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 #define pr_fmt(fmt) PFX fmt
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/slab.h>
  38 #include <linux/err.h>
  39 #include <linux/string.h>
  40 #include <linux/parser.h>
  41 #include <linux/random.h>
  42 #include <linux/jiffies.h>
  43
  44 #include <linux/atomic.h>
  45
  46 #include <scsi/scsi.h>
  47 #include <scsi/scsi_device.h>
  48 #include <scsi/scsi_dbg.h>
  49 #include <scsi/srp.h>
  50 #include <scsi/scsi_transport_srp.h>
  51
  52 #include "ib_srp.h"
  53
  54 #define DRV_NAME        "ib_srp"
  55 #define PFX             DRV_NAME ": "
  56 #define DRV_VERSION     "1.0"
  57 #define DRV_RELDATE     "July 1, 2013"
  58
  59 MODULE_AUTHOR("Roland Dreier");
  60 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
  61                    "v" DRV_VERSION " (" DRV_RELDATE ")");
  62 MODULE_LICENSE("Dual BSD/GPL");
  63
  64 static unsigned int srp_sg_tablesize;
  65 static unsigned int cmd_sg_entries;
  66 static unsigned int indirect_sg_entries;
  67 static bool allow_ext_sg;
  68 static int topspin_workarounds = 1;
  69
  70 module_param(srp_sg_tablesize, uint, 0444);
  71 MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
  72
  73 module_param(cmd_sg_entries, uint, 0444);
  74 MODULE_PARM_DESC(cmd_sg_entries,
  75                  "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
  76
  77 module_param(indirect_sg_entries, uint, 0444);
  78 MODULE_PARM_DESC(indirect_sg_entries,
  79                  "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");
  80
  81 module_param(allow_ext_sg, bool, 0444);
  82 MODULE_PARM_DESC(allow_ext_sg,
  83                   "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");
  84
  85 module_param(topspin_workarounds, int, 0444);
  86 MODULE_PARM_DESC(topspin_workarounds,
  87                  "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
  88
  89 static void srp_add_one(struct ib_device *device);
  90 static void srp_remove_one(struct ib_device *device);
  91 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
  92 static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
  93 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
  94
  95 static struct scsi_transport_template *ib_srp_transport_template;
  96
  97 static struct ib_client srp_client = {
  98         .name   = "srp",
  99         .add    = srp_add_one,
 100         .remove = srp_remove_one
 101 };
 102
 103 static struct ib_sa_client srp_sa_client;
 104
 105 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
 106 {
 107         return (struct srp_target_port *) host->hostdata;
 108 }
 109
 110 static const char *srp_target_info(struct Scsi_Host *host)
 111 {
 112         return host_to_target(host)->target_name;
 113 }
 114
 115 static int srp_target_is_topspin(struct srp_target_port *target)
 116 {
 117         static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
 118         static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
 119
 120         return topspin_workarounds &&
 121                 (!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
 122                  !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
 123 }
 124
 125 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
 126                                    gfp_t gfp_mask,
 127                                    enum dma_data_direction direction)
 128 {
 129         struct srp_iu *iu;
 130
 131         iu = kmalloc(sizeof *iu, gfp_mask);
 132         if (!iu)
 133                 goto out;
 134
 135         iu->buf = kzalloc(size, gfp_mask);
 136         if (!iu->buf)
 137                 goto out_free_iu;
 138
 139         iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
 140                                     direction);
 141         if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
 142                 goto out_free_buf;
 143
 144         iu->size      = size;
 145         iu->direction = direction;
 146
 147         return iu;
 148
 149 out_free_buf:
 150         kfree(iu->buf);
 151 out_free_iu:
 152         kfree(iu);
 153 out:
 154         return NULL;
 155 }
 156
 157 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
 158 {
 159         if (!iu)
 160                 return;
 161
 162         ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
 163                             iu->direction);
 164         kfree(iu->buf);
 165         kfree(iu);
 166 }
 167
 168 static void srp_qp_event(struct ib_event *event, void *context)
 169 {
 170         pr_debug("QP event %d\n", event->event);
 171 }
 172
 173 static int srp_init_qp(struct srp_target_port *target,
 174                        struct ib_qp *qp)
 175 {
 176         struct ib_qp_attr *attr;
 177         int ret;
 178
 179         attr = kmalloc(sizeof *attr, GFP_KERNEL);
 180         if (!attr)
 181                 return -ENOMEM;
 182
 183         ret = ib_find_pkey(target->srp_host->srp_dev->dev,
 184                            target->srp_host->port,
 185                            be16_to_cpu(target->path.pkey),
 186                            &attr->pkey_index);
 187         if (ret)
 188                 goto out;
 189
 190         attr->qp_state        = IB_QPS_INIT;
 191         attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
 192                                     IB_ACCESS_REMOTE_WRITE);
 193         attr->port_num        = target->srp_host->port;
 194
 195         ret = ib_modify_qp(qp, attr,
 196                            IB_QP_STATE          |
 197                            IB_QP_PKEY_INDEX     |
 198                            IB_QP_ACCESS_FLAGS   |
 199                            IB_QP_PORT);
 200
 201 out:
 202         kfree(attr);
 203         return ret;
 204 }
 205
 206 static int srp_new_cm_id(struct srp_target_port *target)
 207 {
 208         struct ib_cm_id *new_cm_id;
 209
 210         new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
 211                                     srp_cm_handler, target);
 212         if (IS_ERR(new_cm_id))
 213                 return PTR_ERR(new_cm_id);
 214
 215         if (target->cm_id)
 216                 ib_destroy_cm_id(target->cm_id);
 217         target->cm_id = new_cm_id;
 218
 219         return 0;
 220 }
 221
 222 static int srp_create_target_ib(struct srp_target_port *target)
 223 {
 224         struct ib_qp_init_attr *init_attr;
 225         struct ib_cq *recv_cq, *send_cq;
 226         struct ib_qp *qp;
 227         int ret;
 228
 229         init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
 230         if (!init_attr)
 231                 return -ENOMEM;
 232
 233         recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 234                                srp_recv_completion, NULL, target, SRP_RQ_SIZE,
 235                                target->comp_vector);
 236         if (IS_ERR(recv_cq)) {
 237                 ret = PTR_ERR(recv_cq);
 238                 goto err;
 239         }
 240
 241         send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 242                                srp_send_completion, NULL, target, SRP_SQ_SIZE,
 243                                target->comp_vector);
 244         if (IS_ERR(send_cq)) {
 245                 ret = PTR_ERR(send_cq);
 246                 goto err_recv_cq;
 247         }
 248
 249         ib_req_notify_cq(recv_cq, IB_CQ_NEXT_COMP);
 250
 251         init_attr->event_handler       = srp_qp_event;
 252         init_attr->cap.max_send_wr     = SRP_SQ_SIZE;
 253         init_attr->cap.max_recv_wr     = SRP_RQ_SIZE;
 254         init_attr->cap.max_recv_sge    = 1;
 255         init_attr->cap.max_send_sge    = 1;
 256         init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
 257         init_attr->qp_type             = IB_QPT_RC;
 258         init_attr->send_cq             = send_cq;
 259         init_attr->recv_cq             = recv_cq;
 260
 261         qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
 262         if (IS_ERR(qp)) {
 263                 ret = PTR_ERR(qp);
 264                 goto err_send_cq;
 265         }
 266
 267         ret = srp_init_qp(target, qp);
 268         if (ret)
 269                 goto err_qp;
 270
 271         if (target->qp)
 272                 ib_destroy_qp(target->qp);
 273         if (target->recv_cq)
 274                 ib_destroy_cq(target->recv_cq);
 275         if (target->send_cq)
 276                 ib_destroy_cq(target->send_cq);
 277
 278         target->qp = qp;
 279         target->recv_cq = recv_cq;
 280         target->send_cq = send_cq;
 281
 282         kfree(init_attr);
 283         return 0;
 284
 285 err_qp:
 286         ib_destroy_qp(qp);
 287
 288 err_send_cq:
 289         ib_destroy_cq(send_cq);
 290
 291 err_recv_cq:
 292         ib_destroy_cq(recv_cq);
 293
 294 err:
 295         kfree(init_attr);
 296         return ret;
 297 }
 298
 299 static void srp_free_target_ib(struct srp_target_port *target)
 300 {
 301         int i;
 302
 303         ib_destroy_qp(target->qp);
 304         ib_destroy_cq(target->send_cq);
 305         ib_destroy_cq(target->recv_cq);
 306
 307         target->qp = NULL;
 308         target->send_cq = target->recv_cq = NULL;
 309
 310         for (i = 0; i < SRP_RQ_SIZE; ++i)
 311                 srp_free_iu(target->srp_host, target->rx_ring[i]);
 312         for (i = 0; i < SRP_SQ_SIZE; ++i)
 313                 srp_free_iu(target->srp_host, target->tx_ring[i]);
 314 }
 315
 316 static void srp_path_rec_completion(int status,
 317                                     struct ib_sa_path_rec *pathrec,
 318                                     void *target_ptr)
 319 {
 320         struct srp_target_port *target = target_ptr;
 321
 322         target->status = status;
 323         if (status)
 324                 shost_printk(KERN_ERR, target->scsi_host,
 325                              PFX "Got failed path rec status %d\n", status);
 326         else
 327                 target->path = *pathrec;
 328         complete(&target->done);
 329 }
 330
 331 static int srp_lookup_path(struct srp_target_port *target)
 332 {
 333         target->path.numb_path = 1;
 334
 335         init_completion(&target->done);
 336
 337         target->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
 338                                                    target->srp_host->srp_dev->dev,
 339                                                    target->srp_host->port,
 340                                                    &target->path,
 341                                                    IB_SA_PATH_REC_SERVICE_ID    |
 342                                                    IB_SA_PATH_REC_DGID          |
 343                                                    IB_SA_PATH_REC_SGID          |
 344                                                    IB_SA_PATH_REC_NUMB_PATH     |
 345                                                    IB_SA_PATH_REC_PKEY,
 346                                                    SRP_PATH_REC_TIMEOUT_MS,
 347                                                    GFP_KERNEL,
 348                                                    srp_path_rec_completion,
 349                                                    target, &target->path_query);
 350         if (target->path_query_id < 0)
 351                 return target->path_query_id;
 352
 353         wait_for_completion(&target->done);
 354
 355         if (target->status < 0)
 356                 shost_printk(KERN_WARNING, target->scsi_host,
 357                              PFX "Path record query failed\n");
 358
 359         return target->status;
 360 }
 361
 362 static int srp_send_req(struct srp_target_port *target)
 363 {
 364         struct {
 365                 struct ib_cm_req_param param;
 366                 struct srp_login_req   priv;
 367         } *req = NULL;
 368         int status;
 369
 370         req = kzalloc(sizeof *req, GFP_KERNEL);
 371         if (!req)
 372                 return -ENOMEM;
 373
 374         req->param.primary_path               = &target->path;
 375         req->param.alternate_path             = NULL;
 376         req->param.service_id                 = target->service_id;
 377         req->param.qp_num                     = target->qp->qp_num;
 378         req->param.qp_type                    = target->qp->qp_type;
 379         req->param.private_data               = &req->priv;
 380         req->param.private_data_len           = sizeof req->priv;
 381         req->param.flow_control               = 1;
 382
 383         get_random_bytes(&req->param.starting_psn, 4);
 384         req->param.starting_psn              &= 0xffffff;
 385
 386         /*
 387          * Pick some arbitrary defaults here; we could make these
 388          * module parameters if anyone cared about setting them.
 389          */
 390         req->param.responder_resources        = 4;
 391         req->param.remote_cm_response_timeout = 20;
 392         req->param.local_cm_response_timeout  = 20;
 393         req->param.retry_count                = 7;
 394         req->param.rnr_retry_count            = 7;
 395         req->param.max_cm_retries             = 15;
 396
 397         req->priv.opcode        = SRP_LOGIN_REQ;
 398         req->priv.tag           = 0;
 399         req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
 400         req->priv.req_buf_fmt   = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
 401                                               SRP_BUF_FORMAT_INDIRECT);
 402         /*
 403          * In the published SRP specification (draft rev. 16a), the
 404          * port identifier format is 8 bytes of ID extension followed
 405          * by 8 bytes of GUID.  Older drafts put the two halves in the
 406          * opposite order, so that the GUID comes first.
 407          *
 408          * Targets conforming to these obsolete drafts can be
 409          * recognized by the I/O Class they report.
 410          */
 411         if (target->io_class == SRP_REV10_IB_IO_CLASS) {
 412                 memcpy(req->priv.initiator_port_id,
 413                        &target->path.sgid.global.interface_id, 8);
 414                 memcpy(req->priv.initiator_port_id + 8,
 415                        &target->initiator_ext, 8);
 416                 memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
 417                 memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
 418         } else {
 419                 memcpy(req->priv.initiator_port_id,
 420                        &target->initiator_ext, 8);
 421                 memcpy(req->priv.initiator_port_id + 8,
 422                        &target->path.sgid.global.interface_id, 8);
 423                 memcpy(req->priv.target_port_id,     &target->id_ext, 8);
 424                 memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
 425         }
 426
 427         /*
 428          * Topspin/Cisco SRP targets will reject our login unless we
 429          * zero out the first 8 bytes of our initiator port ID and set
 430          * the second 8 bytes to the local node GUID.
 431          */
 432         if (srp_target_is_topspin(target)) {
 433                 shost_printk(KERN_DEBUG, target->scsi_host,
 434                              PFX "Topspin/Cisco initiator port ID workaround "
 435                              "activated for target GUID %016llx\n",
 436                              (unsigned long long) be64_to_cpu(target->ioc_guid));
 437                 memset(req->priv.initiator_port_id, 0, 8);
 438                 memcpy(req->priv.initiator_port_id + 8,
 439                        &target->srp_host->srp_dev->dev->node_guid, 8);
 440         }
 441
 442         status = ib_send_cm_req(target->cm_id, &req->param);
 443
 444         kfree(req);
 445
 446         return status;
 447 }
 448
 449 static bool srp_queue_remove_work(struct srp_target_port *target)
 450 {
 451         bool changed = false;
 452
 453         spin_lock_irq(&target->lock);
 454         if (target->state != SRP_TARGET_REMOVED) {
 455                 target->state = SRP_TARGET_REMOVED;
 456                 changed = true;
 457         }
 458         spin_unlock_irq(&target->lock);
 459
 460         if (changed)
 461                 queue_work(system_long_wq, &target->remove_work);
 462
 463         return changed;
 464 }
 465
 466 static bool srp_change_conn_state(struct srp_target_port *target,
 467                                   bool connected)
 468 {
 469         bool changed = false;
 470
 471         spin_lock_irq(&target->lock);
 472         if (target->connected != connected) {
 473                 target->connected = connected;
 474                 changed = true;
 475         }
 476         spin_unlock_irq(&target->lock);
 477
 478         return changed;
 479 }
 480
 481 static void srp_disconnect_target(struct srp_target_port *target)
 482 {
 483         if (srp_change_conn_state(target, false)) {
 484                 /* XXX should send SRP_I_LOGOUT request */
 485
 486                 if (ib_send_cm_dreq(target->cm_id, NULL, 0)) {
 487                         shost_printk(KERN_DEBUG, target->scsi_host,
 488                                      PFX "Sending CM DREQ failed\n");
 489                 }
 490         }
 491 }
 492
 493 static void srp_free_req_data(struct srp_target_port *target)
 494 {
 495         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 496         struct srp_request *req;
 497         int i;
 498
 499         for (i = 0, req = target->req_ring; i < SRP_CMD_SQ_SIZE; ++i, ++req) {
 500                 kfree(req->fmr_list);
 501                 kfree(req->map_page);
 502                 if (req->indirect_dma_addr) {
 503                         ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
 504                                             target->indirect_size,
 505                                             DMA_TO_DEVICE);
 506                 }
 507                 kfree(req->indirect_desc);
 508         }
 509 }
 510
 511 /**
 512  * srp_del_scsi_host_attr() - Remove attributes defined in the host template.
 513  * @shost: SCSI host whose attributes to remove from sysfs.
 514  *
 515  * Note: Any attributes defined in the host template and that did not exist
 516  * before invocation of this function will be ignored.
 517  */
 518 static void srp_del_scsi_host_attr(struct Scsi_Host *shost)
 519 {
 520         struct device_attribute **attr;
 521
 522         for (attr = shost->hostt->shost_attrs; attr && *attr; ++attr)
 523                 device_remove_file(&shost->shost_dev, *attr);
 524 }
 525
 526 static void srp_remove_target(struct srp_target_port *target)
 527 {
 528         WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
 529
 530         srp_del_scsi_host_attr(target->scsi_host);
 531         srp_remove_host(target->scsi_host);
 532         scsi_remove_host(target->scsi_host);
 533         srp_disconnect_target(target);
 534         ib_destroy_cm_id(target->cm_id);
 535         srp_free_target_ib(target);
 536         srp_free_req_data(target);
 537         scsi_host_put(target->scsi_host);
 538 }
 539
 540 static void srp_remove_work(struct work_struct *work)
 541 {
 542         struct srp_target_port *target =
 543                 container_of(work, struct srp_target_port, remove_work);
 544
 545         WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
 546
 547         srp_remove_target(target);
 548
 549         spin_lock(&target->srp_host->target_lock);
 550         list_del(&target->list);
 551         spin_unlock(&target->srp_host->target_lock);
 552 }
 553
 554 static void srp_rport_delete(struct srp_rport *rport)
 555 {
 556         struct srp_target_port *target = rport->lld_data;
 557
 558         srp_queue_remove_work(target);
 559 }
 560
 561 static int srp_connect_target(struct srp_target_port *target)
 562 {
 563         int retries = 3;
 564         int ret;
 565
 566         WARN_ON_ONCE(target->connected);
 567
 568         target->qp_in_error = false;
 569
 570         ret = srp_lookup_path(target);
 571         if (ret)
 572                 return ret;
 573
 574         while (1) {
 575                 init_completion(&target->done);
 576                 ret = srp_send_req(target);
 577                 if (ret)
 578                         return ret;
 579                 wait_for_completion(&target->done);
 580
 581                 /*
 582                  * The CM event handling code will set status to
 583                  * SRP_PORT_REDIRECT if we get a port redirect REJ
 584                  * back, or SRP_DLID_REDIRECT if we get a lid/qp
 585                  * redirect REJ back.
 586                  */
 587                 switch (target->status) {
 588                 case 0:
 589                         srp_change_conn_state(target, true);
 590                         return 0;
 591
 592                 case SRP_PORT_REDIRECT:
 593                         ret = srp_lookup_path(target);
 594                         if (ret)
 595                                 return ret;
 596                         break;
 597
 598                 case SRP_DLID_REDIRECT:
 599                         break;
 600
 601                 case SRP_STALE_CONN:
 602                         /* Our current CM id was stale, and is now in timewait.
 603                          * Try to reconnect with a new one.
 604                          */
 605                         if (!retries-- || srp_new_cm_id(target)) {
 606                                 shost_printk(KERN_ERR, target->scsi_host, PFX
 607                                              "giving up on stale connection\n");
 608                                 target->status = -ECONNRESET;
 609                                 return target->status;
 610                         }
 611
 612                         shost_printk(KERN_ERR, target->scsi_host, PFX
 613                                      "retrying stale connection\n");
 614                         break;
 615
 616                 default:
 617                         return target->status;
 618                 }
 619         }
 620 }
 621
 622 static void srp_unmap_data(struct scsi_cmnd *scmnd,
 623                            struct srp_target_port *target,
 624                            struct srp_request *req)
 625 {
 626         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 627         struct ib_pool_fmr **pfmr;
 628
 629         if (!scsi_sglist(scmnd) ||
 630             (scmnd->sc_data_direction != DMA_TO_DEVICE &&
 631              scmnd->sc_data_direction != DMA_FROM_DEVICE))
 632                 return;
 633
 634         pfmr = req->fmr_list;
 635         while (req->nfmr--)
 636                 ib_fmr_pool_unmap(*pfmr++);
 637
 638         ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
 639                         scmnd->sc_data_direction);
 640 }
 641
 642 /**
 643  * srp_claim_req - Take ownership of the scmnd associated with a request.
 644  * @target: SRP target port.
 645  * @req: SRP request.
 646  * @scmnd: If NULL, take ownership of @req->scmnd. If not NULL, only take
 647  *         ownership of @req->scmnd if it equals @scmnd.
 648  *
 649  * Return value:
 650  * Either NULL or a pointer to the SCSI command the caller became owner of.
 651  */
 652 static struct scsi_cmnd *srp_claim_req(struct srp_target_port *target,
 653                                        struct srp_request *req,
 654                                        struct scsi_cmnd *scmnd)
 655 {
 656         unsigned long flags;
 657
 658         spin_lock_irqsave(&target->lock, flags);
 659         if (!scmnd) {
 660                 scmnd = req->scmnd;
 661                 req->scmnd = NULL;
 662         } else if (req->scmnd == scmnd) {
 663                 req->scmnd = NULL;
 664         } else {
 665                 scmnd = NULL;
 666         }
 667         spin_unlock_irqrestore(&target->lock, flags);
 668
 669         return scmnd;
 670 }
 671
 672 /**
 673  * srp_free_req() - Unmap data and add request to the free request list.
 674  */
 675 static void srp_free_req(struct srp_target_port *target,
 676                          struct srp_request *req, struct scsi_cmnd *scmnd,
 677                          s32 req_lim_delta)
 678 {
 679         unsigned long flags;
 680
 681         srp_unmap_data(scmnd, target, req);
 682
 683         spin_lock_irqsave(&target->lock, flags);
 684         target->req_lim += req_lim_delta;
 685         list_add_tail(&req->list, &target->free_reqs);
 686         spin_unlock_irqrestore(&target->lock, flags);
 687 }
 688
 689 static void srp_reset_req(struct srp_target_port *target, struct srp_request *req)
 690 {
 691         struct scsi_cmnd *scmnd = srp_claim_req(target, req, NULL);
 692
 693         if (scmnd) {
 694                 srp_free_req(target, req, scmnd, 0);
 695                 scmnd->result = DID_RESET << 16;
 696                 scmnd->scsi_done(scmnd);
 697         }
 698 }
 699
 700 static int srp_reconnect_target(struct srp_target_port *target)
 701 {
 702         struct Scsi_Host *shost = target->scsi_host;
 703         int i, ret;
 704
 705         scsi_target_block(&shost->shost_gendev);
 706
 707         srp_disconnect_target(target);
 708         /*
 709          * Now get a new local CM ID so that we avoid confusing the target in
 710          * case things are really fouled up. Doing so also ensures that all CM
 711          * callbacks will have finished before a new QP is allocated.
 712          */
 713         ret = srp_new_cm_id(target);
 714         /*
 715          * Whether or not creating a new CM ID succeeded, create a new
 716          * QP. This guarantees that all completion callback function
 717          * invocations have finished before request resetting starts.
 718          */
 719         if (ret == 0)
 720                 ret = srp_create_target_ib(target);
 721         else
 722                 srp_create_target_ib(target);
 723
 724         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
 725                 struct srp_request *req = &target->req_ring[i];
 726                 if (req->scmnd)
 727                         srp_reset_req(target, req);
 728         }
 729
 730         INIT_LIST_HEAD(&target->free_tx);
 731         for (i = 0; i < SRP_SQ_SIZE; ++i)
 732                 list_add(&target->tx_ring[i]->list, &target->free_tx);
 733
 734         if (ret == 0)
 735                 ret = srp_connect_target(target);
 736
 737         scsi_target_unblock(&shost->shost_gendev, ret == 0 ? SDEV_RUNNING :
 738                             SDEV_TRANSPORT_OFFLINE);
 739         target->transport_offline = !!ret;
 740
 741         if (ret)
 742                 goto err;
 743
 744         shost_printk(KERN_INFO, target->scsi_host, PFX "reconnect succeeded\n");
 745
 746         return ret;
 747
 748 err:
 749         shost_printk(KERN_ERR, target->scsi_host,
 750                      PFX "reconnect failed (%d), removing target port.\n", ret);
 751
 752         /*
 753          * We couldn't reconnect, so kill our target port off.
 754          * However, we have to defer the real removal because we
 755          * are in the context of the SCSI error handler now, which
 756          * will deadlock if we call scsi_remove_host().
 757          */
 758         srp_queue_remove_work(target);
 759
 760         return ret;
 761 }
 762
 763 static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
 764                          unsigned int dma_len, u32 rkey)
 765 {
 766         struct srp_direct_buf *desc = state->desc;
 767
 768         desc->va = cpu_to_be64(dma_addr);
 769         desc->key = cpu_to_be32(rkey);
 770         desc->len = cpu_to_be32(dma_len);
 771
 772         state->total_len += dma_len;
 773         state->desc++;
 774         state->ndesc++;
 775 }
 776
 777 static int srp_map_finish_fmr(struct srp_map_state *state,
 778                               struct srp_target_port *target)
 779 {
 780         struct srp_device *dev = target->srp_host->srp_dev;
 781         struct ib_pool_fmr *fmr;
 782         u64 io_addr = 0;
 783
 784         if (!state->npages)
 785                 return 0;
 786
 787         if (state->npages == 1) {
 788                 srp_map_desc(state, state->base_dma_addr, state->fmr_len,
 789                              target->rkey);
 790                 state->npages = state->fmr_len = 0;
 791                 return 0;
 792         }
 793
 794         fmr = ib_fmr_pool_map_phys(dev->fmr_pool, state->pages,
 795                                    state->npages, io_addr);
 796         if (IS_ERR(fmr))
 797                 return PTR_ERR(fmr);
 798
 799         *state->next_fmr++ = fmr;
 800         state->nfmr++;
 801
 802         srp_map_desc(state, 0, state->fmr_len, fmr->fmr->rkey);
 803         state->npages = state->fmr_len = 0;
 804         return 0;
 805 }
 806
 807 static void srp_map_update_start(struct srp_map_state *state,
 808                                  struct scatterlist *sg, int sg_index,
 809                                  dma_addr_t dma_addr)
 810 {
 811         state->unmapped_sg = sg;
 812         state->unmapped_index = sg_index;
 813         state->unmapped_addr = dma_addr;
 814 }
 815
 816 static int srp_map_sg_entry(struct srp_map_state *state,
 817                             struct srp_target_port *target,
 818                             struct scatterlist *sg, int sg_index,
 819                             int use_fmr)
 820 {
 821         struct srp_device *dev = target->srp_host->srp_dev;
 822         struct ib_device *ibdev = dev->dev;
 823         dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
 824         unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
 825         unsigned int len;
 826         int ret;
 827
 828         if (!dma_len)
 829                 return 0;
 830
 831         if (use_fmr == SRP_MAP_NO_FMR) {
 832                 /* Once we're in direct map mode for a request, we don't
 833                  * go back to FMR mode, so no need to update anything
 834                  * other than the descriptor.
 835                  */
 836                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 837                 return 0;
 838         }
 839
 840         /* If we start at an offset into the FMR page, don't merge into
 841          * the current FMR. Finish it out, and use the kernel's MR for this
 842          * sg entry. This is to avoid potential bugs on some SRP targets
 843          * that were never quite defined, but went away when the initiator
 844          * avoided using FMR on such page fragments.
 845          */
 846         if (dma_addr & ~dev->fmr_page_mask || dma_len > dev->fmr_max_size) {
 847                 ret = srp_map_finish_fmr(state, target);
 848                 if (ret)
 849                         return ret;
 850
 851                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 852                 srp_map_update_start(state, NULL, 0, 0);
 853                 return 0;
 854         }
 855
 856         /* If this is the first sg to go into the FMR, save our position.
 857          * We need to know the first unmapped entry, its index, and the
 858          * first unmapped address within that entry to be able to restart
 859          * mapping after an error.
 860          */
 861         if (!state->unmapped_sg)
 862                 srp_map_update_start(state, sg, sg_index, dma_addr);
 863
 864         while (dma_len) {
 865                 if (state->npages == SRP_FMR_SIZE) {
 866                         ret = srp_map_finish_fmr(state, target);
 867                         if (ret)
 868                                 return ret;
 869
 870                         srp_map_update_start(state, sg, sg_index, dma_addr);
 871                 }
 872
 873                 len = min_t(unsigned int, dma_len, dev->fmr_page_size);
 874
 875                 if (!state->npages)
 876                         state->base_dma_addr = dma_addr;
 877                 state->pages[state->npages++] = dma_addr;
 878                 state->fmr_len += len;
 879                 dma_addr += len;
 880                 dma_len -= len;
 881         }
 882
 883         /* If the last entry of the FMR wasn't a full page, then we need to
 884          * close it out and start a new one -- we can only merge at page
 885          * boundries.
 886          */
 887         ret = 0;
 888         if (len != dev->fmr_page_size) {
 889                 ret = srp_map_finish_fmr(state, target);
 890                 if (!ret)
 891                         srp_map_update_start(state, NULL, 0, 0);
 892         }
 893         return ret;
 894 }
 895
 896 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
 897                         struct srp_request *req)
 898 {
 899         struct scatterlist *scat, *sg;
 900         struct srp_cmd *cmd = req->cmd->buf;
 901         int i, len, nents, count, use_fmr;
 902         struct srp_device *dev;
 903         struct ib_device *ibdev;
 904         struct srp_map_state state;
 905         struct srp_indirect_buf *indirect_hdr;
 906         u32 table_len;
 907         u8 fmt;
 908
 909         if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
 910                 return sizeof (struct srp_cmd);
 911
 912         if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
 913             scmnd->sc_data_direction != DMA_TO_DEVICE) {
 914                 shost_printk(KERN_WARNING, target->scsi_host,
 915                              PFX "Unhandled data direction %d\n",
 916                              scmnd->sc_data_direction);
 917                 return -EINVAL;
 918         }
 919
 920         nents = scsi_sg_count(scmnd);
 921         scat  = scsi_sglist(scmnd);
 922
 923         dev = target->srp_host->srp_dev;
 924         ibdev = dev->dev;
 925
 926         count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
 927         if (unlikely(count == 0))
 928                 return -EIO;
 929
 930         fmt = SRP_DATA_DESC_DIRECT;
 931         len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
 932
 933         if (count == 1) {
 934                 /*
 935                  * The midlayer only generated a single gather/scatter
 936                  * entry, or DMA mapping coalesced everything to a
 937                  * single entry.  So a direct descriptor along with
 938                  * the DMA MR suffices.
 939                  */
 940                 struct srp_direct_buf *buf = (void *) cmd->add_data;
 941
 942                 buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
 943                 buf->key = cpu_to_be32(target->rkey);
 944                 buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
 945
 946                 req->nfmr = 0;
 947                 goto map_complete;
 948         }
 949
 950         /* We have more than one scatter/gather entry, so build our indirect
 951          * descriptor table, trying to merge as many entries with FMR as we
 952          * can.
 953          */
 954         indirect_hdr = (void *) cmd->add_data;
 955
 956         ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
 957                                    target->indirect_size, DMA_TO_DEVICE);
 958
 959         memset(&state, 0, sizeof(state));
 960         state.desc      = req->indirect_desc;
 961         state.pages     = req->map_page;
 962         state.next_fmr  = req->fmr_list;
 963
 964         use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
 965
 966         for_each_sg(scat, sg, count, i) {
 967                 if (srp_map_sg_entry(&state, target, sg, i, use_fmr)) {
 968                         /* FMR mapping failed, so backtrack to the first
 969                          * unmapped entry and continue on without using FMR.
 970                          */
 971                         dma_addr_t dma_addr;
 972                         unsigned int dma_len;
 973
 974 backtrack:
 975                         sg = state.unmapped_sg;
 976                         i = state.unmapped_index;
 977
 978                         dma_addr = ib_sg_dma_address(ibdev, sg);
 979                         dma_len = ib_sg_dma_len(ibdev, sg);
 980                         dma_len -= (state.unmapped_addr - dma_addr);
 981                         dma_addr = state.unmapped_addr;
 982                         use_fmr = SRP_MAP_NO_FMR;
 983                         srp_map_desc(&state, dma_addr, dma_len, target->rkey);
 984                 }
 985         }
 986
 987         if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(&state, target))
 988                 goto backtrack;
 989
 990         /* We've mapped the request, now pull as much of the indirect
 991          * descriptor table as we can into the command buffer. If this
 992          * target is not using an external indirect table, we are
 993          * guaranteed to fit into the command, as the SCSI layer won't
 994          * give us more S/G entries than we allow.
 995          */
 996         req->nfmr = state.nfmr;
 997         if (state.ndesc == 1) {
 998                 /* FMR mapping was able to collapse this to one entry,
 999                  * so use a direct descriptor.
1000                  */
1001                 struct srp_direct_buf *buf = (void *) cmd->add_data;
1002
1003                 *buf = req->indirect_desc[0];
1004                 goto map_complete;
1005         }
1006
1007         if (unlikely(target->cmd_sg_cnt < state.ndesc &&
1008                                                 !target->allow_ext_sg)) {
1009                 shost_printk(KERN_ERR, target->scsi_host,
1010                              "Could not fit S/G list into SRP_CMD\n");
1011                 return -EIO;
1012         }
1013
1014         count = min(state.ndesc, target->cmd_sg_cnt);
1015         table_len = state.ndesc * sizeof (struct srp_direct_buf);
1016
1017         fmt = SRP_DATA_DESC_INDIRECT;
1018         len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
1019         len += count * sizeof (struct srp_direct_buf);
1020
1021         memcpy(indirect_hdr->desc_list, req->indirect_desc,
1022                count * sizeof (struct srp_direct_buf));
1023
1024         indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
1025         indirect_hdr->table_desc.key = cpu_to_be32(target->rkey);
1026         indirect_hdr->table_desc.len = cpu_to_be32(table_len);
1027         indirect_hdr->len = cpu_to_be32(state.total_len);
1028
1029         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1030                 cmd->data_out_desc_cnt = count;
1031         else
1032                 cmd->data_in_desc_cnt = count;
1033
1034         ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
1035                                       DMA_TO_DEVICE);
1036
1037 map_complete:
1038         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1039                 cmd->buf_fmt = fmt << 4;
1040         else
1041                 cmd->buf_fmt = fmt;
1042
1043         return len;
1044 }
1045
1046 /*
1047  * Return an IU and possible credit to the free pool
1048  */
1049 static void srp_put_tx_iu(struct srp_target_port *target, struct srp_iu *iu,
1050                           enum srp_iu_type iu_type)
1051 {
1052         unsigned long flags;
1053
1054         spin_lock_irqsave(&target->lock, flags);
1055         list_add(&iu->list, &target->free_tx);
1056         if (iu_type != SRP_IU_RSP)
1057                 ++target->req_lim;
1058         spin_unlock_irqrestore(&target->lock, flags);
1059 }
1060
1061 /*
1062  * Must be called with target->lock held to protect req_lim and free_tx.
1063  * If IU is not sent, it must be returned using srp_put_tx_iu().
1064  *
1065  * Note:
1066  * An upper limit for the number of allocated information units for each
1067  * request type is:
1068  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
1069  *   more than Scsi_Host.can_queue requests.
1070  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
1071  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
1072  *   one unanswered SRP request to an initiator.
1073  */
1074 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
1075                                       enum srp_iu_type iu_type)
1076 {
1077         s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
1078         struct srp_iu *iu;
1079
1080         srp_send_completion(target->send_cq, target);
1081
1082         if (list_empty(&target->free_tx))
1083                 return NULL;
1084
1085         /* Initiator responses to target requests do not consume credits */
1086         if (iu_type != SRP_IU_RSP) {
1087                 if (target->req_lim <= rsv) {
1088                         ++target->zero_req_lim;
1089                         return NULL;
1090                 }
1091
1092                 --target->req_lim;
1093         }
1094
1095         iu = list_first_entry(&target->free_tx, struct srp_iu, list);
1096         list_del(&iu->list);
1097         return iu;
1098 }
1099
1100 static int srp_post_send(struct srp_target_port *target,
1101                          struct srp_iu *iu, int len)
1102 {
1103         struct ib_sge list;
1104         struct ib_send_wr wr, *bad_wr;
1105
1106         list.addr   = iu->dma;
1107         list.length = len;
1108         list.lkey   = target->lkey;
1109
1110         wr.next       = NULL;
1111         wr.wr_id      = (uintptr_t) iu;
1112         wr.sg_list    = &list;
1113         wr.num_sge    = 1;
1114         wr.opcode     = IB_WR_SEND;
1115         wr.send_flags = IB_SEND_SIGNALED;
1116
1117         return ib_post_send(target->qp, &wr, &bad_wr);
1118 }
1119
1120 static int srp_post_recv(struct srp_target_port *target, struct srp_iu *iu)
1121 {
1122         struct ib_recv_wr wr, *bad_wr;
1123         struct ib_sge list;
1124
1125         list.addr   = iu->dma;
1126         list.length = iu->size;
1127         list.lkey   = target->lkey;
1128
1129         wr.next     = NULL;
1130         wr.wr_id    = (uintptr_t) iu;
1131         wr.sg_list  = &list;
1132         wr.num_sge  = 1;
1133
1134         return ib_post_recv(target->qp, &wr, &bad_wr);
1135 }
1136
1137 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
1138 {
1139         struct srp_request *req;
1140         struct scsi_cmnd *scmnd;
1141         unsigned long flags;
1142
1143         if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1144                 spin_lock_irqsave(&target->lock, flags);
1145                 target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1146                 spin_unlock_irqrestore(&target->lock, flags);
1147
1148                 target->tsk_mgmt_status = -1;
1149                 if (be32_to_cpu(rsp->resp_data_len) >= 4)
1150                         target->tsk_mgmt_status = rsp->data[3];
1151                 complete(&target->tsk_mgmt_done);
1152         } else {
1153                 req = &target->req_ring[rsp->tag];
1154                 scmnd = srp_claim_req(target, req, NULL);
1155                 if (!scmnd) {
1156                         shost_printk(KERN_ERR, target->scsi_host,
1157                                      "Null scmnd for RSP w/tag %016llx\n",
1158                                      (unsigned long long) rsp->tag);
1159
1160                         spin_lock_irqsave(&target->lock, flags);
1161                         target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1162                         spin_unlock_irqrestore(&target->lock, flags);
1163
1164                         return;
1165                 }
1166                 scmnd->result = rsp->status;
1167
1168                 if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
1169                         memcpy(scmnd->sense_buffer, rsp->data +
1170                                be32_to_cpu(rsp->resp_data_len),
1171                                min_t(int, be32_to_cpu(rsp->sense_data_len),
1172                                      SCSI_SENSE_BUFFERSIZE));
1173                 }
1174
1175                 if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
1176                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
1177                 else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
1178                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
1179
1180                 srp_free_req(target, req, scmnd,
1181                              be32_to_cpu(rsp->req_lim_delta));
1182
1183                 scmnd->host_scribble = NULL;
1184                 scmnd->scsi_done(scmnd);
1185         }
1186 }
1187
1188 static int srp_response_common(struct srp_target_port *target, s32 req_delta,
1189                                void *rsp, int len)
1190 {
1191         struct ib_device *dev = target->srp_host->srp_dev->dev;
1192         unsigned long flags;
1193         struct srp_iu *iu;
1194         int err;
1195
1196         spin_lock_irqsave(&target->lock, flags);
1197         target->req_lim += req_delta;
1198         iu = __srp_get_tx_iu(target, SRP_IU_RSP);
1199         spin_unlock_irqrestore(&target->lock, flags);
1200
1201         if (!iu) {
1202                 shost_printk(KERN_ERR, target->scsi_host, PFX
1203                              "no IU available to send response\n");
1204                 return 1;
1205         }
1206
1207         ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
1208         memcpy(iu->buf, rsp, len);
1209         ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
1210
1211         err = srp_post_send(target, iu, len);
1212         if (err) {
1213                 shost_printk(KERN_ERR, target->scsi_host, PFX
1214                              "unable to post response: %d\n", err);
1215                 srp_put_tx_iu(target, iu, SRP_IU_RSP);
1216         }
1217
1218         return err;
1219 }
1220
1221 static void srp_process_cred_req(struct srp_target_port *target,
1222                                  struct srp_cred_req *req)
1223 {
1224         struct srp_cred_rsp rsp = {
1225                 .opcode = SRP_CRED_RSP,
1226                 .tag = req->tag,
1227         };
1228         s32 delta = be32_to_cpu(req->req_lim_delta);
1229
1230         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1231                 shost_printk(KERN_ERR, target->scsi_host, PFX
1232                              "problems processing SRP_CRED_REQ\n");
1233 }
1234
1235 static void srp_process_aer_req(struct srp_target_port *target,
1236                                 struct srp_aer_req *req)
1237 {
1238         struct srp_aer_rsp rsp = {
1239                 .opcode = SRP_AER_RSP,
1240                 .tag = req->tag,
1241         };
1242         s32 delta = be32_to_cpu(req->req_lim_delta);
1243
1244         shost_printk(KERN_ERR, target->scsi_host, PFX
1245                      "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
1246
1247         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1248                 shost_printk(KERN_ERR, target->scsi_host, PFX
1249                              "problems processing SRP_AER_REQ\n");
1250 }
1251
1252 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
1253 {
1254         struct ib_device *dev = target->srp_host->srp_dev->dev;
1255         struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1256         int res;
1257         u8 opcode;
1258
1259         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
1260                                    DMA_FROM_DEVICE);
1261
1262         opcode = *(u8 *) iu->buf;
1263
1264         if (0) {
1265                 shost_printk(KERN_ERR, target->scsi_host,
1266                              PFX "recv completion, opcode 0x%02x\n", opcode);
1267                 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1268                                iu->buf, wc->byte_len, true);
1269         }
1270
1271         switch (opcode) {
1272         case SRP_RSP:
1273                 srp_process_rsp(target, iu->buf);
1274                 break;
1275
1276         case SRP_CRED_REQ:
1277                 srp_process_cred_req(target, iu->buf);
1278                 break;
1279
1280         case SRP_AER_REQ:
1281                 srp_process_aer_req(target, iu->buf);
1282                 break;
1283
1284         case SRP_T_LOGOUT:
1285                 /* XXX Handle target logout */
1286                 shost_printk(KERN_WARNING, target->scsi_host,
1287                              PFX "Got target logout request\n");
1288                 break;
1289
1290         default:
1291                 shost_printk(KERN_WARNING, target->scsi_host,
1292                              PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1293                 break;
1294         }
1295
1296         ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
1297                                       DMA_FROM_DEVICE);
1298
1299         res = srp_post_recv(target, iu);
1300         if (res != 0)
1301                 shost_printk(KERN_ERR, target->scsi_host,
1302                              PFX "Recv failed with error code %d\n", res);
1303 }
1304
1305 static void srp_handle_qp_err(enum ib_wc_status wc_status,
1306                               enum ib_wc_opcode wc_opcode,
1307                               struct srp_target_port *target)
1308 {
1309         if (target->connected && !target->qp_in_error) {
1310                 shost_printk(KERN_ERR, target->scsi_host,
1311                              PFX "failed %s status %d\n",
1312                              wc_opcode & IB_WC_RECV ? "receive" : "send",
1313                              wc_status);
1314         }
1315         target->qp_in_error = true;
1316 }
1317
1318 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
1319 {
1320         struct srp_target_port *target = target_ptr;
1321         struct ib_wc wc;
1322
1323         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1324         while (ib_poll_cq(cq, 1, &wc) > 0) {
1325                 if (likely(wc.status == IB_WC_SUCCESS)) {
1326                         srp_handle_recv(target, &wc);
1327                 } else {
1328                         srp_handle_qp_err(wc.status, wc.opcode, target);
1329                 }
1330         }
1331 }
1332
1333 static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
1334 {
1335         struct srp_target_port *target = target_ptr;
1336         struct ib_wc wc;
1337         struct srp_iu *iu;
1338
1339         while (ib_poll_cq(cq, 1, &wc) > 0) {
1340                 if (likely(wc.status == IB_WC_SUCCESS)) {
1341                         iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1342                         list_add(&iu->list, &target->free_tx);
1343                 } else {
1344                         srp_handle_qp_err(wc.status, wc.opcode, target);
1345                 }
1346         }
1347 }
1348
1349 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1350 {
1351         struct srp_target_port *target = host_to_target(shost);
1352         struct srp_request *req;
1353         struct srp_iu *iu;
1354         struct srp_cmd *cmd;
1355         struct ib_device *dev;
1356         unsigned long flags;
1357         int len;
1358
1359         if (unlikely(target->transport_offline)) {
1360                 scmnd->result = DID_NO_CONNECT << 16;
1361                 scmnd->scsi_done(scmnd);
1362                 return 0;
1363         }
1364
1365         spin_lock_irqsave(&target->lock, flags);
1366         iu = __srp_get_tx_iu(target, SRP_IU_CMD);
1367         if (!iu)
1368                 goto err_unlock;
1369
1370         req = list_first_entry(&target->free_reqs, struct srp_request, list);
1371         list_del(&req->list);
1372         spin_unlock_irqrestore(&target->lock, flags);
1373
1374         dev = target->srp_host->srp_dev->dev;
1375         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
1376                                    DMA_TO_DEVICE);
1377
1378         scmnd->result        = 0;
1379         scmnd->host_scribble = (void *) req;
1380
1381         cmd = iu->buf;
1382         memset(cmd, 0, sizeof *cmd);
1383
1384         cmd->opcode = SRP_CMD;
1385         cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
1386         cmd->tag    = req->index;
1387         memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
1388
1389         req->scmnd    = scmnd;
1390         req->cmd      = iu;
1391
1392         len = srp_map_data(scmnd, target, req);
1393         if (len < 0) {
1394                 shost_printk(KERN_ERR, target->scsi_host,
1395                              PFX "Failed to map data\n");
1396                 goto err_iu;
1397         }
1398
1399         ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
1400                                       DMA_TO_DEVICE);
1401
1402         if (srp_post_send(target, iu, len)) {
1403                 shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
1404                 goto err_unmap;
1405         }
1406
1407         return 0;
1408
1409 err_unmap:
1410         srp_unmap_data(scmnd, target, req);
1411
1412 err_iu:
1413         srp_put_tx_iu(target, iu, SRP_IU_CMD);
1414
1415         spin_lock_irqsave(&target->lock, flags);
1416         list_add(&req->list, &target->free_reqs);
1417
1418 err_unlock:
1419         spin_unlock_irqrestore(&target->lock, flags);
1420
1421         return SCSI_MLQUEUE_HOST_BUSY;
1422 }
1423
1424 static int srp_alloc_iu_bufs(struct srp_target_port *target)
1425 {
1426         int i;
1427
1428         for (i = 0; i < SRP_RQ_SIZE; ++i) {
1429                 target->rx_ring[i] = srp_alloc_iu(target->srp_host,
1430                                                   target->max_ti_iu_len,
1431                                                   GFP_KERNEL, DMA_FROM_DEVICE);
1432                 if (!target->rx_ring[i])
1433                         goto err;
1434         }
1435
1436         for (i = 0; i < SRP_SQ_SIZE; ++i) {
1437                 target->tx_ring[i] = srp_alloc_iu(target->srp_host,
1438                                                   target->max_iu_len,
1439                                                   GFP_KERNEL, DMA_TO_DEVICE);
1440                 if (!target->tx_ring[i])
1441                         goto err;
1442
1443                 list_add(&target->tx_ring[i]->list, &target->free_tx);
1444         }
1445
1446         return 0;
1447
1448 err:
1449         for (i = 0; i < SRP_RQ_SIZE; ++i) {
1450                 srp_free_iu(target->srp_host, target->rx_ring[i]);
1451                 target->rx_ring[i] = NULL;
1452         }
1453
1454         for (i = 0; i < SRP_SQ_SIZE; ++i) {
1455                 srp_free_iu(target->srp_host, target->tx_ring[i]);
1456                 target->tx_ring[i] = NULL;
1457         }
1458
1459         return -ENOMEM;
1460 }
1461
1462 static uint32_t srp_compute_rq_tmo(struct ib_qp_attr *qp_attr, int attr_mask)
1463 {
1464         uint64_t T_tr_ns, max_compl_time_ms;
1465         uint32_t rq_tmo_jiffies;
1466
1467         /*
1468          * According to section 11.2.4.2 in the IBTA spec (Modify Queue Pair,
1469          * table 91), both the QP timeout and the retry count have to be set
1470          * for RC QP's during the RTR to RTS transition.
1471          */
1472         WARN_ON_ONCE((attr_mask & (IB_QP_TIMEOUT | IB_QP_RETRY_CNT)) !=
1473                      (IB_QP_TIMEOUT | IB_QP_RETRY_CNT));
1474
1475         /*
1476          * Set target->rq_tmo_jiffies to one second more than the largest time
1477          * it can take before an error completion is generated. See also
1478          * C9-140..142 in the IBTA spec for more information about how to
1479          * convert the QP Local ACK Timeout value to nanoseconds.
1480          */
1481         T_tr_ns = 4096 * (1ULL << qp_attr->timeout);
1482         max_compl_time_ms = qp_attr->retry_cnt * 4 * T_tr_ns;
1483         do_div(max_compl_time_ms, NSEC_PER_MSEC);
1484         rq_tmo_jiffies = msecs_to_jiffies(max_compl_time_ms + 1000);
1485
1486         return rq_tmo_jiffies;
1487 }
1488
1489 static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
1490                                struct srp_login_rsp *lrsp,
1491                                struct srp_target_port *target)
1492 {
1493         struct ib_qp_attr *qp_attr = NULL;
1494         int attr_mask = 0;
1495         int ret;
1496         int i;
1497
1498         if (lrsp->opcode == SRP_LOGIN_RSP) {
1499                 target->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
1500                 target->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
1501
1502                 /*
1503                  * Reserve credits for task management so we don't
1504                  * bounce requests back to the SCSI mid-layer.
1505                  */
1506                 target->scsi_host->can_queue
1507                         = min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1508                               target->scsi_host->can_queue);
1509         } else {
1510                 shost_printk(KERN_WARNING, target->scsi_host,
1511                              PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
1512                 ret = -ECONNRESET;
1513                 goto error;
1514         }
1515
1516         if (!target->rx_ring[0]) {
1517                 ret = srp_alloc_iu_bufs(target);
1518                 if (ret)
1519                         goto error;
1520         }
1521
1522         ret = -ENOMEM;
1523         qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1524         if (!qp_attr)
1525                 goto error;
1526
1527         qp_attr->qp_state = IB_QPS_RTR;
1528         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1529         if (ret)
1530                 goto error_free;
1531
1532         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1533         if (ret)
1534                 goto error_free;
1535
1536         for (i = 0; i < SRP_RQ_SIZE; i++) {
1537                 struct srp_iu *iu = target->rx_ring[i];
1538                 ret = srp_post_recv(target, iu);
1539                 if (ret)
1540                         goto error_free;
1541         }
1542
1543         qp_attr->qp_state = IB_QPS_RTS;
1544         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1545         if (ret)
1546                 goto error_free;
1547
1548         target->rq_tmo_jiffies = srp_compute_rq_tmo(qp_attr, attr_mask);
1549
1550         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1551         if (ret)
1552                 goto error_free;
1553
1554         ret = ib_send_cm_rtu(cm_id, NULL, 0);
1555
1556 error_free:
1557         kfree(qp_attr);
1558
1559 error:
1560         target->status = ret;
1561 }
1562
1563 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
1564                                struct ib_cm_event *event,
1565                                struct srp_target_port *target)
1566 {
1567         struct Scsi_Host *shost = target->scsi_host;
1568         struct ib_class_port_info *cpi;
1569         int opcode;
1570
1571         switch (event->param.rej_rcvd.reason) {
1572         case IB_CM_REJ_PORT_CM_REDIRECT:
1573                 cpi = event->param.rej_rcvd.ari;
1574                 target->path.dlid = cpi->redirect_lid;
1575                 target->path.pkey = cpi->redirect_pkey;
1576                 cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
1577                 memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
1578
1579                 target->status = target->path.dlid ?
1580                         SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
1581                 break;
1582
1583         case IB_CM_REJ_PORT_REDIRECT:
1584                 if (srp_target_is_topspin(target)) {
1585                         /*
1586                          * Topspin/Cisco SRP gateways incorrectly send
1587                          * reject reason code 25 when they mean 24
1588                          * (port redirect).
1589                          */
1590                         memcpy(target->path.dgid.raw,
1591                                event->param.rej_rcvd.ari, 16);
1592
1593                         shost_printk(KERN_DEBUG, shost,
1594                                      PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1595                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1596                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1597
1598                         target->status = SRP_PORT_REDIRECT;
1599                 } else {
1600                         shost_printk(KERN_WARNING, shost,
1601                                      "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1602                         target->status = -ECONNRESET;
1603                 }
1604                 break;
1605
1606         case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1607                 shost_printk(KERN_WARNING, shost,
1608                             "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1609                 target->status = -ECONNRESET;
1610                 break;
1611
1612         case IB_CM_REJ_CONSUMER_DEFINED:
1613                 opcode = *(u8 *) event->private_data;
1614                 if (opcode == SRP_LOGIN_REJ) {
1615                         struct srp_login_rej *rej = event->private_data;
1616                         u32 reason = be32_to_cpu(rej->reason);
1617
1618                         if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1619                                 shost_printk(KERN_WARNING, shost,
1620                                              PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1621                         else
1622                                 shost_printk(KERN_WARNING, shost,
1623                                             PFX "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1624                 } else
1625                         shost_printk(KERN_WARNING, shost,
1626                                      "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1627                                      " opcode 0x%02x\n", opcode);
1628                 target->status = -ECONNRESET;
1629                 break;
1630
1631         case IB_CM_REJ_STALE_CONN:
1632                 shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
1633                 target->status = SRP_STALE_CONN;
1634                 break;
1635
1636         default:
1637                 shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
1638                              event->param.rej_rcvd.reason);
1639                 target->status = -ECONNRESET;
1640         }
1641 }
1642
1643 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1644 {
1645         struct srp_target_port *target = cm_id->context;
1646         int comp = 0;
1647
1648         switch (event->event) {
1649         case IB_CM_REQ_ERROR:
1650                 shost_printk(KERN_DEBUG, target->scsi_host,
1651                              PFX "Sending CM REQ failed\n");
1652                 comp = 1;
1653                 target->status = -ECONNRESET;
1654                 break;
1655
1656         case IB_CM_REP_RECEIVED:
1657                 comp = 1;
1658                 srp_cm_rep_handler(cm_id, event->private_data, target);
1659                 break;
1660
1661         case IB_CM_REJ_RECEIVED:
1662                 shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
1663                 comp = 1;
1664
1665                 srp_cm_rej_handler(cm_id, event, target);
1666                 break;
1667
1668         case IB_CM_DREQ_RECEIVED:
1669                 shost_printk(KERN_WARNING, target->scsi_host,
1670                              PFX "DREQ received - connection closed\n");
1671                 srp_change_conn_state(target, false);
1672                 if (ib_send_cm_drep(cm_id, NULL, 0))
1673                         shost_printk(KERN_ERR, target->scsi_host,
1674                                      PFX "Sending CM DREP failed\n");
1675                 break;
1676
1677         case IB_CM_TIMEWAIT_EXIT:
1678                 shost_printk(KERN_ERR, target->scsi_host,
1679                              PFX "connection closed\n");
1680
1681                 target->status = 0;
1682                 break;
1683
1684         case IB_CM_MRA_RECEIVED:
1685         case IB_CM_DREQ_ERROR:
1686         case IB_CM_DREP_RECEIVED:
1687                 break;
1688
1689         default:
1690                 shost_printk(KERN_WARNING, target->scsi_host,
1691                              PFX "Unhandled CM event %d\n", event->event);
1692                 break;
1693         }
1694
1695         if (comp)
1696                 complete(&target->done);
1697
1698         return 0;
1699 }
1700
1701 static int srp_send_tsk_mgmt(struct srp_target_port *target,
1702                              u64 req_tag, unsigned int lun, u8 func)
1703 {
1704         struct ib_device *dev = target->srp_host->srp_dev->dev;
1705         struct srp_iu *iu;
1706         struct srp_tsk_mgmt *tsk_mgmt;
1707
1708         if (!target->connected || target->qp_in_error)
1709                 return -1;
1710
1711         init_completion(&target->tsk_mgmt_done);
1712
1713         spin_lock_irq(&target->lock);
1714         iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT);
1715         spin_unlock_irq(&target->lock);
1716
1717         if (!iu)
1718                 return -1;
1719
1720         ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
1721                                    DMA_TO_DEVICE);
1722         tsk_mgmt = iu->buf;
1723         memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1724
1725         tsk_mgmt->opcode        = SRP_TSK_MGMT;
1726         tsk_mgmt->lun           = cpu_to_be64((u64) lun << 48);
1727         tsk_mgmt->tag           = req_tag | SRP_TAG_TSK_MGMT;
1728         tsk_mgmt->tsk_mgmt_func = func;
1729         tsk_mgmt->task_tag      = req_tag;
1730
1731         ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
1732                                       DMA_TO_DEVICE);
1733         if (srp_post_send(target, iu, sizeof *tsk_mgmt)) {
1734                 srp_put_tx_iu(target, iu, SRP_IU_TSK_MGMT);
1735                 return -1;
1736         }
1737
1738         if (!wait_for_completion_timeout(&target->tsk_mgmt_done,
1739                                          msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1740                 return -1;
1741
1742         return 0;
1743 }
1744
1745 static int srp_abort(struct scsi_cmnd *scmnd)
1746 {
1747         struct srp_target_port *target = host_to_target(scmnd->device->host);
1748         struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
1749         int ret;
1750
1751         shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
1752
1753         if (!req || !srp_claim_req(target, req, scmnd))
1754                 return FAILED;
1755         if (srp_send_tsk_mgmt(target, req->index, scmnd->device->lun,
1756                               SRP_TSK_ABORT_TASK) == 0)
1757                 ret = SUCCESS;
1758         else if (target->transport_offline)
1759                 ret = FAST_IO_FAIL;
1760         else
1761                 ret = FAILED;
1762         srp_free_req(target, req, scmnd, 0);
1763         scmnd->result = DID_ABORT << 16;
1764         scmnd->scsi_done(scmnd);
1765
1766         return ret;
1767 }
1768
1769 static int srp_reset_device(struct scsi_cmnd *scmnd)
1770 {
1771         struct srp_target_port *target = host_to_target(scmnd->device->host);
1772         int i;
1773
1774         shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
1775
1776         if (srp_send_tsk_mgmt(target, SRP_TAG_NO_REQ, scmnd->device->lun,
1777                               SRP_TSK_LUN_RESET))
1778                 return FAILED;
1779         if (target->tsk_mgmt_status)
1780                 return FAILED;
1781
1782         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
1783                 struct srp_request *req = &target->req_ring[i];
1784                 if (req->scmnd && req->scmnd->device == scmnd->device)
1785                         srp_reset_req(target, req);
1786         }
1787
1788         return SUCCESS;
1789 }
1790
1791 static int srp_reset_host(struct scsi_cmnd *scmnd)
1792 {
1793         struct srp_target_port *target = host_to_target(scmnd->device->host);
1794         int ret = FAILED;
1795
1796         shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
1797
1798         if (!srp_reconnect_target(target))
1799                 ret = SUCCESS;
1800
1801         return ret;
1802 }
1803
1804 static int srp_slave_configure(struct scsi_device *sdev)
1805 {
1806         struct Scsi_Host *shost = sdev->host;
1807         struct srp_target_port *target = host_to_target(shost);
1808         struct request_queue *q = sdev->request_queue;
1809         unsigned long timeout;
1810
1811         if (sdev->type == TYPE_DISK) {
1812                 timeout = max_t(unsigned, 30 * HZ, target->rq_tmo_jiffies);
1813                 blk_queue_rq_timeout(q, timeout);
1814         }
1815
1816         return 0;
1817 }
1818
1819 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
1820                            char *buf)
1821 {
1822         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1823
1824         return sprintf(buf, "0x%016llx\n",
1825                        (unsigned long long) be64_to_cpu(target->id_ext));
1826 }
1827
1828 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
1829                              char *buf)
1830 {
1831         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1832
1833         return sprintf(buf, "0x%016llx\n",
1834                        (unsigned long long) be64_to_cpu(target->ioc_guid));
1835 }
1836
1837 static ssize_t show_service_id(struct device *dev,
1838                                struct device_attribute *attr, char *buf)
1839 {
1840         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1841
1842         return sprintf(buf, "0x%016llx\n",
1843                        (unsigned long long) be64_to_cpu(target->service_id));
1844 }
1845
1846 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
1847                          char *buf)
1848 {
1849         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1850
1851         return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
1852 }
1853
1854 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
1855                          char *buf)
1856 {
1857         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1858
1859         return sprintf(buf, "%pI6\n", target->path.dgid.raw);
1860 }
1861
1862 static ssize_t show_orig_dgid(struct device *dev,
1863                               struct device_attribute *attr, char *buf)
1864 {
1865         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1866
1867         return sprintf(buf, "%pI6\n", target->orig_dgid);
1868 }
1869
1870 static ssize_t show_req_lim(struct device *dev,
1871                             struct device_attribute *attr, char *buf)
1872 {
1873         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1874
1875         return sprintf(buf, "%d\n", target->req_lim);
1876 }
1877
1878 static ssize_t show_zero_req_lim(struct device *dev,
1879                                  struct device_attribute *attr, char *buf)
1880 {
1881         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1882
1883         return sprintf(buf, "%d\n", target->zero_req_lim);
1884 }
1885
1886 static ssize_t show_local_ib_port(struct device *dev,
1887                                   struct device_attribute *attr, char *buf)
1888 {
1889         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1890
1891         return sprintf(buf, "%d\n", target->srp_host->port);
1892 }
1893
1894 static ssize_t show_local_ib_device(struct device *dev,
1895                                     struct device_attribute *attr, char *buf)
1896 {
1897         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1898
1899         return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
1900 }
1901
1902 static ssize_t show_comp_vector(struct device *dev,
1903                                 struct device_attribute *attr, char *buf)
1904 {
1905         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1906
1907         return sprintf(buf, "%d\n", target->comp_vector);
1908 }
1909
1910 static ssize_t show_cmd_sg_entries(struct device *dev,
1911                                    struct device_attribute *attr, char *buf)
1912 {
1913         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1914
1915         return sprintf(buf, "%u\n", target->cmd_sg_cnt);
1916 }
1917
1918 static ssize_t show_allow_ext_sg(struct device *dev,
1919                                  struct device_attribute *attr, char *buf)
1920 {
1921         struct srp_target_port *target = host_to_target(class_to_shost(dev));
1922
1923         return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
1924 }
1925
1926 static DEVICE_ATTR(id_ext,          S_IRUGO, show_id_ext,          NULL);
1927 static DEVICE_ATTR(ioc_guid,        S_IRUGO, show_ioc_guid,        NULL);
1928 static DEVICE_ATTR(service_id,      S_IRUGO, show_service_id,      NULL);
1929 static DEVICE_ATTR(pkey,            S_IRUGO, show_pkey,            NULL);
1930 static DEVICE_ATTR(dgid,            S_IRUGO, show_dgid,            NULL);
1931 static DEVICE_ATTR(orig_dgid,       S_IRUGO, show_orig_dgid,       NULL);
1932 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
1933 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,    NULL);
1934 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
1935 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
1936 static DEVICE_ATTR(comp_vector,     S_IRUGO, show_comp_vector,     NULL);
1937 static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
1938 static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
1939
1940 static struct device_attribute *srp_host_attrs[] = {
1941         &dev_attr_id_ext,
1942         &dev_attr_ioc_guid,
1943         &dev_attr_service_id,
1944         &dev_attr_pkey,
1945         &dev_attr_dgid,
1946         &dev_attr_orig_dgid,
1947         &dev_attr_req_lim,
1948         &dev_attr_zero_req_lim,
1949         &dev_attr_local_ib_port,
1950         &dev_attr_local_ib_device,
1951         &dev_attr_comp_vector,
1952         &dev_attr_cmd_sg_entries,
1953         &dev_attr_allow_ext_sg,
1954         NULL
1955 };
1956
1957 static struct scsi_host_template srp_template = {
1958         .module                         = THIS_MODULE,
1959         .name                           = "InfiniBand SRP initiator",
1960         .proc_name                      = DRV_NAME,
1961         .slave_configure                = srp_slave_configure,
1962         .info                           = srp_target_info,
1963         .queuecommand                   = srp_queuecommand,
1964         .eh_abort_handler               = srp_abort,
1965         .eh_device_reset_handler        = srp_reset_device,
1966         .eh_host_reset_handler          = srp_reset_host,
1967         .skip_settle_delay              = true,
1968         .sg_tablesize                   = SRP_DEF_SG_TABLESIZE,
1969         .can_queue                      = SRP_CMD_SQ_SIZE,
1970         .this_id                        = -1,
1971         .cmd_per_lun                    = SRP_CMD_SQ_SIZE,
1972         .use_clustering                 = ENABLE_CLUSTERING,
1973         .shost_attrs                    = srp_host_attrs
1974 };
1975
1976 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
1977 {
1978         struct srp_rport_identifiers ids;
1979         struct srp_rport *rport;
1980
1981         sprintf(target->target_name, "SRP.T10:%016llX",
1982                  (unsigned long long) be64_to_cpu(target->id_ext));
1983
1984         if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
1985                 return -ENODEV;
1986
1987         memcpy(ids.port_id, &target->id_ext, 8);
1988         memcpy(ids.port_id + 8, &target->ioc_guid, 8);
1989         ids.roles = SRP_RPORT_ROLE_TARGET;
1990         rport = srp_rport_add(target->scsi_host, &ids);
1991         if (IS_ERR(rport)) {
1992                 scsi_remove_host(target->scsi_host);
1993                 return PTR_ERR(rport);
1994         }
1995
1996         rport->lld_data = target;
1997
1998         spin_lock(&host->target_lock);
1999         list_add_tail(&target->list, &host->target_list);
2000         spin_unlock(&host->target_lock);
2001
2002         target->state = SRP_TARGET_LIVE;
2003
2004         scsi_scan_target(&target->scsi_host->shost_gendev,
2005                          0, target->scsi_id, SCAN_WILD_CARD, 0);
2006
2007         return 0;
2008 }
2009
2010 static void srp_release_dev(struct device *dev)
2011 {
2012         struct srp_host *host =
2013                 container_of(dev, struct srp_host, dev);
2014
2015         complete(&host->released);
2016 }
2017
2018 static struct class srp_class = {
2019         .name    = "infiniband_srp",
2020         .dev_release = srp_release_dev
2021 };
2022
2023 /**
2024  * srp_conn_unique() - check whether the connection to a target is unique
2025  */
2026 static bool srp_conn_unique(struct srp_host *host,
2027                             struct srp_target_port *target)
2028 {
2029         struct srp_target_port *t;
2030         bool ret = false;
2031
2032         if (target->state == SRP_TARGET_REMOVED)
2033                 goto out;
2034
2035         ret = true;
2036
2037         spin_lock(&host->target_lock);
2038         list_for_each_entry(t, &host->target_list, list) {
2039                 if (t != target &&
2040                     target->id_ext == t->id_ext &&
2041                     target->ioc_guid == t->ioc_guid &&
2042                     target->initiator_ext == t->initiator_ext) {
2043                         ret = false;
2044                         break;
2045                 }
2046         }
2047         spin_unlock(&host->target_lock);
2048
2049 out:
2050         return ret;
2051 }
2052
2053 /*
2054  * Target ports are added by writing
2055  *
2056  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
2057  *     pkey=<P_Key>,service_id=<service ID>
2058  *
2059  * to the add_target sysfs attribute.
2060  */
2061 enum {
2062         SRP_OPT_ERR             = 0,
2063         SRP_OPT_ID_EXT          = 1 << 0,
2064         SRP_OPT_IOC_GUID        = 1 << 1,
2065         SRP_OPT_DGID            = 1 << 2,
2066         SRP_OPT_PKEY            = 1 << 3,
2067         SRP_OPT_SERVICE_ID      = 1 << 4,
2068         SRP_OPT_MAX_SECT        = 1 << 5,
2069         SRP_OPT_MAX_CMD_PER_LUN = 1 << 6,
2070         SRP_OPT_IO_CLASS        = 1 << 7,
2071         SRP_OPT_INITIATOR_EXT   = 1 << 8,
2072         SRP_OPT_CMD_SG_ENTRIES  = 1 << 9,
2073         SRP_OPT_ALLOW_EXT_SG    = 1 << 10,
2074         SRP_OPT_SG_TABLESIZE    = 1 << 11,
2075         SRP_OPT_COMP_VECTOR     = 1 << 12,
2076         SRP_OPT_ALL             = (SRP_OPT_ID_EXT       |
2077                                    SRP_OPT_IOC_GUID     |
2078                                    SRP_OPT_DGID         |
2079                                    SRP_OPT_PKEY         |
2080                                    SRP_OPT_SERVICE_ID),
2081 };
2082
2083 static const match_table_t srp_opt_tokens = {
2084         { SRP_OPT_ID_EXT,               "id_ext=%s"             },
2085         { SRP_OPT_IOC_GUID,             "ioc_guid=%s"           },
2086         { SRP_OPT_DGID,                 "dgid=%s"               },
2087         { SRP_OPT_PKEY,                 "pkey=%x"               },
2088         { SRP_OPT_SERVICE_ID,           "service_id=%s"         },
2089         { SRP_OPT_MAX_SECT,             "max_sect=%d"           },
2090         { SRP_OPT_MAX_CMD_PER_LUN,      "max_cmd_per_lun=%d"    },
2091         { SRP_OPT_IO_CLASS,             "io_class=%x"           },
2092         { SRP_OPT_INITIATOR_EXT,        "initiator_ext=%s"      },
2093         { SRP_OPT_CMD_SG_ENTRIES,       "cmd_sg_entries=%u"     },
2094         { SRP_OPT_ALLOW_EXT_SG,         "allow_ext_sg=%u"       },
2095         { SRP_OPT_SG_TABLESIZE,         "sg_tablesize=%u"       },
2096         { SRP_OPT_COMP_VECTOR,          "comp_vector=%u"        },
2097         { SRP_OPT_ERR,                  NULL                    }
2098 };
2099
2100 static int srp_parse_options(const char *buf, struct srp_target_port *target)
2101 {
2102         char *options, *sep_opt;
2103         char *p;
2104         char dgid[3];
2105         substring_t args[MAX_OPT_ARGS];
2106         int opt_mask = 0;
2107         int token;
2108         int ret = -EINVAL;
2109         int i;
2110
2111         options = kstrdup(buf, GFP_KERNEL);
2112         if (!options)
2113                 return -ENOMEM;
2114
2115         sep_opt = options;
2116         while ((p = strsep(&sep_opt, ",")) != NULL) {
2117                 if (!*p)
2118                         continue;
2119
2120                 token = match_token(p, srp_opt_tokens, args);
2121                 opt_mask |= token;
2122
2123                 switch (token) {
2124                 case SRP_OPT_ID_EXT:
2125                         p = match_strdup(args);
2126                         if (!p) {
2127                                 ret = -ENOMEM;
2128                                 goto out;
2129                         }
2130                         target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2131                         kfree(p);
2132                         break;
2133
2134                 case SRP_OPT_IOC_GUID:
2135                         p = match_strdup(args);
2136                         if (!p) {
2137                                 ret = -ENOMEM;
2138                                 goto out;
2139                         }
2140                         target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
2141                         kfree(p);
2142                         break;
2143
2144                 case SRP_OPT_DGID:
2145                         p = match_strdup(args);
2146                         if (!p) {
2147                                 ret = -ENOMEM;
2148                                 goto out;
2149                         }
2150                         if (strlen(p) != 32) {
2151                                 pr_warn("bad dest GID parameter '%s'\n", p);
2152                                 kfree(p);
2153                                 goto out;
2154                         }
2155
2156                         for (i = 0; i < 16; ++i) {
2157                                 strlcpy(dgid, p + i * 2, 3);
2158                                 target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
2159                         }
2160                         kfree(p);
2161                         memcpy(target->orig_dgid, target->path.dgid.raw, 16);
2162                         break;
2163
2164                 case SRP_OPT_PKEY:
2165                         if (match_hex(args, &token)) {
2166                                 pr_warn("bad P_Key parameter '%s'\n", p);
2167                                 goto out;
2168                         }
2169                         target->path.pkey = cpu_to_be16(token);
2170                         break;
2171
2172                 case SRP_OPT_SERVICE_ID:
2173                         p = match_strdup(args);
2174                         if (!p) {
2175                                 ret = -ENOMEM;
2176                                 goto out;
2177                         }
2178                         target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
2179                         target->path.service_id = target->service_id;
2180                         kfree(p);
2181                         break;
2182
2183                 case SRP_OPT_MAX_SECT:
2184                         if (match_int(args, &token)) {
2185                                 pr_warn("bad max sect parameter '%s'\n", p);
2186                                 goto out;
2187                         }
2188                         target->scsi_host->max_sectors = token;
2189                         break;
2190
2191                 case SRP_OPT_MAX_CMD_PER_LUN:
2192                         if (match_int(args, &token)) {
2193                                 pr_warn("bad max cmd_per_lun parameter '%s'\n",
2194                                         p);
2195                                 goto out;
2196                         }
2197                         target->scsi_host->cmd_per_lun = min(token, SRP_CMD_SQ_SIZE);
2198                         break;
2199
2200                 case SRP_OPT_IO_CLASS:
2201                         if (match_hex(args, &token)) {
2202                                 pr_warn("bad IO class parameter '%s'\n", p);
2203                                 goto out;
2204                         }
2205                         if (token != SRP_REV10_IB_IO_CLASS &&
2206                             token != SRP_REV16A_IB_IO_CLASS) {
2207                                 pr_warn("unknown IO class parameter value %x specified (use %x or %x).\n",
2208                                         token, SRP_REV10_IB_IO_CLASS,
2209                                         SRP_REV16A_IB_IO_CLASS);
2210                                 goto out;
2211                         }
2212                         target->io_class = token;
2213                         break;
2214
2215                 case SRP_OPT_INITIATOR_EXT:
2216                         p = match_strdup(args);
2217                         if (!p) {
2218                                 ret = -ENOMEM;
2219                                 goto out;
2220                         }
2221                         target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2222                         kfree(p);
2223                         break;
2224
2225                 case SRP_OPT_CMD_SG_ENTRIES:
2226                         if (match_int(args, &token) || token < 1 || token > 255) {
2227                                 pr_warn("bad max cmd_sg_entries parameter '%s'\n",
2228                                         p);
2229                                 goto out;
2230                         }
2231                         target->cmd_sg_cnt = token;
2232                         break;
2233
2234                 case SRP_OPT_ALLOW_EXT_SG:
2235                         if (match_int(args, &token)) {
2236                                 pr_warn("bad allow_ext_sg parameter '%s'\n", p);
2237                                 goto out;
2238                         }
2239                         target->allow_ext_sg = !!token;
2240                         break;
2241
2242                 case SRP_OPT_SG_TABLESIZE:
2243                         if (match_int(args, &token) || token < 1 ||
2244                                         token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
2245                                 pr_warn("bad max sg_tablesize parameter '%s'\n",
2246                                         p);
2247                                 goto out;
2248                         }
2249                         target->sg_tablesize = token;
2250                         break;
2251
2252                 case SRP_OPT_COMP_VECTOR:
2253                         if (match_int(args, &token) || token < 0) {
2254                                 pr_warn("bad comp_vector parameter '%s'\n", p);
2255                                 goto out;
2256                         }
2257                         target->comp_vector = token;
2258                         break;
2259
2260                 default:
2261                         pr_warn("unknown parameter or missing value '%s' in target creation request\n",
2262                                 p);
2263                         goto out;
2264                 }
2265         }
2266
2267         if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
2268                 ret = 0;
2269         else
2270                 for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
2271                         if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
2272                             !(srp_opt_tokens[i].token & opt_mask))
2273                                 pr_warn("target creation request is missing parameter '%s'\n",
2274                                         srp_opt_tokens[i].pattern);
2275
2276 out:
2277         kfree(options);
2278         return ret;
2279 }
2280
2281 static ssize_t srp_create_target(struct device *dev,
2282                                  struct device_attribute *attr,
2283                                  const char *buf, size_t count)
2284 {
2285         struct srp_host *host =
2286                 container_of(dev, struct srp_host, dev);
2287         struct Scsi_Host *target_host;
2288         struct srp_target_port *target;
2289         struct ib_device *ibdev = host->srp_dev->dev;
2290         dma_addr_t dma_addr;
2291         int i, ret;
2292
2293         target_host = scsi_host_alloc(&srp_template,
2294                                       sizeof (struct srp_target_port));
2295         if (!target_host)
2296                 return -ENOMEM;
2297
2298         target_host->transportt  = ib_srp_transport_template;
2299         target_host->max_channel = 0;
2300         target_host->max_id      = 1;
2301         target_host->max_lun     = SRP_MAX_LUN;
2302         target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
2303
2304         target = host_to_target(target_host);
2305
2306         target->io_class        = SRP_REV16A_IB_IO_CLASS;
2307         target->scsi_host       = target_host;
2308         target->srp_host        = host;
2309         target->lkey            = host->srp_dev->mr->lkey;
2310         target->rkey            = host->srp_dev->mr->rkey;
2311         target->cmd_sg_cnt      = cmd_sg_entries;
2312         target->sg_tablesize    = indirect_sg_entries ? : cmd_sg_entries;
2313         target->allow_ext_sg    = allow_ext_sg;
2314
2315         ret = srp_parse_options(buf, target);
2316         if (ret)
2317                 goto err;
2318
2319         if (!srp_conn_unique(target->srp_host, target)) {
2320                 shost_printk(KERN_INFO, target->scsi_host,
2321                              PFX "Already connected to target port with id_ext=%016llx;ioc_guid=%016llx;initiator_ext=%016llx\n",
2322                              be64_to_cpu(target->id_ext),
2323                              be64_to_cpu(target->ioc_guid),
2324                              be64_to_cpu(target->initiator_ext));
2325                 ret = -EEXIST;
2326                 goto err;
2327         }
2328
2329         if (!host->srp_dev->fmr_pool && !target->allow_ext_sg &&
2330                                 target->cmd_sg_cnt < target->sg_tablesize) {
2331                 pr_warn("No FMR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
2332                 target->sg_tablesize = target->cmd_sg_cnt;
2333         }
2334
2335         target_host->sg_tablesize = target->sg_tablesize;
2336         target->indirect_size = target->sg_tablesize *
2337                                 sizeof (struct srp_direct_buf);
2338         target->max_iu_len = sizeof (struct srp_cmd) +
2339                              sizeof (struct srp_indirect_buf) +
2340                              target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
2341
2342         INIT_WORK(&target->remove_work, srp_remove_work);
2343         spin_lock_init(&target->lock);
2344         INIT_LIST_HEAD(&target->free_tx);
2345         INIT_LIST_HEAD(&target->free_reqs);
2346         for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
2347                 struct srp_request *req = &target->req_ring[i];
2348
2349                 req->fmr_list = kmalloc(target->cmd_sg_cnt * sizeof (void *),
2350                                         GFP_KERNEL);
2351                 req->map_page = kmalloc(SRP_FMR_SIZE * sizeof (void *),
2352                                         GFP_KERNEL);
2353                 req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
2354                 if (!req->fmr_list || !req->map_page || !req->indirect_desc)
2355                         goto err_free_mem;
2356
2357                 dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
2358                                              target->indirect_size,
2359                                              DMA_TO_DEVICE);
2360                 if (ib_dma_mapping_error(ibdev, dma_addr))
2361                         goto err_free_mem;
2362
2363                 req->indirect_dma_addr = dma_addr;
2364                 req->index = i;
2365                 list_add_tail(&req->list, &target->free_reqs);
2366         }
2367
2368         ib_query_gid(ibdev, host->port, 0, &target->path.sgid);
2369
2370         shost_printk(KERN_DEBUG, target->scsi_host, PFX
2371                      "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
2372                      "service_id %016llx dgid %pI6\n",
2373                (unsigned long long) be64_to_cpu(target->id_ext),
2374                (unsigned long long) be64_to_cpu(target->ioc_guid),
2375                be16_to_cpu(target->path.pkey),
2376                (unsigned long long) be64_to_cpu(target->service_id),
2377                target->path.dgid.raw);
2378
2379         ret = srp_create_target_ib(target);
2380         if (ret)
2381                 goto err_free_mem;
2382
2383         ret = srp_new_cm_id(target);
2384         if (ret)
2385                 goto err_free_ib;
2386
2387         ret = srp_connect_target(target);
2388         if (ret) {
2389                 shost_printk(KERN_ERR, target->scsi_host,
2390                              PFX "Connection failed\n");
2391                 goto err_cm_id;
2392         }
2393
2394         ret = srp_add_target(host, target);
2395         if (ret)
2396                 goto err_disconnect;
2397
2398         return count;
2399
2400 err_disconnect:
2401         srp_disconnect_target(target);
2402
2403 err_cm_id:
2404         ib_destroy_cm_id(target->cm_id);
2405
2406 err_free_ib:
2407         srp_free_target_ib(target);
2408
2409 err_free_mem:
2410         srp_free_req_data(target);
2411
2412 err:
2413         scsi_host_put(target_host);
2414
2415         return ret;
2416 }
2417
2418 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
2419
2420 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
2421                           char *buf)
2422 {
2423         struct srp_host *host = container_of(dev, struct srp_host, dev);
2424
2425         return sprintf(buf, "%s\n", host->srp_dev->dev->name);
2426 }
2427
2428 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
2429
2430 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
2431                          char *buf)
2432 {
2433         struct srp_host *host = container_of(dev, struct srp_host, dev);
2434
2435         return sprintf(buf, "%d\n", host->port);
2436 }
2437
2438 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
2439
2440 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
2441 {
2442         struct srp_host *host;
2443
2444         host = kzalloc(sizeof *host, GFP_KERNEL);
2445         if (!host)
2446                 return NULL;
2447
2448         INIT_LIST_HEAD(&host->target_list);
2449         spin_lock_init(&host->target_lock);
2450         init_completion(&host->released);
2451         host->srp_dev = device;
2452         host->port = port;
2453
2454         host->dev.class = &srp_class;
2455         host->dev.parent = device->dev->dma_device;
2456         dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
2457
2458         if (device_register(&host->dev))
2459                 goto free_host;
2460         if (device_create_file(&host->dev, &dev_attr_add_target))
2461                 goto err_class;
2462         if (device_create_file(&host->dev, &dev_attr_ibdev))
2463                 goto err_class;
2464         if (device_create_file(&host->dev, &dev_attr_port))
2465                 goto err_class;
2466
2467         return host;
2468
2469 err_class:
2470         device_unregister(&host->dev);
2471
2472 free_host:
2473         kfree(host);
2474
2475         return NULL;
2476 }
2477
2478 static void srp_add_one(struct ib_device *device)
2479 {
2480         struct srp_device *srp_dev;
2481         struct ib_device_attr *dev_attr;
2482         struct ib_fmr_pool_param fmr_param;
2483         struct srp_host *host;
2484         int max_pages_per_fmr, fmr_page_shift, s, e, p;
2485
2486         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
2487         if (!dev_attr)
2488                 return;
2489
2490         if (ib_query_device(device, dev_attr)) {
2491                 pr_warn("Query device failed for %s\n", device->name);
2492                 goto free_attr;
2493         }
2494
2495         srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
2496         if (!srp_dev)
2497                 goto free_attr;
2498
2499         /*
2500          * Use the smallest page size supported by the HCA, down to a
2501          * minimum of 4096 bytes. We're unlikely to build large sglists
2502          * out of smaller entries.
2503          */
2504         fmr_page_shift          = max(12, ffs(dev_attr->page_size_cap) - 1);
2505         srp_dev->fmr_page_size  = 1 << fmr_page_shift;
2506         srp_dev->fmr_page_mask  = ~((u64) srp_dev->fmr_page_size - 1);
2507         srp_dev->fmr_max_size   = srp_dev->fmr_page_size * SRP_FMR_SIZE;
2508
2509         INIT_LIST_HEAD(&srp_dev->dev_list);
2510
2511         srp_dev->dev = device;
2512         srp_dev->pd  = ib_alloc_pd(device);
2513         if (IS_ERR(srp_dev->pd))
2514                 goto free_dev;
2515
2516         srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
2517                                     IB_ACCESS_LOCAL_WRITE |
2518                                     IB_ACCESS_REMOTE_READ |
2519                                     IB_ACCESS_REMOTE_WRITE);
2520         if (IS_ERR(srp_dev->mr))
2521                 goto err_pd;
2522
2523         for (max_pages_per_fmr = SRP_FMR_SIZE;
2524                         max_pages_per_fmr >= SRP_FMR_MIN_SIZE;
2525                         max_pages_per_fmr /= 2, srp_dev->fmr_max_size /= 2) {
2526                 memset(&fmr_param, 0, sizeof fmr_param);
2527                 fmr_param.pool_size         = SRP_FMR_POOL_SIZE;
2528                 fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
2529                 fmr_param.cache             = 1;
2530                 fmr_param.max_pages_per_fmr = max_pages_per_fmr;
2531                 fmr_param.page_shift        = fmr_page_shift;
2532                 fmr_param.access            = (IB_ACCESS_LOCAL_WRITE |
2533                                                IB_ACCESS_REMOTE_WRITE |
2534                                                IB_ACCESS_REMOTE_READ);
2535
2536                 srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
2537                 if (!IS_ERR(srp_dev->fmr_pool))
2538                         break;
2539         }
2540
2541         if (IS_ERR(srp_dev->fmr_pool))
2542                 srp_dev->fmr_pool = NULL;
2543
2544         if (device->node_type == RDMA_NODE_IB_SWITCH) {
2545                 s = 0;
2546                 e = 0;
2547         } else {
2548                 s = 1;
2549                 e = device->phys_port_cnt;
2550         }
2551
2552         for (p = s; p <= e; ++p) {
2553                 host = srp_add_port(srp_dev, p);
2554                 if (host)
2555                         list_add_tail(&host->list, &srp_dev->dev_list);
2556         }
2557
2558         ib_set_client_data(device, &srp_client, srp_dev);
2559
2560         goto free_attr;
2561
2562 err_pd:
2563         ib_dealloc_pd(srp_dev->pd);
2564
2565 free_dev:
2566         kfree(srp_dev);
2567
2568 free_attr:
2569         kfree(dev_attr);
2570 }
2571
2572 static void srp_remove_one(struct ib_device *device)
2573 {
2574         struct srp_device *srp_dev;
2575         struct srp_host *host, *tmp_host;
2576         struct srp_target_port *target;
2577
2578         srp_dev = ib_get_client_data(device, &srp_client);
2579         if (!srp_dev)
2580                 return;
2581
2582         list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
2583                 device_unregister(&host->dev);
2584                 /*
2585                  * Wait for the sysfs entry to go away, so that no new
2586                  * target ports can be created.
2587                  */
2588                 wait_for_completion(&host->released);
2589
2590                 /*
2591                  * Remove all target ports.
2592                  */
2593                 spin_lock(&host->target_lock);
2594                 list_for_each_entry(target, &host->target_list, list)
2595                         srp_queue_remove_work(target);
2596                 spin_unlock(&host->target_lock);
2597
2598                 /*
2599                  * Wait for target port removal tasks.
2600                  */
2601                 flush_workqueue(system_long_wq);
2602
2603                 kfree(host);
2604         }
2605
2606         if (srp_dev->fmr_pool)
2607                 ib_destroy_fmr_pool(srp_dev->fmr_pool);
2608         ib_dereg_mr(srp_dev->mr);
2609         ib_dealloc_pd(srp_dev->pd);
2610
2611         kfree(srp_dev);
2612 }
2613
2614 static struct srp_function_template ib_srp_transport_functions = {
2615         .rport_delete            = srp_rport_delete,
2616 };
2617
2618 static int __init srp_init_module(void)
2619 {
2620         int ret;
2621
2622         BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
2623
2624         if (srp_sg_tablesize) {
2625                 pr_warn("srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
2626                 if (!cmd_sg_entries)
2627                         cmd_sg_entries = srp_sg_tablesize;
2628         }
2629
2630         if (!cmd_sg_entries)
2631                 cmd_sg_entries = SRP_DEF_SG_TABLESIZE;
2632
2633         if (cmd_sg_entries > 255) {
2634                 pr_warn("Clamping cmd_sg_entries to 255\n");
2635                 cmd_sg_entries = 255;
2636         }
2637
2638         if (!indirect_sg_entries)
2639                 indirect_sg_entries = cmd_sg_entries;
2640         else if (indirect_sg_entries < cmd_sg_entries) {
2641                 pr_warn("Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n",
2642                         cmd_sg_entries);
2643                 indirect_sg_entries = cmd_sg_entries;
2644         }
2645
2646         ib_srp_transport_template =
2647                 srp_attach_transport(&ib_srp_transport_functions);
2648         if (!ib_srp_transport_template)
2649                 return -ENOMEM;
2650
2651         ret = class_register(&srp_class);
2652         if (ret) {
2653                 pr_err("couldn't register class infiniband_srp\n");
2654                 srp_release_transport(ib_srp_transport_template);
2655                 return ret;
2656         }
2657
2658         ib_sa_register_client(&srp_sa_client);
2659
2660         ret = ib_register_client(&srp_client);
2661         if (ret) {
2662                 pr_err("couldn't register IB client\n");
2663                 srp_release_transport(ib_srp_transport_template);
2664                 ib_sa_unregister_client(&srp_sa_client);
2665                 class_unregister(&srp_class);
2666                 return ret;
2667         }
2668
2669         return 0;
2670 }
2671
2672 static void __exit srp_cleanup_module(void)
2673 {
2674         ib_unregister_client(&srp_client);
2675         ib_sa_unregister_client(&srp_sa_client);
2676         class_unregister(&srp_class);
2677         srp_release_transport(ib_srp_transport_template);
2678 }
2679
2680 module_init(srp_init_module);
2681 module_exit(srp_cleanup_module);