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, 2008
   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 #include <linux/miscdevice.h>
  29 #include "zfcp_ext.h"
  30
  31 static char *device;
  32
  33 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  34 MODULE_DESCRIPTION("FCP HBA driver");
  35 MODULE_LICENSE("GPL");
  36
  37 module_param(device, charp, 0400);
  38 MODULE_PARM_DESC(device, "specify initial device");
  39
  40 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
  41 {
  42         int idx;
  43
  44         adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
  45                                     GFP_KERNEL);
  46         if (!adapter->req_list)
  47                 return -ENOMEM;
  48
  49         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  50                 INIT_LIST_HEAD(&adapter->req_list[idx]);
  51         return 0;
  52 }
  53
  54 /**
  55  * zfcp_reqlist_isempty - is the request list empty
  56  * @adapter: pointer to struct zfcp_adapter
  57  *
  58  * Returns: true if list is empty, false otherwise
  59  */
  60 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
  61 {
  62         unsigned int idx;
  63
  64         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  65                 if (!list_empty(&adapter->req_list[idx]))
  66                         return 0;
  67         return 1;
  68 }
  69
  70 static int __init zfcp_device_setup(char *devstr)
  71 {
  72         char *token;
  73         char *str;
  74
  75         if (!devstr)
  76                 return 0;
  77
  78         /* duplicate devstr and keep the original for sysfs presentation*/
  79         str = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
  80         if (!str)
  81                 return 0;
  82
  83         strcpy(str, devstr);
  84
  85         token = strsep(&str, ",");
  86         if (!token || strlen(token) >= BUS_ID_SIZE)
  87                 goto err_out;
  88         strncpy(zfcp_data.init_busid, token, BUS_ID_SIZE);
  89
  90         token = strsep(&str, ",");
  91         if (!token || strict_strtoull(token, 0,
  92                                 (unsigned long long *) &zfcp_data.init_wwpn))
  93                 goto err_out;
  94
  95         token = strsep(&str, ",");
  96         if (!token || strict_strtoull(token, 0,
  97                                 (unsigned long long *) &zfcp_data.init_fcp_lun))
  98                 goto err_out;
  99
 100         kfree(str);
 101         return 1;
 102
 103  err_out:
 104         kfree(str);
 105         pr_err("zfcp: %s is not a valid SCSI device\n", devstr);
 106         return 0;
 107 }
 108
 109 static void __init zfcp_init_device_configure(void)
 110 {
 111         struct zfcp_adapter *adapter;
 112         struct zfcp_port *port;
 113         struct zfcp_unit *unit;
 114
 115         down(&zfcp_data.config_sema);
 116         read_lock_irq(&zfcp_data.config_lock);
 117         adapter = zfcp_get_adapter_by_busid(zfcp_data.init_busid);
 118         if (adapter)
 119                 zfcp_adapter_get(adapter);
 120         read_unlock_irq(&zfcp_data.config_lock);
 121
 122         if (!adapter)
 123                 goto out_adapter;
 124         port = zfcp_port_enqueue(adapter, zfcp_data.init_wwpn, 0, 0);
 125         if (IS_ERR(port))
 126                 goto out_port;
 127         unit = zfcp_unit_enqueue(port, zfcp_data.init_fcp_lun);
 128         if (IS_ERR(unit))
 129                 goto out_unit;
 130         up(&zfcp_data.config_sema);
 131         ccw_device_set_online(adapter->ccw_device);
 132         zfcp_erp_wait(adapter);
 133         down(&zfcp_data.config_sema);
 134         zfcp_unit_put(unit);
 135 out_unit:
 136         zfcp_port_put(port);
 137 out_port:
 138         zfcp_adapter_put(adapter);
 139 out_adapter:
 140         up(&zfcp_data.config_sema);
 141         return;
 142 }
 143
 144 static struct kmem_cache *zfcp_cache_create(int size, char *name)
 145 {
 146         int align = 1;
 147         while ((size - align) > 0)
 148                 align <<= 1;
 149         return kmem_cache_create(name , size, align, 0, NULL);
 150 }
 151
 152 static int __init zfcp_module_init(void)
 153 {
 154         int retval = -ENOMEM;
 155
 156         zfcp_data.fsf_req_qtcb_cache = zfcp_cache_create(
 157                         sizeof(struct zfcp_fsf_req_qtcb), "zfcp_fsf");
 158         if (!zfcp_data.fsf_req_qtcb_cache)
 159                 goto out;
 160
 161         zfcp_data.sr_buffer_cache = zfcp_cache_create(
 162                         sizeof(struct fsf_status_read_buffer), "zfcp_sr");
 163         if (!zfcp_data.sr_buffer_cache)
 164                 goto out_sr_cache;
 165
 166         zfcp_data.gid_pn_cache = zfcp_cache_create(
 167                         sizeof(struct zfcp_gid_pn_data), "zfcp_gid");
 168         if (!zfcp_data.gid_pn_cache)
 169                 goto out_gid_cache;
 170
 171         INIT_LIST_HEAD(&zfcp_data.adapter_list_head);
 172         sema_init(&zfcp_data.config_sema, 1);
 173         rwlock_init(&zfcp_data.config_lock);
 174
 175         zfcp_data.scsi_transport_template =
 176                 fc_attach_transport(&zfcp_transport_functions);
 177         if (!zfcp_data.scsi_transport_template)
 178                 goto out_transport;
 179
 180         retval = misc_register(&zfcp_cfdc_misc);
 181         if (retval) {
 182                 pr_err("zfcp: Registering the misc device zfcp_cfdc failed\n");
 183                 goto out_misc;
 184         }
 185
 186         retval = zfcp_ccw_register();
 187         if (retval) {
 188                 pr_err("zfcp: The zfcp device driver could not register with "
 189                        "the common I/O layer\n");
 190                 goto out_ccw_register;
 191         }
 192
 193         if (zfcp_device_setup(device))
 194                 zfcp_init_device_configure();
 195
 196         goto out;
 197
 198 out_ccw_register:
 199         misc_deregister(&zfcp_cfdc_misc);
 200 out_misc:
 201         fc_release_transport(zfcp_data.scsi_transport_template);
 202 out_transport:
 203         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 204 out_gid_cache:
 205         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 206 out_sr_cache:
 207         kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
 208 out:
 209         return retval;
 210 }
 211
 212 module_init(zfcp_module_init);
 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         struct zfcp_unit *unit;
 224
 225         list_for_each_entry(unit, &port->unit_list_head, list)
 226                 if ((unit->fcp_lun == fcp_lun) &&
 227                     !(atomic_read(&unit->status) & ZFCP_STATUS_COMMON_REMOVE))
 228                     return unit;
 229         return NULL;
 230 }
 231
 232 /**
 233  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 234  * @adapter: pointer to adapter to search for port
 235  * @wwpn: wwpn to search for
 236  *
 237  * Returns: pointer to zfcp_port or NULL
 238  */
 239 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 240                                         u64 wwpn)
 241 {
 242         struct zfcp_port *port;
 243
 244         list_for_each_entry(port, &adapter->port_list_head, list)
 245                 if ((port->wwpn == wwpn) && !(atomic_read(&port->status) &
 246                       (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE)))
 247                         return port;
 248         return NULL;
 249 }
 250
 251 static void zfcp_sysfs_unit_release(struct device *dev)
 252 {
 253         kfree(container_of(dev, struct zfcp_unit, sysfs_device));
 254 }
 255
 256 /**
 257  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 258  * @port: pointer to port where unit is added
 259  * @fcp_lun: FCP LUN of unit to be enqueued
 260  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 261  * Locks: config_sema must be held to serialize changes to the unit list
 262  *
 263  * Sets up some unit internal structures and creates sysfs entry.
 264  */
 265 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 266 {
 267         struct zfcp_unit *unit;
 268
 269         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 270         if (!unit)
 271                 return ERR_PTR(-ENOMEM);
 272
 273         atomic_set(&unit->refcount, 0);
 274         init_waitqueue_head(&unit->remove_wq);
 275
 276         unit->port = port;
 277         unit->fcp_lun = fcp_lun;
 278
 279         snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx",
 280                  (unsigned long long) fcp_lun);
 281         unit->sysfs_device.parent = &port->sysfs_device;
 282         unit->sysfs_device.release = zfcp_sysfs_unit_release;
 283         dev_set_drvdata(&unit->sysfs_device, unit);
 284
 285         /* mark unit unusable as long as sysfs registration is not complete */
 286         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 287
 288         spin_lock_init(&unit->latencies.lock);
 289         unit->latencies.write.channel.min = 0xFFFFFFFF;
 290         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 291         unit->latencies.read.channel.min = 0xFFFFFFFF;
 292         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 293         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 294         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 295
 296         read_lock_irq(&zfcp_data.config_lock);
 297         if (zfcp_get_unit_by_lun(port, fcp_lun)) {
 298                 read_unlock_irq(&zfcp_data.config_lock);
 299                 goto err_out_free;
 300         }
 301         read_unlock_irq(&zfcp_data.config_lock);
 302
 303         if (device_register(&unit->sysfs_device))
 304                 goto err_out_free;
 305
 306         if (sysfs_create_group(&unit->sysfs_device.kobj,
 307                                &zfcp_sysfs_unit_attrs)) {
 308                 device_unregister(&unit->sysfs_device);
 309                 return ERR_PTR(-EIO);
 310         }
 311
 312         zfcp_unit_get(unit);
 313
 314         write_lock_irq(&zfcp_data.config_lock);
 315         list_add_tail(&unit->list, &port->unit_list_head);
 316         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 317         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 318
 319         write_unlock_irq(&zfcp_data.config_lock);
 320
 321         zfcp_port_get(port);
 322
 323         return unit;
 324
 325 err_out_free:
 326         kfree(unit);
 327         return ERR_PTR(-EINVAL);
 328 }
 329
 330 /**
 331  * zfcp_unit_dequeue - dequeue unit
 332  * @unit: pointer to zfcp_unit
 333  *
 334  * waits until all work is done on unit and removes it then from the unit->list
 335  * of the associated port.
 336  */
 337 void zfcp_unit_dequeue(struct zfcp_unit *unit)
 338 {
 339         wait_event(unit->remove_wq, atomic_read(&unit->refcount) == 0);
 340         write_lock_irq(&zfcp_data.config_lock);
 341         list_del(&unit->list);
 342         write_unlock_irq(&zfcp_data.config_lock);
 343         zfcp_port_put(unit->port);
 344         sysfs_remove_group(&unit->sysfs_device.kobj, &zfcp_sysfs_unit_attrs);
 345         device_unregister(&unit->sysfs_device);
 346 }
 347
 348 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 349 {
 350         /* must only be called with zfcp_data.config_sema taken */
 351         adapter->pool.fsf_req_erp =
 352                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 353         if (!adapter->pool.fsf_req_erp)
 354                 return -ENOMEM;
 355
 356         adapter->pool.fsf_req_scsi =
 357                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 358         if (!adapter->pool.fsf_req_scsi)
 359                 return -ENOMEM;
 360
 361         adapter->pool.fsf_req_abort =
 362                 mempool_create_slab_pool(1, zfcp_data.fsf_req_qtcb_cache);
 363         if (!adapter->pool.fsf_req_abort)
 364                 return -ENOMEM;
 365
 366         adapter->pool.fsf_req_status_read =
 367                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 368                                             sizeof(struct zfcp_fsf_req));
 369         if (!adapter->pool.fsf_req_status_read)
 370                 return -ENOMEM;
 371
 372         adapter->pool.data_status_read =
 373                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 374                                          zfcp_data.sr_buffer_cache);
 375         if (!adapter->pool.data_status_read)
 376                 return -ENOMEM;
 377
 378         adapter->pool.data_gid_pn =
 379                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 380         if (!adapter->pool.data_gid_pn)
 381                 return -ENOMEM;
 382
 383         return 0;
 384 }
 385
 386 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 387 {
 388         /* zfcp_data.config_sema must be held */
 389         if (adapter->pool.fsf_req_erp)
 390                 mempool_destroy(adapter->pool.fsf_req_erp);
 391         if (adapter->pool.fsf_req_scsi)
 392                 mempool_destroy(adapter->pool.fsf_req_scsi);
 393         if (adapter->pool.fsf_req_abort)
 394                 mempool_destroy(adapter->pool.fsf_req_abort);
 395         if (adapter->pool.fsf_req_status_read)
 396                 mempool_destroy(adapter->pool.fsf_req_status_read);
 397         if (adapter->pool.data_status_read)
 398                 mempool_destroy(adapter->pool.data_status_read);
 399         if (adapter->pool.data_gid_pn)
 400                 mempool_destroy(adapter->pool.data_gid_pn);
 401 }
 402
 403 /**
 404  * zfcp_status_read_refill - refill the long running status_read_requests
 405  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 406  *
 407  * Returns: 0 on success, 1 otherwise
 408  *
 409  * if there are 16 or more status_read requests missing an adapter_reopen
 410  * is triggered
 411  */
 412 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 413 {
 414         while (atomic_read(&adapter->stat_miss) > 0)
 415                 if (zfcp_fsf_status_read(adapter)) {
 416                         if (atomic_read(&adapter->stat_miss) >= 16) {
 417                                 zfcp_erp_adapter_reopen(adapter, 0, 103, NULL);
 418                                 return 1;
 419                         }
 420                         break;
 421                 } else
 422                         atomic_dec(&adapter->stat_miss);
 423         return 0;
 424 }
 425
 426 static void _zfcp_status_read_scheduler(struct work_struct *work)
 427 {
 428         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 429                                              stat_work));
 430 }
 431
 432 /**
 433  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 434  * @ccw_device: pointer to the struct cc_device
 435  *
 436  * Returns:     0             if a new adapter was successfully enqueued
 437  *              -ENOMEM       if alloc failed
 438  * Enqueues an adapter at the end of the adapter list in the driver data.
 439  * All adapter internal structures are set up.
 440  * Proc-fs entries are also created.
 441  * locks:       config_sema must be held to serialise changes to the adapter list
 442  */
 443 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 444 {
 445         struct zfcp_adapter *adapter;
 446
 447         /*
 448          * Note: It is safe to release the list_lock, as any list changes
 449          * are protected by the config_sema, which must be held to get here
 450          */
 451
 452         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 453         if (!adapter)
 454                 return -ENOMEM;
 455
 456         ccw_device->handler = NULL;
 457         adapter->ccw_device = ccw_device;
 458         atomic_set(&adapter->refcount, 0);
 459
 460         if (zfcp_qdio_allocate(adapter))
 461                 goto qdio_allocate_failed;
 462
 463         if (zfcp_allocate_low_mem_buffers(adapter))
 464                 goto failed_low_mem_buffers;
 465
 466         if (zfcp_reqlist_alloc(adapter))
 467                 goto failed_low_mem_buffers;
 468
 469         if (zfcp_adapter_debug_register(adapter))
 470                 goto debug_register_failed;
 471
 472         init_waitqueue_head(&adapter->remove_wq);
 473         init_waitqueue_head(&adapter->erp_thread_wqh);
 474         init_waitqueue_head(&adapter->erp_done_wqh);
 475
 476         INIT_LIST_HEAD(&adapter->port_list_head);
 477         INIT_LIST_HEAD(&adapter->erp_ready_head);
 478         INIT_LIST_HEAD(&adapter->erp_running_head);
 479
 480         spin_lock_init(&adapter->req_list_lock);
 481
 482         spin_lock_init(&adapter->hba_dbf_lock);
 483         spin_lock_init(&adapter->san_dbf_lock);
 484         spin_lock_init(&adapter->scsi_dbf_lock);
 485         spin_lock_init(&adapter->rec_dbf_lock);
 486         spin_lock_init(&adapter->req_q_lock);
 487
 488         rwlock_init(&adapter->erp_lock);
 489         rwlock_init(&adapter->abort_lock);
 490
 491         sema_init(&adapter->erp_ready_sem, 0);
 492
 493         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 494         INIT_WORK(&adapter->scan_work, _zfcp_scan_ports_later);
 495
 496         /* mark adapter unusable as long as sysfs registration is not complete */
 497         atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
 498
 499         dev_set_drvdata(&ccw_device->dev, adapter);
 500
 501         if (sysfs_create_group(&ccw_device->dev.kobj,
 502                                &zfcp_sysfs_adapter_attrs))
 503                 goto sysfs_failed;
 504
 505         write_lock_irq(&zfcp_data.config_lock);
 506         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
 507         list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
 508         write_unlock_irq(&zfcp_data.config_lock);
 509
 510         zfcp_fc_nameserver_init(adapter);
 511
 512         return 0;
 513
 514 sysfs_failed:
 515         zfcp_adapter_debug_unregister(adapter);
 516 debug_register_failed:
 517         dev_set_drvdata(&ccw_device->dev, NULL);
 518         kfree(adapter->req_list);
 519 failed_low_mem_buffers:
 520         zfcp_free_low_mem_buffers(adapter);
 521 qdio_allocate_failed:
 522         zfcp_qdio_free(adapter);
 523         kfree(adapter);
 524         return -ENOMEM;
 525 }
 526
 527 /**
 528  * zfcp_adapter_dequeue - remove the adapter from the resource list
 529  * @adapter: pointer to struct zfcp_adapter which should be removed
 530  * locks:       adapter list write lock is assumed to be held by caller
 531  */
 532 void zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
 533 {
 534         int retval = 0;
 535         unsigned long flags;
 536
 537         cancel_work_sync(&adapter->scan_work);
 538         cancel_work_sync(&adapter->stat_work);
 539         zfcp_adapter_scsi_unregister(adapter);
 540         sysfs_remove_group(&adapter->ccw_device->dev.kobj,
 541                            &zfcp_sysfs_adapter_attrs);
 542         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 543         /* sanity check: no pending FSF requests */
 544         spin_lock_irqsave(&adapter->req_list_lock, flags);
 545         retval = zfcp_reqlist_isempty(adapter);
 546         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
 547         if (!retval)
 548                 return;
 549
 550         zfcp_adapter_debug_unregister(adapter);
 551
 552         /* remove specified adapter data structure from list */
 553         write_lock_irq(&zfcp_data.config_lock);
 554         list_del(&adapter->list);
 555         write_unlock_irq(&zfcp_data.config_lock);
 556
 557         zfcp_qdio_free(adapter);
 558
 559         zfcp_free_low_mem_buffers(adapter);
 560         kfree(adapter->req_list);
 561         kfree(adapter->fc_stats);
 562         kfree(adapter->stats_reset_data);
 563         kfree(adapter);
 564 }
 565
 566 static void zfcp_sysfs_port_release(struct device *dev)
 567 {
 568         kfree(container_of(dev, struct zfcp_port, sysfs_device));
 569 }
 570
 571 /**
 572  * zfcp_port_enqueue - enqueue port to port list of adapter
 573  * @adapter: adapter where remote port is added
 574  * @wwpn: WWPN of the remote port to be enqueued
 575  * @status: initial status for the port
 576  * @d_id: destination id of the remote port to be enqueued
 577  * Returns: pointer to enqueued port on success, ERR_PTR on error
 578  * Locks: config_sema must be held to serialize changes to the port list
 579  *
 580  * All port internal structures are set up and the sysfs entry is generated.
 581  * d_id is used to enqueue ports with a well known address like the Directory
 582  * Service for nameserver lookup.
 583  */
 584 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 585                                      u32 status, u32 d_id)
 586 {
 587         struct zfcp_port *port;
 588         int retval;
 589
 590         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 591         if (!port)
 592                 return ERR_PTR(-ENOMEM);
 593
 594         init_waitqueue_head(&port->remove_wq);
 595         INIT_LIST_HEAD(&port->unit_list_head);
 596         INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
 597
 598         port->adapter = adapter;
 599         port->d_id = d_id;
 600         port->wwpn = wwpn;
 601
 602         /* mark port unusable as long as sysfs registration is not complete */
 603         atomic_set_mask(status | ZFCP_STATUS_COMMON_REMOVE, &port->status);
 604         atomic_set(&port->refcount, 0);
 605
 606         snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx",
 607                  (unsigned long long) wwpn);
 608         port->sysfs_device.parent = &adapter->ccw_device->dev;
 609
 610         port->sysfs_device.release = zfcp_sysfs_port_release;
 611         dev_set_drvdata(&port->sysfs_device, port);
 612
 613         read_lock_irq(&zfcp_data.config_lock);
 614         if (!(status & ZFCP_STATUS_PORT_NO_WWPN))
 615                 if (zfcp_get_port_by_wwpn(adapter, wwpn)) {
 616                         read_unlock_irq(&zfcp_data.config_lock);
 617                         goto err_out_free;
 618                 }
 619         read_unlock_irq(&zfcp_data.config_lock);
 620
 621         if (device_register(&port->sysfs_device))
 622                 goto err_out_free;
 623
 624         retval = sysfs_create_group(&port->sysfs_device.kobj,
 625                                     &zfcp_sysfs_port_attrs);
 626
 627         if (retval) {
 628                 device_unregister(&port->sysfs_device);
 629                 goto err_out;
 630         }
 631
 632         zfcp_port_get(port);
 633
 634         write_lock_irq(&zfcp_data.config_lock);
 635         list_add_tail(&port->list, &adapter->port_list_head);
 636         atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
 637         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
 638
 639         write_unlock_irq(&zfcp_data.config_lock);
 640
 641         zfcp_adapter_get(adapter);
 642         return port;
 643
 644 err_out_free:
 645         kfree(port);
 646 err_out:
 647         return ERR_PTR(-EINVAL);
 648 }
 649
 650 /**
 651  * zfcp_port_dequeue - dequeues a port from the port list of the adapter
 652  * @port: pointer to struct zfcp_port which should be removed
 653  */
 654 void zfcp_port_dequeue(struct zfcp_port *port)
 655 {
 656         wait_event(port->remove_wq, atomic_read(&port->refcount) == 0);
 657         write_lock_irq(&zfcp_data.config_lock);
 658         list_del(&port->list);
 659         write_unlock_irq(&zfcp_data.config_lock);
 660         if (port->rport)
 661                 fc_remote_port_delete(port->rport);
 662         port->rport = NULL;
 663         zfcp_adapter_put(port->adapter);
 664         sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs);
 665         device_unregister(&port->sysfs_device);
 666 }
 667
 668 /**
 669  * zfcp_sg_free_table - free memory used by scatterlists
 670  * @sg: pointer to scatterlist
 671  * @count: number of scatterlist which are to be free'ed
 672  * the scatterlist are expected to reference pages always
 673  */
 674 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 675 {
 676         int i;
 677
 678         for (i = 0; i < count; i++, sg++)
 679                 if (sg)
 680                         free_page((unsigned long) sg_virt(sg));
 681                 else
 682                         break;
 683 }
 684
 685 /**
 686  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 687  * @sg: pointer to struct scatterlist
 688  * @count: number of scatterlists which should be assigned with buffers
 689  * of size page
 690  *
 691  * Returns: 0 on success, -ENOMEM otherwise
 692  */
 693 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 694 {
 695         void *addr;
 696         int i;
 697
 698         sg_init_table(sg, count);
 699         for (i = 0; i < count; i++, sg++) {
 700                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 701                 if (!addr) {
 702                         zfcp_sg_free_table(sg, i);
 703                         return -ENOMEM;
 704                 }
 705                 sg_set_buf(sg, addr, PAGE_SIZE);
 706         }
 707         return 0;
 708 }