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  * $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         int rc = 0;
 308         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 309
 310         write_lock_bh(conn->recv_lock);
 311         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 312             ISER_QP_MAX_REQ_DTOS) {
 313                 iser_dbg("%ld can't xmit task %p, suspending tx\n",jiffies,task);
 314                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 315                 rc = -EAGAIN;
 316         }
 317         write_unlock_bh(conn->recv_lock);
 318         return rc;
 319 }
 320
 321
 322 /**
 323  * iser_send_command - send command PDU
 324  */
 325 int iser_send_command(struct iscsi_conn     *conn,
 326                       struct iscsi_cmd_task *ctask)
 327 {
 328         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 329         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 330         struct iser_dto *send_dto = NULL;
 331         unsigned long edtl;
 332         int err = 0;
 333         struct iser_data_buf *data_buf;
 334
 335         struct iscsi_cmd *hdr =  ctask->hdr;
 336         struct scsi_cmnd *sc  =  ctask->sc;
 337
 338         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 339                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 340                 return -EPERM;
 341         }
 342         if (iser_check_xmit(conn, ctask))
 343                 return -EAGAIN;
 344
 345         edtl = ntohl(hdr->data_length);
 346
 347         /* build the tx desc regd header and add it to the tx desc dto */
 348         iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
 349         send_dto = &iser_ctask->desc.dto;
 350         send_dto->ctask = iser_ctask;
 351         iser_create_send_desc(iser_conn, &iser_ctask->desc);
 352
 353         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 354                 data_buf = &iser_ctask->data[ISER_DIR_IN];
 355         else
 356                 data_buf = &iser_ctask->data[ISER_DIR_OUT];
 357
 358         if (sc->use_sg) { /* using a scatter list */
 359                 data_buf->buf  = sc->request_buffer;
 360                 data_buf->size = sc->use_sg;
 361         } else if (sc->request_bufflen) {
 362                 /* using a single buffer - convert it into one entry SG */
 363                 sg_init_one(&data_buf->sg_single,
 364                             sc->request_buffer, sc->request_bufflen);
 365                 data_buf->buf   = &data_buf->sg_single;
 366                 data_buf->size  = 1;
 367         }
 368
 369         data_buf->data_len = sc->request_bufflen;
 370
 371         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 372                 err = iser_prepare_read_cmd(ctask, edtl);
 373                 if (err)
 374                         goto send_command_error;
 375         }
 376         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 377                 err = iser_prepare_write_cmd(ctask,
 378                                              ctask->imm_count,
 379                                              ctask->imm_count +
 380                                              ctask->unsol_count,
 381                                              edtl);
 382                 if (err)
 383                         goto send_command_error;
 384         }
 385
 386         iser_reg_single(iser_conn->ib_conn->device,
 387                         send_dto->regd[0], DMA_TO_DEVICE);
 388
 389         if (iser_post_receive_control(conn) != 0) {
 390                 iser_err("post_recv failed!\n");
 391                 err = -ENOMEM;
 392                 goto send_command_error;
 393         }
 394
 395         iser_ctask->status = ISER_TASK_STATUS_STARTED;
 396
 397         err = iser_post_send(&iser_ctask->desc);
 398         if (!err)
 399                 return 0;
 400
 401 send_command_error:
 402         iser_dto_buffs_release(send_dto);
 403         iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
 404         return err;
 405 }
 406
 407 /**
 408  * iser_send_data_out - send data out PDU
 409  */
 410 int iser_send_data_out(struct iscsi_conn     *conn,
 411                        struct iscsi_cmd_task *ctask,
 412                        struct iscsi_data *hdr)
 413 {
 414         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 415         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 416         struct iser_desc *tx_desc = NULL;
 417         struct iser_dto *send_dto = NULL;
 418         unsigned long buf_offset;
 419         unsigned long data_seg_len;
 420         unsigned int itt;
 421         int err = 0;
 422
 423         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 424                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 425                 return -EPERM;
 426         }
 427
 428         if (iser_check_xmit(conn, ctask))
 429                 return -EAGAIN;
 430
 431         itt = ntohl(hdr->itt);
 432         data_seg_len = ntoh24(hdr->dlength);
 433         buf_offset   = ntohl(hdr->offset);
 434
 435         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 436                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 437
 438         tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 439         if (tx_desc == NULL) {
 440                 iser_err("Failed to alloc desc for post dataout\n");
 441                 return -ENOMEM;
 442         }
 443
 444         tx_desc->type = ISCSI_TX_DATAOUT;
 445         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 446
 447         /* build the tx desc regd header and add it to the tx desc dto */
 448         send_dto = &tx_desc->dto;
 449         send_dto->ctask = iser_ctask;
 450         iser_create_send_desc(iser_conn, tx_desc);
 451
 452         iser_reg_single(iser_conn->ib_conn->device,
 453                         send_dto->regd[0], DMA_TO_DEVICE);
 454
 455         /* all data was registered for RDMA, we can use the lkey */
 456         iser_dto_add_regd_buff(send_dto,
 457                                &iser_ctask->rdma_regd[ISER_DIR_OUT],
 458                                buf_offset,
 459                                data_seg_len);
 460
 461         if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
 462                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 463                          "inconsistent with total len:%ld, itt:%d\n",
 464                          buf_offset, data_seg_len,
 465                          iser_ctask->data[ISER_DIR_OUT].data_len, itt);
 466                 err = -EINVAL;
 467                 goto send_data_out_error;
 468         }
 469         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 470                  itt, buf_offset, data_seg_len);
 471
 472
 473         err = iser_post_send(tx_desc);
 474         if (!err)
 475                 return 0;
 476
 477 send_data_out_error:
 478         iser_dto_buffs_release(send_dto);
 479         kmem_cache_free(ig.desc_cache, tx_desc);
 480         iser_err("conn %p failed err %d\n",conn, err);
 481         return err;
 482 }
 483
 484 int iser_send_control(struct iscsi_conn *conn,
 485                       struct iscsi_mgmt_task *mtask)
 486 {
 487         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 488         struct iser_desc *mdesc = mtask->dd_data;
 489         struct iser_dto *send_dto = NULL;
 490         unsigned int itt;
 491         unsigned long data_seg_len;
 492         int err = 0;
 493         unsigned char opcode;
 494         struct iser_regd_buf *regd_buf;
 495         struct iser_device *device;
 496
 497         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 498                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 499                 return -EPERM;
 500         }
 501
 502         if (iser_check_xmit(conn,mtask))
 503                 return -EAGAIN;
 504
 505         /* build the tx desc regd header and add it to the tx desc dto */
 506         mdesc->type = ISCSI_TX_CONTROL;
 507         send_dto = &mdesc->dto;
 508         send_dto->ctask = NULL;
 509         iser_create_send_desc(iser_conn, mdesc);
 510
 511         device = iser_conn->ib_conn->device;
 512
 513         iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
 514
 515         itt = ntohl(mtask->hdr->itt);
 516         opcode = mtask->hdr->opcode & ISCSI_OPCODE_MASK;
 517         data_seg_len = ntoh24(mtask->hdr->dlength);
 518
 519         if (data_seg_len > 0) {
 520                 regd_buf = &mdesc->data_regd_buf;
 521                 memset(regd_buf, 0, sizeof(struct iser_regd_buf));
 522                 regd_buf->device = device;
 523                 regd_buf->virt_addr = mtask->data;
 524                 regd_buf->data_size = mtask->data_count;
 525                 iser_reg_single(device, regd_buf,
 526                                 DMA_TO_DEVICE);
 527                 iser_dto_add_regd_buff(send_dto, regd_buf,
 528                                        0,
 529                                        data_seg_len);
 530         }
 531
 532         if (iser_post_receive_control(conn) != 0) {
 533                 iser_err("post_rcv_buff failed!\n");
 534                 err = -ENOMEM;
 535                 goto send_control_error;
 536         }
 537
 538         err = iser_post_send(mdesc);
 539         if (!err)
 540                 return 0;
 541
 542 send_control_error:
 543         iser_dto_buffs_release(send_dto);
 544         iser_err("conn %p failed err %d\n",conn, err);
 545         return err;
 546 }
 547
 548 /**
 549  * iser_rcv_dto_completion - recv DTO completion
 550  */
 551 void iser_rcv_completion(struct iser_desc *rx_desc,
 552                          unsigned long dto_xfer_len)
 553 {
 554         struct iser_dto        *dto = &rx_desc->dto;
 555         struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
 556         struct iscsi_session *session = conn->iscsi_conn->session;
 557         struct iscsi_cmd_task *ctask;
 558         struct iscsi_iser_cmd_task *iser_ctask;
 559         struct iscsi_hdr *hdr;
 560         char   *rx_data = NULL;
 561         int     rx_data_len = 0;
 562         unsigned int itt;
 563         unsigned char opcode;
 564
 565         hdr = &rx_desc->iscsi_header;
 566
 567         iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
 568
 569         if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
 570                 rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
 571                 rx_data     = dto->regd[1]->virt_addr;
 572                 rx_data    += dto->offset[1];
 573         }
 574
 575         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 576
 577         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 578                 itt = hdr->itt & ISCSI_ITT_MASK; /* mask out cid and age bits */
 579                 if (!(itt < session->cmds_max))
 580                         iser_err("itt can't be matched to task!!!"
 581                                  "conn %p opcode %d cmds_max %d itt %d\n",
 582                                  conn->iscsi_conn,opcode,session->cmds_max,itt);
 583                 /* use the mapping given with the cmds array indexed by itt */
 584                 ctask = (struct iscsi_cmd_task *)session->cmds[itt];
 585                 iser_ctask = ctask->dd_data;
 586                 iser_dbg("itt %d ctask %p\n",itt,ctask);
 587                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 588                 iser_ctask_rdma_finalize(iser_ctask);
 589         }
 590
 591         iser_dto_buffs_release(dto);
 592
 593         iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
 594
 595         kfree(rx_desc->data);
 596         kmem_cache_free(ig.desc_cache, rx_desc);
 597
 598         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 599          * task eliminates the need to worry on tasks which are completed in   *
 600          * parallel to the execution of iser_conn_term. So the code that waits *
 601          * for the posted rx bufs refcount to become zero handles everything   */
 602         atomic_dec(&conn->ib_conn->post_recv_buf_count);
 603 }
 604
 605 void iser_snd_completion(struct iser_desc *tx_desc)
 606 {
 607         struct iser_dto        *dto = &tx_desc->dto;
 608         struct iser_conn       *ib_conn = dto->ib_conn;
 609         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 610         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 611         struct iscsi_mgmt_task *mtask;
 612
 613         iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
 614
 615         iser_dto_buffs_release(dto);
 616
 617         if (tx_desc->type == ISCSI_TX_DATAOUT)
 618                 kmem_cache_free(ig.desc_cache, tx_desc);
 619
 620         atomic_dec(&ib_conn->post_send_buf_count);
 621
 622         write_lock(conn->recv_lock);
 623         if (conn->suspend_tx) {
 624                 iser_dbg("%ld resuming tx\n",jiffies);
 625                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 626                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 627         }
 628         write_unlock(conn->recv_lock);
 629
 630         if (tx_desc->type == ISCSI_TX_CONTROL) {
 631                 /* this arithmetic is legal by libiscsi dd_data allocation */
 632                 mtask = (void *) ((long)(void *)tx_desc -
 633                                   sizeof(struct iscsi_mgmt_task));
 634                 if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
 635                         struct iscsi_session *session = conn->session;
 636
 637                         spin_lock(&conn->session->lock);
 638                         list_del(&mtask->running);
 639                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
 640                                     sizeof(void*));
 641                         spin_unlock(&session->lock);
 642                 }
 643         }
 644 }
 645
 646 void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)
 647
 648 {
 649         iser_ctask->status = ISER_TASK_STATUS_INIT;
 650
 651         iser_ctask->dir[ISER_DIR_IN] = 0;
 652         iser_ctask->dir[ISER_DIR_OUT] = 0;
 653
 654         iser_ctask->data[ISER_DIR_IN].data_len  = 0;
 655         iser_ctask->data[ISER_DIR_OUT].data_len = 0;
 656
 657         memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
 658                sizeof(struct iser_regd_buf));
 659         memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
 660                sizeof(struct iser_regd_buf));
 661 }
 662
 663 void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
 664 {
 665         int deferred;
 666         int is_rdma_aligned = 1;
 667
 668         /* if we were reading, copy back to unaligned sglist,
 669          * anyway dma_unmap and free the copy
 670          */
 671         if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 672                 is_rdma_aligned = 0;
 673                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
 674         }
 675         if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 676                 is_rdma_aligned = 0;
 677                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
 678         }
 679
 680         if (iser_ctask->dir[ISER_DIR_IN]) {
 681                 deferred = iser_regd_buff_release
 682                         (&iser_ctask->rdma_regd[ISER_DIR_IN]);
 683                 if (deferred) {
 684                         iser_err("References remain for BUF-IN rdma reg\n");
 685                         BUG();
 686                 }
 687         }
 688
 689         if (iser_ctask->dir[ISER_DIR_OUT]) {
 690                 deferred = iser_regd_buff_release
 691                         (&iser_ctask->rdma_regd[ISER_DIR_OUT]);
 692                 if (deferred) {
 693                         iser_err("References remain for BUF-OUT rdma reg\n");
 694                         BUG();
 695                 }
 696         }
 697
 698        /* if the data was unaligned, it was already unmapped and then copied */
 699        if (is_rdma_aligned)
 700                 iser_dma_unmap_task_data(iser_ctask);
 701 }
 702
 703 void iser_dto_buffs_release(struct iser_dto *dto)
 704 {
 705         int i;
 706
 707         for (i = 0; i < dto->regd_vector_len; i++)
 708                 iser_regd_buff_release(dto->regd[i]);
 709 }
 710