Pileus Git - ~andy/linux/blob - 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/scsi_tcq.h>
  50 #include <scsi/srp.h>
  51 #include <scsi/scsi_transport_srp.h>
  52
  53 #include "ib_srp.h"
  54
  55 #define DRV_NAME        "ib_srp"
  56 #define PFX             DRV_NAME ": "
  57 #define DRV_VERSION     "1.0"
  58 #define DRV_RELDATE     "July 1, 2013"
  59
  60 MODULE_AUTHOR("Roland Dreier");
  61 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol initiator "
  62                    "v" DRV_VERSION " (" DRV_RELDATE ")");
  63 MODULE_LICENSE("Dual BSD/GPL");
  64
  65 static unsigned int srp_sg_tablesize;
  66 static unsigned int cmd_sg_entries;
  67 static unsigned int indirect_sg_entries;
  68 static bool allow_ext_sg;
  69 static int topspin_workarounds = 1;
  70
  71 module_param(srp_sg_tablesize, uint, 0444);
  72 MODULE_PARM_DESC(srp_sg_tablesize, "Deprecated name for cmd_sg_entries");
  73
  74 module_param(cmd_sg_entries, uint, 0444);
  75 MODULE_PARM_DESC(cmd_sg_entries,
  76                  "Default number of gather/scatter entries in the SRP command (default is 12, max 255)");
  77
  78 module_param(indirect_sg_entries, uint, 0444);
  79 MODULE_PARM_DESC(indirect_sg_entries,
  80                  "Default max number of gather/scatter entries (default is 12, max is " __stringify(SCSI_MAX_SG_CHAIN_SEGMENTS) ")");
  81
  82 module_param(allow_ext_sg, bool, 0444);
  83 MODULE_PARM_DESC(allow_ext_sg,
  84                   "Default behavior when there are more than cmd_sg_entries S/G entries after mapping; fails the request when false (default false)");
  85
  86 module_param(topspin_workarounds, int, 0444);
  87 MODULE_PARM_DESC(topspin_workarounds,
  88                  "Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
  89
  90 static struct kernel_param_ops srp_tmo_ops;
  91
  92 static int srp_reconnect_delay = 10;
  93 module_param_cb(reconnect_delay, &srp_tmo_ops, &srp_reconnect_delay,
  94                 S_IRUGO | S_IWUSR);
  95 MODULE_PARM_DESC(reconnect_delay, "Time between successive reconnect attempts");
  96
  97 static int srp_fast_io_fail_tmo = 15;
  98 module_param_cb(fast_io_fail_tmo, &srp_tmo_ops, &srp_fast_io_fail_tmo,
  99                 S_IRUGO | S_IWUSR);
 100 MODULE_PARM_DESC(fast_io_fail_tmo,
 101                  "Number of seconds between the observation of a transport"
 102                  " layer error and failing all I/O. \"off\" means that this"
 103                  " functionality is disabled.");
 104
 105 static int srp_dev_loss_tmo = 600;
 106 module_param_cb(dev_loss_tmo, &srp_tmo_ops, &srp_dev_loss_tmo,
 107                 S_IRUGO | S_IWUSR);
 108 MODULE_PARM_DESC(dev_loss_tmo,
 109                  "Maximum number of seconds that the SRP transport should"
 110                  " insulate transport layer errors. After this time has been"
 111                  " exceeded the SCSI host is removed. Should be"
 112                  " between 1 and " __stringify(SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
 113                  " if fast_io_fail_tmo has not been set. \"off\" means that"
 114                  " this functionality is disabled.");
 115
 116 static void srp_add_one(struct ib_device *device);
 117 static void srp_remove_one(struct ib_device *device);
 118 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
 119 static void srp_send_completion(struct ib_cq *cq, void *target_ptr);
 120 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event);
 121
 122 static struct scsi_transport_template *ib_srp_transport_template;
 123
 124 static struct ib_client srp_client = {
 125         .name   = "srp",
 126         .add    = srp_add_one,
 127         .remove = srp_remove_one
 128 };
 129
 130 static struct ib_sa_client srp_sa_client;
 131
 132 static int srp_tmo_get(char *buffer, const struct kernel_param *kp)
 133 {
 134         int tmo = *(int *)kp->arg;
 135
 136         if (tmo >= 0)
 137                 return sprintf(buffer, "%d", tmo);
 138         else
 139                 return sprintf(buffer, "off");
 140 }
 141
 142 static int srp_tmo_set(const char *val, const struct kernel_param *kp)
 143 {
 144         int tmo, res;
 145
 146         if (strncmp(val, "off", 3) != 0) {
 147                 res = kstrtoint(val, 0, &tmo);
 148                 if (res)
 149                         goto out;
 150         } else {
 151                 tmo = -1;
 152         }
 153         if (kp->arg == &srp_reconnect_delay)
 154                 res = srp_tmo_valid(tmo, srp_fast_io_fail_tmo,
 155                                     srp_dev_loss_tmo);
 156         else if (kp->arg == &srp_fast_io_fail_tmo)
 157                 res = srp_tmo_valid(srp_reconnect_delay, tmo, srp_dev_loss_tmo);
 158         else
 159                 res = srp_tmo_valid(srp_reconnect_delay, srp_fast_io_fail_tmo,
 160                                     tmo);
 161         if (res)
 162                 goto out;
 163         *(int *)kp->arg = tmo;
 164
 165 out:
 166         return res;
 167 }
 168
 169 static struct kernel_param_ops srp_tmo_ops = {
 170         .get = srp_tmo_get,
 171         .set = srp_tmo_set,
 172 };
 173
 174 static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
 175 {
 176         return (struct srp_target_port *) host->hostdata;
 177 }
 178
 179 static const char *srp_target_info(struct Scsi_Host *host)
 180 {
 181         return host_to_target(host)->target_name;
 182 }
 183
 184 static int srp_target_is_topspin(struct srp_target_port *target)
 185 {
 186         static const u8 topspin_oui[3] = { 0x00, 0x05, 0xad };
 187         static const u8 cisco_oui[3]   = { 0x00, 0x1b, 0x0d };
 188
 189         return topspin_workarounds &&
 190                 (!memcmp(&target->ioc_guid, topspin_oui, sizeof topspin_oui) ||
 191                  !memcmp(&target->ioc_guid, cisco_oui, sizeof cisco_oui));
 192 }
 193
 194 static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
 195                                    gfp_t gfp_mask,
 196                                    enum dma_data_direction direction)
 197 {
 198         struct srp_iu *iu;
 199
 200         iu = kmalloc(sizeof *iu, gfp_mask);
 201         if (!iu)
 202                 goto out;
 203
 204         iu->buf = kzalloc(size, gfp_mask);
 205         if (!iu->buf)
 206                 goto out_free_iu;
 207
 208         iu->dma = ib_dma_map_single(host->srp_dev->dev, iu->buf, size,
 209                                     direction);
 210         if (ib_dma_mapping_error(host->srp_dev->dev, iu->dma))
 211                 goto out_free_buf;
 212
 213         iu->size      = size;
 214         iu->direction = direction;
 215
 216         return iu;
 217
 218 out_free_buf:
 219         kfree(iu->buf);
 220 out_free_iu:
 221         kfree(iu);
 222 out:
 223         return NULL;
 224 }
 225
 226 static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
 227 {
 228         if (!iu)
 229                 return;
 230
 231         ib_dma_unmap_single(host->srp_dev->dev, iu->dma, iu->size,
 232                             iu->direction);
 233         kfree(iu->buf);
 234         kfree(iu);
 235 }
 236
 237 static void srp_qp_event(struct ib_event *event, void *context)
 238 {
 239         pr_debug("QP event %d\n", event->event);
 240 }
 241
 242 static int srp_init_qp(struct srp_target_port *target,
 243                        struct ib_qp *qp)
 244 {
 245         struct ib_qp_attr *attr;
 246         int ret;
 247
 248         attr = kmalloc(sizeof *attr, GFP_KERNEL);
 249         if (!attr)
 250                 return -ENOMEM;
 251
 252         ret = ib_find_pkey(target->srp_host->srp_dev->dev,
 253                            target->srp_host->port,
 254                            be16_to_cpu(target->path.pkey),
 255                            &attr->pkey_index);
 256         if (ret)
 257                 goto out;
 258
 259         attr->qp_state        = IB_QPS_INIT;
 260         attr->qp_access_flags = (IB_ACCESS_REMOTE_READ |
 261                                     IB_ACCESS_REMOTE_WRITE);
 262         attr->port_num        = target->srp_host->port;
 263
 264         ret = ib_modify_qp(qp, attr,
 265                            IB_QP_STATE          |
 266                            IB_QP_PKEY_INDEX     |
 267                            IB_QP_ACCESS_FLAGS   |
 268                            IB_QP_PORT);
 269
 270 out:
 271         kfree(attr);
 272         return ret;
 273 }
 274
 275 static int srp_new_cm_id(struct srp_target_port *target)
 276 {
 277         struct ib_cm_id *new_cm_id;
 278
 279         new_cm_id = ib_create_cm_id(target->srp_host->srp_dev->dev,
 280                                     srp_cm_handler, target);
 281         if (IS_ERR(new_cm_id))
 282                 return PTR_ERR(new_cm_id);
 283
 284         if (target->cm_id)
 285                 ib_destroy_cm_id(target->cm_id);
 286         target->cm_id = new_cm_id;
 287
 288         return 0;
 289 }
 290
 291 static int srp_create_target_ib(struct srp_target_port *target)
 292 {
 293         struct ib_qp_init_attr *init_attr;
 294         struct ib_cq *recv_cq, *send_cq;
 295         struct ib_qp *qp;
 296         int ret;
 297
 298         init_attr = kzalloc(sizeof *init_attr, GFP_KERNEL);
 299         if (!init_attr)
 300                 return -ENOMEM;
 301
 302         recv_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 303                                srp_recv_completion, NULL, target,
 304                                target->queue_size, target->comp_vector);
 305         if (IS_ERR(recv_cq)) {
 306                 ret = PTR_ERR(recv_cq);
 307                 goto err;
 308         }
 309
 310         send_cq = ib_create_cq(target->srp_host->srp_dev->dev,
 311                                srp_send_completion, NULL, target,
 312                                target->queue_size, target->comp_vector);
 313         if (IS_ERR(send_cq)) {
 314                 ret = PTR_ERR(send_cq);
 315                 goto err_recv_cq;
 316         }
 317
 318         ib_req_notify_cq(recv_cq, IB_CQ_NEXT_COMP);
 319
 320         init_attr->event_handler       = srp_qp_event;
 321         init_attr->cap.max_send_wr     = target->queue_size;
 322         init_attr->cap.max_recv_wr     = target->queue_size;
 323         init_attr->cap.max_recv_sge    = 1;
 324         init_attr->cap.max_send_sge    = 1;
 325         init_attr->sq_sig_type         = IB_SIGNAL_ALL_WR;
 326         init_attr->qp_type             = IB_QPT_RC;
 327         init_attr->send_cq             = send_cq;
 328         init_attr->recv_cq             = recv_cq;
 329
 330         qp = ib_create_qp(target->srp_host->srp_dev->pd, init_attr);
 331         if (IS_ERR(qp)) {
 332                 ret = PTR_ERR(qp);
 333                 goto err_send_cq;
 334         }
 335
 336         ret = srp_init_qp(target, qp);
 337         if (ret)
 338                 goto err_qp;
 339
 340         if (target->qp)
 341                 ib_destroy_qp(target->qp);
 342         if (target->recv_cq)
 343                 ib_destroy_cq(target->recv_cq);
 344         if (target->send_cq)
 345                 ib_destroy_cq(target->send_cq);
 346
 347         target->qp = qp;
 348         target->recv_cq = recv_cq;
 349         target->send_cq = send_cq;
 350
 351         kfree(init_attr);
 352         return 0;
 353
 354 err_qp:
 355         ib_destroy_qp(qp);
 356
 357 err_send_cq:
 358         ib_destroy_cq(send_cq);
 359
 360 err_recv_cq:
 361         ib_destroy_cq(recv_cq);
 362
 363 err:
 364         kfree(init_attr);
 365         return ret;
 366 }
 367
 368 /*
 369  * Note: this function may be called without srp_alloc_iu_bufs() having been
 370  * invoked. Hence the target->[rt]x_ring checks.
 371  */
 372 static void srp_free_target_ib(struct srp_target_port *target)
 373 {
 374         int i;
 375
 376         ib_destroy_qp(target->qp);
 377         ib_destroy_cq(target->send_cq);
 378         ib_destroy_cq(target->recv_cq);
 379
 380         target->qp = NULL;
 381         target->send_cq = target->recv_cq = NULL;
 382
 383         if (target->rx_ring) {
 384                 for (i = 0; i < target->queue_size; ++i)
 385                         srp_free_iu(target->srp_host, target->rx_ring[i]);
 386                 kfree(target->rx_ring);
 387                 target->rx_ring = NULL;
 388         }
 389         if (target->tx_ring) {
 390                 for (i = 0; i < target->queue_size; ++i)
 391                         srp_free_iu(target->srp_host, target->tx_ring[i]);
 392                 kfree(target->tx_ring);
 393                 target->tx_ring = NULL;
 394         }
 395 }
 396
 397 static void srp_path_rec_completion(int status,
 398                                     struct ib_sa_path_rec *pathrec,
 399                                     void *target_ptr)
 400 {
 401         struct srp_target_port *target = target_ptr;
 402
 403         target->status = status;
 404         if (status)
 405                 shost_printk(KERN_ERR, target->scsi_host,
 406                              PFX "Got failed path rec status %d\n", status);
 407         else
 408                 target->path = *pathrec;
 409         complete(&target->done);
 410 }
 411
 412 static int srp_lookup_path(struct srp_target_port *target)
 413 {
 414         target->path.numb_path = 1;
 415
 416         init_completion(&target->done);
 417
 418         target->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
 419                                                    target->srp_host->srp_dev->dev,
 420                                                    target->srp_host->port,
 421                                                    &target->path,
 422                                                    IB_SA_PATH_REC_SERVICE_ID    |
 423                                                    IB_SA_PATH_REC_DGID          |
 424                                                    IB_SA_PATH_REC_SGID          |
 425                                                    IB_SA_PATH_REC_NUMB_PATH     |
 426                                                    IB_SA_PATH_REC_PKEY,
 427                                                    SRP_PATH_REC_TIMEOUT_MS,
 428                                                    GFP_KERNEL,
 429                                                    srp_path_rec_completion,
 430                                                    target, &target->path_query);
 431         if (target->path_query_id < 0)
 432                 return target->path_query_id;
 433
 434         wait_for_completion(&target->done);
 435
 436         if (target->status < 0)
 437                 shost_printk(KERN_WARNING, target->scsi_host,
 438                              PFX "Path record query failed\n");
 439
 440         return target->status;
 441 }
 442
 443 static int srp_send_req(struct srp_target_port *target)
 444 {
 445         struct {
 446                 struct ib_cm_req_param param;
 447                 struct srp_login_req   priv;
 448         } *req = NULL;
 449         int status;
 450
 451         req = kzalloc(sizeof *req, GFP_KERNEL);
 452         if (!req)
 453                 return -ENOMEM;
 454
 455         req->param.primary_path               = &target->path;
 456         req->param.alternate_path             = NULL;
 457         req->param.service_id                 = target->service_id;
 458         req->param.qp_num                     = target->qp->qp_num;
 459         req->param.qp_type                    = target->qp->qp_type;
 460         req->param.private_data               = &req->priv;
 461         req->param.private_data_len           = sizeof req->priv;
 462         req->param.flow_control               = 1;
 463
 464         get_random_bytes(&req->param.starting_psn, 4);
 465         req->param.starting_psn              &= 0xffffff;
 466
 467         /*
 468          * Pick some arbitrary defaults here; we could make these
 469          * module parameters if anyone cared about setting them.
 470          */
 471         req->param.responder_resources        = 4;
 472         req->param.remote_cm_response_timeout = 20;
 473         req->param.local_cm_response_timeout  = 20;
 474         req->param.retry_count                = target->tl_retry_count;
 475         req->param.rnr_retry_count            = 7;
 476         req->param.max_cm_retries             = 15;
 477
 478         req->priv.opcode        = SRP_LOGIN_REQ;
 479         req->priv.tag           = 0;
 480         req->priv.req_it_iu_len = cpu_to_be32(target->max_iu_len);
 481         req->priv.req_buf_fmt   = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
 482                                               SRP_BUF_FORMAT_INDIRECT);
 483         /*
 484          * In the published SRP specification (draft rev. 16a), the
 485          * port identifier format is 8 bytes of ID extension followed
 486          * by 8 bytes of GUID.  Older drafts put the two halves in the
 487          * opposite order, so that the GUID comes first.
 488          *
 489          * Targets conforming to these obsolete drafts can be
 490          * recognized by the I/O Class they report.
 491          */
 492         if (target->io_class == SRP_REV10_IB_IO_CLASS) {
 493                 memcpy(req->priv.initiator_port_id,
 494                        &target->path.sgid.global.interface_id, 8);
 495                 memcpy(req->priv.initiator_port_id + 8,
 496                        &target->initiator_ext, 8);
 497                 memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
 498                 memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
 499         } else {
 500                 memcpy(req->priv.initiator_port_id,
 501                        &target->initiator_ext, 8);
 502                 memcpy(req->priv.initiator_port_id + 8,
 503                        &target->path.sgid.global.interface_id, 8);
 504                 memcpy(req->priv.target_port_id,     &target->id_ext, 8);
 505                 memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
 506         }
 507
 508         /*
 509          * Topspin/Cisco SRP targets will reject our login unless we
 510          * zero out the first 8 bytes of our initiator port ID and set
 511          * the second 8 bytes to the local node GUID.
 512          */
 513         if (srp_target_is_topspin(target)) {
 514                 shost_printk(KERN_DEBUG, target->scsi_host,
 515                              PFX "Topspin/Cisco initiator port ID workaround "
 516                              "activated for target GUID %016llx\n",
 517                              (unsigned long long) be64_to_cpu(target->ioc_guid));
 518                 memset(req->priv.initiator_port_id, 0, 8);
 519                 memcpy(req->priv.initiator_port_id + 8,
 520                        &target->srp_host->srp_dev->dev->node_guid, 8);
 521         }
 522
 523         status = ib_send_cm_req(target->cm_id, &req->param);
 524
 525         kfree(req);
 526
 527         return status;
 528 }
 529
 530 static bool srp_queue_remove_work(struct srp_target_port *target)
 531 {
 532         bool changed = false;
 533
 534         spin_lock_irq(&target->lock);
 535         if (target->state != SRP_TARGET_REMOVED) {
 536                 target->state = SRP_TARGET_REMOVED;
 537                 changed = true;
 538         }
 539         spin_unlock_irq(&target->lock);
 540
 541         if (changed)
 542                 queue_work(system_long_wq, &target->remove_work);
 543
 544         return changed;
 545 }
 546
 547 static bool srp_change_conn_state(struct srp_target_port *target,
 548                                   bool connected)
 549 {
 550         bool changed = false;
 551
 552         spin_lock_irq(&target->lock);
 553         if (target->connected != connected) {
 554                 target->connected = connected;
 555                 changed = true;
 556         }
 557         spin_unlock_irq(&target->lock);
 558
 559         return changed;
 560 }
 561
 562 static void srp_disconnect_target(struct srp_target_port *target)
 563 {
 564         if (srp_change_conn_state(target, false)) {
 565                 /* XXX should send SRP_I_LOGOUT request */
 566
 567                 if (ib_send_cm_dreq(target->cm_id, NULL, 0)) {
 568                         shost_printk(KERN_DEBUG, target->scsi_host,
 569                                      PFX "Sending CM DREQ failed\n");
 570                 }
 571         }
 572 }
 573
 574 static void srp_free_req_data(struct srp_target_port *target)
 575 {
 576         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 577         struct srp_request *req;
 578         int i;
 579
 580         if (!target->req_ring)
 581                 return;
 582
 583         for (i = 0; i < target->req_ring_size; ++i) {
 584                 req = &target->req_ring[i];
 585                 kfree(req->fmr_list);
 586                 kfree(req->map_page);
 587                 if (req->indirect_dma_addr) {
 588                         ib_dma_unmap_single(ibdev, req->indirect_dma_addr,
 589                                             target->indirect_size,
 590                                             DMA_TO_DEVICE);
 591                 }
 592                 kfree(req->indirect_desc);
 593         }
 594
 595         kfree(target->req_ring);
 596         target->req_ring = NULL;
 597 }
 598
 599 static int srp_alloc_req_data(struct srp_target_port *target)
 600 {
 601         struct srp_device *srp_dev = target->srp_host->srp_dev;
 602         struct ib_device *ibdev = srp_dev->dev;
 603         struct srp_request *req;
 604         dma_addr_t dma_addr;
 605         int i, ret = -ENOMEM;
 606
 607         INIT_LIST_HEAD(&target->free_reqs);
 608
 609         target->req_ring = kzalloc(target->req_ring_size *
 610                                    sizeof(*target->req_ring), GFP_KERNEL);
 611         if (!target->req_ring)
 612                 goto out;
 613
 614         for (i = 0; i < target->req_ring_size; ++i) {
 615                 req = &target->req_ring[i];
 616                 req->fmr_list = kmalloc(target->cmd_sg_cnt * sizeof(void *),
 617                                         GFP_KERNEL);
 618                 req->map_page = kmalloc(SRP_FMR_SIZE * sizeof(void *),
 619                                         GFP_KERNEL);
 620                 req->indirect_desc = kmalloc(target->indirect_size, GFP_KERNEL);
 621                 if (!req->fmr_list || !req->map_page || !req->indirect_desc)
 622                         goto out;
 623
 624                 dma_addr = ib_dma_map_single(ibdev, req->indirect_desc,
 625                                              target->indirect_size,
 626                                              DMA_TO_DEVICE);
 627                 if (ib_dma_mapping_error(ibdev, dma_addr))
 628                         goto out;
 629
 630                 req->indirect_dma_addr = dma_addr;
 631                 req->index = i;
 632                 list_add_tail(&req->list, &target->free_reqs);
 633         }
 634         ret = 0;
 635
 636 out:
 637         return ret;
 638 }
 639
 640 /**
 641  * srp_del_scsi_host_attr() - Remove attributes defined in the host template.
 642  * @shost: SCSI host whose attributes to remove from sysfs.
 643  *
 644  * Note: Any attributes defined in the host template and that did not exist
 645  * before invocation of this function will be ignored.
 646  */
 647 static void srp_del_scsi_host_attr(struct Scsi_Host *shost)
 648 {
 649         struct device_attribute **attr;
 650
 651         for (attr = shost->hostt->shost_attrs; attr && *attr; ++attr)
 652                 device_remove_file(&shost->shost_dev, *attr);
 653 }
 654
 655 static void srp_remove_target(struct srp_target_port *target)
 656 {
 657         WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
 658
 659         srp_del_scsi_host_attr(target->scsi_host);
 660         srp_rport_get(target->rport);
 661         srp_remove_host(target->scsi_host);
 662         scsi_remove_host(target->scsi_host);
 663         srp_stop_rport_timers(target->rport);
 664         srp_disconnect_target(target);
 665         ib_destroy_cm_id(target->cm_id);
 666         srp_free_target_ib(target);
 667         cancel_work_sync(&target->tl_err_work);
 668         srp_rport_put(target->rport);
 669         srp_free_req_data(target);
 670
 671         spin_lock(&target->srp_host->target_lock);
 672         list_del(&target->list);
 673         spin_unlock(&target->srp_host->target_lock);
 674
 675         scsi_host_put(target->scsi_host);
 676 }
 677
 678 static void srp_remove_work(struct work_struct *work)
 679 {
 680         struct srp_target_port *target =
 681                 container_of(work, struct srp_target_port, remove_work);
 682
 683         WARN_ON_ONCE(target->state != SRP_TARGET_REMOVED);
 684
 685         srp_remove_target(target);
 686 }
 687
 688 static void srp_rport_delete(struct srp_rport *rport)
 689 {
 690         struct srp_target_port *target = rport->lld_data;
 691
 692         srp_queue_remove_work(target);
 693 }
 694
 695 static int srp_connect_target(struct srp_target_port *target)
 696 {
 697         int retries = 3;
 698         int ret;
 699
 700         WARN_ON_ONCE(target->connected);
 701
 702         target->qp_in_error = false;
 703
 704         ret = srp_lookup_path(target);
 705         if (ret)
 706                 return ret;
 707
 708         while (1) {
 709                 init_completion(&target->done);
 710                 ret = srp_send_req(target);
 711                 if (ret)
 712                         return ret;
 713                 wait_for_completion(&target->done);
 714
 715                 /*
 716                  * The CM event handling code will set status to
 717                  * SRP_PORT_REDIRECT if we get a port redirect REJ
 718                  * back, or SRP_DLID_REDIRECT if we get a lid/qp
 719                  * redirect REJ back.
 720                  */
 721                 switch (target->status) {
 722                 case 0:
 723                         srp_change_conn_state(target, true);
 724                         return 0;
 725
 726                 case SRP_PORT_REDIRECT:
 727                         ret = srp_lookup_path(target);
 728                         if (ret)
 729                                 return ret;
 730                         break;
 731
 732                 case SRP_DLID_REDIRECT:
 733                         break;
 734
 735                 case SRP_STALE_CONN:
 736                         /* Our current CM id was stale, and is now in timewait.
 737                          * Try to reconnect with a new one.
 738                          */
 739                         if (!retries-- || srp_new_cm_id(target)) {
 740                                 shost_printk(KERN_ERR, target->scsi_host, PFX
 741                                              "giving up on stale connection\n");
 742                                 target->status = -ECONNRESET;
 743                                 return target->status;
 744                         }
 745
 746                         shost_printk(KERN_ERR, target->scsi_host, PFX
 747                                      "retrying stale connection\n");
 748                         break;
 749
 750                 default:
 751                         return target->status;
 752                 }
 753         }
 754 }
 755
 756 static void srp_unmap_data(struct scsi_cmnd *scmnd,
 757                            struct srp_target_port *target,
 758                            struct srp_request *req)
 759 {
 760         struct ib_device *ibdev = target->srp_host->srp_dev->dev;
 761         struct ib_pool_fmr **pfmr;
 762
 763         if (!scsi_sglist(scmnd) ||
 764             (scmnd->sc_data_direction != DMA_TO_DEVICE &&
 765              scmnd->sc_data_direction != DMA_FROM_DEVICE))
 766                 return;
 767
 768         pfmr = req->fmr_list;
 769         while (req->nfmr--)
 770                 ib_fmr_pool_unmap(*pfmr++);
 771
 772         ib_dma_unmap_sg(ibdev, scsi_sglist(scmnd), scsi_sg_count(scmnd),
 773                         scmnd->sc_data_direction);
 774 }
 775
 776 /**
 777  * srp_claim_req - Take ownership of the scmnd associated with a request.
 778  * @target: SRP target port.
 779  * @req: SRP request.
 780  * @scmnd: If NULL, take ownership of @req->scmnd. If not NULL, only take
 781  *         ownership of @req->scmnd if it equals @scmnd.
 782  *
 783  * Return value:
 784  * Either NULL or a pointer to the SCSI command the caller became owner of.
 785  */
 786 static struct scsi_cmnd *srp_claim_req(struct srp_target_port *target,
 787                                        struct srp_request *req,
 788                                        struct scsi_cmnd *scmnd)
 789 {
 790         unsigned long flags;
 791
 792         spin_lock_irqsave(&target->lock, flags);
 793         if (!scmnd) {
 794                 scmnd = req->scmnd;
 795                 req->scmnd = NULL;
 796         } else if (req->scmnd == scmnd) {
 797                 req->scmnd = NULL;
 798         } else {
 799                 scmnd = NULL;
 800         }
 801         spin_unlock_irqrestore(&target->lock, flags);
 802
 803         return scmnd;
 804 }
 805
 806 /**
 807  * srp_free_req() - Unmap data and add request to the free request list.
 808  */
 809 static void srp_free_req(struct srp_target_port *target,
 810                          struct srp_request *req, struct scsi_cmnd *scmnd,
 811                          s32 req_lim_delta)
 812 {
 813         unsigned long flags;
 814
 815         srp_unmap_data(scmnd, target, req);
 816
 817         spin_lock_irqsave(&target->lock, flags);
 818         target->req_lim += req_lim_delta;
 819         list_add_tail(&req->list, &target->free_reqs);
 820         spin_unlock_irqrestore(&target->lock, flags);
 821 }
 822
 823 static void srp_finish_req(struct srp_target_port *target,
 824                            struct srp_request *req, int result)
 825 {
 826         struct scsi_cmnd *scmnd = srp_claim_req(target, req, NULL);
 827
 828         if (scmnd) {
 829                 srp_free_req(target, req, scmnd, 0);
 830                 scmnd->result = result;
 831                 scmnd->scsi_done(scmnd);
 832         }
 833 }
 834
 835 static void srp_terminate_io(struct srp_rport *rport)
 836 {
 837         struct srp_target_port *target = rport->lld_data;
 838         int i;
 839
 840         for (i = 0; i < target->req_ring_size; ++i) {
 841                 struct srp_request *req = &target->req_ring[i];
 842                 srp_finish_req(target, req, DID_TRANSPORT_FAILFAST << 16);
 843         }
 844 }
 845
 846 /*
 847  * It is up to the caller to ensure that srp_rport_reconnect() calls are
 848  * serialized and that no concurrent srp_queuecommand(), srp_abort(),
 849  * srp_reset_device() or srp_reset_host() calls will occur while this function
 850  * is in progress. One way to realize that is not to call this function
 851  * directly but to call srp_reconnect_rport() instead since that last function
 852  * serializes calls of this function via rport->mutex and also blocks
 853  * srp_queuecommand() calls before invoking this function.
 854  */
 855 static int srp_rport_reconnect(struct srp_rport *rport)
 856 {
 857         struct srp_target_port *target = rport->lld_data;
 858         int i, ret;
 859
 860         srp_disconnect_target(target);
 861         /*
 862          * Now get a new local CM ID so that we avoid confusing the target in
 863          * case things are really fouled up. Doing so also ensures that all CM
 864          * callbacks will have finished before a new QP is allocated.
 865          */
 866         ret = srp_new_cm_id(target);
 867         /*
 868          * Whether or not creating a new CM ID succeeded, create a new
 869          * QP. This guarantees that all completion callback function
 870          * invocations have finished before request resetting starts.
 871          */
 872         if (ret == 0)
 873                 ret = srp_create_target_ib(target);
 874         else
 875                 srp_create_target_ib(target);
 876
 877         for (i = 0; i < target->req_ring_size; ++i) {
 878                 struct srp_request *req = &target->req_ring[i];
 879                 srp_finish_req(target, req, DID_RESET << 16);
 880         }
 881
 882         INIT_LIST_HEAD(&target->free_tx);
 883         for (i = 0; i < target->queue_size; ++i)
 884                 list_add(&target->tx_ring[i]->list, &target->free_tx);
 885
 886         if (ret == 0)
 887                 ret = srp_connect_target(target);
 888
 889         if (ret == 0)
 890                 shost_printk(KERN_INFO, target->scsi_host,
 891                              PFX "reconnect succeeded\n");
 892
 893         return ret;
 894 }
 895
 896 static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr,
 897                          unsigned int dma_len, u32 rkey)
 898 {
 899         struct srp_direct_buf *desc = state->desc;
 900
 901         desc->va = cpu_to_be64(dma_addr);
 902         desc->key = cpu_to_be32(rkey);
 903         desc->len = cpu_to_be32(dma_len);
 904
 905         state->total_len += dma_len;
 906         state->desc++;
 907         state->ndesc++;
 908 }
 909
 910 static int srp_map_finish_fmr(struct srp_map_state *state,
 911                               struct srp_target_port *target)
 912 {
 913         struct srp_device *dev = target->srp_host->srp_dev;
 914         struct ib_pool_fmr *fmr;
 915         u64 io_addr = 0;
 916
 917         if (!state->npages)
 918                 return 0;
 919
 920         if (state->npages == 1) {
 921                 srp_map_desc(state, state->base_dma_addr, state->fmr_len,
 922                              target->rkey);
 923                 state->npages = state->fmr_len = 0;
 924                 return 0;
 925         }
 926
 927         fmr = ib_fmr_pool_map_phys(dev->fmr_pool, state->pages,
 928                                    state->npages, io_addr);
 929         if (IS_ERR(fmr))
 930                 return PTR_ERR(fmr);
 931
 932         *state->next_fmr++ = fmr;
 933         state->nfmr++;
 934
 935         srp_map_desc(state, 0, state->fmr_len, fmr->fmr->rkey);
 936         state->npages = state->fmr_len = 0;
 937         return 0;
 938 }
 939
 940 static void srp_map_update_start(struct srp_map_state *state,
 941                                  struct scatterlist *sg, int sg_index,
 942                                  dma_addr_t dma_addr)
 943 {
 944         state->unmapped_sg = sg;
 945         state->unmapped_index = sg_index;
 946         state->unmapped_addr = dma_addr;
 947 }
 948
 949 static int srp_map_sg_entry(struct srp_map_state *state,
 950                             struct srp_target_port *target,
 951                             struct scatterlist *sg, int sg_index,
 952                             int use_fmr)
 953 {
 954         struct srp_device *dev = target->srp_host->srp_dev;
 955         struct ib_device *ibdev = dev->dev;
 956         dma_addr_t dma_addr = ib_sg_dma_address(ibdev, sg);
 957         unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
 958         unsigned int len;
 959         int ret;
 960
 961         if (!dma_len)
 962                 return 0;
 963
 964         if (use_fmr == SRP_MAP_NO_FMR) {
 965                 /* Once we're in direct map mode for a request, we don't
 966                  * go back to FMR mode, so no need to update anything
 967                  * other than the descriptor.
 968                  */
 969                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 970                 return 0;
 971         }
 972
 973         /* If we start at an offset into the FMR page, don't merge into
 974          * the current FMR. Finish it out, and use the kernel's MR for this
 975          * sg entry. This is to avoid potential bugs on some SRP targets
 976          * that were never quite defined, but went away when the initiator
 977          * avoided using FMR on such page fragments.
 978          */
 979         if (dma_addr & ~dev->fmr_page_mask || dma_len > dev->fmr_max_size) {
 980                 ret = srp_map_finish_fmr(state, target);
 981                 if (ret)
 982                         return ret;
 983
 984                 srp_map_desc(state, dma_addr, dma_len, target->rkey);
 985                 srp_map_update_start(state, NULL, 0, 0);
 986                 return 0;
 987         }
 988
 989         /* If this is the first sg to go into the FMR, save our position.
 990          * We need to know the first unmapped entry, its index, and the
 991          * first unmapped address within that entry to be able to restart
 992          * mapping after an error.
 993          */
 994         if (!state->unmapped_sg)
 995                 srp_map_update_start(state, sg, sg_index, dma_addr);
 996
 997         while (dma_len) {
 998                 if (state->npages == SRP_FMR_SIZE) {
 999                         ret = srp_map_finish_fmr(state, target);
1000                         if (ret)
1001                                 return ret;
1002
1003                         srp_map_update_start(state, sg, sg_index, dma_addr);
1004                 }
1005
1006                 len = min_t(unsigned int, dma_len, dev->fmr_page_size);
1007
1008                 if (!state->npages)
1009                         state->base_dma_addr = dma_addr;
1010                 state->pages[state->npages++] = dma_addr;
1011                 state->fmr_len += len;
1012                 dma_addr += len;
1013                 dma_len -= len;
1014         }
1015
1016         /* If the last entry of the FMR wasn't a full page, then we need to
1017          * close it out and start a new one -- we can only merge at page
1018          * boundries.
1019          */
1020         ret = 0;
1021         if (len != dev->fmr_page_size) {
1022                 ret = srp_map_finish_fmr(state, target);
1023                 if (!ret)
1024                         srp_map_update_start(state, NULL, 0, 0);
1025         }
1026         return ret;
1027 }
1028
1029 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
1030                         struct srp_request *req)
1031 {
1032         struct scatterlist *scat, *sg;
1033         struct srp_cmd *cmd = req->cmd->buf;
1034         int i, len, nents, count, use_fmr;
1035         struct srp_device *dev;
1036         struct ib_device *ibdev;
1037         struct srp_map_state state;
1038         struct srp_indirect_buf *indirect_hdr;
1039         u32 table_len;
1040         u8 fmt;
1041
1042         if (!scsi_sglist(scmnd) || scmnd->sc_data_direction == DMA_NONE)
1043                 return sizeof (struct srp_cmd);
1044
1045         if (scmnd->sc_data_direction != DMA_FROM_DEVICE &&
1046             scmnd->sc_data_direction != DMA_TO_DEVICE) {
1047                 shost_printk(KERN_WARNING, target->scsi_host,
1048                              PFX "Unhandled data direction %d\n",
1049                              scmnd->sc_data_direction);
1050                 return -EINVAL;
1051         }
1052
1053         nents = scsi_sg_count(scmnd);
1054         scat  = scsi_sglist(scmnd);
1055
1056         dev = target->srp_host->srp_dev;
1057         ibdev = dev->dev;
1058
1059         count = ib_dma_map_sg(ibdev, scat, nents, scmnd->sc_data_direction);
1060         if (unlikely(count == 0))
1061                 return -EIO;
1062
1063         fmt = SRP_DATA_DESC_DIRECT;
1064         len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
1065
1066         if (count == 1) {
1067                 /*
1068                  * The midlayer only generated a single gather/scatter
1069                  * entry, or DMA mapping coalesced everything to a
1070                  * single entry.  So a direct descriptor along with
1071                  * the DMA MR suffices.
1072                  */
1073                 struct srp_direct_buf *buf = (void *) cmd->add_data;
1074
1075                 buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
1076                 buf->key = cpu_to_be32(target->rkey);
1077                 buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
1078
1079                 req->nfmr = 0;
1080                 goto map_complete;
1081         }
1082
1083         /* We have more than one scatter/gather entry, so build our indirect
1084          * descriptor table, trying to merge as many entries with FMR as we
1085          * can.
1086          */
1087         indirect_hdr = (void *) cmd->add_data;
1088
1089         ib_dma_sync_single_for_cpu(ibdev, req->indirect_dma_addr,
1090                                    target->indirect_size, DMA_TO_DEVICE);
1091
1092         memset(&state, 0, sizeof(state));
1093         state.desc      = req->indirect_desc;
1094         state.pages     = req->map_page;
1095         state.next_fmr  = req->fmr_list;
1096
1097         use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
1098
1099         for_each_sg(scat, sg, count, i) {
1100                 if (srp_map_sg_entry(&state, target, sg, i, use_fmr)) {
1101                         /* FMR mapping failed, so backtrack to the first
1102                          * unmapped entry and continue on without using FMR.
1103                          */
1104                         dma_addr_t dma_addr;
1105                         unsigned int dma_len;
1106
1107 backtrack:
1108                         sg = state.unmapped_sg;
1109                         i = state.unmapped_index;
1110
1111                         dma_addr = ib_sg_dma_address(ibdev, sg);
1112                         dma_len = ib_sg_dma_len(ibdev, sg);
1113                         dma_len -= (state.unmapped_addr - dma_addr);
1114                         dma_addr = state.unmapped_addr;
1115                         use_fmr = SRP_MAP_NO_FMR;
1116                         srp_map_desc(&state, dma_addr, dma_len, target->rkey);
1117                 }
1118         }
1119
1120         if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(&state, target))
1121                 goto backtrack;
1122
1123         /* We've mapped the request, now pull as much of the indirect
1124          * descriptor table as we can into the command buffer. If this
1125          * target is not using an external indirect table, we are
1126          * guaranteed to fit into the command, as the SCSI layer won't
1127          * give us more S/G entries than we allow.
1128          */
1129         req->nfmr = state.nfmr;
1130         if (state.ndesc == 1) {
1131                 /* FMR mapping was able to collapse this to one entry,
1132                  * so use a direct descriptor.
1133                  */
1134                 struct srp_direct_buf *buf = (void *) cmd->add_data;
1135
1136                 *buf = req->indirect_desc[0];
1137                 goto map_complete;
1138         }
1139
1140         if (unlikely(target->cmd_sg_cnt < state.ndesc &&
1141                                                 !target->allow_ext_sg)) {
1142                 shost_printk(KERN_ERR, target->scsi_host,
1143                              "Could not fit S/G list into SRP_CMD\n");
1144                 return -EIO;
1145         }
1146
1147         count = min(state.ndesc, target->cmd_sg_cnt);
1148         table_len = state.ndesc * sizeof (struct srp_direct_buf);
1149
1150         fmt = SRP_DATA_DESC_INDIRECT;
1151         len = sizeof(struct srp_cmd) + sizeof (struct srp_indirect_buf);
1152         len += count * sizeof (struct srp_direct_buf);
1153
1154         memcpy(indirect_hdr->desc_list, req->indirect_desc,
1155                count * sizeof (struct srp_direct_buf));
1156
1157         indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
1158         indirect_hdr->table_desc.key = cpu_to_be32(target->rkey);
1159         indirect_hdr->table_desc.len = cpu_to_be32(table_len);
1160         indirect_hdr->len = cpu_to_be32(state.total_len);
1161
1162         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1163                 cmd->data_out_desc_cnt = count;
1164         else
1165                 cmd->data_in_desc_cnt = count;
1166
1167         ib_dma_sync_single_for_device(ibdev, req->indirect_dma_addr, table_len,
1168                                       DMA_TO_DEVICE);
1169
1170 map_complete:
1171         if (scmnd->sc_data_direction == DMA_TO_DEVICE)
1172                 cmd->buf_fmt = fmt << 4;
1173         else
1174                 cmd->buf_fmt = fmt;
1175
1176         return len;
1177 }
1178
1179 /*
1180  * Return an IU and possible credit to the free pool
1181  */
1182 static void srp_put_tx_iu(struct srp_target_port *target, struct srp_iu *iu,
1183                           enum srp_iu_type iu_type)
1184 {
1185         unsigned long flags;
1186
1187         spin_lock_irqsave(&target->lock, flags);
1188         list_add(&iu->list, &target->free_tx);
1189         if (iu_type != SRP_IU_RSP)
1190                 ++target->req_lim;
1191         spin_unlock_irqrestore(&target->lock, flags);
1192 }
1193
1194 /*
1195  * Must be called with target->lock held to protect req_lim and free_tx.
1196  * If IU is not sent, it must be returned using srp_put_tx_iu().
1197  *
1198  * Note:
1199  * An upper limit for the number of allocated information units for each
1200  * request type is:
1201  * - SRP_IU_CMD: SRP_CMD_SQ_SIZE, since the SCSI mid-layer never queues
1202  *   more than Scsi_Host.can_queue requests.
1203  * - SRP_IU_TSK_MGMT: SRP_TSK_MGMT_SQ_SIZE.
1204  * - SRP_IU_RSP: 1, since a conforming SRP target never sends more than
1205  *   one unanswered SRP request to an initiator.
1206  */
1207 static struct srp_iu *__srp_get_tx_iu(struct srp_target_port *target,
1208                                       enum srp_iu_type iu_type)
1209 {
1210         s32 rsv = (iu_type == SRP_IU_TSK_MGMT) ? 0 : SRP_TSK_MGMT_SQ_SIZE;
1211         struct srp_iu *iu;
1212
1213         srp_send_completion(target->send_cq, target);
1214
1215         if (list_empty(&target->free_tx))
1216                 return NULL;
1217
1218         /* Initiator responses to target requests do not consume credits */
1219         if (iu_type != SRP_IU_RSP) {
1220                 if (target->req_lim <= rsv) {
1221                         ++target->zero_req_lim;
1222                         return NULL;
1223                 }
1224
1225                 --target->req_lim;
1226         }
1227
1228         iu = list_first_entry(&target->free_tx, struct srp_iu, list);
1229         list_del(&iu->list);
1230         return iu;
1231 }
1232
1233 static int srp_post_send(struct srp_target_port *target,
1234                          struct srp_iu *iu, int len)
1235 {
1236         struct ib_sge list;
1237         struct ib_send_wr wr, *bad_wr;
1238
1239         list.addr   = iu->dma;
1240         list.length = len;
1241         list.lkey   = target->lkey;
1242
1243         wr.next       = NULL;
1244         wr.wr_id      = (uintptr_t) iu;
1245         wr.sg_list    = &list;
1246         wr.num_sge    = 1;
1247         wr.opcode     = IB_WR_SEND;
1248         wr.send_flags = IB_SEND_SIGNALED;
1249
1250         return ib_post_send(target->qp, &wr, &bad_wr);
1251 }
1252
1253 static int srp_post_recv(struct srp_target_port *target, struct srp_iu *iu)
1254 {
1255         struct ib_recv_wr wr, *bad_wr;
1256         struct ib_sge list;
1257
1258         list.addr   = iu->dma;
1259         list.length = iu->size;
1260         list.lkey   = target->lkey;
1261
1262         wr.next     = NULL;
1263         wr.wr_id    = (uintptr_t) iu;
1264         wr.sg_list  = &list;
1265         wr.num_sge  = 1;
1266
1267         return ib_post_recv(target->qp, &wr, &bad_wr);
1268 }
1269
1270 static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
1271 {
1272         struct srp_request *req;
1273         struct scsi_cmnd *scmnd;
1274         unsigned long flags;
1275
1276         if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) {
1277                 spin_lock_irqsave(&target->lock, flags);
1278                 target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1279                 spin_unlock_irqrestore(&target->lock, flags);
1280
1281                 target->tsk_mgmt_status = -1;
1282                 if (be32_to_cpu(rsp->resp_data_len) >= 4)
1283                         target->tsk_mgmt_status = rsp->data[3];
1284                 complete(&target->tsk_mgmt_done);
1285         } else {
1286                 req = &target->req_ring[rsp->tag];
1287                 scmnd = srp_claim_req(target, req, NULL);
1288                 if (!scmnd) {
1289                         shost_printk(KERN_ERR, target->scsi_host,
1290                                      "Null scmnd for RSP w/tag %016llx\n",
1291                                      (unsigned long long) rsp->tag);
1292
1293                         spin_lock_irqsave(&target->lock, flags);
1294                         target->req_lim += be32_to_cpu(rsp->req_lim_delta);
1295                         spin_unlock_irqrestore(&target->lock, flags);
1296
1297                         return;
1298                 }
1299                 scmnd->result = rsp->status;
1300
1301                 if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
1302                         memcpy(scmnd->sense_buffer, rsp->data +
1303                                be32_to_cpu(rsp->resp_data_len),
1304                                min_t(int, be32_to_cpu(rsp->sense_data_len),
1305                                      SCSI_SENSE_BUFFERSIZE));
1306                 }
1307
1308                 if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
1309                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
1310                 else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
1311                         scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
1312
1313                 srp_free_req(target, req, scmnd,
1314                              be32_to_cpu(rsp->req_lim_delta));
1315
1316                 scmnd->host_scribble = NULL;
1317                 scmnd->scsi_done(scmnd);
1318         }
1319 }
1320
1321 static int srp_response_common(struct srp_target_port *target, s32 req_delta,
1322                                void *rsp, int len)
1323 {
1324         struct ib_device *dev = target->srp_host->srp_dev->dev;
1325         unsigned long flags;
1326         struct srp_iu *iu;
1327         int err;
1328
1329         spin_lock_irqsave(&target->lock, flags);
1330         target->req_lim += req_delta;
1331         iu = __srp_get_tx_iu(target, SRP_IU_RSP);
1332         spin_unlock_irqrestore(&target->lock, flags);
1333
1334         if (!iu) {
1335                 shost_printk(KERN_ERR, target->scsi_host, PFX
1336                              "no IU available to send response\n");
1337                 return 1;
1338         }
1339
1340         ib_dma_sync_single_for_cpu(dev, iu->dma, len, DMA_TO_DEVICE);
1341         memcpy(iu->buf, rsp, len);
1342         ib_dma_sync_single_for_device(dev, iu->dma, len, DMA_TO_DEVICE);
1343
1344         err = srp_post_send(target, iu, len);
1345         if (err) {
1346                 shost_printk(KERN_ERR, target->scsi_host, PFX
1347                              "unable to post response: %d\n", err);
1348                 srp_put_tx_iu(target, iu, SRP_IU_RSP);
1349         }
1350
1351         return err;
1352 }
1353
1354 static void srp_process_cred_req(struct srp_target_port *target,
1355                                  struct srp_cred_req *req)
1356 {
1357         struct srp_cred_rsp rsp = {
1358                 .opcode = SRP_CRED_RSP,
1359                 .tag = req->tag,
1360         };
1361         s32 delta = be32_to_cpu(req->req_lim_delta);
1362
1363         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1364                 shost_printk(KERN_ERR, target->scsi_host, PFX
1365                              "problems processing SRP_CRED_REQ\n");
1366 }
1367
1368 static void srp_process_aer_req(struct srp_target_port *target,
1369                                 struct srp_aer_req *req)
1370 {
1371         struct srp_aer_rsp rsp = {
1372                 .opcode = SRP_AER_RSP,
1373                 .tag = req->tag,
1374         };
1375         s32 delta = be32_to_cpu(req->req_lim_delta);
1376
1377         shost_printk(KERN_ERR, target->scsi_host, PFX
1378                      "ignoring AER for LUN %llu\n", be64_to_cpu(req->lun));
1379
1380         if (srp_response_common(target, delta, &rsp, sizeof rsp))
1381                 shost_printk(KERN_ERR, target->scsi_host, PFX
1382                              "problems processing SRP_AER_REQ\n");
1383 }
1384
1385 static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
1386 {
1387         struct ib_device *dev = target->srp_host->srp_dev->dev;
1388         struct srp_iu *iu = (struct srp_iu *) (uintptr_t) wc->wr_id;
1389         int res;
1390         u8 opcode;
1391
1392         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_ti_iu_len,
1393                                    DMA_FROM_DEVICE);
1394
1395         opcode = *(u8 *) iu->buf;
1396
1397         if (0) {
1398                 shost_printk(KERN_ERR, target->scsi_host,
1399                              PFX "recv completion, opcode 0x%02x\n", opcode);
1400                 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 8, 1,
1401                                iu->buf, wc->byte_len, true);
1402         }
1403
1404         switch (opcode) {
1405         case SRP_RSP:
1406                 srp_process_rsp(target, iu->buf);
1407                 break;
1408
1409         case SRP_CRED_REQ:
1410                 srp_process_cred_req(target, iu->buf);
1411                 break;
1412
1413         case SRP_AER_REQ:
1414                 srp_process_aer_req(target, iu->buf);
1415                 break;
1416
1417         case SRP_T_LOGOUT:
1418                 /* XXX Handle target logout */
1419                 shost_printk(KERN_WARNING, target->scsi_host,
1420                              PFX "Got target logout request\n");
1421                 break;
1422
1423         default:
1424                 shost_printk(KERN_WARNING, target->scsi_host,
1425                              PFX "Unhandled SRP opcode 0x%02x\n", opcode);
1426                 break;
1427         }
1428
1429         ib_dma_sync_single_for_device(dev, iu->dma, target->max_ti_iu_len,
1430                                       DMA_FROM_DEVICE);
1431
1432         res = srp_post_recv(target, iu);
1433         if (res != 0)
1434                 shost_printk(KERN_ERR, target->scsi_host,
1435                              PFX "Recv failed with error code %d\n", res);
1436 }
1437
1438 /**
1439  * srp_tl_err_work() - handle a transport layer error
1440  *
1441  * Note: This function may get invoked before the rport has been created,
1442  * hence the target->rport test.
1443  */
1444 static void srp_tl_err_work(struct work_struct *work)
1445 {
1446         struct srp_target_port *target;
1447
1448         target = container_of(work, struct srp_target_port, tl_err_work);
1449         if (target->rport)
1450                 srp_start_tl_fail_timers(target->rport);
1451 }
1452
1453 static void srp_handle_qp_err(enum ib_wc_status wc_status, bool send_err,
1454                               struct srp_target_port *target)
1455 {
1456         if (target->connected && !target->qp_in_error) {
1457                 shost_printk(KERN_ERR, target->scsi_host,
1458                              PFX "failed %s status %d\n",
1459                              send_err ? "send" : "receive",
1460                              wc_status);
1461                 queue_work(system_long_wq, &target->tl_err_work);
1462         }
1463         target->qp_in_error = true;
1464 }
1465
1466 static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
1467 {
1468         struct srp_target_port *target = target_ptr;
1469         struct ib_wc wc;
1470
1471         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
1472         while (ib_poll_cq(cq, 1, &wc) > 0) {
1473                 if (likely(wc.status == IB_WC_SUCCESS)) {
1474                         srp_handle_recv(target, &wc);
1475                 } else {
1476                         srp_handle_qp_err(wc.status, false, target);
1477                 }
1478         }
1479 }
1480
1481 static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
1482 {
1483         struct srp_target_port *target = target_ptr;
1484         struct ib_wc wc;
1485         struct srp_iu *iu;
1486
1487         while (ib_poll_cq(cq, 1, &wc) > 0) {
1488                 if (likely(wc.status == IB_WC_SUCCESS)) {
1489                         iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
1490                         list_add(&iu->list, &target->free_tx);
1491                 } else {
1492                         srp_handle_qp_err(wc.status, true, target);
1493                 }
1494         }
1495 }
1496
1497 static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd)
1498 {
1499         struct srp_target_port *target = host_to_target(shost);
1500         struct srp_rport *rport = target->rport;
1501         struct srp_request *req;
1502         struct srp_iu *iu;
1503         struct srp_cmd *cmd;
1504         struct ib_device *dev;
1505         unsigned long flags;
1506         int len, result;
1507         const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler;
1508
1509         /*
1510          * The SCSI EH thread is the only context from which srp_queuecommand()
1511          * can get invoked for blocked devices (SDEV_BLOCK /
1512          * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by
1513          * locking the rport mutex if invoked from inside the SCSI EH.
1514          */
1515         if (in_scsi_eh)
1516                 mutex_lock(&rport->mutex);
1517
1518         result = srp_chkready(target->rport);
1519         if (unlikely(result)) {
1520                 scmnd->result = result;
1521                 scmnd->scsi_done(scmnd);
1522                 goto unlock_rport;
1523         }
1524
1525         spin_lock_irqsave(&target->lock, flags);
1526         iu = __srp_get_tx_iu(target, SRP_IU_CMD);
1527         if (!iu)
1528                 goto err_unlock;
1529
1530         req = list_first_entry(&target->free_reqs, struct srp_request, list);
1531         list_del(&req->list);
1532         spin_unlock_irqrestore(&target->lock, flags);
1533
1534         dev = target->srp_host->srp_dev->dev;
1535         ib_dma_sync_single_for_cpu(dev, iu->dma, target->max_iu_len,
1536                                    DMA_TO_DEVICE);
1537
1538         scmnd->result        = 0;
1539         scmnd->host_scribble = (void *) req;
1540
1541         cmd = iu->buf;
1542         memset(cmd, 0, sizeof *cmd);
1543
1544         cmd->opcode = SRP_CMD;
1545         cmd->lun    = cpu_to_be64((u64) scmnd->device->lun << 48);
1546         cmd->tag    = req->index;
1547         memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
1548
1549         req->scmnd    = scmnd;
1550         req->cmd      = iu;
1551
1552         len = srp_map_data(scmnd, target, req);
1553         if (len < 0) {
1554                 shost_printk(KERN_ERR, target->scsi_host,
1555                              PFX "Failed to map data\n");
1556                 goto err_iu;
1557         }
1558
1559         ib_dma_sync_single_for_device(dev, iu->dma, target->max_iu_len,
1560                                       DMA_TO_DEVICE);
1561
1562         if (srp_post_send(target, iu, len)) {
1563                 shost_printk(KERN_ERR, target->scsi_host, PFX "Send failed\n");
1564                 goto err_unmap;
1565         }
1566
1567 unlock_rport:
1568         if (in_scsi_eh)
1569                 mutex_unlock(&rport->mutex);
1570
1571         return 0;
1572
1573 err_unmap:
1574         srp_unmap_data(scmnd, target, req);
1575
1576 err_iu:
1577         srp_put_tx_iu(target, iu, SRP_IU_CMD);
1578
1579         spin_lock_irqsave(&target->lock, flags);
1580         list_add(&req->list, &target->free_reqs);
1581
1582 err_unlock:
1583         spin_unlock_irqrestore(&target->lock, flags);
1584
1585         if (in_scsi_eh)
1586                 mutex_unlock(&rport->mutex);
1587
1588         return SCSI_MLQUEUE_HOST_BUSY;
1589 }
1590
1591 /*
1592  * Note: the resources allocated in this function are freed in
1593  * srp_free_target_ib().
1594  */
1595 static int srp_alloc_iu_bufs(struct srp_target_port *target)
1596 {
1597         int i;
1598
1599         target->rx_ring = kzalloc(target->queue_size * sizeof(*target->rx_ring),
1600                                   GFP_KERNEL);
1601         if (!target->rx_ring)
1602                 goto err_no_ring;
1603         target->tx_ring = kzalloc(target->queue_size * sizeof(*target->tx_ring),
1604                                   GFP_KERNEL);
1605         if (!target->tx_ring)
1606                 goto err_no_ring;
1607
1608         for (i = 0; i < target->queue_size; ++i) {
1609                 target->rx_ring[i] = srp_alloc_iu(target->srp_host,
1610                                                   target->max_ti_iu_len,
1611                                                   GFP_KERNEL, DMA_FROM_DEVICE);
1612                 if (!target->rx_ring[i])
1613                         goto err;
1614         }
1615
1616         for (i = 0; i < target->queue_size; ++i) {
1617                 target->tx_ring[i] = srp_alloc_iu(target->srp_host,
1618                                                   target->max_iu_len,
1619                                                   GFP_KERNEL, DMA_TO_DEVICE);
1620                 if (!target->tx_ring[i])
1621                         goto err;
1622
1623                 list_add(&target->tx_ring[i]->list, &target->free_tx);
1624         }
1625
1626         return 0;
1627
1628 err:
1629         for (i = 0; i < target->queue_size; ++i) {
1630                 srp_free_iu(target->srp_host, target->rx_ring[i]);
1631                 srp_free_iu(target->srp_host, target->tx_ring[i]);
1632         }
1633
1634
1635 err_no_ring:
1636         kfree(target->tx_ring);
1637         target->tx_ring = NULL;
1638         kfree(target->rx_ring);
1639         target->rx_ring = NULL;
1640
1641         return -ENOMEM;
1642 }
1643
1644 static uint32_t srp_compute_rq_tmo(struct ib_qp_attr *qp_attr, int attr_mask)
1645 {
1646         uint64_t T_tr_ns, max_compl_time_ms;
1647         uint32_t rq_tmo_jiffies;
1648
1649         /*
1650          * According to section 11.2.4.2 in the IBTA spec (Modify Queue Pair,
1651          * table 91), both the QP timeout and the retry count have to be set
1652          * for RC QP's during the RTR to RTS transition.
1653          */
1654         WARN_ON_ONCE((attr_mask & (IB_QP_TIMEOUT | IB_QP_RETRY_CNT)) !=
1655                      (IB_QP_TIMEOUT | IB_QP_RETRY_CNT));
1656
1657         /*
1658          * Set target->rq_tmo_jiffies to one second more than the largest time
1659          * it can take before an error completion is generated. See also
1660          * C9-140..142 in the IBTA spec for more information about how to
1661          * convert the QP Local ACK Timeout value to nanoseconds.
1662          */
1663         T_tr_ns = 4096 * (1ULL << qp_attr->timeout);
1664         max_compl_time_ms = qp_attr->retry_cnt * 4 * T_tr_ns;
1665         do_div(max_compl_time_ms, NSEC_PER_MSEC);
1666         rq_tmo_jiffies = msecs_to_jiffies(max_compl_time_ms + 1000);
1667
1668         return rq_tmo_jiffies;
1669 }
1670
1671 static void srp_cm_rep_handler(struct ib_cm_id *cm_id,
1672                                struct srp_login_rsp *lrsp,
1673                                struct srp_target_port *target)
1674 {
1675         struct ib_qp_attr *qp_attr = NULL;
1676         int attr_mask = 0;
1677         int ret;
1678         int i;
1679
1680         if (lrsp->opcode == SRP_LOGIN_RSP) {
1681                 target->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len);
1682                 target->req_lim       = be32_to_cpu(lrsp->req_lim_delta);
1683
1684                 /*
1685                  * Reserve credits for task management so we don't
1686                  * bounce requests back to the SCSI mid-layer.
1687                  */
1688                 target->scsi_host->can_queue
1689                         = min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1690                               target->scsi_host->can_queue);
1691                 target->scsi_host->cmd_per_lun
1692                         = min_t(int, target->scsi_host->can_queue,
1693                                 target->scsi_host->cmd_per_lun);
1694         } else {
1695                 shost_printk(KERN_WARNING, target->scsi_host,
1696                              PFX "Unhandled RSP opcode %#x\n", lrsp->opcode);
1697                 ret = -ECONNRESET;
1698                 goto error;
1699         }
1700
1701         if (!target->rx_ring) {
1702                 ret = srp_alloc_iu_bufs(target);
1703                 if (ret)
1704                         goto error;
1705         }
1706
1707         ret = -ENOMEM;
1708         qp_attr = kmalloc(sizeof *qp_attr, GFP_KERNEL);
1709         if (!qp_attr)
1710                 goto error;
1711
1712         qp_attr->qp_state = IB_QPS_RTR;
1713         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1714         if (ret)
1715                 goto error_free;
1716
1717         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1718         if (ret)
1719                 goto error_free;
1720
1721         for (i = 0; i < target->queue_size; i++) {
1722                 struct srp_iu *iu = target->rx_ring[i];
1723                 ret = srp_post_recv(target, iu);
1724                 if (ret)
1725                         goto error_free;
1726         }
1727
1728         qp_attr->qp_state = IB_QPS_RTS;
1729         ret = ib_cm_init_qp_attr(cm_id, qp_attr, &attr_mask);
1730         if (ret)
1731                 goto error_free;
1732
1733         target->rq_tmo_jiffies = srp_compute_rq_tmo(qp_attr, attr_mask);
1734
1735         ret = ib_modify_qp(target->qp, qp_attr, attr_mask);
1736         if (ret)
1737                 goto error_free;
1738
1739         ret = ib_send_cm_rtu(cm_id, NULL, 0);
1740
1741 error_free:
1742         kfree(qp_attr);
1743
1744 error:
1745         target->status = ret;
1746 }
1747
1748 static void srp_cm_rej_handler(struct ib_cm_id *cm_id,
1749                                struct ib_cm_event *event,
1750                                struct srp_target_port *target)
1751 {
1752         struct Scsi_Host *shost = target->scsi_host;
1753         struct ib_class_port_info *cpi;
1754         int opcode;
1755
1756         switch (event->param.rej_rcvd.reason) {
1757         case IB_CM_REJ_PORT_CM_REDIRECT:
1758                 cpi = event->param.rej_rcvd.ari;
1759                 target->path.dlid = cpi->redirect_lid;
1760                 target->path.pkey = cpi->redirect_pkey;
1761                 cm_id->remote_cm_qpn = be32_to_cpu(cpi->redirect_qp) & 0x00ffffff;
1762                 memcpy(target->path.dgid.raw, cpi->redirect_gid, 16);
1763
1764                 target->status = target->path.dlid ?
1765                         SRP_DLID_REDIRECT : SRP_PORT_REDIRECT;
1766                 break;
1767
1768         case IB_CM_REJ_PORT_REDIRECT:
1769                 if (srp_target_is_topspin(target)) {
1770                         /*
1771                          * Topspin/Cisco SRP gateways incorrectly send
1772                          * reject reason code 25 when they mean 24
1773                          * (port redirect).
1774                          */
1775                         memcpy(target->path.dgid.raw,
1776                                event->param.rej_rcvd.ari, 16);
1777
1778                         shost_printk(KERN_DEBUG, shost,
1779                                      PFX "Topspin/Cisco redirect to target port GID %016llx%016llx\n",
1780                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.subnet_prefix),
1781                                      (unsigned long long) be64_to_cpu(target->path.dgid.global.interface_id));
1782
1783                         target->status = SRP_PORT_REDIRECT;
1784                 } else {
1785                         shost_printk(KERN_WARNING, shost,
1786                                      "  REJ reason: IB_CM_REJ_PORT_REDIRECT\n");
1787                         target->status = -ECONNRESET;
1788                 }
1789                 break;
1790
1791         case IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID:
1792                 shost_printk(KERN_WARNING, shost,
1793                             "  REJ reason: IB_CM_REJ_DUPLICATE_LOCAL_COMM_ID\n");
1794                 target->status = -ECONNRESET;
1795                 break;
1796
1797         case IB_CM_REJ_CONSUMER_DEFINED:
1798                 opcode = *(u8 *) event->private_data;
1799                 if (opcode == SRP_LOGIN_REJ) {
1800                         struct srp_login_rej *rej = event->private_data;
1801                         u32 reason = be32_to_cpu(rej->reason);
1802
1803                         if (reason == SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE)
1804                                 shost_printk(KERN_WARNING, shost,
1805                                              PFX "SRP_LOGIN_REJ: requested max_it_iu_len too large\n");
1806                         else
1807                                 shost_printk(KERN_WARNING, shost,
1808                                             PFX "SRP LOGIN REJECTED, reason 0x%08x\n", reason);
1809                 } else
1810                         shost_printk(KERN_WARNING, shost,
1811                                      "  REJ reason: IB_CM_REJ_CONSUMER_DEFINED,"
1812                                      " opcode 0x%02x\n", opcode);
1813                 target->status = -ECONNRESET;
1814                 break;
1815
1816         case IB_CM_REJ_STALE_CONN:
1817                 shost_printk(KERN_WARNING, shost, "  REJ reason: stale connection\n");
1818                 target->status = SRP_STALE_CONN;
1819                 break;
1820
1821         default:
1822                 shost_printk(KERN_WARNING, shost, "  REJ reason 0x%x\n",
1823                              event->param.rej_rcvd.reason);
1824                 target->status = -ECONNRESET;
1825         }
1826 }
1827
1828 static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
1829 {
1830         struct srp_target_port *target = cm_id->context;
1831         int comp = 0;
1832
1833         switch (event->event) {
1834         case IB_CM_REQ_ERROR:
1835                 shost_printk(KERN_DEBUG, target->scsi_host,
1836                              PFX "Sending CM REQ failed\n");
1837                 comp = 1;
1838                 target->status = -ECONNRESET;
1839                 break;
1840
1841         case IB_CM_REP_RECEIVED:
1842                 comp = 1;
1843                 srp_cm_rep_handler(cm_id, event->private_data, target);
1844                 break;
1845
1846         case IB_CM_REJ_RECEIVED:
1847                 shost_printk(KERN_DEBUG, target->scsi_host, PFX "REJ received\n");
1848                 comp = 1;
1849
1850                 srp_cm_rej_handler(cm_id, event, target);
1851                 break;
1852
1853         case IB_CM_DREQ_RECEIVED:
1854                 shost_printk(KERN_WARNING, target->scsi_host,
1855                              PFX "DREQ received - connection closed\n");
1856                 srp_change_conn_state(target, false);
1857                 if (ib_send_cm_drep(cm_id, NULL, 0))
1858                         shost_printk(KERN_ERR, target->scsi_host,
1859                                      PFX "Sending CM DREP failed\n");
1860                 queue_work(system_long_wq, &target->tl_err_work);
1861                 break;
1862
1863         case IB_CM_TIMEWAIT_EXIT:
1864                 shost_printk(KERN_ERR, target->scsi_host,
1865                              PFX "connection closed\n");
1866
1867                 target->status = 0;
1868                 break;
1869
1870         case IB_CM_MRA_RECEIVED:
1871         case IB_CM_DREQ_ERROR:
1872         case IB_CM_DREP_RECEIVED:
1873                 break;
1874
1875         default:
1876                 shost_printk(KERN_WARNING, target->scsi_host,
1877                              PFX "Unhandled CM event %d\n", event->event);
1878                 break;
1879         }
1880
1881         if (comp)
1882                 complete(&target->done);
1883
1884         return 0;
1885 }
1886
1887 /**
1888  * srp_change_queue_type - changing device queue tag type
1889  * @sdev: scsi device struct
1890  * @tag_type: requested tag type
1891  *
1892  * Returns queue tag type.
1893  */
1894 static int
1895 srp_change_queue_type(struct scsi_device *sdev, int tag_type)
1896 {
1897         if (sdev->tagged_supported) {
1898                 scsi_set_tag_type(sdev, tag_type);
1899                 if (tag_type)
1900                         scsi_activate_tcq(sdev, sdev->queue_depth);
1901                 else
1902                         scsi_deactivate_tcq(sdev, sdev->queue_depth);
1903         } else
1904                 tag_type = 0;
1905
1906         return tag_type;
1907 }
1908
1909 /**
1910  * srp_change_queue_depth - setting device queue depth
1911  * @sdev: scsi device struct
1912  * @qdepth: requested queue depth
1913  * @reason: SCSI_QDEPTH_DEFAULT/SCSI_QDEPTH_QFULL/SCSI_QDEPTH_RAMP_UP
1914  * (see include/scsi/scsi_host.h for definition)
1915  *
1916  * Returns queue depth.
1917  */
1918 static int
1919 srp_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
1920 {
1921         struct Scsi_Host *shost = sdev->host;
1922         int max_depth;
1923         if (reason == SCSI_QDEPTH_DEFAULT || reason == SCSI_QDEPTH_RAMP_UP) {
1924                 max_depth = shost->can_queue;
1925                 if (!sdev->tagged_supported)
1926                         max_depth = 1;
1927                 if (qdepth > max_depth)
1928                         qdepth = max_depth;
1929                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth);
1930         } else if (reason == SCSI_QDEPTH_QFULL)
1931                 scsi_track_queue_full(sdev, qdepth);
1932         else
1933                 return -EOPNOTSUPP;
1934
1935         return sdev->queue_depth;
1936 }
1937
1938 static int srp_send_tsk_mgmt(struct srp_target_port *target,
1939                              u64 req_tag, unsigned int lun, u8 func)
1940 {
1941         struct srp_rport *rport = target->rport;
1942         struct ib_device *dev = target->srp_host->srp_dev->dev;
1943         struct srp_iu *iu;
1944         struct srp_tsk_mgmt *tsk_mgmt;
1945
1946         if (!target->connected || target->qp_in_error)
1947                 return -1;
1948
1949         init_completion(&target->tsk_mgmt_done);
1950
1951         /*
1952          * Lock the rport mutex to avoid that srp_create_target_ib() is
1953          * invoked while a task management function is being sent.
1954          */
1955         mutex_lock(&rport->mutex);
1956         spin_lock_irq(&target->lock);
1957         iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT);
1958         spin_unlock_irq(&target->lock);
1959
1960         if (!iu) {
1961                 mutex_unlock(&rport->mutex);
1962
1963                 return -1;
1964         }
1965
1966         ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt,
1967                                    DMA_TO_DEVICE);
1968         tsk_mgmt = iu->buf;
1969         memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
1970
1971         tsk_mgmt->opcode        = SRP_TSK_MGMT;
1972         tsk_mgmt->lun           = cpu_to_be64((u64) lun << 48);
1973         tsk_mgmt->tag           = req_tag | SRP_TAG_TSK_MGMT;
1974         tsk_mgmt->tsk_mgmt_func = func;
1975         tsk_mgmt->task_tag      = req_tag;
1976
1977         ib_dma_sync_single_for_device(dev, iu->dma, sizeof *tsk_mgmt,
1978                                       DMA_TO_DEVICE);
1979         if (srp_post_send(target, iu, sizeof *tsk_mgmt)) {
1980                 srp_put_tx_iu(target, iu, SRP_IU_TSK_MGMT);
1981                 mutex_unlock(&rport->mutex);
1982
1983                 return -1;
1984         }
1985         mutex_unlock(&rport->mutex);
1986
1987         if (!wait_for_completion_timeout(&target->tsk_mgmt_done,
1988                                          msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
1989                 return -1;
1990
1991         return 0;
1992 }
1993
1994 static int srp_abort(struct scsi_cmnd *scmnd)
1995 {
1996         struct srp_target_port *target = host_to_target(scmnd->device->host);
1997         struct srp_request *req = (struct srp_request *) scmnd->host_scribble;
1998         int ret;
1999
2000         shost_printk(KERN_ERR, target->scsi_host, "SRP abort called\n");
2001
2002         if (!req || !srp_claim_req(target, req, scmnd))
2003                 return SUCCESS;
2004         if (srp_send_tsk_mgmt(target, req->index, scmnd->device->lun,
2005                               SRP_TSK_ABORT_TASK) == 0)
2006                 ret = SUCCESS;
2007         else if (target->rport->state == SRP_RPORT_LOST)
2008                 ret = FAST_IO_FAIL;
2009         else
2010                 ret = FAILED;
2011         srp_free_req(target, req, scmnd, 0);
2012         scmnd->result = DID_ABORT << 16;
2013         scmnd->scsi_done(scmnd);
2014
2015         return ret;
2016 }
2017
2018 static int srp_reset_device(struct scsi_cmnd *scmnd)
2019 {
2020         struct srp_target_port *target = host_to_target(scmnd->device->host);
2021         int i;
2022
2023         shost_printk(KERN_ERR, target->scsi_host, "SRP reset_device called\n");
2024
2025         if (srp_send_tsk_mgmt(target, SRP_TAG_NO_REQ, scmnd->device->lun,
2026                               SRP_TSK_LUN_RESET))
2027                 return FAILED;
2028         if (target->tsk_mgmt_status)
2029                 return FAILED;
2030
2031         for (i = 0; i < target->req_ring_size; ++i) {
2032                 struct srp_request *req = &target->req_ring[i];
2033                 if (req->scmnd && req->scmnd->device == scmnd->device)
2034                         srp_finish_req(target, req, DID_RESET << 16);
2035         }
2036
2037         return SUCCESS;
2038 }
2039
2040 static int srp_reset_host(struct scsi_cmnd *scmnd)
2041 {
2042         struct srp_target_port *target = host_to_target(scmnd->device->host);
2043
2044         shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
2045
2046         return srp_reconnect_rport(target->rport) == 0 ? SUCCESS : FAILED;
2047 }
2048
2049 static int srp_slave_configure(struct scsi_device *sdev)
2050 {
2051         struct Scsi_Host *shost = sdev->host;
2052         struct srp_target_port *target = host_to_target(shost);
2053         struct request_queue *q = sdev->request_queue;
2054         unsigned long timeout;
2055
2056         if (sdev->type == TYPE_DISK) {
2057                 timeout = max_t(unsigned, 30 * HZ, target->rq_tmo_jiffies);
2058                 blk_queue_rq_timeout(q, timeout);
2059         }
2060
2061         return 0;
2062 }
2063
2064 static ssize_t show_id_ext(struct device *dev, struct device_attribute *attr,
2065                            char *buf)
2066 {
2067         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2068
2069         return sprintf(buf, "0x%016llx\n",
2070                        (unsigned long long) be64_to_cpu(target->id_ext));
2071 }
2072
2073 static ssize_t show_ioc_guid(struct device *dev, struct device_attribute *attr,
2074                              char *buf)
2075 {
2076         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2077
2078         return sprintf(buf, "0x%016llx\n",
2079                        (unsigned long long) be64_to_cpu(target->ioc_guid));
2080 }
2081
2082 static ssize_t show_service_id(struct device *dev,
2083                                struct device_attribute *attr, char *buf)
2084 {
2085         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2086
2087         return sprintf(buf, "0x%016llx\n",
2088                        (unsigned long long) be64_to_cpu(target->service_id));
2089 }
2090
2091 static ssize_t show_pkey(struct device *dev, struct device_attribute *attr,
2092                          char *buf)
2093 {
2094         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2095
2096         return sprintf(buf, "0x%04x\n", be16_to_cpu(target->path.pkey));
2097 }
2098
2099 static ssize_t show_sgid(struct device *dev, struct device_attribute *attr,
2100                          char *buf)
2101 {
2102         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2103
2104         return sprintf(buf, "%pI6\n", target->path.sgid.raw);
2105 }
2106
2107 static ssize_t show_dgid(struct device *dev, struct device_attribute *attr,
2108                          char *buf)
2109 {
2110         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2111
2112         return sprintf(buf, "%pI6\n", target->path.dgid.raw);
2113 }
2114
2115 static ssize_t show_orig_dgid(struct device *dev,
2116                               struct device_attribute *attr, char *buf)
2117 {
2118         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2119
2120         return sprintf(buf, "%pI6\n", target->orig_dgid);
2121 }
2122
2123 static ssize_t show_req_lim(struct device *dev,
2124                             struct device_attribute *attr, char *buf)
2125 {
2126         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2127
2128         return sprintf(buf, "%d\n", target->req_lim);
2129 }
2130
2131 static ssize_t show_zero_req_lim(struct device *dev,
2132                                  struct device_attribute *attr, char *buf)
2133 {
2134         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2135
2136         return sprintf(buf, "%d\n", target->zero_req_lim);
2137 }
2138
2139 static ssize_t show_local_ib_port(struct device *dev,
2140                                   struct device_attribute *attr, char *buf)
2141 {
2142         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2143
2144         return sprintf(buf, "%d\n", target->srp_host->port);
2145 }
2146
2147 static ssize_t show_local_ib_device(struct device *dev,
2148                                     struct device_attribute *attr, char *buf)
2149 {
2150         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2151
2152         return sprintf(buf, "%s\n", target->srp_host->srp_dev->dev->name);
2153 }
2154
2155 static ssize_t show_comp_vector(struct device *dev,
2156                                 struct device_attribute *attr, char *buf)
2157 {
2158         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2159
2160         return sprintf(buf, "%d\n", target->comp_vector);
2161 }
2162
2163 static ssize_t show_tl_retry_count(struct device *dev,
2164                                    struct device_attribute *attr, char *buf)
2165 {
2166         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2167
2168         return sprintf(buf, "%d\n", target->tl_retry_count);
2169 }
2170
2171 static ssize_t show_cmd_sg_entries(struct device *dev,
2172                                    struct device_attribute *attr, char *buf)
2173 {
2174         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2175
2176         return sprintf(buf, "%u\n", target->cmd_sg_cnt);
2177 }
2178
2179 static ssize_t show_allow_ext_sg(struct device *dev,
2180                                  struct device_attribute *attr, char *buf)
2181 {
2182         struct srp_target_port *target = host_to_target(class_to_shost(dev));
2183
2184         return sprintf(buf, "%s\n", target->allow_ext_sg ? "true" : "false");
2185 }
2186
2187 static DEVICE_ATTR(id_ext,          S_IRUGO, show_id_ext,          NULL);
2188 static DEVICE_ATTR(ioc_guid,        S_IRUGO, show_ioc_guid,        NULL);
2189 static DEVICE_ATTR(service_id,      S_IRUGO, show_service_id,      NULL);
2190 static DEVICE_ATTR(pkey,            S_IRUGO, show_pkey,            NULL);
2191 static DEVICE_ATTR(sgid,            S_IRUGO, show_sgid,            NULL);
2192 static DEVICE_ATTR(dgid,            S_IRUGO, show_dgid,            NULL);
2193 static DEVICE_ATTR(orig_dgid,       S_IRUGO, show_orig_dgid,       NULL);
2194 static DEVICE_ATTR(req_lim,         S_IRUGO, show_req_lim,         NULL);
2195 static DEVICE_ATTR(zero_req_lim,    S_IRUGO, show_zero_req_lim,    NULL);
2196 static DEVICE_ATTR(local_ib_port,   S_IRUGO, show_local_ib_port,   NULL);
2197 static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
2198 static DEVICE_ATTR(comp_vector,     S_IRUGO, show_comp_vector,     NULL);
2199 static DEVICE_ATTR(tl_retry_count,  S_IRUGO, show_tl_retry_count,  NULL);
2200 static DEVICE_ATTR(cmd_sg_entries,  S_IRUGO, show_cmd_sg_entries,  NULL);
2201 static DEVICE_ATTR(allow_ext_sg,    S_IRUGO, show_allow_ext_sg,    NULL);
2202
2203 static struct device_attribute *srp_host_attrs[] = {
2204         &dev_attr_id_ext,
2205         &dev_attr_ioc_guid,
2206         &dev_attr_service_id,
2207         &dev_attr_pkey,
2208         &dev_attr_sgid,
2209         &dev_attr_dgid,
2210         &dev_attr_orig_dgid,
2211         &dev_attr_req_lim,
2212         &dev_attr_zero_req_lim,
2213         &dev_attr_local_ib_port,
2214         &dev_attr_local_ib_device,
2215         &dev_attr_comp_vector,
2216         &dev_attr_tl_retry_count,
2217         &dev_attr_cmd_sg_entries,
2218         &dev_attr_allow_ext_sg,
2219         NULL
2220 };
2221
2222 static struct scsi_host_template srp_template = {
2223         .module                         = THIS_MODULE,
2224         .name                           = "InfiniBand SRP initiator",
2225         .proc_name                      = DRV_NAME,
2226         .slave_configure                = srp_slave_configure,
2227         .info                           = srp_target_info,
2228         .queuecommand                   = srp_queuecommand,
2229         .change_queue_depth             = srp_change_queue_depth,
2230         .change_queue_type              = srp_change_queue_type,
2231         .eh_abort_handler               = srp_abort,
2232         .eh_device_reset_handler        = srp_reset_device,
2233         .eh_host_reset_handler          = srp_reset_host,
2234         .skip_settle_delay              = true,
2235         .sg_tablesize                   = SRP_DEF_SG_TABLESIZE,
2236         .can_queue                      = SRP_DEFAULT_CMD_SQ_SIZE,
2237         .this_id                        = -1,
2238         .cmd_per_lun                    = SRP_DEFAULT_CMD_SQ_SIZE,
2239         .use_clustering                 = ENABLE_CLUSTERING,
2240         .shost_attrs                    = srp_host_attrs
2241 };
2242
2243 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
2244 {
2245         struct srp_rport_identifiers ids;
2246         struct srp_rport *rport;
2247
2248         sprintf(target->target_name, "SRP.T10:%016llX",
2249                  (unsigned long long) be64_to_cpu(target->id_ext));
2250
2251         if (scsi_add_host(target->scsi_host, host->srp_dev->dev->dma_device))
2252                 return -ENODEV;
2253
2254         memcpy(ids.port_id, &target->id_ext, 8);
2255         memcpy(ids.port_id + 8, &target->ioc_guid, 8);
2256         ids.roles = SRP_RPORT_ROLE_TARGET;
2257         rport = srp_rport_add(target->scsi_host, &ids);
2258         if (IS_ERR(rport)) {
2259                 scsi_remove_host(target->scsi_host);
2260                 return PTR_ERR(rport);
2261         }
2262
2263         rport->lld_data = target;
2264         target->rport = rport;
2265
2266         spin_lock(&host->target_lock);
2267         list_add_tail(&target->list, &host->target_list);
2268         spin_unlock(&host->target_lock);
2269
2270         target->state = SRP_TARGET_LIVE;
2271
2272         scsi_scan_target(&target->scsi_host->shost_gendev,
2273                          0, target->scsi_id, SCAN_WILD_CARD, 0);
2274
2275         return 0;
2276 }
2277
2278 static void srp_release_dev(struct device *dev)
2279 {
2280         struct srp_host *host =
2281                 container_of(dev, struct srp_host, dev);
2282
2283         complete(&host->released);
2284 }
2285
2286 static struct class srp_class = {
2287         .name    = "infiniband_srp",
2288         .dev_release = srp_release_dev
2289 };
2290
2291 /**
2292  * srp_conn_unique() - check whether the connection to a target is unique
2293  */
2294 static bool srp_conn_unique(struct srp_host *host,
2295                             struct srp_target_port *target)
2296 {
2297         struct srp_target_port *t;
2298         bool ret = false;
2299
2300         if (target->state == SRP_TARGET_REMOVED)
2301                 goto out;
2302
2303         ret = true;
2304
2305         spin_lock(&host->target_lock);
2306         list_for_each_entry(t, &host->target_list, list) {
2307                 if (t != target &&
2308                     target->id_ext == t->id_ext &&
2309                     target->ioc_guid == t->ioc_guid &&
2310                     target->initiator_ext == t->initiator_ext) {
2311                         ret = false;
2312                         break;
2313                 }
2314         }
2315         spin_unlock(&host->target_lock);
2316
2317 out:
2318         return ret;
2319 }
2320
2321 /*
2322  * Target ports are added by writing
2323  *
2324  *     id_ext=<SRP ID ext>,ioc_guid=<SRP IOC GUID>,dgid=<dest GID>,
2325  *     pkey=<P_Key>,service_id=<service ID>
2326  *
2327  * to the add_target sysfs attribute.
2328  */
2329 enum {
2330         SRP_OPT_ERR             = 0,
2331         SRP_OPT_ID_EXT          = 1 << 0,
2332         SRP_OPT_IOC_GUID        = 1 << 1,
2333         SRP_OPT_DGID            = 1 << 2,
2334         SRP_OPT_PKEY            = 1 << 3,
2335         SRP_OPT_SERVICE_ID      = 1 << 4,
2336         SRP_OPT_MAX_SECT        = 1 << 5,
2337         SRP_OPT_MAX_CMD_PER_LUN = 1 << 6,
2338         SRP_OPT_IO_CLASS        = 1 << 7,
2339         SRP_OPT_INITIATOR_EXT   = 1 << 8,
2340         SRP_OPT_CMD_SG_ENTRIES  = 1 << 9,
2341         SRP_OPT_ALLOW_EXT_SG    = 1 << 10,
2342         SRP_OPT_SG_TABLESIZE    = 1 << 11,
2343         SRP_OPT_COMP_VECTOR     = 1 << 12,
2344         SRP_OPT_TL_RETRY_COUNT  = 1 << 13,
2345         SRP_OPT_QUEUE_SIZE      = 1 << 14,
2346         SRP_OPT_ALL             = (SRP_OPT_ID_EXT       |
2347                                    SRP_OPT_IOC_GUID     |
2348                                    SRP_OPT_DGID         |
2349                                    SRP_OPT_PKEY         |
2350                                    SRP_OPT_SERVICE_ID),
2351 };
2352
2353 static const match_table_t srp_opt_tokens = {
2354         { SRP_OPT_ID_EXT,               "id_ext=%s"             },
2355         { SRP_OPT_IOC_GUID,             "ioc_guid=%s"           },
2356         { SRP_OPT_DGID,                 "dgid=%s"               },
2357         { SRP_OPT_PKEY,                 "pkey=%x"               },
2358         { SRP_OPT_SERVICE_ID,           "service_id=%s"         },
2359         { SRP_OPT_MAX_SECT,             "max_sect=%d"           },
2360         { SRP_OPT_MAX_CMD_PER_LUN,      "max_cmd_per_lun=%d"    },
2361         { SRP_OPT_IO_CLASS,             "io_class=%x"           },
2362         { SRP_OPT_INITIATOR_EXT,        "initiator_ext=%s"      },
2363         { SRP_OPT_CMD_SG_ENTRIES,       "cmd_sg_entries=%u"     },
2364         { SRP_OPT_ALLOW_EXT_SG,         "allow_ext_sg=%u"       },
2365         { SRP_OPT_SG_TABLESIZE,         "sg_tablesize=%u"       },
2366         { SRP_OPT_COMP_VECTOR,          "comp_vector=%u"        },
2367         { SRP_OPT_TL_RETRY_COUNT,       "tl_retry_count=%u"     },
2368         { SRP_OPT_QUEUE_SIZE,           "queue_size=%d"         },
2369         { SRP_OPT_ERR,                  NULL                    }
2370 };
2371
2372 static int srp_parse_options(const char *buf, struct srp_target_port *target)
2373 {
2374         char *options, *sep_opt;
2375         char *p;
2376         char dgid[3];
2377         substring_t args[MAX_OPT_ARGS];
2378         int opt_mask = 0;
2379         int token;
2380         int ret = -EINVAL;
2381         int i;
2382
2383         options = kstrdup(buf, GFP_KERNEL);
2384         if (!options)
2385                 return -ENOMEM;
2386
2387         sep_opt = options;
2388         while ((p = strsep(&sep_opt, ",")) != NULL) {
2389                 if (!*p)
2390                         continue;
2391
2392                 token = match_token(p, srp_opt_tokens, args);
2393                 opt_mask |= token;
2394
2395                 switch (token) {
2396                 case SRP_OPT_ID_EXT:
2397                         p = match_strdup(args);
2398                         if (!p) {
2399                                 ret = -ENOMEM;
2400                                 goto out;
2401                         }
2402                         target->id_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2403                         kfree(p);
2404                         break;
2405
2406                 case SRP_OPT_IOC_GUID:
2407                         p = match_strdup(args);
2408                         if (!p) {
2409                                 ret = -ENOMEM;
2410                                 goto out;
2411                         }
2412                         target->ioc_guid = cpu_to_be64(simple_strtoull(p, NULL, 16));
2413                         kfree(p);
2414                         break;
2415
2416                 case SRP_OPT_DGID:
2417                         p = match_strdup(args);
2418                         if (!p) {
2419                                 ret = -ENOMEM;
2420                                 goto out;
2421                         }
2422                         if (strlen(p) != 32) {
2423                                 pr_warn("bad dest GID parameter '%s'\n", p);
2424                                 kfree(p);
2425                                 goto out;
2426                         }
2427
2428                         for (i = 0; i < 16; ++i) {
2429                                 strlcpy(dgid, p + i * 2, 3);
2430                                 target->path.dgid.raw[i] = simple_strtoul(dgid, NULL, 16);
2431                         }
2432                         kfree(p);
2433                         memcpy(target->orig_dgid, target->path.dgid.raw, 16);
2434                         break;
2435
2436                 case SRP_OPT_PKEY:
2437                         if (match_hex(args, &token)) {
2438                                 pr_warn("bad P_Key parameter '%s'\n", p);
2439                                 goto out;
2440                         }
2441                         target->path.pkey = cpu_to_be16(token);
2442                         break;
2443
2444                 case SRP_OPT_SERVICE_ID:
2445                         p = match_strdup(args);
2446                         if (!p) {
2447                                 ret = -ENOMEM;
2448                                 goto out;
2449                         }
2450                         target->service_id = cpu_to_be64(simple_strtoull(p, NULL, 16));
2451                         target->path.service_id = target->service_id;
2452                         kfree(p);
2453                         break;
2454
2455                 case SRP_OPT_MAX_SECT:
2456                         if (match_int(args, &token)) {
2457                                 pr_warn("bad max sect parameter '%s'\n", p);
2458                                 goto out;
2459                         }
2460                         target->scsi_host->max_sectors = token;
2461                         break;
2462
2463                 case SRP_OPT_QUEUE_SIZE:
2464                         if (match_int(args, &token) || token < 1) {
2465                                 pr_warn("bad queue_size parameter '%s'\n", p);
2466                                 goto out;
2467                         }
2468                         target->scsi_host->can_queue = token;
2469                         target->queue_size = token + SRP_RSP_SQ_SIZE +
2470                                              SRP_TSK_MGMT_SQ_SIZE;
2471                         if (!(opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
2472                                 target->scsi_host->cmd_per_lun = token;
2473                         break;
2474
2475                 case SRP_OPT_MAX_CMD_PER_LUN:
2476                         if (match_int(args, &token) || token < 1) {
2477                                 pr_warn("bad max cmd_per_lun parameter '%s'\n",
2478                                         p);
2479                                 goto out;
2480                         }
2481                         target->scsi_host->cmd_per_lun = token;
2482                         break;
2483
2484                 case SRP_OPT_IO_CLASS:
2485                         if (match_hex(args, &token)) {
2486                                 pr_warn("bad IO class parameter '%s'\n", p);
2487                                 goto out;
2488                         }
2489                         if (token != SRP_REV10_IB_IO_CLASS &&
2490                             token != SRP_REV16A_IB_IO_CLASS) {
2491                                 pr_warn("unknown IO class parameter value %x specified (use %x or %x).\n",
2492                                         token, SRP_REV10_IB_IO_CLASS,
2493                                         SRP_REV16A_IB_IO_CLASS);
2494                                 goto out;
2495                         }
2496                         target->io_class = token;
2497                         break;
2498
2499                 case SRP_OPT_INITIATOR_EXT:
2500                         p = match_strdup(args);
2501                         if (!p) {
2502                                 ret = -ENOMEM;
2503                                 goto out;
2504                         }
2505                         target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
2506                         kfree(p);
2507                         break;
2508
2509                 case SRP_OPT_CMD_SG_ENTRIES:
2510                         if (match_int(args, &token) || token < 1 || token > 255) {
2511                                 pr_warn("bad max cmd_sg_entries parameter '%s'\n",
2512                                         p);
2513                                 goto out;
2514                         }
2515                         target->cmd_sg_cnt = token;
2516                         break;
2517
2518                 case SRP_OPT_ALLOW_EXT_SG:
2519                         if (match_int(args, &token)) {
2520                                 pr_warn("bad allow_ext_sg parameter '%s'\n", p);
2521                                 goto out;
2522                         }
2523                         target->allow_ext_sg = !!token;
2524                         break;
2525
2526                 case SRP_OPT_SG_TABLESIZE:
2527                         if (match_int(args, &token) || token < 1 ||
2528                                         token > SCSI_MAX_SG_CHAIN_SEGMENTS) {
2529                                 pr_warn("bad max sg_tablesize parameter '%s'\n",
2530                                         p);
2531                                 goto out;
2532                         }
2533                         target->sg_tablesize = token;
2534                         break;
2535
2536                 case SRP_OPT_COMP_VECTOR:
2537                         if (match_int(args, &token) || token < 0) {
2538                                 pr_warn("bad comp_vector parameter '%s'\n", p);
2539                                 goto out;
2540                         }
2541                         target->comp_vector = token;
2542                         break;
2543
2544                 case SRP_OPT_TL_RETRY_COUNT:
2545                         if (match_int(args, &token) || token < 2 || token > 7) {
2546                                 pr_warn("bad tl_retry_count parameter '%s' (must be a number between 2 and 7)\n",
2547                                         p);
2548                                 goto out;
2549                         }
2550                         target->tl_retry_count = token;
2551                         break;
2552
2553                 default:
2554                         pr_warn("unknown parameter or missing value '%s' in target creation request\n",
2555                                 p);
2556                         goto out;
2557                 }
2558         }
2559
2560         if ((opt_mask & SRP_OPT_ALL) == SRP_OPT_ALL)
2561                 ret = 0;
2562         else
2563                 for (i = 0; i < ARRAY_SIZE(srp_opt_tokens); ++i)
2564                         if ((srp_opt_tokens[i].token & SRP_OPT_ALL) &&
2565                             !(srp_opt_tokens[i].token & opt_mask))
2566                                 pr_warn("target creation request is missing parameter '%s'\n",
2567                                         srp_opt_tokens[i].pattern);
2568
2569         if (target->scsi_host->cmd_per_lun > target->scsi_host->can_queue
2570             && (opt_mask & SRP_OPT_MAX_CMD_PER_LUN))
2571                 pr_warn("cmd_per_lun = %d > queue_size = %d\n",
2572                         target->scsi_host->cmd_per_lun,
2573                         target->scsi_host->can_queue);
2574
2575 out:
2576         kfree(options);
2577         return ret;
2578 }
2579
2580 static ssize_t srp_create_target(struct device *dev,
2581                                  struct device_attribute *attr,
2582                                  const char *buf, size_t count)
2583 {
2584         struct srp_host *host =
2585                 container_of(dev, struct srp_host, dev);
2586         struct Scsi_Host *target_host;
2587         struct srp_target_port *target;
2588         struct ib_device *ibdev = host->srp_dev->dev;
2589         int ret;
2590
2591         target_host = scsi_host_alloc(&srp_template,
2592                                       sizeof (struct srp_target_port));
2593         if (!target_host)
2594                 return -ENOMEM;
2595
2596         target_host->transportt  = ib_srp_transport_template;
2597         target_host->max_channel = 0;
2598         target_host->max_id      = 1;
2599         target_host->max_lun     = SRP_MAX_LUN;
2600         target_host->max_cmd_len = sizeof ((struct srp_cmd *) (void *) 0L)->cdb;
2601
2602         target = host_to_target(target_host);
2603
2604         target->io_class        = SRP_REV16A_IB_IO_CLASS;
2605         target->scsi_host       = target_host;
2606         target->srp_host        = host;
2607         target->lkey            = host->srp_dev->mr->lkey;
2608         target->rkey            = host->srp_dev->mr->rkey;
2609         target->cmd_sg_cnt      = cmd_sg_entries;
2610         target->sg_tablesize    = indirect_sg_entries ? : cmd_sg_entries;
2611         target->allow_ext_sg    = allow_ext_sg;
2612         target->tl_retry_count  = 7;
2613         target->queue_size      = SRP_DEFAULT_QUEUE_SIZE;
2614
2615         ret = srp_parse_options(buf, target);
2616         if (ret)
2617                 goto err;
2618
2619         target->req_ring_size = target->queue_size - SRP_TSK_MGMT_SQ_SIZE;
2620
2621         if (!srp_conn_unique(target->srp_host, target)) {
2622                 shost_printk(KERN_INFO, target->scsi_host,
2623                              PFX "Already connected to target port with id_ext=%016llx;ioc_guid=%016llx;initiator_ext=%016llx\n",
2624                              be64_to_cpu(target->id_ext),
2625                              be64_to_cpu(target->ioc_guid),
2626                              be64_to_cpu(target->initiator_ext));
2627                 ret = -EEXIST;
2628                 goto err;
2629         }
2630
2631         if (!host->srp_dev->fmr_pool && !target->allow_ext_sg &&
2632                                 target->cmd_sg_cnt < target->sg_tablesize) {
2633                 pr_warn("No FMR pool and no external indirect descriptors, limiting sg_tablesize to cmd_sg_cnt\n");
2634                 target->sg_tablesize = target->cmd_sg_cnt;
2635         }
2636
2637         target_host->sg_tablesize = target->sg_tablesize;
2638         target->indirect_size = target->sg_tablesize *
2639                                 sizeof (struct srp_direct_buf);
2640         target->max_iu_len = sizeof (struct srp_cmd) +
2641                              sizeof (struct srp_indirect_buf) +
2642                              target->cmd_sg_cnt * sizeof (struct srp_direct_buf);
2643
2644         INIT_WORK(&target->tl_err_work, srp_tl_err_work);
2645         INIT_WORK(&target->remove_work, srp_remove_work);
2646         spin_lock_init(&target->lock);
2647         INIT_LIST_HEAD(&target->free_tx);
2648         ret = srp_alloc_req_data(target);
2649         if (ret)
2650                 goto err_free_mem;
2651
2652         ib_query_gid(ibdev, host->port, 0, &target->path.sgid);
2653
2654         shost_printk(KERN_DEBUG, target->scsi_host, PFX
2655                      "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
2656                      "service_id %016llx dgid %pI6\n",
2657                (unsigned long long) be64_to_cpu(target->id_ext),
2658                (unsigned long long) be64_to_cpu(target->ioc_guid),
2659                be16_to_cpu(target->path.pkey),
2660                (unsigned long long) be64_to_cpu(target->service_id),
2661                target->path.dgid.raw);
2662
2663         ret = srp_create_target_ib(target);
2664         if (ret)
2665                 goto err_free_mem;
2666
2667         ret = srp_new_cm_id(target);
2668         if (ret)
2669                 goto err_free_ib;
2670
2671         ret = srp_connect_target(target);
2672         if (ret) {
2673                 shost_printk(KERN_ERR, target->scsi_host,
2674                              PFX "Connection failed\n");
2675                 goto err_cm_id;
2676         }
2677
2678         ret = srp_add_target(host, target);
2679         if (ret)
2680                 goto err_disconnect;
2681
2682         return count;
2683
2684 err_disconnect:
2685         srp_disconnect_target(target);
2686
2687 err_cm_id:
2688         ib_destroy_cm_id(target->cm_id);
2689
2690 err_free_ib:
2691         srp_free_target_ib(target);
2692
2693 err_free_mem:
2694         srp_free_req_data(target);
2695
2696 err:
2697         scsi_host_put(target_host);
2698
2699         return ret;
2700 }
2701
2702 static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
2703
2704 static ssize_t show_ibdev(struct device *dev, struct device_attribute *attr,
2705                           char *buf)
2706 {
2707         struct srp_host *host = container_of(dev, struct srp_host, dev);
2708
2709         return sprintf(buf, "%s\n", host->srp_dev->dev->name);
2710 }
2711
2712 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
2713
2714 static ssize_t show_port(struct device *dev, struct device_attribute *attr,
2715                          char *buf)
2716 {
2717         struct srp_host *host = container_of(dev, struct srp_host, dev);
2718
2719         return sprintf(buf, "%d\n", host->port);
2720 }
2721
2722 static DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
2723
2724 static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
2725 {
2726         struct srp_host *host;
2727
2728         host = kzalloc(sizeof *host, GFP_KERNEL);
2729         if (!host)
2730                 return NULL;
2731
2732         INIT_LIST_HEAD(&host->target_list);
2733         spin_lock_init(&host->target_lock);
2734         init_completion(&host->released);
2735         host->srp_dev = device;
2736         host->port = port;
2737
2738         host->dev.class = &srp_class;
2739         host->dev.parent = device->dev->dma_device;
2740         dev_set_name(&host->dev, "srp-%s-%d", device->dev->name, port);
2741
2742         if (device_register(&host->dev))
2743                 goto free_host;
2744         if (device_create_file(&host->dev, &dev_attr_add_target))
2745                 goto err_class;
2746         if (device_create_file(&host->dev, &dev_attr_ibdev))
2747                 goto err_class;
2748         if (device_create_file(&host->dev, &dev_attr_port))
2749                 goto err_class;
2750
2751         return host;
2752
2753 err_class:
2754         device_unregister(&host->dev);
2755
2756 free_host:
2757         kfree(host);
2758
2759         return NULL;
2760 }
2761
2762 static void srp_add_one(struct ib_device *device)
2763 {
2764         struct srp_device *srp_dev;
2765         struct ib_device_attr *dev_attr;
2766         struct ib_fmr_pool_param fmr_param;
2767         struct srp_host *host;
2768         int max_pages_per_fmr, fmr_page_shift, s, e, p;
2769
2770         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
2771         if (!dev_attr)
2772                 return;
2773
2774         if (ib_query_device(device, dev_attr)) {
2775                 pr_warn("Query device failed for %s\n", device->name);
2776                 goto free_attr;
2777         }
2778
2779         srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
2780         if (!srp_dev)
2781                 goto free_attr;
2782
2783         /*
2784          * Use the smallest page size supported by the HCA, down to a
2785          * minimum of 4096 bytes. We're unlikely to build large sglists
2786          * out of smaller entries.
2787          */
2788         fmr_page_shift          = max(12, ffs(dev_attr->page_size_cap) - 1);
2789         srp_dev->fmr_page_size  = 1 << fmr_page_shift;
2790         srp_dev->fmr_page_mask  = ~((u64) srp_dev->fmr_page_size - 1);
2791         srp_dev->fmr_max_size   = srp_dev->fmr_page_size * SRP_FMR_SIZE;
2792
2793         INIT_LIST_HEAD(&srp_dev->dev_list);
2794
2795         srp_dev->dev = device;
2796         srp_dev->pd  = ib_alloc_pd(device);
2797         if (IS_ERR(srp_dev->pd))
2798                 goto free_dev;
2799
2800         srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
2801                                     IB_ACCESS_LOCAL_WRITE |
2802                                     IB_ACCESS_REMOTE_READ |
2803                                     IB_ACCESS_REMOTE_WRITE);
2804         if (IS_ERR(srp_dev->mr))
2805                 goto err_pd;
2806
2807         for (max_pages_per_fmr = SRP_FMR_SIZE;
2808                         max_pages_per_fmr >= SRP_FMR_MIN_SIZE;
2809                         max_pages_per_fmr /= 2, srp_dev->fmr_max_size /= 2) {
2810                 memset(&fmr_param, 0, sizeof fmr_param);
2811                 fmr_param.pool_size         = SRP_FMR_POOL_SIZE;
2812                 fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
2813                 fmr_param.cache             = 1;
2814                 fmr_param.max_pages_per_fmr = max_pages_per_fmr;
2815                 fmr_param.page_shift        = fmr_page_shift;
2816                 fmr_param.access            = (IB_ACCESS_LOCAL_WRITE |
2817                                                IB_ACCESS_REMOTE_WRITE |
2818                                                IB_ACCESS_REMOTE_READ);
2819
2820                 srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
2821                 if (!IS_ERR(srp_dev->fmr_pool))
2822                         break;
2823         }
2824
2825         if (IS_ERR(srp_dev->fmr_pool))
2826                 srp_dev->fmr_pool = NULL;
2827
2828         if (device->node_type == RDMA_NODE_IB_SWITCH) {
2829                 s = 0;
2830                 e = 0;
2831         } else {
2832                 s = 1;
2833                 e = device->phys_port_cnt;
2834         }
2835
2836         for (p = s; p <= e; ++p) {
2837                 host = srp_add_port(srp_dev, p);
2838                 if (host)
2839                         list_add_tail(&host->list, &srp_dev->dev_list);
2840         }
2841
2842         ib_set_client_data(device, &srp_client, srp_dev);
2843
2844         goto free_attr;
2845
2846 err_pd:
2847         ib_dealloc_pd(srp_dev->pd);
2848
2849 free_dev:
2850         kfree(srp_dev);
2851
2852 free_attr:
2853         kfree(dev_attr);
2854 }
2855
2856 static void srp_remove_one(struct ib_device *device)
2857 {
2858         struct srp_device *srp_dev;
2859         struct srp_host *host, *tmp_host;
2860         struct srp_target_port *target;
2861
2862         srp_dev = ib_get_client_data(device, &srp_client);
2863         if (!srp_dev)
2864                 return;
2865
2866         list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
2867                 device_unregister(&host->dev);
2868                 /*
2869                  * Wait for the sysfs entry to go away, so that no new
2870                  * target ports can be created.
2871                  */
2872                 wait_for_completion(&host->released);
2873
2874                 /*
2875                  * Remove all target ports.
2876                  */
2877                 spin_lock(&host->target_lock);
2878                 list_for_each_entry(target, &host->target_list, list)
2879                         srp_queue_remove_work(target);
2880                 spin_unlock(&host->target_lock);
2881
2882                 /*
2883                  * Wait for target port removal tasks.
2884                  */
2885                 flush_workqueue(system_long_wq);
2886
2887                 kfree(host);
2888         }
2889
2890         if (srp_dev->fmr_pool)
2891                 ib_destroy_fmr_pool(srp_dev->fmr_pool);
2892         ib_dereg_mr(srp_dev->mr);
2893         ib_dealloc_pd(srp_dev->pd);
2894
2895         kfree(srp_dev);
2896 }
2897
2898 static struct srp_function_template ib_srp_transport_functions = {
2899         .has_rport_state         = true,
2900         .reset_timer_if_blocked  = true,
2901         .reconnect_delay         = &srp_reconnect_delay,
2902         .fast_io_fail_tmo        = &srp_fast_io_fail_tmo,
2903         .dev_loss_tmo            = &srp_dev_loss_tmo,
2904         .reconnect               = srp_rport_reconnect,
2905         .rport_delete            = srp_rport_delete,
2906         .terminate_rport_io      = srp_terminate_io,
2907 };
2908
2909 static int __init srp_init_module(void)
2910 {
2911         int ret;
2912
2913         BUILD_BUG_ON(FIELD_SIZEOF(struct ib_wc, wr_id) < sizeof(void *));
2914
2915         if (srp_sg_tablesize) {
2916                 pr_warn("srp_sg_tablesize is deprecated, please use cmd_sg_entries\n");
2917                 if (!cmd_sg_entries)
2918                         cmd_sg_entries = srp_sg_tablesize;
2919         }
2920
2921         if (!cmd_sg_entries)
2922                 cmd_sg_entries = SRP_DEF_SG_TABLESIZE;
2923
2924         if (cmd_sg_entries > 255) {
2925                 pr_warn("Clamping cmd_sg_entries to 255\n");
2926                 cmd_sg_entries = 255;
2927         }
2928
2929         if (!indirect_sg_entries)
2930                 indirect_sg_entries = cmd_sg_entries;
2931         else if (indirect_sg_entries < cmd_sg_entries) {
2932                 pr_warn("Bumping up indirect_sg_entries to match cmd_sg_entries (%u)\n",
2933                         cmd_sg_entries);
2934                 indirect_sg_entries = cmd_sg_entries;
2935         }
2936
2937         ib_srp_transport_template =
2938                 srp_attach_transport(&ib_srp_transport_functions);
2939         if (!ib_srp_transport_template)
2940                 return -ENOMEM;
2941
2942         ret = class_register(&srp_class);
2943         if (ret) {
2944                 pr_err("couldn't register class infiniband_srp\n");
2945                 srp_release_transport(ib_srp_transport_template);
2946                 return ret;
2947         }
2948
2949         ib_sa_register_client(&srp_sa_client);
2950
2951         ret = ib_register_client(&srp_client);
2952         if (ret) {
2953                 pr_err("couldn't register IB client\n");
2954                 srp_release_transport(ib_srp_transport_template);
2955                 ib_sa_unregister_client(&srp_sa_client);
2956                 class_unregister(&srp_class);
2957                 return ret;
2958         }
2959
2960         return 0;
2961 }
2962
2963 static void __exit srp_cleanup_module(void)
2964 {
2965         ib_unregister_client(&srp_client);
2966         ib_sa_unregister_client(&srp_sa_client);
2967         class_unregister(&srp_class);
2968         srp_release_transport(ib_srp_transport_template);
2969 }
2970
2971 module_init(srp_init_module);
2972 module_exit(srp_cleanup_module);