drivers/s390/scsi/zfcp_aux.c

   1 /*
   2  * zfcp device driver
   3  *
   4  * Module interface and handling of zfcp data structures.
   5  *
   6  * Copyright IBM Corporation 2002, 2010
   7  */
   8
   9 /*
  10  * Driver authors:
  11  *            Martin Peschke (originator of the driver)
  12  *            Raimund Schroeder
  13  *            Aron Zeh
  14  *            Wolfgang Taphorn
  15  *            Stefan Bader
  16  *            Heiko Carstens (kernel 2.6 port of the driver)
  17  *            Andreas Herrmann
  18  *            Maxim Shchetynin
  19  *            Volker Sameske
  20  *            Ralph Wuerthner
  21  *            Michael Loehr
  22  *            Swen Schillig
  23  *            Christof Schmitt
  24  *            Martin Petermann
  25  *            Sven Schuetz
  26  */
  27
  28 #define KMSG_COMPONENT "zfcp"
  29 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  30
  31 #include <linux/miscdevice.h>
  32 #include <linux/seq_file.h>
  33 #include "zfcp_ext.h"
  34 #include "zfcp_fc.h"
  35 #include "zfcp_reqlist.h"
  36
  37 #define ZFCP_BUS_ID_SIZE        20
  38
  39 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  40 MODULE_DESCRIPTION("FCP HBA driver");
  41 MODULE_LICENSE("GPL");
  42
  43 static char *init_device;
  44 module_param_named(device, init_device, charp, 0400);
  45 MODULE_PARM_DESC(device, "specify initial device");
  46
  47 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
  48                                               unsigned long size)
  49 {
  50         return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
  51 }
  52
  53 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  54 {
  55         struct ccw_device *cdev;
  56         struct zfcp_adapter *adapter;
  57         struct zfcp_port *port;
  58         struct zfcp_unit *unit;
  59
  60         cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
  61         if (!cdev)
  62                 return;
  63
  64         if (ccw_device_set_online(cdev))
  65                 goto out_ccw_device;
  66
  67         adapter = zfcp_ccw_adapter_by_cdev(cdev);
  68         if (!adapter)
  69                 goto out_ccw_device;
  70
  71         port = zfcp_get_port_by_wwpn(adapter, wwpn);
  72         if (!port)
  73                 goto out_port;
  74
  75         unit = zfcp_unit_enqueue(port, lun);
  76         if (IS_ERR(unit))
  77                 goto out_unit;
  78
  79         zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
  80         zfcp_erp_wait(adapter);
  81         flush_work(&unit->scsi_work);
  82
  83 out_unit:
  84         put_device(&port->dev);
  85 out_port:
  86         zfcp_ccw_adapter_put(adapter);
  87 out_ccw_device:
  88         put_device(&cdev->dev);
  89         return;
  90 }
  91
  92 static void __init zfcp_init_device_setup(char *devstr)
  93 {
  94         char *token;
  95         char *str, *str_saved;
  96         char busid[ZFCP_BUS_ID_SIZE];
  97         u64 wwpn, lun;
  98
  99         /* duplicate devstr and keep the original for sysfs presentation*/
 100         str_saved = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
 101         str = str_saved;
 102         if (!str)
 103                 return;
 104
 105         strcpy(str, devstr);
 106
 107         token = strsep(&str, ",");
 108         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 109                 goto err_out;
 110         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
 111
 112         token = strsep(&str, ",");
 113         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
 114                 goto err_out;
 115
 116         token = strsep(&str, ",");
 117         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
 118                 goto err_out;
 119
 120         kfree(str_saved);
 121         zfcp_init_device_configure(busid, wwpn, lun);
 122         return;
 123
 124 err_out:
 125         kfree(str_saved);
 126         pr_err("%s is not a valid SCSI device\n", devstr);
 127 }
 128
 129 static int __init zfcp_module_init(void)
 130 {
 131         int retval = -ENOMEM;
 132
 133         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
 134                                         sizeof(struct zfcp_fc_gpn_ft_req));
 135         if (!zfcp_data.gpn_ft_cache)
 136                 goto out;
 137
 138         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
 139                                         sizeof(struct fsf_qtcb));
 140         if (!zfcp_data.qtcb_cache)
 141                 goto out_qtcb_cache;
 142
 143         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
 144                                         sizeof(struct fsf_status_read_buffer));
 145         if (!zfcp_data.sr_buffer_cache)
 146                 goto out_sr_cache;
 147
 148         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
 149                                         sizeof(struct zfcp_fc_gid_pn));
 150         if (!zfcp_data.gid_pn_cache)
 151                 goto out_gid_cache;
 152
 153         zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
 154                                         sizeof(struct zfcp_fc_els_adisc));
 155         if (!zfcp_data.adisc_cache)
 156                 goto out_adisc_cache;
 157
 158         zfcp_data.scsi_transport_template =
 159                 fc_attach_transport(&zfcp_transport_functions);
 160         if (!zfcp_data.scsi_transport_template)
 161                 goto out_transport;
 162
 163         retval = misc_register(&zfcp_cfdc_misc);
 164         if (retval) {
 165                 pr_err("Registering the misc device zfcp_cfdc failed\n");
 166                 goto out_misc;
 167         }
 168
 169         retval = ccw_driver_register(&zfcp_ccw_driver);
 170         if (retval) {
 171                 pr_err("The zfcp device driver could not register with "
 172                        "the common I/O layer\n");
 173                 goto out_ccw_register;
 174         }
 175
 176         if (init_device)
 177                 zfcp_init_device_setup(init_device);
 178         return 0;
 179
 180 out_ccw_register:
 181         misc_deregister(&zfcp_cfdc_misc);
 182 out_misc:
 183         fc_release_transport(zfcp_data.scsi_transport_template);
 184 out_transport:
 185         kmem_cache_destroy(zfcp_data.adisc_cache);
 186 out_adisc_cache:
 187         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 188 out_gid_cache:
 189         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 190 out_sr_cache:
 191         kmem_cache_destroy(zfcp_data.qtcb_cache);
 192 out_qtcb_cache:
 193         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 194 out:
 195         return retval;
 196 }
 197
 198 module_init(zfcp_module_init);
 199
 200 static void __exit zfcp_module_exit(void)
 201 {
 202         ccw_driver_unregister(&zfcp_ccw_driver);
 203         misc_deregister(&zfcp_cfdc_misc);
 204         fc_release_transport(zfcp_data.scsi_transport_template);
 205         kmem_cache_destroy(zfcp_data.adisc_cache);
 206         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 207         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 208         kmem_cache_destroy(zfcp_data.qtcb_cache);
 209         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 210 }
 211
 212 module_exit(zfcp_module_exit);
 213
 214 /**
 215  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 216  * @port: pointer to port to search for unit
 217  * @fcp_lun: FCP LUN to search for
 218  *
 219  * Returns: pointer to zfcp_unit or NULL
 220  */
 221 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 222 {
 223         unsigned long flags;
 224         struct zfcp_unit *unit;
 225
 226         read_lock_irqsave(&port->unit_list_lock, flags);
 227         list_for_each_entry(unit, &port->unit_list, list)
 228                 if (unit->fcp_lun == fcp_lun) {
 229                         if (!get_device(&unit->dev))
 230                                 unit = NULL;
 231                         read_unlock_irqrestore(&port->unit_list_lock, flags);
 232                         return unit;
 233                 }
 234         read_unlock_irqrestore(&port->unit_list_lock, flags);
 235         return NULL;
 236 }
 237
 238 /**
 239  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 240  * @adapter: pointer to adapter to search for port
 241  * @wwpn: wwpn to search for
 242  *
 243  * Returns: pointer to zfcp_port or NULL
 244  */
 245 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 246                                         u64 wwpn)
 247 {
 248         unsigned long flags;
 249         struct zfcp_port *port;
 250
 251         read_lock_irqsave(&adapter->port_list_lock, flags);
 252         list_for_each_entry(port, &adapter->port_list, list)
 253                 if (port->wwpn == wwpn) {
 254                         if (!get_device(&port->dev))
 255                                 port = NULL;
 256                         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 257                         return port;
 258                 }
 259         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 260         return NULL;
 261 }
 262
 263 /**
 264  * zfcp_unit_release - dequeue unit
 265  * @dev: pointer to device
 266  *
 267  * waits until all work is done on unit and removes it then from the unit->list
 268  * of the associated port.
 269  */
 270 static void zfcp_unit_release(struct device *dev)
 271 {
 272         struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
 273
 274         put_device(&unit->port->dev);
 275         kfree(unit);
 276 }
 277
 278 /**
 279  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 280  * @port: pointer to port where unit is added
 281  * @fcp_lun: FCP LUN of unit to be enqueued
 282  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 283  *
 284  * Sets up some unit internal structures and creates sysfs entry.
 285  */
 286 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 287 {
 288         struct zfcp_unit *unit;
 289         int retval = -ENOMEM;
 290
 291         get_device(&port->dev);
 292
 293         unit = zfcp_get_unit_by_lun(port, fcp_lun);
 294         if (unit) {
 295                 put_device(&unit->dev);
 296                 retval = -EEXIST;
 297                 goto err_out;
 298         }
 299
 300         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 301         if (!unit)
 302                 goto err_out;
 303
 304         unit->port = port;
 305         unit->fcp_lun = fcp_lun;
 306         unit->dev.parent = &port->dev;
 307         unit->dev.release = zfcp_unit_release;
 308
 309         if (dev_set_name(&unit->dev, "0x%016llx",
 310                          (unsigned long long) fcp_lun)) {
 311                 kfree(unit);
 312                 goto err_out;
 313         }
 314         retval = -EINVAL;
 315
 316         INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
 317
 318         spin_lock_init(&unit->latencies.lock);
 319         unit->latencies.write.channel.min = 0xFFFFFFFF;
 320         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 321         unit->latencies.read.channel.min = 0xFFFFFFFF;
 322         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 323         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 324         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 325
 326         if (device_register(&unit->dev)) {
 327                 put_device(&unit->dev);
 328                 goto err_out;
 329         }
 330
 331         if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
 332                 goto err_out_put;
 333
 334         write_lock_irq(&port->unit_list_lock);
 335         list_add_tail(&unit->list, &port->unit_list);
 336         write_unlock_irq(&port->unit_list_lock);
 337
 338         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 339
 340         return unit;
 341
 342 err_out_put:
 343         device_unregister(&unit->dev);
 344 err_out:
 345         put_device(&port->dev);
 346         return ERR_PTR(retval);
 347 }
 348
 349 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 350 {
 351         adapter->pool.erp_req =
 352                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 353         if (!adapter->pool.erp_req)
 354                 return -ENOMEM;
 355
 356         adapter->pool.gid_pn_req =
 357                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 358         if (!adapter->pool.gid_pn_req)
 359                 return -ENOMEM;
 360
 361         adapter->pool.scsi_req =
 362                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 363         if (!adapter->pool.scsi_req)
 364                 return -ENOMEM;
 365
 366         adapter->pool.scsi_abort =
 367                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 368         if (!adapter->pool.scsi_abort)
 369                 return -ENOMEM;
 370
 371         adapter->pool.status_read_req =
 372                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 373                                             sizeof(struct zfcp_fsf_req));
 374         if (!adapter->pool.status_read_req)
 375                 return -ENOMEM;
 376
 377         adapter->pool.qtcb_pool =
 378                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
 379         if (!adapter->pool.qtcb_pool)
 380                 return -ENOMEM;
 381
 382         adapter->pool.status_read_data =
 383                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 384                                          zfcp_data.sr_buffer_cache);
 385         if (!adapter->pool.status_read_data)
 386                 return -ENOMEM;
 387
 388         adapter->pool.gid_pn =
 389                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 390         if (!adapter->pool.gid_pn)
 391                 return -ENOMEM;
 392
 393         return 0;
 394 }
 395
 396 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 397 {
 398         if (adapter->pool.erp_req)
 399                 mempool_destroy(adapter->pool.erp_req);
 400         if (adapter->pool.scsi_req)
 401                 mempool_destroy(adapter->pool.scsi_req);
 402         if (adapter->pool.scsi_abort)
 403                 mempool_destroy(adapter->pool.scsi_abort);
 404         if (adapter->pool.qtcb_pool)
 405                 mempool_destroy(adapter->pool.qtcb_pool);
 406         if (adapter->pool.status_read_req)
 407                 mempool_destroy(adapter->pool.status_read_req);
 408         if (adapter->pool.status_read_data)
 409                 mempool_destroy(adapter->pool.status_read_data);
 410         if (adapter->pool.gid_pn)
 411                 mempool_destroy(adapter->pool.gid_pn);
 412 }
 413
 414 /**
 415  * zfcp_status_read_refill - refill the long running status_read_requests
 416  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 417  *
 418  * Returns: 0 on success, 1 otherwise
 419  *
 420  * if there are 16 or more status_read requests missing an adapter_reopen
 421  * is triggered
 422  */
 423 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 424 {
 425         while (atomic_read(&adapter->stat_miss) > 0)
 426                 if (zfcp_fsf_status_read(adapter->qdio)) {
 427                         if (atomic_read(&adapter->stat_miss) >= 16) {
 428                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
 429                                                         NULL);
 430                                 return 1;
 431                         }
 432                         break;
 433                 } else
 434                         atomic_dec(&adapter->stat_miss);
 435         return 0;
 436 }
 437
 438 static void _zfcp_status_read_scheduler(struct work_struct *work)
 439 {
 440         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 441                                              stat_work));
 442 }
 443
 444 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
 445 {
 446         struct zfcp_adapter *adapter =
 447                 container_of(sl, struct zfcp_adapter, service_level);
 448
 449         seq_printf(m, "zfcp: %s microcode level %x\n",
 450                    dev_name(&adapter->ccw_device->dev),
 451                    adapter->fsf_lic_version);
 452 }
 453
 454 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
 455 {
 456         char name[TASK_COMM_LEN];
 457
 458         snprintf(name, sizeof(name), "zfcp_q_%s",
 459                  dev_name(&adapter->ccw_device->dev));
 460         adapter->work_queue = create_singlethread_workqueue(name);
 461
 462         if (adapter->work_queue)
 463                 return 0;
 464         return -ENOMEM;
 465 }
 466
 467 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
 468 {
 469         if (adapter->work_queue)
 470                 destroy_workqueue(adapter->work_queue);
 471         adapter->work_queue = NULL;
 472
 473 }
 474
 475 /**
 476  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 477  * @ccw_device: pointer to the struct cc_device
 478  *
 479  * Returns:     struct zfcp_adapter*
 480  * Enqueues an adapter at the end of the adapter list in the driver data.
 481  * All adapter internal structures are set up.
 482  * Proc-fs entries are also created.
 483  */
 484 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 485 {
 486         struct zfcp_adapter *adapter;
 487
 488         if (!get_device(&ccw_device->dev))
 489                 return ERR_PTR(-ENODEV);
 490
 491         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 492         if (!adapter) {
 493                 put_device(&ccw_device->dev);
 494                 return ERR_PTR(-ENOMEM);
 495         }
 496
 497         kref_init(&adapter->ref);
 498
 499         ccw_device->handler = NULL;
 500         adapter->ccw_device = ccw_device;
 501
 502         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 503         INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
 504
 505         if (zfcp_qdio_setup(adapter))
 506                 goto failed;
 507
 508         if (zfcp_allocate_low_mem_buffers(adapter))
 509                 goto failed;
 510
 511         adapter->req_list = zfcp_reqlist_alloc();
 512         if (!adapter->req_list)
 513                 goto failed;
 514
 515         if (zfcp_dbf_adapter_register(adapter))
 516                 goto failed;
 517
 518         if (zfcp_setup_adapter_work_queue(adapter))
 519                 goto failed;
 520
 521         if (zfcp_fc_gs_setup(adapter))
 522                 goto failed;
 523
 524         rwlock_init(&adapter->port_list_lock);
 525         INIT_LIST_HEAD(&adapter->port_list);
 526
 527         init_waitqueue_head(&adapter->erp_ready_wq);
 528         init_waitqueue_head(&adapter->erp_done_wqh);
 529
 530         INIT_LIST_HEAD(&adapter->erp_ready_head);
 531         INIT_LIST_HEAD(&adapter->erp_running_head);
 532
 533         rwlock_init(&adapter->erp_lock);
 534         rwlock_init(&adapter->abort_lock);
 535
 536         if (zfcp_erp_thread_setup(adapter))
 537                 goto failed;
 538
 539         adapter->service_level.seq_print = zfcp_print_sl;
 540
 541         dev_set_drvdata(&ccw_device->dev, adapter);
 542
 543         if (sysfs_create_group(&ccw_device->dev.kobj,
 544                                &zfcp_sysfs_adapter_attrs))
 545                 goto failed;
 546
 547         if (!zfcp_adapter_scsi_register(adapter))
 548                 return adapter;
 549
 550 failed:
 551         zfcp_adapter_unregister(adapter);
 552         return ERR_PTR(-ENOMEM);
 553 }
 554
 555 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
 556 {
 557         struct ccw_device *cdev = adapter->ccw_device;
 558
 559         cancel_work_sync(&adapter->scan_work);
 560         cancel_work_sync(&adapter->stat_work);
 561         zfcp_destroy_adapter_work_queue(adapter);
 562
 563         zfcp_fc_wka_ports_force_offline(adapter->gs);
 564         zfcp_adapter_scsi_unregister(adapter);
 565         sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
 566
 567         zfcp_erp_thread_kill(adapter);
 568         zfcp_dbf_adapter_unregister(adapter->dbf);
 569         zfcp_qdio_destroy(adapter->qdio);
 570
 571         zfcp_ccw_adapter_put(adapter); /* final put to release */
 572 }
 573
 574 /**
 575  * zfcp_adapter_release - remove the adapter from the resource list
 576  * @ref: pointer to struct kref
 577  * locks:       adapter list write lock is assumed to be held by caller
 578  */
 579 void zfcp_adapter_release(struct kref *ref)
 580 {
 581         struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
 582                                                     ref);
 583         struct ccw_device *cdev = adapter->ccw_device;
 584
 585         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 586         zfcp_fc_gs_destroy(adapter);
 587         zfcp_free_low_mem_buffers(adapter);
 588         kfree(adapter->req_list);
 589         kfree(adapter->fc_stats);
 590         kfree(adapter->stats_reset_data);
 591         kfree(adapter);
 592         put_device(&cdev->dev);
 593 }
 594
 595 /**
 596  * zfcp_device_unregister - remove port, unit from system
 597  * @dev: reference to device which is to be removed
 598  * @grp: related reference to attribute group
 599  *
 600  * Helper function to unregister port, unit from system
 601  */
 602 void zfcp_device_unregister(struct device *dev,
 603                             const struct attribute_group *grp)
 604 {
 605         sysfs_remove_group(&dev->kobj, grp);
 606         device_unregister(dev);
 607 }
 608
 609 static void zfcp_port_release(struct device *dev)
 610 {
 611         struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
 612
 613         zfcp_ccw_adapter_put(port->adapter);
 614         kfree(port);
 615 }
 616
 617 /**
 618  * zfcp_port_enqueue - enqueue port to port list of adapter
 619  * @adapter: adapter where remote port is added
 620  * @wwpn: WWPN of the remote port to be enqueued
 621  * @status: initial status for the port
 622  * @d_id: destination id of the remote port to be enqueued
 623  * Returns: pointer to enqueued port on success, ERR_PTR on error
 624  *
 625  * All port internal structures are set up and the sysfs entry is generated.
 626  * d_id is used to enqueue ports with a well known address like the Directory
 627  * Service for nameserver lookup.
 628  */
 629 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 630                                      u32 status, u32 d_id)
 631 {
 632         struct zfcp_port *port;
 633         int retval = -ENOMEM;
 634
 635         kref_get(&adapter->ref);
 636
 637         port = zfcp_get_port_by_wwpn(adapter, wwpn);
 638         if (port) {
 639                 put_device(&port->dev);
 640                 retval = -EEXIST;
 641                 goto err_out;
 642         }
 643
 644         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 645         if (!port)
 646                 goto err_out;
 647
 648         rwlock_init(&port->unit_list_lock);
 649         INIT_LIST_HEAD(&port->unit_list);
 650
 651         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
 652         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 653         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 654
 655         port->adapter = adapter;
 656         port->d_id = d_id;
 657         port->wwpn = wwpn;
 658         port->rport_task = RPORT_NONE;
 659         port->dev.parent = &adapter->ccw_device->dev;
 660         port->dev.release = zfcp_port_release;
 661
 662         if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
 663                 kfree(port);
 664                 goto err_out;
 665         }
 666         retval = -EINVAL;
 667
 668         if (device_register(&port->dev)) {
 669                 put_device(&port->dev);
 670                 goto err_out;
 671         }
 672
 673         if (sysfs_create_group(&port->dev.kobj,
 674                                &zfcp_sysfs_port_attrs))
 675                 goto err_out_put;
 676
 677         write_lock_irq(&adapter->port_list_lock);
 678         list_add_tail(&port->list, &adapter->port_list);
 679         write_unlock_irq(&adapter->port_list_lock);
 680
 681         atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
 682
 683         return port;
 684
 685 err_out_put:
 686         device_unregister(&port->dev);
 687 err_out:
 688         zfcp_ccw_adapter_put(adapter);
 689         return ERR_PTR(retval);
 690 }
 691
 692 /**
 693  * zfcp_sg_free_table - free memory used by scatterlists
 694  * @sg: pointer to scatterlist
 695  * @count: number of scatterlist which are to be free'ed
 696  * the scatterlist are expected to reference pages always
 697  */
 698 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 699 {
 700         int i;
 701
 702         for (i = 0; i < count; i++, sg++)
 703                 if (sg)
 704                         free_page((unsigned long) sg_virt(sg));
 705                 else
 706                         break;
 707 }
 708
 709 /**
 710  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 711  * @sg: pointer to struct scatterlist
 712  * @count: number of scatterlists which should be assigned with buffers
 713  * of size page
 714  *
 715  * Returns: 0 on success, -ENOMEM otherwise
 716  */
 717 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 718 {
 719         void *addr;
 720         int i;
 721
 722         sg_init_table(sg, count);
 723         for (i = 0; i < count; i++, sg++) {
 724                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 725                 if (!addr) {
 726                         zfcp_sg_free_table(sg, i);
 727                         return -ENOMEM;
 728                 }
 729                 sg_set_buf(sg, addr, PAGE_SIZE);
 730         }
 731         return 0;
 732 }