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   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  * $Id: iser_initiator.c 6964 2006-05-07 11:11:43Z ogerlitz $
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/slab.h>
  36 #include <linux/mm.h>
  37 #include <asm/io.h>
  38 #include <asm/scatterlist.h>
  39 #include <linux/scatterlist.h>
  40 #include <linux/kfifo.h>
  41 #include <scsi/scsi_cmnd.h>
  42 #include <scsi/scsi_host.h>
  43
  44 #include "iscsi_iser.h"
  45
  46 /* Constant PDU lengths calculations */
  47 #define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
  48                                  sizeof (struct iscsi_hdr))
  49
  50 /* iser_dto_add_regd_buff - increments the reference count for *
  51  * the registered buffer & adds it to the DTO object           */
  52 static void iser_dto_add_regd_buff(struct iser_dto *dto,
  53                                    struct iser_regd_buf *regd_buf,
  54                                    unsigned long use_offset,
  55                                    unsigned long use_size)
  56 {
  57         int add_idx;
  58
  59         atomic_inc(&regd_buf->ref_count);
  60
  61         add_idx = dto->regd_vector_len;
  62         dto->regd[add_idx] = regd_buf;
  63         dto->used_sz[add_idx] = use_size;
  64         dto->offset[add_idx] = use_offset;
  65
  66         dto->regd_vector_len++;
  67 }
  68
  69 /* Register user buffer memory and initialize passive rdma
  70  *  dto descriptor. Total data size is stored in
  71  *  iser_ctask->data[ISER_DIR_IN].data_len
  72  */
  73 static int iser_prepare_read_cmd(struct iscsi_cmd_task *ctask,
  74                                  unsigned int edtl)
  75
  76 {
  77         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
  78         struct iser_regd_buf *regd_buf;
  79         int err;
  80         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
  81         struct iser_data_buf *buf_in = &iser_ctask->data[ISER_DIR_IN];
  82
  83         err = iser_dma_map_task_data(iser_ctask,
  84                                      buf_in,
  85                                      ISER_DIR_IN,
  86                                      DMA_FROM_DEVICE);
  87         if (err)
  88                 return err;
  89
  90         if (edtl > iser_ctask->data[ISER_DIR_IN].data_len) {
  91                 iser_err("Total data length: %ld, less than EDTL: "
  92                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  93                          iser_ctask->data[ISER_DIR_IN].data_len, edtl,
  94                          ctask->itt, iser_ctask->iser_conn);
  95                 return -EINVAL;
  96         }
  97
  98         err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_IN);
  99         if (err) {
 100                 iser_err("Failed to set up Data-IN RDMA\n");
 101                 return err;
 102         }
 103         regd_buf = &iser_ctask->rdma_regd[ISER_DIR_IN];
 104
 105         hdr->flags    |= ISER_RSV;
 106         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
 107         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
 108
 109         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
 110                  ctask->itt, regd_buf->reg.rkey,
 111                  (unsigned long long)regd_buf->reg.va);
 112
 113         return 0;
 114 }
 115
 116 /* Register user buffer memory and initialize passive rdma
 117  *  dto descriptor. Total data size is stored in
 118  *  ctask->data[ISER_DIR_OUT].data_len
 119  */
 120 static int
 121 iser_prepare_write_cmd(struct iscsi_cmd_task *ctask,
 122                        unsigned int imm_sz,
 123                        unsigned int unsol_sz,
 124                        unsigned int edtl)
 125 {
 126         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 127         struct iser_regd_buf *regd_buf;
 128         int err;
 129         struct iser_dto *send_dto = &iser_ctask->desc.dto;
 130         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
 131         struct iser_data_buf *buf_out = &iser_ctask->data[ISER_DIR_OUT];
 132
 133         err = iser_dma_map_task_data(iser_ctask,
 134                                      buf_out,
 135                                      ISER_DIR_OUT,
 136                                      DMA_TO_DEVICE);
 137         if (err)
 138                 return err;
 139
 140         if (edtl > iser_ctask->data[ISER_DIR_OUT].data_len) {
 141                 iser_err("Total data length: %ld, less than EDTL: %d, "
 142                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 143                          iser_ctask->data[ISER_DIR_OUT].data_len,
 144                          edtl, ctask->itt, ctask->conn);
 145                 return -EINVAL;
 146         }
 147
 148         err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_OUT);
 149         if (err != 0) {
 150                 iser_err("Failed to register write cmd RDMA mem\n");
 151                 return err;
 152         }
 153
 154         regd_buf = &iser_ctask->rdma_regd[ISER_DIR_OUT];
 155
 156         if (unsol_sz < edtl) {
 157                 hdr->flags     |= ISER_WSV;
 158                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 159                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 160
 161                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 162                          "VA:%#llX + unsol:%d\n",
 163                          ctask->itt, regd_buf->reg.rkey,
 164                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 165         }
 166
 167         if (imm_sz > 0) {
 168                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 169                          ctask->itt, imm_sz);
 170                 iser_dto_add_regd_buff(send_dto,
 171                                        regd_buf,
 172                                        0,
 173                                        imm_sz);
 174         }
 175
 176         return 0;
 177 }
 178
 179 /**
 180  * iser_post_receive_control - allocates, initializes and posts receive DTO.
 181  */
 182 static int iser_post_receive_control(struct iscsi_conn *conn)
 183 {
 184         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 185         struct iser_desc     *rx_desc;
 186         struct iser_regd_buf *regd_hdr;
 187         struct iser_regd_buf *regd_data;
 188         struct iser_dto      *recv_dto = NULL;
 189         struct iser_device  *device = iser_conn->ib_conn->device;
 190         int rx_data_size, err = 0;
 191
 192         rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 193         if (rx_desc == NULL) {
 194                 iser_err("Failed to alloc desc for post recv\n");
 195                 return -ENOMEM;
 196         }
 197         rx_desc->type = ISCSI_RX;
 198
 199         /* for the login sequence we must support rx of upto 8K; login is done
 200          * after conn create/bind (connect) and conn stop/bind (reconnect),
 201          * what's common for both schemes is that the connection is not started
 202          */
 203         if (conn->c_stage != ISCSI_CONN_STARTED)
 204                 rx_data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
 205         else /* FIXME till user space sets conn->max_recv_dlength correctly */
 206                 rx_data_size = 128;
 207
 208         rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
 209         if (rx_desc->data == NULL) {
 210                 iser_err("Failed to alloc data buf for post recv\n");
 211                 err = -ENOMEM;
 212                 goto post_rx_kmalloc_failure;
 213         }
 214
 215         recv_dto = &rx_desc->dto;
 216         recv_dto->ib_conn = iser_conn->ib_conn;
 217         recv_dto->regd_vector_len = 0;
 218
 219         regd_hdr = &rx_desc->hdr_regd_buf;
 220         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 221         regd_hdr->device  = device;
 222         regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
 223         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 224
 225         iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);
 226
 227         iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);
 228
 229         regd_data = &rx_desc->data_regd_buf;
 230         memset(regd_data, 0, sizeof(struct iser_regd_buf));
 231         regd_data->device  = device;
 232         regd_data->virt_addr  = rx_desc->data;
 233         regd_data->data_size  = rx_data_size;
 234
 235         iser_reg_single(device, regd_data, DMA_FROM_DEVICE);
 236
 237         iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);
 238
 239         err = iser_post_recv(rx_desc);
 240         if (!err)
 241                 return 0;
 242
 243         /* iser_post_recv failed */
 244         iser_dto_buffs_release(recv_dto);
 245         kfree(rx_desc->data);
 246 post_rx_kmalloc_failure:
 247         kmem_cache_free(ig.desc_cache, rx_desc);
 248         return err;
 249 }
 250
 251 /* creates a new tx descriptor and adds header regd buffer */
 252 static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
 253                                   struct iser_desc       *tx_desc)
 254 {
 255         struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
 256         struct iser_dto      *send_dto = &tx_desc->dto;
 257
 258         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 259         regd_hdr->device  = iser_conn->ib_conn->device;
 260         regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
 261         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 262
 263         send_dto->ib_conn         = iser_conn->ib_conn;
 264         send_dto->notify_enable   = 1;
 265         send_dto->regd_vector_len = 0;
 266
 267         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 268         tx_desc->iser_header.flags = ISER_VER;
 269
 270         iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
 271 }
 272
 273 /**
 274  *  iser_conn_set_full_featured_mode - (iSER API)
 275  */
 276 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 277 {
 278         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 279
 280         int i;
 281         /* no need to keep it in a var, we are after login so if this should
 282          * be negotiated, by now the result should be available here */
 283         int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;
 284
 285         iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
 286
 287         /* Check that there is no posted recv or send buffers left - */
 288         /* they must be consumed during the login phase */
 289         BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
 290         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 291
 292         /* Initial post receive buffers */
 293         for (i = 0; i < initial_post_recv_bufs_num; i++) {
 294                 if (iser_post_receive_control(conn) != 0) {
 295                         iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
 296                                  i, conn);
 297                         return -ENOMEM;
 298                 }
 299         }
 300         iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
 301         return 0;
 302 }
 303
 304 static int
 305 iser_check_xmit(struct iscsi_conn *conn, void *task)
 306 {
 307         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 308
 309         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 310             ISER_QP_MAX_REQ_DTOS) {
 311                 iser_dbg("%ld can't xmit task %p\n",jiffies,task);
 312                 return -ENOBUFS;
 313         }
 314         return 0;
 315 }
 316
 317
 318 /**
 319  * iser_send_command - send command PDU
 320  */
 321 int iser_send_command(struct iscsi_conn     *conn,
 322                       struct iscsi_cmd_task *ctask)
 323 {
 324         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 325         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 326         struct iser_dto *send_dto = NULL;
 327         unsigned long edtl;
 328         int err = 0;
 329         struct iser_data_buf *data_buf;
 330
 331         struct iscsi_cmd *hdr =  ctask->hdr;
 332         struct scsi_cmnd *sc  =  ctask->sc;
 333
 334         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 335                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 336                 return -EPERM;
 337         }
 338         if (iser_check_xmit(conn, ctask))
 339                 return -ENOBUFS;
 340
 341         edtl = ntohl(hdr->data_length);
 342
 343         /* build the tx desc regd header and add it to the tx desc dto */
 344         iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
 345         send_dto = &iser_ctask->desc.dto;
 346         send_dto->ctask = iser_ctask;
 347         iser_create_send_desc(iser_conn, &iser_ctask->desc);
 348
 349         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 350                 data_buf = &iser_ctask->data[ISER_DIR_IN];
 351         else
 352                 data_buf = &iser_ctask->data[ISER_DIR_OUT];
 353
 354         if (sc->use_sg) { /* using a scatter list */
 355                 data_buf->buf  = sc->request_buffer;
 356                 data_buf->size = sc->use_sg;
 357         } else if (sc->request_bufflen) {
 358                 /* using a single buffer - convert it into one entry SG */
 359                 sg_init_one(&data_buf->sg_single,
 360                             sc->request_buffer, sc->request_bufflen);
 361                 data_buf->buf   = &data_buf->sg_single;
 362                 data_buf->size  = 1;
 363         }
 364
 365         data_buf->data_len = sc->request_bufflen;
 366
 367         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 368                 err = iser_prepare_read_cmd(ctask, edtl);
 369                 if (err)
 370                         goto send_command_error;
 371         }
 372         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 373                 err = iser_prepare_write_cmd(ctask,
 374                                              ctask->imm_count,
 375                                              ctask->imm_count +
 376                                              ctask->unsol_count,
 377                                              edtl);
 378                 if (err)
 379                         goto send_command_error;
 380         }
 381
 382         iser_reg_single(iser_conn->ib_conn->device,
 383                         send_dto->regd[0], DMA_TO_DEVICE);
 384
 385         if (iser_post_receive_control(conn) != 0) {
 386                 iser_err("post_recv failed!\n");
 387                 err = -ENOMEM;
 388                 goto send_command_error;
 389         }
 390
 391         iser_ctask->status = ISER_TASK_STATUS_STARTED;
 392
 393         err = iser_post_send(&iser_ctask->desc);
 394         if (!err)
 395                 return 0;
 396
 397 send_command_error:
 398         iser_dto_buffs_release(send_dto);
 399         iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
 400         return err;
 401 }
 402
 403 /**
 404  * iser_send_data_out - send data out PDU
 405  */
 406 int iser_send_data_out(struct iscsi_conn     *conn,
 407                        struct iscsi_cmd_task *ctask,
 408                        struct iscsi_data *hdr)
 409 {
 410         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 411         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 412         struct iser_desc *tx_desc = NULL;
 413         struct iser_dto *send_dto = NULL;
 414         unsigned long buf_offset;
 415         unsigned long data_seg_len;
 416         unsigned int itt;
 417         int err = 0;
 418
 419         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 420                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 421                 return -EPERM;
 422         }
 423
 424         if (iser_check_xmit(conn, ctask))
 425                 return -ENOBUFS;
 426
 427         itt = ntohl(hdr->itt);
 428         data_seg_len = ntoh24(hdr->dlength);
 429         buf_offset   = ntohl(hdr->offset);
 430
 431         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 432                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 433
 434         tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 435         if (tx_desc == NULL) {
 436                 iser_err("Failed to alloc desc for post dataout\n");
 437                 return -ENOMEM;
 438         }
 439
 440         tx_desc->type = ISCSI_TX_DATAOUT;
 441         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 442
 443         /* build the tx desc regd header and add it to the tx desc dto */
 444         send_dto = &tx_desc->dto;
 445         send_dto->ctask = iser_ctask;
 446         iser_create_send_desc(iser_conn, tx_desc);
 447
 448         iser_reg_single(iser_conn->ib_conn->device,
 449                         send_dto->regd[0], DMA_TO_DEVICE);
 450
 451         /* all data was registered for RDMA, we can use the lkey */
 452         iser_dto_add_regd_buff(send_dto,
 453                                &iser_ctask->rdma_regd[ISER_DIR_OUT],
 454                                buf_offset,
 455                                data_seg_len);
 456
 457         if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
 458                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 459                          "inconsistent with total len:%ld, itt:%d\n",
 460                          buf_offset, data_seg_len,
 461                          iser_ctask->data[ISER_DIR_OUT].data_len, itt);
 462                 err = -EINVAL;
 463                 goto send_data_out_error;
 464         }
 465         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 466                  itt, buf_offset, data_seg_len);
 467
 468
 469         err = iser_post_send(tx_desc);
 470         if (!err)
 471                 return 0;
 472
 473 send_data_out_error:
 474         iser_dto_buffs_release(send_dto);
 475         kmem_cache_free(ig.desc_cache, tx_desc);
 476         iser_err("conn %p failed err %d\n",conn, err);
 477         return err;
 478 }
 479
 480 int iser_send_control(struct iscsi_conn *conn,
 481                       struct iscsi_mgmt_task *mtask)
 482 {
 483         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 484         struct iser_desc *mdesc = mtask->dd_data;
 485         struct iser_dto *send_dto = NULL;
 486         unsigned long data_seg_len;
 487         int err = 0;
 488         struct iser_regd_buf *regd_buf;
 489         struct iser_device *device;
 490
 491         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 492                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 493                 return -EPERM;
 494         }
 495
 496         if (iser_check_xmit(conn,mtask))
 497                 return -ENOBUFS;
 498
 499         /* build the tx desc regd header and add it to the tx desc dto */
 500         mdesc->type = ISCSI_TX_CONTROL;
 501         send_dto = &mdesc->dto;
 502         send_dto->ctask = NULL;
 503         iser_create_send_desc(iser_conn, mdesc);
 504
 505         device = iser_conn->ib_conn->device;
 506
 507         iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
 508
 509         data_seg_len = ntoh24(mtask->hdr->dlength);
 510
 511         if (data_seg_len > 0) {
 512                 regd_buf = &mdesc->data_regd_buf;
 513                 memset(regd_buf, 0, sizeof(struct iser_regd_buf));
 514                 regd_buf->device = device;
 515                 regd_buf->virt_addr = mtask->data;
 516                 regd_buf->data_size = mtask->data_count;
 517                 iser_reg_single(device, regd_buf,
 518                                 DMA_TO_DEVICE);
 519                 iser_dto_add_regd_buff(send_dto, regd_buf,
 520                                        0,
 521                                        data_seg_len);
 522         }
 523
 524         if (iser_post_receive_control(conn) != 0) {
 525                 iser_err("post_rcv_buff failed!\n");
 526                 err = -ENOMEM;
 527                 goto send_control_error;
 528         }
 529
 530         err = iser_post_send(mdesc);
 531         if (!err)
 532                 return 0;
 533
 534 send_control_error:
 535         iser_dto_buffs_release(send_dto);
 536         iser_err("conn %p failed err %d\n",conn, err);
 537         return err;
 538 }
 539
 540 /**
 541  * iser_rcv_dto_completion - recv DTO completion
 542  */
 543 void iser_rcv_completion(struct iser_desc *rx_desc,
 544                          unsigned long dto_xfer_len)
 545 {
 546         struct iser_dto        *dto = &rx_desc->dto;
 547         struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
 548         struct iscsi_session *session = conn->iscsi_conn->session;
 549         struct iscsi_cmd_task *ctask;
 550         struct iscsi_iser_cmd_task *iser_ctask;
 551         struct iscsi_hdr *hdr;
 552         char   *rx_data = NULL;
 553         int     rx_data_len = 0;
 554         unsigned int itt;
 555         unsigned char opcode;
 556
 557         hdr = &rx_desc->iscsi_header;
 558
 559         iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
 560
 561         if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
 562                 rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
 563                 rx_data     = dto->regd[1]->virt_addr;
 564                 rx_data    += dto->offset[1];
 565         }
 566
 567         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 568
 569         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 570                 itt = get_itt(hdr->itt); /* mask out cid and age bits */
 571                 if (!(itt < session->cmds_max))
 572                         iser_err("itt can't be matched to task!!!"
 573                                  "conn %p opcode %d cmds_max %d itt %d\n",
 574                                  conn->iscsi_conn,opcode,session->cmds_max,itt);
 575                 /* use the mapping given with the cmds array indexed by itt */
 576                 ctask = (struct iscsi_cmd_task *)session->cmds[itt];
 577                 iser_ctask = ctask->dd_data;
 578                 iser_dbg("itt %d ctask %p\n",itt,ctask);
 579                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 580                 iser_ctask_rdma_finalize(iser_ctask);
 581         }
 582
 583         iser_dto_buffs_release(dto);
 584
 585         iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
 586
 587         kfree(rx_desc->data);
 588         kmem_cache_free(ig.desc_cache, rx_desc);
 589
 590         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 591          * task eliminates the need to worry on tasks which are completed in   *
 592          * parallel to the execution of iser_conn_term. So the code that waits *
 593          * for the posted rx bufs refcount to become zero handles everything   */
 594         atomic_dec(&conn->ib_conn->post_recv_buf_count);
 595 }
 596
 597 void iser_snd_completion(struct iser_desc *tx_desc)
 598 {
 599         struct iser_dto        *dto = &tx_desc->dto;
 600         struct iser_conn       *ib_conn = dto->ib_conn;
 601         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 602         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 603         struct iscsi_mgmt_task *mtask;
 604         int resume_tx = 0;
 605
 606         iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
 607
 608         iser_dto_buffs_release(dto);
 609
 610         if (tx_desc->type == ISCSI_TX_DATAOUT)
 611                 kmem_cache_free(ig.desc_cache, tx_desc);
 612
 613         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 614             ISER_QP_MAX_REQ_DTOS)
 615                 resume_tx = 1;
 616
 617         atomic_dec(&ib_conn->post_send_buf_count);
 618
 619         if (resume_tx) {
 620                 iser_dbg("%ld resuming tx\n",jiffies);
 621                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 622         }
 623
 624         if (tx_desc->type == ISCSI_TX_CONTROL) {
 625                 /* this arithmetic is legal by libiscsi dd_data allocation */
 626                 mtask = (void *) ((long)(void *)tx_desc -
 627                                   sizeof(struct iscsi_mgmt_task));
 628                 if (mtask->hdr->itt == RESERVED_ITT) {
 629                         struct iscsi_session *session = conn->session;
 630
 631                         spin_lock(&conn->session->lock);
 632                         list_del(&mtask->running);
 633                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
 634                                     sizeof(void*));
 635                         spin_unlock(&session->lock);
 636                 }
 637         }
 638 }
 639
 640 void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)
 641
 642 {
 643         iser_ctask->status = ISER_TASK_STATUS_INIT;
 644
 645         iser_ctask->dir[ISER_DIR_IN] = 0;
 646         iser_ctask->dir[ISER_DIR_OUT] = 0;
 647
 648         iser_ctask->data[ISER_DIR_IN].data_len  = 0;
 649         iser_ctask->data[ISER_DIR_OUT].data_len = 0;
 650
 651         memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
 652                sizeof(struct iser_regd_buf));
 653         memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
 654                sizeof(struct iser_regd_buf));
 655 }
 656
 657 void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
 658 {
 659         int deferred;
 660         int is_rdma_aligned = 1;
 661
 662         /* if we were reading, copy back to unaligned sglist,
 663          * anyway dma_unmap and free the copy
 664          */
 665         if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 666                 is_rdma_aligned = 0;
 667                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
 668         }
 669         if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 670                 is_rdma_aligned = 0;
 671                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
 672         }
 673
 674         if (iser_ctask->dir[ISER_DIR_IN]) {
 675                 deferred = iser_regd_buff_release
 676                         (&iser_ctask->rdma_regd[ISER_DIR_IN]);
 677                 if (deferred) {
 678                         iser_err("References remain for BUF-IN rdma reg\n");
 679                         BUG();
 680                 }
 681         }
 682
 683         if (iser_ctask->dir[ISER_DIR_OUT]) {
 684                 deferred = iser_regd_buff_release
 685                         (&iser_ctask->rdma_regd[ISER_DIR_OUT]);
 686                 if (deferred) {
 687                         iser_err("References remain for BUF-OUT rdma reg\n");
 688                         BUG();
 689                 }
 690         }
 691
 692        /* if the data was unaligned, it was already unmapped and then copied */
 693        if (is_rdma_aligned)
 694                 iser_dma_unmap_task_data(iser_ctask);
 695 }
 696
 697 void iser_dto_buffs_release(struct iser_dto *dto)
 698 {
 699         int i;
 700
 701         for (i = 0; i < dto->regd_vector_len; i++)
 702                 iser_regd_buff_release(dto->regd[i]);
 703 }
 704