drivers/infiniband/hw/hfi1/ruc.c

   1 /*
   2  * Copyright(c) 2015 - 2018 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 #include <linux/spinlock.h>
  49
  50 #include "hfi.h"
  51 #include "mad.h"
  52 #include "qp.h"
  53 #include "verbs_txreq.h"
  54 #include "trace.h"
  55
  56 static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
  57 {
  58         return (gid->global.interface_id == id &&
  59                 (gid->global.subnet_prefix == gid_prefix ||
  60                  gid->global.subnet_prefix == IB_DEFAULT_GID_PREFIX));
  61 }
  62
  63 /*
  64  *
  65  * This should be called with the QP r_lock held.
  66  *
  67  * The s_lock will be acquired around the hfi1_migrate_qp() call.
  68  */
  69 int hfi1_ruc_check_hdr(struct hfi1_ibport *ibp, struct hfi1_packet *packet)
  70 {
  71         __be64 guid;
  72         unsigned long flags;
  73         struct rvt_qp *qp = packet->qp;
  74         u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
  75         u32 dlid = packet->dlid;
  76         u32 slid = packet->slid;
  77         u32 sl = packet->sl;
  78         bool migrated = packet->migrated;
  79         u16 pkey = packet->pkey;
  80
  81         if (qp->s_mig_state == IB_MIG_ARMED && migrated) {
  82                 if (!packet->grh) {
  83                         if ((rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
  84                              IB_AH_GRH) &&
  85                             (packet->etype != RHF_RCV_TYPE_BYPASS))
  86                                 return 1;
  87                 } else {
  88                         const struct ib_global_route *grh;
  89
  90                         if (!(rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
  91                               IB_AH_GRH))
  92                                 return 1;
  93                         grh = rdma_ah_read_grh(&qp->alt_ah_attr);
  94                         guid = get_sguid(ibp, grh->sgid_index);
  95                         if (!gid_ok(&packet->grh->dgid, ibp->rvp.gid_prefix,
  96                                     guid))
  97                                 return 1;
  98                         if (!gid_ok(
  99                                 &packet->grh->sgid,
 100                                 grh->dgid.global.subnet_prefix,
 101                                 grh->dgid.global.interface_id))
 102                                 return 1;
 103                 }
 104                 if (unlikely(rcv_pkey_check(ppd_from_ibp(ibp), pkey,
 105                                             sc5, slid))) {
 106                         hfi1_bad_pkey(ibp, pkey, sl, 0, qp->ibqp.qp_num,
 107                                       slid, dlid);
 108                         return 1;
 109                 }
 110                 /* Validate the SLID. See Ch. 9.6.1.5 and 17.2.8 */
 111                 if (slid != rdma_ah_get_dlid(&qp->alt_ah_attr) ||
 112                     ppd_from_ibp(ibp)->port !=
 113                         rdma_ah_get_port_num(&qp->alt_ah_attr))
 114                         return 1;
 115                 spin_lock_irqsave(&qp->s_lock, flags);
 116                 hfi1_migrate_qp(qp);
 117                 spin_unlock_irqrestore(&qp->s_lock, flags);
 118         } else {
 119                 if (!packet->grh) {
 120                         if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
 121                              IB_AH_GRH) &&
 122                             (packet->etype != RHF_RCV_TYPE_BYPASS))
 123                                 return 1;
 124                 } else {
 125                         const struct ib_global_route *grh;
 126
 127                         if (!(rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
 128                                                    IB_AH_GRH))
 129                                 return 1;
 130                         grh = rdma_ah_read_grh(&qp->remote_ah_attr);
 131                         guid = get_sguid(ibp, grh->sgid_index);
 132                         if (!gid_ok(&packet->grh->dgid, ibp->rvp.gid_prefix,
 133                                     guid))
 134                                 return 1;
 135                         if (!gid_ok(
 136                              &packet->grh->sgid,
 137                              grh->dgid.global.subnet_prefix,
 138                              grh->dgid.global.interface_id))
 139                                 return 1;
 140                 }
 141                 if (unlikely(rcv_pkey_check(ppd_from_ibp(ibp), pkey,
 142                                             sc5, slid))) {
 143                         hfi1_bad_pkey(ibp, pkey, sl, 0, qp->ibqp.qp_num,
 144                                       slid, dlid);
 145                         return 1;
 146                 }
 147                 /* Validate the SLID. See Ch. 9.6.1.5 */
 148                 if ((slid != rdma_ah_get_dlid(&qp->remote_ah_attr)) ||
 149                     ppd_from_ibp(ibp)->port != qp->port_num)
 150                         return 1;
 151                 if (qp->s_mig_state == IB_MIG_REARM && !migrated)
 152                         qp->s_mig_state = IB_MIG_ARMED;
 153         }
 154
 155         return 0;
 156 }
 157
 158 /**
 159  * hfi1_make_grh - construct a GRH header
 160  * @ibp: a pointer to the IB port
 161  * @hdr: a pointer to the GRH header being constructed
 162  * @grh: the global route address to send to
 163  * @hwords: size of header after grh being sent in dwords
 164  * @nwords: the number of 32 bit words of data being sent
 165  *
 166  * Return the size of the header in 32 bit words.
 167  */
 168 u32 hfi1_make_grh(struct hfi1_ibport *ibp, struct ib_grh *hdr,
 169                   const struct ib_global_route *grh, u32 hwords, u32 nwords)
 170 {
 171         hdr->version_tclass_flow =
 172                 cpu_to_be32((IB_GRH_VERSION << IB_GRH_VERSION_SHIFT) |
 173                             (grh->traffic_class << IB_GRH_TCLASS_SHIFT) |
 174                             (grh->flow_label << IB_GRH_FLOW_SHIFT));
 175         hdr->paylen = cpu_to_be16((hwords + nwords) << 2);
 176         /* next_hdr is defined by C8-7 in ch. 8.4.1 */
 177         hdr->next_hdr = IB_GRH_NEXT_HDR;
 178         hdr->hop_limit = grh->hop_limit;
 179         /* The SGID is 32-bit aligned. */
 180         hdr->sgid.global.subnet_prefix = ibp->rvp.gid_prefix;
 181         hdr->sgid.global.interface_id =
 182                 grh->sgid_index < HFI1_GUIDS_PER_PORT ?
 183                 get_sguid(ibp, grh->sgid_index) :
 184                 get_sguid(ibp, HFI1_PORT_GUID_INDEX);
 185         hdr->dgid = grh->dgid;
 186
 187         /* GRH header size in 32-bit words. */
 188         return sizeof(struct ib_grh) / sizeof(u32);
 189 }
 190
 191 #define BTH2_OFFSET (offsetof(struct hfi1_sdma_header, \
 192                               hdr.ibh.u.oth.bth[2]) / 4)
 193
 194 /**
 195  * build_ahg - create ahg in s_ahg
 196  * @qp: a pointer to QP
 197  * @npsn: the next PSN for the request/response
 198  *
 199  * This routine handles the AHG by allocating an ahg entry and causing the
 200  * copy of the first middle.
 201  *
 202  * Subsequent middles use the copied entry, editing the
 203  * PSN with 1 or 2 edits.
 204  */
 205 static inline void build_ahg(struct rvt_qp *qp, u32 npsn)
 206 {
 207         struct hfi1_qp_priv *priv = qp->priv;
 208
 209         if (unlikely(qp->s_flags & HFI1_S_AHG_CLEAR))
 210                 clear_ahg(qp);
 211         if (!(qp->s_flags & HFI1_S_AHG_VALID)) {
 212                 /* first middle that needs copy  */
 213                 if (qp->s_ahgidx < 0)
 214                         qp->s_ahgidx = sdma_ahg_alloc(priv->s_sde);
 215                 if (qp->s_ahgidx >= 0) {
 216                         qp->s_ahgpsn = npsn;
 217                         priv->s_ahg->tx_flags |= SDMA_TXREQ_F_AHG_COPY;
 218                         /* save to protect a change in another thread */
 219                         priv->s_ahg->ahgidx = qp->s_ahgidx;
 220                         qp->s_flags |= HFI1_S_AHG_VALID;
 221                 }
 222         } else {
 223                 /* subsequent middle after valid */
 224                 if (qp->s_ahgidx >= 0) {
 225                         priv->s_ahg->tx_flags |= SDMA_TXREQ_F_USE_AHG;
 226                         priv->s_ahg->ahgidx = qp->s_ahgidx;
 227                         priv->s_ahg->ahgcount++;
 228                         priv->s_ahg->ahgdesc[0] =
 229                                 sdma_build_ahg_descriptor(
 230                                         (__force u16)cpu_to_be16((u16)npsn),
 231                                         BTH2_OFFSET,
 232                                         16,
 233                                         16);
 234                         if ((npsn & 0xffff0000) !=
 235                                         (qp->s_ahgpsn & 0xffff0000)) {
 236                                 priv->s_ahg->ahgcount++;
 237                                 priv->s_ahg->ahgdesc[1] =
 238                                         sdma_build_ahg_descriptor(
 239                                                 (__force u16)cpu_to_be16(
 240                                                         (u16)(npsn >> 16)),
 241                                                 BTH2_OFFSET,
 242                                                 0,
 243                                                 16);
 244                         }
 245                 }
 246         }
 247 }
 248
 249 static inline void hfi1_make_ruc_bth(struct rvt_qp *qp,
 250                                      struct ib_other_headers *ohdr,
 251                                      u32 bth0, u32 bth1, u32 bth2)
 252 {
 253         ohdr->bth[0] = cpu_to_be32(bth0);
 254         ohdr->bth[1] = cpu_to_be32(bth1);
 255         ohdr->bth[2] = cpu_to_be32(bth2);
 256 }
 257
 258 /**
 259  * hfi1_make_ruc_header_16B - build a 16B header
 260  * @qp: the queue pair
 261  * @ohdr: a pointer to the destination header memory
 262  * @bth0: bth0 passed in from the RC/UC builder
 263  * @bth2: bth2 passed in from the RC/UC builder
 264  * @middle: non zero implies indicates ahg "could" be used
 265  * @ps: the current packet state
 266  *
 267  * This routine may disarm ahg under these situations:
 268  * - packet needs a GRH
 269  * - BECN needed
 270  * - migration state not IB_MIG_MIGRATED
 271  */
 272 static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp,
 273                                             struct ib_other_headers *ohdr,
 274                                             u32 bth0, u32 bth1, u32 bth2,
 275                                             int middle,
 276                                             struct hfi1_pkt_state *ps)
 277 {
 278         struct hfi1_qp_priv *priv = qp->priv;
 279         struct hfi1_ibport *ibp = ps->ibp;
 280         struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
 281         u32 slid;
 282         u16 pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
 283         u8 l4 = OPA_16B_L4_IB_LOCAL;
 284         u8 extra_bytes = hfi1_get_16b_padding(
 285                                 (ps->s_txreq->hdr_dwords << 2),
 286                                 ps->s_txreq->s_cur_size);
 287         u32 nwords = SIZE_OF_CRC + ((ps->s_txreq->s_cur_size +
 288                                  extra_bytes + SIZE_OF_LT) >> 2);
 289         bool becn = false;
 290
 291         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
 292             hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
 293                 struct ib_grh *grh;
 294                 struct ib_global_route *grd =
 295                         rdma_ah_retrieve_grh(&qp->remote_ah_attr);
 296                 /*
 297                  * Ensure OPA GIDs are transformed to IB gids
 298                  * before creating the GRH.
 299                  */
 300                 if (grd->sgid_index == OPA_GID_INDEX)
 301                         grd->sgid_index = 0;
 302                 grh = &ps->s_txreq->phdr.hdr.opah.u.l.grh;
 303                 l4 = OPA_16B_L4_IB_GLOBAL;
 304                 ps->s_txreq->hdr_dwords +=
 305                         hfi1_make_grh(ibp, grh, grd,
 306                                       ps->s_txreq->hdr_dwords - LRH_16B_DWORDS,
 307                                       nwords);
 308                 middle = 0;
 309         }
 310
 311         if (qp->s_mig_state == IB_MIG_MIGRATED)
 312                 bth1 |= OPA_BTH_MIG_REQ;
 313         else
 314                 middle = 0;
 315
 316         if (qp->s_flags & RVT_S_ECN) {
 317                 qp->s_flags &= ~RVT_S_ECN;
 318                 /* we recently received a FECN, so return a BECN */
 319                 becn = true;
 320                 middle = 0;
 321         }
 322         if (middle)
 323                 build_ahg(qp, bth2);
 324         else
 325                 qp->s_flags &= ~HFI1_S_AHG_VALID;
 326
 327         bth0 |= pkey;
 328         bth0 |= extra_bytes << 20;
 329         hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);
 330
 331         if (!ppd->lid)
 332                 slid = be32_to_cpu(OPA_LID_PERMISSIVE);
 333         else
 334                 slid = ppd->lid |
 335                         (rdma_ah_get_path_bits(&qp->remote_ah_attr) &
 336                         ((1 << ppd->lmc) - 1));
 337
 338         hfi1_make_16b_hdr(&ps->s_txreq->phdr.hdr.opah,
 339                           slid,
 340                           opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
 341                                       16B),
 342                           (ps->s_txreq->hdr_dwords + nwords) >> 1,
 343                           pkey, becn, 0, l4, priv->s_sc);
 344 }
 345
 346 /**
 347  * hfi1_make_ruc_header_9B - build a 9B header
 348  * @qp: the queue pair
 349  * @ohdr: a pointer to the destination header memory
 350  * @bth0: bth0 passed in from the RC/UC builder
 351  * @bth2: bth2 passed in from the RC/UC builder
 352  * @middle: non zero implies indicates ahg "could" be used
 353  * @ps: the current packet state
 354  *
 355  * This routine may disarm ahg under these situations:
 356  * - packet needs a GRH
 357  * - BECN needed
 358  * - migration state not IB_MIG_MIGRATED
 359  */
 360 static inline void hfi1_make_ruc_header_9B(struct rvt_qp *qp,
 361                                            struct ib_other_headers *ohdr,
 362                                            u32 bth0, u32 bth1, u32 bth2,
 363                                            int middle,
 364                                            struct hfi1_pkt_state *ps)
 365 {
 366         struct hfi1_qp_priv *priv = qp->priv;
 367         struct hfi1_ibport *ibp = ps->ibp;
 368         u16 pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
 369         u16 lrh0 = HFI1_LRH_BTH;
 370         u8 extra_bytes = -ps->s_txreq->s_cur_size & 3;
 371         u32 nwords = SIZE_OF_CRC + ((ps->s_txreq->s_cur_size +
 372                                          extra_bytes) >> 2);
 373
 374         if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
 375                 struct ib_grh *grh = &ps->s_txreq->phdr.hdr.ibh.u.l.grh;
 376
 377                 lrh0 = HFI1_LRH_GRH;
 378                 ps->s_txreq->hdr_dwords +=
 379                         hfi1_make_grh(ibp, grh,
 380                                       rdma_ah_read_grh(&qp->remote_ah_attr),
 381                                       ps->s_txreq->hdr_dwords - LRH_9B_DWORDS,
 382                                       nwords);
 383                 middle = 0;
 384         }
 385         lrh0 |= (priv->s_sc & 0xf) << 12 |
 386                 (rdma_ah_get_sl(&qp->remote_ah_attr) & 0xf) << 4;
 387
 388         if (qp->s_mig_state == IB_MIG_MIGRATED)
 389                 bth0 |= IB_BTH_MIG_REQ;
 390         else
 391                 middle = 0;
 392
 393         if (qp->s_flags & RVT_S_ECN) {
 394                 qp->s_flags &= ~RVT_S_ECN;
 395                 /* we recently received a FECN, so return a BECN */
 396                 bth1 |= (IB_BECN_MASK << IB_BECN_SHIFT);
 397                 middle = 0;
 398         }
 399         if (middle)
 400                 build_ahg(qp, bth2);
 401         else
 402                 qp->s_flags &= ~HFI1_S_AHG_VALID;
 403
 404         bth0 |= pkey;
 405         bth0 |= extra_bytes << 20;
 406         hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);
 407         hfi1_make_ib_hdr(&ps->s_txreq->phdr.hdr.ibh,
 408                          lrh0,
 409                          ps->s_txreq->hdr_dwords + nwords,
 410                          opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
 411                          ppd_from_ibp(ibp)->lid |
 412                                 rdma_ah_get_path_bits(&qp->remote_ah_attr));
 413 }
 414
 415 typedef void (*hfi1_make_ruc_hdr)(struct rvt_qp *qp,
 416                                   struct ib_other_headers *ohdr,
 417                                   u32 bth0, u32 bth1, u32 bth2, int middle,
 418                                   struct hfi1_pkt_state *ps);
 419
 420 /* We support only two types - 9B and 16B for now */
 421 static const hfi1_make_ruc_hdr hfi1_ruc_header_tbl[2] = {
 422         [HFI1_PKT_TYPE_9B] = &hfi1_make_ruc_header_9B,
 423         [HFI1_PKT_TYPE_16B] = &hfi1_make_ruc_header_16B
 424 };
 425
 426 void hfi1_make_ruc_header(struct rvt_qp *qp, struct ib_other_headers *ohdr,
 427                           u32 bth0, u32 bth1, u32 bth2, int middle,
 428                           struct hfi1_pkt_state *ps)
 429 {
 430         struct hfi1_qp_priv *priv = qp->priv;
 431
 432         /*
 433          * reset s_ahg/AHG fields
 434          *
 435          * This insures that the ahgentry/ahgcount
 436          * are at a non-AHG default to protect
 437          * build_verbs_tx_desc() from using
 438          * an include ahgidx.
 439          *
 440          * build_ahg() will modify as appropriate
 441          * to use the AHG feature.
 442          */
 443         priv->s_ahg->tx_flags = 0;
 444         priv->s_ahg->ahgcount = 0;
 445         priv->s_ahg->ahgidx = 0;
 446
 447         /* Make the appropriate header */
 448         hfi1_ruc_header_tbl[priv->hdr_type](qp, ohdr, bth0, bth1, bth2, middle,
 449                                             ps);
 450 }
 451
 452 /* when sending, force a reschedule every one of these periods */
 453 #define SEND_RESCHED_TIMEOUT (5 * HZ)  /* 5s in jiffies */
 454
 455 /**
 456  * hfi1_schedule_send_yield - test for a yield required for QP
 457  * send engine
 458  * @timeout: Final time for timeout slice for jiffies
 459  * @qp: a pointer to QP
 460  * @ps: a pointer to a structure with commonly lookup values for
 461  *      the the send engine progress
 462  * @tid - true if it is the tid leg
 463  *
 464  * This routine checks if the time slice for the QP has expired
 465  * for RC QPs, if so an additional work entry is queued. At this
 466  * point, other QPs have an opportunity to be scheduled. It
 467  * returns true if a yield is required, otherwise, false
 468  * is returned.
 469  */
 470 bool hfi1_schedule_send_yield(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 471                               bool tid)
 472 {
 473         ps->pkts_sent = true;
 474
 475         if (unlikely(time_after(jiffies, ps->timeout))) {
 476                 if (!ps->in_thread ||
 477                     workqueue_congested(ps->cpu, ps->ppd->hfi1_wq)) {
 478                         spin_lock_irqsave(&qp->s_lock, ps->flags);
 479                         if (!tid) {
 480                                 qp->s_flags &= ~RVT_S_BUSY;
 481                                 hfi1_schedule_send(qp);
 482                         } else {
 483                                 struct hfi1_qp_priv *priv = qp->priv;
 484
 485                                 if (priv->s_flags &
 486                                     HFI1_S_TID_BUSY_SET) {
 487                                         qp->s_flags &= ~RVT_S_BUSY;
 488                                         priv->s_flags &=
 489                                                 ~(HFI1_S_TID_BUSY_SET |
 490                                                   RVT_S_BUSY);
 491                                 } else {
 492                                         priv->s_flags &= ~RVT_S_BUSY;
 493                                 }
 494                                 hfi1_schedule_tid_send(qp);
 495                         }
 496
 497                         spin_unlock_irqrestore(&qp->s_lock, ps->flags);
 498                         this_cpu_inc(*ps->ppd->dd->send_schedule);
 499                         trace_hfi1_rc_expired_time_slice(qp, true);
 500                         return true;
 501                 }
 502
 503                 cond_resched();
 504                 this_cpu_inc(*ps->ppd->dd->send_schedule);
 505                 ps->timeout = jiffies + ps->timeout_int;
 506         }
 507
 508         trace_hfi1_rc_expired_time_slice(qp, false);
 509         return false;
 510 }
 511
 512 void hfi1_do_send_from_rvt(struct rvt_qp *qp)
 513 {
 514         hfi1_do_send(qp, false);
 515 }
 516
 517 void _hfi1_do_send(struct work_struct *work)
 518 {
 519         struct iowait_work *w = container_of(work, struct iowait_work, iowork);
 520         struct rvt_qp *qp = iowait_to_qp(w->iow);
 521
 522         hfi1_do_send(qp, true);
 523 }
 524
 525 /**
 526  * hfi1_do_send - perform a send on a QP
 527  * @qp: a pointer to the QP
 528  * @in_thread: true if in a workqueue thread
 529  *
 530  * Process entries in the send work queue until credit or queue is
 531  * exhausted.  Only allow one CPU to send a packet per QP.
 532  * Otherwise, two threads could send packets out of order.
 533  */
 534 void hfi1_do_send(struct rvt_qp *qp, bool in_thread)
 535 {
 536         struct hfi1_pkt_state ps;
 537         struct hfi1_qp_priv *priv = qp->priv;
 538         int (*make_req)(struct rvt_qp *qp, struct hfi1_pkt_state *ps);
 539
 540         ps.dev = to_idev(qp->ibqp.device);
 541         ps.ibp = to_iport(qp->ibqp.device, qp->port_num);
 542         ps.ppd = ppd_from_ibp(ps.ibp);
 543         ps.in_thread = in_thread;
 544         ps.wait = iowait_get_ib_work(&priv->s_iowait);
 545
 546         trace_hfi1_rc_do_send(qp, in_thread);
 547
 548         switch (qp->ibqp.qp_type) {
 549         case IB_QPT_RC:
 550                 if (!loopback && ((rdma_ah_get_dlid(&qp->remote_ah_attr) &
 551                                    ~((1 << ps.ppd->lmc) - 1)) ==
 552                                   ps.ppd->lid)) {
 553                         rvt_ruc_loopback(qp);
 554                         return;
 555                 }
 556                 make_req = hfi1_make_rc_req;
 557                 ps.timeout_int = qp->timeout_jiffies;
 558                 break;
 559         case IB_QPT_UC:
 560                 if (!loopback && ((rdma_ah_get_dlid(&qp->remote_ah_attr) &
 561                                    ~((1 << ps.ppd->lmc) - 1)) ==
 562                                   ps.ppd->lid)) {
 563                         rvt_ruc_loopback(qp);
 564                         return;
 565                 }
 566                 make_req = hfi1_make_uc_req;
 567                 ps.timeout_int = SEND_RESCHED_TIMEOUT;
 568                 break;
 569         default:
 570                 make_req = hfi1_make_ud_req;
 571                 ps.timeout_int = SEND_RESCHED_TIMEOUT;
 572         }
 573
 574         spin_lock_irqsave(&qp->s_lock, ps.flags);
 575
 576         /* Return if we are already busy processing a work request. */
 577         if (!hfi1_send_ok(qp)) {
 578                 if (qp->s_flags & HFI1_S_ANY_WAIT_IO)
 579                         iowait_set_flag(&priv->s_iowait, IOWAIT_PENDING_IB);
 580                 spin_unlock_irqrestore(&qp->s_lock, ps.flags);
 581                 return;
 582         }
 583
 584         qp->s_flags |= RVT_S_BUSY;
 585
 586         ps.timeout_int = ps.timeout_int / 8;
 587         ps.timeout = jiffies + ps.timeout_int;
 588         ps.cpu = priv->s_sde ? priv->s_sde->cpu :
 589                         cpumask_first(cpumask_of_node(ps.ppd->dd->node));
 590         ps.pkts_sent = false;
 591
 592         /* insure a pre-built packet is handled  */
 593         ps.s_txreq = get_waiting_verbs_txreq(ps.wait);
 594         do {
 595                 /* Check for a constructed packet to be sent. */
 596                 if (ps.s_txreq) {
 597                         if (priv->s_flags & HFI1_S_TID_BUSY_SET)
 598                                 qp->s_flags |= RVT_S_BUSY;
 599                         spin_unlock_irqrestore(&qp->s_lock, ps.flags);
 600                         /*
 601                          * If the packet cannot be sent now, return and
 602                          * the send engine will be woken up later.
 603                          */
 604                         if (hfi1_verbs_send(qp, &ps))
 605                                 return;
 606
 607                         /* allow other tasks to run */
 608                         if (hfi1_schedule_send_yield(qp, &ps, false))
 609                                 return;
 610
 611                         spin_lock_irqsave(&qp->s_lock, ps.flags);
 612                 }
 613         } while (make_req(qp, &ps));
 614         iowait_starve_clear(ps.pkts_sent, &priv->s_iowait);
 615         spin_unlock_irqrestore(&qp->s_lock, ps.flags);
 616 }