drivers/infiniband/ulp/iser/iser_verbs.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/slab.h>
  37 #include <linux/delay.h>
  38
  39 #include "iscsi_iser.h"
  40
  41 #define ISCSI_ISER_MAX_CONN     8
  42 #define ISER_MAX_RX_CQ_LEN      (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
  43 #define ISER_MAX_TX_CQ_LEN      (ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
  44
  45 static void iser_cq_tasklet_fn(unsigned long data);
  46 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
  47
  48 static void iser_cq_event_callback(struct ib_event *cause, void *context)
  49 {
  50         iser_err("got cq event %d \n", cause->event);
  51 }
  52
  53 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  54 {
  55         iser_err("got qp event %d\n",cause->event);
  56 }
  57
  58 static void iser_event_handler(struct ib_event_handler *handler,
  59                                 struct ib_event *event)
  60 {
  61         iser_err("async event %d on device %s port %d\n", event->event,
  62                 event->device->name, event->element.port_num);
  63 }
  64
  65 /**
  66  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  67  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  68  * the adapator.
  69  *
  70  * returns 0 on success, -1 on failure
  71  */
  72 static int iser_create_device_ib_res(struct iser_device *device)
  73 {
  74         struct iser_cq_desc *cq_desc;
  75         struct ib_device_attr *dev_attr = &device->dev_attr;
  76         int ret, i;
  77
  78         ret = ib_query_device(device->ib_device, dev_attr);
  79         if (ret) {
  80                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  81                 return ret;
  82         }
  83
  84         /* Assign function handles  - based on FMR support */
  85         if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
  86             device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
  87                 iser_info("FMR supported, using FMR for registration\n");
  88                 device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
  89                 device->iser_free_rdma_reg_res = iser_free_fmr_pool;
  90                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
  91                 device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
  92         } else
  93         if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
  94                 iser_info("FastReg supported, using FastReg for registration\n");
  95                 device->iser_alloc_rdma_reg_res = iser_create_fastreg_pool;
  96                 device->iser_free_rdma_reg_res = iser_free_fastreg_pool;
  97                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fastreg;
  98                 device->iser_unreg_rdma_mem = iser_unreg_mem_fastreg;
  99         } else {
 100                 iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
 101                 return -1;
 102         }
 103
 104         device->cqs_used = min(ISER_MAX_CQ, device->ib_device->num_comp_vectors);
 105         iser_info("using %d CQs, device %s supports %d vectors\n",
 106                   device->cqs_used, device->ib_device->name,
 107                   device->ib_device->num_comp_vectors);
 108
 109         device->cq_desc = kmalloc(sizeof(struct iser_cq_desc) * device->cqs_used,
 110                                   GFP_KERNEL);
 111         if (device->cq_desc == NULL)
 112                 goto cq_desc_err;
 113         cq_desc = device->cq_desc;
 114
 115         device->pd = ib_alloc_pd(device->ib_device);
 116         if (IS_ERR(device->pd))
 117                 goto pd_err;
 118
 119         for (i = 0; i < device->cqs_used; i++) {
 120                 cq_desc[i].device   = device;
 121                 cq_desc[i].cq_index = i;
 122
 123                 device->rx_cq[i] = ib_create_cq(device->ib_device,
 124                                           iser_cq_callback,
 125                                           iser_cq_event_callback,
 126                                           (void *)&cq_desc[i],
 127                                           ISER_MAX_RX_CQ_LEN, i);
 128                 if (IS_ERR(device->rx_cq[i])) {
 129                         device->rx_cq[i] = NULL;
 130                         goto cq_err;
 131                 }
 132
 133                 device->tx_cq[i] = ib_create_cq(device->ib_device,
 134                                           NULL, iser_cq_event_callback,
 135                                           (void *)&cq_desc[i],
 136                                           ISER_MAX_TX_CQ_LEN, i);
 137
 138                 if (IS_ERR(device->tx_cq[i])) {
 139                         device->tx_cq[i] = NULL;
 140                         goto cq_err;
 141                 }
 142
 143                 if (ib_req_notify_cq(device->rx_cq[i], IB_CQ_NEXT_COMP))
 144                         goto cq_err;
 145
 146                 tasklet_init(&device->cq_tasklet[i],
 147                              iser_cq_tasklet_fn,
 148                         (unsigned long)&cq_desc[i]);
 149         }
 150
 151         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 152                                    IB_ACCESS_REMOTE_WRITE |
 153                                    IB_ACCESS_REMOTE_READ);
 154         if (IS_ERR(device->mr))
 155                 goto dma_mr_err;
 156
 157         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 158                                 iser_event_handler);
 159         if (ib_register_event_handler(&device->event_handler))
 160                 goto handler_err;
 161
 162         return 0;
 163
 164 handler_err:
 165         ib_dereg_mr(device->mr);
 166 dma_mr_err:
 167         for (i = 0; i < device->cqs_used; i++)
 168                 tasklet_kill(&device->cq_tasklet[i]);
 169 cq_err:
 170         for (i = 0; i < device->cqs_used; i++) {
 171                 if (device->tx_cq[i])
 172                         ib_destroy_cq(device->tx_cq[i]);
 173                 if (device->rx_cq[i])
 174                         ib_destroy_cq(device->rx_cq[i]);
 175         }
 176         ib_dealloc_pd(device->pd);
 177 pd_err:
 178         kfree(device->cq_desc);
 179 cq_desc_err:
 180         iser_err("failed to allocate an IB resource\n");
 181         return -1;
 182 }
 183
 184 /**
 185  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 186  * CQ and PD created with the device associated with the adapator.
 187  */
 188 static void iser_free_device_ib_res(struct iser_device *device)
 189 {
 190         int i;
 191         BUG_ON(device->mr == NULL);
 192
 193         for (i = 0; i < device->cqs_used; i++) {
 194                 tasklet_kill(&device->cq_tasklet[i]);
 195                 (void)ib_destroy_cq(device->tx_cq[i]);
 196                 (void)ib_destroy_cq(device->rx_cq[i]);
 197                 device->tx_cq[i] = NULL;
 198                 device->rx_cq[i] = NULL;
 199         }
 200
 201         (void)ib_unregister_event_handler(&device->event_handler);
 202         (void)ib_dereg_mr(device->mr);
 203         (void)ib_dealloc_pd(device->pd);
 204
 205         kfree(device->cq_desc);
 206
 207         device->mr = NULL;
 208         device->pd = NULL;
 209 }
 210
 211 /**
 212  * iser_create_fmr_pool - Creates FMR pool and page_vector
 213  *
 214  * returns 0 on success, or errno code on failure
 215  */
 216 int iser_create_fmr_pool(struct iser_conn *ib_conn, unsigned cmds_max)
 217 {
 218         struct iser_device *device = ib_conn->device;
 219         struct ib_fmr_pool_param params;
 220         int ret = -ENOMEM;
 221
 222         ib_conn->fmr.page_vec = kmalloc(sizeof(*ib_conn->fmr.page_vec) +
 223                                         (sizeof(u64)*(ISCSI_ISER_SG_TABLESIZE + 1)),
 224                                         GFP_KERNEL);
 225         if (!ib_conn->fmr.page_vec)
 226                 return ret;
 227
 228         ib_conn->fmr.page_vec->pages = (u64 *)(ib_conn->fmr.page_vec + 1);
 229
 230         params.page_shift        = SHIFT_4K;
 231         /* when the first/last SG element are not start/end *
 232          * page aligned, the map whould be of N+1 pages     */
 233         params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
 234         /* make the pool size twice the max number of SCSI commands *
 235          * the ML is expected to queue, watermark for unmap at 50%  */
 236         params.pool_size         = cmds_max * 2;
 237         params.dirty_watermark   = cmds_max;
 238         params.cache             = 0;
 239         params.flush_function    = NULL;
 240         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 241                                     IB_ACCESS_REMOTE_WRITE |
 242                                     IB_ACCESS_REMOTE_READ);
 243
 244         ib_conn->fmr.pool = ib_create_fmr_pool(device->pd, &params);
 245         if (!IS_ERR(ib_conn->fmr.pool))
 246                 return 0;
 247
 248         /* no FMR => no need for page_vec */
 249         kfree(ib_conn->fmr.page_vec);
 250         ib_conn->fmr.page_vec = NULL;
 251
 252         ret = PTR_ERR(ib_conn->fmr.pool);
 253         ib_conn->fmr.pool = NULL;
 254         if (ret != -ENOSYS) {
 255                 iser_err("FMR allocation failed, err %d\n", ret);
 256                 return ret;
 257         } else {
 258                 iser_warn("FMRs are not supported, using unaligned mode\n");
 259                 return 0;
 260         }
 261 }
 262
 263 /**
 264  * iser_free_fmr_pool - releases the FMR pool and page vec
 265  */
 266 void iser_free_fmr_pool(struct iser_conn *ib_conn)
 267 {
 268         iser_info("freeing conn %p fmr pool %p\n",
 269                   ib_conn, ib_conn->fmr.pool);
 270
 271         if (ib_conn->fmr.pool != NULL)
 272                 ib_destroy_fmr_pool(ib_conn->fmr.pool);
 273
 274         ib_conn->fmr.pool = NULL;
 275
 276         kfree(ib_conn->fmr.page_vec);
 277         ib_conn->fmr.page_vec = NULL;
 278 }
 279
 280 static int
 281 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
 282                          bool pi_enable, struct fast_reg_descriptor *desc)
 283 {
 284         int ret;
 285
 286         desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
 287                                                       ISCSI_ISER_SG_TABLESIZE + 1);
 288         if (IS_ERR(desc->data_frpl)) {
 289                 ret = PTR_ERR(desc->data_frpl);
 290                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 291                          ret);
 292                 return PTR_ERR(desc->data_frpl);
 293         }
 294
 295         desc->data_mr = ib_alloc_fast_reg_mr(pd, ISCSI_ISER_SG_TABLESIZE + 1);
 296         if (IS_ERR(desc->data_mr)) {
 297                 ret = PTR_ERR(desc->data_mr);
 298                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 299                 goto fast_reg_mr_failure;
 300         }
 301         desc->reg_indicators |= ISER_DATA_KEY_VALID;
 302
 303         if (pi_enable) {
 304                 struct ib_mr_init_attr mr_init_attr = {0};
 305                 struct iser_pi_context *pi_ctx = NULL;
 306
 307                 desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 308                 if (!desc->pi_ctx) {
 309                         iser_err("Failed to allocate pi context\n");
 310                         ret = -ENOMEM;
 311                         goto pi_ctx_alloc_failure;
 312                 }
 313                 pi_ctx = desc->pi_ctx;
 314
 315                 pi_ctx->prot_frpl = ib_alloc_fast_reg_page_list(ib_device,
 316                                                     ISCSI_ISER_SG_TABLESIZE);
 317                 if (IS_ERR(pi_ctx->prot_frpl)) {
 318                         ret = PTR_ERR(pi_ctx->prot_frpl);
 319                         iser_err("Failed to allocate prot frpl ret=%d\n",
 320                                  ret);
 321                         goto prot_frpl_failure;
 322                 }
 323
 324                 pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd,
 325                                                 ISCSI_ISER_SG_TABLESIZE + 1);
 326                 if (IS_ERR(pi_ctx->prot_mr)) {
 327                         ret = PTR_ERR(pi_ctx->prot_mr);
 328                         iser_err("Failed to allocate prot frmr ret=%d\n",
 329                                  ret);
 330                         goto prot_mr_failure;
 331                 }
 332                 desc->reg_indicators |= ISER_PROT_KEY_VALID;
 333
 334                 mr_init_attr.max_reg_descriptors = 2;
 335                 mr_init_attr.flags |= IB_MR_SIGNATURE_EN;
 336                 pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
 337                 if (IS_ERR(pi_ctx->sig_mr)) {
 338                         ret = PTR_ERR(pi_ctx->sig_mr);
 339                         iser_err("Failed to allocate signature enabled mr err=%d\n",
 340                                  ret);
 341                         goto sig_mr_failure;
 342                 }
 343                 desc->reg_indicators |= ISER_SIG_KEY_VALID;
 344         }
 345         desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
 346
 347         iser_dbg("Create fr_desc %p page_list %p\n",
 348                  desc, desc->data_frpl->page_list);
 349
 350         return 0;
 351 sig_mr_failure:
 352         ib_dereg_mr(desc->pi_ctx->prot_mr);
 353 prot_mr_failure:
 354         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 355 prot_frpl_failure:
 356         kfree(desc->pi_ctx);
 357 pi_ctx_alloc_failure:
 358         ib_dereg_mr(desc->data_mr);
 359 fast_reg_mr_failure:
 360         ib_free_fast_reg_page_list(desc->data_frpl);
 361
 362         return ret;
 363 }
 364
 365 /**
 366  * iser_create_fastreg_pool - Creates pool of fast_reg descriptors
 367  * for fast registration work requests.
 368  * returns 0 on success, or errno code on failure
 369  */
 370 int iser_create_fastreg_pool(struct iser_conn *ib_conn, unsigned cmds_max)
 371 {
 372         struct iser_device      *device = ib_conn->device;
 373         struct fast_reg_descriptor      *desc;
 374         int i, ret;
 375
 376         INIT_LIST_HEAD(&ib_conn->fastreg.pool);
 377         ib_conn->fastreg.pool_size = 0;
 378         for (i = 0; i < cmds_max; i++) {
 379                 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 380                 if (!desc) {
 381                         iser_err("Failed to allocate a new fast_reg descriptor\n");
 382                         ret = -ENOMEM;
 383                         goto err;
 384                 }
 385
 386                 ret = iser_create_fastreg_desc(device->ib_device, device->pd,
 387                                                ib_conn->pi_support, desc);
 388                 if (ret) {
 389                         iser_err("Failed to create fastreg descriptor err=%d\n",
 390                                  ret);
 391                         kfree(desc);
 392                         goto err;
 393                 }
 394
 395                 list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 396                 ib_conn->fastreg.pool_size++;
 397         }
 398
 399         return 0;
 400
 401 err:
 402         iser_free_fastreg_pool(ib_conn);
 403         return ret;
 404 }
 405
 406 /**
 407  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 408  */
 409 void iser_free_fastreg_pool(struct iser_conn *ib_conn)
 410 {
 411         struct fast_reg_descriptor *desc, *tmp;
 412         int i = 0;
 413
 414         if (list_empty(&ib_conn->fastreg.pool))
 415                 return;
 416
 417         iser_info("freeing conn %p fr pool\n", ib_conn);
 418
 419         list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
 420                 list_del(&desc->list);
 421                 ib_free_fast_reg_page_list(desc->data_frpl);
 422                 ib_dereg_mr(desc->data_mr);
 423                 if (desc->pi_ctx) {
 424                         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 425                         ib_dereg_mr(desc->pi_ctx->prot_mr);
 426                         ib_destroy_mr(desc->pi_ctx->sig_mr);
 427                         kfree(desc->pi_ctx);
 428                 }
 429                 kfree(desc);
 430                 ++i;
 431         }
 432
 433         if (i < ib_conn->fastreg.pool_size)
 434                 iser_warn("pool still has %d regions registered\n",
 435                           ib_conn->fastreg.pool_size - i);
 436 }
 437
 438 /**
 439  * iser_create_ib_conn_res - Queue-Pair (QP)
 440  *
 441  * returns 0 on success, -1 on failure
 442  */
 443 static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
 444 {
 445         struct iser_device      *device;
 446         struct ib_qp_init_attr  init_attr;
 447         int                     ret = -ENOMEM;
 448         int index, min_index = 0;
 449
 450         BUG_ON(ib_conn->device == NULL);
 451
 452         device = ib_conn->device;
 453
 454         memset(&init_attr, 0, sizeof init_attr);
 455
 456         mutex_lock(&ig.connlist_mutex);
 457         /* select the CQ with the minimal number of usages */
 458         for (index = 0; index < device->cqs_used; index++)
 459                 if (device->cq_active_qps[index] <
 460                     device->cq_active_qps[min_index])
 461                         min_index = index;
 462         device->cq_active_qps[min_index]++;
 463         mutex_unlock(&ig.connlist_mutex);
 464         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 465
 466         init_attr.event_handler = iser_qp_event_callback;
 467         init_attr.qp_context    = (void *)ib_conn;
 468         init_attr.send_cq       = device->tx_cq[min_index];
 469         init_attr.recv_cq       = device->rx_cq[min_index];
 470         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 471         init_attr.cap.max_send_sge = 2;
 472         init_attr.cap.max_recv_sge = 1;
 473         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 474         init_attr.qp_type       = IB_QPT_RC;
 475         if (ib_conn->pi_support) {
 476                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS;
 477                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 478         } else {
 479                 init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS;
 480         }
 481
 482         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 483         if (ret)
 484                 goto out_err;
 485
 486         ib_conn->qp = ib_conn->cma_id->qp;
 487         iser_info("setting conn %p cma_id %p qp %p\n",
 488                   ib_conn, ib_conn->cma_id,
 489                   ib_conn->cma_id->qp);
 490         return ret;
 491
 492 out_err:
 493         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 494         return ret;
 495 }
 496
 497 /**
 498  * releases the QP object
 499  */
 500 static void iser_free_ib_conn_res(struct iser_conn *ib_conn)
 501 {
 502         int cq_index;
 503         BUG_ON(ib_conn == NULL);
 504
 505         iser_info("freeing conn %p cma_id %p qp %p\n",
 506                   ib_conn, ib_conn->cma_id,
 507                   ib_conn->qp);
 508
 509         /* qp is created only once both addr & route are resolved */
 510
 511         if (ib_conn->qp != NULL) {
 512                 cq_index = ((struct iser_cq_desc *)ib_conn->qp->recv_cq->cq_context)->cq_index;
 513                 ib_conn->device->cq_active_qps[cq_index]--;
 514
 515                 rdma_destroy_qp(ib_conn->cma_id);
 516         }
 517
 518         ib_conn->qp       = NULL;
 519 }
 520
 521 /**
 522  * based on the resolved device node GUID see if there already allocated
 523  * device for this device. If there's no such, create one.
 524  */
 525 static
 526 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 527 {
 528         struct iser_device *device;
 529
 530         mutex_lock(&ig.device_list_mutex);
 531
 532         list_for_each_entry(device, &ig.device_list, ig_list)
 533                 /* find if there's a match using the node GUID */
 534                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 535                         goto inc_refcnt;
 536
 537         device = kzalloc(sizeof *device, GFP_KERNEL);
 538         if (device == NULL)
 539                 goto out;
 540
 541         /* assign this device to the device */
 542         device->ib_device = cma_id->device;
 543         /* init the device and link it into ig device list */
 544         if (iser_create_device_ib_res(device)) {
 545                 kfree(device);
 546                 device = NULL;
 547                 goto out;
 548         }
 549         list_add(&device->ig_list, &ig.device_list);
 550
 551 inc_refcnt:
 552         device->refcount++;
 553 out:
 554         mutex_unlock(&ig.device_list_mutex);
 555         return device;
 556 }
 557
 558 /* if there's no demand for this device, release it */
 559 static void iser_device_try_release(struct iser_device *device)
 560 {
 561         mutex_lock(&ig.device_list_mutex);
 562         device->refcount--;
 563         iser_info("device %p refcount %d\n", device, device->refcount);
 564         if (!device->refcount) {
 565                 iser_free_device_ib_res(device);
 566                 list_del(&device->ig_list);
 567                 kfree(device);
 568         }
 569         mutex_unlock(&ig.device_list_mutex);
 570 }
 571
 572 /**
 573  * Called with state mutex held
 574  **/
 575 static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
 576                                      enum iser_ib_conn_state comp,
 577                                      enum iser_ib_conn_state exch)
 578 {
 579         int ret;
 580
 581         if ((ret = (ib_conn->state == comp)))
 582                 ib_conn->state = exch;
 583         return ret;
 584 }
 585
 586 void iser_release_work(struct work_struct *work)
 587 {
 588         struct iser_conn *ib_conn;
 589         int rc;
 590
 591         ib_conn = container_of(work, struct iser_conn, release_work);
 592
 593         /* wait for .conn_stop callback */
 594         rc = wait_for_completion_timeout(&ib_conn->stop_completion, 30 * HZ);
 595         WARN_ON(rc == 0);
 596
 597         /* wait for the qp`s post send and post receive buffers to empty */
 598         rc = wait_for_completion_timeout(&ib_conn->flush_completion, 30 * HZ);
 599         WARN_ON(rc == 0);
 600
 601         ib_conn->state = ISER_CONN_DOWN;
 602
 603         mutex_lock(&ib_conn->state_mutex);
 604         ib_conn->state = ISER_CONN_DOWN;
 605         mutex_unlock(&ib_conn->state_mutex);
 606
 607         iser_conn_release(ib_conn);
 608 }
 609
 610 /**
 611  * Frees all conn objects and deallocs conn descriptor
 612  */
 613 void iser_conn_release(struct iser_conn *ib_conn)
 614 {
 615         struct iser_device  *device = ib_conn->device;
 616
 617         mutex_lock(&ig.connlist_mutex);
 618         list_del(&ib_conn->conn_list);
 619         mutex_unlock(&ig.connlist_mutex);
 620
 621         mutex_lock(&ib_conn->state_mutex);
 622         BUG_ON(ib_conn->state != ISER_CONN_DOWN);
 623
 624         iser_free_rx_descriptors(ib_conn);
 625         iser_free_ib_conn_res(ib_conn);
 626         ib_conn->device = NULL;
 627         /* on EVENT_ADDR_ERROR there's no device yet for this conn */
 628         if (device != NULL)
 629                 iser_device_try_release(device);
 630         mutex_unlock(&ib_conn->state_mutex);
 631
 632         /* if cma handler context, the caller actually destroy the id */
 633         if (ib_conn->cma_id != NULL) {
 634                 rdma_destroy_id(ib_conn->cma_id);
 635                 ib_conn->cma_id = NULL;
 636         }
 637         kfree(ib_conn);
 638 }
 639
 640 /**
 641  * triggers start of the disconnect procedures and wait for them to be done
 642  */
 643 void iser_conn_terminate(struct iser_conn *ib_conn)
 644 {
 645         int err = 0;
 646
 647         /* change the ib conn state only if the conn is UP, however always call
 648          * rdma_disconnect since this is the only way to cause the CMA to change
 649          * the QP state to ERROR
 650          */
 651
 652         iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
 653         err = rdma_disconnect(ib_conn->cma_id);
 654         if (err)
 655                 iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 656                          ib_conn,err);
 657 }
 658
 659 /**
 660  * Called with state mutex held
 661  **/
 662 static void iser_connect_error(struct rdma_cm_id *cma_id)
 663 {
 664         struct iser_conn *ib_conn;
 665
 666         ib_conn = (struct iser_conn *)cma_id->context;
 667         ib_conn->state = ISER_CONN_DOWN;
 668 }
 669
 670 /**
 671  * Called with state mutex held
 672  **/
 673 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 674 {
 675         struct iser_device *device;
 676         struct iser_conn   *ib_conn;
 677         int    ret;
 678
 679         ib_conn = (struct iser_conn *)cma_id->context;
 680         if (ib_conn->state != ISER_CONN_PENDING)
 681                 /* bailout */
 682                 return;
 683
 684         device = iser_device_find_by_ib_device(cma_id);
 685         if (!device) {
 686                 iser_err("device lookup/creation failed\n");
 687                 iser_connect_error(cma_id);
 688                 return;
 689         }
 690
 691         ib_conn->device = device;
 692
 693         /* connection T10-PI support */
 694         if (iser_pi_enable) {
 695                 if (!(device->dev_attr.device_cap_flags &
 696                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 697                         iser_warn("T10-PI requested but not supported on %s, "
 698                                   "continue without T10-PI\n",
 699                                   ib_conn->device->ib_device->name);
 700                         ib_conn->pi_support = false;
 701                 } else {
 702                         ib_conn->pi_support = true;
 703                 }
 704         }
 705
 706         ret = rdma_resolve_route(cma_id, 1000);
 707         if (ret) {
 708                 iser_err("resolve route failed: %d\n", ret);
 709                 iser_connect_error(cma_id);
 710                 return;
 711         }
 712 }
 713
 714 /**
 715  * Called with state mutex held
 716  **/
 717 static void iser_route_handler(struct rdma_cm_id *cma_id)
 718 {
 719         struct rdma_conn_param conn_param;
 720         int    ret;
 721         struct iser_cm_hdr req_hdr;
 722         struct iser_conn *ib_conn = (struct iser_conn *)cma_id->context;
 723         struct iser_device *device = ib_conn->device;
 724
 725         if (ib_conn->state != ISER_CONN_PENDING)
 726                 /* bailout */
 727                 return;
 728
 729         ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
 730         if (ret)
 731                 goto failure;
 732
 733         memset(&conn_param, 0, sizeof conn_param);
 734         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 735         conn_param.initiator_depth     = 1;
 736         conn_param.retry_count         = 7;
 737         conn_param.rnr_retry_count     = 6;
 738
 739         memset(&req_hdr, 0, sizeof(req_hdr));
 740         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 741                         ISER_SEND_W_INV_NOT_SUPPORTED);
 742         conn_param.private_data         = (void *)&req_hdr;
 743         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 744
 745         ret = rdma_connect(cma_id, &conn_param);
 746         if (ret) {
 747                 iser_err("failure connecting: %d\n", ret);
 748                 goto failure;
 749         }
 750
 751         return;
 752 failure:
 753         iser_connect_error(cma_id);
 754 }
 755
 756 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 757 {
 758         struct iser_conn *ib_conn;
 759         struct ib_qp_attr attr;
 760         struct ib_qp_init_attr init_attr;
 761
 762         ib_conn = (struct iser_conn *)cma_id->context;
 763         if (ib_conn->state != ISER_CONN_PENDING)
 764                 /* bailout */
 765                 return;
 766
 767         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 768         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 769
 770         ib_conn->state = ISER_CONN_UP;
 771         complete(&ib_conn->up_completion);
 772 }
 773
 774 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 775 {
 776         struct iser_conn *ib_conn;
 777
 778         ib_conn = (struct iser_conn *)cma_id->context;
 779
 780         /* getting here when the state is UP means that the conn is being *
 781          * terminated asynchronously from the iSCSI layer's perspective.  */
 782         if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
 783                                         ISER_CONN_TERMINATING)){
 784                 if (ib_conn->iscsi_conn)
 785                         iscsi_conn_failure(ib_conn->iscsi_conn, ISCSI_ERR_CONN_FAILED);
 786                 else
 787                         iser_err("iscsi_iser connection isn't bound\n");
 788         }
 789
 790         /* Complete the termination process if no posts are pending. This code
 791          * block also exists in iser_handle_comp_error(), but it is needed here
 792          * for cases of no flushes at all, e.g. discovery over rdma.
 793          */
 794         if (ib_conn->post_recv_buf_count == 0 &&
 795             (atomic_read(&ib_conn->post_send_buf_count) == 0)) {
 796                 complete(&ib_conn->flush_completion);
 797         }
 798 }
 799
 800 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 801 {
 802         struct iser_conn *ib_conn;
 803
 804         ib_conn = (struct iser_conn *)cma_id->context;
 805         iser_info("event %d status %d conn %p id %p\n",
 806                   event->event, event->status, cma_id->context, cma_id);
 807
 808         mutex_lock(&ib_conn->state_mutex);
 809         switch (event->event) {
 810         case RDMA_CM_EVENT_ADDR_RESOLVED:
 811                 iser_addr_handler(cma_id);
 812                 break;
 813         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 814                 iser_route_handler(cma_id);
 815                 break;
 816         case RDMA_CM_EVENT_ESTABLISHED:
 817                 iser_connected_handler(cma_id);
 818                 break;
 819         case RDMA_CM_EVENT_ADDR_ERROR:
 820         case RDMA_CM_EVENT_ROUTE_ERROR:
 821         case RDMA_CM_EVENT_CONNECT_ERROR:
 822         case RDMA_CM_EVENT_UNREACHABLE:
 823         case RDMA_CM_EVENT_REJECTED:
 824                 iser_connect_error(cma_id);
 825                 break;
 826         case RDMA_CM_EVENT_DISCONNECTED:
 827         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 828         case RDMA_CM_EVENT_ADDR_CHANGE:
 829         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 830                 iser_disconnected_handler(cma_id);
 831                 break;
 832         default:
 833                 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
 834                 break;
 835         }
 836         mutex_unlock(&ib_conn->state_mutex);
 837         return 0;
 838 }
 839
 840 void iser_conn_init(struct iser_conn *ib_conn)
 841 {
 842         ib_conn->state = ISER_CONN_INIT;
 843         ib_conn->post_recv_buf_count = 0;
 844         atomic_set(&ib_conn->post_send_buf_count, 0);
 845         init_completion(&ib_conn->stop_completion);
 846         init_completion(&ib_conn->flush_completion);
 847         init_completion(&ib_conn->up_completion);
 848         INIT_LIST_HEAD(&ib_conn->conn_list);
 849         spin_lock_init(&ib_conn->lock);
 850         mutex_init(&ib_conn->state_mutex);
 851 }
 852
 853  /**
 854  * starts the process of connecting to the target
 855  * sleeps until the connection is established or rejected
 856  */
 857 int iser_connect(struct iser_conn   *ib_conn,
 858                  struct sockaddr    *src_addr,
 859                  struct sockaddr    *dst_addr,
 860                  int                 non_blocking)
 861 {
 862         int err = 0;
 863
 864         mutex_lock(&ib_conn->state_mutex);
 865
 866         sprintf(ib_conn->name, "%pISp", dst_addr);
 867
 868         iser_info("connecting to: %s\n", ib_conn->name);
 869
 870         /* the device is known only --after-- address resolution */
 871         ib_conn->device = NULL;
 872
 873         ib_conn->state = ISER_CONN_PENDING;
 874
 875         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 876                                              (void *)ib_conn,
 877                                              RDMA_PS_TCP, IB_QPT_RC);
 878         if (IS_ERR(ib_conn->cma_id)) {
 879                 err = PTR_ERR(ib_conn->cma_id);
 880                 iser_err("rdma_create_id failed: %d\n", err);
 881                 goto id_failure;
 882         }
 883
 884         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 885         if (err) {
 886                 iser_err("rdma_resolve_addr failed: %d\n", err);
 887                 goto addr_failure;
 888         }
 889
 890         if (!non_blocking) {
 891                 wait_for_completion_interruptible(&ib_conn->up_completion);
 892
 893                 if (ib_conn->state != ISER_CONN_UP) {
 894                         err =  -EIO;
 895                         goto connect_failure;
 896                 }
 897         }
 898         mutex_unlock(&ib_conn->state_mutex);
 899
 900         mutex_lock(&ig.connlist_mutex);
 901         list_add(&ib_conn->conn_list, &ig.connlist);
 902         mutex_unlock(&ig.connlist_mutex);
 903         return 0;
 904
 905 id_failure:
 906         ib_conn->cma_id = NULL;
 907 addr_failure:
 908         ib_conn->state = ISER_CONN_DOWN;
 909 connect_failure:
 910         mutex_unlock(&ib_conn->state_mutex);
 911         iser_conn_release(ib_conn);
 912         return err;
 913 }
 914
 915 /**
 916  * iser_reg_page_vec - Register physical memory
 917  *
 918  * returns: 0 on success, errno code on failure
 919  */
 920 int iser_reg_page_vec(struct iser_conn     *ib_conn,
 921                       struct iser_page_vec *page_vec,
 922                       struct iser_mem_reg  *mem_reg)
 923 {
 924         struct ib_pool_fmr *mem;
 925         u64                io_addr;
 926         u64                *page_list;
 927         int                status;
 928
 929         page_list = page_vec->pages;
 930         io_addr   = page_list[0];
 931
 932         mem  = ib_fmr_pool_map_phys(ib_conn->fmr.pool,
 933                                     page_list,
 934                                     page_vec->length,
 935                                     io_addr);
 936
 937         if (IS_ERR(mem)) {
 938                 status = (int)PTR_ERR(mem);
 939                 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
 940                 return status;
 941         }
 942
 943         mem_reg->lkey  = mem->fmr->lkey;
 944         mem_reg->rkey  = mem->fmr->rkey;
 945         mem_reg->len   = page_vec->length * SIZE_4K;
 946         mem_reg->va    = io_addr;
 947         mem_reg->is_mr = 1;
 948         mem_reg->mem_h = (void *)mem;
 949
 950         mem_reg->va   += page_vec->offset;
 951         mem_reg->len   = page_vec->data_size;
 952
 953         iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
 954                  "entry[0]: (0x%08lx,%ld)] -> "
 955                  "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
 956                  page_vec, page_vec->length,
 957                  (unsigned long)page_vec->pages[0],
 958                  (unsigned long)page_vec->data_size,
 959                  (unsigned int)mem_reg->lkey, mem_reg->mem_h,
 960                  (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
 961         return 0;
 962 }
 963
 964 /**
 965  * Unregister (previosuly registered using FMR) memory.
 966  * If memory is non-FMR does nothing.
 967  */
 968 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
 969                         enum iser_data_dir cmd_dir)
 970 {
 971         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 972         int ret;
 973
 974         if (!reg->is_mr)
 975                 return;
 976
 977         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
 978
 979         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
 980         if (ret)
 981                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
 982
 983         reg->mem_h = NULL;
 984 }
 985
 986 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 987                             enum iser_data_dir cmd_dir)
 988 {
 989         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 990         struct iser_conn *ib_conn = iser_task->ib_conn;
 991         struct fast_reg_descriptor *desc = reg->mem_h;
 992
 993         if (!reg->is_mr)
 994                 return;
 995
 996         reg->mem_h = NULL;
 997         reg->is_mr = 0;
 998         spin_lock_bh(&ib_conn->lock);
 999         list_add_tail(&desc->list, &ib_conn->fastreg.pool);
1000         spin_unlock_bh(&ib_conn->lock);
1001 }
1002
1003 int iser_post_recvl(struct iser_conn *ib_conn)
1004 {
1005         struct ib_recv_wr rx_wr, *rx_wr_failed;
1006         struct ib_sge     sge;
1007         int ib_ret;
1008
1009         sge.addr   = ib_conn->login_resp_dma;
1010         sge.length = ISER_RX_LOGIN_SIZE;
1011         sge.lkey   = ib_conn->device->mr->lkey;
1012
1013         rx_wr.wr_id   = (unsigned long)ib_conn->login_resp_buf;
1014         rx_wr.sg_list = &sge;
1015         rx_wr.num_sge = 1;
1016         rx_wr.next    = NULL;
1017
1018         ib_conn->post_recv_buf_count++;
1019         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1020         if (ib_ret) {
1021                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1022                 ib_conn->post_recv_buf_count--;
1023         }
1024         return ib_ret;
1025 }
1026
1027 int iser_post_recvm(struct iser_conn *ib_conn, int count)
1028 {
1029         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1030         int i, ib_ret;
1031         unsigned int my_rx_head = ib_conn->rx_desc_head;
1032         struct iser_rx_desc *rx_desc;
1033
1034         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1035                 rx_desc         = &ib_conn->rx_descs[my_rx_head];
1036                 rx_wr->wr_id    = (unsigned long)rx_desc;
1037                 rx_wr->sg_list  = &rx_desc->rx_sg;
1038                 rx_wr->num_sge  = 1;
1039                 rx_wr->next     = rx_wr + 1;
1040                 my_rx_head = (my_rx_head + 1) & ib_conn->qp_max_recv_dtos_mask;
1041         }
1042
1043         rx_wr--;
1044         rx_wr->next = NULL; /* mark end of work requests list */
1045
1046         ib_conn->post_recv_buf_count += count;
1047         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1048         if (ib_ret) {
1049                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1050                 ib_conn->post_recv_buf_count -= count;
1051         } else
1052                 ib_conn->rx_desc_head = my_rx_head;
1053         return ib_ret;
1054 }
1055
1056
1057 /**
1058  * iser_start_send - Initiate a Send DTO operation
1059  *
1060  * returns 0 on success, -1 on failure
1061  */
1062 int iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc)
1063 {
1064         int               ib_ret;
1065         struct ib_send_wr send_wr, *send_wr_failed;
1066
1067         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1068                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
1069
1070         send_wr.next       = NULL;
1071         send_wr.wr_id      = (unsigned long)tx_desc;
1072         send_wr.sg_list    = tx_desc->tx_sg;
1073         send_wr.num_sge    = tx_desc->num_sge;
1074         send_wr.opcode     = IB_WR_SEND;
1075         send_wr.send_flags = IB_SEND_SIGNALED;
1076
1077         atomic_inc(&ib_conn->post_send_buf_count);
1078
1079         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1080         if (ib_ret) {
1081                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1082                 atomic_dec(&ib_conn->post_send_buf_count);
1083         }
1084         return ib_ret;
1085 }
1086
1087 static void iser_handle_comp_error(struct iser_tx_desc *desc,
1088                                 struct iser_conn *ib_conn)
1089 {
1090         if (desc && desc->type == ISCSI_TX_DATAOUT)
1091                 kmem_cache_free(ig.desc_cache, desc);
1092
1093         if (ib_conn->post_recv_buf_count == 0 &&
1094             atomic_read(&ib_conn->post_send_buf_count) == 0) {
1095                 /**
1096                  * getting here when the state is UP means that the conn is
1097                  * being terminated asynchronously from the iSCSI layer's
1098                  * perspective. It is safe to peek at the connection state
1099                  * since iscsi_conn_failure is allowed to be called twice.
1100                  **/
1101                 if (ib_conn->state == ISER_CONN_UP)
1102                         iscsi_conn_failure(ib_conn->iscsi_conn,
1103                                            ISCSI_ERR_CONN_FAILED);
1104
1105                 /* no more non completed posts to the QP, complete the
1106                  * termination process w.o worrying on disconnect event */
1107                 complete(&ib_conn->flush_completion);
1108         }
1109 }
1110
1111 static int iser_drain_tx_cq(struct iser_device  *device, int cq_index)
1112 {
1113         struct ib_cq  *cq = device->tx_cq[cq_index];
1114         struct ib_wc  wc;
1115         struct iser_tx_desc *tx_desc;
1116         struct iser_conn *ib_conn;
1117         int completed_tx = 0;
1118
1119         while (ib_poll_cq(cq, 1, &wc) == 1) {
1120                 tx_desc = (struct iser_tx_desc *) (unsigned long) wc.wr_id;
1121                 ib_conn = wc.qp->qp_context;
1122                 if (wc.status == IB_WC_SUCCESS) {
1123                         if (wc.opcode == IB_WC_SEND)
1124                                 iser_snd_completion(tx_desc, ib_conn);
1125                         else
1126                                 iser_err("expected opcode %d got %d\n",
1127                                         IB_WC_SEND, wc.opcode);
1128                 } else {
1129                         iser_err("tx id %llx status %d vend_err %x\n",
1130                                  wc.wr_id, wc.status, wc.vendor_err);
1131                         if (wc.wr_id != ISER_FASTREG_LI_WRID) {
1132                                 atomic_dec(&ib_conn->post_send_buf_count);
1133                                 iser_handle_comp_error(tx_desc, ib_conn);
1134                         }
1135                 }
1136                 completed_tx++;
1137         }
1138         return completed_tx;
1139 }
1140
1141
1142 static void iser_cq_tasklet_fn(unsigned long data)
1143 {
1144         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)data;
1145         struct iser_device  *device = cq_desc->device;
1146         int cq_index = cq_desc->cq_index;
1147         struct ib_cq         *cq = device->rx_cq[cq_index];
1148          struct ib_wc        wc;
1149          struct iser_rx_desc *desc;
1150          unsigned long       xfer_len;
1151         struct iser_conn *ib_conn;
1152         int completed_tx, completed_rx = 0;
1153
1154         /* First do tx drain, so in a case where we have rx flushes and a successful
1155          * tx completion we will still go through completion error handling.
1156          */
1157         completed_tx = iser_drain_tx_cq(device, cq_index);
1158
1159         while (ib_poll_cq(cq, 1, &wc) == 1) {
1160                 desc     = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
1161                 BUG_ON(desc == NULL);
1162                 ib_conn = wc.qp->qp_context;
1163                 if (wc.status == IB_WC_SUCCESS) {
1164                         if (wc.opcode == IB_WC_RECV) {
1165                                 xfer_len = (unsigned long)wc.byte_len;
1166                                 iser_rcv_completion(desc, xfer_len, ib_conn);
1167                         } else
1168                                 iser_err("expected opcode %d got %d\n",
1169                                         IB_WC_RECV, wc.opcode);
1170                 } else {
1171                         if (wc.status != IB_WC_WR_FLUSH_ERR)
1172                                 iser_err("rx id %llx status %d vend_err %x\n",
1173                                         wc.wr_id, wc.status, wc.vendor_err);
1174                         ib_conn->post_recv_buf_count--;
1175                         iser_handle_comp_error(NULL, ib_conn);
1176                 }
1177                 completed_rx++;
1178                 if (!(completed_rx & 63))
1179                         completed_tx += iser_drain_tx_cq(device, cq_index);
1180         }
1181         /* #warning "it is assumed here that arming CQ only once its empty" *
1182          * " would not cause interrupts to be missed"                       */
1183         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1184
1185         iser_dbg("got %d rx %d tx completions\n", completed_rx, completed_tx);
1186 }
1187
1188 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1189 {
1190         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)cq_context;
1191         struct iser_device  *device = cq_desc->device;
1192         int cq_index = cq_desc->cq_index;
1193
1194         tasklet_schedule(&device->cq_tasklet[cq_index]);
1195 }
1196
1197 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1198                              enum iser_data_dir cmd_dir, sector_t *sector)
1199 {
1200         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1201         struct fast_reg_descriptor *desc = reg->mem_h;
1202         unsigned long sector_size = iser_task->sc->device->sector_size;
1203         struct ib_mr_status mr_status;
1204         int ret;
1205
1206         if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1207                 desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1208                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1209                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1210                 if (ret) {
1211                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1212                         goto err;
1213                 }
1214
1215                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1216                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1217
1218                         do_div(sector_off, sector_size + 8);
1219                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1220
1221                         pr_err("PI error found type %d at sector %llx "
1222                                "expected %x vs actual %x\n",
1223                                mr_status.sig_err.err_type,
1224                                (unsigned long long)*sector,
1225                                mr_status.sig_err.expected,
1226                                mr_status.sig_err.actual);
1227
1228                         switch (mr_status.sig_err.err_type) {
1229                         case IB_SIG_BAD_GUARD:
1230                                 return 0x1;
1231                         case IB_SIG_BAD_REFTAG:
1232                                 return 0x3;
1233                         case IB_SIG_BAD_APPTAG:
1234                                 return 0x2;
1235                         }
1236                 }
1237         }
1238
1239         return 0;
1240 err:
1241         /* Not alot we can do here, return ambiguous guard error */
1242         return 0x1;
1243 }