drivers/infiniband/ulp/iser/iser_initiator.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33 #include <linux/kernel.h>
  34 #include <linux/slab.h>
  35 #include <linux/mm.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/kfifo.h>
  38 #include <scsi/scsi_cmnd.h>
  39 #include <scsi/scsi_host.h>
  40
  41 #include "iscsi_iser.h"
  42
  43 /* Register user buffer memory and initialize passive rdma
  44  *  dto descriptor. Data size is stored in
  45  *  task->data[ISER_DIR_IN].data_len, Protection size
  46  *  os stored in task->prot[ISER_DIR_IN].data_len
  47  */
  48 static int iser_prepare_read_cmd(struct iscsi_task *task)
  49
  50 {
  51         struct iscsi_iser_task *iser_task = task->dd_data;
  52         struct iser_mem_reg *mem_reg;
  53         int err;
  54         struct iser_hdr *hdr = &iser_task->desc.iser_header;
  55         struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
  56
  57         err = iser_dma_map_task_data(iser_task,
  58                                      buf_in,
  59                                      ISER_DIR_IN,
  60                                      DMA_FROM_DEVICE);
  61         if (err)
  62                 return err;
  63
  64         if (scsi_prot_sg_count(iser_task->sc)) {
  65                 struct iser_data_buf *pbuf_in = &iser_task->prot[ISER_DIR_IN];
  66
  67                 err = iser_dma_map_task_data(iser_task,
  68                                              pbuf_in,
  69                                              ISER_DIR_IN,
  70                                              DMA_FROM_DEVICE);
  71                 if (err)
  72                         return err;
  73         }
  74
  75         err = iser_reg_rdma_mem(iser_task, ISER_DIR_IN);
  76         if (err) {
  77                 iser_err("Failed to set up Data-IN RDMA\n");
  78                 return err;
  79         }
  80         mem_reg = &iser_task->rdma_reg[ISER_DIR_IN];
  81
  82         hdr->flags    |= ISER_RSV;
  83         hdr->read_stag = cpu_to_be32(mem_reg->rkey);
  84         hdr->read_va   = cpu_to_be64(mem_reg->sge.addr);
  85
  86         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  87                  task->itt, mem_reg->rkey,
  88                  (unsigned long long)mem_reg->sge.addr);
  89
  90         return 0;
  91 }
  92
  93 /* Register user buffer memory and initialize passive rdma
  94  *  dto descriptor. Data size is stored in
  95  *  task->data[ISER_DIR_OUT].data_len, Protection size
  96  *  is stored at task->prot[ISER_DIR_OUT].data_len
  97  */
  98 static int
  99 iser_prepare_write_cmd(struct iscsi_task *task,
 100                        unsigned int imm_sz,
 101                        unsigned int unsol_sz,
 102                        unsigned int edtl)
 103 {
 104         struct iscsi_iser_task *iser_task = task->dd_data;
 105         struct iser_mem_reg *mem_reg;
 106         int err;
 107         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 108         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 109         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 110
 111         err = iser_dma_map_task_data(iser_task,
 112                                      buf_out,
 113                                      ISER_DIR_OUT,
 114                                      DMA_TO_DEVICE);
 115         if (err)
 116                 return err;
 117
 118         if (scsi_prot_sg_count(iser_task->sc)) {
 119                 struct iser_data_buf *pbuf_out = &iser_task->prot[ISER_DIR_OUT];
 120
 121                 err = iser_dma_map_task_data(iser_task,
 122                                              pbuf_out,
 123                                              ISER_DIR_OUT,
 124                                              DMA_TO_DEVICE);
 125                 if (err)
 126                         return err;
 127         }
 128
 129         err = iser_reg_rdma_mem(iser_task, ISER_DIR_OUT);
 130         if (err != 0) {
 131                 iser_err("Failed to register write cmd RDMA mem\n");
 132                 return err;
 133         }
 134
 135         mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
 136
 137         if (unsol_sz < edtl) {
 138                 hdr->flags     |= ISER_WSV;
 139                 hdr->write_stag = cpu_to_be32(mem_reg->rkey);
 140                 hdr->write_va   = cpu_to_be64(mem_reg->sge.addr + unsol_sz);
 141
 142                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 143                          "VA:%#llX + unsol:%d\n",
 144                          task->itt, mem_reg->rkey,
 145                          (unsigned long long)mem_reg->sge.addr, unsol_sz);
 146         }
 147
 148         if (imm_sz > 0) {
 149                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 150                          task->itt, imm_sz);
 151                 tx_dsg->addr = mem_reg->sge.addr;
 152                 tx_dsg->length = imm_sz;
 153                 tx_dsg->lkey = mem_reg->sge.lkey;
 154                 iser_task->desc.num_sge = 2;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /* creates a new tx descriptor and adds header regd buffer */
 161 static void iser_create_send_desc(struct iser_conn      *iser_conn,
 162                                   struct iser_tx_desc   *tx_desc)
 163 {
 164         struct iser_device *device = iser_conn->ib_conn.device;
 165
 166         ib_dma_sync_single_for_cpu(device->ib_device,
 167                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 168
 169         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 170         tx_desc->iser_header.flags = ISER_VER;
 171         tx_desc->num_sge = 1;
 172 }
 173
 174 static void iser_free_login_buf(struct iser_conn *iser_conn)
 175 {
 176         struct iser_device *device = iser_conn->ib_conn.device;
 177
 178         if (!iser_conn->login_buf)
 179                 return;
 180
 181         if (iser_conn->login_req_dma)
 182                 ib_dma_unmap_single(device->ib_device,
 183                                     iser_conn->login_req_dma,
 184                                     ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 185
 186         if (iser_conn->login_resp_dma)
 187                 ib_dma_unmap_single(device->ib_device,
 188                                     iser_conn->login_resp_dma,
 189                                     ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 190
 191         kfree(iser_conn->login_buf);
 192
 193         /* make sure we never redo any unmapping */
 194         iser_conn->login_req_dma = 0;
 195         iser_conn->login_resp_dma = 0;
 196         iser_conn->login_buf = NULL;
 197 }
 198
 199 static int iser_alloc_login_buf(struct iser_conn *iser_conn)
 200 {
 201         struct iser_device *device = iser_conn->ib_conn.device;
 202         int                     req_err, resp_err;
 203
 204         BUG_ON(device == NULL);
 205
 206         iser_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
 207                                      ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 208         if (!iser_conn->login_buf)
 209                 goto out_err;
 210
 211         iser_conn->login_req_buf  = iser_conn->login_buf;
 212         iser_conn->login_resp_buf = iser_conn->login_buf +
 213                                                 ISCSI_DEF_MAX_RECV_SEG_LEN;
 214
 215         iser_conn->login_req_dma = ib_dma_map_single(device->ib_device,
 216                                                      iser_conn->login_req_buf,
 217                                                      ISCSI_DEF_MAX_RECV_SEG_LEN,
 218                                                      DMA_TO_DEVICE);
 219
 220         iser_conn->login_resp_dma = ib_dma_map_single(device->ib_device,
 221                                                       iser_conn->login_resp_buf,
 222                                                       ISER_RX_LOGIN_SIZE,
 223                                                       DMA_FROM_DEVICE);
 224
 225         req_err  = ib_dma_mapping_error(device->ib_device,
 226                                         iser_conn->login_req_dma);
 227         resp_err = ib_dma_mapping_error(device->ib_device,
 228                                         iser_conn->login_resp_dma);
 229
 230         if (req_err || resp_err) {
 231                 if (req_err)
 232                         iser_conn->login_req_dma = 0;
 233                 if (resp_err)
 234                         iser_conn->login_resp_dma = 0;
 235                 goto free_login_buf;
 236         }
 237         return 0;
 238
 239 free_login_buf:
 240         iser_free_login_buf(iser_conn);
 241
 242 out_err:
 243         iser_err("unable to alloc or map login buf\n");
 244         return -ENOMEM;
 245 }
 246
 247 int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
 248                               struct iscsi_session *session)
 249 {
 250         int i, j;
 251         u64 dma_addr;
 252         struct iser_rx_desc *rx_desc;
 253         struct ib_sge       *rx_sg;
 254         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 255         struct iser_device *device = ib_conn->device;
 256
 257         iser_conn->qp_max_recv_dtos = session->cmds_max;
 258         iser_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 259         iser_conn->min_posted_rx = iser_conn->qp_max_recv_dtos >> 2;
 260
 261         if (device->reg_ops->alloc_reg_res(ib_conn, session->scsi_cmds_max,
 262                                            iser_conn->scsi_sg_tablesize))
 263                 goto create_rdma_reg_res_failed;
 264
 265         if (iser_alloc_login_buf(iser_conn))
 266                 goto alloc_login_buf_fail;
 267
 268         iser_conn->num_rx_descs = session->cmds_max;
 269         iser_conn->rx_descs = kmalloc(iser_conn->num_rx_descs *
 270                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 271         if (!iser_conn->rx_descs)
 272                 goto rx_desc_alloc_fail;
 273
 274         rx_desc = iser_conn->rx_descs;
 275
 276         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 277                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 278                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 279                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 280                         goto rx_desc_dma_map_failed;
 281
 282                 rx_desc->dma_addr = dma_addr;
 283
 284                 rx_sg = &rx_desc->rx_sg;
 285                 rx_sg->addr   = rx_desc->dma_addr;
 286                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 287                 rx_sg->lkey   = device->mr->lkey;
 288         }
 289
 290         iser_conn->rx_desc_head = 0;
 291         return 0;
 292
 293 rx_desc_dma_map_failed:
 294         rx_desc = iser_conn->rx_descs;
 295         for (j = 0; j < i; j++, rx_desc++)
 296                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 297                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 298         kfree(iser_conn->rx_descs);
 299         iser_conn->rx_descs = NULL;
 300 rx_desc_alloc_fail:
 301         iser_free_login_buf(iser_conn);
 302 alloc_login_buf_fail:
 303         device->reg_ops->free_reg_res(ib_conn);
 304 create_rdma_reg_res_failed:
 305         iser_err("failed allocating rx descriptors / data buffers\n");
 306         return -ENOMEM;
 307 }
 308
 309 void iser_free_rx_descriptors(struct iser_conn *iser_conn)
 310 {
 311         int i;
 312         struct iser_rx_desc *rx_desc;
 313         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 314         struct iser_device *device = ib_conn->device;
 315
 316         if (device->reg_ops->free_reg_res)
 317                 device->reg_ops->free_reg_res(ib_conn);
 318
 319         rx_desc = iser_conn->rx_descs;
 320         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)
 321                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 322                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 323         kfree(iser_conn->rx_descs);
 324         /* make sure we never redo any unmapping */
 325         iser_conn->rx_descs = NULL;
 326
 327         iser_free_login_buf(iser_conn);
 328 }
 329
 330 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 331 {
 332         struct iser_conn *iser_conn = conn->dd_data;
 333         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 334         struct iscsi_session *session = conn->session;
 335
 336         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 337         /* check if this is the last login - going to full feature phase */
 338         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 339                 return 0;
 340
 341         /*
 342          * Check that there is one posted recv buffer
 343          * (for the last login response).
 344          */
 345         WARN_ON(ib_conn->post_recv_buf_count != 1);
 346
 347         if (session->discovery_sess) {
 348                 iser_info("Discovery session, re-using login RX buffer\n");
 349                 return 0;
 350         } else
 351                 iser_info("Normal session, posting batch of RX %d buffers\n",
 352                           iser_conn->min_posted_rx);
 353
 354         /* Initial post receive buffers */
 355         if (iser_post_recvm(iser_conn, iser_conn->min_posted_rx))
 356                 return -ENOMEM;
 357
 358         return 0;
 359 }
 360
 361 static inline bool iser_signal_comp(u8 sig_count)
 362 {
 363         return ((sig_count % ISER_SIGNAL_CMD_COUNT) == 0);
 364 }
 365
 366 /**
 367  * iser_send_command - send command PDU
 368  */
 369 int iser_send_command(struct iscsi_conn *conn,
 370                       struct iscsi_task *task)
 371 {
 372         struct iser_conn *iser_conn = conn->dd_data;
 373         struct iscsi_iser_task *iser_task = task->dd_data;
 374         unsigned long edtl;
 375         int err;
 376         struct iser_data_buf *data_buf, *prot_buf;
 377         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 378         struct scsi_cmnd *sc  =  task->sc;
 379         struct iser_tx_desc *tx_desc = &iser_task->desc;
 380         u8 sig_count = ++iser_conn->ib_conn.sig_count;
 381
 382         edtl = ntohl(hdr->data_length);
 383
 384         /* build the tx desc regd header and add it to the tx desc dto */
 385         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 386         iser_create_send_desc(iser_conn, tx_desc);
 387
 388         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 389                 data_buf = &iser_task->data[ISER_DIR_IN];
 390                 prot_buf = &iser_task->prot[ISER_DIR_IN];
 391         } else {
 392                 data_buf = &iser_task->data[ISER_DIR_OUT];
 393                 prot_buf = &iser_task->prot[ISER_DIR_OUT];
 394         }
 395
 396         if (scsi_sg_count(sc)) { /* using a scatter list */
 397                 data_buf->sg = scsi_sglist(sc);
 398                 data_buf->size = scsi_sg_count(sc);
 399         }
 400         data_buf->data_len = scsi_bufflen(sc);
 401
 402         if (scsi_prot_sg_count(sc)) {
 403                 prot_buf->sg  = scsi_prot_sglist(sc);
 404                 prot_buf->size = scsi_prot_sg_count(sc);
 405                 prot_buf->data_len = (data_buf->data_len >>
 406                                      ilog2(sc->device->sector_size)) * 8;
 407         }
 408
 409         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 410                 err = iser_prepare_read_cmd(task);
 411                 if (err)
 412                         goto send_command_error;
 413         }
 414         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 415                 err = iser_prepare_write_cmd(task,
 416                                              task->imm_count,
 417                                              task->imm_count +
 418                                              task->unsol_r2t.data_length,
 419                                              edtl);
 420                 if (err)
 421                         goto send_command_error;
 422         }
 423
 424         iser_task->status = ISER_TASK_STATUS_STARTED;
 425
 426         err = iser_post_send(&iser_conn->ib_conn, tx_desc,
 427                              iser_signal_comp(sig_count));
 428         if (!err)
 429                 return 0;
 430
 431 send_command_error:
 432         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 433         return err;
 434 }
 435
 436 /**
 437  * iser_send_data_out - send data out PDU
 438  */
 439 int iser_send_data_out(struct iscsi_conn *conn,
 440                        struct iscsi_task *task,
 441                        struct iscsi_data *hdr)
 442 {
 443         struct iser_conn *iser_conn = conn->dd_data;
 444         struct iscsi_iser_task *iser_task = task->dd_data;
 445         struct iser_tx_desc *tx_desc = NULL;
 446         struct iser_mem_reg *mem_reg;
 447         unsigned long buf_offset;
 448         unsigned long data_seg_len;
 449         uint32_t itt;
 450         int err;
 451         struct ib_sge *tx_dsg;
 452
 453         itt = (__force uint32_t)hdr->itt;
 454         data_seg_len = ntoh24(hdr->dlength);
 455         buf_offset   = ntohl(hdr->offset);
 456
 457         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 458                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 459
 460         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 461         if (tx_desc == NULL) {
 462                 iser_err("Failed to alloc desc for post dataout\n");
 463                 return -ENOMEM;
 464         }
 465
 466         tx_desc->type = ISCSI_TX_DATAOUT;
 467         tx_desc->iser_header.flags = ISER_VER;
 468         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 469
 470         /* build the tx desc */
 471         err = iser_initialize_task_headers(task, tx_desc);
 472         if (err)
 473                 goto send_data_out_error;
 474
 475         mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
 476         tx_dsg = &tx_desc->tx_sg[1];
 477         tx_dsg->addr = mem_reg->sge.addr + buf_offset;
 478         tx_dsg->length = data_seg_len;
 479         tx_dsg->lkey = mem_reg->sge.lkey;
 480         tx_desc->num_sge = 2;
 481
 482         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 483                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 484                          "inconsistent with total len:%ld, itt:%d\n",
 485                          buf_offset, data_seg_len,
 486                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 487                 err = -EINVAL;
 488                 goto send_data_out_error;
 489         }
 490         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 491                  itt, buf_offset, data_seg_len);
 492
 493
 494         err = iser_post_send(&iser_conn->ib_conn, tx_desc, true);
 495         if (!err)
 496                 return 0;
 497
 498 send_data_out_error:
 499         kmem_cache_free(ig.desc_cache, tx_desc);
 500         iser_err("conn %p failed err %d\n", conn, err);
 501         return err;
 502 }
 503
 504 int iser_send_control(struct iscsi_conn *conn,
 505                       struct iscsi_task *task)
 506 {
 507         struct iser_conn *iser_conn = conn->dd_data;
 508         struct iscsi_iser_task *iser_task = task->dd_data;
 509         struct iser_tx_desc *mdesc = &iser_task->desc;
 510         unsigned long data_seg_len;
 511         int err = 0;
 512         struct iser_device *device;
 513
 514         /* build the tx desc regd header and add it to the tx desc dto */
 515         mdesc->type = ISCSI_TX_CONTROL;
 516         iser_create_send_desc(iser_conn, mdesc);
 517
 518         device = iser_conn->ib_conn.device;
 519
 520         data_seg_len = ntoh24(task->hdr->dlength);
 521
 522         if (data_seg_len > 0) {
 523                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 524                 if (task != conn->login_task) {
 525                         iser_err("data present on non login task!!!\n");
 526                         goto send_control_error;
 527                 }
 528
 529                 ib_dma_sync_single_for_cpu(device->ib_device,
 530                         iser_conn->login_req_dma, task->data_count,
 531                         DMA_TO_DEVICE);
 532
 533                 memcpy(iser_conn->login_req_buf, task->data, task->data_count);
 534
 535                 ib_dma_sync_single_for_device(device->ib_device,
 536                         iser_conn->login_req_dma, task->data_count,
 537                         DMA_TO_DEVICE);
 538
 539                 tx_dsg->addr    = iser_conn->login_req_dma;
 540                 tx_dsg->length  = task->data_count;
 541                 tx_dsg->lkey    = device->mr->lkey;
 542                 mdesc->num_sge = 2;
 543         }
 544
 545         if (task == conn->login_task) {
 546                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 547                          task->hdr->opcode, data_seg_len);
 548                 err = iser_post_recvl(iser_conn);
 549                 if (err)
 550                         goto send_control_error;
 551                 err = iser_post_rx_bufs(conn, task->hdr);
 552                 if (err)
 553                         goto send_control_error;
 554         }
 555
 556         err = iser_post_send(&iser_conn->ib_conn, mdesc, true);
 557         if (!err)
 558                 return 0;
 559
 560 send_control_error:
 561         iser_err("conn %p failed err %d\n",conn, err);
 562         return err;
 563 }
 564
 565 /**
 566  * iser_rcv_dto_completion - recv DTO completion
 567  */
 568 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 569                          unsigned long rx_xfer_len,
 570                          struct ib_conn *ib_conn)
 571 {
 572         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 573                                                    ib_conn);
 574         struct iscsi_hdr *hdr;
 575         u64 rx_dma;
 576         int rx_buflen, outstanding, count, err;
 577
 578         /* differentiate between login to all other PDUs */
 579         if ((char *)rx_desc == iser_conn->login_resp_buf) {
 580                 rx_dma = iser_conn->login_resp_dma;
 581                 rx_buflen = ISER_RX_LOGIN_SIZE;
 582         } else {
 583                 rx_dma = rx_desc->dma_addr;
 584                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 585         }
 586
 587         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 588                                    rx_buflen, DMA_FROM_DEVICE);
 589
 590         hdr = &rx_desc->iscsi_header;
 591
 592         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 593                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 594
 595         iscsi_iser_recv(iser_conn->iscsi_conn, hdr, rx_desc->data,
 596                         rx_xfer_len - ISER_HEADERS_LEN);
 597
 598         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 599                                       rx_buflen, DMA_FROM_DEVICE);
 600
 601         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 602          * task eliminates the need to worry on tasks which are completed in   *
 603          * parallel to the execution of iser_conn_term. So the code that waits *
 604          * for the posted rx bufs refcount to become zero handles everything   */
 605         ib_conn->post_recv_buf_count--;
 606
 607         if (rx_dma == iser_conn->login_resp_dma)
 608                 return;
 609
 610         outstanding = ib_conn->post_recv_buf_count;
 611         if (outstanding + iser_conn->min_posted_rx <= iser_conn->qp_max_recv_dtos) {
 612                 count = min(iser_conn->qp_max_recv_dtos - outstanding,
 613                             iser_conn->min_posted_rx);
 614                 err = iser_post_recvm(iser_conn, count);
 615                 if (err)
 616                         iser_err("posting %d rx bufs err %d\n", count, err);
 617         }
 618 }
 619
 620 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 621                         struct ib_conn *ib_conn)
 622 {
 623         struct iscsi_task *task;
 624         struct iser_device *device = ib_conn->device;
 625
 626         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 627                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 628                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 629                 kmem_cache_free(ig.desc_cache, tx_desc);
 630                 tx_desc = NULL;
 631         }
 632
 633         if (tx_desc && tx_desc->type == ISCSI_TX_CONTROL) {
 634                 /* this arithmetic is legal by libiscsi dd_data allocation */
 635                 task = (void *) ((long)(void *)tx_desc -
 636                                   sizeof(struct iscsi_task));
 637                 if (task->hdr->itt == RESERVED_ITT)
 638                         iscsi_put_task(task);
 639         }
 640 }
 641
 642 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 643
 644 {
 645         iser_task->status = ISER_TASK_STATUS_INIT;
 646
 647         iser_task->dir[ISER_DIR_IN] = 0;
 648         iser_task->dir[ISER_DIR_OUT] = 0;
 649
 650         iser_task->data[ISER_DIR_IN].data_len  = 0;
 651         iser_task->data[ISER_DIR_OUT].data_len = 0;
 652
 653         iser_task->prot[ISER_DIR_IN].data_len  = 0;
 654         iser_task->prot[ISER_DIR_OUT].data_len = 0;
 655
 656         memset(&iser_task->rdma_reg[ISER_DIR_IN], 0,
 657                sizeof(struct iser_mem_reg));
 658         memset(&iser_task->rdma_reg[ISER_DIR_OUT], 0,
 659                sizeof(struct iser_mem_reg));
 660 }
 661
 662 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 663 {
 664         int is_rdma_data_aligned = 1;
 665         int is_rdma_prot_aligned = 1;
 666         int prot_count = scsi_prot_sg_count(iser_task->sc);
 667
 668         /* if we were reading, copy back to unaligned sglist,
 669          * anyway dma_unmap and free the copy
 670          */
 671         if (iser_task->data[ISER_DIR_IN].orig_sg) {
 672                 is_rdma_data_aligned = 0;
 673                 iser_finalize_rdma_unaligned_sg(iser_task,
 674                                                 &iser_task->data[ISER_DIR_IN],
 675                                                 ISER_DIR_IN);
 676         }
 677
 678         if (iser_task->data[ISER_DIR_OUT].orig_sg) {
 679                 is_rdma_data_aligned = 0;
 680                 iser_finalize_rdma_unaligned_sg(iser_task,
 681                                                 &iser_task->data[ISER_DIR_OUT],
 682                                                 ISER_DIR_OUT);
 683         }
 684
 685         if (iser_task->prot[ISER_DIR_IN].orig_sg) {
 686                 is_rdma_prot_aligned = 0;
 687                 iser_finalize_rdma_unaligned_sg(iser_task,
 688                                                 &iser_task->prot[ISER_DIR_IN],
 689                                                 ISER_DIR_IN);
 690         }
 691
 692         if (iser_task->prot[ISER_DIR_OUT].orig_sg) {
 693                 is_rdma_prot_aligned = 0;
 694                 iser_finalize_rdma_unaligned_sg(iser_task,
 695                                                 &iser_task->prot[ISER_DIR_OUT],
 696                                                 ISER_DIR_OUT);
 697         }
 698
 699         if (iser_task->dir[ISER_DIR_IN]) {
 700                 iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 701                 if (is_rdma_data_aligned)
 702                         iser_dma_unmap_task_data(iser_task,
 703                                                  &iser_task->data[ISER_DIR_IN],
 704                                                  DMA_FROM_DEVICE);
 705                 if (prot_count && is_rdma_prot_aligned)
 706                         iser_dma_unmap_task_data(iser_task,
 707                                                  &iser_task->prot[ISER_DIR_IN],
 708                                                  DMA_FROM_DEVICE);
 709         }
 710
 711         if (iser_task->dir[ISER_DIR_OUT]) {
 712                 iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
 713                 if (is_rdma_data_aligned)
 714                         iser_dma_unmap_task_data(iser_task,
 715                                                  &iser_task->data[ISER_DIR_OUT],
 716                                                  DMA_TO_DEVICE);
 717                 if (prot_count && is_rdma_prot_aligned)
 718                         iser_dma_unmap_task_data(iser_task,
 719                                                  &iser_task->prot[ISER_DIR_OUT],
 720                                                  DMA_TO_DEVICE);
 721         }
 722 }