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 r)
  52 {
  53         if (qpt->mask) {
  54                 off++;
  55                 if ((off & qpt->mask) >> 1 != r)
  56                         off = ((off & qpt->mask) ?
  57                                 (off | qpt->mask) + 1 : off) | (r << 1);
  58         } else
  59                 off = find_next_zero_bit(map->page, BITS_PER_PAGE, off);
  60         return off;
  61 }
  62
  63 /*
  64  * Convert the AETH credit code into the number of credits.
  65  */
  66 static u32 credit_table[31] = {
  67         0,                      /* 0 */
  68         1,                      /* 1 */
  69         2,                      /* 2 */
  70         3,                      /* 3 */
  71         4,                      /* 4 */
  72         6,                      /* 5 */
  73         8,                      /* 6 */
  74         12,                     /* 7 */
  75         16,                     /* 8 */
  76         24,                     /* 9 */
  77         32,                     /* A */
  78         48,                     /* B */
  79         64,                     /* C */
  80         96,                     /* D */
  81         128,                    /* E */
  82         192,                    /* F */
  83         256,                    /* 10 */
  84         384,                    /* 11 */
  85         512,                    /* 12 */
  86         768,                    /* 13 */
  87         1024,                   /* 14 */
  88         1536,                   /* 15 */
  89         2048,                   /* 16 */
  90         3072,                   /* 17 */
  91         4096,                   /* 18 */
  92         6144,                   /* 19 */
  93         8192,                   /* 1A */
  94         12288,                  /* 1B */
  95         16384,                  /* 1C */
  96         24576,                  /* 1D */
  97         32768                   /* 1E */
  98 };
  99
 100 static void get_map_page(struct qib_qpn_table *qpt, struct qpn_map *map)
 101 {
 102         unsigned long page = get_zeroed_page(GFP_KERNEL);
 103
 104         /*
 105          * Free the page if someone raced with us installing it.
 106          */
 107
 108         spin_lock(&qpt->lock);
 109         if (map->page)
 110                 free_page(page);
 111         else
 112                 map->page = (void *)page;
 113         spin_unlock(&qpt->lock);
 114 }
 115
 116 /*
 117  * Allocate the next available QPN or
 118  * zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
 119  */
 120 static int alloc_qpn(struct qib_devdata *dd, struct qib_qpn_table *qpt,
 121                      enum ib_qp_type type, u8 port)
 122 {
 123         u32 i, offset, max_scan, qpn;
 124         struct qpn_map *map;
 125         u32 ret;
 126         int r;
 127
 128         if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
 129                 unsigned n;
 130
 131                 ret = type == IB_QPT_GSI;
 132                 n = 1 << (ret + 2 * (port - 1));
 133                 spin_lock(&qpt->lock);
 134                 if (qpt->flags & n)
 135                         ret = -EINVAL;
 136                 else
 137                         qpt->flags |= n;
 138                 spin_unlock(&qpt->lock);
 139                 goto bail;
 140         }
 141
 142         r = smp_processor_id();
 143         if (r >= dd->n_krcv_queues)
 144                 r %= dd->n_krcv_queues;
 145         qpn = qpt->last + 1;
 146         if (qpn >= QPN_MAX)
 147                 qpn = 2;
 148         if (qpt->mask && ((qpn & qpt->mask) >> 1) != r)
 149                 qpn = ((qpn & qpt->mask) ? (qpn | qpt->mask) + 1 : qpn) |
 150                         (r << 1);
 151         offset = qpn & BITS_PER_PAGE_MASK;
 152         map = &qpt->map[qpn / BITS_PER_PAGE];
 153         max_scan = qpt->nmaps - !offset;
 154         for (i = 0;;) {
 155                 if (unlikely(!map->page)) {
 156                         get_map_page(qpt, map);
 157                         if (unlikely(!map->page))
 158                                 break;
 159                 }
 160                 do {
 161                         if (!test_and_set_bit(offset, map->page)) {
 162                                 qpt->last = qpn;
 163                                 ret = qpn;
 164                                 goto bail;
 165                         }
 166                         offset = find_next_offset(qpt, map, offset, r);
 167                         qpn = mk_qpn(qpt, map, offset);
 168                         /*
 169                          * This test differs from alloc_pidmap().
 170                          * If find_next_offset() does find a zero
 171                          * bit, we don't need to check for QPN
 172                          * wrapping around past our starting QPN.
 173                          * We just need to be sure we don't loop
 174                          * forever.
 175                          */
 176                 } while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
 177                 /*
 178                  * In order to keep the number of pages allocated to a
 179                  * minimum, we scan the all existing pages before increasing
 180                  * the size of the bitmap table.
 181                  */
 182                 if (++i > max_scan) {
 183                         if (qpt->nmaps == QPNMAP_ENTRIES)
 184                                 break;
 185                         map = &qpt->map[qpt->nmaps++];
 186                         offset = qpt->mask ? (r << 1) : 0;
 187                 } else if (map < &qpt->map[qpt->nmaps]) {
 188                         ++map;
 189                         offset = qpt->mask ? (r << 1) : 0;
 190                 } else {
 191                         map = &qpt->map[0];
 192                         offset = qpt->mask ? (r << 1) : 2;
 193                 }
 194                 qpn = mk_qpn(qpt, map, offset);
 195         }
 196
 197         ret = -ENOMEM;
 198
 199 bail:
 200         return ret;
 201 }
 202
 203 static void free_qpn(struct qib_qpn_table *qpt, u32 qpn)
 204 {
 205         struct qpn_map *map;
 206
 207         map = qpt->map + qpn / BITS_PER_PAGE;
 208         if (map->page)
 209                 clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
 210 }
 211
 212 /*
 213  * Put the QP into the hash table.
 214  * The hash table holds a reference to the QP.
 215  */
 216 static void insert_qp(struct qib_ibdev *dev, struct qib_qp *qp)
 217 {
 218         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 219         unsigned n = qp->ibqp.qp_num % dev->qp_table_size;
 220         unsigned long flags;
 221
 222         spin_lock_irqsave(&dev->qpt_lock, flags);
 223
 224         if (qp->ibqp.qp_num == 0)
 225                 ibp->qp0 = qp;
 226         else if (qp->ibqp.qp_num == 1)
 227                 ibp->qp1 = qp;
 228         else {
 229                 qp->next = dev->qp_table[n];
 230                 dev->qp_table[n] = qp;
 231         }
 232         atomic_inc(&qp->refcount);
 233
 234         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 235 }
 236
 237 /*
 238  * Remove the QP from the table so it can't be found asynchronously by
 239  * the receive interrupt routine.
 240  */
 241 static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp)
 242 {
 243         struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
 244         struct qib_qp *q, **qpp;
 245         unsigned long flags;
 246
 247         qpp = &dev->qp_table[qp->ibqp.qp_num % dev->qp_table_size];
 248
 249         spin_lock_irqsave(&dev->qpt_lock, flags);
 250
 251         if (ibp->qp0 == qp) {
 252                 ibp->qp0 = NULL;
 253                 atomic_dec(&qp->refcount);
 254         } else if (ibp->qp1 == qp) {
 255                 ibp->qp1 = NULL;
 256                 atomic_dec(&qp->refcount);
 257         } else
 258                 for (; (q = *qpp) != NULL; qpp = &q->next)
 259                         if (q == qp) {
 260                                 *qpp = qp->next;
 261                                 qp->next = NULL;
 262                                 atomic_dec(&qp->refcount);
 263                                 break;
 264                         }
 265
 266         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 267 }
 268
 269 /**
 270  * qib_free_all_qps - check for QPs still in use
 271  * @qpt: the QP table to empty
 272  *
 273  * There should not be any QPs still in use.
 274  * Free memory for table.
 275  */
 276 unsigned qib_free_all_qps(struct qib_devdata *dd)
 277 {
 278         struct qib_ibdev *dev = &dd->verbs_dev;
 279         unsigned long flags;
 280         struct qib_qp *qp;
 281         unsigned n, qp_inuse = 0;
 282
 283         for (n = 0; n < dd->num_pports; n++) {
 284                 struct qib_ibport *ibp = &dd->pport[n].ibport_data;
 285
 286                 if (!qib_mcast_tree_empty(ibp))
 287                         qp_inuse++;
 288                 if (ibp->qp0)
 289                         qp_inuse++;
 290                 if (ibp->qp1)
 291                         qp_inuse++;
 292         }
 293
 294         spin_lock_irqsave(&dev->qpt_lock, flags);
 295         for (n = 0; n < dev->qp_table_size; n++) {
 296                 qp = dev->qp_table[n];
 297                 dev->qp_table[n] = NULL;
 298
 299                 for (; qp; qp = qp->next)
 300                         qp_inuse++;
 301         }
 302         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 303
 304         return qp_inuse;
 305 }
 306
 307 /**
 308  * qib_lookup_qpn - return the QP with the given QPN
 309  * @qpt: the QP table
 310  * @qpn: the QP number to look up
 311  *
 312  * The caller is responsible for decrementing the QP reference count
 313  * when done.
 314  */
 315 struct qib_qp *qib_lookup_qpn(struct qib_ibport *ibp, u32 qpn)
 316 {
 317         struct qib_ibdev *dev = &ppd_from_ibp(ibp)->dd->verbs_dev;
 318         unsigned long flags;
 319         struct qib_qp *qp;
 320
 321         spin_lock_irqsave(&dev->qpt_lock, flags);
 322
 323         if (qpn == 0)
 324                 qp = ibp->qp0;
 325         else if (qpn == 1)
 326                 qp = ibp->qp1;
 327         else
 328                 for (qp = dev->qp_table[qpn % dev->qp_table_size]; qp;
 329                      qp = qp->next)
 330                         if (qp->ibqp.qp_num == qpn)
 331                                 break;
 332         if (qp)
 333                 atomic_inc(&qp->refcount);
 334
 335         spin_unlock_irqrestore(&dev->qpt_lock, flags);
 336         return qp;
 337 }
 338
 339 /**
 340  * qib_reset_qp - initialize the QP state to the reset state
 341  * @qp: the QP to reset
 342  * @type: the QP type
 343  */
 344 static void qib_reset_qp(struct qib_qp *qp, enum ib_qp_type type)
 345 {
 346         qp->remote_qpn = 0;
 347         qp->qkey = 0;
 348         qp->qp_access_flags = 0;
 349         atomic_set(&qp->s_dma_busy, 0);
 350         qp->s_flags &= QIB_S_SIGNAL_REQ_WR;
 351         qp->s_hdrwords = 0;
 352         qp->s_wqe = NULL;
 353         qp->s_draining = 0;
 354         qp->s_next_psn = 0;
 355         qp->s_last_psn = 0;
 356         qp->s_sending_psn = 0;
 357         qp->s_sending_hpsn = 0;
 358         qp->s_psn = 0;
 359         qp->r_psn = 0;
 360         qp->r_msn = 0;
 361         if (type == IB_QPT_RC) {
 362                 qp->s_state = IB_OPCODE_RC_SEND_LAST;
 363                 qp->r_state = IB_OPCODE_RC_SEND_LAST;
 364         } else {
 365                 qp->s_state = IB_OPCODE_UC_SEND_LAST;
 366                 qp->r_state = IB_OPCODE_UC_SEND_LAST;
 367         }
 368         qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
 369         qp->r_nak_state = 0;
 370         qp->r_aflags = 0;
 371         qp->r_flags = 0;
 372         qp->s_head = 0;
 373         qp->s_tail = 0;
 374         qp->s_cur = 0;
 375         qp->s_acked = 0;
 376         qp->s_last = 0;
 377         qp->s_ssn = 1;
 378         qp->s_lsn = 0;
 379         qp->s_mig_state = IB_MIG_MIGRATED;
 380         memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
 381         qp->r_head_ack_queue = 0;
 382         qp->s_tail_ack_queue = 0;
 383         qp->s_num_rd_atomic = 0;
 384         if (qp->r_rq.wq) {
 385                 qp->r_rq.wq->head = 0;
 386                 qp->r_rq.wq->tail = 0;
 387         }
 388         qp->r_sge.num_sge = 0;
 389 }
 390
 391 static void clear_mr_refs(struct qib_qp *qp, int clr_sends)
 392 {
 393         unsigned n;
 394
 395         if (test_and_clear_bit(QIB_R_REWIND_SGE, &qp->r_aflags))
 396                 while (qp->s_rdma_read_sge.num_sge) {
 397                         atomic_dec(&qp->s_rdma_read_sge.sge.mr->refcount);
 398                         if (--qp->s_rdma_read_sge.num_sge)
 399                                 qp->s_rdma_read_sge.sge =
 400                                         *qp->s_rdma_read_sge.sg_list++;
 401                 }
 402
 403         while (qp->r_sge.num_sge) {
 404                 atomic_dec(&qp->r_sge.sge.mr->refcount);
 405                 if (--qp->r_sge.num_sge)
 406                         qp->r_sge.sge = *qp->r_sge.sg_list++;
 407         }
 408
 409         if (clr_sends) {
 410                 while (qp->s_last != qp->s_head) {
 411                         struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
 412                         unsigned i;
 413
 414                         for (i = 0; i < wqe->wr.num_sge; i++) {
 415                                 struct qib_sge *sge = &wqe->sg_list[i];
 416
 417                                 atomic_dec(&sge->mr->refcount);
 418                         }
 419                         if (qp->ibqp.qp_type == IB_QPT_UD ||
 420                             qp->ibqp.qp_type == IB_QPT_SMI ||
 421                             qp->ibqp.qp_type == IB_QPT_GSI)
 422                                 atomic_dec(&to_iah(wqe->wr.wr.ud.ah)->refcount);
 423                         if (++qp->s_last >= qp->s_size)
 424                                 qp->s_last = 0;
 425                 }
 426                 if (qp->s_rdma_mr) {
 427                         atomic_dec(&qp->s_rdma_mr->refcount);
 428                         qp->s_rdma_mr = NULL;
 429                 }
 430         }
 431
 432         if (qp->ibqp.qp_type != IB_QPT_RC)
 433                 return;
 434
 435         for (n = 0; n < ARRAY_SIZE(qp->s_ack_queue); n++) {
 436                 struct qib_ack_entry *e = &qp->s_ack_queue[n];
 437
 438                 if (e->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST &&
 439                     e->rdma_sge.mr) {
 440                         atomic_dec(&e->rdma_sge.mr->refcount);
 441                         e->rdma_sge.mr = NULL;
 442                 }
 443         }
 444 }
 445
 446 /**
 447  * qib_error_qp - put a QP into the error state
 448  * @qp: the QP to put into the error state
 449  * @err: the receive completion error to signal if a RWQE is active
 450  *
 451  * Flushes both send and receive work queues.
 452  * Returns true if last WQE event should be generated.
 453  * The QP r_lock and s_lock should be held and interrupts disabled.
 454  * If we are already in error state, just return.
 455  */
 456 int qib_error_qp(struct qib_qp *qp, enum ib_wc_status err)
 457 {
 458         struct qib_ibdev *dev = to_idev(qp->ibqp.device);
 459         struct ib_wc wc;
 460         int ret = 0;
 461
 462         if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
 463                 goto bail;
 464
 465         qp->state = IB_QPS_ERR;
 466
 467         if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) {
 468                 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR);
 469                 del_timer(&qp->s_timer);
 470         }
 471         spin_lock(&dev->pending_lock);
 472         if (!list_empty(&qp->iowait) && !(qp->s_flags & QIB_S_BUSY)) {
 473                 qp->s_flags &= ~QIB_S_ANY_WAIT_IO;
 474                 list_del_init(&qp->iowait);
 475         }
 476         spin_unlock(&dev->pending_lock);
 477
 478         if (!(qp->s_flags & QIB_S_BUSY)) {
 479                 qp->s_hdrwords = 0;
 480                 if (qp->s_rdma_mr) {
 481                         atomic_dec(&qp->s_rdma_mr->refcount);
 482                         qp->s_rdma_mr = NULL;
 483                 }
 484                 if (qp->s_tx) {
 485                         qib_put_txreq(qp->s_tx);
 486                         qp->s_tx = NULL;
 487                 }
 488         }
 489
 490         /* Schedule the sending tasklet to drain the send work queue. */
 491         if (qp->s_last != qp->s_head)
 492                 qib_schedule_send(qp);
 493
 494         clear_mr_refs(qp, 0);
 495
 496         memset(&wc, 0, sizeof(wc));
 497         wc.qp = &qp->ibqp;
 498         wc.opcode = IB_WC_RECV;
 499
 500         if (test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) {
 501                 wc.wr_id = qp->r_wr_id;
 502                 wc.status = err;
 503                 qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
 504         }
 505         wc.status = IB_WC_WR_FLUSH_ERR;
 506
 507         if (qp->r_rq.wq) {
 508                 struct qib_rwq *wq;
 509                 u32 head;
 510                 u32 tail;
 511
 512                 spin_lock(&qp->r_rq.lock);
 513
 514                 /* sanity check pointers before trusting them */
 515                 wq = qp->r_rq.wq;
 516                 head = wq->head;
 517                 if (head >= qp->r_rq.size)
 518                         head = 0;
 519                 tail = wq->tail;
 520                 if (tail >= qp->r_rq.size)
 521                         tail = 0;
 522                 while (tail != head) {
 523                         wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
 524                         if (++tail >= qp->r_rq.size)
 525                                 tail = 0;
 526                         qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
 527                 }
 528                 wq->tail = tail;
 529
 530                 spin_unlock(&qp->r_rq.lock);
 531         } else if (qp->ibqp.event_handler)
 532                 ret = 1;
 533
 534 bail:
 535         return ret;
 536 }
 537
 538 /**
 539  * qib_modify_qp - modify the attributes of a queue pair
 540  * @ibqp: the queue pair who's attributes we're modifying
 541  * @attr: the new attributes
 542  * @attr_mask: the mask of attributes to modify
 543  * @udata: user data for libibverbs.so
 544  *
 545  * Returns 0 on success, otherwise returns an errno.
 546  */
 547 int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 548                   int attr_mask, struct ib_udata *udata)
 549 {
 550         struct qib_ibdev *dev = to_idev(ibqp->device);
 551         struct qib_qp *qp = to_iqp(ibqp);
 552         enum ib_qp_state cur_state, new_state;
 553         struct ib_event ev;
 554         int lastwqe = 0;
 555         int mig = 0;
 556         int ret;
 557         u32 pmtu = 0; /* for gcc warning only */
 558
 559         spin_lock_irq(&qp->r_lock);
 560         spin_lock(&qp->s_lock);
 561
 562         cur_state = attr_mask & IB_QP_CUR_STATE ?
 563                 attr->cur_qp_state : qp->state;
 564         new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
 565
 566         if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
 567                                 attr_mask))
 568                 goto inval;
 569
 570         if (attr_mask & IB_QP_AV) {
 571                 if (attr->ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
 572                         goto inval;
 573                 if (qib_check_ah(qp->ibqp.device, &attr->ah_attr))
 574                         goto inval;
 575         }
 576
 577         if (attr_mask & IB_QP_ALT_PATH) {
 578                 if (attr->alt_ah_attr.dlid >= QIB_MULTICAST_LID_BASE)
 579                         goto inval;
 580                 if (qib_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
 581                         goto inval;
 582                 if (attr->alt_pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
 583                         goto inval;
 584         }
 585
 586         if (attr_mask & IB_QP_PKEY_INDEX)
 587                 if (attr->pkey_index >= qib_get_npkeys(dd_from_dev(dev)))
 588                         goto inval;
 589
 590         if (attr_mask & IB_QP_MIN_RNR_TIMER)
 591                 if (attr->min_rnr_timer > 31)
 592                         goto inval;
 593
 594         if (attr_mask & IB_QP_PORT)
 595                 if (qp->ibqp.qp_type == IB_QPT_SMI ||
 596                     qp->ibqp.qp_type == IB_QPT_GSI ||
 597                     attr->port_num == 0 ||
 598                     attr->port_num > ibqp->device->phys_port_cnt)
 599                         goto inval;
 600
 601         if (attr_mask & IB_QP_DEST_QPN)
 602                 if (attr->dest_qp_num > QIB_QPN_MASK)
 603                         goto inval;
 604
 605         if (attr_mask & IB_QP_RETRY_CNT)
 606                 if (attr->retry_cnt > 7)
 607                         goto inval;
 608
 609         if (attr_mask & IB_QP_RNR_RETRY)
 610                 if (attr->rnr_retry > 7)
 611                         goto inval;
 612
 613         /*
 614          * Don't allow invalid path_mtu values.  OK to set greater
 615          * than the active mtu (or even the max_cap, if we have tuned
 616          * that to a small mtu.  We'll set qp->path_mtu
 617          * to the lesser of requested attribute mtu and active,
 618          * for packetizing messages.
 619          * Note that the QP port has to be set in INIT and MTU in RTR.
 620          */
 621         if (attr_mask & IB_QP_PATH_MTU) {
 622                 struct qib_devdata *dd = dd_from_dev(dev);
 623                 int mtu, pidx = qp->port_num - 1;
 624
 625                 mtu = ib_mtu_enum_to_int(attr->path_mtu);
 626                 if (mtu == -1)
 627                         goto inval;
 628                 if (mtu > dd->pport[pidx].ibmtu) {
 629                         switch (dd->pport[pidx].ibmtu) {
 630                         case 4096:
 631                                 pmtu = IB_MTU_4096;
 632                                 break;
 633                         case 2048:
 634                                 pmtu = IB_MTU_2048;
 635                                 break;
 636                         case 1024:
 637                                 pmtu = IB_MTU_1024;
 638                                 break;
 639                         case 512:
 640                                 pmtu = IB_MTU_512;
 641                                 break;
 642                         case 256:
 643                                 pmtu = IB_MTU_256;
 644                                 break;
 645                         default:
 646                                 pmtu = IB_MTU_2048;
 647                         }
 648                 } else
 649                         pmtu = attr->path_mtu;
 650         }
 651
 652         if (attr_mask & IB_QP_PATH_MIG_STATE) {
 653                 if (attr->path_mig_state == IB_MIG_REARM) {
 654                         if (qp->s_mig_state == IB_MIG_ARMED)
 655                                 goto inval;
 656                         if (new_state != IB_QPS_RTS)
 657                                 goto inval;
 658                 } else if (attr->path_mig_state == IB_MIG_MIGRATED) {
 659                         if (qp->s_mig_state == IB_MIG_REARM)
 660                                 goto inval;
 661                         if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
 662                                 goto inval;
 663                         if (qp->s_mig_state == IB_MIG_ARMED)
 664                                 mig = 1;
 665                 } else
 666                         goto inval;
 667         }
 668
 669         if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
 670                 if (attr->max_dest_rd_atomic > QIB_MAX_RDMA_ATOMIC)
 671                         goto inval;
 672
 673         switch (new_state) {
 674         case IB_QPS_RESET:
 675                 if (qp->state != IB_QPS_RESET) {
 676                         qp->state = IB_QPS_RESET;
 677                         spin_lock(&dev->pending_lock);
 678                         if (!list_empty(&qp->iowait))
 679                                 list_del_init(&qp->iowait);
 680                         spin_unlock(&dev->pending_lock);
 681                         qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
 682                         spin_unlock(&qp->s_lock);
 683                         spin_unlock_irq(&qp->r_lock);
 684                         /* Stop the sending work queue and retry timer */
 685                         cancel_work_sync(&qp->s_work);
 686                         del_timer_sync(&qp->s_timer);
 687                         wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
 688                         if (qp->s_tx) {
 689                                 qib_put_txreq(qp->s_tx);
 690                                 qp->s_tx = NULL;
 691                         }
 692                         remove_qp(dev, qp);
 693                         wait_event(qp->wait, !atomic_read(&qp->refcount));
 694                         spin_lock_irq(&qp->r_lock);
 695                         spin_lock(&qp->s_lock);
 696                         clear_mr_refs(qp, 1);
 697                         qib_reset_qp(qp, ibqp->qp_type);
 698                 }
 699                 break;
 700
 701         case IB_QPS_RTR:
 702                 /* Allow event to retrigger if QP set to RTR more than once */
 703                 qp->r_flags &= ~QIB_R_COMM_EST;
 704                 qp->state = new_state;
 705                 break;
 706
 707         case IB_QPS_SQD:
 708                 qp->s_draining = qp->s_last != qp->s_cur;
 709                 qp->state = new_state;
 710                 break;
 711
 712         case IB_QPS_SQE:
 713                 if (qp->ibqp.qp_type == IB_QPT_RC)
 714                         goto inval;
 715                 qp->state = new_state;
 716                 break;
 717
 718         case IB_QPS_ERR:
 719                 lastwqe = qib_error_qp(qp, IB_WC_WR_FLUSH_ERR);
 720                 break;
 721
 722         default:
 723                 qp->state = new_state;
 724                 break;
 725         }
 726
 727         if (attr_mask & IB_QP_PKEY_INDEX)
 728                 qp->s_pkey_index = attr->pkey_index;
 729
 730         if (attr_mask & IB_QP_PORT)
 731                 qp->port_num = attr->port_num;
 732
 733         if (attr_mask & IB_QP_DEST_QPN)
 734                 qp->remote_qpn = attr->dest_qp_num;
 735
 736         if (attr_mask & IB_QP_SQ_PSN) {
 737                 qp->s_next_psn = attr->sq_psn & QIB_PSN_MASK;
 738                 qp->s_psn = qp->s_next_psn;
 739                 qp->s_sending_psn = qp->s_next_psn;
 740                 qp->s_last_psn = qp->s_next_psn - 1;
 741                 qp->s_sending_hpsn = qp->s_last_psn;
 742         }
 743
 744         if (attr_mask & IB_QP_RQ_PSN)
 745                 qp->r_psn = attr->rq_psn & QIB_PSN_MASK;
 746
 747         if (attr_mask & IB_QP_ACCESS_FLAGS)
 748                 qp->qp_access_flags = attr->qp_access_flags;
 749
 750         if (attr_mask & IB_QP_AV) {
 751                 qp->remote_ah_attr = attr->ah_attr;
 752                 qp->s_srate = attr->ah_attr.static_rate;
 753         }
 754
 755         if (attr_mask & IB_QP_ALT_PATH) {
 756                 qp->alt_ah_attr = attr->alt_ah_attr;
 757                 qp->s_alt_pkey_index = attr->alt_pkey_index;
 758         }
 759
 760         if (attr_mask & IB_QP_PATH_MIG_STATE) {
 761                 qp->s_mig_state = attr->path_mig_state;
 762                 if (mig) {
 763                         qp->remote_ah_attr = qp->alt_ah_attr;
 764                         qp->port_num = qp->alt_ah_attr.port_num;
 765                         qp->s_pkey_index = qp->s_alt_pkey_index;
 766                 }
 767         }
 768
 769         if (attr_mask & IB_QP_PATH_MTU)
 770                 qp->path_mtu = pmtu;
 771
 772         if (attr_mask & IB_QP_RETRY_CNT) {
 773                 qp->s_retry_cnt = attr->retry_cnt;
 774                 qp->s_retry = attr->retry_cnt;
 775         }
 776
 777         if (attr_mask & IB_QP_RNR_RETRY) {
 778                 qp->s_rnr_retry_cnt = attr->rnr_retry;
 779                 qp->s_rnr_retry = attr->rnr_retry;
 780         }
 781
 782         if (attr_mask & IB_QP_MIN_RNR_TIMER)
 783                 qp->r_min_rnr_timer = attr->min_rnr_timer;
 784
 785         if (attr_mask & IB_QP_TIMEOUT)
 786                 qp->timeout = attr->timeout;
 787
 788         if (attr_mask & IB_QP_QKEY)
 789                 qp->qkey = attr->qkey;
 790
 791         if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
 792                 qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
 793
 794         if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
 795                 qp->s_max_rd_atomic = attr->max_rd_atomic;
 796
 797         spin_unlock(&qp->s_lock);
 798         spin_unlock_irq(&qp->r_lock);
 799
 800         if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
 801                 insert_qp(dev, qp);
 802
 803         if (lastwqe) {
 804                 ev.device = qp->ibqp.device;
 805                 ev.element.qp = &qp->ibqp;
 806                 ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
 807                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
 808         }
 809         if (mig) {
 810                 ev.device = qp->ibqp.device;
 811                 ev.element.qp = &qp->ibqp;
 812                 ev.event = IB_EVENT_PATH_MIG;
 813                 qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
 814         }
 815         ret = 0;
 816         goto bail;
 817
 818 inval:
 819         spin_unlock(&qp->s_lock);
 820         spin_unlock_irq(&qp->r_lock);
 821         ret = -EINVAL;
 822
 823 bail:
 824         return ret;
 825 }
 826
 827 int qib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 828                  int attr_mask, struct ib_qp_init_attr *init_attr)
 829 {
 830         struct qib_qp *qp = to_iqp(ibqp);
 831
 832         attr->qp_state = qp->state;
 833         attr->cur_qp_state = attr->qp_state;
 834         attr->path_mtu = qp->path_mtu;
 835         attr->path_mig_state = qp->s_mig_state;
 836         attr->qkey = qp->qkey;
 837         attr->rq_psn = qp->r_psn & QIB_PSN_MASK;
 838         attr->sq_psn = qp->s_next_psn & QIB_PSN_MASK;
 839         attr->dest_qp_num = qp->remote_qpn;
 840         attr->qp_access_flags = qp->qp_access_flags;
 841         attr->cap.max_send_wr = qp->s_size - 1;
 842         attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
 843         attr->cap.max_send_sge = qp->s_max_sge;
 844         attr->cap.max_recv_sge = qp->r_rq.max_sge;
 845         attr->cap.max_inline_data = 0;
 846         attr->ah_attr = qp->remote_ah_attr;
 847         attr->alt_ah_attr = qp->alt_ah_attr;
 848         attr->pkey_index = qp->s_pkey_index;
 849         attr->alt_pkey_index = qp->s_alt_pkey_index;
 850         attr->en_sqd_async_notify = 0;
 851         attr->sq_draining = qp->s_draining;
 852         attr->max_rd_atomic = qp->s_max_rd_atomic;
 853         attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
 854         attr->min_rnr_timer = qp->r_min_rnr_timer;
 855         attr->port_num = qp->port_num;
 856         attr->timeout = qp->timeout;
 857         attr->retry_cnt = qp->s_retry_cnt;
 858         attr->rnr_retry = qp->s_rnr_retry_cnt;
 859         attr->alt_port_num = qp->alt_ah_attr.port_num;
 860         attr->alt_timeout = qp->alt_timeout;
 861
 862         init_attr->event_handler = qp->ibqp.event_handler;
 863         init_attr->qp_context = qp->ibqp.qp_context;
 864         init_attr->send_cq = qp->ibqp.send_cq;
 865         init_attr->recv_cq = qp->ibqp.recv_cq;
 866         init_attr->srq = qp->ibqp.srq;
 867         init_attr->cap = attr->cap;
 868         if (qp->s_flags & QIB_S_SIGNAL_REQ_WR)
 869                 init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
 870         else
 871                 init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
 872         init_attr->qp_type = qp->ibqp.qp_type;
 873         init_attr->port_num = qp->port_num;
 874         return 0;
 875 }
 876
 877 /**
 878  * qib_compute_aeth - compute the AETH (syndrome + MSN)
 879  * @qp: the queue pair to compute the AETH for
 880  *
 881  * Returns the AETH.
 882  */
 883 __be32 qib_compute_aeth(struct qib_qp *qp)
 884 {
 885         u32 aeth = qp->r_msn & QIB_MSN_MASK;
 886
 887         if (qp->ibqp.srq) {
 888                 /*
 889                  * Shared receive queues don't generate credits.
 890                  * Set the credit field to the invalid value.
 891                  */
 892                 aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
 893         } else {
 894                 u32 min, max, x;
 895                 u32 credits;
 896                 struct qib_rwq *wq = qp->r_rq.wq;
 897                 u32 head;
 898                 u32 tail;
 899
 900                 /* sanity check pointers before trusting them */
 901                 head = wq->head;
 902                 if (head >= qp->r_rq.size)
 903                         head = 0;
 904                 tail = wq->tail;
 905                 if (tail >= qp->r_rq.size)
 906                         tail = 0;
 907                 /*
 908                  * Compute the number of credits available (RWQEs).
 909                  * XXX Not holding the r_rq.lock here so there is a small
 910                  * chance that the pair of reads are not atomic.
 911                  */
 912                 credits = head - tail;
 913                 if ((int)credits < 0)
 914                         credits += qp->r_rq.size;
 915                 /*
 916                  * Binary search the credit table to find the code to
 917                  * use.
 918                  */
 919                 min = 0;
 920                 max = 31;
 921                 for (;;) {
 922                         x = (min + max) / 2;
 923                         if (credit_table[x] == credits)
 924                                 break;
 925                         if (credit_table[x] > credits)
 926                                 max = x;
 927                         else if (min == x)
 928                                 break;
 929                         else
 930                                 min = x;
 931                 }
 932                 aeth |= x << QIB_AETH_CREDIT_SHIFT;
 933         }
 934         return cpu_to_be32(aeth);
 935 }
 936
 937 /**
 938  * qib_create_qp - create a queue pair for a device
 939  * @ibpd: the protection domain who's device we create the queue pair for
 940  * @init_attr: the attributes of the queue pair
 941  * @udata: user data for libibverbs.so
 942  *
 943  * Returns the queue pair on success, otherwise returns an errno.
 944  *
 945  * Called by the ib_create_qp() core verbs function.
 946  */
 947 struct ib_qp *qib_create_qp(struct ib_pd *ibpd,
 948                             struct ib_qp_init_attr *init_attr,
 949                             struct ib_udata *udata)
 950 {
 951         struct qib_qp *qp;
 952         int err;
 953         struct qib_swqe *swq = NULL;
 954         struct qib_ibdev *dev;
 955         struct qib_devdata *dd;
 956         size_t sz;
 957         size_t sg_list_sz;
 958         struct ib_qp *ret;
 959
 960         if (init_attr->cap.max_send_sge > ib_qib_max_sges ||
 961             init_attr->cap.max_send_wr > ib_qib_max_qp_wrs) {
 962                 ret = ERR_PTR(-EINVAL);
 963                 goto bail;
 964         }
 965
 966         /* Check receive queue parameters if no SRQ is specified. */
 967         if (!init_attr->srq) {
 968                 if (init_attr->cap.max_recv_sge > ib_qib_max_sges ||
 969                     init_attr->cap.max_recv_wr > ib_qib_max_qp_wrs) {
 970                         ret = ERR_PTR(-EINVAL);
 971                         goto bail;
 972                 }
 973                 if (init_attr->cap.max_send_sge +
 974                     init_attr->cap.max_send_wr +
 975                     init_attr->cap.max_recv_sge +
 976                     init_attr->cap.max_recv_wr == 0) {
 977                         ret = ERR_PTR(-EINVAL);
 978                         goto bail;
 979                 }
 980         }
 981
 982         switch (init_attr->qp_type) {
 983         case IB_QPT_SMI:
 984         case IB_QPT_GSI:
 985                 if (init_attr->port_num == 0 ||
 986                     init_attr->port_num > ibpd->device->phys_port_cnt) {
 987                         ret = ERR_PTR(-EINVAL);
 988                         goto bail;
 989                 }
 990         case IB_QPT_UC:
 991         case IB_QPT_RC:
 992         case IB_QPT_UD:
 993                 sz = sizeof(struct qib_sge) *
 994                         init_attr->cap.max_send_sge +
 995                         sizeof(struct qib_swqe);
 996                 swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
 997                 if (swq == NULL) {
 998                         ret = ERR_PTR(-ENOMEM);
 999                         goto bail;
1000                 }
1001                 sz = sizeof(*qp);
1002                 sg_list_sz = 0;
1003                 if (init_attr->srq) {
1004                         struct qib_srq *srq = to_isrq(init_attr->srq);
1005
1006                         if (srq->rq.max_sge > 1)
1007                                 sg_list_sz = sizeof(*qp->r_sg_list) *
1008                                         (srq->rq.max_sge - 1);
1009                 } else if (init_attr->cap.max_recv_sge > 1)
1010                         sg_list_sz = sizeof(*qp->r_sg_list) *
1011                                 (init_attr->cap.max_recv_sge - 1);
1012                 qp = kzalloc(sz + sg_list_sz, GFP_KERNEL);
1013                 if (!qp) {
1014                         ret = ERR_PTR(-ENOMEM);
1015                         goto bail_swq;
1016                 }
1017                 if (init_attr->srq)
1018                         sz = 0;
1019                 else {
1020                         qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
1021                         qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
1022                         sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
1023                                 sizeof(struct qib_rwqe);
1024                         qp->r_rq.wq = vmalloc_user(sizeof(struct qib_rwq) +
1025                                                    qp->r_rq.size * sz);
1026                         if (!qp->r_rq.wq) {
1027                                 ret = ERR_PTR(-ENOMEM);
1028                                 goto bail_qp;
1029                         }
1030                 }
1031
1032                 /*
1033                  * ib_create_qp() will initialize qp->ibqp
1034                  * except for qp->ibqp.qp_num.
1035                  */
1036                 spin_lock_init(&qp->r_lock);
1037                 spin_lock_init(&qp->s_lock);
1038                 spin_lock_init(&qp->r_rq.lock);
1039                 atomic_set(&qp->refcount, 0);
1040                 init_waitqueue_head(&qp->wait);
1041                 init_waitqueue_head(&qp->wait_dma);
1042                 init_timer(&qp->s_timer);
1043                 qp->s_timer.data = (unsigned long)qp;
1044                 INIT_WORK(&qp->s_work, qib_do_send);
1045                 INIT_LIST_HEAD(&qp->iowait);
1046                 INIT_LIST_HEAD(&qp->rspwait);
1047                 qp->state = IB_QPS_RESET;
1048                 qp->s_wq = swq;
1049                 qp->s_size = init_attr->cap.max_send_wr + 1;
1050                 qp->s_max_sge = init_attr->cap.max_send_sge;
1051                 if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
1052                         qp->s_flags = QIB_S_SIGNAL_REQ_WR;
1053                 dev = to_idev(ibpd->device);
1054                 dd = dd_from_dev(dev);
1055                 err = alloc_qpn(dd, &dev->qpn_table, init_attr->qp_type,
1056                                 init_attr->port_num);
1057                 if (err < 0) {
1058                         ret = ERR_PTR(err);
1059                         vfree(qp->r_rq.wq);
1060                         goto bail_qp;
1061                 }
1062                 qp->ibqp.qp_num = err;
1063                 qp->port_num = init_attr->port_num;
1064                 qp->processor_id = smp_processor_id();
1065                 qib_reset_qp(qp, init_attr->qp_type);
1066                 break;
1067
1068         default:
1069                 /* Don't support raw QPs */
1070                 ret = ERR_PTR(-ENOSYS);
1071                 goto bail;
1072         }
1073
1074         init_attr->cap.max_inline_data = 0;
1075
1076         /*
1077          * Return the address of the RWQ as the offset to mmap.
1078          * See qib_mmap() for details.
1079          */
1080         if (udata && udata->outlen >= sizeof(__u64)) {
1081                 if (!qp->r_rq.wq) {
1082                         __u64 offset = 0;
1083
1084                         err = ib_copy_to_udata(udata, &offset,
1085                                                sizeof(offset));
1086                         if (err) {
1087                                 ret = ERR_PTR(err);
1088                                 goto bail_ip;
1089                         }
1090                 } else {
1091                         u32 s = sizeof(struct qib_rwq) + qp->r_rq.size * sz;
1092
1093                         qp->ip = qib_create_mmap_info(dev, s,
1094                                                       ibpd->uobject->context,
1095                                                       qp->r_rq.wq);
1096                         if (!qp->ip) {
1097                                 ret = ERR_PTR(-ENOMEM);
1098                                 goto bail_ip;
1099                         }
1100
1101                         err = ib_copy_to_udata(udata, &(qp->ip->offset),
1102                                                sizeof(qp->ip->offset));
1103                         if (err) {
1104                                 ret = ERR_PTR(err);
1105                                 goto bail_ip;
1106                         }
1107                 }
1108         }
1109
1110         spin_lock(&dev->n_qps_lock);
1111         if (dev->n_qps_allocated == ib_qib_max_qps) {
1112                 spin_unlock(&dev->n_qps_lock);
1113                 ret = ERR_PTR(-ENOMEM);
1114                 goto bail_ip;
1115         }
1116
1117         dev->n_qps_allocated++;
1118         spin_unlock(&dev->n_qps_lock);
1119
1120         if (qp->ip) {
1121                 spin_lock_irq(&dev->pending_lock);
1122                 list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
1123                 spin_unlock_irq(&dev->pending_lock);
1124         }
1125
1126         ret = &qp->ibqp;
1127         goto bail;
1128
1129 bail_ip:
1130         if (qp->ip)
1131                 kref_put(&qp->ip->ref, qib_release_mmap_info);
1132         else
1133                 vfree(qp->r_rq.wq);
1134         free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1135 bail_qp:
1136         kfree(qp);
1137 bail_swq:
1138         vfree(swq);
1139 bail:
1140         return ret;
1141 }
1142
1143 /**
1144  * qib_destroy_qp - destroy a queue pair
1145  * @ibqp: the queue pair to destroy
1146  *
1147  * Returns 0 on success.
1148  *
1149  * Note that this can be called while the QP is actively sending or
1150  * receiving!
1151  */
1152 int qib_destroy_qp(struct ib_qp *ibqp)
1153 {
1154         struct qib_qp *qp = to_iqp(ibqp);
1155         struct qib_ibdev *dev = to_idev(ibqp->device);
1156
1157         /* Make sure HW and driver activity is stopped. */
1158         spin_lock_irq(&qp->s_lock);
1159         if (qp->state != IB_QPS_RESET) {
1160                 qp->state = IB_QPS_RESET;
1161                 spin_lock(&dev->pending_lock);
1162                 if (!list_empty(&qp->iowait))
1163                         list_del_init(&qp->iowait);
1164                 spin_unlock(&dev->pending_lock);
1165                 qp->s_flags &= ~(QIB_S_TIMER | QIB_S_ANY_WAIT);
1166                 spin_unlock_irq(&qp->s_lock);
1167                 cancel_work_sync(&qp->s_work);
1168                 del_timer_sync(&qp->s_timer);
1169                 wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
1170                 if (qp->s_tx) {
1171                         qib_put_txreq(qp->s_tx);
1172                         qp->s_tx = NULL;
1173                 }
1174                 remove_qp(dev, qp);
1175                 wait_event(qp->wait, !atomic_read(&qp->refcount));
1176                 clear_mr_refs(qp, 1);
1177         } else
1178                 spin_unlock_irq(&qp->s_lock);
1179
1180         /* all user's cleaned up, mark it available */
1181         free_qpn(&dev->qpn_table, qp->ibqp.qp_num);
1182         spin_lock(&dev->n_qps_lock);
1183         dev->n_qps_allocated--;
1184         spin_unlock(&dev->n_qps_lock);
1185
1186         if (qp->ip)
1187                 kref_put(&qp->ip->ref, qib_release_mmap_info);
1188         else
1189                 vfree(qp->r_rq.wq);
1190         vfree(qp->s_wq);
1191         kfree(qp);
1192         return 0;
1193 }
1194
1195 /**
1196  * qib_init_qpn_table - initialize the QP number table for a device
1197  * @qpt: the QPN table
1198  */
1199 void qib_init_qpn_table(struct qib_devdata *dd, struct qib_qpn_table *qpt)
1200 {
1201         spin_lock_init(&qpt->lock);
1202         qpt->last = 1;          /* start with QPN 2 */
1203         qpt->nmaps = 1;
1204         qpt->mask = dd->qpn_mask;
1205 }
1206
1207 /**
1208  * qib_free_qpn_table - free the QP number table for a device
1209  * @qpt: the QPN table
1210  */
1211 void qib_free_qpn_table(struct qib_qpn_table *qpt)
1212 {
1213         int i;
1214
1215         for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
1216                 if (qpt->map[i].page)
1217                         free_page((unsigned long) qpt->map[i].page);
1218 }
1219
1220 /**
1221  * qib_get_credit - flush the send work queue of a QP
1222  * @qp: the qp who's send work queue to flush
1223  * @aeth: the Acknowledge Extended Transport Header
1224  *
1225  * The QP s_lock should be held.
1226  */
1227 void qib_get_credit(struct qib_qp *qp, u32 aeth)
1228 {
1229         u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;
1230
1231         /*
1232          * If the credit is invalid, we can send
1233          * as many packets as we like.  Otherwise, we have to
1234          * honor the credit field.
1235          */
1236         if (credit == QIB_AETH_CREDIT_INVAL) {
1237                 if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1238                         qp->s_flags |= QIB_S_UNLIMITED_CREDIT;
1239                         if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1240                                 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1241                                 qib_schedule_send(qp);
1242                         }
1243                 }
1244         } else if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) {
1245                 /* Compute new LSN (i.e., MSN + credit) */
1246                 credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
1247                 if (qib_cmp24(credit, qp->s_lsn) > 0) {
1248                         qp->s_lsn = credit;
1249                         if (qp->s_flags & QIB_S_WAIT_SSN_CREDIT) {
1250                                 qp->s_flags &= ~QIB_S_WAIT_SSN_CREDIT;
1251                                 qib_schedule_send(qp);
1252                         }
1253                 }
1254         }
1255 }