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, j;
  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                         goto cq_err;
 130
 131                 device->tx_cq[i] = ib_create_cq(device->ib_device,
 132                                           NULL, iser_cq_event_callback,
 133                                           (void *)&cq_desc[i],
 134                                           ISER_MAX_TX_CQ_LEN, i);
 135
 136                 if (IS_ERR(device->tx_cq[i]))
 137                         goto cq_err;
 138
 139                 if (ib_req_notify_cq(device->rx_cq[i], IB_CQ_NEXT_COMP))
 140                         goto cq_err;
 141
 142                 tasklet_init(&device->cq_tasklet[i],
 143                              iser_cq_tasklet_fn,
 144                         (unsigned long)&cq_desc[i]);
 145         }
 146
 147         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
 148                                    IB_ACCESS_REMOTE_WRITE |
 149                                    IB_ACCESS_REMOTE_READ);
 150         if (IS_ERR(device->mr))
 151                 goto dma_mr_err;
 152
 153         INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
 154                                 iser_event_handler);
 155         if (ib_register_event_handler(&device->event_handler))
 156                 goto handler_err;
 157
 158         return 0;
 159
 160 handler_err:
 161         ib_dereg_mr(device->mr);
 162 dma_mr_err:
 163         for (j = 0; j < device->cqs_used; j++)
 164                 tasklet_kill(&device->cq_tasklet[j]);
 165 cq_err:
 166         for (j = 0; j < i; j++) {
 167                 if (device->tx_cq[j])
 168                         ib_destroy_cq(device->tx_cq[j]);
 169                 if (device->rx_cq[j])
 170                         ib_destroy_cq(device->rx_cq[j]);
 171         }
 172         ib_dealloc_pd(device->pd);
 173 pd_err:
 174         kfree(device->cq_desc);
 175 cq_desc_err:
 176         iser_err("failed to allocate an IB resource\n");
 177         return -1;
 178 }
 179
 180 /**
 181  * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
 182  * CQ and PD created with the device associated with the adapator.
 183  */
 184 static void iser_free_device_ib_res(struct iser_device *device)
 185 {
 186         int i;
 187         BUG_ON(device->mr == NULL);
 188
 189         for (i = 0; i < device->cqs_used; i++) {
 190                 tasklet_kill(&device->cq_tasklet[i]);
 191                 (void)ib_destroy_cq(device->tx_cq[i]);
 192                 (void)ib_destroy_cq(device->rx_cq[i]);
 193                 device->tx_cq[i] = NULL;
 194                 device->rx_cq[i] = NULL;
 195         }
 196
 197         (void)ib_unregister_event_handler(&device->event_handler);
 198         (void)ib_dereg_mr(device->mr);
 199         (void)ib_dealloc_pd(device->pd);
 200
 201         kfree(device->cq_desc);
 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 iser_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 iser_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 iser_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 iser_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 iser_conn *ib_conn)
 440 {
 441         struct iser_device      *device;
 442         struct ib_qp_init_attr  init_attr;
 443         int                     ret = -ENOMEM;
 444         int index, min_index = 0;
 445
 446         BUG_ON(ib_conn->device == NULL);
 447
 448         device = ib_conn->device;
 449
 450         memset(&init_attr, 0, sizeof init_attr);
 451
 452         mutex_lock(&ig.connlist_mutex);
 453         /* select the CQ with the minimal number of usages */
 454         for (index = 0; index < device->cqs_used; index++)
 455                 if (device->cq_active_qps[index] <
 456                     device->cq_active_qps[min_index])
 457                         min_index = index;
 458         device->cq_active_qps[min_index]++;
 459         mutex_unlock(&ig.connlist_mutex);
 460         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 461
 462         init_attr.event_handler = iser_qp_event_callback;
 463         init_attr.qp_context    = (void *)ib_conn;
 464         init_attr.send_cq       = device->tx_cq[min_index];
 465         init_attr.recv_cq       = device->rx_cq[min_index];
 466         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
 467         init_attr.cap.max_send_sge = 2;
 468         init_attr.cap.max_recv_sge = 1;
 469         init_attr.sq_sig_type   = IB_SIGNAL_REQ_WR;
 470         init_attr.qp_type       = IB_QPT_RC;
 471         if (ib_conn->pi_support) {
 472                 init_attr.cap.max_send_wr = ISER_QP_SIG_MAX_REQ_DTOS;
 473                 init_attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 474         } else {
 475                 init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS;
 476         }
 477
 478         ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
 479         if (ret)
 480                 goto out_err;
 481
 482         ib_conn->qp = ib_conn->cma_id->qp;
 483         iser_info("setting conn %p cma_id %p qp %p\n",
 484                   ib_conn, ib_conn->cma_id,
 485                   ib_conn->cma_id->qp);
 486         return ret;
 487
 488 out_err:
 489         iser_err("unable to alloc mem or create resource, err %d\n", ret);
 490         return ret;
 491 }
 492
 493 /**
 494  * releases the QP object
 495  */
 496 static void iser_free_ib_conn_res(struct iser_conn *ib_conn)
 497 {
 498         int cq_index;
 499         BUG_ON(ib_conn == NULL);
 500
 501         iser_info("freeing conn %p cma_id %p qp %p\n",
 502                   ib_conn, ib_conn->cma_id,
 503                   ib_conn->qp);
 504
 505         /* qp is created only once both addr & route are resolved */
 506
 507         if (ib_conn->qp != NULL) {
 508                 cq_index = ((struct iser_cq_desc *)ib_conn->qp->recv_cq->cq_context)->cq_index;
 509                 ib_conn->device->cq_active_qps[cq_index]--;
 510
 511                 rdma_destroy_qp(ib_conn->cma_id);
 512         }
 513
 514         ib_conn->qp       = NULL;
 515 }
 516
 517 /**
 518  * based on the resolved device node GUID see if there already allocated
 519  * device for this device. If there's no such, create one.
 520  */
 521 static
 522 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 523 {
 524         struct iser_device *device;
 525
 526         mutex_lock(&ig.device_list_mutex);
 527
 528         list_for_each_entry(device, &ig.device_list, ig_list)
 529                 /* find if there's a match using the node GUID */
 530                 if (device->ib_device->node_guid == cma_id->device->node_guid)
 531                         goto inc_refcnt;
 532
 533         device = kzalloc(sizeof *device, GFP_KERNEL);
 534         if (device == NULL)
 535                 goto out;
 536
 537         /* assign this device to the device */
 538         device->ib_device = cma_id->device;
 539         /* init the device and link it into ig device list */
 540         if (iser_create_device_ib_res(device)) {
 541                 kfree(device);
 542                 device = NULL;
 543                 goto out;
 544         }
 545         list_add(&device->ig_list, &ig.device_list);
 546
 547 inc_refcnt:
 548         device->refcount++;
 549 out:
 550         mutex_unlock(&ig.device_list_mutex);
 551         return device;
 552 }
 553
 554 /* if there's no demand for this device, release it */
 555 static void iser_device_try_release(struct iser_device *device)
 556 {
 557         mutex_lock(&ig.device_list_mutex);
 558         device->refcount--;
 559         iser_info("device %p refcount %d\n", device, device->refcount);
 560         if (!device->refcount) {
 561                 iser_free_device_ib_res(device);
 562                 list_del(&device->ig_list);
 563                 kfree(device);
 564         }
 565         mutex_unlock(&ig.device_list_mutex);
 566 }
 567
 568 /**
 569  * Called with state mutex held
 570  **/
 571 static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
 572                                      enum iser_ib_conn_state comp,
 573                                      enum iser_ib_conn_state exch)
 574 {
 575         int ret;
 576
 577         if ((ret = (ib_conn->state == comp)))
 578                 ib_conn->state = exch;
 579         return ret;
 580 }
 581
 582 void iser_release_work(struct work_struct *work)
 583 {
 584         struct iser_conn *ib_conn;
 585         int rc;
 586
 587         ib_conn = container_of(work, struct iser_conn, release_work);
 588
 589         /* wait for .conn_stop callback */
 590         rc = wait_for_completion_timeout(&ib_conn->stop_completion, 30 * HZ);
 591         WARN_ON(rc == 0);
 592
 593         /* wait for the qp`s post send and post receive buffers to empty */
 594         rc = wait_for_completion_timeout(&ib_conn->flush_completion, 30 * HZ);
 595         WARN_ON(rc == 0);
 596
 597         ib_conn->state = ISER_CONN_DOWN;
 598
 599         mutex_lock(&ib_conn->state_mutex);
 600         ib_conn->state = ISER_CONN_DOWN;
 601         mutex_unlock(&ib_conn->state_mutex);
 602
 603         iser_conn_release(ib_conn);
 604 }
 605
 606 /**
 607  * Frees all conn objects and deallocs conn descriptor
 608  */
 609 void iser_conn_release(struct iser_conn *ib_conn)
 610 {
 611         struct iser_device  *device = ib_conn->device;
 612
 613         mutex_lock(&ig.connlist_mutex);
 614         list_del(&ib_conn->conn_list);
 615         mutex_unlock(&ig.connlist_mutex);
 616
 617         mutex_lock(&ib_conn->state_mutex);
 618         BUG_ON(ib_conn->state != ISER_CONN_DOWN);
 619
 620         iser_free_rx_descriptors(ib_conn);
 621         iser_free_ib_conn_res(ib_conn);
 622         ib_conn->device = NULL;
 623         /* on EVENT_ADDR_ERROR there's no device yet for this conn */
 624         if (device != NULL)
 625                 iser_device_try_release(device);
 626         mutex_unlock(&ib_conn->state_mutex);
 627
 628         /* if cma handler context, the caller actually destroy the id */
 629         if (ib_conn->cma_id != NULL) {
 630                 rdma_destroy_id(ib_conn->cma_id);
 631                 ib_conn->cma_id = NULL;
 632         }
 633         kfree(ib_conn);
 634 }
 635
 636 /**
 637  * triggers start of the disconnect procedures and wait for them to be done
 638  */
 639 void iser_conn_terminate(struct iser_conn *ib_conn)
 640 {
 641         int err = 0;
 642
 643         /* change the ib conn state only if the conn is UP, however always call
 644          * rdma_disconnect since this is the only way to cause the CMA to change
 645          * the QP state to ERROR
 646          */
 647
 648         iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
 649         err = rdma_disconnect(ib_conn->cma_id);
 650         if (err)
 651                 iser_err("Failed to disconnect, conn: 0x%p err %d\n",
 652                          ib_conn,err);
 653 }
 654
 655 /**
 656  * Called with state mutex held
 657  **/
 658 static void iser_connect_error(struct rdma_cm_id *cma_id)
 659 {
 660         struct iser_conn *ib_conn;
 661
 662         ib_conn = (struct iser_conn *)cma_id->context;
 663         ib_conn->state = ISER_CONN_DOWN;
 664 }
 665
 666 /**
 667  * Called with state mutex held
 668  **/
 669 static void iser_addr_handler(struct rdma_cm_id *cma_id)
 670 {
 671         struct iser_device *device;
 672         struct iser_conn   *ib_conn;
 673         int    ret;
 674
 675         ib_conn = (struct iser_conn *)cma_id->context;
 676         if (ib_conn->state != ISER_CONN_PENDING)
 677                 /* bailout */
 678                 return;
 679
 680         device = iser_device_find_by_ib_device(cma_id);
 681         if (!device) {
 682                 iser_err("device lookup/creation failed\n");
 683                 iser_connect_error(cma_id);
 684                 return;
 685         }
 686
 687         ib_conn->device = device;
 688
 689         /* connection T10-PI support */
 690         if (iser_pi_enable) {
 691                 if (!(device->dev_attr.device_cap_flags &
 692                       IB_DEVICE_SIGNATURE_HANDOVER)) {
 693                         iser_warn("T10-PI requested but not supported on %s, "
 694                                   "continue without T10-PI\n",
 695                                   ib_conn->device->ib_device->name);
 696                         ib_conn->pi_support = false;
 697                 } else {
 698                         ib_conn->pi_support = true;
 699                 }
 700         }
 701
 702         ret = rdma_resolve_route(cma_id, 1000);
 703         if (ret) {
 704                 iser_err("resolve route failed: %d\n", ret);
 705                 iser_connect_error(cma_id);
 706                 return;
 707         }
 708 }
 709
 710 /**
 711  * Called with state mutex held
 712  **/
 713 static void iser_route_handler(struct rdma_cm_id *cma_id)
 714 {
 715         struct rdma_conn_param conn_param;
 716         int    ret;
 717         struct iser_cm_hdr req_hdr;
 718         struct iser_conn *ib_conn = (struct iser_conn *)cma_id->context;
 719         struct iser_device *device = ib_conn->device;
 720
 721         if (ib_conn->state != ISER_CONN_PENDING)
 722                 /* bailout */
 723                 return;
 724
 725         ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
 726         if (ret)
 727                 goto failure;
 728
 729         memset(&conn_param, 0, sizeof conn_param);
 730         conn_param.responder_resources = device->dev_attr.max_qp_rd_atom;
 731         conn_param.initiator_depth     = 1;
 732         conn_param.retry_count         = 7;
 733         conn_param.rnr_retry_count     = 6;
 734
 735         memset(&req_hdr, 0, sizeof(req_hdr));
 736         req_hdr.flags = (ISER_ZBVA_NOT_SUPPORTED |
 737                         ISER_SEND_W_INV_NOT_SUPPORTED);
 738         conn_param.private_data         = (void *)&req_hdr;
 739         conn_param.private_data_len     = sizeof(struct iser_cm_hdr);
 740
 741         ret = rdma_connect(cma_id, &conn_param);
 742         if (ret) {
 743                 iser_err("failure connecting: %d\n", ret);
 744                 goto failure;
 745         }
 746
 747         return;
 748 failure:
 749         iser_connect_error(cma_id);
 750 }
 751
 752 static void iser_connected_handler(struct rdma_cm_id *cma_id)
 753 {
 754         struct iser_conn *ib_conn;
 755         struct ib_qp_attr attr;
 756         struct ib_qp_init_attr init_attr;
 757
 758         ib_conn = (struct iser_conn *)cma_id->context;
 759         if (ib_conn->state != ISER_CONN_PENDING)
 760                 /* bailout */
 761                 return;
 762
 763         (void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 764         iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 765
 766         ib_conn->state = ISER_CONN_UP;
 767         complete(&ib_conn->up_completion);
 768 }
 769
 770 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
 771 {
 772         struct iser_conn *ib_conn;
 773
 774         ib_conn = (struct iser_conn *)cma_id->context;
 775
 776         /* getting here when the state is UP means that the conn is being *
 777          * terminated asynchronously from the iSCSI layer's perspective.  */
 778         if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
 779                                         ISER_CONN_TERMINATING)){
 780                 if (ib_conn->iscsi_conn)
 781                         iscsi_conn_failure(ib_conn->iscsi_conn, ISCSI_ERR_CONN_FAILED);
 782                 else
 783                         iser_err("iscsi_iser connection isn't bound\n");
 784         }
 785
 786         /* Complete the termination process if no posts are pending. This code
 787          * block also exists in iser_handle_comp_error(), but it is needed here
 788          * for cases of no flushes at all, e.g. discovery over rdma.
 789          */
 790         if (ib_conn->post_recv_buf_count == 0 &&
 791             (atomic_read(&ib_conn->post_send_buf_count) == 0)) {
 792                 complete(&ib_conn->flush_completion);
 793         }
 794 }
 795
 796 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 797 {
 798         struct iser_conn *ib_conn;
 799
 800         ib_conn = (struct iser_conn *)cma_id->context;
 801         iser_info("event %d status %d conn %p id %p\n",
 802                   event->event, event->status, cma_id->context, cma_id);
 803
 804         mutex_lock(&ib_conn->state_mutex);
 805         switch (event->event) {
 806         case RDMA_CM_EVENT_ADDR_RESOLVED:
 807                 iser_addr_handler(cma_id);
 808                 break;
 809         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 810                 iser_route_handler(cma_id);
 811                 break;
 812         case RDMA_CM_EVENT_ESTABLISHED:
 813                 iser_connected_handler(cma_id);
 814                 break;
 815         case RDMA_CM_EVENT_ADDR_ERROR:
 816         case RDMA_CM_EVENT_ROUTE_ERROR:
 817         case RDMA_CM_EVENT_CONNECT_ERROR:
 818         case RDMA_CM_EVENT_UNREACHABLE:
 819         case RDMA_CM_EVENT_REJECTED:
 820                 iser_connect_error(cma_id);
 821                 break;
 822         case RDMA_CM_EVENT_DISCONNECTED:
 823         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 824         case RDMA_CM_EVENT_ADDR_CHANGE:
 825         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 826                 iser_disconnected_handler(cma_id);
 827                 break;
 828         default:
 829                 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
 830                 break;
 831         }
 832         mutex_unlock(&ib_conn->state_mutex);
 833         return 0;
 834 }
 835
 836 void iser_conn_init(struct iser_conn *ib_conn)
 837 {
 838         ib_conn->state = ISER_CONN_INIT;
 839         ib_conn->post_recv_buf_count = 0;
 840         atomic_set(&ib_conn->post_send_buf_count, 0);
 841         init_completion(&ib_conn->stop_completion);
 842         init_completion(&ib_conn->flush_completion);
 843         init_completion(&ib_conn->up_completion);
 844         INIT_LIST_HEAD(&ib_conn->conn_list);
 845         spin_lock_init(&ib_conn->lock);
 846         mutex_init(&ib_conn->state_mutex);
 847 }
 848
 849  /**
 850  * starts the process of connecting to the target
 851  * sleeps until the connection is established or rejected
 852  */
 853 int iser_connect(struct iser_conn   *ib_conn,
 854                  struct sockaddr    *src_addr,
 855                  struct sockaddr    *dst_addr,
 856                  int                 non_blocking)
 857 {
 858         int err = 0;
 859
 860         mutex_lock(&ib_conn->state_mutex);
 861
 862         sprintf(ib_conn->name, "%pISp", dst_addr);
 863
 864         iser_info("connecting to: %s\n", ib_conn->name);
 865
 866         /* the device is known only --after-- address resolution */
 867         ib_conn->device = NULL;
 868
 869         ib_conn->state = ISER_CONN_PENDING;
 870
 871         ib_conn->cma_id = rdma_create_id(iser_cma_handler,
 872                                              (void *)ib_conn,
 873                                              RDMA_PS_TCP, IB_QPT_RC);
 874         if (IS_ERR(ib_conn->cma_id)) {
 875                 err = PTR_ERR(ib_conn->cma_id);
 876                 iser_err("rdma_create_id failed: %d\n", err);
 877                 goto id_failure;
 878         }
 879
 880         err = rdma_resolve_addr(ib_conn->cma_id, src_addr, dst_addr, 1000);
 881         if (err) {
 882                 iser_err("rdma_resolve_addr failed: %d\n", err);
 883                 goto addr_failure;
 884         }
 885
 886         if (!non_blocking) {
 887                 wait_for_completion_interruptible(&ib_conn->up_completion);
 888
 889                 if (ib_conn->state != ISER_CONN_UP) {
 890                         err =  -EIO;
 891                         goto connect_failure;
 892                 }
 893         }
 894         mutex_unlock(&ib_conn->state_mutex);
 895
 896         mutex_lock(&ig.connlist_mutex);
 897         list_add(&ib_conn->conn_list, &ig.connlist);
 898         mutex_unlock(&ig.connlist_mutex);
 899         return 0;
 900
 901 id_failure:
 902         ib_conn->cma_id = NULL;
 903 addr_failure:
 904         ib_conn->state = ISER_CONN_DOWN;
 905 connect_failure:
 906         mutex_unlock(&ib_conn->state_mutex);
 907         iser_conn_release(ib_conn);
 908         return err;
 909 }
 910
 911 /**
 912  * iser_reg_page_vec - Register physical memory
 913  *
 914  * returns: 0 on success, errno code on failure
 915  */
 916 int iser_reg_page_vec(struct iser_conn     *ib_conn,
 917                       struct iser_page_vec *page_vec,
 918                       struct iser_mem_reg  *mem_reg)
 919 {
 920         struct ib_pool_fmr *mem;
 921         u64                io_addr;
 922         u64                *page_list;
 923         int                status;
 924
 925         page_list = page_vec->pages;
 926         io_addr   = page_list[0];
 927
 928         mem  = ib_fmr_pool_map_phys(ib_conn->fmr.pool,
 929                                     page_list,
 930                                     page_vec->length,
 931                                     io_addr);
 932
 933         if (IS_ERR(mem)) {
 934                 status = (int)PTR_ERR(mem);
 935                 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
 936                 return status;
 937         }
 938
 939         mem_reg->lkey  = mem->fmr->lkey;
 940         mem_reg->rkey  = mem->fmr->rkey;
 941         mem_reg->len   = page_vec->length * SIZE_4K;
 942         mem_reg->va    = io_addr;
 943         mem_reg->is_mr = 1;
 944         mem_reg->mem_h = (void *)mem;
 945
 946         mem_reg->va   += page_vec->offset;
 947         mem_reg->len   = page_vec->data_size;
 948
 949         iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
 950                  "entry[0]: (0x%08lx,%ld)] -> "
 951                  "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
 952                  page_vec, page_vec->length,
 953                  (unsigned long)page_vec->pages[0],
 954                  (unsigned long)page_vec->data_size,
 955                  (unsigned int)mem_reg->lkey, mem_reg->mem_h,
 956                  (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
 957         return 0;
 958 }
 959
 960 /**
 961  * Unregister (previosuly registered using FMR) memory.
 962  * If memory is non-FMR does nothing.
 963  */
 964 void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
 965                         enum iser_data_dir cmd_dir)
 966 {
 967         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 968         int ret;
 969
 970         if (!reg->is_mr)
 971                 return;
 972
 973         iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
 974
 975         ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
 976         if (ret)
 977                 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
 978
 979         reg->mem_h = NULL;
 980 }
 981
 982 void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
 983                             enum iser_data_dir cmd_dir)
 984 {
 985         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
 986         struct iser_conn *ib_conn = iser_task->ib_conn;
 987         struct fast_reg_descriptor *desc = reg->mem_h;
 988
 989         if (!reg->is_mr)
 990                 return;
 991
 992         reg->mem_h = NULL;
 993         reg->is_mr = 0;
 994         spin_lock_bh(&ib_conn->lock);
 995         list_add_tail(&desc->list, &ib_conn->fastreg.pool);
 996         spin_unlock_bh(&ib_conn->lock);
 997 }
 998
 999 int iser_post_recvl(struct iser_conn *ib_conn)
1000 {
1001         struct ib_recv_wr rx_wr, *rx_wr_failed;
1002         struct ib_sge     sge;
1003         int ib_ret;
1004
1005         sge.addr   = ib_conn->login_resp_dma;
1006         sge.length = ISER_RX_LOGIN_SIZE;
1007         sge.lkey   = ib_conn->device->mr->lkey;
1008
1009         rx_wr.wr_id   = (unsigned long)ib_conn->login_resp_buf;
1010         rx_wr.sg_list = &sge;
1011         rx_wr.num_sge = 1;
1012         rx_wr.next    = NULL;
1013
1014         ib_conn->post_recv_buf_count++;
1015         ib_ret  = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
1016         if (ib_ret) {
1017                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1018                 ib_conn->post_recv_buf_count--;
1019         }
1020         return ib_ret;
1021 }
1022
1023 int iser_post_recvm(struct iser_conn *ib_conn, int count)
1024 {
1025         struct ib_recv_wr *rx_wr, *rx_wr_failed;
1026         int i, ib_ret;
1027         unsigned int my_rx_head = ib_conn->rx_desc_head;
1028         struct iser_rx_desc *rx_desc;
1029
1030         for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
1031                 rx_desc         = &ib_conn->rx_descs[my_rx_head];
1032                 rx_wr->wr_id    = (unsigned long)rx_desc;
1033                 rx_wr->sg_list  = &rx_desc->rx_sg;
1034                 rx_wr->num_sge  = 1;
1035                 rx_wr->next     = rx_wr + 1;
1036                 my_rx_head = (my_rx_head + 1) & ib_conn->qp_max_recv_dtos_mask;
1037         }
1038
1039         rx_wr--;
1040         rx_wr->next = NULL; /* mark end of work requests list */
1041
1042         ib_conn->post_recv_buf_count += count;
1043         ib_ret  = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
1044         if (ib_ret) {
1045                 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
1046                 ib_conn->post_recv_buf_count -= count;
1047         } else
1048                 ib_conn->rx_desc_head = my_rx_head;
1049         return ib_ret;
1050 }
1051
1052
1053 /**
1054  * iser_start_send - Initiate a Send DTO operation
1055  *
1056  * returns 0 on success, -1 on failure
1057  */
1058 int iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc)
1059 {
1060         int               ib_ret;
1061         struct ib_send_wr send_wr, *send_wr_failed;
1062
1063         ib_dma_sync_single_for_device(ib_conn->device->ib_device,
1064                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
1065
1066         send_wr.next       = NULL;
1067         send_wr.wr_id      = (unsigned long)tx_desc;
1068         send_wr.sg_list    = tx_desc->tx_sg;
1069         send_wr.num_sge    = tx_desc->num_sge;
1070         send_wr.opcode     = IB_WR_SEND;
1071         send_wr.send_flags = IB_SEND_SIGNALED;
1072
1073         atomic_inc(&ib_conn->post_send_buf_count);
1074
1075         ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
1076         if (ib_ret) {
1077                 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
1078                 atomic_dec(&ib_conn->post_send_buf_count);
1079         }
1080         return ib_ret;
1081 }
1082
1083 static void iser_handle_comp_error(struct iser_tx_desc *desc,
1084                                 struct iser_conn *ib_conn)
1085 {
1086         if (desc && desc->type == ISCSI_TX_DATAOUT)
1087                 kmem_cache_free(ig.desc_cache, desc);
1088
1089         if (ib_conn->post_recv_buf_count == 0 &&
1090             atomic_read(&ib_conn->post_send_buf_count) == 0) {
1091                 /**
1092                  * getting here when the state is UP means that the conn is
1093                  * being terminated asynchronously from the iSCSI layer's
1094                  * perspective. It is safe to peek at the connection state
1095                  * since iscsi_conn_failure is allowed to be called twice.
1096                  **/
1097                 if (ib_conn->state == ISER_CONN_UP)
1098                         iscsi_conn_failure(ib_conn->iscsi_conn,
1099                                            ISCSI_ERR_CONN_FAILED);
1100
1101                 /* no more non completed posts to the QP, complete the
1102                  * termination process w.o worrying on disconnect event */
1103                 complete(&ib_conn->flush_completion);
1104         }
1105 }
1106
1107 static int iser_drain_tx_cq(struct iser_device  *device, int cq_index)
1108 {
1109         struct ib_cq  *cq = device->tx_cq[cq_index];
1110         struct ib_wc  wc;
1111         struct iser_tx_desc *tx_desc;
1112         struct iser_conn *ib_conn;
1113         int completed_tx = 0;
1114
1115         while (ib_poll_cq(cq, 1, &wc) == 1) {
1116                 tx_desc = (struct iser_tx_desc *) (unsigned long) wc.wr_id;
1117                 ib_conn = wc.qp->qp_context;
1118                 if (wc.status == IB_WC_SUCCESS) {
1119                         if (wc.opcode == IB_WC_SEND)
1120                                 iser_snd_completion(tx_desc, ib_conn);
1121                         else
1122                                 iser_err("expected opcode %d got %d\n",
1123                                         IB_WC_SEND, wc.opcode);
1124                 } else {
1125                         iser_err("tx id %llx status %d vend_err %x\n",
1126                                  wc.wr_id, wc.status, wc.vendor_err);
1127                         if (wc.wr_id != ISER_FASTREG_LI_WRID) {
1128                                 atomic_dec(&ib_conn->post_send_buf_count);
1129                                 iser_handle_comp_error(tx_desc, ib_conn);
1130                         }
1131                 }
1132                 completed_tx++;
1133         }
1134         return completed_tx;
1135 }
1136
1137
1138 static void iser_cq_tasklet_fn(unsigned long data)
1139 {
1140         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)data;
1141         struct iser_device  *device = cq_desc->device;
1142         int cq_index = cq_desc->cq_index;
1143         struct ib_cq         *cq = device->rx_cq[cq_index];
1144          struct ib_wc        wc;
1145          struct iser_rx_desc *desc;
1146          unsigned long       xfer_len;
1147         struct iser_conn *ib_conn;
1148         int completed_tx, completed_rx = 0;
1149
1150         /* First do tx drain, so in a case where we have rx flushes and a successful
1151          * tx completion we will still go through completion error handling.
1152          */
1153         completed_tx = iser_drain_tx_cq(device, cq_index);
1154
1155         while (ib_poll_cq(cq, 1, &wc) == 1) {
1156                 desc     = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
1157                 BUG_ON(desc == NULL);
1158                 ib_conn = wc.qp->qp_context;
1159                 if (wc.status == IB_WC_SUCCESS) {
1160                         if (wc.opcode == IB_WC_RECV) {
1161                                 xfer_len = (unsigned long)wc.byte_len;
1162                                 iser_rcv_completion(desc, xfer_len, ib_conn);
1163                         } else
1164                                 iser_err("expected opcode %d got %d\n",
1165                                         IB_WC_RECV, wc.opcode);
1166                 } else {
1167                         if (wc.status != IB_WC_WR_FLUSH_ERR)
1168                                 iser_err("rx id %llx status %d vend_err %x\n",
1169                                         wc.wr_id, wc.status, wc.vendor_err);
1170                         ib_conn->post_recv_buf_count--;
1171                         iser_handle_comp_error(NULL, ib_conn);
1172                 }
1173                 completed_rx++;
1174                 if (!(completed_rx & 63))
1175                         completed_tx += iser_drain_tx_cq(device, cq_index);
1176         }
1177         /* #warning "it is assumed here that arming CQ only once its empty" *
1178          * " would not cause interrupts to be missed"                       */
1179         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1180
1181         iser_dbg("got %d rx %d tx completions\n", completed_rx, completed_tx);
1182 }
1183
1184 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
1185 {
1186         struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)cq_context;
1187         struct iser_device  *device = cq_desc->device;
1188         int cq_index = cq_desc->cq_index;
1189
1190         tasklet_schedule(&device->cq_tasklet[cq_index]);
1191 }
1192
1193 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,
1194                              enum iser_data_dir cmd_dir, sector_t *sector)
1195 {
1196         struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
1197         struct fast_reg_descriptor *desc = reg->mem_h;
1198         unsigned long sector_size = iser_task->sc->device->sector_size;
1199         struct ib_mr_status mr_status;
1200         int ret;
1201
1202         if (desc && desc->reg_indicators & ISER_FASTREG_PROTECTED) {
1203                 desc->reg_indicators &= ~ISER_FASTREG_PROTECTED;
1204                 ret = ib_check_mr_status(desc->pi_ctx->sig_mr,
1205                                          IB_MR_CHECK_SIG_STATUS, &mr_status);
1206                 if (ret) {
1207                         pr_err("ib_check_mr_status failed, ret %d\n", ret);
1208                         goto err;
1209                 }
1210
1211                 if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
1212                         sector_t sector_off = mr_status.sig_err.sig_err_offset;
1213
1214                         do_div(sector_off, sector_size + 8);
1215                         *sector = scsi_get_lba(iser_task->sc) + sector_off;
1216
1217                         pr_err("PI error found type %d at sector %llx "
1218                                "expected %x vs actual %x\n",
1219                                mr_status.sig_err.err_type,
1220                                (unsigned long long)*sector,
1221                                mr_status.sig_err.expected,
1222                                mr_status.sig_err.actual);
1223
1224                         switch (mr_status.sig_err.err_type) {
1225                         case IB_SIG_BAD_GUARD:
1226                                 return 0x1;
1227                         case IB_SIG_BAD_REFTAG:
1228                                 return 0x3;
1229                         case IB_SIG_BAD_APPTAG:
1230                                 return 0x2;
1231                         }
1232                 }
1233         }
1234
1235         return 0;
1236 err:
1237         /* Not alot we can do here, return ambiguous guard error */
1238         return 0x1;
1239 }