drivers/infiniband/ulp/iser/iser_initiator.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  * Copyright (c) 2013 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. Total data size is stored in
  45  *  iser_task->data[ISER_DIR_IN].data_len
  46  */
  47 static int iser_prepare_read_cmd(struct iscsi_task *task,
  48                                  unsigned int edtl)
  49
  50 {
  51         struct iscsi_iser_task *iser_task = task->dd_data;
  52         struct iser_device  *device = iser_task->iser_conn->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 (edtl > iser_task->data[ISER_DIR_IN].data_len) {
  66                 iser_err("Total data length: %ld, less than EDTL: "
  67                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  68                          iser_task->data[ISER_DIR_IN].data_len, edtl,
  69                          task->itt, iser_task->iser_conn);
  70                 return -EINVAL;
  71         }
  72
  73         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_IN);
  74         if (err) {
  75                 iser_err("Failed to set up Data-IN RDMA\n");
  76                 return err;
  77         }
  78         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
  79
  80         hdr->flags    |= ISER_RSV;
  81         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
  82         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
  83
  84         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  85                  task->itt, regd_buf->reg.rkey,
  86                  (unsigned long long)regd_buf->reg.va);
  87
  88         return 0;
  89 }
  90
  91 /* Register user buffer memory and initialize passive rdma
  92  *  dto descriptor. Total data size is stored in
  93  *  task->data[ISER_DIR_OUT].data_len
  94  */
  95 static int
  96 iser_prepare_write_cmd(struct iscsi_task *task,
  97                        unsigned int imm_sz,
  98                        unsigned int unsol_sz,
  99                        unsigned int edtl)
 100 {
 101         struct iscsi_iser_task *iser_task = task->dd_data;
 102         struct iser_device  *device = iser_task->iser_conn->ib_conn->device;
 103         struct iser_regd_buf *regd_buf;
 104         int err;
 105         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 106         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 107         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 108
 109         err = iser_dma_map_task_data(iser_task,
 110                                      buf_out,
 111                                      ISER_DIR_OUT,
 112                                      DMA_TO_DEVICE);
 113         if (err)
 114                 return err;
 115
 116         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
 117                 iser_err("Total data length: %ld, less than EDTL: %d, "
 118                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 119                          iser_task->data[ISER_DIR_OUT].data_len,
 120                          edtl, task->itt, task->conn);
 121                 return -EINVAL;
 122         }
 123
 124         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_OUT);
 125         if (err != 0) {
 126                 iser_err("Failed to register write cmd RDMA mem\n");
 127                 return err;
 128         }
 129
 130         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 131
 132         if (unsol_sz < edtl) {
 133                 hdr->flags     |= ISER_WSV;
 134                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 135                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 136
 137                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 138                          "VA:%#llX + unsol:%d\n",
 139                          task->itt, regd_buf->reg.rkey,
 140                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 141         }
 142
 143         if (imm_sz > 0) {
 144                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 145                          task->itt, imm_sz);
 146                 tx_dsg->addr   = regd_buf->reg.va;
 147                 tx_dsg->length = imm_sz;
 148                 tx_dsg->lkey   = regd_buf->reg.lkey;
 149                 iser_task->desc.num_sge = 2;
 150         }
 151
 152         return 0;
 153 }
 154
 155 /* creates a new tx descriptor and adds header regd buffer */
 156 static void iser_create_send_desc(struct iser_conn      *ib_conn,
 157                                   struct iser_tx_desc   *tx_desc)
 158 {
 159         struct iser_device *device = ib_conn->device;
 160
 161         ib_dma_sync_single_for_cpu(device->ib_device,
 162                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 163
 164         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 165         tx_desc->iser_header.flags = ISER_VER;
 166
 167         tx_desc->num_sge = 1;
 168
 169         if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
 170                 tx_desc->tx_sg[0].lkey = device->mr->lkey;
 171                 iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
 172         }
 173 }
 174
 175 static void iser_free_login_buf(struct iser_conn *ib_conn)
 176 {
 177         if (!ib_conn->login_buf)
 178                 return;
 179
 180         if (ib_conn->login_req_dma)
 181                 ib_dma_unmap_single(ib_conn->device->ib_device,
 182                                     ib_conn->login_req_dma,
 183                                     ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 184
 185         if (ib_conn->login_resp_dma)
 186                 ib_dma_unmap_single(ib_conn->device->ib_device,
 187                                     ib_conn->login_resp_dma,
 188                                     ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 189
 190         kfree(ib_conn->login_buf);
 191
 192         /* make sure we never redo any unmapping */
 193         ib_conn->login_req_dma = 0;
 194         ib_conn->login_resp_dma = 0;
 195         ib_conn->login_buf = NULL;
 196 }
 197
 198 static int iser_alloc_login_buf(struct iser_conn *ib_conn)
 199 {
 200         struct iser_device      *device;
 201         int                     req_err, resp_err;
 202
 203         BUG_ON(ib_conn->device == NULL);
 204
 205         device = ib_conn->device;
 206
 207         ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
 208                                      ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 209         if (!ib_conn->login_buf)
 210                 goto out_err;
 211
 212         ib_conn->login_req_buf  = ib_conn->login_buf;
 213         ib_conn->login_resp_buf = ib_conn->login_buf +
 214                                                 ISCSI_DEF_MAX_RECV_SEG_LEN;
 215
 216         ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
 217                                 (void *)ib_conn->login_req_buf,
 218                                 ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 219
 220         ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
 221                                 (void *)ib_conn->login_resp_buf,
 222                                 ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 223
 224         req_err  = ib_dma_mapping_error(device->ib_device,
 225                                         ib_conn->login_req_dma);
 226         resp_err = ib_dma_mapping_error(device->ib_device,
 227                                         ib_conn->login_resp_dma);
 228
 229         if (req_err || resp_err) {
 230                 if (req_err)
 231                         ib_conn->login_req_dma = 0;
 232                 if (resp_err)
 233                         ib_conn->login_resp_dma = 0;
 234                 goto free_login_buf;
 235         }
 236         return 0;
 237
 238 free_login_buf:
 239         iser_free_login_buf(ib_conn);
 240
 241 out_err:
 242         iser_err("unable to alloc or map login buf\n");
 243         return -ENOMEM;
 244 }
 245
 246 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn, struct iscsi_session *session)
 247 {
 248         int i, j;
 249         u64 dma_addr;
 250         struct iser_rx_desc *rx_desc;
 251         struct ib_sge       *rx_sg;
 252         struct iser_device  *device = ib_conn->device;
 253
 254         ib_conn->qp_max_recv_dtos = session->cmds_max;
 255         ib_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 256         ib_conn->min_posted_rx = ib_conn->qp_max_recv_dtos >> 2;
 257
 258         if (device->iser_alloc_rdma_reg_res(ib_conn, session->scsi_cmds_max))
 259                 goto create_rdma_reg_res_failed;
 260
 261         if (iser_alloc_login_buf(ib_conn))
 262                 goto alloc_login_buf_fail;
 263
 264         ib_conn->rx_descs = kmalloc(session->cmds_max *
 265                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 266         if (!ib_conn->rx_descs)
 267                 goto rx_desc_alloc_fail;
 268
 269         rx_desc = ib_conn->rx_descs;
 270
 271         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 272                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 273                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 274                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 275                         goto rx_desc_dma_map_failed;
 276
 277                 rx_desc->dma_addr = dma_addr;
 278
 279                 rx_sg = &rx_desc->rx_sg;
 280                 rx_sg->addr   = rx_desc->dma_addr;
 281                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 282                 rx_sg->lkey   = device->mr->lkey;
 283         }
 284
 285         ib_conn->rx_desc_head = 0;
 286         return 0;
 287
 288 rx_desc_dma_map_failed:
 289         rx_desc = ib_conn->rx_descs;
 290         for (j = 0; j < i; j++, rx_desc++)
 291                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 292                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 293         kfree(ib_conn->rx_descs);
 294         ib_conn->rx_descs = NULL;
 295 rx_desc_alloc_fail:
 296         iser_free_login_buf(ib_conn);
 297 alloc_login_buf_fail:
 298         device->iser_free_rdma_reg_res(ib_conn);
 299 create_rdma_reg_res_failed:
 300         iser_err("failed allocating rx descriptors / data buffers\n");
 301         return -ENOMEM;
 302 }
 303
 304 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 305 {
 306         int i;
 307         struct iser_rx_desc *rx_desc;
 308         struct iser_device *device = ib_conn->device;
 309
 310         if (!ib_conn->rx_descs)
 311                 goto free_login_buf;
 312
 313         if (device->iser_free_rdma_reg_res)
 314                 device->iser_free_rdma_reg_res(ib_conn);
 315
 316         rx_desc = ib_conn->rx_descs;
 317         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)
 318                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 319                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 320         kfree(ib_conn->rx_descs);
 321         /* make sure we never redo any unmapping */
 322         ib_conn->rx_descs = NULL;
 323
 324 free_login_buf:
 325         iser_free_login_buf(ib_conn);
 326 }
 327
 328 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 329 {
 330         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 331         struct iscsi_session *session = conn->session;
 332
 333         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 334         /* check if this is the last login - going to full feature phase */
 335         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 336                 return 0;
 337
 338         /*
 339          * Check that there is one posted recv buffer (for the last login
 340          * response) and no posted send buffers left - they must have been
 341          * consumed during previous login phases.
 342          */
 343         WARN_ON(iser_conn->ib_conn->post_recv_buf_count != 1);
 344         WARN_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 345
 346         if (session->discovery_sess) {
 347                 iser_info("Discovery session, re-using login RX buffer\n");
 348                 return 0;
 349         } else
 350                 iser_info("Normal session, posting batch of RX %d buffers\n",
 351                           iser_conn->ib_conn->min_posted_rx);
 352
 353         /* Initial post receive buffers */
 354         if (iser_post_recvm(iser_conn->ib_conn,
 355                             iser_conn->ib_conn->min_posted_rx))
 356                 return -ENOMEM;
 357
 358         return 0;
 359 }
 360
 361 /**
 362  * iser_send_command - send command PDU
 363  */
 364 int iser_send_command(struct iscsi_conn *conn,
 365                       struct iscsi_task *task)
 366 {
 367         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 368         struct iscsi_iser_task *iser_task = task->dd_data;
 369         unsigned long edtl;
 370         int err;
 371         struct iser_data_buf *data_buf;
 372         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 373         struct scsi_cmnd *sc  =  task->sc;
 374         struct iser_tx_desc *tx_desc = &iser_task->desc;
 375
 376         edtl = ntohl(hdr->data_length);
 377
 378         /* build the tx desc regd header and add it to the tx desc dto */
 379         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 380         iser_create_send_desc(iser_conn->ib_conn, tx_desc);
 381
 382         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 383                 data_buf = &iser_task->data[ISER_DIR_IN];
 384         else
 385                 data_buf = &iser_task->data[ISER_DIR_OUT];
 386
 387         if (scsi_sg_count(sc)) { /* using a scatter list */
 388                 data_buf->buf  = scsi_sglist(sc);
 389                 data_buf->size = scsi_sg_count(sc);
 390         }
 391
 392         data_buf->data_len = scsi_bufflen(sc);
 393
 394         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 395                 err = iser_prepare_read_cmd(task, edtl);
 396                 if (err)
 397                         goto send_command_error;
 398         }
 399         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 400                 err = iser_prepare_write_cmd(task,
 401                                              task->imm_count,
 402                                              task->imm_count +
 403                                              task->unsol_r2t.data_length,
 404                                              edtl);
 405                 if (err)
 406                         goto send_command_error;
 407         }
 408
 409         iser_task->status = ISER_TASK_STATUS_STARTED;
 410
 411         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 412         if (!err)
 413                 return 0;
 414
 415 send_command_error:
 416         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 417         return err;
 418 }
 419
 420 /**
 421  * iser_send_data_out - send data out PDU
 422  */
 423 int iser_send_data_out(struct iscsi_conn *conn,
 424                        struct iscsi_task *task,
 425                        struct iscsi_data *hdr)
 426 {
 427         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 428         struct iscsi_iser_task *iser_task = task->dd_data;
 429         struct iser_tx_desc *tx_desc = NULL;
 430         struct iser_regd_buf *regd_buf;
 431         unsigned long buf_offset;
 432         unsigned long data_seg_len;
 433         uint32_t itt;
 434         int err = 0;
 435         struct ib_sge *tx_dsg;
 436
 437         itt = (__force uint32_t)hdr->itt;
 438         data_seg_len = ntoh24(hdr->dlength);
 439         buf_offset   = ntohl(hdr->offset);
 440
 441         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 442                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 443
 444         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 445         if (tx_desc == NULL) {
 446                 iser_err("Failed to alloc desc for post dataout\n");
 447                 return -ENOMEM;
 448         }
 449
 450         tx_desc->type = ISCSI_TX_DATAOUT;
 451         tx_desc->iser_header.flags = ISER_VER;
 452         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 453
 454         /* build the tx desc */
 455         iser_initialize_task_headers(task, tx_desc);
 456
 457         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 458         tx_dsg = &tx_desc->tx_sg[1];
 459         tx_dsg->addr    = regd_buf->reg.va + buf_offset;
 460         tx_dsg->length  = data_seg_len;
 461         tx_dsg->lkey    = regd_buf->reg.lkey;
 462         tx_desc->num_sge = 2;
 463
 464         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 465                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 466                          "inconsistent with total len:%ld, itt:%d\n",
 467                          buf_offset, data_seg_len,
 468                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 469                 err = -EINVAL;
 470                 goto send_data_out_error;
 471         }
 472         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 473                  itt, buf_offset, data_seg_len);
 474
 475
 476         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 477         if (!err)
 478                 return 0;
 479
 480 send_data_out_error:
 481         kmem_cache_free(ig.desc_cache, tx_desc);
 482         iser_err("conn %p failed err %d\n",conn, err);
 483         return err;
 484 }
 485
 486 int iser_send_control(struct iscsi_conn *conn,
 487                       struct iscsi_task *task)
 488 {
 489         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 490         struct iscsi_iser_task *iser_task = task->dd_data;
 491         struct iser_tx_desc *mdesc = &iser_task->desc;
 492         unsigned long data_seg_len;
 493         int err = 0;
 494         struct iser_device *device;
 495         struct iser_conn *ib_conn = iser_conn->ib_conn;
 496
 497         /* build the tx desc regd header and add it to the tx desc dto */
 498         mdesc->type = ISCSI_TX_CONTROL;
 499         iser_create_send_desc(iser_conn->ib_conn, mdesc);
 500
 501         device = iser_conn->ib_conn->device;
 502
 503         data_seg_len = ntoh24(task->hdr->dlength);
 504
 505         if (data_seg_len > 0) {
 506                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 507                 if (task != conn->login_task) {
 508                         iser_err("data present on non login task!!!\n");
 509                         goto send_control_error;
 510                 }
 511
 512                 ib_dma_sync_single_for_cpu(device->ib_device,
 513                         ib_conn->login_req_dma, task->data_count,
 514                         DMA_TO_DEVICE);
 515
 516                 memcpy(iser_conn->ib_conn->login_req_buf, task->data,
 517                                                         task->data_count);
 518
 519                 ib_dma_sync_single_for_device(device->ib_device,
 520                         ib_conn->login_req_dma, task->data_count,
 521                         DMA_TO_DEVICE);
 522
 523                 tx_dsg->addr    = iser_conn->ib_conn->login_req_dma;
 524                 tx_dsg->length  = task->data_count;
 525                 tx_dsg->lkey    = device->mr->lkey;
 526                 mdesc->num_sge = 2;
 527         }
 528
 529         if (task == conn->login_task) {
 530                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 531                          task->hdr->opcode, data_seg_len);
 532                 err = iser_post_recvl(iser_conn->ib_conn);
 533                 if (err)
 534                         goto send_control_error;
 535                 err = iser_post_rx_bufs(conn, task->hdr);
 536                 if (err)
 537                         goto send_control_error;
 538         }
 539
 540         err = iser_post_send(iser_conn->ib_conn, mdesc);
 541         if (!err)
 542                 return 0;
 543
 544 send_control_error:
 545         iser_err("conn %p failed err %d\n",conn, err);
 546         return err;
 547 }
 548
 549 /**
 550  * iser_rcv_dto_completion - recv DTO completion
 551  */
 552 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 553                          unsigned long rx_xfer_len,
 554                          struct iser_conn *ib_conn)
 555 {
 556         struct iscsi_iser_conn *conn = ib_conn->iser_conn;
 557         struct iscsi_hdr *hdr;
 558         u64 rx_dma;
 559         int rx_buflen, outstanding, count, err;
 560
 561         /* differentiate between login to all other PDUs */
 562         if ((char *)rx_desc == ib_conn->login_resp_buf) {
 563                 rx_dma = ib_conn->login_resp_dma;
 564                 rx_buflen = ISER_RX_LOGIN_SIZE;
 565         } else {
 566                 rx_dma = rx_desc->dma_addr;
 567                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 568         }
 569
 570         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 571                         rx_buflen, DMA_FROM_DEVICE);
 572
 573         hdr = &rx_desc->iscsi_header;
 574
 575         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 576                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 577
 578         iscsi_iser_recv(conn->iscsi_conn, hdr,
 579                 rx_desc->data, rx_xfer_len - ISER_HEADERS_LEN);
 580
 581         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 582                         rx_buflen, DMA_FROM_DEVICE);
 583
 584         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 585          * task eliminates the need to worry on tasks which are completed in   *
 586          * parallel to the execution of iser_conn_term. So the code that waits *
 587          * for the posted rx bufs refcount to become zero handles everything   */
 588         conn->ib_conn->post_recv_buf_count--;
 589
 590         if (rx_dma == ib_conn->login_resp_dma)
 591                 return;
 592
 593         outstanding = ib_conn->post_recv_buf_count;
 594         if (outstanding + ib_conn->min_posted_rx <= ib_conn->qp_max_recv_dtos) {
 595                 count = min(ib_conn->qp_max_recv_dtos - outstanding,
 596                                                 ib_conn->min_posted_rx);
 597                 err = iser_post_recvm(ib_conn, count);
 598                 if (err)
 599                         iser_err("posting %d rx bufs err %d\n", count, err);
 600         }
 601 }
 602
 603 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 604                         struct iser_conn *ib_conn)
 605 {
 606         struct iscsi_task *task;
 607         struct iser_device *device = ib_conn->device;
 608
 609         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 610                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 611                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 612                 kmem_cache_free(ig.desc_cache, tx_desc);
 613         }
 614
 615         atomic_dec(&ib_conn->post_send_buf_count);
 616
 617         if (tx_desc->type == ISCSI_TX_CONTROL) {
 618                 /* this arithmetic is legal by libiscsi dd_data allocation */
 619                 task = (void *) ((long)(void *)tx_desc -
 620                                   sizeof(struct iscsi_task));
 621                 if (task->hdr->itt == RESERVED_ITT)
 622                         iscsi_put_task(task);
 623         }
 624 }
 625
 626 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 627
 628 {
 629         iser_task->status = ISER_TASK_STATUS_INIT;
 630
 631         iser_task->dir[ISER_DIR_IN] = 0;
 632         iser_task->dir[ISER_DIR_OUT] = 0;
 633
 634         iser_task->data[ISER_DIR_IN].data_len  = 0;
 635         iser_task->data[ISER_DIR_OUT].data_len = 0;
 636
 637         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 638                sizeof(struct iser_regd_buf));
 639         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 640                sizeof(struct iser_regd_buf));
 641 }
 642
 643 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 644 {
 645         struct iser_device *device = iser_task->iser_conn->ib_conn->device;
 646         int is_rdma_aligned = 1;
 647
 648         /* if we were reading, copy back to unaligned sglist,
 649          * anyway dma_unmap and free the copy
 650          */
 651         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 652                 is_rdma_aligned = 0;
 653                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
 654         }
 655         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 656                 is_rdma_aligned = 0;
 657                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
 658         }
 659
 660         if (iser_task->dir[ISER_DIR_IN])
 661                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 662
 663         if (iser_task->dir[ISER_DIR_OUT])
 664                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
 665
 666        /* if the data was unaligned, it was already unmapped and then copied */
 667        if (is_rdma_aligned)
 668                 iser_dma_unmap_task_data(iser_task);
 669 }