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, 2009
   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
  36 #define ZFCP_BUS_ID_SIZE        20
  37
  38 MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
  39 MODULE_DESCRIPTION("FCP HBA driver");
  40 MODULE_LICENSE("GPL");
  41
  42 static char *init_device;
  43 module_param_named(device, init_device, charp, 0400);
  44 MODULE_PARM_DESC(device, "specify initial device");
  45
  46 static struct kmem_cache *zfcp_cache_hw_align(const char *name,
  47                                               unsigned long size)
  48 {
  49         return kmem_cache_create(name, size, roundup_pow_of_two(size), 0, NULL);
  50 }
  51
  52 static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
  53 {
  54         int idx;
  55
  56         adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
  57                                     GFP_KERNEL);
  58         if (!adapter->req_list)
  59                 return -ENOMEM;
  60
  61         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  62                 INIT_LIST_HEAD(&adapter->req_list[idx]);
  63         return 0;
  64 }
  65
  66 /**
  67  * zfcp_reqlist_isempty - is the request list empty
  68  * @adapter: pointer to struct zfcp_adapter
  69  *
  70  * Returns: true if list is empty, false otherwise
  71  */
  72 int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
  73 {
  74         unsigned int idx;
  75
  76         for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
  77                 if (!list_empty(&adapter->req_list[idx]))
  78                         return 0;
  79         return 1;
  80 }
  81
  82 static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
  83 {
  84         struct ccw_device *cdev;
  85         struct zfcp_adapter *adapter;
  86         struct zfcp_port *port;
  87         struct zfcp_unit *unit;
  88
  89         cdev = get_ccwdev_by_busid(&zfcp_ccw_driver, busid);
  90         if (!cdev)
  91                 return;
  92
  93         if (ccw_device_set_online(cdev))
  94                 goto out_ccw_device;
  95
  96         adapter = zfcp_ccw_adapter_by_cdev(cdev);
  97         if (!adapter)
  98                 goto out_ccw_device;
  99
 100         port = zfcp_get_port_by_wwpn(adapter, wwpn);
 101         if (!port)
 102                 goto out_port;
 103
 104         unit = zfcp_unit_enqueue(port, lun);
 105         if (IS_ERR(unit))
 106                 goto out_unit;
 107
 108         zfcp_erp_unit_reopen(unit, 0, "auidc_1", NULL);
 109         zfcp_erp_wait(adapter);
 110         flush_work(&unit->scsi_work);
 111
 112 out_unit:
 113         put_device(&port->sysfs_device);
 114 out_port:
 115         zfcp_ccw_adapter_put(adapter);
 116 out_ccw_device:
 117         put_device(&cdev->dev);
 118         return;
 119 }
 120
 121 static void __init zfcp_init_device_setup(char *devstr)
 122 {
 123         char *token;
 124         char *str, *str_saved;
 125         char busid[ZFCP_BUS_ID_SIZE];
 126         u64 wwpn, lun;
 127
 128         /* duplicate devstr and keep the original for sysfs presentation*/
 129         str_saved = kmalloc(strlen(devstr) + 1, GFP_KERNEL);
 130         str = str_saved;
 131         if (!str)
 132                 return;
 133
 134         strcpy(str, devstr);
 135
 136         token = strsep(&str, ",");
 137         if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 138                 goto err_out;
 139         strncpy(busid, token, ZFCP_BUS_ID_SIZE);
 140
 141         token = strsep(&str, ",");
 142         if (!token || strict_strtoull(token, 0, (unsigned long long *) &wwpn))
 143                 goto err_out;
 144
 145         token = strsep(&str, ",");
 146         if (!token || strict_strtoull(token, 0, (unsigned long long *) &lun))
 147                 goto err_out;
 148
 149         kfree(str_saved);
 150         zfcp_init_device_configure(busid, wwpn, lun);
 151         return;
 152
 153 err_out:
 154         kfree(str_saved);
 155         pr_err("%s is not a valid SCSI device\n", devstr);
 156 }
 157
 158 static int __init zfcp_module_init(void)
 159 {
 160         int retval = -ENOMEM;
 161
 162         zfcp_data.gpn_ft_cache = zfcp_cache_hw_align("zfcp_gpn",
 163                                         sizeof(struct zfcp_fc_gpn_ft_req));
 164         if (!zfcp_data.gpn_ft_cache)
 165                 goto out;
 166
 167         zfcp_data.qtcb_cache = zfcp_cache_hw_align("zfcp_qtcb",
 168                                         sizeof(struct fsf_qtcb));
 169         if (!zfcp_data.qtcb_cache)
 170                 goto out_qtcb_cache;
 171
 172         zfcp_data.sr_buffer_cache = zfcp_cache_hw_align("zfcp_sr",
 173                                         sizeof(struct fsf_status_read_buffer));
 174         if (!zfcp_data.sr_buffer_cache)
 175                 goto out_sr_cache;
 176
 177         zfcp_data.gid_pn_cache = zfcp_cache_hw_align("zfcp_gid",
 178                                         sizeof(struct zfcp_fc_gid_pn));
 179         if (!zfcp_data.gid_pn_cache)
 180                 goto out_gid_cache;
 181
 182         zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
 183                                         sizeof(struct zfcp_fc_els_adisc));
 184         if (!zfcp_data.adisc_cache)
 185                 goto out_adisc_cache;
 186
 187         zfcp_data.scsi_transport_template =
 188                 fc_attach_transport(&zfcp_transport_functions);
 189         if (!zfcp_data.scsi_transport_template)
 190                 goto out_transport;
 191
 192         retval = misc_register(&zfcp_cfdc_misc);
 193         if (retval) {
 194                 pr_err("Registering the misc device zfcp_cfdc failed\n");
 195                 goto out_misc;
 196         }
 197
 198         retval = ccw_driver_register(&zfcp_ccw_driver);
 199         if (retval) {
 200                 pr_err("The zfcp device driver could not register with "
 201                        "the common I/O layer\n");
 202                 goto out_ccw_register;
 203         }
 204
 205         if (init_device)
 206                 zfcp_init_device_setup(init_device);
 207         return 0;
 208
 209 out_ccw_register:
 210         misc_deregister(&zfcp_cfdc_misc);
 211 out_misc:
 212         fc_release_transport(zfcp_data.scsi_transport_template);
 213 out_transport:
 214         kmem_cache_destroy(zfcp_data.adisc_cache);
 215 out_adisc_cache:
 216         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 217 out_gid_cache:
 218         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 219 out_sr_cache:
 220         kmem_cache_destroy(zfcp_data.qtcb_cache);
 221 out_qtcb_cache:
 222         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 223 out:
 224         return retval;
 225 }
 226
 227 module_init(zfcp_module_init);
 228
 229 static void __exit zfcp_module_exit(void)
 230 {
 231         ccw_driver_unregister(&zfcp_ccw_driver);
 232         misc_deregister(&zfcp_cfdc_misc);
 233         fc_release_transport(zfcp_data.scsi_transport_template);
 234         kmem_cache_destroy(zfcp_data.adisc_cache);
 235         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 236         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 237         kmem_cache_destroy(zfcp_data.qtcb_cache);
 238         kmem_cache_destroy(zfcp_data.gpn_ft_cache);
 239 }
 240
 241 module_exit(zfcp_module_exit);
 242
 243 /**
 244  * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 245  * @port: pointer to port to search for unit
 246  * @fcp_lun: FCP LUN to search for
 247  *
 248  * Returns: pointer to zfcp_unit or NULL
 249  */
 250 struct zfcp_unit *zfcp_get_unit_by_lun(struct zfcp_port *port, u64 fcp_lun)
 251 {
 252         unsigned long flags;
 253         struct zfcp_unit *unit;
 254
 255         read_lock_irqsave(&port->unit_list_lock, flags);
 256         list_for_each_entry(unit, &port->unit_list, list)
 257                 if (unit->fcp_lun == fcp_lun) {
 258                         if (!get_device(&unit->sysfs_device))
 259                                 unit = NULL;
 260                         read_unlock_irqrestore(&port->unit_list_lock, flags);
 261                         return unit;
 262                 }
 263         read_unlock_irqrestore(&port->unit_list_lock, flags);
 264         return NULL;
 265 }
 266
 267 /**
 268  * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 269  * @adapter: pointer to adapter to search for port
 270  * @wwpn: wwpn to search for
 271  *
 272  * Returns: pointer to zfcp_port or NULL
 273  */
 274 struct zfcp_port *zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter,
 275                                         u64 wwpn)
 276 {
 277         unsigned long flags;
 278         struct zfcp_port *port;
 279
 280         read_lock_irqsave(&adapter->port_list_lock, flags);
 281         list_for_each_entry(port, &adapter->port_list, list)
 282                 if (port->wwpn == wwpn) {
 283                         if (!get_device(&port->sysfs_device))
 284                                 port = NULL;
 285                         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 286                         return port;
 287                 }
 288         read_unlock_irqrestore(&adapter->port_list_lock, flags);
 289         return NULL;
 290 }
 291
 292 /**
 293  * zfcp_unit_release - dequeue unit
 294  * @dev: pointer to device
 295  *
 296  * waits until all work is done on unit and removes it then from the unit->list
 297  * of the associated port.
 298  */
 299 static void zfcp_unit_release(struct device *dev)
 300 {
 301         struct zfcp_unit *unit = container_of(dev, struct zfcp_unit,
 302                                               sysfs_device);
 303
 304         put_device(&unit->port->sysfs_device);
 305         kfree(unit);
 306 }
 307
 308 /**
 309  * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 310  * @port: pointer to port where unit is added
 311  * @fcp_lun: FCP LUN of unit to be enqueued
 312  * Returns: pointer to enqueued unit on success, ERR_PTR on error
 313  *
 314  * Sets up some unit internal structures and creates sysfs entry.
 315  */
 316 struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun)
 317 {
 318         struct zfcp_unit *unit;
 319         int retval = -ENOMEM;
 320
 321         get_device(&port->sysfs_device);
 322
 323         unit = zfcp_get_unit_by_lun(port, fcp_lun);
 324         if (unit) {
 325                 put_device(&unit->sysfs_device);
 326                 retval = -EEXIST;
 327                 goto err_out;
 328         }
 329
 330         unit = kzalloc(sizeof(struct zfcp_unit), GFP_KERNEL);
 331         if (!unit)
 332                 goto err_out;
 333
 334         unit->port = port;
 335         unit->fcp_lun = fcp_lun;
 336         unit->sysfs_device.parent = &port->sysfs_device;
 337         unit->sysfs_device.release = zfcp_unit_release;
 338
 339         if (dev_set_name(&unit->sysfs_device, "0x%016llx",
 340                          (unsigned long long) fcp_lun)) {
 341                 kfree(unit);
 342                 goto err_out;
 343         }
 344         retval = -EINVAL;
 345
 346         INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);
 347
 348         spin_lock_init(&unit->latencies.lock);
 349         unit->latencies.write.channel.min = 0xFFFFFFFF;
 350         unit->latencies.write.fabric.min = 0xFFFFFFFF;
 351         unit->latencies.read.channel.min = 0xFFFFFFFF;
 352         unit->latencies.read.fabric.min = 0xFFFFFFFF;
 353         unit->latencies.cmd.channel.min = 0xFFFFFFFF;
 354         unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
 355
 356         if (device_register(&unit->sysfs_device)) {
 357                 put_device(&unit->sysfs_device);
 358                 goto err_out;
 359         }
 360
 361         if (sysfs_create_group(&unit->sysfs_device.kobj,
 362                                &zfcp_sysfs_unit_attrs))
 363                 goto err_out_put;
 364
 365         write_lock_irq(&port->unit_list_lock);
 366         list_add_tail(&unit->list, &port->unit_list);
 367         write_unlock_irq(&port->unit_list_lock);
 368
 369         atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 370
 371         return unit;
 372
 373 err_out_put:
 374         device_unregister(&unit->sysfs_device);
 375 err_out:
 376         put_device(&port->sysfs_device);
 377         return ERR_PTR(retval);
 378 }
 379
 380 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 381 {
 382         adapter->pool.erp_req =
 383                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 384         if (!adapter->pool.erp_req)
 385                 return -ENOMEM;
 386
 387         adapter->pool.gid_pn_req =
 388                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 389         if (!adapter->pool.gid_pn_req)
 390                 return -ENOMEM;
 391
 392         adapter->pool.scsi_req =
 393                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 394         if (!adapter->pool.scsi_req)
 395                 return -ENOMEM;
 396
 397         adapter->pool.scsi_abort =
 398                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
 399         if (!adapter->pool.scsi_abort)
 400                 return -ENOMEM;
 401
 402         adapter->pool.status_read_req =
 403                 mempool_create_kmalloc_pool(FSF_STATUS_READS_RECOM,
 404                                             sizeof(struct zfcp_fsf_req));
 405         if (!adapter->pool.status_read_req)
 406                 return -ENOMEM;
 407
 408         adapter->pool.qtcb_pool =
 409                 mempool_create_slab_pool(4, zfcp_data.qtcb_cache);
 410         if (!adapter->pool.qtcb_pool)
 411                 return -ENOMEM;
 412
 413         adapter->pool.status_read_data =
 414                 mempool_create_slab_pool(FSF_STATUS_READS_RECOM,
 415                                          zfcp_data.sr_buffer_cache);
 416         if (!adapter->pool.status_read_data)
 417                 return -ENOMEM;
 418
 419         adapter->pool.gid_pn =
 420                 mempool_create_slab_pool(1, zfcp_data.gid_pn_cache);
 421         if (!adapter->pool.gid_pn)
 422                 return -ENOMEM;
 423
 424         return 0;
 425 }
 426
 427 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 428 {
 429         if (adapter->pool.erp_req)
 430                 mempool_destroy(adapter->pool.erp_req);
 431         if (adapter->pool.scsi_req)
 432                 mempool_destroy(adapter->pool.scsi_req);
 433         if (adapter->pool.scsi_abort)
 434                 mempool_destroy(adapter->pool.scsi_abort);
 435         if (adapter->pool.qtcb_pool)
 436                 mempool_destroy(adapter->pool.qtcb_pool);
 437         if (adapter->pool.status_read_req)
 438                 mempool_destroy(adapter->pool.status_read_req);
 439         if (adapter->pool.status_read_data)
 440                 mempool_destroy(adapter->pool.status_read_data);
 441         if (adapter->pool.gid_pn)
 442                 mempool_destroy(adapter->pool.gid_pn);
 443 }
 444
 445 /**
 446  * zfcp_status_read_refill - refill the long running status_read_requests
 447  * @adapter: ptr to struct zfcp_adapter for which the buffers should be refilled
 448  *
 449  * Returns: 0 on success, 1 otherwise
 450  *
 451  * if there are 16 or more status_read requests missing an adapter_reopen
 452  * is triggered
 453  */
 454 int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 455 {
 456         while (atomic_read(&adapter->stat_miss) > 0)
 457                 if (zfcp_fsf_status_read(adapter->qdio)) {
 458                         if (atomic_read(&adapter->stat_miss) >= 16) {
 459                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
 460                                                         NULL);
 461                                 return 1;
 462                         }
 463                         break;
 464                 } else
 465                         atomic_dec(&adapter->stat_miss);
 466         return 0;
 467 }
 468
 469 static void _zfcp_status_read_scheduler(struct work_struct *work)
 470 {
 471         zfcp_status_read_refill(container_of(work, struct zfcp_adapter,
 472                                              stat_work));
 473 }
 474
 475 static void zfcp_print_sl(struct seq_file *m, struct service_level *sl)
 476 {
 477         struct zfcp_adapter *adapter =
 478                 container_of(sl, struct zfcp_adapter, service_level);
 479
 480         seq_printf(m, "zfcp: %s microcode level %x\n",
 481                    dev_name(&adapter->ccw_device->dev),
 482                    adapter->fsf_lic_version);
 483 }
 484
 485 static int zfcp_setup_adapter_work_queue(struct zfcp_adapter *adapter)
 486 {
 487         char name[TASK_COMM_LEN];
 488
 489         snprintf(name, sizeof(name), "zfcp_q_%s",
 490                  dev_name(&adapter->ccw_device->dev));
 491         adapter->work_queue = create_singlethread_workqueue(name);
 492
 493         if (adapter->work_queue)
 494                 return 0;
 495         return -ENOMEM;
 496 }
 497
 498 static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
 499 {
 500         if (adapter->work_queue)
 501                 destroy_workqueue(adapter->work_queue);
 502         adapter->work_queue = NULL;
 503
 504 }
 505
 506 /**
 507  * zfcp_adapter_enqueue - enqueue a new adapter to the list
 508  * @ccw_device: pointer to the struct cc_device
 509  *
 510  * Returns:     struct zfcp_adapter*
 511  * Enqueues an adapter at the end of the adapter list in the driver data.
 512  * All adapter internal structures are set up.
 513  * Proc-fs entries are also created.
 514  */
 515 struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 516 {
 517         struct zfcp_adapter *adapter;
 518
 519         if (!get_device(&ccw_device->dev))
 520                 return ERR_PTR(-ENODEV);
 521
 522         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
 523         if (!adapter) {
 524                 put_device(&ccw_device->dev);
 525                 return ERR_PTR(-ENOMEM);
 526         }
 527
 528         kref_init(&adapter->ref);
 529
 530         ccw_device->handler = NULL;
 531         adapter->ccw_device = ccw_device;
 532
 533         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
 534         INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
 535
 536         if (zfcp_qdio_setup(adapter))
 537                 goto failed;
 538
 539         if (zfcp_allocate_low_mem_buffers(adapter))
 540                 goto failed;
 541
 542         if (zfcp_reqlist_alloc(adapter))
 543                 goto failed;
 544
 545         if (zfcp_dbf_adapter_register(adapter))
 546                 goto failed;
 547
 548         if (zfcp_setup_adapter_work_queue(adapter))
 549                 goto failed;
 550
 551         if (zfcp_fc_gs_setup(adapter))
 552                 goto failed;
 553
 554         rwlock_init(&adapter->port_list_lock);
 555         INIT_LIST_HEAD(&adapter->port_list);
 556
 557         init_waitqueue_head(&adapter->erp_ready_wq);
 558         init_waitqueue_head(&adapter->erp_done_wqh);
 559
 560         INIT_LIST_HEAD(&adapter->erp_ready_head);
 561         INIT_LIST_HEAD(&adapter->erp_running_head);
 562
 563         spin_lock_init(&adapter->req_list_lock);
 564
 565         rwlock_init(&adapter->erp_lock);
 566         rwlock_init(&adapter->abort_lock);
 567
 568         if (zfcp_erp_thread_setup(adapter))
 569                 goto failed;
 570
 571         adapter->service_level.seq_print = zfcp_print_sl;
 572
 573         dev_set_drvdata(&ccw_device->dev, adapter);
 574
 575         if (sysfs_create_group(&ccw_device->dev.kobj,
 576                                &zfcp_sysfs_adapter_attrs))
 577                 goto failed;
 578
 579         if (!zfcp_adapter_scsi_register(adapter))
 580                 return adapter;
 581
 582 failed:
 583         zfcp_adapter_unregister(adapter);
 584         return ERR_PTR(-ENOMEM);
 585 }
 586
 587 void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
 588 {
 589         struct ccw_device *cdev = adapter->ccw_device;
 590
 591         cancel_work_sync(&adapter->scan_work);
 592         cancel_work_sync(&adapter->stat_work);
 593         zfcp_destroy_adapter_work_queue(adapter);
 594
 595         zfcp_fc_wka_ports_force_offline(adapter->gs);
 596         zfcp_adapter_scsi_unregister(adapter);
 597         sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
 598
 599         zfcp_erp_thread_kill(adapter);
 600         zfcp_dbf_adapter_unregister(adapter->dbf);
 601         zfcp_qdio_destroy(adapter->qdio);
 602
 603         zfcp_ccw_adapter_put(adapter); /* final put to release */
 604 }
 605
 606 /**
 607  * zfcp_adapter_release - remove the adapter from the resource list
 608  * @ref: pointer to struct kref
 609  * locks:       adapter list write lock is assumed to be held by caller
 610  */
 611 void zfcp_adapter_release(struct kref *ref)
 612 {
 613         struct zfcp_adapter *adapter = container_of(ref, struct zfcp_adapter,
 614                                                     ref);
 615         struct ccw_device *cdev = adapter->ccw_device;
 616
 617         dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 618         zfcp_fc_gs_destroy(adapter);
 619         zfcp_free_low_mem_buffers(adapter);
 620         kfree(adapter->req_list);
 621         kfree(adapter->fc_stats);
 622         kfree(adapter->stats_reset_data);
 623         kfree(adapter);
 624         put_device(&cdev->dev);
 625 }
 626
 627 /**
 628  * zfcp_device_unregister - remove port, unit from system
 629  * @dev: reference to device which is to be removed
 630  * @grp: related reference to attribute group
 631  *
 632  * Helper function to unregister port, unit from system
 633  */
 634 void zfcp_device_unregister(struct device *dev,
 635                             const struct attribute_group *grp)
 636 {
 637         sysfs_remove_group(&dev->kobj, grp);
 638         device_unregister(dev);
 639 }
 640
 641 static void zfcp_port_release(struct device *dev)
 642 {
 643         struct zfcp_port *port = container_of(dev, struct zfcp_port,
 644                                               sysfs_device);
 645
 646         zfcp_ccw_adapter_put(port->adapter);
 647         kfree(port);
 648 }
 649
 650 /**
 651  * zfcp_port_enqueue - enqueue port to port list of adapter
 652  * @adapter: adapter where remote port is added
 653  * @wwpn: WWPN of the remote port to be enqueued
 654  * @status: initial status for the port
 655  * @d_id: destination id of the remote port to be enqueued
 656  * Returns: pointer to enqueued port on success, ERR_PTR on error
 657  *
 658  * All port internal structures are set up and the sysfs entry is generated.
 659  * d_id is used to enqueue ports with a well known address like the Directory
 660  * Service for nameserver lookup.
 661  */
 662 struct zfcp_port *zfcp_port_enqueue(struct zfcp_adapter *adapter, u64 wwpn,
 663                                      u32 status, u32 d_id)
 664 {
 665         struct zfcp_port *port;
 666         int retval = -ENOMEM;
 667
 668         kref_get(&adapter->ref);
 669
 670         port = zfcp_get_port_by_wwpn(adapter, wwpn);
 671         if (port) {
 672                 put_device(&port->sysfs_device);
 673                 retval = -EEXIST;
 674                 goto err_out;
 675         }
 676
 677         port = kzalloc(sizeof(struct zfcp_port), GFP_KERNEL);
 678         if (!port)
 679                 goto err_out;
 680
 681         rwlock_init(&port->unit_list_lock);
 682         INIT_LIST_HEAD(&port->unit_list);
 683
 684         INIT_WORK(&port->gid_pn_work, zfcp_fc_port_did_lookup);
 685         INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
 686         INIT_WORK(&port->rport_work, zfcp_scsi_rport_work);
 687
 688         port->adapter = adapter;
 689         port->d_id = d_id;
 690         port->wwpn = wwpn;
 691         port->rport_task = RPORT_NONE;
 692         port->sysfs_device.parent = &adapter->ccw_device->dev;
 693         port->sysfs_device.release = zfcp_port_release;
 694
 695         if (dev_set_name(&port->sysfs_device, "0x%016llx",
 696                          (unsigned long long)wwpn)) {
 697                 kfree(port);
 698                 goto err_out;
 699         }
 700         retval = -EINVAL;
 701
 702         if (device_register(&port->sysfs_device)) {
 703                 put_device(&port->sysfs_device);
 704                 goto err_out;
 705         }
 706
 707         if (sysfs_create_group(&port->sysfs_device.kobj,
 708                                &zfcp_sysfs_port_attrs))
 709                 goto err_out_put;
 710
 711         write_lock_irq(&adapter->port_list_lock);
 712         list_add_tail(&port->list, &adapter->port_list);
 713         write_unlock_irq(&adapter->port_list_lock);
 714
 715         atomic_set_mask(status | ZFCP_STATUS_COMMON_RUNNING, &port->status);
 716
 717         return port;
 718
 719 err_out_put:
 720         device_unregister(&port->sysfs_device);
 721 err_out:
 722         zfcp_ccw_adapter_put(adapter);
 723         return ERR_PTR(retval);
 724 }
 725
 726 /**
 727  * zfcp_sg_free_table - free memory used by scatterlists
 728  * @sg: pointer to scatterlist
 729  * @count: number of scatterlist which are to be free'ed
 730  * the scatterlist are expected to reference pages always
 731  */
 732 void zfcp_sg_free_table(struct scatterlist *sg, int count)
 733 {
 734         int i;
 735
 736         for (i = 0; i < count; i++, sg++)
 737                 if (sg)
 738                         free_page((unsigned long) sg_virt(sg));
 739                 else
 740                         break;
 741 }
 742
 743 /**
 744  * zfcp_sg_setup_table - init scatterlist and allocate, assign buffers
 745  * @sg: pointer to struct scatterlist
 746  * @count: number of scatterlists which should be assigned with buffers
 747  * of size page
 748  *
 749  * Returns: 0 on success, -ENOMEM otherwise
 750  */
 751 int zfcp_sg_setup_table(struct scatterlist *sg, int count)
 752 {
 753         void *addr;
 754         int i;
 755
 756         sg_init_table(sg, count);
 757         for (i = 0; i < count; i++, sg++) {
 758                 addr = (void *) get_zeroed_page(GFP_KERNEL);
 759                 if (!addr) {
 760                         zfcp_sg_free_table(sg, i);
 761                         return -ENOMEM;
 762                 }
 763                 sg_set_buf(sg, addr, PAGE_SIZE);
 764         }
 765         return 0;
 766 }