drivers/infiniband/hw/mthca/mthca_srq.c

   1 /*
   2  * Copyright (c) 2005 Cisco Systems. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/slab.h>
  34 #include <linux/string.h>
  35 #include <linux/sched.h>
  36
  37 #include <asm/io.h>
  38
  39 #include "mthca_dev.h"
  40 #include "mthca_cmd.h"
  41 #include "mthca_memfree.h"
  42 #include "mthca_wqe.h"
  43
  44 enum {
  45         MTHCA_MAX_DIRECT_SRQ_SIZE = 4 * PAGE_SIZE
  46 };
  47
  48 struct mthca_tavor_srq_context {
  49         __be64 wqe_base_ds;     /* low 6 bits is descriptor size */
  50         __be32 state_pd;
  51         __be32 lkey;
  52         __be32 uar;
  53         __be16 limit_watermark;
  54         __be16 wqe_cnt;
  55         u32    reserved[2];
  56 };
  57
  58 struct mthca_arbel_srq_context {
  59         __be32 state_logsize_srqn;
  60         __be32 lkey;
  61         __be32 db_index;
  62         __be32 logstride_usrpage;
  63         __be64 wqe_base;
  64         __be32 eq_pd;
  65         __be16 limit_watermark;
  66         __be16 wqe_cnt;
  67         u16    reserved1;
  68         __be16 wqe_counter;
  69         u32    reserved2[3];
  70 };
  71
  72 static void *get_wqe(struct mthca_srq *srq, int n)
  73 {
  74         if (srq->is_direct)
  75                 return srq->queue.direct.buf + (n << srq->wqe_shift);
  76         else
  77                 return srq->queue.page_list[(n << srq->wqe_shift) >> PAGE_SHIFT].buf +
  78                         ((n << srq->wqe_shift) & (PAGE_SIZE - 1));
  79 }
  80
  81 /*
  82  * Return a pointer to the location within a WQE that we're using as a
  83  * link when the WQE is in the free list.  We use the imm field
  84  * because in the Tavor case, posting a WQE may overwrite the next
  85  * segment of the previous WQE, but a receive WQE will never touch the
  86  * imm field.  This avoids corrupting our free list if the previous
  87  * WQE has already completed and been put on the free list when we
  88  * post the next WQE.
  89  */
  90 static inline int *wqe_to_link(void *wqe)
  91 {
  92         return (int *) (wqe + offsetof(struct mthca_next_seg, imm));
  93 }
  94
  95 static void mthca_tavor_init_srq_context(struct mthca_dev *dev,
  96                                          struct mthca_pd *pd,
  97                                          struct mthca_srq *srq,
  98                                          struct mthca_tavor_srq_context *context)
  99 {
 100         memset(context, 0, sizeof *context);
 101
 102         context->wqe_base_ds = cpu_to_be64(1 << (srq->wqe_shift - 4));
 103         context->state_pd    = cpu_to_be32(pd->pd_num);
 104         context->lkey        = cpu_to_be32(srq->mr.ibmr.lkey);
 105
 106         if (pd->ibpd.uobject)
 107                 context->uar =
 108                         cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
 109         else
 110                 context->uar = cpu_to_be32(dev->driver_uar.index);
 111 }
 112
 113 static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
 114                                          struct mthca_pd *pd,
 115                                          struct mthca_srq *srq,
 116                                          struct mthca_arbel_srq_context *context)
 117 {
 118         int logsize, max;
 119
 120         memset(context, 0, sizeof *context);
 121
 122         /*
 123          * Put max in a temporary variable to work around gcc bug
 124          * triggered by ilog2() on sparc64.
 125          */
 126         max = srq->max;
 127         logsize = ilog2(max);
 128         context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
 129         context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
 130         context->db_index = cpu_to_be32(srq->db_index);
 131         context->logstride_usrpage = cpu_to_be32((srq->wqe_shift - 4) << 29);
 132         if (pd->ibpd.uobject)
 133                 context->logstride_usrpage |=
 134                         cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
 135         else
 136                 context->logstride_usrpage |= cpu_to_be32(dev->driver_uar.index);
 137         context->eq_pd = cpu_to_be32(MTHCA_EQ_ASYNC << 24 | pd->pd_num);
 138 }
 139
 140 static void mthca_free_srq_buf(struct mthca_dev *dev, struct mthca_srq *srq)
 141 {
 142         mthca_buf_free(dev, srq->max << srq->wqe_shift, &srq->queue,
 143                        srq->is_direct, &srq->mr);
 144         kfree(srq->wrid);
 145 }
 146
 147 static int mthca_alloc_srq_buf(struct mthca_dev *dev, struct mthca_pd *pd,
 148                                struct mthca_srq *srq)
 149 {
 150         struct mthca_data_seg *scatter;
 151         void *wqe;
 152         int err;
 153         int i;
 154
 155         if (pd->ibpd.uobject)
 156                 return 0;
 157
 158         srq->wrid = kmalloc(srq->max * sizeof (u64), GFP_KERNEL);
 159         if (!srq->wrid)
 160                 return -ENOMEM;
 161
 162         err = mthca_buf_alloc(dev, srq->max << srq->wqe_shift,
 163                               MTHCA_MAX_DIRECT_SRQ_SIZE,
 164                               &srq->queue, &srq->is_direct, pd, 1, &srq->mr);
 165         if (err) {
 166                 kfree(srq->wrid);
 167                 return err;
 168         }
 169
 170         /*
 171          * Now initialize the SRQ buffer so that all of the WQEs are
 172          * linked into the list of free WQEs.  In addition, set the
 173          * scatter list L_Keys to the sentry value of 0x100.
 174          */
 175         for (i = 0; i < srq->max; ++i) {
 176                 struct mthca_next_seg *next;
 177
 178                 next = wqe = get_wqe(srq, i);
 179
 180                 if (i < srq->max - 1) {
 181                         *wqe_to_link(wqe) = i + 1;
 182                         next->nda_op = htonl(((i + 1) << srq->wqe_shift) | 1);
 183                 } else {
 184                         *wqe_to_link(wqe) = -1;
 185                         next->nda_op = 0;
 186                 }
 187
 188                 for (scatter = wqe + sizeof (struct mthca_next_seg);
 189                      (void *) scatter < wqe + (1 << srq->wqe_shift);
 190                      ++scatter)
 191                         scatter->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
 192         }
 193
 194         srq->last = get_wqe(srq, srq->max - 1);
 195
 196         return 0;
 197 }
 198
 199 int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
 200                     struct ib_srq_attr *attr, struct mthca_srq *srq)
 201 {
 202         struct mthca_mailbox *mailbox;
 203         u8 status;
 204         int ds;
 205         int err;
 206
 207         /* Sanity check SRQ size before proceeding */
 208         if (attr->max_wr  > dev->limits.max_srq_wqes ||
 209             attr->max_sge > dev->limits.max_srq_sge)
 210                 return -EINVAL;
 211
 212         srq->max      = attr->max_wr;
 213         srq->max_gs   = attr->max_sge;
 214         srq->counter  = 0;
 215
 216         if (mthca_is_memfree(dev))
 217                 srq->max = roundup_pow_of_two(srq->max + 1);
 218         else
 219                 srq->max = srq->max + 1;
 220
 221         ds = max(64UL,
 222                  roundup_pow_of_two(sizeof (struct mthca_next_seg) +
 223                                     srq->max_gs * sizeof (struct mthca_data_seg)));
 224
 225         if (!mthca_is_memfree(dev) && (ds > dev->limits.max_desc_sz))
 226                 return -EINVAL;
 227
 228         srq->wqe_shift = ilog2(ds);
 229
 230         srq->srqn = mthca_alloc(&dev->srq_table.alloc);
 231         if (srq->srqn == -1)
 232                 return -ENOMEM;
 233
 234         if (mthca_is_memfree(dev)) {
 235                 err = mthca_table_get(dev, dev->srq_table.table, srq->srqn);
 236                 if (err)
 237                         goto err_out;
 238
 239                 if (!pd->ibpd.uobject) {
 240                         srq->db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_SRQ,
 241                                                        srq->srqn, &srq->db);
 242                         if (srq->db_index < 0) {
 243                                 err = -ENOMEM;
 244                                 goto err_out_icm;
 245                         }
 246                 }
 247         }
 248
 249         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 250         if (IS_ERR(mailbox)) {
 251                 err = PTR_ERR(mailbox);
 252                 goto err_out_db;
 253         }
 254
 255         err = mthca_alloc_srq_buf(dev, pd, srq);
 256         if (err)
 257                 goto err_out_mailbox;
 258
 259         spin_lock_init(&srq->lock);
 260         srq->refcount = 1;
 261         init_waitqueue_head(&srq->wait);
 262         mutex_init(&srq->mutex);
 263
 264         if (mthca_is_memfree(dev))
 265                 mthca_arbel_init_srq_context(dev, pd, srq, mailbox->buf);
 266         else
 267                 mthca_tavor_init_srq_context(dev, pd, srq, mailbox->buf);
 268
 269         err = mthca_SW2HW_SRQ(dev, mailbox, srq->srqn, &status);
 270
 271         if (err) {
 272                 mthca_warn(dev, "SW2HW_SRQ failed (%d)\n", err);
 273                 goto err_out_free_buf;
 274         }
 275         if (status) {
 276                 mthca_warn(dev, "SW2HW_SRQ returned status 0x%02x\n",
 277                            status);
 278                 err = -EINVAL;
 279                 goto err_out_free_buf;
 280         }
 281
 282         spin_lock_irq(&dev->srq_table.lock);
 283         if (mthca_array_set(&dev->srq_table.srq,
 284                             srq->srqn & (dev->limits.num_srqs - 1),
 285                             srq)) {
 286                 spin_unlock_irq(&dev->srq_table.lock);
 287                 goto err_out_free_srq;
 288         }
 289         spin_unlock_irq(&dev->srq_table.lock);
 290
 291         mthca_free_mailbox(dev, mailbox);
 292
 293         srq->first_free = 0;
 294         srq->last_free  = srq->max - 1;
 295
 296         attr->max_wr    = srq->max - 1;
 297         attr->max_sge   = srq->max_gs;
 298
 299         return 0;
 300
 301 err_out_free_srq:
 302         err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
 303         if (err)
 304                 mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
 305         else if (status)
 306                 mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
 307
 308 err_out_free_buf:
 309         if (!pd->ibpd.uobject)
 310                 mthca_free_srq_buf(dev, srq);
 311
 312 err_out_mailbox:
 313         mthca_free_mailbox(dev, mailbox);
 314
 315 err_out_db:
 316         if (!pd->ibpd.uobject && mthca_is_memfree(dev))
 317                 mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
 318
 319 err_out_icm:
 320         mthca_table_put(dev, dev->srq_table.table, srq->srqn);
 321
 322 err_out:
 323         mthca_free(&dev->srq_table.alloc, srq->srqn);
 324
 325         return err;
 326 }
 327
 328 static inline int get_srq_refcount(struct mthca_dev *dev, struct mthca_srq *srq)
 329 {
 330         int c;
 331
 332         spin_lock_irq(&dev->srq_table.lock);
 333         c = srq->refcount;
 334         spin_unlock_irq(&dev->srq_table.lock);
 335
 336         return c;
 337 }
 338
 339 void mthca_free_srq(struct mthca_dev *dev, struct mthca_srq *srq)
 340 {
 341         struct mthca_mailbox *mailbox;
 342         int err;
 343         u8 status;
 344
 345         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 346         if (IS_ERR(mailbox)) {
 347                 mthca_warn(dev, "No memory for mailbox to free SRQ.\n");
 348                 return;
 349         }
 350
 351         err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
 352         if (err)
 353                 mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
 354         else if (status)
 355                 mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
 356
 357         spin_lock_irq(&dev->srq_table.lock);
 358         mthca_array_clear(&dev->srq_table.srq,
 359                           srq->srqn & (dev->limits.num_srqs - 1));
 360         --srq->refcount;
 361         spin_unlock_irq(&dev->srq_table.lock);
 362
 363         wait_event(srq->wait, !get_srq_refcount(dev, srq));
 364
 365         if (!srq->ibsrq.uobject) {
 366                 mthca_free_srq_buf(dev, srq);
 367                 if (mthca_is_memfree(dev))
 368                         mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
 369         }
 370
 371         mthca_table_put(dev, dev->srq_table.table, srq->srqn);
 372         mthca_free(&dev->srq_table.alloc, srq->srqn);
 373         mthca_free_mailbox(dev, mailbox);
 374 }
 375
 376 int mthca_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 377                      enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
 378 {
 379         struct mthca_dev *dev = to_mdev(ibsrq->device);
 380         struct mthca_srq *srq = to_msrq(ibsrq);
 381         int ret;
 382         u8 status;
 383
 384         /* We don't support resizing SRQs (yet?) */
 385         if (attr_mask & IB_SRQ_MAX_WR)
 386                 return -EINVAL;
 387
 388         if (attr_mask & IB_SRQ_LIMIT) {
 389                 u32 max_wr = mthca_is_memfree(dev) ? srq->max - 1 : srq->max;
 390                 if (attr->srq_limit > max_wr)
 391                         return -EINVAL;
 392
 393                 mutex_lock(&srq->mutex);
 394                 ret = mthca_ARM_SRQ(dev, srq->srqn, attr->srq_limit, &status);
 395                 mutex_unlock(&srq->mutex);
 396
 397                 if (ret)
 398                         return ret;
 399                 if (status)
 400                         return -EINVAL;
 401         }
 402
 403         return 0;
 404 }
 405
 406 int mthca_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
 407 {
 408         struct mthca_dev *dev = to_mdev(ibsrq->device);
 409         struct mthca_srq *srq = to_msrq(ibsrq);
 410         struct mthca_mailbox *mailbox;
 411         struct mthca_arbel_srq_context *arbel_ctx;
 412         struct mthca_tavor_srq_context *tavor_ctx;
 413         u8 status;
 414         int err;
 415
 416         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 417         if (IS_ERR(mailbox))
 418                 return PTR_ERR(mailbox);
 419
 420         err = mthca_QUERY_SRQ(dev, srq->srqn, mailbox, &status);
 421         if (err)
 422                 goto out;
 423
 424         if (mthca_is_memfree(dev)) {
 425                 arbel_ctx = mailbox->buf;
 426                 srq_attr->srq_limit = be16_to_cpu(arbel_ctx->limit_watermark);
 427         } else {
 428                 tavor_ctx = mailbox->buf;
 429                 srq_attr->srq_limit = be16_to_cpu(tavor_ctx->limit_watermark);
 430         }
 431
 432         srq_attr->max_wr  = srq->max - 1;
 433         srq_attr->max_sge = srq->max_gs;
 434
 435 out:
 436         mthca_free_mailbox(dev, mailbox);
 437
 438         return err;
 439 }
 440
 441 void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
 442                      enum ib_event_type event_type)
 443 {
 444         struct mthca_srq *srq;
 445         struct ib_event event;
 446
 447         spin_lock(&dev->srq_table.lock);
 448         srq = mthca_array_get(&dev->srq_table.srq, srqn & (dev->limits.num_srqs - 1));
 449         if (srq)
 450                 ++srq->refcount;
 451         spin_unlock(&dev->srq_table.lock);
 452
 453         if (!srq) {
 454                 mthca_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
 455                 return;
 456         }
 457
 458         if (!srq->ibsrq.event_handler)
 459                 goto out;
 460
 461         event.device      = &dev->ib_dev;
 462         event.event       = event_type;
 463         event.element.srq = &srq->ibsrq;
 464         srq->ibsrq.event_handler(&event, srq->ibsrq.srq_context);
 465
 466 out:
 467         spin_lock(&dev->srq_table.lock);
 468         if (!--srq->refcount)
 469                 wake_up(&srq->wait);
 470         spin_unlock(&dev->srq_table.lock);
 471 }
 472
 473 /*
 474  * This function must be called with IRQs disabled.
 475  */
 476 void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr)
 477 {
 478         int ind;
 479         struct mthca_next_seg *last_free;
 480
 481         ind = wqe_addr >> srq->wqe_shift;
 482
 483         spin_lock(&srq->lock);
 484
 485         last_free = get_wqe(srq, srq->last_free);
 486         *wqe_to_link(last_free) = ind;
 487         last_free->nda_op = htonl((ind << srq->wqe_shift) | 1);
 488         *wqe_to_link(get_wqe(srq, ind)) = -1;
 489         srq->last_free = ind;
 490
 491         spin_unlock(&srq->lock);
 492 }
 493
 494 int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
 495                               struct ib_recv_wr **bad_wr)
 496 {
 497         struct mthca_dev *dev = to_mdev(ibsrq->device);
 498         struct mthca_srq *srq = to_msrq(ibsrq);
 499         unsigned long flags;
 500         int err = 0;
 501         int first_ind;
 502         int ind;
 503         int next_ind;
 504         int nreq;
 505         int i;
 506         void *wqe;
 507         void *prev_wqe;
 508
 509         spin_lock_irqsave(&srq->lock, flags);
 510
 511         first_ind = srq->first_free;
 512
 513         for (nreq = 0; wr; wr = wr->next) {
 514                 ind       = srq->first_free;
 515                 wqe       = get_wqe(srq, ind);
 516                 next_ind  = *wqe_to_link(wqe);
 517
 518                 if (unlikely(next_ind < 0)) {
 519                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 520                         err = -ENOMEM;
 521                         *bad_wr = wr;
 522                         break;
 523                 }
 524
 525                 prev_wqe  = srq->last;
 526                 srq->last = wqe;
 527
 528                 ((struct mthca_next_seg *) wqe)->ee_nds = 0;
 529                 /* flags field will always remain 0 */
 530
 531                 wqe += sizeof (struct mthca_next_seg);
 532
 533                 if (unlikely(wr->num_sge > srq->max_gs)) {
 534                         err = -EINVAL;
 535                         *bad_wr = wr;
 536                         srq->last = prev_wqe;
 537                         break;
 538                 }
 539
 540                 for (i = 0; i < wr->num_sge; ++i) {
 541                         mthca_set_data_seg(wqe, wr->sg_list + i);
 542                         wqe += sizeof (struct mthca_data_seg);
 543                 }
 544
 545                 if (i < srq->max_gs)
 546                         mthca_set_data_seg_inval(wqe);
 547
 548                 ((struct mthca_next_seg *) prev_wqe)->ee_nds =
 549                         cpu_to_be32(MTHCA_NEXT_DBD);
 550
 551                 srq->wrid[ind]  = wr->wr_id;
 552                 srq->first_free = next_ind;
 553
 554                 ++nreq;
 555                 if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
 556                         nreq = 0;
 557
 558                         /*
 559                          * Make sure that descriptors are written
 560                          * before doorbell is rung.
 561                          */
 562                         wmb();
 563
 564                         mthca_write64(first_ind << srq->wqe_shift, srq->srqn << 8,
 565                                       dev->kar + MTHCA_RECEIVE_DOORBELL,
 566                                       MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
 567
 568                         first_ind = srq->first_free;
 569                 }
 570         }
 571
 572         if (likely(nreq)) {
 573                 /*
 574                  * Make sure that descriptors are written before
 575                  * doorbell is rung.
 576                  */
 577                 wmb();
 578
 579                 mthca_write64(first_ind << srq->wqe_shift, (srq->srqn << 8) | nreq,
 580                               dev->kar + MTHCA_RECEIVE_DOORBELL,
 581                               MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
 582         }
 583
 584         /*
 585          * Make sure doorbells don't leak out of SRQ spinlock and
 586          * reach the HCA out of order:
 587          */
 588         mmiowb();
 589
 590         spin_unlock_irqrestore(&srq->lock, flags);
 591         return err;
 592 }
 593
 594 int mthca_arbel_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
 595                               struct ib_recv_wr **bad_wr)
 596 {
 597         struct mthca_dev *dev = to_mdev(ibsrq->device);
 598         struct mthca_srq *srq = to_msrq(ibsrq);
 599         unsigned long flags;
 600         int err = 0;
 601         int ind;
 602         int next_ind;
 603         int nreq;
 604         int i;
 605         void *wqe;
 606
 607         spin_lock_irqsave(&srq->lock, flags);
 608
 609         for (nreq = 0; wr; ++nreq, wr = wr->next) {
 610                 ind       = srq->first_free;
 611                 wqe       = get_wqe(srq, ind);
 612                 next_ind  = *wqe_to_link(wqe);
 613
 614                 if (unlikely(next_ind < 0)) {
 615                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 616                         err = -ENOMEM;
 617                         *bad_wr = wr;
 618                         break;
 619                 }
 620
 621                 ((struct mthca_next_seg *) wqe)->ee_nds = 0;
 622                 /* flags field will always remain 0 */
 623
 624                 wqe += sizeof (struct mthca_next_seg);
 625
 626                 if (unlikely(wr->num_sge > srq->max_gs)) {
 627                         err = -EINVAL;
 628                         *bad_wr = wr;
 629                         break;
 630                 }
 631
 632                 for (i = 0; i < wr->num_sge; ++i) {
 633                         mthca_set_data_seg(wqe, wr->sg_list + i);
 634                         wqe += sizeof (struct mthca_data_seg);
 635                 }
 636
 637                 if (i < srq->max_gs)
 638                         mthca_set_data_seg_inval(wqe);
 639
 640                 srq->wrid[ind]  = wr->wr_id;
 641                 srq->first_free = next_ind;
 642         }
 643
 644         if (likely(nreq)) {
 645                 srq->counter += nreq;
 646
 647                 /*
 648                  * Make sure that descriptors are written before
 649                  * we write doorbell record.
 650                  */
 651                 wmb();
 652                 *srq->db = cpu_to_be32(srq->counter);
 653         }
 654
 655         spin_unlock_irqrestore(&srq->lock, flags);
 656         return err;
 657 }
 658
 659 int mthca_max_srq_sge(struct mthca_dev *dev)
 660 {
 661         if (mthca_is_memfree(dev))
 662                 return dev->limits.max_sg;
 663
 664         /*
 665          * SRQ allocations are based on powers of 2 for Tavor,
 666          * (although they only need to be multiples of 16 bytes).
 667          *
 668          * Therefore, we need to base the max number of sg entries on
 669          * the largest power of 2 descriptor size that is <= to the
 670          * actual max WQE descriptor size, rather than return the
 671          * max_sg value given by the firmware (which is based on WQE
 672          * sizes as multiples of 16, not powers of 2).
 673          *
 674          * If SRQ implementation is changed for Tavor to be based on
 675          * multiples of 16, the calculation below can be deleted and
 676          * the FW max_sg value returned.
 677          */
 678         return min_t(int, dev->limits.max_sg,
 679                      ((1 << (fls(dev->limits.max_desc_sz) - 1)) -
 680                       sizeof (struct mthca_next_seg)) /
 681                      sizeof (struct mthca_data_seg));
 682 }
 683
 684 int mthca_init_srq_table(struct mthca_dev *dev)
 685 {
 686         int err;
 687
 688         if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
 689                 return 0;
 690
 691         spin_lock_init(&dev->srq_table.lock);
 692
 693         err = mthca_alloc_init(&dev->srq_table.alloc,
 694                                dev->limits.num_srqs,
 695                                dev->limits.num_srqs - 1,
 696                                dev->limits.reserved_srqs);
 697         if (err)
 698                 return err;
 699
 700         err = mthca_array_init(&dev->srq_table.srq,
 701                                dev->limits.num_srqs);
 702         if (err)
 703                 mthca_alloc_cleanup(&dev->srq_table.alloc);
 704
 705         return err;
 706 }
 707
 708 void mthca_cleanup_srq_table(struct mthca_dev *dev)
 709 {
 710         if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
 711                 return;
 712
 713         mthca_array_cleanup(&dev->srq_table.srq, dev->limits.num_srqs);
 714         mthca_alloc_cleanup(&dev->srq_table.alloc);
 715 }