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_LEN         (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
  43 #define ISER_MAX_TX_LEN         (ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
  44 #define ISER_MAX_CQ_LEN         (ISER_MAX_RX_LEN + ISER_MAX_TX_LEN + \
  45                                  ISCSI_ISER_MAX_CONN)
  46
  47 static int iser_cq_poll_limit = 512;
  48
  49 static void iser_cq_tasklet_fn(unsigned long data);
  50 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
  51
  52 static void iser_cq_event_callback(struct ib_event *cause, void *context)
  53 {
  54         iser_err("cq event %s (%d)\n",
  55                  ib_event_msg(cause->event), cause->event);
  56 }
  57
  58 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  59 {
  60         iser_err("qp event %s (%d)\n",
  61                  ib_event_msg(cause->event), cause->event);
  62 }
  63
  64 static void iser_event_handler(struct ib_event_handler *handler,
  65                                 struct ib_event *event)
  66 {
  67         iser_err("async event %s (%d) on device %s port %d\n",
  68                  ib_event_msg(event->event), event->event,
  69                  event->device->name, event->element.port_num);
  70 }
  71
  72 /**
  73  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  74  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  75  * the adapator.
  76  *
  77  * returns 0 on success, -1 on failure
  78  */
  79 static int iser_create_device_ib_res(struct iser_device *device)
  80 {
  81         struct ib_device_attr *dev_attr = &device->dev_attr;
  82         int ret, i, max_cqe;
  83
  84         ret = ib_query_device(device->ib_device, dev_attr);
  85         if (ret) {
  86                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  87                 return ret;
  88         }
  89
  90         ret = iser_assign_reg_ops(device);
  91         if (ret)
  92                 return ret;
  93
  94         device->comps_used = min_t(int, num_online_cpus(),
  95                                  device->ib_device->num_comp_vectors);
  96
  97         device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
  98                                 GFP_KERNEL);
  99         if (!device->comps)
 100                 goto comps_err;
 101
 102         max_cqe = min(ISER_MAX_CQ_LEN, dev_attr->max_cqe);
 103
 104         iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
 105                   device->comps_used, device->ib_device->name,
 106                   device->ib_device->num_comp_vectors, max_cqe);
 107
 108         device->pd = ib_alloc_pd(device->ib_device);
 109         if (IS_ERR(device->pd))
 110                 goto pd_err;
 111
 112         for (i = 0; i < device->comps_used; i++) {
 113                 struct ib_cq_init_attr cq_attr = {};
 114                 struct iser_comp *comp = &device->comps[i];
 115
 116                 comp->device = device;
 117                 cq_attr.cqe = max_cqe;
 118                 cq_attr.comp_vector = i;
 119                 comp->cq = ib_create_cq(device->ib_device,
 120                                         iser_cq_callback,
 121                                         iser_cq_event_callback,
 122                                         (void *)comp,
 123                                         &cq_attr);
 124                 if (IS_ERR(comp->cq)) {
 125                         comp->cq = NULL;
 126                         goto cq_err;
 127                 }
 128
 129                 if (ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP))
 130                         goto cq_err;
 131
 132                 tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
 133                              (unsigned long)comp);
 134         }
 135
 136         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 137                                    IB_ACCESS_REMOTE_WRITE |
 138                                    IB_ACCESS_REMOTE_READ);
 139         if (IS_ERR(device->mr))
 140                 goto dma_mr_err;
 141
 142         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 143                                 iser_event_handler);
 144         if (ib_register_event_handler(&device->event_handler))
 145                 goto handler_err;
 146
 147         return 0;
 148
 149 handler_err:
 150         ib_dereg_mr(device->mr);
 151 dma_mr_err:
 152         for (i = 0; i < device->comps_used; i++)
 153                 tasklet_kill(&device->comps[i].tasklet);
 154 cq_err:
 155         for (i = 0; i < device->comps_used; i++) {
 156                 struct iser_comp *comp = &device->comps[i];
 157
 158                 if (comp->cq)
 159                         ib_destroy_cq(comp->cq);
 160         }
 161         ib_dealloc_pd(device->pd);
 162 pd_err:
 163         kfree(device->comps);
 164 comps_err:
 165         iser_err("failed to allocate an IB resource\n");
 166         return -1;
 167 }
 168
 169 /**
 170  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 171  * CQ and PD created with the device associated with the adapator.
 172  */
 173 static void iser_free_device_ib_res(struct iser_device *device)
 174 {
 175         int i;
 176         BUG_ON(device->mr == NULL);
 177
 178         for (i = 0; i < device->comps_used; i++) {
 179                 struct iser_comp *comp = &device->comps[i];
 180
 181                 tasklet_kill(&comp->tasklet);
 182                 ib_destroy_cq(comp->cq);
 183                 comp->cq = NULL;
 184         }
 185
 186         (void)ib_unregister_event_handler(&device->event_handler);
 187         (void)ib_dereg_mr(device->mr);
 188         (void)ib_dealloc_pd(device->pd);
 189
 190         kfree(device->comps);
 191         device->comps = NULL;
 192
 193         device->mr = NULL;
 194         device->pd = NULL;
 195 }
 196
 197 /**
 198  * iser_alloc_fmr_pool - Creates FMR pool and page_vector
 199  *
 200  * returns 0 on success, or errno code on failure
 201  */
 202 int iser_alloc_fmr_pool(struct ib_conn *ib_conn, unsigned cmds_max)
 203 {
 204         struct iser_device *device = ib_conn->device;
 205         struct ib_fmr_pool_param params;
 206         int ret = -ENOMEM;
 207
 208         ib_conn->fmr.page_vec = kmalloc(sizeof(*ib_conn->fmr.page_vec) +
 209                                         (sizeof(u64)*(ISCSI_ISER_SG_TABLESIZE + 1)),
 210                                         GFP_KERNEL);
 211         if (!ib_conn->fmr.page_vec)
 212                 return ret;
 213
 214         ib_conn->fmr.page_vec->pages = (u64 *)(ib_conn->fmr.page_vec + 1);
 215
 216         params.page_shift        = SHIFT_4K;
 217         /* when the first/last SG element are not start/end *
 218          * page aligned, the map whould be of N+1 pages     */
 219         params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
 220         /* make the pool size twice the max number of SCSI commands *
 221          * the ML is expected to queue, watermark for unmap at 50%  */
 222         params.pool_size         = cmds_max * 2;
 223         params.dirty_watermark   = cmds_max;
 224         params.cache             = 0;
 225         params.flush_function    = NULL;
 226         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 227                                     IB_ACCESS_REMOTE_WRITE |
 228                                     IB_ACCESS_REMOTE_READ);
 229
 230         ib_conn->fmr.pool = ib_create_fmr_pool(device->pd, &params);
 231         if (IS_ERR(ib_conn->fmr.pool)) {
 232                 ret = PTR_ERR(ib_conn->fmr.pool);
 233                 iser_err("FMR allocation failed, err %d\n", ret);
 234                 goto err;
 235         }
 236
 237         return 0;
 238
 239 err:
 240         kfree(ib_conn->fmr.page_vec);
 241         ib_conn->fmr.page_vec = NULL;
 242         return ret;
 243 }
 244
 245 /**
 246  * iser_free_fmr_pool - releases the FMR pool and page vec
 247  */
 248 void iser_free_fmr_pool(struct ib_conn *ib_conn)
 249 {
 250         iser_info("freeing conn %p fmr pool %p\n",
 251                   ib_conn, ib_conn->fmr.pool);
 252
 253         ib_destroy_fmr_pool(ib_conn->fmr.pool);
 254         ib_conn->fmr.pool = NULL;
 255
 256         kfree(ib_conn->fmr.page_vec);
 257         ib_conn->fmr.page_vec = NULL;
 258 }
 259
 260 static int
 261 iser_alloc_reg_res(struct ib_device *ib_device, struct ib_pd *pd,
 262                    struct iser_reg_resources *res)
 263 {
 264         int ret;
 265
 266         res->frpl = ib_alloc_fast_reg_page_list(ib_device,
 267                                                 ISCSI_ISER_SG_TABLESIZE + 1);
 268         if (IS_ERR(res->frpl)) {
 269                 ret = PTR_ERR(res->frpl);
 270                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 271                          ret);
 272                 return PTR_ERR(res->frpl);
 273         }
 274
 275         res->mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
 276                               ISCSI_ISER_SG_TABLESIZE + 1);
 277         if (IS_ERR(res->mr)) {
 278                 ret = PTR_ERR(res->mr);
 279                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 280                 goto fast_reg_mr_failure;
 281         }
 282         res->mr_valid = 1;
 283
 284         return 0;
 285
 286 fast_reg_mr_failure:
 287         ib_free_fast_reg_page_list(res->frpl);
 288
 289         return ret;
 290 }
 291
 292 static void
 293 iser_free_reg_res(struct iser_reg_resources *rsc)
 294 {
 295         ib_dereg_mr(rsc->mr);
 296         ib_free_fast_reg_page_list(rsc->frpl);
 297 }
 298
 299 static int
 300 iser_alloc_pi_ctx(struct ib_device *ib_device, struct ib_pd *pd,
 301                   struct iser_fr_desc *desc)
 302 {
 303         struct iser_pi_context *pi_ctx = NULL;
 304         int ret;
 305
 306         desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 307         if (!desc->pi_ctx)
 308                 return -ENOMEM;
 309
 310         pi_ctx = desc->pi_ctx;
 311
 312         ret = iser_alloc_reg_res(ib_device, pd, &pi_ctx->rsc);
 313         if (ret) {
 314                 iser_err("failed to allocate reg_resources\n");
 315                 goto alloc_reg_res_err;
 316         }
 317
 318         pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
 319         if (IS_ERR(pi_ctx->sig_mr)) {
 320                 ret = PTR_ERR(pi_ctx->sig_mr);
 321                 goto sig_mr_failure;
 322         }
 323         pi_ctx->sig_mr_valid = 1;
 324         desc->pi_ctx->sig_protected = 0;
 325
 326         return 0;
 327
 328 sig_mr_failure:
 329         iser_free_reg_res(&pi_ctx->rsc);
 330 alloc_reg_res_err:
 331         kfree(desc->pi_ctx);
 332
 333         return ret;
 334 }
 335
 336 static void
 337 iser_free_pi_ctx(struct iser_pi_context *pi_ctx)
 338 {
 339         iser_free_reg_res(&pi_ctx->rsc);
 340         ib_dereg_mr(pi_ctx->sig_mr);
 341         kfree(pi_ctx);
 342 }
 343
 344 static struct iser_fr_desc *
 345 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
 346                          bool pi_enable)
 347 {
 348         struct iser_fr_desc *desc;
 349         int ret;
 350
 351         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 352         if (!desc)
 353                 return ERR_PTR(-ENOMEM);
 354
 355         ret = iser_alloc_reg_res(ib_device, pd, &desc->rsc);
 356         if (ret)
 357                 goto reg_res_alloc_failure;
 358
 359         if (pi_enable) {
 360                 ret = iser_alloc_pi_ctx(ib_device, pd, desc);
 361                 if (ret)
 362                         goto pi_ctx_alloc_failure;
 363         }
 364
 365         return desc;
 366
 367 pi_ctx_alloc_failure:
 368         iser_free_reg_res(&desc->rsc);
 369 reg_res_alloc_failure:
 370         kfree(desc);
 371
 372         return ERR_PTR(ret);
 373 }
 374
 375 /**
 376  * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
 377  * for fast registration work requests.
 378  * returns 0 on success, or errno code on failure
 379  */
 380 int iser_alloc_fastreg_pool(struct ib_conn *ib_conn, unsigned cmds_max)
 381 {
 382         struct iser_device *device = ib_conn->device;
 383         struct iser_fr_desc *desc;
 384         int i, ret;
 385
 386         INIT_LIST_HEAD(&ib_conn->fastreg.pool);
 387         ib_conn->fastreg.pool_size = 0;
 388         for (i = 0; i < cmds_max; i++) {
 389                 desc = iser_create_fastreg_desc(device->ib_device, device->pd,
 390                                                 ib_conn->pi_support);
 391                 if (IS_ERR(desc)) {
 392                         ret = PTR_ERR(desc);
 393                         goto err;
 394                 }
 395
 396                 list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 397                 ib_conn->fastreg.pool_size++;
 398         }
 399
 400         return 0;
 401
 402 err:
 403         iser_free_fastreg_pool(ib_conn);
 404         return ret;
 405 }
 406
 407 /**
 408  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 409  */
 410 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
 411 {
 412         struct iser_fr_desc *desc, *tmp;
 413         int i = 0;
 414
 415         if (list_empty(&ib_conn->fastreg.pool))
 416                 return;
 417
 418         iser_info("freeing conn %p fr pool\n", ib_conn);
 419
 420         list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
 421                 list_del(&desc->list);
 422                 iser_free_reg_res(&desc->rsc);
 423                 if (desc->pi_ctx)
 424                         iser_free_pi_ctx(desc->pi_ctx);
 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 ib_conn *ib_conn)
 440 {
 441         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 442                                                    ib_conn);
 443         struct iser_device      *device;
 444         struct ib_device_attr *dev_attr;
 445         struct ib_qp_init_attr  init_attr;
 446         int                     ret = -ENOMEM;
 447         int index, min_index = 0;
 448
 449         BUG_ON(ib_conn->device == NULL);
 450
 451         device = ib_conn->device;
 452         dev_attr = &device->dev_attr;
 453
 454         memset(&init_attr, 0, sizeof init_attr);
 455
 456         mutex_lock(&ig.connlist_mutex);
 457         /* select the CQ with the minimal number of usages */
 458         for (index = 0; index < device->comps_used; index++) {
 459                 if (device->comps[index].active_qps <
 460                     device->comps[min_index].active_qps)
 461                         min_index = index;
 462         }
 463         ib_conn->comp = &device->comps[min_index];
 464         ib_conn->comp->active_qps++;
 465         mutex_unlock(&ig.connlist_mutex);
 466         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 467
 468         init_attr.event_handler = iser_qp_event_callback;
 469         init_attr.qp_context    = (void *)ib_conn;
 470         init_attr.send_cq       = ib_conn->comp->cq;
 471         init_attr.recv_cq       = ib_conn->comp->cq;
 472         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 473         init_attr.cap.max_send_sge = 2;
 474         init_attr.cap.max_recv_sge = 1;
 475         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 476         init_attr.qp_type       = IB_QPT_RC;
 477         if (ib_conn->pi_support) {
 478                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
 479                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 480                 iser_conn->max_cmds =
 481                         ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
 482         } else {
 483                 if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
 484                         init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
 485                         iser_conn->max_cmds =
 486                                 ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
 487                 } else {
 488                         init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
 489                         iser_conn->max_cmds =
 490                                 ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
 491                         iser_dbg("device %s supports max_send_wr %d\n",
 492                                  device->ib_device->name, dev_attr->max_qp_wr);
 493                 }
 494         }
 495
 496         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 497         if (ret)
 498                 goto out_err;
 499
 500         ib_conn->qp = ib_conn->cma_id->qp;
 501         iser_info("setting conn %p cma_id %p qp %p\n",
 502                   ib_conn, ib_conn->cma_id,
 503                   ib_conn->cma_id->qp);
 504         return ret;
 505
 506 out_err:
 507         mutex_lock(&ig.connlist_mutex);
 508         ib_conn->comp->active_qps--;
 509         mutex_unlock(&ig.connlist_mutex);
 510         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 511
 512         return ret;
 513 }
 514
 515 /**
 516  * based on the resolved device node GUID see if there already allocated
 517  * device for this device. If there's no such, create one.
 518  */
 519 static
 520 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 521 {
 522         struct iser_device *device;
 523
 524         mutex_lock(&ig.device_list_mutex);
 525
 526         list_for_each_entry(device, &ig.device_list, ig_list)
 527                 /* find if there's a match using the node GUID */
 528                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 529                         goto inc_refcnt;
 530
 531         device = kzalloc(sizeof *device, GFP_KERNEL);
 532         if (device == NULL)
 533                 goto out;
 534
 535         /* assign this device to the device */
 536         device->ib_device = cma_id->device;
 537         /* init the device and link it into ig device list */
 538         if (iser_create_device_ib_res(device)) {
 539                 kfree(device);
 540                 device = NULL;
 541                 goto out;
 542         }
 543         list_add(&device->ig_list, &ig.device_list);
 544
 545 inc_refcnt:
 546         device->refcount++;
 547 out:
 548         mutex_unlock(&ig.device_list_mutex);
 549         return device;
 550 }
 551
 552 /* if there's no demand for this device, release it */
 553 static void iser_device_try_release(struct iser_device *device)
 554 {
 555         mutex_lock(&ig.device_list_mutex);
 556         device->refcount--;
 557         iser_info("device %p refcount %d\n", device, device->refcount);
 558         if (!device->refcount) {
 559                 iser_free_device_ib_res(device);
 560                 list_del(&device->ig_list);
 561                 kfree(device);
 562         }
 563         mutex_unlock(&ig.device_list_mutex);
 564 }
 565
 566 /**
 567  * Called with state mutex held
 568  **/
 569 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
 570                                      enum iser_conn_state comp,
 571                                      enum iser_conn_state exch)
 572 {
 573         int ret;
 574
 575         ret = (iser_conn->state == comp);
 576         if (ret)
 577                 iser_conn->state = exch;
 578
 579         return ret;
 580 }
 581
 582 void iser_release_work(struct work_struct *work)
 583 {
 584         struct iser_conn *iser_conn;
 585
 586         iser_conn = container_of(work, struct iser_conn, release_work);
 587
 588         /* Wait for conn_stop to complete */
 589         wait_for_completion(&iser_conn->stop_completion);
 590         /* Wait for IB resouces cleanup to complete */
 591         wait_for_completion(&iser_conn->ib_completion);
 592
 593         mutex_lock(&iser_conn->state_mutex);
 594         iser_conn->state = ISER_CONN_DOWN;
 595         mutex_unlock(&iser_conn->state_mutex);
 596
 597         iser_conn_release(iser_conn);
 598 }
 599
 600 /**
 601  * iser_free_ib_conn_res - release IB related resources
 602  * @iser_conn: iser connection struct
 603  * @destroy: indicator if we need to try to release the
 604  *     iser device and memory regoins pool (only iscsi
 605  *     shutdown and DEVICE_REMOVAL will use this).
 606  *
 607  * This routine is called with the iser state mutex held
 608  * so the cm_id removal is out of here. It is Safe to
 609  * be invoked multiple times.
 610  */
 611 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
 612                                   bool destroy)
 613 {
 614         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 615         struct iser_device *device = ib_conn->device;
 616
 617         iser_info("freeing conn %p cma_id %p qp %p\n",
 618                   iser_conn, ib_conn->cma_id, ib_conn->qp);
 619
 620         if (ib_conn->qp != NULL) {
 621                 ib_conn->comp->active_qps--;
 622                 rdma_destroy_qp(ib_conn->cma_id);
 623                 ib_conn->qp = NULL;
 624         }
 625
 626         if (destroy) {
 627                 if (iser_conn->rx_descs)
 628                         iser_free_rx_descriptors(iser_conn);
 629
 630                 if (device != NULL) {
 631                         iser_device_try_release(device);
 632                         ib_conn->device = NULL;
 633                 }
 634         }
 635 }
 636
 637 /**
 638  * Frees all conn objects and deallocs conn descriptor
 639  */
 640 void iser_conn_release(struct iser_conn *iser_conn)
 641 {
 642         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 643
 644         mutex_lock(&ig.connlist_mutex);
 645         list_del(&iser_conn->conn_list);
 646         mutex_unlock(&ig.connlist_mutex);
 647
 648         mutex_lock(&iser_conn->state_mutex);
 649         /* In case we endup here without ep_disconnect being invoked. */
 650         if (iser_conn->state != ISER_CONN_DOWN) {
 651                 iser_warn("iser conn %p state %d, expected state down.\n",
 652                           iser_conn, iser_conn->state);
 653                 iscsi_destroy_endpoint(iser_conn->ep);
 654                 iser_conn->state = ISER_CONN_DOWN;
 655         }
 656         /*
 657          * In case we never got to bind stage, we still need to
 658          * release IB resources (which is safe to call more than once).
 659          */
 660         iser_free_ib_conn_res(iser_conn, true);
 661         mutex_unlock(&iser_conn->state_mutex);
 662
 663         if (ib_conn->cma_id != NULL) {
 664                 rdma_destroy_id(ib_conn->cma_id);
 665                 ib_conn->cma_id = NULL;
 666         }
 667
 668         kfree(iser_conn);
 669 }
 670
 671 /**
 672  * triggers start of the disconnect procedures and wait for them to be done
 673  * Called with state mutex held
 674  */
 675 int iser_conn_terminate(struct iser_conn *iser_conn)
 676 {
 677         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 678         struct ib_send_wr *bad_wr;
 679         int err = 0;
 680
 681         /* terminate the iser conn only if the conn state is UP */
 682         if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
 683                                        ISER_CONN_TERMINATING))
 684                 return 0;
 685
 686         iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
 687
 688         /* suspend queuing of new iscsi commands */
 689         if (iser_conn->iscsi_conn)
 690                 iscsi_suspend_queue(iser_conn->iscsi_conn);
 691
 692         /*
 693          * In case we didn't already clean up the cma_id (peer initiated
 694          * a disconnection), we need to Cause the CMA to change the QP
 695          * state to ERROR.
 696          */
 697         if (ib_conn->cma_id) {
 698                 err = rdma_disconnect(ib_conn->cma_id);
 699                 if (err)
 700                         iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 701                                  iser_conn, err);
 702
 703                 /* post an indication that all flush errors were consumed */
 704                 err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
 705                 if (err) {
 706                         iser_err("conn %p failed to post beacon", ib_conn);
 707                         return 1;
 708                 }
 709
 710                 wait_for_completion(&ib_conn->flush_comp);
 711         }
 712
 713         return 1;
 714 }
 715
 716 /**
 717  * Called with state mutex held
 718  **/
 719 static void iser_connect_error(struct rdma_cm_id *cma_id)
 720 {
 721         struct iser_conn *iser_conn;
 722
 723         iser_conn = (struct iser_conn *)cma_id->context;
 724         iser_conn->state = ISER_CONN_TERMINATING;
 725 }
 726
 727 /**
 728  * Called with state mutex held
 729  **/
 730 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 731 {
 732         struct iser_device *device;
 733         struct iser_conn   *iser_conn;
 734         struct ib_conn   *ib_conn;
 735         int    ret;
 736
 737         iser_conn = (struct iser_conn *)cma_id->context;
 738         if (iser_conn->state != ISER_CONN_PENDING)
 739                 /* bailout */
 740                 return;
 741
 742         ib_conn = &iser_conn->ib_conn;
 743         device = iser_device_find_by_ib_device(cma_id);
 744         if (!device) {
 745                 iser_err("device lookup/creation failed\n");
 746                 iser_connect_error(cma_id);
 747                 return;
 748         }
 749
 750         ib_conn->device = device;
 751
 752         /* connection T10-PI support */
 753         if (iser_pi_enable) {
 754                 if (!(device->dev_attr.device_cap_flags &
 755                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 756                         iser_warn("T10-PI requested but not supported on %s, "
 757                                   "continue without T10-PI\n",
 758                                   ib_conn->device->ib_device->name);
 759                         ib_conn->pi_support = false;
 760                 } else {
 761                         ib_conn->pi_support = true;
 762                 }
 763         }
 764
 765         ret = rdma_resolve_route(cma_id, 1000);
 766         if (ret) {
 767                 iser_err("resolve route failed: %d\n", ret);
 768                 iser_connect_error(cma_id);
 769                 return;
 770         }
 771 }
 772
 773 /**
 774  * Called with state mutex held
 775  **/
 776 static void iser_route_handler(struct rdma_cm_id *cma_id)
 777 {
 778         struct rdma_conn_param conn_param;
 779         int    ret;
 780         struct iser_cm_hdr req_hdr;
 781         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 782         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 783         struct iser_device *device = ib_conn->device;
 784
 785         if (iser_conn->state != ISER_CONN_PENDING)
 786                 /* bailout */
 787                 return;
 788
 789         ret = iser_create_ib_conn_res(ib_conn);
 790         if (ret)
 791                 goto failure;
 792
 793         memset(&conn_param, 0, sizeof conn_param);
 794         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 795         conn_param.initiator_depth     = 1;
 796         conn_param.retry_count         = 7;
 797         conn_param.rnr_retry_count     = 6;
 798
 799         memset(&req_hdr, 0, sizeof(req_hdr));
 800         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 801                         ISER_SEND_W_INV_NOT_SUPPORTED);
 802         conn_param.private_data         = (void *)&req_hdr;
 803         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 804
 805         ret = rdma_connect(cma_id, &conn_param);
 806         if (ret) {
 807                 iser_err("failure connecting: %d\n", ret);
 808                 goto failure;
 809         }
 810
 811         return;
 812 failure:
 813         iser_connect_error(cma_id);
 814 }
 815
 816 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 817 {
 818         struct iser_conn *iser_conn;
 819         struct ib_qp_attr attr;
 820         struct ib_qp_init_attr init_attr;
 821
 822         iser_conn = (struct iser_conn *)cma_id->context;
 823         if (iser_conn->state != ISER_CONN_PENDING)
 824                 /* bailout */
 825                 return;
 826
 827         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 828         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 829
 830         iser_conn->state = ISER_CONN_UP;
 831         complete(&iser_conn->up_completion);
 832 }
 833
 834 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 835 {
 836         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 837
 838         if (iser_conn_terminate(iser_conn)) {
 839                 if (iser_conn->iscsi_conn)
 840                         iscsi_conn_failure(iser_conn->iscsi_conn,
 841                                            ISCSI_ERR_CONN_FAILED);
 842                 else
 843                         iser_err("iscsi_iser connection isn't bound\n");
 844         }
 845 }
 846
 847 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
 848                                  bool destroy)
 849 {
 850         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 851
 852         /*
 853          * We are not guaranteed that we visited disconnected_handler
 854          * by now, call it here to be safe that we handle CM drep
 855          * and flush errors.
 856          */
 857         iser_disconnected_handler(cma_id);
 858         iser_free_ib_conn_res(iser_conn, destroy);
 859         complete(&iser_conn->ib_completion);
 860 };
 861
 862 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 863 {
 864         struct iser_conn *iser_conn;
 865         int ret = 0;
 866
 867         iser_conn = (struct iser_conn *)cma_id->context;
 868         iser_info("%s (%d): status %d conn %p id %p\n",
 869                   rdma_event_msg(event->event), event->event,
 870                   event->status, cma_id->context, cma_id);
 871
 872         mutex_lock(&iser_conn->state_mutex);
 873         switch (event->event) {
 874         case RDMA_CM_EVENT_ADDR_RESOLVED:
 875                 iser_addr_handler(cma_id);
 876                 break;
 877         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 878                 iser_route_handler(cma_id);
 879                 break;
 880         case RDMA_CM_EVENT_ESTABLISHED:
 881                 iser_connected_handler(cma_id);
 882                 break;
 883         case RDMA_CM_EVENT_ADDR_ERROR:
 884         case RDMA_CM_EVENT_ROUTE_ERROR:
 885         case RDMA_CM_EVENT_CONNECT_ERROR:
 886         case RDMA_CM_EVENT_UNREACHABLE:
 887         case RDMA_CM_EVENT_REJECTED:
 888                 iser_connect_error(cma_id);
 889                 break;
 890         case RDMA_CM_EVENT_DISCONNECTED:
 891         case RDMA_CM_EVENT_ADDR_CHANGE:
 892         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 893                 iser_cleanup_handler(cma_id, false);
 894                 break;
 895         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 896                 /*
 897                  * we *must* destroy the device as we cannot rely
 898                  * on iscsid to be around to initiate error handling.
 899                  * also if we are not in state DOWN implicitly destroy
 900                  * the cma_id.
 901                  */
 902                 iser_cleanup_handler(cma_id, true);
 903                 if (iser_conn->state != ISER_CONN_DOWN) {
 904                         iser_conn->ib_conn.cma_id = NULL;
 905                         ret = 1;
 906                 }
 907                 break;
 908         default:
 909                 iser_err("Unexpected RDMA CM event: %s (%d)\n",
 910                          rdma_event_msg(event->event), event->event);
 911                 break;
 912         }
 913         mutex_unlock(&iser_conn->state_mutex);
 914
 915         return ret;
 916 }
 917
 918 void iser_conn_init(struct iser_conn *iser_conn)
 919 {
 920         iser_conn->state = ISER_CONN_INIT;
 921         iser_conn->ib_conn.post_recv_buf_count = 0;
 922         init_completion(&iser_conn->ib_conn.flush_comp);
 923         init_completion(&iser_conn->stop_completion);
 924         init_completion(&iser_conn->ib_completion);
 925         init_completion(&iser_conn->up_completion);
 926         INIT_LIST_HEAD(&iser_conn->conn_list);
 927         spin_lock_init(&iser_conn->ib_conn.lock);
 928         mutex_init(&iser_conn->state_mutex);
 929 }
 930
 931  /**
 932  * starts the process of connecting to the target
 933  * sleeps until the connection is established or rejected
 934  */
 935 int iser_connect(struct iser_conn   *iser_conn,
 936                  struct sockaddr    *src_addr,
 937                  struct sockaddr    *dst_addr,
 938                  int                 non_blocking)
 939 {
 940         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 941         int err = 0;
 942
 943         mutex_lock(&iser_conn->state_mutex);
 944
 945         sprintf(iser_conn->name, "%pISp", dst_addr);
 946
 947         iser_info("connecting to: %s\n", iser_conn->name);
 948
 949         /* the device is known only --after-- address resolution */
 950         ib_conn->device = NULL;
 951
 952         iser_conn->state = ISER_CONN_PENDING;
 953
 954         ib_conn->beacon.wr_id = ISER_BEACON_WRID;
 955         ib_conn->beacon.opcode = IB_WR_SEND;
 956
 957         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 958                                          (void *)iser_conn,
 959                                          RDMA_PS_TCP, IB_QPT_RC);
 960         if (IS_ERR(ib_conn->cma_id)) {
 961                 err = PTR_ERR(ib_conn->cma_id);
 962                 iser_err("rdma_create_id failed: %d\n", err);
 963                 goto id_failure;
 964         }
 965
 966         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 967         if (err) {
 968                 iser_err("rdma_resolve_addr failed: %d\n", err);
 969                 goto addr_failure;
 970         }
 971
 972         if (!non_blocking) {
 973                 wait_for_completion_interruptible(&iser_conn->up_completion);
 974
 975                 if (iser_conn->state != ISER_CONN_UP) {
 976                         err =  -EIO;
 977                         goto connect_failure;
 978                 }
 979         }
 980         mutex_unlock(&iser_conn->state_mutex);
 981
 982         mutex_lock(&ig.connlist_mutex);
 983         list_add(&iser_conn->conn_list, &ig.connlist);
 984         mutex_unlock(&ig.connlist_mutex);
 985         return 0;
 986
 987 id_failure:
 988         ib_conn->cma_id = NULL;
 989 addr_failure:
 990         iser_conn->state = ISER_CONN_DOWN;
 991 connect_failure:
 992         mutex_unlock(&iser_conn->state_mutex);
 993         iser_conn_release(iser_conn);
 994         return err;
 995 }
 996
 997 int iser_post_recvl(struct iser_conn *iser_conn)
 998 {
 999         struct ib_recv_wr rx_wr, *rx_wr_failed;
1000         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1001         struct ib_sge     sge;
1002         int ib_ret;
1003
1004         sge.addr   = iser_conn->login_resp_dma;
1005         sge.length = ISER_RX_LOGIN_SIZE;
1006         sge.lkey   = ib_conn->device->mr->lkey;
1007
1008         rx_wr.wr_id   = (uintptr_t)iser_conn->login_resp_buf;
1009         rx_wr.sg_list = &sge;
1010         rx_wr.num_sge = 1;
1011         rx_wr.next    = NULL;
1012
1013         ib_conn->post_recv_buf_count++;
1014         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1015         if (ib_ret) {
1016                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1017                 ib_conn->post_recv_buf_count--;
1018         }
1019         return ib_ret;
1020 }
1021
1022 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1023 {
1024         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1025         int i, ib_ret;
1026         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1027         unsigned int my_rx_head = iser_conn->rx_desc_head;
1028         struct iser_rx_desc *rx_desc;
1029
1030         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1031                 rx_desc         = &iser_conn->rx_descs[my_rx_head];
1032                 rx_wr->wr_id    = (uintptr_t)rx_desc;
1033                 rx_wr->sg_list  = &rx_desc->rx_sg;
1034                 rx_wr->num_sge  = 1;
1035                 rx_wr->next     = rx_wr + 1;
1036                 my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1037         }
1038
1039         rx_wr--;
1040         rx_wr->next = NULL; /* mark end of work requests list */
1041
1042         ib_conn->post_recv_buf_count += count;
1043         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1044         if (ib_ret) {
1045                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1046                 ib_conn->post_recv_buf_count -= count;
1047         } else
1048                 iser_conn->rx_desc_head = my_rx_head;
1049         return ib_ret;
1050 }
1051
1052
1053 /**
1054  * iser_start_send - Initiate a Send DTO operation
1055  *
1056  * returns 0 on success, -1 on failure
1057  */
1058 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1059                    bool signal)
1060 {
1061         int               ib_ret;
1062         struct ib_send_wr send_wr, *send_wr_failed;
1063
1064         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1065                                       tx_desc->dma_addr, ISER_HEADERS_LEN,
1066                                       DMA_TO_DEVICE);
1067
1068         send_wr.next       = NULL;
1069         send_wr.wr_id      = (uintptr_t)tx_desc;
1070         send_wr.sg_list    = tx_desc->tx_sg;
1071         send_wr.num_sge    = tx_desc->num_sge;
1072         send_wr.opcode     = IB_WR_SEND;
1073         send_wr.send_flags = signal ? IB_SEND_SIGNALED : 0;
1074
1075         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1076         if (ib_ret)
1077                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1078
1079         return ib_ret;
1080 }
1081
1082 /**
1083  * is_iser_tx_desc - Indicate if the completion wr_id
1084  *     is a TX descriptor or not.
1085  * @iser_conn: iser connection
1086  * @wr_id: completion WR identifier
1087  *
1088  * Since we cannot rely on wc opcode in FLUSH errors
1089  * we must work around it by checking if the wr_id address
1090  * falls in the iser connection rx_descs buffer. If so
1091  * it is an RX descriptor, otherwize it is a TX.
1092  */
1093 static inline bool
1094 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1095 {
1096         void *start = iser_conn->rx_descs;
1097         int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1098
1099         if (wr_id >= start && wr_id < start + len)
1100                 return false;
1101
1102         return true;
1103 }
1104
1105 /**
1106  * iser_handle_comp_error() - Handle error completion
1107  * @ib_conn:   connection RDMA resources
1108  * @wc:        work completion
1109  *
1110  * Notes: We may handle a FLUSH error completion and in this case
1111  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1112  *        error completion we should also notify iscsi layer that
1113  *        connection is failed (in case we passed bind stage).
1114  */
1115 static void
1116 iser_handle_comp_error(struct ib_conn *ib_conn,
1117                        struct ib_wc *wc)
1118 {
1119         void *wr_id = (void *)(uintptr_t)wc->wr_id;
1120         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1121                                                    ib_conn);
1122
1123         if (wc->status != IB_WC_WR_FLUSH_ERR)
1124                 if (iser_conn->iscsi_conn)
1125                         iscsi_conn_failure(iser_conn->iscsi_conn,
1126                                            ISCSI_ERR_CONN_FAILED);
1127
1128         if (wc->wr_id == ISER_FASTREG_LI_WRID)
1129                 return;
1130
1131         if (is_iser_tx_desc(iser_conn, wr_id)) {
1132                 struct iser_tx_desc *desc = wr_id;
1133
1134                 if (desc->type == ISCSI_TX_DATAOUT)
1135                         kmem_cache_free(ig.desc_cache, desc);
1136         } else {
1137                 ib_conn->post_recv_buf_count--;
1138         }
1139 }
1140
1141 /**
1142  * iser_handle_wc - handle a single work completion
1143  * @wc: work completion
1144  *
1145  * Soft-IRQ context, work completion can be either
1146  * SEND or RECV, and can turn out successful or
1147  * with error (or flush error).
1148  */
1149 static void iser_handle_wc(struct ib_wc *wc)
1150 {
1151         struct ib_conn *ib_conn;
1152         struct iser_tx_desc *tx_desc;
1153         struct iser_rx_desc *rx_desc;
1154
1155         ib_conn = wc->qp->qp_context;
1156         if (likely(wc->status == IB_WC_SUCCESS)) {
1157                 if (wc->opcode == IB_WC_RECV) {
1158                         rx_desc = (struct iser_rx_desc *)(uintptr_t)wc->wr_id;
1159                         iser_rcv_completion(rx_desc, wc->byte_len,
1160                                             ib_conn);
1161                 } else
1162                 if (wc->opcode == IB_WC_SEND) {
1163                         tx_desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
1164                         iser_snd_completion(tx_desc, ib_conn);
1165                 } else {
1166                         iser_err("Unknown wc opcode %d\n", wc->opcode);
1167                 }
1168         } else {
1169                 if (wc->status != IB_WC_WR_FLUSH_ERR)
1170                         iser_err("%s (%d): wr id %llx vend_err %x\n",
1171                                  ib_wc_status_msg(wc->status), wc->status,
1172                                  wc->wr_id, wc->vendor_err);
1173                 else
1174                         iser_dbg("%s (%d): wr id %llx\n",
1175                                  ib_wc_status_msg(wc->status), wc->status,
1176                                  wc->wr_id);
1177
1178                 if (wc->wr_id == ISER_BEACON_WRID)
1179                         /* all flush errors were consumed */
1180                         complete(&ib_conn->flush_comp);
1181                 else
1182                         iser_handle_comp_error(ib_conn, wc);
1183         }
1184 }
1185
1186 /**
1187  * iser_cq_tasklet_fn - iSER completion polling loop
1188  * @data: iSER completion context
1189  *
1190  * Soft-IRQ context, polling connection CQ until
1191  * either CQ was empty or we exausted polling budget
1192  */
1193 static void iser_cq_tasklet_fn(unsigned long data)
1194 {
1195         struct iser_comp *comp = (struct iser_comp *)data;
1196         struct ib_cq *cq = comp->cq;
1197         struct ib_wc *const wcs = comp->wcs;
1198         int i, n, completed = 0;
1199
1200         while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1201                 for (i = 0; i < n; i++)
1202                         iser_handle_wc(&wcs[i]);
1203
1204                 completed += n;
1205                 if (completed >= iser_cq_poll_limit)
1206                         break;
1207         }
1208
1209         /*
1210          * It is assumed here that arming CQ only once its empty
1211          * would not cause interrupts to be missed.
1212          */
1213         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1214
1215         iser_dbg("got %d completions\n", completed);
1216 }
1217
1218 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1219 {
1220         struct iser_comp *comp = cq_context;
1221
1222         tasklet_schedule(&comp->tasklet);
1223 }
1224
1225 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1226                              enum iser_data_dir cmd_dir, sector_t *sector)
1227 {
1228         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
1229         struct iser_fr_desc *desc = reg->mem_h;
1230         unsigned long sector_size = iser_task->sc->device->sector_size;
1231         struct ib_mr_status mr_status;
1232         int ret;
1233
1234         if (desc && desc->pi_ctx->sig_protected) {
1235                 desc->pi_ctx->sig_protected = 0;
1236                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1237                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1238                 if (ret) {
1239                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1240                         goto err;
1241                 }
1242
1243                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1244                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1245
1246                         do_div(sector_off, sector_size + 8);
1247                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1248
1249                         pr_err("PI error found type %d at sector %llx "
1250                                "expected %x vs actual %x\n",
1251                                mr_status.sig_err.err_type,
1252                                (unsigned long long)*sector,
1253                                mr_status.sig_err.expected,
1254                                mr_status.sig_err.actual);
1255
1256                         switch (mr_status.sig_err.err_type) {
1257                         case IB_SIG_BAD_GUARD:
1258                                 return 0x1;
1259                         case IB_SIG_BAD_REFTAG:
1260                                 return 0x3;
1261                         case IB_SIG_BAD_APPTAG:
1262                                 return 0x2;
1263                         }
1264                 }
1265         }
1266
1267         return 0;
1268 err:
1269         /* Not alot we can do here, return ambiguous guard error */
1270         return 0x1;
1271 }