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. 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->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         if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
  77                 iser_err("Total data length: %ld, less than EDTL: "
  78                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  79                          iser_task->data[ISER_DIR_IN].data_len, edtl,
  80                          task->itt, iser_task->ib_conn);
  81                 return -EINVAL;
  82         }
  83
  84         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_IN);
  85         if (err) {
  86                 iser_err("Failed to set up Data-IN RDMA\n");
  87                 return err;
  88         }
  89         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
  90
  91         hdr->flags    |= ISER_RSV;
  92         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
  93         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
  94
  95         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  96                  task->itt, regd_buf->reg.rkey,
  97                  (unsigned long long)regd_buf->reg.va);
  98
  99         return 0;
 100 }
 101
 102 /* Register user buffer memory and initialize passive rdma
 103  *  dto descriptor. Total data size is stored in
 104  *  task->data[ISER_DIR_OUT].data_len
 105  */
 106 static int
 107 iser_prepare_write_cmd(struct iscsi_task *task,
 108                        unsigned int imm_sz,
 109                        unsigned int unsol_sz,
 110                        unsigned int edtl)
 111 {
 112         struct iscsi_iser_task *iser_task = task->dd_data;
 113         struct iser_device  *device = iser_task->ib_conn->device;
 114         struct iser_regd_buf *regd_buf;
 115         int err;
 116         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 117         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 118         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 119
 120         err = iser_dma_map_task_data(iser_task,
 121                                      buf_out,
 122                                      ISER_DIR_OUT,
 123                                      DMA_TO_DEVICE);
 124         if (err)
 125                 return err;
 126
 127         if (scsi_prot_sg_count(iser_task->sc)) {
 128                 struct iser_data_buf *pbuf_out = &iser_task->prot[ISER_DIR_OUT];
 129
 130                 err = iser_dma_map_task_data(iser_task,
 131                                              pbuf_out,
 132                                              ISER_DIR_OUT,
 133                                              DMA_TO_DEVICE);
 134                 if (err)
 135                         return err;
 136         }
 137
 138         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
 139                 iser_err("Total data length: %ld, less than EDTL: %d, "
 140                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 141                          iser_task->data[ISER_DIR_OUT].data_len,
 142                          edtl, task->itt, task->conn);
 143                 return -EINVAL;
 144         }
 145
 146         err = device->iser_reg_rdma_mem(iser_task, ISER_DIR_OUT);
 147         if (err != 0) {
 148                 iser_err("Failed to register write cmd RDMA mem\n");
 149                 return err;
 150         }
 151
 152         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 153
 154         if (unsol_sz < edtl) {
 155                 hdr->flags     |= ISER_WSV;
 156                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 157                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 158
 159                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 160                          "VA:%#llX + unsol:%d\n",
 161                          task->itt, regd_buf->reg.rkey,
 162                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 163         }
 164
 165         if (imm_sz > 0) {
 166                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 167                          task->itt, imm_sz);
 168                 tx_dsg->addr   = regd_buf->reg.va;
 169                 tx_dsg->length = imm_sz;
 170                 tx_dsg->lkey   = regd_buf->reg.lkey;
 171                 iser_task->desc.num_sge = 2;
 172         }
 173
 174         return 0;
 175 }
 176
 177 /* creates a new tx descriptor and adds header regd buffer */
 178 static void iser_create_send_desc(struct iser_conn      *ib_conn,
 179                                   struct iser_tx_desc   *tx_desc)
 180 {
 181         struct iser_device *device = ib_conn->device;
 182
 183         ib_dma_sync_single_for_cpu(device->ib_device,
 184                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 185
 186         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 187         tx_desc->iser_header.flags = ISER_VER;
 188
 189         tx_desc->num_sge = 1;
 190
 191         if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
 192                 tx_desc->tx_sg[0].lkey = device->mr->lkey;
 193                 iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
 194         }
 195 }
 196
 197 static void iser_free_login_buf(struct iser_conn *ib_conn)
 198 {
 199         if (!ib_conn->login_buf)
 200                 return;
 201
 202         if (ib_conn->login_req_dma)
 203                 ib_dma_unmap_single(ib_conn->device->ib_device,
 204                                     ib_conn->login_req_dma,
 205                                     ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 206
 207         if (ib_conn->login_resp_dma)
 208                 ib_dma_unmap_single(ib_conn->device->ib_device,
 209                                     ib_conn->login_resp_dma,
 210                                     ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 211
 212         kfree(ib_conn->login_buf);
 213
 214         /* make sure we never redo any unmapping */
 215         ib_conn->login_req_dma = 0;
 216         ib_conn->login_resp_dma = 0;
 217         ib_conn->login_buf = NULL;
 218 }
 219
 220 static int iser_alloc_login_buf(struct iser_conn *ib_conn)
 221 {
 222         struct iser_device      *device;
 223         int                     req_err, resp_err;
 224
 225         BUG_ON(ib_conn->device == NULL);
 226
 227         device = ib_conn->device;
 228
 229         ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
 230                                      ISER_RX_LOGIN_SIZE, GFP_KERNEL);
 231         if (!ib_conn->login_buf)
 232                 goto out_err;
 233
 234         ib_conn->login_req_buf  = ib_conn->login_buf;
 235         ib_conn->login_resp_buf = ib_conn->login_buf +
 236                                                 ISCSI_DEF_MAX_RECV_SEG_LEN;
 237
 238         ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
 239                                 (void *)ib_conn->login_req_buf,
 240                                 ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
 241
 242         ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
 243                                 (void *)ib_conn->login_resp_buf,
 244                                 ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 245
 246         req_err  = ib_dma_mapping_error(device->ib_device,
 247                                         ib_conn->login_req_dma);
 248         resp_err = ib_dma_mapping_error(device->ib_device,
 249                                         ib_conn->login_resp_dma);
 250
 251         if (req_err || resp_err) {
 252                 if (req_err)
 253                         ib_conn->login_req_dma = 0;
 254                 if (resp_err)
 255                         ib_conn->login_resp_dma = 0;
 256                 goto free_login_buf;
 257         }
 258         return 0;
 259
 260 free_login_buf:
 261         iser_free_login_buf(ib_conn);
 262
 263 out_err:
 264         iser_err("unable to alloc or map login buf\n");
 265         return -ENOMEM;
 266 }
 267
 268 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn, struct iscsi_session *session)
 269 {
 270         int i, j;
 271         u64 dma_addr;
 272         struct iser_rx_desc *rx_desc;
 273         struct ib_sge       *rx_sg;
 274         struct iser_device  *device = ib_conn->device;
 275
 276         ib_conn->qp_max_recv_dtos = session->cmds_max;
 277         ib_conn->qp_max_recv_dtos_mask = session->cmds_max - 1; /* cmds_max is 2^N */
 278         ib_conn->min_posted_rx = ib_conn->qp_max_recv_dtos >> 2;
 279
 280         if (device->iser_alloc_rdma_reg_res(ib_conn, session->scsi_cmds_max))
 281                 goto create_rdma_reg_res_failed;
 282
 283         if (iser_alloc_login_buf(ib_conn))
 284                 goto alloc_login_buf_fail;
 285
 286         ib_conn->rx_descs = kmalloc(session->cmds_max *
 287                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 288         if (!ib_conn->rx_descs)
 289                 goto rx_desc_alloc_fail;
 290
 291         rx_desc = ib_conn->rx_descs;
 292
 293         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)  {
 294                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 295                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 296                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 297                         goto rx_desc_dma_map_failed;
 298
 299                 rx_desc->dma_addr = dma_addr;
 300
 301                 rx_sg = &rx_desc->rx_sg;
 302                 rx_sg->addr   = rx_desc->dma_addr;
 303                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 304                 rx_sg->lkey   = device->mr->lkey;
 305         }
 306
 307         ib_conn->rx_desc_head = 0;
 308         return 0;
 309
 310 rx_desc_dma_map_failed:
 311         rx_desc = ib_conn->rx_descs;
 312         for (j = 0; j < i; j++, rx_desc++)
 313                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 314                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 315         kfree(ib_conn->rx_descs);
 316         ib_conn->rx_descs = NULL;
 317 rx_desc_alloc_fail:
 318         iser_free_login_buf(ib_conn);
 319 alloc_login_buf_fail:
 320         device->iser_free_rdma_reg_res(ib_conn);
 321 create_rdma_reg_res_failed:
 322         iser_err("failed allocating rx descriptors / data buffers\n");
 323         return -ENOMEM;
 324 }
 325
 326 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 327 {
 328         int i;
 329         struct iser_rx_desc *rx_desc;
 330         struct iser_device *device = ib_conn->device;
 331
 332         if (!ib_conn->rx_descs)
 333                 goto free_login_buf;
 334
 335         if (device->iser_free_rdma_reg_res)
 336                 device->iser_free_rdma_reg_res(ib_conn);
 337
 338         rx_desc = ib_conn->rx_descs;
 339         for (i = 0; i < ib_conn->qp_max_recv_dtos; i++, rx_desc++)
 340                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 341                                     ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 342         kfree(ib_conn->rx_descs);
 343         /* make sure we never redo any unmapping */
 344         ib_conn->rx_descs = NULL;
 345
 346 free_login_buf:
 347         iser_free_login_buf(ib_conn);
 348 }
 349
 350 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
 351 {
 352         struct iser_conn *ib_conn = conn->dd_data;
 353         struct iscsi_session *session = conn->session;
 354
 355         iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
 356         /* check if this is the last login - going to full feature phase */
 357         if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
 358                 return 0;
 359
 360         /*
 361          * Check that there is one posted recv buffer (for the last login
 362          * response) and no posted send buffers left - they must have been
 363          * consumed during previous login phases.
 364          */
 365         WARN_ON(ib_conn->post_recv_buf_count != 1);
 366         WARN_ON(atomic_read(&ib_conn->post_send_buf_count) != 0);
 367
 368         if (session->discovery_sess) {
 369                 iser_info("Discovery session, re-using login RX buffer\n");
 370                 return 0;
 371         } else
 372                 iser_info("Normal session, posting batch of RX %d buffers\n",
 373                           ib_conn->min_posted_rx);
 374
 375         /* Initial post receive buffers */
 376         if (iser_post_recvm(ib_conn, ib_conn->min_posted_rx))
 377                 return -ENOMEM;
 378
 379         return 0;
 380 }
 381
 382 /**
 383  * iser_send_command - send command PDU
 384  */
 385 int iser_send_command(struct iscsi_conn *conn,
 386                       struct iscsi_task *task)
 387 {
 388         struct iser_conn *ib_conn = conn->dd_data;
 389         struct iscsi_iser_task *iser_task = task->dd_data;
 390         unsigned long edtl;
 391         int err;
 392         struct iser_data_buf *data_buf, *prot_buf;
 393         struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
 394         struct scsi_cmnd *sc  =  task->sc;
 395         struct iser_tx_desc *tx_desc = &iser_task->desc;
 396
 397         edtl = ntohl(hdr->data_length);
 398
 399         /* build the tx desc regd header and add it to the tx desc dto */
 400         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 401         iser_create_send_desc(ib_conn, tx_desc);
 402
 403         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 404                 data_buf = &iser_task->data[ISER_DIR_IN];
 405                 prot_buf = &iser_task->prot[ISER_DIR_IN];
 406         } else {
 407                 data_buf = &iser_task->data[ISER_DIR_OUT];
 408                 prot_buf = &iser_task->prot[ISER_DIR_OUT];
 409         }
 410
 411         if (scsi_sg_count(sc)) { /* using a scatter list */
 412                 data_buf->buf  = scsi_sglist(sc);
 413                 data_buf->size = scsi_sg_count(sc);
 414         }
 415         data_buf->data_len = scsi_bufflen(sc);
 416
 417         if (scsi_prot_sg_count(sc)) {
 418                 prot_buf->buf  = scsi_prot_sglist(sc);
 419                 prot_buf->size = scsi_prot_sg_count(sc);
 420                 prot_buf->data_len = sc->prot_sdb->length;
 421         }
 422
 423         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 424                 err = iser_prepare_read_cmd(task, edtl);
 425                 if (err)
 426                         goto send_command_error;
 427         }
 428         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 429                 err = iser_prepare_write_cmd(task,
 430                                              task->imm_count,
 431                                              task->imm_count +
 432                                              task->unsol_r2t.data_length,
 433                                              edtl);
 434                 if (err)
 435                         goto send_command_error;
 436         }
 437
 438         iser_task->status = ISER_TASK_STATUS_STARTED;
 439
 440         err = iser_post_send(ib_conn, tx_desc);
 441         if (!err)
 442                 return 0;
 443
 444 send_command_error:
 445         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 446         return err;
 447 }
 448
 449 /**
 450  * iser_send_data_out - send data out PDU
 451  */
 452 int iser_send_data_out(struct iscsi_conn *conn,
 453                        struct iscsi_task *task,
 454                        struct iscsi_data *hdr)
 455 {
 456         struct iser_conn *ib_conn = conn->dd_data;
 457         struct iscsi_iser_task *iser_task = task->dd_data;
 458         struct iser_tx_desc *tx_desc = NULL;
 459         struct iser_regd_buf *regd_buf;
 460         unsigned long buf_offset;
 461         unsigned long data_seg_len;
 462         uint32_t itt;
 463         int err = 0;
 464         struct ib_sge *tx_dsg;
 465
 466         itt = (__force uint32_t)hdr->itt;
 467         data_seg_len = ntoh24(hdr->dlength);
 468         buf_offset   = ntohl(hdr->offset);
 469
 470         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 471                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 472
 473         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 474         if (tx_desc == NULL) {
 475                 iser_err("Failed to alloc desc for post dataout\n");
 476                 return -ENOMEM;
 477         }
 478
 479         tx_desc->type = ISCSI_TX_DATAOUT;
 480         tx_desc->iser_header.flags = ISER_VER;
 481         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 482
 483         /* build the tx desc */
 484         iser_initialize_task_headers(task, tx_desc);
 485
 486         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 487         tx_dsg = &tx_desc->tx_sg[1];
 488         tx_dsg->addr    = regd_buf->reg.va + buf_offset;
 489         tx_dsg->length  = data_seg_len;
 490         tx_dsg->lkey    = regd_buf->reg.lkey;
 491         tx_desc->num_sge = 2;
 492
 493         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 494                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 495                          "inconsistent with total len:%ld, itt:%d\n",
 496                          buf_offset, data_seg_len,
 497                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 498                 err = -EINVAL;
 499                 goto send_data_out_error;
 500         }
 501         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 502                  itt, buf_offset, data_seg_len);
 503
 504
 505         err = iser_post_send(ib_conn, tx_desc);
 506         if (!err)
 507                 return 0;
 508
 509 send_data_out_error:
 510         kmem_cache_free(ig.desc_cache, tx_desc);
 511         iser_err("conn %p failed err %d\n",conn, err);
 512         return err;
 513 }
 514
 515 int iser_send_control(struct iscsi_conn *conn,
 516                       struct iscsi_task *task)
 517 {
 518         struct iser_conn *ib_conn = conn->dd_data;
 519         struct iscsi_iser_task *iser_task = task->dd_data;
 520         struct iser_tx_desc *mdesc = &iser_task->desc;
 521         unsigned long data_seg_len;
 522         int err = 0;
 523         struct iser_device *device;
 524
 525         /* build the tx desc regd header and add it to the tx desc dto */
 526         mdesc->type = ISCSI_TX_CONTROL;
 527         iser_create_send_desc(ib_conn, mdesc);
 528
 529         device = ib_conn->device;
 530
 531         data_seg_len = ntoh24(task->hdr->dlength);
 532
 533         if (data_seg_len > 0) {
 534                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 535                 if (task != conn->login_task) {
 536                         iser_err("data present on non login task!!!\n");
 537                         goto send_control_error;
 538                 }
 539
 540                 ib_dma_sync_single_for_cpu(device->ib_device,
 541                         ib_conn->login_req_dma, task->data_count,
 542                         DMA_TO_DEVICE);
 543
 544                 memcpy(ib_conn->login_req_buf, task->data, task->data_count);
 545
 546                 ib_dma_sync_single_for_device(device->ib_device,
 547                         ib_conn->login_req_dma, task->data_count,
 548                         DMA_TO_DEVICE);
 549
 550                 tx_dsg->addr    = ib_conn->login_req_dma;
 551                 tx_dsg->length  = task->data_count;
 552                 tx_dsg->lkey    = device->mr->lkey;
 553                 mdesc->num_sge = 2;
 554         }
 555
 556         if (task == conn->login_task) {
 557                 iser_dbg("op %x dsl %lx, posting login rx buffer\n",
 558                          task->hdr->opcode, data_seg_len);
 559                 err = iser_post_recvl(ib_conn);
 560                 if (err)
 561                         goto send_control_error;
 562                 err = iser_post_rx_bufs(conn, task->hdr);
 563                 if (err)
 564                         goto send_control_error;
 565         }
 566
 567         err = iser_post_send(ib_conn, mdesc);
 568         if (!err)
 569                 return 0;
 570
 571 send_control_error:
 572         iser_err("conn %p failed err %d\n",conn, err);
 573         return err;
 574 }
 575
 576 /**
 577  * iser_rcv_dto_completion - recv DTO completion
 578  */
 579 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 580                          unsigned long rx_xfer_len,
 581                          struct iser_conn *ib_conn)
 582 {
 583         struct iscsi_hdr *hdr;
 584         u64 rx_dma;
 585         int rx_buflen, outstanding, count, err;
 586
 587         /* differentiate between login to all other PDUs */
 588         if ((char *)rx_desc == ib_conn->login_resp_buf) {
 589                 rx_dma = ib_conn->login_resp_dma;
 590                 rx_buflen = ISER_RX_LOGIN_SIZE;
 591         } else {
 592                 rx_dma = rx_desc->dma_addr;
 593                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 594         }
 595
 596         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 597                         rx_buflen, DMA_FROM_DEVICE);
 598
 599         hdr = &rx_desc->iscsi_header;
 600
 601         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 602                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 603
 604         iscsi_iser_recv(ib_conn->iscsi_conn, hdr, rx_desc->data,
 605                         rx_xfer_len - ISER_HEADERS_LEN);
 606
 607         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 608                                       rx_buflen, DMA_FROM_DEVICE);
 609
 610         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 611          * task eliminates the need to worry on tasks which are completed in   *
 612          * parallel to the execution of iser_conn_term. So the code that waits *
 613          * for the posted rx bufs refcount to become zero handles everything   */
 614         ib_conn->post_recv_buf_count--;
 615
 616         if (rx_dma == ib_conn->login_resp_dma)
 617                 return;
 618
 619         outstanding = ib_conn->post_recv_buf_count;
 620         if (outstanding + ib_conn->min_posted_rx <= ib_conn->qp_max_recv_dtos) {
 621                 count = min(ib_conn->qp_max_recv_dtos - outstanding,
 622                                                 ib_conn->min_posted_rx);
 623                 err = iser_post_recvm(ib_conn, count);
 624                 if (err)
 625                         iser_err("posting %d rx bufs err %d\n", count, err);
 626         }
 627 }
 628
 629 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 630                         struct iser_conn *ib_conn)
 631 {
 632         struct iscsi_task *task;
 633         struct iser_device *device = ib_conn->device;
 634
 635         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 636                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 637                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 638                 kmem_cache_free(ig.desc_cache, tx_desc);
 639                 tx_desc = NULL;
 640         }
 641
 642         atomic_dec(&ib_conn->post_send_buf_count);
 643
 644         if (tx_desc && tx_desc->type == ISCSI_TX_CONTROL) {
 645                 /* this arithmetic is legal by libiscsi dd_data allocation */
 646                 task = (void *) ((long)(void *)tx_desc -
 647                                   sizeof(struct iscsi_task));
 648                 if (task->hdr->itt == RESERVED_ITT)
 649                         iscsi_put_task(task);
 650         }
 651 }
 652
 653 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 654
 655 {
 656         iser_task->status = ISER_TASK_STATUS_INIT;
 657
 658         iser_task->dir[ISER_DIR_IN] = 0;
 659         iser_task->dir[ISER_DIR_OUT] = 0;
 660
 661         iser_task->data[ISER_DIR_IN].data_len  = 0;
 662         iser_task->data[ISER_DIR_OUT].data_len = 0;
 663
 664         iser_task->prot[ISER_DIR_IN].data_len  = 0;
 665         iser_task->prot[ISER_DIR_OUT].data_len = 0;
 666
 667         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 668                sizeof(struct iser_regd_buf));
 669         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 670                sizeof(struct iser_regd_buf));
 671 }
 672
 673 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 674 {
 675         struct iser_device *device = iser_task->ib_conn->device;
 676         int is_rdma_data_aligned = 1;
 677         int is_rdma_prot_aligned = 1;
 678         int prot_count = scsi_prot_sg_count(iser_task->sc);
 679
 680         /* if we were reading, copy back to unaligned sglist,
 681          * anyway dma_unmap and free the copy
 682          */
 683         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 684                 is_rdma_data_aligned = 0;
 685                 iser_finalize_rdma_unaligned_sg(iser_task,
 686                                                 &iser_task->data[ISER_DIR_IN],
 687                                                 &iser_task->data_copy[ISER_DIR_IN],
 688                                                 ISER_DIR_IN);
 689         }
 690
 691         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 692                 is_rdma_data_aligned = 0;
 693                 iser_finalize_rdma_unaligned_sg(iser_task,
 694                                                 &iser_task->data[ISER_DIR_OUT],
 695                                                 &iser_task->data_copy[ISER_DIR_OUT],
 696                                                 ISER_DIR_OUT);
 697         }
 698
 699         if (iser_task->prot_copy[ISER_DIR_IN].copy_buf != NULL) {
 700                 is_rdma_prot_aligned = 0;
 701                 iser_finalize_rdma_unaligned_sg(iser_task,
 702                                                 &iser_task->prot[ISER_DIR_IN],
 703                                                 &iser_task->prot_copy[ISER_DIR_IN],
 704                                                 ISER_DIR_IN);
 705         }
 706
 707         if (iser_task->prot_copy[ISER_DIR_OUT].copy_buf != NULL) {
 708                 is_rdma_prot_aligned = 0;
 709                 iser_finalize_rdma_unaligned_sg(iser_task,
 710                                                 &iser_task->prot[ISER_DIR_OUT],
 711                                                 &iser_task->prot_copy[ISER_DIR_OUT],
 712                                                 ISER_DIR_OUT);
 713         }
 714
 715         if (iser_task->dir[ISER_DIR_IN]) {
 716                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_IN);
 717                 if (is_rdma_data_aligned)
 718                         iser_dma_unmap_task_data(iser_task,
 719                                                  &iser_task->data[ISER_DIR_IN]);
 720                 if (prot_count && is_rdma_prot_aligned)
 721                         iser_dma_unmap_task_data(iser_task,
 722                                                  &iser_task->prot[ISER_DIR_IN]);
 723         }
 724
 725         if (iser_task->dir[ISER_DIR_OUT]) {
 726                 device->iser_unreg_rdma_mem(iser_task, ISER_DIR_OUT);
 727                 if (is_rdma_data_aligned)
 728                         iser_dma_unmap_task_data(iser_task,
 729                                                  &iser_task->data[ISER_DIR_OUT]);
 730                 if (prot_count && is_rdma_prot_aligned)
 731                         iser_dma_unmap_task_data(iser_task,
 732                                                  &iser_task->prot[ISER_DIR_OUT]);
 733         }
 734 }