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_ctask->data[ISER_DIR_IN].data_len
  68  */
  69 static int iser_prepare_read_cmd(struct iscsi_cmd_task *ctask,
  70                                  unsigned int edtl)
  71
  72 {
  73         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
  74         struct iser_regd_buf *regd_buf;
  75         int err;
  76         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
  77         struct iser_data_buf *buf_in = &iser_ctask->data[ISER_DIR_IN];
  78
  79         err = iser_dma_map_task_data(iser_ctask,
  80                                      buf_in,
  81                                      ISER_DIR_IN,
  82                                      DMA_FROM_DEVICE);
  83         if (err)
  84                 return err;
  85
  86         if (edtl > iser_ctask->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_ctask->data[ISER_DIR_IN].data_len, edtl,
  90                          ctask->itt, iser_ctask->iser_conn);
  91                 return -EINVAL;
  92         }
  93
  94         err = iser_reg_rdma_mem(iser_ctask,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_ctask->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                  ctask->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  *  ctask->data[ISER_DIR_OUT].data_len
 115  */
 116 static int
 117 iser_prepare_write_cmd(struct iscsi_cmd_task *ctask,
 118                        unsigned int imm_sz,
 119                        unsigned int unsol_sz,
 120                        unsigned int edtl)
 121 {
 122         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 123         struct iser_regd_buf *regd_buf;
 124         int err;
 125         struct iser_dto *send_dto = &iser_ctask->desc.dto;
 126         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
 127         struct iser_data_buf *buf_out = &iser_ctask->data[ISER_DIR_OUT];
 128
 129         err = iser_dma_map_task_data(iser_ctask,
 130                                      buf_out,
 131                                      ISER_DIR_OUT,
 132                                      DMA_TO_DEVICE);
 133         if (err)
 134                 return err;
 135
 136         if (edtl > iser_ctask->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_ctask->data[ISER_DIR_OUT].data_len,
 140                          edtl, ctask->itt, ctask->conn);
 141                 return -EINVAL;
 142         }
 143
 144         err = iser_reg_rdma_mem(iser_ctask,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_ctask->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                          ctask->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                          ctask->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 = 0;
 187
 188         rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 189         if (rx_desc == NULL) {
 190                 iser_err("Failed to alloc desc for post recv\n");
 191                 return -ENOMEM;
 192         }
 193         rx_desc->type = ISCSI_RX;
 194
 195         /* for the login sequence we must support rx of upto 8K; login is done
 196          * after conn create/bind (connect) and conn stop/bind (reconnect),
 197          * what's common for both schemes is that the connection is not started
 198          */
 199         if (conn->c_stage != ISCSI_CONN_STARTED)
 200                 rx_data_size = ISCSI_DEF_MAX_RECV_SEG_LEN;
 201         else /* FIXME till user space sets conn->max_recv_dlength correctly */
 202                 rx_data_size = 128;
 203
 204         rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
 205         if (rx_desc->data == NULL) {
 206                 iser_err("Failed to alloc data buf for post recv\n");
 207                 err = -ENOMEM;
 208                 goto post_rx_kmalloc_failure;
 209         }
 210
 211         recv_dto = &rx_desc->dto;
 212         recv_dto->ib_conn = iser_conn->ib_conn;
 213         recv_dto->regd_vector_len = 0;
 214
 215         regd_hdr = &rx_desc->hdr_regd_buf;
 216         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 217         regd_hdr->device  = device;
 218         regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
 219         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 220
 221         iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);
 222
 223         iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);
 224
 225         regd_data = &rx_desc->data_regd_buf;
 226         memset(regd_data, 0, sizeof(struct iser_regd_buf));
 227         regd_data->device  = device;
 228         regd_data->virt_addr  = rx_desc->data;
 229         regd_data->data_size  = rx_data_size;
 230
 231         iser_reg_single(device, regd_data, DMA_FROM_DEVICE);
 232
 233         iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);
 234
 235         err = iser_post_recv(rx_desc);
 236         if (!err)
 237                 return 0;
 238
 239         /* iser_post_recv failed */
 240         iser_dto_buffs_release(recv_dto);
 241         kfree(rx_desc->data);
 242 post_rx_kmalloc_failure:
 243         kmem_cache_free(ig.desc_cache, rx_desc);
 244         return err;
 245 }
 246
 247 /* creates a new tx descriptor and adds header regd buffer */
 248 static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
 249                                   struct iser_desc       *tx_desc)
 250 {
 251         struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
 252         struct iser_dto      *send_dto = &tx_desc->dto;
 253
 254         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 255         regd_hdr->device  = iser_conn->ib_conn->device;
 256         regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
 257         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 258
 259         send_dto->ib_conn         = iser_conn->ib_conn;
 260         send_dto->notify_enable   = 1;
 261         send_dto->regd_vector_len = 0;
 262
 263         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 264         tx_desc->iser_header.flags = ISER_VER;
 265
 266         iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
 267 }
 268
 269 /**
 270  *  iser_conn_set_full_featured_mode - (iSER API)
 271  */
 272 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 273 {
 274         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 275
 276         int i;
 277         /* no need to keep it in a var, we are after login so if this should
 278          * be negotiated, by now the result should be available here */
 279         int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;
 280
 281         iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
 282
 283         /* Check that there is no posted recv or send buffers left - */
 284         /* they must be consumed during the login phase */
 285         BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
 286         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 287
 288         /* Initial post receive buffers */
 289         for (i = 0; i < initial_post_recv_bufs_num; i++) {
 290                 if (iser_post_receive_control(conn) != 0) {
 291                         iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
 292                                  i, conn);
 293                         return -ENOMEM;
 294                 }
 295         }
 296         iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
 297         return 0;
 298 }
 299
 300 static int
 301 iser_check_xmit(struct iscsi_conn *conn, void *task)
 302 {
 303         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 304
 305         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 306             ISER_QP_MAX_REQ_DTOS) {
 307                 iser_dbg("%ld can't xmit task %p\n",jiffies,task);
 308                 return -ENOBUFS;
 309         }
 310         return 0;
 311 }
 312
 313
 314 /**
 315  * iser_send_command - send command PDU
 316  */
 317 int iser_send_command(struct iscsi_conn     *conn,
 318                       struct iscsi_cmd_task *ctask)
 319 {
 320         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 321         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 322         struct iser_dto *send_dto = NULL;
 323         unsigned long edtl;
 324         int err = 0;
 325         struct iser_data_buf *data_buf;
 326
 327         struct iscsi_cmd *hdr =  ctask->hdr;
 328         struct scsi_cmnd *sc  =  ctask->sc;
 329
 330         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 331                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 332                 return -EPERM;
 333         }
 334         if (iser_check_xmit(conn, ctask))
 335                 return -ENOBUFS;
 336
 337         edtl = ntohl(hdr->data_length);
 338
 339         /* build the tx desc regd header and add it to the tx desc dto */
 340         iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
 341         send_dto = &iser_ctask->desc.dto;
 342         send_dto->ctask = iser_ctask;
 343         iser_create_send_desc(iser_conn, &iser_ctask->desc);
 344
 345         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 346                 data_buf = &iser_ctask->data[ISER_DIR_IN];
 347         else
 348                 data_buf = &iser_ctask->data[ISER_DIR_OUT];
 349
 350         if (scsi_sg_count(sc)) { /* using a scatter list */
 351                 data_buf->buf  = scsi_sglist(sc);
 352                 data_buf->size = scsi_sg_count(sc);
 353         }
 354
 355         data_buf->data_len = scsi_bufflen(sc);
 356
 357         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 358                 err = iser_prepare_read_cmd(ctask, edtl);
 359                 if (err)
 360                         goto send_command_error;
 361         }
 362         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 363                 err = iser_prepare_write_cmd(ctask,
 364                                              ctask->imm_count,
 365                                              ctask->imm_count +
 366                                              ctask->unsol_count,
 367                                              edtl);
 368                 if (err)
 369                         goto send_command_error;
 370         }
 371
 372         iser_reg_single(iser_conn->ib_conn->device,
 373                         send_dto->regd[0], DMA_TO_DEVICE);
 374
 375         if (iser_post_receive_control(conn) != 0) {
 376                 iser_err("post_recv failed!\n");
 377                 err = -ENOMEM;
 378                 goto send_command_error;
 379         }
 380
 381         iser_ctask->status = ISER_TASK_STATUS_STARTED;
 382
 383         err = iser_post_send(&iser_ctask->desc);
 384         if (!err)
 385                 return 0;
 386
 387 send_command_error:
 388         iser_dto_buffs_release(send_dto);
 389         iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
 390         return err;
 391 }
 392
 393 /**
 394  * iser_send_data_out - send data out PDU
 395  */
 396 int iser_send_data_out(struct iscsi_conn     *conn,
 397                        struct iscsi_cmd_task *ctask,
 398                        struct iscsi_data *hdr)
 399 {
 400         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 401         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 402         struct iser_desc *tx_desc = NULL;
 403         struct iser_dto *send_dto = NULL;
 404         unsigned long buf_offset;
 405         unsigned long data_seg_len;
 406         uint32_t itt;
 407         int err = 0;
 408
 409         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 410                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 411                 return -EPERM;
 412         }
 413
 414         if (iser_check_xmit(conn, ctask))
 415                 return -ENOBUFS;
 416
 417         itt = (__force uint32_t)hdr->itt;
 418         data_seg_len = ntoh24(hdr->dlength);
 419         buf_offset   = ntohl(hdr->offset);
 420
 421         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 422                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 423
 424         tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 425         if (tx_desc == NULL) {
 426                 iser_err("Failed to alloc desc for post dataout\n");
 427                 return -ENOMEM;
 428         }
 429
 430         tx_desc->type = ISCSI_TX_DATAOUT;
 431         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 432
 433         /* build the tx desc regd header and add it to the tx desc dto */
 434         send_dto = &tx_desc->dto;
 435         send_dto->ctask = iser_ctask;
 436         iser_create_send_desc(iser_conn, tx_desc);
 437
 438         iser_reg_single(iser_conn->ib_conn->device,
 439                         send_dto->regd[0], DMA_TO_DEVICE);
 440
 441         /* all data was registered for RDMA, we can use the lkey */
 442         iser_dto_add_regd_buff(send_dto,
 443                                &iser_ctask->rdma_regd[ISER_DIR_OUT],
 444                                buf_offset,
 445                                data_seg_len);
 446
 447         if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
 448                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 449                          "inconsistent with total len:%ld, itt:%d\n",
 450                          buf_offset, data_seg_len,
 451                          iser_ctask->data[ISER_DIR_OUT].data_len, itt);
 452                 err = -EINVAL;
 453                 goto send_data_out_error;
 454         }
 455         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 456                  itt, buf_offset, data_seg_len);
 457
 458
 459         err = iser_post_send(tx_desc);
 460         if (!err)
 461                 return 0;
 462
 463 send_data_out_error:
 464         iser_dto_buffs_release(send_dto);
 465         kmem_cache_free(ig.desc_cache, tx_desc);
 466         iser_err("conn %p failed err %d\n",conn, err);
 467         return err;
 468 }
 469
 470 int iser_send_control(struct iscsi_conn *conn,
 471                       struct iscsi_mgmt_task *mtask)
 472 {
 473         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 474         struct iser_desc *mdesc = mtask->dd_data;
 475         struct iser_dto *send_dto = NULL;
 476         unsigned long data_seg_len;
 477         int err = 0;
 478         struct iser_regd_buf *regd_buf;
 479         struct iser_device *device;
 480
 481         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 482                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 483                 return -EPERM;
 484         }
 485
 486         if (iser_check_xmit(conn,mtask))
 487                 return -ENOBUFS;
 488
 489         /* build the tx desc regd header and add it to the tx desc dto */
 490         mdesc->type = ISCSI_TX_CONTROL;
 491         send_dto = &mdesc->dto;
 492         send_dto->ctask = NULL;
 493         iser_create_send_desc(iser_conn, mdesc);
 494
 495         device = iser_conn->ib_conn->device;
 496
 497         iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
 498
 499         data_seg_len = ntoh24(mtask->hdr->dlength);
 500
 501         if (data_seg_len > 0) {
 502                 regd_buf = &mdesc->data_regd_buf;
 503                 memset(regd_buf, 0, sizeof(struct iser_regd_buf));
 504                 regd_buf->device = device;
 505                 regd_buf->virt_addr = mtask->data;
 506                 regd_buf->data_size = mtask->data_count;
 507                 iser_reg_single(device, regd_buf,
 508                                 DMA_TO_DEVICE);
 509                 iser_dto_add_regd_buff(send_dto, regd_buf,
 510                                        0,
 511                                        data_seg_len);
 512         }
 513
 514         if (iser_post_receive_control(conn) != 0) {
 515                 iser_err("post_rcv_buff failed!\n");
 516                 err = -ENOMEM;
 517                 goto send_control_error;
 518         }
 519
 520         err = iser_post_send(mdesc);
 521         if (!err)
 522                 return 0;
 523
 524 send_control_error:
 525         iser_dto_buffs_release(send_dto);
 526         iser_err("conn %p failed err %d\n",conn, err);
 527         return err;
 528 }
 529
 530 /**
 531  * iser_rcv_dto_completion - recv DTO completion
 532  */
 533 void iser_rcv_completion(struct iser_desc *rx_desc,
 534                          unsigned long dto_xfer_len)
 535 {
 536         struct iser_dto        *dto = &rx_desc->dto;
 537         struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
 538         struct iscsi_session *session = conn->iscsi_conn->session;
 539         struct iscsi_cmd_task *ctask;
 540         struct iscsi_iser_cmd_task *iser_ctask;
 541         struct iscsi_hdr *hdr;
 542         char   *rx_data = NULL;
 543         int     rx_data_len = 0;
 544         unsigned int itt;
 545         unsigned char opcode;
 546
 547         hdr = &rx_desc->iscsi_header;
 548
 549         iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
 550
 551         if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
 552                 rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
 553                 rx_data     = dto->regd[1]->virt_addr;
 554                 rx_data    += dto->offset[1];
 555         }
 556
 557         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 558
 559         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 560                 itt = get_itt(hdr->itt); /* mask out cid and age bits */
 561                 if (!(itt < session->cmds_max))
 562                         iser_err("itt can't be matched to task!!! "
 563                                  "conn %p opcode %d cmds_max %d itt %d\n",
 564                                  conn->iscsi_conn,opcode,session->cmds_max,itt);
 565                 /* use the mapping given with the cmds array indexed by itt */
 566                 ctask = (struct iscsi_cmd_task *)session->cmds[itt];
 567                 iser_ctask = ctask->dd_data;
 568                 iser_dbg("itt %d ctask %p\n",itt,ctask);
 569                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 570                 iser_ctask_rdma_finalize(iser_ctask);
 571         }
 572
 573         iser_dto_buffs_release(dto);
 574
 575         iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
 576
 577         kfree(rx_desc->data);
 578         kmem_cache_free(ig.desc_cache, rx_desc);
 579
 580         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 581          * task eliminates the need to worry on tasks which are completed in   *
 582          * parallel to the execution of iser_conn_term. So the code that waits *
 583          * for the posted rx bufs refcount to become zero handles everything   */
 584         atomic_dec(&conn->ib_conn->post_recv_buf_count);
 585 }
 586
 587 void iser_snd_completion(struct iser_desc *tx_desc)
 588 {
 589         struct iser_dto        *dto = &tx_desc->dto;
 590         struct iser_conn       *ib_conn = dto->ib_conn;
 591         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 592         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 593         struct iscsi_mgmt_task *mtask;
 594         int resume_tx = 0;
 595
 596         iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
 597
 598         iser_dto_buffs_release(dto);
 599
 600         if (tx_desc->type == ISCSI_TX_DATAOUT)
 601                 kmem_cache_free(ig.desc_cache, tx_desc);
 602
 603         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 604             ISER_QP_MAX_REQ_DTOS)
 605                 resume_tx = 1;
 606
 607         atomic_dec(&ib_conn->post_send_buf_count);
 608
 609         if (resume_tx) {
 610                 iser_dbg("%ld resuming tx\n",jiffies);
 611                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 612         }
 613
 614         if (tx_desc->type == ISCSI_TX_CONTROL) {
 615                 /* this arithmetic is legal by libiscsi dd_data allocation */
 616                 mtask = (void *) ((long)(void *)tx_desc -
 617                                   sizeof(struct iscsi_mgmt_task));
 618                 if (mtask->hdr->itt == RESERVED_ITT) {
 619                         struct iscsi_session *session = conn->session;
 620
 621                         spin_lock(&conn->session->lock);
 622                         iscsi_free_mgmt_task(conn, mtask);
 623                         spin_unlock(&session->lock);
 624                 }
 625         }
 626 }
 627
 628 void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)
 629
 630 {
 631         iser_ctask->status = ISER_TASK_STATUS_INIT;
 632
 633         iser_ctask->dir[ISER_DIR_IN] = 0;
 634         iser_ctask->dir[ISER_DIR_OUT] = 0;
 635
 636         iser_ctask->data[ISER_DIR_IN].data_len  = 0;
 637         iser_ctask->data[ISER_DIR_OUT].data_len = 0;
 638
 639         memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
 640                sizeof(struct iser_regd_buf));
 641         memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
 642                sizeof(struct iser_regd_buf));
 643 }
 644
 645 void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
 646 {
 647         int deferred;
 648         int is_rdma_aligned = 1;
 649         struct iser_regd_buf *regd;
 650
 651         /* if we were reading, copy back to unaligned sglist,
 652          * anyway dma_unmap and free the copy
 653          */
 654         if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 655                 is_rdma_aligned = 0;
 656                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
 657         }
 658         if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 659                 is_rdma_aligned = 0;
 660                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
 661         }
 662
 663         if (iser_ctask->dir[ISER_DIR_IN]) {
 664                 regd = &iser_ctask->rdma_regd[ISER_DIR_IN];
 665                 deferred = iser_regd_buff_release(regd);
 666                 if (deferred) {
 667                         iser_err("%d references remain for BUF-IN rdma reg\n",
 668                                  atomic_read(&regd->ref_count));
 669                 }
 670         }
 671
 672         if (iser_ctask->dir[ISER_DIR_OUT]) {
 673                 regd = &iser_ctask->rdma_regd[ISER_DIR_OUT];
 674                 deferred = iser_regd_buff_release(regd);
 675                 if (deferred) {
 676                         iser_err("%d references remain for BUF-OUT rdma reg\n",
 677                                  atomic_read(&regd->ref_count));
 678                 }
 679         }
 680
 681        /* if the data was unaligned, it was already unmapped and then copied */
 682        if (is_rdma_aligned)
 683                 iser_dma_unmap_task_data(iser_ctask);
 684 }
 685
 686 void iser_dto_buffs_release(struct iser_dto *dto)
 687 {
 688         int i;
 689
 690         for (i = 0; i < dto->regd_vector_len; i++)
 691                 iser_regd_buff_release(dto->regd[i]);
 692 }
 693