drivers/infiniband/ulp/iser/iser_memory.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/slab.h>
  36 #include <linux/mm.h>
  37 #include <linux/highmem.h>
  38 #include <linux/scatterlist.h>
  39
  40 #include "iscsi_iser.h"
  41 static
  42 int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
  43                       struct iser_data_buf *mem,
  44                       struct iser_reg_resources *rsc,
  45                       struct iser_mem_reg *mem_reg);
  46 static
  47 int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
  48                      struct iser_data_buf *mem,
  49                      struct iser_reg_resources *rsc,
  50                      struct iser_mem_reg *mem_reg);
  51
  52 static const struct iser_reg_ops fastreg_ops = {
  53         .alloc_reg_res  = iser_alloc_fastreg_pool,
  54         .free_reg_res   = iser_free_fastreg_pool,
  55         .reg_mem        = iser_fast_reg_mr,
  56         .unreg_mem      = iser_unreg_mem_fastreg,
  57         .reg_desc_get   = iser_reg_desc_get_fr,
  58         .reg_desc_put   = iser_reg_desc_put_fr,
  59 };
  60
  61 static const struct iser_reg_ops fmr_ops = {
  62         .alloc_reg_res  = iser_alloc_fmr_pool,
  63         .free_reg_res   = iser_free_fmr_pool,
  64         .reg_mem        = iser_fast_reg_fmr,
  65         .unreg_mem      = iser_unreg_mem_fmr,
  66         .reg_desc_get   = iser_reg_desc_get_fmr,
  67         .reg_desc_put   = iser_reg_desc_put_fmr,
  68 };
  69
  70 void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
  71 {
  72         iser_err_comp(wc, "memreg");
  73 }
  74
  75 int iser_assign_reg_ops(struct iser_device *device)
  76 {
  77         struct ib_device *ib_dev = device->ib_device;
  78
  79         /* Assign function handles  - based on FMR support */
  80         if (ib_dev->ops.alloc_fmr && ib_dev->ops.dealloc_fmr &&
  81             ib_dev->ops.map_phys_fmr && ib_dev->ops.unmap_fmr) {
  82                 iser_info("FMR supported, using FMR for registration\n");
  83                 device->reg_ops = &fmr_ops;
  84         } else if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
  85                 iser_info("FastReg supported, using FastReg for registration\n");
  86                 device->reg_ops = &fastreg_ops;
  87                 device->remote_inv_sup = iser_always_reg;
  88         } else {
  89                 iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
  90                 return -1;
  91         }
  92
  93         return 0;
  94 }
  95
  96 struct iser_fr_desc *
  97 iser_reg_desc_get_fr(struct ib_conn *ib_conn)
  98 {
  99         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 100         struct iser_fr_desc *desc;
 101         unsigned long flags;
 102
 103         spin_lock_irqsave(&fr_pool->lock, flags);
 104         desc = list_first_entry(&fr_pool->list,
 105                                 struct iser_fr_desc, list);
 106         list_del(&desc->list);
 107         spin_unlock_irqrestore(&fr_pool->lock, flags);
 108
 109         return desc;
 110 }
 111
 112 void
 113 iser_reg_desc_put_fr(struct ib_conn *ib_conn,
 114                      struct iser_fr_desc *desc)
 115 {
 116         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 117         unsigned long flags;
 118
 119         spin_lock_irqsave(&fr_pool->lock, flags);
 120         list_add(&desc->list, &fr_pool->list);
 121         spin_unlock_irqrestore(&fr_pool->lock, flags);
 122 }
 123
 124 struct iser_fr_desc *
 125 iser_reg_desc_get_fmr(struct ib_conn *ib_conn)
 126 {
 127         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 128
 129         return list_first_entry(&fr_pool->list,
 130                                 struct iser_fr_desc, list);
 131 }
 132
 133 void
 134 iser_reg_desc_put_fmr(struct ib_conn *ib_conn,
 135                       struct iser_fr_desc *desc)
 136 {
 137 }
 138
 139 static void iser_data_buf_dump(struct iser_data_buf *data,
 140                                struct ib_device *ibdev)
 141 {
 142         struct scatterlist *sg;
 143         int i;
 144
 145         for_each_sg(data->sg, sg, data->dma_nents, i)
 146                 iser_dbg("sg[%d] dma_addr:0x%lX page:0x%p "
 147                          "off:0x%x sz:0x%x dma_len:0x%x\n",
 148                          i, (unsigned long)sg_dma_address(sg),
 149                          sg_page(sg), sg->offset, sg->length, sg_dma_len(sg));
 150 }
 151
 152 static void iser_dump_page_vec(struct iser_page_vec *page_vec)
 153 {
 154         int i;
 155
 156         iser_err("page vec npages %d data length %lld\n",
 157                  page_vec->npages, page_vec->fake_mr.length);
 158         for (i = 0; i < page_vec->npages; i++)
 159                 iser_err("vec[%d]: %llx\n", i, page_vec->pages[i]);
 160 }
 161
 162 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
 163                             struct iser_data_buf *data,
 164                             enum iser_data_dir iser_dir,
 165                             enum dma_data_direction dma_dir)
 166 {
 167         struct ib_device *dev;
 168
 169         iser_task->dir[iser_dir] = 1;
 170         dev = iser_task->iser_conn->ib_conn.device->ib_device;
 171
 172         data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
 173         if (data->dma_nents == 0) {
 174                 iser_err("dma_map_sg failed!!!\n");
 175                 return -EINVAL;
 176         }
 177         return 0;
 178 }
 179
 180 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
 181                               struct iser_data_buf *data,
 182                               enum dma_data_direction dir)
 183 {
 184         struct ib_device *dev;
 185
 186         dev = iser_task->iser_conn->ib_conn.device->ib_device;
 187         ib_dma_unmap_sg(dev, data->sg, data->size, dir);
 188 }
 189
 190 static int
 191 iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
 192              struct iser_mem_reg *reg)
 193 {
 194         struct scatterlist *sg = mem->sg;
 195
 196         reg->sge.lkey = device->pd->local_dma_lkey;
 197         /*
 198          * FIXME: rework the registration code path to differentiate
 199          * rkey/lkey use cases
 200          */
 201
 202         if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
 203                 reg->rkey = device->pd->unsafe_global_rkey;
 204         else
 205                 reg->rkey = 0;
 206         reg->sge.addr = sg_dma_address(&sg[0]);
 207         reg->sge.length = sg_dma_len(&sg[0]);
 208
 209         iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
 210                  " length=0x%x\n", reg->sge.lkey, reg->rkey,
 211                  reg->sge.addr, reg->sge.length);
 212
 213         return 0;
 214 }
 215
 216 static int iser_set_page(struct ib_mr *mr, u64 addr)
 217 {
 218         struct iser_page_vec *page_vec =
 219                 container_of(mr, struct iser_page_vec, fake_mr);
 220
 221         page_vec->pages[page_vec->npages++] = addr;
 222
 223         return 0;
 224 }
 225
 226 static
 227 int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
 228                       struct iser_data_buf *mem,
 229                       struct iser_reg_resources *rsc,
 230                       struct iser_mem_reg *reg)
 231 {
 232         struct ib_conn *ib_conn = &iser_task->iser_conn->ib_conn;
 233         struct iser_device *device = ib_conn->device;
 234         struct iser_page_vec *page_vec = rsc->page_vec;
 235         struct ib_fmr_pool *fmr_pool = rsc->fmr_pool;
 236         struct ib_pool_fmr *fmr;
 237         int ret, plen;
 238
 239         page_vec->npages = 0;
 240         page_vec->fake_mr.page_size = SIZE_4K;
 241         plen = ib_sg_to_pages(&page_vec->fake_mr, mem->sg,
 242                               mem->dma_nents, NULL, iser_set_page);
 243         if (unlikely(plen < mem->dma_nents)) {
 244                 iser_err("page vec too short to hold this SG\n");
 245                 iser_data_buf_dump(mem, device->ib_device);
 246                 iser_dump_page_vec(page_vec);
 247                 return -EINVAL;
 248         }
 249
 250         fmr  = ib_fmr_pool_map_phys(fmr_pool, page_vec->pages,
 251                                     page_vec->npages, page_vec->pages[0]);
 252         if (IS_ERR(fmr)) {
 253                 ret = PTR_ERR(fmr);
 254                 iser_err("ib_fmr_pool_map_phys failed: %d\n", ret);
 255                 return ret;
 256         }
 257
 258         reg->sge.lkey = fmr->fmr->lkey;
 259         reg->rkey = fmr->fmr->rkey;
 260         reg->sge.addr = page_vec->fake_mr.iova;
 261         reg->sge.length = page_vec->fake_mr.length;
 262         reg->mem_h = fmr;
 263
 264         iser_dbg("fmr reg: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
 265                  " length=0x%x\n", reg->sge.lkey, reg->rkey,
 266                  reg->sge.addr, reg->sge.length);
 267
 268         return 0;
 269 }
 270
 271 /**
 272  * Unregister (previosuly registered using FMR) memory.
 273  * If memory is non-FMR does nothing.
 274  */
 275 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
 276                         enum iser_data_dir cmd_dir)
 277 {
 278         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
 279
 280         if (!reg->mem_h)
 281                 return;
 282
 283         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n", reg->mem_h);
 284
 285         ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
 286
 287         reg->mem_h = NULL;
 288 }
 289
 290 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 291                             enum iser_data_dir cmd_dir)
 292 {
 293         struct iser_device *device = iser_task->iser_conn->ib_conn.device;
 294         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
 295
 296         if (!reg->mem_h)
 297                 return;
 298
 299         device->reg_ops->reg_desc_put(&iser_task->iser_conn->ib_conn,
 300                                      reg->mem_h);
 301         reg->mem_h = NULL;
 302 }
 303
 304 static void
 305 iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs,
 306                     struct ib_sig_domain *domain)
 307 {
 308         domain->sig_type = IB_SIG_TYPE_T10_DIF;
 309         domain->sig.dif.pi_interval = scsi_prot_interval(sc);
 310         domain->sig.dif.ref_tag = t10_pi_ref_tag(sc->request);
 311         /*
 312          * At the moment we hard code those, but in the future
 313          * we will take them from sc.
 314          */
 315         domain->sig.dif.apptag_check_mask = 0xffff;
 316         domain->sig.dif.app_escape = true;
 317         domain->sig.dif.ref_escape = true;
 318         if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
 319                 domain->sig.dif.ref_remap = true;
 320 };
 321
 322 static int
 323 iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
 324 {
 325         switch (scsi_get_prot_op(sc)) {
 326         case SCSI_PROT_WRITE_INSERT:
 327         case SCSI_PROT_READ_STRIP:
 328                 sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
 329                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->wire);
 330                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 331                 break;
 332         case SCSI_PROT_READ_INSERT:
 333         case SCSI_PROT_WRITE_STRIP:
 334                 sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
 335                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->mem);
 336                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 337                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 338                 break;
 339         case SCSI_PROT_READ_PASS:
 340         case SCSI_PROT_WRITE_PASS:
 341                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->wire);
 342                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 343                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->mem);
 344                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 345                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 346                 break;
 347         default:
 348                 iser_err("Unsupported PI operation %d\n",
 349                          scsi_get_prot_op(sc));
 350                 return -EINVAL;
 351         }
 352
 353         return 0;
 354 }
 355
 356 static inline void
 357 iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
 358 {
 359         *mask = 0;
 360         if (sc->prot_flags & SCSI_PROT_REF_CHECK)
 361                 *mask |= IB_SIG_CHECK_REFTAG;
 362         if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
 363                 *mask |= IB_SIG_CHECK_GUARD;
 364 }
 365
 366 static inline void
 367 iser_inv_rkey(struct ib_send_wr *inv_wr,
 368               struct ib_mr *mr,
 369               struct ib_cqe *cqe)
 370 {
 371         inv_wr->opcode = IB_WR_LOCAL_INV;
 372         inv_wr->wr_cqe = cqe;
 373         inv_wr->ex.invalidate_rkey = mr->rkey;
 374         inv_wr->send_flags = 0;
 375         inv_wr->num_sge = 0;
 376 }
 377
 378 static int
 379 iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
 380                 struct iser_pi_context *pi_ctx,
 381                 struct iser_mem_reg *data_reg,
 382                 struct iser_mem_reg *prot_reg,
 383                 struct iser_mem_reg *sig_reg)
 384 {
 385         struct iser_tx_desc *tx_desc = &iser_task->desc;
 386         struct ib_sig_attrs *sig_attrs = &tx_desc->sig_attrs;
 387         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 388         struct ib_sig_handover_wr *wr;
 389         struct ib_mr *mr = pi_ctx->sig_mr;
 390         int ret;
 391
 392         memset(sig_attrs, 0, sizeof(*sig_attrs));
 393         ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
 394         if (ret)
 395                 goto err;
 396
 397         iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
 398
 399         if (pi_ctx->sig_mr_valid)
 400                 iser_inv_rkey(iser_tx_next_wr(tx_desc), mr, cqe);
 401
 402         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 403
 404         wr = container_of(iser_tx_next_wr(tx_desc), struct ib_sig_handover_wr,
 405                           wr);
 406         wr->wr.opcode = IB_WR_REG_SIG_MR;
 407         wr->wr.wr_cqe = cqe;
 408         wr->wr.sg_list = &data_reg->sge;
 409         wr->wr.num_sge = 1;
 410         wr->wr.send_flags = 0;
 411         wr->sig_attrs = sig_attrs;
 412         wr->sig_mr = mr;
 413         if (scsi_prot_sg_count(iser_task->sc))
 414                 wr->prot = &prot_reg->sge;
 415         else
 416                 wr->prot = NULL;
 417         wr->access_flags = IB_ACCESS_LOCAL_WRITE |
 418                            IB_ACCESS_REMOTE_READ |
 419                            IB_ACCESS_REMOTE_WRITE;
 420         pi_ctx->sig_mr_valid = 1;
 421
 422         sig_reg->sge.lkey = mr->lkey;
 423         sig_reg->rkey = mr->rkey;
 424         sig_reg->sge.addr = 0;
 425         sig_reg->sge.length = scsi_transfer_length(iser_task->sc);
 426
 427         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
 428                  sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
 429                  sig_reg->sge.length);
 430 err:
 431         return ret;
 432 }
 433
 434 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
 435                             struct iser_data_buf *mem,
 436                             struct iser_reg_resources *rsc,
 437                             struct iser_mem_reg *reg)
 438 {
 439         struct iser_tx_desc *tx_desc = &iser_task->desc;
 440         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 441         struct ib_mr *mr = rsc->mr;
 442         struct ib_reg_wr *wr;
 443         int n;
 444
 445         if (rsc->mr_valid)
 446                 iser_inv_rkey(iser_tx_next_wr(tx_desc), mr, cqe);
 447
 448         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 449
 450         n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SIZE_4K);
 451         if (unlikely(n != mem->dma_nents)) {
 452                 iser_err("failed to map sg (%d/%d)\n",
 453                          n, mem->dma_nents);
 454                 return n < 0 ? n : -EINVAL;
 455         }
 456
 457         wr = container_of(iser_tx_next_wr(tx_desc), struct ib_reg_wr, wr);
 458         wr->wr.opcode = IB_WR_REG_MR;
 459         wr->wr.wr_cqe = cqe;
 460         wr->wr.send_flags = 0;
 461         wr->wr.num_sge = 0;
 462         wr->mr = mr;
 463         wr->key = mr->rkey;
 464         wr->access = IB_ACCESS_LOCAL_WRITE  |
 465                      IB_ACCESS_REMOTE_WRITE |
 466                      IB_ACCESS_REMOTE_READ;
 467
 468         rsc->mr_valid = 1;
 469
 470         reg->sge.lkey = mr->lkey;
 471         reg->rkey = mr->rkey;
 472         reg->sge.addr = mr->iova;
 473         reg->sge.length = mr->length;
 474
 475         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
 476                  reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
 477
 478         return 0;
 479 }
 480
 481 static int
 482 iser_reg_prot_sg(struct iscsi_iser_task *task,
 483                  struct iser_data_buf *mem,
 484                  struct iser_fr_desc *desc,
 485                  bool use_dma_key,
 486                  struct iser_mem_reg *reg)
 487 {
 488         struct iser_device *device = task->iser_conn->ib_conn.device;
 489
 490         if (use_dma_key)
 491                 return iser_reg_dma(device, mem, reg);
 492
 493         return device->reg_ops->reg_mem(task, mem, &desc->pi_ctx->rsc, reg);
 494 }
 495
 496 static int
 497 iser_reg_data_sg(struct iscsi_iser_task *task,
 498                  struct iser_data_buf *mem,
 499                  struct iser_fr_desc *desc,
 500                  bool use_dma_key,
 501                  struct iser_mem_reg *reg)
 502 {
 503         struct iser_device *device = task->iser_conn->ib_conn.device;
 504
 505         if (use_dma_key)
 506                 return iser_reg_dma(device, mem, reg);
 507
 508         return device->reg_ops->reg_mem(task, mem, &desc->rsc, reg);
 509 }
 510
 511 int iser_reg_rdma_mem(struct iscsi_iser_task *task,
 512                       enum iser_data_dir dir,
 513                       bool all_imm)
 514 {
 515         struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
 516         struct iser_device *device = ib_conn->device;
 517         struct iser_data_buf *mem = &task->data[dir];
 518         struct iser_mem_reg *reg = &task->rdma_reg[dir];
 519         struct iser_mem_reg *data_reg;
 520         struct iser_fr_desc *desc = NULL;
 521         bool use_dma_key;
 522         int err;
 523
 524         use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
 525                       scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
 526
 527         if (!use_dma_key) {
 528                 desc = device->reg_ops->reg_desc_get(ib_conn);
 529                 reg->mem_h = desc;
 530         }
 531
 532         if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL)
 533                 data_reg = reg;
 534         else
 535                 data_reg = &task->desc.data_reg;
 536
 537         err = iser_reg_data_sg(task, mem, desc, use_dma_key, data_reg);
 538         if (unlikely(err))
 539                 goto err_reg;
 540
 541         if (scsi_get_prot_op(task->sc) != SCSI_PROT_NORMAL) {
 542                 struct iser_mem_reg *prot_reg = &task->desc.prot_reg;
 543
 544                 if (scsi_prot_sg_count(task->sc)) {
 545                         mem = &task->prot[dir];
 546                         err = iser_reg_prot_sg(task, mem, desc,
 547                                                use_dma_key, prot_reg);
 548                         if (unlikely(err))
 549                                 goto err_reg;
 550                 }
 551
 552                 err = iser_reg_sig_mr(task, desc->pi_ctx, data_reg,
 553                                       prot_reg, reg);
 554                 if (unlikely(err))
 555                         goto err_reg;
 556
 557                 desc->pi_ctx->sig_protected = 1;
 558         }
 559
 560         return 0;
 561
 562 err_reg:
 563         if (desc)
 564                 device->reg_ops->reg_desc_put(ib_conn, desc);
 565
 566         return err;
 567 }
 568
 569 void iser_unreg_rdma_mem(struct iscsi_iser_task *task,
 570                          enum iser_data_dir dir)
 571 {
 572         struct iser_device *device = task->iser_conn->ib_conn.device;
 573
 574         device->reg_ops->unreg_mem(task, dir);
 575 }