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 <linux/slab.h>
  34 #include "zfcp_ext.h"
  35 #include "zfcp_fc.h"
  36 #include "zfcp_reqlist.h"
  37
  38 #define ZFCP_BUS_ID_SIZE        20
  39
  40 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  41 MODULE_DESCRIPTION("FCP HBA driver");
  42 MODULE_LICENSE("GPL");
  43
  44 static char *init_device;
  45 module_param_named(device, init_device, charp, 0400);
  46 MODULE_PARM_DESC(device, "specify initial device");
  47
  48 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
  49                                               unsigned long size)
  50 {
  51         return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
  52 }
  53
  54 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  55 {
  56         struct ccw_device *cdev;
  57         struct zfcp_adapter *adapter;
  58         struct zfcp_port *port;
  59         struct zfcp_unit *unit;
  60
  61         cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
  62         if (!cdev)
  63                 return;
  64
  65         if (ccw_device_set_online(cdev))
  66                 goto out_ccw_device;
  67
  68         adapter = zfcp_ccw_adapter_by_cdev(cdev);
  69         if (!adapter)
  70                 goto out_ccw_device;
  71
  72         port = zfcp_get_port_by_wwpn(adapter, wwpn);
  73         if (!port)
  74                 goto out_port;
  75
  76         unit = zfcp_unit_enqueue(port, lun);
  77         if (IS_ERR(unit))
  78                 goto out_unit;
  79
  80         zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
  81         zfcp_erp_wait(adapter);
  82         flush_work(&unit->scsi_work);
  83
  84 out_unit:
  85         put_device(&port->dev);
  86 out_port:
  87         zfcp_ccw_adapter_put(adapter);
  88 out_ccw_device:
  89         put_device(&cdev->dev);
  90         return;
  91 }
  92
  93 static void __init zfcp_init_device_setup(char *devstr)
  94 {
  95         char *token;
  96         char *str, *str_saved;
  97         char busid[ZFCP_BUS_ID_SIZE];
  98         u64 wwpn, lun;
  99
 100         /* duplicate devstr and keep the original for sysfs presentation*/
 101         str_saved = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
 102         str = str_saved;
 103         if (!str)
 104                 return;
 105
 106         strcpy(str, devstr);
 107
 108         token = strsep(&str, ",");
 109         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 110                 goto err_out;
 111         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
 112
 113         token = strsep(&str, ",");
 114         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
 115                 goto err_out;
 116
 117         token = strsep(&str, ",");
 118         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
 119                 goto err_out;
 120
 121         kfree(str_saved);
 122         zfcp_init_device_configure(busid, wwpn, lun);
 123         return;
 124
 125 err_out:
 126         kfree(str_saved);
 127         pr_err("%s is not a valid SCSI device\n", devstr);
 128 }
 129
 130 static int __init zfcp_module_init(void)
 131 {
 132         int retval = -ENOMEM;
 133
 134         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
 135                                         sizeof(struct zfcp_fc_gpn_ft_req));
 136         if (!zfcp_data.gpn_ft_cache)
 137                 goto out;
 138
 139         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
 140                                         sizeof(struct fsf_qtcb));
 141         if (!zfcp_data.qtcb_cache)
 142                 goto out_qtcb_cache;
 143
 144         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
 145                                         sizeof(struct fsf_status_read_buffer));
 146         if (!zfcp_data.sr_buffer_cache)
 147                 goto out_sr_cache;
 148
 149         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
 150                                         sizeof(struct zfcp_fc_gid_pn));
 151         if (!zfcp_data.gid_pn_cache)
 152                 goto out_gid_cache;
 153
 154         zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
 155                                         sizeof(struct zfcp_fc_els_adisc));
 156         if (!zfcp_data.adisc_cache)
 157                 goto out_adisc_cache;
 158
 159         zfcp_data.scsi_transport_template =
 160                 fc_attach_transport(&zfcp_transport_functions);
 161         if (!zfcp_data.scsi_transport_template)
 162                 goto out_transport;
 163
 164         retval = misc_register(&zfcp_cfdc_misc);
 165         if (retval) {
 166                 pr_err("Registering the misc device zfcp_cfdc failed\n");
 167                 goto out_misc;
 168         }
 169
 170         retval = ccw_driver_register(&zfcp_ccw_driver);
 171         if (retval) {
 172                 pr_err("The zfcp device driver could not register with "
 173                        "the common I/O layer\n");
 174                 goto out_ccw_register;
 175         }
 176
 177         if (init_device)
 178                 zfcp_init_device_setup(init_device);
 179         return 0;
 180
 181 out_ccw_register:
 182         misc_deregister(&zfcp_cfdc_misc);
 183 out_misc:
 184         fc_release_transport(zfcp_data.scsi_transport_template);
 185 out_transport:
 186         kmem_cache_destroy(zfcp_data.adisc_cache);
 187 out_adisc_cache:
 188         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 189 out_gid_cache:
 190         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 191 out_sr_cache:
 192         kmem_cache_destroy(zfcp_data.qtcb_cache);
 193 out_qtcb_cache:
 194         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 195 out:
 196         return retval;
 197 }
 198
 199 module_init(zfcp_module_init);
 200
 201 static void __exit zfcp_module_exit(void)
 202 {
 203         ccw_driver_unregister(&zfcp_ccw_driver);
 204         misc_deregister(&zfcp_cfdc_misc);
 205         fc_release_transport(zfcp_data.scsi_transport_template);
 206         kmem_cache_destroy(zfcp_data.adisc_cache);
 207         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 208         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 209         kmem_cache_destroy(zfcp_data.qtcb_cache);
 210         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 211 }
 212
 213 module_exit(zfcp_module_exit);
 214
 215 /**
 216  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 217  * @port: pointer to port to search for unit
 218  * @fcp_lun: FCP LUN to search for
 219  *
 220  * Returns: pointer to zfcp_unit or NULL
 221  */
 222 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 223 {
 224         unsigned long flags;
 225         struct zfcp_unit *unit;
 226
 227         read_lock_irqsave(&port->unit_list_lock, flags);
 228         list_for_each_entry(unit, &port->unit_list, list)
 229                 if (unit->fcp_lun == fcp_lun) {
 230                         if (!get_device(&unit->dev))
 231                                 unit = NULL;
 232                         read_unlock_irqrestore(&port->unit_list_lock, flags);
 233                         return unit;
 234                 }
 235         read_unlock_irqrestore(&port->unit_list_lock, flags);
 236         return NULL;
 237 }
 238
 239 /**
 240  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 241  * @adapter: pointer to adapter to search for port
 242  * @wwpn: wwpn to search for
 243  *
 244  * Returns: pointer to zfcp_port or NULL
 245  */
 246 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 247                                         u64 wwpn)
 248 {
 249         unsigned long flags;
 250         struct zfcp_port *port;
 251
 252         read_lock_irqsave(&adapter->port_list_lock, flags);
 253         list_for_each_entry(port, &adapter->port_list, list)
 254                 if (port->wwpn == wwpn) {
 255                         if (!get_device(&port->dev))
 256                                 port = NULL;
 257                         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 258                         return port;
 259                 }
 260         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 261         return NULL;
 262 }
 263
 264 /**
 265  * zfcp_unit_release - dequeue unit
 266  * @dev: pointer to device
 267  *
 268  * waits until all work is done on unit and removes it then from the unit->list
 269  * of the associated port.
 270  */
 271 static void zfcp_unit_release(struct device *dev)
 272 {
 273         struct zfcp_unit *unit = container_of(dev, struct zfcp_unit, dev);
 274
 275         put_device(&unit->port->dev);
 276         kfree(unit);
 277 }
 278
 279 /**
 280  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 281  * @port: pointer to port where unit is added
 282  * @fcp_lun: FCP LUN of unit to be enqueued
 283  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 284  *
 285  * Sets up some unit internal structures and creates sysfs entry.
 286  */
 287 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 288 {
 289         struct zfcp_unit *unit;
 290         int retval = -ENOMEM;
 291
 292         get_device(&port->dev);
 293
 294         unit = zfcp_get_unit_by_lun(port, fcp_lun);
 295         if (unit) {
 296                 put_device(&unit->dev);
 297                 retval = -EEXIST;
 298                 goto err_out;
 299         }
 300
 301         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 302         if (!unit)
 303                 goto err_out;
 304
 305         unit->port = port;
 306         unit->fcp_lun = fcp_lun;
 307         unit->dev.parent = &port->dev;
 308         unit->dev.release = zfcp_unit_release;
 309
 310         if (dev_set_name(&unit->dev, "0x%016llx",
 311                          (unsigned long long) fcp_lun)) {
 312                 kfree(unit);
 313                 goto err_out;
 314         }
 315         retval = -EINVAL;
 316
 317         INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
 318
 319         spin_lock_init(&unit->latencies.lock);
 320         unit->latencies.write.channel.min = 0xFFFFFFFF;
 321         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 322         unit->latencies.read.channel.min = 0xFFFFFFFF;
 323         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 324         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 325         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 326
 327         if (device_register(&unit->dev)) {
 328                 put_device(&unit->dev);
 329                 goto err_out;
 330         }
 331
 332         if (sysfs_create_group(&unit->dev.kobj, &zfcp_sysfs_unit_attrs))
 333                 goto err_out_put;
 334
 335         write_lock_irq(&port->unit_list_lock);
 336         list_add_tail(&unit->list, &port->unit_list);
 337         write_unlock_irq(&port->unit_list_lock);
 338
 339         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 340
 341         return unit;
 342
 343 err_out_put:
 344         device_unregister(&unit->dev);
 345 err_out:
 346         put_device(&port->dev);
 347         return ERR_PTR(retval);
 348 }
 349
 350 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 351 {
 352         adapter->pool.erp_req =
 353                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 354         if (!adapter->pool.erp_req)
 355                 return -ENOMEM;
 356
 357         adapter->pool.gid_pn_req =
 358                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 359         if (!adapter->pool.gid_pn_req)
 360                 return -ENOMEM;
 361
 362         adapter->pool.scsi_req =
 363                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 364         if (!adapter->pool.scsi_req)
 365                 return -ENOMEM;
 366
 367         adapter->pool.scsi_abort =
 368                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 369         if (!adapter->pool.scsi_abort)
 370                 return -ENOMEM;
 371
 372         adapter->pool.status_read_req =
 373                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 374                                             sizeof(struct zfcp_fsf_req));
 375         if (!adapter->pool.status_read_req)
 376                 return -ENOMEM;
 377
 378         adapter->pool.qtcb_pool =
 379                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
 380         if (!adapter->pool.qtcb_pool)
 381                 return -ENOMEM;
 382
 383         adapter->pool.status_read_data =
 384                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 385                                          zfcp_data.sr_buffer_cache);
 386         if (!adapter->pool.status_read_data)
 387                 return -ENOMEM;
 388
 389         adapter->pool.gid_pn =
 390                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 391         if (!adapter->pool.gid_pn)
 392                 return -ENOMEM;
 393
 394         return 0;
 395 }
 396
 397 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 398 {
 399         if (adapter->pool.erp_req)
 400                 mempool_destroy(adapter->pool.erp_req);
 401         if (adapter->pool.scsi_req)
 402                 mempool_destroy(adapter->pool.scsi_req);
 403         if (adapter->pool.scsi_abort)
 404                 mempool_destroy(adapter->pool.scsi_abort);
 405         if (adapter->pool.qtcb_pool)
 406                 mempool_destroy(adapter->pool.qtcb_pool);
 407         if (adapter->pool.status_read_req)
 408                 mempool_destroy(adapter->pool.status_read_req);
 409         if (adapter->pool.status_read_data)
 410                 mempool_destroy(adapter->pool.status_read_data);
 411         if (adapter->pool.gid_pn)
 412                 mempool_destroy(adapter->pool.gid_pn);
 413 }
 414
 415 /**
 416  * zfcp_status_read_refill - refill the long running status_read_requests
 417  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 418  *
 419  * Returns: 0 on success, 1 otherwise
 420  *
 421  * if there are 16 or more status_read requests missing an adapter_reopen
 422  * is triggered
 423  */
 424 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 425 {
 426         while (atomic_read(&adapter->stat_miss) > 0)
 427                 if (zfcp_fsf_status_read(adapter->qdio)) {
 428                         if (atomic_read(&adapter->stat_miss) >= 16) {
 429                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
 430                                                         NULL);
 431                                 return 1;
 432                         }
 433                         break;
 434                 } else
 435                         atomic_dec(&adapter->stat_miss);
 436         return 0;
 437 }
 438
 439 static void _zfcp_status_read_scheduler(struct work_struct *work)
 440 {
 441         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 442                                              stat_work));
 443 }
 444
 445 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
 446 {
 447         struct zfcp_adapter *adapter =
 448                 container_of(sl, struct zfcp_adapter, service_level);
 449
 450         seq_printf(m, "zfcp: %s microcode level %x\n",
 451                    dev_name(&adapter->ccw_device->dev),
 452                    adapter->fsf_lic_version);
 453 }
 454
 455 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
 456 {
 457         char name[TASK_COMM_LEN];
 458
 459         snprintf(name, sizeof(name), "zfcp_q_%s",
 460                  dev_name(&adapter->ccw_device->dev));
 461         adapter->work_queue = create_singlethread_workqueue(name);
 462
 463         if (adapter->work_queue)
 464                 return 0;
 465         return -ENOMEM;
 466 }
 467
 468 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
 469 {
 470         if (adapter->work_queue)
 471                 destroy_workqueue(adapter->work_queue);
 472         adapter->work_queue = NULL;
 473
 474 }
 475
 476 /**
 477  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 478  * @ccw_device: pointer to the struct cc_device
 479  *
 480  * Returns:     struct zfcp_adapter*
 481  * Enqueues an adapter at the end of the adapter list in the driver data.
 482  * All adapter internal structures are set up.
 483  * Proc-fs entries are also created.
 484  */
 485 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 486 {
 487         struct zfcp_adapter *adapter;
 488
 489         if (!get_device(&ccw_device->dev))
 490                 return ERR_PTR(-ENODEV);
 491
 492         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 493         if (!adapter) {
 494                 put_device(&ccw_device->dev);
 495                 return ERR_PTR(-ENOMEM);
 496         }
 497
 498         kref_init(&adapter->ref);
 499
 500         ccw_device->handler = NULL;
 501         adapter->ccw_device = ccw_device;
 502
 503         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 504         INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
 505
 506         if (zfcp_qdio_setup(adapter))
 507                 goto failed;
 508
 509         if (zfcp_allocate_low_mem_buffers(adapter))
 510                 goto failed;
 511
 512         adapter->req_list = zfcp_reqlist_alloc();
 513         if (!adapter->req_list)
 514                 goto failed;
 515
 516         if (zfcp_dbf_adapter_register(adapter))
 517                 goto failed;
 518
 519         if (zfcp_setup_adapter_work_queue(adapter))
 520                 goto failed;
 521
 522         if (zfcp_fc_gs_setup(adapter))
 523                 goto failed;
 524
 525         rwlock_init(&adapter->port_list_lock);
 526         INIT_LIST_HEAD(&adapter->port_list);
 527
 528         init_waitqueue_head(&adapter->erp_ready_wq);
 529         init_waitqueue_head(&adapter->erp_done_wqh);
 530
 531         INIT_LIST_HEAD(&adapter->erp_ready_head);
 532         INIT_LIST_HEAD(&adapter->erp_running_head);
 533
 534         rwlock_init(&adapter->erp_lock);
 535         rwlock_init(&adapter->abort_lock);
 536
 537         if (zfcp_erp_thread_setup(adapter))
 538                 goto failed;
 539
 540         adapter->service_level.seq_print = zfcp_print_sl;
 541
 542         dev_set_drvdata(&ccw_device->dev, adapter);
 543
 544         if (sysfs_create_group(&ccw_device->dev.kobj,
 545                                &zfcp_sysfs_adapter_attrs))
 546                 goto failed;
 547
 548         if (!zfcp_adapter_scsi_register(adapter))
 549                 return adapter;
 550
 551 failed:
 552         zfcp_adapter_unregister(adapter);
 553         return ERR_PTR(-ENOMEM);
 554 }
 555
 556 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
 557 {
 558         struct ccw_device *cdev = adapter->ccw_device;
 559
 560         cancel_work_sync(&adapter->scan_work);
 561         cancel_work_sync(&adapter->stat_work);
 562         zfcp_destroy_adapter_work_queue(adapter);
 563
 564         zfcp_fc_wka_ports_force_offline(adapter->gs);
 565         zfcp_adapter_scsi_unregister(adapter);
 566         sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
 567
 568         zfcp_erp_thread_kill(adapter);
 569         zfcp_dbf_adapter_unregister(adapter->dbf);
 570         zfcp_qdio_destroy(adapter->qdio);
 571
 572         zfcp_ccw_adapter_put(adapter); /* final put to release */
 573 }
 574
 575 /**
 576  * zfcp_adapter_release - remove the adapter from the resource list
 577  * @ref: pointer to struct kref
 578  * locks:       adapter list write lock is assumed to be held by caller
 579  */
 580 void zfcp_adapter_release(struct kref *ref)
 581 {
 582         struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
 583                                                     ref);
 584         struct ccw_device *cdev = adapter->ccw_device;
 585
 586         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 587         zfcp_fc_gs_destroy(adapter);
 588         zfcp_free_low_mem_buffers(adapter);
 589         kfree(adapter->req_list);
 590         kfree(adapter->fc_stats);
 591         kfree(adapter->stats_reset_data);
 592         kfree(adapter);
 593         put_device(&cdev->dev);
 594 }
 595
 596 /**
 597  * zfcp_device_unregister - remove port, unit from system
 598  * @dev: reference to device which is to be removed
 599  * @grp: related reference to attribute group
 600  *
 601  * Helper function to unregister port, unit from system
 602  */
 603 void zfcp_device_unregister(struct device *dev,
 604                             const struct attribute_group *grp)
 605 {
 606         sysfs_remove_group(&dev->kobj, grp);
 607         device_unregister(dev);
 608 }
 609
 610 static void zfcp_port_release(struct device *dev)
 611 {
 612         struct zfcp_port *port = container_of(dev, struct zfcp_port, dev);
 613
 614         zfcp_ccw_adapter_put(port->adapter);
 615         kfree(port);
 616 }
 617
 618 /**
 619  * zfcp_port_enqueue - enqueue port to port list of adapter
 620  * @adapter: adapter where remote port is added
 621  * @wwpn: WWPN of the remote port to be enqueued
 622  * @status: initial status for the port
 623  * @d_id: destination id of the remote port to be enqueued
 624  * Returns: pointer to enqueued port on success, ERR_PTR on error
 625  *
 626  * All port internal structures are set up and the sysfs entry is generated.
 627  * d_id is used to enqueue ports with a well known address like the Directory
 628  * Service for nameserver lookup.
 629  */
 630 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 631                                      u32 status, u32 d_id)
 632 {
 633         struct zfcp_port *port;
 634         int retval = -ENOMEM;
 635
 636         kref_get(&adapter->ref);
 637
 638         port = zfcp_get_port_by_wwpn(adapter, wwpn);
 639         if (port) {
 640                 put_device(&port->dev);
 641                 retval = -EEXIST;
 642                 goto err_out;
 643         }
 644
 645         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 646         if (!port)
 647                 goto err_out;
 648
 649         rwlock_init(&port->unit_list_lock);
 650         INIT_LIST_HEAD(&port->unit_list);
 651
 652         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
 653         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 654         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 655
 656         port->adapter = adapter;
 657         port->d_id = d_id;
 658         port->wwpn = wwpn;
 659         port->rport_task = RPORT_NONE;
 660         port->dev.parent = &adapter->ccw_device->dev;
 661         port->dev.release = zfcp_port_release;
 662
 663         if (dev_set_name(&port->dev, "0x%016llx", (unsigned long long)wwpn)) {
 664                 kfree(port);
 665                 goto err_out;
 666         }
 667         retval = -EINVAL;
 668
 669         if (device_register(&port->dev)) {
 670                 put_device(&port->dev);
 671                 goto err_out;
 672         }
 673
 674         if (sysfs_create_group(&port->dev.kobj,
 675                                &zfcp_sysfs_port_attrs))
 676                 goto err_out_put;
 677
 678         write_lock_irq(&adapter->port_list_lock);
 679         list_add_tail(&port->list, &adapter->port_list);
 680         write_unlock_irq(&adapter->port_list_lock);
 681
 682         atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
 683
 684         return port;
 685
 686 err_out_put:
 687         device_unregister(&port->dev);
 688 err_out:
 689         zfcp_ccw_adapter_put(adapter);
 690         return ERR_PTR(retval);
 691 }
 692
 693 /**
 694  * zfcp_sg_free_table - free memory used by scatterlists
 695  * @sg: pointer to scatterlist
 696  * @count: number of scatterlist which are to be free'ed
 697  * the scatterlist are expected to reference pages always
 698  */
 699 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 700 {
 701         int i;
 702
 703         for (i = 0; i < count; i++, sg++)
 704                 if (sg)
 705                         free_page((unsigned long) sg_virt(sg));
 706                 else
 707                         break;
 708 }
 709
 710 /**
 711  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 712  * @sg: pointer to struct scatterlist
 713  * @count: number of scatterlists which should be assigned with buffers
 714  * of size page
 715  *
 716  * Returns: 0 on success, -ENOMEM otherwise
 717  */
 718 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 719 {
 720         void *addr;
 721         int i;
 722
 723         sg_init_table(sg, count);
 724         for (i = 0; i < count; i++, sg++) {
 725                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 726                 if (!addr) {
 727                         zfcp_sg_free_table(sg, i);
 728                         return -ENOMEM;
 729                 }
 730                 sg_set_buf(sg, addr, PAGE_SIZE);
 731         }
 732         return 0;
 733 }