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_device  *device = iser_task->ib_conn->device;
  53         struct iser_regd_buf *regd_buf;
  54         int err;
  55         struct iser_hdr *hdr = &iser_task->desc.iser_header;
  56         struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
  57
  58         err = iser_dma_map_task_data(iser_task,
  59                                      buf_in,
  60                                      ISER_DIR_IN,
  61                                      DMA_FROM_DEVICE);
  62         if (err)
  63                 return err;
  64
  65         if (scsi_prot_sg_count(iser_task->sc)) {
  66                 struct iser_data_buf *pbuf_in = &iser_task->prot[ISER_DIR_IN];
  67
  68                 err = iser_dma_map_task_data(iser_task,
  69                                              pbuf_in,
  70                                              ISER_DIR_IN,
  71                                              DMA_FROM_DEVICE);
  72                 if (err)
  73                         return err;
  74         }
  75
  76         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_IN);
  77         if (err) {
  78                 iser_err("Failed to set up Data-IN RDMA\n");
  79                 return err;
  80         }
  81         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
  82
  83         hdr->flags    |= ISER_RSV;
  84         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
  85         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
  86
  87         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  88                  task->itt, regd_buf->reg.rkey,
  89                  (unsigned long long)regd_buf->reg.va);
  90
  91         return 0;
  92 }
  93
  94 /* Register user buffer memory and initialize passive rdma
  95  *  dto descriptor. Data size is stored in
  96  *  task->data[ISER_DIR_OUT].data_len, Protection size
  97  *  is stored at task->prot[ISER_DIR_OUT].data_len
  98  */
  99 static int
 100 iser_prepare_write_cmd(struct iscsi_task *task,
 101                        unsigned int imm_sz,
 102                        unsigned int unsol_sz,
 103                        unsigned int edtl)
 104 {
 105         struct iscsi_iser_task *iser_task = task->dd_data;
 106         struct iser_device  *device = iser_task->ib_conn->device;
 107         struct iser_regd_buf *regd_buf;
 108         int err;
 109         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 110         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 111         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 112
 113         err = iser_dma_map_task_data(iser_task,
 114                                      buf_out,
 115                                      ISER_DIR_OUT,
 116                                      DMA_TO_DEVICE);
 117         if (err)
 118                 return err;
 119
 120         if (scsi_prot_sg_count(iser_task->sc)) {
 121                 struct iser_data_buf *pbuf_out = &iser_task->prot[ISER_DIR_OUT];
 122
 123                 err = iser_dma_map_task_data(iser_task,
 124                                              pbuf_out,
 125                                              ISER_DIR_OUT,
 126                                              DMA_TO_DEVICE);
 127                 if (err)
 128                         return err;
 129         }
 130
 131         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_OUT);
 132         if (err != 0) {
 133                 iser_err("Failed to register write cmd RDMA mem\n");
 134                 return err;
 135         }
 136
 137         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 138
 139         if (unsol_sz < edtl) {
 140                 hdr->flags     |= ISER_WSV;
 141                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 142                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 143
 144                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 145                          "VA:%#llX + unsol:%d\n",
 146                          task->itt, regd_buf->reg.rkey,
 147                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 148         }
 149
 150         if (imm_sz > 0) {
 151                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 152                          task->itt, imm_sz);
 153                 tx_dsg->addr   = regd_buf->reg.va;
 154                 tx_dsg->length = imm_sz;
 155                 tx_dsg->lkey   = regd_buf->reg.lkey;
 156                 iser_task->desc.num_sge = 2;
 157         }
 158
 159         return 0;
 160 }
 161
 162 /* creates a new tx descriptor and adds header regd buffer */
 163 static void iser_create_send_desc(struct iser_conn      *ib_conn,
 164                                   struct iser_tx_desc   *tx_desc)
 165 {
 166         struct iser_device *device = ib_conn->device;
 167
 168         ib_dma_sync_single_for_cpu(device->ib_device,
 169                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 170
 171         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 172         tx_desc->iser_header.flags = ISER_VER;
 173
 174         tx_desc->num_sge = 1;
 175
 176         if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
 177                 tx_desc->tx_sg[0].lkey = device->mr->lkey;
 178                 iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
 179         }
 180 }
 181
 182 static void iser_free_login_buf(struct iser_conn *ib_conn)
 183 {
 184         if (!ib_conn->login_buf)
 185                 return;
 186
 187         if (ib_conn->login_req_dma)
 188                 ib_dma_unmap_single(ib_conn->device->ib_device,
 189                                     ib_conn->login_req_dma,
 190                                     ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 191
 192         if (ib_conn->login_resp_dma)
 193                 ib_dma_unmap_single(ib_conn->device->ib_device,
 194                                     ib_conn->login_resp_dma,
 195                                     ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 196
 197         kfree(ib_conn->login_buf);
 198
 199         /* make sure we never redo any unmapping */
 200         ib_conn->login_req_dma = 0;
 201         ib_conn->login_resp_dma = 0;
 202         ib_conn->login_buf = NULL;
 203 }
 204
 205 static int iser_alloc_login_buf(struct iser_conn *ib_conn)
 206 {
 207         struct iser_device      *device;
 208         int                     req_err, resp_err;
 209
 210         BUG_ON(ib_conn->device == NULL);
 211
 212         device = ib_conn->device;
 213
 214         ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
 215                                      ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 216         if (!ib_conn->login_buf)
 217                 goto out_err;
 218
 219         ib_conn->login_req_buf  = ib_conn->login_buf;
 220         ib_conn->login_resp_buf = ib_conn->login_buf +
 221                                                 ISCSI_DEF_MAX_RECV_SEG_LEN;
 222
 223         ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
 224                                 (void *)ib_conn->login_req_buf,
 225                                 ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 226
 227         ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
 228                                 (void *)ib_conn->login_resp_buf,
 229                                 ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 230
 231         req_err  = ib_dma_mapping_error(device->ib_device,
 232                                         ib_conn->login_req_dma);
 233         resp_err = ib_dma_mapping_error(device->ib_device,
 234                                         ib_conn->login_resp_dma);
 235
 236         if (req_err || resp_err) {
 237                 if (req_err)
 238                         ib_conn->login_req_dma = 0;
 239                 if (resp_err)
 240                         ib_conn->login_resp_dma = 0;
 241                 goto free_login_buf;
 242         }
 243         return 0;
 244
 245 free_login_buf:
 246         iser_free_login_buf(ib_conn);
 247
 248 out_err:
 249         iser_err("unable to alloc or map login buf\n");
 250         return -ENOMEM;
 251 }
 252
 253 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn, struct iscsi_session *session)
 254 {
 255         int i, j;
 256         u64 dma_addr;
 257         struct iser_rx_desc *rx_desc;
 258         struct ib_sge       *rx_sg;
 259         struct iser_device  *device = ib_conn->device;
 260
 261         ib_conn->qp_max_recv_dtos = session->cmds_max;
 262         ib_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 263         ib_conn->min_posted_rx = ib_conn->qp_max_recv_dtos >> 2;
 264
 265         if (device->iser_alloc_rdma_reg_res(ib_conn, session->scsi_cmds_max))
 266                 goto create_rdma_reg_res_failed;
 267
 268         if (iser_alloc_login_buf(ib_conn))
 269                 goto alloc_login_buf_fail;
 270
 271         ib_conn->rx_descs = kmalloc(session->cmds_max *
 272                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 273         if (!ib_conn->rx_descs)
 274                 goto rx_desc_alloc_fail;
 275
 276         rx_desc = ib_conn->rx_descs;
 277
 278         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 279                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 280                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 281                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 282                         goto rx_desc_dma_map_failed;
 283
 284                 rx_desc->dma_addr = dma_addr;
 285
 286                 rx_sg = &rx_desc->rx_sg;
 287                 rx_sg->addr   = rx_desc->dma_addr;
 288                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 289                 rx_sg->lkey   = device->mr->lkey;
 290         }
 291
 292         ib_conn->rx_desc_head = 0;
 293         return 0;
 294
 295 rx_desc_dma_map_failed:
 296         rx_desc = ib_conn->rx_descs;
 297         for (j = 0; j < i; j++, rx_desc++)
 298                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 299                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 300         kfree(ib_conn->rx_descs);
 301         ib_conn->rx_descs = NULL;
 302 rx_desc_alloc_fail:
 303         iser_free_login_buf(ib_conn);
 304 alloc_login_buf_fail:
 305         device->iser_free_rdma_reg_res(ib_conn);
 306 create_rdma_reg_res_failed:
 307         iser_err("failed allocating rx descriptors / data buffers\n");
 308         return -ENOMEM;
 309 }
 310
 311 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 312 {
 313         int i;
 314         struct iser_rx_desc *rx_desc;
 315         struct iser_device *device = ib_conn->device;
 316
 317         if (!ib_conn->rx_descs)
 318                 goto free_login_buf;
 319
 320         if (device->iser_free_rdma_reg_res)
 321                 device->iser_free_rdma_reg_res(ib_conn);
 322
 323         rx_desc = ib_conn->rx_descs;
 324         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)
 325                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 326                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 327         kfree(ib_conn->rx_descs);
 328         /* make sure we never redo any unmapping */
 329         ib_conn->rx_descs = NULL;
 330
 331 free_login_buf:
 332         iser_free_login_buf(ib_conn);
 333 }
 334
 335 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 336 {
 337         struct iser_conn *ib_conn = conn->dd_data;
 338         struct iscsi_session *session = conn->session;
 339
 340         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 341         /* check if this is the last login - going to full feature phase */
 342         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 343                 return 0;
 344
 345         /*
 346          * Check that there is one posted recv buffer (for the last login
 347          * response) and no posted send buffers left - they must have been
 348          * consumed during previous login phases.
 349          */
 350         WARN_ON(ib_conn->post_recv_buf_count != 1);
 351         WARN_ON(atomic_read(&ib_conn->post_send_buf_count) != 0);
 352
 353         if (session->discovery_sess) {
 354                 iser_info("Discovery session, re-using login RX buffer\n");
 355                 return 0;
 356         } else
 357                 iser_info("Normal session, posting batch of RX %d buffers\n",
 358                           ib_conn->min_posted_rx);
 359
 360         /* Initial post receive buffers */
 361         if (iser_post_recvm(ib_conn, ib_conn->min_posted_rx))
 362                 return -ENOMEM;
 363
 364         return 0;
 365 }
 366
 367 /**
 368  * iser_send_command - send command PDU
 369  */
 370 int iser_send_command(struct iscsi_conn *conn,
 371                       struct iscsi_task *task)
 372 {
 373         struct iser_conn *ib_conn = conn->dd_data;
 374         struct iscsi_iser_task *iser_task = task->dd_data;
 375         unsigned long edtl;
 376         int err;
 377         struct iser_data_buf *data_buf, *prot_buf;
 378         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 379         struct scsi_cmnd *sc  =  task->sc;
 380         struct iser_tx_desc *tx_desc = &iser_task->desc;
 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(ib_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->buf  = 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->buf  = 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(ib_conn, tx_desc);
 427         if (!err)
 428                 return 0;
 429
 430 send_command_error:
 431         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 432         return err;
 433 }
 434
 435 /**
 436  * iser_send_data_out - send data out PDU
 437  */
 438 int iser_send_data_out(struct iscsi_conn *conn,
 439                        struct iscsi_task *task,
 440                        struct iscsi_data *hdr)
 441 {
 442         struct iser_conn *ib_conn = conn->dd_data;
 443         struct iscsi_iser_task *iser_task = task->dd_data;
 444         struct iser_tx_desc *tx_desc = NULL;
 445         struct iser_regd_buf *regd_buf;
 446         unsigned long buf_offset;
 447         unsigned long data_seg_len;
 448         uint32_t itt;
 449         int err = 0;
 450         struct ib_sge *tx_dsg;
 451
 452         itt = (__force uint32_t)hdr->itt;
 453         data_seg_len = ntoh24(hdr->dlength);
 454         buf_offset   = ntohl(hdr->offset);
 455
 456         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 457                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 458
 459         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 460         if (tx_desc == NULL) {
 461                 iser_err("Failed to alloc desc for post dataout\n");
 462                 return -ENOMEM;
 463         }
 464
 465         tx_desc->type = ISCSI_TX_DATAOUT;
 466         tx_desc->iser_header.flags = ISER_VER;
 467         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 468
 469         /* build the tx desc */
 470         iser_initialize_task_headers(task, tx_desc);
 471
 472         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 473         tx_dsg = &tx_desc->tx_sg[1];
 474         tx_dsg->addr    = regd_buf->reg.va + buf_offset;
 475         tx_dsg->length  = data_seg_len;
 476         tx_dsg->lkey    = regd_buf->reg.lkey;
 477         tx_desc->num_sge = 2;
 478
 479         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 480                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 481                          "inconsistent with total len:%ld, itt:%d\n",
 482                          buf_offset, data_seg_len,
 483                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 484                 err = -EINVAL;
 485                 goto send_data_out_error;
 486         }
 487         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 488                  itt, buf_offset, data_seg_len);
 489
 490
 491         err = iser_post_send(ib_conn, tx_desc);
 492         if (!err)
 493                 return 0;
 494
 495 send_data_out_error:
 496         kmem_cache_free(ig.desc_cache, tx_desc);
 497         iser_err("conn %p failed err %d\n",conn, err);
 498         return err;
 499 }
 500
 501 int iser_send_control(struct iscsi_conn *conn,
 502                       struct iscsi_task *task)
 503 {
 504         struct iser_conn *ib_conn = conn->dd_data;
 505         struct iscsi_iser_task *iser_task = task->dd_data;
 506         struct iser_tx_desc *mdesc = &iser_task->desc;
 507         unsigned long data_seg_len;
 508         int err = 0;
 509         struct iser_device *device;
 510
 511         /* build the tx desc regd header and add it to the tx desc dto */
 512         mdesc->type = ISCSI_TX_CONTROL;
 513         iser_create_send_desc(ib_conn, mdesc);
 514
 515         device = ib_conn->device;
 516
 517         data_seg_len = ntoh24(task->hdr->dlength);
 518
 519         if (data_seg_len > 0) {
 520                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 521                 if (task != conn->login_task) {
 522                         iser_err("data present on non login task!!!\n");
 523                         goto send_control_error;
 524                 }
 525
 526                 ib_dma_sync_single_for_cpu(device->ib_device,
 527                         ib_conn->login_req_dma, task->data_count,
 528                         DMA_TO_DEVICE);
 529
 530                 memcpy(ib_conn->login_req_buf, task->data, task->data_count);
 531
 532                 ib_dma_sync_single_for_device(device->ib_device,
 533                         ib_conn->login_req_dma, task->data_count,
 534                         DMA_TO_DEVICE);
 535
 536                 tx_dsg->addr    = ib_conn->login_req_dma;
 537                 tx_dsg->length  = task->data_count;
 538                 tx_dsg->lkey    = device->mr->lkey;
 539                 mdesc->num_sge = 2;
 540         }
 541
 542         if (task == conn->login_task) {
 543                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 544                          task->hdr->opcode, data_seg_len);
 545                 err = iser_post_recvl(ib_conn);
 546                 if (err)
 547                         goto send_control_error;
 548                 err = iser_post_rx_bufs(conn, task->hdr);
 549                 if (err)
 550                         goto send_control_error;
 551         }
 552
 553         err = iser_post_send(ib_conn, mdesc);
 554         if (!err)
 555                 return 0;
 556
 557 send_control_error:
 558         iser_err("conn %p failed err %d\n",conn, err);
 559         return err;
 560 }
 561
 562 /**
 563  * iser_rcv_dto_completion - recv DTO completion
 564  */
 565 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 566                          unsigned long rx_xfer_len,
 567                          struct iser_conn *ib_conn)
 568 {
 569         struct iscsi_hdr *hdr;
 570         u64 rx_dma;
 571         int rx_buflen, outstanding, count, err;
 572
 573         /* differentiate between login to all other PDUs */
 574         if ((char *)rx_desc == ib_conn->login_resp_buf) {
 575                 rx_dma = ib_conn->login_resp_dma;
 576                 rx_buflen = ISER_RX_LOGIN_SIZE;
 577         } else {
 578                 rx_dma = rx_desc->dma_addr;
 579                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 580         }
 581
 582         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 583                         rx_buflen, DMA_FROM_DEVICE);
 584
 585         hdr = &rx_desc->iscsi_header;
 586
 587         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 588                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 589
 590         iscsi_iser_recv(ib_conn->iscsi_conn, hdr, rx_desc->data,
 591                         rx_xfer_len - ISER_HEADERS_LEN);
 592
 593         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 594                                       rx_buflen, DMA_FROM_DEVICE);
 595
 596         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 597          * task eliminates the need to worry on tasks which are completed in   *
 598          * parallel to the execution of iser_conn_term. So the code that waits *
 599          * for the posted rx bufs refcount to become zero handles everything   */
 600         ib_conn->post_recv_buf_count--;
 601
 602         if (rx_dma == ib_conn->login_resp_dma)
 603                 return;
 604
 605         outstanding = ib_conn->post_recv_buf_count;
 606         if (outstanding + ib_conn->min_posted_rx <= ib_conn->qp_max_recv_dtos) {
 607                 count = min(ib_conn->qp_max_recv_dtos - outstanding,
 608                                                 ib_conn->min_posted_rx);
 609                 err = iser_post_recvm(ib_conn, count);
 610                 if (err)
 611                         iser_err("posting %d rx bufs err %d\n", count, err);
 612         }
 613 }
 614
 615 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 616                         struct iser_conn *ib_conn)
 617 {
 618         struct iscsi_task *task;
 619         struct iser_device *device = ib_conn->device;
 620
 621         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 622                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 623                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 624                 kmem_cache_free(ig.desc_cache, tx_desc);
 625                 tx_desc = NULL;
 626         }
 627
 628         atomic_dec(&ib_conn->post_send_buf_count);
 629
 630         if (tx_desc && tx_desc->type == ISCSI_TX_CONTROL) {
 631                 /* this arithmetic is legal by libiscsi dd_data allocation */
 632                 task = (void *) ((long)(void *)tx_desc -
 633                                   sizeof(struct iscsi_task));
 634                 if (task->hdr->itt == RESERVED_ITT)
 635                         iscsi_put_task(task);
 636         }
 637 }
 638
 639 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 640
 641 {
 642         iser_task->status = ISER_TASK_STATUS_INIT;
 643
 644         iser_task->dir[ISER_DIR_IN] = 0;
 645         iser_task->dir[ISER_DIR_OUT] = 0;
 646
 647         iser_task->data[ISER_DIR_IN].data_len  = 0;
 648         iser_task->data[ISER_DIR_OUT].data_len = 0;
 649
 650         iser_task->prot[ISER_DIR_IN].data_len  = 0;
 651         iser_task->prot[ISER_DIR_OUT].data_len = 0;
 652
 653         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 654                sizeof(struct iser_regd_buf));
 655         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 656                sizeof(struct iser_regd_buf));
 657 }
 658
 659 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 660 {
 661         struct iser_device *device = iser_task->ib_conn->device;
 662         int is_rdma_data_aligned = 1;
 663         int is_rdma_prot_aligned = 1;
 664         int prot_count = scsi_prot_sg_count(iser_task->sc);
 665
 666         /* if we were reading, copy back to unaligned sglist,
 667          * anyway dma_unmap and free the copy
 668          */
 669         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 670                 is_rdma_data_aligned = 0;
 671                 iser_finalize_rdma_unaligned_sg(iser_task,
 672                                                 &iser_task->data[ISER_DIR_IN],
 673                                                 &iser_task->data_copy[ISER_DIR_IN],
 674                                                 ISER_DIR_IN);
 675         }
 676
 677         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 678                 is_rdma_data_aligned = 0;
 679                 iser_finalize_rdma_unaligned_sg(iser_task,
 680                                                 &iser_task->data[ISER_DIR_OUT],
 681                                                 &iser_task->data_copy[ISER_DIR_OUT],
 682                                                 ISER_DIR_OUT);
 683         }
 684
 685         if (iser_task->prot_copy[ISER_DIR_IN].copy_buf != NULL) {
 686                 is_rdma_prot_aligned = 0;
 687                 iser_finalize_rdma_unaligned_sg(iser_task,
 688                                                 &iser_task->prot[ISER_DIR_IN],
 689                                                 &iser_task->prot_copy[ISER_DIR_IN],
 690                                                 ISER_DIR_IN);
 691         }
 692
 693         if (iser_task->prot_copy[ISER_DIR_OUT].copy_buf != NULL) {
 694                 is_rdma_prot_aligned = 0;
 695                 iser_finalize_rdma_unaligned_sg(iser_task,
 696                                                 &iser_task->prot[ISER_DIR_OUT],
 697                                                 &iser_task->prot_copy[ISER_DIR_OUT],
 698                                                 ISER_DIR_OUT);
 699         }
 700
 701         if (iser_task->dir[ISER_DIR_IN]) {
 702                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 703                 if (is_rdma_data_aligned)
 704                         iser_dma_unmap_task_data(iser_task,
 705                                                  &iser_task->data[ISER_DIR_IN]);
 706                 if (prot_count && is_rdma_prot_aligned)
 707                         iser_dma_unmap_task_data(iser_task,
 708                                                  &iser_task->prot[ISER_DIR_IN]);
 709         }
 710
 711         if (iser_task->dir[ISER_DIR_OUT]) {
 712                 device->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                 if (prot_count && is_rdma_prot_aligned)
 717                         iser_dma_unmap_task_data(iser_task,
 718                                                  &iser_task->prot[ISER_DIR_OUT]);
 719         }
 720 }