198{
 199        struct rds_ib_connection *ic = conn->c_transport_data;
 200        struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 201
 202        memset(conn_param, 0, sizeof(struct rdma_conn_param));
 203
 204        conn_param->responder_resources =
 205                min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
 206        conn_param->initiator_depth =
 207                min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
 208        conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
 209        conn_param->rnr_retry_count = 7;
 210
 211        if (dp) {
 212                memset(dp, 0, sizeof(*dp));
 213                dp->dp_saddr = conn->c_laddr;
 214                dp->dp_daddr = conn->c_faddr;
 215                dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 216                dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 217                dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
 218                dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
 219
 220                /* Advertise flow control */
 221                if (ic->i_flowctl) {
 222                        unsigned int credits;
 223
 224                        credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 225                        dp->dp_credit = cpu_to_be32(credits);
 226                        atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 227                }
 228
 229                conn_param->private_data = dp;
 230                conn_param->private_data_len = sizeof(*dp);
 231        }
 232}
 233
 234static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
 235{
 236        rdsdebug("event %u (%s) data %p\n",
 237                 event->event, rds_ib_event_str(event->event), data);
 238}
 239
 240static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
 241{
 242        struct rds_connection *conn = data;
 243        struct rds_ib_connection *ic = conn->c_transport_data;
 244
 245        rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
 246                 rds_ib_event_str(event->event));
 247
 248        switch (event->event) {
 249        case IB_EVENT_COMM_EST:
 250                rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 251                break;
 252        default:
 253                rdsdebug("Fatal QP Event %u (%s) "
 254                        "- connection %pI4->%pI4, reconnecting\n",
 255                        event->event, rds_ib_event_str(event->event),
 256                        &conn->c_laddr, &conn->c_faddr);
 257                rds_conn_drop(conn);
 258                break;
 259        }
 260}
 261
 262/*
 263 * This needs to be very careful to not leave IS_ERR pointers around for
 264 * cleanup to trip over.
 265 */
 266static int rds_ib_setup_qp(struct rds_connection *conn)
 267{
 268        struct rds_ib_connection *ic = conn->c_transport_data;
 269        struct ib_device *dev = ic->i_cm_id->device;
 270        struct ib_qp_init_attr attr;
 271        struct rds_ib_device *rds_ibdev;
 272        int ret;
 273
 274        /*
 275         * It's normal to see a null device if an incoming connection races
 276         * with device removal, so we don't print a warning.
 277         */
 278        rds_ibdev = rds_ib_get_client_data(dev);
 279        if (!rds_ibdev)
 280                return -EOPNOTSUPP;
 281
 282        /* add the conn now so that connection establishment has the dev */
 283        rds_ib_add_conn(rds_ibdev, conn);
 284
 285        if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
 286                rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
 287        if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
 288                rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
 289
 290        /* Protection domain and memory range */
 291        ic->i_pd = rds_ibdev->pd;
 292        ic->i_mr = rds_ibdev->mr;
 293
 294        ic->i_send_cq = ib_create_cq(dev, rds_ib_send_cq_comp_handler,
 295                                     rds_ib_cq_event_handler, conn,
 296                                     ic->i_send_ring.w_nr + 1, 0);
 297        if (IS_ERR(ic->i_send_cq)) {
 298                ret = PTR_ERR(ic->i_send_cq);
 299                ic->i_send_cq = NULL;
 300                rdsdebug("ib_create_cq send failed: %d\n", ret);
 301                goto out;
 302        }
 303
 304        ic->i_recv_cq = ib_create_cq(dev, rds_ib_recv_cq_comp_handler,
 305                                     rds_ib_cq_event_handler, conn,
 306                                     ic->i_recv_ring.w_nr, 0);
 307        if (IS_ERR(ic->i_recv_cq)) {
 308                ret = PTR_ERR(ic->i_recv_cq);
 309                ic->i_recv_cq = NULL;
 310                rdsdebug("ib_create_cq recv failed: %d\n", ret);
 311                goto out;
 312        }
 313
 314        ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 315        if (ret) {
 316                rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 317                goto out;
 318        }
 319
 320        ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 321        if (ret) {
 322                rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 323                goto out;
 324        }
 325
 326        /* XXX negotiate max send/recv with remote? */
 327        memset(&attr, 0, sizeof(attr));
 328        attr.event_handler = rds_ib_qp_event_handler;
 329        attr.qp_context = conn;
 330        /* + 1 to allow for the single ack message */
 331        attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
 332        attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
 333        attr.cap.max_send_sge = rds_ibdev->max_sge;
 334        attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
 335        attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 336        attr.qp_type = IB_QPT_RC;
 337        attr.send_cq = ic->i_send_cq;
 338        attr.recv_cq = ic->i_recv_cq;
 339
 340        /*
 341         * XXX this can fail if max_*_wr is too large?  Are we supposed
 342         * to back off until we get a value that the hardware can support?
 343         */
 344        ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 345        if (ret) {
 346                rdsdebug("rdma_create_qp failed: %d\n", ret);
 347                goto out;
 348        }
 349
 350        ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 351                                           ic->i_send_ring.w_nr *
 352                                                sizeof(struct rds_header),
 353                                           &ic->i_send_hdrs_dma, GFP_KERNEL);
 354        if (!ic->i_send_hdrs) {
 355                ret = -ENOMEM;
 356                rdsdebug("ib_dma_alloc_coherent send failed\n");
 357                goto out;
 358        }
 359
 360        ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 361                                           ic->i_recv_ring.w_nr *
 362                                                sizeof(struct rds_header),
 363                                           &ic->i_recv_hdrs_dma, GFP_KERNEL);
 364        if (!ic->i_recv_hdrs) {
 365                ret = -ENOMEM;
 366                rdsdebug("ib_dma_alloc_coherent recv failed\n");
 367                goto out;
 368        }
 369
 370        ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 371                                       &ic->i_ack_dma, GFP_KERNEL);
 372        if (!ic->i_ack) {
 373                ret = -ENOMEM;
 374                rdsdebug("ib_dma_alloc_coherent ack failed\n");
 375                goto out;
 376        }
 377
 378        ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
 379                                   ibdev_to_node(dev));
 380        if (!ic->i_sends) {
 381                ret = -ENOMEM;
 382                rdsdebug("send allocation failed\n");
 383                goto out;
 384        }
 385
 386        ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
 387                                   ibdev_to_node(dev));
 388        if (!ic->i_recvs) {
 389                ret = -ENOMEM;
 390                rdsdebug("recv allocation failed\n");
 391                goto out;
 392        }
 393
 394        rds_ib_recv_init_ack(ic);
 395
 396        rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
 397                 ic->i_send_cq, ic->i_recv_cq);
 398
 399out:
 400        rds_ib_dev_put(rds_ibdev);
 401        return ret;
 402}
 403
 404static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
 405{
 406        const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 407        u16 common;
 408        u32 version = 0;
 409
 410        /*
 411         * rdma_cm private data is odd - when there is any private data in the
 412         * request, we will be given a pretty large buffer without telling us the
 413         * original size. The only way to tell the difference is by looking at
 414         * the contents, which are initialized to zero.
 415         * If the protocol version fields aren't set, this is a connection attempt
 416         * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 417         * We really should have changed this for OFED 1.3 :-(
 418         */
 419
 420        /* Be paranoid. RDS always has privdata */
 421        if (!event->param.conn.private_data_len) {
 422                printk(KERN_NOTICE "RDS incoming connection has no private data, "
 423                        "rejecting\n");
 424                return 0;
 425        }
 426
 427        /* Even if len is crap *now* I still want to check it. -ASG */
 428        if (event->param.conn.private_data_len < sizeof (*dp) ||
 429            dp->dp_protocol_major == 0)
 430                return RDS_PROTOCOL_3_0;
 431
 432        common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
 433        if (dp->dp_protocol_major == 3 && common) {
 434                version = RDS_PROTOCOL_3_0;
 435                while ((common >>= 1) != 0)
 436                        version++;
 437        }
 438        printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using "
 439                        "incompatible protocol version %u.%u\n",
 440                        &dp->dp_saddr,
 441                        dp->dp_protocol_major,
 442                        dp->dp_protocol_minor);
 443        return version;
 444}
 445
 446int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 447                                    struct rdma_cm_event *event)
 448{
 449        __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
 450        __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
 451        const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 452        struct rds_ib_connect_private dp_rep;
 453        struct rds_connection *conn = NULL;
 454        struct rds_ib_connection *ic = NULL;
 455        struct rdma_conn_param conn_param;
 456        u32 version;
 457        int err = 1, destroy = 1;
 458
 459        /* Check whether the remote protocol version matches ours. */
 460        version = rds_ib_protocol_compatible(event);
 461        if (!version)
 462                goto out;
 463
 464        rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
 465                 "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
 466                 RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
 467                 (unsigned long long)be64_to_cpu(lguid),
 468                 (unsigned long long)be64_to_cpu(fguid));
 469
 470        conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
 471                               GFP_KERNEL);
 472        if (IS_ERR(conn)) {
 473                rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 474                conn = NULL;
 475                goto out;
 476        }
 477
 478        /*
 479         * The connection request may occur while the
 480         * previous connection exist, e.g. in case of failover.
 481         * But as connections may be initiated simultaneously
 482         * by both hosts, we have a random backoff mechanism -
 483         * see the comment above rds_queue_reconnect()
 484         */
 485        mutex_lock(&conn->c_cm_lock);
 486        if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 487                if (rds_conn_state(conn) == RDS_CONN_UP) {
 488                        rdsdebug("incoming connect while connecting\n");
 489                        rds_conn_drop(conn);
 490                        rds_ib_stats_inc(s_ib_listen_closed_stale);
 491                } else
 492                if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 493                        /* Wait and see - our connect may still be succeeding */
 494                        rds_ib_stats_inc(s_ib_connect_raced);
 495                }
 496                goto out;
 497        }
 498
 499        ic = conn->c_transport_data;
 500
 501        rds_ib_set_protocol(conn, version);
 502        rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 503
 504        /* If the peer gave us the last packet it saw, process this as if
 505         * we had received a regular ACK. */
 506        if (dp->dp_ack_seq)
 507                rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 508
 509        BUG_ON(cm_id->context);
 510        BUG_ON(ic->i_cm_id);
 511
 512        ic->i_cm_id = cm_id;
 513        cm_id->context = conn;
 514
 515        /* We got halfway through setting up the ib_connection, if we
 516         * fail now, we have to take the long route out of this mess. */
 517        destroy = 0;
 518
 519        err = rds_ib_setup_qp(conn);
 520        if (err) {
 521                rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
 522                goto out;
 523        }
 524
 525        rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
 526                event->param.conn.responder_resources,
 527                event->param.conn.initiator_depth);
 528
 529        /* rdma_accept() calls rdma_reject() internally if it fails */
 530        err = rdma_accept(cm_id, &conn_param);
 531        if (err)
 532                rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
 533
 534out:
 535        if (conn)
 536                mutex_unlock(&conn->c_cm_lock);
 537        if (err)
 538                rdma_reject(cm_id, NULL, 0);
 539        return destroy;
 540}
 541
 542
 543int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
 544{
 545        struct rds_connection *conn = cm_id->context;
 546        struct rds_ib_connection *ic = conn->c_transport_data;
 547        struct rdma_conn_param conn_param;
 548        struct rds_ib_connect_private dp;
 549        int ret;
 550
 551        /* If the peer doesn't do protocol negotiation, we must
 552         * default to RDSv3.0 */
 553        rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
 554        ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
 555
 556        ret = rds_ib_setup_qp(conn);
 557        if (ret) {
 558                rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
 559                goto out;
 560        }
 561
 562        rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
 563                UINT_MAX, UINT_MAX);
 564        ret = rdma_connect(cm_id, &conn_param);
 565        if (ret)
 566                rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 567
 568out:
 569        /* Beware - returning non-zero tells the rdma_cm to destroy
 570         * the cm_id. We should certainly not do it as long as we still
 571         * "own" the cm_id. */
 572        if (ret) {
 573                if (ic->i_cm_id == cm_id)
 574                        ret = 0;
 575        }
 576        return ret;
 577}
 578
 579int rds_ib_conn_connect(struct rds_connection *conn)
 580{
 581        struct rds_ib_connection *ic = conn->c_transport_data;
 582        struct sockaddr_in src, dest;
 583        int ret;
 584
 585        /* XXX I wonder what affect the port space has */
 586        /* delegate cm event handler to rdma_transport */
 587        ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
 588                                     RDMA_PS_TCP, IB_QPT_RC);
 589        if (IS_ERR(ic->i_cm_id)) {
 590                ret = PTR_ERR(ic->i_cm_id);
 591                ic->i_cm_id = NULL;
 592                rdsdebug("rdma_create_id() failed: %d\n", ret);
 593                goto out;
 594        }
 595
 596        rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 597
 598        src.sin_family = AF_INET;
 599        src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 600        src.sin_port = (__force u16)htons(0);
 601
 602        dest.sin_family = AF_INET;
 603        dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 604        dest.sin_port = (__force u16)htons(RDS_PORT);
 605
 606        ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 607                                (struct sockaddr *)&dest,
 608                                RDS_RDMA_RESOLVE_TIMEOUT_MS);
 609        if (ret) {
 610                rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 611                         ret);
 612                rdma_destroy_id(ic->i_cm_id);
 613                ic->i_cm_id = NULL;
 614        }
 615
 616out:
 617        return ret;
 618}
 619
 620/*
 621 * This is so careful about only cleaning up resources that were built up
 622 * so that it can be called at any point during startup.  In fact it
 623 * can be called multiple times for a given connection.
 624 */
 625void rds_ib_conn_shutdown(struct rds_connection *conn)
 626{
 627        struct rds_ib_connection *ic = conn->c_transport_data;
 628        int err = 0;
 629
 630        rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 631                 ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 632                 ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 633
 634        if (ic->i_cm_id) {
 635                struct ib_device *dev = ic->i_cm_id->device;
 636
 637                rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 638                err = rdma_disconnect(ic->i_cm_id);
 639                if (err) {
 640                        /* Actually this may happen quite frequently, when
 641                         * an outgoing connect raced with an incoming connect.
 642                         */
 643                        rdsdebug("failed to disconnect, cm: %p err %d\n",
 644                                ic->i_cm_id, err);
 645                }
 646
 647                /*
 648                 * We want to wait for tx and rx completion to finish
 649                 * before we tear down the connection, but we have to be
 650                 * careful not to get stuck waiting on a send ring that
 651                 * only has unsignaled sends in it.  We've shutdown new
 652                 * sends before getting here so by waiting for signaled
 653                 * sends to complete we're ensured that there will be no
 654                 * more tx processing.
 655                 */
 656                wait_event(rds_ib_ring_empty_wait,
 657                           rds_ib_ring_empty(&ic->i_recv_ring) &&
 658                           (atomic_read(&ic->i_signaled_sends) == 0));
 659                tasklet_kill(&ic->i_recv_tasklet);
 660
 661                if (ic->i_send_hdrs)
 662                        ib_dma_free_coherent(dev,
 663                                           ic->i_send_ring.w_nr *
 664                                                sizeof(struct rds_header),
 665                                           ic->i_send_hdrs,
 666                                           ic->i_send_hdrs_dma);
 667
 668                if (ic->i_recv_hdrs)
 669                        ib_dma_free_coherent(dev,
 670                                           ic->i_recv_ring.w_nr *
 671                                                sizeof(struct rds_header),
 672                                           ic->i_recv_hdrs,
 673                                           ic->i_recv_hdrs_dma);
 674
 675                if (ic->i_ack)
 676                        ib_dma_free_coherent(dev, sizeof(struct rds_header),
 677                                             ic->i_ack, ic->i_ack_dma);
 678
 679                if (ic->i_sends)
 680                        rds_ib_send_clear_ring(ic);
 681                if (ic->i_recvs)
 682                        rds_ib_recv_clear_ring(ic);
 683
 684                if (ic->i_cm_id->qp)
 685                        rdma_destroy_qp(ic->i_cm_id);
 686                if (ic->i_send_cq)
 687                        ib_destroy_cq(ic->i_send_cq);
 688                if (ic->i_recv_cq)
 689                        ib_destroy_cq(ic->i_recv_cq);
 690                rdma_destroy_id(ic->i_cm_id);
 691
 692                /*
 693                 * Move connection back to the nodev list.
 694                 */
 695                if (ic->rds_ibdev)
 696                        rds_ib_remove_conn(ic->rds_ibdev, conn);
 697
 698                ic->i_cm_id = NULL;
 699                ic->i_pd = NULL;
 700                ic->i_mr = NULL;
 701                ic->i_send_cq = NULL;
 702                ic->i_recv_cq = NULL;
 703                ic->i_send_hdrs = NULL;
 704                ic->i_recv_hdrs = NULL;
 705                ic->i_ack = NULL;
 706        }
 707        BUG_ON(ic->rds_ibdev);
 708
 709        /* Clear pending transmit */
 710        if (ic->i_data_op) {
 711                struct rds_message *rm;
 712
 713                rm = container_of(ic->i_data_op, struct rds_message, data);
 714                rds_message_put(rm);
 715                ic->i_data_op = NULL;
 716        }
 717
 718        /* Clear the ACK state */
 719        clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 720#ifdef KERNEL_HAS_ATOMIC64
 721        atomic64_set(&ic->i_ack_next, 0);
 722#else
 723        ic->i_ack_next = 0;
 724#endif
 725        ic->i_ack_recv = 0;
 726
 727        /* Clear flow control state */
 728        ic->i_flowctl = 0;
 729        atomic_set(&ic->i_credits, 0);
 730
 731        rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 732        rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 733
 734        if (ic->i_ibinc) {
 735                rds_inc_put(&ic->i_ibinc->ii_inc);
 736                ic->i_ibinc = NULL;
 737        }
 738
 739        vfree(ic->i_sends);
 740        ic->i_sends = NULL;
 741        vfree(ic->i_recvs);
 742        ic->i_recvs = NULL;
 743}
 744
 745int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 746{
 747        struct rds_ib_connection *ic;
 748        unsigned long flags;
 749        int ret;
 750
 751        /* XXX too lazy? */
 752        ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
 753        if (!ic)
 754                return -ENOMEM;
 755
 756        ret = rds_ib_recv_alloc_caches(ic);
 757        if (ret) {
 758                kfree(ic);
 759                return ret;
 760        }
 761
 762        INIT_LIST_HEAD(&ic->ib_node);
 763        tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn,
 764                     (unsigned long) ic);
 765        mutex_init(&ic->i_recv_mutex);
 766#ifndef KERNEL_HAS_ATOMIC64
 767        spin_lock_init(&ic->i_ack_lock);
 768#endif
 769        atomic_set(&ic->i_signaled_sends, 0);
 770
 771        /*
 772         * rds_ib_conn_shutdown() waits for these to be emptied so they
 773         * must be initialized before it can be called.
 774         */
 775        rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 776        rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 777
 778        ic->conn = conn;
 779        conn->c_transport_data = ic;
 780
 781        spin_lock_irqsave(&ib_nodev_conns_lock, flags);
 782        list_add_tail(&ic->ib_node, &ib_nodev_conns);
 783        spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
 784
 785
 786        rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 787        return 0;
 788}
 789
 790/*
 791 * Free a connection. Connection must be shut down and not set for reconnect.
 792 */
 793void rds_ib_conn_free(void *arg)
 794{
 795        struct rds_ib_connection *ic = arg;
 796        spinlock_t      *lock_ptr;
 797
 798        rdsdebug("ic %p\n", ic);
 799
 800        /*
 801         * Conn is either on a dev's list or on the nodev list.
 802         * A race with shutdown() or connect() would cause problems
 803         * (since rds_ibdev would change) but that should never happen.
 804         */
 805        lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
 806
 807        spin_lock_irq(lock_ptr);
 808        list_del(&ic->ib_node);
 809        spin_unlock_irq(lock_ptr);
 810
 811        rds_ib_recv_free_caches(ic);
 812
 813        kfree(ic);
 814}
 815
 816
 817/*
 818 * An error occurred on the connection
 819 */
 820void
 821__rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
 822{
 823        va_list ap;
 824
 825        rds_conn_drop(conn);
 826
 827        va_start(ap, fmt);
 828        vprintk(fmt, ap);
 829        va_end(ap);
 830}
 831
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