drivers/infiniband/ulp/iser/iser_initiator.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32 #include <linux/kernel.h>
  33 #include <linux/slab.h>
  34 #include <linux/mm.h>
  35 #include <linux/scatterlist.h>
  36 #include <linux/kfifo.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39
  40 #include "iscsi_iser.h"
  41
  42 /* Constant PDU lengths calculations */
  43 #define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
  44                                  sizeof (struct iscsi_hdr))
  45
  46 /* iser_dto_add_regd_buff - increments the reference count for *
  47  * the registered buffer & adds it to the DTO object           */
  48 static void iser_dto_add_regd_buff(struct iser_dto *dto,
  49                                    struct iser_regd_buf *regd_buf,
  50                                    unsigned long use_offset,
  51                                    unsigned long use_size)
  52 {
  53         int add_idx;
  54
  55         atomic_inc(&regd_buf->ref_count);
  56
  57         add_idx = dto->regd_vector_len;
  58         dto->regd[add_idx] = regd_buf;
  59         dto->used_sz[add_idx] = use_size;
  60         dto->offset[add_idx] = use_offset;
  61
  62         dto->regd_vector_len++;
  63 }
  64
  65 /* Register user buffer memory and initialize passive rdma
  66  *  dto descriptor. Total data size is stored in
  67  *  iser_task->data[ISER_DIR_IN].data_len
  68  */
  69 static int iser_prepare_read_cmd(struct iscsi_task *task,
  70                                  unsigned int edtl)
  71
  72 {
  73         struct iscsi_iser_task *iser_task = task->dd_data;
  74         struct iser_regd_buf *regd_buf;
  75         int err;
  76         struct iser_hdr *hdr = &iser_task->desc.iser_header;
  77         struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
  78
  79         err = iser_dma_map_task_data(iser_task,
  80                                      buf_in,
  81                                      ISER_DIR_IN,
  82                                      DMA_FROM_DEVICE);
  83         if (err)
  84                 return err;
  85
  86         if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
  87                 iser_err("Total data length: %ld, less than EDTL: "
  88                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  89                          iser_task->data[ISER_DIR_IN].data_len, edtl,
  90                          task->itt, iser_task->iser_conn);
  91                 return -EINVAL;
  92         }
  93
  94         err = iser_reg_rdma_mem(iser_task,ISER_DIR_IN);
  95         if (err) {
  96                 iser_err("Failed to set up Data-IN RDMA\n");
  97                 return err;
  98         }
  99         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
 100
 101         hdr->flags    |= ISER_RSV;
 102         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
 103         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
 104
 105         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
 106                  task->itt, regd_buf->reg.rkey,
 107                  (unsigned long long)regd_buf->reg.va);
 108
 109         return 0;
 110 }
 111
 112 /* Register user buffer memory and initialize passive rdma
 113  *  dto descriptor. Total data size is stored in
 114  *  task->data[ISER_DIR_OUT].data_len
 115  */
 116 static int
 117 iser_prepare_write_cmd(struct iscsi_task *task,
 118                        unsigned int imm_sz,
 119                        unsigned int unsol_sz,
 120                        unsigned int edtl)
 121 {
 122         struct iscsi_iser_task *iser_task = task->dd_data;
 123         struct iser_regd_buf *regd_buf;
 124         int err;
 125         struct iser_dto *send_dto = &iser_task->desc.dto;
 126         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 127         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 128
 129         err = iser_dma_map_task_data(iser_task,
 130                                      buf_out,
 131                                      ISER_DIR_OUT,
 132                                      DMA_TO_DEVICE);
 133         if (err)
 134                 return err;
 135
 136         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
 137                 iser_err("Total data length: %ld, less than EDTL: %d, "
 138                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 139                          iser_task->data[ISER_DIR_OUT].data_len,
 140                          edtl, task->itt, task->conn);
 141                 return -EINVAL;
 142         }
 143
 144         err = iser_reg_rdma_mem(iser_task,ISER_DIR_OUT);
 145         if (err != 0) {
 146                 iser_err("Failed to register write cmd RDMA mem\n");
 147                 return err;
 148         }
 149
 150         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 151
 152         if (unsol_sz < edtl) {
 153                 hdr->flags     |= ISER_WSV;
 154                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 155                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 156
 157                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 158                          "VA:%#llX + unsol:%d\n",
 159                          task->itt, regd_buf->reg.rkey,
 160                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 161         }
 162
 163         if (imm_sz > 0) {
 164                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 165                          task->itt, imm_sz);
 166                 iser_dto_add_regd_buff(send_dto,
 167                                        regd_buf,
 168                                        0,
 169                                        imm_sz);
 170         }
 171
 172         return 0;
 173 }
 174
 175 /**
 176  * iser_post_receive_control - allocates, initializes and posts receive DTO.
 177  */
 178 static int iser_post_receive_control(struct iscsi_conn *conn)
 179 {
 180         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 181         struct iser_desc     *rx_desc;
 182         struct iser_regd_buf *regd_hdr;
 183         struct iser_regd_buf *regd_data;
 184         struct iser_dto      *recv_dto = NULL;
 185         struct iser_device  *device = iser_conn->ib_conn->device;
 186         int rx_data_size, err;
 187         int posts, outstanding_unexp_pdus;
 188
 189         /* for the login sequence we must support rx of upto 8K; login is done
 190          * after conn create/bind (connect) and conn stop/bind (reconnect),
 191          * what's common for both schemes is that the connection is not started
 192          */
 193         if (conn->c_stage != ISCSI_CONN_STARTED)
 194                 rx_data_size = ISCSI_DEF_MAX_RECV_SEG_LEN;
 195         else /* FIXME till user space sets conn->max_recv_dlength correctly */
 196                 rx_data_size = 128;
 197
 198         outstanding_unexp_pdus =
 199                 atomic_xchg(&iser_conn->ib_conn->unexpected_pdu_count, 0);
 200
 201         /*
 202          * in addition to the response buffer, replace those consumed by
 203          * unexpected pdus.
 204          */
 205         for (posts = 0; posts < 1 + outstanding_unexp_pdus; posts++) {
 206                 rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 207                 if (rx_desc == NULL) {
 208                         iser_err("Failed to alloc desc for post recv %d\n",
 209                                  posts);
 210                         err = -ENOMEM;
 211                         goto post_rx_cache_alloc_failure;
 212                 }
 213                 rx_desc->type = ISCSI_RX;
 214                 rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
 215                 if (rx_desc->data == NULL) {
 216                         iser_err("Failed to alloc data buf for post recv %d\n",
 217                                  posts);
 218                         err = -ENOMEM;
 219                         goto post_rx_kmalloc_failure;
 220                 }
 221
 222                 recv_dto = &rx_desc->dto;
 223                 recv_dto->ib_conn = iser_conn->ib_conn;
 224                 recv_dto->regd_vector_len = 0;
 225
 226                 regd_hdr = &rx_desc->hdr_regd_buf;
 227                 memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 228                 regd_hdr->device  = device;
 229                 regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
 230                 regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 231
 232                 iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);
 233
 234                 iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);
 235
 236                 regd_data = &rx_desc->data_regd_buf;
 237                 memset(regd_data, 0, sizeof(struct iser_regd_buf));
 238                 regd_data->device  = device;
 239                 regd_data->virt_addr  = rx_desc->data;
 240                 regd_data->data_size  = rx_data_size;
 241
 242                 iser_reg_single(device, regd_data, DMA_FROM_DEVICE);
 243
 244                 iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);
 245
 246                 err = iser_post_recv(rx_desc);
 247                 if (err) {
 248                         iser_err("Failed iser_post_recv for post %d\n", posts);
 249                         goto post_rx_post_recv_failure;
 250                 }
 251         }
 252         /* all posts successful */
 253         return 0;
 254
 255 post_rx_post_recv_failure:
 256         iser_dto_buffs_release(recv_dto);
 257         kfree(rx_desc->data);
 258 post_rx_kmalloc_failure:
 259         kmem_cache_free(ig.desc_cache, rx_desc);
 260 post_rx_cache_alloc_failure:
 261         if (posts > 0) {
 262                 /*
 263                  * response buffer posted, but did not replace all unexpected
 264                  * pdu recv bufs. Ignore error, retry occurs next send
 265                  */
 266                 outstanding_unexp_pdus -= (posts - 1);
 267                 err = 0;
 268         }
 269         atomic_add(outstanding_unexp_pdus,
 270                    &iser_conn->ib_conn->unexpected_pdu_count);
 271
 272         return err;
 273 }
 274
 275 /* creates a new tx descriptor and adds header regd buffer */
 276 static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
 277                                   struct iser_desc       *tx_desc)
 278 {
 279         struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
 280         struct iser_dto      *send_dto = &tx_desc->dto;
 281
 282         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 283         regd_hdr->device  = iser_conn->ib_conn->device;
 284         regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
 285         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 286
 287         send_dto->ib_conn         = iser_conn->ib_conn;
 288         send_dto->notify_enable   = 1;
 289         send_dto->regd_vector_len = 0;
 290
 291         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 292         tx_desc->iser_header.flags = ISER_VER;
 293
 294         iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
 295 }
 296
 297 /**
 298  *  iser_conn_set_full_featured_mode - (iSER API)
 299  */
 300 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 301 {
 302         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 303
 304         int i;
 305         /*
 306          * FIXME this value should be declared to the target during login with
 307          * the MaxOutstandingUnexpectedPDUs key when supported
 308          */
 309         int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;
 310
 311         iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
 312
 313         /* Check that there is no posted recv or send buffers left - */
 314         /* they must be consumed during the login phase */
 315         BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
 316         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 317
 318         /* Initial post receive buffers */
 319         for (i = 0; i < initial_post_recv_bufs_num; i++) {
 320                 if (iser_post_receive_control(conn) != 0) {
 321                         iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
 322                                  i, conn);
 323                         return -ENOMEM;
 324                 }
 325         }
 326         iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
 327         return 0;
 328 }
 329
 330 static int
 331 iser_check_xmit(struct iscsi_conn *conn, void *task)
 332 {
 333         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 334
 335         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 336             ISER_QP_MAX_REQ_DTOS) {
 337                 iser_dbg("%ld can't xmit task %p\n",jiffies,task);
 338                 return -ENOBUFS;
 339         }
 340         return 0;
 341 }
 342
 343
 344 /**
 345  * iser_send_command - send command PDU
 346  */
 347 int iser_send_command(struct iscsi_conn *conn,
 348                       struct iscsi_task *task)
 349 {
 350         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 351         struct iscsi_iser_task *iser_task = task->dd_data;
 352         struct iser_dto *send_dto = NULL;
 353         unsigned long edtl;
 354         int err = 0;
 355         struct iser_data_buf *data_buf;
 356
 357         struct iscsi_cmd *hdr =  task->hdr;
 358         struct scsi_cmnd *sc  =  task->sc;
 359
 360         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 361                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 362                 return -EPERM;
 363         }
 364         if (iser_check_xmit(conn, task))
 365                 return -ENOBUFS;
 366
 367         edtl = ntohl(hdr->data_length);
 368
 369         /* build the tx desc regd header and add it to the tx desc dto */
 370         iser_task->desc.type = ISCSI_TX_SCSI_COMMAND;
 371         send_dto = &iser_task->desc.dto;
 372         send_dto->task = iser_task;
 373         iser_create_send_desc(iser_conn, &iser_task->desc);
 374
 375         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 376                 data_buf = &iser_task->data[ISER_DIR_IN];
 377         else
 378                 data_buf = &iser_task->data[ISER_DIR_OUT];
 379
 380         if (scsi_sg_count(sc)) { /* using a scatter list */
 381                 data_buf->buf  = scsi_sglist(sc);
 382                 data_buf->size = scsi_sg_count(sc);
 383         }
 384
 385         data_buf->data_len = scsi_bufflen(sc);
 386
 387         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 388                 err = iser_prepare_read_cmd(task, edtl);
 389                 if (err)
 390                         goto send_command_error;
 391         }
 392         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 393                 err = iser_prepare_write_cmd(task,
 394                                              task->imm_count,
 395                                              task->imm_count +
 396                                              task->unsol_count,
 397                                              edtl);
 398                 if (err)
 399                         goto send_command_error;
 400         }
 401
 402         iser_reg_single(iser_conn->ib_conn->device,
 403                         send_dto->regd[0], DMA_TO_DEVICE);
 404
 405         if (iser_post_receive_control(conn) != 0) {
 406                 iser_err("post_recv failed!\n");
 407                 err = -ENOMEM;
 408                 goto send_command_error;
 409         }
 410
 411         iser_task->status = ISER_TASK_STATUS_STARTED;
 412
 413         err = iser_post_send(&iser_task->desc);
 414         if (!err)
 415                 return 0;
 416
 417 send_command_error:
 418         iser_dto_buffs_release(send_dto);
 419         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 420         return err;
 421 }
 422
 423 /**
 424  * iser_send_data_out - send data out PDU
 425  */
 426 int iser_send_data_out(struct iscsi_conn *conn,
 427                        struct iscsi_task *task,
 428                        struct iscsi_data *hdr)
 429 {
 430         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 431         struct iscsi_iser_task *iser_task = task->dd_data;
 432         struct iser_desc *tx_desc = NULL;
 433         struct iser_dto *send_dto = NULL;
 434         unsigned long buf_offset;
 435         unsigned long data_seg_len;
 436         uint32_t itt;
 437         int err = 0;
 438
 439         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 440                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 441                 return -EPERM;
 442         }
 443
 444         if (iser_check_xmit(conn, task))
 445                 return -ENOBUFS;
 446
 447         itt = (__force uint32_t)hdr->itt;
 448         data_seg_len = ntoh24(hdr->dlength);
 449         buf_offset   = ntohl(hdr->offset);
 450
 451         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 452                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 453
 454         tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 455         if (tx_desc == NULL) {
 456                 iser_err("Failed to alloc desc for post dataout\n");
 457                 return -ENOMEM;
 458         }
 459
 460         tx_desc->type = ISCSI_TX_DATAOUT;
 461         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 462
 463         /* build the tx desc regd header and add it to the tx desc dto */
 464         send_dto = &tx_desc->dto;
 465         send_dto->task = iser_task;
 466         iser_create_send_desc(iser_conn, tx_desc);
 467
 468         iser_reg_single(iser_conn->ib_conn->device,
 469                         send_dto->regd[0], DMA_TO_DEVICE);
 470
 471         /* all data was registered for RDMA, we can use the lkey */
 472         iser_dto_add_regd_buff(send_dto,
 473                                &iser_task->rdma_regd[ISER_DIR_OUT],
 474                                buf_offset,
 475                                data_seg_len);
 476
 477         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 478                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 479                          "inconsistent with total len:%ld, itt:%d\n",
 480                          buf_offset, data_seg_len,
 481                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 482                 err = -EINVAL;
 483                 goto send_data_out_error;
 484         }
 485         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 486                  itt, buf_offset, data_seg_len);
 487
 488
 489         err = iser_post_send(tx_desc);
 490         if (!err)
 491                 return 0;
 492
 493 send_data_out_error:
 494         iser_dto_buffs_release(send_dto);
 495         kmem_cache_free(ig.desc_cache, tx_desc);
 496         iser_err("conn %p failed err %d\n",conn, err);
 497         return err;
 498 }
 499
 500 int iser_send_control(struct iscsi_conn *conn,
 501                       struct iscsi_task *task)
 502 {
 503         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 504         struct iscsi_iser_task *iser_task = task->dd_data;
 505         struct iser_desc *mdesc = &iser_task->desc;
 506         struct iser_dto *send_dto = NULL;
 507         unsigned long data_seg_len;
 508         int err = 0;
 509         struct iser_regd_buf *regd_buf;
 510         struct iser_device *device;
 511         unsigned char opcode;
 512
 513         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 514                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 515                 return -EPERM;
 516         }
 517
 518         if (iser_check_xmit(conn, task))
 519                 return -ENOBUFS;
 520
 521         /* build the tx desc regd header and add it to the tx desc dto */
 522         mdesc->type = ISCSI_TX_CONTROL;
 523         send_dto = &mdesc->dto;
 524         send_dto->task = NULL;
 525         iser_create_send_desc(iser_conn, mdesc);
 526
 527         device = iser_conn->ib_conn->device;
 528
 529         iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
 530
 531         data_seg_len = ntoh24(task->hdr->dlength);
 532
 533         if (data_seg_len > 0) {
 534                 regd_buf = &mdesc->data_regd_buf;
 535                 memset(regd_buf, 0, sizeof(struct iser_regd_buf));
 536                 regd_buf->device = device;
 537                 regd_buf->virt_addr = task->data;
 538                 regd_buf->data_size = task->data_count;
 539                 iser_reg_single(device, regd_buf,
 540                                 DMA_TO_DEVICE);
 541                 iser_dto_add_regd_buff(send_dto, regd_buf,
 542                                        0,
 543                                        data_seg_len);
 544         }
 545
 546         opcode = task->hdr->opcode & ISCSI_OPCODE_MASK;
 547
 548         /* post recv buffer for response if one is expected */
 549         if (!(opcode == ISCSI_OP_NOOP_OUT && task->hdr->itt == RESERVED_ITT)) {
 550                 if (iser_post_receive_control(conn) != 0) {
 551                         iser_err("post_rcv_buff failed!\n");
 552                         err = -ENOMEM;
 553                         goto send_control_error;
 554                 }
 555         }
 556
 557         err = iser_post_send(mdesc);
 558         if (!err)
 559                 return 0;
 560
 561 send_control_error:
 562         iser_dto_buffs_release(send_dto);
 563         iser_err("conn %p failed err %d\n",conn, err);
 564         return err;
 565 }
 566
 567 /**
 568  * iser_rcv_dto_completion - recv DTO completion
 569  */
 570 void iser_rcv_completion(struct iser_desc *rx_desc,
 571                          unsigned long dto_xfer_len)
 572 {
 573         struct iser_dto *dto = &rx_desc->dto;
 574         struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
 575         struct iscsi_task *task;
 576         struct iscsi_iser_task *iser_task;
 577         struct iscsi_hdr *hdr;
 578         char   *rx_data = NULL;
 579         int     rx_data_len = 0;
 580         unsigned char opcode;
 581
 582         hdr = &rx_desc->iscsi_header;
 583
 584         iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
 585
 586         if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
 587                 rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
 588                 rx_data     = dto->regd[1]->virt_addr;
 589                 rx_data    += dto->offset[1];
 590         }
 591
 592         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 593
 594         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 595                 spin_lock(&conn->iscsi_conn->session->lock);
 596                 task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);
 597                 if (task)
 598                         __iscsi_get_task(task);
 599                 spin_unlock(&conn->iscsi_conn->session->lock);
 600
 601                 if (!task)
 602                         iser_err("itt can't be matched to task!!! "
 603                                  "conn %p opcode %d itt %d\n",
 604                                  conn->iscsi_conn, opcode, hdr->itt);
 605                 else {
 606                         iser_task = task->dd_data;
 607                         iser_dbg("itt %d task %p\n",hdr->itt, task);
 608                         iser_task->status = ISER_TASK_STATUS_COMPLETED;
 609                         iser_task_rdma_finalize(iser_task);
 610                         iscsi_put_task(task);
 611                 }
 612         }
 613         iser_dto_buffs_release(dto);
 614
 615         iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
 616
 617         kfree(rx_desc->data);
 618         kmem_cache_free(ig.desc_cache, rx_desc);
 619
 620         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 621          * task eliminates the need to worry on tasks which are completed in   *
 622          * parallel to the execution of iser_conn_term. So the code that waits *
 623          * for the posted rx bufs refcount to become zero handles everything   */
 624         atomic_dec(&conn->ib_conn->post_recv_buf_count);
 625
 626         /*
 627          * if an unexpected PDU was received then the recv wr consumed must
 628          * be replaced, this is done in the next send of a control-type PDU
 629          */
 630         if (opcode == ISCSI_OP_NOOP_IN && hdr->itt == RESERVED_ITT) {
 631                 /* nop-in with itt = 0xffffffff */
 632                 atomic_inc(&conn->ib_conn->unexpected_pdu_count);
 633         }
 634         else if (opcode == ISCSI_OP_ASYNC_EVENT) {
 635                 /* asyncronous message */
 636                 atomic_inc(&conn->ib_conn->unexpected_pdu_count);
 637         }
 638         /* a reject PDU consumes the recv buf posted for the response */
 639 }
 640
 641 void iser_snd_completion(struct iser_desc *tx_desc)
 642 {
 643         struct iser_dto        *dto = &tx_desc->dto;
 644         struct iser_conn       *ib_conn = dto->ib_conn;
 645         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 646         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 647         struct iscsi_task *task;
 648         int resume_tx = 0;
 649
 650         iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
 651
 652         iser_dto_buffs_release(dto);
 653
 654         if (tx_desc->type == ISCSI_TX_DATAOUT)
 655                 kmem_cache_free(ig.desc_cache, tx_desc);
 656
 657         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 658             ISER_QP_MAX_REQ_DTOS)
 659                 resume_tx = 1;
 660
 661         atomic_dec(&ib_conn->post_send_buf_count);
 662
 663         if (resume_tx) {
 664                 iser_dbg("%ld resuming tx\n",jiffies);
 665                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 666         }
 667
 668         if (tx_desc->type == ISCSI_TX_CONTROL) {
 669                 /* this arithmetic is legal by libiscsi dd_data allocation */
 670                 task = (void *) ((long)(void *)tx_desc -
 671                                   sizeof(struct iscsi_task));
 672                 if (task->hdr->itt == RESERVED_ITT)
 673                         iscsi_put_task(task);
 674         }
 675 }
 676
 677 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 678
 679 {
 680         iser_task->status = ISER_TASK_STATUS_INIT;
 681
 682         iser_task->dir[ISER_DIR_IN] = 0;
 683         iser_task->dir[ISER_DIR_OUT] = 0;
 684
 685         iser_task->data[ISER_DIR_IN].data_len  = 0;
 686         iser_task->data[ISER_DIR_OUT].data_len = 0;
 687
 688         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 689                sizeof(struct iser_regd_buf));
 690         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 691                sizeof(struct iser_regd_buf));
 692 }
 693
 694 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 695 {
 696         int deferred;
 697         int is_rdma_aligned = 1;
 698         struct iser_regd_buf *regd;
 699
 700         /* if we were reading, copy back to unaligned sglist,
 701          * anyway dma_unmap and free the copy
 702          */
 703         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 704                 is_rdma_aligned = 0;
 705                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
 706         }
 707         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 708                 is_rdma_aligned = 0;
 709                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
 710         }
 711
 712         if (iser_task->dir[ISER_DIR_IN]) {
 713                 regd = &iser_task->rdma_regd[ISER_DIR_IN];
 714                 deferred = iser_regd_buff_release(regd);
 715                 if (deferred) {
 716                         iser_err("%d references remain for BUF-IN rdma reg\n",
 717                                  atomic_read(&regd->ref_count));
 718                 }
 719         }
 720
 721         if (iser_task->dir[ISER_DIR_OUT]) {
 722                 regd = &iser_task->rdma_regd[ISER_DIR_OUT];
 723                 deferred = iser_regd_buff_release(regd);
 724                 if (deferred) {
 725                         iser_err("%d references remain for BUF-OUT rdma reg\n",
 726                                  atomic_read(&regd->ref_count));
 727                 }
 728         }
 729
 730        /* if the data was unaligned, it was already unmapped and then copied */
 731        if (is_rdma_aligned)
 732                 iser_dma_unmap_task_data(iser_task);
 733 }
 734
 735 void iser_dto_buffs_release(struct iser_dto *dto)
 736 {
 737         int i;
 738
 739         for (i = 0; i < dto->regd_vector_len; i++)
 740                 iser_regd_buff_release(dto->regd[i]);
 741 }
 742