kernel/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->iser_conn->ib_conn.device;
  53         struct iser_mem_reg *mem_reg;
  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         mem_reg = &iser_task->rdma_reg[ISER_DIR_IN];
  82
  83         hdr->flags    |= ISER_RSV;
  84         hdr->read_stag = cpu_to_be32(mem_reg->rkey);
  85         hdr->read_va   = cpu_to_be64(mem_reg->sge.addr);
  86
  87         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  88                  task->itt, mem_reg->rkey,
  89                  (unsigned long long)mem_reg->sge.addr);
  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->iser_conn->ib_conn.device;
 107         struct iser_mem_reg *mem_reg;
 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         mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
 138
 139         if (unsol_sz < edtl) {
 140                 hdr->flags     |= ISER_WSV;
 141                 hdr->write_stag = cpu_to_be32(mem_reg->rkey);
 142                 hdr->write_va   = cpu_to_be64(mem_reg->sge.addr + unsol_sz);
 143
 144                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 145                          "VA:%#llX + unsol:%d\n",
 146                          task->itt, mem_reg->rkey,
 147                          (unsigned long long)mem_reg->sge.addr, 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 = mem_reg->sge.addr;
 154                 tx_dsg->length = imm_sz;
 155                 tx_dsg->lkey = mem_reg->sge.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      *iser_conn,
 164                                   struct iser_tx_desc   *tx_desc)
 165 {
 166         struct iser_device *device = iser_conn->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 *iser_conn)
 183 {
 184         struct iser_device *device = iser_conn->ib_conn.device;
 185
 186         if (!iser_conn->login_buf)
 187                 return;
 188
 189         if (iser_conn->login_req_dma)
 190                 ib_dma_unmap_single(device->ib_device,
 191                                     iser_conn->login_req_dma,
 192                                     ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 193
 194         if (iser_conn->login_resp_dma)
 195                 ib_dma_unmap_single(device->ib_device,
 196                                     iser_conn->login_resp_dma,
 197                                     ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 198
 199         kfree(iser_conn->login_buf);
 200
 201         /* make sure we never redo any unmapping */
 202         iser_conn->login_req_dma = 0;
 203         iser_conn->login_resp_dma = 0;
 204         iser_conn->login_buf = NULL;
 205 }
 206
 207 static int iser_alloc_login_buf(struct iser_conn *iser_conn)
 208 {
 209         struct iser_device *device = iser_conn->ib_conn.device;
 210         int                     req_err, resp_err;
 211
 212         BUG_ON(device == NULL);
 213
 214         iser_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
 215                                      ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 216         if (!iser_conn->login_buf)
 217                 goto out_err;
 218
 219         iser_conn->login_req_buf  = iser_conn->login_buf;
 220         iser_conn->login_resp_buf = iser_conn->login_buf +
 221                                                 ISCSI_DEF_MAX_RECV_SEG_LEN;
 222
 223         iser_conn->login_req_dma = ib_dma_map_single(device->ib_device,
 224                                                      iser_conn->login_req_buf,
 225                                                      ISCSI_DEF_MAX_RECV_SEG_LEN,
 226                                                      DMA_TO_DEVICE);
 227
 228         iser_conn->login_resp_dma = ib_dma_map_single(device->ib_device,
 229                                                       iser_conn->login_resp_buf,
 230                                                       ISER_RX_LOGIN_SIZE,
 231                                                       DMA_FROM_DEVICE);
 232
 233         req_err  = ib_dma_mapping_error(device->ib_device,
 234                                         iser_conn->login_req_dma);
 235         resp_err = ib_dma_mapping_error(device->ib_device,
 236                                         iser_conn->login_resp_dma);
 237
 238         if (req_err || resp_err) {
 239                 if (req_err)
 240                         iser_conn->login_req_dma = 0;
 241                 if (resp_err)
 242                         iser_conn->login_resp_dma = 0;
 243                 goto free_login_buf;
 244         }
 245         return 0;
 246
 247 free_login_buf:
 248         iser_free_login_buf(iser_conn);
 249
 250 out_err:
 251         iser_err("unable to alloc or map login buf\n");
 252         return -ENOMEM;
 253 }
 254
 255 int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
 256                               struct iscsi_session *session)
 257 {
 258         int i, j;
 259         u64 dma_addr;
 260         struct iser_rx_desc *rx_desc;
 261         struct ib_sge       *rx_sg;
 262         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 263         struct iser_device *device = ib_conn->device;
 264
 265         iser_conn->qp_max_recv_dtos = session->cmds_max;
 266         iser_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 267         iser_conn->min_posted_rx = iser_conn->qp_max_recv_dtos >> 2;
 268
 269         if (device->iser_alloc_rdma_reg_res(ib_conn, session->scsi_cmds_max))
 270                 goto create_rdma_reg_res_failed;
 271
 272         if (iser_alloc_login_buf(iser_conn))
 273                 goto alloc_login_buf_fail;
 274
 275         iser_conn->num_rx_descs = session->cmds_max;
 276         iser_conn->rx_descs = kmalloc(iser_conn->num_rx_descs *
 277                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 278         if (!iser_conn->rx_descs)
 279                 goto rx_desc_alloc_fail;
 280
 281         rx_desc = iser_conn->rx_descs;
 282
 283         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 284                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 285                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 286                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 287                         goto rx_desc_dma_map_failed;
 288
 289                 rx_desc->dma_addr = dma_addr;
 290
 291                 rx_sg = &rx_desc->rx_sg;
 292                 rx_sg->addr   = rx_desc->dma_addr;
 293                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 294                 rx_sg->lkey   = device->mr->lkey;
 295         }
 296
 297         iser_conn->rx_desc_head = 0;
 298         return 0;
 299
 300 rx_desc_dma_map_failed:
 301         rx_desc = iser_conn->rx_descs;
 302         for (j = 0; j < i; j++, rx_desc++)
 303                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 304                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 305         kfree(iser_conn->rx_descs);
 306         iser_conn->rx_descs = NULL;
 307 rx_desc_alloc_fail:
 308         iser_free_login_buf(iser_conn);
 309 alloc_login_buf_fail:
 310         device->iser_free_rdma_reg_res(ib_conn);
 311 create_rdma_reg_res_failed:
 312         iser_err("failed allocating rx descriptors / data buffers\n");
 313         return -ENOMEM;
 314 }
 315
 316 void iser_free_rx_descriptors(struct iser_conn *iser_conn)
 317 {
 318         int i;
 319         struct iser_rx_desc *rx_desc;
 320         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 321         struct iser_device *device = ib_conn->device;
 322
 323         if (device->iser_free_rdma_reg_res)
 324                 device->iser_free_rdma_reg_res(ib_conn);
 325
 326         rx_desc = iser_conn->rx_descs;
 327         for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)
 328                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 329                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 330         kfree(iser_conn->rx_descs);
 331         /* make sure we never redo any unmapping */
 332         iser_conn->rx_descs = NULL;
 333
 334         iser_free_login_buf(iser_conn);
 335 }
 336
 337 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 338 {
 339         struct iser_conn *iser_conn = conn->dd_data;
 340         struct ib_conn *ib_conn = &iser_conn->ib_conn;
 341         struct iscsi_session *session = conn->session;
 342
 343         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 344         /* check if this is the last login - going to full feature phase */
 345         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 346                 return 0;
 347
 348         /*
 349          * Check that there is one posted recv buffer
 350          * (for the last login response).
 351          */
 352         WARN_ON(ib_conn->post_recv_buf_count != 1);
 353
 354         if (session->discovery_sess) {
 355                 iser_info("Discovery session, re-using login RX buffer\n");
 356                 return 0;
 357         } else
 358                 iser_info("Normal session, posting batch of RX %d buffers\n",
 359                           iser_conn->min_posted_rx);
 360
 361         /* Initial post receive buffers */
 362         if (iser_post_recvm(iser_conn, iser_conn->min_posted_rx))
 363                 return -ENOMEM;
 364
 365         return 0;
 366 }
 367
 368 static inline bool iser_signal_comp(u8 sig_count)
 369 {
 370         return ((sig_count % ISER_SIGNAL_CMD_COUNT) == 0);
 371 }
 372
 373 /**
 374  * iser_send_command - send command PDU
 375  */
 376 int iser_send_command(struct iscsi_conn *conn,
 377                       struct iscsi_task *task)
 378 {
 379         struct iser_conn *iser_conn = conn->dd_data;
 380         struct iscsi_iser_task *iser_task = task->dd_data;
 381         unsigned long edtl;
 382         int err;
 383         struct iser_data_buf *data_buf, *prot_buf;
 384         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 385         struct scsi_cmnd *sc  =  task->sc;
 386         struct iser_tx_desc *tx_desc = &iser_task->desc;
 387         u8 sig_count = ++iser_conn->ib_conn.sig_count;
 388
 389         edtl = ntohl(hdr->data_length);
 390
 391         /* build the tx desc regd header and add it to the tx desc dto */
 392         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 393         iser_create_send_desc(iser_conn, tx_desc);
 394
 395         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 396                 data_buf = &iser_task->data[ISER_DIR_IN];
 397                 prot_buf = &iser_task->prot[ISER_DIR_IN];
 398         } else {
 399                 data_buf = &iser_task->data[ISER_DIR_OUT];
 400                 prot_buf = &iser_task->prot[ISER_DIR_OUT];
 401         }
 402
 403         if (scsi_sg_count(sc)) { /* using a scatter list */
 404                 data_buf->sg = scsi_sglist(sc);
 405                 data_buf->size = scsi_sg_count(sc);
 406         }
 407         data_buf->data_len = scsi_bufflen(sc);
 408
 409         if (scsi_prot_sg_count(sc)) {
 410                 prot_buf->sg  = scsi_prot_sglist(sc);
 411                 prot_buf->size = scsi_prot_sg_count(sc);
 412                 prot_buf->data_len = (data_buf->data_len >>
 413                                      ilog2(sc->device->sector_size)) * 8;
 414         }
 415
 416         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 417                 err = iser_prepare_read_cmd(task);
 418                 if (err)
 419                         goto send_command_error;
 420         }
 421         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 422                 err = iser_prepare_write_cmd(task,
 423                                              task->imm_count,
 424                                              task->imm_count +
 425                                              task->unsol_r2t.data_length,
 426                                              edtl);
 427                 if (err)
 428                         goto send_command_error;
 429         }
 430
 431         iser_task->status = ISER_TASK_STATUS_STARTED;
 432
 433         err = iser_post_send(&iser_conn->ib_conn, tx_desc,
 434                              iser_signal_comp(sig_count));
 435         if (!err)
 436                 return 0;
 437
 438 send_command_error:
 439         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 440         return err;
 441 }
 442
 443 /**
 444  * iser_send_data_out - send data out PDU
 445  */
 446 int iser_send_data_out(struct iscsi_conn *conn,
 447                        struct iscsi_task *task,
 448                        struct iscsi_data *hdr)
 449 {
 450         struct iser_conn *iser_conn = conn->dd_data;
 451         struct iscsi_iser_task *iser_task = task->dd_data;
 452         struct iser_tx_desc *tx_desc = NULL;
 453         struct iser_mem_reg *mem_reg;
 454         unsigned long buf_offset;
 455         unsigned long data_seg_len;
 456         uint32_t itt;
 457         int err;
 458         struct ib_sge *tx_dsg;
 459
 460         itt = (__force uint32_t)hdr->itt;
 461         data_seg_len = ntoh24(hdr->dlength);
 462         buf_offset   = ntohl(hdr->offset);
 463
 464         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 465                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 466
 467         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 468         if (tx_desc == NULL) {
 469                 iser_err("Failed to alloc desc for post dataout\n");
 470                 return -ENOMEM;
 471         }
 472
 473         tx_desc->type = ISCSI_TX_DATAOUT;
 474         tx_desc->iser_header.flags = ISER_VER;
 475         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 476
 477         /* build the tx desc */
 478         err = iser_initialize_task_headers(task, tx_desc);
 479         if (err)
 480                 goto send_data_out_error;
 481
 482         mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
 483         tx_dsg = &tx_desc->tx_sg[1];
 484         tx_dsg->addr = mem_reg->sge.addr + buf_offset;
 485         tx_dsg->length = data_seg_len;
 486         tx_dsg->lkey = mem_reg->sge.lkey;
 487         tx_desc->num_sge = 2;
 488
 489         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 490                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 491                          "inconsistent with total len:%ld, itt:%d\n",
 492                          buf_offset, data_seg_len,
 493                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 494                 err = -EINVAL;
 495                 goto send_data_out_error;
 496         }
 497         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 498                  itt, buf_offset, data_seg_len);
 499
 500
 501         err = iser_post_send(&iser_conn->ib_conn, tx_desc, true);
 502         if (!err)
 503                 return 0;
 504
 505 send_data_out_error:
 506         kmem_cache_free(ig.desc_cache, tx_desc);
 507         iser_err("conn %p failed err %d\n", conn, err);
 508         return err;
 509 }
 510
 511 int iser_send_control(struct iscsi_conn *conn,
 512                       struct iscsi_task *task)
 513 {
 514         struct iser_conn *iser_conn = conn->dd_data;
 515         struct iscsi_iser_task *iser_task = task->dd_data;
 516         struct iser_tx_desc *mdesc = &iser_task->desc;
 517         unsigned long data_seg_len;
 518         int err = 0;
 519         struct iser_device *device;
 520
 521         /* build the tx desc regd header and add it to the tx desc dto */
 522         mdesc->type = ISCSI_TX_CONTROL;
 523         iser_create_send_desc(iser_conn, mdesc);
 524
 525         device = iser_conn->ib_conn.device;
 526
 527         data_seg_len = ntoh24(task->hdr->dlength);
 528
 529         if (data_seg_len > 0) {
 530                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 531                 if (task != conn->login_task) {
 532                         iser_err("data present on non login task!!!\n");
 533                         goto send_control_error;
 534                 }
 535
 536                 ib_dma_sync_single_for_cpu(device->ib_device,
 537                         iser_conn->login_req_dma, task->data_count,
 538                         DMA_TO_DEVICE);
 539
 540                 memcpy(iser_conn->login_req_buf, task->data, task->data_count);
 541
 542                 ib_dma_sync_single_for_device(device->ib_device,
 543                         iser_conn->login_req_dma, task->data_count,
 544                         DMA_TO_DEVICE);
 545
 546                 tx_dsg->addr    = iser_conn->login_req_dma;
 547                 tx_dsg->length  = task->data_count;
 548                 tx_dsg->lkey    = device->mr->lkey;
 549                 mdesc->num_sge = 2;
 550         }
 551
 552         if (task == conn->login_task) {
 553                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 554                          task->hdr->opcode, data_seg_len);
 555                 err = iser_post_recvl(iser_conn);
 556                 if (err)
 557                         goto send_control_error;
 558                 err = iser_post_rx_bufs(conn, task->hdr);
 559                 if (err)
 560                         goto send_control_error;
 561         }
 562
 563         err = iser_post_send(&iser_conn->ib_conn, mdesc, true);
 564         if (!err)
 565                 return 0;
 566
 567 send_control_error:
 568         iser_err("conn %p failed err %d\n",conn, err);
 569         return err;
 570 }
 571
 572 /**
 573  * iser_rcv_dto_completion - recv DTO completion
 574  */
 575 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 576                          unsigned long rx_xfer_len,
 577                          struct ib_conn *ib_conn)
 578 {
 579         struct iser_conn *iser_conn = container_of(ib_conn, struct iser_conn,
 580                                                    ib_conn);
 581         struct iscsi_hdr *hdr;
 582         u64 rx_dma;
 583         int rx_buflen, outstanding, count, err;
 584
 585         /* differentiate between login to all other PDUs */
 586         if ((char *)rx_desc == iser_conn->login_resp_buf) {
 587                 rx_dma = iser_conn->login_resp_dma;
 588                 rx_buflen = ISER_RX_LOGIN_SIZE;
 589         } else {
 590                 rx_dma = rx_desc->dma_addr;
 591                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 592         }
 593
 594         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 595                                    rx_buflen, DMA_FROM_DEVICE);
 596
 597         hdr = &rx_desc->iscsi_header;
 598
 599         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 600                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 601
 602         iscsi_iser_recv(iser_conn->iscsi_conn, hdr, rx_desc->data,
 603                         rx_xfer_len - ISER_HEADERS_LEN);
 604
 605         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 606                                       rx_buflen, DMA_FROM_DEVICE);
 607
 608         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 609          * task eliminates the need to worry on tasks which are completed in   *
 610          * parallel to the execution of iser_conn_term. So the code that waits *
 611          * for the posted rx bufs refcount to become zero handles everything   */
 612         ib_conn->post_recv_buf_count--;
 613
 614         if (rx_dma == iser_conn->login_resp_dma)
 615                 return;
 616
 617         outstanding = ib_conn->post_recv_buf_count;
 618         if (outstanding + iser_conn->min_posted_rx <= iser_conn->qp_max_recv_dtos) {
 619                 count = min(iser_conn->qp_max_recv_dtos - outstanding,
 620                             iser_conn->min_posted_rx);
 621                 err = iser_post_recvm(iser_conn, count);
 622                 if (err)
 623                         iser_err("posting %d rx bufs err %d\n", count, err);
 624         }
 625 }
 626
 627 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 628                         struct ib_conn *ib_conn)
 629 {
 630         struct iscsi_task *task;
 631         struct iser_device *device = ib_conn->device;
 632
 633         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 634                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 635                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 636                 kmem_cache_free(ig.desc_cache, tx_desc);
 637                 tx_desc = NULL;
 638         }
 639
 640         if (tx_desc && tx_desc->type == ISCSI_TX_CONTROL) {
 641                 /* this arithmetic is legal by libiscsi dd_data allocation */
 642                 task = (void *) ((long)(void *)tx_desc -
 643                                   sizeof(struct iscsi_task));
 644                 if (task->hdr->itt == RESERVED_ITT)
 645                         iscsi_put_task(task);
 646         }
 647 }
 648
 649 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 650
 651 {
 652         iser_task->status = ISER_TASK_STATUS_INIT;
 653
 654         iser_task->dir[ISER_DIR_IN] = 0;
 655         iser_task->dir[ISER_DIR_OUT] = 0;
 656
 657         iser_task->data[ISER_DIR_IN].data_len  = 0;
 658         iser_task->data[ISER_DIR_OUT].data_len = 0;
 659
 660         iser_task->prot[ISER_DIR_IN].data_len  = 0;
 661         iser_task->prot[ISER_DIR_OUT].data_len = 0;
 662
 663         memset(&iser_task->rdma_reg[ISER_DIR_IN], 0,
 664                sizeof(struct iser_mem_reg));
 665         memset(&iser_task->rdma_reg[ISER_DIR_OUT], 0,
 666                sizeof(struct iser_mem_reg));
 667 }
 668
 669 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 670 {
 671         struct iser_device *device = iser_task->iser_conn->ib_conn.device;
 672         int is_rdma_data_aligned = 1;
 673         int is_rdma_prot_aligned = 1;
 674         int prot_count = scsi_prot_sg_count(iser_task->sc);
 675
 676         /* if we were reading, copy back to unaligned sglist,
 677          * anyway dma_unmap and free the copy
 678          */
 679         if (iser_task->data[ISER_DIR_IN].orig_sg) {
 680                 is_rdma_data_aligned = 0;
 681                 iser_finalize_rdma_unaligned_sg(iser_task,
 682                                                 &iser_task->data[ISER_DIR_IN],
 683                                                 ISER_DIR_IN);
 684         }
 685
 686         if (iser_task->data[ISER_DIR_OUT].orig_sg) {
 687                 is_rdma_data_aligned = 0;
 688                 iser_finalize_rdma_unaligned_sg(iser_task,
 689                                                 &iser_task->data[ISER_DIR_OUT],
 690                                                 ISER_DIR_OUT);
 691         }
 692
 693         if (iser_task->prot[ISER_DIR_IN].orig_sg) {
 694                 is_rdma_prot_aligned = 0;
 695                 iser_finalize_rdma_unaligned_sg(iser_task,
 696                                                 &iser_task->prot[ISER_DIR_IN],
 697                                                 ISER_DIR_IN);
 698         }
 699
 700         if (iser_task->prot[ISER_DIR_OUT].orig_sg) {
 701                 is_rdma_prot_aligned = 0;
 702                 iser_finalize_rdma_unaligned_sg(iser_task,
 703                                                 &iser_task->prot[ISER_DIR_OUT],
 704                                                 ISER_DIR_OUT);
 705         }
 706
 707         if (iser_task->dir[ISER_DIR_IN]) {
 708                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 709                 if (is_rdma_data_aligned)
 710                         iser_dma_unmap_task_data(iser_task,
 711                                                  &iser_task->data[ISER_DIR_IN],
 712                                                  DMA_FROM_DEVICE);
 713                 if (prot_count && is_rdma_prot_aligned)
 714                         iser_dma_unmap_task_data(iser_task,
 715                                                  &iser_task->prot[ISER_DIR_IN],
 716                                                  DMA_FROM_DEVICE);
 717         }
 718
 719         if (iser_task->dir[ISER_DIR_OUT]) {
 720                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
 721                 if (is_rdma_data_aligned)
 722                         iser_dma_unmap_task_data(iser_task,
 723                                                  &iser_task->data[ISER_DIR_OUT],
 724                                                  DMA_TO_DEVICE);
 725                 if (prot_count && is_rdma_prot_aligned)
 726                         iser_dma_unmap_task_data(iser_task,
 727                                                  &iser_task->prot[ISER_DIR_OUT],
 728                                                  DMA_TO_DEVICE);
 729         }
 730 }