net/rds/ib_cm.c

   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_single_path.h"
  40 #include "rds.h"
  41 #include "ib.h"
  42
  43 /*
  44  * Set the selected protocol version
  45  */
  46 static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
  47 {
  48         conn->c_version = version;
  49 }
  50
  51 /*
  52  * Set up flow control
  53  */
  54 static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
  55 {
  56         struct rds_ib_connection *ic = conn->c_transport_data;
  57
  58         if (rds_ib_sysctl_flow_control && credits != 0) {
  59                 /* We're doing flow control */
  60                 ic->i_flowctl = 1;
  61                 rds_ib_send_add_credits(conn, credits);
  62         } else {
  63                 ic->i_flowctl = 0;
  64         }
  65 }
  66
  67 /*
  68  * Tune RNR behavior. Without flow control, we use a rather
  69  * low timeout, but not the absolute minimum - this should
  70  * be tunable.
  71  *
  72  * We already set the RNR retry count to 7 (which is the
  73  * smallest infinite number :-) above.
  74  * If flow control is off, we want to change this back to 0
  75  * so that we learn quickly when our credit accounting is
  76  * buggy.
  77  *
  78  * Caller passes in a qp_attr pointer - don't waste stack spacv
  79  * by allocation this twice.
  80  */
  81 static void
  82 rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
  83 {
  84         int ret;
  85
  86         attr->min_rnr_timer = IB_RNR_TIMER_000_32;
  87         ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
  88         if (ret)
  89                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
  90 }
  91
  92 /*
  93  * Connection established.
  94  * We get here for both outgoing and incoming connection.
  95  */
  96 void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
  97 {
  98         const struct rds_ib_connect_private *dp = NULL;
  99         struct rds_ib_connection *ic = conn->c_transport_data;
 100         struct ib_qp_attr qp_attr;
 101         int err;
 102
 103         if (event->param.conn.private_data_len >= sizeof(*dp)) {
 104                 dp = event->param.conn.private_data;
 105
 106                 /* make sure it isn't empty data */
 107                 if (dp->dp_protocol_major) {
 108                         rds_ib_set_protocol(conn,
 109                                 RDS_PROTOCOL(dp->dp_protocol_major,
 110                                 dp->dp_protocol_minor));
 111                         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 112                 }
 113         }
 114
 115         if (conn->c_version < RDS_PROTOCOL(3, 1)) {
 116                 printk(KERN_NOTICE "RDS/IB: Connection to %pI4 version %u.%u failed,"
 117                        " no longer supported\n",
 118                        &conn->c_faddr,
 119                        RDS_PROTOCOL_MAJOR(conn->c_version),
 120                        RDS_PROTOCOL_MINOR(conn->c_version));
 121                 rds_conn_destroy(conn);
 122                 return;
 123         } else {
 124                 printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
 125                        &conn->c_faddr,
 126                        RDS_PROTOCOL_MAJOR(conn->c_version),
 127                        RDS_PROTOCOL_MINOR(conn->c_version),
 128                        ic->i_flowctl ? ", flow control" : "");
 129         }
 130
 131         /*
 132          * Init rings and fill recv. this needs to wait until protocol negotiation
 133          * is complete, since ring layout is different from 3.0 to 3.1.
 134          */
 135         rds_ib_send_init_ring(ic);
 136         rds_ib_recv_init_ring(ic);
 137         /* Post receive buffers - as a side effect, this will update
 138          * the posted credit count. */
 139         rds_ib_recv_refill(conn, 1, GFP_KERNEL);
 140
 141         /* Tune RNR behavior */
 142         rds_ib_tune_rnr(ic, &qp_attr);
 143
 144         qp_attr.qp_state = IB_QPS_RTS;
 145         err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 146         if (err)
 147                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
 148
 149         /* update ib_device with this local ipaddr */
 150         err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
 151         if (err)
 152                 printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
 153                         err);
 154
 155         /* If the peer gave us the last packet it saw, process this as if
 156          * we had received a regular ACK. */
 157         if (dp) {
 158                 /* dp structure start is not guaranteed to be 8 bytes aligned.
 159                  * Since dp_ack_seq is 64-bit extended load operations can be
 160                  * used so go through get_unaligned to avoid unaligned errors.
 161                  */
 162                 __be64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
 163
 164                 if (dp_ack_seq)
 165                         rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
 166                                             NULL);
 167         }
 168
 169         rds_connect_complete(conn);
 170 }
 171
 172 static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
 173                         struct rdma_conn_param *conn_param,
 174                         struct rds_ib_connect_private *dp,
 175                         u32 protocol_version,
 176                         u32 max_responder_resources,
 177                         u32 max_initiator_depth)
 178 {
 179         struct rds_ib_connection *ic = conn->c_transport_data;
 180         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 181
 182         memset(conn_param, 0, sizeof(struct rdma_conn_param));
 183
 184         conn_param->responder_resources =
 185                 min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
 186         conn_param->initiator_depth =
 187                 min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
 188         conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
 189         conn_param->rnr_retry_count = 7;
 190
 191         if (dp) {
 192                 memset(dp, 0, sizeof(*dp));
 193                 dp->dp_saddr = conn->c_laddr;
 194                 dp->dp_daddr = conn->c_faddr;
 195                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 196                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 197                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
 198                 dp->dp_ack_seq = cpu_to_be64(rds_ib_piggyb_ack(ic));
 199
 200                 /* Advertise flow control */
 201                 if (ic->i_flowctl) {
 202                         unsigned int credits;
 203
 204                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 205                         dp->dp_credit = cpu_to_be32(credits);
 206                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 207                 }
 208
 209                 conn_param->private_data = dp;
 210                 conn_param->private_data_len = sizeof(*dp);
 211         }
 212 }
 213
 214 static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
 215 {
 216         rdsdebug("event %u (%s) data %p\n",
 217                  event->event, ib_event_msg(event->event), data);
 218 }
 219
 220 /* Plucking the oldest entry from the ring can be done concurrently with
 221  * the thread refilling the ring.  Each ring operation is protected by
 222  * spinlocks and the transient state of refilling doesn't change the
 223  * recording of which entry is oldest.
 224  *
 225  * This relies on IB only calling one cq comp_handler for each cq so that
 226  * there will only be one caller of rds_recv_incoming() per RDS connection.
 227  */
 228 static void rds_ib_cq_comp_handler_recv(struct ib_cq *cq, void *context)
 229 {
 230         struct rds_connection *conn = context;
 231         struct rds_ib_connection *ic = conn->c_transport_data;
 232
 233         rdsdebug("conn %p cq %p\n", conn, cq);
 234
 235         rds_ib_stats_inc(s_ib_evt_handler_call);
 236
 237         tasklet_schedule(&ic->i_recv_tasklet);
 238 }
 239
 240 static void poll_scq(struct rds_ib_connection *ic, struct ib_cq *cq,
 241                      struct ib_wc *wcs)
 242 {
 243         int nr, i;
 244         struct ib_wc *wc;
 245
 246         while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
 247                 for (i = 0; i < nr; i++) {
 248                         wc = wcs + i;
 249                         rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
 250                                  (unsigned long long)wc->wr_id, wc->status,
 251                                  wc->byte_len, be32_to_cpu(wc->ex.imm_data));
 252
 253                         if (wc->wr_id <= ic->i_send_ring.w_nr ||
 254                             wc->wr_id == RDS_IB_ACK_WR_ID)
 255                                 rds_ib_send_cqe_handler(ic, wc);
 256                         else
 257                                 rds_ib_mr_cqe_handler(ic, wc);
 258
 259                 }
 260         }
 261 }
 262
 263 static void rds_ib_tasklet_fn_send(unsigned long data)
 264 {
 265         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 266         struct rds_connection *conn = ic->conn;
 267
 268         rds_ib_stats_inc(s_ib_tasklet_call);
 269
 270         poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
 271         ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 272         poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
 273
 274         if (rds_conn_up(conn) &&
 275             (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
 276             test_bit(0, &conn->c_map_queued)))
 277                 rds_send_xmit(&ic->conn->c_path[0]);
 278 }
 279
 280 static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,
 281                      struct ib_wc *wcs,
 282                      struct rds_ib_ack_state *ack_state)
 283 {
 284         int nr, i;
 285         struct ib_wc *wc;
 286
 287         while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
 288                 for (i = 0; i < nr; i++) {
 289                         wc = wcs + i;
 290                         rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
 291                                  (unsigned long long)wc->wr_id, wc->status,
 292                                  wc->byte_len, be32_to_cpu(wc->ex.imm_data));
 293
 294                         rds_ib_recv_cqe_handler(ic, wc, ack_state);
 295                 }
 296         }
 297 }
 298
 299 static void rds_ib_tasklet_fn_recv(unsigned long data)
 300 {
 301         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 302         struct rds_connection *conn = ic->conn;
 303         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 304         struct rds_ib_ack_state state;
 305
 306         if (!rds_ibdev)
 307                 rds_conn_drop(conn);
 308
 309         rds_ib_stats_inc(s_ib_tasklet_call);
 310
 311         memset(&state, 0, sizeof(state));
 312         poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 313         ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 314         poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 315
 316         if (state.ack_next_valid)
 317                 rds_ib_set_ack(ic, state.ack_next, state.ack_required);
 318         if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
 319                 rds_send_drop_acked(conn, state.ack_recv, NULL);
 320                 ic->i_ack_recv = state.ack_recv;
 321         }
 322
 323         if (rds_conn_up(conn))
 324                 rds_ib_attempt_ack(ic);
 325 }
 326
 327 static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
 328 {
 329         struct rds_connection *conn = data;
 330         struct rds_ib_connection *ic = conn->c_transport_data;
 331
 332         rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
 333                  ib_event_msg(event->event));
 334
 335         switch (event->event) {
 336         case IB_EVENT_COMM_EST:
 337                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 338                 break;
 339         default:
 340                 rdsdebug("Fatal QP Event %u (%s) "
 341                         "- connection %pI4->%pI4, reconnecting\n",
 342                         event->event, ib_event_msg(event->event),
 343                         &conn->c_laddr, &conn->c_faddr);
 344                 rds_conn_drop(conn);
 345                 break;
 346         }
 347 }
 348
 349 static void rds_ib_cq_comp_handler_send(struct ib_cq *cq, void *context)
 350 {
 351         struct rds_connection *conn = context;
 352         struct rds_ib_connection *ic = conn->c_transport_data;
 353
 354         rdsdebug("conn %p cq %p\n", conn, cq);
 355
 356         rds_ib_stats_inc(s_ib_evt_handler_call);
 357
 358         tasklet_schedule(&ic->i_send_tasklet);
 359 }
 360
 361 /*
 362  * This needs to be very careful to not leave IS_ERR pointers around for
 363  * cleanup to trip over.
 364  */
 365 static int rds_ib_setup_qp(struct rds_connection *conn)
 366 {
 367         struct rds_ib_connection *ic = conn->c_transport_data;
 368         struct ib_device *dev = ic->i_cm_id->device;
 369         struct ib_qp_init_attr attr;
 370         struct ib_cq_init_attr cq_attr = {};
 371         struct rds_ib_device *rds_ibdev;
 372         int ret, fr_queue_space;
 373
 374         /*
 375          * It's normal to see a null device if an incoming connection races
 376          * with device removal, so we don't print a warning.
 377          */
 378         rds_ibdev = rds_ib_get_client_data(dev);
 379         if (!rds_ibdev)
 380                 return -EOPNOTSUPP;
 381
 382         /* The fr_queue_space is currently set to 512, to add extra space on
 383          * completion queue and send queue. This extra space is used for FRMR
 384          * registration and invalidation work requests
 385          */
 386         fr_queue_space = (rds_ibdev->use_fastreg ? RDS_IB_DEFAULT_FR_WR : 0);
 387
 388         /* add the conn now so that connection establishment has the dev */
 389         rds_ib_add_conn(rds_ibdev, conn);
 390
 391         if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
 392                 rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
 393         if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
 394                 rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
 395
 396         /* Protection domain and memory range */
 397         ic->i_pd = rds_ibdev->pd;
 398
 399         cq_attr.cqe = ic->i_send_ring.w_nr + fr_queue_space + 1;
 400
 401         ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
 402                                      rds_ib_cq_event_handler, conn,
 403                                      &cq_attr);
 404         if (IS_ERR(ic->i_send_cq)) {
 405                 ret = PTR_ERR(ic->i_send_cq);
 406                 ic->i_send_cq = NULL;
 407                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 408                 goto out;
 409         }
 410
 411         cq_attr.cqe = ic->i_recv_ring.w_nr;
 412         ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
 413                                      rds_ib_cq_event_handler, conn,
 414                                      &cq_attr);
 415         if (IS_ERR(ic->i_recv_cq)) {
 416                 ret = PTR_ERR(ic->i_recv_cq);
 417                 ic->i_recv_cq = NULL;
 418                 rdsdebug("ib_create_cq recv failed: %d\n", ret);
 419                 goto out;
 420         }
 421
 422         ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 423         if (ret) {
 424                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 425                 goto out;
 426         }
 427
 428         ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 429         if (ret) {
 430                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 431                 goto out;
 432         }
 433
 434         /* XXX negotiate max send/recv with remote? */
 435         memset(&attr, 0, sizeof(attr));
 436         attr.event_handler = rds_ib_qp_event_handler;
 437         attr.qp_context = conn;
 438         /* + 1 to allow for the single ack message */
 439         attr.cap.max_send_wr = ic->i_send_ring.w_nr + fr_queue_space + 1;
 440         attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
 441         attr.cap.max_send_sge = rds_ibdev->max_sge;
 442         attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
 443         attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 444         attr.qp_type = IB_QPT_RC;
 445         attr.send_cq = ic->i_send_cq;
 446         attr.recv_cq = ic->i_recv_cq;
 447         atomic_set(&ic->i_fastreg_wrs, RDS_IB_DEFAULT_FR_WR);
 448
 449         /*
 450          * XXX this can fail if max_*_wr is too large?  Are we supposed
 451          * to back off until we get a value that the hardware can support?
 452          */
 453         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 454         if (ret) {
 455                 rdsdebug("rdma_create_qp failed: %d\n", ret);
 456                 goto out;
 457         }
 458
 459         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 460                                            ic->i_send_ring.w_nr *
 461                                                 sizeof(struct rds_header),
 462                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
 463         if (!ic->i_send_hdrs) {
 464                 ret = -ENOMEM;
 465                 rdsdebug("ib_dma_alloc_coherent send failed\n");
 466                 goto out;
 467         }
 468
 469         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 470                                            ic->i_recv_ring.w_nr *
 471                                                 sizeof(struct rds_header),
 472                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
 473         if (!ic->i_recv_hdrs) {
 474                 ret = -ENOMEM;
 475                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
 476                 goto out;
 477         }
 478
 479         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 480                                        &ic->i_ack_dma, GFP_KERNEL);
 481         if (!ic->i_ack) {
 482                 ret = -ENOMEM;
 483                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
 484                 goto out;
 485         }
 486
 487         ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
 488                                    ibdev_to_node(dev));
 489         if (!ic->i_sends) {
 490                 ret = -ENOMEM;
 491                 rdsdebug("send allocation failed\n");
 492                 goto out;
 493         }
 494
 495         ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
 496                                    ibdev_to_node(dev));
 497         if (!ic->i_recvs) {
 498                 ret = -ENOMEM;
 499                 rdsdebug("recv allocation failed\n");
 500                 goto out;
 501         }
 502
 503         rds_ib_recv_init_ack(ic);
 504
 505         rdsdebug("conn %p pd %p cq %p %p\n", conn, ic->i_pd,
 506                  ic->i_send_cq, ic->i_recv_cq);
 507
 508 out:
 509         rds_ib_dev_put(rds_ibdev);
 510         return ret;
 511 }
 512
 513 static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
 514 {
 515         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 516         u16 common;
 517         u32 version = 0;
 518
 519         /*
 520          * rdma_cm private data is odd - when there is any private data in the
 521          * request, we will be given a pretty large buffer without telling us the
 522          * original size. The only way to tell the difference is by looking at
 523          * the contents, which are initialized to zero.
 524          * If the protocol version fields aren't set, this is a connection attempt
 525          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 526          * We really should have changed this for OFED 1.3 :-(
 527          */
 528
 529         /* Be paranoid. RDS always has privdata */
 530         if (!event->param.conn.private_data_len) {
 531                 printk(KERN_NOTICE "RDS incoming connection has no private data, "
 532                         "rejecting\n");
 533                 return 0;
 534         }
 535
 536         /* Even if len is crap *now* I still want to check it. -ASG */
 537         if (event->param.conn.private_data_len < sizeof (*dp) ||
 538             dp->dp_protocol_major == 0)
 539                 return RDS_PROTOCOL_3_0;
 540
 541         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
 542         if (dp->dp_protocol_major == 3 && common) {
 543                 version = RDS_PROTOCOL_3_0;
 544                 while ((common >>= 1) != 0)
 545                         version++;
 546         } else
 547                 printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using incompatible protocol version %u.%u\n",
 548                                 &dp->dp_saddr,
 549                                 dp->dp_protocol_major,
 550                                 dp->dp_protocol_minor);
 551         return version;
 552 }
 553
 554 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 555                                     struct rdma_cm_event *event)
 556 {
 557         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
 558         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
 559         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 560         struct rds_ib_connect_private dp_rep;
 561         struct rds_connection *conn = NULL;
 562         struct rds_ib_connection *ic = NULL;
 563         struct rdma_conn_param conn_param;
 564         u32 version;
 565         int err = 1, destroy = 1;
 566
 567         /* Check whether the remote protocol version matches ours. */
 568         version = rds_ib_protocol_compatible(event);
 569         if (!version)
 570                 goto out;
 571
 572         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
 573                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
 574                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
 575                  (unsigned long long)be64_to_cpu(lguid),
 576                  (unsigned long long)be64_to_cpu(fguid));
 577
 578         /* RDS/IB is not currently netns aware, thus init_net */
 579         conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
 580                                &rds_ib_transport, GFP_KERNEL);
 581         if (IS_ERR(conn)) {
 582                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 583                 conn = NULL;
 584                 goto out;
 585         }
 586
 587         /*
 588          * The connection request may occur while the
 589          * previous connection exist, e.g. in case of failover.
 590          * But as connections may be initiated simultaneously
 591          * by both hosts, we have a random backoff mechanism -
 592          * see the comment above rds_queue_reconnect()
 593          */
 594         mutex_lock(&conn->c_cm_lock);
 595         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 596                 if (rds_conn_state(conn) == RDS_CONN_UP) {
 597                         rdsdebug("incoming connect while connecting\n");
 598                         rds_conn_drop(conn);
 599                         rds_ib_stats_inc(s_ib_listen_closed_stale);
 600                 } else
 601                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 602                         /* Wait and see - our connect may still be succeeding */
 603                         rds_ib_stats_inc(s_ib_connect_raced);
 604                 }
 605                 goto out;
 606         }
 607
 608         ic = conn->c_transport_data;
 609
 610         rds_ib_set_protocol(conn, version);
 611         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 612
 613         /* If the peer gave us the last packet it saw, process this as if
 614          * we had received a regular ACK. */
 615         if (dp->dp_ack_seq)
 616                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 617
 618         BUG_ON(cm_id->context);
 619         BUG_ON(ic->i_cm_id);
 620
 621         ic->i_cm_id = cm_id;
 622         cm_id->context = conn;
 623
 624         /* We got halfway through setting up the ib_connection, if we
 625          * fail now, we have to take the long route out of this mess. */
 626         destroy = 0;
 627
 628         err = rds_ib_setup_qp(conn);
 629         if (err) {
 630                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
 631                 goto out;
 632         }
 633
 634         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
 635                 event->param.conn.responder_resources,
 636                 event->param.conn.initiator_depth);
 637
 638         /* rdma_accept() calls rdma_reject() internally if it fails */
 639         err = rdma_accept(cm_id, &conn_param);
 640         if (err)
 641                 rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
 642
 643 out:
 644         if (conn)
 645                 mutex_unlock(&conn->c_cm_lock);
 646         if (err)
 647                 rdma_reject(cm_id, NULL, 0);
 648         return destroy;
 649 }
 650
 651
 652 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
 653 {
 654         struct rds_connection *conn = cm_id->context;
 655         struct rds_ib_connection *ic = conn->c_transport_data;
 656         struct rdma_conn_param conn_param;
 657         struct rds_ib_connect_private dp;
 658         int ret;
 659
 660         /* If the peer doesn't do protocol negotiation, we must
 661          * default to RDSv3.0 */
 662         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
 663         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
 664
 665         ret = rds_ib_setup_qp(conn);
 666         if (ret) {
 667                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
 668                 goto out;
 669         }
 670
 671         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
 672                 UINT_MAX, UINT_MAX);
 673         ret = rdma_connect(cm_id, &conn_param);
 674         if (ret)
 675                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 676
 677 out:
 678         /* Beware - returning non-zero tells the rdma_cm to destroy
 679          * the cm_id. We should certainly not do it as long as we still
 680          * "own" the cm_id. */
 681         if (ret) {
 682                 if (ic->i_cm_id == cm_id)
 683                         ret = 0;
 684         }
 685         return ret;
 686 }
 687
 688 int rds_ib_conn_path_connect(struct rds_conn_path *cp)
 689 {
 690         struct rds_connection *conn = cp->cp_conn;
 691         struct rds_ib_connection *ic = conn->c_transport_data;
 692         struct sockaddr_in src, dest;
 693         int ret;
 694
 695         /* XXX I wonder what affect the port space has */
 696         /* delegate cm event handler to rdma_transport */
 697         ic->i_cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, conn,
 698                                      RDMA_PS_TCP, IB_QPT_RC);
 699         if (IS_ERR(ic->i_cm_id)) {
 700                 ret = PTR_ERR(ic->i_cm_id);
 701                 ic->i_cm_id = NULL;
 702                 rdsdebug("rdma_create_id() failed: %d\n", ret);
 703                 goto out;
 704         }
 705
 706         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 707
 708         src.sin_family = AF_INET;
 709         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 710         src.sin_port = (__force u16)htons(0);
 711
 712         dest.sin_family = AF_INET;
 713         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 714         dest.sin_port = (__force u16)htons(RDS_PORT);
 715
 716         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 717                                 (struct sockaddr *)&dest,
 718                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
 719         if (ret) {
 720                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 721                          ret);
 722                 rdma_destroy_id(ic->i_cm_id);
 723                 ic->i_cm_id = NULL;
 724         }
 725
 726 out:
 727         return ret;
 728 }
 729
 730 /*
 731  * This is so careful about only cleaning up resources that were built up
 732  * so that it can be called at any point during startup.  In fact it
 733  * can be called multiple times for a given connection.
 734  */
 735 void rds_ib_conn_path_shutdown(struct rds_conn_path *cp)
 736 {
 737         struct rds_connection *conn = cp->cp_conn;
 738         struct rds_ib_connection *ic = conn->c_transport_data;
 739         int err = 0;
 740
 741         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 742                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 743                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 744
 745         if (ic->i_cm_id) {
 746                 struct ib_device *dev = ic->i_cm_id->device;
 747
 748                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 749                 err = rdma_disconnect(ic->i_cm_id);
 750                 if (err) {
 751                         /* Actually this may happen quite frequently, when
 752                          * an outgoing connect raced with an incoming connect.
 753                          */
 754                         rdsdebug("failed to disconnect, cm: %p err %d\n",
 755                                 ic->i_cm_id, err);
 756                 }
 757
 758                 /*
 759                  * We want to wait for tx and rx completion to finish
 760                  * before we tear down the connection, but we have to be
 761                  * careful not to get stuck waiting on a send ring that
 762                  * only has unsignaled sends in it.  We've shutdown new
 763                  * sends before getting here so by waiting for signaled
 764                  * sends to complete we're ensured that there will be no
 765                  * more tx processing.
 766                  */
 767                 wait_event(rds_ib_ring_empty_wait,
 768                            rds_ib_ring_empty(&ic->i_recv_ring) &&
 769                            (atomic_read(&ic->i_signaled_sends) == 0) &&
 770                            (atomic_read(&ic->i_fastreg_wrs) == RDS_IB_DEFAULT_FR_WR));
 771                 tasklet_kill(&ic->i_send_tasklet);
 772                 tasklet_kill(&ic->i_recv_tasklet);
 773
 774                 /* first destroy the ib state that generates callbacks */
 775                 if (ic->i_cm_id->qp)
 776                         rdma_destroy_qp(ic->i_cm_id);
 777                 if (ic->i_send_cq)
 778                         ib_destroy_cq(ic->i_send_cq);
 779                 if (ic->i_recv_cq)
 780                         ib_destroy_cq(ic->i_recv_cq);
 781
 782                 /* then free the resources that ib callbacks use */
 783                 if (ic->i_send_hdrs)
 784                         ib_dma_free_coherent(dev,
 785                                            ic->i_send_ring.w_nr *
 786                                                 sizeof(struct rds_header),
 787                                            ic->i_send_hdrs,
 788                                            ic->i_send_hdrs_dma);
 789
 790                 if (ic->i_recv_hdrs)
 791                         ib_dma_free_coherent(dev,
 792                                            ic->i_recv_ring.w_nr *
 793                                                 sizeof(struct rds_header),
 794                                            ic->i_recv_hdrs,
 795                                            ic->i_recv_hdrs_dma);
 796
 797                 if (ic->i_ack)
 798                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 799                                              ic->i_ack, ic->i_ack_dma);
 800
 801                 if (ic->i_sends)
 802                         rds_ib_send_clear_ring(ic);
 803                 if (ic->i_recvs)
 804                         rds_ib_recv_clear_ring(ic);
 805
 806                 rdma_destroy_id(ic->i_cm_id);
 807
 808                 /*
 809                  * Move connection back to the nodev list.
 810                  */
 811                 if (ic->rds_ibdev)
 812                         rds_ib_remove_conn(ic->rds_ibdev, conn);
 813
 814                 ic->i_cm_id = NULL;
 815                 ic->i_pd = NULL;
 816                 ic->i_send_cq = NULL;
 817                 ic->i_recv_cq = NULL;
 818                 ic->i_send_hdrs = NULL;
 819                 ic->i_recv_hdrs = NULL;
 820                 ic->i_ack = NULL;
 821         }
 822         BUG_ON(ic->rds_ibdev);
 823
 824         /* Clear pending transmit */
 825         if (ic->i_data_op) {
 826                 struct rds_message *rm;
 827
 828                 rm = container_of(ic->i_data_op, struct rds_message, data);
 829                 rds_message_put(rm);
 830                 ic->i_data_op = NULL;
 831         }
 832
 833         /* Clear the ACK state */
 834         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 835 #ifdef KERNEL_HAS_ATOMIC64
 836         atomic64_set(&ic->i_ack_next, 0);
 837 #else
 838         ic->i_ack_next = 0;
 839 #endif
 840         ic->i_ack_recv = 0;
 841
 842         /* Clear flow control state */
 843         ic->i_flowctl = 0;
 844         atomic_set(&ic->i_credits, 0);
 845
 846         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 847         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 848
 849         if (ic->i_ibinc) {
 850                 rds_inc_put(&ic->i_ibinc->ii_inc);
 851                 ic->i_ibinc = NULL;
 852         }
 853
 854         vfree(ic->i_sends);
 855         ic->i_sends = NULL;
 856         vfree(ic->i_recvs);
 857         ic->i_recvs = NULL;
 858 }
 859
 860 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 861 {
 862         struct rds_ib_connection *ic;
 863         unsigned long flags;
 864         int ret;
 865
 866         /* XXX too lazy? */
 867         ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
 868         if (!ic)
 869                 return -ENOMEM;
 870
 871         ret = rds_ib_recv_alloc_caches(ic);
 872         if (ret) {
 873                 kfree(ic);
 874                 return ret;
 875         }
 876
 877         INIT_LIST_HEAD(&ic->ib_node);
 878         tasklet_init(&ic->i_send_tasklet, rds_ib_tasklet_fn_send,
 879                      (unsigned long)ic);
 880         tasklet_init(&ic->i_recv_tasklet, rds_ib_tasklet_fn_recv,
 881                      (unsigned long)ic);
 882         mutex_init(&ic->i_recv_mutex);
 883 #ifndef KERNEL_HAS_ATOMIC64
 884         spin_lock_init(&ic->i_ack_lock);
 885 #endif
 886         atomic_set(&ic->i_signaled_sends, 0);
 887
 888         /*
 889          * rds_ib_conn_shutdown() waits for these to be emptied so they
 890          * must be initialized before it can be called.
 891          */
 892         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 893         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 894
 895         ic->conn = conn;
 896         conn->c_transport_data = ic;
 897
 898         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
 899         list_add_tail(&ic->ib_node, &ib_nodev_conns);
 900         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
 901
 902
 903         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 904         return 0;
 905 }
 906
 907 /*
 908  * Free a connection. Connection must be shut down and not set for reconnect.
 909  */
 910 void rds_ib_conn_free(void *arg)
 911 {
 912         struct rds_ib_connection *ic = arg;
 913         spinlock_t      *lock_ptr;
 914
 915         rdsdebug("ic %p\n", ic);
 916
 917         /*
 918          * Conn is either on a dev's list or on the nodev list.
 919          * A race with shutdown() or connect() would cause problems
 920          * (since rds_ibdev would change) but that should never happen.
 921          */
 922         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
 923
 924         spin_lock_irq(lock_ptr);
 925         list_del(&ic->ib_node);
 926         spin_unlock_irq(lock_ptr);
 927
 928         rds_ib_recv_free_caches(ic);
 929
 930         kfree(ic);
 931 }
 932
 933
 934 /*
 935  * An error occurred on the connection
 936  */
 937 void
 938 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
 939 {
 940         va_list ap;
 941
 942         rds_conn_drop(conn);
 943
 944         va_start(ap, fmt);
 945         vprintk(fmt, ap);
 946         va_end(ap);
 947 }