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