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  * $Id: mthca_srq.c 3047 2005-08-10 03:59:35Z roland $
  33  */
  34
  35 #include <linux/slab.h>
  36 #include <linux/string.h>
  37 #include <linux/sched.h>
  38
  39 #include <asm/io.h>
  40
  41 #include "mthca_dev.h"
  42 #include "mthca_cmd.h"
  43 #include "mthca_memfree.h"
  44 #include "mthca_wqe.h"
  45
  46 enum {
  47         MTHCA_MAX_DIRECT_SRQ_SIZE = 4 * PAGE_SIZE
  48 };
  49
  50 struct mthca_tavor_srq_context {
  51         __be64 wqe_base_ds;     /* low 6 bits is descriptor size */
  52         __be32 state_pd;
  53         __be32 lkey;
  54         __be32 uar;
  55         __be16 limit_watermark;
  56         __be16 wqe_cnt;
  57         u32    reserved[2];
  58 };
  59
  60 struct mthca_arbel_srq_context {
  61         __be32 state_logsize_srqn;
  62         __be32 lkey;
  63         __be32 db_index;
  64         __be32 logstride_usrpage;
  65         __be64 wqe_base;
  66         __be32 eq_pd;
  67         __be16 limit_watermark;
  68         __be16 wqe_cnt;
  69         u16    reserved1;
  70         __be16 wqe_counter;
  71         u32    reserved2[3];
  72 };
  73
  74 static void *get_wqe(struct mthca_srq *srq, int n)
  75 {
  76         if (srq->is_direct)
  77                 return srq->queue.direct.buf + (n << srq->wqe_shift);
  78         else
  79                 return srq->queue.page_list[(n << srq->wqe_shift) >> PAGE_SHIFT].buf +
  80                         ((n << srq->wqe_shift) & (PAGE_SIZE - 1));
  81 }
  82
  83 /*
  84  * Return a pointer to the location within a WQE that we're using as a
  85  * link when the WQE is in the free list.  We use the imm field
  86  * because in the Tavor case, posting a WQE may overwrite the next
  87  * segment of the previous WQE, but a receive WQE will never touch the
  88  * imm field.  This avoids corrupting our free list if the previous
  89  * WQE has already completed and been put on the free list when we
  90  * post the next WQE.
  91  */
  92 static inline int *wqe_to_link(void *wqe)
  93 {
  94         return (int *) (wqe + offsetof(struct mthca_next_seg, imm));
  95 }
  96
  97 static void mthca_tavor_init_srq_context(struct mthca_dev *dev,
  98                                          struct mthca_pd *pd,
  99                                          struct mthca_srq *srq,
 100                                          struct mthca_tavor_srq_context *context)
 101 {
 102         memset(context, 0, sizeof *context);
 103
 104         context->wqe_base_ds = cpu_to_be64(1 << (srq->wqe_shift - 4));
 105         context->state_pd    = cpu_to_be32(pd->pd_num);
 106         context->lkey        = cpu_to_be32(srq->mr.ibmr.lkey);
 107
 108         if (pd->ibpd.uobject)
 109                 context->uar =
 110                         cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
 111         else
 112                 context->uar = cpu_to_be32(dev->driver_uar.index);
 113 }
 114
 115 static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
 116                                          struct mthca_pd *pd,
 117                                          struct mthca_srq *srq,
 118                                          struct mthca_arbel_srq_context *context)
 119 {
 120         int logsize, max;
 121
 122         memset(context, 0, sizeof *context);
 123
 124         /*
 125          * Put max in a temporary variable to work around gcc bug
 126          * triggered by ilog2() on sparc64.
 127          */
 128         max = srq->max;
 129         logsize = ilog2(max);
 130         context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
 131         context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
 132         context->db_index = cpu_to_be32(srq->db_index);
 133         context->logstride_usrpage = cpu_to_be32((srq->wqe_shift - 4) << 29);
 134         if (pd->ibpd.uobject)
 135                 context->logstride_usrpage |=
 136                         cpu_to_be32(to_mucontext(pd->ibpd.uobject->context)->uar.index);
 137         else
 138                 context->logstride_usrpage |= cpu_to_be32(dev->driver_uar.index);
 139         context->eq_pd = cpu_to_be32(MTHCA_EQ_ASYNC << 24 | pd->pd_num);
 140 }
 141
 142 static void mthca_free_srq_buf(struct mthca_dev *dev, struct mthca_srq *srq)
 143 {
 144         mthca_buf_free(dev, srq->max << srq->wqe_shift, &srq->queue,
 145                        srq->is_direct, &srq->mr);
 146         kfree(srq->wrid);
 147 }
 148
 149 static int mthca_alloc_srq_buf(struct mthca_dev *dev, struct mthca_pd *pd,
 150                                struct mthca_srq *srq)
 151 {
 152         struct mthca_data_seg *scatter;
 153         void *wqe;
 154         int err;
 155         int i;
 156
 157         if (pd->ibpd.uobject)
 158                 return 0;
 159
 160         srq->wrid = kmalloc(srq->max * sizeof (u64), GFP_KERNEL);
 161         if (!srq->wrid)
 162                 return -ENOMEM;
 163
 164         err = mthca_buf_alloc(dev, srq->max << srq->wqe_shift,
 165                               MTHCA_MAX_DIRECT_SRQ_SIZE,
 166                               &srq->queue, &srq->is_direct, pd, 1, &srq->mr);
 167         if (err) {
 168                 kfree(srq->wrid);
 169                 return err;
 170         }
 171
 172         /*
 173          * Now initialize the SRQ buffer so that all of the WQEs are
 174          * linked into the list of free WQEs.  In addition, set the
 175          * scatter list L_Keys to the sentry value of 0x100.
 176          */
 177         for (i = 0; i < srq->max; ++i) {
 178                 wqe = get_wqe(srq, i);
 179
 180                 *wqe_to_link(wqe) = i < srq->max - 1 ? i + 1 : -1;
 181
 182                 for (scatter = wqe + sizeof (struct mthca_next_seg);
 183                      (void *) scatter < wqe + (1 << srq->wqe_shift);
 184                      ++scatter)
 185                         scatter->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
 186         }
 187
 188         srq->last = get_wqe(srq, srq->max - 1);
 189
 190         return 0;
 191 }
 192
 193 int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
 194                     struct ib_srq_attr *attr, struct mthca_srq *srq)
 195 {
 196         struct mthca_mailbox *mailbox;
 197         u8 status;
 198         int ds;
 199         int err;
 200
 201         /* Sanity check SRQ size before proceeding */
 202         if (attr->max_wr  > dev->limits.max_srq_wqes ||
 203             attr->max_sge > dev->limits.max_srq_sge)
 204                 return -EINVAL;
 205
 206         srq->max      = attr->max_wr;
 207         srq->max_gs   = attr->max_sge;
 208         srq->counter  = 0;
 209
 210         if (mthca_is_memfree(dev))
 211                 srq->max = roundup_pow_of_two(srq->max + 1);
 212         else
 213                 srq->max = srq->max + 1;
 214
 215         ds = max(64UL,
 216                  roundup_pow_of_two(sizeof (struct mthca_next_seg) +
 217                                     srq->max_gs * sizeof (struct mthca_data_seg)));
 218
 219         if (!mthca_is_memfree(dev) && (ds > dev->limits.max_desc_sz))
 220                 return -EINVAL;
 221
 222         srq->wqe_shift = ilog2(ds);
 223
 224         srq->srqn = mthca_alloc(&dev->srq_table.alloc);
 225         if (srq->srqn == -1)
 226                 return -ENOMEM;
 227
 228         if (mthca_is_memfree(dev)) {
 229                 err = mthca_table_get(dev, dev->srq_table.table, srq->srqn);
 230                 if (err)
 231                         goto err_out;
 232
 233                 if (!pd->ibpd.uobject) {
 234                         srq->db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_SRQ,
 235                                                        srq->srqn, &srq->db);
 236                         if (srq->db_index < 0) {
 237                                 err = -ENOMEM;
 238                                 goto err_out_icm;
 239                         }
 240                 }
 241         }
 242
 243         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 244         if (IS_ERR(mailbox)) {
 245                 err = PTR_ERR(mailbox);
 246                 goto err_out_db;
 247         }
 248
 249         err = mthca_alloc_srq_buf(dev, pd, srq);
 250         if (err)
 251                 goto err_out_mailbox;
 252
 253         spin_lock_init(&srq->lock);
 254         srq->refcount = 1;
 255         init_waitqueue_head(&srq->wait);
 256         mutex_init(&srq->mutex);
 257
 258         if (mthca_is_memfree(dev))
 259                 mthca_arbel_init_srq_context(dev, pd, srq, mailbox->buf);
 260         else
 261                 mthca_tavor_init_srq_context(dev, pd, srq, mailbox->buf);
 262
 263         err = mthca_SW2HW_SRQ(dev, mailbox, srq->srqn, &status);
 264
 265         if (err) {
 266                 mthca_warn(dev, "SW2HW_SRQ failed (%d)\n", err);
 267                 goto err_out_free_buf;
 268         }
 269         if (status) {
 270                 mthca_warn(dev, "SW2HW_SRQ returned status 0x%02x\n",
 271                            status);
 272                 err = -EINVAL;
 273                 goto err_out_free_buf;
 274         }
 275
 276         spin_lock_irq(&dev->srq_table.lock);
 277         if (mthca_array_set(&dev->srq_table.srq,
 278                             srq->srqn & (dev->limits.num_srqs - 1),
 279                             srq)) {
 280                 spin_unlock_irq(&dev->srq_table.lock);
 281                 goto err_out_free_srq;
 282         }
 283         spin_unlock_irq(&dev->srq_table.lock);
 284
 285         mthca_free_mailbox(dev, mailbox);
 286
 287         srq->first_free = 0;
 288         srq->last_free  = srq->max - 1;
 289
 290         attr->max_wr    = srq->max - 1;
 291         attr->max_sge   = srq->max_gs;
 292
 293         return 0;
 294
 295 err_out_free_srq:
 296         err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
 297         if (err)
 298                 mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
 299         else if (status)
 300                 mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
 301
 302 err_out_free_buf:
 303         if (!pd->ibpd.uobject)
 304                 mthca_free_srq_buf(dev, srq);
 305
 306 err_out_mailbox:
 307         mthca_free_mailbox(dev, mailbox);
 308
 309 err_out_db:
 310         if (!pd->ibpd.uobject && mthca_is_memfree(dev))
 311                 mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
 312
 313 err_out_icm:
 314         mthca_table_put(dev, dev->srq_table.table, srq->srqn);
 315
 316 err_out:
 317         mthca_free(&dev->srq_table.alloc, srq->srqn);
 318
 319         return err;
 320 }
 321
 322 static inline int get_srq_refcount(struct mthca_dev *dev, struct mthca_srq *srq)
 323 {
 324         int c;
 325
 326         spin_lock_irq(&dev->srq_table.lock);
 327         c = srq->refcount;
 328         spin_unlock_irq(&dev->srq_table.lock);
 329
 330         return c;
 331 }
 332
 333 void mthca_free_srq(struct mthca_dev *dev, struct mthca_srq *srq)
 334 {
 335         struct mthca_mailbox *mailbox;
 336         int err;
 337         u8 status;
 338
 339         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 340         if (IS_ERR(mailbox)) {
 341                 mthca_warn(dev, "No memory for mailbox to free SRQ.\n");
 342                 return;
 343         }
 344
 345         err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn, &status);
 346         if (err)
 347                 mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);
 348         else if (status)
 349                 mthca_warn(dev, "HW2SW_SRQ returned status 0x%02x\n", status);
 350
 351         spin_lock_irq(&dev->srq_table.lock);
 352         mthca_array_clear(&dev->srq_table.srq,
 353                           srq->srqn & (dev->limits.num_srqs - 1));
 354         --srq->refcount;
 355         spin_unlock_irq(&dev->srq_table.lock);
 356
 357         wait_event(srq->wait, !get_srq_refcount(dev, srq));
 358
 359         if (!srq->ibsrq.uobject) {
 360                 mthca_free_srq_buf(dev, srq);
 361                 if (mthca_is_memfree(dev))
 362                         mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
 363         }
 364
 365         mthca_table_put(dev, dev->srq_table.table, srq->srqn);
 366         mthca_free(&dev->srq_table.alloc, srq->srqn);
 367         mthca_free_mailbox(dev, mailbox);
 368 }
 369
 370 int mthca_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
 371                      enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
 372 {
 373         struct mthca_dev *dev = to_mdev(ibsrq->device);
 374         struct mthca_srq *srq = to_msrq(ibsrq);
 375         int ret;
 376         u8 status;
 377
 378         /* We don't support resizing SRQs (yet?) */
 379         if (attr_mask & IB_SRQ_MAX_WR)
 380                 return -EINVAL;
 381
 382         if (attr_mask & IB_SRQ_LIMIT) {
 383                 u32 max_wr = mthca_is_memfree(dev) ? srq->max - 1 : srq->max;
 384                 if (attr->srq_limit > max_wr)
 385                         return -EINVAL;
 386
 387                 mutex_lock(&srq->mutex);
 388                 ret = mthca_ARM_SRQ(dev, srq->srqn, attr->srq_limit, &status);
 389                 mutex_unlock(&srq->mutex);
 390
 391                 if (ret)
 392                         return ret;
 393                 if (status)
 394                         return -EINVAL;
 395         }
 396
 397         return 0;
 398 }
 399
 400 int mthca_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
 401 {
 402         struct mthca_dev *dev = to_mdev(ibsrq->device);
 403         struct mthca_srq *srq = to_msrq(ibsrq);
 404         struct mthca_mailbox *mailbox;
 405         struct mthca_arbel_srq_context *arbel_ctx;
 406         struct mthca_tavor_srq_context *tavor_ctx;
 407         u8 status;
 408         int err;
 409
 410         mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
 411         if (IS_ERR(mailbox))
 412                 return PTR_ERR(mailbox);
 413
 414         err = mthca_QUERY_SRQ(dev, srq->srqn, mailbox, &status);
 415         if (err)
 416                 goto out;
 417
 418         if (mthca_is_memfree(dev)) {
 419                 arbel_ctx = mailbox->buf;
 420                 srq_attr->srq_limit = be16_to_cpu(arbel_ctx->limit_watermark);
 421         } else {
 422                 tavor_ctx = mailbox->buf;
 423                 srq_attr->srq_limit = be16_to_cpu(tavor_ctx->limit_watermark);
 424         }
 425
 426         srq_attr->max_wr  = srq->max - 1;
 427         srq_attr->max_sge = srq->max_gs;
 428
 429 out:
 430         mthca_free_mailbox(dev, mailbox);
 431
 432         return err;
 433 }
 434
 435 void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
 436                      enum ib_event_type event_type)
 437 {
 438         struct mthca_srq *srq;
 439         struct ib_event event;
 440
 441         spin_lock(&dev->srq_table.lock);
 442         srq = mthca_array_get(&dev->srq_table.srq, srqn & (dev->limits.num_srqs - 1));
 443         if (srq)
 444                 ++srq->refcount;
 445         spin_unlock(&dev->srq_table.lock);
 446
 447         if (!srq) {
 448                 mthca_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
 449                 return;
 450         }
 451
 452         if (!srq->ibsrq.event_handler)
 453                 goto out;
 454
 455         event.device      = &dev->ib_dev;
 456         event.event       = event_type;
 457         event.element.srq = &srq->ibsrq;
 458         srq->ibsrq.event_handler(&event, srq->ibsrq.srq_context);
 459
 460 out:
 461         spin_lock(&dev->srq_table.lock);
 462         if (!--srq->refcount)
 463                 wake_up(&srq->wait);
 464         spin_unlock(&dev->srq_table.lock);
 465 }
 466
 467 /*
 468  * This function must be called with IRQs disabled.
 469  */
 470 void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr)
 471 {
 472         int ind;
 473
 474         ind = wqe_addr >> srq->wqe_shift;
 475
 476         spin_lock(&srq->lock);
 477
 478         if (likely(srq->first_free >= 0))
 479                 *wqe_to_link(get_wqe(srq, srq->last_free)) = ind;
 480         else
 481                 srq->first_free = ind;
 482
 483         *wqe_to_link(get_wqe(srq, ind)) = -1;
 484         srq->last_free = ind;
 485
 486         spin_unlock(&srq->lock);
 487 }
 488
 489 int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
 490                               struct ib_recv_wr **bad_wr)
 491 {
 492         struct mthca_dev *dev = to_mdev(ibsrq->device);
 493         struct mthca_srq *srq = to_msrq(ibsrq);
 494         unsigned long flags;
 495         int err = 0;
 496         int first_ind;
 497         int ind;
 498         int next_ind;
 499         int nreq;
 500         int i;
 501         void *wqe;
 502         void *prev_wqe;
 503
 504         spin_lock_irqsave(&srq->lock, flags);
 505
 506         first_ind = srq->first_free;
 507
 508         for (nreq = 0; wr; wr = wr->next) {
 509                 ind = srq->first_free;
 510
 511                 if (unlikely(ind < 0)) {
 512                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 513                         err = -ENOMEM;
 514                         *bad_wr = wr;
 515                         break;
 516                 }
 517
 518                 wqe       = get_wqe(srq, ind);
 519                 next_ind  = *wqe_to_link(wqe);
 520
 521                 if (unlikely(next_ind < 0)) {
 522                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 523                         err = -ENOMEM;
 524                         *bad_wr = wr;
 525                         break;
 526                 }
 527
 528                 prev_wqe  = srq->last;
 529                 srq->last = wqe;
 530
 531                 ((struct mthca_next_seg *) wqe)->nda_op = 0;
 532                 ((struct mthca_next_seg *) wqe)->ee_nds = 0;
 533                 /* flags field will always remain 0 */
 534
 535                 wqe += sizeof (struct mthca_next_seg);
 536
 537                 if (unlikely(wr->num_sge > srq->max_gs)) {
 538                         err = -EINVAL;
 539                         *bad_wr = wr;
 540                         srq->last = prev_wqe;
 541                         break;
 542                 }
 543
 544                 for (i = 0; i < wr->num_sge; ++i) {
 545                         mthca_set_data_seg(wqe, wr->sg_list + i);
 546                         wqe += sizeof (struct mthca_data_seg);
 547                 }
 548
 549                 if (i < srq->max_gs)
 550                         mthca_set_data_seg_inval(wqe);
 551
 552                 ((struct mthca_next_seg *) prev_wqe)->nda_op =
 553                         cpu_to_be32((ind << srq->wqe_shift) | 1);
 554                 wmb();
 555                 ((struct mthca_next_seg *) prev_wqe)->ee_nds =
 556                         cpu_to_be32(MTHCA_NEXT_DBD);
 557
 558                 srq->wrid[ind]  = wr->wr_id;
 559                 srq->first_free = next_ind;
 560
 561                 ++nreq;
 562                 if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
 563                         nreq = 0;
 564
 565                         /*
 566                          * Make sure that descriptors are written
 567                          * before doorbell is rung.
 568                          */
 569                         wmb();
 570
 571                         mthca_write64(first_ind << srq->wqe_shift, srq->srqn << 8,
 572                                       dev->kar + MTHCA_RECEIVE_DOORBELL,
 573                                       MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
 574
 575                         first_ind = srq->first_free;
 576                 }
 577         }
 578
 579         if (likely(nreq)) {
 580                 /*
 581                  * Make sure that descriptors are written before
 582                  * doorbell is rung.
 583                  */
 584                 wmb();
 585
 586                 mthca_write64(first_ind << srq->wqe_shift, (srq->srqn << 8) | nreq,
 587                               dev->kar + MTHCA_RECEIVE_DOORBELL,
 588                               MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
 589         }
 590
 591         /*
 592          * Make sure doorbells don't leak out of SRQ spinlock and
 593          * reach the HCA out of order:
 594          */
 595         mmiowb();
 596
 597         spin_unlock_irqrestore(&srq->lock, flags);
 598         return err;
 599 }
 600
 601 int mthca_arbel_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
 602                               struct ib_recv_wr **bad_wr)
 603 {
 604         struct mthca_dev *dev = to_mdev(ibsrq->device);
 605         struct mthca_srq *srq = to_msrq(ibsrq);
 606         unsigned long flags;
 607         int err = 0;
 608         int ind;
 609         int next_ind;
 610         int nreq;
 611         int i;
 612         void *wqe;
 613
 614         spin_lock_irqsave(&srq->lock, flags);
 615
 616         for (nreq = 0; wr; ++nreq, wr = wr->next) {
 617                 ind = srq->first_free;
 618
 619                 if (unlikely(ind < 0)) {
 620                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 621                         err = -ENOMEM;
 622                         *bad_wr = wr;
 623                         break;
 624                 }
 625
 626                 wqe       = get_wqe(srq, ind);
 627                 next_ind  = *wqe_to_link(wqe);
 628
 629                 if (unlikely(next_ind < 0)) {
 630                         mthca_err(dev, "SRQ %06x full\n", srq->srqn);
 631                         err = -ENOMEM;
 632                         *bad_wr = wr;
 633                         break;
 634                 }
 635
 636                 ((struct mthca_next_seg *) wqe)->nda_op =
 637                         cpu_to_be32((next_ind << srq->wqe_shift) | 1);
 638                 ((struct mthca_next_seg *) wqe)->ee_nds = 0;
 639                 /* flags field will always remain 0 */
 640
 641                 wqe += sizeof (struct mthca_next_seg);
 642
 643                 if (unlikely(wr->num_sge > srq->max_gs)) {
 644                         err = -EINVAL;
 645                         *bad_wr = wr;
 646                         break;
 647                 }
 648
 649                 for (i = 0; i < wr->num_sge; ++i) {
 650                         mthca_set_data_seg(wqe, wr->sg_list + i);
 651                         wqe += sizeof (struct mthca_data_seg);
 652                 }
 653
 654                 if (i < srq->max_gs)
 655                         mthca_set_data_seg_inval(wqe);
 656
 657                 srq->wrid[ind]  = wr->wr_id;
 658                 srq->first_free = next_ind;
 659         }
 660
 661         if (likely(nreq)) {
 662                 srq->counter += nreq;
 663
 664                 /*
 665                  * Make sure that descriptors are written before
 666                  * we write doorbell record.
 667                  */
 668                 wmb();
 669                 *srq->db = cpu_to_be32(srq->counter);
 670         }
 671
 672         spin_unlock_irqrestore(&srq->lock, flags);
 673         return err;
 674 }
 675
 676 int mthca_max_srq_sge(struct mthca_dev *dev)
 677 {
 678         if (mthca_is_memfree(dev))
 679                 return dev->limits.max_sg;
 680
 681         /*
 682          * SRQ allocations are based on powers of 2 for Tavor,
 683          * (although they only need to be multiples of 16 bytes).
 684          *
 685          * Therefore, we need to base the max number of sg entries on
 686          * the largest power of 2 descriptor size that is <= to the
 687          * actual max WQE descriptor size, rather than return the
 688          * max_sg value given by the firmware (which is based on WQE
 689          * sizes as multiples of 16, not powers of 2).
 690          *
 691          * If SRQ implementation is changed for Tavor to be based on
 692          * multiples of 16, the calculation below can be deleted and
 693          * the FW max_sg value returned.
 694          */
 695         return min_t(int, dev->limits.max_sg,
 696                      ((1 << (fls(dev->limits.max_desc_sz) - 1)) -
 697                       sizeof (struct mthca_next_seg)) /
 698                      sizeof (struct mthca_data_seg));
 699 }
 700
 701 int mthca_init_srq_table(struct mthca_dev *dev)
 702 {
 703         int err;
 704
 705         if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
 706                 return 0;
 707
 708         spin_lock_init(&dev->srq_table.lock);
 709
 710         err = mthca_alloc_init(&dev->srq_table.alloc,
 711                                dev->limits.num_srqs,
 712                                dev->limits.num_srqs - 1,
 713                                dev->limits.reserved_srqs);
 714         if (err)
 715                 return err;
 716
 717         err = mthca_array_init(&dev->srq_table.srq,
 718                                dev->limits.num_srqs);
 719         if (err)
 720                 mthca_alloc_cleanup(&dev->srq_table.alloc);
 721
 722         return err;
 723 }
 724
 725 void mthca_cleanup_srq_table(struct mthca_dev *dev)
 726 {
 727         if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
 728                 return;
 729
 730         mthca_array_cleanup(&dev->srq_table.srq, dev->limits.num_srqs);
 731         mthca_alloc_cleanup(&dev->srq_table.alloc);
 732 }