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         struct iser_login_desc *desc = &iser_conn->login_desc;
 178
 179         if (!desc->req)
 180                 return;
 181
 182         ib_dma_unmap_single(device->ib_device, desc->req_dma,
 183                             ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 184
 185         ib_dma_unmap_single(device->ib_device, desc->rsp_dma,
 186                             ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 187
 188         kfree(desc->req);
 189         kfree(desc->rsp);
 190
 191         /* make sure we never redo any unmapping */
 192         desc->req = NULL;
 193         desc->rsp = NULL;
 194 }
 195
 196 static int iser_alloc_login_buf(struct iser_conn *iser_conn)
 197 {
 198         struct iser_device *device = iser_conn->ib_conn.device;
 199         struct iser_login_desc *desc = &iser_conn->login_desc;
 200
 201         desc->req = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
 202         if (!desc->req)
 203                 return -ENOMEM;
 204
 205         desc->req_dma = ib_dma_map_single(device->ib_device, desc->req,
 206                                           ISCSI_DEF_MAX_RECV_SEG_LEN,
 207                                           DMA_TO_DEVICE);
 208         if (ib_dma_mapping_error(device->ib_device,
 209                                 desc->req_dma))
 210                 goto free_req;
 211
 212         desc->rsp = kmalloc(ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 213         if (!desc->rsp)
 214                 goto unmap_req;
 215
 216         desc->rsp_dma = ib_dma_map_single(device->ib_device, desc->rsp,
 217                                            ISER_RX_LOGIN_SIZE,
 218                                            DMA_FROM_DEVICE);
 219         if (ib_dma_mapping_error(device->ib_device,
 220                                 desc->rsp_dma))
 221                 goto free_rsp;
 222
 223         return 0;
 224
 225 free_rsp:
 226         kfree(desc->rsp);
 227 unmap_req:
 228         ib_dma_unmap_single(device->ib_device, desc->req_dma,
 229                             ISCSI_DEF_MAX_RECV_SEG_LEN,
 230                             DMA_TO_DEVICE);
 231 free_req:
 232         kfree(desc->req);
 233
 234         return -ENOMEM;
 235 }
 236
 237 int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
 238                               struct iscsi_session *session)
 239 {
 240         int i, j;
 241         u64 dma_addr;
 242         struct iser_rx_desc *rx_desc;
 243         struct ib_sge       *rx_sg;
 244         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 245         struct iser_device *device = ib_conn->device;
 246
 247         iser_conn->qp_max_recv_dtos = session->cmds_max;
 248         iser_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 249         iser_conn->min_posted_rx = iser_conn->qp_max_recv_dtos >> 2;
 250
 251         if (device->reg_ops->alloc_reg_res(ib_conn, session->scsi_cmds_max,
 252                                            iser_conn->scsi_sg_tablesize))
 253                 goto create_rdma_reg_res_failed;
 254
 255         if (iser_alloc_login_buf(iser_conn))
 256                 goto alloc_login_buf_fail;
 257
 258         iser_conn->num_rx_descs = session->cmds_max;
 259         iser_conn->rx_descs = kmalloc(iser_conn->num_rx_descs *
 260                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 261         if (!iser_conn->rx_descs)
 262                 goto rx_desc_alloc_fail;
 263
 264         rx_desc = iser_conn->rx_descs;
 265
 266         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 267                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 268                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 269                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 270                         goto rx_desc_dma_map_failed;
 271
 272                 rx_desc->dma_addr = dma_addr;
 273
 274                 rx_sg = &rx_desc->rx_sg;
 275                 rx_sg->addr   = rx_desc->dma_addr;
 276                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 277                 rx_sg->lkey   = device->pd->local_dma_lkey;
 278         }
 279
 280         iser_conn->rx_desc_head = 0;
 281         return 0;
 282
 283 rx_desc_dma_map_failed:
 284         rx_desc = iser_conn->rx_descs;
 285         for (j = 0; j < i; j++, rx_desc++)
 286                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 287                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 288         kfree(iser_conn->rx_descs);
 289         iser_conn->rx_descs = NULL;
 290 rx_desc_alloc_fail:
 291         iser_free_login_buf(iser_conn);
 292 alloc_login_buf_fail:
 293         device->reg_ops->free_reg_res(ib_conn);
 294 create_rdma_reg_res_failed:
 295         iser_err("failed allocating rx descriptors / data buffers\n");
 296         return -ENOMEM;
 297 }
 298
 299 void iser_free_rx_descriptors(struct iser_conn *iser_conn)
 300 {
 301         int i;
 302         struct iser_rx_desc *rx_desc;
 303         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 304         struct iser_device *device = ib_conn->device;
 305
 306         if (device->reg_ops->free_reg_res)
 307                 device->reg_ops->free_reg_res(ib_conn);
 308
 309         rx_desc = iser_conn->rx_descs;
 310         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)
 311                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 312                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 313         kfree(iser_conn->rx_descs);
 314         /* make sure we never redo any unmapping */
 315         iser_conn->rx_descs = NULL;
 316
 317         iser_free_login_buf(iser_conn);
 318 }
 319
 320 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 321 {
 322         struct iser_conn *iser_conn = conn->dd_data;
 323         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 324         struct iscsi_session *session = conn->session;
 325
 326         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 327         /* check if this is the last login - going to full feature phase */
 328         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 329                 return 0;
 330
 331         /*
 332          * Check that there is one posted recv buffer
 333          * (for the last login response).
 334          */
 335         WARN_ON(ib_conn->post_recv_buf_count != 1);
 336
 337         if (session->discovery_sess) {
 338                 iser_info("Discovery session, re-using login RX buffer\n");
 339                 return 0;
 340         } else
 341                 iser_info("Normal session, posting batch of RX %d buffers\n",
 342                           iser_conn->min_posted_rx);
 343
 344         /* Initial post receive buffers */
 345         if (iser_post_recvm(iser_conn, iser_conn->min_posted_rx))
 346                 return -ENOMEM;
 347
 348         return 0;
 349 }
 350
 351 static inline bool iser_signal_comp(u8 sig_count)
 352 {
 353         return ((sig_count % ISER_SIGNAL_CMD_COUNT) == 0);
 354 }
 355
 356 /**
 357  * iser_send_command - send command PDU
 358  */
 359 int iser_send_command(struct iscsi_conn *conn,
 360                       struct iscsi_task *task)
 361 {
 362         struct iser_conn *iser_conn = conn->dd_data;
 363         struct iscsi_iser_task *iser_task = task->dd_data;
 364         unsigned long edtl;
 365         int err;
 366         struct iser_data_buf *data_buf, *prot_buf;
 367         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 368         struct scsi_cmnd *sc  =  task->sc;
 369         struct iser_tx_desc *tx_desc = &iser_task->desc;
 370         u8 sig_count = ++iser_conn->ib_conn.sig_count;
 371
 372         edtl = ntohl(hdr->data_length);
 373
 374         /* build the tx desc regd header and add it to the tx desc dto */
 375         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 376         iser_create_send_desc(iser_conn, tx_desc);
 377
 378         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 379                 data_buf = &iser_task->data[ISER_DIR_IN];
 380                 prot_buf = &iser_task->prot[ISER_DIR_IN];
 381         } else {
 382                 data_buf = &iser_task->data[ISER_DIR_OUT];
 383                 prot_buf = &iser_task->prot[ISER_DIR_OUT];
 384         }
 385
 386         if (scsi_sg_count(sc)) { /* using a scatter list */
 387                 data_buf->sg = scsi_sglist(sc);
 388                 data_buf->size = scsi_sg_count(sc);
 389         }
 390         data_buf->data_len = scsi_bufflen(sc);
 391
 392         if (scsi_prot_sg_count(sc)) {
 393                 prot_buf->sg  = scsi_prot_sglist(sc);
 394                 prot_buf->size = scsi_prot_sg_count(sc);
 395                 prot_buf->data_len = (data_buf->data_len >>
 396                                      ilog2(sc->device->sector_size)) * 8;
 397         }
 398
 399         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 400                 err = iser_prepare_read_cmd(task);
 401                 if (err)
 402                         goto send_command_error;
 403         }
 404         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 405                 err = iser_prepare_write_cmd(task,
 406                                              task->imm_count,
 407                                              task->imm_count +
 408                                              task->unsol_r2t.data_length,
 409                                              edtl);
 410                 if (err)
 411                         goto send_command_error;
 412         }
 413
 414         iser_task->status = ISER_TASK_STATUS_STARTED;
 415
 416         err = iser_post_send(&iser_conn->ib_conn, tx_desc,
 417                              iser_signal_comp(sig_count));
 418         if (!err)
 419                 return 0;
 420
 421 send_command_error:
 422         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 423         return err;
 424 }
 425
 426 /**
 427  * iser_send_data_out - send data out PDU
 428  */
 429 int iser_send_data_out(struct iscsi_conn *conn,
 430                        struct iscsi_task *task,
 431                        struct iscsi_data *hdr)
 432 {
 433         struct iser_conn *iser_conn = conn->dd_data;
 434         struct iscsi_iser_task *iser_task = task->dd_data;
 435         struct iser_tx_desc *tx_desc = NULL;
 436         struct iser_mem_reg *mem_reg;
 437         unsigned long buf_offset;
 438         unsigned long data_seg_len;
 439         uint32_t itt;
 440         int err;
 441         struct ib_sge *tx_dsg;
 442
 443         itt = (__force uint32_t)hdr->itt;
 444         data_seg_len = ntoh24(hdr->dlength);
 445         buf_offset   = ntohl(hdr->offset);
 446
 447         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 448                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 449
 450         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 451         if (tx_desc == NULL) {
 452                 iser_err("Failed to alloc desc for post dataout\n");
 453                 return -ENOMEM;
 454         }
 455
 456         tx_desc->type = ISCSI_TX_DATAOUT;
 457         tx_desc->iser_header.flags = ISER_VER;
 458         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 459
 460         /* build the tx desc */
 461         err = iser_initialize_task_headers(task, tx_desc);
 462         if (err)
 463                 goto send_data_out_error;
 464
 465         mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
 466         tx_dsg = &tx_desc->tx_sg[1];
 467         tx_dsg->addr = mem_reg->sge.addr + buf_offset;
 468         tx_dsg->length = data_seg_len;
 469         tx_dsg->lkey = mem_reg->sge.lkey;
 470         tx_desc->num_sge = 2;
 471
 472         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 473                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 474                          "inconsistent with total len:%ld, itt:%d\n",
 475                          buf_offset, data_seg_len,
 476                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 477                 err = -EINVAL;
 478                 goto send_data_out_error;
 479         }
 480         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 481                  itt, buf_offset, data_seg_len);
 482
 483
 484         err = iser_post_send(&iser_conn->ib_conn, tx_desc, true);
 485         if (!err)
 486                 return 0;
 487
 488 send_data_out_error:
 489         kmem_cache_free(ig.desc_cache, tx_desc);
 490         iser_err("conn %p failed err %d\n", conn, err);
 491         return err;
 492 }
 493
 494 int iser_send_control(struct iscsi_conn *conn,
 495                       struct iscsi_task *task)
 496 {
 497         struct iser_conn *iser_conn = conn->dd_data;
 498         struct iscsi_iser_task *iser_task = task->dd_data;
 499         struct iser_tx_desc *mdesc = &iser_task->desc;
 500         unsigned long data_seg_len;
 501         int err = 0;
 502         struct iser_device *device;
 503
 504         /* build the tx desc regd header and add it to the tx desc dto */
 505         mdesc->type = ISCSI_TX_CONTROL;
 506         iser_create_send_desc(iser_conn, mdesc);
 507
 508         device = iser_conn->ib_conn.device;
 509
 510         data_seg_len = ntoh24(task->hdr->dlength);
 511
 512         if (data_seg_len > 0) {
 513                 struct iser_login_desc *desc = &iser_conn->login_desc;
 514                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 515
 516                 if (task != conn->login_task) {
 517                         iser_err("data present on non login task!!!\n");
 518                         goto send_control_error;
 519                 }
 520
 521                 ib_dma_sync_single_for_cpu(device->ib_device, desc->req_dma,
 522                                            task->data_count, DMA_TO_DEVICE);
 523
 524                 memcpy(desc->req, task->data, task->data_count);
 525
 526                 ib_dma_sync_single_for_device(device->ib_device, desc->req_dma,
 527                                               task->data_count, DMA_TO_DEVICE);
 528
 529                 tx_dsg->addr = desc->req_dma;
 530                 tx_dsg->length = task->data_count;
 531                 tx_dsg->lkey = device->pd->local_dma_lkey;
 532                 mdesc->num_sge = 2;
 533         }
 534
 535         if (task == conn->login_task) {
 536                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 537                          task->hdr->opcode, data_seg_len);
 538                 err = iser_post_recvl(iser_conn);
 539                 if (err)
 540                         goto send_control_error;
 541                 err = iser_post_rx_bufs(conn, task->hdr);
 542                 if (err)
 543                         goto send_control_error;
 544         }
 545
 546         err = iser_post_send(&iser_conn->ib_conn, mdesc, true);
 547         if (!err)
 548                 return 0;
 549
 550 send_control_error:
 551         iser_err("conn %p failed err %d\n",conn, err);
 552         return err;
 553 }
 554
 555 /**
 556  * iser_rcv_dto_completion - recv DTO completion
 557  */
 558 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 559                          unsigned long rx_xfer_len,
 560                          struct ib_conn *ib_conn)
 561 {
 562         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 563                                                    ib_conn);
 564         struct iscsi_hdr *hdr;
 565         char *data;
 566         u64 rx_dma;
 567         int rx_buflen, outstanding, count, err;
 568
 569         /* differentiate between login to all other PDUs */
 570         if (rx_desc == (void *)&iser_conn->login_desc) {
 571                 rx_dma = iser_conn->login_desc.rsp_dma;
 572                 rx_buflen = ISER_RX_LOGIN_SIZE;
 573                 hdr = iser_conn->login_desc.rsp + sizeof(struct iser_hdr);
 574                 data = iser_conn->login_desc.rsp + ISER_HEADERS_LEN;
 575         } else {
 576                 rx_dma = rx_desc->dma_addr;
 577                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 578                 hdr = &rx_desc->iscsi_header;
 579                 data = rx_desc->data;
 580         }
 581
 582         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 583                                    rx_buflen, DMA_FROM_DEVICE);
 584
 585
 586         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 587                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 588
 589         iscsi_iser_recv(iser_conn->iscsi_conn, hdr, data,
 590                         rx_xfer_len - ISER_HEADERS_LEN);
 591
 592         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 593                                       rx_buflen, DMA_FROM_DEVICE);
 594
 595         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 596          * task eliminates the need to worry on tasks which are completed in   *
 597          * parallel to the execution of iser_conn_term. So the code that waits *
 598          * for the posted rx bufs refcount to become zero handles everything   */
 599         ib_conn->post_recv_buf_count--;
 600
 601         if (rx_desc == (void *)&iser_conn->login_desc)
 602                 return;
 603
 604         outstanding = ib_conn->post_recv_buf_count;
 605         if (outstanding + iser_conn->min_posted_rx <= iser_conn->qp_max_recv_dtos) {
 606                 count = min(iser_conn->qp_max_recv_dtos - outstanding,
 607                             iser_conn->min_posted_rx);
 608                 err = iser_post_recvm(iser_conn, count);
 609                 if (err)
 610                         iser_err("posting %d rx bufs err %d\n", count, err);
 611         }
 612 }
 613
 614 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 615                         struct ib_conn *ib_conn)
 616 {
 617         struct iscsi_task *task;
 618         struct iser_device *device = ib_conn->device;
 619
 620         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 621                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 622                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 623                 kmem_cache_free(ig.desc_cache, tx_desc);
 624                 tx_desc = NULL;
 625         }
 626
 627         if (tx_desc && tx_desc->type == ISCSI_TX_CONTROL) {
 628                 /* this arithmetic is legal by libiscsi dd_data allocation */
 629                 task = (void *) ((long)(void *)tx_desc -
 630                                   sizeof(struct iscsi_task));
 631                 if (task->hdr->itt == RESERVED_ITT)
 632                         iscsi_put_task(task);
 633         }
 634 }
 635
 636 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 637
 638 {
 639         iser_task->status = ISER_TASK_STATUS_INIT;
 640
 641         iser_task->dir[ISER_DIR_IN] = 0;
 642         iser_task->dir[ISER_DIR_OUT] = 0;
 643
 644         iser_task->data[ISER_DIR_IN].data_len  = 0;
 645         iser_task->data[ISER_DIR_OUT].data_len = 0;
 646
 647         iser_task->prot[ISER_DIR_IN].data_len  = 0;
 648         iser_task->prot[ISER_DIR_OUT].data_len = 0;
 649
 650         memset(&iser_task->rdma_reg[ISER_DIR_IN], 0,
 651                sizeof(struct iser_mem_reg));
 652         memset(&iser_task->rdma_reg[ISER_DIR_OUT], 0,
 653                sizeof(struct iser_mem_reg));
 654 }
 655
 656 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 657 {
 658         int prot_count = scsi_prot_sg_count(iser_task->sc);
 659
 660         if (iser_task->dir[ISER_DIR_IN]) {
 661                 iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 662                 iser_dma_unmap_task_data(iser_task,
 663                                          &iser_task->data[ISER_DIR_IN],
 664                                          DMA_FROM_DEVICE);
 665                 if (prot_count)
 666                         iser_dma_unmap_task_data(iser_task,
 667                                                  &iser_task->prot[ISER_DIR_IN],
 668                                                  DMA_FROM_DEVICE);
 669         }
 670
 671         if (iser_task->dir[ISER_DIR_OUT]) {
 672                 iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
 673                 iser_dma_unmap_task_data(iser_task,
 674                                          &iser_task->data[ISER_DIR_OUT],
 675                                          DMA_TO_DEVICE);
 676                 if (prot_count)
 677                         iser_dma_unmap_task_data(iser_task,
 678                                                  &iser_task->prot[ISER_DIR_OUT],
 679                                                  DMA_TO_DEVICE);
 680         }
 681 }