drivers/infiniband/ulp/iser/iser_verbs.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/slab.h>
  37 #include <linux/delay.h>
  38
  39 #include "iscsi_iser.h"
  40
  41 #define ISCSI_ISER_MAX_CONN     8
  42 #define ISER_MAX_RX_LEN         (ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
  43 #define ISER_MAX_TX_LEN         (ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
  44 #define ISER_MAX_CQ_LEN         (ISER_MAX_RX_LEN + ISER_MAX_TX_LEN + \
  45                                  ISCSI_ISER_MAX_CONN)
  46
  47 static int iser_cq_poll_limit = 512;
  48
  49 static void iser_cq_tasklet_fn(unsigned long data);
  50 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
  51
  52 static void iser_cq_event_callback(struct ib_event *cause, void *context)
  53 {
  54         iser_err("got cq event %d \n", cause->event);
  55 }
  56
  57 static void iser_qp_event_callback(struct ib_event *cause, void *context)
  58 {
  59         iser_err("got qp event %d\n",cause->event);
  60 }
  61
  62 static void iser_event_handler(struct ib_event_handler *handler,
  63                                 struct ib_event *event)
  64 {
  65         iser_err("async event %d on device %s port %d\n", event->event,
  66                 event->device->name, event->element.port_num);
  67 }
  68
  69 /**
  70  * iser_create_device_ib_res - creates Protection Domain (PD), Completion
  71  * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
  72  * the adapator.
  73  *
  74  * returns 0 on success, -1 on failure
  75  */
  76 static int iser_create_device_ib_res(struct iser_device *device)
  77 {
  78         struct ib_device_attr *dev_attr = &device->dev_attr;
  79         int ret, i, max_cqe;
  80
  81         ret = ib_query_device(device->ib_device, dev_attr);
  82         if (ret) {
  83                 pr_warn("Query device failed for %s\n", device->ib_device->name);
  84                 return ret;
  85         }
  86
  87         /* Assign function handles  - based on FMR support */
  88         if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
  89             device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
  90                 iser_info("FMR supported, using FMR for registration\n");
  91                 device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
  92                 device->iser_free_rdma_reg_res = iser_free_fmr_pool;
  93                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
  94                 device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
  95         } else
  96         if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
  97                 iser_info("FastReg supported, using FastReg for registration\n");
  98                 device->iser_alloc_rdma_reg_res = iser_create_fastreg_pool;
  99                 device->iser_free_rdma_reg_res = iser_free_fastreg_pool;
 100                 device->iser_reg_rdma_mem = iser_reg_rdma_mem_fastreg;
 101                 device->iser_unreg_rdma_mem = iser_unreg_mem_fastreg;
 102         } else {
 103                 iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
 104                 return -1;
 105         }
 106
 107         device->comps_used = min_t(int, num_online_cpus(),
 108                                  device->ib_device->num_comp_vectors);
 109
 110         device->comps = kcalloc(device->comps_used, sizeof(*device->comps),
 111                                 GFP_KERNEL);
 112         if (!device->comps)
 113                 goto comps_err;
 114
 115         max_cqe = min(ISER_MAX_CQ_LEN, dev_attr->max_cqe);
 116
 117         iser_info("using %d CQs, device %s supports %d vectors max_cqe %d\n",
 118                   device->comps_used, device->ib_device->name,
 119                   device->ib_device->num_comp_vectors, max_cqe);
 120
 121         device->pd = ib_alloc_pd(device->ib_device);
 122         if (IS_ERR(device->pd))
 123                 goto pd_err;
 124
 125         for (i = 0; i < device->comps_used; i++) {
 126                 struct iser_comp *comp = &device->comps[i];
 127
 128                 comp->device = device;
 129                 comp->cq = ib_create_cq(device->ib_device,
 130                                         iser_cq_callback,
 131                                         iser_cq_event_callback,
 132                                         (void *)comp,
 133                                         max_cqe, i);
 134                 if (IS_ERR(comp->cq)) {
 135                         comp->cq = NULL;
 136                         goto cq_err;
 137                 }
 138
 139                 if (ib_req_notify_cq(comp->cq, IB_CQ_NEXT_COMP))
 140                         goto cq_err;
 141
 142                 tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
 143                              (unsigned long)comp);
 144         }
 145
 146         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 147                                    IB_ACCESS_REMOTE_WRITE |
 148                                    IB_ACCESS_REMOTE_READ);
 149         if (IS_ERR(device->mr))
 150                 goto dma_mr_err;
 151
 152         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 153                                 iser_event_handler);
 154         if (ib_register_event_handler(&device->event_handler))
 155                 goto handler_err;
 156
 157         return 0;
 158
 159 handler_err:
 160         ib_dereg_mr(device->mr);
 161 dma_mr_err:
 162         for (i = 0; i < device->comps_used; i++)
 163                 tasklet_kill(&device->comps[i].tasklet);
 164 cq_err:
 165         for (i = 0; i < device->comps_used; i++) {
 166                 struct iser_comp *comp = &device->comps[i];
 167
 168                 if (comp->cq)
 169                         ib_destroy_cq(comp->cq);
 170         }
 171         ib_dealloc_pd(device->pd);
 172 pd_err:
 173         kfree(device->comps);
 174 comps_err:
 175         iser_err("failed to allocate an IB resource\n");
 176         return -1;
 177 }
 178
 179 /**
 180  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 181  * CQ and PD created with the device associated with the adapator.
 182  */
 183 static void iser_free_device_ib_res(struct iser_device *device)
 184 {
 185         int i;
 186         BUG_ON(device->mr == NULL);
 187
 188         for (i = 0; i < device->comps_used; i++) {
 189                 struct iser_comp *comp = &device->comps[i];
 190
 191                 tasklet_kill(&comp->tasklet);
 192                 ib_destroy_cq(comp->cq);
 193                 comp->cq = NULL;
 194         }
 195
 196         (void)ib_unregister_event_handler(&device->event_handler);
 197         (void)ib_dereg_mr(device->mr);
 198         (void)ib_dealloc_pd(device->pd);
 199
 200         kfree(device->comps);
 201         device->comps = NULL;
 202
 203         device->mr = NULL;
 204         device->pd = NULL;
 205 }
 206
 207 /**
 208  * iser_create_fmr_pool - Creates FMR pool and page_vector
 209  *
 210  * returns 0 on success, or errno code on failure
 211  */
 212 int iser_create_fmr_pool(struct ib_conn *ib_conn, unsigned cmds_max)
 213 {
 214         struct iser_device *device = ib_conn->device;
 215         struct ib_fmr_pool_param params;
 216         int ret = -ENOMEM;
 217
 218         ib_conn->fmr.page_vec = kmalloc(sizeof(*ib_conn->fmr.page_vec) +
 219                                         (sizeof(u64)*(ISCSI_ISER_SG_TABLESIZE + 1)),
 220                                         GFP_KERNEL);
 221         if (!ib_conn->fmr.page_vec)
 222                 return ret;
 223
 224         ib_conn->fmr.page_vec->pages = (u64 *)(ib_conn->fmr.page_vec + 1);
 225
 226         params.page_shift        = SHIFT_4K;
 227         /* when the first/last SG element are not start/end *
 228          * page aligned, the map whould be of N+1 pages     */
 229         params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
 230         /* make the pool size twice the max number of SCSI commands *
 231          * the ML is expected to queue, watermark for unmap at 50%  */
 232         params.pool_size         = cmds_max * 2;
 233         params.dirty_watermark   = cmds_max;
 234         params.cache             = 0;
 235         params.flush_function    = NULL;
 236         params.access            = (IB_ACCESS_LOCAL_WRITE  |
 237                                     IB_ACCESS_REMOTE_WRITE |
 238                                     IB_ACCESS_REMOTE_READ);
 239
 240         ib_conn->fmr.pool = ib_create_fmr_pool(device->pd, &params);
 241         if (!IS_ERR(ib_conn->fmr.pool))
 242                 return 0;
 243
 244         /* no FMR => no need for page_vec */
 245         kfree(ib_conn->fmr.page_vec);
 246         ib_conn->fmr.page_vec = NULL;
 247
 248         ret = PTR_ERR(ib_conn->fmr.pool);
 249         ib_conn->fmr.pool = NULL;
 250         if (ret != -ENOSYS) {
 251                 iser_err("FMR allocation failed, err %d\n", ret);
 252                 return ret;
 253         } else {
 254                 iser_warn("FMRs are not supported, using unaligned mode\n");
 255                 return 0;
 256         }
 257 }
 258
 259 /**
 260  * iser_free_fmr_pool - releases the FMR pool and page vec
 261  */
 262 void iser_free_fmr_pool(struct ib_conn *ib_conn)
 263 {
 264         iser_info("freeing conn %p fmr pool %p\n",
 265                   ib_conn, ib_conn->fmr.pool);
 266
 267         if (ib_conn->fmr.pool != NULL)
 268                 ib_destroy_fmr_pool(ib_conn->fmr.pool);
 269
 270         ib_conn->fmr.pool = NULL;
 271
 272         kfree(ib_conn->fmr.page_vec);
 273         ib_conn->fmr.page_vec = NULL;
 274 }
 275
 276 static int
 277 iser_create_fastreg_desc(struct ib_device *ib_device, struct ib_pd *pd,
 278                          bool pi_enable, struct fast_reg_descriptor *desc)
 279 {
 280         int ret;
 281
 282         desc->data_frpl = ib_alloc_fast_reg_page_list(ib_device,
 283                                                       ISCSI_ISER_SG_TABLESIZE + 1);
 284         if (IS_ERR(desc->data_frpl)) {
 285                 ret = PTR_ERR(desc->data_frpl);
 286                 iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n",
 287                          ret);
 288                 return PTR_ERR(desc->data_frpl);
 289         }
 290
 291         desc->data_mr = ib_alloc_fast_reg_mr(pd, ISCSI_ISER_SG_TABLESIZE + 1);
 292         if (IS_ERR(desc->data_mr)) {
 293                 ret = PTR_ERR(desc->data_mr);
 294                 iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
 295                 goto fast_reg_mr_failure;
 296         }
 297         desc->reg_indicators |= ISER_DATA_KEY_VALID;
 298
 299         if (pi_enable) {
 300                 struct ib_mr_init_attr mr_init_attr = {0};
 301                 struct iser_pi_context *pi_ctx = NULL;
 302
 303                 desc->pi_ctx = kzalloc(sizeof(*desc->pi_ctx), GFP_KERNEL);
 304                 if (!desc->pi_ctx) {
 305                         iser_err("Failed to allocate pi context\n");
 306                         ret = -ENOMEM;
 307                         goto pi_ctx_alloc_failure;
 308                 }
 309                 pi_ctx = desc->pi_ctx;
 310
 311                 pi_ctx->prot_frpl = ib_alloc_fast_reg_page_list(ib_device,
 312                                                     ISCSI_ISER_SG_TABLESIZE);
 313                 if (IS_ERR(pi_ctx->prot_frpl)) {
 314                         ret = PTR_ERR(pi_ctx->prot_frpl);
 315                         iser_err("Failed to allocate prot frpl ret=%d\n",
 316                                  ret);
 317                         goto prot_frpl_failure;
 318                 }
 319
 320                 pi_ctx->prot_mr = ib_alloc_fast_reg_mr(pd,
 321                                                 ISCSI_ISER_SG_TABLESIZE + 1);
 322                 if (IS_ERR(pi_ctx->prot_mr)) {
 323                         ret = PTR_ERR(pi_ctx->prot_mr);
 324                         iser_err("Failed to allocate prot frmr ret=%d\n",
 325                                  ret);
 326                         goto prot_mr_failure;
 327                 }
 328                 desc->reg_indicators |= ISER_PROT_KEY_VALID;
 329
 330                 mr_init_attr.max_reg_descriptors = 2;
 331                 mr_init_attr.flags |= IB_MR_SIGNATURE_EN;
 332                 pi_ctx->sig_mr = ib_create_mr(pd, &mr_init_attr);
 333                 if (IS_ERR(pi_ctx->sig_mr)) {
 334                         ret = PTR_ERR(pi_ctx->sig_mr);
 335                         iser_err("Failed to allocate signature enabled mr err=%d\n",
 336                                  ret);
 337                         goto sig_mr_failure;
 338                 }
 339                 desc->reg_indicators |= ISER_SIG_KEY_VALID;
 340         }
 341         desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
 342
 343         iser_dbg("Create fr_desc %p page_list %p\n",
 344                  desc, desc->data_frpl->page_list);
 345
 346         return 0;
 347 sig_mr_failure:
 348         ib_dereg_mr(desc->pi_ctx->prot_mr);
 349 prot_mr_failure:
 350         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 351 prot_frpl_failure:
 352         kfree(desc->pi_ctx);
 353 pi_ctx_alloc_failure:
 354         ib_dereg_mr(desc->data_mr);
 355 fast_reg_mr_failure:
 356         ib_free_fast_reg_page_list(desc->data_frpl);
 357
 358         return ret;
 359 }
 360
 361 /**
 362  * iser_create_fastreg_pool - Creates pool of fast_reg descriptors
 363  * for fast registration work requests.
 364  * returns 0 on success, or errno code on failure
 365  */
 366 int iser_create_fastreg_pool(struct ib_conn *ib_conn, unsigned cmds_max)
 367 {
 368         struct iser_device *device = ib_conn->device;
 369         struct fast_reg_descriptor *desc;
 370         int i, ret;
 371
 372         INIT_LIST_HEAD(&ib_conn->fastreg.pool);
 373         ib_conn->fastreg.pool_size = 0;
 374         for (i = 0; i < cmds_max; i++) {
 375                 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 376                 if (!desc) {
 377                         iser_err("Failed to allocate a new fast_reg descriptor\n");
 378                         ret = -ENOMEM;
 379                         goto err;
 380                 }
 381
 382                 ret = iser_create_fastreg_desc(device->ib_device, device->pd,
 383                                                ib_conn->pi_support, desc);
 384                 if (ret) {
 385                         iser_err("Failed to create fastreg descriptor err=%d\n",
 386                                  ret);
 387                         kfree(desc);
 388                         goto err;
 389                 }
 390
 391                 list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 392                 ib_conn->fastreg.pool_size++;
 393         }
 394
 395         return 0;
 396
 397 err:
 398         iser_free_fastreg_pool(ib_conn);
 399         return ret;
 400 }
 401
 402 /**
 403  * iser_free_fastreg_pool - releases the pool of fast_reg descriptors
 404  */
 405 void iser_free_fastreg_pool(struct ib_conn *ib_conn)
 406 {
 407         struct fast_reg_descriptor *desc, *tmp;
 408         int i = 0;
 409
 410         if (list_empty(&ib_conn->fastreg.pool))
 411                 return;
 412
 413         iser_info("freeing conn %p fr pool\n", ib_conn);
 414
 415         list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.pool, list) {
 416                 list_del(&desc->list);
 417                 ib_free_fast_reg_page_list(desc->data_frpl);
 418                 ib_dereg_mr(desc->data_mr);
 419                 if (desc->pi_ctx) {
 420                         ib_free_fast_reg_page_list(desc->pi_ctx->prot_frpl);
 421                         ib_dereg_mr(desc->pi_ctx->prot_mr);
 422                         ib_destroy_mr(desc->pi_ctx->sig_mr);
 423                         kfree(desc->pi_ctx);
 424                 }
 425                 kfree(desc);
 426                 ++i;
 427         }
 428
 429         if (i < ib_conn->fastreg.pool_size)
 430                 iser_warn("pool still has %d regions registered\n",
 431                           ib_conn->fastreg.pool_size - i);
 432 }
 433
 434 /**
 435  * iser_create_ib_conn_res - Queue-Pair (QP)
 436  *
 437  * returns 0 on success, -1 on failure
 438  */
 439 static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
 440 {
 441         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 442                                                    ib_conn);
 443         struct iser_device      *device;
 444         struct ib_device_attr *dev_attr;
 445         struct ib_qp_init_attr  init_attr;
 446         int                     ret = -ENOMEM;
 447         int index, min_index = 0;
 448
 449         BUG_ON(ib_conn->device == NULL);
 450
 451         device = ib_conn->device;
 452         dev_attr = &device->dev_attr;
 453
 454         memset(&init_attr, 0, sizeof init_attr);
 455
 456         mutex_lock(&ig.connlist_mutex);
 457         /* select the CQ with the minimal number of usages */
 458         for (index = 0; index < device->comps_used; index++) {
 459                 if (device->comps[index].active_qps <
 460                     device->comps[min_index].active_qps)
 461                         min_index = index;
 462         }
 463         ib_conn->comp = &device->comps[min_index];
 464         ib_conn->comp->active_qps++;
 465         mutex_unlock(&ig.connlist_mutex);
 466         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 467
 468         init_attr.event_handler = iser_qp_event_callback;
 469         init_attr.qp_context    = (void *)ib_conn;
 470         init_attr.send_cq       = ib_conn->comp->cq;
 471         init_attr.recv_cq       = ib_conn->comp->cq;
 472         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 473         init_attr.cap.max_send_sge = 2;
 474         init_attr.cap.max_recv_sge = 1;
 475         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 476         init_attr.qp_type       = IB_QPT_RC;
 477         if (ib_conn->pi_support) {
 478                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS + 1;
 479                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 480                 iser_conn->max_cmds =
 481                         ISER_GET_MAX_XMIT_CMDS(ISER_QP_SIG_MAX_REQ_DTOS);
 482         } else {
 483                 if (dev_attr->max_qp_wr > ISER_QP_MAX_REQ_DTOS) {
 484                         init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS + 1;
 485                         iser_conn->max_cmds =
 486                                 ISER_GET_MAX_XMIT_CMDS(ISER_QP_MAX_REQ_DTOS);
 487                 } else {
 488                         init_attr.cap.max_send_wr = dev_attr->max_qp_wr;
 489                         iser_conn->max_cmds =
 490                                 ISER_GET_MAX_XMIT_CMDS(dev_attr->max_qp_wr);
 491                         iser_dbg("device %s supports max_send_wr %d\n",
 492                                  device->ib_device->name, dev_attr->max_qp_wr);
 493                 }
 494         }
 495
 496         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 497         if (ret)
 498                 goto out_err;
 499
 500         ib_conn->qp = ib_conn->cma_id->qp;
 501         iser_info("setting conn %p cma_id %p qp %p\n",
 502                   ib_conn, ib_conn->cma_id,
 503                   ib_conn->cma_id->qp);
 504         return ret;
 505
 506 out_err:
 507         mutex_lock(&ig.connlist_mutex);
 508         ib_conn->comp->active_qps--;
 509         mutex_unlock(&ig.connlist_mutex);
 510         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 511
 512         return ret;
 513 }
 514
 515 /**
 516  * based on the resolved device node GUID see if there already allocated
 517  * device for this device. If there's no such, create one.
 518  */
 519 static
 520 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 521 {
 522         struct iser_device *device;
 523
 524         mutex_lock(&ig.device_list_mutex);
 525
 526         list_for_each_entry(device, &ig.device_list, ig_list)
 527                 /* find if there's a match using the node GUID */
 528                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 529                         goto inc_refcnt;
 530
 531         device = kzalloc(sizeof *device, GFP_KERNEL);
 532         if (device == NULL)
 533                 goto out;
 534
 535         /* assign this device to the device */
 536         device->ib_device = cma_id->device;
 537         /* init the device and link it into ig device list */
 538         if (iser_create_device_ib_res(device)) {
 539                 kfree(device);
 540                 device = NULL;
 541                 goto out;
 542         }
 543         list_add(&device->ig_list, &ig.device_list);
 544
 545 inc_refcnt:
 546         device->refcount++;
 547 out:
 548         mutex_unlock(&ig.device_list_mutex);
 549         return device;
 550 }
 551
 552 /* if there's no demand for this device, release it */
 553 static void iser_device_try_release(struct iser_device *device)
 554 {
 555         mutex_lock(&ig.device_list_mutex);
 556         device->refcount--;
 557         iser_info("device %p refcount %d\n", device, device->refcount);
 558         if (!device->refcount) {
 559                 iser_free_device_ib_res(device);
 560                 list_del(&device->ig_list);
 561                 kfree(device);
 562         }
 563         mutex_unlock(&ig.device_list_mutex);
 564 }
 565
 566 /**
 567  * Called with state mutex held
 568  **/
 569 static int iser_conn_state_comp_exch(struct iser_conn *iser_conn,
 570                                      enum iser_conn_state comp,
 571                                      enum iser_conn_state exch)
 572 {
 573         int ret;
 574
 575         ret = (iser_conn->state == comp);
 576         if (ret)
 577                 iser_conn->state = exch;
 578
 579         return ret;
 580 }
 581
 582 void iser_release_work(struct work_struct *work)
 583 {
 584         struct iser_conn *iser_conn;
 585
 586         iser_conn = container_of(work, struct iser_conn, release_work);
 587
 588         /* Wait for conn_stop to complete */
 589         wait_for_completion(&iser_conn->stop_completion);
 590         /* Wait for IB resouces cleanup to complete */
 591         wait_for_completion(&iser_conn->ib_completion);
 592
 593         mutex_lock(&iser_conn->state_mutex);
 594         iser_conn->state = ISER_CONN_DOWN;
 595         mutex_unlock(&iser_conn->state_mutex);
 596
 597         iser_conn_release(iser_conn);
 598 }
 599
 600 /**
 601  * iser_free_ib_conn_res - release IB related resources
 602  * @iser_conn: iser connection struct
 603  * @destroy: indicator if we need to try to release the
 604  *     iser device and memory regoins pool (only iscsi
 605  *     shutdown and DEVICE_REMOVAL will use this).
 606  *
 607  * This routine is called with the iser state mutex held
 608  * so the cm_id removal is out of here. It is Safe to
 609  * be invoked multiple times.
 610  */
 611 static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
 612                                   bool destroy)
 613 {
 614         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 615         struct iser_device *device = ib_conn->device;
 616
 617         iser_info("freeing conn %p cma_id %p qp %p\n",
 618                   iser_conn, ib_conn->cma_id, ib_conn->qp);
 619
 620         if (ib_conn->qp != NULL) {
 621                 ib_conn->comp->active_qps--;
 622                 rdma_destroy_qp(ib_conn->cma_id);
 623                 ib_conn->qp = NULL;
 624         }
 625
 626         if (destroy) {
 627                 if (iser_conn->rx_descs)
 628                         iser_free_rx_descriptors(iser_conn);
 629
 630                 if (device != NULL) {
 631                         iser_device_try_release(device);
 632                         ib_conn->device = NULL;
 633                 }
 634         }
 635 }
 636
 637 /**
 638  * Frees all conn objects and deallocs conn descriptor
 639  */
 640 void iser_conn_release(struct iser_conn *iser_conn)
 641 {
 642         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 643
 644         mutex_lock(&ig.connlist_mutex);
 645         list_del(&iser_conn->conn_list);
 646         mutex_unlock(&ig.connlist_mutex);
 647
 648         mutex_lock(&iser_conn->state_mutex);
 649         /* In case we endup here without ep_disconnect being invoked. */
 650         if (iser_conn->state != ISER_CONN_DOWN) {
 651                 iser_warn("iser conn %p state %d, expected state down.\n",
 652                           iser_conn, iser_conn->state);
 653                 iscsi_destroy_endpoint(iser_conn->ep);
 654                 iser_conn->state = ISER_CONN_DOWN;
 655         }
 656         /*
 657          * In case we never got to bind stage, we still need to
 658          * release IB resources (which is safe to call more than once).
 659          */
 660         iser_free_ib_conn_res(iser_conn, true);
 661         mutex_unlock(&iser_conn->state_mutex);
 662
 663         if (ib_conn->cma_id != NULL) {
 664                 rdma_destroy_id(ib_conn->cma_id);
 665                 ib_conn->cma_id = NULL;
 666         }
 667
 668         kfree(iser_conn);
 669 }
 670
 671 /**
 672  * triggers start of the disconnect procedures and wait for them to be done
 673  * Called with state mutex held
 674  */
 675 int iser_conn_terminate(struct iser_conn *iser_conn)
 676 {
 677         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 678         struct ib_send_wr *bad_wr;
 679         int err = 0;
 680
 681         /* terminate the iser conn only if the conn state is UP */
 682         if (!iser_conn_state_comp_exch(iser_conn, ISER_CONN_UP,
 683                                        ISER_CONN_TERMINATING))
 684                 return 0;
 685
 686         iser_info("iser_conn %p state %d\n", iser_conn, iser_conn->state);
 687
 688         /* suspend queuing of new iscsi commands */
 689         if (iser_conn->iscsi_conn)
 690                 iscsi_suspend_queue(iser_conn->iscsi_conn);
 691
 692         /*
 693          * In case we didn't already clean up the cma_id (peer initiated
 694          * a disconnection), we need to Cause the CMA to change the QP
 695          * state to ERROR.
 696          */
 697         if (ib_conn->cma_id) {
 698                 err = rdma_disconnect(ib_conn->cma_id);
 699                 if (err)
 700                         iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 701                                  iser_conn, err);
 702
 703                 /* post an indication that all flush errors were consumed */
 704                 err = ib_post_send(ib_conn->qp, &ib_conn->beacon, &bad_wr);
 705                 if (err) {
 706                         iser_err("conn %p failed to post beacon", ib_conn);
 707                         return 1;
 708                 }
 709
 710                 wait_for_completion(&ib_conn->flush_comp);
 711         }
 712
 713         return 1;
 714 }
 715
 716 /**
 717  * Called with state mutex held
 718  **/
 719 static void iser_connect_error(struct rdma_cm_id *cma_id)
 720 {
 721         struct iser_conn *iser_conn;
 722
 723         iser_conn = (struct iser_conn *)cma_id->context;
 724         iser_conn->state = ISER_CONN_DOWN;
 725 }
 726
 727 /**
 728  * Called with state mutex held
 729  **/
 730 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 731 {
 732         struct iser_device *device;
 733         struct iser_conn   *iser_conn;
 734         struct ib_conn   *ib_conn;
 735         int    ret;
 736
 737         iser_conn = (struct iser_conn *)cma_id->context;
 738         if (iser_conn->state != ISER_CONN_PENDING)
 739                 /* bailout */
 740                 return;
 741
 742         ib_conn = &iser_conn->ib_conn;
 743         device = iser_device_find_by_ib_device(cma_id);
 744         if (!device) {
 745                 iser_err("device lookup/creation failed\n");
 746                 iser_connect_error(cma_id);
 747                 return;
 748         }
 749
 750         ib_conn->device = device;
 751
 752         /* connection T10-PI support */
 753         if (iser_pi_enable) {
 754                 if (!(device->dev_attr.device_cap_flags &
 755                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 756                         iser_warn("T10-PI requested but not supported on %s, "
 757                                   "continue without T10-PI\n",
 758                                   ib_conn->device->ib_device->name);
 759                         ib_conn->pi_support = false;
 760                 } else {
 761                         ib_conn->pi_support = true;
 762                 }
 763         }
 764
 765         ret = rdma_resolve_route(cma_id, 1000);
 766         if (ret) {
 767                 iser_err("resolve route failed: %d\n", ret);
 768                 iser_connect_error(cma_id);
 769                 return;
 770         }
 771 }
 772
 773 /**
 774  * Called with state mutex held
 775  **/
 776 static void iser_route_handler(struct rdma_cm_id *cma_id)
 777 {
 778         struct rdma_conn_param conn_param;
 779         int    ret;
 780         struct iser_cm_hdr req_hdr;
 781         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 782         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 783         struct iser_device *device = ib_conn->device;
 784
 785         if (iser_conn->state != ISER_CONN_PENDING)
 786                 /* bailout */
 787                 return;
 788
 789         ret = iser_create_ib_conn_res(ib_conn);
 790         if (ret)
 791                 goto failure;
 792
 793         memset(&conn_param, 0, sizeof conn_param);
 794         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 795         conn_param.initiator_depth     = 1;
 796         conn_param.retry_count         = 7;
 797         conn_param.rnr_retry_count     = 6;
 798
 799         memset(&req_hdr, 0, sizeof(req_hdr));
 800         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 801                         ISER_SEND_W_INV_NOT_SUPPORTED);
 802         conn_param.private_data         = (void *)&req_hdr;
 803         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 804
 805         ret = rdma_connect(cma_id, &conn_param);
 806         if (ret) {
 807                 iser_err("failure connecting: %d\n", ret);
 808                 goto failure;
 809         }
 810
 811         return;
 812 failure:
 813         iser_connect_error(cma_id);
 814 }
 815
 816 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 817 {
 818         struct iser_conn *iser_conn;
 819         struct ib_qp_attr attr;
 820         struct ib_qp_init_attr init_attr;
 821
 822         iser_conn = (struct iser_conn *)cma_id->context;
 823         if (iser_conn->state != ISER_CONN_PENDING)
 824                 /* bailout */
 825                 return;
 826
 827         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 828         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 829
 830         iser_conn->state = ISER_CONN_UP;
 831         complete(&iser_conn->up_completion);
 832 }
 833
 834 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 835 {
 836         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 837
 838         if (iser_conn_terminate(iser_conn)) {
 839                 if (iser_conn->iscsi_conn)
 840                         iscsi_conn_failure(iser_conn->iscsi_conn,
 841                                            ISCSI_ERR_CONN_FAILED);
 842                 else
 843                         iser_err("iscsi_iser connection isn't bound\n");
 844         }
 845 }
 846
 847 static void iser_cleanup_handler(struct rdma_cm_id *cma_id,
 848                                  bool destroy)
 849 {
 850         struct iser_conn *iser_conn = (struct iser_conn *)cma_id->context;
 851
 852         /*
 853          * We are not guaranteed that we visited disconnected_handler
 854          * by now, call it here to be safe that we handle CM drep
 855          * and flush errors.
 856          */
 857         iser_disconnected_handler(cma_id);
 858         iser_free_ib_conn_res(iser_conn, destroy);
 859         complete(&iser_conn->ib_completion);
 860 };
 861
 862 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 863 {
 864         struct iser_conn *iser_conn;
 865         int ret = 0;
 866
 867         iser_conn = (struct iser_conn *)cma_id->context;
 868         iser_info("event %d status %d conn %p id %p\n",
 869                   event->event, event->status, cma_id->context, cma_id);
 870
 871         mutex_lock(&iser_conn->state_mutex);
 872         switch (event->event) {
 873         case RDMA_CM_EVENT_ADDR_RESOLVED:
 874                 iser_addr_handler(cma_id);
 875                 break;
 876         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 877                 iser_route_handler(cma_id);
 878                 break;
 879         case RDMA_CM_EVENT_ESTABLISHED:
 880                 iser_connected_handler(cma_id);
 881                 break;
 882         case RDMA_CM_EVENT_ADDR_ERROR:
 883         case RDMA_CM_EVENT_ROUTE_ERROR:
 884         case RDMA_CM_EVENT_CONNECT_ERROR:
 885         case RDMA_CM_EVENT_UNREACHABLE:
 886         case RDMA_CM_EVENT_REJECTED:
 887                 iser_connect_error(cma_id);
 888                 break;
 889         case RDMA_CM_EVENT_DISCONNECTED:
 890         case RDMA_CM_EVENT_ADDR_CHANGE:
 891         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 892                 iser_cleanup_handler(cma_id, false);
 893                 break;
 894         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 895                 /*
 896                  * we *must* destroy the device as we cannot rely
 897                  * on iscsid to be around to initiate error handling.
 898                  * also if we are not in state DOWN implicitly destroy
 899                  * the cma_id.
 900                  */
 901                 iser_cleanup_handler(cma_id, true);
 902                 if (iser_conn->state != ISER_CONN_DOWN) {
 903                         iser_conn->ib_conn.cma_id = NULL;
 904                         ret = 1;
 905                 }
 906                 break;
 907         default:
 908                 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
 909                 break;
 910         }
 911         mutex_unlock(&iser_conn->state_mutex);
 912
 913         return ret;
 914 }
 915
 916 void iser_conn_init(struct iser_conn *iser_conn)
 917 {
 918         iser_conn->state = ISER_CONN_INIT;
 919         iser_conn->ib_conn.post_recv_buf_count = 0;
 920         init_completion(&iser_conn->ib_conn.flush_comp);
 921         init_completion(&iser_conn->stop_completion);
 922         init_completion(&iser_conn->ib_completion);
 923         init_completion(&iser_conn->up_completion);
 924         INIT_LIST_HEAD(&iser_conn->conn_list);
 925         spin_lock_init(&iser_conn->ib_conn.lock);
 926         mutex_init(&iser_conn->state_mutex);
 927 }
 928
 929  /**
 930  * starts the process of connecting to the target
 931  * sleeps until the connection is established or rejected
 932  */
 933 int iser_connect(struct iser_conn   *iser_conn,
 934                  struct sockaddr    *src_addr,
 935                  struct sockaddr    *dst_addr,
 936                  int                 non_blocking)
 937 {
 938         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 939         int err = 0;
 940
 941         mutex_lock(&iser_conn->state_mutex);
 942
 943         sprintf(iser_conn->name, "%pISp", dst_addr);
 944
 945         iser_info("connecting to: %s\n", iser_conn->name);
 946
 947         /* the device is known only --after-- address resolution */
 948         ib_conn->device = NULL;
 949
 950         iser_conn->state = ISER_CONN_PENDING;
 951
 952         ib_conn->beacon.wr_id = ISER_BEACON_WRID;
 953         ib_conn->beacon.opcode = IB_WR_SEND;
 954
 955         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 956                                          (void *)iser_conn,
 957                                          RDMA_PS_TCP, IB_QPT_RC);
 958         if (IS_ERR(ib_conn->cma_id)) {
 959                 err = PTR_ERR(ib_conn->cma_id);
 960                 iser_err("rdma_create_id failed: %d\n", err);
 961                 goto id_failure;
 962         }
 963
 964         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 965         if (err) {
 966                 iser_err("rdma_resolve_addr failed: %d\n", err);
 967                 goto addr_failure;
 968         }
 969
 970         if (!non_blocking) {
 971                 wait_for_completion_interruptible(&iser_conn->up_completion);
 972
 973                 if (iser_conn->state != ISER_CONN_UP) {
 974                         err =  -EIO;
 975                         goto connect_failure;
 976                 }
 977         }
 978         mutex_unlock(&iser_conn->state_mutex);
 979
 980         mutex_lock(&ig.connlist_mutex);
 981         list_add(&iser_conn->conn_list, &ig.connlist);
 982         mutex_unlock(&ig.connlist_mutex);
 983         return 0;
 984
 985 id_failure:
 986         ib_conn->cma_id = NULL;
 987 addr_failure:
 988         iser_conn->state = ISER_CONN_DOWN;
 989 connect_failure:
 990         mutex_unlock(&iser_conn->state_mutex);
 991         iser_conn_release(iser_conn);
 992         return err;
 993 }
 994
 995 /**
 996  * iser_reg_page_vec - Register physical memory
 997  *
 998  * returns: 0 on success, errno code on failure
 999  */
1000 int iser_reg_page_vec(struct ib_conn *ib_conn,
1001                       struct iser_page_vec *page_vec,
1002                       struct iser_mem_reg  *mem_reg)
1003 {
1004         struct ib_pool_fmr *mem;
1005         u64                io_addr;
1006         u64                *page_list;
1007         int                status;
1008
1009         page_list = page_vec->pages;
1010         io_addr   = page_list[0];
1011
1012         mem  = ib_fmr_pool_map_phys(ib_conn->fmr.pool,
1013                                     page_list,
1014                                     page_vec->length,
1015                                     io_addr);
1016
1017         if (IS_ERR(mem)) {
1018                 status = (int)PTR_ERR(mem);
1019                 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
1020                 return status;
1021         }
1022
1023         mem_reg->lkey  = mem->fmr->lkey;
1024         mem_reg->rkey  = mem->fmr->rkey;
1025         mem_reg->len   = page_vec->length * SIZE_4K;
1026         mem_reg->va    = io_addr;
1027         mem_reg->mem_h = (void *)mem;
1028
1029         mem_reg->va   += page_vec->offset;
1030         mem_reg->len   = page_vec->data_size;
1031
1032         iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
1033                  "entry[0]: (0x%08lx,%ld)] -> "
1034                  "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
1035                  page_vec, page_vec->length,
1036                  (unsigned long)page_vec->pages[0],
1037                  (unsigned long)page_vec->data_size,
1038                  (unsigned int)mem_reg->lkey, mem_reg->mem_h,
1039                  (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
1040         return 0;
1041 }
1042
1043 /**
1044  * Unregister (previosuly registered using FMR) memory.
1045  * If memory is non-FMR does nothing.
1046  */
1047 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
1048                         enum iser_data_dir cmd_dir)
1049 {
1050         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1051         int ret;
1052
1053         if (!reg->mem_h)
1054                 return;
1055
1056         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
1057
1058         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
1059         if (ret)
1060                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
1061
1062         reg->mem_h = NULL;
1063 }
1064
1065 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
1066                             enum iser_data_dir cmd_dir)
1067 {
1068         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1069         struct iser_conn *iser_conn = iser_task->iser_conn;
1070         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1071         struct fast_reg_descriptor *desc = reg->mem_h;
1072
1073         if (!desc)
1074                 return;
1075
1076         reg->mem_h = NULL;
1077         spin_lock_bh(&ib_conn->lock);
1078         list_add_tail(&desc->list, &ib_conn->fastreg.pool);
1079         spin_unlock_bh(&ib_conn->lock);
1080 }
1081
1082 int iser_post_recvl(struct iser_conn *iser_conn)
1083 {
1084         struct ib_recv_wr rx_wr, *rx_wr_failed;
1085         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1086         struct ib_sge     sge;
1087         int ib_ret;
1088
1089         sge.addr   = iser_conn->login_resp_dma;
1090         sge.length = ISER_RX_LOGIN_SIZE;
1091         sge.lkey   = ib_conn->device->mr->lkey;
1092
1093         rx_wr.wr_id   = (uintptr_t)iser_conn->login_resp_buf;
1094         rx_wr.sg_list = &sge;
1095         rx_wr.num_sge = 1;
1096         rx_wr.next    = NULL;
1097
1098         ib_conn->post_recv_buf_count++;
1099         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1100         if (ib_ret) {
1101                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1102                 ib_conn->post_recv_buf_count--;
1103         }
1104         return ib_ret;
1105 }
1106
1107 int iser_post_recvm(struct iser_conn *iser_conn, int count)
1108 {
1109         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1110         int i, ib_ret;
1111         struct ib_conn *ib_conn = &iser_conn->ib_conn;
1112         unsigned int my_rx_head = iser_conn->rx_desc_head;
1113         struct iser_rx_desc *rx_desc;
1114
1115         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1116                 rx_desc         = &iser_conn->rx_descs[my_rx_head];
1117                 rx_wr->wr_id    = (uintptr_t)rx_desc;
1118                 rx_wr->sg_list  = &rx_desc->rx_sg;
1119                 rx_wr->num_sge  = 1;
1120                 rx_wr->next     = rx_wr + 1;
1121                 my_rx_head = (my_rx_head + 1) & iser_conn->qp_max_recv_dtos_mask;
1122         }
1123
1124         rx_wr--;
1125         rx_wr->next = NULL; /* mark end of work requests list */
1126
1127         ib_conn->post_recv_buf_count += count;
1128         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1129         if (ib_ret) {
1130                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1131                 ib_conn->post_recv_buf_count -= count;
1132         } else
1133                 iser_conn->rx_desc_head = my_rx_head;
1134         return ib_ret;
1135 }
1136
1137
1138 /**
1139  * iser_start_send - Initiate a Send DTO operation
1140  *
1141  * returns 0 on success, -1 on failure
1142  */
1143 int iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc,
1144                    bool signal)
1145 {
1146         int               ib_ret;
1147         struct ib_send_wr send_wr, *send_wr_failed;
1148
1149         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1150                                       tx_desc->dma_addr, ISER_HEADERS_LEN,
1151                                       DMA_TO_DEVICE);
1152
1153         send_wr.next       = NULL;
1154         send_wr.wr_id      = (uintptr_t)tx_desc;
1155         send_wr.sg_list    = tx_desc->tx_sg;
1156         send_wr.num_sge    = tx_desc->num_sge;
1157         send_wr.opcode     = IB_WR_SEND;
1158         send_wr.send_flags = signal ? IB_SEND_SIGNALED : 0;
1159
1160         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1161         if (ib_ret)
1162                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1163
1164         return ib_ret;
1165 }
1166
1167 /**
1168  * is_iser_tx_desc - Indicate if the completion wr_id
1169  *     is a TX descriptor or not.
1170  * @iser_conn: iser connection
1171  * @wr_id: completion WR identifier
1172  *
1173  * Since we cannot rely on wc opcode in FLUSH errors
1174  * we must work around it by checking if the wr_id address
1175  * falls in the iser connection rx_descs buffer. If so
1176  * it is an RX descriptor, otherwize it is a TX.
1177  */
1178 static inline bool
1179 is_iser_tx_desc(struct iser_conn *iser_conn, void *wr_id)
1180 {
1181         void *start = iser_conn->rx_descs;
1182         int len = iser_conn->num_rx_descs * sizeof(*iser_conn->rx_descs);
1183
1184         if (wr_id >= start && wr_id < start + len)
1185                 return false;
1186
1187         return true;
1188 }
1189
1190 /**
1191  * iser_handle_comp_error() - Handle error completion
1192  * @ib_conn:   connection RDMA resources
1193  * @wc:        work completion
1194  *
1195  * Notes: We may handle a FLUSH error completion and in this case
1196  *        we only cleanup in case TX type was DATAOUT. For non-FLUSH
1197  *        error completion we should also notify iscsi layer that
1198  *        connection is failed (in case we passed bind stage).
1199  */
1200 static void
1201 iser_handle_comp_error(struct ib_conn *ib_conn,
1202                        struct ib_wc *wc)
1203 {
1204         void *wr_id = (void *)(uintptr_t)wc->wr_id;
1205         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
1206                                                    ib_conn);
1207
1208         if (wc->status != IB_WC_WR_FLUSH_ERR)
1209                 if (iser_conn->iscsi_conn)
1210                         iscsi_conn_failure(iser_conn->iscsi_conn,
1211                                            ISCSI_ERR_CONN_FAILED);
1212
1213         if (is_iser_tx_desc(iser_conn, wr_id)) {
1214                 struct iser_tx_desc *desc = wr_id;
1215
1216                 if (desc->type == ISCSI_TX_DATAOUT)
1217                         kmem_cache_free(ig.desc_cache, desc);
1218         } else {
1219                 ib_conn->post_recv_buf_count--;
1220         }
1221 }
1222
1223 /**
1224  * iser_handle_wc - handle a single work completion
1225  * @wc: work completion
1226  *
1227  * Soft-IRQ context, work completion can be either
1228  * SEND or RECV, and can turn out successful or
1229  * with error (or flush error).
1230  */
1231 static void iser_handle_wc(struct ib_wc *wc)
1232 {
1233         struct ib_conn *ib_conn;
1234         struct iser_tx_desc *tx_desc;
1235         struct iser_rx_desc *rx_desc;
1236
1237         ib_conn = wc->qp->qp_context;
1238         if (likely(wc->status == IB_WC_SUCCESS)) {
1239                 if (wc->opcode == IB_WC_RECV) {
1240                         rx_desc = (struct iser_rx_desc *)(uintptr_t)wc->wr_id;
1241                         iser_rcv_completion(rx_desc, wc->byte_len,
1242                                             ib_conn);
1243                 } else
1244                 if (wc->opcode == IB_WC_SEND) {
1245                         tx_desc = (struct iser_tx_desc *)(uintptr_t)wc->wr_id;
1246                         iser_snd_completion(tx_desc, ib_conn);
1247                 } else {
1248                         iser_err("Unknown wc opcode %d\n", wc->opcode);
1249                 }
1250         } else {
1251                 if (wc->status != IB_WC_WR_FLUSH_ERR)
1252                         iser_err("wr id %llx status %d vend_err %x\n",
1253                                  wc->wr_id, wc->status, wc->vendor_err);
1254                 else
1255                         iser_dbg("flush error: wr id %llx\n", wc->wr_id);
1256
1257                 if (wc->wr_id != ISER_FASTREG_LI_WRID &&
1258                     wc->wr_id != ISER_BEACON_WRID)
1259                         iser_handle_comp_error(ib_conn, wc);
1260
1261                 /* complete in case all flush errors were consumed */
1262                 if (wc->wr_id == ISER_BEACON_WRID)
1263                         complete(&ib_conn->flush_comp);
1264         }
1265 }
1266
1267 /**
1268  * iser_cq_tasklet_fn - iSER completion polling loop
1269  * @data: iSER completion context
1270  *
1271  * Soft-IRQ context, polling connection CQ until
1272  * either CQ was empty or we exausted polling budget
1273  */
1274 static void iser_cq_tasklet_fn(unsigned long data)
1275 {
1276         struct iser_comp *comp = (struct iser_comp *)data;
1277         struct ib_cq *cq = comp->cq;
1278         struct ib_wc *const wcs = comp->wcs;
1279         int i, n, completed = 0;
1280
1281         while ((n = ib_poll_cq(cq, ARRAY_SIZE(comp->wcs), wcs)) > 0) {
1282                 for (i = 0; i < n; i++)
1283                         iser_handle_wc(&wcs[i]);
1284
1285                 completed += n;
1286                 if (completed >= iser_cq_poll_limit)
1287                         break;
1288         }
1289
1290         /*
1291          * It is assumed here that arming CQ only once its empty
1292          * would not cause interrupts to be missed.
1293          */
1294         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1295
1296         iser_dbg("got %d completions\n", completed);
1297 }
1298
1299 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1300 {
1301         struct iser_comp *comp = cq_context;
1302
1303         tasklet_schedule(&comp->tasklet);
1304 }
1305
1306 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1307                              enum iser_data_dir cmd_dir, sector_t *sector)
1308 {
1309         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1310         struct fast_reg_descriptor *desc = reg->mem_h;
1311         unsigned long sector_size = iser_task->sc->device->sector_size;
1312         struct ib_mr_status mr_status;
1313         int ret;
1314
1315         if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1316                 desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1317                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1318                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1319                 if (ret) {
1320                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1321                         goto err;
1322                 }
1323
1324                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1325                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1326
1327                         do_div(sector_off, sector_size + 8);
1328                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1329
1330                         pr_err("PI error found type %d at sector %llx "
1331                                "expected %x vs actual %x\n",
1332                                mr_status.sig_err.err_type,
1333                                (unsigned long long)*sector,
1334                                mr_status.sig_err.expected,
1335                                mr_status.sig_err.actual);
1336
1337                         switch (mr_status.sig_err.err_type) {
1338                         case IB_SIG_BAD_GUARD:
1339                                 return 0x1;
1340                         case IB_SIG_BAD_REFTAG:
1341                                 return 0x3;
1342                         case IB_SIG_BAD_APPTAG:
1343                                 return 0x2;
1344                         }
1345                 }
1346         }
1347
1348         return 0;
1349 err:
1350         /* Not alot we can do here, return ambiguous guard error */
1351         return 0x1;
1352 }