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("got cq event %d \n", cause->event);
  55 }
  56
  57 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  58 {
  59         iser_err("got qp event %d\n",cause->event);
  60 }
  61
  62 static void iser_event_handler(struct ib_event_handler *handler,
  63                                 struct ib_event *event)
  64 {
  65         iser_err("async event %d on device %s port %d\n", event->event,
  66                 event->device->name, event->element.port_num);
  67 }
  68
  69 /**
  70  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  71  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  72  * the adapator.
  73  *
  74  * returns 0 on success, -1 on failure
  75  */
  76 static int iser_create_device_ib_res(struct iser_device *device)
  77 {
  78         struct ib_device_attr *dev_attr = &device->dev_attr;
  79         int ret, i, max_cqe;
  80
  81         ret = ib_query_device(device->ib_device, dev_attr);
  82         if (ret) {
  83                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  84                 return ret;
  85         }
  86
  87         /* Assign function handles  - based on FMR support */
  88         if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
  89             device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
  90                 iser_info("FMR supported, using FMR for registration\n");
  91                 device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
  92                 device->iser_free_rdma_reg_res = iser_free_fmr_pool;
  93                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
  94                 device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
  95         } else
  96         if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
  97                 iser_info("FastReg supported, using FastReg for registration\n");
  98                 device->iser_alloc_rdma_reg_res = iser_create_fastreg_pool;
  99                 device->iser_free_rdma_reg_res = iser_free_fastreg_pool;
 100                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fastreg;
 101                 device->iser_unreg_rdma_mem = iser_unreg_mem_fastreg;
 102         } else {
 103                 iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
 104                 return -1;
 105         }
 106
 107         device->comps_used = min(ISER_MAX_CQ,
 108                                  device->ib_device->num_comp_vectors);
 109
 110         max_cqe = min(ISER_MAX_CQ_LEN, dev_attr->max_cqe);
 111
 112         iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
 113                   device->comps_used, device->ib_device->name,
 114                   device->ib_device->num_comp_vectors, max_cqe);
 115
 116         device->pd = ib_alloc_pd(device->ib_device);
 117         if (IS_ERR(device->pd))
 118                 goto pd_err;
 119
 120         for (i = 0; i < device->comps_used; i++) {
 121                 struct iser_comp *comp = &device->comps[i];
 122
 123                 comp->device = device;
 124                 comp->cq = ib_create_cq(device->ib_device,
 125                                         iser_cq_callback,
 126                                         iser_cq_event_callback,
 127                                         (void *)comp,
 128                                         max_cqe, i);
 129                 if (IS_ERR(comp->cq)) {
 130                         comp->cq = NULL;
 131                         goto cq_err;
 132                 }
 133
 134                 if (ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP))
 135                         goto cq_err;
 136
 137                 tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
 138                              (unsigned long)comp);
 139         }
 140
 141         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 142                                    IB_ACCESS_REMOTE_WRITE |
 143                                    IB_ACCESS_REMOTE_READ);
 144         if (IS_ERR(device->mr))
 145                 goto dma_mr_err;
 146
 147         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 148                                 iser_event_handler);
 149         if (ib_register_event_handler(&device->event_handler))
 150                 goto handler_err;
 151
 152         return 0;
 153
 154 handler_err:
 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         iser_err("failed to allocate an IB resource\n");
 169         return -1;
 170 }
 171
 172 /**
 173  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 174  * CQ and PD created with the device associated with the adapator.
 175  */
 176 static void iser_free_device_ib_res(struct iser_device *device)
 177 {
 178         int i;
 179         BUG_ON(device->mr == NULL);
 180
 181         for (i = 0; i < device->comps_used; i++) {
 182                 struct iser_comp *comp = &device->comps[i];
 183
 184                 tasklet_kill(&comp->tasklet);
 185                 ib_destroy_cq(comp->cq);
 186                 comp->cq = NULL;
 187         }
 188
 189         (void)ib_unregister_event_handler(&device->event_handler);
 190         (void)ib_dereg_mr(device->mr);
 191         (void)ib_dealloc_pd(device->pd);
 192
 193         device->mr = NULL;
 194         device->pd = NULL;
 195 }
 196
 197 /**
 198  * iser_create_fmr_pool - Creates FMR pool and page_vector
 199  *
 200  * returns 0 on success, or errno code on failure
 201  */
 202 int iser_create_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                 return 0;
 233
 234         /* no FMR => no need for page_vec */
 235         kfree(ib_conn->fmr.page_vec);
 236         ib_conn->fmr.page_vec = NULL;
 237
 238         ret = PTR_ERR(ib_conn->fmr.pool);
 239         ib_conn->fmr.pool = NULL;
 240         if (ret != -ENOSYS) {
 241                 iser_err("FMR allocation failed, err %d\n", ret);
 242                 return ret;
 243         } else {
 244                 iser_warn("FMRs are not supported, using unaligned mode\n");
 245                 return 0;
 246         }
 247 }
 248
 249 /**
 250  * iser_free_fmr_pool - releases the FMR pool and page vec
 251  */
 252 void iser_free_fmr_pool(struct ib_conn *ib_conn)
 253 {
 254         iser_info("freeing conn %p fmr pool %p\n",
 255                   ib_conn, ib_conn->fmr.pool);
 256
 257         if (ib_conn->fmr.pool != NULL)
 258                 ib_destroy_fmr_pool(ib_conn->fmr.pool);
 259
 260         ib_conn->fmr.pool = NULL;
 261
 262         kfree(ib_conn->fmr.page_vec);
 263         ib_conn->fmr.page_vec = NULL;
 264 }
 265
 266 static int
 267 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
 268                          bool pi_enable, struct fast_reg_descriptor *desc)
 269 {
 270         int ret;
 271
 272         desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
 273                                                       ISCSI_ISER_SG_TABLESIZE + 1);
 274         if (IS_ERR(desc->data_frpl)) {
 275                 ret = PTR_ERR(desc->data_frpl);
 276                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 277                          ret);
 278                 return PTR_ERR(desc->data_frpl);
 279         }
 280
 281         desc->data_mr = ib_alloc_fast_reg_mr(pd, ISCSI_ISER_SG_TABLESIZE + 1);
 282         if (IS_ERR(desc->data_mr)) {
 283                 ret = PTR_ERR(desc->data_mr);
 284                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 285                 goto fast_reg_mr_failure;
 286         }
 287         desc->reg_indicators |= ISER_DATA_KEY_VALID;
 288
 289         if (pi_enable) {
 290                 struct ib_mr_init_attr mr_init_attr = {0};
 291                 struct iser_pi_context *pi_ctx = NULL;
 292
 293                 desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 294                 if (!desc->pi_ctx) {
 295                         iser_err("Failed to allocate pi context\n");
 296                         ret = -ENOMEM;
 297                         goto pi_ctx_alloc_failure;
 298                 }
 299                 pi_ctx = desc->pi_ctx;
 300
 301                 pi_ctx->prot_frpl = ib_alloc_fast_reg_page_list(ib_device,
 302                                                     ISCSI_ISER_SG_TABLESIZE);
 303                 if (IS_ERR(pi_ctx->prot_frpl)) {
 304                         ret = PTR_ERR(pi_ctx->prot_frpl);
 305                         iser_err("Failed to allocate prot frpl ret=%d\n",
 306                                  ret);
 307                         goto prot_frpl_failure;
 308                 }
 309
 310                 pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd,
 311                                                 ISCSI_ISER_SG_TABLESIZE + 1);
 312                 if (IS_ERR(pi_ctx->prot_mr)) {
 313                         ret = PTR_ERR(pi_ctx->prot_mr);
 314                         iser_err("Failed to allocate prot frmr ret=%d\n",
 315                                  ret);
 316                         goto prot_mr_failure;
 317                 }
 318                 desc->reg_indicators |= ISER_PROT_KEY_VALID;
 319
 320                 mr_init_attr.max_reg_descriptors = 2;
 321                 mr_init_attr.flags |= IB_MR_SIGNATURE_EN;
 322                 pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
 323                 if (IS_ERR(pi_ctx->sig_mr)) {
 324                         ret = PTR_ERR(pi_ctx->sig_mr);
 325                         iser_err("Failed to allocate signature enabled mr err=%d\n",
 326                                  ret);
 327                         goto sig_mr_failure;
 328                 }
 329                 desc->reg_indicators |= ISER_SIG_KEY_VALID;
 330         }
 331         desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
 332
 333         iser_dbg("Create fr_desc %p page_list %p\n",
 334                  desc, desc->data_frpl->page_list);
 335
 336         return 0;
 337 sig_mr_failure:
 338         ib_dereg_mr(desc->pi_ctx->prot_mr);
 339 prot_mr_failure:
 340         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 341 prot_frpl_failure:
 342         kfree(desc->pi_ctx);
 343 pi_ctx_alloc_failure:
 344         ib_dereg_mr(desc->data_mr);
 345 fast_reg_mr_failure:
 346         ib_free_fast_reg_page_list(desc->data_frpl);
 347
 348         return ret;
 349 }
 350
 351 /**
 352  * iser_create_fastreg_pool - Creates pool of fast_reg descriptors
 353  * for fast registration work requests.
 354  * returns 0 on success, or errno code on failure
 355  */
 356 int iser_create_fastreg_pool(struct ib_conn *ib_conn, unsigned cmds_max)
 357 {
 358         struct iser_device *device = ib_conn->device;
 359         struct fast_reg_descriptor *desc;
 360         int i, ret;
 361
 362         INIT_LIST_HEAD(&ib_conn->fastreg.pool);
 363         ib_conn->fastreg.pool_size = 0;
 364         for (i = 0; i < cmds_max; i++) {
 365                 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 366                 if (!desc) {
 367                         iser_err("Failed to allocate a new fast_reg descriptor\n");
 368                         ret = -ENOMEM;
 369                         goto err;
 370                 }
 371
 372                 ret = iser_create_fastreg_desc(device->ib_device, device->pd,
 373                                                ib_conn->pi_support, desc);
 374                 if (ret) {
 375                         iser_err("Failed to create fastreg descriptor err=%d\n",
 376                                  ret);
 377                         kfree(desc);
 378                         goto err;
 379                 }
 380
 381                 list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 382                 ib_conn->fastreg.pool_size++;
 383         }
 384
 385         return 0;
 386
 387 err:
 388         iser_free_fastreg_pool(ib_conn);
 389         return ret;
 390 }
 391
 392 /**
 393  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 394  */
 395 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
 396 {
 397         struct fast_reg_descriptor *desc, *tmp;
 398         int i = 0;
 399
 400         if (list_empty(&ib_conn->fastreg.pool))
 401                 return;
 402
 403         iser_info("freeing conn %p fr pool\n", ib_conn);
 404
 405         list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
 406                 list_del(&desc->list);
 407                 ib_free_fast_reg_page_list(desc->data_frpl);
 408                 ib_dereg_mr(desc->data_mr);
 409                 if (desc->pi_ctx) {
 410                         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 411                         ib_dereg_mr(desc->pi_ctx->prot_mr);
 412                         ib_destroy_mr(desc->pi_ctx->sig_mr);
 413                         kfree(desc->pi_ctx);
 414                 }
 415                 kfree(desc);
 416                 ++i;
 417         }
 418
 419         if (i < ib_conn->fastreg.pool_size)
 420                 iser_warn("pool still has %d regions registered\n",
 421                           ib_conn->fastreg.pool_size - i);
 422 }
 423
 424 /**
 425  * iser_create_ib_conn_res - Queue-Pair (QP)
 426  *
 427  * returns 0 on success, -1 on failure
 428  */
 429 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
 430 {
 431         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 432                                                    ib_conn);
 433         struct iser_device      *device;
 434         struct ib_device_attr *dev_attr;
 435         struct ib_qp_init_attr  init_attr;
 436         int                     ret = -ENOMEM;
 437         int index, min_index = 0;
 438
 439         BUG_ON(ib_conn->device == NULL);
 440
 441         device = ib_conn->device;
 442         dev_attr = &device->dev_attr;
 443
 444         memset(&init_attr, 0, sizeof init_attr);
 445
 446         mutex_lock(&ig.connlist_mutex);
 447         /* select the CQ with the minimal number of usages */
 448         for (index = 0; index < device->comps_used; index++) {
 449                 if (device->comps[index].active_qps <
 450                     device->comps[min_index].active_qps)
 451                         min_index = index;
 452         }
 453         ib_conn->comp = &device->comps[min_index];
 454         ib_conn->comp->active_qps++;
 455         mutex_unlock(&ig.connlist_mutex);
 456         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 457
 458         init_attr.event_handler = iser_qp_event_callback;
 459         init_attr.qp_context    = (void *)ib_conn;
 460         init_attr.send_cq       = ib_conn->comp->cq;
 461         init_attr.recv_cq       = ib_conn->comp->cq;
 462         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 463         init_attr.cap.max_send_sge = 2;
 464         init_attr.cap.max_recv_sge = 1;
 465         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 466         init_attr.qp_type       = IB_QPT_RC;
 467         if (ib_conn->pi_support) {
 468                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
 469                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 470                 iser_conn->max_cmds =
 471                         ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
 472         } else {
 473                 if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
 474                         init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
 475                         iser_conn->max_cmds =
 476                                 ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
 477                 } else {
 478                         init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
 479                         iser_conn->max_cmds =
 480                                 ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
 481                         iser_dbg("device %s supports max_send_wr %d\n",
 482                                  device->ib_device->name, dev_attr->max_qp_wr);
 483                 }
 484         }
 485
 486         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 487         if (ret)
 488                 goto out_err;
 489
 490         ib_conn->qp = ib_conn->cma_id->qp;
 491         iser_info("setting conn %p cma_id %p qp %p\n",
 492                   ib_conn, ib_conn->cma_id,
 493                   ib_conn->cma_id->qp);
 494         return ret;
 495
 496 out_err:
 497         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 498         return ret;
 499 }
 500
 501 /**
 502  * based on the resolved device node GUID see if there already allocated
 503  * device for this device. If there's no such, create one.
 504  */
 505 static
 506 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 507 {
 508         struct iser_device *device;
 509
 510         mutex_lock(&ig.device_list_mutex);
 511
 512         list_for_each_entry(device, &ig.device_list, ig_list)
 513                 /* find if there's a match using the node GUID */
 514                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 515                         goto inc_refcnt;
 516
 517         device = kzalloc(sizeof *device, GFP_KERNEL);
 518         if (device == NULL)
 519                 goto out;
 520
 521         /* assign this device to the device */
 522         device->ib_device = cma_id->device;
 523         /* init the device and link it into ig device list */
 524         if (iser_create_device_ib_res(device)) {
 525                 kfree(device);
 526                 device = NULL;
 527                 goto out;
 528         }
 529         list_add(&device->ig_list, &ig.device_list);
 530
 531 inc_refcnt:
 532         device->refcount++;
 533 out:
 534         mutex_unlock(&ig.device_list_mutex);
 535         return device;
 536 }
 537
 538 /* if there's no demand for this device, release it */
 539 static void iser_device_try_release(struct iser_device *device)
 540 {
 541         mutex_lock(&ig.device_list_mutex);
 542         device->refcount--;
 543         iser_info("device %p refcount %d\n", device, device->refcount);
 544         if (!device->refcount) {
 545                 iser_free_device_ib_res(device);
 546                 list_del(&device->ig_list);
 547                 kfree(device);
 548         }
 549         mutex_unlock(&ig.device_list_mutex);
 550 }
 551
 552 /**
 553  * Called with state mutex held
 554  **/
 555 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
 556                                      enum iser_conn_state comp,
 557                                      enum iser_conn_state exch)
 558 {
 559         int ret;
 560
 561         ret = (iser_conn->state == comp);
 562         if (ret)
 563                 iser_conn->state = exch;
 564
 565         return ret;
 566 }
 567
 568 void iser_release_work(struct work_struct *work)
 569 {
 570         struct iser_conn *iser_conn;
 571
 572         iser_conn = container_of(work, struct iser_conn, release_work);
 573
 574         /* Wait for conn_stop to complete */
 575         wait_for_completion(&iser_conn->stop_completion);
 576         /* Wait for IB resouces cleanup to complete */
 577         wait_for_completion(&iser_conn->ib_completion);
 578
 579         mutex_lock(&iser_conn->state_mutex);
 580         iser_conn->state = ISER_CONN_DOWN;
 581         mutex_unlock(&iser_conn->state_mutex);
 582
 583         iser_conn_release(iser_conn);
 584 }
 585
 586 /**
 587  * iser_free_ib_conn_res - release IB related resources
 588  * @iser_conn: iser connection struct
 589  * @destroy_device: indicator if we need to try to release
 590  *     the iser device (only iscsi shutdown and DEVICE_REMOVAL
 591  *     will use this.
 592  *
 593  * This routine is called with the iser state mutex held
 594  * so the cm_id removal is out of here. It is Safe to
 595  * be invoked multiple times.
 596  */
 597 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
 598                                   bool destroy_device)
 599 {
 600         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 601         struct iser_device *device = ib_conn->device;
 602
 603         iser_info("freeing conn %p cma_id %p qp %p\n",
 604                   iser_conn, ib_conn->cma_id, ib_conn->qp);
 605
 606         iser_free_rx_descriptors(iser_conn);
 607
 608         if (ib_conn->qp != NULL) {
 609                 ib_conn->comp->active_qps--;
 610                 rdma_destroy_qp(ib_conn->cma_id);
 611                 ib_conn->qp = NULL;
 612         }
 613
 614         if (destroy_device && device != NULL) {
 615                 iser_device_try_release(device);
 616                 ib_conn->device = NULL;
 617         }
 618 }
 619
 620 /**
 621  * Frees all conn objects and deallocs conn descriptor
 622  */
 623 void iser_conn_release(struct iser_conn *iser_conn)
 624 {
 625         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 626
 627         mutex_lock(&ig.connlist_mutex);
 628         list_del(&iser_conn->conn_list);
 629         mutex_unlock(&ig.connlist_mutex);
 630
 631         mutex_lock(&iser_conn->state_mutex);
 632         if (iser_conn->state != ISER_CONN_DOWN)
 633                 iser_warn("iser conn %p state %d, expected state down.\n",
 634                           iser_conn, iser_conn->state);
 635         /*
 636          * In case we never got to bind stage, we still need to
 637          * release IB resources (which is safe to call more than once).
 638          */
 639         iser_free_ib_conn_res(iser_conn, true);
 640         mutex_unlock(&iser_conn->state_mutex);
 641
 642         if (ib_conn->cma_id != NULL) {
 643                 rdma_destroy_id(ib_conn->cma_id);
 644                 ib_conn->cma_id = NULL;
 645         }
 646
 647         kfree(iser_conn);
 648 }
 649
 650 /**
 651  * triggers start of the disconnect procedures and wait for them to be done
 652  * Called with state mutex held
 653  */
 654 int iser_conn_terminate(struct iser_conn *iser_conn)
 655 {
 656         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 657         struct ib_send_wr *bad_wr;
 658         int err = 0;
 659
 660         /* terminate the iser conn only if the conn state is UP */
 661         if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
 662                                        ISER_CONN_TERMINATING))
 663                 return 0;
 664
 665         iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
 666
 667         /* suspend queuing of new iscsi commands */
 668         if (iser_conn->iscsi_conn)
 669                 iscsi_suspend_queue(iser_conn->iscsi_conn);
 670
 671         /*
 672          * In case we didn't already clean up the cma_id (peer initiated
 673          * a disconnection), we need to Cause the CMA to change the QP
 674          * state to ERROR.
 675          */
 676         if (ib_conn->cma_id) {
 677                 err = rdma_disconnect(ib_conn->cma_id);
 678                 if (err)
 679                         iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 680                                  iser_conn, err);
 681
 682                 /* post an indication that all flush errors were consumed */
 683                 err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
 684                 if (err)
 685                         iser_err("conn %p failed to post beacon", ib_conn);
 686
 687                 wait_for_completion(&ib_conn->flush_comp);
 688         }
 689
 690         return 1;
 691 }
 692
 693 /**
 694  * Called with state mutex held
 695  **/
 696 static void iser_connect_error(struct rdma_cm_id *cma_id)
 697 {
 698         struct iser_conn *iser_conn;
 699
 700         iser_conn = (struct iser_conn *)cma_id->context;
 701         iser_conn->state = ISER_CONN_DOWN;
 702 }
 703
 704 /**
 705  * Called with state mutex held
 706  **/
 707 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 708 {
 709         struct iser_device *device;
 710         struct iser_conn   *iser_conn;
 711         struct ib_conn   *ib_conn;
 712         int    ret;
 713
 714         iser_conn = (struct iser_conn *)cma_id->context;
 715         if (iser_conn->state != ISER_CONN_PENDING)
 716                 /* bailout */
 717                 return;
 718
 719         ib_conn = &iser_conn->ib_conn;
 720         device = iser_device_find_by_ib_device(cma_id);
 721         if (!device) {
 722                 iser_err("device lookup/creation failed\n");
 723                 iser_connect_error(cma_id);
 724                 return;
 725         }
 726
 727         ib_conn->device = device;
 728
 729         /* connection T10-PI support */
 730         if (iser_pi_enable) {
 731                 if (!(device->dev_attr.device_cap_flags &
 732                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 733                         iser_warn("T10-PI requested but not supported on %s, "
 734                                   "continue without T10-PI\n",
 735                                   ib_conn->device->ib_device->name);
 736                         ib_conn->pi_support = false;
 737                 } else {
 738                         ib_conn->pi_support = true;
 739                 }
 740         }
 741
 742         ret = rdma_resolve_route(cma_id, 1000);
 743         if (ret) {
 744                 iser_err("resolve route failed: %d\n", ret);
 745                 iser_connect_error(cma_id);
 746                 return;
 747         }
 748 }
 749
 750 /**
 751  * Called with state mutex held
 752  **/
 753 static void iser_route_handler(struct rdma_cm_id *cma_id)
 754 {
 755         struct rdma_conn_param conn_param;
 756         int    ret;
 757         struct iser_cm_hdr req_hdr;
 758         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 759         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 760         struct iser_device *device = ib_conn->device;
 761
 762         if (iser_conn->state != ISER_CONN_PENDING)
 763                 /* bailout */
 764                 return;
 765
 766         ret = iser_create_ib_conn_res(ib_conn);
 767         if (ret)
 768                 goto failure;
 769
 770         memset(&conn_param, 0, sizeof conn_param);
 771         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 772         conn_param.initiator_depth     = 1;
 773         conn_param.retry_count         = 7;
 774         conn_param.rnr_retry_count     = 6;
 775
 776         memset(&req_hdr, 0, sizeof(req_hdr));
 777         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 778                         ISER_SEND_W_INV_NOT_SUPPORTED);
 779         conn_param.private_data         = (void *)&req_hdr;
 780         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 781
 782         ret = rdma_connect(cma_id, &conn_param);
 783         if (ret) {
 784                 iser_err("failure connecting: %d\n", ret);
 785                 goto failure;
 786         }
 787
 788         return;
 789 failure:
 790         iser_connect_error(cma_id);
 791 }
 792
 793 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 794 {
 795         struct iser_conn *iser_conn;
 796         struct ib_qp_attr attr;
 797         struct ib_qp_init_attr init_attr;
 798
 799         iser_conn = (struct iser_conn *)cma_id->context;
 800         if (iser_conn->state != ISER_CONN_PENDING)
 801                 /* bailout */
 802                 return;
 803
 804         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 805         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 806
 807         iser_conn->state = ISER_CONN_UP;
 808         complete(&iser_conn->up_completion);
 809 }
 810
 811 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 812 {
 813         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 814
 815         if (iser_conn_terminate(iser_conn)) {
 816                 if (iser_conn->iscsi_conn)
 817                         iscsi_conn_failure(iser_conn->iscsi_conn,
 818                                            ISCSI_ERR_CONN_FAILED);
 819                 else
 820                         iser_err("iscsi_iser connection isn't bound\n");
 821         }
 822 }
 823
 824 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
 825                                  bool destroy_device)
 826 {
 827         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 828
 829         /*
 830          * We are not guaranteed that we visited disconnected_handler
 831          * by now, call it here to be safe that we handle CM drep
 832          * and flush errors.
 833          */
 834         iser_disconnected_handler(cma_id);
 835         iser_free_ib_conn_res(iser_conn, destroy_device);
 836         complete(&iser_conn->ib_completion);
 837 };
 838
 839 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 840 {
 841         struct iser_conn *iser_conn;
 842         int ret = 0;
 843
 844         iser_conn = (struct iser_conn *)cma_id->context;
 845         iser_info("event %d status %d conn %p id %p\n",
 846                   event->event, event->status, cma_id->context, cma_id);
 847
 848         mutex_lock(&iser_conn->state_mutex);
 849         switch (event->event) {
 850         case RDMA_CM_EVENT_ADDR_RESOLVED:
 851                 iser_addr_handler(cma_id);
 852                 break;
 853         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 854                 iser_route_handler(cma_id);
 855                 break;
 856         case RDMA_CM_EVENT_ESTABLISHED:
 857                 iser_connected_handler(cma_id);
 858                 break;
 859         case RDMA_CM_EVENT_ADDR_ERROR:
 860         case RDMA_CM_EVENT_ROUTE_ERROR:
 861         case RDMA_CM_EVENT_CONNECT_ERROR:
 862         case RDMA_CM_EVENT_UNREACHABLE:
 863         case RDMA_CM_EVENT_REJECTED:
 864                 iser_connect_error(cma_id);
 865                 break;
 866         case RDMA_CM_EVENT_DISCONNECTED:
 867         case RDMA_CM_EVENT_ADDR_CHANGE:
 868                 iser_disconnected_handler(cma_id);
 869                 break;
 870         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 871                 /*
 872                  * we *must* destroy the device as we cannot rely
 873                  * on iscsid to be around to initiate error handling.
 874                  * also implicitly destroy the cma_id.
 875                  */
 876                 iser_cleanup_handler(cma_id, true);
 877                 iser_conn->ib_conn.cma_id = NULL;
 878                 ret = 1;
 879                 break;
 880         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 881                 iser_cleanup_handler(cma_id, false);
 882                 break;
 883         default:
 884                 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
 885                 break;
 886         }
 887         mutex_unlock(&iser_conn->state_mutex);
 888
 889         return ret;
 890 }
 891
 892 void iser_conn_init(struct iser_conn *iser_conn)
 893 {
 894         iser_conn->state = ISER_CONN_INIT;
 895         iser_conn->ib_conn.post_recv_buf_count = 0;
 896         init_completion(&iser_conn->ib_conn.flush_comp);
 897         init_completion(&iser_conn->stop_completion);
 898         init_completion(&iser_conn->ib_completion);
 899         init_completion(&iser_conn->up_completion);
 900         INIT_LIST_HEAD(&iser_conn->conn_list);
 901         spin_lock_init(&iser_conn->ib_conn.lock);
 902         mutex_init(&iser_conn->state_mutex);
 903 }
 904
 905  /**
 906  * starts the process of connecting to the target
 907  * sleeps until the connection is established or rejected
 908  */
 909 int iser_connect(struct iser_conn   *iser_conn,
 910                  struct sockaddr    *src_addr,
 911                  struct sockaddr    *dst_addr,
 912                  int                 non_blocking)
 913 {
 914         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 915         int err = 0;
 916
 917         mutex_lock(&iser_conn->state_mutex);
 918
 919         sprintf(iser_conn->name, "%pISp", dst_addr);
 920
 921         iser_info("connecting to: %s\n", iser_conn->name);
 922
 923         /* the device is known only --after-- address resolution */
 924         ib_conn->device = NULL;
 925
 926         iser_conn->state = ISER_CONN_PENDING;
 927
 928         ib_conn->beacon.wr_id = ISER_BEACON_WRID;
 929         ib_conn->beacon.opcode = IB_WR_SEND;
 930
 931         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 932                                          (void *)iser_conn,
 933                                          RDMA_PS_TCP, IB_QPT_RC);
 934         if (IS_ERR(ib_conn->cma_id)) {
 935                 err = PTR_ERR(ib_conn->cma_id);
 936                 iser_err("rdma_create_id failed: %d\n", err);
 937                 goto id_failure;
 938         }
 939
 940         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 941         if (err) {
 942                 iser_err("rdma_resolve_addr failed: %d\n", err);
 943                 goto addr_failure;
 944         }
 945
 946         if (!non_blocking) {
 947                 wait_for_completion_interruptible(&iser_conn->up_completion);
 948
 949                 if (iser_conn->state != ISER_CONN_UP) {
 950                         err =  -EIO;
 951                         goto connect_failure;
 952                 }
 953         }
 954         mutex_unlock(&iser_conn->state_mutex);
 955
 956         mutex_lock(&ig.connlist_mutex);
 957         list_add(&iser_conn->conn_list, &ig.connlist);
 958         mutex_unlock(&ig.connlist_mutex);
 959         return 0;
 960
 961 id_failure:
 962         ib_conn->cma_id = NULL;
 963 addr_failure:
 964         iser_conn->state = ISER_CONN_DOWN;
 965 connect_failure:
 966         mutex_unlock(&iser_conn->state_mutex);
 967         iser_conn_release(iser_conn);
 968         return err;
 969 }
 970
 971 /**
 972  * iser_reg_page_vec - Register physical memory
 973  *
 974  * returns: 0 on success, errno code on failure
 975  */
 976 int iser_reg_page_vec(struct ib_conn *ib_conn,
 977                       struct iser_page_vec *page_vec,
 978                       struct iser_mem_reg  *mem_reg)
 979 {
 980         struct ib_pool_fmr *mem;
 981         u64                io_addr;
 982         u64                *page_list;
 983         int                status;
 984
 985         page_list = page_vec->pages;
 986         io_addr   = page_list[0];
 987
 988         mem  = ib_fmr_pool_map_phys(ib_conn->fmr.pool,
 989                                     page_list,
 990                                     page_vec->length,
 991                                     io_addr);
 992
 993         if (IS_ERR(mem)) {
 994                 status = (int)PTR_ERR(mem);
 995                 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
 996                 return status;
 997         }
 998
 999         mem_reg->lkey  = mem->fmr->lkey;
1000         mem_reg->rkey  = mem->fmr->rkey;
1001         mem_reg->len   = page_vec->length * SIZE_4K;
1002         mem_reg->va    = io_addr;
1003         mem_reg->is_mr = 1;
1004         mem_reg->mem_h = (void *)mem;
1005
1006         mem_reg->va   += page_vec->offset;
1007         mem_reg->len   = page_vec->data_size;
1008
1009         iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
1010                  "entry[0]: (0x%08lx,%ld)] -> "
1011                  "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
1012                  page_vec, page_vec->length,
1013                  (unsigned long)page_vec->pages[0],
1014                  (unsigned long)page_vec->data_size,
1015                  (unsigned int)mem_reg->lkey, mem_reg->mem_h,
1016                  (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
1017         return 0;
1018 }
1019
1020 /**
1021  * Unregister (previosuly registered using FMR) memory.
1022  * If memory is non-FMR does nothing.
1023  */
1024 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
1025                         enum iser_data_dir cmd_dir)
1026 {
1027         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1028         int ret;
1029
1030         if (!reg->is_mr)
1031                 return;
1032
1033         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
1034
1035         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
1036         if (ret)
1037                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
1038
1039         reg->mem_h = NULL;
1040 }
1041
1042 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
1043                             enum iser_data_dir cmd_dir)
1044 {
1045         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1046         struct iser_conn *iser_conn = iser_task->iser_conn;
1047         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1048         struct fast_reg_descriptor *desc = reg->mem_h;
1049
1050         if (!reg->is_mr)
1051                 return;
1052
1053         reg->mem_h = NULL;
1054         reg->is_mr = 0;
1055         spin_lock_bh(&ib_conn->lock);
1056         list_add_tail(&desc->list, &ib_conn->fastreg.pool);
1057         spin_unlock_bh(&ib_conn->lock);
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->mr->lkey;
1070
1071         rx_wr.wr_id   = (unsigned long)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    = (unsigned long)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         int               ib_ret;
1125         struct ib_send_wr send_wr, *send_wr_failed;
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         send_wr.next       = NULL;
1132         send_wr.wr_id      = (unsigned long)tx_desc;
1133         send_wr.sg_list    = tx_desc->tx_sg;
1134         send_wr.num_sge    = tx_desc->num_sge;
1135         send_wr.opcode     = IB_WR_SEND;
1136         send_wr.send_flags = signal ? IB_SEND_SIGNALED : 0;
1137
1138         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1139         if (ib_ret)
1140                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1141
1142         return ib_ret;
1143 }
1144
1145 /**
1146  * is_iser_tx_desc - Indicate if the completion wr_id
1147  *     is a TX descriptor or not.
1148  * @iser_conn: iser connection
1149  * @wr_id: completion WR identifier
1150  *
1151  * Since we cannot rely on wc opcode in FLUSH errors
1152  * we must work around it by checking if the wr_id address
1153  * falls in the iser connection rx_descs buffer. If so
1154  * it is an RX descriptor, otherwize it is a TX.
1155  */
1156 static inline bool
1157 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1158 {
1159         void *start = iser_conn->rx_descs;
1160         int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1161
1162         if (wr_id >= start && wr_id < start + len)
1163                 return false;
1164
1165         return true;
1166 }
1167
1168 /**
1169  * iser_handle_comp_error() - Handle error completion
1170  * @ib_conn:   connection RDMA resources
1171  * @wc:        work completion
1172  *
1173  * Notes: We may handle a FLUSH error completion and in this case
1174  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1175  *        error completion we should also notify iscsi layer that
1176  *        connection is failed (in case we passed bind stage).
1177  */
1178 static void
1179 iser_handle_comp_error(struct ib_conn *ib_conn,
1180                        struct ib_wc *wc)
1181 {
1182         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1183                                                    ib_conn);
1184
1185         if (wc->status != IB_WC_WR_FLUSH_ERR)
1186                 if (iser_conn->iscsi_conn)
1187                         iscsi_conn_failure(iser_conn->iscsi_conn,
1188                                            ISCSI_ERR_CONN_FAILED);
1189
1190         if (is_iser_tx_desc(iser_conn, (void *)wc->wr_id)) {
1191                 struct iser_tx_desc *desc = (struct iser_tx_desc *)wc->wr_id;
1192
1193                 if (desc->type == ISCSI_TX_DATAOUT)
1194                         kmem_cache_free(ig.desc_cache, desc);
1195         } else {
1196                 ib_conn->post_recv_buf_count--;
1197         }
1198 }
1199
1200 /**
1201  * iser_handle_wc - handle a single work completion
1202  * @wc: work completion
1203  *
1204  * Soft-IRQ context, work completion can be either
1205  * SEND or RECV, and can turn out successful or
1206  * with error (or flush error).
1207  */
1208 static void iser_handle_wc(struct ib_wc *wc)
1209 {
1210         struct ib_conn *ib_conn;
1211         struct iser_tx_desc *tx_desc;
1212         struct iser_rx_desc *rx_desc;
1213
1214         ib_conn = wc->qp->qp_context;
1215         if (wc->status == IB_WC_SUCCESS) {
1216                 if (wc->opcode == IB_WC_RECV) {
1217                         rx_desc = (struct iser_rx_desc *)wc->wr_id;
1218                         iser_rcv_completion(rx_desc, wc->byte_len,
1219                                             ib_conn);
1220                 } else
1221                 if (wc->opcode == IB_WC_SEND) {
1222                         tx_desc = (struct iser_tx_desc *)wc->wr_id;
1223                         iser_snd_completion(tx_desc, ib_conn);
1224                 } else {
1225                         iser_err("Unknown wc opcode %d\n", wc->opcode);
1226                 }
1227         } else {
1228                 if (wc->status != IB_WC_WR_FLUSH_ERR)
1229                         iser_err("wr id %llx status %d vend_err %x\n",
1230                                  wc->wr_id, wc->status, wc->vendor_err);
1231                 else
1232                         iser_dbg("flush error: wr id %llx\n", wc->wr_id);
1233
1234                 if (wc->wr_id != ISER_FASTREG_LI_WRID &&
1235                     wc->wr_id != ISER_BEACON_WRID)
1236                         iser_handle_comp_error(ib_conn, wc);
1237
1238                 /* complete in case all flush errors were consumed */
1239                 if (wc->wr_id == ISER_BEACON_WRID)
1240                         complete(&ib_conn->flush_comp);
1241         }
1242 }
1243
1244 /**
1245  * iser_cq_tasklet_fn - iSER completion polling loop
1246  * @data: iSER completion context
1247  *
1248  * Soft-IRQ context, polling connection CQ until
1249  * either CQ was empty or we exausted polling budget
1250  */
1251 static void iser_cq_tasklet_fn(unsigned long data)
1252 {
1253         struct iser_comp *comp = (struct iser_comp *)data;
1254         struct ib_cq *cq = comp->cq;
1255         struct ib_wc *const wcs = comp->wcs;
1256         int i, n, completed = 0;
1257
1258         while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1259                 for (i = 0; i < n; i++)
1260                         iser_handle_wc(&wcs[i]);
1261
1262                 completed += n;
1263                 if (completed >= iser_cq_poll_limit)
1264                         break;
1265         }
1266
1267         /*
1268          * It is assumed here that arming CQ only once its empty
1269          * would not cause interrupts to be missed.
1270          */
1271         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1272
1273         iser_dbg("got %d completions\n", completed);
1274 }
1275
1276 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1277 {
1278         struct iser_comp *comp = cq_context;
1279
1280         tasklet_schedule(&comp->tasklet);
1281 }
1282
1283 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1284                              enum iser_data_dir cmd_dir, sector_t *sector)
1285 {
1286         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1287         struct fast_reg_descriptor *desc = reg->mem_h;
1288         unsigned long sector_size = iser_task->sc->device->sector_size;
1289         struct ib_mr_status mr_status;
1290         int ret;
1291
1292         if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1293                 desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1294                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1295                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1296                 if (ret) {
1297                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1298                         goto err;
1299                 }
1300
1301                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1302                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1303
1304                         do_div(sector_off, sector_size + 8);
1305                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1306
1307                         pr_err("PI error found type %d at sector %llx "
1308                                "expected %x vs actual %x\n",
1309                                mr_status.sig_err.err_type,
1310                                (unsigned long long)*sector,
1311                                mr_status.sig_err.expected,
1312                                mr_status.sig_err.actual);
1313
1314                         switch (mr_status.sig_err.err_type) {
1315                         case IB_SIG_BAD_GUARD:
1316                                 return 0x1;
1317                         case IB_SIG_BAD_REFTAG:
1318                                 return 0x3;
1319                         case IB_SIG_BAD_APPTAG:
1320                                 return 0x2;
1321                         }
1322                 }
1323         }
1324
1325         return 0;
1326 err:
1327         /* Not alot we can do here, return ambiguous guard error */
1328         return 0x1;
1329 }