drivers/infiniband/hw/qib/qib_qp.c

   1 /*
   2  * Copyright (c) 2006, 2007, 2008, 2009, 2010 QLogic Corporation.
   3  * All rights reserved.
   4  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34
  35 #include <linux/err.h>
  36 #include <linux/vmalloc.h>
  37
  38 #include "qib.h"
  39
  40 #define BITS_PER_PAGE           (PAGE_SIZE*BITS_PER_BYTE)
  41 #define BITS_PER_PAGE_MASK      (BITS_PER_PAGE-1)
  42
  43 static inline unsigned mk_qpn(struct qib_qpn_table *qpt,
  44                               struct qpn_map *map, unsigned off)
  45 {
  46         return (map - qpt->map) * BITS_PER_PAGE + off;
  47 }
  48
  49 static inline unsigned find_next_offset(struct qib_qpn_table *qpt,
  50                                         struct qpn_map *map, unsigned off,
  51                                         unsigned n)
  52 {
  53         if (qpt->mask) {
  54                 off++;
  55                 if (((off & qpt->mask) >> 1) >= n)
  56                         off = (off | qpt->mask) + 2;
  57         } else
  58                 off = find_next_zero_bit(map->page, BITS_PER_PAGE, off);
  59         return off;
  60 }
  61
  62 /*
  63  * Convert the AETH credit code into the number of credits.
  64  */
  65 static u32 credit_table[31] = {
  66         0,                      /* 0 */
  67         1,                      /* 1 */
  68         2,                      /* 2 */
  69         3,                      /* 3 */
  70         4,                      /* 4 */
  71         6,                      /* 5 */
  72         8,                      /* 6 */
  73         12,                     /* 7 */
  74         16,                     /* 8 */
  75         24,                     /* 9 */
  76         32,                     /* A */
  77         48,                     /* B */
  78         64,                     /* C */
  79         96,                     /* D */
  80         128,                    /* E */
  81         192,                    /* F */
  82         256,                    /* 10 */
  83         384,                    /* 11 */
  84         512,                    /* 12 */
  85         768,                    /* 13 */
  86         1024,                   /* 14 */
  87         1536,                   /* 15 */
  88         2048,                   /* 16 */
  89         3072,                   /* 17 */
  90         4096,                   /* 18 */
  91         6144,                   /* 19 */
  92         8192,                   /* 1A */
  93         12288,                  /* 1B */
  94         16384,                  /* 1C */
  95         24576,                  /* 1D */
  96         32768                   /* 1E */
  97 };
  98
  99 static void get_map_page(struct qib_qpn_table *qpt, struct qpn_map *map)
 100 {
 101         unsigned long page = get_zeroed_page(GFP_KERNEL);
 102
 103         /*
 104          * Free the page if someone raced with us installing it.
 105          */
 106
 107         spin_lock(&qpt->lock);
 108         if (map->page)
 109                 free_page(page);
 110         else
 111                 map->page = (void *)page;
 112         spin_unlock(&qpt->lock);
 113 }
 114
 115 /*
 116  * Allocate the next available QPN or
 117  * zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
 118  */
 119 static int alloc_qpn(struct qib_devdata *dd, struct qib_qpn_table *qpt,
 120                      enum ib_qp_type type, u8 port)
 121 {
 122         u32 i, offset, max_scan, qpn;
 123         struct qpn_map *map;
 124         u32 ret;
 125
 126         if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
 127                 unsigned n;
 128
 129                 ret = type == IB_QPT_GSI;
 130                 n = 1 << (ret + 2 * (port - 1));
 131                 spin_lock(&qpt->lock);
 132                 if (qpt->flags & n)
 133                         ret = -EINVAL;
 134                 else
 135                         qpt->flags |= n;
 136                 spin_unlock(&qpt->lock);
 137                 goto bail;
 138         }
 139
 140         qpn = qpt->last + 1;
 141         if (qpn >= QPN_MAX)
 142                 qpn = 2;
 143         if (qpt->mask && ((qpn & qpt->mask) >> 1) >= dd->n_krcv_queues)
 144                 qpn = (qpn | qpt->mask) + 2;
 145         offset = qpn & BITS_PER_PAGE_MASK;
 146         map = &qpt->map[qpn / BITS_PER_PAGE];
 147         max_scan = qpt->nmaps - !offset;
 148         for (i = 0;;) {
 149                 if (unlikely(!map->page)) {
 150                         get_map_page(qpt, map);
 151                         if (unlikely(!map->page))
 152                                 break;
 153                 }
 154                 do {
 155                         if (!test_and_set_bit(offset, map->page)) {
 156                                 qpt->last = qpn;
 157                                 ret = qpn;
 158                                 goto bail;
 159                         }
 160                         offset = find_next_offset(qpt, map, offset,
 161                                 dd->n_krcv_queues);
 162                         qpn = mk_qpn(qpt, map, offset);
 163                         /*
 164                          * This test differs from alloc_pidmap().
 165                          * If find_next_offset() does find a zero
 166                          * bit, we don't need to check for QPN
 167                          * wrapping around past our starting QPN.
 168                          * We just need to be sure we don't loop
 169                          * forever.
 170                          */
 171                 } while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
 172                 /*
 173                  * In order to keep the number of pages allocated to a
 174                  * minimum, we scan the all existing pages before increasing
 175                  * the size of the bitmap table.
 176                  */
 177                 if (++i > max_scan) {
 178                         if (qpt->nmaps == QPNMAP_ENTRIES)
 179                                 break;
 180                         map = &qpt->map[qpt->nmaps++];
 181                         offset = 0;
 182                 } else if (map < &qpt->map[qpt->nmaps]) {
 183                         ++map;
 184                         offset = 0;
 185                 } else {
 186                         map = &qpt->map[0];
 187                         offset = 2;
 188                 }
 189                 qpn = mk_qpn(qpt, map, offset);
 190         }
 191
 192         ret = -ENOMEM;
 193
 194 bail:
 195         return ret;
 196 }
 197
 198 static void free_qpn(struct qib_qpn_table *qpt, u32 qpn)
 199 {
 200         struct qpn_map *map;
 201
 202         map = qpt->map + qpn / BITS_PER_PAGE;
 203         if (map->page)
 204                 clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
 205 }
 206
 207 /*
 208  * Put the QP into the hash table.
 209  * The hash table holds a reference to the QP.
 210  */
 211 static void insert_qp(struct qib_ibdev *dev, struct qib_qp *qp)
 212 {
 213         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 214         unsigned n = qp->ibqp.qp_num % dev->qp_table_size;
 215         unsigned long flags;
 216
 217         spin_lock_irqsave(&dev->qpt_lock, flags);
 218
 219         if (qp->ibqp.qp_num == 0)
 220                 ibp->qp0 = qp;
 221         else if (qp->ibqp.qp_num == 1)
 222                 ibp->qp1 = qp;
 223         else {
 224                 qp->next = dev->qp_table[n];
 225                 dev->qp_table[n] = qp;
 226         }
 227         atomic_inc(&qp->refcount);
 228
 229         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 230 }
 231
 232 /*
 233  * Remove the QP from the table so it can't be found asynchronously by
 234  * the receive interrupt routine.
 235  */
 236 static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
 237 {
 238         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 239         struct qib_qp *q, **qpp;
 240         unsigned long flags;
 241
 242         qpp = &dev->qp_table[qp->ibqp.qp_num % dev->qp_table_size];
 243
 244         spin_lock_irqsave(&dev->qpt_lock, flags);
 245
 246         if (ibp->qp0 == qp) {
 247                 ibp->qp0 = NULL;
 248                 atomic_dec(&qp->refcount);
 249         } else if (ibp->qp1 == qp) {
 250                 ibp->qp1 = NULL;
 251                 atomic_dec(&qp->refcount);
 252         } else
 253                 for (; (q = *qpp) != NULL; qpp = &q->next)
 254                         if (q == qp) {
 255                                 *qpp = qp->next;
 256                                 qp->next = NULL;
 257                                 atomic_dec(&qp->refcount);
 258                                 break;
 259                         }
 260
 261         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 262 }
 263
 264 /**
 265  * qib_free_all_qps - check for QPs still in use
 266  * @qpt: the QP table to empty
 267  *
 268  * There should not be any QPs still in use.
 269  * Free memory for table.
 270  */
 271 unsigned qib_free_all_qps(struct qib_devdata *dd)
 272 {
 273         struct qib_ibdev *dev = &dd->verbs_dev;
 274         unsigned long flags;
 275         struct qib_qp *qp;
 276         unsigned n, qp_inuse = 0;
 277
 278         for (n = 0; n < dd->num_pports; n++) {
 279                 struct qib_ibport *ibp = &dd->pport[n].ibport_data;
 280
 281                 if (!qib_mcast_tree_empty(ibp))
 282                         qp_inuse++;
 283                 if (ibp->qp0)
 284                         qp_inuse++;
 285                 if (ibp->qp1)
 286                         qp_inuse++;
 287         }
 288
 289         spin_lock_irqsave(&dev->qpt_lock, flags);
 290         for (n = 0; n < dev->qp_table_size; n++) {
 291                 qp = dev->qp_table[n];
 292                 dev->qp_table[n] = NULL;
 293
 294                 for (; qp; qp = qp->next)
 295                         qp_inuse++;
 296         }
 297         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 298
 299         return qp_inuse;
 300 }
 301
 302 /**
 303  * qib_lookup_qpn - return the QP with the given QPN
 304  * @qpt: the QP table
 305  * @qpn: the QP number to look up
 306  *
 307  * The caller is responsible for decrementing the QP reference count
 308  * when done.
 309  */
 310 struct qib_qp *qib_lookup_qpn(struct qib_ibport *ibp, u32 qpn)
 311 {
 312         struct qib_ibdev *dev = &ppd_from_ibp(ibp)->dd->verbs_dev;
 313         unsigned long flags;
 314         struct qib_qp *qp;
 315
 316         spin_lock_irqsave(&dev->qpt_lock, flags);
 317
 318         if (qpn == 0)
 319                 qp = ibp->qp0;
 320         else if (qpn == 1)
 321                 qp = ibp->qp1;
 322         else
 323                 for (qp = dev->qp_table[qpn % dev->qp_table_size]; qp;
 324                      qp = qp->next)
 325                         if (qp->ibqp.qp_num == qpn)
 326                                 break;
 327         if (qp)
 328                 atomic_inc(&qp->refcount);
 329
 330         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 331         return qp;
 332 }
 333
 334 /**
 335  * qib_reset_qp - initialize the QP state to the reset state
 336  * @qp: the QP to reset
 337  * @type: the QP type
 338  */
 339 static void qib_reset_qp(struct qib_qp *qp, enum ib_qp_type type)
 340 {
 341         qp->remote_qpn = 0;
 342         qp->qkey = 0;
 343         qp->qp_access_flags = 0;
 344         atomic_set(&qp->s_dma_busy, 0);
 345         qp->s_flags &= QIB_S_SIGNAL_REQ_WR;
 346         qp->s_hdrwords = 0;
 347         qp->s_wqe = NULL;
 348         qp->s_draining = 0;
 349         qp->s_next_psn = 0;
 350         qp->s_last_psn = 0;
 351         qp->s_sending_psn = 0;
 352         qp->s_sending_hpsn = 0;
 353         qp->s_psn = 0;
 354         qp->r_psn = 0;
 355         qp->r_msn = 0;
 356         if (type == IB_QPT_RC) {
 357                 qp->s_state = IB_OPCODE_RC_SEND_LAST;
 358                 qp->r_state = IB_OPCODE_RC_SEND_LAST;
 359         } else {
 360                 qp->s_state = IB_OPCODE_UC_SEND_LAST;
 361                 qp->r_state = IB_OPCODE_UC_SEND_LAST;
 362         }
 363         qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
 364         qp->r_nak_state = 0;
 365         qp->r_aflags = 0;
 366         qp->r_flags = 0;
 367         qp->s_head = 0;
 368         qp->s_tail = 0;
 369         qp->s_cur = 0;
 370         qp->s_acked = 0;
 371         qp->s_last = 0;
 372         qp->s_ssn = 1;
 373         qp->s_lsn = 0;
 374         qp->s_mig_state = IB_MIG_MIGRATED;
 375         memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
 376         qp->r_head_ack_queue = 0;
 377         qp->s_tail_ack_queue = 0;
 378         qp->s_num_rd_atomic = 0;
 379         if (qp->r_rq.wq) {
 380                 qp->r_rq.wq->head = 0;
 381                 qp->r_rq.wq->tail = 0;
 382         }
 383         qp->r_sge.num_sge = 0;
 384 }
 385
 386 static void clear_mr_refs(struct qib_qp *qp, int clr_sends)
 387 {
 388         unsigned n;
 389
 390         if (test_and_clear_bit(QIB_R_REWIND_SGE, &qp->r_aflags))
 391                 while (qp->s_rdma_read_sge.num_sge) {
 392                         atomic_dec(&qp->s_rdma_read_sge.sge.mr->refcount);
 393                         if (--qp->s_rdma_read_sge.num_sge)
 394                                 qp->s_rdma_read_sge.sge =
 395                                         *qp->s_rdma_read_sge.sg_list++;
 396                 }
 397
 398         while (qp->r_sge.num_sge) {
 399                 atomic_dec(&qp->r_sge.sge.mr->refcount);
 400                 if (--qp->r_sge.num_sge)
 401                         qp->r_sge.sge = *qp->r_sge.sg_list++;
 402         }
 403
 404         if (clr_sends) {
 405                 while (qp->s_last != qp->s_head) {
 406                         struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
 407                         unsigned i;
 408
 409                         for (i = 0; i < wqe->wr.num_sge; i++) {
 410                                 struct qib_sge *sge = &wqe->sg_list[i];
 411
 412                                 atomic_dec(&sge->mr->refcount);
 413                         }
 414                         if (qp->ibqp.qp_type == IB_QPT_UD ||
 415                             qp->ibqp.qp_type == IB_QPT_SMI ||
 416                             qp->ibqp.qp_type == IB_QPT_GSI)
 417                                 atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
 418                         if (++qp->s_last >= qp->s_size)
 419                                 qp->s_last = 0;
 420                 }
 421                 if (qp->s_rdma_mr) {
 422                         atomic_dec(&qp->s_rdma_mr->refcount);
 423                         qp->s_rdma_mr = NULL;
 424                 }
 425         }
 426
 427         if (qp->ibqp.qp_type != IB_QPT_RC)
 428                 return;
 429
 430         for (n = 0; n < ARRAY_SIZE(qp->s_ack_queue); n++) {
 431                 struct qib_ack_entry *e = &qp->s_ack_queue[n];
 432
 433                 if (e->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST &&
 434                     e->rdma_sge.mr) {
 435                         atomic_dec(&e->rdma_sge.mr->refcount);
 436                         e->rdma_sge.mr = NULL;
 437                 }
 438         }
 439 }
 440
 441 /**
 442  * qib_error_qp - put a QP into the error state
 443  * @qp: the QP to put into the error state
 444  * @err: the receive completion error to signal if a RWQE is active
 445  *
 446  * Flushes both send and receive work queues.
 447  * Returns true if last WQE event should be generated.
 448  * The QP r_lock and s_lock should be held and interrupts disabled.
 449  * If we are already in error state, just return.
 450  */
 451 int qib_error_qp(struct qib_qp *qp, enum ib_wc_status err)
 452 {
 453         struct qib_ibdev *dev = to_idev(qp->ibqp.device);
 454         struct ib_wc wc;
 455         int ret = 0;
 456
 457         if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
 458                 goto bail;
 459
 460         qp->state = IB_QPS_ERR;
 461
 462         if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
 463                 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
 464                 del_timer(&qp->s_timer);
 465         }
 466
 467         if (qp->s_flags & QIB_S_ANY_WAIT_SEND)
 468                 qp->s_flags &= ~QIB_S_ANY_WAIT_SEND;
 469
 470         spin_lock(&dev->pending_lock);
 471         if (!list_empty(&qp->iowait) && !(qp->s_flags & QIB_S_BUSY)) {
 472                 qp->s_flags &= ~QIB_S_ANY_WAIT_IO;
 473                 list_del_init(&qp->iowait);
 474         }
 475         spin_unlock(&dev->pending_lock);
 476
 477         if (!(qp->s_flags & QIB_S_BUSY)) {
 478                 qp->s_hdrwords = 0;
 479                 if (qp->s_rdma_mr) {
 480                         atomic_dec(&qp->s_rdma_mr->refcount);
 481                         qp->s_rdma_mr = NULL;
 482                 }
 483                 if (qp->s_tx) {
 484                         qib_put_txreq(qp->s_tx);
 485                         qp->s_tx = NULL;
 486                 }
 487         }
 488
 489         /* Schedule the sending tasklet to drain the send work queue. */
 490         if (qp->s_last != qp->s_head)
 491                 qib_schedule_send(qp);
 492
 493         clear_mr_refs(qp, 0);
 494
 495         memset(&wc, 0, sizeof(wc));
 496         wc.qp = &qp->ibqp;
 497         wc.opcode = IB_WC_RECV;
 498
 499         if (test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) {
 500                 wc.wr_id = qp->r_wr_id;
 501                 wc.status = err;
 502                 qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
 503         }
 504         wc.status = IB_WC_WR_FLUSH_ERR;
 505
 506         if (qp->r_rq.wq) {
 507                 struct qib_rwq *wq;
 508                 u32 head;
 509                 u32 tail;
 510
 511                 spin_lock(&qp->r_rq.lock);
 512
 513                 /* sanity check pointers before trusting them */
 514                 wq = qp->r_rq.wq;
 515                 head = wq->head;
 516                 if (head >= qp->r_rq.size)
 517                         head = 0;
 518                 tail = wq->tail;
 519                 if (tail >= qp->r_rq.size)
 520                         tail = 0;
 521                 while (tail != head) {
 522                         wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
 523                         if (++tail >= qp->r_rq.size)
 524                                 tail = 0;
 525                         qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
 526                 }
 527                 wq->tail = tail;
 528
 529                 spin_unlock(&qp->r_rq.lock);
 530         } else if (qp->ibqp.event_handler)
 531                 ret = 1;
 532
 533 bail:
 534         return ret;
 535 }
 536
 537 /**
 538  * qib_modify_qp - modify the attributes of a queue pair
 539  * @ibqp: the queue pair who's attributes we're modifying
 540  * @attr: the new attributes
 541  * @attr_mask: the mask of attributes to modify
 542  * @udata: user data for libibverbs.so
 543  *
 544  * Returns 0 on success, otherwise returns an errno.
 545  */
 546 int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 547                   int attr_mask, struct ib_udata *udata)
 548 {
 549         struct qib_ibdev *dev = to_idev(ibqp->device);
 550         struct qib_qp *qp = to_iqp(ibqp);
 551         enum ib_qp_state cur_state, new_state;
 552         struct ib_event ev;
 553         int lastwqe = 0;
 554         int mig = 0;
 555         int ret;
 556         u32 pmtu = 0; /* for gcc warning only */
 557
 558         spin_lock_irq(&qp->r_lock);
 559         spin_lock(&qp->s_lock);
 560
 561         cur_state = attr_mask & IB_QP_CUR_STATE ?
 562                 attr->cur_qp_state : qp->state;
 563         new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
 564
 565         if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
 566                                 attr_mask))
 567                 goto inval;
 568
 569         if (attr_mask & IB_QP_AV) {
 570                 if (attr->ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
 571                         goto inval;
 572                 if (qib_check_ah(qp->ibqp.device, &attr->ah_attr))
 573                         goto inval;
 574         }
 575
 576         if (attr_mask & IB_QP_ALT_PATH) {
 577                 if (attr->alt_ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
 578                         goto inval;
 579                 if (qib_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
 580                         goto inval;
 581                 if (attr->alt_pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
 582                         goto inval;
 583         }
 584
 585         if (attr_mask & IB_QP_PKEY_INDEX)
 586                 if (attr->pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
 587                         goto inval;
 588
 589         if (attr_mask & IB_QP_MIN_RNR_TIMER)
 590                 if (attr->min_rnr_timer > 31)
 591                         goto inval;
 592
 593         if (attr_mask & IB_QP_PORT)
 594                 if (qp->ibqp.qp_type == IB_QPT_SMI ||
 595                     qp->ibqp.qp_type == IB_QPT_GSI ||
 596                     attr->port_num == 0 ||
 597                     attr->port_num > ibqp->device->phys_port_cnt)
 598                         goto inval;
 599
 600         if (attr_mask & IB_QP_DEST_QPN)
 601                 if (attr->dest_qp_num > QIB_QPN_MASK)
 602                         goto inval;
 603
 604         if (attr_mask & IB_QP_RETRY_CNT)
 605                 if (attr->retry_cnt > 7)
 606                         goto inval;
 607
 608         if (attr_mask & IB_QP_RNR_RETRY)
 609                 if (attr->rnr_retry > 7)
 610                         goto inval;
 611
 612         /*
 613          * Don't allow invalid path_mtu values.  OK to set greater
 614          * than the active mtu (or even the max_cap, if we have tuned
 615          * that to a small mtu.  We'll set qp->path_mtu
 616          * to the lesser of requested attribute mtu and active,
 617          * for packetizing messages.
 618          * Note that the QP port has to be set in INIT and MTU in RTR.
 619          */
 620         if (attr_mask & IB_QP_PATH_MTU) {
 621                 struct qib_devdata *dd = dd_from_dev(dev);
 622                 int mtu, pidx = qp->port_num - 1;
 623
 624                 mtu = ib_mtu_enum_to_int(attr->path_mtu);
 625                 if (mtu == -1)
 626                         goto inval;
 627                 if (mtu > dd->pport[pidx].ibmtu) {
 628                         switch (dd->pport[pidx].ibmtu) {
 629                         case 4096:
 630                                 pmtu = IB_MTU_4096;
 631                                 break;
 632                         case 2048:
 633                                 pmtu = IB_MTU_2048;
 634                                 break;
 635                         case 1024:
 636                                 pmtu = IB_MTU_1024;
 637                                 break;
 638                         case 512:
 639                                 pmtu = IB_MTU_512;
 640                                 break;
 641                         case 256:
 642                                 pmtu = IB_MTU_256;
 643                                 break;
 644                         default:
 645                                 pmtu = IB_MTU_2048;
 646                         }
 647                 } else
 648                         pmtu = attr->path_mtu;
 649         }
 650
 651         if (attr_mask & IB_QP_PATH_MIG_STATE) {
 652                 if (attr->path_mig_state == IB_MIG_REARM) {
 653                         if (qp->s_mig_state == IB_MIG_ARMED)
 654                                 goto inval;
 655                         if (new_state != IB_QPS_RTS)
 656                                 goto inval;
 657                 } else if (attr->path_mig_state == IB_MIG_MIGRATED) {
 658                         if (qp->s_mig_state == IB_MIG_REARM)
 659                                 goto inval;
 660                         if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
 661                                 goto inval;
 662                         if (qp->s_mig_state == IB_MIG_ARMED)
 663                                 mig = 1;
 664                 } else
 665                         goto inval;
 666         }
 667
 668         if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
 669                 if (attr->max_dest_rd_atomic > QIB_MAX_RDMA_ATOMIC)
 670                         goto inval;
 671
 672         switch (new_state) {
 673         case IB_QPS_RESET:
 674                 if (qp->state != IB_QPS_RESET) {
 675                         qp->state = IB_QPS_RESET;
 676                         spin_lock(&dev->pending_lock);
 677                         if (!list_empty(&qp->iowait))
 678                                 list_del_init(&qp->iowait);
 679                         spin_unlock(&dev->pending_lock);
 680                         qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
 681                         spin_unlock(&qp->s_lock);
 682                         spin_unlock_irq(&qp->r_lock);
 683                         /* Stop the sending work queue and retry timer */
 684                         cancel_work_sync(&qp->s_work);
 685                         del_timer_sync(&qp->s_timer);
 686                         wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
 687                         if (qp->s_tx) {
 688                                 qib_put_txreq(qp->s_tx);
 689                                 qp->s_tx = NULL;
 690                         }
 691                         remove_qp(dev, qp);
 692                         wait_event(qp->wait, !atomic_read(&qp->refcount));
 693                         spin_lock_irq(&qp->r_lock);
 694                         spin_lock(&qp->s_lock);
 695                         clear_mr_refs(qp, 1);
 696                         qib_reset_qp(qp, ibqp->qp_type);
 697                 }
 698                 break;
 699
 700         case IB_QPS_RTR:
 701                 /* Allow event to retrigger if QP set to RTR more than once */
 702                 qp->r_flags &= ~QIB_R_COMM_EST;
 703                 qp->state = new_state;
 704                 break;
 705
 706         case IB_QPS_SQD:
 707                 qp->s_draining = qp->s_last != qp->s_cur;
 708                 qp->state = new_state;
 709                 break;
 710
 711         case IB_QPS_SQE:
 712                 if (qp->ibqp.qp_type == IB_QPT_RC)
 713                         goto inval;
 714                 qp->state = new_state;
 715                 break;
 716
 717         case IB_QPS_ERR:
 718                 lastwqe = qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 719                 break;
 720
 721         default:
 722                 qp->state = new_state;
 723                 break;
 724         }
 725
 726         if (attr_mask & IB_QP_PKEY_INDEX)
 727                 qp->s_pkey_index = attr->pkey_index;
 728
 729         if (attr_mask & IB_QP_PORT)
 730                 qp->port_num = attr->port_num;
 731
 732         if (attr_mask & IB_QP_DEST_QPN)
 733                 qp->remote_qpn = attr->dest_qp_num;
 734
 735         if (attr_mask & IB_QP_SQ_PSN) {
 736                 qp->s_next_psn = attr->sq_psn & QIB_PSN_MASK;
 737                 qp->s_psn = qp->s_next_psn;
 738                 qp->s_sending_psn = qp->s_next_psn;
 739                 qp->s_last_psn = qp->s_next_psn - 1;
 740                 qp->s_sending_hpsn = qp->s_last_psn;
 741         }
 742
 743         if (attr_mask & IB_QP_RQ_PSN)
 744                 qp->r_psn = attr->rq_psn & QIB_PSN_MASK;
 745
 746         if (attr_mask & IB_QP_ACCESS_FLAGS)
 747                 qp->qp_access_flags = attr->qp_access_flags;
 748
 749         if (attr_mask & IB_QP_AV) {
 750                 qp->remote_ah_attr = attr->ah_attr;
 751                 qp->s_srate = attr->ah_attr.static_rate;
 752         }
 753
 754         if (attr_mask & IB_QP_ALT_PATH) {
 755                 qp->alt_ah_attr = attr->alt_ah_attr;
 756                 qp->s_alt_pkey_index = attr->alt_pkey_index;
 757         }
 758
 759         if (attr_mask & IB_QP_PATH_MIG_STATE) {
 760                 qp->s_mig_state = attr->path_mig_state;
 761                 if (mig) {
 762                         qp->remote_ah_attr = qp->alt_ah_attr;
 763                         qp->port_num = qp->alt_ah_attr.port_num;
 764                         qp->s_pkey_index = qp->s_alt_pkey_index;
 765                 }
 766         }
 767
 768         if (attr_mask & IB_QP_PATH_MTU)
 769                 qp->path_mtu = pmtu;
 770
 771         if (attr_mask & IB_QP_RETRY_CNT) {
 772                 qp->s_retry_cnt = attr->retry_cnt;
 773                 qp->s_retry = attr->retry_cnt;
 774         }
 775
 776         if (attr_mask & IB_QP_RNR_RETRY) {
 777                 qp->s_rnr_retry_cnt = attr->rnr_retry;
 778                 qp->s_rnr_retry = attr->rnr_retry;
 779         }
 780
 781         if (attr_mask & IB_QP_MIN_RNR_TIMER)
 782                 qp->r_min_rnr_timer = attr->min_rnr_timer;
 783
 784         if (attr_mask & IB_QP_TIMEOUT)
 785                 qp->timeout = attr->timeout;
 786
 787         if (attr_mask & IB_QP_QKEY)
 788                 qp->qkey = attr->qkey;
 789
 790         if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
 791                 qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
 792
 793         if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
 794                 qp->s_max_rd_atomic = attr->max_rd_atomic;
 795
 796         spin_unlock(&qp->s_lock);
 797         spin_unlock_irq(&qp->r_lock);
 798
 799         if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
 800                 insert_qp(dev, qp);
 801
 802         if (lastwqe) {
 803                 ev.device = qp->ibqp.device;
 804                 ev.element.qp = &qp->ibqp;
 805                 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
 806                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
 807         }
 808         if (mig) {
 809                 ev.device = qp->ibqp.device;
 810                 ev.element.qp = &qp->ibqp;
 811                 ev.event = IB_EVENT_PATH_MIG;
 812                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
 813         }
 814         ret = 0;
 815         goto bail;
 816
 817 inval:
 818         spin_unlock(&qp->s_lock);
 819         spin_unlock_irq(&qp->r_lock);
 820         ret = -EINVAL;
 821
 822 bail:
 823         return ret;
 824 }
 825
 826 int qib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 827                  int attr_mask, struct ib_qp_init_attr *init_attr)
 828 {
 829         struct qib_qp *qp = to_iqp(ibqp);
 830
 831         attr->qp_state = qp->state;
 832         attr->cur_qp_state = attr->qp_state;
 833         attr->path_mtu = qp->path_mtu;
 834         attr->path_mig_state = qp->s_mig_state;
 835         attr->qkey = qp->qkey;
 836         attr->rq_psn = qp->r_psn & QIB_PSN_MASK;
 837         attr->sq_psn = qp->s_next_psn & QIB_PSN_MASK;
 838         attr->dest_qp_num = qp->remote_qpn;
 839         attr->qp_access_flags = qp->qp_access_flags;
 840         attr->cap.max_send_wr = qp->s_size - 1;
 841         attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
 842         attr->cap.max_send_sge = qp->s_max_sge;
 843         attr->cap.max_recv_sge = qp->r_rq.max_sge;
 844         attr->cap.max_inline_data = 0;
 845         attr->ah_attr = qp->remote_ah_attr;
 846         attr->alt_ah_attr = qp->alt_ah_attr;
 847         attr->pkey_index = qp->s_pkey_index;
 848         attr->alt_pkey_index = qp->s_alt_pkey_index;
 849         attr->en_sqd_async_notify = 0;
 850         attr->sq_draining = qp->s_draining;
 851         attr->max_rd_atomic = qp->s_max_rd_atomic;
 852         attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
 853         attr->min_rnr_timer = qp->r_min_rnr_timer;
 854         attr->port_num = qp->port_num;
 855         attr->timeout = qp->timeout;
 856         attr->retry_cnt = qp->s_retry_cnt;
 857         attr->rnr_retry = qp->s_rnr_retry_cnt;
 858         attr->alt_port_num = qp->alt_ah_attr.port_num;
 859         attr->alt_timeout = qp->alt_timeout;
 860
 861         init_attr->event_handler = qp->ibqp.event_handler;
 862         init_attr->qp_context = qp->ibqp.qp_context;
 863         init_attr->send_cq = qp->ibqp.send_cq;
 864         init_attr->recv_cq = qp->ibqp.recv_cq;
 865         init_attr->srq = qp->ibqp.srq;
 866         init_attr->cap = attr->cap;
 867         if (qp->s_flags & QIB_S_SIGNAL_REQ_WR)
 868                 init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
 869         else
 870                 init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
 871         init_attr->qp_type = qp->ibqp.qp_type;
 872         init_attr->port_num = qp->port_num;
 873         return 0;
 874 }
 875
 876 /**
 877  * qib_compute_aeth - compute the AETH (syndrome + MSN)
 878  * @qp: the queue pair to compute the AETH for
 879  *
 880  * Returns the AETH.
 881  */
 882 __be32 qib_compute_aeth(struct qib_qp *qp)
 883 {
 884         u32 aeth = qp->r_msn & QIB_MSN_MASK;
 885
 886         if (qp->ibqp.srq) {
 887                 /*
 888                  * Shared receive queues don't generate credits.
 889                  * Set the credit field to the invalid value.
 890                  */
 891                 aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
 892         } else {
 893                 u32 min, max, x;
 894                 u32 credits;
 895                 struct qib_rwq *wq = qp->r_rq.wq;
 896                 u32 head;
 897                 u32 tail;
 898
 899                 /* sanity check pointers before trusting them */
 900                 head = wq->head;
 901                 if (head >= qp->r_rq.size)
 902                         head = 0;
 903                 tail = wq->tail;
 904                 if (tail >= qp->r_rq.size)
 905                         tail = 0;
 906                 /*
 907                  * Compute the number of credits available (RWQEs).
 908                  * XXX Not holding the r_rq.lock here so there is a small
 909                  * chance that the pair of reads are not atomic.
 910                  */
 911                 credits = head - tail;
 912                 if ((int)credits < 0)
 913                         credits += qp->r_rq.size;
 914                 /*
 915                  * Binary search the credit table to find the code to
 916                  * use.
 917                  */
 918                 min = 0;
 919                 max = 31;
 920                 for (;;) {
 921                         x = (min + max) / 2;
 922                         if (credit_table[x] == credits)
 923                                 break;
 924                         if (credit_table[x] > credits)
 925                                 max = x;
 926                         else if (min == x)
 927                                 break;
 928                         else
 929                                 min = x;
 930                 }
 931                 aeth |= x << QIB_AETH_CREDIT_SHIFT;
 932         }
 933         return cpu_to_be32(aeth);
 934 }
 935
 936 /**
 937  * qib_create_qp - create a queue pair for a device
 938  * @ibpd: the protection domain who's device we create the queue pair for
 939  * @init_attr: the attributes of the queue pair
 940  * @udata: user data for libibverbs.so
 941  *
 942  * Returns the queue pair on success, otherwise returns an errno.
 943  *
 944  * Called by the ib_create_qp() core verbs function.
 945  */
 946 struct ib_qp *qib_create_qp(struct ib_pd *ibpd,
 947                             struct ib_qp_init_attr *init_attr,
 948                             struct ib_udata *udata)
 949 {
 950         struct qib_qp *qp;
 951         int err;
 952         struct qib_swqe *swq = NULL;
 953         struct qib_ibdev *dev;
 954         struct qib_devdata *dd;
 955         size_t sz;
 956         size_t sg_list_sz;
 957         struct ib_qp *ret;
 958
 959         if (init_attr->cap.max_send_sge > ib_qib_max_sges ||
 960             init_attr->cap.max_send_wr > ib_qib_max_qp_wrs) {
 961                 ret = ERR_PTR(-EINVAL);
 962                 goto bail;
 963         }
 964
 965         /* Check receive queue parameters if no SRQ is specified. */
 966         if (!init_attr->srq) {
 967                 if (init_attr->cap.max_recv_sge > ib_qib_max_sges ||
 968                     init_attr->cap.max_recv_wr > ib_qib_max_qp_wrs) {
 969                         ret = ERR_PTR(-EINVAL);
 970                         goto bail;
 971                 }
 972                 if (init_attr->cap.max_send_sge +
 973                     init_attr->cap.max_send_wr +
 974                     init_attr->cap.max_recv_sge +
 975                     init_attr->cap.max_recv_wr == 0) {
 976                         ret = ERR_PTR(-EINVAL);
 977                         goto bail;
 978                 }
 979         }
 980
 981         switch (init_attr->qp_type) {
 982         case IB_QPT_SMI:
 983         case IB_QPT_GSI:
 984                 if (init_attr->port_num == 0 ||
 985                     init_attr->port_num > ibpd->device->phys_port_cnt) {
 986                         ret = ERR_PTR(-EINVAL);
 987                         goto bail;
 988                 }
 989         case IB_QPT_UC:
 990         case IB_QPT_RC:
 991         case IB_QPT_UD:
 992                 sz = sizeof(struct qib_sge) *
 993                         init_attr->cap.max_send_sge +
 994                         sizeof(struct qib_swqe);
 995                 swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
 996                 if (swq == NULL) {
 997                         ret = ERR_PTR(-ENOMEM);
 998                         goto bail;
 999                 }
1000                 sz = sizeof(*qp);
1001                 sg_list_sz = 0;
1002                 if (init_attr->srq) {
1003                         struct qib_srq *srq = to_isrq(init_attr->srq);
1004
1005                         if (srq->rq.max_sge > 1)
1006                                 sg_list_sz = sizeof(*qp->r_sg_list) *
1007                                         (srq->rq.max_sge - 1);
1008                 } else if (init_attr->cap.max_recv_sge > 1)
1009                         sg_list_sz = sizeof(*qp->r_sg_list) *
1010                                 (init_attr->cap.max_recv_sge - 1);
1011                 qp = kzalloc(sz + sg_list_sz, GFP_KERNEL);
1012                 if (!qp) {
1013                         ret = ERR_PTR(-ENOMEM);
1014                         goto bail_swq;
1015                 }
1016                 if (init_attr->srq)
1017                         sz = 0;
1018                 else {
1019                         qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
1020                         qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
1021                         sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
1022                                 sizeof(struct qib_rwqe);
1023                         qp->r_rq.wq = vmalloc_user(sizeof(struct qib_rwq) +
1024                                                    qp->r_rq.size * sz);
1025                         if (!qp->r_rq.wq) {
1026                                 ret = ERR_PTR(-ENOMEM);
1027                                 goto bail_qp;
1028                         }
1029                 }
1030
1031                 /*
1032                  * ib_create_qp() will initialize qp->ibqp
1033                  * except for qp->ibqp.qp_num.
1034                  */
1035                 spin_lock_init(&qp->r_lock);
1036                 spin_lock_init(&qp->s_lock);
1037                 spin_lock_init(&qp->r_rq.lock);
1038                 atomic_set(&qp->refcount, 0);
1039                 init_waitqueue_head(&qp->wait);
1040                 init_waitqueue_head(&qp->wait_dma);
1041                 init_timer(&qp->s_timer);
1042                 qp->s_timer.data = (unsigned long)qp;
1043                 INIT_WORK(&qp->s_work, qib_do_send);
1044                 INIT_LIST_HEAD(&qp->iowait);
1045                 INIT_LIST_HEAD(&qp->rspwait);
1046                 qp->state = IB_QPS_RESET;
1047                 qp->s_wq = swq;
1048                 qp->s_size = init_attr->cap.max_send_wr + 1;
1049                 qp->s_max_sge = init_attr->cap.max_send_sge;
1050                 if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
1051                         qp->s_flags = QIB_S_SIGNAL_REQ_WR;
1052                 dev = to_idev(ibpd->device);
1053                 dd = dd_from_dev(dev);
1054                 err = alloc_qpn(dd, &dev->qpn_table, init_attr->qp_type,
1055                                 init_attr->port_num);
1056                 if (err < 0) {
1057                         ret = ERR_PTR(err);
1058                         vfree(qp->r_rq.wq);
1059                         goto bail_qp;
1060                 }
1061                 qp->ibqp.qp_num = err;
1062                 qp->port_num = init_attr->port_num;
1063                 qib_reset_qp(qp, init_attr->qp_type);
1064                 break;
1065
1066         default:
1067                 /* Don't support raw QPs */
1068                 ret = ERR_PTR(-ENOSYS);
1069                 goto bail;
1070         }
1071
1072         init_attr->cap.max_inline_data = 0;
1073
1074         /*
1075          * Return the address of the RWQ as the offset to mmap.
1076          * See qib_mmap() for details.
1077          */
1078         if (udata && udata->outlen >= sizeof(__u64)) {
1079                 if (!qp->r_rq.wq) {
1080                         __u64 offset = 0;
1081
1082                         err = ib_copy_to_udata(udata, &offset,
1083                                                sizeof(offset));
1084                         if (err) {
1085                                 ret = ERR_PTR(err);
1086                                 goto bail_ip;
1087                         }
1088                 } else {
1089                         u32 s = sizeof(struct qib_rwq) + qp->r_rq.size * sz;
1090
1091                         qp->ip = qib_create_mmap_info(dev, s,
1092                                                       ibpd->uobject->context,
1093                                                       qp->r_rq.wq);
1094                         if (!qp->ip) {
1095                                 ret = ERR_PTR(-ENOMEM);
1096                                 goto bail_ip;
1097                         }
1098
1099                         err = ib_copy_to_udata(udata, &(qp->ip->offset),
1100                                                sizeof(qp->ip->offset));
1101                         if (err) {
1102                                 ret = ERR_PTR(err);
1103                                 goto bail_ip;
1104                         }
1105                 }
1106         }
1107
1108         spin_lock(&dev->n_qps_lock);
1109         if (dev->n_qps_allocated == ib_qib_max_qps) {
1110                 spin_unlock(&dev->n_qps_lock);
1111                 ret = ERR_PTR(-ENOMEM);
1112                 goto bail_ip;
1113         }
1114
1115         dev->n_qps_allocated++;
1116         spin_unlock(&dev->n_qps_lock);
1117
1118         if (qp->ip) {
1119                 spin_lock_irq(&dev->pending_lock);
1120                 list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
1121                 spin_unlock_irq(&dev->pending_lock);
1122         }
1123
1124         ret = &qp->ibqp;
1125         goto bail;
1126
1127 bail_ip:
1128         if (qp->ip)
1129                 kref_put(&qp->ip->ref, qib_release_mmap_info);
1130         else
1131                 vfree(qp->r_rq.wq);
1132         free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1133 bail_qp:
1134         kfree(qp);
1135 bail_swq:
1136         vfree(swq);
1137 bail:
1138         return ret;
1139 }
1140
1141 /**
1142  * qib_destroy_qp - destroy a queue pair
1143  * @ibqp: the queue pair to destroy
1144  *
1145  * Returns 0 on success.
1146  *
1147  * Note that this can be called while the QP is actively sending or
1148  * receiving!
1149  */
1150 int qib_destroy_qp(struct ib_qp *ibqp)
1151 {
1152         struct qib_qp *qp = to_iqp(ibqp);
1153         struct qib_ibdev *dev = to_idev(ibqp->device);
1154
1155         /* Make sure HW and driver activity is stopped. */
1156         spin_lock_irq(&qp->s_lock);
1157         if (qp->state != IB_QPS_RESET) {
1158                 qp->state = IB_QPS_RESET;
1159                 spin_lock(&dev->pending_lock);
1160                 if (!list_empty(&qp->iowait))
1161                         list_del_init(&qp->iowait);
1162                 spin_unlock(&dev->pending_lock);
1163                 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
1164                 spin_unlock_irq(&qp->s_lock);
1165                 cancel_work_sync(&qp->s_work);
1166                 del_timer_sync(&qp->s_timer);
1167                 wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
1168                 if (qp->s_tx) {
1169                         qib_put_txreq(qp->s_tx);
1170                         qp->s_tx = NULL;
1171                 }
1172                 remove_qp(dev, qp);
1173                 wait_event(qp->wait, !atomic_read(&qp->refcount));
1174                 clear_mr_refs(qp, 1);
1175         } else
1176                 spin_unlock_irq(&qp->s_lock);
1177
1178         /* all user's cleaned up, mark it available */
1179         free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1180         spin_lock(&dev->n_qps_lock);
1181         dev->n_qps_allocated--;
1182         spin_unlock(&dev->n_qps_lock);
1183
1184         if (qp->ip)
1185                 kref_put(&qp->ip->ref, qib_release_mmap_info);
1186         else
1187                 vfree(qp->r_rq.wq);
1188         vfree(qp->s_wq);
1189         kfree(qp);
1190         return 0;
1191 }
1192
1193 /**
1194  * qib_init_qpn_table - initialize the QP number table for a device
1195  * @qpt: the QPN table
1196  */
1197 void qib_init_qpn_table(struct qib_devdata *dd, struct qib_qpn_table *qpt)
1198 {
1199         spin_lock_init(&qpt->lock);
1200         qpt->last = 1;          /* start with QPN 2 */
1201         qpt->nmaps = 1;
1202         qpt->mask = dd->qpn_mask;
1203 }
1204
1205 /**
1206  * qib_free_qpn_table - free the QP number table for a device
1207  * @qpt: the QPN table
1208  */
1209 void qib_free_qpn_table(struct qib_qpn_table *qpt)
1210 {
1211         int i;
1212
1213         for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
1214                 if (qpt->map[i].page)
1215                         free_page((unsigned long) qpt->map[i].page);
1216 }
1217
1218 /**
1219  * qib_get_credit - flush the send work queue of a QP
1220  * @qp: the qp who's send work queue to flush
1221  * @aeth: the Acknowledge Extended Transport Header
1222  *
1223  * The QP s_lock should be held.
1224  */
1225 void qib_get_credit(struct qib_qp *qp, u32 aeth)
1226 {
1227         u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;
1228
1229         /*
1230          * If the credit is invalid, we can send
1231          * as many packets as we like.  Otherwise, we have to
1232          * honor the credit field.
1233          */
1234         if (credit == QIB_AETH_CREDIT_INVAL) {
1235                 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1236                         qp->s_flags |= QIB_S_UNLIMITED_CREDIT;
1237                         if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1238                                 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1239                                 qib_schedule_send(qp);
1240                         }
1241                 }
1242         } else if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1243                 /* Compute new LSN (i.e., MSN + credit) */
1244                 credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
1245                 if (qib_cmp24(credit, qp->s_lsn) > 0) {
1246                         qp->s_lsn = credit;
1247                         if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1248                                 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1249                                 qib_schedule_send(qp);
1250                         }
1251                 }
1252         }
1253 }