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 /* Register user buffer memory and initialize passive rdma
  43  *  dto descriptor. Total data size is stored in
  44  *  iser_task->data[ISER_DIR_IN].data_len
  45  */
  46 static int iser_prepare_read_cmd(struct iscsi_task *task,
  47                                  unsigned int edtl)
  48
  49 {
  50         struct iscsi_iser_task *iser_task = task->dd_data;
  51         struct iser_regd_buf *regd_buf;
  52         int err;
  53         struct iser_hdr *hdr = &iser_task->desc.iser_header;
  54         struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
  55
  56         err = iser_dma_map_task_data(iser_task,
  57                                      buf_in,
  58                                      ISER_DIR_IN,
  59                                      DMA_FROM_DEVICE);
  60         if (err)
  61                 return err;
  62
  63         if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
  64                 iser_err("Total data length: %ld, less than EDTL: "
  65                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  66                          iser_task->data[ISER_DIR_IN].data_len, edtl,
  67                          task->itt, iser_task->iser_conn);
  68                 return -EINVAL;
  69         }
  70
  71         err = iser_reg_rdma_mem(iser_task,ISER_DIR_IN);
  72         if (err) {
  73                 iser_err("Failed to set up Data-IN RDMA\n");
  74                 return err;
  75         }
  76         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
  77
  78         hdr->flags    |= ISER_RSV;
  79         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
  80         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
  81
  82         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  83                  task->itt, regd_buf->reg.rkey,
  84                  (unsigned long long)regd_buf->reg.va);
  85
  86         return 0;
  87 }
  88
  89 /* Register user buffer memory and initialize passive rdma
  90  *  dto descriptor. Total data size is stored in
  91  *  task->data[ISER_DIR_OUT].data_len
  92  */
  93 static int
  94 iser_prepare_write_cmd(struct iscsi_task *task,
  95                        unsigned int imm_sz,
  96                        unsigned int unsol_sz,
  97                        unsigned int edtl)
  98 {
  99         struct iscsi_iser_task *iser_task = task->dd_data;
 100         struct iser_regd_buf *regd_buf;
 101         int err;
 102         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 103         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 104         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 105
 106         err = iser_dma_map_task_data(iser_task,
 107                                      buf_out,
 108                                      ISER_DIR_OUT,
 109                                      DMA_TO_DEVICE);
 110         if (err)
 111                 return err;
 112
 113         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
 114                 iser_err("Total data length: %ld, less than EDTL: %d, "
 115                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 116                          iser_task->data[ISER_DIR_OUT].data_len,
 117                          edtl, task->itt, task->conn);
 118                 return -EINVAL;
 119         }
 120
 121         err = iser_reg_rdma_mem(iser_task,ISER_DIR_OUT);
 122         if (err != 0) {
 123                 iser_err("Failed to register write cmd RDMA mem\n");
 124                 return err;
 125         }
 126
 127         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 128
 129         if (unsol_sz < edtl) {
 130                 hdr->flags     |= ISER_WSV;
 131                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 132                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 133
 134                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 135                          "VA:%#llX + unsol:%d\n",
 136                          task->itt, regd_buf->reg.rkey,
 137                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 138         }
 139
 140         if (imm_sz > 0) {
 141                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 142                          task->itt, imm_sz);
 143                 tx_dsg->addr   = regd_buf->reg.va;
 144                 tx_dsg->length = imm_sz;
 145                 tx_dsg->lkey   = regd_buf->reg.lkey;
 146                 iser_task->desc.num_sge = 2;
 147         }
 148
 149         return 0;
 150 }
 151
 152 /* creates a new tx descriptor and adds header regd buffer */
 153 static void iser_create_send_desc(struct iser_conn      *ib_conn,
 154                                   struct iser_tx_desc   *tx_desc)
 155 {
 156         struct iser_device *device = ib_conn->device;
 157
 158         ib_dma_sync_single_for_cpu(device->ib_device,
 159                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 160
 161         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 162         tx_desc->iser_header.flags = ISER_VER;
 163
 164         tx_desc->num_sge = 1;
 165
 166         if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
 167                 tx_desc->tx_sg[0].lkey = device->mr->lkey;
 168                 iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
 169         }
 170 }
 171
 172
 173 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
 174 {
 175         int i, j;
 176         u64 dma_addr;
 177         struct iser_rx_desc *rx_desc;
 178         struct ib_sge       *rx_sg;
 179         struct iser_device  *device = ib_conn->device;
 180
 181         ib_conn->rx_descs = kmalloc(ISER_QP_MAX_RECV_DTOS *
 182                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 183         if (!ib_conn->rx_descs)
 184                 goto rx_desc_alloc_fail;
 185
 186         rx_desc = ib_conn->rx_descs;
 187
 188         for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
 189                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 190                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 191                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 192                         goto rx_desc_dma_map_failed;
 193
 194                 rx_desc->dma_addr = dma_addr;
 195
 196                 rx_sg = &rx_desc->rx_sg;
 197                 rx_sg->addr   = rx_desc->dma_addr;
 198                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 199                 rx_sg->lkey   = device->mr->lkey;
 200         }
 201
 202         ib_conn->rx_desc_head = 0;
 203         return 0;
 204
 205 rx_desc_dma_map_failed:
 206         rx_desc = ib_conn->rx_descs;
 207         for (j = 0; j < i; j++, rx_desc++)
 208                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 209                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 210         kfree(ib_conn->rx_descs);
 211         ib_conn->rx_descs = NULL;
 212 rx_desc_alloc_fail:
 213         iser_err("failed allocating rx descriptors / data buffers\n");
 214         return -ENOMEM;
 215 }
 216
 217 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 218 {
 219         int i;
 220         struct iser_rx_desc *rx_desc;
 221         struct iser_device *device = ib_conn->device;
 222
 223         if (ib_conn->login_buf) {
 224                 ib_dma_unmap_single(device->ib_device, ib_conn->login_dma,
 225                         ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 226                 kfree(ib_conn->login_buf);
 227         }
 228
 229         if (!ib_conn->rx_descs)
 230                 return;
 231
 232         rx_desc = ib_conn->rx_descs;
 233         for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)
 234                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 235                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 236         kfree(ib_conn->rx_descs);
 237 }
 238
 239 /**
 240  *  iser_conn_set_full_featured_mode - (iSER API)
 241  */
 242 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 243 {
 244         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 245
 246         iser_dbg("Initially post: %d\n", ISER_MIN_POSTED_RX);
 247
 248         /* Check that there is no posted recv or send buffers left - */
 249         /* they must be consumed during the login phase */
 250         BUG_ON(iser_conn->ib_conn->post_recv_buf_count != 0);
 251         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 252
 253         if (iser_alloc_rx_descriptors(iser_conn->ib_conn))
 254                 return -ENOMEM;
 255
 256         /* Initial post receive buffers */
 257         if (iser_post_recvm(iser_conn->ib_conn, ISER_MIN_POSTED_RX))
 258                 return -ENOMEM;
 259
 260         return 0;
 261 }
 262
 263 static int
 264 iser_check_xmit(struct iscsi_conn *conn, void *task)
 265 {
 266         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 267
 268         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 269             ISER_QP_MAX_REQ_DTOS) {
 270                 iser_dbg("%ld can't xmit task %p\n",jiffies,task);
 271                 return -ENOBUFS;
 272         }
 273         return 0;
 274 }
 275
 276
 277 /**
 278  * iser_send_command - send command PDU
 279  */
 280 int iser_send_command(struct iscsi_conn *conn,
 281                       struct iscsi_task *task)
 282 {
 283         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 284         struct iscsi_iser_task *iser_task = task->dd_data;
 285         unsigned long edtl;
 286         int err;
 287         struct iser_data_buf *data_buf;
 288         struct iscsi_cmd *hdr =  (struct iscsi_cmd *)task->hdr;
 289         struct scsi_cmnd *sc  =  task->sc;
 290         struct iser_tx_desc *tx_desc = &iser_task->desc;
 291
 292         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 293                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 294                 return -EPERM;
 295         }
 296         if (iser_check_xmit(conn, task))
 297                 return -ENOBUFS;
 298
 299         edtl = ntohl(hdr->data_length);
 300
 301         /* build the tx desc regd header and add it to the tx desc dto */
 302         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 303         iser_create_send_desc(iser_conn->ib_conn, tx_desc);
 304
 305         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 306                 data_buf = &iser_task->data[ISER_DIR_IN];
 307         else
 308                 data_buf = &iser_task->data[ISER_DIR_OUT];
 309
 310         if (scsi_sg_count(sc)) { /* using a scatter list */
 311                 data_buf->buf  = scsi_sglist(sc);
 312                 data_buf->size = scsi_sg_count(sc);
 313         }
 314
 315         data_buf->data_len = scsi_bufflen(sc);
 316
 317         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 318                 err = iser_prepare_read_cmd(task, edtl);
 319                 if (err)
 320                         goto send_command_error;
 321         }
 322         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 323                 err = iser_prepare_write_cmd(task,
 324                                              task->imm_count,
 325                                              task->imm_count +
 326                                              task->unsol_r2t.data_length,
 327                                              edtl);
 328                 if (err)
 329                         goto send_command_error;
 330         }
 331
 332         iser_task->status = ISER_TASK_STATUS_STARTED;
 333
 334         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 335         if (!err)
 336                 return 0;
 337
 338 send_command_error:
 339         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 340         return err;
 341 }
 342
 343 /**
 344  * iser_send_data_out - send data out PDU
 345  */
 346 int iser_send_data_out(struct iscsi_conn *conn,
 347                        struct iscsi_task *task,
 348                        struct iscsi_data *hdr)
 349 {
 350         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 351         struct iscsi_iser_task *iser_task = task->dd_data;
 352         struct iser_tx_desc *tx_desc = NULL;
 353         struct iser_regd_buf *regd_buf;
 354         unsigned long buf_offset;
 355         unsigned long data_seg_len;
 356         uint32_t itt;
 357         int err = 0;
 358         struct ib_sge *tx_dsg;
 359
 360
 361         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 362                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 363                 return -EPERM;
 364         }
 365
 366         if (iser_check_xmit(conn, task))
 367                 return -ENOBUFS;
 368
 369         itt = (__force uint32_t)hdr->itt;
 370         data_seg_len = ntoh24(hdr->dlength);
 371         buf_offset   = ntohl(hdr->offset);
 372
 373         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 374                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 375
 376         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 377         if (tx_desc == NULL) {
 378                 iser_err("Failed to alloc desc for post dataout\n");
 379                 return -ENOMEM;
 380         }
 381
 382         tx_desc->type = ISCSI_TX_DATAOUT;
 383         tx_desc->iser_header.flags = ISER_VER;
 384         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 385
 386         /* build the tx desc */
 387         iser_initialize_task_headers(task, tx_desc);
 388
 389         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 390         tx_dsg = &tx_desc->tx_sg[1];
 391         tx_dsg->addr    = regd_buf->reg.va + buf_offset;
 392         tx_dsg->length  = data_seg_len;
 393         tx_dsg->lkey    = regd_buf->reg.lkey;
 394         tx_desc->num_sge = 2;
 395
 396         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 397                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 398                          "inconsistent with total len:%ld, itt:%d\n",
 399                          buf_offset, data_seg_len,
 400                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 401                 err = -EINVAL;
 402                 goto send_data_out_error;
 403         }
 404         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 405                  itt, buf_offset, data_seg_len);
 406
 407
 408         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 409         if (!err)
 410                 return 0;
 411
 412 send_data_out_error:
 413         kmem_cache_free(ig.desc_cache, tx_desc);
 414         iser_err("conn %p failed err %d\n",conn, err);
 415         return err;
 416 }
 417
 418 int iser_send_control(struct iscsi_conn *conn,
 419                       struct iscsi_task *task)
 420 {
 421         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 422         struct iscsi_iser_task *iser_task = task->dd_data;
 423         struct iser_tx_desc *mdesc = &iser_task->desc;
 424         unsigned long data_seg_len;
 425         int err = 0;
 426         struct iser_device *device;
 427
 428         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 429                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 430                 return -EPERM;
 431         }
 432
 433         if (iser_check_xmit(conn, task))
 434                 return -ENOBUFS;
 435
 436         /* build the tx desc regd header and add it to the tx desc dto */
 437         mdesc->type = ISCSI_TX_CONTROL;
 438         iser_create_send_desc(iser_conn->ib_conn, mdesc);
 439
 440         device = iser_conn->ib_conn->device;
 441
 442         data_seg_len = ntoh24(task->hdr->dlength);
 443
 444         if (data_seg_len > 0) {
 445                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 446                 if (task != conn->login_task) {
 447                         iser_err("data present on non login task!!!\n");
 448                         goto send_control_error;
 449                 }
 450                 memcpy(iser_conn->ib_conn->login_buf, task->data,
 451                                                         task->data_count);
 452                 tx_dsg->addr    = iser_conn->ib_conn->login_dma;
 453                 tx_dsg->length  = data_seg_len;
 454                 tx_dsg->lkey    = device->mr->lkey;
 455                 mdesc->num_sge = 2;
 456         }
 457
 458         if (task == conn->login_task) {
 459                 err = iser_post_recvl(iser_conn->ib_conn);
 460                 if (err)
 461                         goto send_control_error;
 462         }
 463
 464         err = iser_post_send(iser_conn->ib_conn, mdesc);
 465         if (!err)
 466                 return 0;
 467
 468 send_control_error:
 469         iser_err("conn %p failed err %d\n",conn, err);
 470         return err;
 471 }
 472
 473 /**
 474  * iser_rcv_dto_completion - recv DTO completion
 475  */
 476 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 477                          unsigned long rx_xfer_len,
 478                          struct iser_conn *ib_conn)
 479 {
 480         struct iscsi_iser_conn *conn = ib_conn->iser_conn;
 481         struct iscsi_task *task;
 482         struct iscsi_iser_task *iser_task;
 483         struct iscsi_hdr *hdr;
 484         unsigned char opcode;
 485         u64 rx_dma;
 486         int rx_buflen, outstanding, count, err;
 487
 488         /* differentiate between login to all other PDUs */
 489         if ((char *)rx_desc == ib_conn->login_buf) {
 490                 rx_dma = ib_conn->login_dma;
 491                 rx_buflen = ISER_RX_LOGIN_SIZE;
 492         } else {
 493                 rx_dma = rx_desc->dma_addr;
 494                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 495         }
 496
 497         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 498                         rx_buflen, DMA_FROM_DEVICE);
 499
 500         hdr = &rx_desc->iscsi_header;
 501
 502         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 503                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 504
 505         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 506
 507         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 508                 spin_lock(&conn->iscsi_conn->session->lock);
 509                 task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);
 510                 if (task)
 511                         __iscsi_get_task(task);
 512                 spin_unlock(&conn->iscsi_conn->session->lock);
 513
 514                 if (!task)
 515                         iser_err("itt can't be matched to task!!! "
 516                                  "conn %p opcode %d itt %d\n",
 517                                  conn->iscsi_conn, opcode, hdr->itt);
 518                 else {
 519                         iser_task = task->dd_data;
 520                         iser_dbg("itt %d task %p\n",hdr->itt, task);
 521                         iser_task->status = ISER_TASK_STATUS_COMPLETED;
 522                         iser_task_rdma_finalize(iser_task);
 523                         iscsi_put_task(task);
 524                 }
 525         }
 526
 527         iscsi_iser_recv(conn->iscsi_conn, hdr,
 528                 rx_desc->data, rx_xfer_len - ISER_HEADERS_LEN);
 529
 530         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 531                         rx_buflen, DMA_FROM_DEVICE);
 532
 533         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 534          * task eliminates the need to worry on tasks which are completed in   *
 535          * parallel to the execution of iser_conn_term. So the code that waits *
 536          * for the posted rx bufs refcount to become zero handles everything   */
 537         conn->ib_conn->post_recv_buf_count--;
 538
 539         if (rx_dma == ib_conn->login_dma)
 540                 return;
 541
 542         outstanding = ib_conn->post_recv_buf_count;
 543         if (outstanding + ISER_MIN_POSTED_RX <= ISER_QP_MAX_RECV_DTOS) {
 544                 count = min(ISER_QP_MAX_RECV_DTOS - outstanding,
 545                                                 ISER_MIN_POSTED_RX);
 546                 err = iser_post_recvm(ib_conn, count);
 547                 if (err)
 548                         iser_err("posting %d rx bufs err %d\n", count, err);
 549         }
 550 }
 551
 552 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 553                         struct iser_conn *ib_conn)
 554 {
 555         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 556         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 557         struct iscsi_task *task;
 558         int resume_tx = 0;
 559         struct iser_device *device = ib_conn->device;
 560
 561         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 562                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 563                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 564                 kmem_cache_free(ig.desc_cache, tx_desc);
 565         }
 566
 567         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 568             ISER_QP_MAX_REQ_DTOS)
 569                 resume_tx = 1;
 570
 571         atomic_dec(&ib_conn->post_send_buf_count);
 572
 573         if (resume_tx) {
 574                 iser_dbg("%ld resuming tx\n",jiffies);
 575                 iscsi_conn_queue_work(conn);
 576         }
 577
 578         if (tx_desc->type == ISCSI_TX_CONTROL) {
 579                 /* this arithmetic is legal by libiscsi dd_data allocation */
 580                 task = (void *) ((long)(void *)tx_desc -
 581                                   sizeof(struct iscsi_task));
 582                 if (task->hdr->itt == RESERVED_ITT)
 583                         iscsi_put_task(task);
 584         }
 585 }
 586
 587 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 588
 589 {
 590         iser_task->status = ISER_TASK_STATUS_INIT;
 591
 592         iser_task->dir[ISER_DIR_IN] = 0;
 593         iser_task->dir[ISER_DIR_OUT] = 0;
 594
 595         iser_task->data[ISER_DIR_IN].data_len  = 0;
 596         iser_task->data[ISER_DIR_OUT].data_len = 0;
 597
 598         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 599                sizeof(struct iser_regd_buf));
 600         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 601                sizeof(struct iser_regd_buf));
 602 }
 603
 604 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 605 {
 606         int is_rdma_aligned = 1;
 607         struct iser_regd_buf *regd;
 608
 609         /* if we were reading, copy back to unaligned sglist,
 610          * anyway dma_unmap and free the copy
 611          */
 612         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 613                 is_rdma_aligned = 0;
 614                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
 615         }
 616         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 617                 is_rdma_aligned = 0;
 618                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
 619         }
 620
 621         if (iser_task->dir[ISER_DIR_IN]) {
 622                 regd = &iser_task->rdma_regd[ISER_DIR_IN];
 623                 if (regd->reg.is_fmr)
 624                         iser_unreg_mem(&regd->reg);
 625         }
 626
 627         if (iser_task->dir[ISER_DIR_OUT]) {
 628                 regd = &iser_task->rdma_regd[ISER_DIR_OUT];
 629                 if (regd->reg.is_fmr)
 630                         iser_unreg_mem(&regd->reg);
 631         }
 632
 633        /* if the data was unaligned, it was already unmapped and then copied */
 634        if (is_rdma_aligned)
 635                 iser_dma_unmap_task_data(iser_task);
 636 }