drivers/infiniband/ulp/iser/iser_verbs.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/slab.h>
  37 #include <linux/delay.h>
  38
  39 #include "iscsi_iser.h"
  40
  41 #define ISCSI_ISER_MAX_CONN     8
  42 #define ISER_MAX_RX_CQ_LEN      (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
  43 #define ISER_MAX_TX_CQ_LEN      (ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
  44
  45 static void iser_cq_tasklet_fn(unsigned long data);
  46 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
  47
  48 static void iser_cq_event_callback(struct ib_event *cause, void *context)
  49 {
  50         iser_err("got cq event %d \n", cause->event);
  51 }
  52
  53 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  54 {
  55         iser_err("got qp event %d\n",cause->event);
  56 }
  57
  58 static void iser_event_handler(struct ib_event_handler *handler,
  59                                 struct ib_event *event)
  60 {
  61         iser_err("async event %d on device %s port %d\n", event->event,
  62                 event->device->name, event->element.port_num);
  63 }
  64
  65 /**
  66  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  67  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  68  * the adapator.
  69  *
  70  * returns 0 on success, -1 on failure
  71  */
  72 static int iser_create_device_ib_res(struct iser_device *device)
  73 {
  74         struct iser_cq_desc *cq_desc;
  75         struct ib_device_attr *dev_attr = &device->dev_attr;
  76         int ret, i, j;
  77
  78         ret = ib_query_device(device->ib_device, dev_attr);
  79         if (ret) {
  80                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  81                 return ret;
  82         }
  83
  84         /* Assign function handles  - based on FMR support */
  85         if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
  86             device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
  87                 iser_info("FMR supported, using FMR for registration\n");
  88                 device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
  89                 device->iser_free_rdma_reg_res = iser_free_fmr_pool;
  90                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
  91                 device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
  92         } else
  93         if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
  94                 iser_info("FastReg supported, using FastReg for registration\n");
  95                 device->iser_alloc_rdma_reg_res = iser_create_fastreg_pool;
  96                 device->iser_free_rdma_reg_res = iser_free_fastreg_pool;
  97                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fastreg;
  98                 device->iser_unreg_rdma_mem = iser_unreg_mem_fastreg;
  99         } else {
 100                 iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
 101                 return -1;
 102         }
 103
 104         device->cqs_used = min(ISER_MAX_CQ, device->ib_device->num_comp_vectors);
 105         iser_info("using %d CQs, device %s supports %d vectors\n",
 106                   device->cqs_used, device->ib_device->name,
 107                   device->ib_device->num_comp_vectors);
 108
 109         device->cq_desc = kmalloc(sizeof(struct iser_cq_desc) * device->cqs_used,
 110                                   GFP_KERNEL);
 111         if (device->cq_desc == NULL)
 112                 goto cq_desc_err;
 113         cq_desc = device->cq_desc;
 114
 115         device->pd = ib_alloc_pd(device->ib_device);
 116         if (IS_ERR(device->pd))
 117                 goto pd_err;
 118
 119         for (i = 0; i < device->cqs_used; i++) {
 120                 cq_desc[i].device   = device;
 121                 cq_desc[i].cq_index = i;
 122
 123                 device->rx_cq[i] = ib_create_cq(device->ib_device,
 124                                           iser_cq_callback,
 125                                           iser_cq_event_callback,
 126                                           (void *)&cq_desc[i],
 127                                           ISER_MAX_RX_CQ_LEN, i);
 128                 if (IS_ERR(device->rx_cq[i]))
 129                         goto cq_err;
 130
 131                 device->tx_cq[i] = ib_create_cq(device->ib_device,
 132                                           NULL, iser_cq_event_callback,
 133                                           (void *)&cq_desc[i],
 134                                           ISER_MAX_TX_CQ_LEN, i);
 135
 136                 if (IS_ERR(device->tx_cq[i]))
 137                         goto cq_err;
 138
 139                 if (ib_req_notify_cq(device->rx_cq[i], IB_CQ_NEXT_COMP))
 140                         goto cq_err;
 141
 142                 tasklet_init(&device->cq_tasklet[i],
 143                              iser_cq_tasklet_fn,
 144                         (unsigned long)&cq_desc[i]);
 145         }
 146
 147         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 148                                    IB_ACCESS_REMOTE_WRITE |
 149                                    IB_ACCESS_REMOTE_READ);
 150         if (IS_ERR(device->mr))
 151                 goto dma_mr_err;
 152
 153         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 154                                 iser_event_handler);
 155         if (ib_register_event_handler(&device->event_handler))
 156                 goto handler_err;
 157
 158         return 0;
 159
 160 handler_err:
 161         ib_dereg_mr(device->mr);
 162 dma_mr_err:
 163         for (j = 0; j < device->cqs_used; j++)
 164                 tasklet_kill(&device->cq_tasklet[j]);
 165 cq_err:
 166         for (j = 0; j < i; j++) {
 167                 if (device->tx_cq[j])
 168                         ib_destroy_cq(device->tx_cq[j]);
 169                 if (device->rx_cq[j])
 170                         ib_destroy_cq(device->rx_cq[j]);
 171         }
 172         ib_dealloc_pd(device->pd);
 173 pd_err:
 174         kfree(device->cq_desc);
 175 cq_desc_err:
 176         iser_err("failed to allocate an IB resource\n");
 177         return -1;
 178 }
 179
 180 /**
 181  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 182  * CQ and PD created with the device associated with the adapator.
 183  */
 184 static void iser_free_device_ib_res(struct iser_device *device)
 185 {
 186         int i;
 187         BUG_ON(device->mr == NULL);
 188
 189         for (i = 0; i < device->cqs_used; i++) {
 190                 tasklet_kill(&device->cq_tasklet[i]);
 191                 (void)ib_destroy_cq(device->tx_cq[i]);
 192                 (void)ib_destroy_cq(device->rx_cq[i]);
 193                 device->tx_cq[i] = NULL;
 194                 device->rx_cq[i] = NULL;
 195         }
 196
 197         (void)ib_unregister_event_handler(&device->event_handler);
 198         (void)ib_dereg_mr(device->mr);
 199         (void)ib_dealloc_pd(device->pd);
 200
 201         kfree(device->cq_desc);
 202
 203         device->mr = NULL;
 204         device->pd = NULL;
 205 }
 206
 207 /**
 208  * iser_create_fmr_pool - Creates FMR pool and page_vector
 209  *
 210  * returns 0 on success, or errno code on failure
 211  */
 212 int iser_create_fmr_pool(struct iser_conn *ib_conn, unsigned cmds_max)
 213 {
 214         struct iser_device *device = ib_conn->device;
 215         struct ib_fmr_pool_param params;
 216         int ret = -ENOMEM;
 217
 218         ib_conn->fmr.page_vec = kmalloc(sizeof(*ib_conn->fmr.page_vec) +
 219                                         (sizeof(u64)*(ISCSI_ISER_SG_TABLESIZE + 1)),
 220                                         GFP_KERNEL);
 221         if (!ib_conn->fmr.page_vec)
 222                 return ret;
 223
 224         ib_conn->fmr.page_vec->pages = (u64 *)(ib_conn->fmr.page_vec + 1);
 225
 226         params.page_shift        = SHIFT_4K;
 227         /* when the first/last SG element are not start/end *
 228          * page aligned, the map whould be of N+1 pages     */
 229         params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
 230         /* make the pool size twice the max number of SCSI commands *
 231          * the ML is expected to queue, watermark for unmap at 50%  */
 232         params.pool_size         = cmds_max * 2;
 233         params.dirty_watermark   = cmds_max;
 234         params.cache             = 0;
 235         params.flush_function    = NULL;
 236         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 237                                     IB_ACCESS_REMOTE_WRITE |
 238                                     IB_ACCESS_REMOTE_READ);
 239
 240         ib_conn->fmr.pool = ib_create_fmr_pool(device->pd, &params);
 241         if (!IS_ERR(ib_conn->fmr.pool))
 242                 return 0;
 243
 244         /* no FMR => no need for page_vec */
 245         kfree(ib_conn->fmr.page_vec);
 246         ib_conn->fmr.page_vec = NULL;
 247
 248         ret = PTR_ERR(ib_conn->fmr.pool);
 249         ib_conn->fmr.pool = NULL;
 250         if (ret != -ENOSYS) {
 251                 iser_err("FMR allocation failed, err %d\n", ret);
 252                 return ret;
 253         } else {
 254                 iser_warn("FMRs are not supported, using unaligned mode\n");
 255                 return 0;
 256         }
 257 }
 258
 259 /**
 260  * iser_free_fmr_pool - releases the FMR pool and page vec
 261  */
 262 void iser_free_fmr_pool(struct iser_conn *ib_conn)
 263 {
 264         iser_info("freeing conn %p fmr pool %p\n",
 265                   ib_conn, ib_conn->fmr.pool);
 266
 267         if (ib_conn->fmr.pool != NULL)
 268                 ib_destroy_fmr_pool(ib_conn->fmr.pool);
 269
 270         ib_conn->fmr.pool = NULL;
 271
 272         kfree(ib_conn->fmr.page_vec);
 273         ib_conn->fmr.page_vec = NULL;
 274 }
 275
 276 static int
 277 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
 278                          bool pi_enable, struct fast_reg_descriptor *desc)
 279 {
 280         int ret;
 281
 282         desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
 283                                                       ISCSI_ISER_SG_TABLESIZE + 1);
 284         if (IS_ERR(desc->data_frpl)) {
 285                 ret = PTR_ERR(desc->data_frpl);
 286                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 287                          ret);
 288                 return PTR_ERR(desc->data_frpl);
 289         }
 290
 291         desc->data_mr = ib_alloc_fast_reg_mr(pd, ISCSI_ISER_SG_TABLESIZE + 1);
 292         if (IS_ERR(desc->data_mr)) {
 293                 ret = PTR_ERR(desc->data_mr);
 294                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 295                 goto fast_reg_mr_failure;
 296         }
 297         desc->reg_indicators |= ISER_DATA_KEY_VALID;
 298
 299         if (pi_enable) {
 300                 struct ib_mr_init_attr mr_init_attr = {0};
 301                 struct iser_pi_context *pi_ctx = NULL;
 302
 303                 desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 304                 if (!desc->pi_ctx) {
 305                         iser_err("Failed to allocate pi context\n");
 306                         ret = -ENOMEM;
 307                         goto pi_ctx_alloc_failure;
 308                 }
 309                 pi_ctx = desc->pi_ctx;
 310
 311                 pi_ctx->prot_frpl = ib_alloc_fast_reg_page_list(ib_device,
 312                                                     ISCSI_ISER_SG_TABLESIZE);
 313                 if (IS_ERR(pi_ctx->prot_frpl)) {
 314                         ret = PTR_ERR(pi_ctx->prot_frpl);
 315                         iser_err("Failed to allocate prot frpl ret=%d\n",
 316                                  ret);
 317                         goto prot_frpl_failure;
 318                 }
 319
 320                 pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd,
 321                                                 ISCSI_ISER_SG_TABLESIZE + 1);
 322                 if (IS_ERR(pi_ctx->prot_mr)) {
 323                         ret = PTR_ERR(pi_ctx->prot_mr);
 324                         iser_err("Failed to allocate prot frmr ret=%d\n",
 325                                  ret);
 326                         goto prot_mr_failure;
 327                 }
 328                 desc->reg_indicators |= ISER_PROT_KEY_VALID;
 329
 330                 mr_init_attr.max_reg_descriptors = 2;
 331                 mr_init_attr.flags |= IB_MR_SIGNATURE_EN;
 332                 pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
 333                 if (IS_ERR(pi_ctx->sig_mr)) {
 334                         ret = PTR_ERR(pi_ctx->sig_mr);
 335                         iser_err("Failed to allocate signature enabled mr err=%d\n",
 336                                  ret);
 337                         goto sig_mr_failure;
 338                 }
 339                 desc->reg_indicators |= ISER_SIG_KEY_VALID;
 340         }
 341         desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
 342
 343         iser_dbg("Create fr_desc %p page_list %p\n",
 344                  desc, desc->data_frpl->page_list);
 345
 346         return 0;
 347 sig_mr_failure:
 348         ib_dereg_mr(desc->pi_ctx->prot_mr);
 349 prot_mr_failure:
 350         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 351 prot_frpl_failure:
 352         kfree(desc->pi_ctx);
 353 pi_ctx_alloc_failure:
 354         ib_dereg_mr(desc->data_mr);
 355 fast_reg_mr_failure:
 356         ib_free_fast_reg_page_list(desc->data_frpl);
 357
 358         return ret;
 359 }
 360
 361 /**
 362  * iser_create_fastreg_pool - Creates pool of fast_reg descriptors
 363  * for fast registration work requests.
 364  * returns 0 on success, or errno code on failure
 365  */
 366 int iser_create_fastreg_pool(struct iser_conn *ib_conn, unsigned cmds_max)
 367 {
 368         struct iser_device      *device = ib_conn->device;
 369         struct fast_reg_descriptor      *desc;
 370         int i, ret;
 371
 372         INIT_LIST_HEAD(&ib_conn->fastreg.pool);
 373         ib_conn->fastreg.pool_size = 0;
 374         for (i = 0; i < cmds_max; i++) {
 375                 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 376                 if (!desc) {
 377                         iser_err("Failed to allocate a new fast_reg descriptor\n");
 378                         ret = -ENOMEM;
 379                         goto err;
 380                 }
 381
 382                 ret = iser_create_fastreg_desc(device->ib_device, device->pd,
 383                                                ib_conn->pi_support, desc);
 384                 if (ret) {
 385                         iser_err("Failed to create fastreg descriptor err=%d\n",
 386                                  ret);
 387                         kfree(desc);
 388                         goto err;
 389                 }
 390
 391                 list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 392                 ib_conn->fastreg.pool_size++;
 393         }
 394
 395         return 0;
 396
 397 err:
 398         iser_free_fastreg_pool(ib_conn);
 399         return ret;
 400 }
 401
 402 /**
 403  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 404  */
 405 void iser_free_fastreg_pool(struct iser_conn *ib_conn)
 406 {
 407         struct fast_reg_descriptor *desc, *tmp;
 408         int i = 0;
 409
 410         if (list_empty(&ib_conn->fastreg.pool))
 411                 return;
 412
 413         iser_info("freeing conn %p fr pool\n", ib_conn);
 414
 415         list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
 416                 list_del(&desc->list);
 417                 ib_free_fast_reg_page_list(desc->data_frpl);
 418                 ib_dereg_mr(desc->data_mr);
 419                 if (desc->pi_ctx) {
 420                         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 421                         ib_dereg_mr(desc->pi_ctx->prot_mr);
 422                         ib_destroy_mr(desc->pi_ctx->sig_mr);
 423                         kfree(desc->pi_ctx);
 424                 }
 425                 kfree(desc);
 426                 ++i;
 427         }
 428
 429         if (i < ib_conn->fastreg.pool_size)
 430                 iser_warn("pool still has %d regions registered\n",
 431                           ib_conn->fastreg.pool_size - i);
 432 }
 433
 434 /**
 435  * iser_create_ib_conn_res - Queue-Pair (QP)
 436  *
 437  * returns 0 on success, -1 on failure
 438  */
 439 static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
 440 {
 441         struct iser_device      *device;
 442         struct ib_qp_init_attr  init_attr;
 443         int                     ret = -ENOMEM;
 444         int index, min_index = 0;
 445
 446         BUG_ON(ib_conn->device == NULL);
 447
 448         device = ib_conn->device;
 449
 450         memset(&init_attr, 0, sizeof init_attr);
 451
 452         mutex_lock(&ig.connlist_mutex);
 453         /* select the CQ with the minimal number of usages */
 454         for (index = 0; index < device->cqs_used; index++)
 455                 if (device->cq_active_qps[index] <
 456                     device->cq_active_qps[min_index])
 457                         min_index = index;
 458         device->cq_active_qps[min_index]++;
 459         mutex_unlock(&ig.connlist_mutex);
 460         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 461
 462         init_attr.event_handler = iser_qp_event_callback;
 463         init_attr.qp_context    = (void *)ib_conn;
 464         init_attr.send_cq       = device->tx_cq[min_index];
 465         init_attr.recv_cq       = device->rx_cq[min_index];
 466         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 467         init_attr.cap.max_send_sge = 2;
 468         init_attr.cap.max_recv_sge = 1;
 469         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 470         init_attr.qp_type       = IB_QPT_RC;
 471         if (ib_conn->pi_support) {
 472                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS;
 473                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 474         } else {
 475                 init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS;
 476         }
 477
 478         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 479         if (ret)
 480                 goto out_err;
 481
 482         ib_conn->qp = ib_conn->cma_id->qp;
 483         iser_info("setting conn %p cma_id %p qp %p\n",
 484                   ib_conn, ib_conn->cma_id,
 485                   ib_conn->cma_id->qp);
 486         return ret;
 487
 488 out_err:
 489         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 490         return ret;
 491 }
 492
 493 /**
 494  * releases the QP objects, returns 0 on success,
 495  * -1 on failure
 496  */
 497 static int iser_free_ib_conn_res(struct iser_conn *ib_conn)
 498 {
 499         int cq_index;
 500         BUG_ON(ib_conn == NULL);
 501
 502         iser_info("freeing conn %p cma_id %p qp %p\n",
 503                   ib_conn, ib_conn->cma_id,
 504                   ib_conn->qp);
 505
 506         /* qp is created only once both addr & route are resolved */
 507
 508         if (ib_conn->qp != NULL) {
 509                 cq_index = ((struct iser_cq_desc *)ib_conn->qp->recv_cq->cq_context)->cq_index;
 510                 ib_conn->device->cq_active_qps[cq_index]--;
 511
 512                 rdma_destroy_qp(ib_conn->cma_id);
 513         }
 514
 515         ib_conn->qp       = NULL;
 516
 517         return 0;
 518 }
 519
 520 /**
 521  * based on the resolved device node GUID see if there already allocated
 522  * device for this device. If there's no such, create one.
 523  */
 524 static
 525 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 526 {
 527         struct iser_device *device;
 528
 529         mutex_lock(&ig.device_list_mutex);
 530
 531         list_for_each_entry(device, &ig.device_list, ig_list)
 532                 /* find if there's a match using the node GUID */
 533                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 534                         goto inc_refcnt;
 535
 536         device = kzalloc(sizeof *device, GFP_KERNEL);
 537         if (device == NULL)
 538                 goto out;
 539
 540         /* assign this device to the device */
 541         device->ib_device = cma_id->device;
 542         /* init the device and link it into ig device list */
 543         if (iser_create_device_ib_res(device)) {
 544                 kfree(device);
 545                 device = NULL;
 546                 goto out;
 547         }
 548         list_add(&device->ig_list, &ig.device_list);
 549
 550 inc_refcnt:
 551         device->refcount++;
 552 out:
 553         mutex_unlock(&ig.device_list_mutex);
 554         return device;
 555 }
 556
 557 /* if there's no demand for this device, release it */
 558 static void iser_device_try_release(struct iser_device *device)
 559 {
 560         mutex_lock(&ig.device_list_mutex);
 561         device->refcount--;
 562         iser_info("device %p refcount %d\n", device, device->refcount);
 563         if (!device->refcount) {
 564                 iser_free_device_ib_res(device);
 565                 list_del(&device->ig_list);
 566                 kfree(device);
 567         }
 568         mutex_unlock(&ig.device_list_mutex);
 569 }
 570
 571 static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
 572                                      enum iser_ib_conn_state comp,
 573                                      enum iser_ib_conn_state exch)
 574 {
 575         int ret;
 576
 577         spin_lock_bh(&ib_conn->lock);
 578         if ((ret = (ib_conn->state == comp)))
 579                 ib_conn->state = exch;
 580         spin_unlock_bh(&ib_conn->lock);
 581         return ret;
 582 }
 583
 584 void iser_release_work(struct work_struct *work)
 585 {
 586         struct iser_conn *ib_conn;
 587
 588         ib_conn = container_of(work, struct iser_conn, release_work);
 589
 590         /* wait for .conn_stop callback */
 591         wait_for_completion(&ib_conn->stop_completion);
 592
 593         /* wait for the qp`s post send and post receive buffers to empty */
 594         wait_event_interruptible(ib_conn->wait,
 595                                  ib_conn->state == ISER_CONN_DOWN);
 596
 597         iser_conn_release(ib_conn);
 598 }
 599
 600 /**
 601  * Frees all conn objects and deallocs conn descriptor
 602  */
 603 void iser_conn_release(struct iser_conn *ib_conn)
 604 {
 605         struct iser_device  *device = ib_conn->device;
 606
 607         BUG_ON(ib_conn->state == ISER_CONN_UP);
 608
 609         mutex_lock(&ig.connlist_mutex);
 610         list_del(&ib_conn->conn_list);
 611         mutex_unlock(&ig.connlist_mutex);
 612         iser_free_rx_descriptors(ib_conn);
 613         iser_free_ib_conn_res(ib_conn);
 614         ib_conn->device = NULL;
 615         /* on EVENT_ADDR_ERROR there's no device yet for this conn */
 616         if (device != NULL)
 617                 iser_device_try_release(device);
 618         /* if cma handler context, the caller actually destroy the id */
 619         if (ib_conn->cma_id != NULL) {
 620                 rdma_destroy_id(ib_conn->cma_id);
 621                 ib_conn->cma_id = NULL;
 622         }
 623         iscsi_destroy_endpoint(ib_conn->ep);
 624 }
 625
 626 /**
 627  * triggers start of the disconnect procedures and wait for them to be done
 628  */
 629 void iser_conn_terminate(struct iser_conn *ib_conn)
 630 {
 631         int err = 0;
 632
 633         /* change the ib conn state only if the conn is UP, however always call
 634          * rdma_disconnect since this is the only way to cause the CMA to change
 635          * the QP state to ERROR
 636          */
 637
 638         iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
 639         err = rdma_disconnect(ib_conn->cma_id);
 640         if (err)
 641                 iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 642                          ib_conn,err);
 643 }
 644
 645 static void iser_connect_error(struct rdma_cm_id *cma_id)
 646 {
 647         struct iser_conn *ib_conn;
 648
 649         ib_conn = (struct iser_conn *)cma_id->context;
 650
 651         ib_conn->state = ISER_CONN_DOWN;
 652         wake_up_interruptible(&ib_conn->wait);
 653 }
 654
 655 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 656 {
 657         struct iser_device *device;
 658         struct iser_conn   *ib_conn;
 659         int    ret;
 660
 661         device = iser_device_find_by_ib_device(cma_id);
 662         if (!device) {
 663                 iser_err("device lookup/creation failed\n");
 664                 iser_connect_error(cma_id);
 665                 return;
 666         }
 667
 668         ib_conn = (struct iser_conn *)cma_id->context;
 669         ib_conn->device = device;
 670
 671         /* connection T10-PI support */
 672         if (iser_pi_enable) {
 673                 if (!(device->dev_attr.device_cap_flags &
 674                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 675                         iser_warn("T10-PI requested but not supported on %s, "
 676                                   "continue without T10-PI\n",
 677                                   ib_conn->device->ib_device->name);
 678                         ib_conn->pi_support = false;
 679                 } else {
 680                         ib_conn->pi_support = true;
 681                 }
 682         }
 683
 684         ret = rdma_resolve_route(cma_id, 1000);
 685         if (ret) {
 686                 iser_err("resolve route failed: %d\n", ret);
 687                 iser_connect_error(cma_id);
 688                 return;
 689         }
 690 }
 691
 692 static void iser_route_handler(struct rdma_cm_id *cma_id)
 693 {
 694         struct rdma_conn_param conn_param;
 695         int    ret;
 696         struct iser_cm_hdr req_hdr;
 697         struct iser_conn *ib_conn = (struct iser_conn *)cma_id->context;
 698         struct iser_device *device = ib_conn->device;
 699
 700         ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
 701         if (ret)
 702                 goto failure;
 703
 704         memset(&conn_param, 0, sizeof conn_param);
 705         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 706         conn_param.initiator_depth     = 1;
 707         conn_param.retry_count         = 7;
 708         conn_param.rnr_retry_count     = 6;
 709
 710         memset(&req_hdr, 0, sizeof(req_hdr));
 711         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 712                         ISER_SEND_W_INV_NOT_SUPPORTED);
 713         conn_param.private_data         = (void *)&req_hdr;
 714         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 715
 716         ret = rdma_connect(cma_id, &conn_param);
 717         if (ret) {
 718                 iser_err("failure connecting: %d\n", ret);
 719                 goto failure;
 720         }
 721
 722         return;
 723 failure:
 724         iser_connect_error(cma_id);
 725 }
 726
 727 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 728 {
 729         struct iser_conn *ib_conn;
 730         struct ib_qp_attr attr;
 731         struct ib_qp_init_attr init_attr;
 732
 733         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 734         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 735
 736         ib_conn = (struct iser_conn *)cma_id->context;
 737         if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_PENDING, ISER_CONN_UP))
 738                 wake_up_interruptible(&ib_conn->wait);
 739 }
 740
 741 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 742 {
 743         struct iser_conn *ib_conn;
 744
 745         ib_conn = (struct iser_conn *)cma_id->context;
 746
 747         /* getting here when the state is UP means that the conn is being *
 748          * terminated asynchronously from the iSCSI layer's perspective.  */
 749         if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
 750                                         ISER_CONN_TERMINATING)){
 751                 if (ib_conn->iscsi_conn)
 752                         iscsi_conn_failure(ib_conn->iscsi_conn, ISCSI_ERR_CONN_FAILED);
 753                 else
 754                         iser_err("iscsi_iser connection isn't bound\n");
 755         }
 756
 757         /* Complete the termination process if no posts are pending */
 758         if (ib_conn->post_recv_buf_count == 0 &&
 759             (atomic_read(&ib_conn->post_send_buf_count) == 0)) {
 760                 ib_conn->state = ISER_CONN_DOWN;
 761                 wake_up_interruptible(&ib_conn->wait);
 762         }
 763 }
 764
 765 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 766 {
 767         iser_info("event %d status %d conn %p id %p\n",
 768                   event->event, event->status, cma_id->context, cma_id);
 769
 770         switch (event->event) {
 771         case RDMA_CM_EVENT_ADDR_RESOLVED:
 772                 iser_addr_handler(cma_id);
 773                 break;
 774         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 775                 iser_route_handler(cma_id);
 776                 break;
 777         case RDMA_CM_EVENT_ESTABLISHED:
 778                 iser_connected_handler(cma_id);
 779                 break;
 780         case RDMA_CM_EVENT_ADDR_ERROR:
 781         case RDMA_CM_EVENT_ROUTE_ERROR:
 782         case RDMA_CM_EVENT_CONNECT_ERROR:
 783         case RDMA_CM_EVENT_UNREACHABLE:
 784         case RDMA_CM_EVENT_REJECTED:
 785                 iser_connect_error(cma_id);
 786                 break;
 787         case RDMA_CM_EVENT_DISCONNECTED:
 788         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 789         case RDMA_CM_EVENT_ADDR_CHANGE:
 790         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 791                 iser_disconnected_handler(cma_id);
 792                 break;
 793         default:
 794                 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
 795                 break;
 796         }
 797         return 0;
 798 }
 799
 800 void iser_conn_init(struct iser_conn *ib_conn)
 801 {
 802         ib_conn->state = ISER_CONN_INIT;
 803         init_waitqueue_head(&ib_conn->wait);
 804         ib_conn->post_recv_buf_count = 0;
 805         atomic_set(&ib_conn->post_send_buf_count, 0);
 806         init_completion(&ib_conn->stop_completion);
 807         INIT_LIST_HEAD(&ib_conn->conn_list);
 808         spin_lock_init(&ib_conn->lock);
 809 }
 810
 811  /**
 812  * starts the process of connecting to the target
 813  * sleeps until the connection is established or rejected
 814  */
 815 int iser_connect(struct iser_conn   *ib_conn,
 816                  struct sockaddr    *src_addr,
 817                  struct sockaddr    *dst_addr,
 818                  int                 non_blocking)
 819 {
 820         int err = 0;
 821
 822         sprintf(ib_conn->name, "%pISp", dst_addr);
 823
 824         iser_info("connecting to: %s\n", ib_conn->name);
 825
 826         /* the device is known only --after-- address resolution */
 827         ib_conn->device = NULL;
 828
 829         ib_conn->state = ISER_CONN_PENDING;
 830
 831         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 832                                              (void *)ib_conn,
 833                                              RDMA_PS_TCP, IB_QPT_RC);
 834         if (IS_ERR(ib_conn->cma_id)) {
 835                 err = PTR_ERR(ib_conn->cma_id);
 836                 iser_err("rdma_create_id failed: %d\n", err);
 837                 goto id_failure;
 838         }
 839
 840         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 841         if (err) {
 842                 iser_err("rdma_resolve_addr failed: %d\n", err);
 843                 goto addr_failure;
 844         }
 845
 846         if (!non_blocking) {
 847                 wait_event_interruptible(ib_conn->wait,
 848                                          (ib_conn->state != ISER_CONN_PENDING));
 849
 850                 if (ib_conn->state != ISER_CONN_UP) {
 851                         err =  -EIO;
 852                         goto connect_failure;
 853                 }
 854         }
 855
 856         mutex_lock(&ig.connlist_mutex);
 857         list_add(&ib_conn->conn_list, &ig.connlist);
 858         mutex_unlock(&ig.connlist_mutex);
 859         return 0;
 860
 861 id_failure:
 862         ib_conn->cma_id = NULL;
 863 addr_failure:
 864         ib_conn->state = ISER_CONN_DOWN;
 865 connect_failure:
 866         iser_conn_release(ib_conn);
 867         return err;
 868 }
 869
 870 /**
 871  * iser_reg_page_vec - Register physical memory
 872  *
 873  * returns: 0 on success, errno code on failure
 874  */
 875 int iser_reg_page_vec(struct iser_conn     *ib_conn,
 876                       struct iser_page_vec *page_vec,
 877                       struct iser_mem_reg  *mem_reg)
 878 {
 879         struct ib_pool_fmr *mem;
 880         u64                io_addr;
 881         u64                *page_list;
 882         int                status;
 883
 884         page_list = page_vec->pages;
 885         io_addr   = page_list[0];
 886
 887         mem  = ib_fmr_pool_map_phys(ib_conn->fmr.pool,
 888                                     page_list,
 889                                     page_vec->length,
 890                                     io_addr);
 891
 892         if (IS_ERR(mem)) {
 893                 status = (int)PTR_ERR(mem);
 894                 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
 895                 return status;
 896         }
 897
 898         mem_reg->lkey  = mem->fmr->lkey;
 899         mem_reg->rkey  = mem->fmr->rkey;
 900         mem_reg->len   = page_vec->length * SIZE_4K;
 901         mem_reg->va    = io_addr;
 902         mem_reg->is_mr = 1;
 903         mem_reg->mem_h = (void *)mem;
 904
 905         mem_reg->va   += page_vec->offset;
 906         mem_reg->len   = page_vec->data_size;
 907
 908         iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
 909                  "entry[0]: (0x%08lx,%ld)] -> "
 910                  "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
 911                  page_vec, page_vec->length,
 912                  (unsigned long)page_vec->pages[0],
 913                  (unsigned long)page_vec->data_size,
 914                  (unsigned int)mem_reg->lkey, mem_reg->mem_h,
 915                  (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
 916         return 0;
 917 }
 918
 919 /**
 920  * Unregister (previosuly registered using FMR) memory.
 921  * If memory is non-FMR does nothing.
 922  */
 923 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
 924                         enum iser_data_dir cmd_dir)
 925 {
 926         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 927         int ret;
 928
 929         if (!reg->is_mr)
 930                 return;
 931
 932         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
 933
 934         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
 935         if (ret)
 936                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
 937
 938         reg->mem_h = NULL;
 939 }
 940
 941 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 942                             enum iser_data_dir cmd_dir)
 943 {
 944         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 945         struct iser_conn *ib_conn = iser_task->ib_conn;
 946         struct fast_reg_descriptor *desc = reg->mem_h;
 947
 948         if (!reg->is_mr)
 949                 return;
 950
 951         reg->mem_h = NULL;
 952         reg->is_mr = 0;
 953         spin_lock_bh(&ib_conn->lock);
 954         list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 955         spin_unlock_bh(&ib_conn->lock);
 956 }
 957
 958 int iser_post_recvl(struct iser_conn *ib_conn)
 959 {
 960         struct ib_recv_wr rx_wr, *rx_wr_failed;
 961         struct ib_sge     sge;
 962         int ib_ret;
 963
 964         sge.addr   = ib_conn->login_resp_dma;
 965         sge.length = ISER_RX_LOGIN_SIZE;
 966         sge.lkey   = ib_conn->device->mr->lkey;
 967
 968         rx_wr.wr_id   = (unsigned long)ib_conn->login_resp_buf;
 969         rx_wr.sg_list = &sge;
 970         rx_wr.num_sge = 1;
 971         rx_wr.next    = NULL;
 972
 973         ib_conn->post_recv_buf_count++;
 974         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
 975         if (ib_ret) {
 976                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
 977                 ib_conn->post_recv_buf_count--;
 978         }
 979         return ib_ret;
 980 }
 981
 982 int iser_post_recvm(struct iser_conn *ib_conn, int count)
 983 {
 984         struct ib_recv_wr *rx_wr, *rx_wr_failed;
 985         int i, ib_ret;
 986         unsigned int my_rx_head = ib_conn->rx_desc_head;
 987         struct iser_rx_desc *rx_desc;
 988
 989         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
 990                 rx_desc         = &ib_conn->rx_descs[my_rx_head];
 991                 rx_wr->wr_id    = (unsigned long)rx_desc;
 992                 rx_wr->sg_list  = &rx_desc->rx_sg;
 993                 rx_wr->num_sge  = 1;
 994                 rx_wr->next     = rx_wr + 1;
 995                 my_rx_head = (my_rx_head + 1) & ib_conn->qp_max_recv_dtos_mask;
 996         }
 997
 998         rx_wr--;
 999         rx_wr->next = NULL; /* mark end of work requests list */
1000
1001         ib_conn->post_recv_buf_count += count;
1002         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1003         if (ib_ret) {
1004                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1005                 ib_conn->post_recv_buf_count -= count;
1006         } else
1007                 ib_conn->rx_desc_head = my_rx_head;
1008         return ib_ret;
1009 }
1010
1011
1012 /**
1013  * iser_start_send - Initiate a Send DTO operation
1014  *
1015  * returns 0 on success, -1 on failure
1016  */
1017 int iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc)
1018 {
1019         int               ib_ret;
1020         struct ib_send_wr send_wr, *send_wr_failed;
1021
1022         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1023                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
1024
1025         send_wr.next       = NULL;
1026         send_wr.wr_id      = (unsigned long)tx_desc;
1027         send_wr.sg_list    = tx_desc->tx_sg;
1028         send_wr.num_sge    = tx_desc->num_sge;
1029         send_wr.opcode     = IB_WR_SEND;
1030         send_wr.send_flags = IB_SEND_SIGNALED;
1031
1032         atomic_inc(&ib_conn->post_send_buf_count);
1033
1034         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1035         if (ib_ret) {
1036                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1037                 atomic_dec(&ib_conn->post_send_buf_count);
1038         }
1039         return ib_ret;
1040 }
1041
1042 static void iser_handle_comp_error(struct iser_tx_desc *desc,
1043                                 struct iser_conn *ib_conn)
1044 {
1045         if (desc && desc->type == ISCSI_TX_DATAOUT)
1046                 kmem_cache_free(ig.desc_cache, desc);
1047
1048         if (ib_conn->post_recv_buf_count == 0 &&
1049             atomic_read(&ib_conn->post_send_buf_count) == 0) {
1050                 /* getting here when the state is UP means that the conn is *
1051                  * being terminated asynchronously from the iSCSI layer's   *
1052                  * perspective.                                             */
1053                 if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
1054                     ISER_CONN_TERMINATING))
1055                         iscsi_conn_failure(ib_conn->iscsi_conn,
1056                                            ISCSI_ERR_CONN_FAILED);
1057
1058                 /* no more non completed posts to the QP, complete the
1059                  * termination process w.o worrying on disconnect event */
1060                 ib_conn->state = ISER_CONN_DOWN;
1061                 wake_up_interruptible(&ib_conn->wait);
1062         }
1063 }
1064
1065 static int iser_drain_tx_cq(struct iser_device  *device, int cq_index)
1066 {
1067         struct ib_cq  *cq = device->tx_cq[cq_index];
1068         struct ib_wc  wc;
1069         struct iser_tx_desc *tx_desc;
1070         struct iser_conn *ib_conn;
1071         int completed_tx = 0;
1072
1073         while (ib_poll_cq(cq, 1, &wc) == 1) {
1074                 tx_desc = (struct iser_tx_desc *) (unsigned long) wc.wr_id;
1075                 ib_conn = wc.qp->qp_context;
1076                 if (wc.status == IB_WC_SUCCESS) {
1077                         if (wc.opcode == IB_WC_SEND)
1078                                 iser_snd_completion(tx_desc, ib_conn);
1079                         else
1080                                 iser_err("expected opcode %d got %d\n",
1081                                         IB_WC_SEND, wc.opcode);
1082                 } else {
1083                         iser_err("tx id %llx status %d vend_err %x\n",
1084                                  wc.wr_id, wc.status, wc.vendor_err);
1085                         if (wc.wr_id != ISER_FASTREG_LI_WRID) {
1086                                 atomic_dec(&ib_conn->post_send_buf_count);
1087                                 iser_handle_comp_error(tx_desc, ib_conn);
1088                         }
1089                 }
1090                 completed_tx++;
1091         }
1092         return completed_tx;
1093 }
1094
1095
1096 static void iser_cq_tasklet_fn(unsigned long data)
1097 {
1098         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)data;
1099         struct iser_device  *device = cq_desc->device;
1100         int cq_index = cq_desc->cq_index;
1101         struct ib_cq         *cq = device->rx_cq[cq_index];
1102          struct ib_wc        wc;
1103          struct iser_rx_desc *desc;
1104          unsigned long       xfer_len;
1105         struct iser_conn *ib_conn;
1106         int completed_tx, completed_rx = 0;
1107
1108         /* First do tx drain, so in a case where we have rx flushes and a successful
1109          * tx completion we will still go through completion error handling.
1110          */
1111         completed_tx = iser_drain_tx_cq(device, cq_index);
1112
1113         while (ib_poll_cq(cq, 1, &wc) == 1) {
1114                 desc     = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
1115                 BUG_ON(desc == NULL);
1116                 ib_conn = wc.qp->qp_context;
1117                 if (wc.status == IB_WC_SUCCESS) {
1118                         if (wc.opcode == IB_WC_RECV) {
1119                                 xfer_len = (unsigned long)wc.byte_len;
1120                                 iser_rcv_completion(desc, xfer_len, ib_conn);
1121                         } else
1122                                 iser_err("expected opcode %d got %d\n",
1123                                         IB_WC_RECV, wc.opcode);
1124                 } else {
1125                         if (wc.status != IB_WC_WR_FLUSH_ERR)
1126                                 iser_err("rx id %llx status %d vend_err %x\n",
1127                                         wc.wr_id, wc.status, wc.vendor_err);
1128                         ib_conn->post_recv_buf_count--;
1129                         iser_handle_comp_error(NULL, ib_conn);
1130                 }
1131                 completed_rx++;
1132                 if (!(completed_rx & 63))
1133                         completed_tx += iser_drain_tx_cq(device, cq_index);
1134         }
1135         /* #warning "it is assumed here that arming CQ only once its empty" *
1136          * " would not cause interrupts to be missed"                       */
1137         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1138
1139         iser_dbg("got %d rx %d tx completions\n", completed_rx, completed_tx);
1140 }
1141
1142 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1143 {
1144         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)cq_context;
1145         struct iser_device  *device = cq_desc->device;
1146         int cq_index = cq_desc->cq_index;
1147
1148         tasklet_schedule(&device->cq_tasklet[cq_index]);
1149 }
1150
1151 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1152                              enum iser_data_dir cmd_dir, sector_t *sector)
1153 {
1154         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1155         struct fast_reg_descriptor *desc = reg->mem_h;
1156         unsigned long sector_size = iser_task->sc->device->sector_size;
1157         struct ib_mr_status mr_status;
1158         int ret;
1159
1160         if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1161                 desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1162                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1163                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1164                 if (ret) {
1165                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1166                         goto err;
1167                 }
1168
1169                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1170                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1171
1172                         do_div(sector_off, sector_size + 8);
1173                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1174
1175                         pr_err("PI error found type %d at sector %llx "
1176                                "expected %x vs actual %x\n",
1177                                mr_status.sig_err.err_type,
1178                                (unsigned long long)*sector,
1179                                mr_status.sig_err.expected,
1180                                mr_status.sig_err.actual);
1181
1182                         switch (mr_status.sig_err.err_type) {
1183                         case IB_SIG_BAD_GUARD:
1184                                 return 0x1;
1185                         case IB_SIG_BAD_REFTAG:
1186                                 return 0x3;
1187                         case IB_SIG_BAD_APPTAG:
1188                                 return 0x2;
1189                         }
1190                 }
1191         }
1192
1193         return 0;
1194 err:
1195         /* Not alot we can do here, return ambiguous guard error */
1196         return 0x1;
1197 }