drivers/infiniband/ulp/srp/ib_srp.c

   1 /*
   2  * Copyright (c) 2005 Cisco Systems.  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
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/slab.h>
  36 #include <linux/err.h>
  37 #include <linux/string.h>
  38 #include <linux/parser.h>
  39 #include <linux/random.h>
  40 #include <linux/jiffies.h>
  41
  42 #include <linux/atomic.h>
  43
  44 #include <scsi/scsi.h>
  45 #include <scsi/scsi_device.h>
  46 #include <scsi/scsi_dbg.h>
  47 #include <scsi/srp.h>
  48 #include <scsi/scsi_transport_srp.h>
  49
  50 #include "ib_srp.h"
  51
  52 #define DRV_NAME        "ib_srp"
  53 #define PFX             DRV_NAME ": "
  54 #define DRV_VERSION     "0.2"
  55 #define DRV_RELDATE     "November 1, 2005"
  56
  57 MODULE_AUTHOR("Roland Dreier");
  58 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
  59                    "v" DRV_VERSION " (" DRV_RELDATE ")");
  60 MODULE_LICENSE("Dual BSD/GPL");
  61
  62 static unsigned int srp_sg_tablesize;
  63 static unsigned int cmd_sg_entries;
  64 static unsigned int indirect_sg_entries;
  65 static bool allow_ext_sg;
  66 static int topspin_workarounds = 1;
  67
  68 module_param(srp_sg_tablesize, uint, 0444);
  69 MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
  70
  71 module_param(cmd_sg_entries, uint, 0444);
  72 MODULE_PARM_DESC(cmd_sg_entries,
  73                  "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
  74
  75 module_param(indirect_sg_entries, uint, 0444);
  76 MODULE_PARM_DESC(indirect_sg_entries,
  77                  "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");
  78
  79 module_param(allow_ext_sg, bool, 0444);
  80 MODULE_PARM_DESC(allow_ext_sg,
  81                   "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");
  82
  83 module_param(topspin_workarounds, int, 0444);
  84 MODULE_PARM_DESC(topspin_workarounds,
  85                  "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
  86
  87 static void srp_add_one(struct ib_device *device);
  88 static void srp_remove_one(struct ib_device *device);
  89 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
  90 static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
  91 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
  92
  93 static struct scsi_transport_template *ib_srp_transport_template;
  94
  95 static struct ib_client srp_client = {
  96         .name   = "srp",
  97         .add    = srp_add_one,
  98         .remove = srp_remove_one
  99 };
 100
 101 static struct ib_sa_client srp_sa_client;
 102
 103 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
 104 {
 105         return (struct srp_target_port *) host->hostdata;
 106 }
 107
 108 static const char *srp_target_info(struct Scsi_Host *host)
 109 {
 110         return host_to_target(host)->target_name;
 111 }
 112
 113 static int srp_target_is_topspin(struct srp_target_port *target)
 114 {
 115         static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
 116         static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
 117
 118         return topspin_workarounds &&
 119                 (!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
 120                  !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
 121 }
 122
 123 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
 124                                    gfp_t gfp_mask,
 125                                    enum dma_data_direction direction)
 126 {
 127         struct srp_iu *iu;
 128
 129         iu = kmalloc(sizeof *iu, gfp_mask);
 130         if (!iu)
 131                 goto out;
 132
 133         iu->buf = kzalloc(size, gfp_mask);
 134         if (!iu->buf)
 135                 goto out_free_iu;
 136
 137         iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
 138                                     direction);
 139         if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
 140                 goto out_free_buf;
 141
 142         iu->size      = size;
 143         iu->direction = direction;
 144
 145         return iu;
 146
 147 out_free_buf:
 148         kfree(iu->buf);
 149 out_free_iu:
 150         kfree(iu);
 151 out:
 152         return NULL;
 153 }
 154
 155 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
 156 {
 157         if (!iu)
 158                 return;
 159
 160         ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
 161                             iu->direction);
 162         kfree(iu->buf);
 163         kfree(iu);
 164 }
 165
 166 static void srp_qp_event(struct ib_event *event, void *context)
 167 {
 168         printk(KERN_ERR PFX "QP event %d\n", event->event);
 169 }
 170
 171 static int srp_init_qp(struct srp_target_port *target,
 172                        struct ib_qp *qp)
 173 {
 174         struct ib_qp_attr *attr;
 175         int ret;
 176
 177         attr = kmalloc(sizeof *attr, GFP_KERNEL);
 178         if (!attr)
 179                 return -ENOMEM;
 180
 181         ret = ib_find_pkey(target->srp_host->srp_dev->dev,
 182                            target->srp_host->port,
 183                            be16_to_cpu(target->path.pkey),
 184                            &attr->pkey_index);
 185         if (ret)
 186                 goto out;
 187
 188         attr->qp_state        = IB_QPS_INIT;
 189         attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
 190                                     IB_ACCESS_REMOTE_WRITE);
 191         attr->port_num        = target->srp_host->port;
 192
 193         ret = ib_modify_qp(qp, attr,
 194                            IB_QP_STATE          |
 195                            IB_QP_PKEY_INDEX     |
 196                            IB_QP_ACCESS_FLAGS   |
 197                            IB_QP_PORT);
 198
 199 out:
 200         kfree(attr);
 201         return ret;
 202 }
 203
 204 static int srp_new_cm_id(struct srp_target_port *target)
 205 {
 206         struct ib_cm_id *new_cm_id;
 207
 208         new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
 209                                     srp_cm_handler, target);
 210         if (IS_ERR(new_cm_id))
 211                 return PTR_ERR(new_cm_id);
 212
 213         if (target->cm_id)
 214                 ib_destroy_cm_id(target->cm_id);
 215         target->cm_id = new_cm_id;
 216
 217         return 0;
 218 }
 219
 220 static int srp_create_target_ib(struct srp_target_port *target)
 221 {
 222         struct ib_qp_init_attr *init_attr;
 223         int ret;
 224
 225         init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
 226         if (!init_attr)
 227                 return -ENOMEM;
 228
 229         target->recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 230                                        srp_recv_completion, NULL, target, SRP_RQ_SIZE, 0);
 231         if (IS_ERR(target->recv_cq)) {
 232                 ret = PTR_ERR(target->recv_cq);
 233                 goto err;
 234         }
 235
 236         target->send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 237                                        srp_send_completion, NULL, target, SRP_SQ_SIZE, 0);
 238         if (IS_ERR(target->send_cq)) {
 239                 ret = PTR_ERR(target->send_cq);
 240                 goto err_recv_cq;
 241         }
 242
 243         ib_req_notify_cq(target->recv_cq, IB_CQ_NEXT_COMP);
 244
 245         init_attr->event_handler       = srp_qp_event;
 246         init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
 247         init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
 248         init_attr->cap.max_recv_sge    = 1;
 249         init_attr->cap.max_send_sge    = 1;
 250         init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
 251         init_attr->qp_type             = IB_QPT_RC;
 252         init_attr->send_cq             = target->send_cq;
 253         init_attr->recv_cq             = target->recv_cq;
 254
 255         target->qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
 256         if (IS_ERR(target->qp)) {
 257                 ret = PTR_ERR(target->qp);
 258                 goto err_send_cq;
 259         }
 260
 261         ret = srp_init_qp(target, target->qp);
 262         if (ret)
 263                 goto err_qp;
 264
 265         kfree(init_attr);
 266         return 0;
 267
 268 err_qp:
 269         ib_destroy_qp(target->qp);
 270
 271 err_send_cq:
 272         ib_destroy_cq(target->send_cq);
 273
 274 err_recv_cq:
 275         ib_destroy_cq(target->recv_cq);
 276
 277 err:
 278         kfree(init_attr);
 279         return ret;
 280 }
 281
 282 static void srp_free_target_ib(struct srp_target_port *target)
 283 {
 284         int i;
 285
 286         ib_destroy_qp(target->qp);
 287         ib_destroy_cq(target->send_cq);
 288         ib_destroy_cq(target->recv_cq);
 289
 290         for (i = 0; i < SRP_RQ_SIZE; ++i)
 291                 srp_free_iu(target->srp_host, target->rx_ring[i]);
 292         for (i = 0; i < SRP_SQ_SIZE; ++i)
 293                 srp_free_iu(target->srp_host, target->tx_ring[i]);
 294 }
 295
 296 static void srp_path_rec_completion(int status,
 297                                     struct ib_sa_path_rec *pathrec,
 298                                     void *target_ptr)
 299 {
 300         struct srp_target_port *target = target_ptr;
 301
 302         target->status = status;
 303         if (status)
 304                 shost_printk(KERN_ERR, target->scsi_host,
 305                              PFX "Got failed path rec status %d\n", status);
 306         else
 307                 target->path = *pathrec;
 308         complete(&target->done);
 309 }
 310
 311 static int srp_lookup_path(struct srp_target_port *target)
 312 {
 313         int ret = -ENODEV;
 314
 315         target->path.numb_path = 1;
 316
 317         init_completion(&target->done);
 318
 319         /*
 320          * Avoid that the SCSI host can be removed by srp_remove_target()
 321          * before srp_path_rec_completion() is called.
 322          */
 323         if (!scsi_host_get(target->scsi_host))
 324                 goto out;
 325
 326         target->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
 327                                                    target->srp_host->srp_dev->dev,
 328                                                    target->srp_host->port,
 329                                                    &target->path,
 330                                                    IB_SA_PATH_REC_SERVICE_ID    |
 331                                                    IB_SA_PATH_REC_DGID          |
 332                                                    IB_SA_PATH_REC_SGID          |
 333                                                    IB_SA_PATH_REC_NUMB_PATH     |
 334                                                    IB_SA_PATH_REC_PKEY,
 335                                                    SRP_PATH_REC_TIMEOUT_MS,
 336                                                    GFP_KERNEL,
 337                                                    srp_path_rec_completion,
 338                                                    target, &target->path_query);
 339         ret = target->path_query_id;
 340         if (ret < 0)
 341                 goto put;
 342
 343         wait_for_completion(&target->done);
 344
 345         ret = target->status;
 346         if (ret < 0)
 347                 shost_printk(KERN_WARNING, target->scsi_host,
 348                              PFX "Path record query failed\n");
 349
 350 put:
 351         scsi_host_put(target->scsi_host);
 352
 353 out:
 354         return ret;
 355 }
 356
 357 static int srp_send_req(struct srp_target_port *target)
 358 {
 359         struct {
 360                 struct ib_cm_req_param param;
 361                 struct srp_login_req   priv;
 362         } *req = NULL;
 363         int status;
 364
 365         req = kzalloc(sizeof *req, GFP_KERNEL);
 366         if (!req)
 367                 return -ENOMEM;
 368
 369         req->param.primary_path               = &target->path;
 370         req->param.alternate_path             = NULL;
 371         req->param.service_id                 = target->service_id;
 372         req->param.qp_num                     = target->qp->qp_num;
 373         req->param.qp_type                    = target->qp->qp_type;
 374         req->param.private_data               = &req->priv;
 375         req->param.private_data_len           = sizeof req->priv;
 376         req->param.flow_control               = 1;
 377
 378         get_random_bytes(&req->param.starting_psn, 4);
 379         req->param.starting_psn              &= 0xffffff;
 380
 381         /*
 382          * Pick some arbitrary defaults here; we could make these
 383          * module parameters if anyone cared about setting them.
 384          */
 385         req->param.responder_resources        = 4;
 386         req->param.remote_cm_response_timeout = 20;
 387         req->param.local_cm_response_timeout  = 20;
 388         req->param.retry_count                = 7;
 389         req->param.rnr_retry_count            = 7;
 390         req->param.max_cm_retries             = 15;
 391
 392         req->priv.opcode        = SRP_LOGIN_REQ;
 393         req->priv.tag           = 0;
 394         req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
 395         req->priv.req_buf_fmt   = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
 396                                               SRP_BUF_FORMAT_INDIRECT);
 397         /*
 398          * In the published SRP specification (draft rev. 16a), the
 399          * port identifier format is 8 bytes of ID extension followed
 400          * by 8 bytes of GUID.  Older drafts put the two halves in the
 401          * opposite order, so that the GUID comes first.
 402          *
 403          * Targets conforming to these obsolete drafts can be
 404          * recognized by the I/O Class they report.
 405          */
 406         if (target->io_class == SRP_REV10_IB_IO_CLASS) {
 407                 memcpy(req->priv.initiator_port_id,
 408                        &target->path.sgid.global.interface_id, 8);
 409                 memcpy(req->priv.initiator_port_id + 8,
 410                        &target->initiator_ext, 8);
 411                 memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
 412                 memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
 413         } else {
 414                 memcpy(req->priv.initiator_port_id,
 415                        &target->initiator_ext, 8);
 416                 memcpy(req->priv.initiator_port_id + 8,
 417                        &target->path.sgid.global.interface_id, 8);
 418                 memcpy(req->priv.target_port_id,     &target->id_ext, 8);
 419                 memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
 420         }
 421
 422         /*
 423          * Topspin/Cisco SRP targets will reject our login unless we
 424          * zero out the first 8 bytes of our initiator port ID and set
 425          * the second 8 bytes to the local node GUID.
 426          */
 427         if (srp_target_is_topspin(target)) {
 428                 shost_printk(KERN_DEBUG, target->scsi_host,
 429                              PFX "Topspin/Cisco initiator port ID workaround "
 430                              "activated for target GUID %016llx\n",
 431                              (unsigned long long) be64_to_cpu(target->ioc_guid));
 432                 memset(req->priv.initiator_port_id, 0, 8);
 433                 memcpy(req->priv.initiator_port_id + 8,
 434                        &target->srp_host->srp_dev->dev->node_guid, 8);
 435         }
 436
 437         status = ib_send_cm_req(target->cm_id, &req->param);
 438
 439         kfree(req);
 440
 441         return status;
 442 }
 443
 444 static void srp_disconnect_target(struct srp_target_port *target)
 445 {
 446         /* XXX should send SRP_I_LOGOUT request */
 447
 448         init_completion(&target->done);
 449         if (ib_send_cm_dreq(target->cm_id, NULL, 0)) {
 450                 shost_printk(KERN_DEBUG, target->scsi_host,
 451                              PFX "Sending CM DREQ failed\n");
 452                 return;
 453         }
 454         wait_for_completion(&target->done);
 455 }
 456
 457 static bool srp_change_state(struct srp_target_port *target,
 458                             enum srp_target_state old,
 459                             enum srp_target_state new)
 460 {
 461         bool changed = false;
 462
 463         spin_lock_irq(&target->lock);
 464         if (target->state == old) {
 465                 target->state = new;
 466                 changed = true;
 467         }
 468         spin_unlock_irq(&target->lock);
 469         return changed;
 470 }
 471
 472 static void srp_free_req_data(struct srp_target_port *target)
 473 {
 474         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 475         struct srp_request *req;
 476         int i;
 477
 478         for (i = 0, req = target->req_ring; i < SRP_CMD_SQ_SIZE; ++i, ++req) {
 479                 kfree(req->fmr_list);
 480                 kfree(req->map_page);
 481                 if (req->indirect_dma_addr) {
 482                         ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
 483                                             target->indirect_size,
 484                                             DMA_TO_DEVICE);
 485                 }
 486                 kfree(req->indirect_desc);
 487         }
 488 }
 489
 490 static void srp_remove_work(struct work_struct *work)
 491 {
 492         struct srp_target_port *target =
 493                 container_of(work, struct srp_target_port, work);
 494
 495         if (!srp_change_state(target, SRP_TARGET_DEAD, SRP_TARGET_REMOVED))
 496                 return;
 497
 498         spin_lock(&target->srp_host->target_lock);
 499         list_del(&target->list);
 500         spin_unlock(&target->srp_host->target_lock);
 501
 502         srp_remove_host(target->scsi_host);
 503         scsi_remove_host(target->scsi_host);
 504         ib_destroy_cm_id(target->cm_id);
 505         srp_free_target_ib(target);
 506         srp_free_req_data(target);
 507         scsi_host_put(target->scsi_host);
 508 }
 509
 510 static int srp_connect_target(struct srp_target_port *target)
 511 {
 512         int retries = 3;
 513         int ret;
 514
 515         ret = srp_lookup_path(target);
 516         if (ret)
 517                 return ret;
 518
 519         while (1) {
 520                 init_completion(&target->done);
 521                 ret = srp_send_req(target);
 522                 if (ret)
 523                         return ret;
 524                 wait_for_completion(&target->done);
 525
 526                 /*
 527                  * The CM event handling code will set status to
 528                  * SRP_PORT_REDIRECT if we get a port redirect REJ
 529                  * back, or SRP_DLID_REDIRECT if we get a lid/qp
 530                  * redirect REJ back.
 531                  */
 532                 switch (target->status) {
 533                 case 0:
 534                         return 0;
 535
 536                 case SRP_PORT_REDIRECT:
 537                         ret = srp_lookup_path(target);
 538                         if (ret)
 539                                 return ret;
 540                         break;
 541
 542                 case SRP_DLID_REDIRECT:
 543                         break;
 544
 545                 case SRP_STALE_CONN:
 546                         /* Our current CM id was stale, and is now in timewait.
 547                          * Try to reconnect with a new one.
 548                          */
 549                         if (!retries-- || srp_new_cm_id(target)) {
 550                                 shost_printk(KERN_ERR, target->scsi_host, PFX
 551                                              "giving up on stale connection\n");
 552                                 target->status = -ECONNRESET;
 553                                 return target->status;
 554                         }
 555
 556                         shost_printk(KERN_ERR, target->scsi_host, PFX
 557                                      "retrying stale connection\n");
 558                         break;
 559
 560                 default:
 561                         return target->status;
 562                 }
 563         }
 564 }
 565
 566 static void srp_unmap_data(struct scsi_cmnd *scmnd,
 567                            struct srp_target_port *target,
 568                            struct srp_request *req)
 569 {
 570         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 571         struct ib_pool_fmr **pfmr;
 572
 573         if (!scsi_sglist(scmnd) ||
 574             (scmnd->sc_data_direction != DMA_TO_DEVICE &&
 575              scmnd->sc_data_direction != DMA_FROM_DEVICE))
 576                 return;
 577
 578         pfmr = req->fmr_list;
 579         while (req->nfmr--)
 580                 ib_fmr_pool_unmap(*pfmr++);
 581
 582         ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
 583                         scmnd->sc_data_direction);
 584 }
 585
 586 /**
 587  * srp_claim_req - Take ownership of the scmnd associated with a request.
 588  * @target: SRP target port.
 589  * @req: SRP request.
 590  * @scmnd: If NULL, take ownership of @req->scmnd. If not NULL, only take
 591  *         ownership of @req->scmnd if it equals @scmnd.
 592  *
 593  * Return value:
 594  * Either NULL or a pointer to the SCSI command the caller became owner of.
 595  */
 596 static struct scsi_cmnd *srp_claim_req(struct srp_target_port *target,
 597                                        struct srp_request *req,
 598                                        struct scsi_cmnd *scmnd)
 599 {
 600         unsigned long flags;
 601
 602         spin_lock_irqsave(&target->lock, flags);
 603         if (!scmnd) {
 604                 scmnd = req->scmnd;
 605                 req->scmnd = NULL;
 606         } else if (req->scmnd == scmnd) {
 607                 req->scmnd = NULL;
 608         } else {
 609                 scmnd = NULL;
 610         }
 611         spin_unlock_irqrestore(&target->lock, flags);
 612
 613         return scmnd;
 614 }
 615
 616 /**
 617  * srp_free_req() - Unmap data and add request to the free request list.
 618  */
 619 static void srp_free_req(struct srp_target_port *target,
 620                          struct srp_request *req, struct scsi_cmnd *scmnd,
 621                          s32 req_lim_delta)
 622 {
 623         unsigned long flags;
 624
 625         srp_unmap_data(scmnd, target, req);
 626
 627         spin_lock_irqsave(&target->lock, flags);
 628         target->req_lim += req_lim_delta;
 629         list_add_tail(&req->list, &target->free_reqs);
 630         spin_unlock_irqrestore(&target->lock, flags);
 631 }
 632
 633 static void srp_reset_req(struct srp_target_port *target, struct srp_request *req)
 634 {
 635         struct scsi_cmnd *scmnd = srp_claim_req(target, req, NULL);
 636
 637         if (scmnd) {
 638                 srp_free_req(target, req, scmnd, 0);
 639                 scmnd->result = DID_RESET << 16;
 640                 scmnd->scsi_done(scmnd);
 641         }
 642 }
 643
 644 static int srp_reconnect_target(struct srp_target_port *target)
 645 {
 646         struct ib_qp_attr qp_attr;
 647         struct ib_wc wc;
 648         int i, ret;
 649
 650         if (!srp_change_state(target, SRP_TARGET_LIVE, SRP_TARGET_CONNECTING))
 651                 return -EAGAIN;
 652
 653         srp_disconnect_target(target);
 654         /*
 655          * Now get a new local CM ID so that we avoid confusing the
 656          * target in case things are really fouled up.
 657          */
 658         ret = srp_new_cm_id(target);
 659         if (ret)
 660                 goto err;
 661
 662         qp_attr.qp_state = IB_QPS_RESET;
 663         ret = ib_modify_qp(target->qp, &qp_attr, IB_QP_STATE);
 664         if (ret)
 665                 goto err;
 666
 667         ret = srp_init_qp(target, target->qp);
 668         if (ret)
 669                 goto err;
 670
 671         while (ib_poll_cq(target->recv_cq, 1, &wc) > 0)
 672                 ; /* nothing */
 673         while (ib_poll_cq(target->send_cq, 1, &wc) > 0)
 674                 ; /* nothing */
 675
 676         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
 677                 struct srp_request *req = &target->req_ring[i];
 678                 if (req->scmnd)
 679                         srp_reset_req(target, req);
 680         }
 681
 682         INIT_LIST_HEAD(&target->free_tx);
 683         for (i = 0; i < SRP_SQ_SIZE; ++i)
 684                 list_add(&target->tx_ring[i]->list, &target->free_tx);
 685
 686         target->qp_in_error = 0;
 687         ret = srp_connect_target(target);
 688         if (ret)
 689                 goto err;
 690
 691         if (!srp_change_state(target, SRP_TARGET_CONNECTING, SRP_TARGET_LIVE))
 692                 ret = -EAGAIN;
 693
 694         return ret;
 695
 696 err:
 697         shost_printk(KERN_ERR, target->scsi_host,
 698                      PFX "reconnect failed (%d), removing target port.\n", ret);
 699
 700         /*
 701          * We couldn't reconnect, so kill our target port off.
 702          * However, we have to defer the real removal because we
 703          * are in the context of the SCSI error handler now, which
 704          * will deadlock if we call scsi_remove_host().
 705          *
 706          * Schedule our work inside the lock to avoid a race with
 707          * the flush_scheduled_work() in srp_remove_one().
 708          */
 709         spin_lock_irq(&target->lock);
 710         if (target->state == SRP_TARGET_CONNECTING) {
 711                 target->state = SRP_TARGET_DEAD;
 712                 INIT_WORK(&target->work, srp_remove_work);
 713                 queue_work(ib_wq, &target->work);
 714         }
 715         spin_unlock_irq(&target->lock);
 716
 717         return ret;
 718 }
 719
 720 static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
 721                          unsigned int dma_len, u32 rkey)
 722 {
 723         struct srp_direct_buf *desc = state->desc;
 724
 725         desc->va = cpu_to_be64(dma_addr);
 726         desc->key = cpu_to_be32(rkey);
 727         desc->len = cpu_to_be32(dma_len);
 728
 729         state->total_len += dma_len;
 730         state->desc++;
 731         state->ndesc++;
 732 }
 733
 734 static int srp_map_finish_fmr(struct srp_map_state *state,
 735                               struct srp_target_port *target)
 736 {
 737         struct srp_device *dev = target->srp_host->srp_dev;
 738         struct ib_pool_fmr *fmr;
 739         u64 io_addr = 0;
 740
 741         if (!state->npages)
 742                 return 0;
 743
 744         if (state->npages == 1) {
 745                 srp_map_desc(state, state->base_dma_addr, state->fmr_len,
 746                              target->rkey);
 747                 state->npages = state->fmr_len = 0;
 748                 return 0;
 749         }
 750
 751         fmr = ib_fmr_pool_map_phys(dev->fmr_pool, state->pages,
 752                                    state->npages, io_addr);
 753         if (IS_ERR(fmr))
 754                 return PTR_ERR(fmr);
 755
 756         *state->next_fmr++ = fmr;
 757         state->nfmr++;
 758
 759         srp_map_desc(state, 0, state->fmr_len, fmr->fmr->rkey);
 760         state->npages = state->fmr_len = 0;
 761         return 0;
 762 }
 763
 764 static void srp_map_update_start(struct srp_map_state *state,
 765                                  struct scatterlist *sg, int sg_index,
 766                                  dma_addr_t dma_addr)
 767 {
 768         state->unmapped_sg = sg;
 769         state->unmapped_index = sg_index;
 770         state->unmapped_addr = dma_addr;
 771 }
 772
 773 static int srp_map_sg_entry(struct srp_map_state *state,
 774                             struct srp_target_port *target,
 775                             struct scatterlist *sg, int sg_index,
 776                             int use_fmr)
 777 {
 778         struct srp_device *dev = target->srp_host->srp_dev;
 779         struct ib_device *ibdev = dev->dev;
 780         dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
 781         unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
 782         unsigned int len;
 783         int ret;
 784
 785         if (!dma_len)
 786                 return 0;
 787
 788         if (use_fmr == SRP_MAP_NO_FMR) {
 789                 /* Once we're in direct map mode for a request, we don't
 790                  * go back to FMR mode, so no need to update anything
 791                  * other than the descriptor.
 792                  */
 793                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 794                 return 0;
 795         }
 796
 797         /* If we start at an offset into the FMR page, don't merge into
 798          * the current FMR. Finish it out, and use the kernel's MR for this
 799          * sg entry. This is to avoid potential bugs on some SRP targets
 800          * that were never quite defined, but went away when the initiator
 801          * avoided using FMR on such page fragments.
 802          */
 803         if (dma_addr & ~dev->fmr_page_mask || dma_len > dev->fmr_max_size) {
 804                 ret = srp_map_finish_fmr(state, target);
 805                 if (ret)
 806                         return ret;
 807
 808                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 809                 srp_map_update_start(state, NULL, 0, 0);
 810                 return 0;
 811         }
 812
 813         /* If this is the first sg to go into the FMR, save our position.
 814          * We need to know the first unmapped entry, its index, and the
 815          * first unmapped address within that entry to be able to restart
 816          * mapping after an error.
 817          */
 818         if (!state->unmapped_sg)
 819                 srp_map_update_start(state, sg, sg_index, dma_addr);
 820
 821         while (dma_len) {
 822                 if (state->npages == SRP_FMR_SIZE) {
 823                         ret = srp_map_finish_fmr(state, target);
 824                         if (ret)
 825                                 return ret;
 826
 827                         srp_map_update_start(state, sg, sg_index, dma_addr);
 828                 }
 829
 830                 len = min_t(unsigned int, dma_len, dev->fmr_page_size);
 831
 832                 if (!state->npages)
 833                         state->base_dma_addr = dma_addr;
 834                 state->pages[state->npages++] = dma_addr;
 835                 state->fmr_len += len;
 836                 dma_addr += len;
 837                 dma_len -= len;
 838         }
 839
 840         /* If the last entry of the FMR wasn't a full page, then we need to
 841          * close it out and start a new one -- we can only merge at page
 842          * boundries.
 843          */
 844         ret = 0;
 845         if (len != dev->fmr_page_size) {
 846                 ret = srp_map_finish_fmr(state, target);
 847                 if (!ret)
 848                         srp_map_update_start(state, NULL, 0, 0);
 849         }
 850         return ret;
 851 }
 852
 853 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
 854                         struct srp_request *req)
 855 {
 856         struct scatterlist *scat, *sg;
 857         struct srp_cmd *cmd = req->cmd->buf;
 858         int i, len, nents, count, use_fmr;
 859         struct srp_device *dev;
 860         struct ib_device *ibdev;
 861         struct srp_map_state state;
 862         struct srp_indirect_buf *indirect_hdr;
 863         u32 table_len;
 864         u8 fmt;
 865
 866         if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
 867                 return sizeof (struct srp_cmd);
 868
 869         if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
 870             scmnd->sc_data_direction != DMA_TO_DEVICE) {
 871                 shost_printk(KERN_WARNING, target->scsi_host,
 872                              PFX "Unhandled data direction %d\n",
 873                              scmnd->sc_data_direction);
 874                 return -EINVAL;
 875         }
 876
 877         nents = scsi_sg_count(scmnd);
 878         scat  = scsi_sglist(scmnd);
 879
 880         dev = target->srp_host->srp_dev;
 881         ibdev = dev->dev;
 882
 883         count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
 884         if (unlikely(count == 0))
 885                 return -EIO;
 886
 887         fmt = SRP_DATA_DESC_DIRECT;
 888         len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
 889
 890         if (count == 1) {
 891                 /*
 892                  * The midlayer only generated a single gather/scatter
 893                  * entry, or DMA mapping coalesced everything to a
 894                  * single entry.  So a direct descriptor along with
 895                  * the DMA MR suffices.
 896                  */
 897                 struct srp_direct_buf *buf = (void *) cmd->add_data;
 898
 899                 buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
 900                 buf->key = cpu_to_be32(target->rkey);
 901                 buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
 902
 903                 req->nfmr = 0;
 904                 goto map_complete;
 905         }
 906
 907         /* We have more than one scatter/gather entry, so build our indirect
 908          * descriptor table, trying to merge as many entries with FMR as we
 909          * can.
 910          */
 911         indirect_hdr = (void *) cmd->add_data;
 912
 913         ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
 914                                    target->indirect_size, DMA_TO_DEVICE);
 915
 916         memset(&state, 0, sizeof(state));
 917         state.desc      = req->indirect_desc;
 918         state.pages     = req->map_page;
 919         state.next_fmr  = req->fmr_list;
 920
 921         use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
 922
 923         for_each_sg(scat, sg, count, i) {
 924                 if (srp_map_sg_entry(&state, target, sg, i, use_fmr)) {
 925                         /* FMR mapping failed, so backtrack to the first
 926                          * unmapped entry and continue on without using FMR.
 927                          */
 928                         dma_addr_t dma_addr;
 929                         unsigned int dma_len;
 930
 931 backtrack:
 932                         sg = state.unmapped_sg;
 933                         i = state.unmapped_index;
 934
 935                         dma_addr = ib_sg_dma_address(ibdev, sg);
 936                         dma_len = ib_sg_dma_len(ibdev, sg);
 937                         dma_len -= (state.unmapped_addr - dma_addr);
 938                         dma_addr = state.unmapped_addr;
 939                         use_fmr = SRP_MAP_NO_FMR;
 940                         srp_map_desc(&state, dma_addr, dma_len, target->rkey);
 941                 }
 942         }
 943
 944         if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(&state, target))
 945                 goto backtrack;
 946
 947         /* We've mapped the request, now pull as much of the indirect
 948          * descriptor table as we can into the command buffer. If this
 949          * target is not using an external indirect table, we are
 950          * guaranteed to fit into the command, as the SCSI layer won't
 951          * give us more S/G entries than we allow.
 952          */
 953         req->nfmr = state.nfmr;
 954         if (state.ndesc == 1) {
 955                 /* FMR mapping was able to collapse this to one entry,
 956                  * so use a direct descriptor.
 957                  */
 958                 struct srp_direct_buf *buf = (void *) cmd->add_data;
 959
 960                 *buf = req->indirect_desc[0];
 961                 goto map_complete;
 962         }
 963
 964         if (unlikely(target->cmd_sg_cnt < state.ndesc &&
 965                                                 !target->allow_ext_sg)) {
 966                 shost_printk(KERN_ERR, target->scsi_host,
 967                              "Could not fit S/G list into SRP_CMD\n");
 968                 return -EIO;
 969         }
 970
 971         count = min(state.ndesc, target->cmd_sg_cnt);
 972         table_len = state.ndesc * sizeof (struct srp_direct_buf);
 973
 974         fmt = SRP_DATA_DESC_INDIRECT;
 975         len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
 976         len += count * sizeof (struct srp_direct_buf);
 977
 978         memcpy(indirect_hdr->desc_list, req->indirect_desc,
 979                count * sizeof (struct srp_direct_buf));
 980
 981         indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
 982         indirect_hdr->table_desc.key = cpu_to_be32(target->rkey);
 983         indirect_hdr->table_desc.len = cpu_to_be32(table_len);
 984         indirect_hdr->len = cpu_to_be32(state.total_len);
 985
 986         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
 987                 cmd->data_out_desc_cnt = count;
 988         else
 989                 cmd->data_in_desc_cnt = count;
 990
 991         ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
 992                                       DMA_TO_DEVICE);
 993
 994 map_complete:
 995         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
 996                 cmd->buf_fmt = fmt << 4;
 997         else
 998                 cmd->buf_fmt = fmt;
 999
1000         return len;
1001 }
1002
1003 /*
1004  * Return an IU and possible credit to the free pool
1005  */
1006 static void srp_put_tx_iu(struct srp_target_port *target, struct srp_iu *iu,
1007                           enum srp_iu_type iu_type)
1008 {
1009         unsigned long flags;
1010
1011         spin_lock_irqsave(&target->lock, flags);
1012         list_add(&iu->list, &target->free_tx);
1013         if (iu_type != SRP_IU_RSP)
1014                 ++target->req_lim;
1015         spin_unlock_irqrestore(&target->lock, flags);
1016 }
1017
1018 /*
1019  * Must be called with target->lock held to protect req_lim and free_tx.
1020  * If IU is not sent, it must be returned using srp_put_tx_iu().
1021  *
1022  * Note:
1023  * An upper limit for the number of allocated information units for each
1024  * request type is:
1025  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
1026  *   more than Scsi_Host.can_queue requests.
1027  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
1028  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
1029  *   one unanswered SRP request to an initiator.
1030  */
1031 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
1032                                       enum srp_iu_type iu_type)
1033 {
1034         s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
1035         struct srp_iu *iu;
1036
1037         srp_send_completion(target->send_cq, target);
1038
1039         if (list_empty(&target->free_tx))
1040                 return NULL;
1041
1042         /* Initiator responses to target requests do not consume credits */
1043         if (iu_type != SRP_IU_RSP) {
1044                 if (target->req_lim <= rsv) {
1045                         ++target->zero_req_lim;
1046                         return NULL;
1047                 }
1048
1049                 --target->req_lim;
1050         }
1051
1052         iu = list_first_entry(&target->free_tx, struct srp_iu, list);
1053         list_del(&iu->list);
1054         return iu;
1055 }
1056
1057 static int srp_post_send(struct srp_target_port *target,
1058                          struct srp_iu *iu, int len)
1059 {
1060         struct ib_sge list;
1061         struct ib_send_wr wr, *bad_wr;
1062
1063         list.addr   = iu->dma;
1064         list.length = len;
1065         list.lkey   = target->lkey;
1066
1067         wr.next       = NULL;
1068         wr.wr_id      = (uintptr_t) iu;
1069         wr.sg_list    = &list;
1070         wr.num_sge    = 1;
1071         wr.opcode     = IB_WR_SEND;
1072         wr.send_flags = IB_SEND_SIGNALED;
1073
1074         return ib_post_send(target->qp, &wr, &bad_wr);
1075 }
1076
1077 static int srp_post_recv(struct srp_target_port *target, struct srp_iu *iu)
1078 {
1079         struct ib_recv_wr wr, *bad_wr;
1080         struct ib_sge list;
1081
1082         list.addr   = iu->dma;
1083         list.length = iu->size;
1084         list.lkey   = target->lkey;
1085
1086         wr.next     = NULL;
1087         wr.wr_id    = (uintptr_t) iu;
1088         wr.sg_list  = &list;
1089         wr.num_sge  = 1;
1090
1091         return ib_post_recv(target->qp, &wr, &bad_wr);
1092 }
1093
1094 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
1095 {
1096         struct srp_request *req;
1097         struct scsi_cmnd *scmnd;
1098         unsigned long flags;
1099
1100         if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1101                 spin_lock_irqsave(&target->lock, flags);
1102                 target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1103                 spin_unlock_irqrestore(&target->lock, flags);
1104
1105                 target->tsk_mgmt_status = -1;
1106                 if (be32_to_cpu(rsp->resp_data_len) >= 4)
1107                         target->tsk_mgmt_status = rsp->data[3];
1108                 complete(&target->tsk_mgmt_done);
1109         } else {
1110                 req = &target->req_ring[rsp->tag];
1111                 scmnd = srp_claim_req(target, req, NULL);
1112                 if (!scmnd) {
1113                         shost_printk(KERN_ERR, target->scsi_host,
1114                                      "Null scmnd for RSP w/tag %016llx\n",
1115                                      (unsigned long long) rsp->tag);
1116
1117                         spin_lock_irqsave(&target->lock, flags);
1118                         target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1119                         spin_unlock_irqrestore(&target->lock, flags);
1120
1121                         return;
1122                 }
1123                 scmnd->result = rsp->status;
1124
1125                 if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
1126                         memcpy(scmnd->sense_buffer, rsp->data +
1127                                be32_to_cpu(rsp->resp_data_len),
1128                                min_t(int, be32_to_cpu(rsp->sense_data_len),
1129                                      SCSI_SENSE_BUFFERSIZE));
1130                 }
1131
1132                 if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
1133                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
1134                 else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
1135                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
1136
1137                 srp_free_req(target, req, scmnd,
1138                              be32_to_cpu(rsp->req_lim_delta));
1139
1140                 scmnd->host_scribble = NULL;
1141                 scmnd->scsi_done(scmnd);
1142         }
1143 }
1144
1145 static int srp_response_common(struct srp_target_port *target, s32 req_delta,
1146                                void *rsp, int len)
1147 {
1148         struct ib_device *dev = target->srp_host->srp_dev->dev;
1149         unsigned long flags;
1150         struct srp_iu *iu;
1151         int err;
1152
1153         spin_lock_irqsave(&target->lock, flags);
1154         target->req_lim += req_delta;
1155         iu = __srp_get_tx_iu(target, SRP_IU_RSP);
1156         spin_unlock_irqrestore(&target->lock, flags);
1157
1158         if (!iu) {
1159                 shost_printk(KERN_ERR, target->scsi_host, PFX
1160                              "no IU available to send response\n");
1161                 return 1;
1162         }
1163
1164         ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
1165         memcpy(iu->buf, rsp, len);
1166         ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
1167
1168         err = srp_post_send(target, iu, len);
1169         if (err) {
1170                 shost_printk(KERN_ERR, target->scsi_host, PFX
1171                              "unable to post response: %d\n", err);
1172                 srp_put_tx_iu(target, iu, SRP_IU_RSP);
1173         }
1174
1175         return err;
1176 }
1177
1178 static void srp_process_cred_req(struct srp_target_port *target,
1179                                  struct srp_cred_req *req)
1180 {
1181         struct srp_cred_rsp rsp = {
1182                 .opcode = SRP_CRED_RSP,
1183                 .tag = req->tag,
1184         };
1185         s32 delta = be32_to_cpu(req->req_lim_delta);
1186
1187         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1188                 shost_printk(KERN_ERR, target->scsi_host, PFX
1189                              "problems processing SRP_CRED_REQ\n");
1190 }
1191
1192 static void srp_process_aer_req(struct srp_target_port *target,
1193                                 struct srp_aer_req *req)
1194 {
1195         struct srp_aer_rsp rsp = {
1196                 .opcode = SRP_AER_RSP,
1197                 .tag = req->tag,
1198         };
1199         s32 delta = be32_to_cpu(req->req_lim_delta);
1200
1201         shost_printk(KERN_ERR, target->scsi_host, PFX
1202                      "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
1203
1204         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1205                 shost_printk(KERN_ERR, target->scsi_host, PFX
1206                              "problems processing SRP_AER_REQ\n");
1207 }
1208
1209 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
1210 {
1211         struct ib_device *dev = target->srp_host->srp_dev->dev;
1212         struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1213         int res;
1214         u8 opcode;
1215
1216         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
1217                                    DMA_FROM_DEVICE);
1218
1219         opcode = *(u8 *) iu->buf;
1220
1221         if (0) {
1222                 shost_printk(KERN_ERR, target->scsi_host,
1223                              PFX "recv completion, opcode 0x%02x\n", opcode);
1224                 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1225                                iu->buf, wc->byte_len, true);
1226         }
1227
1228         switch (opcode) {
1229         case SRP_RSP:
1230                 srp_process_rsp(target, iu->buf);
1231                 break;
1232
1233         case SRP_CRED_REQ:
1234                 srp_process_cred_req(target, iu->buf);
1235                 break;
1236
1237         case SRP_AER_REQ:
1238                 srp_process_aer_req(target, iu->buf);
1239                 break;
1240
1241         case SRP_T_LOGOUT:
1242                 /* XXX Handle target logout */
1243                 shost_printk(KERN_WARNING, target->scsi_host,
1244                              PFX "Got target logout request\n");
1245                 break;
1246
1247         default:
1248                 shost_printk(KERN_WARNING, target->scsi_host,
1249                              PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1250                 break;
1251         }
1252
1253         ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
1254                                       DMA_FROM_DEVICE);
1255
1256         res = srp_post_recv(target, iu);
1257         if (res != 0)
1258                 shost_printk(KERN_ERR, target->scsi_host,
1259                              PFX "Recv failed with error code %d\n", res);
1260 }
1261
1262 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
1263 {
1264         struct srp_target_port *target = target_ptr;
1265         struct ib_wc wc;
1266
1267         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1268         while (ib_poll_cq(cq, 1, &wc) > 0) {
1269                 if (wc.status) {
1270                         shost_printk(KERN_ERR, target->scsi_host,
1271                                      PFX "failed receive status %d\n",
1272                                      wc.status);
1273                         target->qp_in_error = 1;
1274                         break;
1275                 }
1276
1277                 srp_handle_recv(target, &wc);
1278         }
1279 }
1280
1281 static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
1282 {
1283         struct srp_target_port *target = target_ptr;
1284         struct ib_wc wc;
1285         struct srp_iu *iu;
1286
1287         while (ib_poll_cq(cq, 1, &wc) > 0) {
1288                 if (wc.status) {
1289                         shost_printk(KERN_ERR, target->scsi_host,
1290                                      PFX "failed send status %d\n",
1291                                      wc.status);
1292                         target->qp_in_error = 1;
1293                         break;
1294                 }
1295
1296                 iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1297                 list_add(&iu->list, &target->free_tx);
1298         }
1299 }
1300
1301 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1302 {
1303         struct srp_target_port *target = host_to_target(shost);
1304         struct srp_request *req;
1305         struct srp_iu *iu;
1306         struct srp_cmd *cmd;
1307         struct ib_device *dev;
1308         unsigned long flags;
1309         int len;
1310
1311         if (target->state == SRP_TARGET_CONNECTING)
1312                 goto err;
1313
1314         if (target->state == SRP_TARGET_DEAD ||
1315             target->state == SRP_TARGET_REMOVED) {
1316                 scmnd->result = DID_BAD_TARGET << 16;
1317                 scmnd->scsi_done(scmnd);
1318                 return 0;
1319         }
1320
1321         spin_lock_irqsave(&target->lock, flags);
1322         iu = __srp_get_tx_iu(target, SRP_IU_CMD);
1323         if (!iu)
1324                 goto err_unlock;
1325
1326         req = list_first_entry(&target->free_reqs, struct srp_request, list);
1327         list_del(&req->list);
1328         spin_unlock_irqrestore(&target->lock, flags);
1329
1330         dev = target->srp_host->srp_dev->dev;
1331         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
1332                                    DMA_TO_DEVICE);
1333
1334         scmnd->result        = 0;
1335         scmnd->host_scribble = (void *) req;
1336
1337         cmd = iu->buf;
1338         memset(cmd, 0, sizeof *cmd);
1339
1340         cmd->opcode = SRP_CMD;
1341         cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
1342         cmd->tag    = req->index;
1343         memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
1344
1345         req->scmnd    = scmnd;
1346         req->cmd      = iu;
1347
1348         len = srp_map_data(scmnd, target, req);
1349         if (len < 0) {
1350                 shost_printk(KERN_ERR, target->scsi_host,
1351                              PFX "Failed to map data\n");
1352                 goto err_iu;
1353         }
1354
1355         ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
1356                                       DMA_TO_DEVICE);
1357
1358         if (srp_post_send(target, iu, len)) {
1359                 shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
1360                 goto err_unmap;
1361         }
1362
1363         return 0;
1364
1365 err_unmap:
1366         srp_unmap_data(scmnd, target, req);
1367
1368 err_iu:
1369         srp_put_tx_iu(target, iu, SRP_IU_CMD);
1370
1371         /*
1372          * Avoid that the loops that iterate over the request ring can
1373          * encounter a dangling SCSI command pointer.
1374          */
1375         req->scmnd = NULL;
1376
1377         spin_lock_irqsave(&target->lock, flags);
1378         list_add(&req->list, &target->free_reqs);
1379
1380 err_unlock:
1381         spin_unlock_irqrestore(&target->lock, flags);
1382
1383 err:
1384         return SCSI_MLQUEUE_HOST_BUSY;
1385 }
1386
1387 static int srp_alloc_iu_bufs(struct srp_target_port *target)
1388 {
1389         int i;
1390
1391         for (i = 0; i < SRP_RQ_SIZE; ++i) {
1392                 target->rx_ring[i] = srp_alloc_iu(target->srp_host,
1393                                                   target->max_ti_iu_len,
1394                                                   GFP_KERNEL, DMA_FROM_DEVICE);
1395                 if (!target->rx_ring[i])
1396                         goto err;
1397         }
1398
1399         for (i = 0; i < SRP_SQ_SIZE; ++i) {
1400                 target->tx_ring[i] = srp_alloc_iu(target->srp_host,
1401                                                   target->max_iu_len,
1402                                                   GFP_KERNEL, DMA_TO_DEVICE);
1403                 if (!target->tx_ring[i])
1404                         goto err;
1405
1406                 list_add(&target->tx_ring[i]->list, &target->free_tx);
1407         }
1408
1409         return 0;
1410
1411 err:
1412         for (i = 0; i < SRP_RQ_SIZE; ++i) {
1413                 srp_free_iu(target->srp_host, target->rx_ring[i]);
1414                 target->rx_ring[i] = NULL;
1415         }
1416
1417         for (i = 0; i < SRP_SQ_SIZE; ++i) {
1418                 srp_free_iu(target->srp_host, target->tx_ring[i]);
1419                 target->tx_ring[i] = NULL;
1420         }
1421
1422         return -ENOMEM;
1423 }
1424
1425 static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
1426                                struct srp_login_rsp *lrsp,
1427                                struct srp_target_port *target)
1428 {
1429         struct ib_qp_attr *qp_attr = NULL;
1430         int attr_mask = 0;
1431         int ret;
1432         int i;
1433
1434         if (lrsp->opcode == SRP_LOGIN_RSP) {
1435                 target->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
1436                 target->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
1437
1438                 /*
1439                  * Reserve credits for task management so we don't
1440                  * bounce requests back to the SCSI mid-layer.
1441                  */
1442                 target->scsi_host->can_queue
1443                         = min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1444                               target->scsi_host->can_queue);
1445         } else {
1446                 shost_printk(KERN_WARNING, target->scsi_host,
1447                              PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
1448                 ret = -ECONNRESET;
1449                 goto error;
1450         }
1451
1452         if (!target->rx_ring[0]) {
1453                 ret = srp_alloc_iu_bufs(target);
1454                 if (ret)
1455                         goto error;
1456         }
1457
1458         ret = -ENOMEM;
1459         qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1460         if (!qp_attr)
1461                 goto error;
1462
1463         qp_attr->qp_state = IB_QPS_RTR;
1464         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1465         if (ret)
1466                 goto error_free;
1467
1468         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1469         if (ret)
1470                 goto error_free;
1471
1472         for (i = 0; i < SRP_RQ_SIZE; i++) {
1473                 struct srp_iu *iu = target->rx_ring[i];
1474                 ret = srp_post_recv(target, iu);
1475                 if (ret)
1476                         goto error_free;
1477         }
1478
1479         qp_attr->qp_state = IB_QPS_RTS;
1480         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1481         if (ret)
1482                 goto error_free;
1483
1484         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1485         if (ret)
1486                 goto error_free;
1487
1488         ret = ib_send_cm_rtu(cm_id, NULL, 0);
1489
1490 error_free:
1491         kfree(qp_attr);
1492
1493 error:
1494         target->status = ret;
1495 }
1496
1497 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
1498                                struct ib_cm_event *event,
1499                                struct srp_target_port *target)
1500 {
1501         struct Scsi_Host *shost = target->scsi_host;
1502         struct ib_class_port_info *cpi;
1503         int opcode;
1504
1505         switch (event->param.rej_rcvd.reason) {
1506         case IB_CM_REJ_PORT_CM_REDIRECT:
1507                 cpi = event->param.rej_rcvd.ari;
1508                 target->path.dlid = cpi->redirect_lid;
1509                 target->path.pkey = cpi->redirect_pkey;
1510                 cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
1511                 memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
1512
1513                 target->status = target->path.dlid ?
1514                         SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
1515                 break;
1516
1517         case IB_CM_REJ_PORT_REDIRECT:
1518                 if (srp_target_is_topspin(target)) {
1519                         /*
1520                          * Topspin/Cisco SRP gateways incorrectly send
1521                          * reject reason code 25 when they mean 24
1522                          * (port redirect).
1523                          */
1524                         memcpy(target->path.dgid.raw,
1525                                event->param.rej_rcvd.ari, 16);
1526
1527                         shost_printk(KERN_DEBUG, shost,
1528                                      PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1529                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1530                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1531
1532                         target->status = SRP_PORT_REDIRECT;
1533                 } else {
1534                         shost_printk(KERN_WARNING, shost,
1535                                      "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1536                         target->status = -ECONNRESET;
1537                 }
1538                 break;
1539
1540         case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1541                 shost_printk(KERN_WARNING, shost,
1542                             "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1543                 target->status = -ECONNRESET;
1544                 break;
1545
1546         case IB_CM_REJ_CONSUMER_DEFINED:
1547                 opcode = *(u8 *) event->private_data;
1548                 if (opcode == SRP_LOGIN_REJ) {
1549                         struct srp_login_rej *rej = event->private_data;
1550                         u32 reason = be32_to_cpu(rej->reason);
1551
1552                         if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1553                                 shost_printk(KERN_WARNING, shost,
1554                                              PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1555                         else
1556                                 shost_printk(KERN_WARNING, shost,
1557                                             PFX "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1558                 } else
1559                         shost_printk(KERN_WARNING, shost,
1560                                      "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1561                                      " opcode 0x%02x\n", opcode);
1562                 target->status = -ECONNRESET;
1563                 break;
1564
1565         case IB_CM_REJ_STALE_CONN:
1566                 shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
1567                 target->status = SRP_STALE_CONN;
1568                 break;
1569
1570         default:
1571                 shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
1572                              event->param.rej_rcvd.reason);
1573                 target->status = -ECONNRESET;
1574         }
1575 }
1576
1577 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1578 {
1579         struct srp_target_port *target = cm_id->context;
1580         int comp = 0;
1581
1582         switch (event->event) {
1583         case IB_CM_REQ_ERROR:
1584                 shost_printk(KERN_DEBUG, target->scsi_host,
1585                              PFX "Sending CM REQ failed\n");
1586                 comp = 1;
1587                 target->status = -ECONNRESET;
1588                 break;
1589
1590         case IB_CM_REP_RECEIVED:
1591                 comp = 1;
1592                 srp_cm_rep_handler(cm_id, event->private_data, target);
1593                 break;
1594
1595         case IB_CM_REJ_RECEIVED:
1596                 shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
1597                 comp = 1;
1598
1599                 srp_cm_rej_handler(cm_id, event, target);
1600                 break;
1601
1602         case IB_CM_DREQ_RECEIVED:
1603                 shost_printk(KERN_WARNING, target->scsi_host,
1604                              PFX "DREQ received - connection closed\n");
1605                 if (ib_send_cm_drep(cm_id, NULL, 0))
1606                         shost_printk(KERN_ERR, target->scsi_host,
1607                                      PFX "Sending CM DREP failed\n");
1608                 break;
1609
1610         case IB_CM_TIMEWAIT_EXIT:
1611                 shost_printk(KERN_ERR, target->scsi_host,
1612                              PFX "connection closed\n");
1613
1614                 comp = 1;
1615                 target->status = 0;
1616                 break;
1617
1618         case IB_CM_MRA_RECEIVED:
1619         case IB_CM_DREQ_ERROR:
1620         case IB_CM_DREP_RECEIVED:
1621                 break;
1622
1623         default:
1624                 shost_printk(KERN_WARNING, target->scsi_host,
1625                              PFX "Unhandled CM event %d\n", event->event);
1626                 break;
1627         }
1628
1629         if (comp)
1630                 complete(&target->done);
1631
1632         return 0;
1633 }
1634
1635 static int srp_send_tsk_mgmt(struct srp_target_port *target,
1636                              u64 req_tag, unsigned int lun, u8 func)
1637 {
1638         struct ib_device *dev = target->srp_host->srp_dev->dev;
1639         struct srp_iu *iu;
1640         struct srp_tsk_mgmt *tsk_mgmt;
1641
1642         if (target->state == SRP_TARGET_DEAD ||
1643             target->state == SRP_TARGET_REMOVED)
1644                 return -1;
1645
1646         init_completion(&target->tsk_mgmt_done);
1647
1648         spin_lock_irq(&target->lock);
1649         iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT);
1650         spin_unlock_irq(&target->lock);
1651
1652         if (!iu)
1653                 return -1;
1654
1655         ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
1656                                    DMA_TO_DEVICE);
1657         tsk_mgmt = iu->buf;
1658         memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1659
1660         tsk_mgmt->opcode        = SRP_TSK_MGMT;
1661         tsk_mgmt->lun           = cpu_to_be64((u64) lun << 48);
1662         tsk_mgmt->tag           = req_tag | SRP_TAG_TSK_MGMT;
1663         tsk_mgmt->tsk_mgmt_func = func;
1664         tsk_mgmt->task_tag      = req_tag;
1665
1666         ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
1667                                       DMA_TO_DEVICE);
1668         if (srp_post_send(target, iu, sizeof *tsk_mgmt)) {
1669                 srp_put_tx_iu(target, iu, SRP_IU_TSK_MGMT);
1670                 return -1;
1671         }
1672
1673         if (!wait_for_completion_timeout(&target->tsk_mgmt_done,
1674                                          msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1675                 return -1;
1676
1677         return 0;
1678 }
1679
1680 static int srp_abort(struct scsi_cmnd *scmnd)
1681 {
1682         struct srp_target_port *target = host_to_target(scmnd->device->host);
1683         struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
1684
1685         shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
1686
1687         if (!req || target->qp_in_error || !srp_claim_req(target, req, scmnd))
1688                 return FAILED;
1689         srp_send_tsk_mgmt(target, req->index, scmnd->device->lun,
1690                           SRP_TSK_ABORT_TASK);
1691         srp_free_req(target, req, scmnd, 0);
1692         scmnd->result = DID_ABORT << 16;
1693         scmnd->scsi_done(scmnd);
1694
1695         return SUCCESS;
1696 }
1697
1698 static int srp_reset_device(struct scsi_cmnd *scmnd)
1699 {
1700         struct srp_target_port *target = host_to_target(scmnd->device->host);
1701         int i;
1702
1703         shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
1704
1705         if (target->qp_in_error)
1706                 return FAILED;
1707         if (srp_send_tsk_mgmt(target, SRP_TAG_NO_REQ, scmnd->device->lun,
1708                               SRP_TSK_LUN_RESET))
1709                 return FAILED;
1710         if (target->tsk_mgmt_status)
1711                 return FAILED;
1712
1713         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
1714                 struct srp_request *req = &target->req_ring[i];
1715                 if (req->scmnd && req->scmnd->device == scmnd->device)
1716                         srp_reset_req(target, req);
1717         }
1718
1719         return SUCCESS;
1720 }
1721
1722 static int srp_reset_host(struct scsi_cmnd *scmnd)
1723 {
1724         struct srp_target_port *target = host_to_target(scmnd->device->host);
1725         int ret = FAILED;
1726
1727         shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
1728
1729         if (!srp_reconnect_target(target))
1730                 ret = SUCCESS;
1731
1732         return ret;
1733 }
1734
1735 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
1736                            char *buf)
1737 {
1738         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1739
1740         if (target->state == SRP_TARGET_DEAD ||
1741             target->state == SRP_TARGET_REMOVED)
1742                 return -ENODEV;
1743
1744         return sprintf(buf, "0x%016llx\n",
1745                        (unsigned long long) be64_to_cpu(target->id_ext));
1746 }
1747
1748 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
1749                              char *buf)
1750 {
1751         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1752
1753         if (target->state == SRP_TARGET_DEAD ||
1754             target->state == SRP_TARGET_REMOVED)
1755                 return -ENODEV;
1756
1757         return sprintf(buf, "0x%016llx\n",
1758                        (unsigned long long) be64_to_cpu(target->ioc_guid));
1759 }
1760
1761 static ssize_t show_service_id(struct device *dev,
1762                                struct device_attribute *attr, char *buf)
1763 {
1764         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1765
1766         if (target->state == SRP_TARGET_DEAD ||
1767             target->state == SRP_TARGET_REMOVED)
1768                 return -ENODEV;
1769
1770         return sprintf(buf, "0x%016llx\n",
1771                        (unsigned long long) be64_to_cpu(target->service_id));
1772 }
1773
1774 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
1775                          char *buf)
1776 {
1777         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1778
1779         if (target->state == SRP_TARGET_DEAD ||
1780             target->state == SRP_TARGET_REMOVED)
1781                 return -ENODEV;
1782
1783         return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1784 }
1785
1786 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
1787                          char *buf)
1788 {
1789         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1790
1791         if (target->state == SRP_TARGET_DEAD ||
1792             target->state == SRP_TARGET_REMOVED)
1793                 return -ENODEV;
1794
1795         return sprintf(buf, "%pI6\n", target->path.dgid.raw);
1796 }
1797
1798 static ssize_t show_orig_dgid(struct device *dev,
1799                               struct device_attribute *attr, char *buf)
1800 {
1801         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1802
1803         if (target->state == SRP_TARGET_DEAD ||
1804             target->state == SRP_TARGET_REMOVED)
1805                 return -ENODEV;
1806
1807         return sprintf(buf, "%pI6\n", target->orig_dgid);
1808 }
1809
1810 static ssize_t show_req_lim(struct device *dev,
1811                             struct device_attribute *attr, char *buf)
1812 {
1813         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1814
1815         if (target->state == SRP_TARGET_DEAD ||
1816             target->state == SRP_TARGET_REMOVED)
1817                 return -ENODEV;
1818
1819         return sprintf(buf, "%d\n", target->req_lim);
1820 }
1821
1822 static ssize_t show_zero_req_lim(struct device *dev,
1823                                  struct device_attribute *attr, char *buf)
1824 {
1825         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1826
1827         if (target->state == SRP_TARGET_DEAD ||
1828             target->state == SRP_TARGET_REMOVED)
1829                 return -ENODEV;
1830
1831         return sprintf(buf, "%d\n", target->zero_req_lim);
1832 }
1833
1834 static ssize_t show_local_ib_port(struct device *dev,
1835                                   struct device_attribute *attr, char *buf)
1836 {
1837         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1838
1839         return sprintf(buf, "%d\n", target->srp_host->port);
1840 }
1841
1842 static ssize_t show_local_ib_device(struct device *dev,
1843                                     struct device_attribute *attr, char *buf)
1844 {
1845         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1846
1847         return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
1848 }
1849
1850 static ssize_t show_cmd_sg_entries(struct device *dev,
1851                                    struct device_attribute *attr, char *buf)
1852 {
1853         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1854
1855         return sprintf(buf, "%u\n", target->cmd_sg_cnt);
1856 }
1857
1858 static ssize_t show_allow_ext_sg(struct device *dev,
1859                                  struct device_attribute *attr, char *buf)
1860 {
1861         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1862
1863         return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
1864 }
1865
1866 static DEVICE_ATTR(id_ext,          S_IRUGO, show_id_ext,          NULL);
1867 static DEVICE_ATTR(ioc_guid,        S_IRUGO, show_ioc_guid,        NULL);
1868 static DEVICE_ATTR(service_id,      S_IRUGO, show_service_id,      NULL);
1869 static DEVICE_ATTR(pkey,            S_IRUGO, show_pkey,            NULL);
1870 static DEVICE_ATTR(dgid,            S_IRUGO, show_dgid,            NULL);
1871 static DEVICE_ATTR(orig_dgid,       S_IRUGO, show_orig_dgid,       NULL);
1872 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
1873 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,    NULL);
1874 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
1875 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
1876 static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
1877 static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
1878
1879 static struct device_attribute *srp_host_attrs[] = {
1880         &dev_attr_id_ext,
1881         &dev_attr_ioc_guid,
1882         &dev_attr_service_id,
1883         &dev_attr_pkey,
1884         &dev_attr_dgid,
1885         &dev_attr_orig_dgid,
1886         &dev_attr_req_lim,
1887         &dev_attr_zero_req_lim,
1888         &dev_attr_local_ib_port,
1889         &dev_attr_local_ib_device,
1890         &dev_attr_cmd_sg_entries,
1891         &dev_attr_allow_ext_sg,
1892         NULL
1893 };
1894
1895 static struct scsi_host_template srp_template = {
1896         .module                         = THIS_MODULE,
1897         .name                           = "InfiniBand SRP initiator",
1898         .proc_name                      = DRV_NAME,
1899         .info                           = srp_target_info,
1900         .queuecommand                   = srp_queuecommand,
1901         .eh_abort_handler               = srp_abort,
1902         .eh_device_reset_handler        = srp_reset_device,
1903         .eh_host_reset_handler          = srp_reset_host,
1904         .sg_tablesize                   = SRP_DEF_SG_TABLESIZE,
1905         .can_queue                      = SRP_CMD_SQ_SIZE,
1906         .this_id                        = -1,
1907         .cmd_per_lun                    = SRP_CMD_SQ_SIZE,
1908         .use_clustering                 = ENABLE_CLUSTERING,
1909         .shost_attrs                    = srp_host_attrs
1910 };
1911
1912 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1913 {
1914         struct srp_rport_identifiers ids;
1915         struct srp_rport *rport;
1916
1917         sprintf(target->target_name, "SRP.T10:%016llX",
1918                  (unsigned long long) be64_to_cpu(target->id_ext));
1919
1920         if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
1921                 return -ENODEV;
1922
1923         memcpy(ids.port_id, &target->id_ext, 8);
1924         memcpy(ids.port_id + 8, &target->ioc_guid, 8);
1925         ids.roles = SRP_RPORT_ROLE_TARGET;
1926         rport = srp_rport_add(target->scsi_host, &ids);
1927         if (IS_ERR(rport)) {
1928                 scsi_remove_host(target->scsi_host);
1929                 return PTR_ERR(rport);
1930         }
1931
1932         spin_lock(&host->target_lock);
1933         list_add_tail(&target->list, &host->target_list);
1934         spin_unlock(&host->target_lock);
1935
1936         target->state = SRP_TARGET_LIVE;
1937
1938         scsi_scan_target(&target->scsi_host->shost_gendev,
1939                          0, target->scsi_id, SCAN_WILD_CARD, 0);
1940
1941         return 0;
1942 }
1943
1944 static void srp_release_dev(struct device *dev)
1945 {
1946         struct srp_host *host =
1947                 container_of(dev, struct srp_host, dev);
1948
1949         complete(&host->released);
1950 }
1951
1952 static struct class srp_class = {
1953         .name    = "infiniband_srp",
1954         .dev_release = srp_release_dev
1955 };
1956
1957 /*
1958  * Target ports are added by writing
1959  *
1960  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
1961  *     pkey=<P_Key>,service_id=<service ID>
1962  *
1963  * to the add_target sysfs attribute.
1964  */
1965 enum {
1966         SRP_OPT_ERR             = 0,
1967         SRP_OPT_ID_EXT          = 1 << 0,
1968         SRP_OPT_IOC_GUID        = 1 << 1,
1969         SRP_OPT_DGID            = 1 << 2,
1970         SRP_OPT_PKEY            = 1 << 3,
1971         SRP_OPT_SERVICE_ID      = 1 << 4,
1972         SRP_OPT_MAX_SECT        = 1 << 5,
1973         SRP_OPT_MAX_CMD_PER_LUN = 1 << 6,
1974         SRP_OPT_IO_CLASS        = 1 << 7,
1975         SRP_OPT_INITIATOR_EXT   = 1 << 8,
1976         SRP_OPT_CMD_SG_ENTRIES  = 1 << 9,
1977         SRP_OPT_ALLOW_EXT_SG    = 1 << 10,
1978         SRP_OPT_SG_TABLESIZE    = 1 << 11,
1979         SRP_OPT_ALL             = (SRP_OPT_ID_EXT       |
1980                                    SRP_OPT_IOC_GUID     |
1981                                    SRP_OPT_DGID         |
1982                                    SRP_OPT_PKEY         |
1983                                    SRP_OPT_SERVICE_ID),
1984 };
1985
1986 static const match_table_t srp_opt_tokens = {
1987         { SRP_OPT_ID_EXT,               "id_ext=%s"             },
1988         { SRP_OPT_IOC_GUID,             "ioc_guid=%s"           },
1989         { SRP_OPT_DGID,                 "dgid=%s"               },
1990         { SRP_OPT_PKEY,                 "pkey=%x"               },
1991         { SRP_OPT_SERVICE_ID,           "service_id=%s"         },
1992         { SRP_OPT_MAX_SECT,             "max_sect=%d"           },
1993         { SRP_OPT_MAX_CMD_PER_LUN,      "max_cmd_per_lun=%d"    },
1994         { SRP_OPT_IO_CLASS,             "io_class=%x"           },
1995         { SRP_OPT_INITIATOR_EXT,        "initiator_ext=%s"      },
1996         { SRP_OPT_CMD_SG_ENTRIES,       "cmd_sg_entries=%u"     },
1997         { SRP_OPT_ALLOW_EXT_SG,         "allow_ext_sg=%u"       },
1998         { SRP_OPT_SG_TABLESIZE,         "sg_tablesize=%u"       },
1999         { SRP_OPT_ERR,                  NULL                    }
2000 };
2001
2002 static int srp_parse_options(const char *buf, struct srp_target_port *target)
2003 {
2004         char *options, *sep_opt;
2005         char *p;
2006         char dgid[3];
2007         substring_t args[MAX_OPT_ARGS];
2008         int opt_mask = 0;
2009         int token;
2010         int ret = -EINVAL;
2011         int i;
2012
2013         options = kstrdup(buf, GFP_KERNEL);
2014         if (!options)
2015                 return -ENOMEM;
2016
2017         sep_opt = options;
2018         while ((p = strsep(&sep_opt, ",")) != NULL) {
2019                 if (!*p)
2020                         continue;
2021
2022                 token = match_token(p, srp_opt_tokens, args);
2023                 opt_mask |= token;
2024
2025                 switch (token) {
2026                 case SRP_OPT_ID_EXT:
2027                         p = match_strdup(args);
2028                         if (!p) {
2029                                 ret = -ENOMEM;
2030                                 goto out;
2031                         }
2032                         target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2033                         kfree(p);
2034                         break;
2035
2036                 case SRP_OPT_IOC_GUID:
2037                         p = match_strdup(args);
2038                         if (!p) {
2039                                 ret = -ENOMEM;
2040                                 goto out;
2041                         }
2042                         target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
2043                         kfree(p);
2044                         break;
2045
2046                 case SRP_OPT_DGID:
2047                         p = match_strdup(args);
2048                         if (!p) {
2049                                 ret = -ENOMEM;
2050                                 goto out;
2051                         }
2052                         if (strlen(p) != 32) {
2053                                 printk(KERN_WARNING PFX "bad dest GID parameter '%s'\n", p);
2054                                 kfree(p);
2055                                 goto out;
2056                         }
2057
2058                         for (i = 0; i < 16; ++i) {
2059                                 strlcpy(dgid, p + i * 2, 3);
2060                                 target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
2061                         }
2062                         kfree(p);
2063                         memcpy(target->orig_dgid, target->path.dgid.raw, 16);
2064                         break;
2065
2066                 case SRP_OPT_PKEY:
2067                         if (match_hex(args, &token)) {
2068                                 printk(KERN_WARNING PFX "bad P_Key parameter '%s'\n", p);
2069                                 goto out;
2070                         }
2071                         target->path.pkey = cpu_to_be16(token);
2072                         break;
2073
2074                 case SRP_OPT_SERVICE_ID:
2075                         p = match_strdup(args);
2076                         if (!p) {
2077                                 ret = -ENOMEM;
2078                                 goto out;
2079                         }
2080                         target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
2081                         target->path.service_id = target->service_id;
2082                         kfree(p);
2083                         break;
2084
2085                 case SRP_OPT_MAX_SECT:
2086                         if (match_int(args, &token)) {
2087                                 printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
2088                                 goto out;
2089                         }
2090                         target->scsi_host->max_sectors = token;
2091                         break;
2092
2093                 case SRP_OPT_MAX_CMD_PER_LUN:
2094                         if (match_int(args, &token)) {
2095                                 printk(KERN_WARNING PFX "bad max cmd_per_lun parameter '%s'\n", p);
2096                                 goto out;
2097                         }
2098                         target->scsi_host->cmd_per_lun = min(token, SRP_CMD_SQ_SIZE);
2099                         break;
2100
2101                 case SRP_OPT_IO_CLASS:
2102                         if (match_hex(args, &token)) {
2103                                 printk(KERN_WARNING PFX "bad  IO class parameter '%s' \n", p);
2104                                 goto out;
2105                         }
2106                         if (token != SRP_REV10_IB_IO_CLASS &&
2107                             token != SRP_REV16A_IB_IO_CLASS) {
2108                                 printk(KERN_WARNING PFX "unknown IO class parameter value"
2109                                        " %x specified (use %x or %x).\n",
2110                                        token, SRP_REV10_IB_IO_CLASS, SRP_REV16A_IB_IO_CLASS);
2111                                 goto out;
2112                         }
2113                         target->io_class = token;
2114                         break;
2115
2116                 case SRP_OPT_INITIATOR_EXT:
2117                         p = match_strdup(args);
2118                         if (!p) {
2119                                 ret = -ENOMEM;
2120                                 goto out;
2121                         }
2122                         target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2123                         kfree(p);
2124                         break;
2125
2126                 case SRP_OPT_CMD_SG_ENTRIES:
2127                         if (match_int(args, &token) || token < 1 || token > 255) {
2128                                 printk(KERN_WARNING PFX "bad max cmd_sg_entries parameter '%s'\n", p);
2129                                 goto out;
2130                         }
2131                         target->cmd_sg_cnt = token;
2132                         break;
2133
2134                 case SRP_OPT_ALLOW_EXT_SG:
2135                         if (match_int(args, &token)) {
2136                                 printk(KERN_WARNING PFX "bad allow_ext_sg parameter '%s'\n", p);
2137                                 goto out;
2138                         }
2139                         target->allow_ext_sg = !!token;
2140                         break;
2141
2142                 case SRP_OPT_SG_TABLESIZE:
2143                         if (match_int(args, &token) || token < 1 ||
2144                                         token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
2145                                 printk(KERN_WARNING PFX "bad max sg_tablesize parameter '%s'\n", p);
2146                                 goto out;
2147                         }
2148                         target->sg_tablesize = token;
2149                         break;
2150
2151                 default:
2152                         printk(KERN_WARNING PFX "unknown parameter or missing value "
2153                                "'%s' in target creation request\n", p);
2154                         goto out;
2155                 }
2156         }
2157
2158         if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
2159                 ret = 0;
2160         else
2161                 for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
2162                         if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
2163                             !(srp_opt_tokens[i].token & opt_mask))
2164                                 printk(KERN_WARNING PFX "target creation request is "
2165                                        "missing parameter '%s'\n",
2166                                        srp_opt_tokens[i].pattern);
2167
2168 out:
2169         kfree(options);
2170         return ret;
2171 }
2172
2173 static ssize_t srp_create_target(struct device *dev,
2174                                  struct device_attribute *attr,
2175                                  const char *buf, size_t count)
2176 {
2177         struct srp_host *host =
2178                 container_of(dev, struct srp_host, dev);
2179         struct Scsi_Host *target_host;
2180         struct srp_target_port *target;
2181         struct ib_device *ibdev = host->srp_dev->dev;
2182         dma_addr_t dma_addr;
2183         int i, ret;
2184
2185         target_host = scsi_host_alloc(&srp_template,
2186                                       sizeof (struct srp_target_port));
2187         if (!target_host)
2188                 return -ENOMEM;
2189
2190         target_host->transportt  = ib_srp_transport_template;
2191         target_host->max_channel = 0;
2192         target_host->max_id      = 1;
2193         target_host->max_lun     = SRP_MAX_LUN;
2194         target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
2195
2196         target = host_to_target(target_host);
2197
2198         target->io_class        = SRP_REV16A_IB_IO_CLASS;
2199         target->scsi_host       = target_host;
2200         target->srp_host        = host;
2201         target->lkey            = host->srp_dev->mr->lkey;
2202         target->rkey            = host->srp_dev->mr->rkey;
2203         target->cmd_sg_cnt      = cmd_sg_entries;
2204         target->sg_tablesize    = indirect_sg_entries ? : cmd_sg_entries;
2205         target->allow_ext_sg    = allow_ext_sg;
2206
2207         ret = srp_parse_options(buf, target);
2208         if (ret)
2209                 goto err;
2210
2211         if (!host->srp_dev->fmr_pool && !target->allow_ext_sg &&
2212                                 target->cmd_sg_cnt < target->sg_tablesize) {
2213                 printk(KERN_WARNING PFX "No FMR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
2214                 target->sg_tablesize = target->cmd_sg_cnt;
2215         }
2216
2217         target_host->sg_tablesize = target->sg_tablesize;
2218         target->indirect_size = target->sg_tablesize *
2219                                 sizeof (struct srp_direct_buf);
2220         target->max_iu_len = sizeof (struct srp_cmd) +
2221                              sizeof (struct srp_indirect_buf) +
2222                              target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
2223
2224         spin_lock_init(&target->lock);
2225         INIT_LIST_HEAD(&target->free_tx);
2226         INIT_LIST_HEAD(&target->free_reqs);
2227         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
2228                 struct srp_request *req = &target->req_ring[i];
2229
2230                 req->fmr_list = kmalloc(target->cmd_sg_cnt * sizeof (void *),
2231                                         GFP_KERNEL);
2232                 req->map_page = kmalloc(SRP_FMR_SIZE * sizeof (void *),
2233                                         GFP_KERNEL);
2234                 req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
2235                 if (!req->fmr_list || !req->map_page || !req->indirect_desc)
2236                         goto err_free_mem;
2237
2238                 dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
2239                                              target->indirect_size,
2240                                              DMA_TO_DEVICE);
2241                 if (ib_dma_mapping_error(ibdev, dma_addr))
2242                         goto err_free_mem;
2243
2244                 req->indirect_dma_addr = dma_addr;
2245                 req->index = i;
2246                 list_add_tail(&req->list, &target->free_reqs);
2247         }
2248
2249         ib_query_gid(ibdev, host->port, 0, &target->path.sgid);
2250
2251         shost_printk(KERN_DEBUG, target->scsi_host, PFX
2252                      "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
2253                      "service_id %016llx dgid %pI6\n",
2254                (unsigned long long) be64_to_cpu(target->id_ext),
2255                (unsigned long long) be64_to_cpu(target->ioc_guid),
2256                be16_to_cpu(target->path.pkey),
2257                (unsigned long long) be64_to_cpu(target->service_id),
2258                target->path.dgid.raw);
2259
2260         ret = srp_create_target_ib(target);
2261         if (ret)
2262                 goto err_free_mem;
2263
2264         ret = srp_new_cm_id(target);
2265         if (ret)
2266                 goto err_free_ib;
2267
2268         target->qp_in_error = 0;
2269         ret = srp_connect_target(target);
2270         if (ret) {
2271                 shost_printk(KERN_ERR, target->scsi_host,
2272                              PFX "Connection failed\n");
2273                 goto err_cm_id;
2274         }
2275
2276         ret = srp_add_target(host, target);
2277         if (ret)
2278                 goto err_disconnect;
2279
2280         return count;
2281
2282 err_disconnect:
2283         srp_disconnect_target(target);
2284
2285 err_cm_id:
2286         ib_destroy_cm_id(target->cm_id);
2287
2288 err_free_ib:
2289         srp_free_target_ib(target);
2290
2291 err_free_mem:
2292         srp_free_req_data(target);
2293
2294 err:
2295         scsi_host_put(target_host);
2296
2297         return ret;
2298 }
2299
2300 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
2301
2302 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
2303                           char *buf)
2304 {
2305         struct srp_host *host = container_of(dev, struct srp_host, dev);
2306
2307         return sprintf(buf, "%s\n", host->srp_dev->dev->name);
2308 }
2309
2310 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
2311
2312 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
2313                          char *buf)
2314 {
2315         struct srp_host *host = container_of(dev, struct srp_host, dev);
2316
2317         return sprintf(buf, "%d\n", host->port);
2318 }
2319
2320 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
2321
2322 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
2323 {
2324         struct srp_host *host;
2325
2326         host = kzalloc(sizeof *host, GFP_KERNEL);
2327         if (!host)
2328                 return NULL;
2329
2330         INIT_LIST_HEAD(&host->target_list);
2331         spin_lock_init(&host->target_lock);
2332         init_completion(&host->released);
2333         host->srp_dev = device;
2334         host->port = port;
2335
2336         host->dev.class = &srp_class;
2337         host->dev.parent = device->dev->dma_device;
2338         dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
2339
2340         if (device_register(&host->dev))
2341                 goto free_host;
2342         if (device_create_file(&host->dev, &dev_attr_add_target))
2343                 goto err_class;
2344         if (device_create_file(&host->dev, &dev_attr_ibdev))
2345                 goto err_class;
2346         if (device_create_file(&host->dev, &dev_attr_port))
2347                 goto err_class;
2348
2349         return host;
2350
2351 err_class:
2352         device_unregister(&host->dev);
2353
2354 free_host:
2355         kfree(host);
2356
2357         return NULL;
2358 }
2359
2360 static void srp_add_one(struct ib_device *device)
2361 {
2362         struct srp_device *srp_dev;
2363         struct ib_device_attr *dev_attr;
2364         struct ib_fmr_pool_param fmr_param;
2365         struct srp_host *host;
2366         int max_pages_per_fmr, fmr_page_shift, s, e, p;
2367
2368         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
2369         if (!dev_attr)
2370                 return;
2371
2372         if (ib_query_device(device, dev_attr)) {
2373                 printk(KERN_WARNING PFX "Query device failed for %s\n",
2374                        device->name);
2375                 goto free_attr;
2376         }
2377
2378         srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
2379         if (!srp_dev)
2380                 goto free_attr;
2381
2382         /*
2383          * Use the smallest page size supported by the HCA, down to a
2384          * minimum of 4096 bytes. We're unlikely to build large sglists
2385          * out of smaller entries.
2386          */
2387         fmr_page_shift          = max(12, ffs(dev_attr->page_size_cap) - 1);
2388         srp_dev->fmr_page_size  = 1 << fmr_page_shift;
2389         srp_dev->fmr_page_mask  = ~((u64) srp_dev->fmr_page_size - 1);
2390         srp_dev->fmr_max_size   = srp_dev->fmr_page_size * SRP_FMR_SIZE;
2391
2392         INIT_LIST_HEAD(&srp_dev->dev_list);
2393
2394         srp_dev->dev = device;
2395         srp_dev->pd  = ib_alloc_pd(device);
2396         if (IS_ERR(srp_dev->pd))
2397                 goto free_dev;
2398
2399         srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
2400                                     IB_ACCESS_LOCAL_WRITE |
2401                                     IB_ACCESS_REMOTE_READ |
2402                                     IB_ACCESS_REMOTE_WRITE);
2403         if (IS_ERR(srp_dev->mr))
2404                 goto err_pd;
2405
2406         for (max_pages_per_fmr = SRP_FMR_SIZE;
2407                         max_pages_per_fmr >= SRP_FMR_MIN_SIZE;
2408                         max_pages_per_fmr /= 2, srp_dev->fmr_max_size /= 2) {
2409                 memset(&fmr_param, 0, sizeof fmr_param);
2410                 fmr_param.pool_size         = SRP_FMR_POOL_SIZE;
2411                 fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
2412                 fmr_param.cache             = 1;
2413                 fmr_param.max_pages_per_fmr = max_pages_per_fmr;
2414                 fmr_param.page_shift        = fmr_page_shift;
2415                 fmr_param.access            = (IB_ACCESS_LOCAL_WRITE |
2416                                                IB_ACCESS_REMOTE_WRITE |
2417                                                IB_ACCESS_REMOTE_READ);
2418
2419                 srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
2420                 if (!IS_ERR(srp_dev->fmr_pool))
2421                         break;
2422         }
2423
2424         if (IS_ERR(srp_dev->fmr_pool))
2425                 srp_dev->fmr_pool = NULL;
2426
2427         if (device->node_type == RDMA_NODE_IB_SWITCH) {
2428                 s = 0;
2429                 e = 0;
2430         } else {
2431                 s = 1;
2432                 e = device->phys_port_cnt;
2433         }
2434
2435         for (p = s; p <= e; ++p) {
2436                 host = srp_add_port(srp_dev, p);
2437                 if (host)
2438                         list_add_tail(&host->list, &srp_dev->dev_list);
2439         }
2440
2441         ib_set_client_data(device, &srp_client, srp_dev);
2442
2443         goto free_attr;
2444
2445 err_pd:
2446         ib_dealloc_pd(srp_dev->pd);
2447
2448 free_dev:
2449         kfree(srp_dev);
2450
2451 free_attr:
2452         kfree(dev_attr);
2453 }
2454
2455 static void srp_remove_one(struct ib_device *device)
2456 {
2457         struct srp_device *srp_dev;
2458         struct srp_host *host, *tmp_host;
2459         LIST_HEAD(target_list);
2460         struct srp_target_port *target, *tmp_target;
2461
2462         srp_dev = ib_get_client_data(device, &srp_client);
2463
2464         list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
2465                 device_unregister(&host->dev);
2466                 /*
2467                  * Wait for the sysfs entry to go away, so that no new
2468                  * target ports can be created.
2469                  */
2470                 wait_for_completion(&host->released);
2471
2472                 /*
2473                  * Mark all target ports as removed, so we stop queueing
2474                  * commands and don't try to reconnect.
2475                  */
2476                 spin_lock(&host->target_lock);
2477                 list_for_each_entry(target, &host->target_list, list) {
2478                         spin_lock_irq(&target->lock);
2479                         target->state = SRP_TARGET_REMOVED;
2480                         spin_unlock_irq(&target->lock);
2481                 }
2482                 spin_unlock(&host->target_lock);
2483
2484                 /*
2485                  * Wait for any reconnection tasks that may have
2486                  * started before we marked our target ports as
2487                  * removed, and any target port removal tasks.
2488                  */
2489                 flush_workqueue(ib_wq);
2490
2491                 list_for_each_entry_safe(target, tmp_target,
2492                                          &host->target_list, list) {
2493                         srp_remove_host(target->scsi_host);
2494                         scsi_remove_host(target->scsi_host);
2495                         srp_disconnect_target(target);
2496                         ib_destroy_cm_id(target->cm_id);
2497                         srp_free_target_ib(target);
2498                         srp_free_req_data(target);
2499                         scsi_host_put(target->scsi_host);
2500                 }
2501
2502                 kfree(host);
2503         }
2504
2505         if (srp_dev->fmr_pool)
2506                 ib_destroy_fmr_pool(srp_dev->fmr_pool);
2507         ib_dereg_mr(srp_dev->mr);
2508         ib_dealloc_pd(srp_dev->pd);
2509
2510         kfree(srp_dev);
2511 }
2512
2513 static struct srp_function_template ib_srp_transport_functions = {
2514 };
2515
2516 static int __init srp_init_module(void)
2517 {
2518         int ret;
2519
2520         BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
2521
2522         if (srp_sg_tablesize) {
2523                 printk(KERN_WARNING PFX "srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
2524                 if (!cmd_sg_entries)
2525                         cmd_sg_entries = srp_sg_tablesize;
2526         }
2527
2528         if (!cmd_sg_entries)
2529                 cmd_sg_entries = SRP_DEF_SG_TABLESIZE;
2530
2531         if (cmd_sg_entries > 255) {
2532                 printk(KERN_WARNING PFX "Clamping cmd_sg_entries to 255\n");
2533                 cmd_sg_entries = 255;
2534         }
2535
2536         if (!indirect_sg_entries)
2537                 indirect_sg_entries = cmd_sg_entries;
2538         else if (indirect_sg_entries < cmd_sg_entries) {
2539                 printk(KERN_WARNING PFX "Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n", cmd_sg_entries);
2540                 indirect_sg_entries = cmd_sg_entries;
2541         }
2542
2543         ib_srp_transport_template =
2544                 srp_attach_transport(&ib_srp_transport_functions);
2545         if (!ib_srp_transport_template)
2546                 return -ENOMEM;
2547
2548         ret = class_register(&srp_class);
2549         if (ret) {
2550                 printk(KERN_ERR PFX "couldn't register class infiniband_srp\n");
2551                 srp_release_transport(ib_srp_transport_template);
2552                 return ret;
2553         }
2554
2555         ib_sa_register_client(&srp_sa_client);
2556
2557         ret = ib_register_client(&srp_client);
2558         if (ret) {
2559                 printk(KERN_ERR PFX "couldn't register IB client\n");
2560                 srp_release_transport(ib_srp_transport_template);
2561                 ib_sa_unregister_client(&srp_sa_client);
2562                 class_unregister(&srp_class);
2563                 return ret;
2564         }
2565
2566         return 0;
2567 }
2568
2569 static void __exit srp_cleanup_module(void)
2570 {
2571         ib_unregister_client(&srp_client);
2572         ib_sa_unregister_client(&srp_sa_client);
2573         class_unregister(&srp_class);
2574         srp_release_transport(ib_srp_transport_template);
2575 }
2576
2577 module_init(srp_init_module);
2578 module_exit(srp_cleanup_module);