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                 pr_notice("RDS/IB: Connection <%pI4,%pI4> version %u.%u no longer supported\n",
 117                           &conn->c_laddr, &conn->c_faddr,
 118                           RDS_PROTOCOL_MAJOR(conn->c_version),
 119                           RDS_PROTOCOL_MINOR(conn->c_version));
 120                 set_bit(RDS_DESTROY_PENDING, &conn->c_path[0].cp_flags);
 121                 rds_conn_destroy(conn);
 122                 return;
 123         } else {
 124                 pr_notice("RDS/IB: %s conn connected <%pI4,%pI4> version %u.%u%s\n",
 125                           ic->i_active_side ? "Active" : "Passive",
 126                           &conn->c_laddr, &conn->c_faddr,
 127                           RDS_PROTOCOL_MAJOR(conn->c_version),
 128                           RDS_PROTOCOL_MINOR(conn->c_version),
 129                           ic->i_flowctl ? ", flow control" : "");
 130         }
 131
 132         atomic_set(&ic->i_cq_quiesce, 0);
 133
 134         /* Init rings and fill recv. this needs to wait until protocol
 135          * negotiation is complete, since ring layout is different
 136          * from 3.1 to 4.1.
 137          */
 138         rds_ib_send_init_ring(ic);
 139         rds_ib_recv_init_ring(ic);
 140         /* Post receive buffers - as a side effect, this will update
 141          * the posted credit count. */
 142         rds_ib_recv_refill(conn, 1, GFP_KERNEL);
 143
 144         /* Tune RNR behavior */
 145         rds_ib_tune_rnr(ic, &qp_attr);
 146
 147         qp_attr.qp_state = IB_QPS_RTS;
 148         err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 149         if (err)
 150                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
 151
 152         /* update ib_device with this local ipaddr */
 153         err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
 154         if (err)
 155                 printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
 156                         err);
 157
 158         /* If the peer gave us the last packet it saw, process this as if
 159          * we had received a regular ACK. */
 160         if (dp) {
 161                 /* dp structure start is not guaranteed to be 8 bytes aligned.
 162                  * Since dp_ack_seq is 64-bit extended load operations can be
 163                  * used so go through get_unaligned to avoid unaligned errors.
 164                  */
 165                 __be64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
 166
 167                 if (dp_ack_seq)
 168                         rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
 169                                             NULL);
 170         }
 171
 172         rds_connect_complete(conn);
 173 }
 174
 175 static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
 176                         struct rdma_conn_param *conn_param,
 177                         struct rds_ib_connect_private *dp,
 178                         u32 protocol_version,
 179                         u32 max_responder_resources,
 180                         u32 max_initiator_depth)
 181 {
 182         struct rds_ib_connection *ic = conn->c_transport_data;
 183         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 184
 185         memset(conn_param, 0, sizeof(struct rdma_conn_param));
 186
 187         conn_param->responder_resources =
 188                 min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
 189         conn_param->initiator_depth =
 190                 min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
 191         conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
 192         conn_param->rnr_retry_count = 7;
 193
 194         if (dp) {
 195                 memset(dp, 0, sizeof(*dp));
 196                 dp->dp_saddr = conn->c_laddr;
 197                 dp->dp_daddr = conn->c_faddr;
 198                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 199                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 200                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
 201                 dp->dp_ack_seq = cpu_to_be64(rds_ib_piggyb_ack(ic));
 202
 203                 /* Advertise flow control */
 204                 if (ic->i_flowctl) {
 205                         unsigned int credits;
 206
 207                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 208                         dp->dp_credit = cpu_to_be32(credits);
 209                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 210                 }
 211
 212                 conn_param->private_data = dp;
 213                 conn_param->private_data_len = sizeof(*dp);
 214         }
 215 }
 216
 217 static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
 218 {
 219         rdsdebug("event %u (%s) data %p\n",
 220                  event->event, ib_event_msg(event->event), data);
 221 }
 222
 223 /* Plucking the oldest entry from the ring can be done concurrently with
 224  * the thread refilling the ring.  Each ring operation is protected by
 225  * spinlocks and the transient state of refilling doesn't change the
 226  * recording of which entry is oldest.
 227  *
 228  * This relies on IB only calling one cq comp_handler for each cq so that
 229  * there will only be one caller of rds_recv_incoming() per RDS connection.
 230  */
 231 static void rds_ib_cq_comp_handler_recv(struct ib_cq *cq, void *context)
 232 {
 233         struct rds_connection *conn = context;
 234         struct rds_ib_connection *ic = conn->c_transport_data;
 235
 236         rdsdebug("conn %p cq %p\n", conn, cq);
 237
 238         rds_ib_stats_inc(s_ib_evt_handler_call);
 239
 240         tasklet_schedule(&ic->i_recv_tasklet);
 241 }
 242
 243 static void poll_scq(struct rds_ib_connection *ic, struct ib_cq *cq,
 244                      struct ib_wc *wcs)
 245 {
 246         int nr, i;
 247         struct ib_wc *wc;
 248
 249         while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
 250                 for (i = 0; i < nr; i++) {
 251                         wc = wcs + i;
 252                         rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
 253                                  (unsigned long long)wc->wr_id, wc->status,
 254                                  wc->byte_len, be32_to_cpu(wc->ex.imm_data));
 255
 256                         if (wc->wr_id <= ic->i_send_ring.w_nr ||
 257                             wc->wr_id == RDS_IB_ACK_WR_ID)
 258                                 rds_ib_send_cqe_handler(ic, wc);
 259                         else
 260                                 rds_ib_mr_cqe_handler(ic, wc);
 261
 262                 }
 263         }
 264 }
 265
 266 static void rds_ib_tasklet_fn_send(unsigned long data)
 267 {
 268         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 269         struct rds_connection *conn = ic->conn;
 270
 271         rds_ib_stats_inc(s_ib_tasklet_call);
 272
 273         /* if cq has been already reaped, ignore incoming cq event */
 274         if (atomic_read(&ic->i_cq_quiesce))
 275                 return;
 276
 277         poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
 278         ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 279         poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
 280
 281         if (rds_conn_up(conn) &&
 282             (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
 283             test_bit(0, &conn->c_map_queued)))
 284                 rds_send_xmit(&ic->conn->c_path[0]);
 285 }
 286
 287 static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,
 288                      struct ib_wc *wcs,
 289                      struct rds_ib_ack_state *ack_state)
 290 {
 291         int nr, i;
 292         struct ib_wc *wc;
 293
 294         while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
 295                 for (i = 0; i < nr; i++) {
 296                         wc = wcs + i;
 297                         rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
 298                                  (unsigned long long)wc->wr_id, wc->status,
 299                                  wc->byte_len, be32_to_cpu(wc->ex.imm_data));
 300
 301                         rds_ib_recv_cqe_handler(ic, wc, ack_state);
 302                 }
 303         }
 304 }
 305
 306 static void rds_ib_tasklet_fn_recv(unsigned long data)
 307 {
 308         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 309         struct rds_connection *conn = ic->conn;
 310         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 311         struct rds_ib_ack_state state;
 312
 313         if (!rds_ibdev)
 314                 rds_conn_drop(conn);
 315
 316         rds_ib_stats_inc(s_ib_tasklet_call);
 317
 318         /* if cq has been already reaped, ignore incoming cq event */
 319         if (atomic_read(&ic->i_cq_quiesce))
 320                 return;
 321
 322         memset(&state, 0, sizeof(state));
 323         poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 324         ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 325         poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 326
 327         if (state.ack_next_valid)
 328                 rds_ib_set_ack(ic, state.ack_next, state.ack_required);
 329         if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
 330                 rds_send_drop_acked(conn, state.ack_recv, NULL);
 331                 ic->i_ack_recv = state.ack_recv;
 332         }
 333
 334         if (rds_conn_up(conn))
 335                 rds_ib_attempt_ack(ic);
 336 }
 337
 338 static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
 339 {
 340         struct rds_connection *conn = data;
 341         struct rds_ib_connection *ic = conn->c_transport_data;
 342
 343         rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
 344                  ib_event_msg(event->event));
 345
 346         switch (event->event) {
 347         case IB_EVENT_COMM_EST:
 348                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 349                 break;
 350         default:
 351                 rdsdebug("Fatal QP Event %u (%s) "
 352                         "- connection %pI4->%pI4, reconnecting\n",
 353                         event->event, ib_event_msg(event->event),
 354                         &conn->c_laddr, &conn->c_faddr);
 355                 rds_conn_drop(conn);
 356                 break;
 357         }
 358 }
 359
 360 static void rds_ib_cq_comp_handler_send(struct ib_cq *cq, void *context)
 361 {
 362         struct rds_connection *conn = context;
 363         struct rds_ib_connection *ic = conn->c_transport_data;
 364
 365         rdsdebug("conn %p cq %p\n", conn, cq);
 366
 367         rds_ib_stats_inc(s_ib_evt_handler_call);
 368
 369         tasklet_schedule(&ic->i_send_tasklet);
 370 }
 371
 372 static inline int ibdev_get_unused_vector(struct rds_ib_device *rds_ibdev)
 373 {
 374         int min = rds_ibdev->vector_load[rds_ibdev->dev->num_comp_vectors - 1];
 375         int index = rds_ibdev->dev->num_comp_vectors - 1;
 376         int i;
 377
 378         for (i = rds_ibdev->dev->num_comp_vectors - 1; i >= 0; i--) {
 379                 if (rds_ibdev->vector_load[i] < min) {
 380                         index = i;
 381                         min = rds_ibdev->vector_load[i];
 382                 }
 383         }
 384
 385         rds_ibdev->vector_load[index]++;
 386         return index;
 387 }
 388
 389 static inline void ibdev_put_vector(struct rds_ib_device *rds_ibdev, int index)
 390 {
 391         rds_ibdev->vector_load[index]--;
 392 }
 393
 394 /*
 395  * This needs to be very careful to not leave IS_ERR pointers around for
 396  * cleanup to trip over.
 397  */
 398 static int rds_ib_setup_qp(struct rds_connection *conn)
 399 {
 400         struct rds_ib_connection *ic = conn->c_transport_data;
 401         struct ib_device *dev = ic->i_cm_id->device;
 402         struct ib_qp_init_attr attr;
 403         struct ib_cq_init_attr cq_attr = {};
 404         struct rds_ib_device *rds_ibdev;
 405         int ret, fr_queue_space;
 406
 407         /*
 408          * It's normal to see a null device if an incoming connection races
 409          * with device removal, so we don't print a warning.
 410          */
 411         rds_ibdev = rds_ib_get_client_data(dev);
 412         if (!rds_ibdev)
 413                 return -EOPNOTSUPP;
 414
 415         /* The fr_queue_space is currently set to 512, to add extra space on
 416          * completion queue and send queue. This extra space is used for FRMR
 417          * registration and invalidation work requests
 418          */
 419         fr_queue_space = rds_ibdev->use_fastreg ?
 420                          (RDS_IB_DEFAULT_FR_WR + 1) +
 421                          (RDS_IB_DEFAULT_FR_INV_WR + 1)
 422                          : 0;
 423
 424         /* add the conn now so that connection establishment has the dev */
 425         rds_ib_add_conn(rds_ibdev, conn);
 426
 427         if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
 428                 rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
 429         if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
 430                 rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
 431
 432         /* Protection domain and memory range */
 433         ic->i_pd = rds_ibdev->pd;
 434
 435         ic->i_scq_vector = ibdev_get_unused_vector(rds_ibdev);
 436         cq_attr.cqe = ic->i_send_ring.w_nr + fr_queue_space + 1;
 437         cq_attr.comp_vector = ic->i_scq_vector;
 438         ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
 439                                      rds_ib_cq_event_handler, conn,
 440                                      &cq_attr);
 441         if (IS_ERR(ic->i_send_cq)) {
 442                 ret = PTR_ERR(ic->i_send_cq);
 443                 ic->i_send_cq = NULL;
 444                 ibdev_put_vector(rds_ibdev, ic->i_scq_vector);
 445                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 446                 goto rds_ibdev_out;
 447         }
 448
 449         ic->i_rcq_vector = ibdev_get_unused_vector(rds_ibdev);
 450         cq_attr.cqe = ic->i_recv_ring.w_nr;
 451         cq_attr.comp_vector = ic->i_rcq_vector;
 452         ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
 453                                      rds_ib_cq_event_handler, conn,
 454                                      &cq_attr);
 455         if (IS_ERR(ic->i_recv_cq)) {
 456                 ret = PTR_ERR(ic->i_recv_cq);
 457                 ic->i_recv_cq = NULL;
 458                 ibdev_put_vector(rds_ibdev, ic->i_rcq_vector);
 459                 rdsdebug("ib_create_cq recv failed: %d\n", ret);
 460                 goto send_cq_out;
 461         }
 462
 463         ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 464         if (ret) {
 465                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 466                 goto recv_cq_out;
 467         }
 468
 469         ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 470         if (ret) {
 471                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 472                 goto recv_cq_out;
 473         }
 474
 475         /* XXX negotiate max send/recv with remote? */
 476         memset(&attr, 0, sizeof(attr));
 477         attr.event_handler = rds_ib_qp_event_handler;
 478         attr.qp_context = conn;
 479         /* + 1 to allow for the single ack message */
 480         attr.cap.max_send_wr = ic->i_send_ring.w_nr + fr_queue_space + 1;
 481         attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
 482         attr.cap.max_send_sge = rds_ibdev->max_sge;
 483         attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
 484         attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 485         attr.qp_type = IB_QPT_RC;
 486         attr.send_cq = ic->i_send_cq;
 487         attr.recv_cq = ic->i_recv_cq;
 488         atomic_set(&ic->i_fastreg_wrs, RDS_IB_DEFAULT_FR_WR);
 489         atomic_set(&ic->i_fastunreg_wrs, RDS_IB_DEFAULT_FR_INV_WR);
 490
 491         /*
 492          * XXX this can fail if max_*_wr is too large?  Are we supposed
 493          * to back off until we get a value that the hardware can support?
 494          */
 495         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 496         if (ret) {
 497                 rdsdebug("rdma_create_qp failed: %d\n", ret);
 498                 goto recv_cq_out;
 499         }
 500
 501         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 502                                            ic->i_send_ring.w_nr *
 503                                                 sizeof(struct rds_header),
 504                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
 505         if (!ic->i_send_hdrs) {
 506                 ret = -ENOMEM;
 507                 rdsdebug("ib_dma_alloc_coherent send failed\n");
 508                 goto qp_out;
 509         }
 510
 511         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 512                                            ic->i_recv_ring.w_nr *
 513                                                 sizeof(struct rds_header),
 514                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
 515         if (!ic->i_recv_hdrs) {
 516                 ret = -ENOMEM;
 517                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
 518                 goto send_hdrs_dma_out;
 519         }
 520
 521         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 522                                        &ic->i_ack_dma, GFP_KERNEL);
 523         if (!ic->i_ack) {
 524                 ret = -ENOMEM;
 525                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
 526                 goto recv_hdrs_dma_out;
 527         }
 528
 529         ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
 530                                    ibdev_to_node(dev));
 531         if (!ic->i_sends) {
 532                 ret = -ENOMEM;
 533                 rdsdebug("send allocation failed\n");
 534                 goto ack_dma_out;
 535         }
 536
 537         ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
 538                                    ibdev_to_node(dev));
 539         if (!ic->i_recvs) {
 540                 ret = -ENOMEM;
 541                 rdsdebug("recv allocation failed\n");
 542                 goto sends_out;
 543         }
 544
 545         rds_ib_recv_init_ack(ic);
 546
 547         rdsdebug("conn %p pd %p cq %p %p\n", conn, ic->i_pd,
 548                  ic->i_send_cq, ic->i_recv_cq);
 549
 550         return ret;
 551
 552 sends_out:
 553         vfree(ic->i_sends);
 554 ack_dma_out:
 555         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 556                              ic->i_ack, ic->i_ack_dma);
 557 recv_hdrs_dma_out:
 558         ib_dma_free_coherent(dev, ic->i_recv_ring.w_nr *
 559                                         sizeof(struct rds_header),
 560                                         ic->i_recv_hdrs, ic->i_recv_hdrs_dma);
 561 send_hdrs_dma_out:
 562         ib_dma_free_coherent(dev, ic->i_send_ring.w_nr *
 563                                         sizeof(struct rds_header),
 564                                         ic->i_send_hdrs, ic->i_send_hdrs_dma);
 565 qp_out:
 566         rdma_destroy_qp(ic->i_cm_id);
 567 recv_cq_out:
 568         if (!ib_destroy_cq(ic->i_recv_cq))
 569                 ic->i_recv_cq = NULL;
 570 send_cq_out:
 571         if (!ib_destroy_cq(ic->i_send_cq))
 572                 ic->i_send_cq = NULL;
 573 rds_ibdev_out:
 574         rds_ib_remove_conn(rds_ibdev, conn);
 575         rds_ib_dev_put(rds_ibdev);
 576
 577         return ret;
 578 }
 579
 580 static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
 581 {
 582         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 583         u16 common;
 584         u32 version = 0;
 585
 586         /*
 587          * rdma_cm private data is odd - when there is any private data in the
 588          * request, we will be given a pretty large buffer without telling us the
 589          * original size. The only way to tell the difference is by looking at
 590          * the contents, which are initialized to zero.
 591          * If the protocol version fields aren't set, this is a connection attempt
 592          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 593          * We really should have changed this for OFED 1.3 :-(
 594          */
 595
 596         /* Be paranoid. RDS always has privdata */
 597         if (!event->param.conn.private_data_len) {
 598                 printk(KERN_NOTICE "RDS incoming connection has no private data, "
 599                         "rejecting\n");
 600                 return 0;
 601         }
 602
 603         /* Even if len is crap *now* I still want to check it. -ASG */
 604         if (event->param.conn.private_data_len < sizeof (*dp) ||
 605             dp->dp_protocol_major == 0)
 606                 return RDS_PROTOCOL_3_0;
 607
 608         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
 609         if (dp->dp_protocol_major == 3 && common) {
 610                 version = RDS_PROTOCOL_3_0;
 611                 while ((common >>= 1) != 0)
 612                         version++;
 613         } else
 614                 printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using incompatible protocol version %u.%u\n",
 615                                 &dp->dp_saddr,
 616                                 dp->dp_protocol_major,
 617                                 dp->dp_protocol_minor);
 618         return version;
 619 }
 620
 621 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 622                                     struct rdma_cm_event *event)
 623 {
 624         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
 625         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
 626         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 627         struct rds_ib_connect_private dp_rep;
 628         struct rds_connection *conn = NULL;
 629         struct rds_ib_connection *ic = NULL;
 630         struct rdma_conn_param conn_param;
 631         u32 version;
 632         int err = 1, destroy = 1;
 633
 634         /* Check whether the remote protocol version matches ours. */
 635         version = rds_ib_protocol_compatible(event);
 636         if (!version)
 637                 goto out;
 638
 639         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
 640                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
 641                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
 642                  (unsigned long long)be64_to_cpu(lguid),
 643                  (unsigned long long)be64_to_cpu(fguid));
 644
 645         /* RDS/IB is not currently netns aware, thus init_net */
 646         conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
 647                                &rds_ib_transport, GFP_KERNEL);
 648         if (IS_ERR(conn)) {
 649                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 650                 conn = NULL;
 651                 goto out;
 652         }
 653
 654         /*
 655          * The connection request may occur while the
 656          * previous connection exist, e.g. in case of failover.
 657          * But as connections may be initiated simultaneously
 658          * by both hosts, we have a random backoff mechanism -
 659          * see the comment above rds_queue_reconnect()
 660          */
 661         mutex_lock(&conn->c_cm_lock);
 662         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 663                 if (rds_conn_state(conn) == RDS_CONN_UP) {
 664                         rdsdebug("incoming connect while connecting\n");
 665                         rds_conn_drop(conn);
 666                         rds_ib_stats_inc(s_ib_listen_closed_stale);
 667                 } else
 668                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 669                         /* Wait and see - our connect may still be succeeding */
 670                         rds_ib_stats_inc(s_ib_connect_raced);
 671                 }
 672                 goto out;
 673         }
 674
 675         ic = conn->c_transport_data;
 676
 677         rds_ib_set_protocol(conn, version);
 678         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 679
 680         /* If the peer gave us the last packet it saw, process this as if
 681          * we had received a regular ACK. */
 682         if (dp->dp_ack_seq)
 683                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 684
 685         BUG_ON(cm_id->context);
 686         BUG_ON(ic->i_cm_id);
 687
 688         ic->i_cm_id = cm_id;
 689         cm_id->context = conn;
 690
 691         /* We got halfway through setting up the ib_connection, if we
 692          * fail now, we have to take the long route out of this mess. */
 693         destroy = 0;
 694
 695         err = rds_ib_setup_qp(conn);
 696         if (err) {
 697                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
 698                 goto out;
 699         }
 700
 701         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
 702                 event->param.conn.responder_resources,
 703                 event->param.conn.initiator_depth);
 704
 705         /* rdma_accept() calls rdma_reject() internally if it fails */
 706         if (rdma_accept(cm_id, &conn_param))
 707                 rds_ib_conn_error(conn, "rdma_accept failed\n");
 708
 709 out:
 710         if (conn)
 711                 mutex_unlock(&conn->c_cm_lock);
 712         if (err)
 713                 rdma_reject(cm_id, NULL, 0);
 714         return destroy;
 715 }
 716
 717
 718 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
 719 {
 720         struct rds_connection *conn = cm_id->context;
 721         struct rds_ib_connection *ic = conn->c_transport_data;
 722         struct rdma_conn_param conn_param;
 723         struct rds_ib_connect_private dp;
 724         int ret;
 725
 726         /* If the peer doesn't do protocol negotiation, we must
 727          * default to RDSv3.0 */
 728         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
 729         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
 730
 731         ret = rds_ib_setup_qp(conn);
 732         if (ret) {
 733                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
 734                 goto out;
 735         }
 736
 737         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
 738                 UINT_MAX, UINT_MAX);
 739         ret = rdma_connect(cm_id, &conn_param);
 740         if (ret)
 741                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 742
 743 out:
 744         /* Beware - returning non-zero tells the rdma_cm to destroy
 745          * the cm_id. We should certainly not do it as long as we still
 746          * "own" the cm_id. */
 747         if (ret) {
 748                 if (ic->i_cm_id == cm_id)
 749                         ret = 0;
 750         }
 751         ic->i_active_side = true;
 752         return ret;
 753 }
 754
 755 int rds_ib_conn_path_connect(struct rds_conn_path *cp)
 756 {
 757         struct rds_connection *conn = cp->cp_conn;
 758         struct rds_ib_connection *ic = conn->c_transport_data;
 759         struct sockaddr_in src, dest;
 760         int ret;
 761
 762         /* XXX I wonder what affect the port space has */
 763         /* delegate cm event handler to rdma_transport */
 764         ic->i_cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, conn,
 765                                      RDMA_PS_TCP, IB_QPT_RC);
 766         if (IS_ERR(ic->i_cm_id)) {
 767                 ret = PTR_ERR(ic->i_cm_id);
 768                 ic->i_cm_id = NULL;
 769                 rdsdebug("rdma_create_id() failed: %d\n", ret);
 770                 goto out;
 771         }
 772
 773         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 774
 775         src.sin_family = AF_INET;
 776         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 777         src.sin_port = (__force u16)htons(0);
 778
 779         dest.sin_family = AF_INET;
 780         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 781         dest.sin_port = (__force u16)htons(RDS_PORT);
 782
 783         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 784                                 (struct sockaddr *)&dest,
 785                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
 786         if (ret) {
 787                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 788                          ret);
 789                 rdma_destroy_id(ic->i_cm_id);
 790                 ic->i_cm_id = NULL;
 791         }
 792
 793 out:
 794         return ret;
 795 }
 796
 797 /*
 798  * This is so careful about only cleaning up resources that were built up
 799  * so that it can be called at any point during startup.  In fact it
 800  * can be called multiple times for a given connection.
 801  */
 802 void rds_ib_conn_path_shutdown(struct rds_conn_path *cp)
 803 {
 804         struct rds_connection *conn = cp->cp_conn;
 805         struct rds_ib_connection *ic = conn->c_transport_data;
 806         int err = 0;
 807
 808         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 809                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 810                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 811
 812         if (ic->i_cm_id) {
 813                 struct ib_device *dev = ic->i_cm_id->device;
 814
 815                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 816                 err = rdma_disconnect(ic->i_cm_id);
 817                 if (err) {
 818                         /* Actually this may happen quite frequently, when
 819                          * an outgoing connect raced with an incoming connect.
 820                          */
 821                         rdsdebug("failed to disconnect, cm: %p err %d\n",
 822                                 ic->i_cm_id, err);
 823                 }
 824
 825                 /*
 826                  * We want to wait for tx and rx completion to finish
 827                  * before we tear down the connection, but we have to be
 828                  * careful not to get stuck waiting on a send ring that
 829                  * only has unsignaled sends in it.  We've shutdown new
 830                  * sends before getting here so by waiting for signaled
 831                  * sends to complete we're ensured that there will be no
 832                  * more tx processing.
 833                  */
 834                 wait_event(rds_ib_ring_empty_wait,
 835                            rds_ib_ring_empty(&ic->i_recv_ring) &&
 836                            (atomic_read(&ic->i_signaled_sends) == 0) &&
 837                            (atomic_read(&ic->i_fastreg_wrs) == RDS_IB_DEFAULT_FR_WR) &&
 838                            (atomic_read(&ic->i_fastunreg_wrs) == RDS_IB_DEFAULT_FR_INV_WR));
 839                 tasklet_kill(&ic->i_send_tasklet);
 840                 tasklet_kill(&ic->i_recv_tasklet);
 841
 842                 atomic_set(&ic->i_cq_quiesce, 1);
 843
 844                 /* first destroy the ib state that generates callbacks */
 845                 if (ic->i_cm_id->qp)
 846                         rdma_destroy_qp(ic->i_cm_id);
 847                 if (ic->i_send_cq) {
 848                         if (ic->rds_ibdev)
 849                                 ibdev_put_vector(ic->rds_ibdev, ic->i_scq_vector);
 850                         ib_destroy_cq(ic->i_send_cq);
 851                 }
 852
 853                 if (ic->i_recv_cq) {
 854                         if (ic->rds_ibdev)
 855                                 ibdev_put_vector(ic->rds_ibdev, ic->i_rcq_vector);
 856                         ib_destroy_cq(ic->i_recv_cq);
 857                 }
 858
 859                 /* then free the resources that ib callbacks use */
 860                 if (ic->i_send_hdrs)
 861                         ib_dma_free_coherent(dev,
 862                                            ic->i_send_ring.w_nr *
 863                                                 sizeof(struct rds_header),
 864                                            ic->i_send_hdrs,
 865                                            ic->i_send_hdrs_dma);
 866
 867                 if (ic->i_recv_hdrs)
 868                         ib_dma_free_coherent(dev,
 869                                            ic->i_recv_ring.w_nr *
 870                                                 sizeof(struct rds_header),
 871                                            ic->i_recv_hdrs,
 872                                            ic->i_recv_hdrs_dma);
 873
 874                 if (ic->i_ack)
 875                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 876                                              ic->i_ack, ic->i_ack_dma);
 877
 878                 if (ic->i_sends)
 879                         rds_ib_send_clear_ring(ic);
 880                 if (ic->i_recvs)
 881                         rds_ib_recv_clear_ring(ic);
 882
 883                 rdma_destroy_id(ic->i_cm_id);
 884
 885                 /*
 886                  * Move connection back to the nodev list.
 887                  */
 888                 if (ic->rds_ibdev)
 889                         rds_ib_remove_conn(ic->rds_ibdev, conn);
 890
 891                 ic->i_cm_id = NULL;
 892                 ic->i_pd = NULL;
 893                 ic->i_send_cq = NULL;
 894                 ic->i_recv_cq = NULL;
 895                 ic->i_send_hdrs = NULL;
 896                 ic->i_recv_hdrs = NULL;
 897                 ic->i_ack = NULL;
 898         }
 899         BUG_ON(ic->rds_ibdev);
 900
 901         /* Clear pending transmit */
 902         if (ic->i_data_op) {
 903                 struct rds_message *rm;
 904
 905                 rm = container_of(ic->i_data_op, struct rds_message, data);
 906                 rds_message_put(rm);
 907                 ic->i_data_op = NULL;
 908         }
 909
 910         /* Clear the ACK state */
 911         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 912 #ifdef KERNEL_HAS_ATOMIC64
 913         atomic64_set(&ic->i_ack_next, 0);
 914 #else
 915         ic->i_ack_next = 0;
 916 #endif
 917         ic->i_ack_recv = 0;
 918
 919         /* Clear flow control state */
 920         ic->i_flowctl = 0;
 921         atomic_set(&ic->i_credits, 0);
 922
 923         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 924         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 925
 926         if (ic->i_ibinc) {
 927                 rds_inc_put(&ic->i_ibinc->ii_inc);
 928                 ic->i_ibinc = NULL;
 929         }
 930
 931         vfree(ic->i_sends);
 932         ic->i_sends = NULL;
 933         vfree(ic->i_recvs);
 934         ic->i_recvs = NULL;
 935         ic->i_active_side = false;
 936 }
 937
 938 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 939 {
 940         struct rds_ib_connection *ic;
 941         unsigned long flags;
 942         int ret;
 943
 944         /* XXX too lazy? */
 945         ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
 946         if (!ic)
 947                 return -ENOMEM;
 948
 949         ret = rds_ib_recv_alloc_caches(ic);
 950         if (ret) {
 951                 kfree(ic);
 952                 return ret;
 953         }
 954
 955         INIT_LIST_HEAD(&ic->ib_node);
 956         tasklet_init(&ic->i_send_tasklet, rds_ib_tasklet_fn_send,
 957                      (unsigned long)ic);
 958         tasklet_init(&ic->i_recv_tasklet, rds_ib_tasklet_fn_recv,
 959                      (unsigned long)ic);
 960         mutex_init(&ic->i_recv_mutex);
 961 #ifndef KERNEL_HAS_ATOMIC64
 962         spin_lock_init(&ic->i_ack_lock);
 963 #endif
 964         atomic_set(&ic->i_signaled_sends, 0);
 965
 966         /*
 967          * rds_ib_conn_shutdown() waits for these to be emptied so they
 968          * must be initialized before it can be called.
 969          */
 970         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 971         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 972
 973         ic->conn = conn;
 974         conn->c_transport_data = ic;
 975
 976         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
 977         list_add_tail(&ic->ib_node, &ib_nodev_conns);
 978         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
 979
 980
 981         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 982         return 0;
 983 }
 984
 985 /*
 986  * Free a connection. Connection must be shut down and not set for reconnect.
 987  */
 988 void rds_ib_conn_free(void *arg)
 989 {
 990         struct rds_ib_connection *ic = arg;
 991         spinlock_t      *lock_ptr;
 992
 993         rdsdebug("ic %p\n", ic);
 994
 995         /*
 996          * Conn is either on a dev's list or on the nodev list.
 997          * A race with shutdown() or connect() would cause problems
 998          * (since rds_ibdev would change) but that should never happen.
 999          */
1000         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
1001
1002         spin_lock_irq(lock_ptr);
1003         list_del(&ic->ib_node);
1004         spin_unlock_irq(lock_ptr);
1005
1006         rds_ib_recv_free_caches(ic);
1007
1008         kfree(ic);
1009 }
1010
1011
1012 /*
1013  * An error occurred on the connection
1014  */
1015 void
1016 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
1017 {
1018         va_list ap;
1019
1020         rds_conn_drop(conn);
1021
1022         va_start(ap, fmt);
1023         vprintk(fmt, ap);
1024         va_end(ap);
1025 }