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   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  * $Id: iser_initiator.c 6964 2006-05-07 11:11:43Z ogerlitz $
  33  */
  34 #include <linux/kernel.h>
  35 #include <linux/slab.h>
  36 #include <linux/mm.h>
  37 #include <asm/io.h>
  38 #include <asm/scatterlist.h>
  39 #include <linux/scatterlist.h>
  40 #include <linux/kfifo.h>
  41 #include <scsi/scsi_cmnd.h>
  42 #include <scsi/scsi_host.h>
  43
  44 #include "iscsi_iser.h"
  45
  46 /* Constant PDU lengths calculations */
  47 #define ISER_TOTAL_HEADERS_LEN  (sizeof (struct iser_hdr) + \
  48                                  sizeof (struct iscsi_hdr))
  49
  50 /* iser_dto_add_regd_buff - increments the reference count for *
  51  * the registered buffer & adds it to the DTO object           */
  52 static void iser_dto_add_regd_buff(struct iser_dto *dto,
  53                                    struct iser_regd_buf *regd_buf,
  54                                    unsigned long use_offset,
  55                                    unsigned long use_size)
  56 {
  57         int add_idx;
  58
  59         atomic_inc(&regd_buf->ref_count);
  60
  61         add_idx = dto->regd_vector_len;
  62         dto->regd[add_idx] = regd_buf;
  63         dto->used_sz[add_idx] = use_size;
  64         dto->offset[add_idx] = use_offset;
  65
  66         dto->regd_vector_len++;
  67 }
  68
  69 static int iser_dma_map_task_data(struct iscsi_iser_cmd_task *iser_ctask,
  70                                   struct iser_data_buf       *data,
  71                                   enum   iser_data_dir       iser_dir,
  72                                   enum   dma_data_direction  dma_dir)
  73 {
  74         struct device *dma_device;
  75
  76         iser_ctask->dir[iser_dir] = 1;
  77         dma_device = iser_ctask->iser_conn->ib_conn->device->ib_device->dma_device;
  78
  79         data->dma_nents = dma_map_sg(dma_device, data->buf, data->size, dma_dir);
  80         if (data->dma_nents == 0) {
  81                 iser_err("dma_map_sg failed!!!\n");
  82                 return -EINVAL;
  83         }
  84         return 0;
  85 }
  86
  87 static void iser_dma_unmap_task_data(struct iscsi_iser_cmd_task *iser_ctask)
  88 {
  89         struct device  *dma_device;
  90         struct iser_data_buf *data;
  91
  92         dma_device = iser_ctask->iser_conn->ib_conn->device->ib_device->dma_device;
  93
  94         if (iser_ctask->dir[ISER_DIR_IN]) {
  95                 data = &iser_ctask->data[ISER_DIR_IN];
  96                 dma_unmap_sg(dma_device, data->buf, data->size, DMA_FROM_DEVICE);
  97         }
  98
  99         if (iser_ctask->dir[ISER_DIR_OUT]) {
 100                 data = &iser_ctask->data[ISER_DIR_OUT];
 101                 dma_unmap_sg(dma_device, data->buf, data->size, DMA_TO_DEVICE);
 102         }
 103 }
 104
 105 /* Register user buffer memory and initialize passive rdma
 106  *  dto descriptor. Total data size is stored in
 107  *  iser_ctask->data[ISER_DIR_IN].data_len
 108  */
 109 static int iser_prepare_read_cmd(struct iscsi_cmd_task *ctask,
 110                                  unsigned int edtl)
 111
 112 {
 113         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 114         struct iser_regd_buf *regd_buf;
 115         int err;
 116         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
 117         struct iser_data_buf *buf_in = &iser_ctask->data[ISER_DIR_IN];
 118
 119         err = iser_dma_map_task_data(iser_ctask,
 120                                      buf_in,
 121                                      ISER_DIR_IN,
 122                                      DMA_FROM_DEVICE);
 123         if (err)
 124                 return err;
 125
 126         if (edtl > iser_ctask->data[ISER_DIR_IN].data_len) {
 127                 iser_err("Total data length: %ld, less than EDTL: "
 128                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
 129                          iser_ctask->data[ISER_DIR_IN].data_len, edtl,
 130                          ctask->itt, iser_ctask->iser_conn);
 131                 return -EINVAL;
 132         }
 133
 134         err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_IN);
 135         if (err) {
 136                 iser_err("Failed to set up Data-IN RDMA\n");
 137                 return err;
 138         }
 139         regd_buf = &iser_ctask->rdma_regd[ISER_DIR_IN];
 140
 141         hdr->flags    |= ISER_RSV;
 142         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
 143         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
 144
 145         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
 146                  ctask->itt, regd_buf->reg.rkey,
 147                  (unsigned long long)regd_buf->reg.va);
 148
 149         return 0;
 150 }
 151
 152 /* Register user buffer memory and initialize passive rdma
 153  *  dto descriptor. Total data size is stored in
 154  *  ctask->data[ISER_DIR_OUT].data_len
 155  */
 156 static int
 157 iser_prepare_write_cmd(struct iscsi_cmd_task *ctask,
 158                        unsigned int imm_sz,
 159                        unsigned int unsol_sz,
 160                        unsigned int edtl)
 161 {
 162         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 163         struct iser_regd_buf *regd_buf;
 164         int err;
 165         struct iser_dto *send_dto = &iser_ctask->desc.dto;
 166         struct iser_hdr *hdr = &iser_ctask->desc.iser_header;
 167         struct iser_data_buf *buf_out = &iser_ctask->data[ISER_DIR_OUT];
 168
 169         err = iser_dma_map_task_data(iser_ctask,
 170                                      buf_out,
 171                                      ISER_DIR_OUT,
 172                                      DMA_TO_DEVICE);
 173         if (err)
 174                 return err;
 175
 176         if (edtl > iser_ctask->data[ISER_DIR_OUT].data_len) {
 177                 iser_err("Total data length: %ld, less than EDTL: %d, "
 178                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 179                          iser_ctask->data[ISER_DIR_OUT].data_len,
 180                          edtl, ctask->itt, ctask->conn);
 181                 return -EINVAL;
 182         }
 183
 184         err = iser_reg_rdma_mem(iser_ctask,ISER_DIR_OUT);
 185         if (err != 0) {
 186                 iser_err("Failed to register write cmd RDMA mem\n");
 187                 return err;
 188         }
 189
 190         regd_buf = &iser_ctask->rdma_regd[ISER_DIR_OUT];
 191
 192         if (unsol_sz < edtl) {
 193                 hdr->flags     |= ISER_WSV;
 194                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 195                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 196
 197                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 198                          "VA:%#llX + unsol:%d\n",
 199                          ctask->itt, regd_buf->reg.rkey,
 200                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 201         }
 202
 203         if (imm_sz > 0) {
 204                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 205                          ctask->itt, imm_sz);
 206                 iser_dto_add_regd_buff(send_dto,
 207                                        regd_buf,
 208                                        0,
 209                                        imm_sz);
 210         }
 211
 212         return 0;
 213 }
 214
 215 /**
 216  * iser_post_receive_control - allocates, initializes and posts receive DTO.
 217  */
 218 static int iser_post_receive_control(struct iscsi_conn *conn)
 219 {
 220         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 221         struct iser_desc     *rx_desc;
 222         struct iser_regd_buf *regd_hdr;
 223         struct iser_regd_buf *regd_data;
 224         struct iser_dto      *recv_dto = NULL;
 225         struct iser_device  *device = iser_conn->ib_conn->device;
 226         int rx_data_size, err = 0;
 227
 228         rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 229         if (rx_desc == NULL) {
 230                 iser_err("Failed to alloc desc for post recv\n");
 231                 return -ENOMEM;
 232         }
 233         rx_desc->type = ISCSI_RX;
 234
 235         /* for the login sequence we must support rx of upto 8K; login is done
 236          * after conn create/bind (connect) and conn stop/bind (reconnect),
 237          * what's common for both schemes is that the connection is not started
 238          */
 239         if (conn->c_stage != ISCSI_CONN_STARTED)
 240                 rx_data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
 241         else /* FIXME till user space sets conn->max_recv_dlength correctly */
 242                 rx_data_size = 128;
 243
 244         rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
 245         if (rx_desc->data == NULL) {
 246                 iser_err("Failed to alloc data buf for post recv\n");
 247                 err = -ENOMEM;
 248                 goto post_rx_kmalloc_failure;
 249         }
 250
 251         recv_dto = &rx_desc->dto;
 252         recv_dto->ib_conn = iser_conn->ib_conn;
 253         recv_dto->regd_vector_len = 0;
 254
 255         regd_hdr = &rx_desc->hdr_regd_buf;
 256         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 257         regd_hdr->device  = device;
 258         regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
 259         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 260
 261         iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);
 262
 263         iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);
 264
 265         regd_data = &rx_desc->data_regd_buf;
 266         memset(regd_data, 0, sizeof(struct iser_regd_buf));
 267         regd_data->device  = device;
 268         regd_data->virt_addr  = rx_desc->data;
 269         regd_data->data_size  = rx_data_size;
 270
 271         iser_reg_single(device, regd_data, DMA_FROM_DEVICE);
 272
 273         iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);
 274
 275         err = iser_post_recv(rx_desc);
 276         if (!err)
 277                 return 0;
 278
 279         /* iser_post_recv failed */
 280         iser_dto_buffs_release(recv_dto);
 281         kfree(rx_desc->data);
 282 post_rx_kmalloc_failure:
 283         kmem_cache_free(ig.desc_cache, rx_desc);
 284         return err;
 285 }
 286
 287 /* creates a new tx descriptor and adds header regd buffer */
 288 static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
 289                                   struct iser_desc       *tx_desc)
 290 {
 291         struct iser_regd_buf *regd_hdr = &tx_desc->hdr_regd_buf;
 292         struct iser_dto      *send_dto = &tx_desc->dto;
 293
 294         memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
 295         regd_hdr->device  = iser_conn->ib_conn->device;
 296         regd_hdr->virt_addr  = tx_desc; /* == &tx_desc->iser_header */
 297         regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;
 298
 299         send_dto->ib_conn         = iser_conn->ib_conn;
 300         send_dto->notify_enable   = 1;
 301         send_dto->regd_vector_len = 0;
 302
 303         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 304         tx_desc->iser_header.flags = ISER_VER;
 305
 306         iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
 307 }
 308
 309 /**
 310  *  iser_conn_set_full_featured_mode - (iSER API)
 311  */
 312 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 313 {
 314         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 315
 316         int i;
 317         /* no need to keep it in a var, we are after login so if this should
 318          * be negotiated, by now the result should be available here */
 319         int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;
 320
 321         iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
 322
 323         /* Check that there is no posted recv or send buffers left - */
 324         /* they must be consumed during the login phase */
 325         BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
 326         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 327
 328         /* Initial post receive buffers */
 329         for (i = 0; i < initial_post_recv_bufs_num; i++) {
 330                 if (iser_post_receive_control(conn) != 0) {
 331                         iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
 332                                  i, conn);
 333                         return -ENOMEM;
 334                 }
 335         }
 336         iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);
 337         return 0;
 338 }
 339
 340 static int
 341 iser_check_xmit(struct iscsi_conn *conn, void *task)
 342 {
 343         int rc = 0;
 344         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 345
 346         write_lock_bh(conn->recv_lock);
 347         if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
 348             ISER_QP_MAX_REQ_DTOS) {
 349                 iser_dbg("%ld can't xmit task %p, suspending tx\n",jiffies,task);
 350                 set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 351                 rc = -EAGAIN;
 352         }
 353         write_unlock_bh(conn->recv_lock);
 354         return rc;
 355 }
 356
 357
 358 /**
 359  * iser_send_command - send command PDU
 360  */
 361 int iser_send_command(struct iscsi_conn     *conn,
 362                       struct iscsi_cmd_task *ctask)
 363 {
 364         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 365         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 366         struct iser_dto *send_dto = NULL;
 367         unsigned long edtl;
 368         int err = 0;
 369         struct iser_data_buf *data_buf;
 370
 371         struct iscsi_cmd *hdr =  ctask->hdr;
 372         struct scsi_cmnd *sc  =  ctask->sc;
 373
 374         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 375                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 376                 return -EPERM;
 377         }
 378         if (iser_check_xmit(conn, ctask))
 379                 return -EAGAIN;
 380
 381         edtl = ntohl(hdr->data_length);
 382
 383         /* build the tx desc regd header and add it to the tx desc dto */
 384         iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
 385         send_dto = &iser_ctask->desc.dto;
 386         send_dto->ctask = iser_ctask;
 387         iser_create_send_desc(iser_conn, &iser_ctask->desc);
 388
 389         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 390                 data_buf = &iser_ctask->data[ISER_DIR_IN];
 391         else
 392                 data_buf = &iser_ctask->data[ISER_DIR_OUT];
 393
 394         if (sc->use_sg) { /* using a scatter list */
 395                 data_buf->buf  = sc->request_buffer;
 396                 data_buf->size = sc->use_sg;
 397         } else if (sc->request_bufflen) {
 398                 /* using a single buffer - convert it into one entry SG */
 399                 sg_init_one(&data_buf->sg_single,
 400                             sc->request_buffer, sc->request_bufflen);
 401                 data_buf->buf   = &data_buf->sg_single;
 402                 data_buf->size  = 1;
 403         }
 404
 405         data_buf->data_len = sc->request_bufflen;
 406
 407         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 408                 err = iser_prepare_read_cmd(ctask, edtl);
 409                 if (err)
 410                         goto send_command_error;
 411         }
 412         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 413                 err = iser_prepare_write_cmd(ctask,
 414                                              ctask->imm_count,
 415                                              ctask->imm_count +
 416                                              ctask->unsol_count,
 417                                              edtl);
 418                 if (err)
 419                         goto send_command_error;
 420         }
 421
 422         iser_reg_single(iser_conn->ib_conn->device,
 423                         send_dto->regd[0], DMA_TO_DEVICE);
 424
 425         if (iser_post_receive_control(conn) != 0) {
 426                 iser_err("post_recv failed!\n");
 427                 err = -ENOMEM;
 428                 goto send_command_error;
 429         }
 430
 431         iser_ctask->status = ISER_TASK_STATUS_STARTED;
 432
 433         err = iser_post_send(&iser_ctask->desc);
 434         if (!err)
 435                 return 0;
 436
 437 send_command_error:
 438         iser_dto_buffs_release(send_dto);
 439         iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->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_cmd_task *ctask,
 448                        struct iscsi_data *hdr)
 449 {
 450         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 451         struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
 452         struct iser_desc *tx_desc = NULL;
 453         struct iser_dto *send_dto = NULL;
 454         unsigned long buf_offset;
 455         unsigned long data_seg_len;
 456         unsigned int itt;
 457         int err = 0;
 458
 459         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 460                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 461                 return -EPERM;
 462         }
 463
 464         if (iser_check_xmit(conn, ctask))
 465                 return -EAGAIN;
 466
 467         itt = ntohl(hdr->itt);
 468         data_seg_len = ntoh24(hdr->dlength);
 469         buf_offset   = ntohl(hdr->offset);
 470
 471         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 472                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 473
 474         tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
 475         if (tx_desc == NULL) {
 476                 iser_err("Failed to alloc desc for post dataout\n");
 477                 return -ENOMEM;
 478         }
 479
 480         tx_desc->type = ISCSI_TX_DATAOUT;
 481         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 482
 483         /* build the tx desc regd header and add it to the tx desc dto */
 484         send_dto = &tx_desc->dto;
 485         send_dto->ctask = iser_ctask;
 486         iser_create_send_desc(iser_conn, tx_desc);
 487
 488         iser_reg_single(iser_conn->ib_conn->device,
 489                         send_dto->regd[0], DMA_TO_DEVICE);
 490
 491         /* all data was registered for RDMA, we can use the lkey */
 492         iser_dto_add_regd_buff(send_dto,
 493                                &iser_ctask->rdma_regd[ISER_DIR_OUT],
 494                                buf_offset,
 495                                data_seg_len);
 496
 497         if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
 498                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 499                          "inconsistent with total len:%ld, itt:%d\n",
 500                          buf_offset, data_seg_len,
 501                          iser_ctask->data[ISER_DIR_OUT].data_len, itt);
 502                 err = -EINVAL;
 503                 goto send_data_out_error;
 504         }
 505         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 506                  itt, buf_offset, data_seg_len);
 507
 508
 509         err = iser_post_send(tx_desc);
 510         if (!err)
 511                 return 0;
 512
 513 send_data_out_error:
 514         iser_dto_buffs_release(send_dto);
 515         kmem_cache_free(ig.desc_cache, tx_desc);
 516         iser_err("conn %p failed err %d\n",conn, err);
 517         return err;
 518 }
 519
 520 int iser_send_control(struct iscsi_conn *conn,
 521                       struct iscsi_mgmt_task *mtask)
 522 {
 523         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 524         struct iser_desc *mdesc = mtask->dd_data;
 525         struct iser_dto *send_dto = NULL;
 526         unsigned int itt;
 527         unsigned long data_seg_len;
 528         int err = 0;
 529         unsigned char opcode;
 530         struct iser_regd_buf *regd_buf;
 531         struct iser_device *device;
 532
 533         if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
 534                 iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
 535                 return -EPERM;
 536         }
 537
 538         if (iser_check_xmit(conn,mtask))
 539                 return -EAGAIN;
 540
 541         /* build the tx desc regd header and add it to the tx desc dto */
 542         mdesc->type = ISCSI_TX_CONTROL;
 543         send_dto = &mdesc->dto;
 544         send_dto->ctask = NULL;
 545         iser_create_send_desc(iser_conn, mdesc);
 546
 547         device = iser_conn->ib_conn->device;
 548
 549         iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);
 550
 551         itt = ntohl(mtask->hdr->itt);
 552         opcode = mtask->hdr->opcode & ISCSI_OPCODE_MASK;
 553         data_seg_len = ntoh24(mtask->hdr->dlength);
 554
 555         if (data_seg_len > 0) {
 556                 regd_buf = &mdesc->data_regd_buf;
 557                 memset(regd_buf, 0, sizeof(struct iser_regd_buf));
 558                 regd_buf->device = device;
 559                 regd_buf->virt_addr = mtask->data;
 560                 regd_buf->data_size = mtask->data_count;
 561                 iser_reg_single(device, regd_buf,
 562                                 DMA_TO_DEVICE);
 563                 iser_dto_add_regd_buff(send_dto, regd_buf,
 564                                        0,
 565                                        data_seg_len);
 566         }
 567
 568         if (iser_post_receive_control(conn) != 0) {
 569                 iser_err("post_rcv_buff failed!\n");
 570                 err = -ENOMEM;
 571                 goto send_control_error;
 572         }
 573
 574         err = iser_post_send(mdesc);
 575         if (!err)
 576                 return 0;
 577
 578 send_control_error:
 579         iser_dto_buffs_release(send_dto);
 580         iser_err("conn %p failed err %d\n",conn, err);
 581         return err;
 582 }
 583
 584 /**
 585  * iser_rcv_dto_completion - recv DTO completion
 586  */
 587 void iser_rcv_completion(struct iser_desc *rx_desc,
 588                          unsigned long dto_xfer_len)
 589 {
 590         struct iser_dto        *dto = &rx_desc->dto;
 591         struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
 592         struct iscsi_session *session = conn->iscsi_conn->session;
 593         struct iscsi_cmd_task *ctask;
 594         struct iscsi_iser_cmd_task *iser_ctask;
 595         struct iscsi_hdr *hdr;
 596         char   *rx_data = NULL;
 597         int     rx_data_len = 0;
 598         unsigned int itt;
 599         unsigned char opcode;
 600
 601         hdr = &rx_desc->iscsi_header;
 602
 603         iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
 604
 605         if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
 606                 rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
 607                 rx_data     = dto->regd[1]->virt_addr;
 608                 rx_data    += dto->offset[1];
 609         }
 610
 611         opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 612
 613         if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
 614                 itt = hdr->itt & ISCSI_ITT_MASK; /* mask out cid and age bits */
 615                 if (!(itt < session->cmds_max))
 616                         iser_err("itt can't be matched to task!!!"
 617                                  "conn %p opcode %d cmds_max %d itt %d\n",
 618                                  conn->iscsi_conn,opcode,session->cmds_max,itt);
 619                 /* use the mapping given with the cmds array indexed by itt */
 620                 ctask = (struct iscsi_cmd_task *)session->cmds[itt];
 621                 iser_ctask = ctask->dd_data;
 622                 iser_dbg("itt %d ctask %p\n",itt,ctask);
 623                 iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
 624                 iser_ctask_rdma_finalize(iser_ctask);
 625         }
 626
 627         iser_dto_buffs_release(dto);
 628
 629         iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
 630
 631         kfree(rx_desc->data);
 632         kmem_cache_free(ig.desc_cache, rx_desc);
 633
 634         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 635          * task eliminates the need to worry on tasks which are completed in   *
 636          * parallel to the execution of iser_conn_term. So the code that waits *
 637          * for the posted rx bufs refcount to become zero handles everything   */
 638         atomic_dec(&conn->ib_conn->post_recv_buf_count);
 639 }
 640
 641 void iser_snd_completion(struct iser_desc *tx_desc)
 642 {
 643         struct iser_dto        *dto = &tx_desc->dto;
 644         struct iser_conn       *ib_conn = dto->ib_conn;
 645         struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
 646         struct iscsi_conn      *conn = iser_conn->iscsi_conn;
 647         struct iscsi_mgmt_task *mtask;
 648
 649         iser_dbg("Initiator, Data sent dto=0x%p\n", dto);
 650
 651         iser_dto_buffs_release(dto);
 652
 653         if (tx_desc->type == ISCSI_TX_DATAOUT)
 654                 kmem_cache_free(ig.desc_cache, tx_desc);
 655
 656         atomic_dec(&ib_conn->post_send_buf_count);
 657
 658         write_lock(conn->recv_lock);
 659         if (conn->suspend_tx) {
 660                 iser_dbg("%ld resuming tx\n",jiffies);
 661                 clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 662                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 663         }
 664         write_unlock(conn->recv_lock);
 665
 666         if (tx_desc->type == ISCSI_TX_CONTROL) {
 667                 /* this arithmetic is legal by libiscsi dd_data allocation */
 668                 mtask = (void *) ((long)(void *)tx_desc -
 669                                   sizeof(struct iscsi_mgmt_task));
 670                 if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
 671                         struct iscsi_session *session = conn->session;
 672
 673                         spin_lock(&conn->session->lock);
 674                         list_del(&mtask->running);
 675                         __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
 676                                     sizeof(void*));
 677                         spin_unlock(&session->lock);
 678                 }
 679         }
 680 }
 681
 682 void iser_ctask_rdma_init(struct iscsi_iser_cmd_task *iser_ctask)
 683
 684 {
 685         iser_ctask->status = ISER_TASK_STATUS_INIT;
 686
 687         iser_ctask->dir[ISER_DIR_IN] = 0;
 688         iser_ctask->dir[ISER_DIR_OUT] = 0;
 689
 690         iser_ctask->data[ISER_DIR_IN].data_len  = 0;
 691         iser_ctask->data[ISER_DIR_OUT].data_len = 0;
 692
 693         memset(&iser_ctask->rdma_regd[ISER_DIR_IN], 0,
 694                sizeof(struct iser_regd_buf));
 695         memset(&iser_ctask->rdma_regd[ISER_DIR_OUT], 0,
 696                sizeof(struct iser_regd_buf));
 697 }
 698
 699 void iser_ctask_rdma_finalize(struct iscsi_iser_cmd_task *iser_ctask)
 700 {
 701         int deferred;
 702
 703         /* if we were reading, copy back to unaligned sglist,
 704          * anyway dma_unmap and free the copy
 705          */
 706         if (iser_ctask->data_copy[ISER_DIR_IN].copy_buf != NULL)
 707                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_IN);
 708         if (iser_ctask->data_copy[ISER_DIR_OUT].copy_buf != NULL)
 709                 iser_finalize_rdma_unaligned_sg(iser_ctask, ISER_DIR_OUT);
 710
 711         if (iser_ctask->dir[ISER_DIR_IN]) {
 712                 deferred = iser_regd_buff_release
 713                         (&iser_ctask->rdma_regd[ISER_DIR_IN]);
 714                 if (deferred) {
 715                         iser_err("References remain for BUF-IN rdma reg\n");
 716                         BUG();
 717                 }
 718         }
 719
 720         if (iser_ctask->dir[ISER_DIR_OUT]) {
 721                 deferred = iser_regd_buff_release
 722                         (&iser_ctask->rdma_regd[ISER_DIR_OUT]);
 723                 if (deferred) {
 724                         iser_err("References remain for BUF-OUT rdma reg\n");
 725                         BUG();
 726                 }
 727         }
 728
 729         iser_dma_unmap_task_data(iser_ctask);
 730 }
 731
 732 void iser_dto_buffs_release(struct iser_dto *dto)
 733 {
 734         int i;
 735
 736         for (i = 0; i < dto->regd_vector_len; i++)
 737                 iser_regd_buff_release(dto->regd[i]);
 738 }
 739