drivers/infiniband/hw/qib/qib_ruc.c

   1 /*
   2  * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
   3  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <linux/spinlock.h>
  35
  36 #include "qib.h"
  37 #include "qib_mad.h"
  38
  39 /*
  40  * Convert the AETH RNR timeout code into the number of microseconds.
  41  */
  42 const u32 ib_qib_rnr_table[32] = {
  43         655360, /* 00: 655.36 */
  44         10,     /* 01:    .01 */
  45         20,     /* 02     .02 */
  46         30,     /* 03:    .03 */
  47         40,     /* 04:    .04 */
  48         60,     /* 05:    .06 */
  49         80,     /* 06:    .08 */
  50         120,    /* 07:    .12 */
  51         160,    /* 08:    .16 */
  52         240,    /* 09:    .24 */
  53         320,    /* 0A:    .32 */
  54         480,    /* 0B:    .48 */
  55         640,    /* 0C:    .64 */
  56         960,    /* 0D:    .96 */
  57         1280,   /* 0E:   1.28 */
  58         1920,   /* 0F:   1.92 */
  59         2560,   /* 10:   2.56 */
  60         3840,   /* 11:   3.84 */
  61         5120,   /* 12:   5.12 */
  62         7680,   /* 13:   7.68 */
  63         10240,  /* 14:  10.24 */
  64         15360,  /* 15:  15.36 */
  65         20480,  /* 16:  20.48 */
  66         30720,  /* 17:  30.72 */
  67         40960,  /* 18:  40.96 */
  68         61440,  /* 19:  61.44 */
  69         81920,  /* 1A:  81.92 */
  70         122880, /* 1B: 122.88 */
  71         163840, /* 1C: 163.84 */
  72         245760, /* 1D: 245.76 */
  73         327680, /* 1E: 327.68 */
  74         491520  /* 1F: 491.52 */
  75 };
  76
  77 /*
  78  * Validate a RWQE and fill in the SGE state.
  79  * Return 1 if OK.
  80  */
  81 static int qib_init_sge(struct qib_qp *qp, struct qib_rwqe *wqe)
  82 {
  83         int i, j, ret;
  84         struct ib_wc wc;
  85         struct qib_lkey_table *rkt;
  86         struct qib_pd *pd;
  87         struct qib_sge_state *ss;
  88
  89         rkt = &to_idev(qp->ibqp.device)->lk_table;
  90         pd = to_ipd(qp->ibqp.srq ? qp->ibqp.srq->pd : qp->ibqp.pd);
  91         ss = &qp->r_sge;
  92         ss->sg_list = qp->r_sg_list;
  93         qp->r_len = 0;
  94         for (i = j = 0; i < wqe->num_sge; i++) {
  95                 if (wqe->sg_list[i].length == 0)
  96                         continue;
  97                 /* Check LKEY */
  98                 if (!qib_lkey_ok(rkt, pd, j ? &ss->sg_list[j - 1] : &ss->sge,
  99                                  &wqe->sg_list[i], IB_ACCESS_LOCAL_WRITE))
 100                         goto bad_lkey;
 101                 qp->r_len += wqe->sg_list[i].length;
 102                 j++;
 103         }
 104         ss->num_sge = j;
 105         ss->total_len = qp->r_len;
 106         ret = 1;
 107         goto bail;
 108
 109 bad_lkey:
 110         while (j) {
 111                 struct qib_sge *sge = --j ? &ss->sg_list[j - 1] : &ss->sge;
 112
 113                 atomic_dec(&sge->mr->refcount);
 114         }
 115         ss->num_sge = 0;
 116         memset(&wc, 0, sizeof(wc));
 117         wc.wr_id = wqe->wr_id;
 118         wc.status = IB_WC_LOC_PROT_ERR;
 119         wc.opcode = IB_WC_RECV;
 120         wc.qp = &qp->ibqp;
 121         /* Signal solicited completion event. */
 122         qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
 123         ret = 0;
 124 bail:
 125         return ret;
 126 }
 127
 128 /**
 129  * qib_get_rwqe - copy the next RWQE into the QP's RWQE
 130  * @qp: the QP
 131  * @wr_id_only: update qp->r_wr_id only, not qp->r_sge
 132  *
 133  * Return -1 if there is a local error, 0 if no RWQE is available,
 134  * otherwise return 1.
 135  *
 136  * Can be called from interrupt level.
 137  */
 138 int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
 139 {
 140         unsigned long flags;
 141         struct qib_rq *rq;
 142         struct qib_rwq *wq;
 143         struct qib_srq *srq;
 144         struct qib_rwqe *wqe;
 145         void (*handler)(struct ib_event *, void *);
 146         u32 tail;
 147         int ret;
 148
 149         if (qp->ibqp.srq) {
 150                 srq = to_isrq(qp->ibqp.srq);
 151                 handler = srq->ibsrq.event_handler;
 152                 rq = &srq->rq;
 153         } else {
 154                 srq = NULL;
 155                 handler = NULL;
 156                 rq = &qp->r_rq;
 157         }
 158
 159         spin_lock_irqsave(&rq->lock, flags);
 160         if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
 161                 ret = 0;
 162                 goto unlock;
 163         }
 164
 165         wq = rq->wq;
 166         tail = wq->tail;
 167         /* Validate tail before using it since it is user writable. */
 168         if (tail >= rq->size)
 169                 tail = 0;
 170         if (unlikely(tail == wq->head)) {
 171                 ret = 0;
 172                 goto unlock;
 173         }
 174         /* Make sure entry is read after head index is read. */
 175         smp_rmb();
 176         wqe = get_rwqe_ptr(rq, tail);
 177         /*
 178          * Even though we update the tail index in memory, the verbs
 179          * consumer is not supposed to post more entries until a
 180          * completion is generated.
 181          */
 182         if (++tail >= rq->size)
 183                 tail = 0;
 184         wq->tail = tail;
 185         if (!wr_id_only && !qib_init_sge(qp, wqe)) {
 186                 ret = -1;
 187                 goto unlock;
 188         }
 189         qp->r_wr_id = wqe->wr_id;
 190
 191         ret = 1;
 192         set_bit(QIB_R_WRID_VALID, &qp->r_aflags);
 193         if (handler) {
 194                 u32 n;
 195
 196                 /*
 197                  * Validate head pointer value and compute
 198                  * the number of remaining WQEs.
 199                  */
 200                 n = wq->head;
 201                 if (n >= rq->size)
 202                         n = 0;
 203                 if (n < tail)
 204                         n += rq->size - tail;
 205                 else
 206                         n -= tail;
 207                 if (n < srq->limit) {
 208                         struct ib_event ev;
 209
 210                         srq->limit = 0;
 211                         spin_unlock_irqrestore(&rq->lock, flags);
 212                         ev.device = qp->ibqp.device;
 213                         ev.element.srq = qp->ibqp.srq;
 214                         ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
 215                         handler(&ev, srq->ibsrq.srq_context);
 216                         goto bail;
 217                 }
 218         }
 219 unlock:
 220         spin_unlock_irqrestore(&rq->lock, flags);
 221 bail:
 222         return ret;
 223 }
 224
 225 /*
 226  * Switch to alternate path.
 227  * The QP s_lock should be held and interrupts disabled.
 228  */
 229 void qib_migrate_qp(struct qib_qp *qp)
 230 {
 231         struct ib_event ev;
 232
 233         qp->s_mig_state = IB_MIG_MIGRATED;
 234         qp->remote_ah_attr = qp->alt_ah_attr;
 235         qp->port_num = qp->alt_ah_attr.port_num;
 236         qp->s_pkey_index = qp->s_alt_pkey_index;
 237
 238         ev.device = qp->ibqp.device;
 239         ev.element.qp = &qp->ibqp;
 240         ev.event = IB_EVENT_PATH_MIG;
 241         qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
 242 }
 243
 244 static __be64 get_sguid(struct qib_ibport *ibp, unsigned index)
 245 {
 246         if (!index) {
 247                 struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 248
 249                 return ppd->guid;
 250         } else
 251                 return ibp->guids[index - 1];
 252 }
 253
 254 static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
 255 {
 256         return (gid->global.interface_id == id &&
 257                 (gid->global.subnet_prefix == gid_prefix ||
 258                  gid->global.subnet_prefix == IB_DEFAULT_GID_PREFIX));
 259 }
 260
 261 /*
 262  *
 263  * This should be called with the QP r_lock held.
 264  *
 265  * The s_lock will be acquired around the qib_migrate_qp() call.
 266  */
 267 int qib_ruc_check_hdr(struct qib_ibport *ibp, struct qib_ib_header *hdr,
 268                       int has_grh, struct qib_qp *qp, u32 bth0)
 269 {
 270         __be64 guid;
 271         unsigned long flags;
 272
 273         if (qp->s_mig_state == IB_MIG_ARMED && (bth0 & IB_BTH_MIG_REQ)) {
 274                 if (!has_grh) {
 275                         if (qp->alt_ah_attr.ah_flags & IB_AH_GRH)
 276                                 goto err;
 277                 } else {
 278                         if (!(qp->alt_ah_attr.ah_flags & IB_AH_GRH))
 279                                 goto err;
 280                         guid = get_sguid(ibp, qp->alt_ah_attr.grh.sgid_index);
 281                         if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
 282                                 goto err;
 283                         if (!gid_ok(&hdr->u.l.grh.sgid,
 284                             qp->alt_ah_attr.grh.dgid.global.subnet_prefix,
 285                             qp->alt_ah_attr.grh.dgid.global.interface_id))
 286                                 goto err;
 287                 }
 288                 if (!qib_pkey_ok((u16)bth0,
 289                                  qib_get_pkey(ibp, qp->s_alt_pkey_index))) {
 290                         qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
 291                                       (u16)bth0,
 292                                       (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
 293                                       0, qp->ibqp.qp_num,
 294                                       hdr->lrh[3], hdr->lrh[1]);
 295                         goto err;
 296                 }
 297                 /* Validate the SLID. See Ch. 9.6.1.5 and 17.2.8 */
 298                 if (be16_to_cpu(hdr->lrh[3]) != qp->alt_ah_attr.dlid ||
 299                     ppd_from_ibp(ibp)->port != qp->alt_ah_attr.port_num)
 300                         goto err;
 301                 spin_lock_irqsave(&qp->s_lock, flags);
 302                 qib_migrate_qp(qp);
 303                 spin_unlock_irqrestore(&qp->s_lock, flags);
 304         } else {
 305                 if (!has_grh) {
 306                         if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
 307                                 goto err;
 308                 } else {
 309                         if (!(qp->remote_ah_attr.ah_flags & IB_AH_GRH))
 310                                 goto err;
 311                         guid = get_sguid(ibp,
 312                                          qp->remote_ah_attr.grh.sgid_index);
 313                         if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
 314                                 goto err;
 315                         if (!gid_ok(&hdr->u.l.grh.sgid,
 316                             qp->remote_ah_attr.grh.dgid.global.subnet_prefix,
 317                             qp->remote_ah_attr.grh.dgid.global.interface_id))
 318                                 goto err;
 319                 }
 320                 if (!qib_pkey_ok((u16)bth0,
 321                                  qib_get_pkey(ibp, qp->s_pkey_index))) {
 322                         qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
 323                                       (u16)bth0,
 324                                       (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
 325                                       0, qp->ibqp.qp_num,
 326                                       hdr->lrh[3], hdr->lrh[1]);
 327                         goto err;
 328                 }
 329                 /* Validate the SLID. See Ch. 9.6.1.5 */
 330                 if (be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid ||
 331                     ppd_from_ibp(ibp)->port != qp->port_num)
 332                         goto err;
 333                 if (qp->s_mig_state == IB_MIG_REARM &&
 334                     !(bth0 & IB_BTH_MIG_REQ))
 335                         qp->s_mig_state = IB_MIG_ARMED;
 336         }
 337
 338         return 0;
 339
 340 err:
 341         return 1;
 342 }
 343
 344 /**
 345  * qib_ruc_loopback - handle UC and RC lookback requests
 346  * @sqp: the sending QP
 347  *
 348  * This is called from qib_do_send() to
 349  * forward a WQE addressed to the same HCA.
 350  * Note that although we are single threaded due to the tasklet, we still
 351  * have to protect against post_send().  We don't have to worry about
 352  * receive interrupts since this is a connected protocol and all packets
 353  * will pass through here.
 354  */
 355 static void qib_ruc_loopback(struct qib_qp *sqp)
 356 {
 357         struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
 358         struct qib_qp *qp;
 359         struct qib_swqe *wqe;
 360         struct qib_sge *sge;
 361         unsigned long flags;
 362         struct ib_wc wc;
 363         u64 sdata;
 364         atomic64_t *maddr;
 365         enum ib_wc_status send_status;
 366         int release;
 367         int ret;
 368
 369         /*
 370          * Note that we check the responder QP state after
 371          * checking the requester's state.
 372          */
 373         qp = qib_lookup_qpn(ibp, sqp->remote_qpn);
 374
 375         spin_lock_irqsave(&sqp->s_lock, flags);
 376
 377         /* Return if we are already busy processing a work request. */
 378         if ((sqp->s_flags & (QIB_S_BUSY | QIB_S_ANY_WAIT)) ||
 379             !(ib_qib_state_ops[sqp->state] & QIB_PROCESS_OR_FLUSH_SEND))
 380                 goto unlock;
 381
 382         sqp->s_flags |= QIB_S_BUSY;
 383
 384 again:
 385         if (sqp->s_last == sqp->s_head)
 386                 goto clr_busy;
 387         wqe = get_swqe_ptr(sqp, sqp->s_last);
 388
 389         /* Return if it is not OK to start a new work reqeust. */
 390         if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_NEXT_SEND_OK)) {
 391                 if (!(ib_qib_state_ops[sqp->state] & QIB_FLUSH_SEND))
 392                         goto clr_busy;
 393                 /* We are in the error state, flush the work request. */
 394                 send_status = IB_WC_WR_FLUSH_ERR;
 395                 goto flush_send;
 396         }
 397
 398         /*
 399          * We can rely on the entry not changing without the s_lock
 400          * being held until we update s_last.
 401          * We increment s_cur to indicate s_last is in progress.
 402          */
 403         if (sqp->s_last == sqp->s_cur) {
 404                 if (++sqp->s_cur >= sqp->s_size)
 405                         sqp->s_cur = 0;
 406         }
 407         spin_unlock_irqrestore(&sqp->s_lock, flags);
 408
 409         if (!qp || !(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) ||
 410             qp->ibqp.qp_type != sqp->ibqp.qp_type) {
 411                 ibp->n_pkt_drops++;
 412                 /*
 413                  * For RC, the requester would timeout and retry so
 414                  * shortcut the timeouts and just signal too many retries.
 415                  */
 416                 if (sqp->ibqp.qp_type == IB_QPT_RC)
 417                         send_status = IB_WC_RETRY_EXC_ERR;
 418                 else
 419                         send_status = IB_WC_SUCCESS;
 420                 goto serr;
 421         }
 422
 423         memset(&wc, 0, sizeof wc);
 424         send_status = IB_WC_SUCCESS;
 425
 426         release = 1;
 427         sqp->s_sge.sge = wqe->sg_list[0];
 428         sqp->s_sge.sg_list = wqe->sg_list + 1;
 429         sqp->s_sge.num_sge = wqe->wr.num_sge;
 430         sqp->s_len = wqe->length;
 431         switch (wqe->wr.opcode) {
 432         case IB_WR_SEND_WITH_IMM:
 433                 wc.wc_flags = IB_WC_WITH_IMM;
 434                 wc.ex.imm_data = wqe->wr.ex.imm_data;
 435                 /* FALLTHROUGH */
 436         case IB_WR_SEND:
 437                 ret = qib_get_rwqe(qp, 0);
 438                 if (ret < 0)
 439                         goto op_err;
 440                 if (!ret)
 441                         goto rnr_nak;
 442                 break;
 443
 444         case IB_WR_RDMA_WRITE_WITH_IMM:
 445                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
 446                         goto inv_err;
 447                 wc.wc_flags = IB_WC_WITH_IMM;
 448                 wc.ex.imm_data = wqe->wr.ex.imm_data;
 449                 ret = qib_get_rwqe(qp, 1);
 450                 if (ret < 0)
 451                         goto op_err;
 452                 if (!ret)
 453                         goto rnr_nak;
 454                 /* FALLTHROUGH */
 455         case IB_WR_RDMA_WRITE:
 456                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
 457                         goto inv_err;
 458                 if (wqe->length == 0)
 459                         break;
 460                 if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
 461                                           wqe->wr.wr.rdma.remote_addr,
 462                                           wqe->wr.wr.rdma.rkey,
 463                                           IB_ACCESS_REMOTE_WRITE)))
 464                         goto acc_err;
 465                 qp->r_sge.sg_list = NULL;
 466                 qp->r_sge.num_sge = 1;
 467                 qp->r_sge.total_len = wqe->length;
 468                 break;
 469
 470         case IB_WR_RDMA_READ:
 471                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
 472                         goto inv_err;
 473                 if (unlikely(!qib_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
 474                                           wqe->wr.wr.rdma.remote_addr,
 475                                           wqe->wr.wr.rdma.rkey,
 476                                           IB_ACCESS_REMOTE_READ)))
 477                         goto acc_err;
 478                 release = 0;
 479                 sqp->s_sge.sg_list = NULL;
 480                 sqp->s_sge.num_sge = 1;
 481                 qp->r_sge.sge = wqe->sg_list[0];
 482                 qp->r_sge.sg_list = wqe->sg_list + 1;
 483                 qp->r_sge.num_sge = wqe->wr.num_sge;
 484                 qp->r_sge.total_len = wqe->length;
 485                 break;
 486
 487         case IB_WR_ATOMIC_CMP_AND_SWP:
 488         case IB_WR_ATOMIC_FETCH_AND_ADD:
 489                 if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
 490                         goto inv_err;
 491                 if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
 492                                           wqe->wr.wr.atomic.remote_addr,
 493                                           wqe->wr.wr.atomic.rkey,
 494                                           IB_ACCESS_REMOTE_ATOMIC)))
 495                         goto acc_err;
 496                 /* Perform atomic OP and save result. */
 497                 maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
 498                 sdata = wqe->wr.wr.atomic.compare_add;
 499                 *(u64 *) sqp->s_sge.sge.vaddr =
 500                         (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
 501                         (u64) atomic64_add_return(sdata, maddr) - sdata :
 502                         (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
 503                                       sdata, wqe->wr.wr.atomic.swap);
 504                 atomic_dec(&qp->r_sge.sge.mr->refcount);
 505                 qp->r_sge.num_sge = 0;
 506                 goto send_comp;
 507
 508         default:
 509                 send_status = IB_WC_LOC_QP_OP_ERR;
 510                 goto serr;
 511         }
 512
 513         sge = &sqp->s_sge.sge;
 514         while (sqp->s_len) {
 515                 u32 len = sqp->s_len;
 516
 517                 if (len > sge->length)
 518                         len = sge->length;
 519                 if (len > sge->sge_length)
 520                         len = sge->sge_length;
 521                 BUG_ON(len == 0);
 522                 qib_copy_sge(&qp->r_sge, sge->vaddr, len, release);
 523                 sge->vaddr += len;
 524                 sge->length -= len;
 525                 sge->sge_length -= len;
 526                 if (sge->sge_length == 0) {
 527                         if (!release)
 528                                 atomic_dec(&sge->mr->refcount);
 529                         if (--sqp->s_sge.num_sge)
 530                                 *sge = *sqp->s_sge.sg_list++;
 531                 } else if (sge->length == 0 && sge->mr->lkey) {
 532                         if (++sge->n >= QIB_SEGSZ) {
 533                                 if (++sge->m >= sge->mr->mapsz)
 534                                         break;
 535                                 sge->n = 0;
 536                         }
 537                         sge->vaddr =
 538                                 sge->mr->map[sge->m]->segs[sge->n].vaddr;
 539                         sge->length =
 540                                 sge->mr->map[sge->m]->segs[sge->n].length;
 541                 }
 542                 sqp->s_len -= len;
 543         }
 544         if (release)
 545                 while (qp->r_sge.num_sge) {
 546                         atomic_dec(&qp->r_sge.sge.mr->refcount);
 547                         if (--qp->r_sge.num_sge)
 548                                 qp->r_sge.sge = *qp->r_sge.sg_list++;
 549                 }
 550
 551         if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
 552                 goto send_comp;
 553
 554         if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
 555                 wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
 556         else
 557                 wc.opcode = IB_WC_RECV;
 558         wc.wr_id = qp->r_wr_id;
 559         wc.status = IB_WC_SUCCESS;
 560         wc.byte_len = wqe->length;
 561         wc.qp = &qp->ibqp;
 562         wc.src_qp = qp->remote_qpn;
 563         wc.slid = qp->remote_ah_attr.dlid;
 564         wc.sl = qp->remote_ah_attr.sl;
 565         wc.port_num = 1;
 566         /* Signal completion event if the solicited bit is set. */
 567         qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 568                        wqe->wr.send_flags & IB_SEND_SOLICITED);
 569
 570 send_comp:
 571         spin_lock_irqsave(&sqp->s_lock, flags);
 572         ibp->n_loop_pkts++;
 573 flush_send:
 574         sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
 575         qib_send_complete(sqp, wqe, send_status);
 576         goto again;
 577
 578 rnr_nak:
 579         /* Handle RNR NAK */
 580         if (qp->ibqp.qp_type == IB_QPT_UC)
 581                 goto send_comp;
 582         ibp->n_rnr_naks++;
 583         /*
 584          * Note: we don't need the s_lock held since the BUSY flag
 585          * makes this single threaded.
 586          */
 587         if (sqp->s_rnr_retry == 0) {
 588                 send_status = IB_WC_RNR_RETRY_EXC_ERR;
 589                 goto serr;
 590         }
 591         if (sqp->s_rnr_retry_cnt < 7)
 592                 sqp->s_rnr_retry--;
 593         spin_lock_irqsave(&sqp->s_lock, flags);
 594         if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_RECV_OK))
 595                 goto clr_busy;
 596         sqp->s_flags |= QIB_S_WAIT_RNR;
 597         sqp->s_timer.function = qib_rc_rnr_retry;
 598         sqp->s_timer.expires = jiffies +
 599                 usecs_to_jiffies(ib_qib_rnr_table[qp->r_min_rnr_timer]);
 600         add_timer(&sqp->s_timer);
 601         goto clr_busy;
 602
 603 op_err:
 604         send_status = IB_WC_REM_OP_ERR;
 605         wc.status = IB_WC_LOC_QP_OP_ERR;
 606         goto err;
 607
 608 inv_err:
 609         send_status = IB_WC_REM_INV_REQ_ERR;
 610         wc.status = IB_WC_LOC_QP_OP_ERR;
 611         goto err;
 612
 613 acc_err:
 614         send_status = IB_WC_REM_ACCESS_ERR;
 615         wc.status = IB_WC_LOC_PROT_ERR;
 616 err:
 617         /* responder goes to error state */
 618         qib_rc_error(qp, wc.status);
 619
 620 serr:
 621         spin_lock_irqsave(&sqp->s_lock, flags);
 622         qib_send_complete(sqp, wqe, send_status);
 623         if (sqp->ibqp.qp_type == IB_QPT_RC) {
 624                 int lastwqe = qib_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
 625
 626                 sqp->s_flags &= ~QIB_S_BUSY;
 627                 spin_unlock_irqrestore(&sqp->s_lock, flags);
 628                 if (lastwqe) {
 629                         struct ib_event ev;
 630
 631                         ev.device = sqp->ibqp.device;
 632                         ev.element.qp = &sqp->ibqp;
 633                         ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
 634                         sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
 635                 }
 636                 goto done;
 637         }
 638 clr_busy:
 639         sqp->s_flags &= ~QIB_S_BUSY;
 640 unlock:
 641         spin_unlock_irqrestore(&sqp->s_lock, flags);
 642 done:
 643         if (qp && atomic_dec_and_test(&qp->refcount))
 644                 wake_up(&qp->wait);
 645 }
 646
 647 /**
 648  * qib_make_grh - construct a GRH header
 649  * @ibp: a pointer to the IB port
 650  * @hdr: a pointer to the GRH header being constructed
 651  * @grh: the global route address to send to
 652  * @hwords: the number of 32 bit words of header being sent
 653  * @nwords: the number of 32 bit words of data being sent
 654  *
 655  * Return the size of the header in 32 bit words.
 656  */
 657 u32 qib_make_grh(struct qib_ibport *ibp, struct ib_grh *hdr,
 658                  struct ib_global_route *grh, u32 hwords, u32 nwords)
 659 {
 660         hdr->version_tclass_flow =
 661                 cpu_to_be32((IB_GRH_VERSION << IB_GRH_VERSION_SHIFT) |
 662                             (grh->traffic_class << IB_GRH_TCLASS_SHIFT) |
 663                             (grh->flow_label << IB_GRH_FLOW_SHIFT));
 664         hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
 665         /* next_hdr is defined by C8-7 in ch. 8.4.1 */
 666         hdr->next_hdr = IB_GRH_NEXT_HDR;
 667         hdr->hop_limit = grh->hop_limit;
 668         /* The SGID is 32-bit aligned. */
 669         hdr->sgid.global.subnet_prefix = ibp->gid_prefix;
 670         hdr->sgid.global.interface_id = grh->sgid_index ?
 671                 ibp->guids[grh->sgid_index - 1] : ppd_from_ibp(ibp)->guid;
 672         hdr->dgid = grh->dgid;
 673
 674         /* GRH header size in 32-bit words. */
 675         return sizeof(struct ib_grh) / sizeof(u32);
 676 }
 677
 678 void qib_make_ruc_header(struct qib_qp *qp, struct qib_other_headers *ohdr,
 679                          u32 bth0, u32 bth2)
 680 {
 681         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 682         u16 lrh0;
 683         u32 nwords;
 684         u32 extra_bytes;
 685
 686         /* Construct the header. */
 687         extra_bytes = -qp->s_cur_size & 3;
 688         nwords = (qp->s_cur_size + extra_bytes) >> 2;
 689         lrh0 = QIB_LRH_BTH;
 690         if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
 691                 qp->s_hdrwords += qib_make_grh(ibp, &qp->s_hdr->u.l.grh,
 692                                                &qp->remote_ah_attr.grh,
 693                                                qp->s_hdrwords, nwords);
 694                 lrh0 = QIB_LRH_GRH;
 695         }
 696         lrh0 |= ibp->sl_to_vl[qp->remote_ah_attr.sl] << 12 |
 697                 qp->remote_ah_attr.sl << 4;
 698         qp->s_hdr->lrh[0] = cpu_to_be16(lrh0);
 699         qp->s_hdr->lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
 700         qp->s_hdr->lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
 701         qp->s_hdr->lrh[3] = cpu_to_be16(ppd_from_ibp(ibp)->lid |
 702                                        qp->remote_ah_attr.src_path_bits);
 703         bth0 |= qib_get_pkey(ibp, qp->s_pkey_index);
 704         bth0 |= extra_bytes << 20;
 705         if (qp->s_mig_state == IB_MIG_MIGRATED)
 706                 bth0 |= IB_BTH_MIG_REQ;
 707         ohdr->bth[0] = cpu_to_be32(bth0);
 708         ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
 709         ohdr->bth[2] = cpu_to_be32(bth2);
 710 }
 711
 712 /**
 713  * qib_do_send - perform a send on a QP
 714  * @work: contains a pointer to the QP
 715  *
 716  * Process entries in the send work queue until credit or queue is
 717  * exhausted.  Only allow one CPU to send a packet per QP (tasklet).
 718  * Otherwise, two threads could send packets out of order.
 719  */
 720 void qib_do_send(struct work_struct *work)
 721 {
 722         struct qib_qp *qp = container_of(work, struct qib_qp, s_work);
 723         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 724         struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 725         int (*make_req)(struct qib_qp *qp);
 726         unsigned long flags;
 727
 728         if ((qp->ibqp.qp_type == IB_QPT_RC ||
 729              qp->ibqp.qp_type == IB_QPT_UC) &&
 730             (qp->remote_ah_attr.dlid & ~((1 << ppd->lmc) - 1)) == ppd->lid) {
 731                 qib_ruc_loopback(qp);
 732                 return;
 733         }
 734
 735         if (qp->ibqp.qp_type == IB_QPT_RC)
 736                 make_req = qib_make_rc_req;
 737         else if (qp->ibqp.qp_type == IB_QPT_UC)
 738                 make_req = qib_make_uc_req;
 739         else
 740                 make_req = qib_make_ud_req;
 741
 742         spin_lock_irqsave(&qp->s_lock, flags);
 743
 744         /* Return if we are already busy processing a work request. */
 745         if (!qib_send_ok(qp)) {
 746                 spin_unlock_irqrestore(&qp->s_lock, flags);
 747                 return;
 748         }
 749
 750         qp->s_flags |= QIB_S_BUSY;
 751
 752         spin_unlock_irqrestore(&qp->s_lock, flags);
 753
 754         do {
 755                 /* Check for a constructed packet to be sent. */
 756                 if (qp->s_hdrwords != 0) {
 757                         /*
 758                          * If the packet cannot be sent now, return and
 759                          * the send tasklet will be woken up later.
 760                          */
 761                         if (qib_verbs_send(qp, qp->s_hdr, qp->s_hdrwords,
 762                                            qp->s_cur_sge, qp->s_cur_size))
 763                                 break;
 764                         /* Record that s_hdr is empty. */
 765                         qp->s_hdrwords = 0;
 766                 }
 767         } while (make_req(qp));
 768 }
 769
 770 /*
 771  * This should be called with s_lock held.
 772  */
 773 void qib_send_complete(struct qib_qp *qp, struct qib_swqe *wqe,
 774                        enum ib_wc_status status)
 775 {
 776         u32 old_last, last;
 777         unsigned i;
 778
 779         if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_OR_FLUSH_SEND))
 780                 return;
 781
 782         for (i = 0; i < wqe->wr.num_sge; i++) {
 783                 struct qib_sge *sge = &wqe->sg_list[i];
 784
 785                 atomic_dec(&sge->mr->refcount);
 786         }
 787         if (qp->ibqp.qp_type == IB_QPT_UD ||
 788             qp->ibqp.qp_type == IB_QPT_SMI ||
 789             qp->ibqp.qp_type == IB_QPT_GSI)
 790                 atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
 791
 792         /* See ch. 11.2.4.1 and 10.7.3.1 */
 793         if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) ||
 794             (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
 795             status != IB_WC_SUCCESS) {
 796                 struct ib_wc wc;
 797
 798                 memset(&wc, 0, sizeof wc);
 799                 wc.wr_id = wqe->wr.wr_id;
 800                 wc.status = status;
 801                 wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode];
 802                 wc.qp = &qp->ibqp;
 803                 if (status == IB_WC_SUCCESS)
 804                         wc.byte_len = wqe->length;
 805                 qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc,
 806                              status != IB_WC_SUCCESS);
 807         }
 808
 809         last = qp->s_last;
 810         old_last = last;
 811         if (++last >= qp->s_size)
 812                 last = 0;
 813         qp->s_last = last;
 814         if (qp->s_acked == old_last)
 815                 qp->s_acked = last;
 816         if (qp->s_cur == old_last)
 817                 qp->s_cur = last;
 818         if (qp->s_tail == old_last)
 819                 qp->s_tail = last;
 820         if (qp->state == IB_QPS_SQD && last == qp->s_cur)
 821                 qp->s_draining = 0;
 822 }