drivers/infiniband/ulp/iser/iser_verbs.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/slab.h>
  37 #include <linux/delay.h>
  38
  39 #include "iscsi_iser.h"
  40
  41 #define ISCSI_ISER_MAX_CONN     8
  42 #define ISER_MAX_RX_LEN         (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
  43 #define ISER_MAX_TX_LEN         (ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
  44 #define ISER_MAX_CQ_LEN         (ISER_MAX_RX_LEN + ISER_MAX_TX_LEN + \
  45                                  ISCSI_ISER_MAX_CONN)
  46
  47 static int iser_cq_poll_limit = 512;
  48
  49 static void iser_cq_tasklet_fn(unsigned long data);
  50 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
  51
  52 static void iser_cq_event_callback(struct ib_event *cause, void *context)
  53 {
  54         iser_err("cq event %s (%d)\n",
  55                  ib_event_msg(cause->event), cause->event);
  56 }
  57
  58 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  59 {
  60         iser_err("qp event %s (%d)\n",
  61                  ib_event_msg(cause->event), cause->event);
  62 }
  63
  64 static void iser_event_handler(struct ib_event_handler *handler,
  65                                 struct ib_event *event)
  66 {
  67         iser_err("async event %s (%d) on device %s port %d\n",
  68                  ib_event_msg(event->event), event->event,
  69                  event->device->name, event->element.port_num);
  70 }
  71
  72 /**
  73  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  74  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  75  * the adapator.
  76  *
  77  * returns 0 on success, -1 on failure
  78  */
  79 static int iser_create_device_ib_res(struct iser_device *device)
  80 {
  81         struct ib_device_attr *dev_attr = &device->dev_attr;
  82         int ret, i, max_cqe;
  83
  84         ret = ib_query_device(device->ib_device, dev_attr);
  85         if (ret) {
  86                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  87                 return ret;
  88         }
  89
  90         ret = iser_assign_reg_ops(device);
  91         if (ret)
  92                 return ret;
  93
  94         device->comps_used = min_t(int, num_online_cpus(),
  95                                  device->ib_device->num_comp_vectors);
  96
  97         device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
  98                                 GFP_KERNEL);
  99         if (!device->comps)
 100                 goto comps_err;
 101
 102         max_cqe = min(ISER_MAX_CQ_LEN, dev_attr->max_cqe);
 103
 104         iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
 105                   device->comps_used, device->ib_device->name,
 106                   device->ib_device->num_comp_vectors, max_cqe);
 107
 108         device->pd = ib_alloc_pd(device->ib_device);
 109         if (IS_ERR(device->pd))
 110                 goto pd_err;
 111
 112         for (i = 0; i < device->comps_used; i++) {
 113                 struct ib_cq_init_attr cq_attr = {};
 114                 struct iser_comp *comp = &device->comps[i];
 115
 116                 comp->device = device;
 117                 cq_attr.cqe = max_cqe;
 118                 cq_attr.comp_vector = i;
 119                 comp->cq = ib_create_cq(device->ib_device,
 120                                         iser_cq_callback,
 121                                         iser_cq_event_callback,
 122                                         (void *)comp,
 123                                         &cq_attr);
 124                 if (IS_ERR(comp->cq)) {
 125                         comp->cq = NULL;
 126                         goto cq_err;
 127                 }
 128
 129                 if (ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP))
 130                         goto cq_err;
 131
 132                 tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
 133                              (unsigned long)comp);
 134         }
 135
 136         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 137                                    IB_ACCESS_REMOTE_WRITE |
 138                                    IB_ACCESS_REMOTE_READ);
 139         if (IS_ERR(device->mr))
 140                 goto dma_mr_err;
 141
 142         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 143                                 iser_event_handler);
 144         if (ib_register_event_handler(&device->event_handler))
 145                 goto handler_err;
 146
 147         return 0;
 148
 149 handler_err:
 150         ib_dereg_mr(device->mr);
 151 dma_mr_err:
 152         for (i = 0; i < device->comps_used; i++)
 153                 tasklet_kill(&device->comps[i].tasklet);
 154 cq_err:
 155         for (i = 0; i < device->comps_used; i++) {
 156                 struct iser_comp *comp = &device->comps[i];
 157
 158                 if (comp->cq)
 159                         ib_destroy_cq(comp->cq);
 160         }
 161         ib_dealloc_pd(device->pd);
 162 pd_err:
 163         kfree(device->comps);
 164 comps_err:
 165         iser_err("failed to allocate an IB resource\n");
 166         return -1;
 167 }
 168
 169 /**
 170  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 171  * CQ and PD created with the device associated with the adapator.
 172  */
 173 static void iser_free_device_ib_res(struct iser_device *device)
 174 {
 175         int i;
 176         BUG_ON(device->mr == NULL);
 177
 178         for (i = 0; i < device->comps_used; i++) {
 179                 struct iser_comp *comp = &device->comps[i];
 180
 181                 tasklet_kill(&comp->tasklet);
 182                 ib_destroy_cq(comp->cq);
 183                 comp->cq = NULL;
 184         }
 185
 186         (void)ib_unregister_event_handler(&device->event_handler);
 187         (void)ib_dereg_mr(device->mr);
 188         (void)ib_dealloc_pd(device->pd);
 189
 190         kfree(device->comps);
 191         device->comps = NULL;
 192
 193         device->mr = NULL;
 194         device->pd = NULL;
 195 }
 196
 197 /**
 198  * iser_alloc_fmr_pool - Creates FMR pool and page_vector
 199  *
 200  * returns 0 on success, or errno code on failure
 201  */
 202 int iser_alloc_fmr_pool(struct ib_conn *ib_conn,
 203                         unsigned cmds_max,
 204                         unsigned int size)
 205 {
 206         struct iser_device *device = ib_conn->device;
 207         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 208         struct iser_page_vec *page_vec;
 209         struct iser_fr_desc *desc;
 210         struct ib_fmr_pool *fmr_pool;
 211         struct ib_fmr_pool_param params;
 212         int ret;
 213
 214         INIT_LIST_HEAD(&fr_pool->list);
 215         spin_lock_init(&fr_pool->lock);
 216
 217         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 218         if (!desc)
 219                 return -ENOMEM;
 220
 221         page_vec = kmalloc(sizeof(*page_vec) + (sizeof(u64) * size),
 222                            GFP_KERNEL);
 223         if (!page_vec) {
 224                 ret = -ENOMEM;
 225                 goto err_frpl;
 226         }
 227
 228         page_vec->pages = (u64 *)(page_vec + 1);
 229
 230         params.page_shift        = SHIFT_4K;
 231         params.max_pages_per_fmr = size;
 232         /* make the pool size twice the max number of SCSI commands *
 233          * the ML is expected to queue, watermark for unmap at 50%  */
 234         params.pool_size         = cmds_max * 2;
 235         params.dirty_watermark   = cmds_max;
 236         params.cache             = 0;
 237         params.flush_function    = NULL;
 238         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 239                                     IB_ACCESS_REMOTE_WRITE |
 240                                     IB_ACCESS_REMOTE_READ);
 241
 242         fmr_pool = ib_create_fmr_pool(device->pd, &params);
 243         if (IS_ERR(fmr_pool)) {
 244                 ret = PTR_ERR(fmr_pool);
 245                 iser_err("FMR allocation failed, err %d\n", ret);
 246                 goto err_fmr;
 247         }
 248
 249         desc->rsc.page_vec = page_vec;
 250         desc->rsc.fmr_pool = fmr_pool;
 251         list_add(&desc->list, &fr_pool->list);
 252
 253         return 0;
 254
 255 err_fmr:
 256         kfree(page_vec);
 257 err_frpl:
 258         kfree(desc);
 259
 260         return ret;
 261 }
 262
 263 /**
 264  * iser_free_fmr_pool - releases the FMR pool and page vec
 265  */
 266 void iser_free_fmr_pool(struct ib_conn *ib_conn)
 267 {
 268         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 269         struct iser_fr_desc *desc;
 270
 271         desc = list_first_entry(&fr_pool->list,
 272                                 struct iser_fr_desc, list);
 273         list_del(&desc->list);
 274
 275         iser_info("freeing conn %p fmr pool %p\n",
 276                   ib_conn, desc->rsc.fmr_pool);
 277
 278         ib_destroy_fmr_pool(desc->rsc.fmr_pool);
 279         kfree(desc->rsc.page_vec);
 280         kfree(desc);
 281 }
 282
 283 static int
 284 iser_alloc_reg_res(struct ib_device *ib_device,
 285                    struct ib_pd *pd,
 286                    struct iser_reg_resources *res,
 287                    unsigned int size)
 288 {
 289         int ret;
 290
 291         res->frpl = ib_alloc_fast_reg_page_list(ib_device, size);
 292         if (IS_ERR(res->frpl)) {
 293                 ret = PTR_ERR(res->frpl);
 294                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 295                          ret);
 296                 return PTR_ERR(res->frpl);
 297         }
 298
 299         res->mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, size);
 300         if (IS_ERR(res->mr)) {
 301                 ret = PTR_ERR(res->mr);
 302                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 303                 goto fast_reg_mr_failure;
 304         }
 305         res->mr_valid = 1;
 306
 307         return 0;
 308
 309 fast_reg_mr_failure:
 310         ib_free_fast_reg_page_list(res->frpl);
 311
 312         return ret;
 313 }
 314
 315 static void
 316 iser_free_reg_res(struct iser_reg_resources *rsc)
 317 {
 318         ib_dereg_mr(rsc->mr);
 319         ib_free_fast_reg_page_list(rsc->frpl);
 320 }
 321
 322 static int
 323 iser_alloc_pi_ctx(struct ib_device *ib_device,
 324                   struct ib_pd *pd,
 325                   struct iser_fr_desc *desc,
 326                   unsigned int size)
 327 {
 328         struct iser_pi_context *pi_ctx = NULL;
 329         int ret;
 330
 331         desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 332         if (!desc->pi_ctx)
 333                 return -ENOMEM;
 334
 335         pi_ctx = desc->pi_ctx;
 336
 337         ret = iser_alloc_reg_res(ib_device, pd, &pi_ctx->rsc, size);
 338         if (ret) {
 339                 iser_err("failed to allocate reg_resources\n");
 340                 goto alloc_reg_res_err;
 341         }
 342
 343         pi_ctx->sig_mr = ib_alloc_mr(pd, IB_MR_TYPE_SIGNATURE, 2);
 344         if (IS_ERR(pi_ctx->sig_mr)) {
 345                 ret = PTR_ERR(pi_ctx->sig_mr);
 346                 goto sig_mr_failure;
 347         }
 348         pi_ctx->sig_mr_valid = 1;
 349         desc->pi_ctx->sig_protected = 0;
 350
 351         return 0;
 352
 353 sig_mr_failure:
 354         iser_free_reg_res(&pi_ctx->rsc);
 355 alloc_reg_res_err:
 356         kfree(desc->pi_ctx);
 357
 358         return ret;
 359 }
 360
 361 static void
 362 iser_free_pi_ctx(struct iser_pi_context *pi_ctx)
 363 {
 364         iser_free_reg_res(&pi_ctx->rsc);
 365         ib_dereg_mr(pi_ctx->sig_mr);
 366         kfree(pi_ctx);
 367 }
 368
 369 static struct iser_fr_desc *
 370 iser_create_fastreg_desc(struct ib_device *ib_device,
 371                          struct ib_pd *pd,
 372                          bool pi_enable,
 373                          unsigned int size)
 374 {
 375         struct iser_fr_desc *desc;
 376         int ret;
 377
 378         desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 379         if (!desc)
 380                 return ERR_PTR(-ENOMEM);
 381
 382         ret = iser_alloc_reg_res(ib_device, pd, &desc->rsc, size);
 383         if (ret)
 384                 goto reg_res_alloc_failure;
 385
 386         if (pi_enable) {
 387                 ret = iser_alloc_pi_ctx(ib_device, pd, desc, size);
 388                 if (ret)
 389                         goto pi_ctx_alloc_failure;
 390         }
 391
 392         return desc;
 393
 394 pi_ctx_alloc_failure:
 395         iser_free_reg_res(&desc->rsc);
 396 reg_res_alloc_failure:
 397         kfree(desc);
 398
 399         return ERR_PTR(ret);
 400 }
 401
 402 /**
 403  * iser_alloc_fastreg_pool - Creates pool of fast_reg descriptors
 404  * for fast registration work requests.
 405  * returns 0 on success, or errno code on failure
 406  */
 407 int iser_alloc_fastreg_pool(struct ib_conn *ib_conn,
 408                             unsigned cmds_max,
 409                             unsigned int size)
 410 {
 411         struct iser_device *device = ib_conn->device;
 412         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 413         struct iser_fr_desc *desc;
 414         int i, ret;
 415
 416         INIT_LIST_HEAD(&fr_pool->list);
 417         spin_lock_init(&fr_pool->lock);
 418         fr_pool->size = 0;
 419         for (i = 0; i < cmds_max; i++) {
 420                 desc = iser_create_fastreg_desc(device->ib_device, device->pd,
 421                                                 ib_conn->pi_support, size);
 422                 if (IS_ERR(desc)) {
 423                         ret = PTR_ERR(desc);
 424                         goto err;
 425                 }
 426
 427                 list_add_tail(&desc->list, &fr_pool->list);
 428                 fr_pool->size++;
 429         }
 430
 431         return 0;
 432
 433 err:
 434         iser_free_fastreg_pool(ib_conn);
 435         return ret;
 436 }
 437
 438 /**
 439  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 440  */
 441 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
 442 {
 443         struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
 444         struct iser_fr_desc *desc, *tmp;
 445         int i = 0;
 446
 447         if (list_empty(&fr_pool->list))
 448                 return;
 449
 450         iser_info("freeing conn %p fr pool\n", ib_conn);
 451
 452         list_for_each_entry_safe(desc, tmp, &fr_pool->list, list) {
 453                 list_del(&desc->list);
 454                 iser_free_reg_res(&desc->rsc);
 455                 if (desc->pi_ctx)
 456                         iser_free_pi_ctx(desc->pi_ctx);
 457                 kfree(desc);
 458                 ++i;
 459         }
 460
 461         if (i < fr_pool->size)
 462                 iser_warn("pool still has %d regions registered\n",
 463                           fr_pool->size - i);
 464 }
 465
 466 /**
 467  * iser_create_ib_conn_res - Queue-Pair (QP)
 468  *
 469  * returns 0 on success, -1 on failure
 470  */
 471 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
 472 {
 473         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 474                                                    ib_conn);
 475         struct iser_device      *device;
 476         struct ib_device_attr *dev_attr;
 477         struct ib_qp_init_attr  init_attr;
 478         int                     ret = -ENOMEM;
 479         int index, min_index = 0;
 480
 481         BUG_ON(ib_conn->device == NULL);
 482
 483         device = ib_conn->device;
 484         dev_attr = &device->dev_attr;
 485
 486         memset(&init_attr, 0, sizeof init_attr);
 487
 488         mutex_lock(&ig.connlist_mutex);
 489         /* select the CQ with the minimal number of usages */
 490         for (index = 0; index < device->comps_used; index++) {
 491                 if (device->comps[index].active_qps <
 492                     device->comps[min_index].active_qps)
 493                         min_index = index;
 494         }
 495         ib_conn->comp = &device->comps[min_index];
 496         ib_conn->comp->active_qps++;
 497         mutex_unlock(&ig.connlist_mutex);
 498         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 499
 500         init_attr.event_handler = iser_qp_event_callback;
 501         init_attr.qp_context    = (void *)ib_conn;
 502         init_attr.send_cq       = ib_conn->comp->cq;
 503         init_attr.recv_cq       = ib_conn->comp->cq;
 504         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 505         init_attr.cap.max_send_sge = 2;
 506         init_attr.cap.max_recv_sge = 1;
 507         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 508         init_attr.qp_type       = IB_QPT_RC;
 509         if (ib_conn->pi_support) {
 510                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
 511                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 512                 iser_conn->max_cmds =
 513                         ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
 514         } else {
 515                 if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
 516                         init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
 517                         iser_conn->max_cmds =
 518                                 ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
 519                 } else {
 520                         init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
 521                         iser_conn->max_cmds =
 522                                 ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
 523                         iser_dbg("device %s supports max_send_wr %d\n",
 524                                  device->ib_device->name, dev_attr->max_qp_wr);
 525                 }
 526         }
 527
 528         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 529         if (ret)
 530                 goto out_err;
 531
 532         ib_conn->qp = ib_conn->cma_id->qp;
 533         iser_info("setting conn %p cma_id %p qp %p\n",
 534                   ib_conn, ib_conn->cma_id,
 535                   ib_conn->cma_id->qp);
 536         return ret;
 537
 538 out_err:
 539         mutex_lock(&ig.connlist_mutex);
 540         ib_conn->comp->active_qps--;
 541         mutex_unlock(&ig.connlist_mutex);
 542         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 543
 544         return ret;
 545 }
 546
 547 /**
 548  * based on the resolved device node GUID see if there already allocated
 549  * device for this device. If there's no such, create one.
 550  */
 551 static
 552 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 553 {
 554         struct iser_device *device;
 555
 556         mutex_lock(&ig.device_list_mutex);
 557
 558         list_for_each_entry(device, &ig.device_list, ig_list)
 559                 /* find if there's a match using the node GUID */
 560                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 561                         goto inc_refcnt;
 562
 563         device = kzalloc(sizeof *device, GFP_KERNEL);
 564         if (device == NULL)
 565                 goto out;
 566
 567         /* assign this device to the device */
 568         device->ib_device = cma_id->device;
 569         /* init the device and link it into ig device list */
 570         if (iser_create_device_ib_res(device)) {
 571                 kfree(device);
 572                 device = NULL;
 573                 goto out;
 574         }
 575         list_add(&device->ig_list, &ig.device_list);
 576
 577 inc_refcnt:
 578         device->refcount++;
 579 out:
 580         mutex_unlock(&ig.device_list_mutex);
 581         return device;
 582 }
 583
 584 /* if there's no demand for this device, release it */
 585 static void iser_device_try_release(struct iser_device *device)
 586 {
 587         mutex_lock(&ig.device_list_mutex);
 588         device->refcount--;
 589         iser_info("device %p refcount %d\n", device, device->refcount);
 590         if (!device->refcount) {
 591                 iser_free_device_ib_res(device);
 592                 list_del(&device->ig_list);
 593                 kfree(device);
 594         }
 595         mutex_unlock(&ig.device_list_mutex);
 596 }
 597
 598 /**
 599  * Called with state mutex held
 600  **/
 601 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
 602                                      enum iser_conn_state comp,
 603                                      enum iser_conn_state exch)
 604 {
 605         int ret;
 606
 607         ret = (iser_conn->state == comp);
 608         if (ret)
 609                 iser_conn->state = exch;
 610
 611         return ret;
 612 }
 613
 614 void iser_release_work(struct work_struct *work)
 615 {
 616         struct iser_conn *iser_conn;
 617
 618         iser_conn = container_of(work, struct iser_conn, release_work);
 619
 620         /* Wait for conn_stop to complete */
 621         wait_for_completion(&iser_conn->stop_completion);
 622         /* Wait for IB resouces cleanup to complete */
 623         wait_for_completion(&iser_conn->ib_completion);
 624
 625         mutex_lock(&iser_conn->state_mutex);
 626         iser_conn->state = ISER_CONN_DOWN;
 627         mutex_unlock(&iser_conn->state_mutex);
 628
 629         iser_conn_release(iser_conn);
 630 }
 631
 632 /**
 633  * iser_free_ib_conn_res - release IB related resources
 634  * @iser_conn: iser connection struct
 635  * @destroy: indicator if we need to try to release the
 636  *     iser device and memory regoins pool (only iscsi
 637  *     shutdown and DEVICE_REMOVAL will use this).
 638  *
 639  * This routine is called with the iser state mutex held
 640  * so the cm_id removal is out of here. It is Safe to
 641  * be invoked multiple times.
 642  */
 643 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
 644                                   bool destroy)
 645 {
 646         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 647         struct iser_device *device = ib_conn->device;
 648
 649         iser_info("freeing conn %p cma_id %p qp %p\n",
 650                   iser_conn, ib_conn->cma_id, ib_conn->qp);
 651
 652         if (ib_conn->qp != NULL) {
 653                 ib_conn->comp->active_qps--;
 654                 rdma_destroy_qp(ib_conn->cma_id);
 655                 ib_conn->qp = NULL;
 656         }
 657
 658         if (destroy) {
 659                 if (iser_conn->rx_descs)
 660                         iser_free_rx_descriptors(iser_conn);
 661
 662                 if (device != NULL) {
 663                         iser_device_try_release(device);
 664                         ib_conn->device = NULL;
 665                 }
 666         }
 667 }
 668
 669 /**
 670  * Frees all conn objects and deallocs conn descriptor
 671  */
 672 void iser_conn_release(struct iser_conn *iser_conn)
 673 {
 674         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 675
 676         mutex_lock(&ig.connlist_mutex);
 677         list_del(&iser_conn->conn_list);
 678         mutex_unlock(&ig.connlist_mutex);
 679
 680         mutex_lock(&iser_conn->state_mutex);
 681         /* In case we endup here without ep_disconnect being invoked. */
 682         if (iser_conn->state != ISER_CONN_DOWN) {
 683                 iser_warn("iser conn %p state %d, expected state down.\n",
 684                           iser_conn, iser_conn->state);
 685                 iscsi_destroy_endpoint(iser_conn->ep);
 686                 iser_conn->state = ISER_CONN_DOWN;
 687         }
 688         /*
 689          * In case we never got to bind stage, we still need to
 690          * release IB resources (which is safe to call more than once).
 691          */
 692         iser_free_ib_conn_res(iser_conn, true);
 693         mutex_unlock(&iser_conn->state_mutex);
 694
 695         if (ib_conn->cma_id != NULL) {
 696                 rdma_destroy_id(ib_conn->cma_id);
 697                 ib_conn->cma_id = NULL;
 698         }
 699
 700         kfree(iser_conn);
 701 }
 702
 703 /**
 704  * triggers start of the disconnect procedures and wait for them to be done
 705  * Called with state mutex held
 706  */
 707 int iser_conn_terminate(struct iser_conn *iser_conn)
 708 {
 709         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 710         struct ib_send_wr *bad_wr;
 711         int err = 0;
 712
 713         /* terminate the iser conn only if the conn state is UP */
 714         if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
 715                                        ISER_CONN_TERMINATING))
 716                 return 0;
 717
 718         iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
 719
 720         /* suspend queuing of new iscsi commands */
 721         if (iser_conn->iscsi_conn)
 722                 iscsi_suspend_queue(iser_conn->iscsi_conn);
 723
 724         /*
 725          * In case we didn't already clean up the cma_id (peer initiated
 726          * a disconnection), we need to Cause the CMA to change the QP
 727          * state to ERROR.
 728          */
 729         if (ib_conn->cma_id) {
 730                 err = rdma_disconnect(ib_conn->cma_id);
 731                 if (err)
 732                         iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 733                                  iser_conn, err);
 734
 735                 /* post an indication that all flush errors were consumed */
 736                 err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
 737                 if (err) {
 738                         iser_err("conn %p failed to post beacon", ib_conn);
 739                         return 1;
 740                 }
 741
 742                 wait_for_completion(&ib_conn->flush_comp);
 743         }
 744
 745         return 1;
 746 }
 747
 748 /**
 749  * Called with state mutex held
 750  **/
 751 static void iser_connect_error(struct rdma_cm_id *cma_id)
 752 {
 753         struct iser_conn *iser_conn;
 754
 755         iser_conn = (struct iser_conn *)cma_id->context;
 756         iser_conn->state = ISER_CONN_TERMINATING;
 757 }
 758
 759 static void
 760 iser_calc_scsi_params(struct iser_conn *iser_conn,
 761                       unsigned int max_sectors)
 762 {
 763         struct iser_device *device = iser_conn->ib_conn.device;
 764         unsigned short sg_tablesize, sup_sg_tablesize;
 765
 766         sg_tablesize = DIV_ROUND_UP(max_sectors * 512, SIZE_4K);
 767         sup_sg_tablesize = min_t(unsigned, ISCSI_ISER_MAX_SG_TABLESIZE,
 768                                  device->dev_attr.max_fast_reg_page_list_len);
 769
 770         if (sg_tablesize > sup_sg_tablesize) {
 771                 sg_tablesize = sup_sg_tablesize;
 772                 iser_conn->scsi_max_sectors = sg_tablesize * SIZE_4K / 512;
 773         } else {
 774                 iser_conn->scsi_max_sectors = max_sectors;
 775         }
 776
 777         iser_conn->scsi_sg_tablesize = sg_tablesize;
 778
 779         iser_dbg("iser_conn %p, sg_tablesize %u, max_sectors %u\n",
 780                  iser_conn, iser_conn->scsi_sg_tablesize,
 781                  iser_conn->scsi_max_sectors);
 782 }
 783
 784 /**
 785  * Called with state mutex held
 786  **/
 787 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 788 {
 789         struct iser_device *device;
 790         struct iser_conn   *iser_conn;
 791         struct ib_conn   *ib_conn;
 792         int    ret;
 793
 794         iser_conn = (struct iser_conn *)cma_id->context;
 795         if (iser_conn->state != ISER_CONN_PENDING)
 796                 /* bailout */
 797                 return;
 798
 799         ib_conn = &iser_conn->ib_conn;
 800         device = iser_device_find_by_ib_device(cma_id);
 801         if (!device) {
 802                 iser_err("device lookup/creation failed\n");
 803                 iser_connect_error(cma_id);
 804                 return;
 805         }
 806
 807         ib_conn->device = device;
 808
 809         /* connection T10-PI support */
 810         if (iser_pi_enable) {
 811                 if (!(device->dev_attr.device_cap_flags &
 812                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 813                         iser_warn("T10-PI requested but not supported on %s, "
 814                                   "continue without T10-PI\n",
 815                                   ib_conn->device->ib_device->name);
 816                         ib_conn->pi_support = false;
 817                 } else {
 818                         ib_conn->pi_support = true;
 819                 }
 820         }
 821
 822         iser_calc_scsi_params(iser_conn, iser_max_sectors);
 823
 824         ret = rdma_resolve_route(cma_id, 1000);
 825         if (ret) {
 826                 iser_err("resolve route failed: %d\n", ret);
 827                 iser_connect_error(cma_id);
 828                 return;
 829         }
 830 }
 831
 832 /**
 833  * Called with state mutex held
 834  **/
 835 static void iser_route_handler(struct rdma_cm_id *cma_id)
 836 {
 837         struct rdma_conn_param conn_param;
 838         int    ret;
 839         struct iser_cm_hdr req_hdr;
 840         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 841         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 842         struct iser_device *device = ib_conn->device;
 843
 844         if (iser_conn->state != ISER_CONN_PENDING)
 845                 /* bailout */
 846                 return;
 847
 848         ret = iser_create_ib_conn_res(ib_conn);
 849         if (ret)
 850                 goto failure;
 851
 852         memset(&conn_param, 0, sizeof conn_param);
 853         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 854         conn_param.initiator_depth     = 1;
 855         conn_param.retry_count         = 7;
 856         conn_param.rnr_retry_count     = 6;
 857
 858         memset(&req_hdr, 0, sizeof(req_hdr));
 859         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 860                         ISER_SEND_W_INV_NOT_SUPPORTED);
 861         conn_param.private_data         = (void *)&req_hdr;
 862         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 863
 864         ret = rdma_connect(cma_id, &conn_param);
 865         if (ret) {
 866                 iser_err("failure connecting: %d\n", ret);
 867                 goto failure;
 868         }
 869
 870         return;
 871 failure:
 872         iser_connect_error(cma_id);
 873 }
 874
 875 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 876 {
 877         struct iser_conn *iser_conn;
 878         struct ib_qp_attr attr;
 879         struct ib_qp_init_attr init_attr;
 880
 881         iser_conn = (struct iser_conn *)cma_id->context;
 882         if (iser_conn->state != ISER_CONN_PENDING)
 883                 /* bailout */
 884                 return;
 885
 886         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 887         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 888
 889         iser_conn->state = ISER_CONN_UP;
 890         complete(&iser_conn->up_completion);
 891 }
 892
 893 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 894 {
 895         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 896
 897         if (iser_conn_terminate(iser_conn)) {
 898                 if (iser_conn->iscsi_conn)
 899                         iscsi_conn_failure(iser_conn->iscsi_conn,
 900                                            ISCSI_ERR_CONN_FAILED);
 901                 else
 902                         iser_err("iscsi_iser connection isn't bound\n");
 903         }
 904 }
 905
 906 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
 907                                  bool destroy)
 908 {
 909         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 910
 911         /*
 912          * We are not guaranteed that we visited disconnected_handler
 913          * by now, call it here to be safe that we handle CM drep
 914          * and flush errors.
 915          */
 916         iser_disconnected_handler(cma_id);
 917         iser_free_ib_conn_res(iser_conn, destroy);
 918         complete(&iser_conn->ib_completion);
 919 };
 920
 921 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 922 {
 923         struct iser_conn *iser_conn;
 924         int ret = 0;
 925
 926         iser_conn = (struct iser_conn *)cma_id->context;
 927         iser_info("%s (%d): status %d conn %p id %p\n",
 928                   rdma_event_msg(event->event), event->event,
 929                   event->status, cma_id->context, cma_id);
 930
 931         mutex_lock(&iser_conn->state_mutex);
 932         switch (event->event) {
 933         case RDMA_CM_EVENT_ADDR_RESOLVED:
 934                 iser_addr_handler(cma_id);
 935                 break;
 936         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 937                 iser_route_handler(cma_id);
 938                 break;
 939         case RDMA_CM_EVENT_ESTABLISHED:
 940                 iser_connected_handler(cma_id);
 941                 break;
 942         case RDMA_CM_EVENT_ADDR_ERROR:
 943         case RDMA_CM_EVENT_ROUTE_ERROR:
 944         case RDMA_CM_EVENT_CONNECT_ERROR:
 945         case RDMA_CM_EVENT_UNREACHABLE:
 946         case RDMA_CM_EVENT_REJECTED:
 947                 iser_connect_error(cma_id);
 948                 break;
 949         case RDMA_CM_EVENT_DISCONNECTED:
 950         case RDMA_CM_EVENT_ADDR_CHANGE:
 951         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 952                 iser_cleanup_handler(cma_id, false);
 953                 break;
 954         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 955                 /*
 956                  * we *must* destroy the device as we cannot rely
 957                  * on iscsid to be around to initiate error handling.
 958                  * also if we are not in state DOWN implicitly destroy
 959                  * the cma_id.
 960                  */
 961                 iser_cleanup_handler(cma_id, true);
 962                 if (iser_conn->state != ISER_CONN_DOWN) {
 963                         iser_conn->ib_conn.cma_id = NULL;
 964                         ret = 1;
 965                 }
 966                 break;
 967         default:
 968                 iser_err("Unexpected RDMA CM event: %s (%d)\n",
 969                          rdma_event_msg(event->event), event->event);
 970                 break;
 971         }
 972         mutex_unlock(&iser_conn->state_mutex);
 973
 974         return ret;
 975 }
 976
 977 void iser_conn_init(struct iser_conn *iser_conn)
 978 {
 979         iser_conn->state = ISER_CONN_INIT;
 980         iser_conn->ib_conn.post_recv_buf_count = 0;
 981         init_completion(&iser_conn->ib_conn.flush_comp);
 982         init_completion(&iser_conn->stop_completion);
 983         init_completion(&iser_conn->ib_completion);
 984         init_completion(&iser_conn->up_completion);
 985         INIT_LIST_HEAD(&iser_conn->conn_list);
 986         mutex_init(&iser_conn->state_mutex);
 987 }
 988
 989  /**
 990  * starts the process of connecting to the target
 991  * sleeps until the connection is established or rejected
 992  */
 993 int iser_connect(struct iser_conn   *iser_conn,
 994                  struct sockaddr    *src_addr,
 995                  struct sockaddr    *dst_addr,
 996                  int                 non_blocking)
 997 {
 998         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 999         int err = 0;
1000
1001         mutex_lock(&iser_conn->state_mutex);
1002
1003         sprintf(iser_conn->name, "%pISp", dst_addr);
1004
1005         iser_info("connecting to: %s\n", iser_conn->name);
1006
1007         /* the device is known only --after-- address resolution */
1008         ib_conn->device = NULL;
1009
1010         iser_conn->state = ISER_CONN_PENDING;
1011
1012         ib_conn->beacon.wr_id = ISER_BEACON_WRID;
1013         ib_conn->beacon.opcode = IB_WR_SEND;
1014
1015         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
1016                                          (void *)iser_conn,
1017                                          RDMA_PS_TCP, IB_QPT_RC);
1018         if (IS_ERR(ib_conn->cma_id)) {
1019                 err = PTR_ERR(ib_conn->cma_id);
1020                 iser_err("rdma_create_id failed: %d\n", err);
1021                 goto id_failure;
1022         }
1023
1024         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
1025         if (err) {
1026                 iser_err("rdma_resolve_addr failed: %d\n", err);
1027                 goto addr_failure;
1028         }
1029
1030         if (!non_blocking) {
1031                 wait_for_completion_interruptible(&iser_conn->up_completion);
1032
1033                 if (iser_conn->state != ISER_CONN_UP) {
1034                         err =  -EIO;
1035                         goto connect_failure;
1036                 }
1037         }
1038         mutex_unlock(&iser_conn->state_mutex);
1039
1040         mutex_lock(&ig.connlist_mutex);
1041         list_add(&iser_conn->conn_list, &ig.connlist);
1042         mutex_unlock(&ig.connlist_mutex);
1043         return 0;
1044
1045 id_failure:
1046         ib_conn->cma_id = NULL;
1047 addr_failure:
1048         iser_conn->state = ISER_CONN_DOWN;
1049 connect_failure:
1050         mutex_unlock(&iser_conn->state_mutex);
1051         iser_conn_release(iser_conn);
1052         return err;
1053 }
1054
1055 int iser_post_recvl(struct iser_conn *iser_conn)
1056 {
1057         struct ib_recv_wr rx_wr, *rx_wr_failed;
1058         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1059         struct ib_sge     sge;
1060         int ib_ret;
1061
1062         sge.addr   = iser_conn->login_resp_dma;
1063         sge.length = ISER_RX_LOGIN_SIZE;
1064         sge.lkey   = ib_conn->device->pd->local_dma_lkey;
1065
1066         rx_wr.wr_id   = (uintptr_t)iser_conn->login_resp_buf;
1067         rx_wr.sg_list = &sge;
1068         rx_wr.num_sge = 1;
1069         rx_wr.next    = NULL;
1070
1071         ib_conn->post_recv_buf_count++;
1072         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1073         if (ib_ret) {
1074                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1075                 ib_conn->post_recv_buf_count--;
1076         }
1077         return ib_ret;
1078 }
1079
1080 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1081 {
1082         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1083         int i, ib_ret;
1084         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1085         unsigned int my_rx_head = iser_conn->rx_desc_head;
1086         struct iser_rx_desc *rx_desc;
1087
1088         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1089                 rx_desc         = &iser_conn->rx_descs[my_rx_head];
1090                 rx_wr->wr_id    = (uintptr_t)rx_desc;
1091                 rx_wr->sg_list  = &rx_desc->rx_sg;
1092                 rx_wr->num_sge  = 1;
1093                 rx_wr->next     = rx_wr + 1;
1094                 my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1095         }
1096
1097         rx_wr--;
1098         rx_wr->next = NULL; /* mark end of work requests list */
1099
1100         ib_conn->post_recv_buf_count += count;
1101         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1102         if (ib_ret) {
1103                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1104                 ib_conn->post_recv_buf_count -= count;
1105         } else
1106                 iser_conn->rx_desc_head = my_rx_head;
1107         return ib_ret;
1108 }
1109
1110
1111 /**
1112  * iser_start_send - Initiate a Send DTO operation
1113  *
1114  * returns 0 on success, -1 on failure
1115  */
1116 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1117                    bool signal)
1118 {
1119         struct ib_send_wr *bad_wr, *wr = iser_tx_next_wr(tx_desc);
1120         int ib_ret;
1121
1122         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1123                                       tx_desc->dma_addr, ISER_HEADERS_LEN,
1124                                       DMA_TO_DEVICE);
1125
1126         wr->next = NULL;
1127         wr->wr_id = (uintptr_t)tx_desc;
1128         wr->sg_list = tx_desc->tx_sg;
1129         wr->num_sge = tx_desc->num_sge;
1130         wr->opcode = IB_WR_SEND;
1131         wr->send_flags = signal ? IB_SEND_SIGNALED : 0;
1132
1133         ib_ret = ib_post_send(ib_conn->qp, &tx_desc->wrs[0], &bad_wr);
1134         if (ib_ret)
1135                 iser_err("ib_post_send failed, ret:%d opcode:%d\n",
1136                          ib_ret, bad_wr->opcode);
1137
1138         return ib_ret;
1139 }
1140
1141 /**
1142  * is_iser_tx_desc - Indicate if the completion wr_id
1143  *     is a TX descriptor or not.
1144  * @iser_conn: iser connection
1145  * @wr_id: completion WR identifier
1146  *
1147  * Since we cannot rely on wc opcode in FLUSH errors
1148  * we must work around it by checking if the wr_id address
1149  * falls in the iser connection rx_descs buffer. If so
1150  * it is an RX descriptor, otherwize it is a TX.
1151  */
1152 static inline bool
1153 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1154 {
1155         void *start = iser_conn->rx_descs;
1156         int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1157
1158         if (wr_id >= start && wr_id < start + len)
1159                 return false;
1160
1161         return true;
1162 }
1163
1164 /**
1165  * iser_handle_comp_error() - Handle error completion
1166  * @ib_conn:   connection RDMA resources
1167  * @wc:        work completion
1168  *
1169  * Notes: We may handle a FLUSH error completion and in this case
1170  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1171  *        error completion we should also notify iscsi layer that
1172  *        connection is failed (in case we passed bind stage).
1173  */
1174 static void
1175 iser_handle_comp_error(struct ib_conn *ib_conn,
1176                        struct ib_wc *wc)
1177 {
1178         void *wr_id = (void *)(uintptr_t)wc->wr_id;
1179         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1180                                                    ib_conn);
1181
1182         if (wc->status != IB_WC_WR_FLUSH_ERR)
1183                 if (iser_conn->iscsi_conn)
1184                         iscsi_conn_failure(iser_conn->iscsi_conn,
1185                                            ISCSI_ERR_CONN_FAILED);
1186
1187         if (wc->wr_id == ISER_FASTREG_LI_WRID)
1188                 return;
1189
1190         if (is_iser_tx_desc(iser_conn, wr_id)) {
1191                 struct iser_tx_desc *desc = 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 (likely(wc->status == IB_WC_SUCCESS)) {
1216                 if (wc->opcode == IB_WC_RECV) {
1217                         rx_desc = (struct iser_rx_desc *)(uintptr_t)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 *)(uintptr_t)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("%s (%d): wr id %llx vend_err %x\n",
1230                                  ib_wc_status_msg(wc->status), wc->status,
1231                                  wc->wr_id, wc->vendor_err);
1232                 else
1233                         iser_dbg("%s (%d): wr id %llx\n",
1234                                  ib_wc_status_msg(wc->status), wc->status,
1235                                  wc->wr_id);
1236
1237                 if (wc->wr_id == ISER_BEACON_WRID)
1238                         /* all flush errors were consumed */
1239                         complete(&ib_conn->flush_comp);
1240                 else
1241                         iser_handle_comp_error(ib_conn, wc);
1242         }
1243 }
1244
1245 /**
1246  * iser_cq_tasklet_fn - iSER completion polling loop
1247  * @data: iSER completion context
1248  *
1249  * Soft-IRQ context, polling connection CQ until
1250  * either CQ was empty or we exausted polling budget
1251  */
1252 static void iser_cq_tasklet_fn(unsigned long data)
1253 {
1254         struct iser_comp *comp = (struct iser_comp *)data;
1255         struct ib_cq *cq = comp->cq;
1256         struct ib_wc *const wcs = comp->wcs;
1257         int i, n, completed = 0;
1258
1259         while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1260                 for (i = 0; i < n; i++)
1261                         iser_handle_wc(&wcs[i]);
1262
1263                 completed += n;
1264                 if (completed >= iser_cq_poll_limit)
1265                         break;
1266         }
1267
1268         /*
1269          * It is assumed here that arming CQ only once its empty
1270          * would not cause interrupts to be missed.
1271          */
1272         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1273
1274         iser_dbg("got %d completions\n", completed);
1275 }
1276
1277 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1278 {
1279         struct iser_comp *comp = cq_context;
1280
1281         tasklet_schedule(&comp->tasklet);
1282 }
1283
1284 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1285                              enum iser_data_dir cmd_dir, sector_t *sector)
1286 {
1287         struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
1288         struct iser_fr_desc *desc = reg->mem_h;
1289         unsigned long sector_size = iser_task->sc->device->sector_size;
1290         struct ib_mr_status mr_status;
1291         int ret;
1292
1293         if (desc && desc->pi_ctx->sig_protected) {
1294                 desc->pi_ctx->sig_protected = 0;
1295                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1296                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1297                 if (ret) {
1298                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1299                         goto err;
1300                 }
1301
1302                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1303                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1304
1305                         do_div(sector_off, sector_size + 8);
1306                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1307
1308                         pr_err("PI error found type %d at sector %llx "
1309                                "expected %x vs actual %x\n",
1310                                mr_status.sig_err.err_type,
1311                                (unsigned long long)*sector,
1312                                mr_status.sig_err.expected,
1313                                mr_status.sig_err.actual);
1314
1315                         switch (mr_status.sig_err.err_type) {
1316                         case IB_SIG_BAD_GUARD:
1317                                 return 0x1;
1318                         case IB_SIG_BAD_REFTAG:
1319                                 return 0x3;
1320                         case IB_SIG_BAD_APPTAG:
1321                                 return 0x2;
1322                         }
1323                 }
1324         }
1325
1326         return 0;
1327 err:
1328         /* Not alot we can do here, return ambiguous guard error */
1329         return 0x1;
1330 }