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         if (!iser_always_reg) {
 137                 int access = IB_ACCESS_LOCAL_WRITE |
 138                              IB_ACCESS_REMOTE_WRITE |
 139                              IB_ACCESS_REMOTE_READ;
 140
 141                 device->mr = ib_get_dma_mr(device->pd, access);
 142                 if (IS_ERR(device->mr))
 143                         goto dma_mr_err;
 144         }
 145
 146         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 147                                 iser_event_handler);
 148         if (ib_register_event_handler(&device->event_handler))
 149                 goto handler_err;
 150
 151         return 0;
 152
 153 handler_err:
 154         if (device->mr)
 155                 ib_dereg_mr(device->mr);
 156 dma_mr_err:
 157         for (i = 0; i < device->comps_used; i++)
 158                 tasklet_kill(&device->comps[i].tasklet);
 159 cq_err:
 160         for (i = 0; i < device->comps_used; i++) {
 161                 struct iser_comp *comp = &device->comps[i];
 162
 163                 if (comp->cq)
 164                         ib_destroy_cq(comp->cq);
 165         }
 166         ib_dealloc_pd(device->pd);
 167 pd_err:
 168         kfree(device->comps);
 169 comps_err:
 170         iser_err("failed to allocate an IB resource\n");
 171         return -1;
 172 }
 173
 174 /**
 175  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 176  * CQ and PD created with the device associated with the adapator.
 177  */
 178 static void iser_free_device_ib_res(struct iser_device *device)
 179 {
 180         int i;
 181
 182         for (i = 0; i < device->comps_used; i++) {
 183                 struct iser_comp *comp = &device->comps[i];
 184
 185                 tasklet_kill(&comp->tasklet);
 186                 ib_destroy_cq(comp->cq);
 187                 comp->cq = NULL;
 188         }
 189
 190         (void)ib_unregister_event_handler(&device->event_handler);
 191         if (device->mr)
 192                 (void)ib_dereg_mr(device->mr);
 193         ib_dealloc_pd(device->pd);
 194
 195         kfree(device->comps);
 196         device->comps = NULL;
 197
 198         device->mr = NULL;
 199         device->pd = NULL;
 200 }
 201
 202 /**
 203  * iser_alloc_fmr_pool - Creates FMR pool and page_vector
 204  *
 205  * returns 0 on success, or errno code on failure
 206  */
 207 int iser_alloc_fmr_pool(struct ib_conn *ib_conn,
 208                         unsigned cmds_max,
 209                         unsigned int size)
 210 {
 211         struct iser_device *device = ib_conn->device;
 212         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 213         struct iser_page_vec *page_vec;
 214         struct iser_fr_desc *desc;
 215         struct ib_fmr_pool *fmr_pool;
 216         struct ib_fmr_pool_param params;
 217         int ret;
 218
 219         INIT_LIST_HEAD(&fr_pool->list);
 220         spin_lock_init(&fr_pool->lock);
 221
 222         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 223         if (!desc)
 224                 return -ENOMEM;
 225
 226         page_vec = kmalloc(sizeof(*page_vec) + (sizeof(u64) * size),
 227                            GFP_KERNEL);
 228         if (!page_vec) {
 229                 ret = -ENOMEM;
 230                 goto err_frpl;
 231         }
 232
 233         page_vec->pages = (u64 *)(page_vec + 1);
 234
 235         params.page_shift        = SHIFT_4K;
 236         params.max_pages_per_fmr = size;
 237         /* make the pool size twice the max number of SCSI commands *
 238          * the ML is expected to queue, watermark for unmap at 50%  */
 239         params.pool_size         = cmds_max * 2;
 240         params.dirty_watermark   = cmds_max;
 241         params.cache             = 0;
 242         params.flush_function    = NULL;
 243         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 244                                     IB_ACCESS_REMOTE_WRITE |
 245                                     IB_ACCESS_REMOTE_READ);
 246
 247         fmr_pool = ib_create_fmr_pool(device->pd, &params);
 248         if (IS_ERR(fmr_pool)) {
 249                 ret = PTR_ERR(fmr_pool);
 250                 iser_err("FMR allocation failed, err %d\n", ret);
 251                 goto err_fmr;
 252         }
 253
 254         desc->rsc.page_vec = page_vec;
 255         desc->rsc.fmr_pool = fmr_pool;
 256         list_add(&desc->list, &fr_pool->list);
 257
 258         return 0;
 259
 260 err_fmr:
 261         kfree(page_vec);
 262 err_frpl:
 263         kfree(desc);
 264
 265         return ret;
 266 }
 267
 268 /**
 269  * iser_free_fmr_pool - releases the FMR pool and page vec
 270  */
 271 void iser_free_fmr_pool(struct ib_conn *ib_conn)
 272 {
 273         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 274         struct iser_fr_desc *desc;
 275
 276         desc = list_first_entry(&fr_pool->list,
 277                                 struct iser_fr_desc, list);
 278         list_del(&desc->list);
 279
 280         iser_info("freeing conn %p fmr pool %p\n",
 281                   ib_conn, desc->rsc.fmr_pool);
 282
 283         ib_destroy_fmr_pool(desc->rsc.fmr_pool);
 284         kfree(desc->rsc.page_vec);
 285         kfree(desc);
 286 }
 287
 288 static int
 289 iser_alloc_reg_res(struct ib_device *ib_device,
 290                    struct ib_pd *pd,
 291                    struct iser_reg_resources *res,
 292                    unsigned int size)
 293 {
 294         int ret;
 295
 296         res->frpl = ib_alloc_fast_reg_page_list(ib_device, size);
 297         if (IS_ERR(res->frpl)) {
 298                 ret = PTR_ERR(res->frpl);
 299                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 300                          ret);
 301                 return PTR_ERR(res->frpl);
 302         }
 303
 304         res->mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, size);
 305         if (IS_ERR(res->mr)) {
 306                 ret = PTR_ERR(res->mr);
 307                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 308                 goto fast_reg_mr_failure;
 309         }
 310         res->mr_valid = 1;
 311
 312         return 0;
 313
 314 fast_reg_mr_failure:
 315         ib_free_fast_reg_page_list(res->frpl);
 316
 317         return ret;
 318 }
 319
 320 static void
 321 iser_free_reg_res(struct iser_reg_resources *rsc)
 322 {
 323         ib_dereg_mr(rsc->mr);
 324         ib_free_fast_reg_page_list(rsc->frpl);
 325 }
 326
 327 static int
 328 iser_alloc_pi_ctx(struct ib_device *ib_device,
 329                   struct ib_pd *pd,
 330                   struct iser_fr_desc *desc,
 331                   unsigned int size)
 332 {
 333         struct iser_pi_context *pi_ctx = NULL;
 334         int ret;
 335
 336         desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 337         if (!desc->pi_ctx)
 338                 return -ENOMEM;
 339
 340         pi_ctx = desc->pi_ctx;
 341
 342         ret = iser_alloc_reg_res(ib_device, pd, &pi_ctx->rsc, size);
 343         if (ret) {
 344                 iser_err("failed to allocate reg_resources\n");
 345                 goto alloc_reg_res_err;
 346         }
 347
 348         pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
 349         if (IS_ERR(pi_ctx->sig_mr)) {
 350                 ret = PTR_ERR(pi_ctx->sig_mr);
 351                 goto sig_mr_failure;
 352         }
 353         pi_ctx->sig_mr_valid = 1;
 354         desc->pi_ctx->sig_protected = 0;
 355
 356         return 0;
 357
 358 sig_mr_failure:
 359         iser_free_reg_res(&pi_ctx->rsc);
 360 alloc_reg_res_err:
 361         kfree(desc->pi_ctx);
 362
 363         return ret;
 364 }
 365
 366 static void
 367 iser_free_pi_ctx(struct iser_pi_context *pi_ctx)
 368 {
 369         iser_free_reg_res(&pi_ctx->rsc);
 370         ib_dereg_mr(pi_ctx->sig_mr);
 371         kfree(pi_ctx);
 372 }
 373
 374 static struct iser_fr_desc *
 375 iser_create_fastreg_desc(struct ib_device *ib_device,
 376                          struct ib_pd *pd,
 377                          bool pi_enable,
 378                          unsigned int size)
 379 {
 380         struct iser_fr_desc *desc;
 381         int ret;
 382
 383         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 384         if (!desc)
 385                 return ERR_PTR(-ENOMEM);
 386
 387         ret = iser_alloc_reg_res(ib_device, pd, &desc->rsc, size);
 388         if (ret)
 389                 goto reg_res_alloc_failure;
 390
 391         if (pi_enable) {
 392                 ret = iser_alloc_pi_ctx(ib_device, pd, desc, size);
 393                 if (ret)
 394                         goto pi_ctx_alloc_failure;
 395         }
 396
 397         return desc;
 398
 399 pi_ctx_alloc_failure:
 400         iser_free_reg_res(&desc->rsc);
 401 reg_res_alloc_failure:
 402         kfree(desc);
 403
 404         return ERR_PTR(ret);
 405 }
 406
 407 /**
 408  * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
 409  * for fast registration work requests.
 410  * returns 0 on success, or errno code on failure
 411  */
 412 int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
 413                             unsigned cmds_max,
 414                             unsigned int size)
 415 {
 416         struct iser_device *device = ib_conn->device;
 417         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 418         struct iser_fr_desc *desc;
 419         int i, ret;
 420
 421         INIT_LIST_HEAD(&fr_pool->list);
 422         spin_lock_init(&fr_pool->lock);
 423         fr_pool->size = 0;
 424         for (i = 0; i < cmds_max; i++) {
 425                 desc = iser_create_fastreg_desc(device->ib_device, device->pd,
 426                                                 ib_conn->pi_support, size);
 427                 if (IS_ERR(desc)) {
 428                         ret = PTR_ERR(desc);
 429                         goto err;
 430                 }
 431
 432                 list_add_tail(&desc->list, &fr_pool->list);
 433                 fr_pool->size++;
 434         }
 435
 436         return 0;
 437
 438 err:
 439         iser_free_fastreg_pool(ib_conn);
 440         return ret;
 441 }
 442
 443 /**
 444  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 445  */
 446 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
 447 {
 448         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 449         struct iser_fr_desc *desc, *tmp;
 450         int i = 0;
 451
 452         if (list_empty(&fr_pool->list))
 453                 return;
 454
 455         iser_info("freeing conn %p fr pool\n", ib_conn);
 456
 457         list_for_each_entry_safe(desc, tmp, &fr_pool->list, list) {
 458                 list_del(&desc->list);
 459                 iser_free_reg_res(&desc->rsc);
 460                 if (desc->pi_ctx)
 461                         iser_free_pi_ctx(desc->pi_ctx);
 462                 kfree(desc);
 463                 ++i;
 464         }
 465
 466         if (i < fr_pool->size)
 467                 iser_warn("pool still has %d regions registered\n",
 468                           fr_pool->size - i);
 469 }
 470
 471 /**
 472  * iser_create_ib_conn_res - Queue-Pair (QP)
 473  *
 474  * returns 0 on success, -1 on failure
 475  */
 476 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
 477 {
 478         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 479                                                    ib_conn);
 480         struct iser_device      *device;
 481         struct ib_device_attr *dev_attr;
 482         struct ib_qp_init_attr  init_attr;
 483         int                     ret = -ENOMEM;
 484         int index, min_index = 0;
 485
 486         BUG_ON(ib_conn->device == NULL);
 487
 488         device = ib_conn->device;
 489         dev_attr = &device->dev_attr;
 490
 491         memset(&init_attr, 0, sizeof init_attr);
 492
 493         mutex_lock(&ig.connlist_mutex);
 494         /* select the CQ with the minimal number of usages */
 495         for (index = 0; index < device->comps_used; index++) {
 496                 if (device->comps[index].active_qps <
 497                     device->comps[min_index].active_qps)
 498                         min_index = index;
 499         }
 500         ib_conn->comp = &device->comps[min_index];
 501         ib_conn->comp->active_qps++;
 502         mutex_unlock(&ig.connlist_mutex);
 503         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 504
 505         init_attr.event_handler = iser_qp_event_callback;
 506         init_attr.qp_context    = (void *)ib_conn;
 507         init_attr.send_cq       = ib_conn->comp->cq;
 508         init_attr.recv_cq       = ib_conn->comp->cq;
 509         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 510         init_attr.cap.max_send_sge = 2;
 511         init_attr.cap.max_recv_sge = 1;
 512         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 513         init_attr.qp_type       = IB_QPT_RC;
 514         if (ib_conn->pi_support) {
 515                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
 516                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 517                 iser_conn->max_cmds =
 518                         ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
 519         } else {
 520                 if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
 521                         init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
 522                         iser_conn->max_cmds =
 523                                 ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
 524                 } else {
 525                         init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
 526                         iser_conn->max_cmds =
 527                                 ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
 528                         iser_dbg("device %s supports max_send_wr %d\n",
 529                                  device->ib_device->name, dev_attr->max_qp_wr);
 530                 }
 531         }
 532
 533         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 534         if (ret)
 535                 goto out_err;
 536
 537         ib_conn->qp = ib_conn->cma_id->qp;
 538         iser_info("setting conn %p cma_id %p qp %p\n",
 539                   ib_conn, ib_conn->cma_id,
 540                   ib_conn->cma_id->qp);
 541         return ret;
 542
 543 out_err:
 544         mutex_lock(&ig.connlist_mutex);
 545         ib_conn->comp->active_qps--;
 546         mutex_unlock(&ig.connlist_mutex);
 547         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 548
 549         return ret;
 550 }
 551
 552 /**
 553  * based on the resolved device node GUID see if there already allocated
 554  * device for this device. If there's no such, create one.
 555  */
 556 static
 557 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 558 {
 559         struct iser_device *device;
 560
 561         mutex_lock(&ig.device_list_mutex);
 562
 563         list_for_each_entry(device, &ig.device_list, ig_list)
 564                 /* find if there's a match using the node GUID */
 565                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 566                         goto inc_refcnt;
 567
 568         device = kzalloc(sizeof *device, GFP_KERNEL);
 569         if (device == NULL)
 570                 goto out;
 571
 572         /* assign this device to the device */
 573         device->ib_device = cma_id->device;
 574         /* init the device and link it into ig device list */
 575         if (iser_create_device_ib_res(device)) {
 576                 kfree(device);
 577                 device = NULL;
 578                 goto out;
 579         }
 580         list_add(&device->ig_list, &ig.device_list);
 581
 582 inc_refcnt:
 583         device->refcount++;
 584 out:
 585         mutex_unlock(&ig.device_list_mutex);
 586         return device;
 587 }
 588
 589 /* if there's no demand for this device, release it */
 590 static void iser_device_try_release(struct iser_device *device)
 591 {
 592         mutex_lock(&ig.device_list_mutex);
 593         device->refcount--;
 594         iser_info("device %p refcount %d\n", device, device->refcount);
 595         if (!device->refcount) {
 596                 iser_free_device_ib_res(device);
 597                 list_del(&device->ig_list);
 598                 kfree(device);
 599         }
 600         mutex_unlock(&ig.device_list_mutex);
 601 }
 602
 603 /**
 604  * Called with state mutex held
 605  **/
 606 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
 607                                      enum iser_conn_state comp,
 608                                      enum iser_conn_state exch)
 609 {
 610         int ret;
 611
 612         ret = (iser_conn->state == comp);
 613         if (ret)
 614                 iser_conn->state = exch;
 615
 616         return ret;
 617 }
 618
 619 void iser_release_work(struct work_struct *work)
 620 {
 621         struct iser_conn *iser_conn;
 622
 623         iser_conn = container_of(work, struct iser_conn, release_work);
 624
 625         /* Wait for conn_stop to complete */
 626         wait_for_completion(&iser_conn->stop_completion);
 627         /* Wait for IB resouces cleanup to complete */
 628         wait_for_completion(&iser_conn->ib_completion);
 629
 630         mutex_lock(&iser_conn->state_mutex);
 631         iser_conn->state = ISER_CONN_DOWN;
 632         mutex_unlock(&iser_conn->state_mutex);
 633
 634         iser_conn_release(iser_conn);
 635 }
 636
 637 /**
 638  * iser_free_ib_conn_res - release IB related resources
 639  * @iser_conn: iser connection struct
 640  * @destroy: indicator if we need to try to release the
 641  *     iser device and memory regoins pool (only iscsi
 642  *     shutdown and DEVICE_REMOVAL will use this).
 643  *
 644  * This routine is called with the iser state mutex held
 645  * so the cm_id removal is out of here. It is Safe to
 646  * be invoked multiple times.
 647  */
 648 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
 649                                   bool destroy)
 650 {
 651         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 652         struct iser_device *device = ib_conn->device;
 653
 654         iser_info("freeing conn %p cma_id %p qp %p\n",
 655                   iser_conn, ib_conn->cma_id, ib_conn->qp);
 656
 657         if (ib_conn->qp != NULL) {
 658                 ib_conn->comp->active_qps--;
 659                 rdma_destroy_qp(ib_conn->cma_id);
 660                 ib_conn->qp = NULL;
 661         }
 662
 663         if (destroy) {
 664                 if (iser_conn->rx_descs)
 665                         iser_free_rx_descriptors(iser_conn);
 666
 667                 if (device != NULL) {
 668                         iser_device_try_release(device);
 669                         ib_conn->device = NULL;
 670                 }
 671         }
 672 }
 673
 674 /**
 675  * Frees all conn objects and deallocs conn descriptor
 676  */
 677 void iser_conn_release(struct iser_conn *iser_conn)
 678 {
 679         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 680
 681         mutex_lock(&ig.connlist_mutex);
 682         list_del(&iser_conn->conn_list);
 683         mutex_unlock(&ig.connlist_mutex);
 684
 685         mutex_lock(&iser_conn->state_mutex);
 686         /* In case we endup here without ep_disconnect being invoked. */
 687         if (iser_conn->state != ISER_CONN_DOWN) {
 688                 iser_warn("iser conn %p state %d, expected state down.\n",
 689                           iser_conn, iser_conn->state);
 690                 iscsi_destroy_endpoint(iser_conn->ep);
 691                 iser_conn->state = ISER_CONN_DOWN;
 692         }
 693         /*
 694          * In case we never got to bind stage, we still need to
 695          * release IB resources (which is safe to call more than once).
 696          */
 697         iser_free_ib_conn_res(iser_conn, true);
 698         mutex_unlock(&iser_conn->state_mutex);
 699
 700         if (ib_conn->cma_id != NULL) {
 701                 rdma_destroy_id(ib_conn->cma_id);
 702                 ib_conn->cma_id = NULL;
 703         }
 704
 705         kfree(iser_conn);
 706 }
 707
 708 /**
 709  * triggers start of the disconnect procedures and wait for them to be done
 710  * Called with state mutex held
 711  */
 712 int iser_conn_terminate(struct iser_conn *iser_conn)
 713 {
 714         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 715         struct ib_send_wr *bad_wr;
 716         int err = 0;
 717
 718         /* terminate the iser conn only if the conn state is UP */
 719         if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
 720                                        ISER_CONN_TERMINATING))
 721                 return 0;
 722
 723         iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
 724
 725         /* suspend queuing of new iscsi commands */
 726         if (iser_conn->iscsi_conn)
 727                 iscsi_suspend_queue(iser_conn->iscsi_conn);
 728
 729         /*
 730          * In case we didn't already clean up the cma_id (peer initiated
 731          * a disconnection), we need to Cause the CMA to change the QP
 732          * state to ERROR.
 733          */
 734         if (ib_conn->cma_id) {
 735                 err = rdma_disconnect(ib_conn->cma_id);
 736                 if (err)
 737                         iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 738                                  iser_conn, err);
 739
 740                 /* post an indication that all flush errors were consumed */
 741                 err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
 742                 if (err) {
 743                         iser_err("conn %p failed to post beacon", ib_conn);
 744                         return 1;
 745                 }
 746
 747                 wait_for_completion(&ib_conn->flush_comp);
 748         }
 749
 750         return 1;
 751 }
 752
 753 /**
 754  * Called with state mutex held
 755  **/
 756 static void iser_connect_error(struct rdma_cm_id *cma_id)
 757 {
 758         struct iser_conn *iser_conn;
 759
 760         iser_conn = (struct iser_conn *)cma_id->context;
 761         iser_conn->state = ISER_CONN_TERMINATING;
 762 }
 763
 764 static void
 765 iser_calc_scsi_params(struct iser_conn *iser_conn,
 766                       unsigned int max_sectors)
 767 {
 768         struct iser_device *device = iser_conn->ib_conn.device;
 769         unsigned short sg_tablesize, sup_sg_tablesize;
 770
 771         sg_tablesize = DIV_ROUND_UP(max_sectors * 512, SIZE_4K);
 772         sup_sg_tablesize = min_t(unsigned, ISCSI_ISER_MAX_SG_TABLESIZE,
 773                                  device->dev_attr.max_fast_reg_page_list_len);
 774
 775         if (sg_tablesize > sup_sg_tablesize) {
 776                 sg_tablesize = sup_sg_tablesize;
 777                 iser_conn->scsi_max_sectors = sg_tablesize * SIZE_4K / 512;
 778         } else {
 779                 iser_conn->scsi_max_sectors = max_sectors;
 780         }
 781
 782         iser_conn->scsi_sg_tablesize = sg_tablesize;
 783
 784         iser_dbg("iser_conn %p, sg_tablesize %u, max_sectors %u\n",
 785                  iser_conn, iser_conn->scsi_sg_tablesize,
 786                  iser_conn->scsi_max_sectors);
 787 }
 788
 789 /**
 790  * Called with state mutex held
 791  **/
 792 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 793 {
 794         struct iser_device *device;
 795         struct iser_conn   *iser_conn;
 796         struct ib_conn   *ib_conn;
 797         int    ret;
 798
 799         iser_conn = (struct iser_conn *)cma_id->context;
 800         if (iser_conn->state != ISER_CONN_PENDING)
 801                 /* bailout */
 802                 return;
 803
 804         ib_conn = &iser_conn->ib_conn;
 805         device = iser_device_find_by_ib_device(cma_id);
 806         if (!device) {
 807                 iser_err("device lookup/creation failed\n");
 808                 iser_connect_error(cma_id);
 809                 return;
 810         }
 811
 812         ib_conn->device = device;
 813
 814         /* connection T10-PI support */
 815         if (iser_pi_enable) {
 816                 if (!(device->dev_attr.device_cap_flags &
 817                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 818                         iser_warn("T10-PI requested but not supported on %s, "
 819                                   "continue without T10-PI\n",
 820                                   ib_conn->device->ib_device->name);
 821                         ib_conn->pi_support = false;
 822                 } else {
 823                         ib_conn->pi_support = true;
 824                 }
 825         }
 826
 827         iser_calc_scsi_params(iser_conn, iser_max_sectors);
 828
 829         ret = rdma_resolve_route(cma_id, 1000);
 830         if (ret) {
 831                 iser_err("resolve route failed: %d\n", ret);
 832                 iser_connect_error(cma_id);
 833                 return;
 834         }
 835 }
 836
 837 /**
 838  * Called with state mutex held
 839  **/
 840 static void iser_route_handler(struct rdma_cm_id *cma_id)
 841 {
 842         struct rdma_conn_param conn_param;
 843         int    ret;
 844         struct iser_cm_hdr req_hdr;
 845         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 846         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 847         struct iser_device *device = ib_conn->device;
 848
 849         if (iser_conn->state != ISER_CONN_PENDING)
 850                 /* bailout */
 851                 return;
 852
 853         ret = iser_create_ib_conn_res(ib_conn);
 854         if (ret)
 855                 goto failure;
 856
 857         memset(&conn_param, 0, sizeof conn_param);
 858         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 859         conn_param.initiator_depth     = 1;
 860         conn_param.retry_count         = 7;
 861         conn_param.rnr_retry_count     = 6;
 862
 863         memset(&req_hdr, 0, sizeof(req_hdr));
 864         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 865                         ISER_SEND_W_INV_NOT_SUPPORTED);
 866         conn_param.private_data         = (void *)&req_hdr;
 867         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 868
 869         ret = rdma_connect(cma_id, &conn_param);
 870         if (ret) {
 871                 iser_err("failure connecting: %d\n", ret);
 872                 goto failure;
 873         }
 874
 875         return;
 876 failure:
 877         iser_connect_error(cma_id);
 878 }
 879
 880 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 881 {
 882         struct iser_conn *iser_conn;
 883         struct ib_qp_attr attr;
 884         struct ib_qp_init_attr init_attr;
 885
 886         iser_conn = (struct iser_conn *)cma_id->context;
 887         if (iser_conn->state != ISER_CONN_PENDING)
 888                 /* bailout */
 889                 return;
 890
 891         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 892         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 893
 894         iser_conn->state = ISER_CONN_UP;
 895         complete(&iser_conn->up_completion);
 896 }
 897
 898 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 899 {
 900         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 901
 902         if (iser_conn_terminate(iser_conn)) {
 903                 if (iser_conn->iscsi_conn)
 904                         iscsi_conn_failure(iser_conn->iscsi_conn,
 905                                            ISCSI_ERR_CONN_FAILED);
 906                 else
 907                         iser_err("iscsi_iser connection isn't bound\n");
 908         }
 909 }
 910
 911 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
 912                                  bool destroy)
 913 {
 914         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 915
 916         /*
 917          * We are not guaranteed that we visited disconnected_handler
 918          * by now, call it here to be safe that we handle CM drep
 919          * and flush errors.
 920          */
 921         iser_disconnected_handler(cma_id);
 922         iser_free_ib_conn_res(iser_conn, destroy);
 923         complete(&iser_conn->ib_completion);
 924 };
 925
 926 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 927 {
 928         struct iser_conn *iser_conn;
 929         int ret = 0;
 930
 931         iser_conn = (struct iser_conn *)cma_id->context;
 932         iser_info("%s (%d): status %d conn %p id %p\n",
 933                   rdma_event_msg(event->event), event->event,
 934                   event->status, cma_id->context, cma_id);
 935
 936         mutex_lock(&iser_conn->state_mutex);
 937         switch (event->event) {
 938         case RDMA_CM_EVENT_ADDR_RESOLVED:
 939                 iser_addr_handler(cma_id);
 940                 break;
 941         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 942                 iser_route_handler(cma_id);
 943                 break;
 944         case RDMA_CM_EVENT_ESTABLISHED:
 945                 iser_connected_handler(cma_id);
 946                 break;
 947         case RDMA_CM_EVENT_ADDR_ERROR:
 948         case RDMA_CM_EVENT_ROUTE_ERROR:
 949         case RDMA_CM_EVENT_CONNECT_ERROR:
 950         case RDMA_CM_EVENT_UNREACHABLE:
 951         case RDMA_CM_EVENT_REJECTED:
 952                 iser_connect_error(cma_id);
 953                 break;
 954         case RDMA_CM_EVENT_DISCONNECTED:
 955         case RDMA_CM_EVENT_ADDR_CHANGE:
 956         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 957                 iser_cleanup_handler(cma_id, false);
 958                 break;
 959         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 960                 /*
 961                  * we *must* destroy the device as we cannot rely
 962                  * on iscsid to be around to initiate error handling.
 963                  * also if we are not in state DOWN implicitly destroy
 964                  * the cma_id.
 965                  */
 966                 iser_cleanup_handler(cma_id, true);
 967                 if (iser_conn->state != ISER_CONN_DOWN) {
 968                         iser_conn->ib_conn.cma_id = NULL;
 969                         ret = 1;
 970                 }
 971                 break;
 972         default:
 973                 iser_err("Unexpected RDMA CM event: %s (%d)\n",
 974                          rdma_event_msg(event->event), event->event);
 975                 break;
 976         }
 977         mutex_unlock(&iser_conn->state_mutex);
 978
 979         return ret;
 980 }
 981
 982 void iser_conn_init(struct iser_conn *iser_conn)
 983 {
 984         iser_conn->state = ISER_CONN_INIT;
 985         iser_conn->ib_conn.post_recv_buf_count = 0;
 986         init_completion(&iser_conn->ib_conn.flush_comp);
 987         init_completion(&iser_conn->stop_completion);
 988         init_completion(&iser_conn->ib_completion);
 989         init_completion(&iser_conn->up_completion);
 990         INIT_LIST_HEAD(&iser_conn->conn_list);
 991         mutex_init(&iser_conn->state_mutex);
 992 }
 993
 994  /**
 995  * starts the process of connecting to the target
 996  * sleeps until the connection is established or rejected
 997  */
 998 int iser_connect(struct iser_conn   *iser_conn,
 999                  struct sockaddr    *src_addr,
1000                  struct sockaddr    *dst_addr,
1001                  int                 non_blocking)
1002 {
1003         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1004         int err = 0;
1005
1006         mutex_lock(&iser_conn->state_mutex);
1007
1008         sprintf(iser_conn->name, "%pISp", dst_addr);
1009
1010         iser_info("connecting to: %s\n", iser_conn->name);
1011
1012         /* the device is known only --after-- address resolution */
1013         ib_conn->device = NULL;
1014
1015         iser_conn->state = ISER_CONN_PENDING;
1016
1017         ib_conn->beacon.wr_id = ISER_BEACON_WRID;
1018         ib_conn->beacon.opcode = IB_WR_SEND;
1019
1020         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
1021                                          (void *)iser_conn,
1022                                          RDMA_PS_TCP, IB_QPT_RC);
1023         if (IS_ERR(ib_conn->cma_id)) {
1024                 err = PTR_ERR(ib_conn->cma_id);
1025                 iser_err("rdma_create_id failed: %d\n", err);
1026                 goto id_failure;
1027         }
1028
1029         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
1030         if (err) {
1031                 iser_err("rdma_resolve_addr failed: %d\n", err);
1032                 goto addr_failure;
1033         }
1034
1035         if (!non_blocking) {
1036                 wait_for_completion_interruptible(&iser_conn->up_completion);
1037
1038                 if (iser_conn->state != ISER_CONN_UP) {
1039                         err =  -EIO;
1040                         goto connect_failure;
1041                 }
1042         }
1043         mutex_unlock(&iser_conn->state_mutex);
1044
1045         mutex_lock(&ig.connlist_mutex);
1046         list_add(&iser_conn->conn_list, &ig.connlist);
1047         mutex_unlock(&ig.connlist_mutex);
1048         return 0;
1049
1050 id_failure:
1051         ib_conn->cma_id = NULL;
1052 addr_failure:
1053         iser_conn->state = ISER_CONN_DOWN;
1054 connect_failure:
1055         mutex_unlock(&iser_conn->state_mutex);
1056         iser_conn_release(iser_conn);
1057         return err;
1058 }
1059
1060 int iser_post_recvl(struct iser_conn *iser_conn)
1061 {
1062         struct ib_recv_wr rx_wr, *rx_wr_failed;
1063         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1064         struct ib_sge     sge;
1065         int ib_ret;
1066
1067         sge.addr   = iser_conn->login_resp_dma;
1068         sge.length = ISER_RX_LOGIN_SIZE;
1069         sge.lkey   = ib_conn->device->pd->local_dma_lkey;
1070
1071         rx_wr.wr_id   = (uintptr_t)iser_conn->login_resp_buf;
1072         rx_wr.sg_list = &sge;
1073         rx_wr.num_sge = 1;
1074         rx_wr.next    = NULL;
1075
1076         ib_conn->post_recv_buf_count++;
1077         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1078         if (ib_ret) {
1079                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1080                 ib_conn->post_recv_buf_count--;
1081         }
1082         return ib_ret;
1083 }
1084
1085 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1086 {
1087         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1088         int i, ib_ret;
1089         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1090         unsigned int my_rx_head = iser_conn->rx_desc_head;
1091         struct iser_rx_desc *rx_desc;
1092
1093         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1094                 rx_desc         = &iser_conn->rx_descs[my_rx_head];
1095                 rx_wr->wr_id    = (uintptr_t)rx_desc;
1096                 rx_wr->sg_list  = &rx_desc->rx_sg;
1097                 rx_wr->num_sge  = 1;
1098                 rx_wr->next     = rx_wr + 1;
1099                 my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1100         }
1101
1102         rx_wr--;
1103         rx_wr->next = NULL; /* mark end of work requests list */
1104
1105         ib_conn->post_recv_buf_count += count;
1106         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1107         if (ib_ret) {
1108                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1109                 ib_conn->post_recv_buf_count -= count;
1110         } else
1111                 iser_conn->rx_desc_head = my_rx_head;
1112         return ib_ret;
1113 }
1114
1115
1116 /**
1117  * iser_start_send - Initiate a Send DTO operation
1118  *
1119  * returns 0 on success, -1 on failure
1120  */
1121 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1122                    bool signal)
1123 {
1124         struct ib_send_wr *bad_wr, *wr = iser_tx_next_wr(tx_desc);
1125         int ib_ret;
1126
1127         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1128                                       tx_desc->dma_addr, ISER_HEADERS_LEN,
1129                                       DMA_TO_DEVICE);
1130
1131         wr->next = NULL;
1132         wr->wr_id = (uintptr_t)tx_desc;
1133         wr->sg_list = tx_desc->tx_sg;
1134         wr->num_sge = tx_desc->num_sge;
1135         wr->opcode = IB_WR_SEND;
1136         wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
1137
1138         ib_ret = ib_post_send(ib_conn->qp, &tx_desc->wrs[0], &bad_wr);
1139         if (ib_ret)
1140                 iser_err("ib_post_send failed, ret:%d opcode:%d\n",
1141                          ib_ret, bad_wr->opcode);
1142
1143         return ib_ret;
1144 }
1145
1146 /**
1147  * is_iser_tx_desc - Indicate if the completion wr_id
1148  *     is a TX descriptor or not.
1149  * @iser_conn: iser connection
1150  * @wr_id: completion WR identifier
1151  *
1152  * Since we cannot rely on wc opcode in FLUSH errors
1153  * we must work around it by checking if the wr_id address
1154  * falls in the iser connection rx_descs buffer. If so
1155  * it is an RX descriptor, otherwize it is a TX.
1156  */
1157 static inline bool
1158 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1159 {
1160         void *start = iser_conn->rx_descs;
1161         int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1162
1163         if (wr_id >= start && wr_id < start + len)
1164                 return false;
1165
1166         return true;
1167 }
1168
1169 /**
1170  * iser_handle_comp_error() - Handle error completion
1171  * @ib_conn:   connection RDMA resources
1172  * @wc:        work completion
1173  *
1174  * Notes: We may handle a FLUSH error completion and in this case
1175  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1176  *        error completion we should also notify iscsi layer that
1177  *        connection is failed (in case we passed bind stage).
1178  */
1179 static void
1180 iser_handle_comp_error(struct ib_conn *ib_conn,
1181                        struct ib_wc *wc)
1182 {
1183         void *wr_id = (void *)(uintptr_t)wc->wr_id;
1184         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1185                                                    ib_conn);
1186
1187         if (wc->status != IB_WC_WR_FLUSH_ERR)
1188                 if (iser_conn->iscsi_conn)
1189                         iscsi_conn_failure(iser_conn->iscsi_conn,
1190                                            ISCSI_ERR_CONN_FAILED);
1191
1192         if (wc->wr_id == ISER_FASTREG_LI_WRID)
1193                 return;
1194
1195         if (is_iser_tx_desc(iser_conn, wr_id)) {
1196                 struct iser_tx_desc *desc = wr_id;
1197
1198                 if (desc->type == ISCSI_TX_DATAOUT)
1199                         kmem_cache_free(ig.desc_cache, desc);
1200         } else {
1201                 ib_conn->post_recv_buf_count--;
1202         }
1203 }
1204
1205 /**
1206  * iser_handle_wc - handle a single work completion
1207  * @wc: work completion
1208  *
1209  * Soft-IRQ context, work completion can be either
1210  * SEND or RECV, and can turn out successful or
1211  * with error (or flush error).
1212  */
1213 static void iser_handle_wc(struct ib_wc *wc)
1214 {
1215         struct ib_conn *ib_conn;
1216         struct iser_tx_desc *tx_desc;
1217         struct iser_rx_desc *rx_desc;
1218
1219         ib_conn = wc->qp->qp_context;
1220         if (likely(wc->status == IB_WC_SUCCESS)) {
1221                 if (wc->opcode == IB_WC_RECV) {
1222                         rx_desc = (struct iser_rx_desc *)(uintptr_t)wc->wr_id;
1223                         iser_rcv_completion(rx_desc, wc->byte_len,
1224                                             ib_conn);
1225                 } else
1226                 if (wc->opcode == IB_WC_SEND) {
1227                         tx_desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
1228                         iser_snd_completion(tx_desc, ib_conn);
1229                 } else {
1230                         iser_err("Unknown wc opcode %d\n", wc->opcode);
1231                 }
1232         } else {
1233                 if (wc->status != IB_WC_WR_FLUSH_ERR)
1234                         iser_err("%s (%d): wr id %llx vend_err %x\n",
1235                                  ib_wc_status_msg(wc->status), wc->status,
1236                                  wc->wr_id, wc->vendor_err);
1237                 else
1238                         iser_dbg("%s (%d): wr id %llx\n",
1239                                  ib_wc_status_msg(wc->status), wc->status,
1240                                  wc->wr_id);
1241
1242                 if (wc->wr_id == ISER_BEACON_WRID)
1243                         /* all flush errors were consumed */
1244                         complete(&ib_conn->flush_comp);
1245                 else
1246                         iser_handle_comp_error(ib_conn, wc);
1247         }
1248 }
1249
1250 /**
1251  * iser_cq_tasklet_fn - iSER completion polling loop
1252  * @data: iSER completion context
1253  *
1254  * Soft-IRQ context, polling connection CQ until
1255  * either CQ was empty or we exausted polling budget
1256  */
1257 static void iser_cq_tasklet_fn(unsigned long data)
1258 {
1259         struct iser_comp *comp = (struct iser_comp *)data;
1260         struct ib_cq *cq = comp->cq;
1261         struct ib_wc *const wcs = comp->wcs;
1262         int i, n, completed = 0;
1263
1264         while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1265                 for (i = 0; i < n; i++)
1266                         iser_handle_wc(&wcs[i]);
1267
1268                 completed += n;
1269                 if (completed >= iser_cq_poll_limit)
1270                         break;
1271         }
1272
1273         /*
1274          * It is assumed here that arming CQ only once its empty
1275          * would not cause interrupts to be missed.
1276          */
1277         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1278
1279         iser_dbg("got %d completions\n", completed);
1280 }
1281
1282 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1283 {
1284         struct iser_comp *comp = cq_context;
1285
1286         tasklet_schedule(&comp->tasklet);
1287 }
1288
1289 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1290                              enum iser_data_dir cmd_dir, sector_t *sector)
1291 {
1292         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
1293         struct iser_fr_desc *desc = reg->mem_h;
1294         unsigned long sector_size = iser_task->sc->device->sector_size;
1295         struct ib_mr_status mr_status;
1296         int ret;
1297
1298         if (desc && desc->pi_ctx->sig_protected) {
1299                 desc->pi_ctx->sig_protected = 0;
1300                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1301                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1302                 if (ret) {
1303                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1304                         goto err;
1305                 }
1306
1307                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1308                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1309
1310                         do_div(sector_off, sector_size + 8);
1311                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1312
1313                         pr_err("PI error found type %d at sector %llx "
1314                                "expected %x vs actual %x\n",
1315                                mr_status.sig_err.err_type,
1316                                (unsigned long long)*sector,
1317                                mr_status.sig_err.expected,
1318                                mr_status.sig_err.actual);
1319
1320                         switch (mr_status.sig_err.err_type) {
1321                         case IB_SIG_BAD_GUARD:
1322                                 return 0x1;
1323                         case IB_SIG_BAD_REFTAG:
1324                                 return 0x3;
1325                         case IB_SIG_BAD_APPTAG:
1326                                 return 0x2;
1327                         }
1328                 }
1329         }
1330
1331         return 0;
1332 err:
1333         /* Not alot we can do here, return ambiguous guard error */
1334         return 0x1;
1335 }