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->alloc_fmr && ib_dev->dealloc_fmr &&
  81             ib_dev->map_phys_fmr && ib_dev->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)ib_sg_dma_address(ibdev, sg),
 149                          sg_page(sg), sg->offset,
 150                          sg->length, ib_sg_dma_len(ibdev, sg));
 151 }
 152
 153 static void iser_dump_page_vec(struct iser_page_vec *page_vec)
 154 {
 155         int i;
 156
 157         iser_err("page vec npages %d data length %lld\n",
 158                  page_vec->npages, page_vec->fake_mr.length);
 159         for (i = 0; i < page_vec->npages; i++)
 160                 iser_err("vec[%d]: %llx\n", i, page_vec->pages[i]);
 161 }
 162
 163 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
 164                             struct iser_data_buf *data,
 165                             enum iser_data_dir iser_dir,
 166                             enum dma_data_direction dma_dir)
 167 {
 168         struct ib_device *dev;
 169
 170         iser_task->dir[iser_dir] = 1;
 171         dev = iser_task->iser_conn->ib_conn.device->ib_device;
 172
 173         data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
 174         if (data->dma_nents == 0) {
 175                 iser_err("dma_map_sg failed!!!\n");
 176                 return -EINVAL;
 177         }
 178         return 0;
 179 }
 180
 181 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
 182                               struct iser_data_buf *data,
 183                               enum dma_data_direction dir)
 184 {
 185         struct ib_device *dev;
 186
 187         dev = iser_task->iser_conn->ib_conn.device->ib_device;
 188         ib_dma_unmap_sg(dev, data->sg, data->size, dir);
 189 }
 190
 191 static int
 192 iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
 193              struct iser_mem_reg *reg)
 194 {
 195         struct scatterlist *sg = mem->sg;
 196
 197         reg->sge.lkey = device->pd->local_dma_lkey;
 198         /*
 199          * FIXME: rework the registration code path to differentiate
 200          * rkey/lkey use cases
 201          */
 202
 203         if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
 204                 reg->rkey = device->pd->unsafe_global_rkey;
 205         else
 206                 reg->rkey = 0;
 207         reg->sge.addr = ib_sg_dma_address(device->ib_device, &sg[0]);
 208         reg->sge.length = ib_sg_dma_len(device->ib_device, &sg[0]);
 209
 210         iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
 211                  " length=0x%x\n", reg->sge.lkey, reg->rkey,
 212                  reg->sge.addr, reg->sge.length);
 213
 214         return 0;
 215 }
 216
 217 static int iser_set_page(struct ib_mr *mr, u64 addr)
 218 {
 219         struct iser_page_vec *page_vec =
 220                 container_of(mr, struct iser_page_vec, fake_mr);
 221
 222         page_vec->pages[page_vec->npages++] = addr;
 223
 224         return 0;
 225 }
 226
 227 static
 228 int iser_fast_reg_fmr(struct iscsi_iser_task *iser_task,
 229                       struct iser_data_buf *mem,
 230                       struct iser_reg_resources *rsc,
 231                       struct iser_mem_reg *reg)
 232 {
 233         struct ib_conn *ib_conn = &iser_task->iser_conn->ib_conn;
 234         struct iser_device *device = ib_conn->device;
 235         struct iser_page_vec *page_vec = rsc->page_vec;
 236         struct ib_fmr_pool *fmr_pool = rsc->fmr_pool;
 237         struct ib_pool_fmr *fmr;
 238         int ret, plen;
 239
 240         page_vec->npages = 0;
 241         page_vec->fake_mr.page_size = SIZE_4K;
 242         plen = ib_sg_to_pages(&page_vec->fake_mr, mem->sg,
 243                               mem->size, NULL, iser_set_page);
 244         if (unlikely(plen < mem->size)) {
 245                 iser_err("page vec too short to hold this SG\n");
 246                 iser_data_buf_dump(mem, device->ib_device);
 247                 iser_dump_page_vec(page_vec);
 248                 return -EINVAL;
 249         }
 250
 251         fmr  = ib_fmr_pool_map_phys(fmr_pool, page_vec->pages,
 252                                     page_vec->npages, page_vec->pages[0]);
 253         if (IS_ERR(fmr)) {
 254                 ret = PTR_ERR(fmr);
 255                 iser_err("ib_fmr_pool_map_phys failed: %d\n", ret);
 256                 return ret;
 257         }
 258
 259         reg->sge.lkey = fmr->fmr->lkey;
 260         reg->rkey = fmr->fmr->rkey;
 261         reg->sge.addr = page_vec->fake_mr.iova;
 262         reg->sge.length = page_vec->fake_mr.length;
 263         reg->mem_h = fmr;
 264
 265         iser_dbg("fmr reg: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
 266                  " length=0x%x\n", reg->sge.lkey, reg->rkey,
 267                  reg->sge.addr, reg->sge.length);
 268
 269         return 0;
 270 }
 271
 272 /**
 273  * Unregister (previosuly registered using FMR) memory.
 274  * If memory is non-FMR does nothing.
 275  */
 276 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
 277                         enum iser_data_dir cmd_dir)
 278 {
 279         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
 280         int ret;
 281
 282         if (!reg->mem_h)
 283                 return;
 284
 285         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n", reg->mem_h);
 286
 287         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
 288         if (ret)
 289                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
 290
 291         reg->mem_h = NULL;
 292 }
 293
 294 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 295                             enum iser_data_dir cmd_dir)
 296 {
 297         struct iser_device *device = iser_task->iser_conn->ib_conn.device;
 298         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
 299
 300         if (!reg->mem_h)
 301                 return;
 302
 303         device->reg_ops->reg_desc_put(&iser_task->iser_conn->ib_conn,
 304                                      reg->mem_h);
 305         reg->mem_h = NULL;
 306 }
 307
 308 static void
 309 iser_set_dif_domain(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs,
 310                     struct ib_sig_domain *domain)
 311 {
 312         domain->sig_type = IB_SIG_TYPE_T10_DIF;
 313         domain->sig.dif.pi_interval = scsi_prot_interval(sc);
 314         domain->sig.dif.ref_tag = scsi_prot_ref_tag(sc);
 315         /*
 316          * At the moment we hard code those, but in the future
 317          * we will take them from sc.
 318          */
 319         domain->sig.dif.apptag_check_mask = 0xffff;
 320         domain->sig.dif.app_escape = true;
 321         domain->sig.dif.ref_escape = true;
 322         if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
 323                 domain->sig.dif.ref_remap = true;
 324 };
 325
 326 static int
 327 iser_set_sig_attrs(struct scsi_cmnd *sc, struct ib_sig_attrs *sig_attrs)
 328 {
 329         switch (scsi_get_prot_op(sc)) {
 330         case SCSI_PROT_WRITE_INSERT:
 331         case SCSI_PROT_READ_STRIP:
 332                 sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
 333                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->wire);
 334                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 335                 break;
 336         case SCSI_PROT_READ_INSERT:
 337         case SCSI_PROT_WRITE_STRIP:
 338                 sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
 339                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->mem);
 340                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 341                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 342                 break;
 343         case SCSI_PROT_READ_PASS:
 344         case SCSI_PROT_WRITE_PASS:
 345                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->wire);
 346                 sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
 347                 iser_set_dif_domain(sc, sig_attrs, &sig_attrs->mem);
 348                 sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
 349                                                 IB_T10DIF_CSUM : IB_T10DIF_CRC;
 350                 break;
 351         default:
 352                 iser_err("Unsupported PI operation %d\n",
 353                          scsi_get_prot_op(sc));
 354                 return -EINVAL;
 355         }
 356
 357         return 0;
 358 }
 359
 360 static inline void
 361 iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
 362 {
 363         *mask = 0;
 364         if (sc->prot_flags & SCSI_PROT_REF_CHECK)
 365                 *mask |= ISER_CHECK_REFTAG;
 366         if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
 367                 *mask |= ISER_CHECK_GUARD;
 368 }
 369
 370 static inline void
 371 iser_inv_rkey(struct ib_send_wr *inv_wr,
 372               struct ib_mr *mr,
 373               struct ib_cqe *cqe)
 374 {
 375         inv_wr->opcode = IB_WR_LOCAL_INV;
 376         inv_wr->wr_cqe = cqe;
 377         inv_wr->ex.invalidate_rkey = mr->rkey;
 378         inv_wr->send_flags = 0;
 379         inv_wr->num_sge = 0;
 380 }
 381
 382 static int
 383 iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
 384                 struct iser_pi_context *pi_ctx,
 385                 struct iser_mem_reg *data_reg,
 386                 struct iser_mem_reg *prot_reg,
 387                 struct iser_mem_reg *sig_reg)
 388 {
 389         struct iser_tx_desc *tx_desc = &iser_task->desc;
 390         struct ib_sig_attrs *sig_attrs = &tx_desc->sig_attrs;
 391         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 392         struct ib_sig_handover_wr *wr;
 393         struct ib_mr *mr = pi_ctx->sig_mr;
 394         int ret;
 395
 396         memset(sig_attrs, 0, sizeof(*sig_attrs));
 397         ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
 398         if (ret)
 399                 goto err;
 400
 401         iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
 402
 403         if (pi_ctx->sig_mr_valid)
 404                 iser_inv_rkey(iser_tx_next_wr(tx_desc), mr, cqe);
 405
 406         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 407
 408         wr = sig_handover_wr(iser_tx_next_wr(tx_desc));
 409         wr->wr.opcode = IB_WR_REG_SIG_MR;
 410         wr->wr.wr_cqe = cqe;
 411         wr->wr.sg_list = &data_reg->sge;
 412         wr->wr.num_sge = 1;
 413         wr->wr.send_flags = 0;
 414         wr->sig_attrs = sig_attrs;
 415         wr->sig_mr = mr;
 416         if (scsi_prot_sg_count(iser_task->sc))
 417                 wr->prot = &prot_reg->sge;
 418         else
 419                 wr->prot = NULL;
 420         wr->access_flags = IB_ACCESS_LOCAL_WRITE |
 421                            IB_ACCESS_REMOTE_READ |
 422                            IB_ACCESS_REMOTE_WRITE;
 423         pi_ctx->sig_mr_valid = 1;
 424
 425         sig_reg->sge.lkey = mr->lkey;
 426         sig_reg->rkey = mr->rkey;
 427         sig_reg->sge.addr = 0;
 428         sig_reg->sge.length = scsi_transfer_length(iser_task->sc);
 429
 430         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
 431                  sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
 432                  sig_reg->sge.length);
 433 err:
 434         return ret;
 435 }
 436
 437 static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
 438                             struct iser_data_buf *mem,
 439                             struct iser_reg_resources *rsc,
 440                             struct iser_mem_reg *reg)
 441 {
 442         struct iser_tx_desc *tx_desc = &iser_task->desc;
 443         struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
 444         struct ib_mr *mr = rsc->mr;
 445         struct ib_reg_wr *wr;
 446         int n;
 447
 448         if (rsc->mr_valid)
 449                 iser_inv_rkey(iser_tx_next_wr(tx_desc), mr, cqe);
 450
 451         ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
 452
 453         n = ib_map_mr_sg(mr, mem->sg, mem->size, NULL, SIZE_4K);
 454         if (unlikely(n != mem->size)) {
 455                 iser_err("failed to map sg (%d/%d)\n",
 456                          n, mem->size);
 457                 return n < 0 ? n : -EINVAL;
 458         }
 459
 460         wr = reg_wr(iser_tx_next_wr(tx_desc));
 461         wr->wr.opcode = IB_WR_REG_MR;
 462         wr->wr.wr_cqe = cqe;
 463         wr->wr.send_flags = 0;
 464         wr->wr.num_sge = 0;
 465         wr->mr = mr;
 466         wr->key = mr->rkey;
 467         wr->access = IB_ACCESS_LOCAL_WRITE  |
 468                      IB_ACCESS_REMOTE_WRITE |
 469                      IB_ACCESS_REMOTE_READ;
 470
 471         rsc->mr_valid = 1;
 472
 473         reg->sge.lkey = mr->lkey;
 474         reg->rkey = mr->rkey;
 475         reg->sge.addr = mr->iova;
 476         reg->sge.length = mr->length;
 477
 478         iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
 479                  reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
 480
 481         return 0;
 482 }
 483
 484 static int
 485 iser_reg_prot_sg(struct iscsi_iser_task *task,
 486                  struct iser_data_buf *mem,
 487                  struct iser_fr_desc *desc,
 488                  bool use_dma_key,
 489                  struct iser_mem_reg *reg)
 490 {
 491         struct iser_device *device = task->iser_conn->ib_conn.device;
 492
 493         if (use_dma_key)
 494                 return iser_reg_dma(device, mem, reg);
 495
 496         return device->reg_ops->reg_mem(task, mem, &desc->pi_ctx->rsc, reg);
 497 }
 498
 499 static int
 500 iser_reg_data_sg(struct iscsi_iser_task *task,
 501                  struct iser_data_buf *mem,
 502                  struct iser_fr_desc *desc,
 503                  bool use_dma_key,
 504                  struct iser_mem_reg *reg)
 505 {
 506         struct iser_device *device = task->iser_conn->ib_conn.device;
 507
 508         if (use_dma_key)
 509                 return iser_reg_dma(device, mem, reg);
 510
 511         return device->reg_ops->reg_mem(task, mem, &desc->rsc, reg);
 512 }
 513
 514 int iser_reg_rdma_mem(struct iscsi_iser_task *task,
 515                       enum iser_data_dir dir,
 516                       bool all_imm)
 517 {
 518         struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
 519         struct iser_device *device = ib_conn->device;
 520         struct iser_data_buf *mem = &task->data[dir];
 521         struct iser_mem_reg *reg = &task->rdma_reg[dir];
 522         struct iser_mem_reg *data_reg;
 523         struct iser_fr_desc *desc = NULL;
 524         bool use_dma_key;
 525         int err;
 526
 527         use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
 528                       scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
 529
 530         if (!use_dma_key) {
 531                 desc = device->reg_ops->reg_desc_get(ib_conn);
 532                 reg->mem_h = desc;
 533         }
 534
 535         if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL)
 536                 data_reg = reg;
 537         else
 538                 data_reg = &task->desc.data_reg;
 539
 540         err = iser_reg_data_sg(task, mem, desc, use_dma_key, data_reg);
 541         if (unlikely(err))
 542                 goto err_reg;
 543
 544         if (scsi_get_prot_op(task->sc) != SCSI_PROT_NORMAL) {
 545                 struct iser_mem_reg *prot_reg = &task->desc.prot_reg;
 546
 547                 if (scsi_prot_sg_count(task->sc)) {
 548                         mem = &task->prot[dir];
 549                         err = iser_reg_prot_sg(task, mem, desc,
 550                                                use_dma_key, prot_reg);
 551                         if (unlikely(err))
 552                                 goto err_reg;
 553                 }
 554
 555                 err = iser_reg_sig_mr(task, desc->pi_ctx, data_reg,
 556                                       prot_reg, reg);
 557                 if (unlikely(err))
 558                         goto err_reg;
 559
 560                 desc->pi_ctx->sig_protected = 1;
 561         }
 562
 563         return 0;
 564
 565 err_reg:
 566         if (desc)
 567                 device->reg_ops->reg_desc_put(ib_conn, desc);
 568
 569         return err;
 570 }
 571
 572 void iser_unreg_rdma_mem(struct iscsi_iser_task *task,
 573                          enum iser_data_dir dir)
 574 {
 575         struct iser_device *device = task->iser_conn->ib_conn.device;
 576
 577         device->reg_ops->unreg_mem(task, dir);
 578 }